The compacted TiAl alloys were prepared and the effects of HIPing time on their properties were studied. At 1 100 °C, 80 MPa, the density of TiAl alloy reached up to 3.46 g/cm³ after 10 min HIPing. The densities of TiAl alloys did not significantly increase with the time increasing from 10 min to 70 min. Under the experimental conditions, the TiAl alloys obtained is an unstable state alloy, and the effect of HIPing time on the TiAl phase is not significant. The micro-cracks appear in inner of TiAl alloy with the HIPing time increase. At 1 380 °C, after one hour heat treatment, the micro-cracks disappear and the phase changes into stable state and its microstructure changs into lamella.

A kind of new scintillating glass based on PbO-Bi₂O₃ heavy-metal oxides was prepared by doping a certain amount of SiO₂, B₂O₃ and a little Ce³⁺ ions as fluorescence agent using conventional melt quenching technology. The fluorescence properties of the glass were investigated by means of ultraviolet-visible (UV-VIS) absorption spectrum, excitation spectrum, emission spectrum, multi-channel time spectrum and transmission spectrum. The results show that the density of the glass reaches 7.89 g/cm³, and its fluorescence emission wavelength is 547 nm, fluorescence fade time 18.68 ns. Compared to CeF₃, YAP, GSO, ThF₄ and PbF₄ etc. scintilla-ting crystals, the glass has a higher density, a faster scintillation decay constant, a longer emission wavelength and cut off wavelength. But its ability of radiation-resistance must be improved in order to meet the requirements of application in high energy physics experiments under 10⁶ rad radiation in Co⁶⁰ source.

Mechanical properties of the warm compacted iron-base powder metallurgy materials were compared with those of conventional cold compacted materials. Factors such as compaction temperature, lubricant concentration and lubricant’s property were studied. A lubricant for warm compaction powder metallurgy was developed. An iron-based powder metallurgy material with a green density of 7.31 g/cm³ (a relative density of 92.5%) can be obtained by pressing the powder at 700 MPa and 175 °C. The sintered materials have a density of 7.2 g/cm³, an elongation of 2.1% and a tensile strength of 751 MPa compared to 546 MPa using conventional cold compaction with the same lubricant and 655 MPa using warm compaction with other lubricant. Compact density and mechanical properties were influenced strongly by the compacting temperature. Although the best quality compacts can be obtained at 175 °C, warm compaction within 165 to 185 °C can give high density compacts. Evidence shows that compact density depends on the friction coefficient of the lubricant.

In order to use the cast method to replace forge method in producing the load-bearing wheel used in certain heavy duty vehicle, simplified and reduced size load-bearing wheels were squeeze cast and studied using Al-Cu alloy. Tensile properties, hardness, microstructures and morphologies of the squeeze-cast wheels were investigated. The results show that the finer microstructure, higher density, strength, toughness and hardness were achieved through the squeeze casting. Ultimate tensile strength of 428 MPa, yield strength of 360 MPa, elongation of 13.1% were achieved for T5 heat-treated squeeze-cast wheels. The Brinell hardness of squeeze-cast wheels is from HB 120 to HB 137.

For developing TiO based imitated gold materials, the wettabilities of Fe and Fe-Cr-Ni-Ti on TiO were studied. The results indicated that the wettabilities of Fe and Fe-Cr on TiO were poor, and their wetting angles were about 90° at melting point. The wetting angles reduced with the increase of wetting temperature, but the influence of temperature was small. Fe and Fe-Cr containing Cr 50% or less could react with TiO on the interface to form Fe₂Ti and Ti₂O₃, but this did not improve the wettability effectively. When Ni-Ti was added into Fe-Cr alloy, Ni₃Ti was formed on the interface, which can reduce the interface energy, improve the wettability, and prevent the formation of Fe₂Ti and Ti₂O₃. The wetting angles could go down to about 40° when 3% Ni-Ti was added to Fe-Cr alloy.

The authors investigated the mechanism of crud formation in copper solvent extraction. It is indicated that pH value of solution and the phase ratio (O/A) are the main factors affecting crud formation in solvent extraction. The amount of crud extraction increases with aqueous pH value increase, and reduces with the increase of the phase ratio. Fe³⁺, Mg²⁺, fine air bubble and suspended particulates in leaching solution contribute to crud formation. One case is that a series of reactions of hydrolization and polymerization occurs for Fe³⁺, while pH>2.5, polyhydric complex or Fe-SO₄ complex are formed. Then the complex-ions of FeOH²⁺, Fe₂(OH)₂⁴⁺ cause poly-reaction, which is likely to lead emulsion. The study on Zeta potential indicates the repulsion between electriferous droplets in solvent extraction prevents phase coalescence, which is one of the major reasons for emulsion.

Volatile oil was extracted from Illicium Verum Hook. f. by using steam distillation. 41 kinds of compounds were separated and identified by GC/MS, and their relative contents were determined by normalization method. Among 41 identified compounds, there are 14 hydrocarbon components and 22 oxygenated hydrocarbon derivatives, and a small amount of nitrogenous compounds. The main component is anethole, accounting for 76.23%, and the other components such as anisyl acetone, anisaldehyde, p-allylanisole, p-cumic aldehyde and p-allylpen take up more than 10%.

A new kind of polyacrylamide derivate, hydroximic polyacrylamide (HPAM), was prepared from polyacrylamide (PAM) with hydroxylamine hydrochloride in KOH/alcohol solution. Based on colorimetric method in the measurement of C_7–9 alkyl hydroximic acid, the substitution degree of HPAM was determined by selecting octyl hydroximic acid as a primary standard substance. The effects of temperature, the amount of hydroxylamine and potassium hydroxide, and the reaction time on the reaction are discussed. HPAM with 5.78% substitution of degree was acquired by optimizing the reaction conditions. IR spectra revealed that tautomerism appears in the HPAM, and that HPAM exists in both the forms of hydroxamic type and hydroximic type, and the latter type can easily lead to the forming of intramolecular hydrogen bond.

Previous researches on the mixed mode fracture initiation criteria were mostly focused on opening mode fracture. In this study, the authors proposed a new criterion for mixed mode sliding fracture initiation, which is the maximum twin shear stress factor criterion. The authors studied a finite width plate with central slant crack, subject to a far-field uniform uniaxial tensile or compressive stress.

It is an attractive method to combine GPS observations with the information from other surveying system to improve the ambiguity resolution. This research is conducted to investigate how to obtain the prior height information in bathymetric surveying by GPS positioning and how to use the prior height information and to obtain a robust result. The authors deal with the collection and the description of the prior height and the method using height validation to improve the ambiguity resolution. The principle of the method, the relationships between the height threshold and the ambiguity search space are presented. A method to determine the threshold for the height validation is suggested. The field tests are carried out to show the feasibility of the proposed methods.

Previously, researchers raised the accuracy for a robot’s hand to track a specified path in Cartesian space mainly through increasing the number of knots on the path and the number of the path’s segments, which results in the heavier online computational burden for the robot controller. Aiming at overcoming this drawback, the authors propose a new kind of real-time accurate hand path tracking and joint trajectory planning method. Through selecting some extra knots on the specified hand path by a certain rule and introducing a sinusoidal function to the joint displacement equation of each segment, this method can greatly raise the path tracking accuracy of robot’s hand and does not change the number of the path’s segments. It also does not increase markedly the computational burden of robot controller. The result of simulation indicates that this method is very effective, and has important value in increasing the application of industrial robots.

In parallel real-time database systems, concurrency control protocols must satisfy time constraints as well as the integrity constraints. The authors present a validation concurrency control(VCC) protocol, which can enhance the performance of real-time concurrency control mechanism by reducing the number of transactions that might miss their deadlines, and compare the performance of validation concurrency control protocol with that of HP2PL (High priority two phase locking) protocol and OCC-TI-WAIT-50(Optimistic concurrency control-time interval-wait-50) protocol under shared-disk architecture by simulation. The simulation results reveal that the protocol the author presented can effectively reduce the number of transactions restarting which might miss their deadlines and performs better than HP2PL and OCC-TI-WAIT-50. It works well when arrival rate of transaction is lesser than threshold. However, due to resource contention the percentage of missing deadline increases sharply when arrival rate is greater than the threshold.

Aiming at the weaknesses of LON bus, combining the coexistence of fieldbus and DCS (Distributed Control Systems) in control networks, the authors introduce a hierarchical hybrid control network design based on LON and master-slave RS-422/485 protocol. This design adopts LON as the trunk, master-slave RS-422/485 control networks are connected to LON as special subnets by dedicated gateways. It is an implementation method for isomerous control network integration. Data management is ranked according to real-time requirements for different network data. The core components, such as control network nodes, router and gateway, are detailed in the paper. The design utilizes both communication advantage of LonWorks technology and the more powerful control ability of universal MCUs or PLCs, thus it greatly increases system response speed and performance-cost ratio.

In an anode baking horizontal flue ring furnace, the temperature distribution is one of the key factors influencing the quality of baked anode and is closely correlated with the gas flow. To understand the gas flow distribution in the flue, Navier-Stokes equation with “κ-ε” two-equation turbulence model was adopted and the simulation on the gas flow was performed. The numerical simulation results showed that the even direction of gas flow should be considered in the design of flue baffles and the gas flow distribution was really uneven in the flue in practical use. By adjusting the number and location of flue baffles rationally, the even distribution of gas flow can be improved obviously.

The authors demonstrate the importance of the simulation of the water quantity exchange between river water and groundwater to a better understanding of the hydrologic relations between a river and nearby aquifer where groundwater is pumped extensively but only seasonally. And MODFLOW is used to design the stream-aquifer model in which the pumpage of more than 1000 wells was simulated. The river gaining and river losing processes were analyzed. Simulation results suggest that continuation of over-extraction of groundwater will gradually increase the depletion volume in the river year after year and more depletion will occur in later years. The exchange manner between groundwater and the Platte River differs from place to place. The Platte River loses water to the adjacent aquifer in the west part of the study area, and gains water from the adjacent aquifer in the east part of the study area.

In this research, major and immobile minor and trace elements are used to study the petrology of Yamaghan deposit. Some major elements of least altered samples were used to classify the host rocks and their magma type. Considering slight to medium alteration of the host rock, immobile minor and trace elements of more than 110 samples were used to get more confidential results as well. The results show the high accuracy and reliability of the implemented techniques in the study area.

A generalized AKNS isospectral problem where the trace of corresponding spectral matrix is not zero, is transformed to a new isospectral problem where the trace of the resulting matrix is zero, by using transformation of Lax pairs, and these two spectral problems lead to the same hierarchy of equations. The authors started from the transformed spectral problem and constructed a new loop algebra which has not appeared before, and obtained the integrable coupling of the generalized AKNS hierarchy. Specially, the integrable couplings of the KdV equation and MKdV equation are obtained.