摘要：Covalent organic frameworks(COFs)have lately emerged as a blooming class of potential materials for photocatalytic water splitting because of their high crystallinity,huge surface areas,and structural ***,the photocatalytic performance for most pure COFs face some limitations factors,such as the significant recombination of photogenerated carriers and slow charge ***,a novel thioether-functionalized pyrene-based COF(S_(4)-COF)was effectively produced and chosen as a support for the immobilization of ultrafine gold nanoparticles(Au NPs).S_(4)-COF photocatalyst with Au as cocatalyst demonstrates remarkable photocatalytic activity with a H_(2) generation rate of 1377μmol g^(−1) h^(−1) under visible light(>420 nm),which is ca.4.5-fold increase comparing to that of pure S_(4)-COF(302μmol g^(−1) h^(−1)).Au NPs anchored on S_(4)-COF possess an ultrafine size distribution ranging from 1.75 to 6.25 nm with an average size centered at 3.8 nm,which benefits from the coordination interaction between thioether groups and ***,the produced Au@S_(4)-COF can generate a stable photocatalytic H_(2) generation during the four recycles and preserve its crystallinity structure after the stability *** Au NPs anchored on the S_(4)-COF photocatalyst can greatly accelerate the separation of photogenerated carriers and increase charge transfer because of the combined function of Au NPs and thioether *** a method can not only prevent the aggregation of Au NPs onto thioether-containing COFs to achieve long-term photostability but also allow uniform dispersion for an ordered structure of *** work provides a rational strategy for designing and preparing COF-based photocatalysts for solar-driven H_(2) production.

摘要：Solar-driven water splitting is considered as a promising method to mitigate the energy crisis and various environmental *** vanadate(BiVO_(4))is photoanode material with tremendous potential for photoelectrochemical(PEC)water ***,its PEC performance is severely hindered owing to poor surface charge transfer,surface recombination at the photoanode/electrolyte junction,and sluggish oxygen evolution reaction(OER)*** this regard,a novel solution was developed in this study to address these issues by decorating the surface of BiVO_(4)with cobalt sulfide,whose attractive features such as low cost,high conductivity,and rapid charge-transfer ability assisted in improving the PEC activity of the BiVO_(4)*** fabricated photoanode exhibited a significantly enhanced photocurrent density of 3.2 m A cm^(-2)under illumination at 1.23 V vs.a reversible hydrogen electrode,which is more than 2.5 times greater than that of pristine BiVO_(4).Moreover,the Co S/BiVO_(4)photoanode also exhibited considerable improvements in the charge injection yield(75.8%vs.36.7%for the bare BiVO_(4)film)and charge separation efficiency(79.8%vs.66.8%for the pristine BiVO_(4)film).These dramatic enhancements were primarily ascribed to rapid charge-transport kinetics and efficient reduction of the anodic overpotential for oxygen evolution enabled by the surface modification of BiVO_(4)by Co *** study provides valuable suggestions for designing efficient photocatalysts via surface modification to improve the PEC performance.

摘要：远程开放教育教学过程的设计以及教学过程质量管理,是现代远程教育中的核心问题。文章论述了教学过程优化设计的原则与具体的设计方法,并对开放教育教学过程的质量管理进行了全面阐述。

摘要：物理化学的学习前提是具有良好的高等数学知识基础及较强的逻辑推理能力,因此物理化学普遍被视为最难学的化学学科。本文紧扣金课标准,以环境科学与工程类专业学生为授课对象,基于近年来作者在物理化学教学内容和方法方面的探索,分析物理化学中的教与学中存在的问题及解决方法。

摘要：近年来,贵重的手性催化剂的回收与再利用越来越引起化学工作者的关注,而离子液体在催化剂回收方面有其独特的优势。本文综述了离子液体在手性催化反应中的应用,在回收催化剂的同时,也能一定程度上提高催化剂的催化效率:着重介绍了新型含咪唑盐手性催化剂及其在不对称催化中的应用,由于它在离子液体和有机溶剂的显著差异可以很容易地得到回收,并且能一定程度地稳定催化剂,提高催化效率,这对我们设计合成新型可回收的催化剂具有重要的借鉴意义。

摘要：设计了基于硅基槽波导的微环谐振型单纤三向滤波器。基于电磁场理论得到了二维情形下的硅基槽波导的模场及有效折射率随波长的变化关系,在此基础上,利用硅基槽微环谐振腔谐振波长与微环半径的关系,优化得到了可将1490nm和1550nm两个下载波长分开的谐振环半径,并同时将1310nm波长上传,三个波长信号从不同端口输出,成功地实现了三向器滤波功能。利用传递函数法模拟了所设计的硅基槽微环谐振型三向滤波器的输出光谱,结果显示其串扰可低至-16.9dB。

摘要：研究目的:半整体式桥台无伸缩缝桥(简称半整体桥)是一种新型桥梁结构形式。由于主梁与桥台刚接,在昼夜及季节性环境温度等长期作用下,主梁会使桥台沿纵桥向发生往复变位,进而引起台后土体的压力变化,产生土抗力。为研究半整体桥的台后土抗力分布规律以及中长期环境温度对土抗力的影响,开展中长期环境温度作用下半整体桥台-土相互作用拟静力试验研究。研究结论:(1)台后土抗力随环境温度变化的规律为在第1~6中周期(约对应由春季至夏季的第一个升温区间段)内快速上升,在第6~16中周期(约对应由夏季至冬季的降温区间段)内有所减小,在第16~20中周期(约对应由冬季至春季的第二个升温区间段)又开始增加,但相比于第一个升温区间段内的增速明显减缓;(2)中长期环境温度作用下台后土抗力沿埋深方向的分布规律为先增加后减小,并在埋深0.8h处达到最大;(3)各周期内土抗力沿纵桥向的规律为在距桥台较近的区域,台后土抗力快速减小;在距桥台较远的区域,土抗力缓慢减小,并在距台背1.0h位置处土抗力基本减小至0;(4)经过一个全年大周期的环境温度作用后,台后土抗力存在明显累积增大效应,其累积效应与土体的纵桥向位置及竖向深度具有较强的相关性;(5)本研究结果可为半整体桥的设计计算以及相关规范制定提供参考。

摘要：针对传统强化学习在空战自主决策应用中信息冗余度高、收敛速度慢等问题,提出一种基于双重观测与复合奖励的近端策略优化空战自主决策算法。设计了以交互信息为主、个体特征信息为辅的双重观测信息,降低战场信息高度冗余对训练效率的影响;设计了结果奖励和过程奖励相结合的复合奖励函数,提高了训练过程收敛速度;采用广义优势函数估计,改进了近端策略优化算法,提高优势函数估计的准确性。仿真结果表明:在对战固定程控对手和矩阵博弈对手实验场景中,该算法决策模型均可根据战场态势准确进行自主决策,完成空战任务。

摘要：已建地下室的综合馆因上部建筑方案变更后现设计为西安曲江电竞中心,原综合馆仅地下室施工完成,考虑已建结构的特点、施工工期等因素,上部结构方案经比选后选用混凝土柱+钢梁的混合框架结构体系。混凝土柱与钢梁之间采用改进的柱贯通梁组合节点形式,并采用有限元软件进行抗震性能分析。结果表明:改进的柱贯通梁组合节点极限位移角为1/40,变形能力较好;混凝土柱与环加劲板、钢梁的刚度相差较大,加载后期,核心区混凝土损伤严重,因而结构耗能能力一般。在原地下室框架柱上部通过布置摇摆柱来解决新增混凝土柱的弯矩传递和无法植筋问题,给出了摇摆柱的上部和柱脚节点做法。对局部楼板大开洞区域进行应力对比分析,设置连接板带来保证楼板的水平力传递;在原地下室上部新增混凝土柱时,通过对原地下室框架柱增大截面后在其周围植筋,保证竖向荷载的传递。

摘要：以数控机床床身用钢为研究对象,采用正交实验法对机床用钢的喷射沉积工艺进行了设计与研究,分析了变形温度、变形速度、变形量和升温速度对致密化效果的影响,并优化了喷射沉积工艺。结果表明,适宜的喷射沉积致密化工艺为变形温度840℃、变形速度0.1 mm/s、变形量60%、升温速度10℃/s。