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science China(Technological sciences) 2023年第12期66卷 3562-3573页

作者： WANG RuiZhi WANG ZhiQiang tang EnLing PENG hui YANG GuoLai hE LiPing ChEN Chuang hAN YaFei Key Laboratory of Transient Physical Mechanics and Energy Conversion Materials of Liaoning Province Shenyang Ligong UniversityShenyang 110159China school of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 621999China

Compared to a quasistatic environment,the electromechanical response of piezoelectric ceramics exhibits a considerably nonlinear behavior when subjected to *** the effect of ambient temperature is further considered,then the situation becomes more *** thermal,mechanical,and electrical properties of soft-doped piezoelectric ceramics(PZT-5h)under compression and impact conditions were analyzed in the temperature range of-60℃to 200℃(below Curie temperature).The experimental results indicate that the fracture strength of PZT-5h has an extreme value near room *** dynamic piezoelectric coefficient is strongly temperature dependent and has a maximum value near 100℃because of the“electric devil's staircase effect”between polarization and domain switching *** temperature-dependent data will enable the accurate prediction of the dynamic performance of devices by computer simulation.

关键词： PZT impact temperature dependence fracture strength dynamic piezoelectric coefficient

A new method to generate relativistic comb bunches with tunable subpicosecond spacing

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Chinese Physics C 2012年第2期36卷 151-155页

作者： DU Ying-Chao hUANG Wen-hui tang Chuan-Xiang Accelerator Laboratory Department of Engineering PhysicsTsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging(Tsinghua University) Ministry of EducationBeijing 100084China Key Laboratory of high Energy Radiation Imaging Fundamental science for National Defense Beijing 100084China

We propose and analyze a scheme to produce comb bunches, i.e. a bunch consisting of micro-bunch trains, with tunable subpicosecond spacing. In the scheme, the electron beam is first deflected by a deflecting cavity which introduces a longitudinal-dependent linear transverse kick to the particles. After passing through a drift space, the transverse beam size is linearly coupled to the longitudinal position of the particle inside the beam, and a mask is placed there to tailor the beam, then the mask distribution is imprinted on the beam＇s longitudinal distribution. A quadrupole magnet and another deflecting cavity are used in the beam line to compensate the transverse angle due to the first deflecting cavity. Analysis shows that the number, length, and spacing of the trains can be controlled through the parameters of the deflecting cavity and the mask. such electron bunch trains can be applied to an infrared free electron laser, a plasma-wakefield accelerator and a supper-radiance Thz source.

关键词： bunch trains mask deflecting cavity

Increasing leaching rate of gold cyanide of two-stage calcination generated from refractory ore containing arsenopyrite and pyrrhotite

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Rare Metals 2016年第10期35卷 804-810页

作者： Xiao-E Dang Wen-shuai Ke Chen tang Jun Lv Xue Zhou Cheng-Peng Liu Key Laboratory for Gold and Resources of shaanxi Xi'an University of Architecture and Technology Jin Rui Mining Technology Development Co. Ltd

For the gold locked within hematite in the two- stage calcination, which leads to a low gold leaching rate, the present work is aiming at pretreating the calcination to selectively dissolve hematite. The calcination was pre- treated by sulfuric acid with cosolvent B. The factors in- fluencing the hematite dissolution rate were studied, and the pretreatment parameters considered were h2sO4 con- tent, B dosage and added time, leaching temperature and time. simultaneously, mineralogy analysis of the calcination, h2sO4 pretreatment residue and cyanide leaching residue were also carried out. Results indicate that the hematite dissolution rate is quicker, the dissolution tem- perature is lower and the dissolution time is shorter in the role of cosolvent B than without B. At the same time, the gold locked within hematite is effectively released, so the leaching rate of gold cyanide increases about 10 % than that in actual factory production. The results have an actual significance in guiding industrial production.

关键词： Locked gold hematite Pretreatment Two-stage calcination Cosolvent B

First-Principles studies for Magnetism in Cu-Doped GaN

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Wuhan University Journal of Natural sciences 2011年第3期16卷 245-248页

作者： YANG Qin sUN Fang tang Zheng Department of Electronic and Engineering East China Normal University Shanghai 200241 China

hole carrier mediated magnetization in Cu-doped GaN is investigated by using the first-principles calculations. By studying the sp-d interaction and the direct exchange interaction among the dopants, we obtain an equation to determine the spontaneous magnetization as a function of the Cu dopant concentration and the hole carrier density. It is demonstrated that nonmagnetic Cu doped GaN can be of room-temperature ferromagnetism. The system＇s Curie temperature Tc can reach about 345 K with Cu concentration of 1.0% and hole carrier density of 5.0×10^19 cm-3. The results are in good agreement with experimental observations and indicate that ferromagnetism in this systems is tunable by controlling the Cu concentration and the hole carrier density.

关键词： Cu-doped GaN diluted magnetic semiconductor ferromagnetism hole carrier density

Nucleation and growth of L1_(2)-Al_(3)RE particles in aluminum alloys:A first-principles study

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Journal of Rare Earths 2023年第7期41卷 1116-1126,I0005页

作者： Touwen Fan Zixiong Ruan Feng Zhong Chaoyang Xie Xiaofeng Li Dongchu Chen Pingying tang Yuanzhi Wu College of science Hunan Institute of TechnologyHengyang 421002China Research Institute of Automobile Parts Technology Hunan Institute of TechnologyHengyang 421002China school of Materials science and Engineering North University of Chin1Taiyuan 030051China school of Material science and hydrogen Energy Engineering Foshan UniversityFoshan 528001China Key Laboratory of New Electric Functional Materials of Guangxi Colleges and Universities Nanning Normal UniversityNanning 530023China

The internal mechanisms of nucleation and growth of L1_(2)-AI_(3)RE(RE=sc,Y,La-Lu) second phases in Al alloys were investigated by combining first-principles calculations with quasi-harmonic approximation(QhA).The calculated results show that the diffusion rate D_s and chemical potential AG_V increase with the increase of *** the increase of atomic number,the D_s and the strain energy ΔE_(Cs)increase firstly from sc to La,and then decreases,while the calculated interface energy γ_(α/β) and ΔG_V show opposite *** on above calculated results,the critical nucleation radius R*and coarsening rate K_(LsW) are obtained from the classical nucleation theory(CNT) and LsW model of the Ostwald ripening of particles,*** the increase of atomic number,the R*increases firstly,and then decreases for all planes at finite *** the K_(LsW) shows opposite variation to the R^(*).From this point of view,it is reasonably speculated that Y and later RE elements can replace the expensive sc for heat-resistance Al *** solubility c_(∞) of particles is usually very small at low temperature,and there is obvious solubility only when the temperature reaches 600 *** surface energies E_(sur) of AI_(3)RE compounds and Al solid solution are respectively larger and smaller than that of pure Al,respectively,except for the surface(001) and(110) of Al_(3)*** all planes,with the increase of atomic number of RE,E_(sur) decreases firstly from sc to La,and then increases linearly to *** results are helpful for designing high performance heat-resistance Al alloys.

关键词： First-principles calculations Diffusion rate Quasi-harmonic approximation Particle nucleation and growth Rare earths

Connection between earthquakes and deep fluids revealed by magnetotelluric imaging in songyuan,China

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science China Earth sciences 2021年第1期64卷 161-176页

作者： Yu tang Aihua WENG Yue YANG shiwen LI Jianjun NIU Yanhui ZhANG Yabin LI Jianping LI College of Geo-exploration sciences&Technology Jilin UniversityChangchun 130026China First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China China Aero Geophysical survey and Remote sensing Center for Natural Resources Beijing 100083China Construction Engineering College of Jilin University Changchun 130026China Guangzhou Marine Geological survey China Geological SurveyGuangzhou 510760China

songyuan is the most earthquake prone area in northeast *** 2006,earthquakes have occurred in the area in the form of swarms,with a maximum magnitude of M_*** is much controversy about the cause of the songyuan *** attempted to determine the cause using a three-dimensional electrical conductivity structure inverted from a regional network of magnetotelluric data in the songyuan *** L-BFGs inversion method was applied,with a fullimpedance tensor data set used as the inversion *** with an evaluation of the earthquake locations,the resistivity model revealed a northeast-oriented hidden fault running through the songyuan earthquake area(sEA),which was speculated to be the preexisting Fuyu-Zhaodong Fault(FZF).Our resistivity model also found an apparent lithospheric low-resistivity anomaly beneath the earthquake area,which breached the high-resistivity lithospheric mantle and stalled at the base of the crust.A petrophysical analysis showed that this lower crustal low-resistivity anomaly was most likely attributed to hydrated partial melting,which could release water into the lower crust during later magma *** weakening the strength of the FZF,these ascending fluids also increased the pore pressure in the fault,further reducing the shear strength of the *** stress action(a fault strike component of the east-west regional compress),together with possible near-surface disturbances,may drive the fault to slip and trigger the earthquakes in *** is possible that the continuous replenishment of fluids from the deeper mantle forces the songyuan earthquakes into the form of *** infer that the songyuan earthquakes could be attributed to a combination of preexisting faults,regional stress,and deep fluids associated with plate subduction,and near surface disturbances might induce the earthquakes in *** songyuan earthquakes are inherently induced earthquakes,fed by deep fluids.

关键词： Magnetotelluric Electrical resistivity Deep fluids Induced earthquakes Northeast China

Effect of Ne Glow Discharge on Ion Density Control in LhD

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Plasma science and Technology 2004年第5期6卷 2440-2444页

作者： s.Morita M.Goto s.Masuzak h.suzuki K.Tanaka h.Nozato Y.Takeiri J.Miyazawa LhD experimental group National Institute for Fusion science Toki 509-5292Gifu Japan College of Engineering Chubu UniversityKasugai 487-8501AichiJapan science and Technology Center for Atoms Molecules and Ions ControlsOsaka UniversitySuita 565-0871OsakaJapan

Neon glow discharge cleaning was firstly attempted in Large helical Device(LhD) instead of he glow discharge to remove hydrogen neutrals and to control the ion density, n_*** Ne glow discharge continued for 8 hours overnight after a three-day experiment. At the secondnight h_α emission became weaker than the emission usually observed in the he glow discharge. Aclear reduction of the hydrogen influx was also observed in neutral beam injection (NBI) dischargeswith Ne puff, whereas the neon recycling was strongly enhanced with appearance of a flat densityprofile. As a result, the lowest density limit was further reduced down to 0.2 X 10^(13)cm^(-3). Theuse of Ar puff formed a peaked density profile with a high T_i of 7 keV.

关键词： hydrogen recycling Ne glow discharge ion density

Masses of the conjectured h-dibaryon at different temperatures

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Chinese Physics C 2024年第8期48卷 83-93页

作者： Liang-Kai Wu han tang Ning Li Xin-Yang Wang school of Physics and Electronic Engineering Jiangsu UniversityZhenjiang 212013China Center for Fundamental Physics School of Mechanics and PhysicsAnhui University of Science and TechnologyHuainan 232001China

We present a lattice QCD determination of masses of the conjectured h-dibaryon,denoted as mh,at nine different temperatures:T/T_(c)=0.24,0.63,0.76,0.84,0.95,1.09,1.27,1.52,and *** masses of baryons N,Σ,Ξ,andΛat different temperatures were also *** simulations were performed on an anisotropic lattice with N_(f)=2+1 flavours of clover fermion at a quark mass corresponding to mπ=384(4)*** thermal ensembles were provided by the FAsTsUM collaboration,whereas the zero temperature ensembles were provided by the hadspec *** also calculated the spectral density of the correlation function of those *** spectral density distributions show a rich peak structure at the lowest temperature;at intermediate temperatures,the mass values of those particles obtained by the extrapolation method reflect a two-peak *** the spectral density for the octet baryon becomes smooth at T/T_(c)=1.27,1.52,and 1.90,the spectral density for the h-dibaryon becomes smooth at T/T_(c)=*** T/T_(c)=0.24,the mass difference of the h-dibaryon andΛpair,expressed asΔm=m_(h)−2m_(Λ),was estimated to beΔm=−14.6(6.2)MeV,which suggests the existence of a bound h-dibaryon state.

关键词： lattice QCD h-dibaryon spectral function clover fermion finite temperature

Changes in soil organic carbon contents and fractionations of forests along a climatic gradient in China

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Forest Ecosystems 2019年第1期6卷 1-12页

作者： Xiaolu sun Zuoxin tang Michael G.Ryan Yeming You Osbert Jianxin sun College of Forest science Beijing Forestry University Institute of Forestry and Climate Change Research Beijing Forestry University Natural Resource Ecology Laboratory Department of Ecosystem Science and Sustainability Colorado State University Rocky Mountain Research station USDA Forest Service College of Forestry Guangxi University

Background: soil organic carbon(sOC) is a large reservoir of terrestrial carbon(C); it consists of different fractions of varying complexity and stability. Partitioning sOC into different pools of decomposability help better predict the trend of changes in sOC dynamics under climate change. Information on how physical fractions and chemical structures of sOC are related to climate and vegetation types is essential for spatial model ing of sOC processes and responses to global change ***: soil samples were col ected from multiple representative forest sites of three contrasting climatic zones(i.e. cool temperate, warm temperate, and subtropical) in eastern China. Measurements were made on sOC contents and physical fractions of the 0–20 cm soil layer, and the chemical composition of sOC of the 0–5 cm soil layer, along with measurements and compilation of the basic site and forest stand variables. The long-term effects of temperature, litter inputs, soil characteristics and vegetation type on the sOC contents and factions were examined by means of "space for time substitution" approach and statistical ***: Mean annual temperature(MAT) varied from 2.1 °C at the cool temperate sites to 20.8 °C at the subtropical sites. Total sOC of the 0–20 cm soil layer decreased with increasing MAT, ranging from 89.2 g·kg^(-1) in cool temperate forests to 57.7 g·kg^(-1) in subtropical forests, at an average rate of 1.87% reduction in sOC with a 1 °C increase in *** increasing MAT, the proportions of aromatic C and phenolic C displayed a tendency of decreases, whereas the proportion of alkyl C and A/O-A value(the ratio of alkyl C to the sum of O-alkyl C and acetal C) displayed a tendency of increases. Overall, there were no significant changes with MAT and forest type in either the physical fractions or the chemical composition. Based on the relationship between the sOC content and MAT, we estimate that sOC in the top 20 soil layer of forests potentially cont

关键词： Carb on fractions Forest soil Global warming solid-state 13C-CPMAs NMR

A Brain-inspired sLAM system Based on ORB Features

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International Journal of Automation and computing 2017年第5期14卷 564-575页

作者： sun-Chun Zhou Rui Yan Jia-Xin Li Ying-Ke Chen huajin tang Neuromorphic Computing Research Center College of Computer ScienceSichuan UniversityChengdu 610065China

This paper describes a brain-inspired simultaneous localization and mapping （sLAM） system using oriented features from accelerated segment test and rotated binary robust independent elementary （ORB） features of RGB （red, green, blue） sensor for a mobile robot. The core sLAM system, dubbed RatsLAM, can construct a cognitive map using information of raw odometry and visual scenes in the path traveled. Different from existing RatsLAM system which only uses a simple vector to represent features of visual image, in this paper, we employ an efficient and very fast descriptor method, called ORB, to extract features from RCB images. Experiments show that these features are suitable to recognize the sequences of familiar visual scenes. Thus, while loop closure errors are detected, the descriptive features will help to modify the pose estimation by driving loop closure and localization in a map correction algorithm. Efficiency and robustness of our method are also demonstrated by comparing with different visual processing algorithms.

关键词： simultaneous localization and mapping (sLAM) RatsLAM mobile robot oriented features from accelerated segment test and rotated binary robust independent elementary (ORB) features of RGB (red green blue) cognitive map.