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Pulses compression in a self-mode-locked Ti:sapphire laser

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Chinese Science Bulletin 1996年第9期41卷 723-728页

作者：赖天树林位株陈毓川徐杏绍郑向阳莫党 Department of physics Zhongshan University Guangzhou 510275 China Natl. lab. Ultrafast Laser S. Zhongshan University Guangzhou 510275 China

A great deal of progress has been made in self-mode-locked Ti: sapphire laser since itwas invented in 1991. It has already found wide uses owing to its broad spectrum abilityto generate short pulses, high output power, simple setup and good stabilities. Recentlypulses as short as 8.5 fs have been generated by a laser of this kind. By improving com-

关键词： Kerr-lens mode-locking (KLM) Ti: sapphire laser femtosecond pulses.

Transformation of ZSM-5 Zeolite Under High Pressure and High Temperature

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Science China Chemistry 1994年第9期37卷 1054-1062页

作者：刘晓旸赵旭东侯为民苏文辉 Group of Solid State physics dilin University Changchun 130023 PRC Group of Solid State physics Jilin University Changchun 130023 PRC CCAST(World lab.) Center for Condensed Matter and Radiation Physics PO Box 8730 Beijing 100080PRC and International Center for Materials Physics Academia Sinica Shenyang 110015 PRC.

The effect of pressure and temperature on the stability of all-silicon ZSM-5 zeolite is re-ported for the first *** has been found that ZSM-5 zeolite is directly transformed into ZSM-11 zeolite un-der the pressure of 4.0 GPa at room temperature and that this transformation is ***-5 zeoliteis transformed into β-quartz by high pressure quenching,which is obtained for the first time at room temper-ature,and coesite under high pressure and high temperature.

关键词： high pressure transformation zeolite quartz

Study of local environment of Cu atoms in Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 alloy with different annealing temperature

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Science China(physics,Mechanics & Astronomy) 2013年第10期56卷 1887-1891页

作者： ZHANG Yu YANG Ying WANG YuXin LU Wei YAN Biao School of Materials Science and Engineering Tongji University Shanghai Key lab. of D&A for metal-Functional Materials Department of Chemical&Materials Engineering the University of AucklandPB 92019 Auckland 1142 New Zealand

The local environment of Cu atoms in Fe73.5Cu1Nb3Si13.5B9 alloy was investigated by extended X-ray absorption fine structure(EXAFS).Cu clusters began to order when the annealing temperature was around 733 K from the results of the Fourier transform *** fitting results showed that the first shell of the near fcc(face-centered cubic)Cu clusters only contained Cu *** coordination number increased with the annealing ***,the occupancy rate increased from 33.3%(annealed at 733 K)to 100% (annealed at 853 K).This local structural change of Cu atoms could probably affect the distribution of the bcc(body-centered cubic)α-Fe in Fe73.5Cu1Nb3Si13.5B9 alloy.

关键词： extended X-ray absorption fine structure Cu clusters average coordination number occupancy rate

Acoustic Properties of metal-Organic Frameworks

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Research 2021年第1期2021卷 1332-1342页

作者： Zhi-Gang Li Kai Li Li-Yuan Dong Tian-Meng Guo Muhammad Azeem Wei Li Xian-He Bu School of Materials Science and Engineering Tianjin Key Lab of Metal and Molecule-Based Material ChemistryNankai UniversityTianjin 300350China School of physics and Wuhan National lab.ratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China

metal-organic frameworks(MOFs)have attracted significant attention in the past two decades due to their diverse physical properties and associated *** numerous advances have been made,the acoustic properties of MOFs have attracted very little ***,we systematically investigate the acoustic velocities and impedances of 19 prototypical MOFs via first-principle *** results demonstrate that these MOFs exhibit a wider range of acoustic velocities,higher anisotropy,and lower acoustic impedances than their inorganic counterparts,which are ascribed to their structural diversity and anisotropy,as well as low *** addition,the piezoelectric properties,which are intimately related to the acoustic properties,were calculated for 3 MOFs via density functional perturbation theory,which reveals that MOFs can exhibit significant piezoelectricity due to the ionic *** work provides a comprehensive study of the fundamental acoustic properties of MOFs,which could stimulate further interest in this new exciting field.

关键词： field. anisotropy impedance

Morphological, Optical and DC Conduction Properties of a-GaSe Semiconductor Nanoparticle Thin Films

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Journal of Materials Science & Technology 2013年第12期29卷 1151-1155页

作者： Sushil Kumar M.A. Majeed Khan Materials Science lab. Department of Physics Chaudhary Devi Lal University Sirsa 125 055 India King Abdullah Institute for Nanotechnology King Saud University Riyadh 11451 Saudi Arabia

Amorphous gallium selenide （a-GaSe） semiconductor nanoparticle thin films were deposited onto well cleaned glass substrates by inert gas condensation （IGC） technique under a vacuum of 400 x 10-6 Pa （3 x 10-6 Torr）. The films were characterized by different structural and optical techniques, including X-ray diffraction, field emission scanning electron microscopy （FESEM）, field emission transmission electron microscopy （FETEM）, UV-visible absorption spectroscopy and I-V measurements. The particle size and size distribution were determined by TEM images which show the presence of spherical particles in the range of 5-50 nm in size. SEM images indicate that the a-GaSe film grown on glass substrate is almost smooth and dense. The optical properties of a-GaSe nanoparticle thin films were determined by optical absorption spectra. The optical bandgap of the film was estimated to be 2.19 eV and the transitions are allowed direct type. The electrical conductivity of the deposited films has been studied as a function of temperature. In the higher temperature range the dominance of thermally activated band conduction was observed; whereas in the low temperature ranqe the hoppinQ conduction in the band tails of localized states was found to be dominated.

关键词： Nanoparticles Thin film Optical bandgap Electrical conductivity

Analysis of the Yrast Bands with q-Deformed Moment of Inertia

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Chinese physics Letters 2001年第2期18卷 193-195页

作者： FANG Xiang-Zheng RUAN Tu-Nan CCAST(World lab.)P.O.Box 8730 Beijing 100080 Department of physics Anhui UniversityHefei 230039(mailing address)University of Science and Technology of ChinaHefei 230027 Department of Modern physics University of Science and Technology of ChinaHefei 230027

The rigid-rotor with a q-deformed moment of inertia is introduced to describe the nuclear rotational *** the representations of quantum algebra,the normal deformed and superdeformed bands are naturally differentiated by *** yrast normal deformed bands in rare earth and actinium regions,as well as the yrast superdeformed bands in A-190 and 150 regions are *** calculated results agree with experimental data qualitatively well,and the values of the parameters are physically *** indicates that the fixed deformation,the stretching effect and the many body statistics effect are three possible dominant factors to govern nuclear rotational bands.

关键词： bands deformed rotational

Design of proton beam optics to realize beam distribution transformation in C-ADS HTBT

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Chinese physics C 2013年第2期37卷 85-91页

作者：王相綦罗焕丽郝浩唐靖宇李为民徐宏亮 National Synchrotron Radiation lab. University of Science and Technology of China School of Nuclear Science and Technology University of Science and Technology of China Institute of High Energy physics Chinese Academy of Sciences

The linac to the transmuter beam transport line （LTBT） connecting the end of the linac to the spallation target is a critical sub-system in the accelerator driven system （ADS）. It has the function of transporting the accel-erated high power proton beam to the target with a beam footprint satisfying the special requirements of the minor actinide （MA） transmuter. In this paper, a preliminary conceptual design of the hurling magnet to transmuter beam transport section （HTBT）, as a part of the LTBT, for the China ADS （C-ADS） system is proposed and developed. In this design, a novel hurling magnet with a two dimensional amplitude modulation （AM） of 1 kHz and scanning of more than 10 kHz at 360 in transverse directions is used to realize a 300 mm diameter uniform distribution of beam on target. The preliminary beam optics design of C-ADS HTBT optimized to minimize the beam loss on the vacuum chamber and the radiation damage caused by back-scattering neutrons will be reported.

关键词： C-ADS LTBT HTBT hurling magnet k-factor double-waist

Catalyst-Free Growth of Nanographene Films on Various Substrates

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Nano Research 2011年第3期4卷 315-321页

作者： Lianchang Zhang Zhiwen Shi Yi Wang Rong Yang Dongxia Shi Guangyu Zhang Nanoscale physics and Device lab Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China Surface physics lab Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China

We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote plasma enhancement chemical vapor deposition （r-PECVD） system at relatively low temperatures, enabling the deposition of graphene films up to 4-inch wafer scale. Scanning tunneling microscopy （STM） confirmed that the films are made up of nanocrystalline graphene particles of tens of nanometers in lateral size. The growth mechanism for the nanographene is analogous to that for diamond grown by PECVD methods, in spite of sp2 carbon atoms being formed in the case of graphene rather than sp3 carbon atoms as in diamond. This growth approach is simple, low-cost, and scalab.e, and might have potential applications in fields such as thin film resistors, gas sensors, electrode materials, and transparent conductive films.

关键词： Nanographene catalyst-free plasma enhancement chemical vapor deposition (PECVD) transparent and conductive film

The magnet design for the HLS storage ring upgrade project

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Chinese physics C 2012年第1期36卷 91-95页

作者：张浩李为民冯光耀王琳张善才李为梁军军 National Synchrotron Radiation lab. University of Science and Technology of China

In order to improve the performance of the Hefei Light Source （HLS）,in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices,an upgrade project called HLSII will be launched *** storage ring lattice,which has a double bend achromatic structure with four periods,comprises eight dipoles,32 quadrupoles and 32 combined function *** design and analysis of the magnets are shown in this paper,along with the optimization of the multipurpose combined function magnet,which consists of three magnets：skew quadrupole,horizontal dipole and vertical dipole,with the main sextupole *** type of magnet is the first one that has been designed and used in *** mechanical design and fabrication procedures for the magnets are also presented.

关键词： storage ring magnet combined function conformal mapping water-cooling channel