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101.
运用密度泛函理论和非平衡格林函数结合的方法,研究电极区N掺杂对扶手椅型石墨烯纳米带电子输运特性的影响.结果表明,与本征扶手椅型石墨烯纳米带电流-电压曲线相比,宽度为7的石墨烯纳米带电流-电压曲线表现出明显的不对称性,其中心N掺杂表现强烈的整流特性,整流系数达到102数量级,且将N原子从电极区中心位置移动到边缘,整流特性减弱.研究结果表明宽度为7的扶手椅型石墨烯纳米带出现强整流现象的原因主要是负向偏压下能量窗内没有透射峰引起的,该研究结果对将来石墨烯整流器件的设计具有重要的意义. 相似文献
102.
Wenting Bu Qiuju Guo Jian Zheng Shigeo Uchida 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(2):999-1005
Surface soil samples collected in the Jiuquan region in the downwind area of the Chinese nuclear test site (CNTs) were analyzed for Pu isotopes. The 239+240Pu activities ranged from 0.025 ± 0.009 to 0.89 ± 0.16 mBq g?1, varying significantly with different sampling sites. The Dunhuang city that is located in the southwestern part of the Jiuquan region received the heaviest Pu deposition (239+240Pu activities, 0.23–0.89 mBq g?1). Most of the 240Pu/239Pu isotopic ratios were similar with that of the global fallout. However, the low values (0.080–0.147) observed in three sampling sites further supported the finding of Pu originated from CNTs in that region. 相似文献
103.
PEG-related adhesives are limited in clinical use because they are easy to swell and cannot support the cell growth.In this study,we produced a series of POSS-modified PEG adhesives with high adhesive strength.Introduction of inorganic hydrophobic POSS units decreased the swelling of the adhesives and enhanced cell adhesion and growth.The in vitro cytotoxicity and in vivo inflammatory response experiments clearly demonstrated that the adhesives were nontoxic and possessed excellent biocompatibility.Compared with the sutured wounds,the adhesive-treated wounds showed an accelerated healing process in wounded skin model of the Bama miniature pig,demonstrating that the POSS-modified PEG adhesive is a promising candidate for wound closure. 相似文献
104.
Lan Luo Ziyi Zhang Yanhua Chen Lixia Zhang Xiangfeng Bu Hanqi Zhang 《International journal of environmental analytical chemistry》2017,97(12):1178-1191
A simple and sensitive surface-enhanced Raman spectroscopy (SERS) method for the detection of safranine T (ST) and Hg2+ using silver nanoparticles (AgNPs) as substrate was developed. ST can absorb on the surface of AgNPs through electrostatic interaction, the electromagnetic effect combined with chemical adsorption effect give a notable Raman enhancement for ST. The presence of Hg2+ well decreased the absorbed ST molecules on AgNPs, leading to a significant decrease of SERS signals thus enabling to detect Hg2+. The determination conditions for SERS, including the amount of AgNPs, the concentration of NaCl, the concentration of HCl, the concentration of ST and the reaction time, were optimised. Under the optimised experimental conditions, good linear responses were obtained for ST and Hg2+ in the concentration ranges of 0.01–4.0 μmol L?1 (3.5–1403.4 ng mL?1) and 0.01–2.0 μmol L?1 (2.0–401.2 ng mL?1), the limit of detection were 3.0 nmol L?1 (1.1 ng mL?1) and 2.0 nmol L?1 (0.4 ng mL?1), respectively. The present method was subsequently applied to the determination of ST in tomato sauces and Hg2+ in environmental waters, the recoveries of ST and Hg2+ in spiked samples are 95.5–107.8% and 91.4–110.8 %, respectively. 相似文献
105.
厚薄板通用三角形位移元 总被引:1,自引:0,他引:1
本文构造出了一种具有九个自由度的厚薄板通用三角形位移单元,并给出了单元刚度矩阵显式。这种单元以其简洁的常规位移元列式可在相当宽的板厚变化范围内(包括板厚为零)获得很高的计算精度,其结果可与相应的矩形单元相比。而且不会出现剪切自锁。 相似文献
106.
107.
5-(1H-Tetrazol-1-yl)isophthalic acid (H(2)L) reacts with Cu(II) ion forming a new metal-organic framework {[CuL]·DMF·H(2)O}(∞) (1) (DMF = N,N-dimethylformamide), with a rutile-related type net topology. Compound 1 possesses a 3D structure with 1D channels that can be desolvated to yield a microporous material. Adsorption properties (N(2), H(2), O(2), CO(2), and CH(4)) of the desolvated solid [CuL] (1a) have been studied, and the results exhibit that 1a possesses fairly good capability of gas sorption for N(2), H(2), O(2), and CO(2) gases, with high selectivity ratios for O(2) over H(2) at 77 K and CO(2) over CH(4) at 195, 273, and 298 K. Furthermore, 1a has excellent O(2) uptake at 77 K and a remarkably high quantity of adsorption for CO(2) at room temperature (298 K) and atmospheric pressure, suggesting its potential applications in gas separation or purification. 相似文献
108.
The importance of the picture change error (PCE) correction in the quasirelativistic electron density of radon atom is presented. PCE correction is considered for the infinite order two-component (IOTC) and second order Douglas-Kroll-Hess (DKH2) wave functions. Implementation details of PCE correction of electron density are outlined. The result section presents the radial distributions of electron density ρ(r) and the 4πr(2)ρ(r) function of the radon atom in the nuclear region. The PCE corrected and contaminated DKH2, IOTC electron densities are presented and compared with the Dirac-Coulomb Hamiltonian and nonrelativistic electron densities. Besides, some additional effects in electron density and SCF energy are considered, such as spin-orbit coupling, the inclusion of the Gaunt term, and the finite nucleus model effects. The effects of p(2)Vp(2) and p(2)ρ(r)p(2) analytic integral classes within IOTC Hamiltonian and PCE correction of IOTC electron density are considered. 相似文献
109.
Hu BW Zhao JP Yang Q Zhang XF Evangelisti M Sañudo EC Bu XH 《Dalton transactions (Cambridge, England : 2003)》2010,39(46):11210-11217
Two new azido-Co(II) complexes with pyrazine carboxylato ligands, [Co(N(3))(L)·H(2)O](n) (L = pyrazine-2-carboxylato) (1) and [CoNa(N(3))(2)(L)](n) (2), have been obtained by carefully tuning the Co(II):N(3)(-) ratio. Here we present the structural and magnetic characterization of these new species. Modulation of the coordination environment of Co(II) leads to a variation of the magnetic properties of the obtained compounds. Complex 1 exhibits ferromagnetically coupled [Co(2)] units that form the rungs of the ladder with a nearly negligible coupling between these units, while complex 2 is a 2D arrangement of 1D Co(II) single-chain magnets. 相似文献
110.
Yuxiang Bu 《Frontiers of Chemistry in China》2010,5(3):309-324
This feature article addresses several novel aspects regarding the peptide-mediated charge migrations, including: i) radical
exchanges with tunable radical types (σ-radical versus π-radical) and electron-transfer (ET)-channel-tunable cooperative proton-coupled
ET (PCET) mechanism, including hydrogen-atom transfer (HAT), single ET-channel PCET, double ET channel PCET, and channel-type-tunable
(σ-channel versus π-channel) PCET; ii) hole hopping migration between the active groups in the side-chains and its controllability;
iii) hole hopping through stepping-stones via a solvated “hole” form; and iv) electron hopping through positively charged
groups as stepping-stones via a solvated electron state. In particular, the controllability of the ET channels (pathways and
types) and solvated-“hole”/“electron”-based relay mechanisms are mainly mentioned. Clearly, this is an important addition
to the well-documented mechanisms for charge migration in proteins. In view of the complexity of protein charge migration,
further exploration on details of the stepping-stone-based relay mechanisms, by considering the properties and structures
of the redox active centers, their intercalators, and the real surroundings, is still needed. 相似文献