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51.
草酸锰分解过程的机理函数判别和动力学研究   总被引:6,自引:1,他引:6  
用等温热重和线性升温热重分析法研究了草酸锰热分解过程,提出了判断其机理函数的3步判别法。经实验和理论分析证明,该反应受随机成核和晶核随后生长的过程(A_3a机理)支配,其活化能E=103.95 kJ/mol,频率因子A=4.448×10~8min~(-1).动力学补偿效应为IgA=0.09661E-1.2856  相似文献   
52.
Wen B  Liu C  Liu Y 《Inorganic chemistry》2005,44(19):6503-6505
Bamboo-shaped Ag-doped TiO2 nanowires with heterojunctions were synthesized by a simple solvothermal method. The diameter of the nanowires was about 50-100 nm, and they had a length of up to a few millimeters. The detailed structure of the heterojunction in the nanowire was also characterized.  相似文献   
53.
将亲和标记技术和基质辅助激光解吸电离飞行时间串联质谱联用,建立了蛋白质相对定量方法,以牛血清白蛋白为实验对象,考察了该方法的准确度、重现性等指标;又以数种标准蛋白混合物为研究对象,考察了该方法的动态范围及相应的标准偏差,为实际生物样品中差异蛋白质分析奠定了基础。  相似文献   
54.
利用蒙特卡洛模拟方法对线形链和星形键在亚浓溶液区的标度律作了验证与讨论。我们的计算结果证明线形链渗透压Π与体积分数Φ在亚浓溶液区的标度规律是与德热纳的理论结果相一致的。同时还证明了星形链在亚浓溶液区具有与线形链相同的标度行为。  相似文献   
55.
Four new iridoids, buergerinins B–E ( 1 – 4 ), along with three known iridoids, were isolated from the roots of Scrophularia buergeriana. Their structures were identified on the basis of spectroscopic analysis.  相似文献   
56.
3-(Triethoxysilyl)propionitrile (TESPN) sol-gel has been prepared under different conditions. It was employed for coating the surfaces of quartz and aluminum. Infrared (IR) and Raman spectra of TESPN and TESPN sol-gels have been recorded in the study of the sol-gel process. Transmission and reflection absorption IR (RAIR) spectra of TESPN sol-gel coated quartz and aluminum have also been collected for better understanding the film formation on the substrate surfaces. Spectra collected at different temperatures indicated that the silane film on quartz decomposes at 700 degrees C. Results from thermal gravimetric analysis (TGA) supported this result. Based on the group frequencies and the spectral behavior in different states, some vibrational modes were assigned to the observed bands. The anticorrosion behavior of the sol-gel coated aluminum in comparison with the uncoated metal was evaluated by measuring the potentiodynamic polarization and electrochemical impedance spectra (EIS).  相似文献   
57.
含噻二唑环苯甲酰脲化合物的合成及杀虫活性   总被引:12,自引:0,他引:12  
李兴海  凌云  杨新玲 《化学通报》2003,66(5):333-336,322
用活性亚结构连接法设计合成了6个新的含1,3,4-噻二唑杂环苯甲酰脲类化合物,其结构经红外光谱、核磁氢谱、元素分析方法确证。同时对其杀虫活性进行了初步研究,发现该类化合物在普筛浓度下对淡色库蚊幼虫具有较好的杀虫活性。化合物Ⅲb(R1=Cl,R2=n-C5H11),Ⅲd(R1=CH3,R2=n-C5H11),Ⅲf(R1=2,6-difluoro,R2=-C5H11)在10mg/L浓度下对淡色库蚊幼虫的杀虫死亡率大于90%。  相似文献   
58.
High-speed counter-current chromatography (HSCCC) was used to purify salidroside from an extract of Rhodiola crenulata with two steps using a two-phase solvent system composed of ethyl acetate-n-butanol-water (1:4:5, v/v) in the first run and chloroform-methanol-isopropanol-water (5:6:1:4) in the second run. The method yielded 21.9 mg of salidroside from 1.216 g of the crude sample at 98% purity determined by HPLC analyses. Identification was performed by 1H NMR, 13C NMR, and MS.  相似文献   
59.
A novel method, modified matrix solid-phase dispersion (MMSPD), has been developed for quantitative analysis of organophosphorus pesticide residues in soil. It was based on matrix solid-phase dispersion (MSPD) and continuous liquid-solid extraction (continuous LSE), using Florisil as sorbent and dichloromethane as the recycling solvent. Two soils with different texture and physicochemical properties were studied to validate the method. The effect of residence time of pesticides in soil was also studied. MMSPD was compared with MSPD and continuous LSE respectively. Determination was carried out by gas chromatography with nitrogen-phosphorus detection (GC-NPD). The method gave recoveries ranging from 72–105% with relative standard deviations (RSDs) lower than 15% for the pesticides studied. The limits of detection (LODs) ranged from 0.1 to 0.6 ng g−1. Two pesticide residues have been detected in real soil samples from Fujian, China, using MMSPD. The pesticides were confirmed by gas chromatography-mass spectrometry (GC-MS) in a selected-ion monitoring (SIM) mode. Revised: 4 and 9 April 2006  相似文献   
60.
IthasbeenreportedthatTrichosanthi11(TCS),isolatedfromrkiI-ilolt)ii,hasanti-tumorI-4andanti-vira1activities5-'.Someanti-tun1orremedies,whicharedesignedfromTCS,arebeingtestedanddeveloped'-.'.StudyingthebioIogicalphenomenonbyelectrochemicalmethodsisanewhotresearchspotemerginginrecentyears".Manyresultsshowedthatnotonlytheenzymesystemsuchassuccinatedehydrogenasedisplayedthediode-likebehaviorduringtheelectrontransferprocess",butalsothehigh1yorganizedorganeIle,forexample,mitochondria,andevenintac…  相似文献   
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