微波烧结Al2O3-TiC复合材料的研究

以纳米级TiC、Al2 O3 为原料 ,用微波烧结制备Al2 O3 -TiC复合材料 ,并与常规烧结比较。分析了两种烧结方法对制备试样的力学性能的影响 ,并探讨了添加剂对Al2 O3 -TiC复合材料烧结性能的影响     

微波烧结Al2O3-TiC复合材料

用微波烧结制备Al2O3-TiC复合材料，并与常规烧结Al2O3-TiC复合材料对比，分析两种烧结方法对试样力学性能的影响，同时探讨添加剂对Al2O3-TiC复合材料烧结性能的影响。     

Al2O3–TiC基复相陶瓷的制备和性能

Al2O3-TiC基复相陶瓷具有高强度、高硬度和较好的高温稳定性, 常用于刀具、发热体和电子器件. 本文综述了Al2O3-TiC基复相陶瓷的各种制备方法及其优缺点、常温和高温性能、各种增韧手段和增韧机制, 并展望了Al2O3-TiC基复相陶瓷研究的发展方向.     

Al2O3-TiC基复相陶瓷的制备和性能

Al2O3-TiC基复相陶瓷具有高强度、高硬度和较好的高温稳定性,常用于刀具、发热体和电子器件。本文综述了Al2O3-TiC基复相陶瓷的各种制备方法及其优缺点、常温和高温性能、各种增韧手段和增韧机制,并展望了Al2O3-TiC基复相陶瓷研究的发展方向。     

ZrO2-Al2O3-TiC纳微米复合陶瓷模具材料的研究

以钇稳定四方氧化锆(Y-TZP)、Al2O3、纳米级的TiC为主要原料,采用真空热压烧结工艺,制备了ZrO2-Al2O3-TiC纳微米复合陶瓷模具材料.研究了该材料的力学性能和微观结构.研究结果表明:当TiC含量为20vol%,Y2O3含量为3mol%时,制备的ZrO2-Al2O3-TiC复合陶瓷模具材料具有良好的力学性能.抗弯强度、断裂韧性和硬度分别达到824 MPa、10.7 MPa·m1/2和11.67 GPa.晶粒细化、穿晶断裂、颗粒桥联、裂纹偏转和相变增韧是主要的增韧补强机理.     

凝胶成型Al2O3-(30vol%)MgO·1.35Al2O3泡沫陶瓷的研制

以板状刚玉和富铝尖晶石为主原料,采用泡沫浸浆凝胶工艺制备了Al2O3-(30 vol%)MgO@1.35Al2O3泡沫陶瓷.研究了分散剂AN-2000与pH值对Al2O3-(30vol%)MgO@1.35Al2O3混合浆料流变特性的影响.在pH值=9.5、AN-2000添加量为0.4 mL@m-2的条件下制备的粘度为O.14 Pa@s,固相体积分数为55%的Al2O3-(30vol%)MgO@1.35Al2O3混合浆料,通过有机泡沫浸浆、引发凝胶反应、湿坯干燥、排胶和烧结,制备出了气孔率为89.3%,强度为5.2 MPa的Al2O3-(30vol%)MgO@1.35Al2O3泡沫陶瓷.     

氧化铝包覆二硫化钼复合粉体的制备与表征

通过Al(NO3)3·9H2O水解,利用非均匀成核方法制备了MoS2/Al2O3的复合粉体,对复合粉体制备的工艺条件进行了研究,并利用SEM/EDS、TEM、XRD等方法对样品进行表征.结果表明:Al3+浓度、pH值、反应温度及滴定速度是影响包覆效果的主要因素,制备MoS2/Al2O3复合粉体的最佳工艺条件是Al3+浓...     

Al2O3增强ZrO2陶瓷的制备及性能研究

本文采用热分解法制备Al2O3微粉、化学共沉淀法制备(Y,Ce)—ZrO2超细粉,通过适当工艺制备出ZrO2／Al2O3复合陶瓷。经研究发现,添加Al2O3,可抑制ZrO2晶粒的长大,提高基体的强度和韧性。当Al2O3含量达到30%(质量分数)时,复合陶瓷的抗弯强度为986MPa,断裂韧性为13.7MPa*m1／2。材料性能的提高可归结为Al2O3颗粒的弥散增韧和ZrO2陶瓷的相变增韧叠加作用的结果。     

Al_2O_3增强ZrO_2陶瓷的制备及性能研究

本文采用热分解法制备Al2 O3 微粉、化学共沉淀法制备 (Y ,Ce)—ZrO2 超细粉 ,通过适当工艺制备出ZrO2 /Al2 O3 复合陶瓷。经研究发现 ,添加Al2 O3,可抑制ZrO2 晶粒的长大 ,提高基体的强度和韧性。当Al2 O3 含量达到 30 % (质量分数 )时 ,复合陶瓷的抗弯强度为 986MPa ,断裂韧性为 13 7MPa·m1/ 2 。材料性能的提高可归结为Al2 O3 颗粒的弥散增韧和ZrO2 陶瓷的相变增韧叠加作用的结果     

以无机盐为前驱体制备超滤膜的研究

以无机盐Al(NO3)和氨水为原料，采用sol-gel法制备出稳定透明的勃姆石溶胶，采用浸渍法工艺将勃姆石溶胶均匀地涂覆在Al2O3载体上，通过对膜与载体的复合工艺条件的研究，制备出孔径均匀的无缺陷的Al2O3超滤膜。     

Occurrence,abundance and origin of minerals in coals and coal ashes

The mineralogy of coal and coal ash samples from a wide variety of deposits worldwide has been studied by X-ray diffractometry, light microscopy, SEM, TEM, and DTA-TGA methods. The common major minerals identified in the crystalline matter of coals are quartz, kaolinite, illite, calcite, pyrite, plagioclase, K-feldspar and gypsum, and occasionally dolomite, ankerite, siderite, Fe oxyhydroxides and sulphates. A number of minor and especially accessory minerals are also present. The modes of occurrence and some genetic peculiarities of the minerals found are described and summarized. Minerals and phases of probable detrital origin include mainly silicates, volcanic glass, oxyhydroxides and phosphates. Authigenic minerals of syngenetic origin may be sulphides, clay minerals, carbonates and rarely sulphates and phosphates. Epigenetic minerals, formed by the infiltration of low-temperature hydrothermal solutions, may include sulphides, carbonates, sulphates, clay minerals, quartz, chlorides, and probably alkaline-earth hydroxides and zeolites. The alteration products of detrital and authigenic minerals may be Fe and Al oxyhydroxides, sulphates, kaolinite, illite, chlorite, muscovite, zeolites and calcite. The behaviour of these minerals and phases during low- and high-temperature ashing is also discussed.     

Some gas phase reactions during the firing of magnesite-chromite refractories in a tunnel kiln

Conclusions A correlation is shown between the high-temperature, physicochemical processes in basic refractories, changes and reactions in the gaseous phase, and the nature of the wear of the roof of a tunnel kiln.As a result of dissociation, oxidation, and volatilization the waste gases are enriched with vapors of alkalis, CrO₃, sulfur trioxide, and oxides of iron and magnesium, and become corrosive with respect to the kiln lining. The reaction of the oxides vapors with each other and with the lining of the roof and their condensation determines the nature of the wear in the magnesite-chromite refractories, the chemical and mineral compositions of the resulting deposits and crusts. The main source of alkalis and sulfur trioxide is the sulfite yeast dregs (sulfite lye) present in the goods being fired.We determined the temperature relationship with the composition and amounts of deposits and crusts. Carcase and skeletal deposits and crusts formed on the firing section of the kiln, mainly periclase and spinel compositions; in the warming-up section the deposits were brittle, granulated, consisting of sulfates, chromates, chromium oxide, periclase, and spinels.It was found that the deposits on the walls of the pores in the MKhS refractories consist of sulfates and chromates, forming solid solutions.Translated from Ogneupory, No. 5, pp. 13–16, May, 1980.     

我国橡胶防老剂和促进剂的进出口情况

介绍近年来我国橡胶防老剂和促进剂进出口情况。2013年,我国防老剂和促进剂进口量分别为19046.61 t和14984.44 t,同比分别增长16.12%和11.64%;进口金额分别为6202.02万美元和7391.97万美元,同比分别增长14.76%和1.39%;出口量分别为29070.40 t和89942.59 t,同比分别增长62.68%和45.72%;出口金额分别为6794.43万美元和27885.34万美元,同比分别增长60.45%和50.17%。我国进口防老剂主要来自中国大陆(以国货复进口形式进口)、美国、韩国以及中国台湾省等,进口促进剂主要来自中国台湾省、美国、韩国、日本以及德国等,防老剂主要出口日本、泰国、印度尼西亚和韩国等,促进剂主要出口美国、韩国、巴西、泰国和日本等。     

松香基表面活性剂研究进展

松香是一类产量丰富、价格低廉的可再生林产资源,被广泛地应用于食品、农业、橡胶、油墨、涂料等领域。松香的三环二萜结构具有超强的疏水性,通过催化异构、Diels-Alder加成等手段引入亲水基团可制备高附加值、易生物降解的绿色表面活性剂。本文从阴离子、阳离子、非离子和两性离子表面活性剂4个大类对松香基表面活性剂应用的文献及专利进行综述,重点分析了羧酸盐、磺酸盐、硫酸盐和磷酸盐4种阴离子型表面活性剂和季铵盐阳离子型表面活性剂,多元醇型和聚氧乙烯型非离子表面活性剂,以及甜菜碱型和氧化胺型两性离子表面活性剂。剖析松香基表面活性剂产业化开发的新技术及新产品概况,提出松香基表面活性剂替代传统表面活性剂的潜在应用领域。同时,对松香基表面活性剂的研究发展与产业化发展进行了评价与展望。     

轻质隔热吸音仿石漆研制、性能及施工

轻质隔热吸音仿石漆是传统仿石漆的升级产品,其具有质轻、隔热、吸音、环保等特点,是一款集节能、降噪、装饰等多功能于一体的新产品,特别适合保温墙面、旧墙面等装饰装修工程.主要讨论了仿石骨料颗粒级配、乳液、增稠剂、成膜助剂、消泡剂等对轻质隔热吸音仿石漆质量的影响,测试了轻质隔热吸音仿石漆的主要性能,介绍了轻质隔热吸音仿石漆施工工艺要点.     

几种杀虫剂对草坪害虫的控制效果

测定了绿僵菌、毒死蜱、辛硫磷等药剂对草坪害虫的控制效果。结果表明绿僵菌、毒死蜱和辛硫磷都是防治草坪地下害虫的有效药剂，毒死蜱和辛硫磷还能有效防治草坪茎叶害虫禾灰翅夜蛾和斜纹夜蛾等。药后45d，绿僵菌对铜绿丽金龟幼虫蛴螬的防效和对地下害虫的总防效分别为91．2％和87．6％。绿僵菌对茎叶害虫的防效较差，药后3、7、10d时，对禾灰翅夜蛾的防效分别为3．7％、9．2％和18．9％；对茎叶害虫的总防效在12．2％以下。辛硫磷和毒死蜱药后3d对禾灰翅夜蛾的防效分别是93．7％和97．6％；对茎叶害虫的总防效分别是92．0％和93．6％。当高效氯氰菊酯分别和辛硫磷、毒死蜱混用防治斜纹夜蛾时，防效更高、速效性更好。     

Properties of poly(alkylene oxide) elastomers

The catalyst comprised of triisobutylaluminum, zinc acetylacetonate, and water was used to prepare homopolymer of epichlorohydrin; copolymers of epichlorohydrin with propylene oxide, ethylene oxide, and allyl glycidyl ether; and terpolymers of epichlorohydrin, propylene oxide, and allyl glycidyl ether and of epichlorohydrin, ethylene oxide, and allyl glycidyl ether. The vulcanizates of these rubbers provide variations of stressstrain and dynamic properties, freeze point, hardness, and solvent resistance depending on the type and amount of comonomer. In general, these rubbers have excellent heat, ozone, and oxidation resistance as well as oil and solvent resistance.     

Mass-independent isotopic compositions in terrestrial and extraterrestrial solids and their applications

In 1983, Thiemens and Heidenreich reported the first chemically produced mass-independent isotope effect. This work has been shown to have a wide range of applications, including atmospheric chemistry, solar system evolution, and chemical physics. This work has recently been reviewed (Weston, R. E. Chem. Rev. 1999, 99, 2115-2136; Thiemens, M. H. Science 1999, 283, 341-345). In this Account, observations of mass-independent isotopic compositions in terrestrial and Martian solids are reviewed. A wide range of applications, including formation and transport of aerosols in the present atmosphere, chemistry of ancient atmospheres and oceans, history and coupling of the atmosphere-surface in the Antarctic dry valleys, origin and evolution of oxygen in the Earth's earliest environment, and the chemistry of the atmosphere and surface of Mars, are discussed.     

Effects of nutrition and origin on the amino acid,grease, and suint composition and color of cashmere and guard hairs

Nutritional and environmental effects on the amino acid, wax, and suint contents and color of raw cashmere were investigated. Cashmere was obtained from goats fed with or without dietary protected protein, goats fed different levels of dietary energy and feeds, and goats from Australia, China, and Iran. The determined attributes included the production, diameter, length, fiber curvature, crimp, wax and suint contents, amino acid composition, lightness, and yellowness of cashmere. The content of suint, but not that of wax, was affected by nutrition management. The amino acid composition of cashmere was affected by the energy and protein nutrition, feed type, and country of origin. The amino acid composition of cashmere was different from that of guard hair. The lightness and yellowness of cashmere was affected by the nutrition treatment, grazing, cashmere production, and sum of the wax and suint contents of the raw cashmere. The variation in the amino acid composition of cashmere likely affected both its physical and chemical reactivity. Nutrition manipulation of cashmere goats and the origin of goats have implications with respect to the properties of cashmere as changes in fiber cell biosynthesis can alter the amino acid composition of the fiber. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Yield and chemical composition of sesame,Sesamum indicum L., as affected by variety and location grown

Summary Observation nurseries including 24 varieties of sesame were grown at 23 locations in 16 states. Data for yield, oil and protein content of the seed, and for iodine value of the oil were obtained from certain locations. Sesame seems reasonably well adapted on the better soils of most of the southern one-half of the United States. Average seed yield for varieties at 14 locations was 506 pounds per acre. Average yield of seed, oil, and protein per acre for seven varieties grown at eight locations was 662, 344, and 163 pounds per acre, respectively. The chemical composition of the seed was found to be well within the acceptable range but was markedly influenced both by the varieties and by the locations where they were grown. The average oil and protein contents on a moisture-free basis were 53.53% and 26.25%, respectively. The average iodine value of the oil was 110.0. Average protein content on the moisture- and oil-free basis was 57.28%. The genetic and environmental influences that affect protein content of the seed also inversely affected the oil content. It was suggested that in sesame protein synthesis is favored over oil synthesis as the nitrogen supply to the seed increases. Contribution of the Division of Tobacco, Medicinal, and Special Crops, Bureau of Plant Industry, Soils, and Agricultural Engineering, and the Southern Regional Research Laboratory, Bureau of Agricultural and Industrial Chemistry, U. S. Department of Agriculture. Agronomist, Division of Tobacco, Medicinal, and Special Crops in cooperation with the Department of Agronomy, Texas Agricultural Experiment Station; and chemist, Southern Regional Research Laboratory, New Orleans, La., respectively. The authors wish to acknowledge the assistance of workers in the various state agricultural experiment stations and government agencies who grew the tests and made data and seed samples available.