超细滑石粉改性MC尼龙的研究

考察了超细滑石粉对MC尼龙复合材料物理力学性能的影响。结果表明,滑石粉与MC尼龙复合,显著地改善了制品的收缩率、吸水率,热变形温度提高24℃。制品具有填料分布均匀、外观光泽优良等优点。同时,加入滑石粉还可以降低MC尼龙制品的成本。硅烷偶联剂可以增加滑石粉与MC尼龙基体的相容性,使复合材料的冲击强度较MC尼龙提高11％。     

Nycoa公司推出尼龙纳米复合材料

世界领先的特种工程塑料尼龙树脂生产商、具有50多年历史的美国Nycoa公司最近推出了一种创新性的尼龙纳米复合材料。这种新材料在设计时具有很大的自由度。与传统的玻纤填充尼龙和超强尼龙相比，新材料可以设计成更薄壁的制品，同时能提高产品的表面性能，使制品变得更轻。     

尼龙制品的表面染色

尼龙制品可以进行表面染色处理，可根据要求染成各种鲜艳的颜色，便于原料及回流料的管理，从而降低生产成本。本文从原理及染色方法上对尼龙制品的表面染色进行了阐述。     

粉煤灰填充尼龙6浇铸制品的研究

将粉煤灰用硅烷偶联剂处理后填充到尼龙6浇铸制品中,可以改善制品的吸水性,收缩率,热稳定性等,还可以降低成本,有很大的应用价值。     

共混型阻隔容器专用料配方及成型工艺的研究

将高密度聚乙烯(HDPE)、相容剂、尼龙以及其他助剂以适当配比干混后,在普通吹塑成型机上制得具有阻隔性能的中空制品。通过对制品阻隔性能、机械性能及制品剖面扫描电子显微照片的分析,研究了成型工艺、相容剂与尼龙的配混比例以及尼龙加入量对制品性能的影响。     

尼龙1010注塑制品工艺设计

从尼龙1010塑料注塑成型的主要设备、工艺条件以及尼龙1010塑料的特性等方面,对尼龙1010的注塑工艺流程进行全面的分析和研究,为尼龙1010注塑件的开发、提高制品质量提供了相关的数据。结合典型制品,运用计算机辅助设计技术,对工艺过程进行了设计。     

铸型尼龙单体反应注塑成型机

一种利用己内酰胺等尼龙单体生产铸型尼龙注塑制品的铸型尼龙单体反应注塑成型机，由活性单体料制备部分、注塑成型部分和自动控制等部分构成。反应釜制备的活性单体料经齿轮计量泵注八柱塞缸中，经混合、聚合、熔融由喷嘴注入模具型腔中，生产铸型尼龙注塑件制品。也可不经聚合直接经柱塞缸、喷嘴注入模具中，生产铸型尼龙反应注射件制品。     

增韧改性技术提高尼龙性能

由北京化工大学开发的增韧技术改性的尼龙，通过对配方中助剂用量的调节，能达到各种柔韧性尼龙制品的性能要求。同时该增韧改性技术还可以大幅提高尼龙与无机填料的黏合力，使增强、阻燃、耐低温性能明显提高。近年来由于石油输送管道和汽车行业的飞速发展，纯尼龙已经满足不了使用要求，市场对改性尼龙的需求量越来越大。     

介绍西安雁塔漳浒工程塑料厂——专业生产填充MC尼龙制品

<正> 西安市雁塔漳浒工程塑料厂,是化工部西北供销公司尼龙产品的定点生产厂,也是我国最早生产工程塑料厂之一。该厂历史悠久,设备精良、工艺先进,产品优良,该厂能够生产当今最优的填充MC尼龙制品,该厂生产的填充MC尼龙制品,已广泛广用在     

介绍西安雁塔漳浒工程塑料厂——专业生产填充MC尼龙制品

<正> 西安市雁塔漳浒工程塑料厂,是化工部西北供销公司尼龙产品的定点生产厂,也是我国最早生产工程塑料厂之一。该厂历史悠久,设备精良、工艺先进,产品优良,该厂能够生产当今最优的填充MC尼龙制品,该厂生产的填充MC尼龙制品,已广泛广用在     

Theanine,Antistress Amino Acid in Tea Leaves,Causes Hippocampal Metabolic Changes and Antidepressant Effects in Stress-Loaded Mice

By comprehensively measuring changes in metabolites in the hippocampus of stress-loaded mice, we investigated the reasons for stress vulnerability and the effect of theanine, i.e., an abundant amino acid in tea leaves, on the metabolism. Stress sensitivity was higher in senescence-accelerated mouse prone 10 (SAMP10) mice than in normal ddY mice when these mice were loaded with stress on the basis of territorial consciousness in males. Group housing was used as the low-stress condition reference. Among the statistically altered metabolites, depression-related kynurenine and excitability-related histamine were significantly higher in SAMP10 mice than in ddY mice. In contrast, carnosine, which has antidepressant-like activity, and ornithine, which has antistress effects, were significantly lower in SAMP10 mice than in ddY mice. The ingestion of theanine, an excellent antistress amino acid, modulated the levels of kynurenine, histamine, and carnosine only in the stress-loaded SAMP10 mice and not in the group-housing mice. Depression-like behavior was suppressed in mice that had ingested theanine only under stress loading. Taken together, changes in these metabolites, such as kynurenine, histamine, carnosine, and ornithine, were suggested to be associated with the stress vulnerability and depression-like behavior of stressed SAMP10 mice. It was also shown that theanine action appears in the metabolism of mice only under stress loading.     

TRPA1 Expression and Pathophysiology in Immune Cells

The non-selective cation channel TRPA1 is best known as a broadly-tuned sensor expressed in nociceptive neurons, where it plays key functions in chemo-, thermo-, and mechano-sensing. However, in this review we illustrate how this channel is expressed also in cells of the immune system. TRPA1 has been detected, mainly with biochemical techniques, in eosinophils, mast cells, macrophages, dendritic cells, T cells, and B cells, but not in neutrophils. Functional measurements, in contrast, remain very scarce. No studies have been reported in basophils and NK cells. TRPA1 in immune cells has been linked to arthritis (neutrophils), anaphylaxis and atopic dermatitis (mast cells), atherosclerosis, renal injury, cardiac hypertrophy and inflammatory bowel disease (macrophages), and colitis (T cells). The contribution of TRPA1 to immunity is dual: as detector of cell stress, tissue injury, and exogenous noxious stimuli it leads to defensive responses, but in conditions of aberrant regulation it contributes to the exacerbation of inflammatory conditions. Future studies should aim at characterizing the functional properties of TRPA1 in immune cells, an essential step in understanding its roles in inflammation and its potential as therapeutic target.     

复合材料在飞机和汽车上的应用动向(二)

复合材料大量用于航空航天工业和汽车工业,特别是先进碳纤维复合材料用于飞机尤为值得注意,不久前,碳纤维复合材料只能在军用飞机用作主结构,但是,由于技术发展的进步,先进复合材料已开始在民航客机上也应用作主结构,如机身、机翼等,在民航客机上使用复合材料的决定,只有波音公司和空车公司这样的拥有雄厚的人力、财力和胆识的大飞机制造公司才可能作出,至于汽车上,主要使用玻纤增强塑料(热固性和热塑性塑料)用作车身、发动机室内零部件、车顶和进气路管;碳纤维复合材料近年来也日益增多的用于汽车上,主要用作车身外板、车门、进气路管和活门盖等。     

Effects of Tyrosine and Tryptophan Supplements on the Vital Indicators in Mice Differently Prone to Diet-Induced Obesity

We studied the effects of the addition of large neutral amino acids, such as tyrosine (Tyr) and tryptophan (Trp), in mice DBA/2J and tetrahybrid mice DBCB receiving a high-fat, high-carbohydrate diet (HFCD) for 65 days. The locomotor activity, anxiety, muscle tone, mass of internal organs, liver morphology, adipokines, cytokines, and biochemical indices of animals were assessed. The Tyr supplementation potentiated increased anxiety in EPM and contributed to a muscle tone increase, a decrease in the AST/ALT ratio, and an increase in protein anabolism in both mice strains. Tyr contributed to a decrease in liver fatty degeneration and ALT reduction only in DBCB that were sensitive to the development of obesity. The addition of Trp caused an increase in muscle tone and potentiated an increase in anxiety with age in animals of both genotypes. Trp had toxic effects on the livers of mice, which was manifested in increased fatty degeneration in DBCB, edema, and the appearance of micronuclei in DBA/2J. The main identified effects of Tyr on mice are considered in the light of its modulating effect on the dopamine neurotransmitter metabolism, while for the Trp supplement, effects were presumably associated with the synthesis of its toxic metabolites by representatives of the intestinal microflora.     

污泥生物炭中氮硫行为及环境效应研究进展

污泥生物炭中氮硫元素含量高，其氮硫行为和环境效应对全球气候变化的影响不容忽视。以往的研究中，研究者往往以富碳生物炭作为主要研究对象，关注碳对全球气候变化的行为和功效，而对氮硫元素的作用关注不够。本文从原始污泥基本性质到其热解过程，再到生物炭的老化，逐步对污泥生物炭整个生命周期内氮硫的行为及其环境效应研究进行综述，并对未来应注重开展的研究方向进行展望，为生物炭中氮硫元素固定、释放及与之关联的环境效应和温室气体排放控制研究提供理论基础。分析表明，污泥中氮元素含量普遍高于硫元素，且热解过程中氮比硫更容易转移至气相产物。氮硫元素随热解温度的增加，在三相产物中的分配都是炭中持续减少，油中先增后减，气中一直增加。高温（＞800℃）条件下，气相中的氮含量高于固相，而硫元素则仍然主要存在于固相中。污泥生物炭老化及其环境效应研究表明，污泥生物炭氮硫元素与土壤的相互作用及其温室效应问题在今后的研究中应引起重视。     

Physiological effects of alarm chemosignal emitted during the forced swim test

Two experiments were conducted. In the first, male rats were immersed for 25 min in fresh water or water previously swum in by another rat. Control rats were not immersed in water. Rats tested in water previously swum in by another rat were significantly less immobile than rats tested in fresh water. Water immersion resulted in significant increases in serum corticosterone, glucose, and phosphorus levels, a decrease in potassium levels, and a higher phosphorus/potassium ratio, compared to nonimmersed controls regardless of water condition. When the two water-immersed groups were compared, rats tested in previously swum water had significantly higher glucose and significantly lower potassium levels and a higher phosphorus/potassium ratio than rats tested in fresh water. Immobility times were significantly correlated with the phosphorus/potassium ratio. In the second experiment, blood gases were measured prior to testing and at 25 min after immersion in rats tested in fresh and previously swum water. Rats in soiled water hypoventilated to a significantly greater extent than rats in fresh water but did not differ significantly in blood oxygenation. These two studies demonstrate that alarm chemosignals can produce physiological effects in conspecifics.     

Trehalose Metabolism: From Osmoprotection to Signaling

Trehalose is a non-reducing disaccharide formed by two glucose molecules. It is widely distributed in Nature and has been isolated from certain species of bacteria, fungi, invertebrates and plants, which are capable of surviving in a dehydrated state for months or years and subsequently being revived after a few hours of being in contact with water. This disaccharide has many biotechnological applications, as its physicochemical properties allow it to be used to preserve foods, enzymes, vaccines, cells etc., in a dehydrated state at room temperature. One of the most striking findings a decade ago was the discovery of the genes involved in trehalose biosynthesis, present in a great number of organisms that do not accumulate trehalose to significant levels. In plants, this disaccharide has diverse functions and plays an essential role in various stages of development, for example in the formation of the embryo and in flowering. Trehalose also appears to be involved in the regulation of carbon metabolism and photosynthesis. Recently it has been discovered that this sugar plays an important role in plant-microorganism interactions.     

木质素在超临界甲醇和乙醇溶剂中液化过程分析

通过研究木质素分别在超临界甲醇和乙醇溶剂中的液化过程，分析反应温度（260～340℃）及反应时间（0～120min）对木质素在两种溶剂中的转化率、生物油收率及其组分差异的影响。实验表明，木质素在超临界乙醇中的转化率及产物收率均高于甲醇。当反应温度340℃，反应时间60min，木质素在超临界乙醇中的转化率和生物油收率比在甲醇中分别提高了16.23%和11.54%，残渣收率降低了16.23%。通过GC-MS和FTIR对生物油和残渣分析，发现生物油组分中芳香族化合物相对含量较高，在甲醇和乙醇溶剂中分别达到66.13%和58.84%；随着反应时间的延长，甲醇溶剂中残渣的醚键官能团逐渐增强，而在乙醇溶剂中则先增强后减弱。分析认为在木质素降解过程中，超临界乙醇和甲醇均可产生氢自由基作为供氢体，攻击木质素及其大分子片段中的官能团，同时使液化产物中的活性片段减活，减弱重聚合反应，从而更利于芳烃产物的生成。而甲醇在液化过程中容易与木质素断键产生的苯酚中间体发生脱氢缩合反应，通过醚键聚合产生长链芳香族化合物，形成残渣，降低生物油收率。     

2001年世界化学工业

2 0 0 1年世界经济增长减缓 ,下半年更是陷入困境。全球化工生产总产值为 1 5 650亿欧元 ,比 2 0 0 0年下降 0 4% ,美国、欧盟、日本的化工总产值分别占整个化工产业比重的 30 42 %、31 1 8%、1 5 1 4 %。美国化工及相关产品生产比上年下降0 7% ,加拿大也出现下降 ;日本下降 3 1 % (不包括医药 ) ;而西欧的增长率从 2 0 0 0年的 4 6 %减少为 1 1 % ;俄罗斯增加了 8% ,高于工业总体增长水平 ;东欧的生产与出口都保持增长 ,而亚洲则面临困难。