花粉症诱因探究

花粉症又称季节性鼻炎或枯草热,是敏感个体对花粉的一种超敏反应.在美国,每一百个人当中就有两个以上的人患花粉症;现在日本有1300万人饱受花粉症折磨,超过总人口的10%[1].我国的发病率为0.5%～1%,高发区达到5%,虽没有上述一些国家那么严重,受害者亦相当可观.全世界花粉症发病人数到1999年就已有5000多万[2],可见花粉症患者是一个绝不可轻视的群体.图1显示了花粉过敏症的发病机制.     

吉安散装人抗冰战雪保平安——江西吉安散办干部职工铲除冰保畅通纪实

春节前后,吉安市遭遇到罕见的冰冻雨雪灾害天气,连续出现了低温、阴雨和雨夹雪,成为全省灾情最严重地区之一.特别是1月25日以后,出现了持续大范围的雨雪冰冻天气.冰冻损坏了市区的电网,压垮了树枝,封锁了道路和桥梁.     

2010～2011年世界塑料工业进展

收集了2010年7月～2011年6月世界塑料工业的相关资料,介绍了2010～2011年世界塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚氯乙烯、聚苯乙烯、ABS树脂),工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚),特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮),通用热固性树脂(酚醛、不饱和聚酯树脂、环氧树脂、聚氨酯)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

欧文斯科宁专访

欧文斯科宁公司(以下简称OC)创建66年来一直致力于开发玻璃纤维的新用途,是建筑材料和复合材料行业的领先创新者和制造商,OC进入亚太市场也已超过30年,长久以来他们专注于推广复合材料的应用领域以及扩大其供应基地.最近,欧文斯科宁在印度扩充了生产能力,并在上海设立了技术中心.至今为止,欧文斯科宁在亚太区已有超过1800名员工,从事建筑材料和复合材料的生产,销售和研发工作.     

酿酒酵母细胞表达异源萜类化合物的研究进展

萜类化合物具有可观的经济价值,但是目前的生产过程复杂、产量低。酿酒酵母甲羟戊酸途径为萜类化合物的合成提供直接前体,因此酿酒酵母细胞具有合成异源萜类化合物的天然优势。对酿酒酵母甲羟戊酸途径的清晰认识是对其进行有效利用的基础,本文从代谢途径、关键酶的特点和全局调控机制3个方面对该途径进行了介绍。从代谢途径的构建和优化、模块与底盘细胞的适配、模块构建及组装方式的角度概述了酿酒酵母细胞异源合成单萜、倍半烯萜、二萜、三萜类化合物的研究进展。指出实现酿酒酵母高效合成萜类化合物所需要解决的基础问题是对酿酒酵母甲羟戊酸途径进行更为全面了解和对萜类化合物的天然代谢途径进行明确解析;另外,合成生物学的进一步发展也将为此提供应用基础。     

喷涂前处理污染源的分析及其处理措施

随着我国国民经济的快速发展和国家"节能减排"重点项目的深入开展,各种污染源的分析及其处理措施的研究备受关注.本文在充分研究若干家电企业的钢铁喷涂制件的前处理工艺(如:预脱脂、脱脂、清洗、表调、磷化等)的基础上,分析喷涂前处理过程中的污染源,研究污染源的处理措施.     

回转窑耐火砖的砌筑及使用

我公司回转窑规格为Φ4.0m×60m.窑内使用的耐火砖为镁铬砖、隔热尖晶石、蓝晶石和黏土砖以及硅莫砖.镁铬砖规格为(81×90×150×200)mm,其它耐火砖规格皆为(81×90×200×200)mm.尽管每个品种的砖品质相同,但由于在镶砌和使用过程中方法不同,寿命有长有短.通过多年实践,现总结如下.     

硅酸钠缓蚀剂的研究现状与展望

硅酸盐资源丰富,无毒,价廉,不繁殖细菌,是一种对环境友好的缓蚀剂.近年来研究的以硅酸盐为主的缓蚀剂复合配方,大大提高了硅酸盐缓蚀剂的应用范围.目前,开发缓蚀剂复合配方已成为一种发展趋势.本文综述了硅酸钠缓蚀剂的应用现状,并对其发展作了展望.     

论啤酒瓶质量与啤酒灌装的协调和统一

为了使啤酒瓶质量与啤酒灌装质量协调统一,探讨了啤酒瓶外形设计、剩余空间和瓶壁厚度与瓶子强度和灌装质量的关系,提出啤酒瓶企业定点向啤酒企业供瓶,两企业协作互动,了解相关的技术、设备性能和工艺流程,以利同步发展.     

化妆品行业如何应对REACH法规

2006年12月7日～2006年12月8日化妆品化学家年会在美国纽约举行,该年会为化学品供应商提供了参与REACH法规的机会.REACH法规的实施引起了业界的广泛关注,来自世界各地的著名化学品及化妆品公司对REACH法规的实施所带来的一些问题,以及新原料、新技术进行了交流.会议主要对就REACH法规、制造及规模化和神经美容品等方面展开了研讨.     

The Mixed Compounds of Calcium and Titanium With Tiron. I

A pH-spectrophotometric study of the Ti-tiron complex in the presence of Ca ions revealed the existence of mixed compounds of Ca-Ti-tiron. These could account for the interference of Ca in the determination of Ti by tiron. The formation of these mixed compounds under varying concentrations of components and at varying pH is discussed. The absorbance of the Ti-tiron was likewise studied in the presence of many colorless salt solutions, but the behavior of Ca was found to be unique. Use was made of the color of the mixed compounds of Ca-Ti-tiron to develop a method for the identification of small amounts of Ca in the presence of large quantities of many common salts.     

Effect of cooling rate on melt-crystallization of random propylene-ethylene and propylene-1-butene copolymers

Summary  The effect of variation of the rate of cooling on melt-crystallization of random copolymers of isotactic polypropylene with low amount of either ethylene or 1-butene is evaluated using X-ray techniques, atomic force microscopy, and calorimetry. Slow non-isothermal melt-crystallization mainly results in formation of monoclinic α-crystals of lamellar geometry. The presence of comonomers leads to a decrease of the degree of crystallinity, and of the thickness of lamellae. These changes are proportional to the concentration of co-units, and are more distinct in propylene-ethylene copolymers. Rapid cooling of propylene-1-butene copolymers leads to formation of non-lamellar mesomorphic domains, independent of the concentration of co-units within the investigated range of concentrations. In quenched propylene-ethylene copolymers, in contrast, the formation of mesomorphic structure partially is replaced by formation of monoclinic α-crystals of still non-lamellar geometry.     

Capillarity and water repellency of fabrics

A method of determining the contact angle of wetting of fibres in the capillaries of fabrics is proposed. A theoretical calculation of the angles of wetting of cotton and blended fabric fibres with water was performed in the condition of formation of a uniform hydrocarbon film on the surface of the fibres. The real contact angles of wetting of water-repellent fabrics were determined; they differ from the angles of wetting of uniform hydrocarbon films by 10-12% due to the presence of hydrophilic molecules of the emulsifiers in the modifying film.     

Effectiveness of operation of a DVKh-1000 mixer in the production of electrical periclase powders

Conclusions The DVKh-1000 mixer provides a completely satisfactory degree of uniformity of the chemical and grain size compositions of the material in production of electrical periclase powders. The optimum conditions are obtained with a weight of charged material of 1.4–1.6 tons and a mixing time of 20 min. The coefficient of averaging is 0.60–0.80 for the content of the impurity CaO and 0.64–0.86 for the grain size composition.With a change in the requirements of the standard for grain size composition of electrical periclase powders and also with a change in the method of their production the optimum operating conditions of the mixer may be established on the basis of special additional investigations.The use of methods of geometrization of quality criteria in mineral resources for evaluation of the degree of uniformity of a material in mixing made it possible to establish an effect consisting of the fact that such properties as plasticity and viscosity characteristics of the aggregate condition of a substance (solid, liquid, gaseous) are revealed in the geometric features of the change in quality criteria and physical and technical characteristics of the pulverized and bulk material. This effect explains the existence of some limit of uniformity in mixing of materials with a different degree of variability of its quality criteria. The numerical value of this limit is determined by the physical properties of the material and the design features of the mixing equipment. For the investigated material and type of mixer this limit is 0.06–0.08%.Translated from Ogneupory, No. 8, pp. 41–45, August, 1988.     

Functional properties of proteins in foods

The measurement of functionality of protein food ingredients has developed somewhat haphazardly, probably due to the wide range of proteins used as ingredients and the diversity of foods. Studies of the physiochemical properties of proteins should enable prediction of a proteins response to process environments and prove more fruitful than many of the empirical measurements of functionality. The effects of pH, salt type and concentration on the phase behaviour of the oilseed globulin and arachin, demonstrates the complexity of protein solubility and the inadequacies of simple tests that have arisen. Studies of the effects of salts and conditioning on meat fibres, coupled with measurement of the location of water in pellets from water holding tests enable the latter to be applied with increased confidence. Comparison of the endothermic transitions observed on heating with the development of storage and loss moduli allow the contributions of domains of skeletal muscle myosin to gel structure to be investigated.     

Study of the criteria for radial distribution of components in cross sections of yarn by computer modeling

Experiments were conducted on computer modeling of the cross section of two-component yarn. The sensitivity of each of the criteria of radial distribution of the fibres in the cross section of yarn made from a blend of chemical fibres was determined. The area of application of each criterion was determined with consideration of the results of the computer experiments.     

几种萘酞菁硅配合物的光动力效应的研究

研究了7种轴向配位的萘酞菁硅配合物的激发态性质、产生单重态氧的能力及对几种氨基酸的光敏氧化能力.研究表明,对于相同浓度的不同配合物来说,随着轴向配位基团推电子能力的逐渐增强,激发三重态寿命降低,产生单重态氧的能力逐渐下降,而产生单重态氧的能力是光敏氧化氨基酸反应速率的决定因素,因此,其光敏氧化氨基酸的一级反应速率常数逐渐减小.     

化工原理传质单元操作工程研究的方法论

基于对化工原理课程中各传质单元操作工程研究方法的分析,笔者论述了各传质单元操作的研究方法,在相平衡描述、传质速率描述、物料衡算、极限处理法和技术经济性分析等几个方面存在着共同的特征。掌握这一共性特征,对于整体上把握传质单元操作的教学内容和教学方法,具有认识论和方法论上的意义。     

串联攻坚战斗部前级爆轰场对后级影响分析

为了研究串联战斗部前级爆轰场作用下,后级随进子弹炸药安全性及其速度降的大小,建立了一维冲击波传播理论分析模型,由图解法得到了后级装药的初始压力。通过与炸药引爆阈值压力比较,判断了后级装药的安全性。根据动量守恒,得到了后级子弹的速度降表达式。进行了串联装药的数值计算,得到一定隔板厚度情况下后级装药受到的冲击压力和后级子弹速度降,计算得到的后级子弹变形情况与试验结果相吻合。     

International Conference on Chemical Fibres. Chemical Fibres: Present and Future. Look at the Next Century. Part 2

The trends in the development of chemical fibre production processes are analyzed and the general characteristics of the change in their manufacture as a function of the fundamental determining factors are found. The characteristics of chemical fibre production processes and subsequent treatments are examined and the possibilities of optimizing and intensifying existing technologies and improving the properties of the fibres by physical and chemical modification are demonstrated. Fibre formation in nature and industry is compared. The possibilities of creating new fibre production technologies, using methods of bionics in particular, are demonstrated. The development of the raw-material base for chemical fibres, including finding new sources of raw materials, is evaluated. The development of alternative principles for spinning chemical fibres and new technologies and types of fibres should be expected: production of fibres of the Lyocell type by dissolving cellulose in organic solvents will solve the problem of development of hydrated cellulose fibres, which is important due to the gradual decrease in production of viscose fibres; creation of fibres based on synthetic polypeptides of the fibroin type and production of chemical fibres @mdash; close analogs of natural silk and cobwebs; use of the principles of bionics based on synthesis of regular block-copolymers of defined structure which allow regulating the properties of the fibres by their self-organization. Use of water as a solvent will allow creating @ldquo;environmentally clean@rdquo; fibre production processes. The development of polyvinyl alcohol fibre production is due to the creation of new methods of synthesis of polyvinyl alcohol. Water is also the basic component of solvents of synthetic polypeptides. New, alternative raw-material sources based on synthesis of monomers from atmospheric components (carbon dioxide, nitrogen) and water, biotechnological processes, growth of highly productive cellulose-containing crops, and others are becoming important for ensuring increasing chemical fibre production volumes.