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991.
The database of open-framework aluminophosphate (AlPO) syntheses has been established, which includes about 1600 synthetic
records. Data analysis has been done on the basis of the framework composition, structure dimension, pore ring, and organic
template. This database will serve as useful guidance for the rational synthesis of microporous functional materials. 相似文献
992.
A novel pentaazadentate bismacrocycle was synthesized through an improved procedure of 1:1 Schiff base condensation of diformyltripyrrane with 3,4,3′,4′‐tetraamino‐biphenyl hydrochloride using Pb2+ as template ion, in which the condensed byproduct water was removed efficiently to make the yield over 90%. Then the bismacrocycle legend reacted with cadmium chloride to yield the title metal complex with molecular weight being 1200.4 by TOF MS and the λmax being 766 nm. 相似文献
993.
本文讨论了与腔体组装方法、温度梯度和边界条件等有关的温度控制问题及其对金刚石生长的影响。 相似文献
994.
Kaixuan Chen Zhenhua Ning Hengyi Xu Zhi Qi Guo Lu Furen Wang Daole Yin 《中国科学G辑(英文版)》2005,48(1):14-25
The amplitude-dependent ac susceptibility of high-temperature superconductors is shown to obey some empirical scaling relations.
We try to analyze this behavior by extending a dc nonlinear response function of mixed state to the ac cases. The derived
equations for critical current and ac susceptibility ξ(T) agree with the scaling relations of experimental data. 相似文献
995.
§ 1.Introduction and Notations In this paper,for any given matrices A and B,A B denotes the Kronecker productof A and B,A is a vector formed by stacking the columns of A under each other,μ(A)is a space generated by the columns of A,and PA=A(A′A) - A′. Fourthmore,if A andB are square matrices,then A>B and A≥ B mean that A-B is a symmetrical positiveand nonnegative matrix,respectively,andλi(A) is the i-th largest eigenvalue of A. Consider general multivariate linear modelY … 相似文献
996.
抗抵赖的签密方案在一些应用中有重要的价值.已有的方案如认证加密方案和签密方案在解决签名者事后抵赖的问题时,必须把恢复的消息提供给第三方,从消息的保密方面看,效果并不理想.基于离散对数问题提出了安全有效的指定接收者恢复消息的抗抵赖数字签名体制,其特点是只有指定接收者才可以恢复消息,任何人可以验证签名的合法性,在解决签名者事后抵赖的问题中克服了已有方案的缺陷,不需要签名者的合作、不需要向第三方提供恢复的消息、不需要与第三方执行交互的零知识证明,在保持恢复消息秘密的同时能揭穿签名者的抵赖行为.同时把该方案扩充到了指定的一群接收者恢复消息的抗抵赖的多重签名的情形. 相似文献
997.
Ling‐Hai Xie Xian‐Yu Deng Lin Chen Shu‐Fen Chen Ran‐Ran Liu Xiao‐Ya Hou King‐Young Wong Qi‐Dan Ling Wei Huang 《Journal of polymer science. Part A, Polymer chemistry》2009,47(20):5221-5229
The combination of π‐stacked with π‐conjugated building blocks offers an essential strategy to construct multifunctional organic semiconductors (MOSs) with the unique optoelectrical properties. Covalent hybrids can efficiently avoid the intrinsic phase‐separation defects in corresponding blend system. In this contribution, poly(vinylcarbazole) tethered with terfluorene, PVK‐TF, as a double‐channeled π‐stacked and π‐conjugated hybrid (SCH), has been constructed via Friedal‐Crafts click postmodification (FCCP). The chemical structure and optoelectrical property were determined by GPC, UV–vis, PL, TGA, DSC, and CV. Its PL spectra in the annealing thin film at N2 atmosphere without low‐energy emission bands centered at the 530 nm indicates that no π‐stacks between carbazole and TF or among TFs dominate the whole condensed phase, which is in agreement with the intrachain T‐shaped π‐pitched motifs in molecular modeling simulation due to steric hindrance effect in complicated diarylfluorenes (CDAFs). A supporting prototype stable deep‐blue PLED was successfully obtained with an Internationale de l'Eclairage (CIE) coordinates of (0.20, 0.10) and a width at half maximum (FWHM) of about 60 nm at high current density of 100 mA/cm2 (35 V). Deep‐blue PVK‐TF is a promising MOS for hole‐transporting and host materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5221–5229, 2009 相似文献
998.
Phytochemical investigation of the whole plant of Leontopodium nanum afforded a new coumarin named leontonanin ( 1 ), together with six known compounds, umbelliferone ( 2 ), 3,4′, 7‐trihydroxyflavone ( 3 ), oleanolic acid ( 4 ), β‐sitosterol ( 5 ), daucosterol ( 6 ) and stearic acid ( 7 ). The structure of compound ( 1 ) was elucidated by spectroscopic methods including 2D‐NMR techniques. 相似文献
999.
Rapid resolution liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry was developed for simultaneous determination of twelve saponins in Radix et Rhizoma Notoginseng (RRN) with macranthoidine A as internal standard. All calibration curves showed good linear regression (r 2 > 0.9935) within test range. The limits of detection of the twelve compounds were in the range of 1.53–5.08 ng mL−1. This method was successfully applied to analyze the saponins in fifteen samples of RRN.
相似文献1000.
高校教学质量评价的属性识别法 总被引:2,自引:1,他引:1
郭奇 《数学的实践与认识》2008,38(6):9-13
阐述了高校教学质量评价的属性识别法.并应用此方法对普通高等学校的教学质量进行评价,指出了属性识别理论与模糊综合评判方法相比的优越之处.为普通高等学校教学质量评价提供了一种量化处理的方法. 相似文献