Single-atom Sn-Zn pairs in CuO catalyst promote dimethyldichlorosilane synthesis

Single-atom catalysts are of great interest because they can maximize the atom-utilization efficiency and generate unique catalytic properties; however, much attention has been paid to single-site active components, rarely to catalyst promoters. Promoters can significantly affect the activity and selectivity of a catalyst, even at their low concentrations in catalysts. In this work, we designed and synthesized CuO catalysts with atomically dispersed co-promoters of Sn and Zn. When used as the catalyst in the Rochow reaction for the synthesis of dimethyldichlorosilane, this catalyst exhibited much-enhanced activity, selectivity and stability compared with the conventional CuO catalysts with promoters in the form of nanoparticles. Density functional theory calculations demonstrate that single-atomic Sn substitution in the CuO surface can enrich surface Cu vacancies and promote dispersion of Zn to its atomic levels. Sn and Zn single sites as the co-promoters cooperatively generate electronic interaction with the CuO support, which further facilitates the adsorption of the reactant molecules on the surface, thereby leading to the superior catalytic performance.     

伤寒免疫学诊断方法的研究现状

对近年伤寒免疫学诊断方法结合作者的研究工作进行了评价。伤寒免疫学诊断可分检测早期病人体液中抗原及测定患者血清中抗体两个方面。检测抗原以SPA-CoA与ELISA(包括Dot-ELISA)较为敏感和特异,而DRLAT则有简便的优点。测定抗体以PHA最为简便与快速。使用LPS-PHA可作伤寒的早期快速诊断,而Vi-PHA可作伤寒病后带菌者的初筛。ELISA有较PHA更高的敏感性,其中LPS-IgM-ELISA亦可作伤寒病人的早期诊断,而LPS-IgG-ELISA可用于该病的追溯诊断和血清流行病学调查。Vi-ELISA还可作伤寒病后带菌者初筛。不同条件实验室可根据取得试剂情况选择使用。     

N-heterocyclic carbene-stabilized metal nanoparticles within porous organic cages for catalytic application

Tuning the surface-embellishing ligands of metal nanoparticles (NPs) is a powerful strategy to modulate their morphology and surface electronic and functional features, impacting their catalytic activity and selectivity. In this work, we report the design and synthesis of a polytriazolium organic cage PIC-T, capable of stabilizing PdNPs within its discrete cavity. The obtained material (denoted Pd@PCC-T) is highly durable and monodispersed with narrow particle-size distribution of 2.06 ± 0.02 nm, exhibiting excellent catalytic performance and recyclability in the Sonogashira coupling and tandem reaction to synthesize benzofuran derivatives. Further investigation indicates that the modulation of N-heterocyclic carbene sites embedded in the organic cage has an impact on NPs’ catalytic efficiency, thus providing a novel methodology to design superior NP catalysts.     

Construction of hollow mesoporous silica nanoreactors for enhanced photo-oxidations over Au-Pt catalysts

It is highly desirable to design hollow structures with multi-scale functions by mimicking cells for the construction of micro/nanoreactors. Herein, we report the construction of hollow-structured submicrometer-photoreactors with bimetallic catalysts loaded within mesoporous silicas. The synthesis parameters are optimized to study the evolution of hollow structure through hydrothermal treatment and an ‘adhesive-contraction’ formation mechanism is proposed. AuPt@HMZS catalysts exhibited a broader absorbance region under visible light and the adsorption edge displayed a red-shift, indicating the strong metal–metal interactions at the alloy interface. The reaction performance of the coupled Au-Pt catalysts can be tuned to achieve excellent catalytic activity in cinnamyl alcohol oxidation to cinnamic acid for 3.1 mmol g⁻¹ with 99% selectivity. The proposed strategy to build hollow structures as multifunctional micro/nanoreactors is promising for the design of high-performance and sustainable catalysts for chemical synthesis.     

非晶态Co（Ni）－B合金催化剂的TPD－MS研究

用化学还原法制备了非晶态合金催化剂Ｎｉ－Ｂ、Ｃｏ－Ｂ和Ｃｏ－Ｎｉ－Ｂ．合金的非晶性质由Ｘ射线衍射（ＸＲＤ）及透射电子显微镜（ＴＥＭ）鉴定．组成用电感耦合等离子发射光谱（ＩＣＰ）分析．在高真空程序升温脱附质谱（ＴＰＤ－ＭＳ）装置上研究了ＣＯ、Ｈ２在三种催化剂上的吸附及ＣＯ和Ｈ２的表面反应（ＴＰＳＲ）．发现ＣＯ和Ｈ２在三种催化剂上分别有二种和一种吸附态，吸附强度和二种吸附态的数目在不同合金上有较大差异．ＣＯ加氢反应的主要产物是ＣＨ４、ＣＯ２和Ｈ２Ｏ，其中ＣＯ在催化剂表面上的解离是反应的控制步骤．     

Serum Lactate Dehydrogenase in Non-Hodgkin’s Lymphoma: A Prognostic Indicator

Non-Hodgkin’s lymphoma constitutes a group of disorders originating from the malignant transformation of lymphocytes and involving either the lymph nodes or extranodal sites. NHL commonly presents in the sixth to seventh decade of life with a male preponderance (50–75 %). Recent studies have shown importance of serum LDH in prognosis of NHL. Authors report a case of a 63 year old male presenting with complaints of fever and backache for past 4 months. General and systemic examination revealed bilateral axillary lymphadenopathy and splenomegaly respectively. Serum LDH level was highly elevated (3441 U/l). Excisional axillary and bone marrow biopsy were done before oncology referral. Complete workup revealed diffuse Non-Hodgkin’s lymphoma with bone marrow infiltration. Patient died because of acute renal failure due to NHL and DM 2 (Type 2 diabetes mellitus).     

Effect of (-)epicatechin in modulating calicum-atpase activity in normal and diabetic human erythrocytes

Aqueous extract of the wood ofPterocarpus marsupium, commonly known as ‘bijasar’, is used in Indian Ayurveda system of medicine for treatment of diabetes. The active anti-diabetic principle in its aqueous extract has been found to be (-)epicatechin, a flavonoid. The present work was undertaken to study the effect of (-)epicatechin on erythrocyte membrane Ca⁺⁺-ATPase from type 2 diabetic patients. The activity of erythrocyte Ca⁺⁺-ATPase was significantly lower in type 2 diabetics.In vitro insulin treatment of erythrocyte ghosts, resulted in the increase of Ca⁺⁺-ATPase activity in diabetic patients. Treatment with (-)epicatechin (1mM) resulted in an increase in the activity of erythrocyte Ca⁺⁺-ATPase in both normal individuals and type 2 diabetic patients. The insulin like effect of (-)epicatechin on erythrocyte membrane Ca⁺⁺-ATPase in type 2 diabetics is an interesting finding. Further work is needed to elucidate the mechanism of action of (-)epicatechin on modulation of erythrocyte membrane bound enzymes.     

Photolysis of the d-glycosides: α benzylfructofuranoside, β benzylfructopyranoside,and α and β phenyl,benzyl and β phenylethyl glucosides; and the bearing of the data upon the transfer of energy within molecules

Direct absorption of light by glycosides dissolved in water has been discovered to produce changes in optical activities and formation of material which reduces the Shaffer, Hartmann, Somogyi reagent. Comparison of these measurements indicates in many cases the same products as are formed by hydrolysis in acid. The β glucosides and α fructoside, however, apparently give optically inactive photolytic products.Absorption spectra were obtained for α benzylfructofuranoside and β benzylfructopyranoside, and were found to be the same in the near ultraviolet as those previously obtained for benzyl glucosides and benzyl alcohol.The absorption spectrum for freshly purified fructose gives a deeper minimum about λ240 mμ than the previously reported values. The latter, however, were approached when the dry crystals had stood in air for several months although no change occurred in their sp.rot., m.p. or general apperance.All the glycosides studied were white crystalline compounds. Less than five per cent. of the ultraviolet light of λ254 mμ they absorb produces reaction; nevertheless, the apparatus and procedures available were adequate to study the reaction conveniently in monochromatic light of this wave-length.The absorption spectra, the products of photolysis, and the quantum yields, the latter based on the reducing material formed, lead to the hypothesis that the photochemical reaction is produced by an intramolecular transfer of absorbed energy from the aglycone to the hemiacetal oxygen bridge which is the reactive center. The efficiency of this transfer is, as expected, greater for benzyl than for phenylethyl glucosides but phenyl glucosides, contrariwise, are the least efficient.The structure and energy possessed by the glycoside outside the aglycone have no measurable effect on the efficiency of the photochemical reaction when followed by measuring the reducing material produced although they change up to one hundred thousand fold the rates of the thermal hydrolyses in acid.     

烯烃配位聚合复合载体催化剂研究进展

自从Ziegler-Natta催化剂发现以来,人们已对该类催化剂作了许多的研究,以MgCl_2为载体的高效催化剂的巨大成功,引起了人们对载体和过渡金属元素的相互作用的浓厚兴趣,近年来许多文献和专利报道了对复合载体催化剂的大量的研究成果,似有可能出现具有更优特性的高效催化剂. 本文就复合载体催化剂的研究现状作一综述.     

VBA编程与函数的应用

日常工作中有一些统计报告,其数据主要来源于清单,需要进行相关汇总及状态呈现。通常使用的手工统计、汇总比较繁琐,且极易出错。比较容易操作、快速得到数据统计结果的方法是：组合使用Visual Basic for Applications（V BA）编程与函数应用。     

基于J2EE的B/S架构高校图书管理信息系统的构建

分析了高校图书信息管理系统在图书管理中的重要性,并简要介绍了基于J2EE的B/S结构的特点及优势,重点论述了在此基础上实现的图书管理信息系统的体系结构与功能,最后用实例说明了基于J2EE的图书管理信息系统的实现过程。     

Molecular design revitalizes the low-cost PTV-polymer for highly efficient organic solar cells

Developing photovoltaic materials with simple chemical structures and easy synthesis still remains a major challenge in the industrialization process of organic solar cells (OSCs). Herein, an ester substituted poly(thiophene vinylene) derivative, PTVT-T, was designed and synthesized in very few steps by adopting commercially available raw materials. The ester groups on the thiophene units enable PTVT-T to have a planar and stable conformation. Moreover, PTVT-T presents a wide absorption band and strong aggregation effect in solution, which are the key characteristics needed to realize high performance in non-fullerene-acceptor (NFA)-based OSCs. We then prepared OSCs by blending PTVT-T with three representative fullerene- and NF-based acceptors, PC₇₁BM, IT-4F and BTP-eC9. It was found that PTVT-T can work well with all the acceptors, showing great potential to match new emerging NFAs. Particularly, a remarkable power conversion efficiency of 16.20% is achieved in a PTVT-T:BTP-eC9-based device, which is the highest value among the counterparts based on PTV derivatives. This work demonstrates that PTVT-T shows great potential for the future commercialization of OSCs.     

Unleash electron transfer in C–H functionalization by mesoporous carbon-supported palladium interstitial catalysts

The functionalization of otherwise unreactive C–H bonds adds a new dimension to synthetic chemistry, yielding useful molecules for a range of applications. Arylation has emerged as an increasingly viable strategy for functionalization of heteroarenes which constitute an important class of structural moieties for organic materials. However, direct bisarylation of heteroarenes to enable aryl-heteroaryl-aryl bond formation remains a formidable challenge, due to the strong coordination between heteroatom of N or S and transitional metals. Here we report Pd interstitial nanocatalysts supported on ordered mesoporous carbon as catalysts for a direct and highly efficient bisarylation method for five-membered heteroarenes that allows for green and mild reaction conditions. Notably, in the absence of any base, ligands and phase transfer agents, high activity (turn-over frequency, TOF, up to 107 h⁻¹) and selectivity (>99%) for the 2,5-bisarylation of five-membered heteroarenes are achieved in water. A combination of characterization reveals that the remarkable catalytic reactivity here is attributable to the parallel adsorption of heteroarene over Pd clusters, which breaks the barrier to electron transfer in traditional homogenous catalysis and creates dual electrophilic sites for aryl radicals and adsorbate at C2 and C5 positions. The d-band filling at Pd sites shows a linear relationship with activation entropy and catalytic activity. The ordered mesopores facilitate the absence of a mass transfer effect. These findings suggest alternative synthesis pathways for the design, synthesis and understanding of a large number of organic chemicals by ordered mesoporous carbon supported palladium catalysts.     

暗物质晕中星系的配置

基于杨小虎的博士论文《宇宙大尺度结构的统计研究》中第4部分内容整理缩写而成。讨论如何利用星系－星系的弱引力透镜观测来获得星系光度－暗物质晕质量之间的关系;并介绍建立的条件光度函数模型,在这个模型中我们预言了给定质量的暗物质晕中所能形成的不同光度的星系的概率。这些结果给出了讨论星系形成理论中各种物理过程的判据。基于这个模型还预言了一些宇宙中光的分布行为：如宇宙中超过一半的光是来自质量小于1012太阳质量的暗物质晕中。     

超细Ni—（Co）—B非晶态合金的XPS研究

非晶态合金可用作催化新材料．本文用ＸＰＳ方法表征了Ｎｉ－Ｂ和Ｎｉ－Ｃｏ－Ｂ超细非晶态合金，并结合其对ＣＯ加氢的反应性能，初步解释了表面物种及状态与催化活性的关系     

The study of the turnover of MIS professionals—The gap between Taiwanese and US societies

There are two issues relating to the turnover of MIS professionals that remain largely unexplored in the literature: (1) the relationship between the turnover and career anchors of MIS professionals; and (2) the role played by national culture in this relationship. Due to the fact that MIS professionals often process significant information by means of specific technical skills in organizations, high turnover rates among these professionals create problems for organizations. Traditionally, MIS professionals have been considered different from other professionals. Therefore, identifying MIS professionals’ motivation for job change and resolving problems they encounter may lead to a reduction in the turnover rate of these professionals in organizations. In this study, 353 MIS professionals in Taiwan were interviewed to identify their career anchors and motivation for job change. The result indicates the value of exploring a new category of anchor—“learning motivation”. The result also suggests that the anchor of greatest concern for these professionals is lifestyle, followed by organizational stability and learning motivation. The finding of this study differs from those made in a US context, where service is ranked top. Finally, this study posits three propositions related to career anchors and cultural factors across different ages.     

Ane electron beam system to fabricate integrated circuits

The economics of integrated circuits makes it likely that the highest possible circuit densities will be attempted in manufacture. Reasons are given for the use of electron beams instead of light for the masking procedures in making integrated circuits. The best total system will consist of two major subsystems. One will be a scanning electron microscope (SEM) fitted with scan controls and a digital mask generating capability. The other is an electron image projection system (ELIPS) to make integrated circuits at economical manufacturing rates. The two subsystems are linked by the fact that the SEM constructs the high resolution photocathode for the ELIPS. Predictions are made for future developments.     

耕地资源社会价值测算方法探讨——以山西省柳林县为例

本文以山西省柳林县耕地资源为研究对象，从剖析耕地资源社会价值的构成入手，按照耕地资源的社会功能，运用分解求和法、替代法、影子价格法等方法，分别从基本生活保障、农民失业保障、社会稳定等对耕地资源进行了价值测算。结果表明：柳林县耕地资源的社会价值总量为152.52×10⁸元，是该县当年耕地征用价格的10倍多，说明耕地具有巨大的社会价值，并在耕地资源总价值中占有重要的地位。从社会价值的构成来看，基本生活保障价值(E_b)占55.16%；失业保障价值(E_e)占20.57%；社会稳定价值(V_w)占24.27%，可见基本生活保障价值是耕地社会价值的重要组成部分，表明耕地资源承担着保障农民生存的巨大任务。从与该县当年耕地征用价格比较分析得出，每公顷耕地的基本生活保障价值和失业保障价值分别是其征用价格的5倍和2倍，说明当前耕地转用过程中，耕地资源的社会保障价值被低估。因此，本文提出提高耕地资源转用的社会成本是有效保护耕地资源和提高非农建设用地效率的有效措施。     

Droplet based microfluidic fabrication of designer microparticles for encapsulation applications

Developing carriers of active ingredients with pre-determined release kinetics is a main challenge in the field of controlled release. In this work, we fabricate designer microparticles as carriers of active ingredients using droplet microfluidics. We show that monodisperse droplet templates do not necessarily produce monodisperse particles. Magnetic stirring, which is often used to enhance the droplet solidification rate, can promote breakup of the resultant microparticles into fragments; with an increase in the stirring time, microparticles become smaller in average size and more irregular in shape. Thus, the droplet solidification conditions affect the size, size distribution and morphology of the fabricated particles, and these attributes of the microparticles strongly influence their release kinetics. The smaller the average size of the microparticles is, the higher the initial release rate is. The release kinetics of drug carriers is strongly related to their characteristics. The understanding of this relationship enables the fabrication of tailor-designed carriers with a specified release rate, and even programmed release to meet the needs of applications that require a complex release profile of the active ingredients.     

Mn/BaCO3催化剂上乙腈与甲醇选择性合成丙烯腈的研究

采用X射线衍射（XRD）和程序升温脱附（TPD）考察了Mn／BaCO3、Mn／KCl-BaCO3和Mn／CeO2-BaCO3催化剂的物相及其表面酸碱性;同时考察了乙腈与甲醇选择性合成丙烯腈的催化性能。结果表明,随着Mn负载量的增加,Mn／BaCO3催化剂对乙腈甲基化制丙烯腈的活性呈提高趋势,其中Mn（20％）／BaCO3催化剂对丙烯腈的选择性最高,收率最大。添加CeO2、KCl对催化剂的活性和选择性均起到抑制作用。NH3-TPD、CO2-TPD结果表明,加入CeO2和KCl后,催化剂表面的酸中心数目与碱中心数目都有所减少,表明催化剂的活性与表面酸碱性有着密切的联系。