基于GO模板法制备金属氧化物超薄纳米片及其超电容性能的研究

采用GO模板法制备ZnO、NiO、Co_3O_4超薄纳米片,选用三维多孔泡沫镍作(NF)为导电基材,并通过一步水热法制备出ZnO/NF、NiO/NF、Co_3O_4/NF复合电极材料,探究三种纳米片材料对复合材料的结构和电化学性能的影响,Co_3O_4/NF复合电极材料,因其具备高度开放的多孔结构,增加了与电解液的接触面积,为氧化还原反应提供了有利的条件,在电流密度为3 A·g~(-1)时,质量比电容高达2633 F·g~(-1),因此,Co_3O_4/NF复合电极材料的电容性能最好。     

分层纳米结构的钴酸镍/四氧化三钴复合电极的制备及其电化学性能研究

通过低温溶剂热和水热两步法成功制备出分层结构的NiCo_2O_4/Co_3O_4纳米片阵列,并均匀生长在泡沫镍基底上。电化学测试表明,这种纳米片阵列复合电极表现出优异的电容性能。在2 mA·cm~(-2)时,面积比电容高达6.05 F·cm~(-2),当电流密度提升至20 mA·cm~(-2),依然保持良好的倍率性能,经1500次恒流充放电之后电容保持率为93.8%。这种优异的性质与介孔、高比表面积的分层纳米片这一新颖的结构有密切关系。     

含Co_3O_4自组装的3D石墨烯气凝胶及其电容器性能研究

设计了一种简单的通过一步水热法制备三维(3D)多孔的Co_3O_4/石墨烯气凝胶(GA)材料。因石墨烯(Graphene)所具有互相连通的三维孔道以及Co_3O_4纳米微球丰富多孔结构,Co_3O_4/GA表现出良好的导电性和赝电容性,是一种优异的用于能量储存装置的电极材料。该Co_3O_4/GA复合物拥有高比表面积(139 m2/g)和较宽的孔径分布(约为1~100nm)。单纯GA的比电容值为175.5 F/g,由于Co_3O_4微球的引入,使复合物气凝胶的比电容值得到了显著提升,在电流密度为1 A/g时,比电容值高达1456.3 F/g。以Co_3O_4/GA为正极、GA为负极、Li OH/PVA为凝胶电解质组装成全固态非对称超级电容器(SASC),当功率密度为648.9 W/kg时,该SASC拥有优异的能量密度(68.1 W·h/kg),说明此Co_3O_4/GA是一种优异的超级电容器电极材料。     

Co3O4纳米簇阵列的制备及其电容特性

采用水热法以不同的填装度分别在泡沫镍和碳纤维基底上制备出了不同形貌的Co_3O_4。运用X射线衍射、红外光谱和扫描电镜对产物的结构和形貌进行表征。结果表明,在水热反应体系中,通过改变装填度大小,可以制备出相同物相、不同形貌的产物。通过循环伏安法、恒流充放电和交流阻抗法对泡沫镍基底Co_3O_4电极材料的电化学特性进行表征。结果表明,在填装度为70%时制备出的Co_3O_4均匀纳米簇阵列,表现出更好的电容特性。在2 mol/L的KOH电解液中,1 A/g的电流密度下,其比电容为961 F/g;当电流密度增至20 A/g时,比电容保持率为76%。     

NiCo_2O_4/炭黑@纳米炭纤维自支撑复合电极制备与电容性能研究

针对炭材料和金属氧化物单独作为电极材料存在的不足,以纳米炭纤维作为基底,通过水热法在纳米炭纤维上同时负载炭黑(CB)和钴酸镍(NiCo_2O_4)纳米线,进一步热处理制备了NiCo_2O_4/炭黑@纳米炭纤维自支撑复合电极。在复合电极材料中,纳米炭纤维网络提供了三维电子传导通道,钴酸镍提供了较高的比电容,炭黑显著地提高了NiCo_2O_4的导电性。通过调整沉积时间有效调节了活性物质的负载量,所得电极显示出优异的导电性(35.3 S·m~(-1)),在1 A·g~(-1)的电流密度下比电容达到846 F·g~(-1),且具有优良的循环稳定性。优异的电容性能使NiCo_2O_4/炭黑@纳米炭纤维复合电极有望成为下一代超级电容器的电极材料。     

基于Co_3O_4/C复合水凝胶的全固态柔性超级电容器的研究

以沸石咪唑骨架-67(ZIF-67)为前驱体,采用两步煅烧法制备了四氧化三钴/碳(Co_3O_4/C)纳米复合材料。利用自由基聚合法合成了Co_3O_4/C-聚丙烯酰胺水凝胶,进一步在水凝胶框架中原位聚合电化学活性聚吡咯颗粒,制备具有优异机械性能的柔性复合电极材料。在此基础上,将该柔性电极材料和水凝胶电解质组装成全固态柔性超级电容器;实验结果表明,Co_3O_4/C纳米材料与导电聚合物复合电极材料具有优异的超级电容器性能。通过恒流充放电曲线计算得到该器件具有197.83 m F/cm~2的面电容。在电化学循环10 000圈后该器件的容量仅下降9%,展示了其优异的循环稳定性;此外,该电容器具有的优异机械柔性,使其有望应用于未来柔性电子器件。     

Co3O4电极材料的制备及其电容性能研究

采用水热法,通过控制反应时间制备出不同形貌和尺寸的Co_3O_4材料。利用XRD和SEM对其结构和形貌进行表征,采用循环伏安、恒电流充放电和交流阻抗等方法测试了其电化学性能。结果表明,随着反应时间的延长, Co_3O_4材料的晶粒尺寸增大,形貌由不规则颗粒状变为正立方体,其比电容不断降低。在电流密度为0.2 A·g~(-1)时,反应5 h、 10 h和15 h所制备的Co_3O_4材料的比电容值分别为153.3 F·g~(-1)、 99.3F·g~(-1)和51.1 F·g~(-1)。当电流密度从0.2 A·g~(-1)增大到1.8 A·g~(-1)时,反应5 h、 10 h和15 h所制备的Co_3O_4材料的比电容值分别为96.3 F·g~(-1)、 91.3 F·g~(-1)和27.1 F·g~(-1),其比电容保持率分别为62.8%、 91.9%和53.0%。水热反应5 h所制备的Co_3O_4材料具有最好的比电容。     

Co_3O_4/g-C_3N_4纳米材料制备超级电容器及其电化学性能研究

采用碳辅助法和原位沉降法将Co_3O_4与石墨相氮化碳(g-C_3N_4)进行复合得到Co_3O_4/g-C3N4复合材料。利用XRD、SEM、TEM等多种表征手段对Co_3O_4和Co_3O_4/g-C_3N_4复合材料进行表征。结果表明,Co_3O_4均匀分布在g-C_3N_4片层中形成了(2D-3D)新型结构。电化学性能测试结果表明,Co_3O_4/g-C_3N_4复合材料电流密度为1 A/g时,比电容达到1 071 F/g,比纯Co_3O_4提升4.9倍;在电流密度为10 A/g时,经过1 000次循环,比电容仍能保持95.5%。     

水热法合成超级电容器电极材料MnO_2/CNT及性能

采用水热合成和200℃、300℃和400℃热出的方法,成功的制备δ-MnO_2复合多壁碳纳米管和α-MnO_2复合多壁碳纳米管超级电容器电极材料。运用XRD,SEM,TEM对实验制备的复合材料结构和形貌的分析。实验结果表明δ-MnO_2复合多壁碳纳米管和α-MnO_2复合多壁碳纳米管材料电极表现出非常理想的比电容,在扫描速度为10m v-1和电解液为1mol·L~(-1)Na_2SO_4,比电容分别为82F g~(-1)和102.5F g~(-1)。充放电循环1000次,δ-MnO_2复合多壁碳纳米管比容量电极能够保持在86.3%和α-MnO_2复合多壁碳纳米管电极保持在66.1%。δ-MnO_2复合多壁碳纳米管和α-MnO_2复合多壁碳纳米管材料具有优异的电化学性能,是一种很有前景的超级电容器电极材料。     

聚苯胺复合对电极的制备及其在太阳能电池中的应用

通过化学浴制备粉末聚苯胺,并将NiO、Co_3O_4粉末和聚苯胺粉末混合制备聚苯胺与镍、钴的氧化物的复合对电极,通过X-射线粉末衍射(XRD),场发射扫描电子显微镜(FESEM)等表征测试手段对复合对电极的表观形貌进行表征,对复合对电极进行了CV、EIS、Tafel、J-V等电化学性能测试,探究了复合电极作为I-/I3-液态电解质DSSC对电极的催化性能。结果表明:NiO/PANI对应DSSC光电转换效率最高(7.38%),Co_3O_4/PANI对应DSSC光电转换效率7.23%,比单一聚苯胺DSSC光电转换效率(6.97%)高,证明了复合电极催化效果要比单一聚苯胺电极具有更优异性能。     

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。     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.