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Urban spatial structure is the city in a variety of material, energy and social culture accumulation in space distribution and combination of the state. It is also the core issue of urban spatial development. Author studies China's urban spatial structure research, and find that China's urban spatial structure research mainly concentrated three times: 1980’s, 1990’s and since 2000.Research emphasis of each period is different. Through the process of urban spatial structure research, author sum up that the research in China has the following features: emphasis on urban spatial structure, advancing with The Times, etc. Authors hope this article can have the implications about the future of China's urban spatial structure research.

In this paper, centrifugal slip casting method was use to prepare carbon fiber/HA composites using the nanoHA particles and carbon fibers as initial materials. The morphology of the carbon fiber after modification of p-aminobenzoic acid was observed. The rheological characteristic of the carbon fibers/HA slurries was studied. The effects of the centrifugal acceleration on green density uniformity of carbon fiber/HA composites were analyzed. The bending strength and fracture toughness of carbon fiber/HA composites were measured. The results show the roughness of carbon fibers treated by p-aminobenzoic acid increases. At the pH of 10 and 5 wt% dispersant, the HA slurries with 3 vol% carbon fibers have good fluidity. After centrifuged at 2860 G for 30 min, the green compacts of HA composites have high and uniform the green density. After sintered at 1100°C for 1h, compared with carbon fiber/HA composites prepared by dry pressing, the modified carbon fiber/HA composites prepared by centrifugal slip casting have higher bending strength and fracture toughness of 89.4 MPa and 1.92MPa1/2, respectively.

In order to eliminate cracks in the chromium coating, a novel method named flexible extrusion assisted chromium electroplating was proposed. The bright and crack-free chromium coatings were electrodeposited by using the perturbation and extrusion of hard and insulating particles. The prepared deposits were characterized by scanning electron microscope (SEM) and three-dimensional topography. The testing results showed that the surface was very smooth and there was no micro cracks in the coating. Micro hardness of the electrodeposited layer was also tested. It was confirmed that the chromium coating electrodeposited with rotating cathode in hard particles had high micro hardness as to 850HV and the micro hardness could be controlled by the process parameters. The rule of the micro hardness was concluded by analyzing current density and rotating speed. In addition the results of salt spray test and electrochemical polarization curve showed that the coating deposited by new method had higher corrosion resistance than that by traditional method.

Glass filament reinforced composite materials have become an indispensable material in national economic construction. The main purpose of this project is to produce the spacer fabric adopting glass filament through changing weaving process. First glass filaments were treated with epoxy resin to prevent from its low bending rigidity. Second ground warps and binding warps were separately warped and double warp beams were used in the weaving. At the shed crossing point the height of heald frames was different between the top layer and down layer warps, then the drafting sequence of the top layer of warps, the down layer of warps and binding warps were adjusted. The cotton yarns were chosen as the selvage warps which have good wear resistance and uniform tension. The long and short beat–up method was used. Eventually 3cm thickness of glass filament spacer fabric is achieved. It is hoped that this work will provide meaningful help to the development of glass filament spacer fabric.

An optoelectronic oscillator (OEO) based on series-coupled double recirculating delay lines (SC-DRDLs) is analyzed and experimentally demonstrated. The SC-DRDLs composed by the coupling cascade of two RDLs, which the free spectral range (FSR) is least common multiple of the two RDLs’ FSR, and then the large FSR can be obtained by properly setting the loop lengths of two RDLs. By consociation with the dual loops system between the dual output of the SC-DRDLs and PBS, the high sidemode suppression performance can be achieved. Meantime, the incoherence of the SC-DRDLs can be performed by using an amplified spontaneous emission (ASE) broadband laser source. An experiment is carried out. A microwave signal with high spectral purity, long-term stability, low single-sideband (SSB) phase noise is generated.

The investigation was carried out to study the effect of a novel process of surface modification, surface nanocrystallization by high energy shot peening (HESP), on osteoblast proliferation and differentiation. A disc of pure titanium was processed to HESP in a commercial shot peening equipment, to create nanostructure at the surface. The surface microstructure was characterized by SEM and osteoblasts were co-cultured with the surface nanostructured titanium and unreceived titanium surface to evaluate their biocompatibility. The nanostructured surface layer on titanium was successfully processed by HESP, and the nanosized grains were about 60 nm in diameter and inhomogeneous distributed on the surface of n-Ti. The results also confirmed the proliferation and differentiation of osteoblasts were highly improved on surface nanostructured titanium. This finding suggests that there is high potential of this novel surface modification process which could enhance bone tissue growth of dental implant.

The core concept of the ecological environment is a benign cycle in line with the design of systems, which needs to overcome the difficulties of a few difficult; green design must be the ultimate development of the industry as a strategic goal, only after a long a historical stage of the efforts to achieve the ultimate indoor green design for human dwelling in the land of poetry to the ideal.

With the development of industry, the phenolic wastewater pollution has become increasingly serious, This paper studies the effects of microbial life activities on D301 resin adsorption and catechol were discussed, Study found that the resin of the ability after the microbial treatment on the adsorption of catechol contribute. The optimum concentration of D301 for 0.8g/L adsorption of catechol; blank treatment was the highest adsorption capacity is 126mg/g, and the maximum adsorption capacity through the resin after the microbial treatment can reach 155mg/g, but its mechanism needs further study.

According to the predistortion technique of travelling wave tube amplifiers (TWTAs), by analyzing TWTA model proposed by Saleh, the gain transmission function curve and phase expansion function curve of the predistortion circuit are deduced. The linear range of TWTA could be enlarged by using predistortion technique, and invariable gain together with zero phase excursions are reached at the working region of the linearized TWTA. As a kind of microwave and millimeter wave amplifiers, TWTAs find a wide utilization in communication, radar and electronic countermeasure applications. To obtain high output power, TWTAs are usually working at their saturation region where severe nonlinear distortion appears. The nonlinearity manifests gain compression and phase excursion. For digital communications application, the nonlinear distortion increase bit error rate, and this limits system efficiency. For electronic countermeasure applications, the nonlinear distortion limits the output power obtainable at the carrier frequency, and this limits the obtainable efficiency of the system. So insights into measures to improve nonlinearity of TWTAs will benefit wireless communications systems and electronic countermeasure systems. Predistortion technique is one of the best choices [1,2,.

Uncertainty has negative effects on mixed-model assembly line balancing. With this uncertainty, the paper built a mathematical model on MMALBP of type II , and designed a solving method which is based on GA. It contributes to the management of the assembly line and production arrangements, and increases production efficiency.

According to the air flow measurement principle, an automobile conditioner each outlet and atmospheric pressure based on zero characteristics has been developed. The experiment platform adopts V cone flowmeter gas flow indirect measurement of automotive air conditioning of the air outlet pipe, a detailed description of the design of the test bench of mechanical structure, measuring circuit, computer software, through the experimental result analysis, can realize the accurate measurement of air.

Through the establishment of contact element simulated the contact between sucker rod and oil pipe. The deformation of sucker rods in oil pipe that caused by the screw pump rotor eccentricity has been researched by the application of transient dynamics analysis. Results show that screw pump rotor eccentricity is one of the reasons which cause rod and oil pipe contact resulting in partial abrasion. Deformation of the sucker rods caused by the rotor eccentricity is mainly concentrated on the bottom of rods, so in order to mitigate partial abrasion, rod centralizer arrangement at the bottom of rods should be strengthened, or change the connection mode between the sucker rod and screw pump rotor to eliminate the effect of the sucker rod deformation caused by rotor eccentric motion.

Pulse current effects during hot tensile process and superplastic forming process of AZ31 magnesium alloy and TA15 titanium alloy were investigated in this paper. The experimental results indicate that the current can produce polarity effect to coarse grain AZ31 magnesium alloy, but to fine grained TA15 titanium alloy, the polarity effect is not obvious. The impact of electron wind force can change the strength of material during tensile process and affect final shape of part, making the dome of AZ31 hemisphere part deviated from the axis to the side of positive pole during superplastic forming process. In addition, the impact of current depends on current density and dislocation density.

In this paper, the nano-β-SiC/Al2O3 composite absorbing coatings produced by plasma spraying technology were reported. Where, β-SiC phase dissipates in the boundary of Al2O3 grains. Then, the relationship between microstructure and dielectric properties was built. Some results are shown as follows: with increasing of flatten ratio of particle and pores, the microwave reflectivity coefficient of composite absorbing coatings decreases and ranges to low frequency. And, there exists a threshold value, about 30wt% of nano β-SiC, the microwave reflectivity coefficient of composite absorbing coatings can reach to -8 dB. The infrared properties of β-SiC/ Al2O3composite absorbing coatings with experiment is about 0.6~0.8, respectively.

The virtual prototype simulation of the underground pumping system can’t realize the timing analysis with the ground pumping unit system. In order to solve this problem, the simulation analysis model of the pumped well virtual prototype was established via the multibody dynamics simulation software Adams by analyzing the working characteristic of the sucker rod string. The simulation was in accordance with the dynamic indicator diagram which verifies the correctness of the simulation analysis model of the pumped well virtual prototype and also offers a new analysis method for the underground pump dianamograph and pumping unit balance, etc.

Flight control system; multiple criteria decision making; multiple objective decision making; multiple attribute decision making; neural network; mean impact value index. Abstract. It is complex and difficult to tune the parameters of the flight controller. To solve such problem, a multiple objective decision making (MODM) method by using the reference model which is built based on the criteria, is proposed. In order to resolve defects of the multiple attribute decision making (MADM) that the arbitrary of the subjective attribute weights and ignoring the objective message of the objective attribute weights, a subjective attribute weights based on the BP neural network by using the MIV (mean impact value) index is proposed. Finally, a combining method based on the TOPSIS is used to give the final attribute weights. The simulation results show that the method could obtain a set of trade-off solutions which satisfy the requirements of the MODM and could tune the controller effectively.

Alumina spinel is widely used as a refractory material in metallurgy industries. Arc furnace melting method is suitable to produce high quality alumina spinel. However, the high melting temperature (> 2200 °C) and high electric energy consumption limit the application of this method. There exists huge opportunity for energy saving through process optimization. A newly designed 2400 kVA electric arc furnace is used as melting facility to produce alumina spinal in this study. It shows from the experiments and analysis that melting voltage has much effect on electric power input and electric efficiency. At voltages higher than 150V, stable electric power input and adequate efficiency can be maintained. Stable melting voltage is difficult to maintain at 100-150V range and power efficiency are also apparently lower. For voltage less than100V, the process is very difficult to control and energy efficiency are very poor. Too high voltage on the other hand can lead the electric arc expose directly to the surroundings and increase the energy loss. In practical melting process, controlling the melting voltage at 140-160V range is suitable for high quality alumina spinel production.

An improved K-ω model, which allows for compressible corrections, is proposed in this paper. Numerical scheme was established utilizing the improved Total Variation Diminishing (TVD) scheme and applying implicit scheme to the negative source terms of the turbulence model. Hypersonic flat-plate boundary-layer flows and hypersonic compression ramp flows marked with separation, reattachment and shock/boundary layer interactions are then computed. Comparisons between the computational results, the experimental results and the semi-empirical formulations show that the compressible correction term of the K-ω turbulence model is a pressure-dilatation correlation. In addition, for flow with separation and without separation, calculation results of wall pressures, friction coefficients and wall heat transfer rate distributions using the improved model and established scheme agree better with the experimental results than that using the original K-ω model.

A novel photonic crystal fibers (PCFs) based polarization splitter is proposed in this paper. It is designed by highly birefringent dual-core PCFs which hollow ring defects are used in its one direction to break the structural symmetry. Compared to the previous methods achieving high birefringence, this new type of PCFs can partly overcome the design and fabrication limitations for the PCF-based polarization splitter. Its transmission properties, coupling lengths for the two orthogonal polarizations and the performance of the proposed polarization splitter are investigated respectively. The results show that a 0.676-mm-long polarization splitter can be obtained. When the splitting ratio is better than -15dB, its bandwidth is about 45.8nm.

Gradient Zirconia toughened alumina (ZTA) ceramics with high fracture strength and toughness were prepared using centrifugal slip casting method. Aqueous Al2O3-20vol% ZrO2 slurries with different solid contents were prepared and the rheological characteristic of the slurries were investigated. The effect of solid loading of slurries on green density difference of ZTA ceramic compacts was observed. Mass segregation of Al2O3 and ZrO2 particles were studied. Microstructure and bending property of the sintered ZTA ceramics were investigated. The results show that the segregation phenomenon of Al2O3-ZrO2 slurries comes form the difference of settling velocity of Al2O3 and ZrO2 particles. With the increase of solid content of slurries, the gradient distribution of green density becomes unconspicuous. After sintered at 1550○C for 2 h, the gradient ZTA ceramics centrifuged with 20vol% slurries have high sintered density (99.2% TD) and continuous gradient distribution of Al2O3 and ZrO2 particles. The fracture strength and toughness of gradient ZTA ceramic are 732MPa and 5.4MPam1/2, respectively.

In this paper, the internal flow field of RH degasser was studied by numerical simulation. The range of the reasonable gas-inlet velocity which is related to the lift gas flow rate was obtained, then the results of two different gas-inlet velocities which are the reasonable velocity and the unreasonable velocity were chosen to be analyzed. Many vortexes and some differences of the flow fields were found in the RH degasser with the two different velocities. Through these results the development of the flow field could be got and it is valuable for the production in factory.

Using fluorinated acrylate (FDA) as functional monomer,the co-polymeric emulsion were prepared with acrylates(homemade) as soft monomers,sodium dodecyl sulfate (SDS) and Span-80 as emulsifie,ammonium persulfate as initiator,and methyl methacrylate(MMA) as stiff monomer.The obtained latex was characterized by FT-IR,and was used to treat cotton fabrics. Adopting two dipping and two padding finishing processes, then the treated fibrics were dried at 110°C for 1.5 min,finally cured at 170°C for 3min.The contact angles, water/oil repellency and mechanical properties of treated fabrics were tested. The results showed that the contact angle can approach to 134.3 °, water-repellency rate and oil-repellency rate of the treated fabrics can reach grade 3-4 and 1, respectively. There was little change in whiteness and wrinkle recovery angle.

Environmental protection and worker safety measures against the extensively used hard chrome plating (EHC) is becoming more stringent, which leads to the development and application of alternative technology. As one of the most promising replacement technology of EHC, WC/Co coatings deposited by High Velocity Oxygen Fuel (HVOF) have well performances in corrosion and wear resistance. The paper analyzed technical characteristics, property and cost of EHC and HVOF deposited WC-Co coatings, while results show that performance of HVOF sprayed WC-Co coatings is superior or equal to EHC with much higher expense, so current replacement of EHC by HVOF centers airplane and military arm field which have relatively higher profit.

The jet temperature of the plasma generator for waste disposal reaches as high as 10000K so that it is difficult to measure directly. By constructing a digital plasma measurement system, the operating parameters of plasma generator can be precisely controlled and measured. According to energy balance principle, the mathematical model was determined to calculate the average enthalpy at the plasma generator exit plane, and the average temperature and its distributions were obtained. Influence of different gas compositions on plasma jet characteristics was studied. The results show that, at the plasma generator exit plane, the maximal temperature and average temperature of argon plasma jet is about 18794K and 10193 K respectively, while that of argon-hydrogen plasma jet is about 22358 K and 12100 K.

This paper presents a dual-mode control scheme for a boost rectifier at both extreme loads. The transition-mode (TM) technique is adopted to reduce the switching loss at light loads. On the other hand, the fixed-off-time (FOT) control with continuous conduction mode (CCM) operation decreases the conduction losses at heavy loads. The principles and design procedures of the proposed dual-mode controller are discussed and analyzed. Finally, a 300-W dual-mode boost rectifier with an output voltage of 380 V is implemented with satisfactory experimental results.

Coal mine engineering mostly underground mining engineering. Underground mining engineering is inseparable from the underground lighting; the lighting can be engaged in underground work. Lighting conditions is gradually improved with the progress of science and technology development, now the production of environmental lighting conditions has been greatly improved. Therefore, Visualization of mining monitoring not only contribute to the safe production of coal mine but also achieve the production disaster forecast according to daily image recording.

Mass segregation of Al2O3 slurries during centrifugal slip casing has important effect on microstructure and mechanical property of sintered Al2O3 ceramic, so the study on effect of centrifugal process parameters on mass segregation of slurries has significant meaning. Al2O3 ceramic slurries with different solid content varying from 30vol% to 50vol% were prepared. The effect of centrifugal time, centrifugal acceleration and solid content of slurries on green density uniformity of Al2O3 ceramic compacts was studied. The microstructure of centrifuged compacts was observed using scanning electron microscopy (SSX-505). The results show with the increase of centrifugal acceleration and solid content of slurries, the mass segregation of Al2O3 particles with different size increases and decreases, respectively. However, centrifugal time has no obvious effect on green density uniformity. SEM observation shows the green compacts have uniform microstructure when centrifuged at 2860g for 2h with 50vol% slurries.

The self-lubricating coating which is dense in microstructure with low porosity and degradation is sprayed by HVOF and the spray powder is Nickel coated MoS2 with 22%wt of MoS2. The mean bonding strength and hardness of Ni-MoS2 coating is respectively about 13.68 MPa and HRB94.5. Tribological performance is evaluated by the test of dry friction coefficient, which fluctuates from 0.25 to 0.32, while the wear granule is symmetry with a uniform distribution in size, moreover, the experiment results indicate the main wear failure mode of coating is abrasive wear.

Gradient porous Ti was prepared by powder metallurgy method using NH4HCO3 as pore former. The effect of content and distribution of NH4HCO3 and sintering temperature on pore characteristic, sintering shrinkage, flexural property was studied. Stress-strain curves of gradient and uniform porous Ti material were compared. The results show the porosity, sintering shrinkage rate and flexural strength vary from 51.8% to 41.3%, from 23.5% to 28.7%, and from 145.7 MPa to 221.6 MPa when the distribution of NH4HCO3 varying form uniformity to gradient. Additionally, with the increase of sintering temperature, the porosity of gradient samples first increases and then decreases. When sintered at 1573K for 2h, the porosity of gradient porous Ti has the maximum of 45.6%. Moreover, there is pseudo yield phenomenon according to the test curve of three points bending of the gradient porous Ti with three layers structure.

In this research paper, the sand casting process of a cover-type part for wind turbine was investigated with ProCAST software . The cover-type casting part is big in two dimensions and it is heavy in some local positions where shrinkage cavity and porosity are very likely to from. A non-uniform mesh is used corresponding to the non-uniform wall thickness. Different casting processes are employed, simulated and optimized to obtain sound castings. Simulation results reveal that with appropriate pouring temperature, correct number, size and location of chills and risers, a smooth mold filling, reduced shrinkage and other defects are available and desired sound castings can be produced

In this paper, a stable lattice Boltzmann model (LBM) based on non-ideal gases is presented for simulation of incompressible two-phase flows with large density ratio. To reduce the parasitic currents across the interface and correspondingly increase the numerical stability, the stress and potential forms of the surface tension force is employed. The applications to a stationary bubble and capillary-gravity wave with density ratio 1000 are given to verify this model. The numerical solutions is agree well with analytic solutions of the Laplace's law and capillary-gravity wave.

A 3-D modeling based on the numerical resolution of fluid flow and heat transfer are utilized to investigate the thermal phenomena during laser laser-cladding processes of BT20 alloy. From this model, it has been found that the shape and size of the molten pool in the work piece are affected by laser cladding parameters such as scanning speed and the incident laser power. The effects of process parameters on the melt pool are quantitatively discussed by numerical analysis. Furthermore, it has been observed that the surface tension temperature coefficient, Marangoni convection, which is sensitive to the active elements in the titanium alloy composition, also affect the pattern of the fluid flow in the molten pool.

There are a great deal and various types of resource in grid, it is important for ensuring share of grid resource and cooperative working to discovery resource efficiently. After two kinds agorithm of resource discovery adopted in grid are analysed, multi-layers resource discovery agorithm is brought up in this text. Time complication and space complication are compared among the three alorithm in theory, and it test the performance of the three agorithm at last.

Gradient porous NiTi alloys were prepared by powder metallurgy method using NH4HCO3 as space-holder and modified by direct current-pulse anodic oxidation technology in low temperature. Pore characteristic and phase composition of gradient porous NiTi alloys were studied. Microstructure, composition, anti-corrosion and Ni ion release behavior of surface film were observed. The results show the porosity of porous NiTi alloys decreases from 53.2% to 42.8%, when the content of NH4HCO3 varying from uniformity to gradient distribution. The sintered gradient porous NiTi alloys composes with TiNi, Ti2Ni and TiNi3 phases. After anodic oxidation, Ti oxidation film with the thick of 240nm was formed on the gradient porous NiTi alloy. The corrosion resistance of gradient porous NiTi alloy was obviously improved and the rate of Ni release was significantly reduced.

From image shooting and recording system, nonlinear editing, parallax adjusting, color grading, live transmitting and broadcasting, Blu–ray ROM discs authorizing to screen display system, 3DTV solution does it all. This paper describes the imaging principles and off-the-screen theory concerning 3DTV, and then analyzes the working principle, advantages and disadvantages of frame sequential display technology based on time-division multiplexing.

BP neural network model was developed for prediction of the flexural properties of Al2O3 ceramic prepared by centrifugal slip casting. In this paper, the model can well reflect the relationship between the process parameters including solid content of Al2O3 ceramic slurries (w), centrifugal acceleration (v), sintering temperature (T) and flexural properties of sintered products including fracture strength ( ) and fracture toughness (KIC). According to the registered BP model, the effects of w, v and T on and KIC were analyzed. The predicted results agree with the actual data within reasonable experimental error, which shows that the BP model is a practically very useful tool in the flexural properties prediction of the Al2O3 ceramic prepared by centrifugal slip casting. The system reduces the time required for planning and optimizing of centrifugal process parameters.

There are strong basal textures in AZ31 magnesium alloy sheet. Through rolling and post-annealing, we can significantly reduce the basal texture, and with the rising of deformation, the texture intensity falls. The peak intensity of basal texture reduced from 12 to 4 when the rolling deformation rises to 35%. The influence of post-annealing on grain refinement is very obvious. When the temperature of pre-annealing is 773K and rolling temperature is 623K, the grain size reduce to 201μm after 1% deformation. But we can reduce the grain size to 30μm after post-annealing. If the rolling deformation is 36.4%, the grain size reduces to 73μm. But after post-annealing, the grain size reduces to 12μm.

Wind power has been recognized as one of the important green energy resources in Taiwan. However, installing large-capacity wind generators needs to meet many environmental regulations, limiting the penetration of wind power to households/communities. In this paper, the design of a novel double-deck vertical-axis wind generator for households is presented, hoping “many a little makes a mickle” and making better use of green energy to reduce carbon emission. The proposed wind generator is an axial-flux permanent-magnet (PM) synchronous generator, which design is different from other existing wind generators in several aspects: (1) double decks for double wind turbines vs. single turbine, (2) silicon-steel-lamination-cored vs. air-cored for armature coils, and (3) axial-flux PM generator vs. conventional PM generator. The performance of the proposed design is simulated with the aid of a finite element software package. The experimental results are consistent with the simulation. The prototype of the proposed wind generator is also compared with a commercial mini wind generator on the market. The proposed wind generator produces satisfactory results.

Several new chiral tridentate ligands with the bispidine moiety were synthesized from N-alkyl bispidines and chiral amino (or hydroxyl) acids. The synthesized ligands were used as catalysts in the enantioselective addition of diethylzinc to several aromatic aldehydes and an aliphatic aldehyde. High yield and enantioselectivity were received in the cases of aromatic aldehydes as substrates especially when the employed chiral ligand has a hydroxyl group attached to the chiral center. The effect of the structure, the amount of tridentate chiral ligands, solvent and temperature on the enantioselectivity of the addition products were studied. A possible mechanism for the addition of diethylzinc to aldehydes in the presence of bispidine-derived ligands were proposed based upon the catalytic reaction results and referred to the mechanisms proposed for other reaction systems in literatures.

A Decoupling method based on feedforward voltage compensation is adopted to eliminate completely the coupling between exciting current and torque current. Based on conventional design methods of single-variable linear system , the paper analyses and designs detailedly the flux loop, speed loop and current loop. A design method based on double closed-loop PI regulator for speed sensorless vector control system is proposed. Through experimental results, we demonstrate its good performance.

As the quality of yarn and the fiber indicators are nonlinear relationship, the traditional mathematical models or empirical formula has been unable to accurately resolve the problem. In view of artificial neural networks do not need to build accurate mathematical models, applicable to solving the problem of yarn quality prediction. In this paper, good nonlinear approximation ability of BP (Back Propagation) neural network be used, the use of neural network toolbox of MATLAB functions for modeling, good results was obtained. Prediction model set a hidden layer, using three-tier network architecture, and take the input layer 4 nodes, hidden layer 8 nodes and output layer 2 nodes. According to forecast results, can ensure the yarn quality effectively, use of raw materials rationally, to achieve optimal distribution of cotton. Meanwhile, the spinning process design can also be provided validation, for the development of new products to provide a theoretical basis.

In the process of low-permeability sandstone reservoir exploitation, stress sensitivity takes place with the effective stress rises gradually, which will cause permeability decline. Allowing to the condition of in-situ stress, the study and experiment on the rock core in Jilin oil field Fuxin326 oil layer are presented. The experimental results show that the stress sensitivity of this oil layer is small; the regularity of permeability changes is in accordance with exponential function. The stress sensitivity of high permeability core is larger than that of low permeability core. Moreover, experimental and theoretical analysis shows that low permeability core has a larger permeability loss than high permeability core in loading and unloading process where elastic plastic deformation of rock will happen, which is the major reason that permeability loss can not return completely.

Gradient porous NiTi alloys were fabricated by powder metallurgy method using NH4HCO3as space-holder. The effect of content and distribution of NH4HCO3on pore characteristic, phase composition and compressive properties was studied. The results showed the content of TiNi phase increased with the decrease of the content of NH4HCO3. When the distribution of NH4HCO3varying form 12wt%-12wt%-12wt% to 12wt%-6wt%-12wt% and 12wt%-0wt%-12wt%, the stress and elastic modulus of porous NiTi alloys increased from 228MPa to 321MP and 446MPa, from 4.8GPa to 5.6GPa and 6.8GPa, respectively. Compared with uniform porous materials, gradient porous NiTi alloy exhibited better superelasticity.

Porous NiTi alloys were prepared by powder metallurgy method using NH4HCO3as space-holder. The effect of sintering temperature on pore characteristic, phase composition and compressive property of porous NiTi alloys was studied by XRD, SEM, EDS and a universal testing machine. The results show with the increase of sintering temperature the porosity of porous NiTi alloys first increases and then decreases, but the content of NiTi phase, compressive strength and modulous of sintered products continuously increase. When sintered at 980°C for 2h, the porous NiTi alloys have higher porosity of 53.6%, better compressive strength of 173.7MPa and elastic modulous of 4.2GPa. The phases of sinter products are mainly composed by TiNi, Ti2Ni, and TiNi3phases.

A series of the magnesium apatite coatings according to (Ca10-xMgx)(PO4)6(OH)2, where x = 0 to 2, was synthesized through a sol-gel dip-coating method. The roughness of the magnesium coatings increased as more magnesium incorporated into the coatings. The mechanical properties of the coatings were analyzed with Nanoindentor. The incorporation of magnesium decreased the hardness and the Young’s modulus of the coating. The X-ray Photoelectron Spectroscopy (XPS) analysis revealed that only part of magnesium was incorporated into the apatite structure while the rest existed in the form of MgO in the coating.

The effect of heating temperature and pulling rate on Young's modulus of steel FAS390Q was studied. The results show that the relationship between Young's modulus and reciprocal of absolute temperature follows exponent change, and Young's modulus and pulling rate follows power function relation (power index for 0.189). Crystal vacancy is one of the most important reasons for elasticity phenomenon of steels, which results in the fact that the Young's modulus is affected by pulling rate. Based on the statistical analysis, the mathematical model between Young's modulus of high temperature and pulling rate is established.

Porous Al2O3ceramic/Al2O3ultrafine particle/epoxy new composites were fabricated using the ordered Al2O3porous ceramic as the frame. The effects of three-dimension interpenetrated Al2O3ceramic, load, and sliding velocity on friction coefficient and wear rate of the composites were studied. The results showed the new composites had better wear resistance compared with Al2O3ultrafine particle/epoxy composites. The friction coefficient and wear rate of new composites with the porous Al2O3ceramic frame of 16.8% were 0.32 and 0.76×10-6mm3/N-1m-1, respectively. The new composites had stable friction coefficient and low wear rate with the change of load and sliding velocity, which is due to the porous Al2O3ceramic frame as undertaker of load during friction process.

Precursor In(OH)3 was synthesized by ultrasonic method with carbamide and indium salt, and was performed microwave radiation, then nano amorphous In2O3 was obtained. The structural and morphology of precursor and In2O3 were characterized by TG-DTA, XRD, TEM, etc. The results show that the In2O3 is nano amorphous with average grain size 12nm by microwave method. This paper discovered that nano amorphous In2O3 has good photocatalysis when we used it to degrade acidic black dye.

Microstructural evolutions of AZ91 magnesium alloy, which applied to homogenizing annealing treatment, hot extrusion and ageing treatment respectively, are investigated in this paper. Results exhibit that the massive β-Mg17Al12 phase appearing in the initial structure dissolves to eliminate in α-Mg matrix mostly due to the homogenizing annealing treatment; dynamic recrystallization and consequent grain refinement occur during extrusion; banded structure, in which the β-Mg17Al12 phase precipitates parallel to the extrusion direction in α-Mg matrix, are observed in the ageing treated specimen. Furthermore, the effects of temperature, keeping time of homogenizing annealing treatment and ageing treatment, and the extrusion processing parameter on the microstructural evolution of this alloy are also discussed according to the experimental results in details. In addition, the various mechanisms of the morphology and quantity of α-Mg and β-Mg17Al12 phase are analyzed corresponded to the various states. As for the banded structure appearing in the ageing treated specimen, it can be attributed to the banded segregation which remained in the extruded one and resulted from the casting dendrite and subsequent extrusion.

Flexible piers have been widely used in bridge engineering due to its superior ductility. The stirrup ratio and slenderness ratio were deemed to have a most important impact on hysteretic behavior of them. Five flexible piers were made under static vertical loads and low cyclic horizontal reversed loads. The process of test was introduced and failure mechanism, hysteretic behavior, skeleton curve, ductility, energy dissipation capacity, and stiffness degeneration of flexible piers were analyzed. Experimental studies show that (1) Failure mode of specimen is bending failure and their ductility factor falls between 4.15 and 6.30; (2) displacement ductility factor improves with increasing of the stirrup ratio. Stirrup could greatly improve the capacity on ductility and energy dissipation, while it has little impact on the bearing capacity; (3) ultimate bearing capacity decline with the increase of slenderness ratio, however, when the slenderness ratio member is larger, the hysteresis curve is fuller and energy-dissipation is better.