系列甘露糖醛酸寡糖的制备与鉴定

用酸降解法制备了系列甘露糖醛酸寡糖(聚合度2～8),并分析测定了寡糖的结构. 褐藻胶经部分酸水解,于pH=2.85处分级获得聚甘露糖醛酸. 继续用酸降解法降解聚甘露糖醛酸,经凝胶柱层析分离纯化,获得系列甘露糖醛酸寡糖. 用荧光标记糖电泳(FACE)对寡糖进行了分析,并用电喷雾离子化质谱(ESI-MS)、 核磁共振波谱(NMR)及红外光谱(FTIR)进行了结构表征. 本研究用酸降解法制备饱和甘露糖醛酸寡糖,用凝胶柱层析法分离获得系列聚合度的寡糖,为褐藻胶大分子构效关系研究和药物的筛选与发现提供了重要的基础资料.     

有机溶剂热生长技术制备硫族化合物及其光学特性的研究

以有机溶剂热生长技术(solvothermaltechnique)制备了半导体硫族化合物(CdS、ZnS、MoS₂)等纳米颗粒,采用XRD、TEM等技术对其结构进行表征.以ITO导电玻璃以及导电聚合物(PANI、PPY)膜为基底,将纳米颗粒涂布其上并以PL法研究其光学特性,实验结果表明:经修饰后,材料的荧光发射位置发生显著的变化.     

CO2加氢合成二甲醚的催化剂的制备

先采用均匀沉淀法制备出CuO—ZnO催化剂,然后以CuO—ZnO催化剂作为晶核采用水热合成法制备出CuO—ZnO／HZSM-5（氢型ZSM-5分子筛）复合催化剂．利用X射线衍射和氨程序升温脱附手段对复合催化剂进行表征,并应用于CO2催化加氢合成二甲醚的反应．研究结果表明,在相同的反应条件下,这种CuO—ZnO／HZSM-5复合催化剂与采用物理混合法制备出的复合催化剂相比具有更好的催化效果,不但提高了CO2的转化率、二甲醚的选择性以及二甲醚和甲醇的总选择性,同时还改善了催化剂的稳定性．     

丁烯-1异构化复杂反应动力学

MoBiP_1:8/SiO₂催化剂的X衍射实验证实存在BiPO₄物相,用吸附指示剂正丁胺滴定法测定了催化剂显中等强度酸性。催化剂上吸附吡啶的红外光谱实验证实催化剂存在质子酸和Lewis酸中心。用脉冲法测定了丁烯-1及丁烯-2的吸附热。     

Polymerization of cyclic derivatives of uracil and thymine

Cyclic derivatives of uracil and thymine were synthesized from their corresponding 1-(2′-chloroethyl) derivatives by dehydrochlorination. These compounds were found to undergo a variety of reactions, giving many valuable derivatives of uracil and thymine. The cyclic derivatives, as monomers, were polymerized with a cationic initiator by a unique ring-opening process. The polymerization proceeded by ring opening with isomerization of the pyrimidine ring to give a polymer in which pyrimidine rings were connected with ethylene between N-1 and N-3 or O-4 in the pyrimidine ring. The structure of these polymers was determined by nuclear magnetic resonance (NMR), ultraviolet (UV), infrared (IR), and mass spectra. The structure was affected by polymerization temperature.     

新型苯并咪唑衍生物的合成

以苯甲醛甘油缩醛和对甲基苯甲醛甘油缩醛为原料,采用次氯酸钠催化氧化法,制得2-芳基-4-羧基-1,3-二氧戊环中间体;中间体分别与邻苯二胺或N-甲基邻苯二胺反应,合成了4种新型苯并咪唑衍生物(3a~3d),收率为78.0%~80.5%,其结构经UV, ¹H NMR, ¹³C NMR, IR和HR-MS(ESI)表征。      

Microstructure of miscible polymer blends

The purpose of this work is to describe the application of new electron microscopy techniques to the study of polymer blends with very fine dispersion of phases (miscible blends). Blends of PVC with PMMA, PCL, POM and SAN were prepared by high temperature mixing on a two roll mill, or by solvent casting. Thin sections (or cast films) were investigated in the scanning transmission electron microscope and small phases were identified in most blends. The contrast was enhanced by electronic combination of bright and dark field signals, by an irradiation and staining technique and by differential mass loss. The specimens were further characterized by measurement of mass loss, resulting from electron beam damage. The non linear changes in the mass loss rate with concentration were interpreted as being influenced by partial solubility and molecular interactions.     

GD-MS法和ICP-MS法测定高纯铌中痕量元素

采用辉光放电质谱法(GD-MS)对高纯铌中Ta,Mo,W等痕量杂质元素进行了测试,并对GD-MS工作参数进行了优化,部分元素与采用电感耦合等离子体质谱法(ICP-MS)定量分析的结果进行比较,对某些元素含量差别较大的原因进行了分析,论述了Element GD辉光放电质谱仪的特点及其在痕量杂质分析上的优势。     

Synthesis and characterization of copolyesters of PET and substituted p-hydroxybenzoic acids

Random copolyesters of different compositions were synthesized by melt polycondensation of poly(ethylene terephthalate) and 3-bromo - and 3,5-dibromo-p-hydroxybenzoic acids. The copolymer compositions were determined by proton nuclear magnetic resonance spectroscopy. The thermal behavior of these copolyesters was investigated by differential scanning calorimetry. The glass transition temperature, crystallization temperature, and decomposition temperature were found to increase with increase in the paraoxybenzoate content of the copolyesters. The limiting viscosity number and the weight-average molecular weight were determined.     

Reversible charging of the ice-water interface. II. Estimation of equilibrium parameters

Equilibrium parameters characterizing the ice-water interface were obtained from electrokinetic and potentiometric data. The dependency of surface potential on pH was measured by the ice electrode. Electrokinetic zeta potentials were measured by electrophoresis. In the interpretation, the 1-pK and 2-pK concepts of the surface complexation model, developed for metal oxides, were used. The equilibrium parameters (constants of surface reactions) were determined. The results were confirmed by numerical simulations. Both 1-pK and 2-pK models fit the experimental data well.     

Application of capillary electrochromatography using macroporous polyacrylamide columns for the analysis of lignans from seeds of Schisandra chinensis

Capillary electrochromatography (CEC) using polymer-based monolithic stationary phase has been developed as a promising method for the determination of lignans of Schisandra chinensis. The columns were prepared by in situ copolymerisation of acrylamide, N,N'-methylenebisacrylamide, vinylsulfonic acid and lauryl acrylate in presence of poly(ethylene glycol) as a porogenic agent. The columns [33 cm (24.5 cm effective length) x 75 microm I.D.] were successfully used to analyse and quantify the major lignans in extract of the seeds of Schisandra chinensis. Good separations were achieved in less than 35 min. The calibration graphs were linear in the range 0.025-1.0 mg/ml of given lignan with correlation coefficients between 0.9951 and 0.9996. The inter-day reproducibility of the peak area were below 3.9% and the inter-day reproducibility of the migration time were below 4.2%. The results of quantitative CEC analyses were compared with those obtained by reversed-phase HPLC, the levels of schizandrin, gomisin A, gomisin N and wuweizisu C determined by CEC were in a good agreement with those determined by HPLC.     

二茂铁氨基化合物的合成

二茂铁与邻甲氧基苯甲酰氯反应生成邻甲氧基苯甲酰基二茂铁,再与一系列芳胺反应合成亚胺,最终还原为二茂铁氨基化合物,其结构均经元素分析、^1H NMR确证。     

聚类分析法研究化妆品的真伪

本文以活性炭吸附丝采集“永芳Ｆ真珠膏”的挥发性组份,用ＧＣ－９Ａ的气相色谱仪进行测定,对２４个真品进行Ｒ型聚类分析和因子分析,提取了１４个特征指标,并以Ｑ型聚类方式建立了鉴别“永芳Ｆ真珠膏”真伪的数学模型,用３个假冒产品和２个真品对模型进行验证,结果令人满意。     

Synthesis of Strontium Carbonate by the Induction of Microbiology

Spherical strontium carbonate was synthesized by the induction of microbial bacillus pasteurii at ambient temperature with strontium chloride and urea as the raw materials. The phase composition, particle size and morphology of the product were studied by XRD and SEM. The results indicated that the strontium carbonate synthesized by the induction of microbial bacillus pasteurii was of good dispersion and uniform particle size. The spherical strontium carbonate particles obtained by adding different control agents were constructed by numerous flakes or olive-shaped nano-particles. The products were orthorhombic according to their XRD patterns.     

污泥中常规生物指标的检测

介绍了污泥中三种常规生物检测指标,即细菌总数、粪大肠菌群和蛔虫卵的检测方法。污泥中细菌总数的检测采用平皿计数法,先将污泥样品稀释后选取2~3个适宜的稀释度进行培养;污泥中粪大肠菌群的检测采用多管发酵法,分别将稀释后的污泥混悬液接种于乳糖蛋白胨培养基和EC培养液中进行初发酵和复发酵实验;污泥中蛔虫卵的检测采用漂浮法,利用饱和硝酸钠溶液的比重大于蛔虫卵的原理,通过分离、离心、洗涤等步骤将样品中的蛔虫卵集中于载物玻片上镜检计数。文章对污水处理厂检测及排放污泥有一定的指导意义。     

Comparison of NAA and ICP-MS for the determination of major and trace elements in environmental sample

Summary Major and trace elements in soil and plant samples, including standard reference materials were determined by means of neutron activation analysis (NAA) and inductively coupled plasma-mass spectrometry (ICP-MS). The analytical procedure for NAA utilized dried powder samples. The concentration of iodine in soil samples was determined by radiochemical NAA. The irradiated samples were cooled and then counted with a Ge gamma-ray detector connected to a multi-channel analyzer. For ICP-MS analysis, the samples were decomposed by microwave digestion with an acid mixture. The concentration of I in the soil samples was measured by ICP-MS after separation by ignition. The analytical values for most elements in the environmental samples by both methods were in good agreement, whereas sample treatments were different. Measured value of Zr in the soil samples by ICP-MS was about 50% lower than that by NAA. It should be assumed that some minerals of Zr in soil particles were not entirely dissolved by the acid mixture. Analytical results of Cd for three different Cd levels in unpolished rice flour samples (NIES 10-a, b and c) determined by ICP-MS were in agreement with certified values. The concentration of Cd in the sample with the lowest Cd level, as determined by NAA with 57% counting error, was 3 times higher than the certified value.     

Supramolecular assembly of hydrophobized polysaccharides

Hydrophobized polysaccharides, which were partly substituted by hydrophobes such as cholesterol, formed a hydrogel nanoparticle by their self-assembly in water. The size, density and colloidal stability of the nanoparticle were controlled by changing the substitution degree of hydrophobes and the hydrophobicity. The hydrophobized polysaccharides were further functionalized by conjugation of cell-specific saccharide, thermoresponsive polymer or polyethylene oxide. The hydrophobized polysaccharides interacted with various soluble proteins or other molecular assemblies, such as monolayer, black lipid membrane, liposome and oil-in-water emulsion. Such supramolecular assemblies with hydrophobized polysaccharides were utilized in biotechnology and medicine.     

Preparation and Characterization of Nanocomposites of Carboxymethyl Cellulose Reinforced with Cellulose Nanocrystals

Summary: Cellulose nanocrystals (CNC) were extracted from Kraft pulp of Eucalyptus urograndis. The CNC were isolated by acid hydrolysis with H₂SO₄ 64% (w/w) solution, for 20 minutes at 45 °C. The morphology and crystallinity of the CNC were investigated by atomic force microscopy (AFM) and X-ray diffraction (XRD), respectively. The AFM image supports the evidence for the development of crystals of cellulose in nanometric scale. These nanoparticles were used as reinforcement material in carboxymethyl cellulose (CMC) matrix. Nanocomposites films were prepared by casting. The nanocomposites were characterized by thermal (TGA) and mechanical (DMA) analyses. A large reinforcing effect of the filler was observed. The tensile strength of nanocomposites was significantly improved by 107%, the elongation at break decreased by 48% and the thermal resistance increased slightly. The improvements in thermo-mechanical properties suggest a close association between filler and matrix.     

钌硫化合物的组成测定和氢还原动力学研究

用静态和动态库仑滴定法分别对元素合成的硫化钌和两种湿法沉淀的硫化钌进行了研究, 确定了硫化钌的组成和分子式, 阐明了化合物在高温被氢还原的动力学特性, 根据研究结果, 推测出非晶态的原始Ru2S3.10H2O具有RuS.RuS2.10H2O的结构。     

Influence of pyrogenic particles on the micromechanical behavior of thin sol-gel layers

Coatings based on sol-gel technology with different types of nanoparticles embedded into the sol-gel matrix were fabricated, and the resulting properties were investigated. Pyrogenic silica nanoparticles were added to the sol before coating. The silica particles varied in primary particle size and agglomerate size, and in their surface modification. The particles were wetted in ethanol and dispersed to certain finenesses. The difference in agglomerate size was partly caused by varying particle types, but also by the dispersing processes that were applied to the particles. The resulting coatings were examined by visual appearance and SEM microscopy. Furthermore, their micromechanical properties were determined by nanoindentation. The results show an important influence from the added nanoparticles and their properties on the visual appearance as well as the micromechanical behavior of the sol-gel coatings. It is shown that, in fact, the particle size distribution can have a major impact on the coating properties as well as the surface modification.