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排序方式: 共有253条查询结果,搜索用时 109 毫秒
101.
LI Yongfang ZHANG Xiangyang SUN Jianfeng ZHANG Yanliang ZHAO Yongmei WANG Yongchang DING Liang'en WANG Zugeng 《Chinese Journal of Lasers》2002,11(1):14-18
1 Introduction Quantuminterferenceresultsinavarietyofneweffects,whichareattractingmuchcurrentinterests .Manyexperimentalandtheoreticalinvestigationshavebeendone .Forexample,inaV typesystem ,thequantuminterferenceprocessescancauselasingwithoutinversion (LW… 相似文献
102.
An insulate to metal transition was investigated based on the measurements of the dependence of the conductivity, activation energy on the protonation state of polyaniline (PANI). An isotropy in conductivity for stretched salt form of PANI was observed.For salt film of PANI, the Ⅰ-Ⅴcurve obeys Ohm's law, which shows a typical metal behavior, however, for base film or film with low protonation state, it can be explained by Space Charge Limited Current (SCLC). It is also found that the Ⅰ-Ⅴcurve of base film of PANI is independent of the work function of electrodes and the polymerization temperature. 相似文献
103.
Yingyu?Hu Guoqiao?Lai Yongjia?ShenEmail author Yongfang?Li 《Monatshefte für Chemie / Chemical Monthly》2004,135(9):1167-1172
Summary. Zinc(II) and magnesium(II) phthalocyanines bearing four substituted propylenedithiotetrathiafulvalene (PDT-TTF) units were synthesized and characterized by NMR, MS, EA, and UV/VIS spectra. The absorption peaks of two target molecules were hypsochromically shifted compared with the phthalocyanine parent compound. Studies using cyclic voltammetry indicated that introduction of Zn and Mg as central metals enhanced the electronwithdrawing between the phthalocyanine core and the PDT-TTF unit, thus losing one electron to form (PDT-TTF)+ becomes more difficult. 相似文献
104.
Haijun Bin Lian Zhong Zhi-Guo Zhang Liang Gao Yankang Yang Lingwei Xue Jing Zhang Zhanjun Zhang Yongfang Li 《中国科学:化学(英文版)》2016,59(10):1317-1322
A new benzodithiophene(BDT)-alt-fluorobenzotriazole(FBTA) D-A copolymer J40 was designed and synthesized by introducing 2-octyldodecyloxy side chains on its BDT units, for expanding the family of the BDT- alt-FBTA-based copolymers and investigating the side chain effect on the photovoltaic performance of the polymer in non-fullerene polymer solar cells(PSCs).J40 exhibits complementary absorption spectra and matched electronic energy levels with the n-type organic semiconductor(n-OS)(3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-sindaceno[1,2-b:5,6-b′]dithiophene)(ITIC) acceptor, and was used as polymer donor in the non-fullerene PSCs with ITIC as acceptor. The power conversion efficiency(PCE) of the PSCs based on J40:ITIC(1:1, w/w) with thermal annealing at 120 °C for 10 min reached 6.48% with a higher open-circuit voltage(Voc) of 0.89 V. The high Voc of the PSCs is benefitted from the lower-lying highest occupied molecular orbital(HOMO) energy level of J40. Although the photovoltaic performance of the polymer J40 with alkoxy side chain is lower than that of J60 and J61 with alkylthio-thienyl conjugated side chains, the PCE of6.48% for the J40-based device is still a relatively higher photovoltaic efficiency in the non-fullerene PSCs reported so far. The results indicate that the family of the BDT-alt-FBTA-based D-A copolymers are high performance polymer donor materials for non-fullerene PSCs and the side chain engineering plays an important role in the design of high performance polymer donors in the non-fullerene PSCs. 相似文献
105.
A phenylenevinylene‐thiophene‐phenyleneethynylene copolymer, poly{[1′,4′‐bis‐(thienyl‐vinyl)]‐2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylene‐vinylene‐alt‐1,4‐dioctyloxyl‐phenyleneethynylene}(PTPPV‐ PPE), was synthesized by the Sonogashira Pd‐catalyzed cross‐coupling reaction. The copolymer possesses higher thermal decomposition temperature (Td = 382°C) compared with poly{[1′,4′‐bis‐ (thienyl‐vinyl)]‐2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylene‐vinylene} (PTPPV). The absorption and photoluminescence (PL) peaks of PTPPV‐PPE solution and solid film locate in between those of the homopolymers of PTPPV and poly(1,4‐dioctyloxyl‐phenyleneethynylene) (PPE), and closer to that of PTPPV. Photovoltaic cell was fabricated based on the blend of PTPPV‐PPE and PCBM with a weight ratio of 1:1. The primary result shows an open circuit voltage (Voc) of 0.72 V which is higher than that of the PTPPV (0.67 V), and a power conversion efficiency (PCE) of 0.3% under the illumination of AM1.5, 100 mW/cm2 which is much better than that of PPEs. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
106.
Chinese Journal of Polymer Science - 相似文献
107.
In this paper, a function space is constructed, in which an arbitrary function satisfies the nonlocal boundary conditions
of a nonlinear pseudoparabolic equation. A very simple numerical algorithm for the approximations of the nonlinear pseudoparabolic
equation with nonlocal boundary conditions based on the function space is provided. A numerical example is given to illustrate
the applicability and efficiency of the algorithm. 相似文献
108.
Xiang Wang Gaofeng Zheng Lei Xu Wei Cheng Bulei Xu Yongfang Huang Daoheng Sun 《Applied Physics A: Materials Science & Processing》2012,108(4):825-828
A simple and low-cost method is suggested to fabricate nanochannels via Near-Field Electrospinning (NFES). In this process, orderly and patterned nanofibers direct-written by NFES are used as sacrificial templates. Well-defined nanochannels are available after the removal process of both sacrificial fibers and material coating over the fibers. The sacrificial fiber, controlled by NFES, dominates the channel geometry. The channel width ranges from 133 nm to 13.54?μm while the applied voltage increases from 1.2 kV to 2.5 kV. Complicated wave-shape and grid pattern channels are presented under a corresponding movement of substrate. This method integrates electrospinning with conventional MEMS fabrication technology and has a potential in micro/nano manufacturing. 相似文献
109.
Lijun Huo Zhan'ao Tan Xiang Wang Yi Zhou Minfang Han Yongfang Li 《Journal of polymer science. Part A, Polymer chemistry》2008,46(12):4038-4049
Novel two‐dimensional donor–acceptor (D–A) structured conjugated polymers, P1–P4, were designed and synthesized by introducing electron‐deficient quinoxaline as core and electron‐rich alkoxyl‐phenylenevinylene in side chains and p‐phenylenevinylene, triphenylamine, or thiophene in main chain. Benefited from the D–A structures, the polymers possess low bandgaps of 1.75 eV, 1.86 eV, 1.59 eV, and 1.58 eV for P1, P2, P3, and P4, respectively, and show broad absorption band in the visible region: the shorter wavelength absorption peak at ~400 nm ascribed to the conjugated side chains and the longer wavelength absorption peak between 500 nm and 750 nm belonging to the absorption of the conjugated main chains. Especially, the absorption band of P4 film covers the whole visible range from 300 nm to 784 nm. The power conversion efficiencies of the polymer solar cells based on P1–P4 as donor and PCBM as acceptor are 0.029%, 0.14%, 0.46%, and 0.57%, respectively, under the illumination of AM 1.5, 100 mW/cm2. The polymers with the low bandgap and broad absorption band are promising photovoltaic materials. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4038–4049, 2008 相似文献
110.
Effect of the device fabrication conditions on photovoltaic performance of the polymer solar cells based on poly(3‐hexylthiophene) (P3HT) as donor and indene‐C70 bisadduct (IC70BA) as acceptor was studied systematically. The device fabrication conditions we studied include pre‐thermal annealing temperature, active layer thickness, and the P3HT:IC70BA weight ratios. For devices with a 188‐nm‐thick active layer of P3HT:IC70BA (1:1, w:w) blend film and pre‐thermal annealing at 150°C for 10 min, maximum power conversion efficiency (PCE) reached 5.82% with Voc of 0.81 V, Isc of 11.37 mA/cm2, and FF of 64.0% under the illumination of AM1.5G, 100 mW/cm2. 相似文献