Fe_3O_4/RGO的制备及其对Pb(Ⅱ)、Cu(Ⅱ)、Cd(Ⅱ)的吸附研究

以氧化石墨烯(GO)和纳米Fe_3O_4为原料,制备磁性石墨烯气凝胶(Fe_3O_4/RGO),通过场发射扫描电镜、X射线衍射仪、傅里叶红外光谱仪对Fe_3O_4/RGO进行表征,研究了Fe_3O_4/RGO对Pb(Ⅱ)、Cu(Ⅱ)、Cd(Ⅱ)的吸附特性,并使用等温吸附模型、吸附动力学模型、吸附热力学模型对吸附机理进行分析。结果表明,纳米Fe_3O_4成功负载在GO气凝胶表面,并能在外加磁场作用下实现快速磁分离。Fe_3O_4/RGO对重金属离子的吸附符合Langmuir等温吸附模型和准2级吸附动力学模型,且反应为是吸热过程,能自发进行。Fe_3O_4/RGO在25℃、p H为6时的吸附容量分别为58.48、314.5、56.12 mg/g,Fe_3O_4/RGO对重金属吸附排序为Cu(Ⅱ)Pb(Ⅱ)Cd(Ⅱ)。     

羊骨炭对Pb(Ⅱ)、Cr(Ⅵ)、Cd(Ⅱ)吸附性能研究

以CO2为活化剂制备羊骨炭,在不同溶液pH、初始浓度、活性炭投加量等条件下,通过动态吸附试验考察羊骨炭对Pb(Ⅱ)、Cr(Ⅵ)和Cd(Ⅱ)的吸附规律,并用Langmuir和Freundlich吸附等温模型对其吸附性能进行了分析。结果表明,当羊骨炭对Pb(Ⅱ)、Cr(Ⅵ)和Cd(Ⅱ)的最佳吸附量分别为:4.2 mg/g、0.07 mg/g和2.7 mg/g时,吸附液的pH值Pb(Ⅱ)、Cd(Ⅱ)为7～8、Cr(Ⅵ)为酸性pH<6;羊骨炭的投加量分别为:0.2、0.7、0.03 g;最佳初始浓度分别为:60 mg/L、15 mg/L、30 mg/L。羊骨炭对3种离子的吸附行为基本符合Langmuir吸附等温模型和Freundlich吸附等温模型,计算得四种离子的最大吸附量分别为:4.854、1.247、0.402 mg/g。     

磁性二氧化硅/壳聚糖复合气凝胶的制备及其对铜离子的吸附研究

采用共沉淀法制备四氧化三铁，通过改进Stober法将二氧化硅包裹在四氧化三铁表面，制备磁性二氧化硅，进一步制得磁性二氧化硅/壳聚糖复合气凝胶。通过扫描电镜(SEM)、X射线衍射仪(XRD)、比表面积测试(BET)和红外光谱分析(FT-IR)对其结构进行表征。结果表明，复合气凝胶的比表面积为24.93 m²/g，平均孔径为19.02 nm，是一种介孔材料，有利于对铜离子的吸附。考察了p H、复合气凝胶用量和铜离子初始浓度对吸附性能的影响。当p H为6.0、复合气凝胶用量为50 mg、铜离子初始质量浓度为10 mg/L时，复合气凝胶对铜离子的吸附率达98.99%，且循环使用4次后吸附率仍较高。复合气凝胶对铜离子的吸附过程遵循Langmuir吸附等温模型和准二级动力学方程，是一种熵增、吸热自发的化学吸附过程。     

氨基化HKUST-1制备及吸附Pb(Ⅱ)和Cd(Ⅱ)性能

采用溶剂热法合成了HKUST-1,以三乙烯四胺(TETA)采用后修饰法对HKUST-1进行改性,制得氨基功能化HKUST-1吸附剂TETA-[Cu_3(BTC)_2],对其进行了表征,并考察了其对Pb(Ⅱ)和Cd(Ⅱ)的吸附性能。结果表明,TETA成功接枝到HKUST-1上,TETA-[Cu_3(BTC)_2]具有介孔材料特性,具有较大的比表面积(976.8 m~2/g)和高密度氨基官能团,对Pb(Ⅱ)和Cd(Ⅱ)有较高的吸附量。吸附等温线拟合结果均符合Langmuir模型,拟合的Pb(Ⅱ)、Cd(Ⅱ)的最大吸附容量分别为310.6、256.4 mg/g;拟合结果均符合拟2级吸附动力学模型,说明过程以化学吸附为主。TETA-[Cu_3(BTC)_2]在去除水溶液中重金属离子方面有潜在的良好应用前景。     

核桃壳、花生壳和木屑对Pb(Ⅱ)的吸附研究

采用农林废弃物核桃壳、花生壳和木屑对重金属铅进行吸附研究。探讨反应时间、温度、pH值、吸附剂用量和初始Pb(Ⅱ)浓度以及吸附剂改性对吸附效果的影响,结果表明,花生壳对Pb(Ⅱ)的吸附效果优于核桃壳和木屑,其在45℃,pH值6.0,Pb(Ⅱ)初始浓度100 mg/L,花生壳投入量10 g/L的条件下反应240 min,其吸附率为88.1%,花生壳改性后的吸附率可达97.8%。花生壳、核桃壳和木屑对Pb(Ⅱ)的吸附均可用Langmuir方程描述。     

粉煤灰改性及其吸附废水中Pb(Ⅱ)的研究

采用高温焙烧法制备改性粉煤灰(MFA),考察了改性粉煤灰投加量、初始pH、吸附时间对水中Pb(Ⅱ)吸附效果的影响,通过吸附动力学方程和吸附等温线方程对吸附机理进行了分析。结果表明,在温度30℃,初始Pb(Ⅱ)浓度40 mg/L,MFA投加量2 g/L,pH为5.5,吸附时间为30 min时,Pb(Ⅱ)的吸附率达到97.97%,水中残留的Pb(Ⅱ)浓度低于1.0 mg/L,满足排放标准的要求。吸附动力学符合拟二级动力学方程,吸附等温线符合Freundlich方程,吸附机制为化学吸附。     

氨基和羧基功能化磁性微球去除水溶液中Cd(Ⅱ)和Pb(Ⅱ)

以甲基丙烯酸和丙烯酰胺为功能单体,通过悬浮聚合法制备了氨基和羧基双功能化的磁性复合微球(Fe3 O4@SiO2-NH2/COOH),并探讨了其对水溶液中Cd(Ⅱ)和Pb(Ⅱ)的吸附性能.X-射线衍射(XRD)分析表明,制备的磁性吸附剂内核为Fe3 O4.红外光谱(FT-IR)和扫描电镜(SEM)测试表明,氨基和羧基对Fe3 O4@SiO2表面改性成功.吸附试验显示,Fe3O4@SiO2-NH2/COOH吸附Cd(Ⅱ)和Pb(Ⅱ)的最优pH值分别为5.0和5.5,吸附过程均符合动力学准二级模型和Langmuir吸附等温模型,吸附剂对Cd(Ⅱ)和Pb(Ⅱ)最大吸附量分别为207.807 mg/g和168.995 mg/g.实际饮用水样中Cd(Ⅱ)和Pb(Ⅱ)的吸附表明,去除率分别可达97.74％和91.44％.该磁性吸附剂对两种重金属离子吸附量大、去除率高,具有良好的实际应用潜力.     

改性泥炭对Pb(Ⅱ)和Cd(Ⅱ)的单一及竞争吸附研究

以强碱改性泥炭,研究改性泥炭对Pb⁽²⁺⁾、Cd(2+)、Cd⁽²⁺⁾的吸附效果及竞争吸附机制。结果表明,改性泥炭对Pb(2+)的吸附效果及竞争吸附机制。结果表明,改性泥炭对Pb⁽²⁺⁾、Cd(2+)、Cd⁽²⁺⁾具有显著的吸附效果,吸附容量分别由118,64 mg/g提高到225,95 mg/g;FTIR分析表明,吸附过程为Pb(2+)具有显著的吸附效果,吸附容量分别由118,64 mg/g提高到225,95 mg/g;FTIR分析表明,吸附过程为Pb⁽²⁺⁾、Cd(2+)、Cd⁽²⁺⁾与—OH、—COO-、C—H等官能团的络合作用或者离子交换作用。当吸附时间为70 min,pH在4～8,改性泥炭添加量分别为0.8,1.6 g/L时,可达到高效与经济双层效益。竞争吸附中,Pb(2+)与—OH、—COO-、C—H等官能团的络合作用或者离子交换作用。当吸附时间为70 min,pH在4～8,改性泥炭添加量分别为0.8,1.6 g/L时,可达到高效与经济双层效益。竞争吸附中,Pb⁽²⁺⁾、Cd(2+)、Cd⁽²⁺⁾的吸附容量均低于单一离子时的吸附容量,且竞争吸附能力Pb(2+)的吸附容量均低于单一离子时的吸附容量,且竞争吸附能力Pb⁽²⁺⁾>Cd(2+)>Cd⁽²⁺⁾。     

FAAS法研究纳米凹凸棒土对铅(Ⅱ)的吸附行为

通过FAAS法探讨纳米凹凸棒土对Pb(Ⅱ)的吸附行为,考察了影响其吸附和解脱的主要因素以及共存离子的影响,研究了纳米凹凸棒土对Pb(Ⅱ)的吸附等温线和静态饱和吸附容量。实验结果表明,纳米凹凸棒土对Pb(Ⅱ)的最大静态饱和吸附容量为25.5mg/g,一次再生和二次再生的纳米凹凸棒土的最大静态饱和吸附容量分别为26.5mg/g和26.3mg/g,结果表明纳米凹凸棒土具有较好的再生能力。     

BP-PSO优化改性凹凸棒土吸附Pb(Ⅱ)条件及其机制研究

为探究Keggin离子改性凹凸棒土对Pb(Ⅱ)的吸附性能及获得Pb(Ⅱ)最大去除率,采用响应面(RSM)及反向传播神经网络结合粒子群算法(BP-PSO)对去除条件进行优化,利用X射线光电子能谱仪表征、动力学、等温吸附及热力学研究对吸附机理进行探讨,采用可渗透反应墙对Pb(Ⅱ)去除进行动态模拟.XPS表征结果显示Pb(Ⅱ)被吸附到改性土表面,该吸附过程并未发现氧化还原反应.RSM优化下,预测和实际Pb(Ⅱ)最大去除率分别为83.85％和81.24％,相对应的去除条件:反应时间为50.02 min、初始Pb(Ⅱ)浓度为150 mg/L、温度为20℃及初始pH值为7.BP-PSO优化下最大去除率为85.68％,对应的实验条件:温度为20℃,反应时间为52.28 min,初始Pb(Ⅱ)浓度为250 mg/L,初始pH值为7,在此条件下验证实验值为84.41％.BP-PSO更合适用于优化改性凹凸棒土吸附水溶液中Pb(Ⅱ).改性凹凸棒土对Pb(Ⅱ)的吸附为吸热、自发及熵驱动的过程.可渗透反应墙中对Pb(Ⅱ)去除率的去除效果不理想.     

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.     

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.     

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.     

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.