氢氧化镁改性活性炭对Cu(Ⅱ)的吸附

以氢氧化镁和活性炭为原料,在30℃条件下采用反应结晶技术制备了氢氧化镁改性活性炭材料(Mg-GAC),通过SEM、XRD对改性前后活性炭进行了表征,考察了温度、时间和pH对复合材料吸附废水中Cu(Ⅱ)的影响。结果表明,GAC经改性后,比表面积增至738.01 m~2/g。在Mg-GAC投加量为0.3 g、Cu(Ⅱ)质量浓度为0.04g/L、温度为25℃、pH为7的条件下反应2h,其吸附量达到11.66mg/g。Cu(Ⅱ)的吸附过程符合Langmuir等温模型,为单层吸附。     

活性炭/粉煤灰处理含铜废水的研究

采用活性炭/粉煤灰处理模拟含铜废水,考察pH、吸附时间、吸附温度、投加量、质量比、活性炭、粉煤灰粒径、铜离子浓度等对吸附效果的影响。结果表明,单纯粉煤灰的吸附效果较差,但100目的粉煤灰与100目的活性炭混合,其吸附效果接近于纯活性炭。活性炭/粉煤灰处理100 m L、30 mg/L模拟含铜废水的最佳吸附条件为:吸附时间3 h,pH 6,吸附温度45℃,活性炭/粉煤灰(质量比1∶1)投加量2.5 g,活性炭和粉煤灰粒径均为100目。在此条件下,铜离子去除率可达97.33%,处理后水中铜离子浓度(0.811 4 mg/L)低于国家二级排放标准(1.0 mg/L)。     

活性炭/粉煤灰处理含铜废水的研究

采用活性炭/粉煤灰处理模拟含铜废水,考察pH、吸附时间、吸附温度、投加量、质量比、活性炭、粉煤灰粒径、铜离子浓度等对吸附效果的影响。结果表明,单纯粉煤灰的吸附效果较差,但100目的粉煤灰与100目的活性炭混合,其吸附效果接近于纯活性炭。活性炭/粉煤灰处理100 m L、30 mg/L模拟含铜废水的最佳吸附条件为:吸附时间3 h,pH 6,吸附温度45℃,活性炭/粉煤灰(质量比1∶1)投加量2.5 g,活性炭和粉煤灰粒径均为100目。在此条件下,铜离子去除率可达97.33%,处理后水中铜离子浓度(0.811 4 mg/L)低于国家二级排放标准(1.0 mg/L)。     

硝酸铁改性活性炭对六价铬离子吸附性能研究

利用硝酸铁改性和无改性两种活性炭吸附六价铬离子探究吸附时间、溶液pH值、两种活性炭投加量对去除效果的影响。结果表明:颗粒活性炭(GAC)和硝酸铁改性活性炭(Fe-GAC)对六价铬离子的吸附效果均随着时间的增加而增加;GAC和Fe-GAC吸附效果均随着投加量的增加而增加,当吸附剂投加量为5 g/L时,去除率分别为65.41%和73.03%;p H值在4～10的范围内GAC和Fe-GAC的吸附效果均随着pH的升高而降低,pH为4时,吸附效果最好,去除率分别达到81.05%和83.99%;二者均为单分子层吸附;Fe-GAC吸附效果优于GAC的原因为改性后酸性含氧官能团增加,表面酸性增强,表面极性增强。     

沙柳活性炭纤维对铜离子的吸附及动力学分析

以沙柳活性炭纤维(ACF)吸附水体中的Cu⁽²⁺⁾离子,讨论吸附时间、ACF投加量、pH、温度及溶液浓度对铜离子去除率的影响,并研究了沙柳ACF对铜离子的吸附动力学。结果表明,在pH为4.1,ACF投加量0.4 g,温度45℃,铜离子溶液浓度100 mg/L,吸附时间90 min的条件下,ACF对铜离子去除率达70%,且pH是影响铜离子去除率的第一因素,准二级动力学模型可以更理想地描述沙柳ACF对铜离子的吸附过程。     

十六烷基三甲基溴化铵改性活性炭的制备及吸附苯酚研究

利用十六烷基三甲基溴化铵(CTAB)对颗粒活性炭进行改性。用红外光谱(FT-IR)、X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)和氮吸附脱附法对改性活性炭的结构和组成进行表征。用单一变量法研究了CTAB的质量浓度和初始pH值对CTAB活性炭改性的影响,研究了吸附时间、吸附温度、苯酚初始质量浓度、苯酚pH、CTAB改性活性炭投加量等对苯酚去除率的影响,并对吸附过程进行了动力学研究。得到了最佳吸附条件为:以质量浓度为2g/L的CTAB改性活性炭为吸附剂,CTAB改性活性炭投加量为7g/L、吸附温度为35℃、吸附时间为90min、苯酚初始质量浓度为200mg/L、初始pH=6时,苯酚去除率达到94.76%,CTAB改性活性炭的吸附量为27.07mg/g。Langmuir等温吸附模型可较好地描述CTAB改性活性炭对水中苯酚的等温吸附过程,通过Langmuir模型计算得到吸附剂对苯酚的最大单位吸附量为72.62mg/g。CTAB改性活性炭对苯酚的吸附过程符合拟二级动力学方程。     

沙柳活性炭纤维对铜离子的吸附及动力学分析

以沙柳活性炭纤维(ACF)吸附水体中的Cu~(2+)离子,讨论吸附时间、ACF投加量、pH、温度及溶液浓度对铜离子去除率的影响,并研究了沙柳ACF对铜离子的吸附动力学。结果表明,在pH为4.1,ACF投加量0.4 g,温度45℃,铜离子溶液浓度100 mg/L,吸附时间90 min的条件下,ACF对铜离子去除率达70%,且pH是影响铜离子去除率的第一因素,准二级动力学模型可以更理想地描述沙柳ACF对铜离子的吸附过程。     

油茶果壳活性炭对铜离子的吸附性能

利用油茶壳活性炭吸附铜离子,探讨了时间、pH值、Cu(Ⅱ)初始质量浓度等因素对油茶壳活性炭吸附性能的影响;并分析了其吸附等温曲线和动力学方程。结果表明,油茶壳活性炭对铜离子吸附量可达到63.6 mg/g。油茶壳活性炭对铜离子的去除率随吸附时间的增加而增大,5 h后达到平衡;随着pH值的升高,油茶壳活性炭吸附铜离子的吸附量不断下降。油茶壳活性炭对铜离子的吸附等温数据符合Langmuir方程,吸附动力学过程可用准二级动力学模型进行模拟,相关系数为0.997 5。     

羧甲基甲壳胺纤维对铜离子的吸附性能

为了提高甲壳胺纤维对重金属离子的吸附性能,用氯乙酸对纤维进行改性处理,在纤维的结构中引入羧甲基团后使纤维同时具有能结合重金属离子的胺基和羧酸基团。研究了改性后纤维在不同的改性程度、添加量、时间、温度、pH值等条件下对铜离子的吸附性能。结果表明:羧甲基化改性后的甲壳胺纤维对铜离子有很好的吸附性能。在同样的条件下,未改性的纤维对铜离子的吸附值为41.3mg/g,而改性后的纤维为79.4mg/g。经过羧甲基化改性的甲壳胺纤维对铜离子的饱和吸附容量可以达到148.1mg/g。     

硝酸铁改性活性炭吸附Pb(Ⅱ)的性能研究

为提高活性炭对Pb~(2+)的吸附效果,用硝酸铁对活性炭进行了改性处理。采用BET、SEM、Boehm等方法对改性前后活性炭的理化特性进行了表征,考察了吸附时间、p H、吸附剂投加量对改性前后活性炭吸附Pb~(2+)效果的影响。结果表明,相比于未改性活性炭(GAC),硝酸铁改性活性炭(Fe-GAC)比表面积减少,酸性含氧官能团增加,极性增强。对于质量浓度为10 mg/L的Pb~(2+)溶液,Fe-GAC的最佳投加量为2.0 g/L,此条件下Pb~(2+)去除率可达到98.73%,比采用GAC提高了30.15%。吸附剂吸附Pb~(2+)过程与Langmuir吸附等温线方程拟合较好,相关系数R2在0.99以上。     

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.     

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。     

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.     

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。