检索结果-南通市图书馆

COP26:Progress,Challenges,and Outlook

Advances in Atmospheric Sciences 2022年第8期39卷 1209-1216页

作者： Yi WANG Yuxuan Liu Baihe GU Institutes of Science and Development Chinese Academy of SciencesBeijing 100190China School of Public Policy and Management University of Chinese Academy of SciencesBeijing 100049China

The 26th Conference of the Parties(COP26)to the United Nations Framework Convention on Climate Change(UNFCCC)was held in Glasgow a year later than scheduled,with expected outcomes achieved under a post-pandemic background.Based on the Issue-Actor-Mechanism Framework,this paper systematically evaluates the outcomes achieved at COP26 and analyzes the tendency of post-COP26 climate negotiations.Overall,with the concerted efforts of all parties,COP26 has achieved a balanced and inclusive package of outcomes and concluded six years of negotiations on the Paris Rulebook.It is fair to say that COP26 is another milestone in climate governance following the implementation of the Paris Agreement.Meanwhile,the Glasgow Climate Pact has cemented the consensus on a global commitment to accelerating climate action over the next decade and reached a breakthrough consensus on reducing coal,controlling methane,and halting deforestation.In the post-COP26 era,we still need to take concrete actions to implement the outcomes of the Paris Agreement and the Glasgow Climate Pact,innovate ways to speed up CO_(2) emissions reduction,and continue to strive for breakthroughs in important issues such as finance,technology,adaptation,and collaboration.In addition to avoiding the escalation of international conflicts,we need to collectively and properly handle the relationship between energy security,carbon reduction,and development and facilitate the efforts of countries to achieve their Sustainable Development Goals(SDGs),including climate-related goals.China will continue to maintain the existing multilateral mechanisms and processes for climate governance,unremittingly take concrete actions to address climate change,promote a domestic comprehensive green transition and global cooperation on carbon neutrality,and contribute constructively to global climate governance.

关键词： COP26 Glasgow climate change Paris Agreement climate governance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Human steering angle estimation in video based on key point detection and Kalman filter

引用

Control Theory and Technology 2022年第3期20卷 408-417页

作者： Yanpeng Hu Yuxuan Liu Yanguang Xu Yinghui Wang School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing100083China KE Holdings Inc. Beijing100085China

Human pose recognition and estimation in video is pervasive.However,the process noise and local occlusion bring great challenge to pose recognition.In this paper,we introduce the Kalman filter into pose recognition to reduce noise and solve local occlusion problem.The core of pose recognition in video is the fast detection of key points and the calculation of human steering angles.Thus,we first build a human key point detection model.Frame skipping is performed based on the Hamming distance of the hash value of every two adjacent frames in video.Noise reduction is performed on key point coordinates with the Kalman filter.To calculate the human steering angle,current state information of key points is predicted using the optimal estimation of key points at the previous time.Then human steering angle can be calculated based on current and previous state information.The improved SENet,NLNet and GCNet modules are integrated into key point detection model for improving accuracy.Tests are also given to illustrate the effectiveness of the proposed algorithm.

关键词： Key point detection Part affinity fields Kalman filter Human steering angle

来源：

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

Achieving Fine-Grained Microstructure and Superior Mechanical Property in a Plain Low-Carbon Steel Using Heavy Cold Rolling Combined with Short-Time Heat Treatment

引用

Acta Metallurgica Sinica(English Letters) 2023年第10期36卷 1719-1734页

作者： Yuxuan Liu Shichang liu Liming Fu Huanrong Wang Wei Wang Mao Wen Aidang Shan School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai200240China Shenyang Research Institute of Foundry Shenyang110022China Baosteel Research Institute Baoshan Iron and Steel Co.Ltd.Shanghai201900China

A new thermomechanical process consisting of heavy cold rolling(HCR)and short-time heat treatment(STH)is developed to fabricate fine-grained martensite microstructure in a low-cost plain low-carbon steel.To achieve the optimal mechanical properties after STH,three different ferrite-pearlite(F-P)dual-phase microstructures are prepared via hot rolling(HR),HR and austenitizing,and HR and HCR.The microstructure evolution and the comprehensive mechanical properties of the alloy during STH are then investigated.We find that the volume fractions of transformed martensite after STH increase with decreasing grain sizes of the pre-STH F-P dual phases.The rapid heating and short-time holding of STH promote grain nucleation and inhibit grain growth,resulting in microstructure refinement.The formation of martensites with different morphologies and different carbon concentrations in the HR and HCR+STH alloy is identified,owing to the inhomogeneous carbon distribution by STH.Tensile experiments demonstrate that STH greatly improves the comprehension mechanical properties of the alloy.Excellent mechanical properties,with a yield strength of 1224 MPa,a tensile strength of 1583 MPa,a uniform elongation of 4.0%and a total elongation of 7.3%are achieved in the HR and HCR+STH alloy.These excellent mechanical properties are principally attributed to the microstructure refinement and martensite formation induced by STH,with a yield strength improvement of 134%and a tensile strength improvement of 150%relative to the HR alloy.

关键词： Heat treatment Microstructure Plain low-carbon steel Mechanical properties

来源：

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

Triboelectric nanogenerators with a constant inherent capacitance design

引用

Nano Research 2023年第3期16卷 4077-4084页

作者： Lanyue Gan Fan Xia Panpan Zhang Xijun Jiang Yuxuan Liu Simiao Niu Youfan Hu Hunan Institute of Advanced Sensing and Information Technology Xiangtan UniversityXiangtan 411102China Key Laboratory for the Physics and Chemistry of Nanodevices Center for Carbon-Based ElectronicsAcademy for Advanced Interdisciplinary StudiesSchool of ElectronicsPeking UniversityBeijing 100871China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Biomedical Engineering Rutgers UniversityPiscatawayNJ 08854USA

Triboelectric nanogenerators(TENGs)utilize the phenomena of contact electrification and electrostatic induction to harvest mechanical energy from the environment.A good match between the motion frequency and the circuit characteristic frequency is critical for the effective power generation of a TENG.However,most TENGs have a time-dependent inherent capacitance(TICTENG),which hinders an optimal design for efficient energy conversion.Here,we propose a novel structure of a TENG with a constant inherent capacitance(CIC-TENG)and a mathematical model is established to provide analytical expressions of key output parameters of the device,which gives numerical simulation results that are in good agreement with the experimentally obtained results.Figures of merit and an optimization strategy are also given as guidelines for the optimization of material selection,geometry design,etc.Furthermore,a disk-formed CIC-TENG(DCIC-TENG)with polarity-switched triboelectric pairs is constructed to harvest unidirectional mechanical energy continuously,achieving an output power density of 55 mW/m^(2).The effects of the motion frequency,the number of electrodes and triboelectric pairs on the charge transfer efficiency of the DCICTENG are assessed and a preferred design strategy is given.Finally,the CIC-TENG demonstrates approximately two-fold advantages in power transfer efficiency over the TIC-TENG,and a DCIC-TENG-based self-powered anemometer was fabricated to measure wind speed in real time.

关键词： triboelectric nanogenerator inherent capacitance output power linearity

来源：

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

Transient spectral and dynamic properties of magic-size Cd_(3)P_(2) nanoclusters in the limit of strong confinement

引用

Science China Chemistry 2023年第12期66卷 3628-3635页

作者： Yuan liu yuxuan Li Yupeng Yang Jingyi Zhu Kaifeng Wu Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

Both semiconductor nanocrystals and organic molecules are important photofunctional materials for an array of applications.It is interesting to examine the intermediate regime between these two families,which can be interpreted as the strong-confinement limit of the nanocrystals or alternatively as the large-size limit of molecules.Here,we choose Cd_(3)P_(2) magic-size clusters(MSCs)as a unique platform and apply time-resolved spectroscopy to investigate their spectral and dynamic properties.We find that these small clusters display molecular-like vibronic progression on their absorption and emission spectra and a large Stokes shift,which leads to well-separated transient absorption bleach and stimulated emission signals distinct from typical nanocrystals.On the other hand,such small size MSCs can still accommodate biexciton states,and the strongly enhanced Coulombic interactions lead to very fast dephasing of the biexciton resonance as well as rapid biexciton Auger annihilation(1.5 ps).Further,temperature-dependent measurements provide evidence for the transformation of band-edge excitons to localized excitons,with the localization likely driven by the softened lattice in these small-size clusters.These collective results demonstrate that strongly-confined nanoclusters indeed bridge the gap between nanocrystals and molecules,and can be a unique library to search for exotic excited state properties.

关键词： time-resolved spectroscopy magic-size clusters quantum confinement excited-state dynamics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Face stability analysis of large shield-driven tunnel in rock-soil interface composite formations

引用

Underground Space 2022年第6期7卷 1021-1035页

作者： Xiaobin Ding Kang Li yuxuan Xie Shuzhuo liu School of Civil Engineering and Transportation South China University of TechnologyGuangzhou 510641China Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology South China Institute of Geotechnical EngineeringGuangzhou 510650China

A new 3D log-spiral model(LS-M model)is proposed to determine the minimal support pressure on the tunnel face of a large shielddriven tunnel in rock-soil interface(RSI)composite formations.In the proposed LS-M model,we define the RSI angle ω and use a new approach to calculate the equivalent tunnel face area,which provides a collapse zone with more realistic geometry than the traditional wedge model.And it has acceptable accuracy with simpler implementation than limit equilibrium analysis.Comparing with previous studies and 3D numerical analysis,it indicates that:(i)the LS-M results agree well with others in full-soil formations on the variation patterns of minimum support pressure and stability coefficients N_(c) and N_(γ);(ii)the critical RSI angle ω_(cr),which is predominantly influenced by soil cohesion,increases with the soil property values;(iii)the limit support pressure starts to increase with ω only when ω>ω_(cr);(iv)the peak support pressure occurs at lower C/D with a lower ω;(v)ω can only affect stability coefficients N_(c) and N_(γ) when ω and the friction angle are relatively small,while N_(s) is substantially influenced by RSI angle ω.

关键词： Tunnel Stability Limit support pressure RSI composite formations 3D failure mechanism

来源：

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

Vinyl Groups Containing Tetraphenylethylene Derivatives as Fluorescent Probes Specific for Palladium and the Quenching Mechanism

引用

Chinese Journal of Chemistry 2021年第6期39卷 1599-1605页

作者： Xiaoqing liu yuxuan Shang Zhong-Ren Chen Shenzhen Grubbs Institute and Department of Chemistry Southern University of Science and TechnologyShenzhenGuangdong 518005China Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhenGuangdong 518055China

We previously reported that a series of tetraphenylethylene(TPE)-containing all-hydrocarbon conjugated polymers exhibited a specific fluorescence quenching by palladium ions(Pd^(2+)).To understand the quenching mechanism,herein we investigate the quenching behaviors of three TPE derivatives in the presence of Pd^(2+).Each TPE derivative,consisting of TPE unit and terminal vinyl groups,shows an aggregation-induced emission(AIE)and its fluorescence turns off specifically to Pd^(2+).The sensitivity is enhanced with increasing numbers of vinyl groups in the molecules.By time-resolved fluorescence measurement,a dynamic quenching is observed where the fluorescence lifetime is reduced with Pd^(2+).Specifically,the quenching occurs via the electron transfer in the excited states,as suggested by the disappearance of the stimulated emission band in transient absorption spectra.A theoretical calculation on the excited states identifies intermolecular electron transfer from TPE derivatives to Pd,especially for electron-rich TPE derivative.The mechanism can be general for the design of novel AIE active chemosensors.

关键词： Aggregation-induced emission Fluorescent probes Palladium detection Electron transfer Time-resolved spectroscopy

来源：

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

Engineering SIRPα cellular membrane-based nanovesicles for combination immunotherapy

引用

Nano Research 2023年第5期16卷 7355-7363页

作者： Mingyue Wang Yanfang Wang Yeteng Mu Fuxu Yang Zebin Yang Yuxuan Liu Lili Huang Shi liu Xingang Guan Zhigang Xie Zhen Gu School of Medicine Taizhou UniversityTaizhou 318000China College of Medical Technology Beihua UniversityJilin 132013China Key Laboratory of Advanced Drug Delivery Systems of Zhejiang Province College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China Jinhua Institute of Zhejiang University Jinhua 321299China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of General Surgery Sir Run Run Shaw HospitalSchool of MedicineZhejiang UniversityHangzhou 310016China Zhejiang Laboratory of Systems&Precision Medicine Zhejiang University Medical CenterHangzhou 311121China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Immune checkpoint inhibitors(ICIs)have revolutionized cancer treatment for their unprecedented clinical efficacy.Signal regulatory proteinα(SIRPα)is a phagocytic checkpoint expressed on macrophages,dendritic cells,other myeloid cells.Cancer cells inhibit macrophage phagocytosis through the interaction of the CD47-SIRPαaxis.Disrupting the CD47-SIRPαaxis has therefore been a promising strategy in restoring the immune attack against cancer.Herein,we engineered cellular membrane nanovesicles(NVs)presenting SIRPαreceptors for phagocytosis checkpoint blockade to augment the antitumor immune response.Furthermore,zebularine(Zeb),an inhibitor of DNA methyltransferase,was encapsulated into SIRPαNVs to reprogram the immunosuppressive tumor microenvironment together with blockade of phagocytosis checkpoint.It is demonstrated that SIRPα@Zeb can improve tumor immunogenicity,the polarization of tumor-associated macrophages to the M1 phenotype,increase the infiltration of CD8^(+)T lymphocytes in tumors.The robust antitumor immune response induced by SIRPα@Zeb significantly suppressed tumor growth and extended mice-bearing melanoma xenograft survival.

关键词： drug delivery signal regulatory proteinα nanovesicle tumor-associated macrophages cancer immunotherapy

来源：

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

Fintech, Macroprudential Supervision and Systematic Risk in China’s Banks

引用

China Finance and Economic Review 2022年第4期11卷 110-129页

作者： Daoping Wang Yangjingzhuo liu yuxuan Xu Linlin liu School of Finance Nankai University School of Economics Peking University

In recent years,the rapid development of fi ntech has brought far-reaching changes to the fi nancial sector.At the same time,fi ntech may cause potential systemic risk in the fi nancial sector,which has aroused special concerns from fi nancial regulatory authorities.Based on the micro data of China’s listed banks from 2013 to 2020,this paper analyzes the impact of fi ntech development on systemic risk in China’s banking industry and its mechanism.It reveals that for a micro bank,fintech progress increases its risk-taking and enhances inter-bank linkages,which results in signifi cantly amplifi ed systemic risk,and the impact is time-lagged and persistent.In addition,the heterogeneity analysis shows that the impacts of fi ntech on state-owned banks and other banks are heterogeneous and the margining risk of state-owned banks is lower when the fi ntech improves.It is also found that enhancing macroprudential supervision can reduce the systemic risk spillover of fintech.Robustness analyses including GMM regression and the method of instrumental variables prove that the conclusion is robust.This paper is of theoretical and policy signifi cance for the prevention of systemic risk in the banking industry as China develops fi ntech.

关键词： fi ntech macroprudential supervision systemic risk

来源：

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

Complementary-Label Adversarial Domain Adaptation Fault Diagnosis Network under Time-Varying Rotational Speed andWeakly-Supervised Conditions

引用

Computers, Materials & Continua 2024年第4期79卷 761-777页

作者： Siyuan liu Jinying Huang Jiancheng Ma Licheng Jing yuxuan Wang School of Data Science and Technology North University of ChinaTaiyuan030051China School of Mechanical Engineering North University of ChinaTaiyuan030051China

Recent research in cross-domain intelligence fault diagnosis of machinery still has some problems,such as relatively ideal speed conditions and sample conditions.In engineering practice,the rotational speed of the machine is often transient and time-varying,which makes the sample annotation increasingly expensive.Meanwhile,the number of samples collected from different health states is often unbalanced.To deal with the above challenges,a complementary-label(CL)adversarial domain adaptation fault diagnosis network(CLADAN)is proposed under time-varying rotational speed and weakly-supervised conditions.In the weakly supervised learning condition,machine prior information is used for sample annotation via cost-friendly complementary label learning.A diagnosticmodel learning strategywith discretized category probabilities is designed to avoidmulti-peak distribution of prediction results.In adversarial training process,we developed virtual adversarial regularization(VAR)strategy,which further enhances the robustness of the model by adding adversarial perturbations in the target domain.Comparative experiments on two case studies validated the superior performance of the proposed method.

关键词： Time-varying rotational speed weakly-supervised fault diagnosis domain adaptation

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：