颜料色浆的选择对外墙涂料耐候性的影响

探讨色浆的选择对外墙涂料色漆耐候性的影响因素。重点讨论色浆类型的选择对性能的影响,同一种颜色用不同的复合色浆对耐候性的影响,色浆与调色基础漆配方设计对耐候性的影响以及墙面基材对保色性的影响。     

Deactivation of the metal and acidic functions for Pt, Pt-Sn and Pt-Sn-K using physically mixed catalysts

The effect of K addition on the amount and dispersion of carbon deposition on metal sites and support sites was investigated on a physical mixture for hexane dehydrogenation. TPO, BET and ESR experiments were used for characterization. The K addition significantly decreases catalyst deactivation involving the amount of coke deposits and the density of carbon radicals on the metal and support sites because of ensemble and electronic effects, especially on the metal sites. Coke on the metal sites associated with carbonaceous species rich in hydrogen is less polymerized than coke on the support sites, corresponding to a more graphitic-like carbon.     

An interpretation on the origin of the specular reflectance change caused by the submonolayer formation of foreign metals on some precious metal electrodes

The optical properties of foreign metal submonolayers formed on Au, Ag, Cu, Pt and Pd electrodes through the underpotential deposition have been investigated by specular reflectivity measurement. Based on the spectral characteristics, 14 adsorbate-substrate systems were classified into 2 groups. The first group, involving Bi on Au, Cu on Au, Pb on Au, Tl on Au, Tl on Ag and Cd on Cu, is characterized by the similarity of the optical properties of the adsorbed metal in the submonolayer to those of bulk metal. The first monolayer was found to form through several submonolayer stages, in which the optical constants are slightly different from each other. In the second group, involving Cd on Au, In on Au, Sn on Au, Ag on Pt, Bi on Pt, Cu on Pt, Pb on Pt and Bi on Pd, the spectra of submonolayer observed experimentally differ from those calculated with the assumption that the optical properties of adatom and substrate are the same as those of corresponding bulk metal. The difference in the work functions between adsorbate and substrate materials in this group is larger than those in the first group.From these findings, some considerations were made to interpret the origin of the specular reflectance change due to the presence of metal adlayer on the electrode surface. The results allow a tentative conclusion that the reflectivity change is predominantly attributed to the optical properties of the adsorbed submonolayer, but at the same time the work function of the substrate and the interband transition in visible should also be taken into consideration.     

热镀锌板的镀层成分对其表面电泳漆膜抗石击腐蚀性能的影响

研究了热镀锌板的镀层成分对其表面电泳漆膜抗石击腐蚀性能的影响。结果表明,经过合金化退火得到的GA板镀层中含有一定量的Fe,镀层较未经合金化退火的GI板硬。GA板镀层表面疏松多孔,电泳漆膜能够充满其缝隙或凹陷之处,固化后在界面区产生了类似勾键作用的机械作用力。因此,GA板与电泳漆膜的附着力优于GI板,石击处的扩蚀速率小于GI板。     

水合氧化铝阻燃EPDM/PP的性能研究

用氧指数测定和力学性能测定方法研究了水合氧化铝 ( ATH)的用量及粒径对共混物性能的影响。结果表明 ATH对 EPDM/ PP有一定的阻燃作用和消烟作用 ,但使其拉伸强度和断裂伸长率降低。随其用量增加和粒径变小 ,阻燃效果提高 ;粒径对阻燃性能的影响随用量增大影响也增大。少量使用 ATH时 ,粒径对拉伸强度影响不大 ,但对断裂伸长率影响明显 ;随用量增大 ,粒径对拉伸强度和断裂伸长率的影响也增大。     

对二甲苯/间二甲苯在KX和CaX上的吸附平衡和动态吸附性能

通过静态吸附实验,测定了对二甲苯、间二甲苯在分子筛KX和CaX上的吸附速率曲线及吸附等温线;动态吸附穿透实验测定了对二甲苯/间二甲苯混合液在固定床中的连续流出曲线。结果表明,对二甲苯、间二甲苯在CaX上的静态饱和吸附量和动态穿透吸附量均高于KX,但CaX对对二甲苯的吸附选择性不及KX;Langmuir吸附等温线方程可以很好地拟合对二甲苯、间二甲苯在CaX上的等温线;二级吸附速率方程可以较好地描述对二甲苯、间二甲苯的吸附动力学行为。     

甲酸在钛基纳米多孔网状铂电极上的电化学氧化

将水热法和电解过程相结合，制备出一种新型的钛基纳米多孔网状铂电极(nanoPt)，它具有特殊的网络状结构及巨大的表面积. 循环伏安曲线表明,在碱性溶液中，甲酸在nanoPt上的氧化电流密度远远大于在多晶Pt上的电流密度，其氧化峰电流几乎是后者的100倍；恒电位电解时，甲酸在nanoPt上的氧化电流开始时随时间的增加而增加，随后达到稳定，其稳定电流也明显高于多晶Pt；在nanoPt上甲酸的非线性现象出现的电流密度范围要比在多晶铂上的宽. 多次循环扫描和长时间电解实验表明. 这种钛基nanoPt结构稳定，催化剂颗粒不易脱落，有可能作为一种新型的燃料电池阳极材料而得到应用.     

Interaction of vitamins and minerals

Several nutrients are known to act on the metabolism of other nutrients and also of some non-nutrient substances. The nutritional importance that may be attributed to these interrelationships depends on the levels considered to be physiological for each nutrient, and on their maintenance at acceptable levels in tissues for the defense of the organism. Interaction of vitamins and minerals has been described in several metabolic situations and continues to be investigated by many authors. This interaction occurs in different ways, i.e. starting from the action of vitamins on mineral metabolism, from the action of both types of nutrients in the protection of the organism, and from the action of minerals on vitamin metabolism. The most significant example of vitamin action on mineral metabolism is the role played by vitamin D in calcium and phosphorus metabolism. The interrelationship of vitamin C and some minerals is also discussed, with emphasis on its relationship with iron. With respect to the synergistic action of vitamins and minerals in the defense of the organism, we comment on the main data reported on the biochemical-physiological role of vitamin E and its interaction with selenium. Finally, in reference to the action of minerals on vitamin metabolism, we point out the interaction existing between vitamin A and zinc. Data observed by the author at the experimental level in laboratory animals are reported on the possible interaction of niacin, vitamin B6 and zinc.     

一些含硫、含氮化合物在卤化银成像过程中的作用

采用在曝光前后用不同浓度的化合物溶液分别处理硫增感立方乳剂样品方法,观察它们在感光特性上的差别,从而判断这些化合物在卤化银成像过程的不同阶段各自所起的作用．本工作中所选用的化合物有1-苯基-5-巯基四氮唑(PMT),6-硝基苯并咪唑(硝酸盐),5-硝基苯并咪唑,5-硝基吲唑,4-羟基-6-甲基-1,3,3a,7-四氮茚(TAI)和硫代乙酰胺．结果表明：PMT在一定的浓度范围内对潜影的形成有促进作用,但对显影有抑制作用;6-硝基苯并咪唑和5-硝基苯并咪唑的情况相似,对潜影的形成无显著影响,而对显影的抑制作用明显;5-硝基吲唑不仅对潜影的形成有明显阻滞作用,而且对显影也有抑制作用;TAI则对潜影的形成有明显的促进作用,对显影的影响较小;硫代乙酰胺在弱酸性介质中对潜影的形成有显著阻滞作用,对显影也有-定的抑制作用,但对灰雾的增长十分显著．     

不锈钢化学着色研究

研究了不锈钢在H2SO4-CrO3体系中化学着色，探讨了除油、抛光、活化、前处理工艺对着色过程的影响及不同前处理对着色膜的形态、微观组织、均匀性、光亮度和重现性等的影响。同时研究了在化学着色液中加入添加剂对着色过程和色膜的影响。在前述研究的基础上探讨了最为可行的着色工艺。     

Effect of Additives on the Physicochemical and Catalytic Properties of Oxide Catalysts in Selective Oxidation Reactions

This paper is a survey of the main facts and concepts concerning the effect of additives on the structure and physicochemical and catalytic properties of oxide catalysts in selective oxidation reactions. The phenomena occurring in monophasic and supported mixed oxides containing the additives, including modification of structure, solid state reactions, segregation, defect formation, and spill-over of the reactants, are briefly described. The effect of additives on acid--base and redox properties, and on their bearing on catalytic performance are discussed, with particular emphasis on alkali metal additives. The perspectives of further studies on the problem are proposed.     

几种活性炭表面酸性基团的测定及其对吸附性能的影响

考察了测定活性炭表面酸性基团方法的影响因素，测定了几种活性炭表面酸性基团的数量，初步研究了苯酚和苯甲酸在活性炭上的吸附与活性炭表面酸性基团的数量、种类之间的关系，结果表明：苯酚和苯甲酸在活性炭上的吸附在相当程度上受活性炭表面酸性基团的数量与种类的影响；苯酚的吸附量，随活性炭单位表面上酚羟基和羧基数量的增加而降低；而苯甲酸的吸附则与炭表面的酸性基团总量有关。     

汽车空调行业ODS替代品的需求与预测

本文对中国汽车空调行业随轿车工业的发展而迅速发展及汽车空调CFC-12替代计划的实施做了简单的介绍,并就汽车空调ODS淘汰过程中的替代品HFC-134a和润滑油的变化进行了分析和需求量的预测。     

Ammoximation of ketones on titanium silicalite. A study of the reaction byproducts

In the new EniChem process cyclohexanone oxime is directly synthesized by ammoximation of cyclohexanone with ammonia and hydrogen peroxide on titanium silicalite catalyst. The ammoximation reaction is suitable for the synthesis of several oximes by reaction of the corresponding ketones with ammonia and hydrogen peroxide on titanium silicalite. New results on ketones ammoximation and on reaction byproducts are reported. The effect of some reaction parameters on the oxime yield and on byproducts formation is discussed.     

三聚磷酸二氢铝对氨气的吸附动力学研究

在真空干燥器中,加入一定量待测气体的水溶液,保持真空干燥器中待测气体浓度恒定。利用此装置研究了氨气浓度、三聚磷酸二氢铝吸附大气和水蒸气后,对三聚磷酸二氢铝吸附氨气动力学的影响。结果表明,三聚磷酸二氢铝吸附氨气,可用一级动力学方程和Elovich动力学方程模型描述;氨水浓度对吸附量和平衡吸附时间有显著影响;三聚磷酸二氢铝吸附空气后,对吸附量和平衡吸附时间无影响;三聚磷酸二氢铝吸附水蒸气后,对吸附量和平衡吸附时间均有影响。     

集料中黏土质泥及其对混凝土性能的影响

混凝土是应用广泛的建筑材料,其中集料是混凝土的重要组成部分.目前集料生产状况表明其不可避免含泥.泥会对混凝土诸多性能产生影响,其中泥的重要组分黏土对混凝土性能产生的影响最大.本文介绍了泥的来源,代表性黏土矿物的结构与性质,含泥量和泥的矿物性质对混凝土工作性能、力学性能以及其它性能的影响,以及泥对水泥水化的影响,并对其原因进行一定程度的探讨.指出了泥应从矿物性质角度对其界定,这一界定对实际工作中集料含泥量的判定和泥对混凝土性能影响以及采取必要措施具有一定的参考价值.     

Methyl Jasmonate Application Induces Increased Densities of Glandular Trichomes on Tomato, <Emphasis Type="Italic">Lycopersicon esculentum</Emphasis>

This study was designed to address whether applications of methyl jasmonate (MJ) or Benzothiadiazole (BTH) to cultivated tomato, Lycopersicon esculentum, induced elevated densities of defense-related glandular trichomes on new leaves. Four-leaf tomato plants were sprayed with MJ, BTH, or control solutions, and the density of type VI glandular trichomes on new leaves was subsequently determined at 3, 7, 14, 21, and 28 d. At 7, 14, and 21 d, the density of type VI glandular trichomes on new leaves was significantly higher on MJ-treated plants than on BTH- or control-treated plants. At 7 and 14 d after treatment, the mean density of glandular trichomes on new leaves of MJ-treated plants was ninefold higher than on leaves of control-treated plants. We observed entrapment of immature western flower thrips in trichomes on MJ-treated plants at higher rates than on BTH or control plants. Studies to evaluate potential trade-offs between reductions in pest populations by increased trichome density and possible negative impacts of trichome induction on biological control agents are needed.     

Influence of subphase on the orientation of helical peptides at interface

Boc-(l-Leu-Aib)_n-OBzl (n=8, 12, 16; OBzl represents benzyl ester) was spread on water or a mixture of water and methanol (1/1 v/v) and the orientation of the helical peptides on subphase was investigated by FTIR-reflection-absorption spectroscopy. When the peptides were spread at a liquid phase on subphase, the peptides took a vertical orientation, which was not attainable by compression of peptide monolayers initially spread at a gas phase on subphase. However, the peptide monolayers on water could not be transferred on gold with keeping the vertical orientation. On the other hand, when the peptides were spread on a mixture of water and methanol, the orientation of helical peptides was closer to vertical than that on water and the monolayers were transferred repeatedly on gold to form multilayers with a vertical orientation. The suppression of orientation change upon transfer of the peptide monolayer is considered to be due to reduction of electrostatic interaction between the peptide and the image dipole when the peptide is spread on a mixture of water and methanol.     

河北冬小麦和夏玉米施用化肥品种结构分析

20 0 0年和 2 0 0 2年对河北农户冬小麦和玉米施用肥料品种结构的调查结果表明 ,施肥中普遍存在重冬小麦而轻夏玉米的现象。冬小麦基肥主要是磷酸二铵 ,追肥主要是尿素 ;夏玉米追肥用量高于基肥 ,主要品种是尿素 ;磷酸二铵和三元复合肥则是基肥的主要品种。提高河北省冬小麦、夏玉米的肥料利用率 ,一方面要指导农民科学施肥 ,平衡区域施肥量 ;另一方面化肥企业也应针对不同农作物的特点 ,开发、生产适宜的肥料品种     

High performance liquid chromatography of oxygenated cholesterols and related compounds

Twenty-four oxygenated cholesterols and structurally related compounds were analyzed by high performance liquid chromatography with silicic acid column and various mobile phases. Hexane–propanol was superior to hexane/tetrahydrofuran and hexane/ethyl acetate for the separation of oxygenated cholesterols. The retention volumes of oxygenated cholesterols depended on the characteristics of the substituting group, its position of substitution, as well as its orientation. The effect of various functional groups at different positions on cholesterol molecules, in general order of decreasing retention volumes, were: hydroxy on the ring, carbonyl on the ring, epoxy on the ring, hydroxy on the side chain, and carbonyl on the side chain. Synergistic effect of multiple hydroxyl substitutions on cholesterol was observed.