检索结果-南通市图书馆

Forming Proterozoic basement within eastern Central Asian Orogenic Belt:Evidence from zircon U-Pb-Hf-O isotopes

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2022年第9期29卷 3088-3105页

作者： WANG Zhi-wei ZHU Tai-chang YU Jing-wen YUAN Ling-ling Hebei key laboratory of Strategic Critical Mineral Resources Hebei GEO UniversityShijiazhuang 050031China key laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(ministry of education) School of Geoscience and Info-PhysicsCentral South UniversityChangsha 410083China College of Earth Sciences Hebei GEO UniversityShijiazhuang 050031China

As part of the mosaic of micro-continents within the Central Asian Orogenic Belt(CAOB), the Xing’anAirgin Sum Block(XAB) features increasingly-recognized Meso-Neoproterozoic geological records. However, the origin, temporal-spatial distribution of ancient materials, and their roles in crust evolution remain to debate. This paper presents an integrated study of zircon U-Pb ages and Hf-O isotopes for Mesoproterozoic and Paleozoic granites from the Erenhot region of central Inner Mongolia, along eastern CAOB. The intrusion of 1450 Ma syenogranite denotes that the Precambrian basement of XAB extends from Sonid Zuoqi westward to Erenhot. The 384 and 281 Ma monzogranites containing Mesoproterozoic xenocrystic zircons possess Proterozoic-dominant two-stage Hf model ages, further suggesting the wide existence of Proterozoic crust beneath western XAB. Cyclic Proterozoic crustal growth and reworking seem to show close linkages with the orogenesis during relevant supercontinent cycles. 1450-1360 Ma juvenile crustal growth at Erenhot and synchronous ancient crust reworking at Sonid Zuoqi and Abagaqi were likely resulted from retreating subduction involved in Columbia breakup, while 1.2-1.0 Ga reworking and 0.9-0.7 Ga growth events within the Erenhot basement might respond to assembly and breakup of Rodinia, respectively. Besides, our work confirms that reworking of Neoproterozoic crust played important roles during Paleozoic multi-stage accretion of CAOB.

关键词： Proterozoic Central Asian Orogenic Belt Xing’an-Airgin Sum Block crystalline basement granitoids zircon U-Pb-Hf-O isotopes

Temperature-Dependent Raman Spectrum of Hexagonal YMnO3 Films Synthesized by Chemical Solution Method

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2010年第5期27卷 182-184页

作者：刘越峰王蓓郑海务刘向阳顾玉宗张伟风 Institute of Microsystems for physics Key Lab for Photovoltaic Materials of Henan Province Department of Physics Henan University Kaifeng 475001 Center of Basic Experiment Henan University Kaifeng 475001

We study the temperature-dependent Raman spectrum of hexagonal YMnO3 films prepared by a chemical solution method. There are seven Raman peaks （3A1 ＋ E1 ＋ 4E2） of the film identified at room temperature. From the results of temperature dependence of the Raman spectrum, it is deduced that the YMnO3 film has a magnetic phase transition temperature of about 123K. The temperature variation phonon mode at 685cm^-1 shows an anomalous frequency variation near 123 K, suggesting either a more complex mechanism of spin-phonon coupling or strong mixing of phonon modes. The reason for the higher antiferromagnetic Néel temperature TN of the film than that of the bulk counterpart is also discussed.

关键词： TEMPERATURE effect RAMAN spectroscopy OXIDES THIN films INORGANIC compounds -- Synthesis SOLUTION (Chemistry) TRANSITION temperature ANTIFERROMAGNETISM

Geant4 analysis and optimization of a double crystal phoswich detector for beta–gamma coincidence detection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2018年第4期29卷 92-97页

作者： Xing Fan Xian-Peng Zhang Geng Tian Chao-Wen Yang department of Nuclear Engineering and Technology College of Physics Science and Technology Sichuan UniversityChengdu 610064 China key laboratory of Radiation physics and Technology Ministry of Education Sichuan University Chengdu 610064China Northwest Institute of Nuclear Technology Xi’an 710024China

In this study, a novel phoswich detector for beta–gamma coincidence detection is designed. Unlike the triple crystal phoswich detector designed by researchers at the University of Missouri, Columbia, this phoswich detector is of the semi-well type, so it has a higher detection efficiency. The detector consists of BC-400 and NaI:Tl with decay time constants of 2.4 and 230 ns, *** BC-400 scintillator detects beta particles, and the Na I:Tl cell is used for gamma detection. Geant4 simulations of this phoswich detector find that a 2-mm-thick BC-400 scintillator can absorb nearly all of the beta particles whose energies are below 700 keV. Further, for a 2.00-cmthick NaI:Tl crystal, the gamma source peak efficiency for photons ranges from a maximum of nearly 90% at 30 keV to 10% at 1 MeV. The self-absorption effect is also discussed in this paper in order to determine the carrier gas' s influence.

关键词： Geant4 Phoswich detector Beta–gamma coincidence detection Detection efficiency

Analysis and Verification on the Chain-like Model with Normal Distribution of Magnetorheological Elastomer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical physics 2009年第5期22卷 545-550,I0002页

作者： Miao Yu Yong-qiang Xia Xiao-rui Yan The key Lab for Optoelectronic Technology and Systems Ministry of Education department of Optoelectronic Engineering Chongqing University Chongqing 400044 China.

Magnetorheological elastomer （MRE） is a new kind of smart materials, the rheological properties can be controlled rapidly by the external magnetic field. It is mainly composed of rubber and micron-sized ferromagnetic particles, which forms a chain-like structure. Therefore its mechanical, electric, and magnetic properties can be changed by the applied magnetic field, which is called as the magneto-induced effect. But this effect is not remarkable enough currently for the engineering application. So it is important for material preparation to optimize parameters to enhance the magneto-induced effect. In this work, based on chain-like model, some factors influencing the magneto-induced effect of MRE were analyzed theoretically by using dipole method with the normal distribution of chain＇s angle introduced. The factors included the oblique angle of particles chains, magnetic field intensity, and shear strain, etc. Some experiments were also carried out.

关键词： Magnetorheological elastomer Dipole Magneto-induced effect Normal distri-bution

CVD growth of perovskite/graphene films for high-performance flexible image sensor

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2020年第5期65卷 343-349页

作者： Kailun Xia Wenqiang Wu Mengjia Zhu Xinyi Shen Zhe Yin Haomin Wang Shuo Li Mingchao Zhang Huimin Wang Haojie Lu Anlian Pan Caofeng Pan Yingying Zhang key laboratory of Organic Optoelectronics and Molecular Engineering of ministry of education Department of ChemistryTsinghua UniversityBeijing 100084China CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-Nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100083China key laboratory for Micro-Nano physics and Technology of Hunan Province State Key Laboratory of Chemo/Biosensing and Chemometrics and College of Materials Science and EngineeringHunan UniversityChangsha 410082China Cavendish laboratory University of CambridgeCambridge CB30HEUK

Hybrid perovskite possesses excellent photoelectric properties,including large light-absorption capacity and high carrier mobility,and is an ideal light-absorbing material for photoelectric *** grain size and compactness of hybrid perovskite are key factors affecting the performance of photoelectric *** photocurrent and photoresponsivity of these devices are relatively low because of the rapidly recombined photoexcited electron-hole pairs in hybrid ***,we develop a facile two-step chemical vapor deposition(CVD)method to synthesize a high-quality van der Waals(vd Ws)MAPb I3/graphene heterostructure for high-performance image *** introduced inorganic sources(PbI2)to vd Ws epitaxially grown Pb I2 film on a seamless graphene monolayer film template through *** iodide(MAI)was then reintroduced to prepare the vd Ws MAPb I3/graphene *** MAPb I3 layer is composed of densely packed,large-size grains and displays a smooth *** photoresponsivity of 107A/W is achieved in the corresponding *** by the human visual system,we designed a flexible photodetector array containing(24?24)pixels,achieving perfect image recognition and color *** study may greatly facilitate the construction of high-performance optoelectronic devices in artificial retina,biomedical imaging,remote sensing,and optical communication.

关键词： Hybrid perovskite Chemical vapor deposition Graphene template Flexible photodetector array Artificial retina

Whispering Gallery Mode Lasing Performance's Evolution of Floating GaN Microdisks Varying with Their Thickness

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2022年第12期39卷 19-23页

作者： Gangyi Zhu Mufei Tian M.Almokhtar Feifei Qin Binghui Li Mengyao Zhou Fei Gao Ying Yang Xin Ji Siqing He Yongjin Wang GaN Optoelectronic Integration International Cooperation Joint laboratory of Jiangsu Province College of Telecommunications and Information EngineeringNanjing University of Posts and TelecommunicationsNanjing 210003China physics department Assiut UniversityAssiut 71516Egypt State key laboratory of Luminescence and Applications Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

Optical gain and loss of microcavity greatly affect the quality of lasing,how to improve optical gain and decrease optical loss is of great significance for the preparation of *** this study,four types standard microdisks with different thicknesses of 2.2μm,1.9μm,1.7μm,and 1.45μm were fabricated by micromachining technology process to modulate optical gain and loss of microdisk *** whispering gallery mode lasing in the ultraviolet range of Ga N microdisk devices was investigated for these devices in order to clarify the effect of microdisk thickness on device *** quality factor Q and lasing mode number for different thicknesses are calculated from the stimulated *** lifetimes of the exciton combination properties of the devices were observed using time-resolved PL *** lasing modes are modulated,and the lifetime decreases,while the Q factor of the devices first increases and then decreases with decreasing *** these results are induced by optical gain and loss competition.

关键词： lasing mode lifetime

Quantum interference induced by initial system-environment correlations

在线全文

学校读者我要写书评

暂无评论

Quantum interference induced by initial system-environment c...

Effects of FeNi-phosphorus-carbon system on crystal growth of diamond under high pressure and high temperature conditions

第十五届全国量子光学学术报告会

作者：满忠晓夏云杰 Shandong Provincial key laboratory of laser Polarization and Information Technology Department of PhysicsQufu Normal University

＜正＞In this paper,we investigate the role of initial system-environment correlations in the dynamics of open quantum systems by taking into account quantum interference effects induced by the relative phase in the c...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese physics B 2015年第3期24卷 398-401页

作者：胡美华毕宁李尚升宿太超周爱国胡强贾晓鹏马红安 School of Materials Science and Engineering Henan Polytechnic University School of physics and Chemistry Henan Polytechnic University State key laboratory of Superhard Materials Jilin University

This paper reports the crystal growth of diamond from the Fe Ni–Carbon system with additive phosphorus at high pressures and high temperatures of 5.4–5.8 GPa and 1280–1360°C. Attributed to the presence of additive phosphorus,the pressure and temperature condition, morphology, and color of diamond crystals change obviously. The pressure and temperature condition of diamond growth increases evidently with the increase of additive phosphorus content and results in the moving up of the V-shape region. The surfaces of the diamonds also become coarse as the additive phosphorus added in the growth system. Raman spectra indicate that diamonds grown from the Fe Ni-phosphorus-carbon system have more crystal defects and impurities. This work provides a new way to enrich the doping of diamond and improve the experimental exploration for future material applications.

关键词： diamond high pressure and high temperature additive phosphorus

Fine micro-thermal structures for Reissner-Nordstr?m black hole

在线全文

学校读者我要写书评

暂无评论

Chinese physics C 2020年第9期44卷 228-234页

作者：许震明吴滨杨文力 Institute of Modern physics Northwest University School of physics Northwest University Shaanxi key laboratory for Theoretical physics Frontiers

We solve the condundrum on whether the molecules of the Reissner-Nordstr?m black hole interact through the Ruppeiner thermodynamic geometry, basing our study on the concept of the black hole molecule proposed in[Phys. Rev. Lett. 115(2015) 111302] and choosing the appropriate extensive variables. Our results show that the Reissner-Nordstr?m black hole is indeed an interaction system that may be dominated by repulsive interaction. More importantly, with the help of a novel quantity, namely the thermal-charge density, we describe the fine micro-thermal structures of the Reissner-Nordstr?m black hole in detail. Three different phases are presented, namely the free, interactive, and balanced phases. The thermal-charge density plays a role similar to the order parameter, and the back hole undergoes a new phase transition between the free phase and interactive phase. The competition between the free phase and interactive phase exists, which leads to extreme behavior of the temperature of the Reissner-Nordstr?m black hole. For the extreme Reissner-Nordstr?m black hole, the entire system is completely in the interactive *** importantly, we provide the thermodynamic micro-mechanism for the formation of the naked singularity of the Reissner-Nordstr?m black hole.

关键词：