A bivariate response surface for growth data

We present a Mitscherlich-related response surface for two variables. The curve for one of the variables, with the other fixed is similar to a Mitscherlich curve, but the curvature changes as the other variable changes. This surface is useful for fitting growth and other responses to two nutrient treatments.     

三聚氰胺的改性及其应用

综述了三聚氰胺对脲醛树脂、酚醛树脂的改性以及改性三聚氰胺在涂料、板材等方面的应用。三聚氰胺可以和其它聚合物发生聚合反应,形成立体网状结构,提高聚合物的强度、韧性、阻燃性等。三聚氰胺可作为改性剂对许多聚合物进行改性,以提高其性能。     

Neurons Induce Tiled Astrocytes with Branches That Avoid Each Other

Neurons induce astrocyte branches that approach synapses. Each astrocyte tiles by expanding branches in an exclusive territory, with limited entries for the neighboring astrocyte branches. However, how astrocytes form exclusive territories is not known. For example, the extensive branching of astrocytes may sterically interfere with the penetration of other astrocyte branches. Alternatively, astrocyte branches may actively avoid each other or remove overlapped branches to establish a territory. Here, we show time-lapse imaging of the multi-order branching process of GFP-labeled astrocytes. Astrocyte branches grow in the direction where other astrocyte branches do not exist. Neurons that had just started to grow dendrites were able to induce astrocyte branching and tiling. Upon neuronal loss by glutamate excitotoxicity, astrocytes’ terminal processes retracted and more branches went over other branches. Our results indicate that neurons induce astrocyte branches and make them avoid each other.     

体育锻炼对掌握专业操作技能的影响

体育作为实施素质教育的重要组成部分,它同其它学科相互促进,相互影响,共同发展。体育锻炼作为学校体育教学的重要手段,它对掌握专业操作技能有着一定的影响。     

含氟丙烯酸酯共聚物乳液

介绍了含氟丙烯酸酯的共聚和共混改性的方法与应用。     

全脂肪族PU－94系列聚脲－聚氨酯水乳型皮革涂饰剂的特性

测定了全脂防族ＰＵ－９４系列水乳型聚脲－聚氨酯皮革涂饰剂的理化性能。通过比较，认为该系列涂饰剂耐紫外光黄变、耐有机溶剂、耐水等性能优异。     

Properties of orthotropic glass–polypropylene composites manufactured by weaving of prepregtapes and other routes

Abstract

This paper reports a study of the melt impregnation and weaving of glass–polypropylene prepreg tapes into sheet for use as a precursor for pressed thermoplastic composite products and a comparison of the properties attainable with those achievable by other comparable routes. Melt impregnation has been used successfully to manufacture well impregnated tapes, with and without internal coupling agent. It appears that weaving could be an economically viable process for converting unidirectional tape into a conformable, press formable prepreg. The properties of glass–polypropylene laminates manufactured by pressing the tape woven product were compared with those of other glass–polypropylene composites, including crossply laminate made from Plytron and samples prepared by film stacking. Quasi-static mechanical properties were found to be comparable with those of Plytron and superior to those of the other materials. In the coupled samples, coupling was somewhat less effective than in Plytron. The impact behaviour of the pressed, tape woven products was impressive and superior to any of the other materials tested.     

腐植酸的表征及其钠盐的阻垢作用

用ＦＴＩＲ和其它化学方法分析了腐植酸的结构，探讨了腐植酸钠的阻垢机理和作用，并和其它阻垢剂进行了阻垢效率对比。     

丁基橡胶的阻尼性能及其应用

丁基橡胶阻尼材料的研究包括：低温性能的改进和高温功能区的拓展。与其他弹性体并用共硫化，可改善其低温性能；与树脂共混，可使阻尼功能区向高温拓展，提高其高温阻尼性能。丁基橡胶共混改性的方法通常有2种：(1)采用动态硫化，将树脂混入丁基橡胶中；(2)加入丁基橡胶与第二组分的接枝或嵌段共聚物作增容剂进行共混。     

On the mechanism of zeolite growing: Crystallization by seeding with delayered zeolites

Seeds of a delaminated precursor of MWW (ITQ-2) are more active for the synthesis of MCM-22 than crystals of MWW or the corresponding layered precursor. The effect is due on one hand to larger surface area and reactivity of the former, as demonstrated when “seeding” with MCM-41 or other delaminated zeolitic materials, and on the other hand to the crystalline structure of ITQ-2. Seeding with the delayered material yields smaller crystallites of MWW which should be positive from a catalytic point of view. The directing effect of seeding with different delayered materials on the synthesis of zeolites other than MWW is also presented.     

利用腈纶废丝合成絮凝剂PAN—DCD

本文以腈纶废丝为原料与双氰双胺在碱性溶液中反应，成功地制得含有多种活性基因的聚合物ＰＡＮ－ＤＣＤ，并用于染料废水脱色及炼油厂废水除油，除酚的处理研究，与常规使用的几种絮凝剂进行处理结果对照，实验结果表明：该产品单独使用处理效果明显优于其他絮凝剂，与聚铝复合使用处理效果更为理想。     

Studying the influence of refrigerant type on thermal efficiency of annular two-phase flows; mass transfer viewpoint

Many parameters influence the thermal efficiency of two-phase systems; among them, the type of refrigerant employed in two-phase systems is of great importance. Carbon dioxide has been reintroduced as a possible R22 replacement, because of having more heat transfer rate and lower pressure drops, along with better environmental treatment compared with widely-used refrigerants. In the present article carbon dioxide is studied and compared with some thermophysically-different refrigerants from the viewpoint of probability of dry-out occurrence. Dry-out phenomenon in two-phase systems should be avoided as far as possible to prevent sudden drops in heat transfer. Dry-out occurrence is strongly influenced by entrainment mass transfer. In the present study a semi-empirical model is proposed for simulation of entrainment mass transfer in annular flow regime of liquid-vapor in a vertical tube. The significance of entrainment phenomenon in carbon dioxide is compared with that of some other refrigerants to figure out the probability of dryout occurrence in different refrigerants. It will be demonstrated that CO2 relative to other refrigerants has much lower amounts of entrainment. This issue along with other mentioned advantages shows the prominent effectiveness of carbon dioxide among other conventional refrigerants.     

针织面料的水性PU整理工艺及其性能研究

采用水性PU整理剂对针织面料进行整理,研究了PU的整理工艺,并比较了PU整理剂与其它整理剂对针织面料性能的影响。结果表明：其较合理的整理工艺为：整理剂浓度70g／L,定型温度175℃,整理方法为浸轧;与其它整理剂相比,经PU整理剂整理后的针织面料具有良好的弹性、吸湿快干性及抗皱性。     

Molecular weight distribution and moments for condensation polymerization of monomers having reactivity different from their homologues

Molecular weight distributions and moments for condensation polymerization of monomer with unequal reactivities have been studied. When the monomer is more reactive than other species, the MWD curves are found to be different for even and odd mers. When the monomer is less reactive than other species, substantial amounts of unreacted monomer are left and a polydispersity index found by excluding the monomer is found to be a more appropriate representation of the dispersion of the curves. Values of this index at constant conversion are found to be larger or smaller depending on whether the monomer is more or less reactive compared with other homologues in the system, respectively.     

Influence of phase ratio on packing efficiency in columns for mass transfer processes

The phase ratio has been found to affect the packing efficiency in packed columns.To ac-count for the effect,a model is set up to correlate the height of a mass transfer unit with the phaseratio with reasonable accuracy.Proposed also is a correlation that allows to predict the efficiency inquestion at any given liquid-gas ratio using the knowledge of other efficiency values at other liquid-gas ratios.     

催化两器衬里烘炉后失强原因分析

对国内某炼油厂催化裂化装置沉降器和再生器（两器）衬里烘炉后出现强度偏低的问题,从系统因素入手,对衬里材料、施工质量控制、烘炉过程控制、环境影响、综合因素等方面进行分析,衬里发生了碱-集料反应是造成衬里质量问题的主要原因.提出改进措施,加强对耐火衬里碱-集料反应研究,严格限制材料中碱和活性物质含量,针对不同地区的实际环境,合理安排设备制造与衬里施工计划,避开不适宜的时间段施工,缩短衬里浇筑后的放置时间,同时加强通风养护,及时脱水烘炉,严格控制烘炉过程的升温速度和持续时间等,避免出现类似问题.     

氯丁橡胶共混改性研究概况

氯丁橡胶(CR)具有良好的物理机械性能,应用广泛。但耐寒性和贮存稳定性较差等缺点限制了它的应用,为此常与其它高聚物共混。本文介绍了CR与其它橡胶、树脂共混改性的研究概况。     

氢化丁腈橡胶共混改性的技术进展

氢化丁腈橡胶是一种新型的综合性能优异的橡胶 ,目前已在许多特种橡胶制品上获得了应用。但其价格昂贵 ,因而开展氢化丁腈橡胶与其它聚合物的共混改性是十分重要的 ,既可降低成本 ,也可赋予共混物优异的性能。本文综述了氢化丁腈橡胶与塑料的共混、氢化丁腈橡胶的增强改性以及氢化丁腈橡胶与其它橡胶共混改性的技术进展。     

CM与弹性体共混改性的研究概况

主要论述了弹性体型氯化聚乙烯(CM)与天然橡胶、丁苯橡胶、丁腈橡胶、三元乙丙橡胶、氯磺化聚乙烯橡胶、氯丁橡胶、顺丁橡胶、1,2-聚丁二烯橡胶、聚丙烯酸酯橡胶、氯醚橡胶共混改性领域的研究概况.     

金属贮氢法在合成氨厂的应用

金属贮氢法是回收、净化获得高纯氢的新技术。具有融回收、净化、压缩、贮运于一体的优点,见长于其它提氢技术。可以广泛应用于合成氨厂和所有含氢工业尾气的工厂。对于综合利用能够取得理想的效益。