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A Damage mechanics finite element numerical computation method was established based on HLC microscopic damage model to solve the problem of damage, crack initialization and growth inside bore during the firing process. The damage and failure process of the bore surface was simulated numerically during multiple rounds of firing. The law of the barrel material performance changing with the number of firing rounds was analyzed during the engraving process of the driving band and compared with the experimental results. It is proved that HLC microscopic damage model can show the complicate damage behavior and predict the cracking defect, which provides a reference for safety design of the gun barrel.

Iron titanate photocatalysts were synthesized by the high-energy ball milling method with titanium ore as the starting material. X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), thermal gravity and differential thermal analysis (TG-DTA), UV-visible diffuse reflectance absorption spectra (UV-Vis), photoluminescence emission spectra (PL) and photocatalytic degradation measurement were conducted to characterize the structure, surface status, UV-visible light response and performance of the obtained sample. After low temperature calcination (above 400 oC), the photocatalytic activity of iron titanate catalyst decreased gradually, which was mainly due to the decrease of surface hydroxyls and reactant adsorption capability.

A newly criterion for the validity limits of the dipole approximation for a dielectric mixture was presented, based on the comparison between the dipole approximation and the numerical solutions by the finite-element method (FEM). In terms of this criterion and the dipole-enhanced model, a simple theoretical formula for the validity limits was derived. This formula includes three variables: the dielectric mismatch, the volume fraction of particles and the precision. Its calculated results have a good agreement with the limits determined by the empirical method in the range of our interest, which indicates the theoretical formula is creditable. Using this formula, we can approximate the precision of the dipole approximation for an arbitrary dielectric mixture. And we found that the dipole approximation is acceptable with the precision equal to 30% when the dielectric mismatch is less than 2.3 (εi/ εe2.3) for the almost touching spheres.

Site degradation caused from environmental pollution and wasteland has absorbed wide concern in China. In contrast to physical remediation and chemical remediation, ecological remediation (or bioremediation) is supposed to be the most environmentally sound solution for the contaminated sites and wasteland. The stone wasteland of Shimenzhai town in Qinhuangdao was investigated on the spot. Based on the terrain and ground, vegetation and soil conditions, the approaches and measures of ecological restoration were analyzed, covering the terrain fixes, soil improvement, and choice of vegetation. Some major recommendations were concluded. 1) Regarding the terrain and ground, retaining wall, shape of slope, treatment of marsh land are raised; 2) With respect to soil improvement, the improved plant and adaptation to local condition should be applied; and 3) As the choice of vegetation, the rules of plant choice are put forward, and the suitable plant and engineering measures are choose for the local stone wasteland. Finally, towards the perfect sites remediation, an excellent engineering management and assessment system should be strengthened and established in the future. Keywords: Contaminated sites; Wasteland; Qinhuangdao; Ecological remediation; Analysis

In this paper, a novel fluorescent material with high conductivity as 0.45 S·cm-1 and strong fluorescence has been successfully synthesized basing on polyaniline (PANI) nanostructures doped with a new prepared fluorescein TPABTDBN. The PANI nanostructures were prepared via a simplified template-free method (STFM) with FeCl3 as oxidant and dopant. The resulting sample was characterized by SEM, IR and fluorescence spectroscopy. The fluorescence intensity of synthesized composite improves with the increasing content of TPABTDBN. The electrical properties of pressed composite pellets were measured from room temperature about 291K down to 132K, the conductance follow the exponential temperature dependence of three-dimensional variable-range hopping (VRH) model.

In this paper, we study the design and development of the system level simulation platform of TD-SCDMA, mainly introducing the design of power control simulation algorithms in multi-carrier cell mode which support mixed service model of UEs. The theory of power control by adaptive integer step-size is described in detail, and the simulation results in TD-SCDMA system level simulation platform with practical examples are analyzed. Taking simulation of power control by our way has certain practical significance.

Coker gas oil (CGO) is difficult to be cracked in the conventional FCC process, due to their high nitrogen content, especially the basic nitrogen compounds. To enhance the conversion of CGO, the high reaction temperature and catalyst to oil ratio processing scheme was performed in a pilot-scale riser FCC apparatus. To study the impact of (basic) nitrogen content, two kinds of CGO were tested. The results show that increasing the reaction temperature and CTO is an effective method for enhancing the conversion of CGO. The (basic) nitrogen content significantly influences the cracking behavior of CGO and the choose of optimal reaction conditions.

Thermal fatigue behavior of a nickel-base directionally solidified superalloy was investigated using the notched flaky specimen. The da/dN K curve and da/dN-a relationship has been applied to analyze the thermal stress.

In this paper, an universal building material monitoring and management system is designed based on C8051F060 SOC and W5200. In the hardware section, the general characteristics of C8051F060 and W5200 is described, the system architecture of management system for monitoring of building materials is represented, the hardware circuit design of the measurement system is described in detail, a problem frequently encountered in using W5200 is elaborated and a feasible solution is given. In the software part, the data acquisition software on the C8051F060 MCU and the monitoring and management software on the host PC are introduced. The implemented system has many functions, including parameter calibration, data acquisition, data display, data transfer and so on.

In this study, pressure drop across a novel CFB riser integrated with an enlarged bottom section was investigated under various operating conditions. Experimental results indicated that total pressure drop was much higher across the riser with larger diameter-enlarged section dimensions, consequently, resulting in lower solids circulation rate realizable in the riser. Based on the measured pressure drop across this novel riser, apparent solids concentrations of the diameter-enlarged section and the conveying section were obtained. Furthermore, empirical correlations for estimating overall average solids concentration in these two sections were established, respectively. And a satisfactory agreement between predictions and experimental results was observed.

The paper investigates the feasibility to reduce Cr (VI) from the aqueous solution by sulfate-modified titanium-bearing blast furnace slag (STBBFS) prepared with the different preparation method. The different photocatalysts were examined by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra and scanning electronic microscopy (SEM). The photocatalytic activities of the different catalysts were evaluated by the photocatalytic reduction of Cr (VI) under UV-vis light irradiation. For the photocatalytic reduction of Cr (VI), the photocatalytic activities of STBBFS catalysts were found to be strongly dependent of absorbance in UV-visible region, adsorption capacity and surface acidity, and STBBFS prepared by dry-process showed a higher photocatalytic activity compared to that prepared by hydro-chemistry method.

In this paper, two heat treatment routes have been carried out on a set of hot compressed 7075 aluminum alloy samples under different deforming conditions. By considering the hot deformation history the law of 7075 aluminum alloy’s microstructure evolution during these two heat treatments was studied and the microhardness was discussed. The results show that: (1) Static recrystallization in 7075 aluminum alloy was discovered during these two heat treatments (solid solution (465°C/40min) +T6 aging (120°C/24h) and solid solution (465°C/40min) + T73 aging (107°C/7h+177°C/7h)), its driving force was from stored energy which was not released in the previous thermal deformation process. Formation of recrystallized grain was due to subgrain merger mechanism. The static recrystallization became more remarkable as the hot deforming temperature decreasing. (2) The effects of strain rate on the statically recrystallized grain size of 7075 aluminum alloy were opposite under different deformation temperatures. Deformed at 450°C, during these two heat treatments the recrystallized grain size became smaller as the strain rate increasing. While deformed at 350°C, during solid solution+T73 aging treatment the recrystallized grain size increased as the strain rate increasing. (3) Under the same deformation conditions a difference existed in the microstructure of 7075 aluminum alloy after solid solution +T6 aging and solid solution + T73 aging, which was mainly due to different precipitated phases in the aging process. (4) Both two heat treatments can raise the microhardness of 7075 aluminum alloy remarkably. The hardness of 7075 aluminum alloy after solid solution+T73 aging was lower than that after solid solution+T6 aging, the main reason was the precipitated small  phase in the first stage of the T73 aging coarsen in the second stage of high-temperature aging process.

Standard discrete element method does not take the effect of rolling resistance into account. To overcome this shortcoming, a contact model considering rolling resistance is developed and implemented into PFC2D. Using this contact model, a series of numerical biaxial compression tests are carried out. The results of these numerical simulations show that rolling resistance has remarkable effects on shear strength and shear dilatancy of granular matters, and these trends are agreed with previous studies, which proves that this model works well. Then the effect of rolling resistance on anisotropy of granular matters is studied in this paper. It can be seen that rolling resistance has dramatic effect on the anisotropy of granular matters. The anisotropy of granular matters increases with rolling resistance.

The numerical control (NC) heat bending of thin-walled Ti-alloy tube with large diameter and small bending radius with Ф50×1×R75mm (diameter OD bending radius CLR) is explored by 3D-FE thermal-mechanical coupling simulation of heat conducting and NC bending. The results show that: (1) The heating of both pressure die and mandrel is proved to be appropriate to obtain the required temperature field. (2) In terms of wall thickness variation, wrinkling and cross-section deformation, the optimum span of the key parameters are obtained: the bending velocity of 0.4rad/s, the matched pressure die speed of 80%-110%, and temperature of 600-800°C.

Tube bending is a complex process with multi-factor coupling effect and multiple defects occurring. The wall thinning, as one of the important defects in tube bending, determines the bending quality. In this study, taking thin-walled 6061-T4 Al-alloy tube with Φ50.8×t0.889×R101.6mm (outer diameter D × wall thickness t × bending radius R) as the objective, the significance of processing parameters on the wall thinning degree is studied using the orthogonal test under ABAQUS/Explicit platform. The results show that: 1) the bending radius, the clearance between the tube and the pressure die, the friction between the tube and the pressure die, the clearance between the tube and the pressure die, the clearance between the tube and the mandrel and the friction between the tube and the mandrel affect the wall thinning significantly, while the coefficient of boost velocity, the number of mandrel balls, the friction between the tube and the wiper die, the mandrel extension length and the friction between the tube and the bending die have little effect on the wall thinning degree.

In this paper, Continuous Basalt Fiber (CBF) was used as the raw materials, and then woven by the Digital sample looms. Experimental results show that CBF has a very high limiting oxygen index, even if which more than 69%, was much higher than 27% of the indicators of the non-combustible fiber. In the Vertical Burning Test, there was no burning, smoldering, continued burning phenomenon, which can be clearly seen, and the mechanical properties can remain stability in the before-and-after-test. The CBF, would be bound to play a significant role in future of fire-retardant materials and high-temperature composite materials, exhibited excellent flame resistance and heat resistance.

In this paper, wool yarns and the slenderized wool yarns were used as raw materials, and knitted under the same process parameter, many methods of testing were applied to analysis the wearing characteristics, An series of experiments show that there was a significantly improvement in the anti-pilling performance and air permeability, and the stiffness of the sample became smaller, increasing soft and comfort, but it had little effect on crease- resistance. The slenderizing not only improved the spinning count, but also enhanced the knitted properties by the structural transformation, was a good choice to develop the high-grade wool knitwear.

To obtain high properties of laser cladding layer, and to expand the service life of the mold, the laser cladding layer with Ni-WC and SiC on the surface of H13 steel made by using a laser. Then the cross-section and surface morphologies of the coatings and wear tracks were observed with a JSM-5610 type scanning microscope. The friction and properties were examined under dry sliding conditions using a WTM-1E type ball-on-disc machine. The wear mechanisms are discussed as well. The results show that the composite coating is very compact and good blinding with the substrate after laser remelting, and the wear mass loss of the composite coating reduced to about 1/4 of the matrix material.

This study developed a new polycrystal plasticity model by deducing a set of linear controlling equations with respect to the controlling equation of rate dependent crystal plasticity (RDCP). It was proved numerically efficient and stable by means of the comparison with experiment and an implicit model. The model was then applied to describe earing in deep drawing process. Remarkable effects of rate sensitivity coefficient of the material, drawing speed and dies clearance on earing were found.

Adding tubes on the bottom of delayed coking furnace is an useful measure for enhancing the throughput, but the distance between tubes and burners is too small to conform design standard. The security of these bottom tubes is uncertain. The processes of turbulence, combustion and heat transfer in the furnace were simulated by numerical method. Detailed information of velocity field, temperature field and heat flux was obtained. The heat transfer of tubes in entrainment zone of jet flame was investigated. The possibility of tube oxidation and hot spot was also discussed. Results show that the bottom tubes are security, which located in the low temperature field and the range of heat flux is 22~45 kW/m2. The results are in good agreement with industrial testing data.

The adsorption behavior of ethylene and propylene in zeolite ZSM-5 was studied by Grand Canonical Monte Carlo (GCMC) simulations. It is found that ethylene and propylene molecules show different adsorption behaviors in the zeolite cavum. The adsorption isotherms of ethylene and propylene in ZSM-5 at 298K and 823K were simulated. The results exhibit that the molecular adsorption is influenced at various temperatures and pressures, leading to different rules for the adsorption of ethylene and propylene molecules in zeolite. At low temperature, when the pressure is enhanced from 100kpa to 1000 kpa, the adsorption amounts of olefin molecule increase obviously and the loading of ethylene are significantly larger than those of propylene. The adsorption of propylene has a preferential adsorption site in cross position, and nearly reaches saturation at pressure higher than 300kPa. While at 823K the adsorption of ethylene is inhibited with lower loading than those of propylene.

In the oil drilling engineering, the choice of the best bit-type can improve penetration rate, shorten the drilling cycle time and speed up the oil field exploration and development pace. The drill bits type optimal selection has important meaning in oil drilling engineering. Based on the brief introduction of fractal theory, it pointes out that the fractal theory can describe the depositional sequence of formations with self-similar characteristics in this paper. It puts forward a method of calculating correlation dimension with multivariate model according to log information. It has also established statistical relationship between correlation dimension and the working performance standard of bits. At the end of the paper the bit types selection method, adopting the correlation dimension, has given out. This method is practically feasible through the example validation.

Oligomerization of ethylene in fluidized catalytic cracking (FCC) dry gas to propylene was investigated as a feasible approach to use FCC dry gas. The thermodynamic calculation indicated that the equilibrium conversion of ethylene decreased with an increasing temperature, while the experimental conversion achieved peak value at nearly 500°C due to kinetic limit. The catalytic performances of HZSM-5 catalysts with FCC dry gas as feedstock were studied in fixed-bed reactor. It was confirmed that oligomerization carried out at a higher temperature using dilute feed or a less active catalyst such as steam treated catalyst favored propylene yield. With ethylene conversion of approximately 50%, the propylene yield was over14% at 0.3MPa, 550°C with dilute ratio of 1:1 over steam treated catalyst. An apparent reaction order of 2.5 with respect to ethylene was obtained.

The four main effect production factors, doping rate, calcination temperature, soaking time and heating rate, are chose to design experiments based on the orthogonal table L9(34) to prepare urea-modified titanium ore (UTO) sorbents. And the decoloration efficiency of methyl orange is examined by using UTO as sorbents under dark-state absorption. Based on the orthogonal experiments, we obtained the optimal operating parameters: urea 8.0wt%, soaking time 3h, calcination temperature 300°C and heating rate 10°C/min. As the preparation condition was run at the optimal conditions, the decoloration efficiency of methyl orange reached 98.1%, which was significantly better than the undoped samples. Thus, it is feasible to treat dye wastewater by these UTO sorbents.

The degree of graphitization, crystallite size, fracture surface and pore morphology of three kinds of isotropic graphite from different companies were characterized by Raman spectroscopy and scanning electron microscopy (SEM). The relationship between physical properties and microstructure was studied.The results showed that the raman values of (ID/IG) of three samples were about from 0.32 to 0.47. The flexural strength and electrical resistivity were directly proportional to the value of (ID/IG) , while the thermal conductivity was inversely proportional to that value.

Using calcined sulfate-modified titanium-bearing blast furnace slag (STBBFS) as photocatalyst, decolorization efficiency of methyl orange (MO) in the presence of Cr(VI) were studied. The effect of solution pH on the decolorization efficiency of MO and reduction efficiency of Cr(VI) have been investigated. The results indicate that the acidic solutions are favorable for the photocatalytic oxidation of MO in the presence of Cr(VI), and the optimum pH for oxidation of MO is 1.5. The increasing of photocatalytic activities in the compound system can be attributed to five main reasons: (1) the redox reaction between Cr(VI) and MO; (2) adsorption of Cr(VI) species and dye molecule onto STBBFS surface; (3) the visible light irradiation; (4) Cr(VI) species reduced to Cr(III) by Mn2+ in STBBFS photocatalyst; (5) Moreover, the addition of Cr(VI) species able to act as electron scavengers to catalyst surface promotes the effective separation of electron-hole, and hence promote the increase of decolorization efficiency of MO and reduction efficiency of Cr(VI) in Cr(VI)-MO system under visible irradiation. UV-vis spectral analysis indicated that MO was completely mineralized in the presence of Cr(VI) after 240 min. FTIR spectral analysis showed that all these characteristic peaks of Cr(VI) and MO disappear after photoreaction, indicating the degradation of Cr(VI) and MO.

This study introduces the current states and progress of the overseas digitization manufacture technology of airplane ducts, and analyzes the problems about manufacture technology of bent tubes in airplane production in China. Thus, instead of the full pattern, the three-dimensional models are proposed to conduct the NC(Numerical Controling) bending and examine the bending quality, and the integrated digitization manufacture technology of airplane ducts is developed. The key problems are solved including standardization modeling of ducts, 3D data transfering, virtual processing analysis, digital modular fixture design/manufacturing, and NC bending/manufacturing/inspection of ducts. The technology has been successfully applied into the digital forming manufacturing of airplan ducts.

The significant die unfittingness and springback, occuring during the numerically controlled (NC) bending process of large diameter thin-walled CT20 titanium alloy tube, has an obvious influence on the shape and the geometrical precision of the bent tube, furthermore on the assembly precision and the sealing capability. The changing rules of die fittingness and springback of large diameter thin-walled CT20 titanium alloy tube under different bending parameters were investigated and the mechanism was analysed using finite element method (FEM) in this paper. The result shows that the springback of large diameter thin-walled CT20 titanium alloy tube is more significant than that of aluminum alloy and stainless steel tubes with the same specification. The die fittingness has a connection with the tangent compressive stress on the intrados of the tube before springback, the larger the tangent compressive stress, the worse is the die fittingness.The results may provide a significant guide to the control of bending radius and bending angle for large diameter thin-walled titanium alloy tube NC bending.

Spring-back is one of the key factors affecting the forming quality of the NC bending of high-strength TA18 tubes (TA18-HS tubes). Since material parameters have a direct influence on stress and strain fields during the bending and after unloading, the springback of TA18-HS tubes after NC bending depends on material properties to a great degree. In order to study the effect of material parameters, the sensitivity of material parameters on spring-back of TA18-HS tubes is analyzed in this study, using the numerical simulation and the multi-parameters sensitivity analysis method. The results show the following: (1) The springback angle has a positive correlation with the strength coefficient and initial yield stress, and has a negative correlation with the elastic modulus and strain hardening exponent. Besides, with the increase of elastic modulus, the fluctuation of springback goes gently; with the increase of the strength coefficient and initial yield stress, the fluctuation of springback goes abruptly; but with the variation of the strain hardening exponent, the springback fluctuates slightly; (2) The elastic modulus is the most sensitive material parameter on spring-back, the strength coefficient and initial yield stress rank the second and third, respectively, and the strain hardening exponent is the last. The achievement of the study is valuable to eliminate the non-sensitivity parameters, simplify the optimization project, and improve the spring-back prediction capability.

Dy-B-Si-O glass-doped Ba0.6Sr0.4TiO3 (BST) ceramics based on sol-gel-derived powders were prepared. Effects of B2O3-SiO2 in Dy-B-Si-O glass on phase structure, microstructures and dielectric properties of the BST ceramics were investigated. The results showed that the main crystal phase of BST ceramics with appropriate B2O3-SiO2 in Dy-B-Si-O glass had a perovskite type structure. Grain size decreased and density increased compared with pure BST ceramics. However, the secondary phase Ba2TiSi2O8 was detected when the percentage of B2O3-SiO2 in Dy-B-Si-O glass additive was over 7 mol%, and increased with the increasing of B2O3-SiO2. With the increasing of B2O3-SiO2, the dielectric constant increased firstly and then decreased, the dielectric loss decreased firstly and then increased, the Curie temperature moved to lower temperature firstly and then to higher temperature.

The flow patterns of oil/water two-phase upward flows in a small vertical tube with an internal diameter of 0.010 m were investigated by high speed video system. Using stainless steel tube as test section, transparent plastic tube as observing section and deionized water and kerosene (density of 796kg/m3) as working fluids, 5 flow patterns, i.e., annular, churn, slug, bubble and dispersed droplets, were observed under the experimental conditions. The transition boundaries of these flow patterns were compared with the literature and theoretical models of Taitel et al [1] for gas-liquid upward flows. There are some differences of the transition boundaries between the present study and the literature of either gas-liquid or liquid-liquid systems. The theoretical models of Taitel et al can well predict the transition boundaries from annular to churn and from churn to bubble.

The effect of quenching temperature, tempering temperature and tempering time on hardness of 45CrMnSi steel was studied by orthogonal test. It was found that the order of significant factors for the hardness was quenching temperature > tempering temperature > tempering time. Based on the results of the range analysis, the optimum process parameters for the maximum hardness were that the quenching temperature was 900°C, the tempering temperature was 150°C, and the tempering time was 180 min. Under the optimum process conditions, the hardness reached to HRC52 with impact toughness of 15 J/cm2. The hardness and toughness met the need of the comprehensive mechanical property and proper toughness of 45CrMnSi.

The FE model of the pretightening assembly moving beam of open-die forging hydraulic press is built with FE simulation software ABAQUS in the study. With the FE model, the force status of pretightening assembly moving beam is studied. Then the pretightening force of assembly moving beam is further studied and the computing method of pretightening force is given. The main achievements of the study include: Under pretightening, the stress of main moving beam is very low and that of guild sleeves is also lower than the allowable stress. Under center loading, the stress of the center field of main moving beam is higher and that of guild sleeves is almost same to that of pretightening. Under eccentric loading, the stress of same deviation field of main moving beam is higher and the effect of pretightening force on the stress of main moving beam is very small. The stress distribution of guild sleeves with different pretightening force is same and the effect of pretightening force on its strength is very low. The pretightening force of tension rod can be computed with the force of press, the allowable eccentric value of the workpiece, the distance between up guild section and down guild section of guild sleeve and the quantity of tension rods. The results of the study are very useful to design and install the pretightening assembly moving beam of open-die forging hydraulic press.

To find new materials which could partly substitute traditional feedstocks for ethylene production, several vegetable oils and swill-cooked dirty oils are pyrolysed under steam-cracking conditions. The properties and product distributions of peanut oil, sesame oil and soybean oil are compared with naphtha. The results showed that vegetable oils can give olefin yields near to naphtha under milder cracking conditions, which prove a potential utilization route for renewable energy.

China is a large agricultural country that has abundant biomass resource which can be generated biogas for heating and lighting. To improve biogas production efficiency of human excreta, which is a main kind of material in household biogas use, a laboratory-scale simulated experimental using self-designed constant temperature anaerobic fermentation equipment was conducted in our study. The results showed that increase of temperature can improve biogas generation efficiency of human excreta, and the other way is to mix the human excreta with other materials especially with the high C materials. Compare with the high costing of increase temperature, co-digestion with wheat straw has obvious advances: the crop straw can easily obtain and both wastes can be handled in the anaerobic fermentation process. The co-digestion developed in our study may be applicable to human excreta with other crop straws such as corn straw for biogas production.

Anaerobic co-digestion of dairy manure, chicken manure with corn stalks were investigated at 15, 35 and 55 °C. Two trials were carried out, one based on co-digestion of dairy or chicken manure alone with corn stalks at ratios of 1:1, 2:1 and 3:1, the other based on co-digestion of dairy and chicken manure together with corn stalks on the premise of the optimal ratio between manure and stalks. In the first trial, the analysis based on the biogas and methane yields showed that co-digestion of dairy or chicken manure with corn stalks at 2:1 both had higher fermentabilities than other ratios. In the second trial, at 15 °C and 35 °C, various ratios of co-digestion of dairy and chicken manure together with corn stalks were all higher than co-digestion of two kinds of manure alone with corn stalks and maximum biogas and methane yields were obtained at the C/N ratios from 25 to 28. At 55 °C, only at the mixture ratios of 1.6:0.4:1, co-digestion of dairy and chicken manure together with corn stalks were higher than co-digestion of dairy manure with corn stalks, indicating the optimal C/N ratios from 28 to 30 in biogas and methane production. Based on regression analysis, maximum biogas and methane yields were found at 49.9 °C and 46.9 °C with the ratios of dairy, chicken manure and corn stalks at 1.14:0.86:1 and 0.74:1.26:1, respectively.

Phenol-formaldehyde (PF) resin coated graphitized needle coke was synthesized by mixing graphitized needle coke with PF alcohol solution, stirring for a long time and then drying. Different processes of direct drying and drying followed filtration were performed to see the effect of coating. The coated materials were also carbonized, graphitized and then characterized. Experiment showed that filtration before dryness process can lead to uniform coating. The concentration of PF resin had an important effect on the coating amount of PF resin. When the PF resin concentration was 30% (wt%), the content of PF resin coated could possibly attain 15% (wt%) for the most. After carbonization, only small amount of carbon residue from PF resin was left which did not affect the crystal structure of graphitized needle coke.

The cross-section of yarn in plain woven fabric has always been viewed as an invariable shape by academe. However, with visualization technology, problems in the classical model are exposed based on traditional convex model, and when solving the problems with calculus, the rule of yarn cross-section deformation is found. The results show the diversity of yarn cross-section shape in both one-layer and multi-layer woven fabric, instead of unitarity, especially for warps weaving multi-layer wefts, whose convex cross-section alternates with concave one periodically in length. The results take exception to “invariant cross-section assumption” and have theoretical value and guidance for the real shape of yarns and the simulation of fabric appearance.

The numetrical representation of yarn structure of reinforcing material has become a precondition in designing architecture and predicting properties of 3D woven composites. The numetrical representation of topological architecture of woven is discussed in this paper. Yarns are sub-classified and according to the warp yarns fabric directions. A key control point method was proposed to solve the descriptive issue of arbitrary 3D woven composite architecture . In the end, the contrastive tests are done to verify the method.

By the uniaxial tensile tests of both the arc and tube section samples, the strain hardening curves of 21-6-9 high-strength stainless steel tube(HSST) are obtained. Considering that the uniform plastic deformation stage of the curve is short and the flow stress in large strain area is unknown for this tube, different strain hardening models have been established based on single and piecewise functions, respectively. By comparing the experimental results and the numerical ones in terms of load-displacement curves, it shows the constitutive model achieved by three Swift fitting functions can better characterize the strain hardening response of the 21-6-9 HSST in large strain region.

Polyacrylonitrile(PAN) microspheres were synthesized by soapless emulsion polymerization of acrylonitrile(AN) in water. The effects of monomer and initiator concentration on the conversion of AN and the diameter of microspheres were investigated. The results showed that when the concentration of monomer increases, the conversion of AN decreases while the diameter of PAN microspheres increases. When the concentration of initiator increases, the conversion of AN and the diameter of PAN microspheres both increase. For this method of PAN microspheres synthesis, the highest conversion of AN is about 60% and the diameter can be controlled in need ranging from approximately 140 to 500nm.

Based on the isothermal compression experiment under constant strain rate, the deformation behavior and flow stress of as-extruded 7075 aluminum alloy at high temperature was studied. Then the fracture behavior and mechanism of 7075 aluminum alloy were investigated, the results showed that longitudinal cracking was easy to occur at a high temperature due to additional tensile stress and low melting point alloy in grain boundaries melting. Through analysis and comparing of C&L and Oyane fracture criteria, it was proved that C&L fracture criterion was more reasonable to predict fracture in 7075 aluminum alloy hot deforming, and the critical damage factor in a forming temperature range(300~450°C) for 7075 aluminum alloy was obtained.

Multi-way loading technology provides an efficient method to form integral triple valve parts. However, some forming defects such as cracking and folding are prone to occur, which will weaken the forming limit and quality of formed triple valves. Based on numerical simulation, taking forming load, damage, stress, strain and folding as objectives the forming limit and feasibility were studied by changing geometric dimension of billet and triple valve to be formed. The results showed that (1) for a given billet, as the inner diameter of triple valve increasing, the forming load, maximum damage value, stress and strain increased, i.e. the larger the inner diameter of triple valve the more difficult to form; (2) For triple valves with a given inner-outer diameter ration the maximum damage, maximum stress and strain values increased as triple valve outer diameter decreasing while forming load changed a little. The possibility of folding would augment with the increase of inner-outer diameter ratio d/D, when d/D≥0.8, folding occurred under the forming condition in this paper.

In fixed-fluidized bed reactor, laboratory evaluation of different catalyst, raw materials and process parameters can be implemented, so it has wide applications in the refining process. In this study, we focused on small fixed-fluidized bed reactor, using Eulerian-Eulerian two-fluid model, simulated the gas-solid flow behavior in it. Gas residence time distribution was measured in order to characterize macro-mixing. At the same time, by changing the reactor structure and operating conditions, we studied their effects on gas-solid macro-mixing characterization. The results show that the effects of structural parameters are larger than operating conditions, and different parameters have different effects. Different parameters can be adjusted to change the gas-solid macro-mixing characterization in small fixed-fluidized bed reactor. Therefore, the small fixed-fluidized bed reactor can provide better results in more application areas.

This paper discusses the main reasons for the leakage of hydraulic cylinder, analyzes the advantages and disadvantages of polyurethane seal rings for hydraulic cylinder reciprocating sealing, compares the performance and characteristics of several commonly-used reciprocating seals, and studies the sealing mechanism, material characteristics , effects of practical applications and gives the solution of Packing PTFE combined sealing.

As an integral element of the space environment, the environmental sculpture plays an important role in the decoration of space environment, the expression of urban culture and reflection of the city's character, etc. Environmental sculpture is a visible symbol independent and outside of the sign of nature or architectural language, which has become an important cultural carrier between the communication of environment and people. From the perspective of cognitive science, this paper analyzes the relationship between people, environment and environmental sculpture to explore the psychological characteristics of cognition of environmental sculpture and examines, analyzes and interprets the phenomenon of environmental sculpture from the cognitive psychology perspective, which brings some enlightenment for the design of environment sculpture.

The spread contributes to the material flow significantly in the in-plane roll-bending of strip and affects the forming precision of the process. To realize precision forming, the unequal deformation characteristics considering spread effects are addressed by employing finite element simulation. The results show that: (1) the rolling pressure is nonuniformly distributed along the ring width with the maximum value occurs near but not at the outer rim of the formed ring part; (2) there is a spreading region near the outer rim, and the spread becomes larger with an increase in average reduction; (3) the nonlinear elongation of the strip along the width direction induces the inner radius to vary at a quadratic law with increasing average reduction. The inner radius reaches a minimum value of 34.1mm with an average reduction of 25.2%.

Three kinds of low cost shielding materials using boron-containing ores and epoxy as starting materials were developed. The three boron-containing ores consist of natural green ore that is specific in China and the two artificial minerals that are boron-containing iron ore concentrate and boron-rich slag. They were got after natural green ore dressing and separation from blast furnace, respectively. The shielding performance of slow neutron and 60Co γ ray among the three shielding materials were compared. The results show that boron-rich slag as neutron absorber performs relative good slow neutron shielding ability, its macroscopic cross section (Σ) is 0.271cm-1 which is about 1.72 times higher than Lead-Boron Polyethylene B201 whose macroscopic cross section (Σ) is 0.158cm-1. Boron-containing iron ore concentrate/epoxy composite performs relative good 60Co γ ray shielding ability and its linear attenuation coefficient (μ) is 0.0772cm-1. The elements boron and iron that exist as compound in ore are the main reasons to affect the slow neutron shielding performance. The iron element that exists as compound in the ore has the main attribution to 60Co γ ray shielding.

A multi-objective optimization method for thin-walled tube NC bending is presented. Firstly, a half-symmetry 3D elastic-plastic FEM model is established based on the initial design values, applying the dynamic explicit code ABAQUS/Explicit. Secondly, virtual orthogonal arrays are designed to optimize friction coefficients, with minimizing the maximum wall-thinning ratio, the maximum cross section distortion ratio and the maximum height of wrinkling waves as the multi-objectives. Lastly, the mandrel radius is optimized by sequential quadratic programming with approximate regressive models fit from uniform design values in the allowed range. Application is put forward for Ф50×1×100 (tube outside diameter ×tube wall thickness × central line bending radius) and Ф100×1.5×200 aluminum alloy tube bending. It is proved that the forming quality has been improved by the method.

To reduced the defect of the layer cladding reinforced by WC/WC-Ni Particles, and to attained the effective handicraft to strengthen the properties of the mold surface, using laser cladding technique , nano TiC reinforced WC/WC-Ni composite cladding were fabricated on the surface of H13 steel substrates. The cladding microhardness was measured with Victoria-hardness tester, the cross-section microstructure of the claddings was observed with optical microscope. The fabrication of the composite claddings was investigated. The friction and properties were examined under dry sliding conditions with a WTM—1E type ball-on-disc tester. The wear tracks were observed with a JSM-5610 type scanning microscope. The wear mechanisms were discussed as well. The results showed that, owing to the NanoTiC fine-crystalline strengthening and dispersive strengthening, the Nano TiC/WC/WC–Ni composite cladding was very compact and good blinding with the substrate after laser remelting, and then sub-micro-fracture and adhesion wear of WC cladding were reduced. During the friction process, Nano TiC particles had a significant influence on the Friction and wear behavior of laser cladding: The friction coefficient reduced and wear-resistance strengthened of composites with increasing proportion of TiC. The wear mass loss of the 20% TiC composite cladding reduced to about 1/3 of those with 5% TiC cladding.