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排序方式: 共有681条查询结果,搜索用时 31 毫秒
51.
Omari Mukbaniani Tamara Tatrishvili Giorgi Titvinidze Sopho Patsatsia 《应用聚合物科学杂志》2009,114(2):892-900
The synthesis of polysiloxanes with pendant unsaturated cyclic fragments have been successfully performed by hydrosilylation reactions of polymethylhydrosiloxane with 4‐vinyl‐1‐cyclohexene in the presence of platinum hydrochloric acid (0.1 M solution in THF), Karstedt's catalyst (Pt2[(VinSiMe2)2O]3) and platinum on the charcoal (5%). Reactions were carried out at various temperatures with different ratios of initial compounds. It was shown, that not all active ≡Si? H groups take part in the hydrosilylation reaction. Some kinetic parameters of reactions were studied. The synthesized oligomers were characterized by FTIR, 1H, 13C, H,H‐COSY, and C,H‐correlation NMR spectroscopy. Calculations using the quantum‐chemical semi empirical AM1 method for modeling reactions between methyldimethoxysilane [Me(MeO)2SiH] and 4‐vinyl‐1‐cyclohexene were performed to evaluate possible reaction paths. Synthesized oligomers were characterized by gel‐permeation chromatography, differential scanning calorimetric, thermogravimetric, and wide‐angle X‐ray analyses. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
52.
Tamara V. Basova Nadezhda M. Kurochkina Aslan Yu. Tsivadze Asim K. Ray 《Journal of Electronic Materials》2010,39(2):145-148
Hybrid inorganic/organic nanocomposites were produced by the exposure of spun films of octa-(benzo-15-crown-5)-substituted
phthalocyanine of Cd(II) to an environment of hydrogen sulfide gas. The formation of cadmium sulfide (CdS) quantum dots in
the metal free phthalocyanine matrix was identified in the phthalocyanine matrix from atomic force microscopy images. The
mean size of CdS quantum dots was estimated to be 2–3 nm, from optical absorption and Raman spectra for the nanocomposites. 相似文献
53.
Palmer Abraham A.; Miller Mark N.; McKinnon Carrie S.; Phillips Tamara J. 《Canadian Metallurgical Quarterly》2002,116(1):126
Allopregnanolone is a neuroactive steroid that, like ethanol (EtOH), has stimulant, anxiolytic, ataxic, and depressant effects. Two experiments tested the hypothesis that sensitivity to the locomotor stimulant effects of these drugs is influenced by a common set of genes. Sensitivity to the locomotor stimulant effects of allopregnanolone was determined in 24 BXD recombinant inbred (RI) strains. Strain means were positively correlated with extant means for EtOH stimulation in 20 of the same strains. Quantitative trait locus (QTL) analysis provisionally identified many loci, including several known to influence sensitivity to EtOH. Sensitivity to allopregnanolone was also measured in FAST and SLOW mice, which were selectively bred for differential locomotor response to EtOH, to determine whether selection has also altered allopregnanolone sensitivity. FAST mice were more sensitive to the stimulant effects of allopregnanolone compared with SLOW mice. These data suggest that sensitivity to the locomotor stimulant effects of these drugs is influenced by common genes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
54.
Crown Eric D.; King Tamara E.; Meagher Mary W.; Grau James W. 《Canadian Metallurgical Quarterly》2000,114(3):561
Rats exposed to a few moderately intense (1 mA) shocks subsequently exhibit lower vocalization thresholds to shock and thermal stimuli. They also exhibit facilitated learning in a Pavlovian conditioning paradigm. Together, these results suggest that shock exposure can enhance pain (hyperalgesia). The present study examined the role of the amygdala and bed nucleus of the stria terminalis (BNST), 2 systems that have been implicated in the induction and maintenance of negative affective states. Experiment 1 showed that lesions of the central, but not the basolateral, amygdala eliminate shock-induced hyperalgesia as measured by a decrease in vocalization thresholds to shock. Experiment 2 revealed that central nucleus lesions also prevent shock-induced sensitization of the vocalization response to heat. Anterior, but not posterior, BNST lesions had a similar effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
55.
Fazio Russell H.; Ledbetter Janet E.; Towles-Schwen Tamara 《Canadian Metallurgical Quarterly》2000,78(2):197
The present research examined whether individuals with more accessible attitudes have more difficulty detecting that the attitude object has changed. While being repeatedly exposed to photographs of undergraduates, participants either rehearsed their attitudes toward each photo or performed a control task. They then saw these original photos and computer-generated morphs representing varying degrees of change in an original. Participants in the attitude rehearsal condition required more time to correctly identify morphs that were similar to the original as "different" (Experiment 1) and made more errors in response to such morphs (Experiment 2). Experiment 3 revealed that participants with accessible attitudes perceived relatively less change; they were less likely to view a morph as a photo of a novel person and more likely to view it as a different photo of a person seen before. The costs and benefits of accessible attitudes are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
56.
Compared 35 maritally distressed couples assigned to 1 of 3 cognitive behavioral marital therapy (BMT) groups. Groups represented (1) couples in which 1 spouse was depressed at pretest, (2) couples in which 1 spouse showed psychopathology other than depression, and (3) couples who showed no symptoms of individual psychopathology. Ss were administered, pre- and posttreatment, the Dyadic Adjustment Scale and the Minnesota Multiphasic Personality Inventory (MMPI). Pretreatment couples in Group 1 were the oldest and the least maritally satisfied, and expressed the most negative communication. 12 wks of BMT was an effective treatment modality for all groups when compared with a group of 12 couples on a wait list. BMT significantly increased marital adjustment for all 3 treatment groups and decreased the rates of negative communication. BMT significantly decreased the level of depression in Group 1 and the level of psychopathology in Group 2. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
57.
由运算放大器构成的反馈系统常用于使系统保持稳定。但是在一些情况下也有意外发生。比如太阳能船的玩具,当有时打开开关时,玩具甚至会发出“噗噗”的声响。这种情况有可能是由于运算放大器发生了意外正反馈(inadvertent positive feedback)导致的。 相似文献
58.
59.
一个电压反馈放大器宏模型可以仿真共同效果,如瞬态响应、频率响应、电压噪声和输入/输出压摆率(slew rate)限制.接下来本文将以实例模型详尽描述每个级和相关实际器件的行为.这里没有提供完整的晶体管原理图,客户可以利用充分提取的3D器件模型进行精确的仿真来开发宏模型. 相似文献
60.
Luccas Fernando Bittencourt De Souza Haywood Dail Laughinghouse IV Tamara Pastori Marília Tedesco Andrielle Wouters Kuhn Thais Scotti Do Canto‐Dorow 《The International journal of environmental studies》2013,70(6):871-877
Artemisia verlotorum, popularly ‘infalivina’, is a medicinal herb used for respiratory, circulatory and digestive treatments. Antiproliferative and genotoxic effects of A. verlotorum aqueous extracts in three different concentrations (6, 32 and 48 g/L) were evaluated on the Allium cepa cell cycle. Results clearly showed a significant difference using the χ2 test (p = 0.05) among treatments with a decrease in the mitotic index as the concentration of the extract increased. Extracts of A. verlotorum proved to be genotoxic and showed antiproliferative potential on the A. cepa cell cycle. This study suggests the use of infusions of A. verloturum for medicinal purposes only after selecting suitable concentrations. 相似文献