基于反应时间的中间视觉道路照明功率密度分析及显色性能研究

给出了一种在人眼中间视觉条件下道路照明光源安全节能性能分析的研究方法.通过构建基于中间视觉行车行为反应时间模拟测试系统,建立了人眼中间视觉条件下的光视光效模型,获得了中间视觉下的光视光效曲线.并通过该模型,给出了基于照明功率密度LPD的光源节能性评价方法.从色度学理论出发,选用Luv均匀颜色空间,基于显色指数的光源显色性评价分析计算方法,探讨了不同主波长光源的相对光谱功率分布变化对光源颜色的影响,建立了光源主波长与显色指数的函数关系表达式,可计算获得人眼敏感度与光源颜色各个波长点的关系.对上述方法进行了反应时间模拟测试实验和道路照明图像清晰度计算实验验证,数据分析与计算结果表明,在中间视觉条件下,以540～ 550 nm为主波长的白绿色照明光源的功率密度和显色性最佳.     

Studies on the Molecular Chain Conformation Stability of Aminated Konjac Glucomannan

Konjac glucomannan （KGM） was aminated by 2-chloroethyl-amine （CEA） as reagent so as to study the influence of concentration of CEA （based on the amount of KGM）, concentration of NaOH, reaction time and temperature on the extent of amination. And the molecular simulation technology was adopted to analyze the conformation stability of aminate （AKGM）. The results indicate that when the amount of CEA is higher, the extent of amination is higher. The optimum concentration of NaOH, reaction time and temperature are 10% NaOH, 70 ℃ and 45 rain, respectively. IR shows KGM is successfully aminated. The conformation of AKGM is in a random clew-like shape.     

Synthesis and Crystal Structure of 10-（3,4-Dichlorophenymethylidyne）-9,10-dihydrofluorene

A novel compound of 10-(3,4-dichlorophenymethylidyne)-9,10-dihydrofluorene (C20H12Cl2, Mr = 323.20) was synthesized via Knoevenagel reaction under microwave irradiation (500 w) within short reaction time (8 min), giving a high yield of product (87%). Its structure was determined by IR, 1H NMR, MS, elemental analysis and X-ray diffraction. The crystal of the new compound is of monoclinic system, space group P21/c with a = 12.8781(13), b = 16.5067(16), c = 7.4656(7), β = 103.567(2)o, V = 1542.7(3)3, Z = 4, Dc = 1.392 g/cm3, μ = 0.413 mm-1, F(000) = 664, R = 0.0569 and wR = 0.1342 for 3355 observed reflections with I > 2σ(I). The crystal structure involves a conjugated system which shows an olefin structure.     

多元醇法合成具有不同长径比的棒状LiFePO_4/C材料(英文)

以三价铁盐为铁源,采用多元醇还原法在低温下制备出了具有不同长径比的棒状LiFePO4材料.通过X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、循环伏安(CV)、交流阻抗谱(EIS)和恒电流充放电测试等手段分析了不同回流反应时间下制备出的前驱体和最终的LiFePO4/C样品.结果表明:回流反应时间对LiFePO4的形貌和特性有明显的影响.通过把回流反应时间从4 h延长至16 h,材料的形貌由不规则的短棒状颗粒变为规则的长棒状颗粒,且棒的直径明显变小.当回流反应时间为10 h时,样品复合了多种形貌,有利于电子的传输,在低倍率下具有优秀的性能,0.1C放电比容量为163 mAh g-1;当回流反应时间为16 h时,样品具有最大的长径比,有利于锂离子的扩散,在高倍率下具有良好的性能,1C、3C、5C、10C、20C倍率下放电比容量分别为135、125、118、110、98 mAh g-1,循环性能良好,几乎无衰减.     

Ceric ammonium nitrate supported HY-zeolite：An efficient catalyst for the synthesis of 1, 8-dioxo-octahydroxanthenes

Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.     

Rapid and efficient synthesis of new chiral aromatic amide molecular tweezers under solvent-free conditions using microwave

An efficient and simple method for the synthesis of new chiral aromatic amide molecular tweezers by irradiation with microwave under solvent-free conditions has been developed.Its main advantages are short reaction times.good conversions and the environmentally friendly nature of the process.     

用原子荧光法测定食品中总砷的经验介绍

由于氢化物原子荧光法具有方法简单、精密度好、灵敏度高、线性范围宽等优点,已在土壤、食品、化妆品等砷含量的测定中得到广泛应用.对该法测定食品总砷过程中还原剂与砷标准的反应时间与荧光强度值之间的关系进行了探讨,得出其最佳反应时间.     

H_6P_2W_（18）O_（62）á18H_2O： A green and reusable catalyst for one-pot synthesis of pyrano[4,3-b]pyrans in water

A convenient,effcient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot,three-component reaction of 4-hydroxy-6-methylpyran-2-one,aldehydes and malononitrile in water using H6P2W18O62á18H2O as catalyst.Reusability of the catalyst and reaction media,short reaction times and easy isolation of products are some added advantages of the present methodology.     

Distereoselective one-pot synthesis of pyrimidopyrimidines using sulfated tin oxide as a reusable catalyst： An extension of Biginelli-type reaction

The Biginelli-type compounds 4,5,8a-triarylhexahydropyrimido[4,5-d]pyrimidine-2,7（1H,3H）-diones were synthesized by a one-pot three-component reaction using sulfated tin oxide as a reusable catalyst. This method has the advantages of high yields, short reaction time, simple starting materials and reusability of catalyst for several times.     

纤蛇纹石纳米管制备及表征

采用水热合成法成功制备纤蛇纹石纳米管,并通过改变前躯体MgO和活性纳米SiO₂的培烧温度及反应时间等因素得到材料制备的最佳条件,利用XRD、TEM等手段对合成样品进行表征。结果表明:前躯体MgO的焙烧温度、SiO₂的焙烧温度及二者的反应时间等都能影响纤蛇纹石纳米管的合成。在本实验条件下,600℃焙烧得到的MgO和500℃焙烧得到的活性纳米SiO₂在反应时间为48h时合成的纤蛇纹石纳米管结晶完美,分散性好,轮廓清晰、完整,管长200—800nm,最长可达1000nm以上。