检索结果-南通市图书馆

Communications in Theoretical Physics 2004年第3期41卷 385-390页

作者： ZHANGHong-bao CAOZhou-jian GAOChong-Shou SchoolofPhysics PekingUniversityBeijing100871China DepartmentofPhysics BeijingNormalUniversityBeijing100875China InstituteofTheoreticalPhysics AcademiaSinicaBeijing100080China

Si-Jie Gao has recently investigated Hawking radiation from spherically symmetrical gravitational collapse to an extremal R-N black hole for a real scalar field. Especially he estimated the upper bound for the expected number of particles in any wave packet belonging to spontaneously produced from the state , which confirms the traditional belief that extremal black holes do not radiate particles. Making some modifications, we demonstrate that the analysis can go through for a charged scalar field.

关键词： Hawking radiation extremal R-N black holes charge scalar field

Effect of the CaO/SiO2 mass ratio and FeO content on the viscosity of CaO–SiO2–“FeO”–12wt%ZnO–3wt%Al2O3 slags

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第7期24卷 756-767页

作者： jian-fang Lü Zhe-nan jin Hong-ying Yang Lin-lin Tong Guo-bao Chen Fa-xin Xiao School of Metallurgy Northeastern University Shenyang 110819 China

An effective process for recycling lead from hazardous waste cathode ray tubes（CRTs） funnel glass through traditional lead smelting has been presented previously. The viscous behavior of the molten high lead slag, which is affected by the addition of funnel glass, plays a critical role in determining the production efficiency. Therefore, the viscosities of the CaO–SiO_2–＂FeO＂–12wt%ZnO–3wt%Al_2O_3 slags were measured in the current study using the rotating spindle method. The slag viscosity decreases as the CaO/SiO_2 mass ratio is increased from 0.8 to 1.2 and also as the FeO content is increased from 8wt% to 20wt%. The breaking temperature of the slag is lowered substantially by the addition of FeO, whereas the influence of the CaO/SiO_2 mass ratio on the breaking temperature is complex. The structural analysis of quenched slags using Fourier transform infrared（FTIR） spectroscopy and Raman spectroscopy reveals that the silicate network structure is depolymerized with increasing CaO/SiO_2 mass ratio or increasing FeO content. The [FeO_6]-octahedra in the slag melt increase as the CaO/SiO_2 mass ratio or the FeO content increases. This increase can further decrease the degree of polymerization（DOP） of the slag. Furthermore, the activation energy for viscous flow decreases both with increasing CaO/SiO_2 mass ratio and increasing FeO content.

关键词： lead smelting slag viscosity basicity ferrous oxide slag structure

Collective effects in an incompressible electronic liquid

在线全文

学校读者我要写书评

暂无评论

National Science Review 2023年第6期10卷 168-182页

作者： jian-jian Miao Hui-Ke jin Yi Zhou Department of Physics The Chinese University of Hong Kong Department of Physics TQM Technische Universitat Munchen Institute of Physics Chinese Academy of Sciences Songshan Lake Materials Laboratory Kavli Institute for Theoretical Sciences & CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences

Starting from Landau’ s kinetic equation,we show that an electronic liquid in d=2,3 spatial dimensions depicted by a Landau-type effective theory will become incompressible on condition that the Landau parameters satisfy either(ⅰ) 1+F1s/d=0 or(ⅱ) F0s→+∞. Condition(ⅰ) is the Pomeranchuk instability in the current channel and suggests a quantum spin liquid(QSL) state with a spinon Fermi surface;while condition(ⅱ) means that the strong repulsion in the charge channel leads to a conventional charge and thermal *** the collisionless regime(ωτ>>1) and the hydrodynamic regime(ωτ<<1),the zero and first sound modes have been studied and classified by symmetries,including the longitudinal and transverse modes in d=2,3 and the higher angular momentum modes in d=*** sufficient(and/or necessary) conditions of these collective modes have been *** has been demonstrated that some of these collective modes will behave in quite different manners under incompressibility condition(ⅰ) or(ⅱ).Possible nematic QSL states and a hierarchy structure for gapless QSL states have been proposed in d=3.

关键词： quantum spin liquid Landau-type effective theory collective modes zero sound first sound

Magneto-Optic Fiber Gratings Useful for Dynamic Dispersion Management and Tunable Comb Filtering

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第6期27卷 225-228页

作者： WU bao-jian LU Xin QIU Kun Key Lab of Broadband Optical Fiber Transmission and Communication Networks of the Ministry of Education University of Electronic Science and Technology of China Chengdu 611 731

Intelligent control of dispersion management and tunable comb filtering in optical network appfications can be performed by using magneto-optic fiber Bragg gratings （MFBGs）. When a nonuniform magnetic field is applied to the MFBG with a constant grating period, the resulting grating response is equivalent to that of a conventional chirped grating. Under a linearly nonuniform magnetic field along the grating, a linear dispersion is achieved in the grating bandgap and the maximal dispersion slope can come to 1260ps/nm2 for a l0-mm-long fiber grating at 1550nm window. Similarly, a Gaussian-apodizing sarnpled MFBG is also useful for magnetically tunable comb filtering, with potential application to clock recovery from return-to-zero optical signals and optical carrier tracking.

关键词： MAGNETOOPTICS BRAGG gratings DISPERSION COMB filters OPTICAL communications MAGNETIC fields GAUSSIAN processes SIGNAL processing

Cloning and Characterization of karmoisin Homologue Gene(Nlka) in Two Brown Planthopper Strains with Different Eye Colors

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

Rice science 2016年第2期23卷 104-110页

作者： LIU Shu-hua TANG jian LUO Ju YANG bao-jun WANG Ai-ying WU jin-cai School of Plant Protection Yangzhou University State Key Laboratory of Rice Biology China National Rice Research Institute

The brown planthopper （BPH）, Nilaparvata lugens, is a destructive insect pest of rice throughout Asia. Different from brown-eye color wild type, BPH also has red-eye color mutation phenotype. As a visible genetic marker, the red-eye mutant in BPH is a valuable material. To reveal the eye color mutation mechanism, a karmoisin homologue gene （named as Nlka） was cloned from BPH. And karmoisin is always deemd as a xanthommatin-related gene in other insects, encoding phenoxazinone synthetase （PHS）. Nlka is consisted of 7 exons and encodes a protein with 502 amino acids （NIKA）. NIKA showed high amino acid identities with its insect homologues （48.8%-51.8%）. Nlka transcripts can be detected at all the developmental stages and in all tissues tested, including egg, nymph, adult, body wall, ovary, fat body, midgut and Malpighian tubule. However, no constant In/Del or non-synonymous mutation was observed between the mutant and the wild type strains. Quantitative real-time PCR experiment also showed that Nlka transcript level had no significant differences between them. These results indicated that Nlka is not the target gene causing the red-eye color mutation phenotype of BPH. Through the second structure and motif analysis, the present study also showed that all the proteins deduced from the karmoisin genes in insects may be members of monocarboxylate transporters （MCTs） rather than PHSs.

关键词： Nilaparvata lugens red-eye mutant karmoisin monocarboxylate transporter phenoxazinone synthetase rice gene clone

Enhanced ferromagnetism and magnetoelectric response in quenched BiFeO3-based ceramics

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第8期29卷 465-470页

作者： Qi Pan bao-jin Chu Key Laboratory of Materials for Energy Conversion Chinese Academy of Sciences(CAS)Department of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

The piezoelectric,ferromagnetism,and magnetoelectric response of BiFeO3-BaTiO3 ceramics with the compositions around the morphotropic phase boundary(MPB)of the solid solution are systematically investigated after the ceramics have been quenched from a high *** find that the ferromagnetism of the quenched ceramics is greatly *** enhanced piezoelectric response d33 larger than 200 pC/N,which could be sustained up to 350℃,is *** a result of enhanced ferromagnetism and piezoelectric response,a large magnetoelectric response^1.3 V/cm·Oe(1 Oe=79.5775 A·m^-1)is obtained near the mechanical resonance frequency of the quenched ceramic *** research also shows that in addition to the ferromagnetism and piezoelectric response,the mechanical quality factor is another important parameter to achieve high magnetoelectric response because the physical effects are coupled through mechanical interaction in BiFeO3-based *** work suggests that quenching is an effective approach to enhancing the magnetoelectric response of BiFeO3-based materials and the materials belong to single-phase multiferroic materials with high magnetoelectric response.

关键词： multiferroic materials magnetoelectric ferromagnetic piezoelectric

Long term integration of radar signals with unknown Doppler shift for ubiquitous radar

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2011年第2期22卷 219-227页

作者： Qinglong bao Zengping Chen Yue Zhang jian Yang ATR National Defense Science and Technology Key Lab National University of Defense Technology Changsha 410073 P. R. China

Ubiquitous radar is a new radar system that provides continuous and uninterrupted multifunction capability within a coverage volume. Continuous coverage from close-in ＂pop-up＂ targets in clutter to long-range targets impacts selection of waveform parameters. The coherent processing interval （CPI） must be long enough to achieve a certain signal-to-noise ratio （SNR） that ensures the efficiency of detection. The condition of detection in the case of low SNR is analyzed, and three different cases that would occur during integration are discussed and a method to determine the CPI is presented. The simulation results show that targets detection with SNR as low as -26 dB in the experimental system can possibly determine the CPI.

关键词： ubiquitous radar low signal-to-noise ratio (SNR),coherent processing interval (CPI) coherent integration non-coherent integration.

Cleanliness of Ti-bearing Al-killed ultra-low-carbon steel during different heating processes

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第12期24卷 1370-1378页

作者： jian-long Guo Yan-ping bao Min Wang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

During the production of Ti-bearing Al-killed ultra-low-carbon(ULC) steel, two different heating processes were used when the converter tapping temperature or the molten steel temperature in the Ruhrstahl–Heraeus(RH) process was low: heating by Al addition during the RH decarburization process and final deoxidation at the end of the RH decarburization process(process-Ⅰ), and increasing the oxygen content at the end of RH decarburization, heating and final deoxidation by one-time Al addition(process-Ⅱ). Temperature increases of 10°C by different processes were studied; the results showed that the two heating processes could achieve the same heating effect. The T.[O] content in the slab and the refining process was better controlled by process-Ⅰ than by process-Ⅱ. Statistical analysis of inclusions showed that the numbers of inclusions in the slab obtained by process-Ⅰ were substantially less than those in the slab obtained by process-Ⅱ. For process-Ⅰ, the Al_2O_3 inclusions produced by Al added to induce heating were substantially removed at the end of decarburization. The amounts of inclusions were substantially greater for process-Ⅱ than for process-Ⅰ at different refining stages because of the higher dissolved oxygen concentration in process-Ⅱ. Industrial test results showed that process-Ⅰ was more beneficial for improving the cleanliness of molten steel.

关键词： low carbon steel cleanliness RH process heating inclusions

Noncollinear Interaction of Guided Optical Waves and Magnetostatic Forward Volume Waves Under Inclined Bias Magnetic Field

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1999年第4期16卷 288-289页

作者： WU bao-jian LIU Gong-qiang Department of Applied Physics Shanghai Jiaotong UniversityShanghai 200240

Coupled-mode equations for Stokes and anti-Stokes interactions of guided optical waves with magnetostatic forward volume waves under inclined magnetic field are *** results indicate that,only at normal magnetization,the diffraction efficiency(DE)is equal to the mode-conversion efficiency(MCE)in magnitude;by comparison to the case of normal magnetization,the DE and the MCE can be increased greatly under appropriate inclined magnetic *** the YIG waveguide used,the DE for the Stokes interaction is much greater than that for the anti-Stokes interaction when the inclined angle|θ|<25o and the MCE is symmetrical aboutθ.For the Bi-doped YIG film,the MCE presents a rapid oscillation withθ.The obtained results tally with the experiments.

关键词： field. magnetization oscillation

Effect of cross wedge rolling on the microstructure of GH4169 alloy

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

International Journal of Minerals,Metallurgy and Materials 2012年第9期19卷 836-842页

作者： Ning Zhang bao-yu Wang jian-guo Lin School of Mechanical Engineering University of Science and Technology Beijing Beijing 100083 China Deparment of Mechanical Engineering Imperial College London SW7 2AZ UK

The metal microstructure during the hot forming process has a significant effect on the mechanical properties of final products. To study the microstructural evolution of the cross wedge rolling （CWR） process, the microstructural model of GH4169 alloy was programmed into the user subroutine of DEFORM-3D by FORTRAN. Then, a coupled thermo-mechanical and microstructural simulation was performed under different conditions of CWR, such as area reduction, rolling temperature, and roll speed. Comparing experimental data with simulation results, the difference in average grain size is from 11.2% to 33.4% so it is verified that the mierostructural model of GH4169 alloy is reliable and accurate. The fine grain of about 12-15 p.m could be obtained by the CWR process, and the grain distribution is very homogeneous. For the symmetry plane, increasing the area reduction is helpful to refine the grain and the value should be around 61%. Moreover, when the roiling temperature changes from 1000 to 1100℃ and the roll speed from 6 to 10 ***-1, the grain size of the rolled piece decreases first and then increases. The temperature may be better to choose the value around 1050℃ and the speed less than 10 r-min-1.

关键词： superalloys nickel alloys cross wedge rolling microstructural evolution grain size numerical analysis