生物酶土壤固化剂在道路工程中的应用研究进展

生物酶固化剂作为一种环境友好的新型土壤固化材料,在路面地基材料加固方面具有重要的应用前景。本文概述了新型生物酶固化剂的性质及固化机理,并对生物酶固化剂在改良我国粉土、粉质黏土、淤泥土和膨胀土等不同土质中的具体研究和应用情况进行综述,指出了生物酶固化剂在路基应用领域存在的问题与未来发展的方向。     

氧化镁基固化剂对镉离子的固化作用及其影响因素

以韶关某地土壤制作模拟污染土壤为研究对象,应用正交实验,研究出氧化镁基固化剂固化土壤重金属Cd2+的主要影响因子为氧化镁、膨润土和硅藻土,其最优质量比例是3∶14∶7。在此基础上,应用批量平衡法,研究了固化剂与单纯氧化镁对Cd2+的对比固化效果和不同初始p H、离子浓度条件下,固化剂对Cd2+的固化作用。结果表明:固化剂对Cd2+的固化主要是氧化镁的沉淀作用,最大固化量为203.2 mg·g-1;随着初始p H(2~6)的提高,固化剂对Cd2+的固化量增加并趋于稳定;随离子强度(0.00~0.30 mol·L-1)的增加,固化剂对Cd2+的固化量减少。     

水性环氧树脂固化剂的研究进展

水性环氧固化剂是水性环氧体系的重要组成部分,其组成和结构对涂膜的物理化学性能起决定性作用。本文介绍了环氧树脂固化剂的种类及优缺点;介绍了离子型和非离子型水性环氧固化剂的制备方法及发展概况;综述了近年来国内外有关水性环氧固化剂的改性技术,包括有机硅、有机磷、聚氨酯以及无机纳米粒子改性;展望了水性环氧固化剂的未来研究方向,指出了水性环氧固化剂应走功能化之路,对特殊环境、特殊行业具有适用性和专用性。     

高性能土壤固化剂的制备与性能

为适应滨州地区土壤盐渍土的土质要求,提高固化土壤的强度,以石灰、石膏为主要原料,通过正交试验的方法研究了影响滨州地区土壤的因素,确定了高性能土壤固化剂的最佳配比.对固化剂稳定土与石灰、水泥等稳定土进行对比试验,并初步分析了其固化机理.结果表明:固化剂稳定土的强度高于石灰、水泥等稳定土,且水稳与冻稳系数均大于0.90.     

国内固化剂修复重金属污染土壤的研究进展

综述了土壤重金属污染来源、修复重金属污染土壤的主要方法及主要方式,并着重论述了常见的无机固化剂、有机固化剂、离子拮抗剂、复合固化剂的修复机理及修复效果。综合来看向土壤施加固化剂可以有效地吸附和固定土壤重金属,但也存在一定风险,使用不当易造成二次污染。研究发现多种固化剂联合修复较单一固化剂修复效果要更好。在使用土壤固化剂时需结合土壤类型、土壤污染物类型及污染物性质等多方面的因素来综合使用,从而达到修复重金属污染土壤最好的效果。     

新型非离子型自乳化水性环氧树脂固化剂的合成与表征

采用十八胺与乙二醇二缩水甘油醚反应,制得一种两端为环氧基,中间氮原子上接有长疏水烷基链的功能性双环氧基化合物,再用脂三乙烯四胺对该化合物进行封端,制得一种非离子型水性环氧固化剂.研究表明:由于该固化剂具有疏水效果的长烷基链和亲水效果的羟基、胺基、醚键,从而使得该固化剂具有表面活性剂的结构.因此相对其他水性固化剂来讲,该固化剂不仅仅不需要采用中和剂就具有亲水性,且其对环氧树脂有良好的乳化效果.该固化剂与液体环氧树脂所制备的双组分室温固化涂膜性能优良,具有优异的铅笔硬度、耐冲击性和耐化学性.同时该固化剂含有较长的柔性烷基链,所以固化后的环氧树脂将有较好的柔韧性.     

双向可调多功能R系列环氧树脂固化剂的粘接性能研究

研究了具有耐高温性、阻燃性、增韧性和耐烧蚀性等多种功能的双重可调性R系列环氧树脂(EP)新型固化剂,该固化剂与EP的配比范围较宽且可调,该固化剂分子中增韧链段的比例范围较宽且可调。利用其多功能性和双重可调性,可以很快地优选出具有特定性能要求的一系列胶粘剂(如具有耐高温性、高韧性和高强度等性能的胶粘剂),并且有望开辟出梯度功能固化剂、梯度功能EP胶粘剂和梯度功能复合材料等新领域。     

环氧固化剂的研究现状与未来

介绍了我国环氧树脂固化剂的研究现状,分析了制约环氧树脂固化剂发展的因素,对环氧树脂固化剂的发展方向作了展望.     

水性双组分环氧/胺体系技术研究

为了全面、深入介绍水性双组分环氧/胺体系的技术方向和路线,论述了双组分水性环氧/胺体系(Ⅰ型和Ⅱ型)技术的发展历程;概述了Ⅰ型和Ⅱ型体系的固化成膜原理和机理;研究了Ⅰ型和Ⅱ型体系水性环氧树脂与固化剂技术提升思路,如,Ⅰ型环氧树脂的物理改进和化学改进的思路,3类Ⅰ型固化剂的技术发展,Ⅱ型环氧树脂及固化剂的技术发展;介绍了环氧丙烯酸杂化新技术的原理和应用。指出,具有相容性好、涂膜初期耐水性好、与锌粉配伍性好且适用期长、高性价比等性能的环氧树脂/固化剂体系将成为未来的发展方向。     

环氧树脂固化剂的发展现状与趋势

介绍了我国环氧树脂固化剂的研究现状,对环氧树脂固化剂的发展方向作了展望。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外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、聚苯乙烯、聚氯乙烯、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、聚氨酯、环氧树脂、不饱和聚酯树脂)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。     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.