TiO2/Nd2Zr2O7复合物的合成及催化性能

通过溶胶-凝胶法成功合成了TiO2/Nd2Zr2O7复合氧化物.采用X射线衍射、透射电子显微镜、扫描电子显微镜对材料进行了表征,并对其比表面积进行了测试.结果表明:TiO2均匀地包覆在了Nd2Zr2O7颗粒的表面,其包覆量为50.36％(质量分数);TiO2/Nd2Zr2O7复合物的BET比表面积为25.62 m2/g,比Nd2Zr2O7纳米晶的表面积3.48 m2/g大得多.通过降解甲基橙评价产物的光催化活性,证实TiO2/Nd2Zr2O7复合物具有好的光催化活性.通过Nd2Zr2O7,TiO2和TiO2/Nd2Zr2O7在20 min内降解甲基橙的降解量分别为20.1％,70.7％和88.2％.     

微波法合成的氮化碳光催化降解苯酚及其机理

以微波法合成了石墨状氮化碳(g–C_3N_4)。采用X射线衍射、X射线光电子能谱及紫外–可见光谱、光致发光谱对g–C_3N_4的微观结构和光学性能进行了表征,以光催化降解苯酚反应为探针,研究了g–C_3N_4的光催化性能,并探讨了其降解苯酚的机理。结果表明:采用微波法制备的g–C_3N_4层状结构完整,光催化稳定活性高;对波长400~550 nm的可见光有明显的吸收,对苯酚降解率为75.4%。同时,H_2O_2的加入使苯酚溶液中产生更多·OH,苯酚的降解率提升至92.9%。     

Synthesis and Photocatalytic Activity of N-doped ZnO

采用溶胶–凝胶法合成纳米 ZnO，用碳酸铵溶液浸渍的方法对其进行 N 掺杂。利用 X 射线衍射仪，透射电子显微镜，X 射线能谱仪，Fourier红外光谱仪，X 射线光电子能谱仪，紫外–可见光谱仪对产物结构进行了表征，通过可见光催化降解甲基橙对 N-ZnO 的光催化活性进行了考察。结果表明：合成的 ZnO 颗粒大小在 20～30 nm，N 的掺杂没有改变 ZnO 的晶型，N 在 ZnO 晶格中形成 N—Zn—O 键；N 掺杂拓宽了 ZnO 的可见光吸收范围。N-ZnO 作为光催化剂在可见光作用下能有效降解甲基橙，表现出较高的可见光催化活性。当（NH4）2CO3和 ZnO 的摩尔比为 0.20 时，N-ZnO 的光催化性能最好。     

水热法制备的Ce-ZnO结构表征及其光催化性能研究

采用水热法制备不同摩尔比的稀土元素Ce掺杂Zn O光催化纳米材料Ce-Zn O,用红外(FTIR)光谱、X射线衍射(XRD)、紫外-可见光谱(UV-Vis)、光致发光(PL)等对其进行表征;研究了不同Ce掺杂量的Ce-Zn O对亚甲基蓝溶液(MB)光催化性能的影响。结果表明,Ce掺杂量2%时,Zn O的表面状态得到明显改善,生成更多的羟基自由基;同时增加光生电子空穴对的浓度,显著提高Zn O的光催化性能;经过2 h紫外汞灯照射,其降解率达到93.68%;且经过5次循环使用后,2%Ce-Zn O的降解率依旧能达到85%以上,具有良好的光催化性能和循环稳定性。     

水热法制备的Ce-ZnO结构表征及其光催化性能研究

采用水热法制备不同摩尔比的稀土元素Ce掺杂Zn O光催化纳米材料Ce-Zn O,用红外(FTIR)光谱、X射线衍射(XRD)、紫外-可见光谱(UV-Vis)、光致发光(PL)等对其进行表征;研究了不同Ce掺杂量的Ce-Zn O对亚甲基蓝溶液(MB)光催化性能的影响。结果表明,Ce掺杂量2%时,Zn O的表面状态得到明显改善,生成更多的羟基自由基;同时增加光生电子空穴对的浓度,显著提高Zn O的光催化性能;经过2 h紫外汞灯照射,其降解率达到93.68%;且经过5次循环使用后,2%Ce-Zn O的降解率依旧能达到85%以上,具有良好的光催化性能和循环稳定性。     

铁-锌卟啉框架材料及其可见光催化降解罗丹明B

以5,10,15,20-四-(4-羧基苯基)锌卟啉(ZnTCPP)为配体，以金属Fe为节点构筑了具有三维网状结构的铁-锌卟啉框架材料PCN-600(Zn)，采用PXRD、SEM、UV-vis DRS对所得材料进行了表征，并将其用于可见光下罗丹明B(RhB)的降解反应，考察了H2O2浓度对PCN-600(Zn)光催化性能的影响，并通过捕获实验确定了光催化反应过程中的主要活性物种，对比了PCN-600(Zn)与另一种锆-锌卟啉框架材料PCN-222(Zn)的光催化性能。结果表明，在H2O2的协同作用下，PCN-600(Zn)对RhB的降解表现出显著的催化活性，可见光照射90分钟后降解率可达94.2%，在实验范围内，随着H2O2浓度的增加，PCN-600(Zn)的催化活性不断提高，H2O2用量为4 mL时可最大程度上提升催化剂效率；实验证明在催化过程中，空穴（h+）为主要活性中间体，·OH 和·O2-也起到了一定的作用。此外，PCN-600(Zn)的光催化性能明显强于PCN-222(Zn)，相同实验条件下，前者罗丹明B的降解率可达95.9%，后者仅达67.6%。     

Cu~(2+)掺杂ZnO的制备及光催化性能研究

采用水热法制备了Zn O以及Cu~(2+)掺杂Zn O(Cu~(2+):Zn O)纳米粉体,并将其用于光催化降解亚甲基蓝,采用X射线衍射仪(XRD)对其物相进行分析,考察了不同的表面活性剂、Cu~(2+)的掺杂量以及焙烧温度对其结构和光催化降解性能的影响。结果表明:以柠檬酸钠和十六烷基三甲基溴化铵为混合表面活性剂制备的Zn O具有最佳的光催化降解性能,其在光照65 min后,降解率达到96%。Cu~(2+)的掺杂量以及焙烧温度对Cu~(2+):Zn O样品产生较大的影响,随着Cu~(2+)的掺杂量和焙烧温度的增加,Cu~(2+):Zn O样品的光催化降解效果呈现先增加后减小的趋势,当Cu~(2+)掺杂浓度为0.01 mol、焙烧温度为600℃时,Cu~(2+):Zn O样品具有最佳的光催化降解性能,其在光照110 min后,降解率达到93%。     

钨酸铋纳米片光催化剂的制备以及四环素类抗生素降解性能研究

以偏钨酸铵以及五水合硝酸铋为原料,采用水热合成法获得了钨酸铋光催化剂。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等方法研究了该光催化材料的结构、表面特征。以兽药用四环素水溶液作为目标溶液,在可见光照射的条件下,探究了钨酸铋对四环素水溶液的光催化降解性能。实验结果表明,制备的钨酸铋为薄片状的纳米结构,比表面积大,为光催化提供了大量的活性位点。在2h的可见光辐射下,投放量为200mg/L的钨酸铋对浓度为30mg/L四环素水溶液的光催化降解率达80%,该光催化降解反应为动力学一级反应。另外,多次回收钨酸铋重复实验结果显示钨酸铋的催化效率没有明显下降,钨酸铋对四环素的光降解有优异的催化效果,并具有较高的回用价值。     

可见光响应的Bi-TiO_2的制备及其对间苯二酚的降解作用

以钛酸四丁酯、硝酸铋为原料,采用水热法制备铋掺杂TiO2光催化剂（Bi-TiO2）。所得材料用X射线衍射、透射电子显微镜、X射线能谱、X射线荧光光谱、UV–Vis漫反射等测试手段分析。结果显示水热法可以直接合成锐钛型纳米TiO2。铋在TiO2中的掺杂方式为Bi3＋替位取代TiO2中Ti4＋。样品具有较大的比表面积,其最大达31.2 m2/g。铋掺杂能引起TiO2光催化剂的吸收光谱明显红移,从而具备较好的可见光响应性。以降解间苯二酚为探针反应研究其可见光催化性能,纯TiO2光催化活性极低,而Bi-TiO2具有较高的可见光催化性能,当铋掺杂量为1.00%时光催化性能最佳。UV–Vis光谱和高效液相色谱显示间苯二酚在70W金卤灯下反应120min能完全分解。     

锆掺杂二氧化钛基可见光催化剂的制备及其催化性能

采用溶胶-凝胶法制备了不同Zr掺杂量的Zr-TiO_2催化剂,并通过X射线衍射、扫描电子显微镜、傅里叶红外光谱对其进行表征,探究Zr元素的掺杂比例、催化剂制备的焙烧温度及反应物初始浓度等条件对催化剂在可见光下降解亚甲基蓝性能的影响。结果表明,制备的Zr-TiO_2催化剂粒径为纳米级,Zr-TiO_2催化剂对亚甲基蓝有明显光催化降解作用,且不同Zr与Ti掺杂比例对亚甲基蓝溶液降解效率影响显著,当Zr元素掺杂量为20%,焙烧温度为550℃时,制备的550℃-20%Zr-TiO_2催化剂对20 mg·L~(-1)的亚甲基蓝溶液降解效果最优,降解5 h时降解率为91.8%。并且550℃-20%Zr-TiO_2催化剂在可见光下催化降解亚甲基蓝符合一级动力学模型,R~20.95,拟合直线有较好的拟合度,表明催化剂具有较强的降解能力。     

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.     

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.     

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。