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951.
正The Kitaev model in a honeycomb lattice,which has an exactly solvable spin liquid as the ground state[1],has attracted a lot of research interests.Recently,Kitaev-type interactions were discovered in several quasi-2D,honeycomb lattice compounds,such as A_2IrO_3(A=Li,Na)[2-7]and α-RuCl_3[8-15].In these compounds,both the spin-orbit coupling and electron correlations play an essential role in the emergent Mott insulator behaviors[2,16-19].Although the 相似文献
952.
All‐Inorganic Hetero‐Structured Cesium Tin Halide Perovskite Light‐Emitting Diodes With Current Density Over 900 A cm−2 and Its Amplified Spontaneous Emission Behaviors 下载免费PDF全文
953.
腺苷酸转移酶(ANT)是位于线粒体内膜上参与能量分子传导的转运蛋白,在细胞凋亡调控网络中发挥重要作用.以虹鳟鱼(Oncorhynchus mykiss)为研究材料,使用RT-PCR和RACE法分离和克隆了虹鳟鱼ant2基因cDNA的全长序列(GenBank登录号:FJ591153).该序列全长1276 bp,其中5'端非翻译区长66 bp,3'端非翻译区长316 bp,开放性阅读框长894 bp,编码297个氨基酸.该蛋白具有3个保守的线粒体穿膜功能结构域和3个转膜区.通过与其他脊椎动物腺苷酸转移酶蛋白序列的比较,发现该基因具有高度保守性,氨基酸序列的同源性均在90%左右.同源模建显示其与牛的线粒体ADP/ATP载体,chain A蛋白有相同的孔洞(cavity)结构. 相似文献
954.
The Galilean invariance and the induced thermo-hydrodynamics of the
lattice Boltzmann Bhatnagar--Gross--Krook model are proposed
together with their rigorous theoretical background. From the
viewpoint of group invariance, recovering the Galilean invariance
for the isothermal lattice Boltzmann Bhatnagar--Gross--Krook
equation (LBGKE) induces a new natural thermal-dynamical system,
which is compatible with the elementary statistical thermodynamics. 相似文献
955.
Lu‐Yi Zou Ai‐Min Ren Ji‐Kang Feng Xue‐Qin Ran 《Journal of Physical Organic Chemistry》2009,22(11):1104-1113
The use of triphenyl amino‐based derivatives in organic light‐emitting diodes (OLEDs) can significantly improve their efficiency and stability and especially their electroluminescence characteristics – most of the new hole‐transport materials have this feature. In this study, a series of triphenyl amino‐based compounds were computed, including two newly designed molecules. They can function as charge transport materials and emitters with high efficiency and stability. To reveal the relationship between the properties and structures of these bifunctional and multifunctional electroluminescent materials, the ground and excited state geometries were optimized at the B3LYP/6‐31G(d), HF/6‐31G(d), TD‐B3LYP/6‐31G(d), and CIS/6‐31G(d) levels, respectively. The ionization potentials (IPs) and electron affinities (EAs) were computed. The lowest excitation energies, the maximum absorption, and emission wavelengths of these compounds were calculated by employing the time‐dependent density functional theory (TD‐DFT) method. Also, the mobilities of holes and electrons were studied computationally based on the Marcus electron transfer theory. The CH2Cl2 solvent effect on the absorption spectra of N,N′‐di‐1‐naphthyl‐N,N′‐diphenylbenzidine ( NPB ) was considered by polarizable continuum model (PCM). The results obtained for these compounds are in good agreement with the experimental values. These data show that the proposed compounds 1 and 2 (N,B‐di‐1‐naphthyl‐N,B‐diphenylbenzidine and Mes2N[p‐4,4′‐biphenyl‐NPh(1‐naphthyl)]), are multifunctional and bifunctional materials similar to Mes2B[p‐4,4′‐biphenyl‐NPh(1‐naphthyl)] ( BNPB ) and NPB , respectively. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
956.
Tae Ho Yeom Ae Ran Lim 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2009,200(2):261-266
Nuclear magnetic resonance (NMR) data and the spin–lattice relaxation times, T1, of 69Ga and 71Ga nuclei in a β-Ga2O3:Cr3+ single crystal were obtained using FT NMR spectrometry. Four sets of NMR spectra for 69Ga (I = 3/2) and 71Ga (I = 3/2) were obtained in the crystallographic planes. The 69Ga and 71Ga nuclei each had two chemically inequivalent GaI and GaII centers. Each of the 69Ga and 71Ga isotopes yielded two different central NMR resonance lines originating from GaI and GaII sites. The nuclear quadrupole coupling constants and asymmetry parameters of 69GaI, 69GaII, 71GaI, and 71GaII centers in a β-Ga2O3:Cr3+ crystal were obtained. Analysis of the EFG tensor principal axes (PAs) for Ga nuclei and the ZFS tensor PAs for the Cr3+ ion confirmed that the Cr3+ paramagnetic impurity ion substitutes for the Ga3+ ion in the oxygen octahedron. In addition, the temperature dependencies of the 69Ga and 71Ga relaxation rates were consistent with Raman processes, as T1−1 ∝ T2. Even though the Cr3+ impurities are paramagnetic, the relaxations were dominated by electric quadrupole interactions of the nuclear spins in the temperature range investigated. 相似文献
957.
Yunxiang Zhang Guang Ran 《Physica E: Low-dimensional Systems and Nanostructures》2009,41(10):1848-1852
Well-ordered and highly uniform nanoripple structures on the surface of single crystal LaAlO3 (1 0 0), SrTiO3 (1 0 0) and Al2O3 (0 0 0 1) were formed via self-assembly (not by beam writing) by focused ion-beam bombardment. The morphology and topography of nanoripple structures were characterized using in-situ focused ion-beam/scanning electron microscope, as well as ex-situ atomic force microscopy. Under off-normal bombardment without sample rotation, the characteristic wavelength of nanoripples varying from 248 to 395 nm on the LaAlO3 (1 0 0) surface can be obtained by changing ion fluence and incident angle. When all sputtering parameters except the ion fluence are constant, the wavelength of nanoripples is increased with the enhanced ion fluence. These results demonstrate the potential application of using ion sputtering method for fabricating the well-ordered and highly uniform nanoripples which can be used in nanodevices. 相似文献
958.
A comparative study on partially premixed combustion (PPC) and reactivity controlled compression ignition (RCCI) in an optical engine 总被引:1,自引:0,他引:1
Haifeng Liu Qinglong Tang Zhi Yang Xingwang Ran Chao Geng Beiling Chen Lei Feng Mingfa Yao 《Proceedings of the Combustion Institute》2019,37(4):4759-4766
Partially premixed combustion (PPC) and reactivity controlled compression ignition (RCCI) are two new combustion modes in compression-ignition (CI) engines. However, the detailed in-cylinder ignition and flame development process in these two CI modes were not clearly understood. In the present study, firstly, the fuel stratification, ignition and flame development in PPC and RCCI were comparatively studied on a light-duty optical engine using multiple optical diagnostic techniques. The overall fuel reactivity (PRF number) and concentration (fuel-air equivalence ratio) were kept at 70 and 0.77 for both modes, respectively. Iso-octane and n-heptane were separately used in the port-injection (PI) and direct-injection (DI) for RCCI, while PRF70 fuel was introduced through direct-injection (DI) for PPC. The DI timing for both modes was fixed at –25°CA ATDC. Secondly, the combustion characteristics of PPC and RCCI with more premixed charge were explored by increasing the PI mass fraction for RCCI and using the split DI strategy for PPC. In the first part, results show that RCCI has shorter ignition delay than PPC due to the fuel reactivity stratification. The natural flame luminosity, formaldehyde and OH PLIF images prove that the flame front propagation in the early stage of PPC can be seen, while there is no distinct flame front propagation in RCCI. In the second part, the higher premixed ratio results in more auto-ignition sites and faster combustion rate for PPC. However, the higher premixed ratio reduces the combustion rate in RCCI mode and the flame front propagation can be clearly seen, the flame speed of which is similar to that in spark ignition engines but lower than that in PPC. It can be concluded that the ratio of flame front propagation and auto-ignition in RCCI and PPC can be modulated by the control over the fuel stratification degree through different fuel-injection strategies. 相似文献
959.
960.
Guan-Ying Wang Ran Han Xiao-Ping Ouyang Jin-Cheng He Jun-Yao Yan 《中国物理C(英文版)》2017,41(5):056201-056201
A reconstruction algorithm for unfolding neutron energy spectra has been developed, based for the first time on the potential reduction interior point algorithm. This algorithm can be easily applied to neutron energy spectrum reconstruction in the recoil proton method. We transform the neutron energy spectrum unfolding problem into a typical nonnegative linear complementarity problem. The recoil proton energy spectrum and response matrix at angles of 0^o and 30^o are generated by the Geant4 simulation toolkit. Several different neutron energy test spectra are also employed. It is found that this unfolding algorithm is stable and provides efficient, accurate results. 相似文献