摘要：The exploration of stable and highly efficient alkaline hydrogen evolution reaction(HER)electrocatalysts is imperative for alkaline water ***,Se-doped NiCoP with hierarchical nanoarray structures directly grown on carbon cloth(Se-NiCoP/CC)was prepared by hydrothermal reaction and phosphorization/selenization *** experimental results reveal that Se doping could increase the electrochemical active sites and alter the electronic structure of *** optimized Se-NiCoP/CC electrode exhibits outstanding HER activity in alkaline electrolyte,which only needs a low overpotential of 79 mV at the current density of 10 mA/cm^(2).When serving as anode and cathode electrode simultaneously,the Se-NiCoP/CC electrodes achieve current density of 50 mA/cm^(2) at a low voltage of only 1.62 *** work provides a feasible way to rationally design high active HER electrocatalysts.

摘要：In order to simultaneously measure the initiation toughness of pure mode Ⅰ and mode Ⅱ cracks in one specimen,a large-size double-cracked concave-convex plate(DCCP)specimen configuration was *** tests were implemented in the drop plate impact *** gauges were employed to measure impact loads and crack initiation *** corresponding numerical model was established by using the dynamic finite difference program AUTODYN,and the experimental-numerical method and ABAQUS code were utilized to obtain the initial fracture toughness of the *** experiments and numerical research,we concluded that the DCCP specimen is suitable for measuring the initial fracture toughness of pure mode Ⅰ and mode Ⅱ cracks at the same time;the dynamic initiation toughness increases with the increase of loading rate and the crack initiation time decreases with increasing loading rate;the initiation toughness of mode Ⅱ crack is 0.5 times that of mode Ⅰ crack when subjected to the same loading *** the pre-crack in the vicinity of the bottom of a sample,when its length increases from 20 to 100 mm,the dynamic initiation toughness of the pure mode Ⅰ crack gradually decreases,and the longer the lower crack length is,the easier the crack would initiate,but the dynamic initiation toughness of pure mode Ⅱ crack varies little.

摘要：The direct hydrogenation of CO2 using H2 gas is a one-stone-two-birds route to produce highly valueadded hydrocarbon compounds and to lower the CO2 level in the ***,the transformation of CO2 and H2 into hydrocarbons has always been a great challenge while ensuring both the activity and selectivity over abundant-element-based *** this work,we designed a Schottky heterojunction composed of electron-rich MoC nanoparticles embedded inside an optimized nitrogen-doped carbon support(MoC@NC)as the first example of noble-metal-free heterogeneous catalysts to boost the activity of and specific selectivity for CO2 hydrogenation to formic acid(FA)in liquid phase under mild conditions(2 MPa pressure and 70℃).The MoC@NC catalyst with a high turnover frequency(TOF)of 8.20 molFA molMoC^-1 h^-1 at 140℃ and an excellent reusability are more favorable for real applications.

摘要：首先提出了一种新的通用设计框架,可以把任何弱不可伪造签名转化为强不可伪造签名.然后,将这种方法用在Waters签名上,得出了一种在标准模型下的强不可伪造签名,其所依赖的安全性前提是双线形群上的CDH假设.在该方案中,最主要的运算可以离线完成,而在线运算量非常少.

摘要：本研究通过8周生长试验研究了饲喂果寡糖对奥尼罗非鱼Oreochromis aurea♂×***♀肠道菌群、存活率及生产性能的影响。试验设计3组果寡糖水平(0、0.8及1.2 g/kg),按每天4次饱食投喂初始重为5.55 g的奥尼罗非鱼,试验系统为淡水养殖系统,试验期间平均水温为28℃,罗非鱼养殖密度40尾/箱,每组3个重复。饲喂试验结束后,试验动物整体称重并测定形态学参数。从每个养殖单元随机取出3尾试验鱼,无菌条件下取肠道通过选择性培养基分别分析副溶血性弧菌Vibrio parahaemolyticus、嗜水气单胞菌Aeromonas hydrophila、乳酸杆菌Lactobacillussp.及粪链球菌Streptococcus faecalis的数量。结果表明:随着饲喂果寡糖水平增加,奥尼罗非鱼末重(FBW,g)和特定生长率(SGR,%/d)均显著增加(P0.10);饲料转化率和肝胰腺指数均降低(P>0.10);而存活率(SR,%)、屠宰率(DCY,%)及丰满度(CF,g/cm3)则不受影响。所检测的全部罗非鱼肠道菌群数量随着饲喂果寡糖水平的上升呈增加状态(P>0.10)。本研究说明,饲料中添加果寡糖对奥尼罗非鱼生产性能、饲料转化效率及肠道菌群有一定改善作用,本研究推荐奥尼罗非鱼饲料中适宜果寡糖水平为1.2 g/kg。[动物营养学报,2007,19(6):691-697]

摘要：In order to reveal the changing law of the mechanical response of asphalt pavements under the action of vehicle load and provide references for the design of durable pavements,three typical asphalt pavement structures with flexible base(S1),combined base(S2),and semi-rigid base(S3)were selected to perform field strain tests under static and dynamic load using the fiber Bragg grating optical sensing *** changing characteristics of the strain field along the horizontal and depth directions of pavements were *** results indicate that the most unfavorable asphalt pavement layers were the upper-middle surface layer and the lower base *** addition,the most unfavorable loading positions on the surface layer and the base layer were the center of wheel load and the gap center between two wheels,*** most unfavorable layer of the surface layers gradually moved from the lower layer to the upper layer with the increase of base layer *** power function relationships between structural layer strain and vehicle speed were *** semi-rigid base asphalt pavement was the most durable pavement type,since its strain value was lower compared to those of the other structures.

摘要：二维范德华Janus材料两侧为不同原子,使得其具有内禀的结构不对称性和面外极化。一类新型的二维Janus材料GeS被发现可用于制备低能耗、高响应速度的铁电隧道结。基于第一性原理计算,我们发现JanusGeS双层有三种堆叠模式,它们的横向滑动和垂直位移都可以调节隧道结中的电子输运。此外,基于GeGe接触的GeS双层的铁电隧道结表现出最高的开/关比。我们的研究将滑移铁电的概念扩展到一类新型的二维范德华Janus材料,并揭示了这些材料在实际器件中可能的电阻开关机制。我们的工作为基于二维范德华Janus材料的低能耗、快速开关纳米器件的设计提供了理论指导。

摘要：The recrystallization behavior,grain boundary characteristic distribution,and mechanical properties of pure Cu sheets that were subjected to different cold rolling paths,and then annealed at 400°C for 10,30,60,and 420 min,were *** rolling paths changed the grain boundary orientations of cold-rolled copper,causing recrystallized grains to nucleate and grow in an oriented ***,the evolution of the texture indicated that cold-rolled copper with different rolling paths did not show an obvious preferred orientation after *** RD-60 specimen exhibited the smallest grain size(6.6μm).The results indicated that the grain size and low-ΣCSL grain boundaries worked together to provide RD-60 samples with appropriate mechanical properties and high *** yield strength,ultimate tensile strength,and elongation of RD-60 sample were 81 MPa,230 MPa,and 49%,*** results could provide guidance for tuning the microstructures and properties of pure Cu foils,as well as designing fabrication routes for pure Cu foils through processes such as rolling and drawing.

摘要：Non-volatile random-access memory（NVRAM） technology is maturing rapidly and its byte-persistence feature allows the design of new and efficient fault tolerance mechanisms. In this paper we propose the versionized process（Ver P）, a new process model based on NVRAM that is natively non-volatile and fault tolerant. We introduce an intermediate software layer that allows us to run a process directly on NVRAM and to put all the process states into NVRAM, and then propose a mechanism to versionize all the process data. Each piece of the process data is given a special version number, which increases with the modification of that piece of data. The version number can effectively help us trace the modification of any data and recover it to a consistent state after a system *** with traditional checkpoint methods, our work can achieve fine-grained fault tolerance at very little cost.

摘要：High-quality seismic geometry is the key to obtain high-quality seismic data, and can affect the accuracy of data processing and imaging. Based on the analysis of the relationship between the quality of the geometry and the four acquisition parameters(the number of traces, shot line spacing, and the space and number of receiver lines), a quality evaluation method of the geometry based on comprehensive quality factor(CQF) is proposed, and the relationship between the geometry quality and the four parameters is given. We use field data collected in an oil field in Western China with complex geology: First we use a wide azimuth geometry. Then, we calculate the relationship curve between geometry and data quality by varying each parameter while keeping the rest fixed. and the analysis results are given by using the CQF evaluation method. The results show that the shot-line spacing has the greatest effect on the quality of the geometry, and the increase of the receiver line spacing can appropriately improve the quality of the geometry, and the increase of the number of receiving traces can improve the geometry quality. The different acquisition parameters have different effects on the imaging quality of shallow and deep events. The model forward and prestack depth migration are used to generate prestack depth migration profiles with different acquisition parameters. The imaging results are consistent with the above calculated results. According to the depth of the target layer, the quality factor evaluation method is applied to guide the design of the geometry and optimize the acquisition parameters to improve the imaging accuracy of seismic data.