The green and sintered densities, and tensile strength of sintered P/M steels produced by cold compaction, warm compaction, warm compaction combined with die wall lubrication (DWL) were measured under various compaction pressures using polytetrafluoroethylene (PTFE) emulsion as the die wall lubricant. The effects of warm compaction on the mechanical properties were studied. The tensile fracture behaviors of cold compaction and warm compaction were studied using scanning electron microscope (SEM). The results show that the density of sintered P/M steel prepared by warm compaction or warm compaction with DWL is higher than that by cold compaction under all compaction pressures. Meanwhile, the highest tensile strength is obtained by combination of warm compaction and die wall lubrication under all compaction pressures. The SEM results show that the fracture modes of the sintered samples prepared by cold compaction and warm compaction at 700 MPa are the mixed mode of ductile fracture and brittle fracture, and obvious dimples can be found in some regions. The fracture of sample prepared by cold compaction is uneven and has irregular and big pores, but that by warm compaction is relatively even and the pores are round mostly, and the samples have many obvious dimples on the whole fracture surface.

The effect of homogenization on the hardness, tensile properties, electrical conductivity and microstructure of as-cast Al-6Mg-0.4Mn-0.25Sc-0.12Zr alloy was studied. The results show that during homogenization as-cast studied alloy has obviously hardening effect that is similar to aging hardening behavior in traditional Al alloys. The precipitates are mainly Al₃(Sc,Zr) and Al₆Mn. When homogenization temperature increases the hardness peak value is declined and the time corresponding to hardness peak value is shortened. The electrical conductivity of the alloy monotonously increases with increasing homogenization temperature and time. The decomposition of the supersaturated solid solution containing Sc and Zr which is formed during direct chilling casting and the precipitation of Al₃(Sc, Zr) cause hardness increasing. The depletion of the matrix solid solubility decreases the ability of electron scattering in the alloy, resulting in the electrical conductivity increased. Tensile property result at hot rolling state shows that the optimal homogenization treatment processing is holding at 300–350 °C for 6–8 h.

The modeling effects of constituents and dispersoids on the tensile ductility of aluminum alloy were studied. The results show that the tensile ductility decreases with the increase of the volume fraction and size of constituents. Thus, purification can improve the tensile ductility by decreasing the volume fraction of constituents (normally compositions of Fe and Si) and the first-class microcracks. The model also indicates that the tensile ductility decreases with the increase in the volume fraction of dispersoids. Decreasing the volume fraction of dispersoids along the grain boundaries by proper heat-treatment and improving the cohesion strength between dispersoids and matrix can also improve the tensile ductility by decreasing the volume fraction of the second-class microcracks.

Microbial community diversities in the drainage from three mines (Dexing Copper Mine, Qibaoshan Copper Mine and Yaogangxian Tungsten Mine, China) were analyzed using 16S rDNA PCR-RFLP approach. The efficiencies of clalcopyrite bioleaching were compared using enrichment of the three cultures. Phylogenetic analysis indicates that the dominant microorganisms are clustered with the Proteobacteria, the remaining is affiliated with Nitrospira, Acidobacteria and Actinobacteria. At the genus level, Acidithiobacillus is the dominant group in both YTW and QBS samples, while Spingomonas is dominant in YGX sample. Moreover, the principal component analysis (PCA) reveals that QBS and YTW have similar geochemical character and microbial communities. The results also show that pH value and tungsten concentration play a key role in microbial community distribution and relative abundance. The bioleaching efficiency of the enrichment cultures from YTW and QBS is similar. After 15 d, the bioleaching rates of low grade chalcopyrite (0.99%) are both up to 99.5% when using 10 g/L pulp density due to the similar microbial composition of YTW and QBS. Moreover, the leaching efficiencies of enrichment cultures containing multiple bioleaching microorganisms are higher than that of pure culture Acidithiobacillus ferrooxidans.

According to physiological and biochemical characteristics of Leptospirillum ferriphilum, a strain of object bacteria was isolated successfully. Bacteria were enriched by selective liquid medium and plated on designed single-layered agar solid medium. Colony was cultured and bacteria were collected. The morphologies of the object bacteria were observed using crystal violet staining, scanning electron microscope(SEM) and transmission electron microscope (TEM). The result of 16S rDNA identification shows that this bacterium belongs to Leptospirillum ferriphilum and it is named as Leptospirillum ferriphilum strain D1. These results indicate that this new single-layered agar solid medium is efficient and simple for isolation of Leptospirillum ferriphilum. Additionally, physiological-biochemical characteristics show that the optimum initial pH value and its growth temperature are 1.68 and 40 °C, respectively. The culture of it is used to leach a complex concentrate chalocpyrite, the leaching efficiencies of copper and iron are 1.93% and 13.74%, respectively, and it is more effective than the A. ferrooxidans culture in the leaching of the complex concentrate chalcopyrite.

A mixed culture of moderately thermophilie microorganisms was enriched from acid mine drainages(AMDs) samples collected from several sulphide mines in China, and the bioleaching of chalcopyrite was conducted both in shake flask and bioreactor. The results show that in the shake flask, the mixture can tolerate 50 g/L chalcopyrite after being acclimated to gradually increased concentrations of chalcopyrite. The copper extraction increases obviously in bioleaching of chalcopyrite with moderately thermophilic microorganisms supplemented with 0.4 g/L yeast extract at 180 r/min, 74% copper can be extracted in the pulp of 50 g/L chalcopyrite after 20 d. Compared with copper extractions of mesophilic culture, unacclimated culture and acclimated culture without addition of yeast extract, that of accliniated culture with addition of yeast extract is increased by 53%, 44% and 16%, respectively. In a completely stirred tank reactor, the mass fraction of copper and total iron extraction reach up to 81% and 56%, respectively. The results also indicate that it is necessary to add a large amount of acid to the pulp to extract copper from chalcopyrite effectively.

Based on the FEA software ANSYS, a model was developed to simulate the thermal stress distribution of inert anode. In order to reduce its thermal stress, the effect of some parameters on thermal stress distribution was investigated, including the temperature of electrolyte, the current, the anode cathode distance, the anode immersion depth, the surrounding temperature and the convection coefficient between anode and circumstance. The results show that there exists a large axial tensile stress near the tangent interface between the anode and bath, which is the major cause of anode breaking. Increasing the temperature of electrolyte or the anode immersion depth will deteriorate the stress distribution of inert anode. When the bath temperature increases from 750 to 970 °C, the maximal value and absolute minimal value of the 1st principal stress increase by 29.7% and 29.6%, respectively. When the anode immersion depth is changed from 1 to 10 cm, the maximal value and absolute minimal value of the 1st principal stress increase by 52.1% and 65.0%, respectively. The effects of other parameters on stress distribution are not significant.

Reaction mechanism of gold dissolving in alkaline thiourea solution was studied by electrochemical methods, such as cyclic voltammetry, chronopotentiometry, AC impedance, linear sweep voltammetry. Apparent activation energy of anodic process of gold electrode dissolving in alkaline thiourea solution is 14.91 kJ/mol. Rate determining step is the process of gold thiourea complex diffusing away from electrode surface to solution. The results of AC impedance and chronopotentiometry indicate that thiourea adsorbs on gold electrode surface before dissolving in solution. There does not exist proceeding chemical reactions. Formamidine disulfide, the decomposed product of thiourea, does not participate the process of gold dissolution and thiourea complex. Species with electro-activity produced in the process of electrode reaction adsorbs on the electrode surface. In alkaline thiourea solution, gold dissolving mechanism undergoes the following courses: adsorption of thiourea on electrode surface; charge transfer from gold atom to thiourea molecule; Au[SC(NH₂)₂]_ads⁺ receiving a thiourea molecule and forming stable Au[SC(NH₂)₂]₂⁺; and then Au[SC(NH₂)₂]₂⁺ diffusing away from the electrode surface to solution, the last step is the rate-determining one.

The effects of SN5040 and polyethylene glycol(PEG) individually and in combination on the dispersion stability of nano-TiO₂ aqueous suspension were investigated by ultraviolet-visible absorption spectroscopy. The adsorption mechanism of these dispersants was detected by zeta potential, isothermal absorption and FTIR analysis. It is found that SN5040 is superior for stabilizing nano-TiO₂ in aqueous suspension to PEG in basic region, and the optimum mass fraction of SN5040 addition is 3%. In the case of NaCl addition, the optimum value increases with the increase of NaCl concentration in the solution. When the mixture of SN5040 and PEG is employed, the antagonism appears preponderant. When SN5040 and PEG are added sequentially, the synergistic reaction takes place. The synergistic reaction can be attributed to the mechanism that PEG adsorption decreases the electronic repulsion between SN5040 molecules, which results in the increase of SN5040 adsorption density. PEG is adsorbed by the interaction with the pre-adsorbed SN5040 layer. Furthermore, the modified inner wall latex paint with well dispersed nano-TiO₂ suspension is endowed with excellent ultraviolet absorption and antibacterial properties.

Based on the turbulence jet model, with respect to Ar-He mixture plasma gas injecting to ambient atmosphere, the temperature filed and velocity field under typical working conditions were investigated. Given the conditions of I=900 A, F_Ar = 1.98 m³/h, F_He = 0.85 m³/h, it is found that both the temperature and the velocity undergo a plateau region near the nozzle exit (0–10 mm) at the very first stage, then decrease abruptly from initial 13 543 K and 778.2 m/s to 4 000 K and 260.0 m/s, and finally decrease slowly again. Meanwhile, the radial temperature and radial velocity change relatively slow. The inner mechanism for such phenomena is due to the complex violent interaction between the high-temperature and high-velocity turbulent plasma jet and the ambient atmosphere. Compared with traditional methods, the initial working conditions can be directly related to the temperature and velocity fields of the plasma jet by deriving basic boundary conditions.

The electrokinetic properties and flotation of diaspore, kaolinite, pyrophyllite and illite with quaternary ammonium salts collectors were studied. The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order (from strong to weak) of octadecyl dimethyl benzyl ammonium chloride(ODBA), cetyl trimethyl ammonium bromide(CTAB), dodecyl trimethyl ammonium chloride(DTAC). Under the condition of alkalescence, it is possible to separate the diaspore from the silicate minerals such as kaolinite, illite and pyrophyllite using quaternary ammonium salts as collector. Isoelectric points (IEP) of diaspore, kaolinite, pyrophyllite and illite are pH=6.0, 3.4, 2.3 and 3.2, respectively. Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously. The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum (FT-IR) measurements. The results demonstrate that only electrostatic interaction takes place between aluminosilicate minerals (diaspore, kaolinite, pyrophyllite and illite) and quaternary ammonium salts.

Chromatography-mass spectrometry (GC-MS) was used to analyze the volatile components of cut tobacco samples with the help of heuristic evolving latent projections (HELP). After extracting with simultaneous distillation and extraction method, the volatile components in cut tobacco were detected by GC-MS. Then the obtained original two-dimensional data were resolved into pure mass spectra and chromatograms. The qualitative analysis was performed by similarity searches in the national institute of standards and technology (NIST) mass database with the obtained pure mass spectrum of each component and the quantitative results were obtained by calculating the volume of total two-way response. The accuracy of qualitative and quantitative results were greatly improved by using the two-dimensional comprehensive information of chromatograms and mass spectra. 107 of 141 separated constituents in the total ion chromatogram of the volatile components were identified and quantified, accounting for about 88.01% of the total content. The result proves that the developed method is powerful for the analysis of complex cut tobacco samples.

Active volatile components in drug pair (DP) Herba Ephedrae-Ramulus Cinnamomi (HE-RC), single drug HE and RC were analyzed by gas chromatography/mass spectrometry (GC/MS), chemometric resolution method (CRM) and overall volume integration. By means of CRM, the two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound. In total, 97, 62, and 78 volatile chemical components in volatile oil of HE, RC, and DP HE-RC, were respectively determined qualitatively and quantitatively, accounting for 90.08%, 91.62%, and 89.76% total contents of volatile oil of HE, RC, and DP HE-RC respectively. It is further demonstrated that the numbers of volatile components of DP HE-RC are almost the sum of those of two single drugs, but some relative contents of them are changed. Some new components, such as 1,6-dimethylhepta-1,3,5-triene, tetracyclo[4.2.1.1(2,5).0(9,10)]deca-3,7-diene, globulol and (E,E)-6,10,14-trimethyl-5,9,13-pentadecatrien-2-one are found in DP HE-RC because of chemical reactions and physical changes during decoction.

The sensitive second derivative waves of Cu(II), Pb(II), Cd(II), Ni(II), Zn(II), Fe(II) and Mn(II), forming in the substrate solution (pH=9.26) consisting of ammonia, ammonium chlorid, gelatin and ascorbic acid were researched. The peak potentials of the polarographic waves of the seven ions are at about −0.48, −0.63, −0.79, −1.04, −1.28, −1.44 and −1.60 V respectively. Combining with microwave technique, a new method for the simultaneous determination of the seven trace elements in Chinese traditional medicine was developed. The method is easy to operate, rapid, simple and convenient. When the signal-to-noise rate equals 3, the detection limits of Cu, Pb, Cd, Ni, Zn, Fe and Mn are 4.2 × 10⁻³, 5.3 × 10⁻³, 2.1 × 10⁻³, 5.8 × 10⁻⁴, 3.0 × 10⁻³, 7.7 × 10⁻⁴ and 1.1 × 10⁻³ μg/mL respectively. Well linear relationships exist between the concentrations and the peak currents when Cu, Pb, Cd, Ni, Zn, Fe and Mn concentrations are within 8.5 × 10⁻³−10, 9.7 × 10⁻³, 4.5 × 10⁻³−10, 1.2 × 10⁻³−10, 6.4 ×10⁻³−10, 1.5 × 10⁻³−10 and 2.8 × 10⁻³−10 μg/mL, respectively. The method has been used to the simultaneous determination of the seven trace elements in Salvia Miltiorrhiza Root and compound Salvia Miltiorrhiza Root injection, the relative standard deviations(RSDs) of the Cu, Pb, Cd, Ni, Zn, Fe and Mn in the two medicines are 3.9% and 5.8%, 4.0% and 4.1%, 4.3% and 5.7%, 4.9% and 5.3%, 4.4% and 4.7%, 3.5% and 4.0%, 0.51% and 2.8%, respectively; the comparisons of the determination results with the values obtained by the standard method indicate that the presented method has very well veracity.

L-aspartic acid (Asp) pillared hydrotalcites were prepared by direct reaction of the L-Asp anion with layered double hydroxides (LDHs). The obtained samples were characterized by X-ray diffractometry (XRD), Fourier transform infrared (FTIR), and thermogravimetric and differential thermal analysis (TG/DTA). The results show that the initial interlayer carbonate ions can be completely replaced by the L-Asp anion under the controlled conditions. The pillared hydrotalcites have a crystallized supramolecular structure and thermal stability. The L-Asp pillared LDHs were used in the enantiosorption of enantiopure phenylalanine (Phe), the results suggest that L-Asp pillared LDHs exhibit an excellent enantiosorption capability for D-Phe, and the adsorption isotherm fits Freundlich equation.

A simple and effective route for the synthesis of mibolerone was described starting from the estr-5(10)-en-3,17-dione in four steps with the overall yield of 47.0%. Thus, two methods for key intermediate methylnorandrost were investigated: one(method A) starting from estr-4-en-3,17-dione underwent 3-keto group protected with ethyl orthoformate to give 3-ethoxy-3,5-dien-estr-17-one, the other(method B) from estr-5(10)-en-3,17-dione and protected 3-keto group to give 3,3-dimethoxy-estr-5(10)-7-one in a mild acidic condition. Then, two intermediates were subsequently reacted with methyllithium followed by a mild hydrolytic procedure and gave methylnorandrost with total yield 25.0% and 86.0%, respectively. In the preparation of 6-dehydrogenation product of methylnorandrost, two procedures(method C and method D) were investigated: one was the protected 17α-methyl-17β-hydroxy Δ^3,5-enol ethers estrendiene brominated and the resulting 6-bromo-19-methylnortestosterone was then immediately dehydrohaloenated to give 6-dehydro-19-methylnortestosterone, the total yield only reaches 36.0%; the other was directly dehydrogenated with chloranil and the yield reaches 75.6% under the optimum conditions: in refluxing tetrahydrofuran, the molar ratio of methylnorandrost to chloranil is 0.66 and reaction time of 5 h. The titled compound and intermediates were characterized by ¹H and ¹³C NMR, IRMS and elemental analysis.

Based on the ant colony system (ACS) algorithm and fuzzy logic control, a new design method for optimal fuzzy PID controller was proposed. In this method, the ACS algorithm was used to optimize the input/output scaling factors of fuzzy PID controller to generate the optimal fuzzy control rules and optimal real-time control action on a given controlled object. The designed controller, called the Fuzzy-ACS PID controller, was used to control the CIP-I intelligent leg. The simulation experiments demonstrate that this controller has good control performance. Compared with other three optimal PID controllers designed respectively by using the differential evolution algorithm, the real-coded genetic algorithm, and the simulated annealing, it was verified that the Fuzzy-ACS PID controller has better control performance. Furthermore, the simulation results also verify that the proposed ACS algorithm has quick convergence speed, small solution variation, good dynamic convergence behavior, and high computation efficiency in searching for the optimal input/output scaling factors.

A robust unified controller was proposed for wheeled mobile robots that do not satisfy the ideal rolling without slipping constraint. Practical trajectory tracking and posture stabilization were achieved in a unified framework. The design procedure was based on the transverse function method and Lyapunov redesign technique. The Lie group was also introduced in the design. The left-invariance property of the nominal model was firstly explored with respect to the standard group operation of the Lie group SE(2). Then, a bounded transverse function was constructed, by which a corresponding smooth embedded submanifold was defined. With the aid of the group operation, a smooth control law was designed, which fulfills practical tracking/stabilization of the nominal system. An additional component was finally constructed to robustify the nominal control law with respect to the slipping disturbance by using the Lyapunov redesign technique. The design procedure can be easily extended to the robot system suffered from general unknown but bounded disturbances. Simulations were provided to demonstrate the effectiveness of the robust unified controller.

A theoretical model of relationship between subsurface damage and surface roughness was established to realize rapid and non-destructive measurement of subsurface damage of ground optical materials. Postulated condition of the model was that subsurface damage depth and peak-to-valley surface roughness are equal to depth of radial and lateral cracks in brittle surface induced by small-radius (radius ⩽ 200 μm) spherical indenter, respectively. And contribution of elastic stress field to the radial cracks propagation was also considered in the loading cycle. Subsurface damage depth of ground BK7 glasses was measured by magnetorheological finishing spot technique to validate theoretical ratio of subsurface damage to surface roughness. The results show that the ratio is directly proportional to load of abrasive grains and hardness of optical materials, while inversely proportional to granularity of abrasive grains and fracture toughness of optical materials. Moreover, the influence of the load and fracture toughness on the ratio is more significant than the granularity and hardness, respectively. The measured ratios of 80 grit and 120 grit fixed abrasive grinding of BK7 glasses are 5.8 and 5.4, respectively.

A 3-D geometrical nonlinear model for the entire lift system of 1000-m sea trial system of China Ocean Mineral Resources R&D Association was established with finite element method. The model was utilized to analyze the dynamic characteristics of the vertical pipe under the influence of moving velocity, current direction and wave. The simulation results show that the axial stress is dominant on the vertical pipe, its maximum is located at the pipe top, all stresses are much less than the allowable value of the vertical pipe and joint; the heave motion leads to violent fluctuation of the force and stress, but a period of 8 s is not likely to resonate the present pipe; against the current, 0.50 m/s is the suggested moving velocity of the ship and miner, while along the current, the moving velocity can be slightly higher than 0.75 m/s.

An effective assemble-oriented framework for grid Web service based on open grid service architecture was proposed, in which Web service semantics network constructed by software reuse was designed to enhance the locating of assemble-oriented service resources. The successful Web services assembled structure was exploited to design semantics network, the logical and the physical structure of the resource was separated in Web service, and the logical resource derived from type ID of Web service was combined with semantic structure. The organizing protocol, data structures and the mechanism of implementation in the model were presented. Experiment results show that the success ratio of Web service request comes to 100% while providing completely assembly semantics set. This model provides guarantee of the reliability of assemble Web service and establishes the foundation of Web service automatic interaction, customizing application service and dynamic service configuration.

The typical features of the coordinate and the curvature as well as the recorded time information were analyzed in the hand-written signatures. In the hand-written signature process 10 biometric features were summarized: the amount of zero speed in direction x and direction y, the amount of zero acceleration in direction x and direction y, the total time of the hand-written signatures, the total distance of the pen traveling in the hand-written process, the frequency for lifting the pen, the time for lifting the pen, the amount of the pressure higher or lower than the threshold values. The formulae of biometric features extraction were summarized. The Gauss function was used to draw the typical information from the above-mentioned biometric features, with which to establish the hidden Markov mode and to train it. The frame of double authentication was proposed by combing the signature with the digital signature. Web service technology was applied in the system to ensure the security of data transmission. The training practice indicates that the hand-written signature verification can satisfy the needs from the office automation systems.

Bainiuchang silver-polymetallic ore deposit is located in the southeast Yunnan tin-polymetallic metallogenic belt. The probable reserves and inferred resources of the deposit are of 6 470 t Ag and 1.10 Mt Pb and 1.72 Mt Zn and 86 kt Sn. Orebodies of the deposit occur in clastic-carbonate rocks of Tianpeng Formation and Longha Formation of the middle Cambrian System above the Bainiuchang concealed granite of the late Yanshan period. The concealed granite has the characteristics of tin-bearing granites. Abundance of the mineralization elements Sn, Cu, Zn, Pb, Ag and Sb is high in the granitic rocks. Sulphur isotope data of the metal sulphides indicate that most sulphur is derived from the magmas. The ores are similar in rare earth element(REE) patterns to the granitic rocks. The granitic magma activity results in ore-bearing structures. Rocks of the Middle Cambrian System above the concealed intrusion suffer from skarnization, hornfelsing, marbleization, siliconizing and carbonatization. The mineralization elements Sn, Cu, Zn, Pb, Ag and Sb successively appear from the top of the granite to surrounding rocks. These evidences indicate that the granitic magmatism is the principal mineralization factor. The opinion that the south Bainiuchang ore field and the north Awei ore block are tin and copper potential exploration areas was put forward and was verified by drilling tests.

The elastic differential equations of load-transfer of single pile either with applied loads on pile-top or only under the soil swelling were established, respectively, based on the theory of pile-soil interaction and the shear-deformation method. The derivation of analytic solution to load-transfer for single pile in expansive soil could hereby be obtained by means of superposition principle under expansive soils swelling. The comparison of two engineering examples was made to prove the credibility of the suggested method. The analyzed results show that this analytic solution can achieve high precision with few parameters required, indicating its’ simplicity and practicability in engineering application. The employed method can contribute to determining the greatest tension along pile shaft resulting from expansive soils swelling and provide reliable bases for engineering design. The method can be employed to obtain various distributive curves of axial force, settlements and skin friction along the pile shaft with the changes of active depth, vertical movements of the surface and loads of pile-top.

Stability condition and quality evaluation formula of layerlike backfilling roof, Q⩾C, where Q denotes is quality index depending on allowable compressive or tensile strength and integrity of backfilling, and C is the technical index depending on mining method and backfilling technology, were inferred according to simply supported beam theorem. Technical treatment measures for instable backfilling roof, including optimum of appropriate filling materials and dosage for excellent flow property and reduction of backfill cost. It is proved that slope equation of backfill slurry in a stope to be filled is y=hexp[−x²/(2σ)²)], where h is height of cone and σ² is mean square, and that optimum drainage point of backfill slurry can be determined by the equation and sizes of stope. Case study indicates that the results can give a theoretical support for quality evaluation and control of layerlike backfilling.

The phenomenon of preferential solution flow during dump leaching of low-grade ores was studied. The formative mechanism of preferential solution flow was investigated through analyzing the relationship between permeability and ore diameter, and the relationship between surface tension and ore diameter. The preferential solution flow happened within the fine ore area when the dump was unsaturated. And it could happen within the coarse ore area when the dump became saturated. The results of experiment show that the outflow of coarse ore area increases sharply with higher applied rate. The outflow of fine ore area is greater than that of coarse ore area when the applied rate is below 3.2 L/min, and the preferential solution flow happens in fine ore area. But the preferential solution flow happens in coarse ore area when the applied rate is higher than 3.2 L/min. The result of the experiment is consistent with the mechanism analyzing.

Based on the discussion about working mechanism of horizontal reinforcement and that of vertical reinforcement, respectively, the working mechanism of two-direction reinforced composite foundation was studied. The enhancing effect of horizontal reinforcement on vertical reinforced composite foundation was analyzed. A simplified calculation method for such two-direction reinforced working system was presented. A model experiment was carried out to validate the proposed method. In the experiment, geocell reinforcement worked as the horizontal reinforcement, while gravel pile composite foundation worked as the vertical reinforcement. The results show that the calculated curve is close to the measured one. The installation of geosynthetic reinforcement can increase the bearing capacity of composite foundation by nearly 68% at normal foundation settlement, which suggests that the enhancing effect by geosynthetic reinforcement should be taken into account in current design/analysis methods.

For optimizing the cutting depth of spiral drum type cutting head, the relations among collecting ratio, interfusing ratio of mullock and cutting depth of the mining cobalt-rich crusts in ocean were discussed. Furthermore, the multi-extremum problem about cutting depth was analyzed in mining at a certain interfusing ratio of mullock. Through introducing genetic algorithm (GA), the cutting depth-control problem when the collecting ratio is maximized by controlling the interfusing ratio of mullock was solved with global-optimization-search algorithms. Then optimization theory for cutting depth in mining cobalt-rich crusts by GA, and computer programming were given to realize the algorithm. The computation result of actual data proves the validity of this method.