乙草胺在土壤中的吸附研究

为了明确乙草胺在3种不同土壤的吸附性能,本试验采用生物测定技术,研究了乙草胺在海南当地垃圾土、菜地土及塘泥土中的吸附特性。结果表明,3种土壤对乙草胺的吸附浓度Cs与溶液中农药的浓度Ce呈良好的线性关系,吸附特性符合Freundlich方程,垃圾土、菜地土、塘泥土对乙草胺的吸附系数分别3.887、2.9833、2.0613,为物理吸附,且有机质含量高的垃圾土的吸附能力大于有机质含量低的菜地土及塘泥土。     

莠灭净在不同土壤中的吸附行为研究

采用振荡平衡法分别对莠灭净在不同甘蔗种植区土壤中的吸附特性进行了比较研究。结果表明,莠灭净在四地土壤中的吸附等温曲线符合Freundlich方程,广西来宾、广西扶绥、广西武鸣蔗土对莠灭净的吸附等温线呈S型,安徽萧县蔗土吸附等温线呈L型,吸附常数分别为4.85,4.00,2.87,0.77。莠灭净难以被土壤吸附,吸附能力与土壤有机质质量分数呈正相关。四地土壤对莠灭净吸附能力依次为广西来宾、广西扶绥、广西武鸣、安徽萧县。     

2,4-二氯苯酚在黄土性土壤中的吸附与解吸

采用静态与动态实验相结合的方法,研究了2,4-二氯苯酚在黄土性土壤中的吸附和解吸规律,测定吸附动力学和吸附热力学曲线,获得吸附热力学模型。研究表明,2,4-二氯苯酚在黄土性土壤中吸附等温线可用Freundlich和Langmuir方程描述,其中q0描述饱和吸附量,由Langmuir吸附等温式拟合数据可以看出:TS-2土的饱和吸附量大于TM-1土(这是因为2,4-二氯苯酚在土壤中的吸附量与土壤中有机质的含量密切相关);由Freundlich吸附等温式拟合得到的常数,1/n均1,证明是优惠吸附;根据吸附符合Langmuir方程,说明在土壤表面,2,4-二氯苯酚为单分子层吸附;吸附-解吸具有一定的可逆性,黄土性土壤对2,4-二氯苯酚的吸附能力不强,2,4-二氯苯酚极易穿透土壤,污染地下水。     

腐植酸对铜、锌、钼和锰的吸附研究

研究了腐植酸对水溶液中重金属铜、锌、钼和锰等离子的吸附行为,并对分析的最佳条件进行了探讨。泥炭经磺化处理,制备不溶性腐植酸,其温度和吸附时间等对吸附的影响结果表明,随着pH的增大,腐植酸对铜、锌、钼和锰的吸附率增加。当pH=5时,铜、锌、钼和锰在腐植酸中的吸附率达到最大值。吸附进行20min后,腐植酸对4种离子的吸附率达到最大值。吸附等温线分别以Freundlich方程和Langmuir方程进行拟合,结果显示：锰、钼和铜吸附的最佳模型为Langmuir方程,锌的最佳吸附模型是Freundlich方程。同时发展了ICP测定重金属铜、锌、钼和锰的分析方法。     

衣藻对重金属生物吸附的实验研究

以衣藻为生物吸附材料,研究了它对重金属钴、铜、锌的生物吸附,并用Freundlich等温吸附方程对实验数据进行处理。结果表明衣藻对这三种金属吸附能力大小顺序为锌钴铜;农藻对重金属的吸附能力很强,可用衣藻来处理含重金属的废水。     

3种拟除虫菊酯类农药在不同土壤中的吸附行为特性分析

[目的]明确氯氟氰菊酯、联苯菊酯和高效氯氰菊酯在沙土、壤土和水稻土中的吸附特性。[方法]试验采用振荡平衡法和气相色谱法进行研究。[结果]得到3种农药在不同土壤中的吸附方程,符合Freundlich方程;氯氟氰菊酯、联苯菊酯和高效氯氰菊酯在沙土、壤土和水稻土中的吸附系数分别为71.38、134.63、181.77、78.26、199.34、239.13、57.18、222.53、603.72,吸附特性等级为易吸附或较易吸附,平均吸附自由能绝对值范围为18.19~22.03,属于物理吸附。[结论]3种农药在不同土壤中都具有较强的吸附能力。     

乙草胺在3种土壤中的吸附和解吸附特性

[目的]明确乙草胺在3种土壤中的吸附和解吸附特性。[方法]试验采用振荡平衡法,研究乙草胺在3种土壤中的吸附特性及其在水稻土中解吸附特性。[结果]乙草胺在3种土壤中的吸附性符合Freundlich方程,吸附常数(Kd)在0.41~11.12 m L/g之间,水稻土比红壤和潮土对其的吸附能力强。Kd-OM之间的r2在0.639~1之间。标准吸附自由能变为-17.63~2.21 k J/mol,焓变为23.18~59.16 k J/mol,熵变为80.24~207.59 k J/mol。[结论]土壤对乙草胺的吸附主要受其有机质支配。红壤对乙草胺的吸附属于吸热、化学吸附、熵变增加过程,水稻土、潮土对乙草胺的吸附均属自发、吸热、物理吸附、熵变增加的过程。     

甲基托布津对土壤中铜离子吸附影响及机理探讨

实验室条件下,土壤吸附试验表明,甲基托布津能够使铜离子在土壤上的表观吸附量增加.对吸附数据进行拟合发现,吸附曲线符合Freundlich方程.甲基托布津的存在使得土壤吸附常数K值增大.铜离子选择电极测定甲基托布津与铜离子的pCu-pL关系曲线表明,铜离子和甲基拖布津能够以1:1的配位数配合.甲基托布津与铜形成不溶性络合物,从而使铜的表观吸附量增加.     

SMZ在2种寒地土壤中的吸附特性实验研究

采用OECD guideline 106批平衡方法,对磺胺甲恶唑(SMZ)在2种寒地土壤——草甸黑土和暗棕壤土中的吸附特性进行研究。研究表明,SMZ在2种土壤中的吸附均符合Freundlich方程和Langmuir方程,相关系数(r)在0.968 6⁰.995 7,达到极显著相关,吸附等温线属"L"型;其中SMZ在暗棕壤土中的吸附量远远大于在草甸黑土中的吸附量,这可能与土壤p H、有机质含量、阳离子交换量等因素有关。随着溶液pH值的升高,2种土壤的吸附能力均减弱;有机质含量升高对SMZ在草甸黑土中的吸附有显著影响,且随着有机质含量的增加而增大;在暗棕壤土中,添加有机质对其吸附量影响并无显著效果。     

凹凸棒土对溶液中Zn(Ⅱ)的吸附性能研究

凹凸棒土比表面积大,对金属离子锌Zn(Ⅱ)有很好的吸附作用。本文以凹凸棒土对溶液中Zn(Ⅱ)离子吸附为研究实验,结果表明在碱性条件下,化学吸附性能好。并通过吸附热力学实验,探讨吸附特性与机理,表明凹凸棒土对Zn(Ⅱ)离子的吸附特性更符合Freundlich单分子层吸附模型;单位浓度吸附量k值随着温度的升高,先增大后减小;温度对吸附量的影响n值,呈减小趋势,表明物理吸附效果好。     

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.     

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.     

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.     

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.     

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。     

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。