检索结果-南通市图书馆

Superfluid λ transition in charged AdS black holes

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 29-36页

作者： Ning-chen bai Lei Li Jun Tao Center for Theoretical Physics College of PhysicsSichuan UniversityChengdu 610065China School of Physics and Electronic Engineering Sichuan University of Science and EngineeringYibin 643000China

We observe a superfluid λ transition in the P-V criticality of charged Ad S black holes,within a holographic extended thermodynamics that considers the variation of Newton’s constant *** calculate the critical exponents and find that they coincide with those of a superfluid transition in liquid4He and the Bose-Einstein condensation of hard-sphere Bose ***,the independence of entropy and thermodynamic volume in the holographic framework allows us to construct a well-defined Ruppeiner *** associated scalar curvature suggests that the black holes show similar microscopic interactions with the hard-sphere Bose gas,where the superfluid(condensed)phase is dominated by repulsive interactions,while the normal(gas)phase is dominated by attractive *** findings might provide us with new insights into the quantum aspect of charged Ad S black holes.

关键词： black hole thermodynamics holography superfluid phase transition Ruppeiner geometry

Repulsive Effect for Unbound High Energy Particles Along Rotation Axis in Kerr-Taub-NUT Spacetime

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2018年第4期69卷 399-406页

作者： Lu Zhang Song-bai chen Department of Physics Hunan Normal University Changsha 410081 China Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education Hunan Normal University Changsha 410081 China Synergetie Innovation Center for Quantum Effects and Applications Hunan Normal University Changsha 410081 China

We have investigated the acceleration of the unbound high energy particles moving along the rotation axis in the Kerr-Taub-NUT spacetime, and then study the dependence of the repulsive effects on the NUT charge for the particles in the spacetime. Whether the repulsive effects with the NUT charge become stronger depends on the Carter constant, the position and velocity of the particles themselves. We also present numerically the changes of the observable velocity and acceleration with the NUT charge for the unbound particles in the Kerr-Taub-NUT spacetime.

关键词： Kerr-Taub-NUT acceleration black hole

PREPARATION OF SINGLE-HOLE HOLLOW POLYMER NANOSPHERES BY RASPBERRY-LIKE TEMPLATE METHOD

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2013年第2期31卷 294-301页

作者： Yong Zhang Jia-jia chen Geng-hui Zhang bai-zhu chen 阎虎生 Key laboratory of Functional Polymer Materials (Ministry of Education) Institute of Polymer Chemistry Nankai University

Single-hole hollow polymer nanospheres were fabricated by raspberry-like template method using ＂graft-from＂ strategy through atom transfer radical polymerization （ATRP）. Nanometer-sized silica spheres were covalently attached onto the surfaces of micrometer-sized silica spheres. Crosslinked polymer shells on the nano-sized spheres outside the attached area were formed by ＂graft-from＂ strategy through ATRP. After removal of the silica cores, single-hole hollow crosslinked polymer nanospheres were obtained. In this strategy, most of ATRP monomers may be used and thus many functional groups can be easily incorporated into the single-hole hollow crosslinked polymer nanospheres.

关键词： Single-hole Hollow polymeric nanoparticles ATRP.

Distributed cooperative guidance for multiple missiles with fixed and switching communication topologies

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2017年第4期30卷 1570-1581页

作者： Qilun ZHAO Xiwang DONG Zixuan LIANG chen bai Jian chen Zhang REN Science and Technology on Aircraft Control Laboratory School of Automation Science and Electronic EngineeringBeihang University Beijing 100083 China School of Astronautics Beihang University Beijing 100083 China China Academy of Launch Vehcle Technology Beijing 100076 China College of Engineering China Agricultural University Beijing 100083 China

This study investigates cooperative guidance problems for multiple missiles with fixed and switching directed communication topologies. A two-step guidance strategy is proposed to realize the simultaneous attack. In the first step, a distributed cooperative guidance law is designed using local neighboring information for multiple missiles to achieve consensus on range-to-go and leading angle. The second step begins when the consensus of multiple missiles is realized. During the second step, multiple missiles disconnect from each other and hit the target using the proportional navigation guidance law. First, based on the local neighboring communications, a sufficient condition for multiple missiles to realize simultaneous attack with a fixed communication topology is presented, where the topology is only required to have a directed spanning tree. Then,the results are extended to the case of switching communication topologies. Finally, numerical simulations are provided to validate the theoretical results.

关键词： Consensus Cooperative guidance Directed topology Missile guidance Multiple missiles Switching communication topologies

Synthesis and application of bilayer-surfactant-enveloped Fe_3O_4 nanoparticles: water-based bilayer-surfactant-enveloped ferrofluids

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第2期23卷 234-240页

作者： bai-yi chen Jian-hui Qiu Hui-xia Feng Department of Machine Intelligence and Systems Engineering Faculty of Systems Engineering Akita Prefectural University College of Petrochemical Technology Lanzhou University of Technology

Superparamagnetic carbon-coated Fe3O4 nanoparticles with high magnetization（85 emu·g-（-1）） and high crystallinity were synthesized using polyethylene glycol-4000（PEG（4000）） as a carbon ***3O4 water-based bilayer-surfactant-enveloped ferrofluids were subsequently prepared using sodium oleate and PEG（4000） as *** using X-ray photoelectron spectroscopy,X-ray diffraction,and Fourier-transform infrared spectroscopy indicate that the Fe3O4 nanoparticles with a bilayer surfactant coating retain the inverse spinel-type structure and are successfully coated with sodium oleate and PEG（4000）.Transmission electron microscopy,vibrating sample magnetometry,and particle-size analysis results indicate that the coated Fe3O4 nanoparticles also retain the good saturation magnetization of Fe3O4（79.6 emu·g^-1） and that the particle size of the bilayer-surfactant-enveloped Fe3O4 nanoparticles is 42.97 nm,which is substantially smaller than that of the unmodified Fe3O4 nanoparticles（486.2 nm）.UV-vis and zeta-potential analyses reveal that the ferrofluids does not agglomerate for 120 h at a concentration of 4 g·L^-1,which indicates that the ferrofluids are highly stable.

关键词： magnetic fluids iron oxides nanoparticles bilayers sodium oleate polyethylene glycol

Suppression of Growth of Hela, EJ, SK-OV-3 and MDA-MB-231 Cells by Recombinant Human NK4

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2009年第1期21卷 28-31页

作者： Hua bai Hong chen Chang-shan Ren Tumor Institute China Medical University Shenyang 110001 China

Objective： To study the effects of recombinant human Nk4 on the growth and invasion activities of tumor cells. Methods： The inhibition of recombinant human NK4 on human oophoroma, cervical tumor, breast tumor and gallbladder tumor cells was evaluated in vitro by basement membrane invasion assay. Results： rhNK4 could markedly inhibited the growth of human oophoroma, cervical tumor and breast tumor cells. The inhibition rates of human oophoroma, cervical tumor, breast tumor and gallbladder tumor cells were 48.2%, 29.2%, 58.4% and 30.1% respectively. Conclusion： rhNK4 factor can markedly inhibit the invasion of multiple tumor cells.

关键词： rhNK4 Tumor cells In vitro invasion

Design of a nanozyme-based magnetic nanoplatform to enhance photodynamic therapy and immunotherapy

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2024年第9期14卷 1320-1329页

作者： chen bai Jiajing Liu Luyao bai Dapeng Yao Xiaofeng Li Haoran Zhang Dong Guo Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy Xuzhou Medical UniversityXuzhouJiangsu221004China Department of Radiology Xuzhou Cancer HospitalXuzhouJiangsu221004China

The tumor microenvironment, particularly the hypoxic property and glutathione (GSH) overexpression, substantially inhibits the efficacy of cancer therapy. In this article, we present the design of a magnetic nanoplatform (MNPT) comprised of a photosensitizer (Ce6) and an iron oxide (Fe3O4)/manganese oxide (MnO2) composite nanozyme. Reactive oxygen species (ROS), such as singlet oxygen (1O2) radicals produced by light irradiation and hydroxyl radicals (·OH) produced by catalysis, are therapeutic species. These therapeutic substances stimulate cell apoptosis by increasing oxidative stress. This apoptosis then triggers the immunological response, which combines photodynamic therapy and T-cell-mediated immunotherapy to treat cancer. Furthermore, MNPT can be utilized as a contrast agent in magnetic resonance and fluorescence dual-modality imaging to give real-time tracking and feedback on treatment.

关键词： Nanozyme Photodynamic therapy Tumor microenvironment Immunotherapy Dual-mode tomography

Extremum response surface method of reliability analysis on two-link flexible robot manipulator

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

Journal of Central South University 2012年第1期19卷 101-107页

作者： ZHANG Chun-yi bai Guang-chen School of Jet Propulsion Beijing University of Aeronautics and AstronauticsBeijing 100191China School of Mechanical and Power Engineering Harbin University of Science and TechnologyHarbin 150080China

In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the integrated modal method and the multi-body system dynamics *** using the Monte Carlo method,the random sample values of the dynamic parameters were obtained and Lagrange dynamics differential equations were solved for each random sample value which revealed their displacement,speed and *** this basis,dynamic stresses and deformations were *** taking the maximum values of the stresses and the deformations as output responses and the random sample values of dynamic parameters as input quantities,extremum response surface functions were established.A number of random samples were then obtained by using the Monte Carlo method and then the reliability was analyzed by using the extremum response surface *** results show that the extremum response surface method is an efficient and fast reliability analysis method with high-accuracy for the two-link flexible robot manipulator.

关键词： reliability Monte Carlo method extremum response surface function flexible manipulator dynamic strength dynamicstiffness

Cramér-Rao bound for multiple parameters estimation using a polarization sensitive array

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2012年第3期19卷 107-113页

作者： ZHENG Gui-mei chen bai-xiao YANG Ming-lei National Laboratory of Radar Signal Processing Xidian UniversityXi'an 710071China

In this paper, new Cramér-Rao lower bounds （CRB） of the estimates of frequencies, two-dimensional arrival angles and polarization parameters of multiple incident signals are derived for a polarization sensitive array. The incident sources have distinct carrier-frequencies, in contrast to the modeling of all sources to be at the same known carrier-frequency, which has been investigated in the existing research literature on the Cramér-Rao bounds （CRB） for polarization sensitive direction finding. The derived CRBs are compact closed-form expressions and applicable to an arbitrary array geometry. Numerical examples and analysis of some special cases provide insights into the fact that the estimation accuracy of all parameters is enhanced with the increasing signal-to-noise ratio （SNR） and number of snapshots. In addition, they are hardly influenced by the sampling frequency and independent of the initial phase of incident sources. These insights offer guidelines to the system engineer on how to improve parameters＇ estimation accuracy.

关键词： array signal processing polarization sensitive array CRB direction of arrival estimation frequency estimation