Thermo-plasticity of homogenized 7050 aluminum ingot was investigated by instantaneous tensile tests conducted at different temperatures. The results show that, with the increase of testing temperatures, the strength decreases, and the plasticity increases firstly and then decreases in homogenized 7050 ingot. When the studied alloy is deformed between 380 °C and 420 °C, the deformation resistance is lower and plasticity is better. And the actual heating temperature for ingot before hot extrusion should be controlled between 360 °C and 400 °C. At low tensile temperatures, the deformation structure is mainly composed of dislocation substructure. With the increase of testing temperatures, transgranular fracture transforms into intergranular fracture progressively during deformation. At high tensile temperatures, the grain boundaries are weakened, deformation is concentrated at the grain boundaries and the re-orientation of equilibrium phases at grain boundaries appears.

Numerical simulation and experimental study of the Vickers indentation testing of the Al₂O₃ ceramic coated by diamond-like carbon (DLC) layer were conducted. The numerical analysis was implemented by a two-dimensional finite element (FE) axis symmetry model. FE analysis results gave insight into the fracture mechanism of DLC films coated on brittle ceramic (Al₂O₃) substrates. The maximum principal stress field was used to locate the most expected area for crack formation and propagation during the Vickers indentation testing. The results show that the median crack initiates in the interface under indenter, before ring crack occurs as the indenter presses down. Finally, the plastic deformation appears when the indenter penetrates into the substrate. The thicker DLC coating increases the Vickers hardness and fracture toughness.

Nonlinear static analysis of piezoelectric plates has been carried out using nonlinear finite element method considering electro-mechanical coupling. The geometrical nonlinearity has been taken into account and electric potential is assumed to be quadratic across the plate thickness. The governing equations are obtained using potential energy and Hamilton’s principle that includes elastic and piezoelectric effects. The finite element model is derived based on constitutive equation of piezoelectric material accounting for coupling between elasticity and electric effect using higher order plate elements. Results are presented for piezoelectric plate under different mechanical boundary conditions. Numerical results for the plate are given in dimensionless graphical forms. Effects of boundary conditions on linear and nonlinear response of the plate are also studied. The numerical results obtained by the present model are in good agreement with the available solutions reported in the literature.

Aging precipitation and solid solution heat treatment were carried out on three steels which have chromium content of 18%, manganese content of 12%, 15%, 18%, and nitrogen content of 0.43%, 0.53%, 0.67%, respectively. The mechanisms of precipitation and solid solution of high nitrogen austenitic stainless steel were studied using the scanning electron microscopy, transmission electron microscopy, electron probe micro analysis and mechanical testing. The results show that, Cr₂N is the primary precipitate in the tested stainless steels instead of Cr₂₃C₆. Cr₂N nucleates at austenitic grain boundaries and grows towards inner grains with a lamellar morphology. By means of pre-precipitation of Cr₂N at 800 °C, the microstructure of the steels at solid solution state can be refined, thus improving the strength and plasticity. After the proposed treatment, the tensile strength, the proof strength and the elongation of the tested steel reach 881 MPa, 542 MPa and 54%, respectively.

The 8% (mass fraction) yttrium-partially-stabilized zirconia (8YSZ) ceramic was fabricated via liquid phase sintering at 1 200–1 400 °C by adding different mass ratios of CuO-16.7%TiO₂ (molar fraction) as sintering aid. Relative density, microstructure, Vickers hardness and bending strength as a function of sintering temperature and additive content were investigated. The experiment results show that liquid phase sintering at low temperature can be realized through adding CuO-16.7% TiO₂ to 8YSZ. The Vickers hardness and bending strength of samples with sintering aid are generally much higher than those of samples without sintering aid for all sintering temperatures, and increase with the increase of sintering temperature. When the addition content of CuO-16.7% TiO₂ is beyond 0.5%, the relative density, Vickers hardness and bending strength decrease with the increase of the mass ratio of sintering aid. Low additions of sintering aid are beneficial to aiding densification; high additions of sintering aid are detrimental to the sintered properties mainly due to greater amounts of pores generated by the volatilization of oxygen with the eutectic reaction between copper oxide and titanium dioxide. It is found that the fine grain size and high relative density are two main reasons of the high bending strength and Vickers hardness of the materials.

The influences of BaCu(B₂O₅) (BCB) addition on sintering, microstructure and microwave dielectric properties of Li₂MgTi₃O₈ ceramics were investigated using X-ray diffractometry, scanning electron microscopy and microwave dielectric measurements. The experimental results show that a small amount of BaCu(B₂O₅) addition can effectively reduce the sintering temperature to 900 °C, and induce only a limited degradation of the microwave dielectric properties. Typically, the best microwave dielectric properties of ɛ_r=24.5, Q×f =24 622 GHz, τ_f=4.2×10⁻⁶ °C⁻¹ are obtained for 1.0% BCB-doped Li₂MgTi₃O₈ ceramics sintered at 900 °C for 3 h. The BCB-doped Li₂MgTi₃O₈ ceramics can be compatible with Ag electrode, which may be a strong candidate for low temperature co-fired ceramics applications.

Surface roughness of quartz particles was determined by measuring the specific surface area of particles. The wettability characteristics of particles were determined by measuring the flotation rate using a laboratory flotation cell. Experimental results show that the rod mill product has higher roughness than the ball mill product. For the particles with larger surface roughness, the flotation kinetics constant is also higher. Finally, empirical relationships between surface roughness (r) and the flotation kinetics constant (k) of quartz particles as k=A+Br+Cr^0.5lnr+D/lnr+E/r and k=A+Br are presented, in which A, B, C, D and E are constants related to experimental conditions and mineralogical properties of mineral.

The quantitative structure-activity relationship (QSAR) of 2-alkyl-4-(biphenylylmethoxy) pyridine derivatives was studied. Three different alignment methods were used to get the models of the comparative molecular field analysis (CoMFA), the comparative molecular similarity indices analysis (CoMSIA), and the hologram quantitative structure-activity relationship (HQSAR). The statistical results from the established models show believable predictivity based on the cross-validated value (q²>0.5) and the non-validated value (r²>0.9). The analysis on contour maps of CoMFA and CoMSIA models suggests that hydrophobic and hydrogen-bond acceptor fields are important factors that affect the AT1 antagonistic activity of 2-alkyl-4-(biphenylylmethoxy) pyridine derivatives besides the steric and electrostatic fields. The structural modification information from different atom contributions in the HQSAR model is in agreement with that in the 3D-QSAR models.

2,4-diphenylpentane- and 2,4-di-p-tolylpentane-2,4-diols were investigated employing experimental and density functional theory (DFT) method at B3LYP/6-31G (d) level. The structure of syn-2,4-di-p-tolylpentane-2,4-diol (2b) was characterized by X-ray diffraction and compared with the crystal structures of anti- and syn-2,4-diphenylpentane-2,4-diols (1a and 1b). X-ray diffraction indicates that inter and intra-molecular hydrogen bonds are formed in the crystal structures. There is π-π staking interaction in 1b and 2b. Good linear correlations and similar results are found between the experimental ¹H and ¹³C NMR chemical shifts (δ_exp) and GIAO (Gauge Independent Atomic Orbital) method calculated magnetic isotropic shielding tensors (δ_calc). HOMO and LUMO molecular orbitals were calculated at the same levels with the different results. UV-vis absorption spectra of the compounds were recorded in EtOH, MeCN, n-BuOH and cyclohexane with different dielectric constants. It is found that the solvent effect is obvious when ɛ is 24.85(EtOH), 35.69(MeCN) and it is weak when ɛ is decreased to 17.33(n-BuOH), 1.18 (cyclohexane).

A new roll shifting strategy with varying stroke and varying step was investigated. Two characteristic parameters including cat ear height and gap contour smoothness were introduced to assess the effect of shifting strategy on roll wear, and the relation between characteristic parameters and shifting strategy was established. Both varying stroke and varying step can reduce cat ear height and gap contour smoothness, so the shifting strategy with varying stroke and varying step is better than the one with either varying stroke or varying step. Based on the effect of shifting control parameters on characteristic parameters of roll wear, the selection principle of these shifting control parameters was gained. A case study was conducted to validate the proposed roll shifting strategy, reducing uncontrollable quartic loading gap contour, improving strip profile and extending rolling length of a rolling campaign.

Energy consumption of block-cutting machines represents a major cost item in the processing of travertines and other natural stones. Therefore, determining the optimum sawing conditions for a particular stone is of major importance in the natural stone-processing industry. An experimental study was carried out utilizing a fully instrumented block-cutter to investigate the sawing performances of five different types of travertine blocks during cutting with a circular diamond saw. The sawing tests were performed in the down-cutting mode. Performance measurements were determined by measuring the cutting speed and energy consumption. Then, specific energy was determined. The one main cutting parameter, cutting speed, was varied in the investigation of optimum cutting performance. Furthermore, some physico-mechanical properties of the travertine blocks were determined in the laboratory. As a result, it is found that the energy consumption (specific energy) of block cutting machines is highly affected by cutting speed. It is determined that specific energy value usually decreases when cutting speed increases. When the cutting speed is higher than the determined value, the diamond saw can become stuck in the travertine block; this situation can be a problem for the block-cutting machine. As a result, the optimum cutting speed obtained for the travertine mines examined is approximately 1.5–2.0 m/min.

The bottom-following problem for underactuated autonomous underwater vehicles^(AUV) was addressed by a new type of nonlinear decoupling control law. The vertical bottom-following error and pitch angle error are stabilized by means of the stern plane, and the thruster is left to stabilize the longitudinal bottom-following error and forward speed. In order to better meet the need of engineering applications, working characteristics of the actuators were sufficiently considered to design the proposed controller. Different from the traditional method, the methodology used to solve the problem is generated by AUV model without a reference orientation, and it deals explicitly with vehicle dynamics and the geometric characteristics of the desired tracking bottom curve. The estimation of systemic uncertainties and disturbances and the pitch velocity PE (persistent excitation) conditions are not required. The stability analysis is given by Lyapunov theorem. Simulation results of a full nonlinear hydrodynamic AUV model are provided to validate the effectiveness and robustness of the proposed controller.

To deal with fault detection and diagnosis with incomplete model for dead reckoning system of mobile robot, an integrative framework of particle filter detection and fuzzy logic diagnosis was devised. Firstly, an adaptive fault space is designed for recognizing both known faults and unknown faults, in corresponding modes of modeled and model-free. Secondly, the particle filter is utilized to diagnose the modeled faults and detect model-free fault according to the low particle weight and reliability. Especially, the proposed fuzzy logic diagnosis can further analyze model-free modes and identify some soft faults in unknown fault space. The MORCS-1 experimental results show that the fuzzy diagnosis particle filter (FDPF) combinational framework improves fault detection and identification completeness. Specifically speaking, FDPF is feasible to diagnose the modeled faults in known space. Furthermore, the types of model-free soft faults can also be further identified and diagnosed in unknown fault space.

To improve the accuracy of strapdown inertial navigation system (SINS) for long term applications, the rotation technique is employed to modulate the errors of the inertial sensors into periodically varied signals, and, as a result, to suppress the divergence of SINS errors. However, the errors of rotation platform will be introduced into SINS and might affect the final navigation accuracy. Considering the disadvantages of the conventional navigation computation scheme, an improved computation scheme of the SINS using rotation technique is proposed which can reduce the effects of the rotation platform errors. And, the error characteristics of the SINS with this navigation computation scheme are analyzed. Theoretical analysis, simulations and real test results show that the proposed navigation computation scheme outperforms the conventional navigation computation scheme, meanwhile reduces the requirement to the measurement accuracy of rotation angles.

A new method of prefetching data blocks from the NVCache to the page cache in main memory and cascading prefetching n-blocks from a hard disk to the NVCache together was proposed to reduce the spin-up frequency of a hybrid hard disk drive and thus enhance I/O performance. The proposed method consists of three steps: 1) Analyzing the pattern of read requests in block units; 2) Determining the number of blocks prefetched to the NVCache; 3) Replacing blocks in the NVCache according to the block replacement policy. The proposed method can reduce the latency time of a hybrid hard disk and optimize the power consumption of an IPTV set-top box. Experimental results show that the proposed method provides better average response time compared to an existing adaptive multistream prefetching (AMP) method by 25.17%. It also reduces by 20.83% the average power consumption over that of the existing external caching in energy saving storage system (EXCES) method.

A low power 640×480 OLED-on-silicon chip design that used in microdisplay was presented. A novel pixel circuit was proposed to meet the special requirement of OLED-on-silicon. The novel pixel consists of three transistors and one capacitor (3T1C). It has simple structure and can effectively reduce the current glitch generated during the AC driving from 55 μA to 7.5 μA, so that it can improve the precision of grayscale of display as well as extend the lifetime of OLED material. Except for the pixel array, low power row driver, column driver and other functional modules were also integrated on the chip. Several techniques were adopted to reduce the power consumption and frequency requirement of the chip. Finally, a 16×3×12 resolution chip was fabricated with standard 0.35 μm CMOS process of CSM and the chip can operate correctly.

Systolic implementation of multiplication over GF(2^m) is usually very efficient in area-time complexity, but its latency is usually very large. Thus, two low latency systolic multipliers over GF(2^m) based on general irreducible polynomials and irreducible pentanomials are presented. First, a signal flow graph (SFG) is used to represent the algorithm for multiplication over GF(2^m). Then, the two low latency systolic structures for multiplications over GF(2^m) based on general irreducible polynomials and pentanomials are presented from the SFG by suitable cut-set retiming, respectively. Analysis indicates that the proposed two low latency designs involve at least one-third less area-delay product when compared with the existing designs. To the authors’ knowledge, the time-complexity of the structures is the lowest found in literature for systolic GF(2^m) multipliers based on general irreducible polynomials and pentanomials. The proposed low latency designs are regular and modular, and therefore they are suitable for many time critical applications.

Hypothesis testing analysis and unknown parameter estimation of both the intermediate frequency (IF) and baseband GPS signal detection are given by using the generalized likelihood ratio test (GLRT) approach, applying the model of GPS signal in white Gaussian noise. It is proved that the test statistic follows central or noncentral F distribution. It is also pointed out that the test statistic is nearly identical to central or noncentral chi-squared distribution because the processing samples are large enough to be considered as infinite in GPS acquisition problem. It is also proved that the probability of false alarm, the probability of detection and the threshold are affected largely when the hypothesis testing refers to the full pseudorandom noise (PRN) code phase and Doppler frequency search space cells instead of each individual cell. The performance of the test statistic is also given with combining the noncoherent integration.

A lifetime prediction method for high-reliability tantalum (Ta) capacitors was proposed, based on multiple degradation measures and grey model (GM). For analyzing performance degradation data, a two-parameter model based on GM was developed. In order to improve the prediction accuracy of the two-parameter model, parameter selection based on particle swarm optimization (PSO) was used. Then, the new PSO-GM(1, 2, ω) optimization model was constructed, which was validated experimentally by conducting an accelerated testing on the Ta capacitors. The experiments were conducted at three different stress levels of 85, 120, and 145 °C. The results of two experiments were used in estimating the parameters. And the reliability of the Ta capacitors was estimated at the same stress conditions of the third experiment. The results indicate that the proposed method is valid and accurate.

In order to effectively analyse the multivariate time series data of complex process, a generic reconstruction technology based on reduction theory of rough sets was proposed. Firstly, the phase space of multivariate time series was originally reconstructed by a classical reconstruction technology. Then, the original decision-table of rough set theory was set up according to the embedding dimensions and time-delays of the original reconstruction phase space, and the rough set reduction was used to delete the redundant dimensions and irrelevant variables and to reconstruct the generic phase space. Finally, the input vectors for the prediction of multivariate time series were extracted according to generic reconstruction results to identify the parameters of prediction model. Verification results show that the developed reconstruction method leads to better generalization ability for the prediction model and it is feasible and worthwhile for application.

To get the scattering loss of the trapezoidal core waveguide, a new analysis model is presented based on the perturbation equivalent method and modified effective-index method. Firstly, the trapezoidal core waveguide is successfully equivalent to the rectangular one with both restricting the same optical field energy by adopting the perturbation method. Then, the equivalent rectangular core waveguide is decomposed into two slab waveguides by employing the modified effective-index method. The trapezoidal core waveguide scattering theory model is established based on the slab waveguide scattering theory. With the sidewalls surface roughness in the range from 0 to 100 nm in the single model trapezodial core waveguide, optical simulation shows excellent agreement with the results from the scattering loss model presented. The relationship between the dimension and side-wall roughness with the scattering loss can be determined in the trapezoidal core waveguide by the scattering loss model.

The classical job shop scheduling problem (JSP) is the most popular machine scheduling model in practice and is known as NP-hard. The formulation of the JSP is based on the assumption that for each part type or job there is only one process plan that prescribes the sequence of operations and the machine on which each operation has to be performed. However, JSP with alternative machines for various operations is an extension of the classical JSP, which allows an operation to be processed by any machine from a given set of machines. Since this problem requires an additional decision of machine allocation during scheduling, it is much more complex than JSP. We present a domain independent genetic algorithm (GA) approach for the job shop scheduling problem with alternative machines. The GA is implemented in a spreadsheet environment. The performance of the proposed GA is analyzed by comparing with various problem instances taken from the literatures. The result shows that the proposed GA is competitive with the existing approaches. A simplified approach that would be beneficial to both practitioners and researchers is presented for solving scheduling problems with alternative machines.

An approach was proposed to specify the C4ISR capability of domain-specific modeling language. To confine the domain modeling within a standard architecture framework, formally a C4ISR capability meta-ontology was defined according to the meta-model of DoD Architecture Framework. The meta-ontology is used for extending UML Profile so that the domain experts can model the C4ISR domains using the C4ISR capability meta-concepts to define a domain-specific modeling language. The domain models can be then checked to guarantee the consistency and completeness through converting the UML models into the Description Logic ontology and making use of inference engine Pellet to verify the ontology.

In order to meet the severe requirements of market and reduce production costs of high quality steels, advanced run-out table cooling based on ultra fast cooling (UFC) and laminar cooling (LC) was proposed and applied to industrial production. Cooling mechanism of UFC and LC was introduced first, and then the control system and control models were described. By using UFC and LC, low-cost Q345B strips had been produced in a large scale, and industrial trials of producing low-cost dual phase strips were completed successfully. Application results show that the ultra fast cooling is uniform along the strip width and length, and does not affect the flatness of strips. The run-out table cooling system runs stably with a high precision, and makes it possible for the user to develop more high quality steels with low costs.

Achieving simultaneous reduction of NO_x, CO and unburned hydrocarbon (UHC) emissions without compromising engine performance at part loads is the current focus of dual fuel engine research. The present work focuses on an experimental investigation conducted on a dual fuel (diesel-natural gas) engine to examine the simultaneous effect of inlet air pre-heating and exhaust gas recirculation (EGR) ratio on performance and emission characteristics at part loads. The use of EGR at high levels seems to be unable to improve the engine performance at part loads. However, it is shown that EGR combined with pre-heating of inlet air can slightly increase thermal efficiency, resulting in reduced levels of both unburned hydrocarbon and NO_x emissions. CO and UHC emissions are reduced by 24% and 31%, respectively. The NO_x emissions decrease by 21% because of the lower combustion temperature due to the much inert gas brought by EGR and decreased oxygen concentration in the cylinder.

The flow pattern behaviour of falling liquid film over three horizontal cylinders was evaluated. These flows can take three forms: discrete droplets, individual jets, and continuous sheet, and special attention is paid to the effects of the physical properties and geometrical parameters of the first two forms (droplets and jets) because these forms are more important in heat-transfer behaviour and less research has been published for these forms. The flow modes and experimental results were successfully compared with previous experimental literatures, and also the effects of liquid flow rate, tube diameter, and tube spacing on departure site spacing, in both drop and jet modes, were evaluated in the low Galileo number and high viscosity fluid (cooking oil), to help developing criteria for determining falling film modes and their transitions, and to understand the heat transfer characteristics associated with each mode.

With the addition of urea as an inhibitor, four groups of reducing dioxin emission experiments in sintering pot were conducted. The results show that, adding 0.05%, 0.1% and 0.5% (mass fraction) urea, the emission concentrations of dioxin are 0.287, 0.258 and 0.217 ng-TEQ/m³, respectively. The dioxin emission rates drop substantially compared to 0.777 ng-TEQ/m³ free of urea. With an increase of the urea content, the concentration of SO₂ emission reduces sharply. (NH₄)₂SO₄, formed by the reaction of SO₂ and NH₃, goes into the dust and part of NH3 is released before reaction with the emission of exhaust gas. The NO_x emission presents an increasing trend because the reaction of NH₃ and O₂ at high temperature produces NO_x. Based on the consideration of factors such as the effect of reducing dioxin emission, and the chemical composition of exhaust gas, 0.05% is the optimum adding content of urea.

The fuzziness exists in spatial distribution of geographic data of land suitability evaluation processes, which makes it difficult to quantify land boundaries by using traditional binary logic-based overlay model. Aiming at this limitation, an ecological suitability evaluation analysis model was presented based on fuzzy theory and a research on urban growth boundary (UGB) of the Great-Hexi Leading District (GHLD) of Changsha was conducted. With the support of GIS, RS and MATLAB, slope, elevation, vegetation, soil productivity, soil permeability, water body and land use are selected as the input of model according to the characteristic properties of soil and terrain in red soil hilly areas. The running result of this model indicates that the ratios of highly suitable land, suitable land, moderately suitable land and unsuitable land in GHLD are 18.75%, 10.31%, 64.16%, 6.78%, respectively. This result accords with spatial structure worked out by Space Development Strategy Planning of GHLD. Based on this result, several suggestions are made to guide UGB developments in future.

To explore the energy saving effect of building envelope, the experiments were carried out through a comparison of basic cubicle in summer. Experiments show that if energy efficiency measures are applied only in the external walls and windows, the energy saving cubicles have an average energy efficiency ratio of 27.75% and 27.05% when the air change rates are 1.1 and 1.4 h⁻¹ in summer, with both values being over the standard target value by 25%. And the indoor air temperature of the energy saving cubicle is below that of the basic cubicle. The daily mean temperature difference between the interior surface of insulation wall and no insulation reaches 1.47 °C, and the mean temperature difference is up to 8.52 °C between the interior surface and exterior surface of insulating glass and single glass. The two cubicles were simulated for energy consumption using VisualDOE4.0 software under real weather conditions in summer. The results show that the mean deviation is 10.02% between experimental and simulated energy efficiency ratio. The correctness and validity of simulation results of the VisualDOE4.0 software are proved.

A district heating and hot water supply system is presented which synthetically utilizes geothermal energy, solar thermal energy and natural gas thermal energy. The multi-energy utilization system has been set at the new campus of Tianjin Polytechnic University (TPU). A couple of deep geothermal wells which are 2 300 m in depth were dug. Deep geothermal energy cascade utilization is achieved by two stages of plate heat exchangers (PHE) and two stages of water source heat pumps (WSHP). Shallow geothermal energy is used in assistant heating by two ground coupled heat pumps (GCHPs) with 580 vertical ground wells which are 120 m in depth. Solar thermal energy collected by vacuum tube arrays (VTAs) and geothermal energy are complementarily utilized to make domestic hot water. Superfluous solar energy can be stored in shallow soil for the GCHP utilization. The system can use fossil fuel thermal energy by two natural gas boilers (NGB) to assist in heating and making hot water. The heating energy efficiency was measured in the winter of 2010-2011. The coefficients of performance (COP) under different heating conditions are discussed. The performance of hot water production is tested in a local typical winter day and the solar thermal energy utilization factor is presented. The rusults show that the average system COP is 5.75 or 4.96 under different working conditions, and the typical solar energy utilization factor is 0.324.

Many sludge curing technologies often have problems like long curing time, high cost, and low efficiency in the condition of low temperature. The compressive strength, moisture content and temperature are defined as the constraint conditions, and solidified cost, pH, COD, NH₄⁺-N concentration are defined as the objective functions. The response surface analysis is used to obtain a variety of response expressions of factors, and the multi-objective optimization model of fast-solidification sludge is established. Then, the curing agent formulas are optimized. After three-day conserving, the curing sludge could meet the landfill conditions.

Based on a synthetic geological study of drilling, well logging and seismic data, core observations and geochemical analysis, it is recognized that Triassic sedimentary facies in the Tahe area of Tarim Basin include braided river deposits filling erosional valleys, and sublacustrine fan, canyon and delta facies. Braided river deposits filling erosional valleys are dominated by coarse-grained lithic quartz sandstone with oblique bedding, and represent the most important sedimentation type of sandstone in the study area. Sublacustrine fan and canyon facies are mainly distributed in the Middle Oil Member. Most delta sediments are deposited in highstand system tract (HST). Because of frequent changes in base level, delta sediments are commonly eroded and rarely preserved. Sedimentary cycles are clearly reflected by lithology, sedimentary structures and well logging data, and are closely related to the changes in lacustrine level. In accordance with the basic principle of sequence subdivision, seven type-I boundaries can be recognized in Triassic strata and six type-I sequences are subdivided correspondingly. In general, lowstand system tract (LST) is well developed within stratigraphic sequences and forms the main body of reservoir sandstone in this area; highstand system tract (HST) and transgressive system tract (TST) are often eroded by upper sequences or missed. Although various factors have different influences on terrestrial sequence stratigraphy, the classical sequence stratigraphy theory proposed by VAIL can be applied to terrestrial strata.

Time domain dynamic analysis of inclined dam-reservoir-foundation interaction was conducted using finite difference method (FDM). The Timoshenko beam theory and the Euler-Bernoulli beam theory were implemented to draw out governing equation of beam. The interactions between the dam and the soil were modeled by using a translational spring and a rotational spring. A Sommerfeld’s radiation condition at the infinity boundary of the fluid domain was adopted. The effects of the reservoir bottom absorption and surface waves on the dam-reservoir-foundation interaction due to the earthquake were studied. To avoid the instability of solution, a semi-implicit scheme was used for the discretization of the governing equation of dam and an explicit scheme was used for the discretization of the governing equation of fluid. The results show that as the slope of upstream dam increases, the hydrodynamic pressure on the dam is reduced. Moreover, when the Timoshenko beam theory is used, the system response increases.

To accurately evaluate the degradation process of prestressed concrete continuous bridges exposed to aggressive environments in life-cycle, a finite element-based approach with respect to the lifetime performance assessment of concrete bridges was proposed. The existing assessment methods were firstly introduced and compared. Some essential mechanics problems involved in the degradation process, such as the deterioration of materials properties, the reduction of sectional areas and the variation of overall structural performance caused by the first two problems, were investigated and solved. A computer program named CBDAS (Concrete Bridge Durability Analysis System) was written to perform the above-metioned approach. Finally, the degradation process of a prestressed concrete continuous bridge under chloride penetration was discussed. The results show that the concrete normal stress for serviceability limit state exceeds the threshold value after 60 a, but the various performance indicators at ultimate limit state are consistently in the allowable level during service life. Therefore, in the case of prestressed concrete bridges, the serviceability limit state is more possible to have durability problems in life-cycle; however, the performance indicators at ultimate limit state can satisfy the requirements.

Based on the compression mechanism for analyzing the cavity expansion problem in soil under high stresses, generalized non-linear failure criterion and large strain and energy conservation in plastic region during the cavity expanding were adopted. The energy conservation equation was established and the limited pressure of cavity expansion under high stresses was given based on the energy dissipation analysis method, in which the energy generated from cavity expansion is absorbed by the volume change and shear strain caused in soil. The factors of large strain and dilatation were considered by the proposed method. The analysis shows that the limited pressure is determined by failure criterion, stress state, large deformation characteristic, dilatation and strength of soil. It is shown from the comparison that the results with the proposed method approximate to those of the in-situ method. The cavity expansion pressure first decreases and then increases nonlinearly with both of shear modulus and dilatation increasing.

Engineering facilities subjected to natural hazards (such as winds and earthquakes) will result in risk when any designed system (i.e. capacity) will not be able to meet the performance required (i.e. demand). Risk might be expressed either as a likelihood of damage or potential financial loss. Engineers tend to make use of the former (i.e. damage). Nevertheless, other non-technical stakeholders cannot get useful information from damage. However, if financial risk is expressed on the basis of probable monetary loss, it will be easily understood by all. Therefore, it is necessary to develop methodologies which communicate the system capacity and demand to financial risk. Incremental dynamic analysis (IDA) was applied in a performance-based earthquake engineering context to do hazard analysis, structural analysis, damage analysis and loss analysis of a reinforced concrete (RC) frame structure. And the financial implications of risk were expressed by expected annual loss (EAL). The quantitative risk analysis proposed is applicable to any engineering facilities and any natural hazards. It is shown that the results from the IDA can be used to assess the overall financial risk exposure to earthquake hazard for a given constructed facility. The computational IDA-EAL method will enable engineers to take into account the long-term financial implications in addition to the construction cost. Consequently, it will help stakeholders make decisions.

Swelling and shrinkage due to moisture-change is one of the characteristics of the expansive soil, which is similar to the behavior of most materials under thermal effect. If the deformation is restricted, stress in expansive soil is caused by the swell-shrinking. The stress is defined as “moisture-change stress” and is adopted to analyze swell-shrinkage deformation based on the elasticity mechanics theory. The state when the total stress becomes equal to the soil tensile strength is considered as the cracking criterion as moisture-change increases. Then, the initial cracking mechanism due to evaporation is revealed as follows: Different rates of moisture loss at different depths result in greater shrinkage deformation on the surface while there is smaller shrinkage deformation at the underlayer in expansive soil; cracks will grow when the nonuniform shrinkage deformation increases to a certain degree. A theoretical model is established, which may be used to calculate the stress caused by moisture-change. The depth of initial cracks growing is predicted by the proposed model in expansive soil. A series of laboratory tests are carried out by exposing expansive soil samples with different moisture-changes. The process of crack propagation is investigated by resistivity method. The test results show good consistency with the predicted results by the proposed theoretical model.

Based on the construction bridge of Xiamen-Shenzhen high-speed railway (9–32 m simply-supported beam + 6×32 m continuous beam), the pier-beam-track finite element model, where the continuous beam of the ballast track and simply-supported beam are combined with each other, was established. The laws of the track stress, the pier longitudinal stress and the beam-track relative displacement were analyzed. The results show that reducing the longitudinal resistance can effectively reduce the track stress and the pier stress of the continuous beam, and increase the beam-track relative displacement. Increasing the rigid pier stiffness of continuous beam can reduce the track braking stress, increase the pier longitudinal stress and reduce the beam-track relative displacement. Increasing the rigid pier stiffness of simply-supported beam can reduce the track braking stress, the rigid pier longitudinal stress and the beam-track relative displacement.

A new vision-based long-distance lane perception and front vehicle location method was developed for decision making of full autonomous vehicles on highway roads. Firstly, a real-time long-distance lane detection approach was presented based on a linear-cubic road model for two-lane highways. By using a novel robust lane marking feature which combines the constraints of intensity, edge and width, the lane markings in far regions were extracted accurately and efficiently. Next, the detected lane lines were selected and tracked by estimating the lateral offset and heading angle of ego vehicle with a Kalman filter. Finally, front vehicles were located on correct lanes using the tracked lane lines. Experiment results show that the proposed lane perception approach can achieve an average correct detection rate of 94.37% with an average false positive detection rate of 0.35%. The proposed approaches for long-distance lane perception and front vehicle location were validated in a 286 km full autonomous drive experiment under real traffic conditions. This successful experiment shows that the approaches are effective and robust enough for full autonomous vehicles on highway roads.

The objective of this work is to develop a novel feature for traffic flow models, when traffic queues on two-way arterials periodically extend until then they block an upstream signal in oversaturated conditions. The new model, proposed as conditional cell transmission model (CCTM) has been developed with two improvements. First, cell transmission model (CTM) is expanded for two-way arterials by taking account of all diverging and merging activities at intersections. Second, a conditional cell is added to simulate periodic spillback and blockages at an intersection. The results of experiments for a multilane, two-way, three-signal sample network demonstrate that CCTM can accommodate various traffic demands and accurate representation of blockages at intersections. The delay of left turns is underestimated by 40 % in moderate conditions and by 58% in oversaturated condition when using the CTM rather than CCTM. Finally, the consistency between HCS 2000 and CCTM shows that CCTM is a reliable methodology of modeling traffic flow in oversaturated condition.