多金属氧酸盐催化烯烃环氧化研究进展

综述了以过氧化氢为氧源,多金属氧酸盐催化烯烃环氧化的研究进展,尤其是针对基于多金属氧酸盐的反应控制相转移催化体系近年来的研究进展进行了详细阐述.     

大孔树脂-高速逆流色谱分离纯化薇甘菊中的黄酮类化合物

该文建立了大孔树脂-高速逆流色谱分离薇甘菊中黄酮类物质的方法。分离条件为:采用大孔树脂AB-8,洗脱液为50%（v/v）乙醇水溶液,高速逆流色谱溶剂体系为正丁醇-乙酸-水（4：1：5,v/v）。从薇甘菊中分离到4种黄酮类物质:槲皮素-3-O-芸香糖苷（纯度90.2%）、山奈酚-3-O-芸香糖苷（纯度98.55%）、木犀草苷（纯度98.33%）和紫云英苷（纯度99.23%）。建立的大孔树脂-高速逆流色谱方法简单、高效,可扩展应用于从其他植物中分离黄酮类物质。     

Solution processable reduced graphene oxide decorated ATO electrode for organic solar cells

A novel concept based on the use of solutions containing already qualified crystalline antimony-doped tin oxide SnO₂:Sb (ATO) nanoparticles has been developed. ATO nanoparticles are decorated by reduced graphene oxide (rGO) through a hydrothermal synthesis method. The electrical and optical properties of the graphene oxide films are investigated systematically. The sheet resistance (R _□) of the ATO–rGO films decreases with the increase in the rGO content in the precursor solution. The R _□ can be decreased after the ATO–rGO films annealing in the air for 1 h and can be further decreased by depositing Au on the surface of the films. The optimum property of the ATO–rGO film shows that the R _□ is 80 Ω/□ and the transmittance is about 70 %. The ATO–rGO films are used as the anode of the organic solar cells. The anode film impact on the performance of the devices is studied. Finally, the power conversion efficiency (PCE) of the device based on the poly-(3-hexylthiophene): [6, 6]-phenyl C61-butyric acid methyl ester (PCBM) blended is 1.85 %, and the PCE of the device based on the poly-benzo[1,2-b:4,5-b′] dithio-phene thieno[3,4-b] thiophene:PCBM blended is 3.4 %.     

附面层抽吸对高负荷扩压叶栅流动及负荷的影响

实验研究了低速条件下附面层吸除对某高负荷扩压叶栅流动及负荷的影响,测量得到了出口二次流速度矢量和型面静压分布,并对壁面做了罹迹流动显示.结果表明,抽吸低能流体有效抑制了分离流动,在分离点后采用较大吸气量时效果更好;吸气量越大,角区低能流体的积聚逐渐减弱,叶栅负荷随之增大,且叶展中部负荷的增加程度大于端部.     

采用直、弯静叶压气机时序效应实验研究

本文实验研究了采用直、弯静叶的某重复级低速压气机在不同时序位置时的总性能及横截面流场特性.在不同流量工况下对压气机整体性能及流场进行了详细测量.结果表明,采用正弯静叶的压气机时序效应相对较弱且喘振裕度有所增加;同时,在压比略有减小的前提下(0.1%级别),凭借消耗扭轴功的大幅F降(3%左右),效率在设计工况下最大可提高...     

Generation of a Plasma Waveguide with Slow-Wave Structure

Using the particle-in-cell simulations,we report an efficient scheme to generate a slow wave structure in the electron density of a plasma waveguide,based on the array laser-plasma interaction.The spatial distribution of the electron density of the plasma waveguide is modulated via effective control of the super-Gaussian index and array pattern code of the lasers.A complete overview of the holding time,and the bearable laser's intensity of the electron density structure of the plasma waveguide,is obtained.In addition,the holding time of the slow wave structure of the plasma waveguide is also controlled by adjusting the frequency of the array laser beam.Finally,effects due to ion motion are discussed in detail.     

Design of the readout electronics for the DAMPE Silicon Tracker detector

The Silicon Tracker (STK) is one of the detectors of the DAMPE satellite used to measure the incidence direction of high energy cosmic rays. It consists of 6 X-Y double layers of silicon micro-strip detectors with 73728 readout channels. It is a great challenge to read out the channels and process the huge volume of data in the harsh environment of space. 1152 Application Specific Integrated Circuits (ASIC) and 384 ADCs are used to read out the detector channels. 192 Tracker Front-end Hybrid (TFH) modules and 8 identical Tracker Readout Board (TRB) modules are designed to control and digitalize the front signals. In this paper, the design of the readout electronics for the STK and its performance are presented in detail.     

掺铬铝酸钇红色颜料的合成、结构和性能表征

研究了高温固相合成制备掺铬铝酸钇红色颜料的方法，着重考察了灼烧温度（1000-1400℃）、灼烧时间（1-2h）、主要原料配比（Al／Y：1：0．5—1：1．5，Cr2O3％：0．3％-5％）等实验条件对产物结构和色泽的影响。XRD等方法对样品进行的相态分析表明，主相为铝酸钇石榴石相；运用反射光谱对红色颜料的色泽进行了反射峰位和相关强度的表征。当Y2O3：Al2O3摩尔比为1：1，掺杂3％的Cr2O3作显色剂，在少量矿化剂存在时，在1300℃下灼烧1 h，得到了色坐标为x=0．577，Y=0．401的红色陶瓷颜料。     

Controlled Joint Remote Preparation of a Six-Qubit Cluster-Type State by Using GHZ States

A scheme for the controlled joint remote preparation of an arbitrary six-qubit cluster-type state by using only two sets of five-qubit GHZ states as quantum channel is proposed. In our scheme, Alice firstly performs two sets of two-qubit projective measurement according to the real coefficients and the complex coefficients of the desired six-qubit cluster-type state. Then, the controller Charlie must apply another two-qubit projective measurement according to the Alice’s measurement result. Finally, Bob can obtain the desired six-qubit cluster-type state according to an appropriate unitary operation. Our scheme can achieve unit success probability.

     

东亚北部地区气温的冬季-冬季再现特征研究

对东亚北部(40—50°N,100—130°E)区域1953—2012年大气温度的冬季-夏季-次年冬季(简称冬季-冬季)的季节变化特征进行了初步研究.结果表明:2008年以来,该区域的气温从低层至高层(1000—400 h Pa)连续三年出现冬季偏冷-夏季偏暖-次年冬季偏冷的典型特征,20世纪50—60年代亦有类似情况;而20世纪90年代则出现了与此相反的冬季偏暖-夏季偏冷-次年冬季偏暖的变化特征.将这种典型的气温季节变化特征定义为一种新的变化机理:冬季-冬季再现(WWR).根据1953—2012年的历年变化情况将这60年划分为四种不同的类型:负(正)冬季-冬季再现(negative/positive WWR)型和负(正)冬季-冬季非再现(negative/positive non-WWR)型.其中,气温表现为WWR型的年份共计23年,出现概率近40%,并且该WWR特征是相对独立于El Nio-南方涛动指数的变化而存在的.对不同类型年份的位势高度场、垂直速度场及其850 h Pa风场进行的合成分析表明:对于WWR型,高层(500 h Pa)至低层(1000 h Pa)的大气内部动力过程具有与气温相匹配的冬季-冬季的再现特征;而non-WWR型则没有出现类似的特征,从而在一定程度验证了WWR存在的可能性.WWR的提出为进一步开展当前全球增暖背景下冬季低温事件的频发提供了一个新的思路.