摘要：A novel multicomponent high-Cr CoNi-based superalloy with superior comprehensive performance was prepared,and the evaluation of its high-temperature microstructural stability,oxidation resistance,and mechanical properties was conducted mainly using its cast polycrystalline *** results disclosed that the morphology of theγ′phase remained stable,and the coarsening rate was slow during the long-term aging at 900–1000℃.The activation energy forγ′precipitate coarsening of alloy 9CoNi-Cr was(402±51)kJ/mol,which is higher compared with those of CMSX-4 and some other Ni-based and Co-based ***,there was no indica-tion of the formation of topologically close-packed phases during this *** these factors demonstrated the superior microstructural stability of the *** mass gain of alloy 9CoNi-Cr was 0.6 mg/cm^(2) after oxidation at 1000℃ for 100 h,and the oxidation resistance was comparable to advanced Ni-based superalloys CMSX-4,which can be attributed to the formation of a continuous Al_(2)O_(3) protective ***,the compressive yield strength of this cast polycrystalline alloy at high temperatures is clearly higher than that of the conventional Ni-based cast superalloy and the compressive minimum creep rate at 950℃ is comparable to that of the conventional Ni-based cast superalloy,demonstrating the alloy’s good mechanical properties at high *** is partially because high Cr is bene-ficial in improving theγandγ′phase strengths of alloy 9CoNi-Cr.

摘要：提出一种用于准确便捷预测析出相增强镍基高温合金稳态蠕变速率的蠕变新模型。基于析出相的空间分布,采用概率依赖的方法将位错-析出相交互作用中Orowan绕过和位错攀移机制的协同模式耦合到新的蠕变模型中。结果表明,新模型预测的稳态蠕变速率与实验数据吻合很好。此外,当前模型不再依赖于可调参数;同时,确定了阈值应力与温度的定量关系。这项工作为蠕变变形过程中位错-析出相交互作用提供新思路,并为设计具有更优异蠕变性能的析出强化合金提供有效模型。

摘要：准二维钙钛矿表现出独特的光物理性质,这使它们成为激光技术潜在进步的优秀候选材料.高性能纳秒脉冲激光和放大自发发射(ASE)是实现连续波抽运光电泵浦激光器的关键工艺.然而,在纳秒脉冲激光泵浦下发展准二维钙钛矿ASE或激光仍然存在一些困难,包括表面缺陷浓度高、俄歇复合和能量传递效率低.本文通过无添加剂的Cs^(+)阳离子掺杂策略,可以很好地控制准二维钙钛矿膜的形貌和相分布,从而解决了低n相导致的能量传递途径不足的问题.本文通过快速的能量传递过程揭示了增益性质和载流子复合.基于此,掺杂适当比例Cs^(+)阳离子的PEA_(2)(FA_(0.7)Cs_(0.3))_(2)Pb_(3)Br_(10)钙钛矿膜的净增益系数比原始钙钛矿薄膜提高了近3倍,从而将纳秒激光激发下的放大自发发射阈值降低到1/3.研究结果表明,在准二维钙钛矿中掺杂Cs^(+)可为实现高性能激光器件的相位分布设计提供见解.

摘要：Ce element was introduced to modify Al−2%Fe(mass fraction)binary *** microstructures,crystallization behavior,electrical/thermal conductivities and mechanical properties of these alloys were systematically *** results indicated that the appropriate Ce addition decreased the recalescence temperature and growth temperature of Al−Fe eutectic structure,improved the morphology and distribution of Fe-containing phase,and simultaneously increased the conductivity and mechanical *** annealed treatment improved the thermal conductivity of these alloys due to the decreasing concentration of point *** process further broke up the coarser Fe-containing phases into finer particles and made the secondary phases uniformly distributed in theα(Al)*** subsequent annealing treatment and rolling deformation,the thermal conductivity,ultimate tensile strength and hardness of the Al−2%Fe−0.3%Ce(mass fraction)alloy reached 226 W/(m·K),(182±1.4)MPa and HBW(49.5±1.7),respectively.

摘要：Bridges crossing active faults are more likely to suffer serious damage or even collapse due to the wreck capabilities of near-fault pulses and surface ruptures under *** a high-speed railway simply-supported girder bridge with eight spans crossing an active strike-slip fault as the research object,a refined coupling dynamic model of the high-speed train-CRTS III slab ballastless track-bridge system was established based on *** rationality of the established model was thoroughly *** horizontal ground motions in a fault rupture zone were simulated and transient dynamic analyses of the high-speed train-track-bridge coupling system under 3-dimensional seismic excitations were subsequently *** safe running speed limits of a high-speed train under different earthquake levels(frequent occurrence,design and rare occurrence)were assessed based on wheel-rail dynamic(lateral wheel-rail force,derailment coefficient and wheel-load reduction rate)and rail deformation(rail dislocation,parallel turning angle and turning angle)*** optimization was then investigated in terms of the rail fastener stiffness and isolation layer friction *** of the wheel-rail dynamic indicators demonstrate the safe running speed limits for the high-speed train to be approximately 200 km/h and 80 km/h under frequent and design earthquakes,while the train is unable to run safely under rare *** addition,the rail deformations under frequent,design and rare earthquakes meet the safe running requirements of the high-speed train for the speeds of 250,100 and 50 km/h,*** speed limits determined for the wheel-rail dynamic indicators are lower due to the complex coupling effect of the train-track-bridge system under track *** running safety of the train was improved by increasing the fastener stiffness and isolation layer friction *** the rail fastener lateral stiffness of 60 kN/mm and isolat

摘要：An on-demand wireless capsule endoscope with fulldigital and bidirectional communication is presented,aiming at fulfilling the requirements of micromation and micropower consumption of modern wireless *** proposed multifunctional operation and unique radio transmission system cuts down the power consumption efficiently and on-demand bidirectional communication in vitro improves the detection rate of ***,gray dilatation is introduced in a bit plane that optimizes the distortion rate in the process of image recording and transmission.

摘要：Biomaterial scaffolds play an important role in maintaining the viability and biological functions of highly metabolic hepatocytes in liver tissue engineering. One of the major challenges involves building a complex microchannel network inside three-dimensional （3D） scaffolds for efficient mass transportation. Here we presented a biomimetic strategy to generate a mi- crochannel network within porous biomaterial scaffolds by mimicking the vascular tree of rat liver. The typical parameters of the blood vessels were incorporated into the biomimetic design of the microchannel network such as branching angle and diameter. Silk fibroin-gelatin scaffolds with biomimetic vascular tree were fabricated by combining micromolding, freeze drying and 3D rolling techniques. The relationship between the micro-channeled design and flow pattern was revealed by a flow experiment, which indicated that the scaffolds with biomimetic vascular tree exhibited unique capability in improving mass transportation inside the 3D scaffold. The 3D scaffolds, preseeded with primary hepatocytes, were dynamically cultured in a bioreactor system. The results confirmed that the pre-designed biomimetic microchannel network facilitated the generation and expansion of hepatocytes.

摘要：This article deals with the design of energy efficient water utilization systems allowing operation split. Practical features such as operating flexibility and capital cost have made the number of sub operations an important parameter of the problem. By treating the direct and indirect heat transfers separately, target freshwater and energy consumption as well as the operation split conditions are first obtained. Subsequently, a mixed integer non-linear programming （MINLP） model is established for the design of water network and the heat exchanger network （HEN）. The proposed systematic approach is limited to a single contaminant. Example from literature is used to illustrate the applicability of the approach.

摘要：A liquid solid semi-moving bed with non-mechanical particle transport system is proposed and used for fractionation of cesium ion in wastewater. The particle transport system, which consists of a suction chamber, a mixing chamber, a nozzle and a riser tube, is designed to be controlled completely by hydraulic force. Experiments show that continuous feeding and discharging of resin can be realized by the transport system. The removal of cesium ion from wastewater is realized, The concentration of cesium ion in effluent liquid remains below 0,1g·L^-1 （the initial concentration is 5,3g·L^-1） during the 73 hours＇ experiment. The average exchange capacity of resin discharged from the bed is 0.57mmol,（g dry resin）^-1, which is close to the saturated capacity of 0.65mmol·g^-1. And it is also proved that the non-homogeneity of particle vertical velocity along the radial direction can seriously influence the ion-exchange process.

摘要：In the process of multidisciplinary design optimization, there exits the calculation complexity problem due to frequently calling high fidelity system analysis models. The high fidelity system analysis models can be surrogated by approximate models. The sensitivity analysis and numerical noise filtering can be done easily by coupling approximate models to optimization. Approximate models can reduce the number of executions of the problem's simulation code during optimization, so the solution efficiency of the multidisciplinary design optimization problem can be improved. Most optimization methods are based on gradient. The gradients of the objective and constrain functions are gained easily. The gra- dient-based Kriging (GBK) approximate model can be constructed by using system response value and its gradients. The gradients can greatly improve prediction precision of system response. The hybrid optimization method is constructed by coupling GBK approximate models to gradient-based optimiza- tion methods. An aircraft aerodynamics shape optimization design example indicates that the methods of this paper can achieve good feasibility and validity.