摘要：高熵合金近年来在电催化领域广受关注.由于其四大“核心效应”,即高熵效应、晶格畸变效应、迟滞扩散效应和鸡尾酒效应,高熵合金在诸多电催化反应中展现出了优异的活性和选择性.然而在已报道的文献综述中,有关其优异性能的理解以及合理设计的系统性总结仍然具有局限性.本文不仅综述了高熵合金电催化剂的特点和设计准则,还对其应用的最新进展进行了系统性的归纳整理,对高熵合金未来的发展具有指导意义.首先我们从多个角度阐明了高熵合金作为一种优异电催化剂的原因,包括其出色的机械性能、可优化的结构和组成、大量具有高本征活性的活性位点,以及出色的稳定性.为了进一步深入对高熵合金电催化剂的理解,我们还从设计准则、元素选择,以及理论计算预测材料性质等角度,详细介绍了高熵合金的合理设计.随后,我们介绍了高熵合金电催化剂在电解水、有机小分子氧化、燃料电池和碳/氮基转化反应的最新研究进展,其中还包括了一系列理论计算和原位表征在理解催化反应机理方面的应用.最后,我们展望了高熵合金电催化剂在未来发展中面临的挑战和机遇.

摘要：The p-xylene(PX) oxidation process is of great industrial importance because of the strong demand of the global polyester fiber.A steady-state model of the PX oxidation has been studied by many *** our previous work,a novel industrial p-xylene oxidation reactor model using the free radical mechanism based kinetics has been ***,the disturbances such as production rate change,feed composition variability and reactor temperature changes widely exist in the industry *** this paper,dynamic simulation of the PX oxidation reactor was designed by Aspen Dynamics and used to develop an effective plantwide control structure,which was capable of effectively handling the disturbances in the load and the temperature of the *** responses of the control structure to the disturbances were shown and served as the foundation of the smooth operation and advanced control strategy of this process in our future work.

摘要：科学正在进入一个新时代——第五范式——它被认为是知识整合到不同领域的主要特征,是基于无所不在的机器学习系统的计算社区中智能驱动的工作。在此,我们通过在天河一号超级计算机系统上构建的催化材料专门设计的典型平台案例,生动地阐明了第五范式的本质,旨在促进第五范式在其他领域的培养。第五范式平台主要包括模型自动构建(原始数据提取)、指纹自动构建(神经网络特征选择)以及跨学科知识串联的重复迭代(“火山图”)。与分解一起进行的是对迭代中实现的体系结构的性能评估。通过讨论,第五范式的智能驱动平台可以极大地简化和改进研究中极其繁琐和具有挑战性的工作,并通过补偿机器学习中缺少样本和替代一些由于计算资源不足而导致的数值计算来实现数值计算与机器学习之间的相互反馈,从而加速探索过程。在数据驱动的学科中,跨学科专家的协同作用和对动态数据需求的急剧增长仍然是一个挑战。我们相信,对第五范式平台的一瞥可以为其在其他领域的应用铺平道路。

摘要：本文基于Winkler地基Timoshenko梁理论,考虑水平地基摩阻力及盾构隧道环缝接头塑性变形特征,提出了一种跨断层盾构隧道纵向响应解析模型。首先,以正断层错动工况为例,采用数值模拟方法验证解析解的合理性。然后,分析了盾构隧道环缝接头的塑性变形特征,并通过参数分析讨论了影响隧道纵向变形响应的因素。研究结果表明:断层错动下盾构隧道环缝接头张开及错台变形均较为显著,解析模型计算得到的盾构隧道纵向力学响应特征与数值模型计算结果规律一致;在断层错动10 cm时,盾构隧道环缝接头已产生显著的塑性变形;在穿越活动断层工况中,地层对隧道纵向变形的限制作用更加明显,导致环缝接头变形量更大;地基刚度越大,盾构隧道纵向变形响应越显著。当不考虑断层破碎带宽度时,计算得到隧道纵向力学响应值是偏安全的;在隧道环缝接头弹性变形阶段,弹性弯曲刚度有效率越大,接头张开量越小;在环缝接头塑性变形阶段,盾构隧道二次塑性等效弯曲刚度比越大,盾构隧道环缝接头塑性变形越小。本文提出的解析模型可以预测跨断层盾构隧道环缝接头变形,同时可以为盾构隧道接缝防水设计提供理论指导。

摘要：本研究用功能磁共振成像技术观察了人脑进行不同难度数字加减计算时的脑区激活情况,并探讨大脑皮层和皮层下结构在数字计算中的作用。用Siemens 1.5 Tesla磁共振机对16名右利手健康志愿者进行简单及复杂数字加减任务的fMRI扫描。实验采用组块设计。刺激任务分为简单加减计算任务、复杂加减计算任务和基线任务。用SPM99软件进行数据分析和脑功能区定位。分别比较同一任务各个脑区平均激活强度和同一脑区在两种任务中的激活强度。结果显示,简单及复杂加减计算激活的被试者的脑区基本相同,激活的皮层区主要见于额叶、顶叶、枕叶、扣带回、丘脑及小脑;简单及复杂加减计算激活的皮层下结构包括两侧尾状核、左纹状体边缘区等基底核结构和丘脑。在简单及复杂计算中,纹状体与皮质结构(额叶、顶叶)间激活强度均无显著性差异。简单计算与复杂计算比较,右顶叶,在复杂任务时出现激活,在简单任务时未出现激活。上述结果提示,完成数字计算任务的脑区除了额叶、顶叶、扣带回等皮层结构外,大脑皮层下的一些结构如纹状体、纹状体边缘区,也是参与数字计算的重要部位。皮层下结构纹状体和优势半球的纹状体边缘区参与了数字工作记忆,可能是进行数字计算神经环路的重要组成部位。右顶叶(缘上回)只在复杂任务出现激活,该区可能是视空间记忆和加工的重要部位。

摘要：通过原子制造技术构建独特的纳米尺度结构可能是改善金属玻璃(MG)薄膜机械性能的有效途径.在此,我们使用脉冲激光沉积作为原子制造策略,制备了一种Ta基金属玻璃.TaNi MG具有小尺寸纳米晶体(1-4纳米)弥散在非晶基体上的双相纳米结构,因此在压缩过程中表现出7.99 GPa的超高屈服强度和15.87 GPa的高硬度,并伴有80%的大塑性.纳米晶体和MG基体之间的相互作用,导致了多个剪切带的形成,从而贡献了高塑性和强度.研究发现,原子制造方法有利于直接调控薄膜材料的微观结构和微观构型,并进一步优化其性能.这项工作为通过原子尺度的结构设计来打破金属材料的强度-塑性权衡提供了一个实用的方法.

摘要：Each conventional alloy has its own specific compositions but the compositional origin is largely unknown due to our insufficient understanding about chemical shortrange ordering in the alloy,in particular,in the solid-solution *** the present paper,the compositions of metallic alloys are discussed and formulated,by unveiling the basic moleculelike structural units in solid *** oscillation theory,which describes the partial charge screening behavior in solid solutions,and henceforth the origin of short-range ordering,is applied to pin down the ideal chemical compositions of conventional metallic *** propose that,at a specific composition,atoms self-assemble into an ideally ordered structure consisting of atoms residing in the nearestneighbor shell(denoted as cluster)plus those in the next outer shell(denoted as glue atoms),which can be formulated as[cluster](glue atoms).This simplified version of short-rangeorder structure represents the smallest charge-neutral and mean-density zone(termed as“chemical units”)and can be regarded as the‘molecules’of solid ***,the chemical units and the corresponding molecule-like formulas for face-centered-cubic(FCC),hexagonal close-packed(HCP),and body-centered cubic(BCC)structures are analyzed and equations are obtained to identify the chemical formulas for FCC solid *** instance,well-knownα-brass Cu-30 Zn alloy is formulated as[Zn-Cu_(12)]*** of aluminum alloys,superalloys and stainless steels are also illustrated,demonstrating the versatility of the present model to interpret chemically complex alloys.

摘要：以现阶段虚拟地理环境发展为背景,介绍了虚拟地理环境平台的整体建设,分析了三维可化系统在平台建设中所起的作用,针对虚拟地理环境的特点设计开发了三维可视化系统VirtualGlobal,并深入探讨了开发过程中数据组织、场景构建、数据调度、渲染策略等关键技术的实现。经验证,该系统能够符合地学分析可视化的要求,较好的完成地理环境的可视化表达。

摘要：为了获得高消光比、窄线宽、信道间隔均匀的高性能梳状滤波器,提出了一种基于高双折射光纤梳状滤波器的结构设计,并利用传输矩阵法对设计的滤波器的滤波特性进行了理论研究.数值分析了该梳状滤波器中高双折射光纤、耦合器以及偏振控制器对梳状谱特性的影响.仿真结果表明,该滤波器信道间隔为50GHz,0.5dB带宽约为0.12nm,消光比高达30dB,满足25/50GHz梳状滤波器的要求.实验验证了推导的传输函数和波长间隔表达式的正确性,测得光谱隔离度可以达到22dB,0.5dB带宽大于波长间隔的30%.由于器件连接中存在各种损耗,实验所测的光谱隔离度总要低于理论值.理论分析、仿真结果与实验结果验证了该滤波器方案的有效性和可行性.

摘要：Background and Objective:Adenovirus vectors were widely used in gene therapy for *** used adenovirus vector to transfer small interfering RNA(siRNA) against vascular epithelium growth factor A(VEGF-A) molecules to mouse lung adenoma LA795 cells and used low dose of chemotherapeutic drugs to further elevate the infection efficiency of adenovirus vector in and therapeutic effect of RNAi on tumor *** hods:LA795 cells were infected by Ad/EGFP and treated with different dosages of gemcitabin,epirubicin,cisplatin,or 5-fluorouracil(5-FU).Cells were observed under fluorescence microscope continuously using green fluorescent protein(GFP) as the reporter *** percentage of GFP-positive cells and fluorescent intensity were tested by flow cytometry to determine optimum concentrations of ***/siVEGF-A containing VEGF-A siRNA was ***-time PCR and ELISA were applied to measure the expression level of VEGF-A after LA795 cells were infected by Ad/siVEGF-A and treated with *** combination of Ad/siVEGF-A and 5-FU was also applied in treating subcutaneous tumor in *** s:Low dose of 5FU elevated the Ad/EGFP infection in LA795 cells significantly,and also enhanced the effect of Ad/siVEGF-A in downregulating VEGF-A mRNA and protein levels in tumor *** used in tumor in vivo,the combination strategy repressed tumor growth ***:Low dose of 5-FU can enhance the capability of adenovirus infecting tumor cells and promote the efficiency of gene therapy by adenovirus.