多级孔分子筛的合成研究进展

多级孔分子筛由于其高的外比表面积、良好的传热及扩散性能,在重油裂化、异丙苯制备、加氢异构化等催化反应中显示出优良的性能。综述近年来多级孔分子筛的合成进展,着重介绍多级孔分子筛的合成方法、合成机理及性质特点。     

合成耐火原料及其展望

本文论述了合成耐火原料的性能、工艺技术和应用。对合成耐火原料的质量等级和原料优化进行了讨论。     

不同方法合成铈掺杂介孔分子筛的结构性能

以硅酸钠、硝酸铈铵为原料,十六烷基三甲基溴化铵为模板剂,分别在微波辐射和水热条件下,合成稀土元素铈掺杂的介孔分子筛（CeMCM-41）。采用X射线粉末衍射（XRD）、透射电子显微镜（TEM）、紫外–可见分光光度计（UV–vis）和N2吸附-脱附等技术对合成的样品进行表征,研究了2种不同方法合成的CeMCM-41的介孔有序性和结构性能。结果表明：在2种不同的合成条件下,成功合成出铈掺杂的MCM-41介孔分子筛,其比表面积高于800 m2/g。合成条件影响着所合成的介孔材料的结构性能。     

SAPO-34制备方法研究进展

综述了近年来SAPO-34分子筛制备方法的研究进展,介绍了超声处理、微波加热等技术在SAPO-34分子筛制备过程中的应用及原位合成、固相合成、气相合成和离子液体合成等新型制备方法。指出在不影响SAPO-34分子筛催化性能的前提下,降低合成低成本、减少环境污染、节水降耗是SAPO-34分子筛今后的开发方向。     

含钛分子筛合成研究的新进展

本文综述了具有独特氧化性能的含钛分子筛合成研究新进展,探讨了在合成TS-1和TS-2沸石中不同硅源、钛源、模板剂及合成路线对其结构性能的影响,评述了Ti-MCM-4、Ti-TMS、Ti-β型等含钛沸石的合成技术。     

聚丙烯酸减水剂合成及性能的研究

研究了一种聚丙烯酸减水剂的合成及性能,采用溶液聚合的方法制得了产物,并对合成中影响减水剂性能的主要因素进行了探讨,对试制产品进行了性能试验,得出了一种最佳配方及合成工艺。结果表明:该产品具有掺量低、减水率高、混凝土性能优良等特点。     

马来酸酐三元共聚物阻垢剂的合成及性能

以马来酸酐(MA)、乙酸乙烯酯(VA)和丙烯酸(AA)为单体,过硫酸铵为引发剂,异丙醇为分子质量调节剂,合成了水溶性马来酸酐三元共聚物阻垢剂PMVA。通过研究各合成条件对聚合物阻垢性能和生物降解性能的影响,得到最佳工艺条件。并对最终产品进行多方面性能测试,结果表明:PMVA具有优良的碳酸钙、硫酸钙阻垢分散性能,较强的稳锌性能和良好的可生物降解性能。     

绿色阻垢剂聚环氧琥珀酸的合成及阻垢性能研究

以顺丁烯二酸酐为主要原料,合成了无氮、无磷和生物降解性好的绿色阻垢剂聚环氧琥珀酸(PESA)。分析了各种合成条件对PESA阻垢性能的影响,得出了合成PESA的最佳工艺条件。采用静态阻垢法考察了阻碳酸钙垢的性能,研究结果表明产物在循环冷却水系统中具有优异的阻垢性能。     

碳热还原法低温合成SiC粉末的研究

研究了碳热还原法低温合成SiC粉末。对SiC-C系统进行了热力学分析以指导合成工艺。研究了合成温度、保温时间、SiO2/C配比等对合成SiC粉末的影响,并对合成SiC粉末的成型性能和烧结性能进行了研究,在此基础上制定出较为合理的合成工艺制度。由此制得晶粒尺寸约为0.1um,二次粒径小于0.5um的烧结性能较佳的β-SiC粉末。     

用于合成金刚石的炭源材料实验及其选择

叙述了不同炭源材料合成金刚石的效果。讨论了炭源材料影响合成金刚石效果的因素。在对多种炭源材料性能测试与分析的基础上，指出了合成金刚石炭源材料的优选原则。     

多菌灵在土壤中的降解及其生态环境效应

多菌灵是国内外广泛使用的一种茎叶喷洒类杀菌剂,过量施用或者喷施后降雨、灌溉会使多菌灵在土壤中累积。明确多菌灵在土壤中的降解转化过程以及对土壤生态环境的影响对于合理施用杀菌剂具有重要意义。综述了多菌灵在土壤中降解的影响因素以及对土壤微生物和氮素转化过程影响的研究进展。认为未来还需进一步加强多菌灵对微生物结构和组成的影响以及对土壤肥力和生态环境影响的综合评价等方面的研究。     

活性炭表面负载金属离子对其吸附苯并噻吩的影响

主要研究了活性炭表面负载不同的金属离子对其吸附苯并噻吩的影响.通过浸渍法分别将6种不同的过渡金属离子负载在活性炭表面上,用静态吸附法测定了苯并噻吩硫化物在改性活性炭上的吸附等温线,应用软硬酸碱理论分析和讨论了其吸附能力的差异.结果表明,活性炭表面负载Ag^＋、Ni^2＋、Cu^2＋或Zn^2＋离子,可提高活性炭吸附苯并噻吩硫化物的能力,而活性炭表面负载Fe^3＋或Co^3＋离子,反而降低了活性炭吸附苯并噻吩硫化物的能力,这主要是活性炭表面的酸碱性质发生变化.采用密度泛函数理论法计算结果表明,苯并噻吩的电负性χ为2.638,属软碱类物质;由于Ag^＋为软酸,活性炭负载Ag^＋离子,增加了其局部表面的软酸,从而增强了对苯并噻吩硫化物的吸附;由于Ni^2＋、Cu^2＋和Zn^2＋离子属交界酸,负载Ni^2＋、Cu^2＋、Zn^2＋离子增加了活性炭表面的交界酸,也在一定程度上提高了其表面对苯并噻吩硫化物的吸附;当活性炭表面负载了硬酸性Fe^3＋或Co^3＋离子,其局部表面硬酸增大从而降低了其对苯并噻吩的吸附.     

The effect of substituents on the adsorption of alkenes on (111) Pt and Pd surfaces: a theoretical study

The coordination modes of ethylene, propene, 1- and 2-butenes, 2-methyl-2-butene, and styrene on a Pt(111) or a Pd(111) surface have been compared on the basis of extended Hückel calculations. The presence of methyl substituents induces a uniform decrease in the binding energies of the alkenes, both on Pt and on Pd. The phenyl group yields the same result on Pt but, on the contrary, gives a stronger adsorption mode on Pd. The interpretation of these results is based on the balance between attractive and repulsive interactions, the role of the latter being predominant. This trend in binding energy is related to the decrease of the hydrogenation reactivity of olefins upon substitutionin the case of a competitive reaction.     

温度对均相化学反应的影响

本文对实际生产中温度的一般影响进行了分析,并分别就温度对单一反应和复合反应的影响进行了探讨。温度对单一反应的影响从可逆和不可逆反应两方面入手,可逆反应又从可逆吸热和可逆放热两方面进行分析。温度对复合反应的影响从平行反应和串联反应两个角度展开进行探讨。最后得出在各种情况下温度对反应的影响规律。     

Mechanisms of Reciprocal Regulation of Gonadotropin-Releasing Hormone (GnRH)-Producing and Immune Systems: The Role of GnRH,Cytokines and Their Receptors in Early Ontogenesis in Normal and Pathological Conditions

Different aspects of the reciprocal regulatory influence on the development of gonadotropin-releasing hormone (GnRH)-producing- and immune systems in the perinatal ontogenesis and their functioning in adults in normal and pathological conditions are discussed. The influence of GnRH on the development of the immune system, on the one hand, and the influence of proinflammatory cytokines on the development of the hypothalamic-pituitary-gonadal system, on the other hand, and their functioning in adult offspring are analyzed. We have focused on the effects of GnRH on the formation and functional activity of the thymus, as the central organ of the immune system, in the perinatal period. The main mechanisms of reciprocal regulation of these systems are discussed. The reproductive health of an individual is programmed by the establishment and development of physiological systems during critical periods. Regulatory epigenetic mechanisms of development are not strictly genetically controlled. These processes are characterized by a high sensitivity to various regulatory factors, which provides possible corrections for disorders.     

单颗粒和颗粒群研究的挑战

Numerical simulation of multiphase flows in processing equipment in industry with two-fluid models and Eulerian-Lagrangian approaches requires the constitutive equations describing the interactions between the dispersed phase of high concentration and the continuous phase. The status of research on the forces on dispersed solid and fluid particles is reviewed in this article. As compared with the knowledge on drag of single solid particles, study on particle swarms and on other forces is not sufficient to meet the demand of reliable and efficient numerical simulation of multiphase flows. Thus, thorough study on the particle swarms becomes the key to accurate multi-scale simulation of multiphase flows. Besides, the development of efficient algorithm dealing with the non-uniformity on both equipment and mesoscopic scales is recognized as an important issue to be resolved. The research topics in the near future are suggested.     

壳聚糖及其衍生物在烟草上的应用研究进展

综述了壳聚糖及其衍生物在卷烟降焦减害、烟草薄片生产、烟草病害防治和烟丝保润剂方面的研究进展,并探讨其在烟草上研究方法以及作为滤嘴添加剂的发展动向。     

Erythrocyte Deformability and Na,K-ATPase Activity in Various Pathophysiological Situations and Their Protection by Selected Nutritional Antioxidants in Humans

The physicochemical and functional properties of erythrocytes are worsened in a variety of diseases. Erythrocyte deformability refers to their ability to adjust their shape according to external forces exerted against them in the circulation. It is influenced by the functionality of the Na,K-ATPase enzyme, which is localized in their membranes. The proposed review is focused on knowledge regarding changes in erythrocyte Na,K-ATPase activity, and their impact on erythrocyte deformability in various pathophysiological situations observed exclusively in human studies, as well as on the potential erytroprotective effects of selected natural nutritional antioxidants. A clear link between the erythrocyte properties and the parameters of oxidative stress was observed. The undesirable consequences of oxidative stress on erythrocyte quality and hemorheology could be at least partially prevented by intake of diverse antioxidants occurring naturally in foodstuffs. Despite intensive research concerning the effect of antioxidants, only a small number of investigations on erythrocyte properties in humans is available in databases. It is worth shifting attention from animal and in vitro experiments and focusing more on antioxidant administration in human studies in order to establish what type of antioxidant, in what concentration, and in which individuals it may provide a beneficial effect on the human organism, by protecting erythrocyte properties.     

复合材料叶片结构设计中的几个关键问题探讨

风力发电技术作为新兴技术,欧美一些国家已发展到相当高的水平,我国风力发电近些年也发展迅猛。风力发电的关键技术之一是风力机复合材料叶片的设计与研制,涉及到空气动力学、结构力学、复合材料力学及成型工艺等。本文着重探讨复合材料叶片的结构设计中几个关键的问题,在广泛分析和研究国内外复合材料结构设计现有技术基础上,并结合实际的研究经验,对复合材料叶片结构设计中的材料选择、载荷工况、结构选型、铺层设计以及力学分析等关键环节进行探讨和分析,并给出可行的意见。     

部分水解聚丙烯酰胺在土壤上静态吸附的研究

采用静态吸附法研究了聚丙烯酰胺（PAM）在黑钙土和盐碱土上的吸附行为。测定了聚丙烯酰胺在土壤上的吸附等温线,考察了不同温度、pH值、离子强度对吸附的影响。结果表明：PAM在土壤上有很强的吸附亲和力,吸附等温线为Langmuir型,温度过高并不利于PAM在土壤中的吸附。pH值对PAM在土壤上的吸附有很大的影响,酸性环境土壤对PAM的吸附呈上升趋势,碱性环境土壤对PAM的吸附呈下降趋势,中性环境最利于盐碱土对PAM的吸附。电解质浓度影响PAM在土壤上的吸附,随着电解质浓度的增大,PAM在土壤上的吸附也增大。