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71.
The disadvantages of Normally White Twisted Nematic Liquid Crystal Display (NW-TN-LCD) were discussed. The reason that the negative birefringent polyimide thin filmswere used to compensate NW-TN-LCD to decrease off-axis leakage, improve contrast ratiosand enlarge viewing angles was explained in this paper. A certain polyimide thin film wastaken as an example to show compensation effect on NW-TN-LCD. 相似文献
72.
研究了(CH_3C_5H_4)_3Ln·THF (Ln = Sm,Ho,Tb,Yb)与环戊二烯高产率生成 (C_5H_5)_3Ln·THF的新反应。反应产物经过了元素分析、质谱和X射线的表征。产 物(C_5H_5)_3Ln·THF的特征结构参数,如五元碳环的碳原子与中心金属的平均距 离,五元碳环质心与中心金属距离,配位的四氢呋喃氧原子与中心金属距离,由于 “镧系收缩现象”,随着中心原子序数的增加而减小。 相似文献
73.
ZNF191 (243-368), a new human zinc finger protein, probably relates to some hereditary diseases and cancers, To obtain adequate amount of ZNF191(243-368) for the study of its property, structure and function, three different expression systems of inclusion-body, glutathione S-transferase (GST), and hexahistidine (6 × His) were used and compared. Among these systems, the expression level of ZNFI91(243-368) was increased in inclusion body system under a higher isopropylthio-β-D-galactoside (IPTG) concentration, but the non-target proteins were also increased more, which made its purification more difficult and the yield lower. The expression of His-tag fusion protein was almost not affected by IPTG concentration, temperature and inducing time. At a high IPTG concentration the highest expression yield for GST fusion protein was obtained. And the fusion proteins can be partially purified by a single affinity chromatography step. The fusion protein systems show advantages for expression of these proteins. 相似文献
74.
光同时诱导水中Cr(Ⅵ)的还原与橙黄Ⅱ的氧化;染料;橙黄Ⅱ;Cr(Ⅵ);光还原;光降解 相似文献
75.
76.
稀土金属作用下芳香醛、酮的还原偶联反应 总被引:4,自引:1,他引:4
由Ln/ROH/TMSCl组成的体系能选择性地使芳香族醛、酮还原偶联形成频哪醇, 产率优良, 而对脂肪族醛酮呈惰性。 相似文献
77.
78.
Four para-dialkylaminophenyl (PDAAP1-PDAAP4) bearing carboxyl groups were studied for application to the dye-sensitized solar cells (DSC). It was found the short spacer CH2 between carboxyl and dialkylaminophenyl chromophore in PDAAP3 and PDAAP4 led to highly efficient monochromatic incident photon-to-current conversion efficiencies (IPCE), however the long alkyl group C4H9 attached on aniline moieties in PDAAP2 and PDAAP4 favored improvement of open-circuit photovoltage. Thus, the solar cell sensitized by PDAAP4, having both short carboxyl groups CH2COOH and long alkyl groups C4H9, exhibited the IPCE maximum of 73% at 670 nm and overall energy conversion efficiency η of 3.06%, representing the highest IPCE and η values so far in dialkylaminophenyl-based organic dye-sensitized semiconductor solar cells. Taking advantage of the highly efficient sensitizing ability of PDAAP4 in far-red region, the data of IPCE above 630 nm of the solar cells were improved greatly by cosensitization with both N3 and PDAAP4. The influences of the TiO2 film thickness and the concentration of 4-tert-butylpyridine (TBP) in electrolyte were also investigated. 相似文献
79.
本文用数学期望方法研究了非线型共缩聚物的重均分子量,并推导出重均分子量表达式,将3种特例的理论曲线与实验结果相比较,两者基本相符。 相似文献
80.