醇盐水解法合成ZSM-5沸石

用正硅酸乙酯（ＴＥＯＳ）冰解作硅源、三氯化铝作铝源合成了ＺＳＭ－５沸石,并和传统的水玻璃作硅源合成ＺＳＭ－５法进行了比较。用ＸＲＤ、热重／差热分析、红外光谱和正己烷吸附等对实验产品进行了表征。醇盐水解法比传统方法结晶速度快,可缩短合成时间。新法合成的ＺＳＭ－５沸石结晶度高、憎水性强、晶粒易于取向生长,对合成沸石膜非常有利。     

干粉合成中氟离子对ZSM—5沸石的结构定向作用

考察了Ｎａ２Ｏ－ＳｉＯ２－Ａｌ２Ｏ３－ＥＤＡ干粉体系中是否加入ＮａＦ以及加入量对产品物相及结晶度的影响。结果表明,当反应体系不加ＮａＦ时,产物为结晶度高的单一晶相的ＺＳＭ－３５沸石,而体系中加入ＮａＦ时,产品中有ＺＳＭ－５沸石物相出现,而且随着ＮａＦ加入量的增加,产品物相完全转化为具有很高结晶度的单一相ＺＳＭ－５沸石。说明氟离子对干粉体系中ＺＳＭ－５沸石的生成具有明显的结构定向作用     

不同结构母体对制备钛沸石的影响

以ＺＳＭ－５，ＺＳＭ－１１，β，Ｙ，ＺＳＭ－１２和ＺＳＭ－４８型沸石为体进行气固相同晶取代，考察了母 体对钛进入沸石骨架难易程度的影响。结果表明，以ＺＳＭ－５，ＺＳＭ－１１和β型沸石为母体，钛较易进入沸石骨架，而以Ｙ，ＺＳＭ－１２和ＺＳＭ－４８型沸石为母体，钛很难进入沸石骨架。     

沸石分子筛选择吸附焦化苯中的噻吩

对Ｘ、Ｙ、Ｍ、ＺＳＭ－ ５、Ｓｉｌｉｃａｌｉｔｅ－Ⅰ沸石分子筛选择吸附焦化苯中噻吩的性能进行了考察,结果表明：ＺＳＭ－ ５ 和Ｓｉｌｉｃａｌｉｔｅ－Ⅰ分子筛具有明显的选择吸附性能。通过对ＺＳＭ－ ５ 分子筛进行Ｃｕ２ ＋ 离子交换及表面硅烷化处理改性,能在一定程度上提高选择吸附性能,并认为沸石分子筛选择吸附性能与表面羟基（ＳｉＯＨ、ＳｉＯＨＡｌ） 的酸性及沸石孔道特征有密切的关系。     

一种气相合成Ｓilicalite—1沸石膜的新方法

由于在分离和催化领域的潜在应用前景，沸石膜近年来受到人们的广泛重视，制备沸石膜的方法很多，如原位水热合成、微波合成、电金属沉积、嵌入法等等，９０年代以来，由于可减少昂贵的模板剂用量，以及能在不同载体上合成沸石膜等优点，蒸汽相合成法（ＶＰＴ）受到关注^[1~3]，通常采用浸渍方法或正硅酸乙酯（ＴＥＯＳ）的水解在载体上形成一层致密的无定形凝胶作为引入的硅源，随即在有机模板剂和水的蒸汽相中转晶得到沸石膜，自１９９２年Ｄong等^[1]首先采用ＶＰＴ方法合成ＺＳＭ－５和ＺＳＭ－３５沸石膜以来，已经成功制备了多各结构类型的沸石膜。     

ZSM—35分子筛的合成及模板效应的研究

以１，６－己二胺为模板剂合成了ＺＳＭ－３５分子筛，通过对比ＺＳＭ－３５、ＺＳＭ－５和丝光沸石的合成条件，采用化学组成分析、热重分析及＾１３ＣＮＭＲ等技术研究了１，６－己二胺的模板效应。结果表明，二者均对ＺＳＭ－３５有较好的模板作用，而１，６－己二胺对ＺＭＳ－５的模板效应更佳。     

模板剂对ZSM—35沸石合成及其物化性能的影响

本文分析了乙二胺和正丁胺为模板剂，在水热体系Ｎａ２Ｏ－ＳｉＯ２－Ａｌ２Ｏ３－Ｈ２Ｏ中合成了ＺＳＭ－３５沸石，并利用ＸＲＤ，ＳＥＭ，ＩＲ及ＣＯ加氢反应手段考察了其物理化学特性。结果表明，模板剂对ＺＳＭ－３５沸石的合成，结构，形貌，红外振动，稳定性及催化性能有显著的影响作用。     

HZSM-5沸石上焦化苯的精制脱硫

研究了用ＺＳＭ－５沸石催化脱除焦化苯中噻吩的方法。通过对不同温度下噻吩在ＺＳＭ－５沸石上的吸附和反应的考察以及红外光谱表征，发现在较低温度下，噻吩通过氢键可逆地吸了会在酸性中心上，吸附在强Ｂ酸中心上的噻吩则部分发生反应生成类似硫醇和硫醚的物种，随着温度的提高，一些不稳定的硫化物分角，并伴有Ｈ２Ｓ气体的生成。     

轻烃在改性ZSM-5催化剂上转化成芳烃与低碳烯烃的选择性控制

研究了Ｃ２－Ｃ９烷烃在不同的改性ＺＳＭ－５沸石上的反应规律。过渡金属离子改性的ＺＳＭ－５沸石显示了较高的芳烃选择性，芳烃的选择性还取决于改性金属离子的脱氧能力并可通过预硫化得到改进。     

不同来源的钛硅沸石的孔结构,酸性和催化性能

用气固相类质同晶取代和水热方法合成了Ｔｉ－ＺＳＭ－５和ＴＳ－１沸石，对它们的组成、孔结构、酸性和催化活性进行了比较。以季铵盐为模板剂水热合成的无铝ＴＳ－１沸石骨架Ｔｉ含量高，表面无强酸位，且随骨架Ｔｉ含量增加，沸石晶内由缺陷造成的二次孔数量增多。类质同晶取代的Ｔｉ－ＺＳＭ－５沸石骨架Ｔｉ含量有限，样品内尚保留部分骨架Ａｌ，沸石表面强弱酸位同时存在。增加沸石骨架Ｔｉ含量和晶内二次孔对提高苯酚过氧化氢     

结构因子的析因子形成

在X射线结晶学中,结构因子表示为 F_(hkl)=Σ j f_jexp[2πi(hx_j+ky_i+lz_j)] (1)式中h、k、l表示衍射指标,f_j表示晶胞中第j个原子的散射因子;(x_j,y_j,z_j)表示第j个原子的坐标,求和遍及晶胞中的所有原子。因为衍射线的强度I_(hkl)正比于结构因子绝对值的平方,即I_(hkl)∝|F_(hkl)|~2所以在晶体结构测定中式(1)用于衍射强度的计算。但是,由于式(1)中     

Heavy metal accumulation by selected plant species along the national highway: a case study of Udaipur,Rajasthan, India

ABSTRACT

A detailed research was conducted to find out the heavy metal accumulation by plant species at the roadside. Bioconcentration, bioaccumulation and translocation factors were estimated in 10 individuals of each investigating plant species. The plant and soil samples used in the research were collected along the National Highway-76 from Chittorgarh to Udaipur, Rajasthan, India. The concentration of cadmium and lead in roadside soil, plant roots, stems and leaves shows a correlation. The highest bioconcentration factor of Cd and Pb was 0.22 ± 0.04 and 0.13 ± 0.02 estimated in Bougainvillea spectabilis Willd. The highest translocation factor of Cd was 1.30 ± 0.50 in Pongamia pinnata L., and the highest translocation factor of Pb was 1.63 ± 0.45 estimated for Nerium oleander L. The average concentrations of Cd and Pb were 11.35 ± 1.60 and 223.70 ± 68 mg kg^?1 in investigated roadside soil. The average concentrations of accumulated Cd and Pb in B. spectabilisWilld. were 2.38 ± 0.49, 1.97 ± 0.51, 3.07 ± 0.78 and 29.34 ± 7.82,18.96 ± 5.62, 37.75 ± 12.93 mg kg^?1 in roots, stems and leaves, respectively. The decreasing order of bioaccumulation factor of cadmium in plants was B. spectabilis Willd.>Butea monosperma (Lam.) Taub>Calotropis procera (Ailton) Dryand>N. oleander L.>P. pinnata L. The decreasing order of bioaccumulation factor of lead in plants was B. spectabilis Willd.>P. pinnataL.>B. monosperma (Lam.) Taub>C. procera (Ailton) Dryand>N. oleander L. The B. spectabilis Willd. was identified as a rhizofiltration tool of heavy metals such as Cd and Pb with higher bioconcentration factor. P. pinnata L. for Cd and N. oleander L. for Pb were revealed for phytoextraction technology with high translocator factor to accumulate and eliminate these toxic elements from soil.     

Automatic window factor analysis—A more efficient method for determining concentration profiles from evolutionary spectra

An algorithm called automatic window factor analysis (AUTOWFA) is developed for the purpose of determining, efficiently and automatically, the concentration profiles of the spectroscopically active components present in evolutionary processes, such as chemical titration, chromatography and kinetics. The method not only yields windows and profiles in agreement with those reported in the literature, but also reveals components not detected by precursor techniques. The method, however, has not been optimized and may require user interaction to fine-tune the windows.     

A new approach to predict the formation of 3D hybrid organic-inorganic perovskites

Recently, hybrid organic-inorganic perovskite (HOIPs) materials are used to enhance the power conversion efficiency of the solar cells. The tolerance factor (TF) and octahedral factor (μ) are widely used to predict the formation of three-dimensional (3D) HOIPs structures. However, in some of the cases (e.g. CH₃NH₃GeI₃ (MAGeI₃) [TF = 1.06, μ = 0.33] NH₂CHNH₂GeI₃ (FAGeI₃) [TF = 1.14, μ = 0.33] and CH₃C(NH₂)₂GeI₃ (ACGeI₃) [TF = 1.17, μ = 0.33]), these factors could not predict the formation of HOIPs structures. Thus, we have introduced a new factor based on the HOMO-LUMO energy gap of the organic cations, metal cations, anions, and volume of the organic cations. We have tested and utilized the HOMO-LUMO energy gap factor (β) on 403 ABX₃ combinations. The factor β successfully predicts and differentiate the perovskite and non-perovskite materials. Further, we also observed that for the formation of HOIPs structure, volume of the organic cation should also be in the range of 20 to 46 cm³/mol. Based on the newly reported factor, we have also designed some new organic cations which may form a 3D HOIPs structure.     

Integral of the boltzmann factor

A new approximation is proposed to the integral of the Boltzmann factor:

影响离子导电高分子材料性能的内因与外因

材料分子设计离不开结构与性能的关系。分析内因与外因两方面影响因素对材料功能特性的影响有助于优化功能材料的结构。本文以离子型导电功能高分子材料为例,详细分析了各种因素对材料电导率的影响,为离子型导电功能高分子材料的结构设计提供依据。     

Proteomic characterization of plasma‐derived clotting factor VIII–von Willebrand factor concentrates

Proteomic methods were used to identify the levels of impurities in three commercial plasma‐derived clotting factor VIII‐von Willebrand factor (FVIII/VWF) concentrates. In all three concentrates, significant amounts of other plasma proteins were found. In Octanate and Haemoctin, two concentrates developed in the 1990s, the major impurities identified were inter‐α inhibitor proteins, fibrinogen and fibronectin. These two concentrates were also found to contain additional components such as clotting factor II (prothrombin) that are known activators of FVIII. In Wilate, a recently developed FVIII/VWF concentrate, the amount of these impurities was significantly reduced. Batch‐to‐batch variations and differences between three investigated products were detected using iTRAQ, an isotope labeling technique for comparative MS, demonstrating the potential value of this technique for quality control analysis. The importance of thorough proteomic investigations of therapeutic FVIII/VWF preparations from human plasma is also discussed.     

时域反射光谱法研究酰胺-醇混合物的介电驰豫

Using time domain reflectometry (TDR),dielectric relaxation studies were carried out on binary mixtures of amides (N-methylformamide (NMF) and N,N-dimethylformamide (DMF)) with alcohols (1-butanol,1-pentanol,1-hexanol,1-heptanol,1-octanol,and 1-decanol) for various concentrations over the frequency range from 10 MHz to 10 GHz at 303 K. The Kirkwood correlation factor and excess dielectric constant properties were determined and discussed to yield information on the molecular interactions of the systems. The relaxation time varied with the chain length of alcohols and substituted amides were noticed. The Bruggeman plot shows a deviation from linearity. This deviation was attributed to some sort of molecular interaction which may take place between the alcohols and substituted amides. The excess static permittivity and excess inverse relaxation time values varied from negative to positive for all the systems indicating that the solute-solvent interaction existed between alcohols and substituted amides for all the dynamics of the mixture.