检索结果-南通市图书馆

Non-universal Fermi polaron in quasi two-dimensional quantum gases

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第8期31卷 246-251页

作者： Yue-Ran Shi Jin-ge chen Kui-Yi Gao Wei Zhang Department of Physics Renmin University of ChinaBeijing 100872China Beijing Academy of Quantum Information Sciences Beijing 100193China Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China

We consider an impurity problem in a quasi-two-dimensional Fermi gas, where a spin-down impurity is immersed in a Fermi sea of N spin-up atoms. Using a variational approach and an effective two-channel model, we obtain the energy for a wide range of interaction strength and for various different mass ratios between the impurity and the background fermion in the context of heteronuclear mixture. We demonstrate that in a quasi-two-dimensional Fermi gas there exists a transition of the ground state from polaron in the weakly interacting region to molecule in the strongly interacting *** critical interaction strength of the polaron–molecule transition is non-universal and depends on the particle density of the background Fermi sea. We also investigate the excited repulsive polaron state, and find similar non-universal behavior.

关键词： Fermi gas polaron problem two-channel model

Recent Progress in Ferroelectric Diodes: Explorations in Switchable Diode Effect

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2013年第2期5卷 81-87页

作者： chen ge Can Wang Kui-juan Jin Hui-bin Lu Guo-zhen Yang Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences

Switchable diode effect in ferroelectric diodes has attracted much attention for its potential applications in novel nonvolatile memories. We briefly review recent investigations on the switchable diode effect in ferroelectric diodes both experimentally and theoretically. Many recent studies demonstrate that the interfacial barrier between the metal-ferroelectrics could be modulated by the polarization charges, and the ferroelectric polarization that can be reversed by an external electric field plays a dominant role in the switchable diode effect. Moreover, we review a self-consistent numerical model, which can well describe the switchable diode effect in ferroelectric diodes. Based on this model, it can be predicted that it is a better choice to select metals with a smaller permittivity, such as noble metals, to obtain a more pronounced switchable diode effect in ferroelectric diodes.

关键词： Ferroelectric diodes Switchable diode effect Metal/ferroelectrics/metal structure Self-consistent mode

Ce1-xSmxO2-x/2—A novel type of ceramic material for thermal barrier coatings

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2016年第3期5卷 244-252页

作者： Xiao-ge chen Haoming ZHANG Hong-song ZHANG Yong-de ZHAO Gang LI Department of Construction Engineering Henan Institute of Engineering Zhengzhou 450007 China Department of Mechanical Engineering Henan Institute of Engineering Zhengzhou 450007 China Department of Mechanical Engineering Henan Institute of Engineering Zhengzhou 450007 ChinaInstitute of Chemistry Henan Academy Sciences Zhengzhou 450052 China Institute of Chemistry Henan Academy Sciences Zhengzhou 450052 China

In this study, Ce1-xSmxO2-x/2 ceramics were synthesized by sol-gel route and solid state sintering method. The phase structure was analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy. The morphologies of the synthesized powders and the corresponding bulk samples were observed using scanning electron microscopy (SEM). Their thermal diffusivities and thermal expansion coefficients were measured by the laser-flash method and the pushing-rod method, respectively. Results show that pure Ce1-xSmxO2-x/2 powders with single fluorite structure are synthesized successfully, and their microstructures of the corresponding bulk samples are very dense. With the increase of Sm2O3 content, their thermal expansion coefficients decrease due to the higher electro-negativity of Sm3+ ions as compared with that of Ce4+ ions. Their thermal conductivities at 1000 degrees C lie in the range of 1.62-2.02 W/(m.K) due to the phonon scattering caused by the substituted atoms and oxygen vacancies. The Ce1-xSmxO2-x/2 ceramics can be used as ceramic candidates for novel thermal barrier coatings (TBCs).

关键词： thermal barrier coatings (TBCs) CeO2 oxides doping thermophyscial properties

Antibacterial Sutures Coated with Smooth Chitosan Layer by Gradient Deposition

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

Chinese Journal of Polymer Science 2022年第9期40卷 1050-1061页

作者： Ying-ge chen Chu-Xin Li Yu Zhang Yong-Dan Qi Jun Feng Xian-Zheng Zhang Key Laboratory of Biomedical Polymers of Ministry of Education&Department of Chemistry Wuhan UniversityWuhan 430072China

Owing to the significant importance in clinics,antibacterial activity is thought as one indispensable feature of the next generation of absorbable *** is challenging but imperative to arm the existing absorbable sutures with antibacterial *** present study describes a“gradient deposition”technique to coat a continuous and smooth layer of chitosan on the surface of absorbable ***,chitosan solution is arranged to undergo gradient pH decline step by step while during each pH interval,the solution is allowed to stand for a predetermined period of time in order to control gradual chitosan *** nanoparticles are found to be first generated on suture surface and finally developed into a smooth chitosan layer as the antibacterial *** vitro and in vivo results demonstrated that coating chitosan on sutures by our technique could relieve wound inflammation,stimulate collagen deposition,regenerate blood vessels,and assist tissue repairing,consequently leading to a significant enhancement of wound healing *** technique is highlighted with low cost,extreme convenience and excellent safety without organic ***,the“gradient deposition”technique would not affect the fundamental properties of matrix and thus hold promises as a universal way for superficial antibacterial modification towards almost all the surgical implanted materials,including but not limited to absorbable sutures.

关键词： Antibacterial sutures Gradient deposition Chitosan coating Wound healing Bacterial infection

Dirichlet Eigenvalue Problem of Degenerate Elliptic Operators with Non-Smooth Coefficients

在线全文

学校读者我要写书评

暂无评论

Communications in Mathematical Research 2022年第4期38卷 498-515页

作者： Hua chen Hong-ge chen Jin-Ning Li School of Mathematics and Statistics Wuhan UniversityWuhan 430072China Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China

The aim of this review is to introduce some recent results in eigenvalues problems for a class of degenerate elliptic operators with non-smooth coefficients,we present the explicit estimates of the lower bound and upp... 详细信息

关键词： Dirichlet eigenvalues weighted Sobolev spaces degenerate elliptic operators homogeneous dimension

Advances of manganese-oxides-based catalysts for indoor formaldehyde removal

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

Green Energy & Environment 2023年第3期8卷 626-653页

作者： Jiayu Zheng Wenkang Zhao Liyun Song Hao Wang Hui Yan ge chen Changbao Han Jiujun Zhang Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing100124China Key Laboratory of Beijing on Regional Air Pollution Control and Beijing Key Laboratory for Green Catalysis and Separation Beijing University of TechnologyBeijing100124China College of Sciences&Institute for Sustainable Energy Shanghai UniversityShanghai200444China

Formaldehyde(HCHO)has been identified as one of the most common indoor pollutions *** oxides(MnO_(x))are considered to be a promising catalytic material used in indoor HCHO oxidation removal due to their high catalytic activity,low-cost,and environmentally *** this paper,the progress in developing MnO_(x)-based catalysts for HCHO removal is comprehensively reviewed for exploring the mechanisms of catalytic oxidation and catalytic *** catalytic oxidation mechanisms based on three typical theory models(Mars-van-Krevelen,Eley-Rideal and Langmuir-Hinshelwood)are discussed and ***,the research status of catalytic deactivation,catalysts’regeneration and integrated application of MnO_(x)-based catalysts for indoor HCHO removal are detailed in the ***,the technical challenges in developing MnO_(x)-based catalysts for indoor HCHO removal are analyzed and the possible research direction is also proposed for overcoming the challenges toward practical application of such catalysts.

关键词： Manganese dioxide(MnOx) Formaldehyde(HCHO) Catalytic oxidation Room temperature Indoors

Propensity score-matched study and meta-analysis of cumulative outcomes of day 2/3 versus day 5/6 embryo transfers

在线全文

学校读者我要写书评

暂无评论

Frontiers of Medicine 2017年第4期11卷 563-569页

作者： Ye Yin ge chen Kezhen Li Qiuyue Liao Sijia Zhang Nieying Ma Jing chen Yan Zhang Jihui Ai Reproductive Medicine Center Tongii Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China Department of Obstetrics and Gynecology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China

The superiority of the cumulative outcomes of day 5/6 embryo transfer to those of day 2/3 embryo transfer in infertile couples has been debated. This retrospective study included data collected from 1051 patients from July 2011 to June 2014. Multiple maternal baseline covariates were subjected to propensity score matching analysis, and each day 5/6 group woman was matched to one day 2/3 group woman. A systematic meta-analysis was conducted to vaUdate the results. After matching was completed, 217 patients on the day 2/3 group were matched with those on the day 5/6 group, and no significant differences in the baseline characteristics were observed between the two groups. The cumulative pregnancy rate （57.14% vs. 53.46%, OR 1.16, 95% CI 0.79-1.70） and cumulative live birth rate （53.00% vs. 49.77%, OR 1.14, 95% CI 0.78-1.66） of day 5/6 embryo transfers were higher than those of day 2/3 embryo transfers, but this difference was not significant. The mean cycles per live birth and mean days per live birth in the day 5/6 group were significantly lower than those in the day 2/3 group. This study demonstrated that day 5/6 embryo transfer is a more cost-effective and time-efficient policy than day 2/3 embryo transfer to produce a live baby.

关键词： blastocyst embryo transfer cumulative pregnancy rate cumulative live birth rate IVF

Structure demonstration of perovskite oxide and its epitaxial thin films by second harmonic generation

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 China(Technological Sciences) 2020年第5期63卷 874-876页

作者： WANG JieSu ge chen GUO Er-Jia XU XiuLai WANG Can JIN KuiJuan Institute of Physics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China

Perovskite oxide materials and their epitaxial thin films have attracted wide attention in various research fields,due to the new properties discovered at every *** the epitaxial perovskite oxide thin films,the interaction between the films and substrates could bring in some novel physical properties,such as two-dimensional electron gas[1],positive colossal magnetoresistance[2],polar metal state[3,4],interfacial enhancement effect[5–7].The(dis)appearance and regulation of these properties are usually accompanied with structural distortion changing of films,which may originate from the thickness variation,substrate replacement,or oxygen vacancies[8].Thus,it is crucial to define what structure it is and figure out how the structure evolves.

关键词： perovskite epitaxial harmonic

Parameterization Method of Wind Drift Factor Based on Deep Learning in the Oil Spill Model

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2023年第6期22卷 1505-1515页

作者： YU Fangjie GU Feiyang ZHAO Yang HU Huimin ZHANG Xiaodong ZHUANG Zhiyuan chen ge College of Marine Technology Faculty of Information Science and EngineeringOcean University of ChinaQingdao 266100China Laboratory for Regional Oceanography and Numerical Modelling Laoshan LaboratoryQingdao 266100China College of Liberal Arts Journalism and CommunicationOcean University of ChinaQingdao 266100China Qingdao Baifa Desalination Corporation Qingdao 266100China

Oil spill prediction is critical for reducing the detrimental impact of oil spills on marine ecosystems,and the wind strong-ly influences the performance of oil spill ***,the wind drift factor is assumed to be constant or parameterized by linear regression and other methods in existing studies,which may limit the accuracy of the oil spill simulation.A parameterization method for wind drift factor(PMOWDF)based on deep learning,which can effectively extract the time-varying characteristics on a regional scale,is proposed in this *** method was adopted to forecast the oil spill in the East China *** discrepancies between predicted positions and actual measurement locations of the drifters are obtained using seasonal statistical *** reveal that PMOWDF can improve the accuracy of oil spill simulation compared with the traditional ***,the parameteriza-tion method is validated with satellite observations of the Sanchi oil spill in 2018.

关键词： oil spill prediction deep learning wind drift factor regional parameterization East China Sea