检索结果-南通市图书馆

Achieving a remarkable low-temperature tensile ductility in a high-strength tungsten alloy

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

Tungsten 2024年第1期6卷 150-161页

作者： xiang Cheng Zhuo-Ming Xie Xue-feng Xie Long-Fei zeng Rui Liu Jun-feng Yang Xue-Bang Wu Xian-Ping Wang Chang-Song Liu Qiang-feng Fang Key Laboratory of Materials Physics Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou 341000China

Hot-swaging yields a high ultimate tensile strength of 712 MPa but a limited tensile ductility with the total elongation of3.6%at a testing temperature of 200℃in a representative W-0.5wt.%ZrC alloy.In this work,the evolution of Vickers microhardness with annealing temperatures is investigated in detail,which contributes to a rough index chart to guide the search for an optimized post-annealing temperature.Through the post-annealing around 1300℃,an outstanding tensile ductility at200℃,including a uniform elongation of 14%and a total elongation of~25%,has been achieved without the sacrifice of its strength.The evolution of dislocations and grain structures with the annealing temperatures accessed through backscattered scanning electron microscope and transmission electron microscope analysis reveals that the improved low-temperature tensile ductility has resulted from the reduction of residual dislocations and dislocation tanglement via the static recovery,which provides more room to accommodate dislocations,and hence stronger strain hardening ability and tensile ductility.

关键词： Tungsten Low-temperature ductility Annealing Dislocations

Control of defensive behavior by the nucleus of Darkschewitsch GABAergic neurons

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第4期11卷 70-83页

作者： Huiying Zhao Jinrong Liu Yujin Shao xiang feng Binhan Zhao Li Sun Yijun Liu Linghui zeng Xiao-ming Li Hongbin Yang Shumin Duan Yan-qin Yu Department of Neurology of Second Affiliated Hospital and School of Brain Science and Brain Medicine Zhejiang University School of Medicine Nanhu Brain-Computer Interface Institute Liangzhu Laboratory MOE Frontier Science Center for Brain Science and Brain-Machine Integration State Key Laboratory of Brain-Machine Intelligence Zhejiang University NHC and CAMS Key Laboratory of Medical Neurobiology Zhejiang University Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province School of Medicine Hangzhou City University

The nucleus of Darkschewitsch(ND), mainly composed of GABAergic neurons, is widely recognized as a component of the eye-movement controlling system. However, the functional contribution of ND GABAergic neurons(NDGABA) in animal behavior is largely unknown. Here, we show that NDGABA neurons were selectively activated by different types of fear stimuli, such as predator odor and foot shock.Optogenetic and chemogenetic manipulations revealed that NDGABA neurons mediate freezing behavior.Moreover, using circuit-based optogenetic and neuroanatomical tracing methods, we identified an excitatory pathway from the lateral periaqueductal gray(l PAG) to the ND that induces freezing by exciting ND inhibitory outputs to the motor-related gigantocellular reticular nucleus, ventral part(Gi V). Together,these findings indicate the NDGABA population as a novel hub for controlling defensive response by relaying fearful information from the l PAG to Gi V, a mechanism critical for understanding how the freezing behavior is encoded in the mammalian brain.

关键词： nucleus of Darkschewitsch GABAergic population defensive behavior freezing neural circuitry

Grain size effect on the assembly quality of micro-scaled barrel formed by microforming

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第1期12卷 19-32页

作者： Dien Hu Jieyichen Fang feng zeng Ming-Wang Fu Department of Mechanical Engineering Research Institute of Advanced ManufacturingThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongPeople’s Republic of China Xiamen Yulong Machinery Co.Ltd. Xiamen361023FujianPeople’s Republic of China

In this research,a method employing micro-extrusion was designed to produce the micro-scaled barrel-shaped parts with complex geometrical features to study the feasibility of the proposed microforming method and its grain size effect on the formability of the complicated internal features in terms of deformation behavior,material evolution,accuracy of dimensions and final components quality.The results reveal that the deformation behavior is highly affected by grain size and becomes unpredictable with increased grain size.In addition,assembly parameters including feature dimension,tolerance and coaxiality also vary with grain size,and the variation of grain size needs to be accommodated by different assembly types,viz.,clearance fit or transition fit.From the microstructural evolution aspect,it was identified there were two dead zones and four shear bands,and the formation of these deformation zones was barely affected by the variation in grain size.Though bulges,cracks,and fracture induced voids were observed on the surface of the final components,tailoring the microstructure of the working material with finer grains could significantly avoid these defects.This study advances the understanding of forming microparts by extrusion processes and provides guidance for microforming of similar microparts.

关键词： Microformed part Size effect Extrusion Microstructural evolution Dimensions Assembly accuracy

Geochemical fractionation and potential release behaviour of heavy metals in lead–zinc smelting soils

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 Environmental Sciences 2024年第5期139卷 1-11页

作者： Xinghua Luo Chao xiang Chuan Wu Wenyan Gao Wenshun Ke Jiaqing zeng Waichin Li Shengguo Xue School of Metallurgy and Environment Central South UniversityChangsha 410083China Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution Central South UniversityChangsha 410083China Department of Science and Environmental Studies The Education University of Hong KongHong Kong 999077China

The lack of understanding of heavy metal speciation and solubility control mechanisms in smelting soils limits the effective pollution control.In this study smelting soils were investigated by an advanced mineralogical analysis(AMICS),leaching tests and thermodynamic modelling.The aims were to identify the partitioning and release behaviour of Pb,Zn,Cd and As.The integration of multiple techniques was necessary and displayed coherent results.In addition to the residual fraction,Pb and Zn were predominantly associated with reducible fractions,and As primarily existed as the crystalline iron oxide-bound fractions.AMICS quantitative analysis further confirmed that Fe oxyhydroxides were the common dominant phase for As,Cd,Pb and Zn.In addition,a metal arsenate(paulmooreite)was an important mineral host for Pb and As.The pH-stat leaching indicted that the release of Pb,Zn and Cd increased towards low pH values while release of As increased towards high p H values.The separate leaching schemes were associated with the geochemical behaviour under the control of minerals and were confirmed by thermodynamic modelling.PHREEQC calculations suggested that the formation of arsenate minerals(schultenite,mimetite and koritnigite)and the binding to Fe oxyhydroxides synchronously controlled the release of Pb,Zn,Cd and As.Our results emphasized the governing role of Fe oxyhydroxides and secondary insoluble minerals in natural attenuation of heavy metals,which provides a novelty strategy for the stabilization of multi-metals in smelting sites.

关键词： Smelting soils Heavy metal Fractionation AMICS Geochemical modelling

Multi-UAVs Collaborative Path Planning in the Cramped Environment

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 529-538页

作者： Siyuan feng Linzhi zeng Jining Liu Yi Yang Wenjie Song School of Automation Beijing Institute of TechnologyNanjing 210039China Nanjing Research Institute of Electronics Technology Nanjing 210039China Yichang Testing Technique Research Institute Yichang 443003China IEEE

Due to its flexibility and complementarity, the multiUAVs system is well adapted to complex and cramped workspaces, with great application potential in the search and rescue(SAR) and indoor goods delivery fields. However, safe and effective path planning of multiple unmanned aerial vehicles(UAVs)in the cramped environment is always challenging: conflicts with each other are frequent because of high-density flight paths, collision probability increases because of space constraints, and the search space increases significantly, including time scale, 3D scale and model scale. Thus, this paper proposes a hierarchical collaborative planning framework with a conflict avoidance module at the high level and a path generation module at the low level. The enhanced conflict-base search(ECBS) in our framework is improved to handle the conflicts in the global path planning and avoid the occurrence of local deadlock. And both the collision and kinematic models of UAVs are considered to improve path smoothness and flight safety. Moreover, we specifically designed and published the cramped environment test set containing various unique obstacles to evaluating our framework performance thoroughly. Experiments are carried out relying on Rviz, with multiple flight missions: random, opposite, and staggered, which showed that the proposed method can generate smooth cooperative paths without conflict for at least 60 UAVs in a few minutes.The benchmark and source code are released in https://***/inin-xingtian/multi-UAVs-path-planner.

关键词： Collision avoidance conflict resolution multi-unmanned aerial vehicles(UAVs)system path planning

A folic acid-decorated nanoparticles loaded JQ1 for oral squamous cell carcinoma therapy

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第3期35卷 332-336页

作者： Dequan zeng Zhongkai Ma Xin Zan Ting Luo xiang Wang xiang Gao xianghui Fu School of Health Management Xihua UniversityChengdu 610039China State Key Laboratory of Oral Diseases National Clinical Research Center for Oral DiseasesWest China College of StomatologySichuan UniversityChengdu 610041China Department of Neurosurgery and Institute of Neurosurgery State Key Laboratory of Biotherapy and Cancer CenterWest China HospitalWest China Medical SchoolSichuan University and Collaborative Innovation Center for BiotherapyChengdu 610041China Breast Disease Center Cancer CenterWest China HospitalSichuan UniversityChengdu 610041China

Oral squamous cell carcinoma(OSCC)is known as one of the most malignant tumors with high recurrence and fatality rate.The poor tumor-targeting ability of traditional chemotherapeutic drugs has been a grand challenge for anti-OSCC therapy.Beyond that,a large quantity of tumor associated macrophages in OSCC tissues further diminish the anti-tumor effects of these drugs.Therefore,we produced a therapeutic nano drug delivery system(FA-PEG-PLA-JQ1)through encapsulating JQ1[a small-molecule inhibitor of bromodomain containing protein 4(BRD4)]into the folic acid(FA)-modified nanoparticle(PEG-PLA),which could prolong the half-life of JQ1 and target the tumor tissues.And then,JQ1 released from this nanoparticle could prevent OSCC growth inducing tumor cell apoptosis,inhibiting tumor angiogenesis and the polarization of M2 type macrophages.In conclusion,our date demonstrated the therapeutic benefits of FA-PEG-PLA-JQ1 against OSCC in vivo or in vitro,which could be a novel treatment strategy for OSCC in coming days.

关键词： Folic acid Nanoparticles JQ1 Oral squamous cell carcinoma Macrophages

Data-driven Anomaly Detection Method Based on Similarities of Multiple Wind Turbines

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 803-818页

作者： xiangjun zeng Ming Yang Chen feng Mingqiang Wang Lingqin Xia the College of Electrical Engineering & New Energy China Three Gorges University the Key Laboratory of Power System Intelligent Dispatch and Control Shandong University

The operating conditions of wind turbines(WTs) in the same wind farm(WF) may share similarities due to their shared manufacturing process, control strategy, and operating environment. However, the similarities of WTs are seldom considered in WT anomaly detection, resulting in the disregard of useful information. This paper proposes a method to improve the reliability and accuracy of WT anomaly detection using the supervisory control and data acquisition(SCADA) data of multiple WTs in the same WF. First, a similarity assessment method based on a comparison of different observation time series is proposed, which objectively quantifies the similarities of WT operating conditions. Then, the SCADA data of the target WT and selected WTs that are similar are used to establish several estimation models through a long short-term memory(LSTM) algorithm. LSTM models that exhibit good estimation performance are used to construct a combined estimation model that estimates the variations in the monitored variables of the target WT. Finally, an anomaly detection method that jointly compares the effective value and information entropy of the residuals is proposed to identify anomalies. The effectiveness and accuracy of the proposed method are verified using the data of two actual WFs.

关键词： Estimation Anomaly detection Data models Fault detection Time series analysis Training data Signal processing algorithms

Comparative observation of the effectiveness and safety of remimazolam besylate versus dexmedetomidine in gastrointestinal surgery in obese patients

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第5期16卷 1320-1327页

作者： Yu-Fu Deng Xue-Run Jiang zeng-Guang feng Department of Anesthesiology Xiangtan Central HospitalXiangtan 411100Hunan ProvinceChina

BACKGROUND Surgery for obese patients carries a higher risk of anesthesia complications compared with surgery for nonobese patients.Thus,a safe and effective anesthesia strategy is necessary to improve the medical experience of such patients and ensure their safety.AIM To compared the effectiveness and safety of remimazolam besylate versus dexmedetomidine(DEX)in gastrointestinal surgery in obese patients.METHODS The study cohort included 60 obese patients undergoing gastrointestinal surgery between July 2021 and April 2023,comprising 30 patients who received DEX intervention(control group)and 30 patients who received remimazolam besylate intervention(research group).Heart rate(HR),respiratory rate(RR),mean arterial pressure(MAP),blood oxygen saturation(SpO_(2)),safety(nausea and vomiting,bradycardia,hypotension,and apnea),anesthesia and examination indices[induction time,anesthesia recovery time,and postanesthesia care unit(PACU)discharge time],sedation effect(Ramsay Sedation Scale),and postoperative pain visual analog scale were comparatively analyzed before anesthesia(T0),during anesthesia(T1),and after anesthesia(T2).RESULTS At T1,the research group showed significantly smaller changes in HR,RR,MAP,and SpO_(2) than the control group,with a significantly lower adverse reaction rate and shorter induction,anesthesia recovery,and PACU discharge times.Additionally,the intra-and postoperative Ramsay Sedation Scale scores were statistically higher in the research group than in the control group.CONCLUSION Remimazolam besylate was significantly more effective than DEX in gastrointestinal surgery in obese patients and had a higher safety profile and value in clinical promotion.

关键词： Remimazolam besylate Dexmedetomidine Obesity Gastrointestinal surgery Effectiveness Safety

Cr-catalyzed allylic C(sp^(3))–H addition to aldehydes enabled by photoinduced ligand-to-metal charge transfer

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 Chemistry 2024年第5期67卷 1589-1595页

作者： Xianrong zeng feng-Hua Zhang Runchen Lai Xiaoyu Lin Zhaobin Wang Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Department of ChemistrySchool of Science and Research Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Instrumentation and Service Center for Molecular SciencesWestlake UniversityHangzhou 310024China

Photoinduced ligand-to-metal charge transfer(LMCT) has emerged as an effective strategy for synthesizing organic molecules in a sustainable manner. However, the majority of existing reports on selective C(sp^(3))–H bond functionalization via photoinduced LMCT focus on the use of late transition metals or rare-earth metals for radical additions or cross-couplings. In contrast, the utilization of photoinduced LMCT with 3d early transition metals poses a significant challenge. Herein, we describe an unprecedented approach to allylic C(sp^(3))–H addition to aldehydes, employing chromium(Cr) complexes as catalysts through visible-light-induced LMCT. By investigating the reaction pathway through various mechanistic studies, including radical trapping, kinetic isotope effect(KIE) analysis, and transient absorption spectroscopy, valuable insights have been gained. The proposed mechanism suggests the intermediacy of bromine radicals through homolysis of the Cr–Br bond. Notably, this protocol expands our understanding of the photochemical properties of earth-abundant Cr complexes.

关键词： Cr catalysis photoinduced ligand-to-metal charge transfer hydrogen-atom transfer carbonyl addition