检索结果-南通市图书馆

Frontiers of Chemical Science and Engineering 2024年第5期18卷 95-103页

作者： Jianxia Gu ying Zhu Haiyan zheng Chunyi Sun Zhongmin Su Department of Chemistry Xinzhou Normal UniversityXinzhou 034000China School of Chemistry Northeast Normal UniversityChangchun 130024China

A novel,cheap and highly efficient Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C nanocomposite has been successfully constructed through simple one-step carbonization method in a nitrogen *** in the precursor can effectively anchor molybdenum-based Keggin-type polyoxometallate and NiCo-layered double hydroxide through electrostatic and coordination interactions,which avoids the aggregation of catalyst particles during the pyrolysis *** optimization,the obtained Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C possesses small size(3-8 nm),large specific surface area and hierarchical pore *** importantly,Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C presents remarkable hydrogen evolution reaction activity with low overpotentials in 0.5 mol·L^(-1)H_(2)SO_(4)(102.3 mV)and 1 mol·L^(-1)KOH(95 mV)to afford the current density of 10 mA·cm^(-2),as well as small Tafel slopes of 82.49 and 99.92 mV·dec^(-1),***,this catalyst also shows outstanding stability for 12 h without a significant change in current *** excellent catalytic performance of Ni-Co/Mo_(2)C/Co_(6)Mo_(6)C_(2)@C can put down to the synergistic effect between multiple components and the small size of the *** work provides unique insights into the preparation of efficient transition metal-based catalysts for HER.

关键词： polyoxometallates layered double hydroxide transition metal-based electrocatalysts hydrogen evolution reaction

A Weakly-Supervised Crowd Density Estimation Method Based on Two-Stage Linear Feature Calibration

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

IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 965-981页

作者： Yong-Chao Li Rui-Sheng Jia ying-Xiang Hu Hong-mei Sun the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590 the Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266000China the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590China the College of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210000China

In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation *** this paper,we aim to reduce the annotation cost of crowd datasets,and propose a crowd density estimation method based on weakly-supervised learning,in the absence of crowd position supervision information,which directly reduces the number of crowds by using the number of pedestrians in the image as the supervised *** this purpose,we design a new training method,which exploits the correlation between global and local image features by incremental learning to train the ***,we design a parent-child network(PC-Net)focusing on the global and local image respectively,and propose a linear feature calibration structure to train the PC-Net simultaneously,and the child network learns feature transfer factors and feature bias weights,and uses the transfer factors and bias weights to linearly feature calibrate the features extracted from the Parent network,to improve the convergence of the network by using local features hidden in the crowd *** addition,we use the pyramid vision transformer as the backbone of the PC-Net to extract crowd features at different levels,and design a global-local feature loss function(L2).We combine it with a crowd counting loss(LC)to enhance the sensitivity of the network to crowd features during the training process,which effectively improves the accuracy of crowd density *** experimental results show that the PC-Net significantly reduces the gap between fullysupervised and weakly-supervised crowd density estimation,and outperforms the comparison methods on five datasets of Shanghai Tech Part A,ShanghaiTech Part B,UCF_CC_50,UCF_QNRF and JHU-CROWD++.

关键词： Crowd density estimation linear feature calibration vision transformer weakly-supervision learning

Preparation and characterization of Rb-doped TiO_(2) powders for photocatalytic applications

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第2期43卷 555-561页

作者： Lu Jia Li-mei Yang Wei Wang Song-Tao Huang zheng Xu National Engineering Laboratory of Biohydrometallurgy General Research Institute for Nonferrous MetalsBeijing100088China

TiO_(2)nanoparticles doped with different concentrations of Rb were prepared by sol–gel *** crystal structures of samples were characterized by X-ray diffraction(XRD)and transmission electron microscopy(TEM).It was confirmed by the Rietveld refinement method that the as-prepared samples crystallize in anatase phase and Rb doping induces expansion and distortion of the crystal *** with the pure TiO_(2),the Rb-doped nanoparticles have smaller crystal size and better *** rate of methylene blue was used to evaluate the photocatalytic activity of Rb–TiO_(2).It indicated that doping Rb into TiO_(2)can effectively improve the photocatalytic activity of TiO_(2)and the mechanisms were discussed in *** using the sample doped with 0.20%Rb,methylene blue degraded with the fastest rate(97%within 60 min).

关键词： Rb doping TiO_(2) Photocatalysis Sol-gel

Mesenchymal stem cells and their derived exosomes for the treatment of COVID-19

在线全文

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2024年第4期16卷 353-374页

作者： Xiang-Yi Hou La-Mu Danzeng Yi-Lin Wu Qian-Hui Ma zheng Yu mei-ying Li Li-Sha Li The Key Laboratory of Pathobiology Ministry of EducationCollege of Basic Medical SciencesJilin UniversityChangchun 130021Jilin ProvinceChina Department of Pharmacy Jilin UniversityChangchun 130021Jilin ProvinceChina The First Hospital of Jilin University Jilin UniversityChangchun 130021Jilin ProvinceChina

Coronavirus disease 2019(COVID-19)is an acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).SARS-CoV-2 infection typically presents with fever and respiratory symptoms,which can progress to severe respiratory distress syndrome and multiple organ *** severe cases,these complications may even lead to *** of the causes of COVID-19 deaths is the cytokine storm caused by an overactive immune ***,suppressing the overactive immune response may be an effective strategy for treating *** stem cells(MSCs)and their derived exosomes(MSCs-Exo)have potent homing abilities,immunomodulatory functions,regenerative repair,and antifibrotic effects,promising an effective tool in treating *** this paper,we review the main mechanisms and potential roles of MSCs and MSCs-Exo in treating *** also summarize relevant recent clinical trials,including the source of cells,the dosage and the efficacy,and the clinical value and problems in this field,providing more theoretical references for the clinical use of MSCs and MSCs-Exo in the treatment of COVID-19.

关键词： COVID-19 Cytokine storm Immunomodulation Mesenchymal stem cell Mesenchymal stem cell-derived exosomes

Multi-electron reaction and fast Al ion diffusion of δ-MnO_(2) cathode materials in rechargeable aluminum batteries via first-principle calculations

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 Chemical Letters 2024年第4期35卷 248-254页

作者： Lumin zheng ying Bai Chuan Wu School of Materials Science&Engineering Beijing Institute of TechnologyBeijing 100081China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing 314019China

Rechargeable aluminum batteries with multi-electron reaction have a high theoretical capacity for next generation of energy storage devices. However, the diffusion mechanism and intrinsic property of Al insertion into MnO_(2) are not clear. Hence, based on the first-principles calculations, key influencing factors of slow Al-ions diffusion are narrow pathways, unstable Al-O bonds and Mn^(3+) type polaron have been identified by investigating four types of δ-MnO_(2)(O3, O'3, P2 and T1). Although Al insert into δ-MnO_(2) leads to a decrease in the spacing of the Mn-Mn layer, P2 type MnO_(2) keeps the long(spacious pathways)and stable(2.007–2.030 A) Al-O bonds resulting in the lower energy barrier of Al diffusion of 0.56 e V. By eliminated the influence of Mn^(3+)(low concentration of Al insertion), the energy barrier of Al migration achieves 0.19 e V in P2 type, confirming the obviously effect of Mn^(3+) polaron. On the contrary, although the T1 type MnO_(2) has the sluggish of Al-ions diffusion, the larger interlayer spacing of Mn-Mn layer,causing by H_(2)O could assist Al-ions diffusion. Furthermore, it is worth to notice that the multilayer δ-MnO_(2) achieves multi-electron reaction of 3|e|. Considering the requirement of high energy density, the average voltage of P2(1.76 V) is not an obstacle for application as cathode in RABs. These discover suggest that layered MnO_(2) should keep more P2-type structure in the synthesis of materials and increase the interlayer spacing of Mn-Mn layer for providing technical support of RABs in large-scale energy storage.

关键词： Rechargeable aluminum batteries δ-MnO_(2) First-principles calculations Multi-electron reaction Diffusion mechanism

New species of spongillafly genus Sisyra Burmeister,1839(Neuroptera:Sisyridae)from China and Laos

在线全文

学校读者我要写书评

暂无评论

Zoological Systematics 2024年第2期49卷 129-142页

作者： ying Yang Yuchen zheng Xingyue Liu Department of Entomology China Agricultural UniversityBeijing 100193China

Three new spongillafly species of Sisyra Burmeister,1839 from southern China and Laos are described,namely *** ***.,*** ***.,and *** ***,*** *** *** *** remarkable forewing marking pattern,which has never been reported in ***,the male of the rare species Sisyra yunana Yang,1986 is described for the first *** these Sisyra species have a highly specialized male gonocoxites 9.

关键词： Aquatic insects Neuropterida taxonomy

Nonreciprocal generation of Schrodinger cat state induced by topology

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 23-30页

作者： Zi-Hao Li Li-Li zheng ying Wu Xin-You Lü School of Physics and Institute for Quantum Science and Engineering Huazhong University of Science and Technologyand Wuhan Institute of Quantum TechnologyWuhan 430074China Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education Jianghan UniversityWuhan 430074China

The Schrodinger cat state produced differently in two directions is anticipated to be a critical quantum resource in quantum information *** exploring the interplay between quantum nonreciprocity and topology in a one-dimensional microcavity array,we obtain the Schrodinger cat state(a pure quantum state)in a chosen direction at the edge cavity,whereas a classical state in the other *** nonreciprocal generation of the cat state originates from the topologically protected chiralitymode excitation in the nontrivial phase,but in the trivial phase,the nonreciprocal generation of cat state ***,our proposal is switchable by tuning the parameters so that a topological phase transition ***,the obtained cat state has nonreciprocal high fidelity,nonclassicality,and quantum coherence,which are sufficient to be used in various one-way quantum technologies,e.g.,invisible quantum sensing,noise-tolerant quantum computing,and chiral quantum *** work provides a general approach to control quantum nonreciprocities with the topological effect,which substantially broadens the fields of nonreciprocal photonics and topological physics.

关键词： Schr?dinger cat state nonreciprocity topology

Evaluation of the effects of health education interventions for hypertensive patients based on the health belief model

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第15期12卷 2578-2585页

作者： Hong-mei Wang ying Chen Yan-Hua Shen Xiao-mei Wang Department of Emergency Lishui Second People's HospitalLishui 323000Zhejiang ProvinceChina Department of Pancreatic and Biliary Surgery The First Affiliated Hospital of China Medical UniversityShenyang 110002Liaoning ProvinceChina

BACKGROUND Hypertension is a major risk factor for cardiovascular disease and stroke,and its prevalence is increasing *** education interventions based on the health belief model(HBM)can improve the knowledge,attitudes,and behaviors of patients with hypertension and help them control their blood *** To evaluate the effects of health education interventions based on the HBM in patients with hypertension in *** Between 2021 and 2023,140 patients with hypertension were randomly assigned to either the intervention or control *** intervention group received health education based on the HBM,including lectures,brochures,videos,and counseling sessions,whereas the control group received routine *** were measured at baseline,three months,and six months after the intervention and included blood pressure,medication adherence,self-efficacy,and perceived benefits,barriers,susceptibility,and *** The intervention group had significantly lower systolic blood pressure[mean difference(MD):-8.2 mmHg,P<0.001]and diastolic blood pressure(MD:-5.1 mmHg,P=0.002)compared to the control group at six *** intervention group also had higher medication adherence(MD:1.8,P<0.001),self-efficacy(MD:12.4,P<0.001),perceived benefits(MD:3.2,P<0.001),lower perceived barriers(MD:-2.6,P=0.001),higher perceived susceptibility(MD:2.8,P=0.002),and higher perceived severity(MD:3.1,P<0.001)than the control group at six *** Health education interventions based on the HBM effectively improve blood pressure control and health beliefs in patients with hypertension and should be implemented in clinical practice and community settings.

关键词： Hypertension Health education Health belief model Blood pressure control Randomized controlled trial

Development of Fixture Layout Optimization for Thin-Walled Parts:A Review

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 Mechanical Engineering 2024年第1期37卷 15-39页

作者： Changhui Liu Jing Wang Binghai Zhou Jianbo Yu ying zheng Jianfeng Liu School of Mechanical Engineering Tongji UniversityShanghai 201804China Shanghai Jiaotong University Shanghai 200240China Shanghai Waigaoqiao Shipbuilding Co. Ltd.Shanghai 200137China

An increasing number of researchers have researched fixture layout optimization for thin-walled part assembly during the past ***,few papers systematically review these *** analyzing existing literature,this paper summarizes the process of fixture layout optimization and the methods *** process of optimization is made up of optimization objective setting,assembly variation/deformation modeling,and fixture layout *** paper makes a review of the fixture layout for thin-walled parts according to these three ***,two different kinds of optimization objectives are *** usually consider in-plane variations or out-of-plane deformations when designing ***,modeling methods for assembly variation and deformation are divided into two categories:Mechanism-based and data-based *** common methods are discussed *** that,optimization algorithms are reviewed *** are two kinds of optimization algorithms:Traditional nonlinear programming and heuristic ***,discussions on the current situation are *** research direction of fixture layout optimization in the future is discussed from three aspects:Objective setting,improving modeling accuracy and optimization ***,a new research point for fixture layout optimization is *** paper systematically reviews the research on fixture layout optimization for thin-walled parts,and provides a reference for future research in this field.

关键词： Thin-walled parts Assembly quality Fixture layout optimization Modeling methods Optimization algorithms

Optimization of Fixture Number in Large Thin-Walled Parts Assembly Based on IPSO

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第2期37卷 213-227页

作者： Changhui Liu Jing Wang ying zheng Ke Jin Jianbo Yu Jianfeng Liu School of Mechanical Engineering Tongji UniversityShanghai 201804China Shanghai Jiaotong University Shanghai 200240China Shanghai Waigaoqiao Shipbuilding Co. Ltd.Shanghai 200137China

There are lots of researches on fixture layout optimization for large thin-walled *** researches focus on the positioning problem,i.e.,optimizing the positions of a constant number of ***,how to determine the number of fixtures is *** most cases,the number of fixtures located on large thin-walled parts is determined based on engineering experience,which leads to huge fixture number and extra ***,this paper constructs an optimization model to minimize the number of *** constraints are set in the optimization model to ensure that the part deformation is within the surface profile *** addition,the assembly gap between two parts is also *** conduct the optimization,this paper develops an improved particle swarm optimization(IPSO)algorithm by integrating the shrinkage factor and adaptive inertia *** the algorithm,particles are encoded according to the fixture *** dimension of the particle is assigned to a sub-region by constraining the optional position range of each fixture to improve the optimization ***,a case study on ship curved panel assembly is provided to prove that our method can optimize the number of fixtures while meeting the assembly quality *** research proposes a method to optimize the number of fixtures,which can reduce the number of fixtures and achieve deformation control at the same time.

关键词： Assembly quality Large thin-walled parts Fixture layout PSO FEM