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91.
H. L. Cheng D. Y. Shi J. W. Zhao Z. D. Geng L. J. Chen P. T. Ma J. Y. Niu 《Russian Journal of Coordination Chemistry》2011,37(4):302-308
A novel 3D 3d–4f heterometallic polymer Pr4(H2O)9Cu3.5Cl0.5(Bpdc)6.5(OH)2 · 5H2O (I) (H2Bpdc = 2,2′-bipyridyl-5,5′-dicarboxylic acid) has been hydrothermally synthesized by the reaction of CuCl2 · 2H2O, PrCl3, H2Bpdc, TAA (TAA = 1H-tetrazolyl-1-acetic acid) and glacial acetic acid and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Single-crystal structural analysis shows that I displays an interesting heterometallic 3D coordination framework constructed from 2D praseodymium-oxygen layers and [Cu(Bpdc)2]3? and [CuCl(Bpdc)]2? pillars. The photofluorescence properties of I have been investigated. 相似文献
92.
Baocai Du Renyong Geng Wenliang Tan Yuchao Mao Donghui Li Xue Zhang Dan Liu Weihua Tang Wenchao Huang Tao Wang 《Journal of Energy Chemistry》2021,(3):131-137
Molecular ordering within the photoactive layer plays a crucial role in determining the device performance of organic solar cells(OSCs).However,the simultaneous molecular ordering processes of polymer donors and non-fullerene acceptors(NFAs)during solution casting usually bring confinement effect,leading to insufficient structural order of photovoltaic components.Herein,the molecular packing of mINPOIC NFA is effectively formed through a heating induced aggregation strategy,with the aggregation of PBDB-T,which has a strong temperature dependence,is retarded by casting on a preheated substrate to reduce its interference toward m-INPOIC.A sequent thermal annealing treatment is then applied to promote the ordering of PBDB-T and achieve balanced aggregation of both donors and acceptors,resulting in the achievement of a maximum efficiency of 13.9% of PBDB-T:m-INPOIC binary OSCs.This work disentangles the interactions of donor polymer and NFA during the solution casting process and develops a rational strategy to enhance the molecular packing of NFAs to boost device performance. 相似文献
93.
本文研究了开链及环状硅氢化合物中硅原子上取代基的电子效应和立体效应对Si-H键伸缩振动频率的影响。 相似文献
94.
Jun‐Ling Jin Hai‐Bin Li Dr. Yun Geng Yong Wu Yu‐Ai Duan Prof. Dr. Zhong‐Min Su 《Chemphyschem》2012,13(16):3714-3722
The geometric and electronic structures and photophysical properties of anilido‐pyridine boron difluoride dyes 1 – 4 , a series of scarce 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) derivatives with large Stokes shift, are investigated by employing density functional theory (DFT) and time‐dependent DFT (TD‐DFT) calculations to shed light on the origin of their large Stokes shifts. To this end, a suitable functional is first determined based on functional tests and a recently proposed index—the charge‐transfer distance. It is found that PBE0 provides satisfactory overall results. An in‐depth insight into Huang–Rhys (HR) factors, Wiberg bond indices, and transition density matrices is provided to scrutinize the geometric distortions and the character of excited states pertaining to absorption and emission. The results show that the pronounced geometric distortion due to the rotation of unlocked phenyl groups and intramolecular charge transfer are responsible for the large Stokes shift of 1 and 2 , while 3 shows a relatively blue‐shifted emission wavelength due to its mild geometric distortion upon photoemission, although it has a comparable energy gap to 1 . Finally, compound 4 , which is designed to realize the rare red emission in BODIPY derivatives, shows desirable and expected properties, such as high Stokes shift (4847 cm?1), red emission at 660 nm, and reasonable fluorescence efficiency. These properties give it great potential as an ideal emitter in organic light‐emitting diodes. The theoretical results could complement and assist in the development of BODIPY‐based dyes with both large Stokes shift and high quantum efficiency. 相似文献
95.
96.
Influence of reaction gas flows on the properties of SiGe:H thin film prepared by plasma assisted
reactive thermal chemical vapour deposition 总被引:1,自引:0,他引:1 下载免费PDF全文
A new preparing technology, very high frequency plasma assisted reactive thermal chemical vapour deposition (VHFPA-RTCVD), is introduced to prepare SiGe:H thin films on substrate kept at a lower temperature. In the previous work, reactive thermal chemical vapour deposition (I~TCVD) technology was successfully used to prepare SiGe:H thin films, but the temperature of the substrate needed to exceed 400℃. In this work, very high frequency plasma method is used to assist RTCVD technology in reducing the temperature of substrate by largely enhancing the temperature of reacting gases on the surface of the substrate. The growth rate, structural properties, surface morphology, photo- conductivity and dark-conductivity of SiGe:H thin films prepared by this new technology are investigated for films with different germanium concentrations, and the experimental results are discussed. 相似文献
97.
Geng NF Goh PG Johnson BF Martin CM Shephard DS Zhou W 《Angewandte Chemie (International ed. in English)》2000,39(9):1661-1664
98.
Signal changes can be detected by proton density-weighted functional imaging in both the brain and the spinal cord. These are attributed to changes in extravascular water proton (signal enhancement by extravascular protons) density during neuronal activation. In this study, we used this technique to detect correlations between acupoint stimulation and neural activity in the spinal cord. Stimulation of acupoints associated with treatment of sensorimotor deficits (LI4 and LI11) was performed on 11 volunteers. During stimulation, 8 of the 11 subjects had consistent functional activations in C6/C7. A bilateral activation pattern was common. Our findings show that acupoint stimulation modulates activity in the spinal cord. 相似文献
99.
Deeply penetrating photoacoustic tomography in biological tissues enhanced with an optical contrast agent 总被引:3,自引:0,他引:3
Photoacoustic tomography (PAT) in a circular scanning configuration was developed to image deeply embedded optical heterogeneity in biological tissues. While the optical penetration was maximized with near-infrared laser pulses of 800-nm wavelength, the optical contrast was enhanced by Indocyanine Green (ICG) dye whose absorption peak matched the laser wavelength. This optimized PAT was able to image objects embedded at depths of as much as 5.2 cm, 6.2 times the 1/e optical penetration depth, in chicken breast muscle at a resolution of <780 microm and a sensitivity of <7 pmol of ICG in blood. The resolution was found to deteriorate slowly with increasing imaging depth. The effects of detection bandwidth on the quality of images acquired simultaneously by four different ultrasonic transducers are described. 相似文献
100.
Zhi-Hui Geng Pu-Kun Liu 《International Journal of Infrared and Millimeter Waves》2004,25(7):1133-1142
The beam-wave interaction in a Ka-band, two-cavity fundamental gyroklystron amplifier is studied by using a self-consistent nonlinear simulation code. The electron efficiency for this gyroklystron amplifier is calculated, and the effect of various parameters, such as beam voltage, beam current, electron guiding center radius, velocity pitch ratio and drift tube length on the electron efficiency is discussed in detail. 相似文献