检索结果-南通市图书馆

Optimizing the key parameter to accelerate the recovery of AMOC under a rapid increase of greenhouse gas forcing

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2025年第1期18卷 39-45页

作者： Haolan Ren Fei Zheng Tingwei cao qiang Wang International Center for Climate and Environment Science(ICCES) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina College of Oceanography Hohai UniversityNanjingChina CAS Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of Sciences and Pilot National Laboratory for Marine Science and Technology(Qingdao)QingdaoChina

Atlantic Meridional Overturning Circulation(AMOC)plays a central role in long-term climate variations through its heat and freshwater transports,which can collapse under a rapid increase of greenhouse gas forcing in climate *** studies have suggested that the deviation of model parameters is one of the major factors in inducing inaccurate AMOC *** this work,with a low-resolution earth system model,the authors try to explore whether a reasonable adjustment of the key model parameter can help to re-establish the AMOC after its *** a new optimization strategy,the extra freshwater flux(FWF)parameter is determined to be the dominant one affecting the AMOC’s *** traditional ensemble optimal interpolation(EnOI)data assimilation and new machine learning methods are adopted to optimize the FWF parameter in an abrupt 4×CO_(2) forcing experiment to improve the adaptability of model parameters and accelerate the recovery of *** results show that,under an abrupt 4×CO_(2) forcing in millennial simulations,the AMOC will first collapse and then re-establish by the default FWF parameter ***,during the parameter adjustment process,the saltier and colder sea water over the North Atlantic region are the dominant factors in usefully improving the adaptability of the FWF parameter and accelerating the recovery of AMOC,according to their physical relationship with FWF on the interdecadal timescale.

关键词： Recovery of AMOC 4×CO_(2)forcing Key parameter Parameter estimation Data assimilation Machine learning

Research on droplet formation and dripping behavior during the electroslag remelting process

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4期23卷 399-407页

作者： Yu-long cao Yan-wu Dong Zhou-hua Jiang Hai-bo cao Dong Hou qian-long Feng School of Materials and Metallurgy Northeastern University

A better understanding of droplet formation and dripping behavior would be useful in the efficient removal of impurity elements and nonmetallic inclusions from liquid metals. In the present work, we developed a transparent experimental apparatus to study the mechanisms of droplet formation and the effects of filling ratio on droplet behavior during the electroslag remelting（ESR） process. A high-speed camera was used to clearly observe, at small time scales, the droplet formation and dripping phenomenon at the slag/metal interface during a stable ESR process. The results illustrate that a two-stage process for droplet formation and dripping occurs during the ESR process and that the droplet diameter exhibits a parabolic distribution with increasing filling ratio because of the different shape and thermal state of the electrode tip. This work also confirms that a relatively large filling ratio reduces electricity consumption and improves ingot quality.

关键词： electroslag remelting droplets dripping physical simulation

探讨维宝铅锌矿维宝西矿区地质特征及找矿标志

在线全文

学校读者我要写书评

暂无评论

世界有色金属 2018年第6期43卷 107-107,109页

作者：沈灯亮张骞李新龙曹东梅新疆地质矿产勘发局地球物理化学探矿大队新疆昌吉831100

新疆祁漫塔格地区成矿地质条件优越,找矿潜力巨大,是新疆十大重要找矿远景区之一,维宝铅锌矿床是本世纪初新发现的产于蓟县系狼牙山组碎屑岩碳酸盐岩建造中的铅锌矿床。文章通过对维宝铅锌矿西矿区成矿地质特征的分析,认为该矿区主要受... 详细信息

新疆祁漫塔格地区成矿地质条件优越,找矿潜力巨大,是新疆十大重要找矿远景区之一,维宝铅锌矿床是本世纪初新发现的产于蓟县系狼牙山组碎屑岩碳酸盐岩建造中的铅锌矿床。文章通过对维宝铅锌矿西矿区成矿地质特征的分析,认为该矿区主要受地层、岩性以及岩浆作用控制,矿床成因可能为与印支期岩浆作用有关的层控矽卡岩型矿床,该区矿体埋深较大,应综合分析地物化资料进行深部找矿。

关键词：维宝西矿区地质特征矿床成因找矿标志

Unraveling post-growth mechanisms of monolayer CsPbBr3 nanocubes:Laser-enhanced transformations and cathodoluminescence-electron microscopy correlations

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 146-156页

作者： Mingxing Li Xiaoge Wang Xiaofan cao Zhiqun He Chunjun Liang Mingxing Chen Jing Ju Fangtian You Key Laboratory of Luminescence and Optical Information Ministry of Education Institute of Optoelectronic Technology Beijing Jiaotong University Beijing National Laboratory for Molecular Sciences (BNLMS) College of Chemistry and Molecular Engineering Peking University

Lead-halide perovskite nanoparticles（LHP NPs） are highly promising materials for next-generation displays and solid-state lighting due to their exceptional optical properties. However, their inherent instability presents a significant challenge. Recent advances have demonstrated that optoelectronic devices based on monolayer nanoparticle films exhibit both high luminescence efficiency and long-term *** research demonstrates that mobility limitations and anisotropic alignments in CsPbBr3nanocube monolayer films are key to their stabilization, hindering spontaneous growth through face-to-face fusion and resulting in the formation of connecting necks in a diagonal direction. Introducing laser irradiation confirmed this by significantly accelerating nanocubes growth, increasing mobility, and enhancing local structural ordering, leading to larger and more regularly shaped nanosheets. Fourier transform infrared spectroscopy and energy dispersive spectroscopy line-scan analyses indicated that laser irradiation did not disrupt the ligand structure. Transmission electron microscopy and correlative cathodoluminescence electron microscopy revealed the effects of post-growth and heterogeneous structures, including enhanced luminescence and inhomogeneous intensity in the nanosheets. These findings deepen the understanding of the post-growth mechanism of monolayer nanoparticles and the structure-emission correlation and highlight the unique role of laser irradiation in directing the formation of well-defined and regular nanostructures.

关键词： Post-growth mechanism Heterogeneous structure Single-particle spectroscopy Laser irradiation

Mitophagy in acute central nervous system injuries:regulatory mechanisms and therapeutic potentials

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2437-2453页

作者： Siyi Xu Junqiu Jia Rui Mao Xiang cao Yun Xu Department of Neurology Nanjing Drum Tower HospitalClinical College of Jiangsu UniversityNanjingJiangsu ProvinceChina Department of Neurology Nanjing Drum Tower HospitalChinese Academy of Medical Science&Peking Union Medical CollegeNanjingJiangsu ProvinceChina Department of Neurology Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingJiangsu ProvinceChina State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases Nanjing UniversityNanjingJiangsu ProvinceChina Jiangsu Key Laboratory for Molecular Medicine Medical School of Nanjing UniversityNanjingJiangsu ProvinceChina Nanjing Neurology Medical Center NanjingJiangsu ProvinceChina

Acute central nervous system injuries,including ischemic stro ke,intracerebral hemorrhage,subarachnoid hemorrhage,traumatic brain injury,and spinal co rd injury,are a major global health *** optimal therapies and improving the long-term neurological functions of patients with acute central nervous system injuries are urgent *** are susceptible to damage after acute central nervous system injury,and this leads to the release of toxic levels of reactive oxygen species,which induce cell ***,a selective form of autophagy,is crucial in eliminating redundant or damaged mitochondria during these *** evidence has highlighted the significant role of mitophagy in acute central nervous system *** this review,we provide a comprehensive overview of the process,classification,and related mechanisms of *** also highlight the recent developments in research into the role of mitophagy in various acute central nervous system injuries and drug therapies that regulate *** the final section of this review,we emphasize the potential for treating these disorders by focusing on mitophagy and suggest future research paths in this area.

关键词： autophagy intracerebral hemorrhage ischemic stroke mitochondria mitochondrial biogenesis mitochondrial quality control mitophagy spinal cord injury subarachnoid hemorrhage traumatic brain injury

Monitoring disulfide bonds making and breaking in biological nanopore at single molecule level

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2018年第11期61卷 1385-1388页

作者： Bing Zhou Ya-qian Wang Chan cao Da-Wei Li Yi-Tao long Key Laboratory for Advanced Materials School of Chemistry and Molecular Engineering East China University of Science and Technology

Monitoring subtle changes in ionic current flow through a nanopore could be applied to observe single molecule reaction. Here,we introduced cysteine to substitute for lysine at position 238 constructing a mutant aerolysin K238 C. It could be regarded as a nanoreactor to efficiently visualize chemical bonds making and breaking. The compound 5,5′-dithiobis-(2-nitrobenzoic acid)(DTNB) was selected as a reactant coming into collisions on the interface of the pore to occur a reversible reaction. Our results showed that the mutant aerolysin could respond to three molecules of DTNB simultaneously and reflect corresponding levels with distinguishable current signals. Therefore, this method constitutes a simple, generic tool for monitoring single molecule reaction, which evokes a guidance for the mutant aerolysin towards the application of tracking other more reactions at single molecule level.

关键词： disulfide bond chemical bond making and breaking aerolysin nanopore single molecule level

Simulated effects of interactions between ocean acidification,marine organism calcification, and organic carbon export on ocean carbon and oxygen cycles

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2018年第6期61卷 804-822页

作者： Han ZHANG long cao Department of Atmospheric Sciences School of Earth Sciences Zhejiang University

Ocean acidification caused by oceanic uptake of anthropogenic carbon dioxide(CO_2) tends to suppress the calcification of some marine organisms. This reduced calcification then enhances surface ocean alkalinity and increases oceanic CO_2 uptake, a process that is termed calcification feedback. On the other hand, decreased calcification also reduces the export flux of calcium carbonate(Ca CO_3), potentially reducing Ca CO_3-bound organic carbon export flux and CO_2 uptake, a process that is termed ballast feedback. In this study, we incorporate a range of different parameterizations of the links between organic carbon export, calcification, and ocean acidification into an Earth system model, in order to quantify the long-term effects on oceanic CO_2 uptake that result from calcification and ballast feedbacks. We utilize an intensive CO_2 emission scenario to drive the model in which an estimated fossil fuel resource of 5000 Pg C is burnt out over the course of just a few centuries. Simulated results show that, in the absence of both calcification and ballast feedbacks, by year 3500, accumulated oceanic CO_2 uptake is2041 Pg C. Inclusion of calcification feedback alone increases the simulated uptake by 629 Pg C(31%), while the inclusion of both calcification and ballast feedbacks increase simulated uptake by 449–498 Pg C(22–24%), depending on the parameter values used in the ballast feedback scheme. These results indicate that ballast effect counteracts calcification effect in oceanic CO_2 uptake. Ballast effect causes more organic carbon to accumulate and decompose in the upper ocean, which in turn leads to decreased oxygen concentration in the upper ocean and increased oxygen at depths. By year 2600, the inclusion of ballast effect would decrease oxygen concentration by 11% at depth of ca. 200 m in tropics. Our study highlights the potentially critical effects of interactions between ocean acidification, marine organism calcification, and Ca CO3-bound organic carbon

关键词： Ocean carbon cycle Ocean acidification Carbon cycle modeling Carbon cycle-climate feedback

Analysis of chaos behaviors of a bistable piezoelectric cantilever power generation system by the second-order Melnikov function

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2017年第1期33卷 200-207页

作者： Shu Sun Shu-qian cao Department of Mechanics School of Mechanical Engineering Tianjin University Tianjin 300350 China College of Science North China University of Science and Technology Tangshan 063009 China Tianjin Key Laboratory of Nonlinear Dynamics and Chaos Control Tianjin 300350 China

By applying the second order Melnikov function, the chaos behaviors of a bistable piezoelectric cantilever power generation system are analyzed. Firstly, the conditions for emerging chaos of the system are derived by the second order Melnikov function. Secondly, the effects of each item in chaos threshold expression are analyzed. The excitation frequency and resistance values, which have the most influence on chaos threshold value, are found. The result from the second order Melnikov function is more accurate compared with that from the first order Melnikov function. Finally, the attraction basins of large amplitude motions under different exciting frequency, exciting amplitude, and resistance parameters are given.

关键词： Bistable piezoelectric cantilever beam Second order Melnikov function Homoclinic bifurcation Basin of attraction

Opportunistic admission and resource allocation for slicing enhanced IoT networks

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2023年第6期9卷 1465-1476页

作者： long Zhang Bin cao Gang Feng National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengdu611731China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China

Network slicing is envisioned as one of the key techniques to meet the extremely diversified service requirements of the Internet of Things(IoT)as it provides an enhanced user experience and elastic resource *** the context of slicing enhanced IoT networks,both the Service Provider(SP)and Infrastructure Provider(InP)face challenges of ensuring efficient slice construction and high profit in dynamic *** challenges arise from randomly generated and departed slice requests from end-users,uncertain resource availability,and multidimensional resource *** and resource allocation for distinct demands of slice requests are the key issues in addressing these challenges and should be handled effectively in dynamic *** this end,we propose an Opportunistic Admission and Resource allocation(OAR)policy to deal with the issues of random slicing requests,uncertain resource availability,and heterogeneous *** key idea of OAR is to allow the SP to decide whether to accept slice requests immediately or defer them according to the load and price of *** cope with the random slice requests and uncertain resource availability,we formulated this issue as a Markov Decision Process(MDP)to obtain the optimal admission policy,with the aim of maximizing the system ***,the buyer-seller game theory approach was adopted to realize the optimal resource allocation,while motivating each SP and InP to maximize their *** numerical results show that the proposed OAR policy can make reasonable decisions effectively and steadily,and outperforms the baseline schemes in terms of the system reward.

关键词： Slice IoT Markov decision process Game theory Admission and resource allocation