含DMIT配体配合物的结构与导电性

本文描述了含DMIT(4,5-二硫基-1,3-二硫杂环戊烯-2-硫酮)配体配合物的含成和导电性,讨论了其各个结构层次及其与导电性的关系。Ni、Pd、Pt、的DMIT导电配合物的分子结构特征是平面构型和离域π电子态,晶体结构特征是配位阴离子堆砌成各种形式的、导电能力不同的分子柱和分子层,作为非导电组元的平衡离子对导电性也有重要影响。     

液相色谱－电致化学发光检测系统的检测性能研究

使用几种常见的反相液相色谱介质和４种多环化合物对液相色谱交流电致化学发光检测系统的性能进行了测试，结果表明：检测器对４种化合物的检测限均可达到２．０ｎｇ，线性范围达３个数量级。     

The behaviour of the negative-branch unstable resonator with an aperture inside

The negative-branch unstable resonator with an aperture inside the cavity at one conjugate image point is studied. The analysis shows that there is only one unique wave existing. The behaviour of the cavity depends only on the magnification and Fresnel numberN ₁.     

Novel Photoinduced Electron Transfer Reaction of N-methylphenothiazine in Carbon Tetrachloride

PhenothiazinederivativeshaveattractedmuchinterestforalongtimeduetotheirdiversechemicalandbioIogicalproperties,aswellasmedicalaPplicationsl.Theradicalcationofphenothiazinesisbelievedtobeinvolvedinthebiotransformationofphenothiazinedrugs2andnumerousstudieshavethusfocusedonthegenerationandreactionsofphenothiazineradicalcations3-6.WereporthereinanovelphotochemicalreactionofN-methylphenothiazineincarbontetrachloridewhichcoupIestwoparentmoleculeswitheliminationofonemethylgroup(Schemel).Resultsandd…     

Progress in Molecular Chaperone Regulation of Heat Shock Protein 90 and Cancer

Heat shock protein 90 (HSP90) is a member of genetically conserved heat shock protein family. As an important molecular chaperone in eukaryotic cells, HSP90 plays a key regulatory role in maintaining cellular protein homeostasis. HSP90 clients encompass a wide range of proteins, thus HSP90 is involved in diverse biological process. With the deeper study, it is found that HSP90 takes an important part in the development and metastasis of cancer, and has become a promising target for the study of anticancer biology. In this review, the progress of HSP90 as molecular chaperone and its relationship with cancer are discussed.     

Non-constant Diffusion Behavior for CO<Subscript>2</Subscript> Diffusion into Brine: Influence of Density-Driven Convection

A graphically-based analysis method used to characterize the diffusion process of carbon dioxide (CO₂) into brine conventionally assumes a constant diffusion coefficient. However, this study found that the assumption is not valid: an inflection point appeared in the calculated dimensionless pressure versus time curve separating the whole diffusion process into unsteady and steady stages, with each stage corresponding to different mechanisms. The unsteady stage, which accounts for the majority of the dissoluble CO₂ diffused into the brine, has hitherto always been neglected in calculating the diffusion coefficient. In this study, a pseudo-diffusion coefficient, which considers both the natural convection effect caused by fluid circulation due to density difference and molecule diffusion driven by the dissolved CO₂ concentration gradient, is proposed to characterize the unsteady stage of the diffusion process. Results from 21 pressure decay experiments indicate that the pseudo-diffusion coefficient of the unsteady stage varies directly with environment’s temperature and inversely with the brine concentration and pressure. The pseudo-diffusion coefficient varied in the range of 10^?8–10^?7 m²·s^?1, while the diffusion coefficient reported in the literature vary in the lower range of 10^?10–10^?8 m²·s^?1. The up to three orders of magnitude difference in the diffusion coefficients representing different diffusive mechanisms testifies to the importance of the unsteady stage in the diffusion of CO₂ in brine. This higher range of variation for the pseudo-diffusion coefficient now incorporating the unsteady stage has also the side effect of introducing higher uncertainties into the prediction of the concentration distribution in CO₂ sequestration calculations.     

纳米钒铬复合氧化物的溶剂热合成、表征及催化2,6-二氯甲苯氨氧化反应（英文）

甲基芳烃气相氨氧化反应制备对应的芳香腈被认为是丙烯氨氧化制备丙烯腈之后化工领域又一重大进展,芳香腈是重要的精细化学品,广泛应用于医药、农药、颜料、染料、橡胶、光电材料等领域.其中2,6-二氯甲苯氨氧化反应制备2,6-二氯苯腈是特别重要的反应,2,6-二氯苯腈工业上可用于制备高效除草剂、杀菌剂及各种特种工程塑料;然而相较于其它的甲基芳烃,2,6-二氯甲苯由于甲基邻位有两个较大位阻且较强吸电子的氯原子影响,甲基活性较低,较难发生氨氧化反应,原料转化率和产品收率均较低.本课题组一直致力于发展高活性和选择性的氨氧化催化剂以及有效的策略实现甲基芳烃高效转化为芳香腈,我们曾以硅胶负载的钒磷氧化物(VPO/SiO_2)和钒铬氧化物(VCrO/SiO_2)为催化剂,成功实现了2,6-二氯甲苯氨氧化反应制备2,6-二氯苯腈.钒铬复合氧化物(VCrO)具有广泛的应用,可用于多相催化、气体传感、能量储存等领域.VCrO通常通过高温固相反应制备,然而一般得到的是混合相,产品形态和颗粒大小也不能很好控制;当用于氧化或氨氧化反应时,需要较高的反应温度,原料也容易发生过度氧化,导致积碳及活性降低.我们以V_2O_5和CrO_3为原料,在醇或者醇水溶液中于180℃进行溶剂热反应制备了无定形的VCrO前驱体,然后将前驱体在不同温度下氮气气氛中煅烧,产品通过粉末X射线衍射、透射电镜和X射线光电子能谱等进行表征.当以甲醇或甲醇水溶液为溶剂热反应介质,并且前驱体700℃进行煅烧后,产品为纯的正交晶系CrVO4纳米晶相;当以甲醇为溶剂时,CrVO_4晶相的尺寸大约为500 nm;而改为甲醇水溶液为溶剂时,产品尺寸急剧减小到50 nm以下,而且通过改变甲醇和水的体积比分别为10:1,5:1,1:1和1:5时,CrVO_4纳米晶相的尺寸从50 nm逐渐减小到30,20和10 nm,能够进行有效调控.据我们所知,这是首次合成纯的CrVO_4纳米晶相.我们以该纳米CrVO4为催化剂催化2,6-二氯甲苯氨氧化反应制备2,6-二氯苯腈,在335℃的相对较低温度下反应,原料转化率为84%,产品收率为75%;进一步升高温度到390℃,原料转化率为99%,产品收率可达81%.在所有已报道的二元复合氧化物催化剂中,纳米CrVO_4显示了最高的催化活性,主要归功于它较小的粒子尺寸、较大的表面积和更多暴露的活性中心     

Catalytic effects of [Ag(H2O)(H3PW11O39)]3− on a TiO2 anode for water oxidation

A [H₃Ag^I(H₂O)PW₁₁O₃₉]^3?-TiO₂/ITO electrode was fabricated by immobilizing a molecular polyoxometalate-based water oxidation catalyst, [H₃Ag^I(H₂O)PW₁₁O₃₉]^3? (AgPW₁₁), on a TiO₂ electrode. The resulting electrode was characterized by X-ray powder diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Linear sweep voltammetry, chronoamperometry, and electrochemical impedance measurements were performed in aqueous Na₂SO₄ solution (0.1 mol L^?1). We found that a higher applied voltage led to better catalytic performance by AgPW₁₁. The AgPW₁₁-TiO₂/ITO electrode gave currents respectively 10 and 2.5 times as high as those of the TiO₂/ITO and AgNO₃-TiO₂/ITO electrodes at an applied voltage of 1.5 V vs Ag/AgCl. This result was attributed to the lower charge transfer resistance at the electrode-electrolyte interface for the AgPW₁₁-TiO₂/ITO electrode. Under illumination, the photocurrent was not obviously enhanced although the total anode current increased. The AgPW₁₁-TiO₂/ITO electrode was relatively stable. Cyclic voltammetry of AgPW₁₁ was performed in phosphate buffer solution (0.1 mol L^?1). We found that oxidation of AgPW₁₁ was a quasi-reversible process related to one-electron and one-proton transfer. We deduced that disproportionation of the oxidized [H₂Ag^II(H₂O)PW₁₁O₃₉]^3? might have occurred and the resulting [H₃Ag^IIIOPW₁₁O₃₉]^3? oxidized water to O₂.     

PPC-based Reactive Hot Melt Polyurethane Adhesive(RHMPA)——Efficient Glues for Multiple Types of Substrates

Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals and materials. Poly(propylene carbonate)(PPC) is an emerging CO_2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive(RHMPA) based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics(PC, PMMA, ABS) and metals(aluminium, steel), which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process(up to 270 °C). The study is expected to expand the applications of PPC and provide a new type of CO_2-based renewable and eco-friendly materials.