An intervention study—The aspirin myocardial infarction study

The Aspirin Myocardial Infarction Study is a randomized, double-blind clinical trial designed to study the potential value of aspirin in the reduction of mortality in patients who have had a prior myocardial infarction. This trial is based upon several previously published studies which suggest that aspirin may be valuable in prevention of coronary thrombosis. The requirement of 4200 patients dictates that the study must be multicenter, and good design requires that the study be collaborative with central monitoring and an elaborate committee structure to insure uniformity and comparability. Principal Investigators: Allan H. Barker, David Bayse, David M. Barekson, William H. Bernstein, Nemat O. Borthani, Elmer E. Cooper, Leonard Dreifus, William T. Friedewald, Mario R. Garcia-Palmieri, Sidney Goldstein, Olga M. Haring, J. Joanne Hoover, Richard C. Hutchinson, Kenneth H. Hyatt, William F. Krol, Peter T. Kuo, Charles Laubach, Ralph Lazzara, Bernard I. Lewis, J. Judson McNamara, Jessie Marmorston, Thaddeus E. Prout, David W. Richardson, Jorge Rios, Donald W. Romhilt, Paul Samuel, Stephen Scheidt, Robert Schlant, Henry K. Schoch, James A. Schoenberger, Marvin Segal, C. Basil Williams, Gary N. Wilner, Pantel S. Vokonas.     

明胶分子量分布测定和表征的研究进展(二)

<正> 6.SDS—PAGE(十二烷基硫酸钠-聚丙烯 酰胺凝胶电泳)法 从1959年Raymond和1964年Davis用聚丙烯酰胺凝胶分离人血清蛋白成功后,聚丙烯酰胺凝胶电泳得到了广泛的发展,成为分离、分析蛋白质、核酸类生物     

全谱直读电感耦合等离子体原子发射光谱测定苦荞麦矿物元素

采用HNO3/H2O2湿法微波消解制样,采用全谱直读电感耦合等离子体原子发射光谱法（ICP-OES）,分析测定了苦荞麦中的矿物元素,共检出P、S、K、Mg、Ca、Si、Al、Fe、Na、Zn、Mn、B、Cu、Se、Ti、Cr、Ba、Sr等18种矿物元素。分析结果的RSD值在0.45%～9.09%之间,其中15种元素在5%以内。苦荞麦中所含P、S、K、Mg、Ca、Na等常量元素的质量分数分别为0.21%、0.21%、0.17%、0.098%、0.019%、0.0017%;微量元素Fe、Zn、Cu、Se、Cr、Si、Mn、B、Ti、Ba、Sr、Al等的含量（mg.kg-1）分别为37.4、16.5、3.67、1.38、0.44、121.6、6.90、4.88、0.63、0.22、0.12、49.9。     

N,N-dialkylamides of long chain fatty acids as plasticizers

A number of N,N-dialkylamides have been prepared, characterized and evaluated as plasticizers for poly (vinyl chloride-vinyl acetate) copolymer. Among these are the N-oleoyl derivatives of diisopropyl, dibutyl, diisobutyl, diamyl, dihexyl, diheptyl, dioctyl, di-2-ethylhexyl and didecylamines. Also included are the N,N-dibutylamides of 2-ethylhexanoic, neodecanoic, neotridecanoic, palmitic, stearic, linoleic, erucic, ricinoleic, naphthenic, dimer, pinic, epoxystearic, animal, cottonseed, hydrogenated cottonseed, rapeseed,Limnanthes douglasii seed and parsley seed acids. Optimum low-temperature plasticizing properties are achieved for the N-oleoyl derivatives of dibutyl, diamyl and dihexyl amines. These low-temperature properties are comparable to those of the adipate and sebacate plasticizers without the adverse volatility characteristics of the adipates. Compatibility of the N,N-dialkyloleamides extends through the dihexyl derivative. A brief heat stability study of some selected plasticized polylvinyl chloride copolymer compositions indicates that the thermal stabilization of amide plasticizers is not an insurmountable problem. Presented at the AOCS Meeting at Houston, Texas, April 1965. Laboratory of the So. Utiliz. Res. Devel. Div., ARS, USDA.     

新疆不同产地沙枣叶微量元素测定及主成分分析

为了测定新疆不同产地沙枣叶中Li、Na、Mg、K、Al、Ca、Fe、Cr、Mn、Cu、Zn、As、Se、Sr、Ag、Cd、Hg和Pb 18种微量元素的含量,利用微波消解法对沙枣叶样品进行前处理,采用ICP-MS测定沙枣叶中18种微量元素的含量,运用主成分分析法并结合SPSS软件对测定结果进行综合分析.结果显示,检测到新疆不同产地沙枣叶中Na、Mg、K、Ca、Fe、Mn、Zn、Sr、Se的含量相对较高,未检测到重金属元素Hg、Ag,这18种元素的加标回收率为95.8％ ～ 102.3％,相对标准偏差＜3.3％.最终主成分分析选出9个主因子,得出沙枣叶的特征元素为Mg、Al、Fe、Cu、Cd、K、Se.喀什地区沙枣叶品质总体高于其他7个产区.本方法能够准确、可靠地测定沙枣叶中微量元素的含量,具有较高的灵敏度,可用于沙枣叶中微量元素的测定,为沙枣叶的深度开发利用以及产区考核提供了参考依据.     

Some environmental factors affecting free amino acid composition in six varieties of peanuts

This study involved six Spanish type entries (five commercial varieties and a plant introduction) grown in the National Variety Tests in Oklahoma and Georgia under both irrigated and nonirrigated conditions. Significant effects (Georgia vs Oklahoma) were observed on aspartic acid, proline, glycine, valine, isoleucine, peptide, ammonia, and histidine. Significant differences for irrigated vs nonirrigated in the two states for aspartic acid, threonine, proline, glutamic acid, isoleucine, leucine, tyrosine, phenylalanine, peptide, ammonia, and histidine were observed. Significant differences among the six entries were observed for glutamic acid, leucine, tyrosine, phenylalanine, ammonia, histidine, arginine, tryptophan, and total amino acids. None of the treatments produced significant changes in measured amounts of serine, alanine, methionine, and lysine. Significant differences for Georgia vs Oklahoma and irrigated vs nonirrigated for Kjeldahl nitrogen of the whole peanut were noted. Presented at the AOCS Spring Meeting, New Orleans, May 1973. Journal paper 2636 of the Oklahoma Agricultural Experiment Station. ARS, USDA.     

Modification and re-interpretation of Geldart's classification of powders

In developing his powder classification, Geldart [D. Geldart, Powder Technol. 7 (1973) 285.] employed fluidization data obtained only at ambient temperature and pressure and from beds fluidized only with air. Unfortunately, industrial applications of fluidized bed technology invariably are at elevated pressure and temperature and with fluidizing gas other than air. Geldart classification of powders does not apply at elevated pressure and temperature. There are ample evidences reported in the literature indicating that normally Geldart Group B powders at ambient conditions, such as polymer particles, can behave like a Group A powder under polymerization conditions at elevated pressure and moderate temperature with substantial emulsion-phase expansion, relatively small bubbles, smooth fluidization, and reduced gas bypassing [J.R. Grace, Can. J. Chem. Eng. 64 (1986) 353; I.D. Burdett, R.S. Elsinger, P. Cai, K.H. Lee, Gas-phase fluidization technology for production of polyolefins, in Fluidization X, Eds. M. Kwauk, J. Li, W.C. Yang, 2001, pp. 39-52; P.N. Rowe, P.U. Foscolo, A.C. Hoffmann, J.G. Yates, X-ray observation of gas fluidized beds under pressure, in Fluidization IV, Eds. D. Kunii, R. Toei, 1983, pp. 53-60]. Similar findings were also reported for Geldart Group B powders fluidized by supercritical carbon dioxide at elevated pressures [C. Vogt, R. Schreiber, J. Werther, G. Brunner, Fluidization at supercritical fluid conditions, in Fluidization X, Eds. M. Kwauk, J. Li, W.C. Yang, 2001, pp. 117-124; C. Vogt, R. Schreiber, G. Brunner, J. Werther, Powder Technol. 158 (2005) 102; D. Liu, M. Kwauk, H. Li, Chem. Eng. Sci. 51 (1996) 4045; M. Poletto, P. Salatino, L. Massimilla, Chem. Eng. Sci. 48 (1993) 617; A. Marzocchella, P. Salatino, AIChE J. 46 (2000) 901].The original Geldart's classification is modified and re-interpreted in this paper by plotting a dimensionless density against the Archimedes number. The new parameters allow powders with different properties fluidized at different pressures and temperatures with gases of different properties to be plotted in the same graph. The proposed modification successfully transforms the normally Geldart Group B particles at ambient conditions to Group A classification when fluidized at elevated pressure and temperature. The selection of these two parameters, the dimensionless density and the Archimedes number, for plotting is not arbitrary, however. The experimental and theoretical development is discussed.     

Experimental technology for manufacturing ceramic articles

The production of ceramic articles includes five principal operations, namely, preparation of the powder, pressing of the preform, its treatment, sintering, and grinding. If it is necessary to increase the adaptability to manufacture and improve the physicomechanical properties of the sintered material, the operations of hydrostatic treatment of the powder, preliminary sintering of the preforms, repeated mechanical treatment, etc. can be added. The technology is used for manufacturing the working part of cutting tools, dies, tools for shaping alloys of nonferrous metals, bearings, hinges, valves, ball locks, nozzles of hydromonitors, parts of pressing molds, lining parts, milling bodies, etc.Translated from Ogneupory i Tekhnicheskaya Keramika, No. 6, pp. 25 – 27, June, 1996.     

Phase-mineral and chemical composition of coal fly ashes as a basis for their multicomponent utilization. 4. Characterization of heavy concentrates and improved fly ash residues

The phase-mineral and chemical composition of heavy concentrates (HCc) and improved fly ash residues (IFAs) recovered from five fly ashes (FAs) produced in four large Spanish thermo-electric power stations was characterized. The HCs were separated by sink-float separation in bromoform, while the IFAs are residues after the isolation of ceramic cenosphere, salt, magnetic, char and heavy concentrates. The HCs recovered are in the range 0.02–0.28% and their phase-mineral composition (in decreasing order of significance) commonly includes aluminosilicate glass, hematite, magnetite, larnite, quartz, periclase, mullite, corundum, lime, char, melilite, rutile, plagioclase, wollastonite, ferrian spinel, and anhydrite. Numerous accessory minerals of Ba, Ce, Cl, Cr, Cu, F, Fe, La, Mn, P, Pb, Th, Ti, Y, and Zr, are also typical components of HCs. These fractions are enriched in As, Ca, Cr, Cu, Gd, Mg, Mn, Mo, Fe, Ni, Pb, S, Se, Ti, V, Zn, and Zr in comparison with the FAs. The IFAs isolated are in the range 71.5–97.1% and their phase-mineral composition (in decresing order of significance) normally includes aluminosilicate glass, mullite, quartz, char, kaolinite, plagioclase, cristobalite, wollastonite, hematite, anhydrite, K-feldspar, melilite, and corundum. The contents of most elements in IFAs are similar to FAs as Ag, Ba, Cl, Cs, Ge, Mo, S, Sb, and Sc are significantly depleted in these residues. The IFAs have an improved composition in comparison with the FAs because they are: more homogeneous and finer-grained products; abundant in pozzolan and inert constituents; and depleted in harmful components. Some genetic features, properties, possible environmental concern, and potential utilization directions related to the HCs and IFAs are described. A basis for the advanced, multicomponent, wasteless, and environmentally safety utilization of various FAs is also discussed.     

Fuel properties of tallow and soybean oil esters

Fuel properties of beef tallow, soybean oil, their esters, and blends with No. 2 diesel fuel and ethanol were determined. Fuel properties tested were viscosity, specific gravity, API gravity, distillation ranges, calculated cetane index, energy content, flash point, water content, sulfur content, carbon residue, particulate matter, acid value, copper-strip corrosion test, ash content, melting point, cloud point, and pour point. Gas-chromatographic analyses of tallow, soybean oil, and their esters were performed to determine their major constituents. Viscosities of soybean oil and tallow were significantly reduced by esterification. Other fuel properties of the esters and their blends with No. 2 diesel fuel and ethanol were similar to the properties of No. 2 diesel fuel.     

Sampling soybeans for analysis

Conclusion Under the conditions of this study, 30-gram samplings of mixtures of soybeans were found to differ significantly in oil and nitrogen content indicating the desirability of larger samples. The use of 120 to 240-gram aliquots from mixtures of soybeans which vary widely in chemical composition should tend to reduce differences due to sampling to a reasonable minimum. Differences among 30-gram samplings of highly uniform soybean seed of a single variety seem to be of slight significance. The limitations of present sampling methods should be recognized in any comparison or interpretation of chemical analyses of soybean seed. The U. S. Regional Soybean Laboratory is a cooperative organization participated in by the Bureau of Plant Industry, Soils, and Agricultural Engineering, Agricultural Research Administration, U. S. Department of Agriculture and the Agricultural Experiment Stations of Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Carolina, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Virginia, and Wisconsin. Assistant Chemists and Assistant Scientific Aide, respectively, U. S. Regional Soybean Laboratory, Urbana, Illinois.     

Book Reviews

Adhesive Chemistry: Developments and Trends, edited by Lieng-Huang Lee, Plenum Press, New York and London, 1984, 868 pp. ($115.00)

Molecular Characterization of Composite Interfaces, edited by H. Ishida and G. Kumar, Plenum Press, New York, 1985. 453 pp. US$79.00.

Durability of Structural Adhesives, Edited by A. J. Kinloch. Applied Science Publishers, Barking, Essex, 1983 (US $74.00).     

微波消解-ICP-OES法测定胡萝卜中19种矿质元素

利用HNO3/H2O2湿法微波消解制样、再应用全谱直读电感耦合等离子体原子发射光谱法(ICP-OES),对胡萝卜中的矿物元素组成进行全面的分析与测定。定量分析了K、Ca、P、Na、S、Mg、Al、Si、Ba、Zn、Fe、Sr、B、Cu、Mn、V、Pb、Cr、Ti等19种矿物元素,定量结果相对标准偏差在0.15%~10.3%之间,标准样品回收率测定在89.0%~109.6%之间。实验结果可为胡萝卜的应用研究提供基础数据。     

Ambiguity of Symmetry

Beyond the universality of the symmetry concept, there are different emphases on its application in different branches of science. Chemistry, being between particle physics and astrophysics, represents a bridge in, and a utilitarian approach to, the application of the symmetry concept, which has proved immensely fruitful in twentieth-century science. Some pivotal discoveries, especially in structural chemistry, molecular biology, and materials science, emerged by relaxing some of the stipulations of the classical teachings about symmetry. This highly personal presentation relies on ideas expressed by a number of notable individuals in recent science, among them J. Desmond Bernal, Francis Crick, Ronald J. Gillespie, Aleksandr I. Kitaigorodskii, Alan L. Mackay, George A. Olah, Linus Pauling, Roger Penrose, Dan Shechtman, James D. Watson, Steven Weinberg, and Eugene P. Wigner.     

新型绿色表面活性剂——烷基葡萄糖酰胺

介绍了新型绿色表面活性剂烷基葡萄糖酰胺,综述了烷基葡萄糖酰胺的合成方法及其主要性能,如表面张力、临界胶束浓度、Krafft点、泡沫、增效性能、生物降解性及毒性等。着重介绍了该类表面活性剂在洗涤剂、制药工业、食品工业、农业、环境等领域的应用研究进展。引用文献14篇。     

微波消解-ICP-OES法测定黑芝麻中的18种矿质元素

采用HNO3/H2O2湿法微波消解制样,利用全谱直读电感耦合等离子原子发射光谱法(ICP-OES),全面详细地分析测定了黑芝麻中的矿质元素,共检出Ca、P、S、Mg、K、Al、Si、Fe、Na、Zn、Se、Sr、Cu、Mn、Ba、B、Ti、Cr等18种矿质元素,RSD值在1.21%～10.1%,其中13种元素在5%以内。黑芝麻中所含人体常量元素Ca、P、S、Mg、K、Na等的质量分数分别为1.79%,1.08%,0.59%,0.43%,0.41%和0.009 1%;微量元素Fe、Zn、Se、Cu、Mn、B、Cr、Sr、Si、Al等的含量分别为18.6,4.55,3.87,1.74,1.62,0.91,3.21,78.8,125.8 mg/100 g,未检出Pb、Hg、Cd、As以及Ni、Co、Mo等元素。     

煤炭高梯度磁选-浮选脱硫降灰试验

通过分析煤样性质,说明原煤中无机硫主要以硫化铁硫为主,有机硫较高,仅依靠物理方法很难达到理想脱除效果。通过煤粉高梯度磁选试验研究了磁介质、磁通密度、脉冲对煤炭磁选效果的影响。结果表明:聚磁介质选用不加铜套细网介质,当磁通密度为1.295 T,脉冲为25次/min时,煤粉湿法高梯度磁选脱硫效果最好,此时硫分为1.59%,精煤产率为85.44%,脱硫率为31.87%,脱灰率为38.17%,黄铁矿硫脱除率为45.02%。通过正交试验确定了最佳高梯度磁选条件为:煤粉粒度0.075 mm,磁通密度1.295 T,脉冲25次/min,可得到硫分1.35%,灰分10.37%的磁选精煤产品。最后对磁选精煤进行再浮选试验,得到最佳浮选条件为:石灰500 g/t,捕收剂1360 g/t,起泡剂90 g/t,可获得产率76.29%,硫分1.28%,灰分8.14%的精煤,产品脱硫率为57.73%,脱灰率为58.52%,黄铁矿硫脱除率为84.56%。采用磁选-浮选综合流程,煤粉基本达到理想的脱硫降灰效果,可作为煤种脱硫降灰技术方案的参考。     

天然植物白芨胶的功能及在化妆品中的应用

介绍了天然植物白芨胶的无毒、安全、收敛、止血、延缓皮肤衰老、增稠、悬浮、保湿和助乳化等功能。对白芨胶在化妆品中的应用作了试验研究,临床实验结果表明,白芨对治疗和防止皮肤冻疮和皲裂、促进血液循环、改善皮肤营养状况和防止皱纹等具有明显疗效,且无副反应和毒性。因此,白芨胶是一种理想的化妆品天然植物添加剂。     

Books Received

MULTICOMPONENT POLYMER SYSTEMS. Edited by I. S. Miles and S. Rostami. Longman Scientific & Technical, Essex, UK, 1992, 435pp. (UK£ 65.00).

HANDBOOK OF ADHESION. Edited by D. E. Packham. Longman Scientific & Technical, Essex, UK, 1992, 570pp. (UK£80.00).

PLASMA SURFACE MODIFICATION OF POLYMERS: Relevance to Adhesion. Edited by M. Strobel, C. S. Lyons and K. L. Mittal. VSP, Utrecht, The Netherlands, 1994, 290pp. (DM122/US$79).

ADHESION MEASUREMENT OF FILMS AND COATINGS. Edited by K. L. Mittal. VSP, Utrecht, The Netherlands, 1995, 456pp. (DM147/US$96).

CONTACT ANGLE, WETTABILITY AND ADHESION. Edited by K. L. Mittal. VSP, Utrecht, The Netherlands, 1993, 971pp. (no price given).     

跨国公司抢滩中国化工呈全方位多领域态势(待续)

报道跨国化工公司投资中国,以收购、技术转让方式涉足中国的石化原料、中间体、塑料和树脂、橡胶和轮胎、化纤、有机硅、氟化物、涂料染料、精细和特种化学品、日用化工、医药、电子材料、煤化工等领域的情况.