结构可靠指标矢量及其计算与应用

从结构可靠指标的几何意义出发 ,提出了可靠指标矢量 ,并给出了它的计算方法。理论分析和算例结果表明 :可靠指标矢量既可表达可靠指标 ,又可方便地表示各失效模式之间的相关性。可靠指标矢量可较好地解决长期困扰结构体系可靠度分析和应用的难点之一——怎样计算各失效模式之间的相关性。     

贮液容器的晃动分析

贮液容器在晃动下的液固耦合振动问题是人们一直想解决的工程难题之一.本文以能量法导出了随时间作交替晃动的贮液容器的广义变分泛函,给出了这类问题的解法,并通过数值算例,对这类耦合振动的特征作了简要的分析.     

Atomic Precise Gold Nanoclusters: Toward the Customize Synthesis,Precision Medicine

With the advantages of controllable atomic composition, unique molecular-like properties, and excellent biocompatibility, atomic precision Au cluster is an ideal candidate for developing materials with customized biological functions to meet the needs of precision medicine. To achieve the rational design of functional materials through structural regulation at the atomic level, it is important to clarify the relationship between the structure and properties of Au clusters. With the development of synthesis methodology, a variety of structural regulation methods of Au clusters have been developed, providing new opportunities for structure–activity relationship establishment and precision medicine application. This review introduces the synthesis and structure regulation methods of atomic precision Au clusters, and the effects of structural regulation on the physicochemical properties are further described. At the same time, the applications of Au clusters in precision medicine, including the detection of biomolecules, functional imaging, and disease therapy are discussed, as well as the recent studies around their biosafety. At last, it also briefly summarizes the current problems and development directions. The present work provides potential theoretical guidance for the rational design of Au clusters with customized biological functions and is of great significance for broadening their applications in the field of precision medicine.     

菲涅尔透镜聚焦声泳打印装置设计及实验研究*

针对现有的喷墨打印技术需根据喷印材料的特性定制而较难直接用于不同材料打印的问题,设计了一种基于菲涅尔透镜聚焦的声泳打印装置,该装置由超声发生器、超声换能器、菲涅尔透镜以及供液系统组成。首先,利用COMSOL软件模拟液滴在声辐射力作用下的滴落过程,并分析了超声发生器功率、喷嘴到基底距离、菲涅尔透镜厚度等参数对声场压力分布的影响,以及声场压力、喷嘴直径及材料粘度对液滴喷射过程的影响。其次,采用构建的声泳打印装置进行喷射成滴实验,通过调整超声发生器输出功率实现了不同粘度的聚乙二醇溶液的喷射以及UV胶的喷射。实验结果表明：该微滴喷射系统能产生一致性较好的微滴,喷印出的微透镜尺寸波动范围在2%以内,证明了该装置的稳定性以及实现了不同材料微滴喷射的可行性。     

环丙鱼藤双腙的合成与抑菌活性

以鱼藤酮为原料,经氧硫叶立德开环、环合,再与水合肼缩合制备关键中间体(2R)-5-[5',6'-二甲氧基-1',1'a,2',7'b-四氢环丙并[c]苯并吡喃-7'b-基)(亚联氨基)甲基]-2-(丙烯-2'-基)-2,3-二氢苯并呋喃-4-酚(2),2与多种醛/酮反应,合成16个结构新颖的环丙鱼藤双腙化合物3a~3p,结构经1H NMR和LRMS确证.初步抑菌活性测试表明,鱼藤双腙化合物对稻纹枯病菌、油菜菌核病菌和小麦白粉病菌的抑制率/防治率较高.其中化合物3d和3o在500 mg/L浓度下对稻纹枯病菌的防治率分别为55.1%和55.5%;化合物3a,3c,3e,3h和3k在25 mg/L浓度下对油菜菌核病菌的抑制率分别为76.8%,87.0%,70.6%,72.5%和65.2%;化合物3a,3c,3g,3i和3l在500 mg/L浓度下对小麦白粉病菌的防治率为80.0%~90.0%.     

四面受火后钢筋砼柱抗震性能研究

火灾后砼的强度和弹性模量损失很大，降低了钢筋砼结构的抗震能力。本文编制了火灾后已损伤钢筋砼柱的全过程分析程序，通过大量数值计算，建立了四面受火后钢筋砼柱恢复力骨架曲线特征参数的统计公式，并探讨了砼力学性质自然恢复对钩件抗震性能的影响，在此基础上，对两榀火灾后框架进行了地震反应分析，得到一些有意义的结论。     

Fabrication of Porous Nitrogen‐Doped Carbon Materials as Anodes for High‐Performance Lithium Ion Batteries

The hierarchical porous nitrogen‐doped carbon materials (HNCs) were prepared by using nitrogen containing gelatin as the carbon source and nano‐silica obtained by a simple flame synthesis approach as the template. All of the as‐obtained HNCs show much higher Li storage capacity as compared with commercial graphite. Specifically, HNC‐700 with biggest micropore volume and highest nitrogen content exhibited optimal reversible capacities of 1084 mAh·g^??1 at the current density of 37.2 mA·g^?1 (0.1 C) and 309 mAh·g^?1 even at 3.72 A·g^?1 (10 C). This result suggests that HNCs should be a promising candidate for anode materials in high‐rate lithium ion batteries (LIBs).     

Four-photon interference with asymmetric beam splitters

Two experiments of four-photon interference are performed with two pairs of photons from parametric downconversion with the help of asymmetric beam splitters. The first experiment is a generalization of the Hong-Ou-Mandel interference effect to two pairs of photons while the second one utilizes this effect to demonstrate a four-photon de Broglie wavelength of lambda/4 by projection measurement.     

Observation of large positive and negative lateral shifts of a reflected beam from symmetrical metal-cladding waveguides

Both large positive and negative lateral shifts were observed for the reflected light beam on a symmetrical metal-cladding waveguide. The positive and negative shifts approach about 480 and 180 microm, respectively, which to our knowledge are the largest experimental results ever reported. The experiment also proves that the positive or the negative shift depends on sign of the difference between the intrinsic and radiative damping.     

Design and analysis of a noncollinear acousto-optic tunable filter

The design of the noncollinear acousto-optic tunable filter (AOTF) is commonly based on the parallel tangents momentum-matching condition. Previous studies either have used an approximation of the birefringence of the interaction material or have ignored the rotatory property of TeO(2). These approaches would obviously decrease the accuracy of designing an acousto-optic tunable filter (AOTF). We introduce an analysis method of calculating the optimum incident optical angle. Besides, an appropriate optical wedge on the output optical facet is designed to reduce the wavelength dependence of the diffracted beam angle, which is very significant in practical applications of AOTF.