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71.
Based on the newly designed ligand 4′‐(3,5‐dicarboxyphenyl)‐4,2′:6′,4′′‐terpyridine (DCTP), a unique semi‐conductive 3D framework {[CuΙCuΙΙ2(DCTP)2]NO3?1.5 DMF}n ( 1 ) with a narrow band gap of 2.1 eV, was obtained and structurally characterized. DFT calculations with van de Waals correction employed to explore the electronic structure of 1 , clearly revealed its semi‐conductive behavior. Furthermore, we found that 1 exhibits a superior band alignment with water to produce hydrogen and degrade organic pollutants. Without adding any photosensitizers, 1 displays an efficiently photocatalytic hydrogen production in water based on the photo‐generated electrons under UV/Vis light. 1 also exhibits excellent photo‐degradation of methyl blue under visible‐light owing to the strong oxidization of excited holes. It is the first example of MOFs with doubly photocatalytic activities related to photo‐generated electrons and holes, respectively.  相似文献   
72.
The famous nonmetal‐to‐metal transition in Na–ammonia solutions is investigated in nanoscale solution droplets by photoelectron spectroscopy. In agreement with the bulk solutions, a strong indication for a transition to the metallic state is found at an average metal concentration of 8.8±2.2 mole%. The smallest entity for the phase transition to be observed consists of approximately 100–200 solvent molecules. The quantification of this critical entity size is a stepping stone toward a deeper understanding of these quantum–classical solutions through direct modeling at the molecular level.  相似文献   
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通过红外可见内窥镜诊断系统对EAST等离子体芯部逃逸电子的同步辐射功率谱进行了分析,得出低能段逃逸电子同步辐射主要在红外波段,随着逃逸电子能量的增加,同步辐射向短波方向移动进入可见光波段。在欧姆放电条件下,对逃逸电子同步辐射所产生的的红外可见光进行了成像分析,同时研究了EAST等离子体在低杂波和中性束注入加热条件下的逃逸电子行为。实验结果显示,低杂波和 NBI 的投入总体抑制电子的逃逸,但低杂波投入初期产生的快电子对逃逸电子的产生具有促进作用。  相似文献   
75.
A comprehensive investigation of the emission characteristics for electrons induced by X‐rays of a few hundred eV at grazing‐incidence angles on an atomically clean Cu(111) sample during laser excitation is presented. Electron energy spectra due to intense infrared laser irradiation are investigated at the BESSY II slicing facility. Furthermore, the influence of the corresponding high degree of target excitation (high peak current of photoemission) on the properties of Auger and photoelectrons liberated by a probe X‐ray beam is investigated in time‐resolved pump and probe measurements. Strong electron energy shifts have been found and assigned to space‐charge acceleration. The variation of the shift with laser power and electron energy is investigated and discussed on the basis of experimental as well as new theoretical results.  相似文献   
76.
In a tokamak with a toroidal electric field, electrons that exceed the critical velocity are freely accelerated and can reach very high energies. These so‐called `runaway electrons' can cause severe damage to the vacuum vessel and are a dangerous source of hard X‐rays. Here the effect of toroidal electric and magnetic field changes on the characteristics of runaway electrons is reported. A possible technique for runaways diagnosis is the detection of hard X‐ray radiation; for this purpose, a scintillator (NaI) was used. Because of the high loop voltage at the beginning of a plasma, this investigation was carried out on toroidal electric field changes in the first 5 ms interval from the beginning of the plasma. In addition, the toroidal magnetic field was monitored for the whole discharge time. The results indicate that with increasing toroidal electric field the mean energy of runaway electrons rises, and also an increase in the toroidal magnetic field can result in a decrease in intensity of magnetohydrodynamic oscillations which means that for both conditions more of these high‐energy electrons will be generated.  相似文献   
77.
We present a framework for efficiently performing Monte Carlo wave-function simulations in cavity QED with moving particles. It relies heavily on the object-oriented programming paradigm as realised in C++, and is extensible and applicable for simulating open interacting qua ntum dynamics in general. The user is provided with a number of “elements”, e.g. pumped moving particles, pumped lossy cavity modes, and various interactions to compose complex interacting systems, which contain several particles moving in electromagnetic fields of various configurations, and perform wave-function simulations on such systems. A number of tools are provided to facilitate the implementation of new elements.  相似文献   
78.
S. Dhar  M. R. Alam 《Pramana》2007,69(3):387-394
The triple differential cross-section for K-shell ionization of silver and copper atoms by relativistic electrons have been computed in the coplanar symmetric geometry with the inclusion of exchange effects following the multiple scattering theory of Das and Seal [1] multiplied by suitable spinors. Present computed results are marginally improved in some cases from the previous computed results [2]. Present results are compared with measured values [3] and with previous computation results [2]. Some other theoretical computational results are also presented here for comparison.   相似文献   
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80.
强磁场下的固体物理研究进展   总被引:2,自引:0,他引:2  
曹效文 《物理》2002,31(11):696-701
强磁场下的物理研究是一个富有成果的研究领域,40T以下稳态强磁场的研制成功为固体物理研究提供了新的科学机遇。文章简要地介绍强磁场下某些固体物理,其中包括高温超导体的H-T相图和非费米液体行为,德哈斯(de Haas)效应和费米面性质,电子的Wigner结晶及其动力学行为,磁场诱导的相变(如绝缘体-金属和超导转变),多级磁有序,串级自旋密度波和大块材料中的量子霍尔效应等的实验研究的近期进展,希望以此引起人们对国内强磁场下物理研究的关注。  相似文献   
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