摘要：Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.

摘要：Single cell temperature difference of lithium-ion battery(LIB) module will significantly affect the safety and cycle life of the battery. The reciprocating air-flow module created by a periodic reversal of the air flow was investigated in an effort to mitigate the inherent temperature gradient problem of the conventional battery system with a unidirectional coolant flow with computational fluid dynamics(CFD). Orthogonal experiment and optimization design method based on computational fluid dynamics virtual experiments were developed. A set of optimized design factors for the cooling of reciprocating air flow of LIB thermal management was determined. The simulation experiments show that the reciprocating flow can achieve good heat dissipation, reduce the temperature difference, improve the temperature homogeneity and effectively lower the maximal temperature of the modular battery. The reciprocating flow improves the safety, long-term performance and life span of LIB.

摘要：The variance-dependent Goldstein radar interferogram filter takes into account the information of both interferometric coherence and multilook factors,and can produce very consistent results for interferograms generated under a wide variety of multilook factors and with very different noise ***,the filter is a bit complicated and its application is still very *** present the designing and implementation of the variance-dependent Goldstein radar interferogram filtering,emphasizing on the logic flow,the generation of look-up table,the determination of filtering parameter,and the handling of edge information *** with real interferograms are provided to demonstrate the applications of the designed *** with the result of the coherence-dependent Goldstein filter show that improvements from 18.4% to 36.9% are achieved when the variance-dependent filter is used,and the noisier the interferogram,the greater the improvement.

摘要：Three donor-(π-spacer)-acceptor(D-π-A) organic dyes,containing different groups(triphenylamine,di(p-tolyl)phenylamine,and 9-octylcarbazole moieties) as electron donors,were designed and *** TiO2 dye-sensitized solar cells were fabricated by using these *** was found that the variation of electron donors in the D-π-A dyes played an important role in modifying and tuning photophysical properties of organic *** standard global AM 1.5 solar condition,the DSSC based on the dye D2 showed the best photovoltaic performance:a short-circuit photocurrent density(Jsc) of 13.93 mA/cm2,an open-circuit photovoltage(Voc) of 0.71 V,and a fill factor(FF) of 0.679,corresponding to solar-to-electric power conversion efficiency(η) of 6.72%.

摘要：A methodology for topology optimization based on element independent nodal density(EIND) is *** densities are implemented as the design variables and interpolated onto element space to determine the density of any point with Shepard interpolation *** influence of the diameter of interpolation is discussed which shows good *** new approach is demonstrated on the minimum volume problem subjected to a displacement *** rational approximation for material properties(RAMP) method and a dual programming optimization algorithm are used to penalize the intermediate density point to achieve nearly 0-1 *** are shown to meet stability,mesh dependence or non-checkerboard patterns of topology optimization without additional ***,the computational efficiency is greatly improved by multithread parallel computing with OpenMP.

摘要：钛的弹性模量受β相稳定性的影响较大。具有低β相稳定性和无毒元素的亚稳定β或近β钛通常可以实现较低的弹性模量。本研究提出了一种高效的组成设计方法,结合CALPHAD计算和纳米压痕测试,以设计具有低模量的Ti-Nb-Zr-Sn-Ta合金。通过这种方法,开发了一种具有低模量、高强度和良好塑性(弹性模量为(58.3±2.0)GPa,抗拉强度为(813.3±7.2)MPa,伸长率为(25.3±2.1)%)的近β钛Ti-18Nb-8Zr-5Sn-2Ta。实验结果显示,传统的钼当量法高估了Sn和Zr对钛合金的β相稳定性的影响,而对于Ti-Nb-Zr-Sn-Ta合金,Nb和Ta能更有效地稳定β相。

摘要：深部岩体具有高地应力的特征,给传统爆破开采方式带来了技术难度大、效率低、成本高等问题。为克服这些困难,采用LS-DYNA软件对扇形中深孔爆破过程进行数值模拟,研究地应力大小对岩体爆破损伤特性的影响。结合矿山实际开采条件,设计爆破试验方案。结果表明:在地应力作用下,岩石质点振动速度峰值和单元有效应力降低,爆破过程中的最大能量降低。使用响应面法,得到最小抵抗线和孔底距对力学响应的影响,并对其进行优化分析。孔底距为2.48 m,最小抵抗线为1.6 m时,获得了最佳的爆破成本和效果。本研究可为深部开采遇到的扇形孔爆破难题提供解决方案。

摘要：A three-dimensional finite element approach based on ABAQUS code was developed to investigate the effect of welding sequence on welding residual stress distribution in a thin-walled 6061 aluminum alloy structure. To obtain sound numerical results, the therrno-mechanical behaviour was simulated using a direct-coupled formulation. Nine different simulation sequences were carried out by single-pass TIG welding of an octagonal pipe-plate joint, and the distributions of longitudinal and transverse residual stresses both on the outer and inner surfaces of the pipe were analyzed. The results suggest that the final residual stresses in the weld and its vicinity are not affected by the initial residual stresses of the structure. Selecting a suitable welding sequence can reduce the final residual stress in an octagonal pipe-plate joint.

摘要：To relieve the increasing traffic load, many early built highways need to be widened or reconstructed. The rapid performance detection to existing subgrades is important to their reasonable evaluation and maximized utilization. Based on five kinds of soils taken from an existing highway in southern china, three commonly detecting methods were used to determine their moisture contents, compaction degrees and resilient moduli. The results showed that the measured moisture contents were greater than the design value, and the compaction degrees decreased sharply compared to the original ones. The moisture and heat exchange produced a decrease in the resilient modulus of plate loading test(PLT) from the standard 60 MPa down to 40 MPa. Afterwards, the portable falling weight deflectometer(PFWD) and dynamic cone penetrometer(DCP) were used to evaluate the subgrade performances. The measured PFWD moduli and the DCP penetration rates were correlated with the resilient moduli of PLT, deflections of the Beckman beam test, compaction degrees and moisture contents. The correlation analysis indicates that both of two methods are suitable in rapid detecting subgrade performances, but PFWD method is more recommended for it has higher accuracy and efficiency.

摘要：Four different welding sequences of double-pulse MIG welding were conducted for 6061-T6 aluminum alloy automobile bumpers by using nonlinear elastoplasticity finite element method based on ABAQUS *** post-welding residual stress and deformation were definitely different among the four welding *** results showed that the highest temperature in Solution A was approximately 200℃higher than the melting point of base *** residual stress was resulted from this large temperature gradient and mainly concentrated on the welding vicinity between beam and crash *** welding deformation primarily occurred in both of the contraction of two-ends of the beam and the self-contraction of crash *** with other welding sequences,the residual stress in Solution A was the smallest,whereas the welding deformation was the ***,the optimal sequence was Solution B because of the effective reduction of residual stress and good assembly requirements.