金属酞菁轴向配合物的合成及性质

综述了金属酞菁轴向配合物的合成方法 ,结构表征及其物理化学性质。金属酞菁轴向配合物的合成重点在于单体的合成。轴向配合物的合成通常有两种方法 :一种是通过金属酞菁的单体来直接合成 ,这种方法分别可以通过三条途径来达到 ,一是以苯腈为原料的途径 ,二是以苯酐为原料的途径 ,三是二亚氨基异吲哚啉路线 ,它们都是以单体为原料 ;第二种合成方法是通过金属酞菁聚合物在配体溶剂中的解离而得到的。金属酞菁轴向配合物的吸收光谱与简单的金属酞菁配合物相比 ,吸收峰明显红移 ,这就大大改进了它的光学性质     

硫化环丙烯与马来酸酐共聚制备硫代碳酸酯工艺研究

采用席夫碱锌金属配合物/助催化剂二元催化体系催化硫化环丙烯与马来酸酐共聚制备聚硫代碳酸酯,探讨了聚合反应温度、反应时间、助催化剂用量、单体配合比等对聚合物链节结构的影响。研究结果表明,在硫化环丙烯、马来酸酐、催化剂和四丁基碘化胺的摩尔配合比为250∶250∶1∶3,反应温度70℃,反应时间300min较优条件下,硫化环丙烯的转化率为72%,聚硫代碳酸酯链节中硫醚含量为9%。     

一种金属有机DMIT类材料的光限幅实验研究

合成了一种金属有机配合物二(四乙基铵)双(4,5-二硫基-1,3-二硫杂环戊烯-2-硫酮)-铜(Et-Cu),配制了其浓度为1.0×10-3mol/L的乙腈溶液,采用开孔Z扫描方法,表征了该样品在波长1053nm,脉宽18ns条件下的非线性光学特性。实验结果表明,在纳秒脉冲下,该材料具有光限幅效应,并认为该效应是基于材料的反饱和吸收特性。该材料在光限幅器件上具有潜在应用价值。     

新型异金属三羰基铼配合物的合成及光学性质研究

将双吡啶基多硫桥式配体(Ⅲ)依次与Ni(dbbpy)Cl2(dbbpy=4,4′-二叔丁基-2,2′-联吡啶)、Re(CO)_5Cl反应,合成了一个新型的双核卤化三羰基一价铼异金属配合物(2)及其前体配合物(1)。采用~1H NMR、IR、MS和元素分析表征1和2的结构,并解析了二者的晶体结构,初步测定了其光学性质。结果表明,配合物1和2的CH_2Cl_2溶液在250~305nm附近有很强的吸收带,摩尔消光系数级数为104,但未观测到二者发射荧光。最后在密度泛函(DFT)水平上研究了配合物1和2的基态轨道能量。     

五氮齿金属配合物溶液对皮秒激光的光限幅

报导了五种五氮龄金属配合物对３５ｐｓ激光光限幅的实验结果,限幅机制属于激发态的反饱和吸收。在实验所用较高激光能量时,没有观察到样品被损坏的现象。配合物「（ＡＰＰＣ－ＣＯＯＨ）Ｃｄ」Ｃｌ（Ⅰ）和「ＡＰＰＣ－ＮＰ）Ｃｄ」Ｃｌ（Ⅱ）的光限幅阈值分别为４４．１ｍＪ／ｃｍ＾２和１４６ｍＪ／ｃｍ＾２,配合物Ⅰ最代非线性透过率达９％。吸电子基团能增强该类配合物对皮秒激光的限幅效果,而重原子效应则起相反的作用。     

有机配合物DVDR光盘存储染料的研究应用

金属有机配合物染料具有优良的光学和热力学性能,是高稳定性DVDR光盘的优良存储介质.文章分类介绍了金属有机光存储染料在DVDR方面的应用现状,对金属有机配合物染料在光盘存储技术中的发展前景作了展望.     

C2H2在硅氢加成反应中的应用研究

讲述了硅氢加成反应的机理,包括Chalk-Harrod机理、金属胶体粒子催化机理和硅基迁移机理;常用催化剂有均相催化荆和负栽型金属配合物催化荆;C2H2在硅氢加成中的应用.     

热致变色过渡金属配合物的变色机理及应用

社会的智能化是未来发展的必然趋势。智能材料作为智能化变革的基础，成为了近几年研究的热点。热致变色材料是一种智能变色材料，可以随着外界温度的改变发生颜色变化，被广泛应用于智能窗、温度传感、防伪、智能纺织、变色涂料等领域。热致变色材料的种类繁多，其中过渡金属配合物热致变色材料通常变色温度较低、变色现象明显并且拥有较独特的电子传递特性，具有良好的应用前景，受到了研究者的广泛关注。在热致变色过渡金属配合物发展初期，科学家们主要研究的是配合物的结构和变色机理，关于配合物应用方面的研究很少，这主要是由于热致变色过渡金属配合物自身具有缺陷(如摩尔吸光系数低、变色需要溶剂等)。在最近十几年，科学家们通过各种方法手段增加热致变色过渡金属配合物的实用性，例如使用离子液、新型配体以及与其他功能材料复合等手段，使热致变色过渡金属配合物在各个领域的应用都取得了很大进展，但相关综述还较少。只有掌握热致变色材料的变色机理，才能更好地设计符合不同应用场景的热致变色材料，本文首先对热致变色过渡金属配合物的变色机理进行介绍，常见变色机理包括构型变化、配体改变、自旋交叉，然后归纳总结了最近几年热致变色过渡金属配合物在温度传...     

稀土有机配合物/树形分子/蒙脱土纳米复合材料的制备及光学性能研究

选择荧光性能较强的稀土元素Eu为金属发光中心,β-二酮为配体,低代树形分子为掺杂剂,合成了高配位数的掺杂树形分子β-二酮配合物;并以蒙脱土为刚性体,采用插层法制得高荧光强度的稀土有机配合物/树形分子/蒙脱土纳米材料.分析结果表明,稀土有机配合物/树形分子/蒙脱土荧光材料较同类稀土有机配合物的荧光性能明显增强.     

热解含硫金属有机配合物法合成亮紫色发光的α-ZnS:Cu纳米荧光粉

以硝酸锌、硝酸铜和二乙基二硫代氨基甲酸钠为原料,制得含硫金属有机配合物.将含硫金属有机配合物在200℃进行热解,制备了亮紫色发光的ZnS： Cu纳米荧光粉.XRD检测结果显示,荧光粉样品为六方晶系的高温相α-ZnS.根据TEM结果,样品为均匀的球形粒子,其粒子尺寸在30nm左右.室温下,样品的激发光谱峰值位于235nm...     

Congestion, ramp metering and tolls

The cell transmission model of a freeway is used to compare four congestion-reducing schemes: (R) ramp control only; (T) one lane is tolled and ramps are uncontrolled; (B) bottlenecks are tolled and ramps are uncontrolled; and (RB) ramps are controlled and bottlenecks are tolled. In the base case, ramps are uncontrolled and there are no tolls. It is found that (T) is inefficient and may leave all travellers worse off; (R), (B) and (RB) can achieve efficient freeway use; (B) can eliminate queues, but has adverse spatial and equity side effects; (RB) minimizes these side effects. (RB) is likely to be least costly to implement and maintain.     

二硝基乙腈钾与火药组分相容性的DSC法评估

为了了解二硝基乙腈钾(DNCK)与火药常用组分之间的相容性,采用差示扫描量热法（DSC）研究了DNCK与这些组分之间的相互作用。结果表明:DNCK与DAGR吸收药、DA吸收药、硝化棉（NC）、硝基胍（NQ）、叠氮硝胺（DIANP）、1,3-二甲基-1,3-二苯基脲（C2）、2-硝基二苯胺（2-NDPA）相容性良好;与六硝基六氮杂异戊兹烷（CL-20）和N 甲基-4-硝基苯胺（MNA）轻微敏感;与黑索今（RDX）、三羟甲基乙烷三硝酸酯（TMETN）和间苯二酚（Res）敏感;DNCK与奥克托今（HMX）和N-丁基硝氧乙基硝胺（BUNENA）混合体系的分解峰温较HMX和BUNENA单质组分分别提前了35.2 ℃和17.4 ℃,因此,与HMX和BUNENA不相容。     

Recent advances in research on cold thermal energy storage

Recent literatures in the field of cold thermal energy storage (CTES) are reviewed. First, the concept of the CTES is explained. Examples of load leveling of electrical energy in various countries are presented. Various types of the CTES are defined and compared as for their merits and demerits. The compared systems are a cold water storage vs. an ice-making storage, a static ice-making storage vs. a dynamic ice-making storage, and direct ice-making vs. indirect ice-making. Approximately 140 papers are reviewed and divided into five categories: (1) performance of successful systems, (2) simulation and control, (3) cold water storage, (4) static ice-making storage, and (5) dynamic ice-making storage. Finally, suggestions for future research are provided.     

Ti(C,N)材料的研究进展

分别介绍了Ti(C,N)陶瓷材料、Ti(C,N)基金属陶瓷材料和Ti(C,N)基复相陶瓷材料的组织结构、性能、优势及其制备方法。Ti(C,N)陶瓷材料的制备方法主要有气相沉积法、激光熔覆法和自反应喷涂法,Ti(C,N)基金属陶瓷材料的制备方法主要有粉末冶金法和自蔓延高温合成法,Ti(C,N)基复相陶瓷材料的制备方法主要有自反应喷射成形法和自反应喷涂法。最后介绍了Ti(C,N)材料的应用及其应用的局限性。     

The chirality of metal-encapsulated silicene-like nanotubes

The energy stability and electronic structures of (3,3) armchair metal-encapsulated SiNTs (M@SiNTs) are systematically studied by using DFT-GGA calculations. Results show that most the metal-encapsulated SiNTs with the same space group can be stabilized through doping by metal atoms with silicene-like structures. Compared with the different chirality, (4,0) zigzag M@SiNTs are more stable than (3,3) armchair M@SiNTs. The band gaps of (3,3) and (4,0) SiNTs are 1.06 eV and 0.06 eV, they are both semiconductors. But most (3,3) armchair and (4,0) zigzag M@SiNTs are conductors, except (3,3) Sn@SiNT, (4,0) K@SiNT and (4,0) Ba@SiNT are semiconductors with small value of band gaps. The interaction between encapsulated metal and silicon atoms makes out orbital hybridizations, and decreases the gap between valence band and conduction band. Finally, electronic structural analysis shows that metal atoms gain electrons and Si atoms lose electrons as a whole, some electrons transfer from Si to metal atoms.     

Free vibration analysis of reinforced thin-walled plates and shells through various finite element models

Abstract

This article deals with free vibration analysis of thin-walled structures reinforced by longitudinal stiffeners using refined one-dimensional (1D) models.The 1D theory, which is used in the present article, has hierarchical features and it is based on the Carrera Unified Formulation (CUF). The displacement field over the cross section is obtained by means of Taylor (TE) or Lagrange (LE) expansions. Finite element (FE) method is applied along the beam axis to obtain weak form solutions of the related governing equations. The obtained results are compared with those from classical finite element formulations based on plate and shell (2D), beam (1D), and solid (3D) elements that are available in commercial software. When solid formulation is used to build the FE solutions, stringers and skin are modeled with only 3D elements while, in the 2D-1D FE models, shell and beam elements are used for skin and stringers, respectively. Three benchmark problems are analyzed: a flat plate, a curved panel, and a thin-walled cylinder. When TE models are used, different orders of expansion, N, are considered, where N is a free parameter of the formulation. As far as Lagrange expansions are concerned, four-node (LE 4) and nine-node (LE 9) elements are used to build different meshes on the cross section. The results show that the present 1D models are able to analyze the dynamic behavior of complex structures and can detect 3D effects as well as very complex shell-like modes typical of thin-walled structures. Moreover, the 1D-CUF elements yield accurate results with a low number of degrees of freedom.     

微乳液法合成羟基磷灰石纳米微晶及其性能研究

在一定的pH值条件下,以DTAC为表面活性剂、正辛醇为助表面活性剂、环己烷为油相形成的微乳液模板,诱导Ca(NO3)2和(NH4)2HPO4在其形成的微反应器中反应,反应物经混合陈化后即可生成片状和长柱状等多种微观形貌的羟基磷灰石纳米微晶(HA).将所得产物在不同温度下焙烧,分别用FTIR、XRD和TEM等对其结构及形貌进行表征,对不同表面活性剂浓度和反应物浓度条件下所得HA的微观形貌分别进行了分析对比.     

ESD in integrated circuits

A review of the effects of electrostatic discharge (ESD) on semiconductor integrated circuits is presented. The principles of the human body model (HBM), the machine model (MM) and the charged device model (CDM) test methods are outlined, and their relative merits and drawbacks are discussed. Techniques, such as the transmission line pulse method, which may be used to characterise ESD protection circuit elements are also presented. The concept of ESD protection circuit designs and some typical ESD protection circuit elements are presented. The main design and process parameters are identified, and the main categories of damage under ESD conditions are shown. Models of the behaviour of the protection circuit elements under high current conditions are presented, and the boundary conditions for damage are discussed. The issues that will influence ESD protection circuit behaviour in the future are discussed.     

Vibro-acoustic analysis of a post-impacted woven composite panel

In this study, vibro-acoustic behavior of centrally damaged woven carbon composite panels is investigated experimentally. For this purpose, evaluations are considered by the followings: (i) ballistic impact measurements are completed regarding with two different shooting distance, (ii) ballistic impact measurements with three different projectiles are obtained, (iii) vibration and vibro-acoustic tests are performed to present the vibration characteristics of the post-impacted woven composite panels. Effects of shooting distance and projectile on modal and sound characteristics are examined. Results are given in tabular and graphical forms.     

(Na0.5Bi0.5)TiO3基无铅压电陶瓷研究进展

综述了（Na0.5Bi0.5)Tio3（简写为NBT）基无铅压电陶瓷的发展现状，特性及影响因素，用分子轨道理论解释了NBT强铁电性的成因，对研究较多的三个体系：NBT-ATiO3(A=Ca,Sr,Ba),NBT-BNbO3(B=Na,K)和NBT－Ln掺杂体系给予了概括介绍，内容包括成分配比，性能和应用，并提出了NBT基无铅压电陶瓷的设计原则。