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991.
Dr. Feng‐Rong Dai Dr. Yung‐Chung Chen Lai‐Fan Lai Dr. Wen‐Jun Wu Chao‐Hua Cui Gui‐Ping Tan Xing‐Zhu Wang Prof. Jiann‐T'suen Lin Prof. He Tian Prof. Wai‐Yeung Wong 《化学:亚洲杂志》2012,7(6):1426-1434
Four new unsymmetric platinum(II) bis(aryleneethynylene) derivatives have been designed and synthesized, which showed good light‐harvesting capabilities for application as photosensitizers in dye‐sensitized solar cells (DSSCs). The absorption, electrochemical, time‐dependent density functional theory (TD‐DFT), impedance spectroscopic, and photovoltaic properties of these platinum(II)‐based sensitizers have been fully characterized. The optical and TD‐DFT studies show that the incorporation of a strongly electron‐donating group significantly enhances the absorption abilities of the complexes. The maximum absorption wavelength of these four organometallic dyes can be tuned by various structural modifications of the triphenylamine and/or thiophene electron donor, improving the light absorption range up to 650 nm. The photovoltaic performance of these dyes as photosensitizers in mesoporous TiO2 solar cells was investigated, and a power conversion efficiency as high as 1.57 % was achieved, with an open‐circuit voltage of 0.59 V, short‐circuit current density of 3.63 mA cm?2, and fill factor of 0.73 under simulated AM 1.5G solar illumination. 相似文献
992.
A hollow-structured heterojunction consisting of Bi2WO6 nanoplatelets and Bi2O3 nanoparticles was successfully prepared by a facile solvothermal process. Bi2O3/Bi2WO6 heterojunction is the aggregate of some hollow spheres with diameter ranging from several hundred nanometers to 1.5 μm and is connected to each other by tube-like cavums. On the basis of scanning and transmission electron microscopy observation and X-ray diffraction analysis of the samples synthesized at different reaction stages, a possible growth mechanism was proposed for the growth of hollow-structured Bi2O3/Bi2WO6 heterojunction. Its photocatalytic activity was evaluated by degradation of rhodamine B under visible-light irradiation (λ>400 nm). The results indicate that the hollow-structured Bi2O3/Bi2WO6 heterojunction exhibits much higher photocatalytic activity than both pure Bi2WO6 and pure Bi2O3. The improved photocatalytic performance can be ascribed to the heterojunction of Bi2O3 and Bi2WO6 in the framework in which the hierarchical hollow structure possesses good permeability and large surface area. More importantly, the hollow-structured Bi2O3/Bi2WO6 heterojunction is not only highly stable but also easy to be separated by simple sedimentation for recycle. 相似文献
993.
Yan-Qing Ge Teng Wang Gui Yun Duan Li Hua Dong Xiao Qun Cao Jian Wu Wang 《Journal of fluorescence》2012,22(6):1531-1538
Novel imidazo[1,5-a]pyridinyl 1,3,4-Oxadiazole derivatives were synthesized and characterised by IR, 1H NMR and HRMS.UV-vis absorption and fluorescence properties of these compounds in different solutions showed that the maximal emission wavelength was not significantly changed in different solvents; however, maximum absorption wavelength was blue-shifted with the increase of solvent polarity. Absorption λmax and emission λmax was less correlated with substituent groups on benzene rings. The calculated molecular orbital correlates well with their absorption. 相似文献
994.
L Qu Y Guo H Luo C Zhong G Yu Y Liu J Qin 《Chemical communications (Cambridge, England)》2012,48(80):9965-9967
A simple nickel bis(dithiolene) complex has been developed as an excellent n-type molecular semiconductor for FETs, with an electron mobility of 0.11 cm(2) V(-1) s(-1) and an on/off ratio of 2 × 10(6) despite its small π-conjugated system. Good FET stability in ambient conditions has also been observed. 相似文献
995.
An intriguing cell concept by applying proton-conducting oxide as the ionic conducting phase in the anode and taking advantage of beneficial interfacial reaction between anode and electrolyte is proposed to successfully achieve both high open circuit voltage (OCV) and power output for SOFCs with thin-film samarium doped ceria (SDC) electrolyte at temperatures higher than 600 °C. The fuel cells were fabricated by conventional route without introducing an additional processing step. A very thin and dense interfacial layer (2-3 μm) with compositional gradient was created by in situ reaction between anode and electrolyte although the anode substrate had high surface roughness (>5 μm), which is, however, beneficial for increasing triple phase boundaries where electrode reactions happen. A fuel cell with Ni-BaZr(0.4)Ce(0.4)Y(0.2)O(3) anode, thin-film SDC electrolyte and Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-δ) (BSCF) cathode has an OCV as high as 1.022 V and delivered a power density of 462 mW cm(-2) at 0.7 V at 600 °C. It greatly promises an intriguing fuel cell concept for efficient power generation. 相似文献
996.
Changfeng Gui 《Journal of Differential Equations》2012,252(11):5853-5874
In this paper, we prove even symmetry and monotonicity of certain solutions of Allen–Cahn equation in a half plane. We also show that entire solutions with finite Morse index and four ends must be evenly symmetric with respect to two orthogonal axes. A classification scheme of general entire solutions with finite Morse index is also presented using energy quantization. 相似文献
997.
采用第一性原理方法研究了二维六角氮化硼(2Dh-BN)在单轴大应变下的结构变化.计算过程中以原胞在垂直和平行于B—N键方向的长度Lx和Ly来描述2Dh-BN所受到的应变.结果表明:在垂直于B—N键的方向施加大应变,当Lx≤0.3388nm时,体系处于简单斜方结构;随着应变的增大,体系逐渐从简单斜方结构向简单长方结构转变,当Lx≥0.3488nm时,体系处于简单长方结构,该结构是由交错并排的BN链相互作用形成;随着应变继续增大,简单长方结构中链之间的作用逐渐减小,当Lx0.6nm最终趋向于孤立的BN链.在平行于B—N键的方向施加大应变,体系从最初的简单斜方结构直接转变成交错并排的BN链结构,没有出现长方结构,当Ly0.571nm时,体系最终也趋向于孤立的BN链结构. 相似文献
998.
在精确放射治疗中,精确计算楔形挡板的楔形因子是精确修正加入楔形挡板后剂量值的关键。提出了基于衰减系数法思想的改进楔形野剂量修正算法,首先计算了楔形挡板材料的线性衰减系数,再根据楔形挡板的实际剖面尺寸,建立了线性拟合公式计算射线束穿过楔形挡板的实际厚度,精确计算楔形因子,并以AAPM55号报告提供的45°楔形挡板进行了验证。该方法在保证计算精度的同时减少了大量离轴测量数据,减轻了物理师的负担,可以作为一种有效的楔形挡板修正算法应用于放射治疗计划系统中。 相似文献
999.
Gui‐Ling Zhao Jonas Hafrn Luca Deiana Armando Crdova 《Macromolecular rapid communications》2010,31(8):740-744
A simple and direct method for derivatization of solid polysaccharides is presented. The novel methodology is based on the combination of organic acid‐catalyzed esterification or etherification and photochemical thiol‐ene click derivatization of a heterogeneous polysaccharide. The solid cellulose was “organoclick” modified with aryl, alkyl and polyester groups, respectively. The modification allows for a highly modular and metal free surface modification of solid polysaccharides.
1000.
对二维变量进行主成分分析相当于对坐标轴按某一角度进行旋转,而对其进行回归分析则可以求出与原坐标轴有夹角的回归直线,探讨了这两个角度之间的关系.结果表明,当二维变量间完全线性相关时,两个角度相等;若两者均在0~π/2范围内,则前者大于等于后者,若两者均在π/2~π范围内,则前者小于等于后者;两者不可能一个在0~π/2范围内,而另一个在π/2~π范围内. 相似文献