高比表面积活性炭负载磷钨酸催化乙醇制乙烯

乙醇脱水制乙烯方法的关键是催化剂及其载体的研究。以高比表面积活性炭为载体,采用浸渍法将催化剂磷钨酸负载到活性炭孔结构中,制备出新型催化剂PW/AC。分别考察了反应温度、进料流量和磷钨酸负载量对乙醇转化率的影响,得出较佳的条件分别为反应温度300℃、进料流量0.09mL/min和磷钨酸负载量60%（质量百分比）。     

浸渍法制备PW12／SBA-15催化合成柠檬酸三丁酯

以分子筛SBA-15为载体,采用浸渍法负载磷钨酸作催化剂,催化合成柠檬酸三丁酯.考察了醇酸比、反应温度、催化剂用量、反应时间等因素对酯化率的影响.实验表明,分子筛SBA-15负载磷钨酸作为柠檬酸合成催化剂,催化活性良好.适宜的反应条件:醇酸摩尔比为4:1,磷钨酸负载质量分数为27%,催化剂用量为反应物总质量的1.3%,反应时间为7 h,酯化率最高可达96%.     

活性炭负载磷钨酸催化脱水反应

使用活性炭负载磷钨酸催化剂,对仲醇脱水反应进行考察,通过对磷钨酸在载体上的吸附量、磷钨酸固载的温度、磷钨酸固载的时间、脱水温度和脱水时间对转化率的影响。确定最佳的工艺条件为:磷钨酸负载质量分数45%,磷钨酸固载的温度130℃,磷钨酸固载的时间3 h,脱水温度110℃,反应时间3 h。在此条件下,转化率为96.4%。     

活性炭负载磷钨酸催化合成氯乙酸正戊酯

制备了活性炭为载体负载型磷钨酸催化剂，并采用XRD、IR、N2吸附等手段进行了表征。将其用作合成氯乙酸正戊酯催化剂。考察了醇酸物质的量比、温度、催化剂用量、反应时间等各种因素对酯化率的影响。实验结果表明，活性炭负载磷钨酸催化活性良好。适宜的反应条件：磷钨酸负载量为18%，醇酸物质的量比为1.3∶1，催化剂用量为反应物总质量的2.5％，反应时间（3~5） h。酯化率最高可达98%。     

ZSM-5负载杂多酸催化剂的制备及其氧化脱硫性能研究

以ZSM-5材料为载体,分别采用浸渍法、溶胶凝胶法、水热分散法将杂多酸（磷钼酸、磷钨酸）负载于ZSM-5上制备催化剂。利用X射线衍射、红外光谱、扫描电镜等方法对催化剂进行了表征,发现杂多酸能够高度分散在载体表面。以苯并噻吩为反应物进行氧化脱硫反应,考察了不同合成条件对反应效率的影响。结果表明：水热分散法合成负载磷钨酸催化剂的脱硫效果最好,在反应温度为60℃,负载量为10%,剂油等体积比的最佳反应条件下,脱硫率为73.2%。     

固体酸催化过氧化氢异丙苯分解制苯酚丙酮反应的研究

对固体酸催化过氧化氢异丙苯分解制苯酚丙酮反应进行了研究,发现以β沸石为载体、磷钨酸为主催化剂、硫酸钛为助催化剂制备的负载型催化剂,对该反应具有较高的催化活性和选择性.同时,考察了催化剂制备条件、反应温度、原料配比等因素对催化剂活性的影响.结果表明,磷钨酸含量为25％、硫酸钛含量为5％、焙烧温度250℃、焙烧时间4 h;...     

负载杂多酸(盐)的表征及其在苹果酯合成反应中的催化性能

用浸渍法制备了一系列负载型磷钨酸及其铯盐催化剂,载体包括超稳Y沸石（USY）、脱铝超稳Y沸石（DUSY）、SiO₂和SBA-15,测定了催化剂的比表面积和酸强度,并在乙酰乙酸乙酯与乙二醇液相缩合制取苹果酯反应中考察了催化剂的性能.结果表明,这些负载型杂多化合物催化剂都表现出较高的催化活性.然而,催化剂在水中的溶脱性能实验表明,负载型磷钨酸催化剂存在严重的活性组分流失现象,不能重复使用,而DUSY负载的磷钨酸铯盐催化剂不仅表现出较高的催化活性,而且显示出较好的重复使用性能.在优化的反应条件下30% (质量分数) Cs_2.5H_0.5PW/DUSY催化剂上乙酰乙酸乙酯的转化率可达98.7%,苹果酯的选择性大于97%.     

苹果酯的合成工艺研究

以酸化的凹凸棒石黏土为载体,用浸渍法制备了凹凸棒石负载磷钨酸催化剂,并采用XRD、IR和紫外可见分光光度法等手段对催化剂进行了表征。将此用做合成苹果酯的催化剂,考察了反应物的摩尔比、催化剂用量、带水剂用量、反应时间和反应温度等各种因素对苹果酯收率的影响。实验结果表明,凹凸棒石负载磷钨酸催化剂催化活性良好,结构稳定且能够重复使用,并得到较佳工艺条件:n(乙酰乙酸乙酯)∶n(乙二醇)=1.0∶1.5,催化剂用量为2 g,带水剂苯为50 mL,110℃下反应180 min,苹果酯收率可达89.7%。     

固体酸催化合成乳酸丁酯

锡、镁、铁、铜和镍等不同金属掺杂的磷酸铝固体酸、杂多磷钨酸及其二氧化硅负载的催化剂用于乳酸正丁酯的合成,考察了各种反应条件的影响。结果表明,反应温度是重要的影响因素,反应温度以120 ℃较适宜。二氧化硅负载的杂多磷钨酸催化剂是较好的催化剂,而且负载的HPW/SiO₂催化剂能大大减少杂多磷钨酸的用量。     

二氧化硅负载磷钨酸催化氧化环己醇为环己酮的研究

以二氧化硅为载体,采用等体积浸渍法制备了负载磷钨酸催化剂,利用XRD和FT-IR对催化剂进行了表征,并以H2O2(30%)为氧化剂,初步评价了催化剂催化氧化环己醇为环己酮的催化性能。结果表明,负载催化剂保持了磷钨酸的Keggin结构,在催化氧化环己醇的反应中表现出较强的催化活性,产物中只有环己酮;反应温度、时间等反应条件对催化氧化反应有明显的影响,在最佳条件下,环己醇转化率为86.5%;该氧化体系具有较宽的应用范围,实验所用伯醇、仲醇较好的氧化转化为相应的醛或酮。     

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。     

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.     

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.