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High-efficiency asymmetric diffraction based on PT-antisymmetry in quantum dot molecules

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Chinese Physics B 2022年第1期31卷 267-272页

作者：程广玲胡永升钟文学陈爱喜 Department of Applied Physics East China Jiaotong UniversityNanchang 330013China Department of Physics Zhejiang Sci-Tech UniversityHangzhou 310018China

We present preparation of asymmetric grating with higher diffraction efficiency in quantum dot molecules by combining the tunneling effect and parity-time antisymmetry.In the presence of tunneling between two quantum dots,the system exhibits the striking PT antisymmetry via spatially modulating the driving field and the detuning with respect to the driven transition.For this reason,the asymmetric grating could be achieved.The results show that the diffraction efficiency can be adjustable via changing the driving intensity,detuning,tunneling strength,and interaction length,and then the high-order diffraction can be reached.The scheme provides a feasible way to obtain the direction-controlled diffraction grating,which can be helpful for optical information processing and realization of controllable optical self-image.

关键词： asymmetric diffraction grating PT antisymmetry tunneling effect

EPR Study on the complex formed by charge-transfer process between ground-state acceptor chloranil and nine donors

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Chinese Journal of Chemistry 1998年第5期16卷 397-403页

作者：史济良周澄明易湖南邱志海傅瑶红蒋锡夔 Shanghai Institute of Organic Chemistry Chinese Academy of SciencesShanghai 200032China

EPR study showed that the semi-quinone radical anion of chloranil (TCQ) was formed in a charge-transfer process between ground state chloranil as acceptor and each one of the following ground state donors, i.e., N, N-diethyl aniline (DEA), phenothiazine (PTZ), carbazole (CBZ), pyrene (PY), ferrocene (FRO), triphenylphosphine (TPP), triethylamine (TEA), anthracene (AN) and N, N-diethyl-3-aminophenyl ester of palmitic acid (DPP). Our results indicate that there is a tunneling effect for the ground-state charge-transfer process between chloranil and the donor.

关键词： EPR charge-transfer tunneling effect

Influence of characteristics' measurement sequence on total ionizing dose effect in PDSOI nMOSFET

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Chinese Physics B 2018年第12期27卷 551-558页

作者：解鑫毕大伟胡志远朱慧龙张梦映张正选邹世昌 State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China University of Chinese Academy of Sciences Beijing 100049China

The influence of characteristics’ measurement sequence on total ionizing dose effect in partially-depleted SOI nMOSFET is comprehensively studied. We find that measuring the front-gate curves has no influence on total ionizing dose effect.However, the back-gate curves’ measurement has a great influence on total ionizing dose effect due to high electric field in the buried oxide during measuring. In this paper, we analyze their mechanisms and we find that there are three kinds of electrons tunneling mechanisms at the bottom corner of the shallow trench isolation and in the buried oxide during the backgate curves’ measurement, which are: Fowler–Nordheim tunneling, trap-assisted tunneling, and charge-assisted tunneling.The tunneling electrons neutralize the radiation-induced positive trapped charges, which weakens the total ionizing dose effect. As the total ionizing dose level increases, the charge-assisted tunneling is enhanced by the radiation-induced positive trapped charges. Hence, the influence of the back-gate curves’ measurement is enhanced as the total ionizing dose level increases. Different irradiation biases are compared with each other. An appropriate measurement sequence and voltage bias are proposed to eliminate the influence of measurement.

关键词： total ionizing dose(TID) silicon-on-insulator(SOI) measurement sequence tunneling effect

ANOMALOUS HOPPING AND tunneling effectS IN A NEW ALUMINUM FILM PERCOLATION SYSTEM

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2001年第4期2卷 20-24页

作者：夏阿根叶剑挺叶全林陶向明金进生叶高翔 Department of Physics Zhejiang University Hangzhou China

A new aluminum thin film percolation system, deposited on glass and silicon wafer surfaces by a vapor deposition method, was investigated. By using the expansive and mobile behaviors of the silicone oil, the Al films are quenched gradually by the silicone oil during the deposition process. The \%R-I\% behavior of the film system was studied, and the anomalous conductivity indicated that, at very low current, the hopping and tunneling effects in the films are much stronger than those of the normal film systems.

关键词： thin film percolation hopping conductance tunneling effect

Dynamics of Bose-Einstein condensate in a harmonic potential and a Gaussian energy barrier

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Chinese Physics B 2011年第1期20卷 165-168页

作者：花巍李彬刘学深 Institute of Atomic and Molecular Physics Jilin University

We have studied the dynamics of Bose-Einstein condensate by solving numerically the Gross-Pitaevskii （CP） equation. We examined the periodic behaviour of the condensate in a shifted harmonic potential, and further demonstrated the tunneling effect of a condensate through a Gaussian energy barrier, which is inserted after the condensate has been excited by shifting the harmonic trapping potential to a side. Moreover, it is shown that the initial condensate evolves dynamically into two separate moving condensates after the tunneling time under certain conditions.

关键词： Gross-Pitaevskii equation Gaussian energy barrier tunneling effect

Mechanism of Functional Responses to Loading of Carbon Fiber Reinforced Cement-based Composites

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Journal of Wuhan University of Technology(Materials Science) 2008年第4期23卷 571-573页

作者： JIANG Cuixiang LI Zhuoqiu SONG Xianhui LU Yong College of Science Wuhan University of Science and Technology Wuhan 430065 China School of Science Wuhan University of Technology Wuhan 430070 China

Single fiber pull-out testing was conducted to study the origin of the functional responses to loading of carbon fiber reinforced cement-based composites. The variation of electrical resistance with the bonding force on the fiber-matrix interface was measured. Single fiber electromechanical testing was also conducted by measuring the electrical resistance under static tension. Comparison of the results shows that the resistance increasing during single fiber pull-out is mainly due to the changes at the interface. The conduction mechanism of the composite can be explained by the tunneling model. The interfacial stress causes the deformation of interfacial structure and the interfacial debonding, which have influences on the tunneling effect and result in the change of resistance.

关键词： carbon fiber functional response tunneling effect single pull-out cement

Theoretical Study on the Kinetics for the Reactions of Heptyl Radicals with Methanol

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Chemical Research in Chinese Universities 2018年第5期34卷 786-791页

作者： ZHAO Zhongrui SONG Jinou SU Boyang WANG Xiaowen State Key Laboratory of Engines Tianjin University Tianjin 300072 R R. China

Ab initio study of the reactions ofn-heptyl radicals（1-C7H15, 2-C7H15, 3-C7H15, and 4-C7H15） with metha- nol was conducted over the temperature range of 300--1500 K. Transition states for the reaction channels producing CTH15OH, CH3, C7H15OCH3, H, C7H16, CH2OH and CH30 were identified and the geometries of all stationary points were calculated at BB1K/MG3S level of theory. The potential barrier heights of the corresponding transition states were predicted by the CBS-QB3//BB1K and G4//BB1K methods, indicating that the eight H-abstraction channels are more kinetically favorable than the channels where OH transfers from CH3OH to C7H15 and where the CTHIsOCH3＋H products are given. Tile rate constants of H-abstraction channels were calculated with TST and TST/Eck. Both the forward and reverse rate constants have positive temperature dependence and the ttmneling effect is only important at the temperature lower than 700 K. For the reactions of H-atom abstraction from methyl in CH3OH by n-heptyl, a reverse and the corresponding forward rate constant are roughly equal. For the reactions of H-atom abstraction from OH in CH3OH by n-heptyl, a reverse rate constant is larger by several orders of magnitude thin1 the corresponding forward one.

关键词： n-Heptane Methanol Ab initio calculation Conventional transition state theory tunneling effect

Theoretical Investigation on the Abstraction Reaction of H with (CH_3)_3SiH

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Chemical Research in Chinese Universities 2002年第1期18卷 47-51页

作者： ZHANG Qing-zhu WANG Ming-gang WANG Shao-kun ZHANG Miao LIU Chuan-pu GU Yue-shu Department of Chemistry Shandong UniversityJinan 250100P.R.China

The abstraction reaction of H with (CH_3)_3SiH was investigated at the high levels of ab initio molecule orbital theory. The geometries were optimized at the MP2 level with 6-31G( d ) basis set, and G2MP2 level was used for the final energy calculations. The theoretical analysis provides the conclusive evidence that the main process is the hydrogen abstraction from the Si-H bond, leading to the formation of H_2 and silyl radicals; the hydrogen abstraction from the C-H bond has a higher barrier and is difficult to react. The kinetics was calculated with canonical variational transition-state theory (CVT) over the temperature range 200-1 000 K, and the theoretical rate constants match well with the later experimental values.

关键词： Reaction mechanism Variational transition state tunneling effect Rate constant

Density Functional Theoretical Study on the Reaction Mechanism of HOCO and Its Radical

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Chinese Journal of Structural Chemistry 2015年第7期34卷 985-994页

作者：于专妮徐香夏树伟于良民 Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education College of Chemistry and Chemical EngineeringOcean University of China College of Chemistry and Pharmacy Qingdao Agricultural University

In this paper, the reaction mechanism of HOCO with its radical has been investigated deeply by density functional theory（DFT）, while the geometries and harmonic vibration frequencies of the reactants, intermediates, transition states and products have been calculated at the B3LYP/6-311＋＋G＊＊ level. The CCSD（T）/cc-p VQZ method was used to further calculate the single-point energy of each stationary point along the reaction channel. The result shows that channels（b） and（d） via carbon-carbon intermediates are competing with the ones（e）,（f）,（i） and（l） through carbon-oxygen intermediates, and the six channels are dominant for the title reaction to produce HCOOH and CO2. The result also indicates that the hydrogen abstraction from the HOCO radical can be performed quickly by the self-interaction of HOCO in the absence of other radicals or atoms, which indirectly proves for the first time that the ground-state cis-HOCO radical is not decomposed by the tunneling effect. In addition, the charges of natural population analysis（NPA） and the variation of chemical bonds have been analyzed by the Natural Bond Orbital（NBO） method along with the important reaction path.

关键词： HOCO radical self-interaction natural bond orbital analysis tunneling effect