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排序方式: 共有304条查询结果,搜索用时 15 毫秒
1.
In photochemical vapor deposition of aluminum film on silicon using dimethylaluminum hydride, (CH3)2AlH, a surface reaction dominated below a (CH3)2AlH pressure of 0.3 m Torr at 200°C, which was induced only with the 160 nm band emitted from a deuterium lamp. A gas-phase reaction occurred above 0.3 mTorr at 200°C, which could be induced by both 160 nm and 240 nm emission bands from the lamp. To distinguish between surface ad gas-phase reactions, a thickness profile was used. At 240°C the surface reaction could be induced even by the 240 nm band, while the deposits formed under illumination of the two bands were thinner than those obtained with only the 240 nm band, indicating occurrence of vacuum ultraviolet (VUV)-enhanced desorption. The mechanism responsible for the observed wavelength dependence in unclear. The electrical resistivity of the films deposited at 200°C was 4.5 μΩ cm, which did not change with wavelength. 相似文献
2.
S.V. Kini 《Tetrahedron letters》2004,45(21):4171-4173
Hofmann degradation of 1-arylmethyl-1,2,3,4-tetrahydro-2,2-dimethylisoquinolinium iodides with methanolic KOH gave stilbene derivatives, for example, (E)-N-2{2-[2-(phenyl)ethenyl]-4,5-dimethoxyphenyl}ethyl-N,N-dimethylamine. Photochemical electrocyclization of these stilbenes afforded the corresponding phenanthrene alkaloids/phenanthrene derivatives. 相似文献
3.
1,2-二乙炔基四苯基乙硅烷与1,2-二乙炔基四甲基乙硅烷在催化剂铑(Ⅰ)络合物[氯化三-(三苯基膦)铑]的作用下得到一种新的含硅共聚物。实验证明此共聚物的主链是有规交替结构。研究了固体薄膜及其溶液的光解作用,并测定了SbF_5蒸气处理后的共聚物薄膜的导电性。 相似文献
4.
Christopher T Burns 《Journal of organometallic chemistry》2003,683(1):240-248
The reaction of (hexyl)HC(mim)2 (1, mim=N-methyl-imidazol-2-yl) with (cod)PdMeCl in C6H6 yields {(hexyl)HC(mim)2}Pd(Me)Cl (3). The photochemical reaction of 3 with CH2Cl2 at 23 °C in ambient room light yields {(hexyl)HC(mim)2}Pd(CHCl2)Cl (4). It is proposed that this reaction proceeds by homolytic scission of the PdMe bond of 3. 相似文献
5.
流动注射光化学敏化化学发光法测定斯帕沙星 总被引:14,自引:0,他引:14
斯帕沙星 (SPFX)在酸性介质中经紫外光照射发生光化学反应 ,其产物与Tb3+ 形成络合物 ,对Ce SO2 - 3化学发光体系有增敏作用。据此 ,采用流动注射技术 ,建立了光化学敏化化学发光测定SPFX的新方法。方法的检出限为 2 .5× 10 - 8mol/L ;SPFX浓度在 1.0× 10 - 7~ 1.0× 10 - 5mol/L范围内与发光强度呈良好的线性关系。对 6.0× 10 - 6 mol/LSPFX平行测定 11次 ,RSD为 3 .8%。利用该法测定了片剂和胶囊中SPFX的含量 ,并对机理进行了初步探讨 相似文献
6.
7.
A. Rivaton B. Mailhot M. Lounaci J.-L. Gardette 《Polymer Degradation and Stability》2006,91(3):565-572
This paper is devoted to the analysis of the photochemical behaviour of copolymers with carbazole units exposed to long-wavelength radiation. These copolymers are constituted of two types of carbazolylethyl methacrylate units (CEM) with octyl methacrylate moieties (OMA). The exposure of copolymers and PVK to UV light results in dramatic modifications of the physical and photophysical properties of the polymer. These modifications can be correlated with modifications of the chemical structure of the matrix. The photoageing of copolymers and PVK has been analysed by fluorescence, ESR, UV-vis and infrared spectroscopies. The effects of crosslinking and chain scissions were determined by gel fraction measurements and size exclusion chromatography. 相似文献
8.
Determination of DNA using sodium 9,10-anthraquinone-2-sulfonate as an in situ photochemical fluorescence probe 总被引:2,自引:0,他引:2
Wen-You Li Xiang-Qun Guo Jin-Gou Xu Qing-Zhi Zhu Yi-Bing Zhao 《Analytica chimica acta》1997,340(1-3):291-296
An in situ photochemical fluorescence probe method for the determination of DNA with sodium 9,10-anthraquinone-2-sulfonate (AQS) as a photochemical fluorescence probe was developed. It was based on the conversion of AQS into an intensively fluorescent product by irradiating with UV radiation. The photochemical reaction is retarded by DNA. The determination can be carried out by measuring the fluorescence intensity at a fixed time. The calibration graph was linear in the range 0–80 ng ml−1 calf thymus (CT) DNA (r = 0.9991), the limit of detection was 3.2 ng ml−1 CT DNA (n = 9). The kinetic behaviour of the photochemical reaction and the effects of experimental conditions were investigated and discussed in detail. The results of absorption spectra and competitive binding experiments suggested the interaction between AQS and DNA to be intercalative. 相似文献
9.
WANG Yan-xia YE Song 《高等学校化学研究》2006,22(4):520-523
IntroductionPhotochemical reactions, which involve a three-membered ring, have been of great interest to experi-mental photochemists[1—10]. A main reason for thisphenomenon is that the cyclopropane ring exhibits somereaction characteristics of double bon… 相似文献
10.
痕量铁的光化学伏安分析法及其应用研究 总被引:1,自引:0,他引:1
在稀硫酸介质中及活化剂草酸存在下,痕量铁(Ⅲ)对结晶紫光化学褪色反应有强烈催化作用,结晶紫的光化学反应产物于-0.70产生一灵敏的2.5次微分级谱波。 相似文献