Determination of Partial Molar Volumes of EPA and DHA Ethyl Esters in Supercritical Carbon Dioxide

The use of supercritical fluids (SCFs) as solvents has been attracting widespread interest in the research and commercial applications. The study of partial molar volumes of solutes at infinite dilution in the near-critical region is of considerable fundamental importance, as these data reflects the interactions occurring between the solute and the solvent. Experimental measurements of partial molar volumes may be divided into two categories: direct and indirect methods. The direct methods…     

固体炭对一氧化氮低温催化解离还原反应的影响——Ⅱ.复合催化剂中铁在载体炭上化学形态的研究

用~(57)Fe穆斯堡尔谱研究了炭载型复合催化剂中铁化学形态随温度的变化,及各活性组分、助剂对铁化学形态的影响;并通过ESR谱考察了复合催化剂中不同活性组分对铁在载体炭表面电子特性的影响。研究结果表明,复合催化剂中各活性组分、助剂和载体炭与铁之间存在着强相互作用。在350～650℃,载体炭可将铁从Fe_2O_3还原到Fe_3O_4、FeO、α-Fe和生成炭化铁。活性组分Cu和助剂K可改变催化剂中铁周围的电子密度,促进铁在载体炭上从高价态向低价态还原。同时还发现催化剂中Na和Cr对铁有很强的助分散作用。     

Adsorption of metal halides from ethanol solutions by a 3-n-propylpyridiniumsilsesquioxane chloride-coated silica gel surface

3-n-propylpyridiniumsilsesquioxane chloride polymer, abbreviated as SiPy+Cl-, was used to coat a porous silica gel, SiO2, surface to form the chemically modified solid SiO2/SiPy+Cl-. The resulting polymer film was well adhered to the surface and presented an ion exchange capacity of 0.74 mmol g(-1). Metal halides, MClz [M=Fe(III), Cu(II), and Zn(II)], were adsorbed by the modified solid from ethanol solutions as neutral species by forming the surface anionic complexes described by the equation: mSiO2/SiPy+Cl-+ MClz <=> (SiO2/SiPy+)m[MCl(z+m)]m-, where the [MCl(z+m)]m- species adsorbed on the surface are FeCl4-, ZnCl4(2-), and CuCl4(2-). Accurate estimates of the specific sorption capacities and the heterogeneous stability constants of the immobilized metal complexes were determined with the aid of computational procedures.     

β沸石分子筛固体酸的制备及其在异丁烷和丁烯烷基化反应中的应用

以四乙基溴化铵(TEABr)为模板剂，硅胶为硅源，铝酸钠为铝源，采用水热晶化法合成β沸石．研究了其晶化温度、晶化时间、硅铝比、碱度、水含量等各种因素对晶化过程和产物性质的影响．得出适宜的初始凝胶组成为SiO2和Al2O3的比值在25-60之间，TEABr和SiO2的比值在0．32～0．4之间，OH^-和SiO2的比值在0．2～0．23之间，H2O和SiO2的比值在8．6～18．0之间．通过XRD，ICP，IR，SEM和NH3-TPD方法分别对样品的结构和性质进行了表征．烷基化反应的结果表明，β分子筛具有较为适宜的孔结构和反应活性．     

Detection of Tumor Necrosis Factor Gene by Piezoelectric Nucleic Acid Senosr

A piezoelectric nucleic acid sensor was constructed ofr detection of tumor necrosis factor gene.Two methods were employed for immobilization of nucleic acid probe on gold electrode of piezoelectric crystal.The results show that polyethyleneimine adbesion and glutaraldehyde cross-linking method has higher sensitivity,stability and selectivity than protein A method.The solid-phase nucleic acid hybridization of oligo unclecotides and tumor necrosis factor target gene sequence were monitorde using this sensor.Tumor necrosis factor gene sequence(580bp) was detected by this nucleic acid sensor for the first time.     

草酸镁二水合物的非等温热分解动力学

The thermal decomposition of the magnesium oxalate dihydrate in a static air atmosphere was investigated by TG-DTG techniques. The intermediate and residue of each decomposition were identified from their TG curve. The kinetic triplet, the activation energy E, the pre-exponential factor A and the mechanism functionsf（a） were obtained from analysis of the TG-DTG curves of thermal decomposition of the first stage and the second stage by the Popesou method and the Flynn-Wall-Ozawa method.     

熔融织构生长强磁浮YBCO超导块材的取向和结构

采用熔融织构生长法结合顶部Ｓｍ１２３籽晶技术，成功地制备了直径为２０ｍｍ的ＹＢＣＯ超导块材。该块材具有极强的磁性能。用Ｘ射线θ／２θ扫描和Φ扫描分析其结构表明，样品在三维方向上具有很强的择优取向，其ｃ、ａ、ｂ轴方向分别与Ｓｍ１２３籽晶的ｃ、ａ、ｂ轴方向一致，并具有类似单晶的结构特点。     

联苯甲酰双缩氨基脲硫氰酸根硝酸根混合阴离子配位钕(Ⅲ)配合物的合成与结构

合成了联苯甲酰双缩氨基脲硫氰酸根、硝酸根混合配位的钕(Ⅲ)配合物。在此配合物中只有1个链状配体,另有2个硫氰酸根、1个硝酸根和1个水分子参与配位。总配位数是9。晶体结构分析表明,该配合物晶体属三斜晶系,P空间群。晶胞参数a=10。866(2),b=13.687(3),c=15.433(3),α=98.75(4)°,β=107.64(5)°,γ=112.14(5)°。最终偏差因子R=0.075。用INDO方法计算结果表明:NCS对Nd(Ⅲ)的配位比=C基对Nd(Ⅲ)的配位强。     

用计算模拟方法研究Al_3P_4O_(16)~(3-)计量比的二维层状磷酸铝中的有机胺模板能力

将快速 Monte Carlo方法与分子动力学方法相结合 ,研究了不同种类有机分子在 Al3P4 O3- 1 6 计量比的二维层状磷酸铝形成中的模板能力 .依据主 -客体之间非键相互作用能 (包括范德华能、氢键能和库仑能 ) ,可合理地解释已知实验现象 ,并能有效地预测出适于形成某一特定无机层结构的有机胺模板剂 .通过选择理论预测的有机胺分子作为模板剂 ,成功地合成了二维层状磷酸铝化合物 Al3P4 O1 6 · 1 .5 H3NC6 H1 0 NH3.     

New Approaches to Coupling TLC with TOF-SIMS

JPC – Journal of Planar Chromatography – Modern TLC - A new hyphenated technique that enables coupling of thin-layer chromatography (TLC) with time-of-flight secondary-ion mass...