检索结果-南通市图书馆

Multi boron-doping effects in hard carbon toward enhanced sodium ion storage

在线全文

学校读者我要写书评

暂无评论

Journal of energy Chemistry 2025年第1期100卷 730-738页

作者： Peng zheng Wang Zhou Ying Mo Biao zheng Miaomiao Han Qin Zhong Wenwen Yang Peng Gao Lezhi Yang Jilei Liu College of Materials Science and engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Greater Bay Area Institute for Innovation Hunan University Changsha Research Institute of Mining & Metallurgy Co. LTD.

Hard carbon （HC） has been considered as promising anode material for sodium-ion batteries （SIBs）.The optimization of hard carbon’s microstructure and solid electrolyte interface （SeI） property are demonstrated effective in enhancing the na+storage capability,however,a one-step regulation strategy to achieve simultaneous multi-scale structures optimization is highly ***,we have systematically investigated the effects of boron doping on hard carbon’s microstructure and interface chemistry.A variety of structure characterizations show that appropriate amount of boron doping can increase the size of closed pores via rearrangement of carbon layers with improved graphitization degree,which provides more na+storage ***-situ Fourier transform infrared spectroscopy/electrochemical impedance spectroscopy （FTIR/eIS） and X-ray photoelectron spectroscopy （XPS） analysis demonstrate the presence of more BC3and less B–C–O structures that result in enhanced ion diffusion kinetics and the formation of inorganic rich and robust SeI,which leads to facilitated charge transfer and excellent rate *** a result,the hard carbon anode with optimized boron doping content exhibits enhanced rate and cycling *** general,this work unravels the critical role of boron doping in optimizing the pore structure,interface chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced na+storage performance.

关键词： X ray photoelectron spectroscopy

Synergistic effect of bonding heterogeneity and phonon localization in introducing excellent thermoelectric properties in layered heteroanionic NdZnSbO material

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of energy Chemistry 2025年第1期100卷 259-272页

作者： Da Wan Shuwei Tang Shulin Bai Xiaodong Li Peng Ai Wanrong Guo Tuo zheng College of Materials Science and engineering Liaoning Technical University Faculty of Chemistry Northeast Normal University

Layered rare-earth metal oxides, harnessing the dual properties of oxides and two-dimensional layered materials, exhibit remarkable thermal stability and quantum confinement effects. Therefore, this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound. The coexistence of weak interlayer van der Waals interactions, robust intralayer ionic bonding, and partial covalent bonding leads to remarkable bonding heterogeneity, which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction. The weakened chemical bonds induced by the antibonding states, together with the rattling-like behavior of the Zn atom, culminate in the profound anharmonicity in the layered NdZnSbO compound. The weakening bond and heavy element contribute to the softness of phonon modes, which significantly diminishes the phonon group velocity. The redistribution-dominated four-phonon scattering process spans a large optical gap, which effectively reduces the lattice thermal conductivity. The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-ernzerhof(HSe06) functional in combination with spin–orbit coupling(SOC) effect. The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy, thus amplifying the power factor. Consequently, an optimal figure-of-merit(ZT) of 3.40 at 900 K is achieved for the n-type NdZnSbO compound. The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.

关键词： Bond strength (chemical)

Joint resource allocation scheme for target tracking in distributed MIMO radar systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems engineering and electronics 2019年第4期30卷 709-719页

作者： zheng na’e SUN Yang SONG Xiyu CHeN Song Data and Target engineering Institute PLA Strategic Support Force Information Engineering University

A joint resource allocation scheme concerned with the sensor subset,power and bandwidth for range-only target tracking in multiple-input multiple-output(MIMO)radar systems is *** selecting an optimal subset of sensors with the predetermined size and implementing the power allocation and bandwidth strategies among them,this algorithm can help achieving a better performance within the same resource ***,the Bayesian Cramer-Rao bound(BCRB)is derived from ***,a criterion for minimizing the BCRB at the target location among all targets tracking in a certain range is ***,the optimization problem involved with three variable vectors is formulated,which can be simplified by deriving the relationship between the optimal power allocation vector and the bandwidth allocation ***,the simplified optimization problem is solved by the cyclic minimization algorithm incorporated with the sequential parametric convex approximation(SPCA)***,the validity of the proposed method is demonstrated with simulation results.

关键词： distributed multiple-input multiple-output(MIMO)radar target tracking joint resource alloction sensor subset selection(SSS) optimal power and bandwidth allocation(OPBA)

Aqueous electrocatalytic N2 reduction under ambient conditions

在线全文

学校读者我要写书评

暂无评论

nano Research 2018年第6期11卷 2992-3008页

作者： na Cao Gengfeng zheng Laboratory of Advanced Materials Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy Materials Fudan University Shanghai200438 China

Recently, the electrochemical N2 reduction reaction （NRR） in aqueous electrolytes at ambient temperature and pressure has demonstrated its unique advantages and potentials. The reactants are directly derived from gaseous N2 and water, which are naturally abundant, and NH3 production is important for fertilizers and other industrial applications. To improve the conversion yield and selectivity （mainly competing with water reduction）, electrocatalysts must be rationally designed to optimize the mass transport, chemisorption, and transduction pathways of protons and electrons. In this review, we summarize recent progress in the electrochemical NRR. Studies of electrocatalyst designs are summarized for different categories, including metal-based catalysts, metal oxide-derived catalysts, and hybrid catalysts. Strategies for enhancing the NRR performance based on the facet orientation, metal oxide interface, crystallinity, and nitrogen vacancies are presented. Additional system designs, such as lithium-nitrogen batteries, and the solvent effect are introduced. Finally, existing challenges and prospects are discussed.

关键词： N2 reduction electrocatalyst aqueous electrolyte faradaic efficiency

Observational Constraints on Quark Matter in Neutron Stars

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 Astronomy and Astrophysics 2007年第5期7卷 675-684页

作者： na-na Pan Xiao-Ping zheng Institute of Astrophysics Huazhong Normal University Wuhan 430079

We study the observational constraints of mass and redshift on the properties of the equation of state （eOS） for quark matter in compact stars based on the quasi-particle description. We discuss two scenarios; strange stars and hybrid stars. We construct the equations of state utilizing an extended MIT bag model taking the medium effect into account for quark matter and the relativistic mean field theory for hadron matter. We show that quark matter may exist in strange stars and in the interior of neutron stars. The bag constant is a key parameter that affects strongly the mass of strange stars. The medium effect can lead to the stiffer hybrid-star eOS approaching the pure hadronic eOS, due to the reduction of quark matter, and hence the existence of heavy hybrid stars. We find that a middle range coupling constant may be the best choice for the hybrid stars being compatible with the observational constraints.

关键词： dense matter -- gravitation -- stars neutron -- stars rotation -- stars oscillations

A head-mounted photoacoustic fiberscope for hemodynamic imaging in mobile mice

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第6期13卷 1012-1014页

作者： Xiaoyan zheng Shuai na national Biomedical Imaging Center College of Future TechnologyPeking UniversityBeijing100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing100871China

A miniaturized photoacoustic fiberscope has been developed, featuring a lateral resolution of 9 microns and a lightweight design at 4.5 grams. engineered to capture hemodynamic processes at single-blood-vessel resolution at a rate of 0.2 Hz, this device represents an advancement in head-mounted tools for exploring intricate brain activities in mobile animals.

关键词： fiber mobile engine

新医科背景下基于eIP-CDIO模式的急危重症护理课程思政教学探究

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

卫生职业教育 2025年第1期43卷 23-27页

作者：郑娜戴月吴晶江西卫生职业学院江西南昌330200

在分析急危重症护理课程教学现状与不足之处的基础上,结合新医科人才培养目标,提出基于eIP-CDIO模式下的急危重症护理课程思政教学理念和实施路径:构思环节,明确课程思政育人目标;设计环节,优化课程思政教学团队,重构知识点,深入挖掘知... 详细信息

在分析急危重症护理课程教学现状与不足之处的基础上,结合新医科人才培养目标,提出基于eIP-CDIO模式下的急危重症护理课程思政教学理念和实施路径:构思环节,明确课程思政育人目标;设计环节,优化课程思政教学团队,重构知识点,深入挖掘知识点中蕴含的思政元素;实现环节,运用多种教学方法,将思政元素潜移默化地融入专业知识教授过程;运作环节,构建持续性教学评价机制,促进课程思政教学效果的良性提升。

关键词： eIP-CDIO模式急危重症护理课程思政新医科

维普期刊数据库博看期刊

Cholesterol metabolism: physiological versus pathological aspects in intracerebral hemorrhage

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1015-1030页

作者： Ruoyu Huang Qiuyu Pang Lexin zheng Jiaxi Lin Hanxi Li Lingbo Wan Tao Wang Department of Forensic Science School of Basic Medicine and Biological SciencesSuzhou Medicine College of Soochow UniversitySuzhouJiangsu ProvinceChina

Cholesterol is an important component of plasma membranes and participates in many basic life functions,such as the maintenance of cell membrane stability,the synthesis of steroid hormones,and *** plays a key role in the establishment and maintenance of the central nervous *** brain contains 20%of the whole body’s cholesterol,80%of which is located within myelin.A huge number of processes(e.g.,the sterol regulatory element-binding protein pathway and liver X receptor pathway)participate in the regulation of cholesterol metabolism in the brain via mechanisms that include cholesterol biosynthesis,intracellular transport,and *** brain injuries or diseases involving crosstalk among the processes above can affect normal cholesterol metabolism to induce detrimental ***,we hypothesized that cholesterol-related molecules and pathways can serve as therapeutic targets for central nervous system *** hemorrhage is the most severe hemorrhagic stroke subtype,with high mortality and *** cholesterol levels are associated with the risk of intracerebral ***,secondary pathological changes after intracerebral hemorrhage are associated with cholesterol metabolism dysregulation,such as neuroinflammation,demyelination,and multiple types of programmed cell *** cholesterol accumulation in the brain has been found after intracerebral *** this paper,we review normal cholesterol metabolism in the central nervous system,the mechanisms known to participate in the disturbance of cholesterol metabolism after intracerebral hemorrhage,and the links between cholesterol metabolism and cell *** also review several possible and constructive therapeutic targets identified based on cholesterol metabolism to provide cholesterol-based perspectives and a reference for those interested in the treatment of intracerebral hemorrhage.

关键词： cell death cholesterol metabolism intracerebral hemorrhage myelination therapeutic target

Asymptotic solutions for laminar flow in a channel with uniformly accelerating rigid porous walls

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2007年第5期14卷 405-409页

作者： Liancun zheng na Zhao Xinxin Zhang Applied Science School University of Science and Technology Beijing Beijing 100083 China Mechanical engineering School University of Science and Technology Beijing Beijing 100083 China

A theoretical investigation was done for the generalized Berman problem, which arises in steady laminar flow of an incompressible viscous fluid along a channel with accelerating rigid porous walls. The existence of multiple solutions and its conditions were established by taking into account exponentially small terms in matched asymptotic expansion. The correctness of the analytical predictions was verified by numerical results.

关键词： porous channel suction/injection asymptotic expansion multiple solutions