溶剂热法制备NaScF_(4):Yb^(3+)/Er^(3+)及其发光性能的研究

利用溶剂热法在油酸(OA),正辛醇(OC)及乙二醇(EG)三溶剂中成功制备出NaScF_(4):Yb^(3+)/Er^(3+)纳米颗粒。调节三种溶剂的不同比例观察对样品晶相、结构、尺寸及发光强度的影响。此外,我们使用了X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、荧光光谱仪对样品进行了表征。通过XRD证明在OA、OC、EG分别为16mL,12mL、4mL时成功合成出了纯相的NaScF_(4):Yb^(3+)/Er^(3+)纳米颗粒。SEM图进一步证明样品形貌均匀,分散性较好,粒径较小,颗粒尺寸为37.62±9.36nm。此外,样品的荧光光谱表明样品在980nm激光激发下能发射出红色荧光。因此,该方法下制备的NaScF_(4):Yb^(3+)/Er^(3+)尺寸较小,形貌较均匀,拥有强的红色发射且该材料有望用于生物成像、信息储存,防伪等领域。

三组分低共熔溶剂制备黄麻纳米纤维素的研究

为了实现黄麻落麻的高价值回收利用,将5种金属氯化物分别与氯化胆碱、二水合草酸复配形成三组分低共熔溶剂(3c-DES)制备黄麻落麻纳米纤维素,探究了不同金属氯化物的加入对制备纳米纤维素性能的影响。结果表明:加入ZnCl_(2)的3c-DES不适宜制备纳米纤维素,加入LiCl、FeCl_(3)·6H_(2)O、MgCl_(2)·6H_(2)O、AlCl_(3)·6H_(2)O形成的3c-DES可以制备出短棒状的纳米纤维素晶体;加入LiCl的3c-DES制备出纳米纤维素的尺寸相对较小,分布最为集中;加入FeCl_(3)·6H_(2)O的3c-DES制备纳米纤维素的热稳定性最好;加入AlCl_(3)·6H_(2)O的3c-DES制备纳米纤维素的结晶度最高,为81.61%;加入LiCl的3c-DES制备纳米纤维素产率最高,为70%。认为:加入不同金属氯化物形成的3c-DES会影响纳米纤维素的性能,其中加入LiCl、FeCl_(3)·6H_(2)O、AlCl_(3)·6H_(2)O制备纳米纤维素效果较好。

用三氧化铬-硫酸溶剂对黑色页岩铼-锇定年方法初探

讨论了铼-锇同位素稀释法测定黑色页岩年龄的溶样方式,比较了王水和不同温度下CrO3-H2SO4的Carius管溶样技术,通过改进流程将铼空白控制在10pg之内,并结合高灵敏度的电感耦合等离子体质谱分析手段,初步研究建立了一种用CrO3-H2SO4溶剂准确测定黑色页岩年龄的方法。

气相色谱法分析过氧化氢生产用含AR–TOP–TBU三元溶剂工作液组分含量

运用气相色谱仪建立了一种测定过氧化氢生产用含AR（重芳烃）–TOP（磷酸三辛酯）–TBU（四丁基脲）三元溶剂工作液组分含量的方法。采用DB–1701毛细管柱和火焰离子化检测器（FID）,以正十四烷作为标准物计算修正系数,优选测试条件。结果表明,该方法的回收率为95.5%-106.4%,相对标准偏差（n=4）〈3%,满足实际使用要求。

非三氯苯溶剂法合成铜酞菁

本文介绍了两种可用以代替三氯苯合成铜酞菁的有机溶剂，它们的价格较低，再生也较容易并可循环使用。实验中发现：在使用的时候，如仍用原来的三氯苯工艺在产品中会带有一种黄褐色杂质，它的存在严重影响了产品的质量，因此，必须改革原有的工艺才能得到高质量的产品。

无三苯溶剂型氯丁喷胶的研究

制备了无三苯 (苯、甲苯、二甲苯 )溶剂型氯丁喷胶 ,研究了混合溶剂组成、氯丁橡胶品种。

我国氯丁胶生产的现状、发展趋势与对策

评述我国氯丁胶生产现状与趋势，提出具体的发展对策。

攻克抽提装置“瓶颈”及抽提加工裂解汽油改造

本文主要阐述了抽提装置优化操作，在运行平衡的基础上，操作负荷由124v%提高至135v%，基本解决了其多年来芳烃联合装置中的“瓶颈”问题。并简单阐述了抽提装置加工裂解汽油的一些装置改造。

Lipase-catalyzed Kinetic Resolution of Racemic 1-Trimethylsilylethanol in Organic Solvent

The enantioselective esterification of racemic 1-trimethylsilylethanol with acids catalyzed by lipase in organic solvent was successfully performed. The influence of some factors on the reaction was investigated. Among the four lipases explored, Candida rugosa lipase (CRL) showed the highest activity and enantioselectivity. Octanoic acid was the best acyl donor among the eleven acids studied and n-hexane was the most suitable medium for the reaction. The optimum shaking rate and temperature were found to be 150r·min-1 and 20℃ to 30℃, respectively. The enantiomeric excess of the remaining (5)-(-)-1-trimethylsilylethanol was 93% when substrate conversion was 53% upon incubation of the reaction mixture at 30℃, 150r·min-1 for 12 h.

Modulating absorption band of triangular silver nanoplates in aqueous solvent and on substrates using tannin as reducing agent

Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin.It was found that both the amount of tannin and the small triangular silver nanoplate seeds added to the growth solution are the key factors to modulation absorption band of triangular silver nanoplates.The optical in-plane dipole surface plasmon resonance (SPR) bands of these Ag nanoplates can be tuned from 608 nm to 980 nm via tannin deoxidization method.The formation mechanism of triangular silver nanoplates was proposed.The tannin deoxidization method realizes a convenient modulation of the absorption band of Ag nanostructures within the visible near-infrared (IR) region both in aqueous solvent and on substrates under mild conditions.

Mathematical model and reaction mechanism of molybdenum and tungsten extraction with TRPO from peroxide solution

To understand the behavior of molybdenum and tungsten extracted by tri-alkyl phosphine oxide(TRPO)from peroxide solution,the extraction mechanism was studied by slope method and Raman and FTIR spectroscopy.The empirical formulas of molybdenum and tungsten extraction distribution ratio(D_(Mo)and D_(W))as functions of equilibrium pH,TRPO concentration and temperature were obtained by establishing mathematical models.Furthermore,the reliability of the empirical formula was verified in the H^(+)-W-Mo-H_(2)O_(2) solution.The results indicate that the calculated values of D_(Mo)or D_(W)were consistent with the experimental values.The apparent extraction equilibrium constants of molybdenum and tungsten wereK_(Mo)^(app)=8.51×10^(3)(0.74≤pH_(e)≤1.7),K_(Mo)^(app)=99.89×10^(3)(1.7<pH_(e)≤4.62)andK_(W)^(app)=2.65×10^(3)(0.92<pH_(e)<2.16)at 20°C,respectively.The main extraction complex of molybdenum or tungsten was[H_(2)(Mo or W)_(2)O_(3)(O_(2))_(4)(H_(2)O)_(2)]·2TRPO.These empirical formulas can be used to analyze and estimate the extraction and separation of Mo and W from low molybdenum and tungsten concentration solutions.

Effects of Surfactant on Zinc Recovery by Solvent Extraction during Leaching in HCl-FeCl_3 Solution

The effects of surfactant on the solvent extraction in leachingsphalerite were investigated. It is found that sodium dodecylsulfonate is the effective surfactant in improving the zinc recoveryfrom sphalerite in the aqueous FeCl_3-HCl-tetrachloroethylene system.Through the measurements of surface tension and viscosity of thesphalerite Slurry modified with different surfactants, it isconcluded that sodium dodecyl sulfonate in the concentration rang Of0.05 to 0.2 g·L^-1 can improve the viscosity of sphalerite slurry inthe water, decrease the surface tension of Leaching solution, preventthe aggregation of ore particles, and give very high zinc extraction.

配方精选

无三苯溶剂型氯丁喷胶A-30氯丁橡胶 50A-100氯丁橡胶

Spectroscopic Properties and Three-photon Absorption Induced Optical Limiting of Series of Novel Nonlinear Chromophores

Three novel nonlinear chromophores with symmetric D-π-D molecular structure and extended conjugated length were synthesized. Solvatochromism analysis shows great symmetric intramolecular charge transfer occurring in chromophores by the enhancement in the dipole moment between the ground and excited states. The properties of optical power limiting induced by three-photon absorption （3PA） are demonstrated. Large 3PA coefficients and the corresponding molecular cross sections as high as 10^-74 cm^6s^2 were obtained for nanosecond laser pulses at 1.06μm from nonlinear transmission measurements.

Measurement and correlation of solubility of trimethylolethane in different pure solvents and binary mixtures

The solubilities of trimethylolethane in butanol,methyl acetate,ethyl acetate as well as in mixed solvents of(methanol+ethyl acetate) and(ethanol+ethyl acetate) were measured with the gravimetric method in the temperature range from 283.15 K to 318.15 K under atmosphere pressure.The experiment results showed that the solubility of trimethylolethane increased with the temperature,or along with the concentration of methanol or ethanol in the solvents of(methanol+ethyl acetate) and(ethanol + ethyl acetate).In addition,the experiment values were correlated by the van't Hoff equation,Modi fied Apelblat Equation,λh Equation,CNIBS/R-K equation and Jouyban–Acree Model.The Modi fied Apelblat Equation provided the best fitting results of the solubility data of TME in the pure solvents while the CNIBS/R-K model showed the best estimation of the solubility in the binary solvent mixtures.Furthermore,the density functional theory(DFT) calculations showed that solubility in different solvents related to the strength of the interaction between the trimethylolethane and the solvent molecules.Finally,the standard molar enthalpy and molar entropy of trimethylolethane during the dissolving process was also calculated by Modi fied Apelblat equation in this work.

Studies on the Extraction of Gold (I) Cyanide by Quaternary Ammonium Salt Using ^(198)Au as Tracer

The solvent extraction of KAu(CN)2 from alkaline solution by quaternary ammonium salts (trialkyl-methylammonium chloride or cetyltrimethylammonium bromide) was investigated by means of 198Au radioactive tracer method. Various parameters, such as the gold (I) concentration in aqueous phase, the modifier, emulsification at the interface of two phases, and phase ratio used in the extraction of gold (I) were studied. The results demonstrate that almost all gold (I) in the aqueous phase was practically extracted into the organic phase. The water content in the organic phase decreased significantly with increase of gold (I) concentration using long chain alcohol as modifier, in contrast with the system with tributyl phosphate (TBP) as modifier. Emulsification at the interface of two phases decreases with an increase of modifier concentration in the organic phase or with the addition of a small amount of lysozyme into the aqueous phase. The method with 198Au tracer can be directly used to determine the Au(I) concentration both in aqueous and organic phases, which is especially suitable for the low concentration of Au(I).

Optimization of conjugated linoleic acid triglycerides via enzymatic esterification in no-solvent system

We compared four esterifiable enzymes. The lipase Novozym 435 possessed the highest activity for the conjugated linoleic acid esterification during the synthesis of triglycerides. The triglycerides were synthesized by esterification of glycerol and conjugated linoleic acid （CLA） in a no-solvent system using lipase catalysis. We investigated the effects of temperature, enzyme concentration, water content, and time on esterification. Enzyme and water concentrations of up to 1% of the total reaction volume and a system temperature of 60℃ proved optimal for esterification. Similarly, when the esterification was carried out for 24 h, the reaction ratio improved to 94.11%. The esterification rate of the rotating screen basket remained high （87.28%） when the enzyme was re-used for the 5th time. We evaluated the substrate selectivity of lipase （NOVO 435） and determined that this lipase prefers the 10,12-octadacadienoic acid to the 9,11-octadecadienoic acid.

Influence of Pressure and Temperature on the Velocity of a Turbulent Jet Flow 3D

To investigate the influence of pressure and temperature on the jet velocity of a three-dimensional flow was the main goal of this study. Using a precipitation chamber with approximate capacity of 600 mL, it was studied the thermodynamic behavior of supercritical carbon dioxide mixture, dichloromethane and grape seed extract via SAS （supercritical antisolvent process）. For the numerical solution, the Navier-Stokes equations were used along with the model of turbulence k-ε and Peng-Robinson equation of state with quadratic mixing rules of Van der Waals. The method of Chung was employed to determine the viscosity, thermal conductivity and mass diffusivity of the flow numerically solved through commercial code based on CFD （computational fluid dynamics）. Simulations for pressures between 80 bar and 160 bar and temperatures between 308.15 K and 318.15 K showed large variations in the jet velocity, an important property in the dynamic mixing process that involves the size, size distribution and particle morphology.