检索结果-南通市图书馆

Migration time prediction and assessment of toxic fumes under forced ventilation in underground mines

在线全文

学校读者我要写书评

暂无评论

Underground Space 2024年第5期18卷 273-294页

作者： Jinrui zhang Tingting zhang Chuanqi Li School of Resources&Civil Engineering Northeastern UniversityShenyang 110819China Laboratory 3SR CNRS UMR 5521Grenoble Alpes UniversityGrenoble 38000France

This study aims to predict the migration time of toxic fumes induced by excavation blasting in underground *** reduce numerical simulation time and optimize ventilation design,several back propagation neural network(BPNN)models optimized by honey badger algorithm(HBA)with four chaos mapping(CM)functions(i.e.,Chebyshev(Che)map,Circle(Cir)map,Logistic(Log)map,and Piecewise(Pie)map)are developed to predict the migration time.125 simulations by the computational fluid dynamics(CFD)method are used to train and test the developed *** determination coefficient(R2),the variance accounted for(VAF),the Willmott’s index(WI),the root mean square error(RMSE),the mean absolute percentage error(MAPE),and the sum of squares error(SSE)are utilized to evaluate the model *** evaluation results indicate that the CirHBA-BPNN model has achieved the most satisfactory performance by reaching the highest values of R2(0.9945),WI(0.9986),VAF(99.4811%),and the lowest values of RMSE(15.7600),MAPE(0.0343)and SSE(6209.4),*** wind velocity in roadway(Wv)is the most important feature for predicting the migration time of toxic ***,the intrinsic response characteristic of the optimal model is implemented to enhance the model interpretability and provide reference for the relationship between features and migration time of toxic fumes in ventilation design.

关键词： Migration time Underground mines Honey badger algorithm Chaos mapping Back propagation neural network

A variable structure passivity control method for elastic joint robots based on cascaded high-order state estimation

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(Technological Sciences) 2024年第2期67卷 395-407页

作者： zhang JieXin NIE PingYun zhang Bo State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China

Passivity-based controllers are widely used to facilitate physical interaction between humans and elastic joint robots,as they enhance the stability of the interaction ***,the joint position tracking performance can be limited by the structures of these controllers when the system is faced with uncertainties and rough high-order system state measurements(such as joint accelerations and jerks).This study presents a variable structure passivity(VSP)control method for joint position tracking of elastic joint robots,which combines the advantages of passive control and variable structure *** method ensures the tracking error converges in a finite time,even when the system faces *** method also preserves the passivity of the ***,a cascaded observer,called CHOSSO,is also proposed to accurately estimate high-order system states,relying only on position and velocity *** observer allows independent implementation of disturbance compensation in the acceleration and jerk estimation *** particular,the observer has an enhanced ability to handle fast time-varying disturbances in physical human-robot *** effectiveness of the proposed method is verified through simulations and experiments on a lower limb rehabilitation robot equipped with elastic joints.

关键词： motion control elastic joint robot finite-time convergence high-order system state estimation physical human-robot interaction

Automated regression test method for scientific computing libraries:Illustration with SPHinXsys

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第3期36卷 466-478页

作者： Bo zhang Chi zhang Xiangyu Hu TUM School of Engineering and Design Technical University of MunichMunichGermany

Scientific computing libraries,whether in-house or open-source,have witnessed enormous progress in both engineering and scientific ***,it is important to ensure that modifications to the source code,prompted by bug fixing or new feature development,do not compromise the accuracy and functionality that have been already validated and *** paper introduces a method for establishing and implementing an automatic regression test environment,using the open-source multi-physics library SPHinXsys as an illustrative ***,a reference database for each benchmark test is generated from observed data across multiple *** comprehensive database encapsulates the maximum variation range of metrics for different strategies,including the time-averaged,ensemble-averaged,and dynamic time warping *** accounts for uncertainties arising from parallel computing,particle relaxation,physical instabilities,and ***,new results obtained after source code modifications undergo testing based on a curve-similarity comparison against the reference *** the source code is updated,the regression test is automatically executed for all test cases,providing a comprehensive assessment of the validity of the current *** regression test environment has been successfully implemented in all dynamic test cases within SPHinXsys,including fluid dynamics,solid mechanics,fluid-structure interaction,thermal and mass diffusion,reaction-diffusion,and their multi-physics couplings,and demonstrates robust capabilities in testing different *** is noted that while the current test environment is built and implemented for a particular scientific computing library,its underlying principles are generic and can be easily adapted for use with other libraries,achieving equal effectiveness.

关键词： Scientific computing open-source library verification and validation regression test automatic test environment curve similarity comparison smoothed particle hydrodynamics

Anion-hosting cathodes for current and late-stage dual-ion batteries

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 1485-1509页

作者： Miao zhang Wenyong zhang Fan zhang Chun-Sing Lee Yongbing Tang School of Chemistry and Materials Science Guangdong University of EducationGuangzhou 510303China Advanced Energy Storage Technology Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Center of Super-Diamond and Advanced Film(COSDAF) City University of Hong KongKowloon 999077China

Anion-hosting cathodes capable of reversibly storing large-size anions play a leading role in dual-ion batteries(DIBs). The purpose of the present review is to summarize the most promising anion-hosting cathodes for current and late-stage DIBs. This review first summarizes the developments in conventional graphite cathodes, especially the latest advances in the graphiterelated research. Next, organic cathodes for the anion storage are discussed, including aromatic amine polymers, heterocyclic polymers, bipolar compounds, and all-carbon-unsaturated compounds. Then, the review focuses on the conversion-type cathodes with high theoretical specific capacities. Finally, the future research directions of the cathodes of DIBs are proposed.

关键词： dual-ion batteries organic cathodes graphite cathodes conversion-type cathodes

Confinement of ionomer for electrocatalytic CO2 reduction reaction via efficient mass transfer pathways

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第2期11卷 168-176页

作者： Xiaowei Du Peng zhang Gong zhang Hui Gao Lili zhang Mengmeng zhang Tuo Wang Jinlong Gong School of Chemical Engineering and Technology Key Laboratory for Green Chemical Technology of the Ministry of Education Tianjin University Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) National Industry-Education Platform of Energy Storage Tianjin University Joint School of the National University of Singapore and Tianjin University International Campus of Tianjin University Haihe Laboratory of Sustainable Chemical Transformations

Gas diffusion electrodes（GDEs） mediate the transport of reactants, products and electrons for the electrocatalytic CO2reduction reaction（CO2RR） in membrane electrode assemblies. The random distribution of ionomer, added by the traditional physical mixing method, in the catalyst layer of GDEs affects the transport of ions and CO2. Such a phenomenon results in elevated cell voltage and decaying selectivity at high current densities. This paper describes a pre-confinement method to construct GDEs with homogeneously distributed ionomer, which enhances mass transfer locally at the active centers. The optimized GDE exhibited comparatively low cell voltages and high CO Faradaic efficiencies（FE > 90%） at a wide range of current densities. It can also operate stably for over 220 h with the cell voltage staying almost unchanged. This good performance can be preserved even with diluted CO2feeds, which is essential for pursuing a high single-pass conversion rate. This study provides a new approach to building efficient mass transfer pathways for ions and reactants in GDEs to promote the electrocatalytic CO2RR for practical applications.

关键词： CO2 electroreduction gas diffusion electrode mass transfer ionomer Ag catalyst

Possibilities for the synthesis of superheavy element Z=121 in fusion reactions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第6期35卷 90-100页

作者： Ming-Hao zhang Yu-Hai zhang Ying Zou Xiu-Xiu Yang Gen zhang Feng-Shou zhang The Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China School of Physical Science and Technology Guangxi UniversityNanning 530004China National Laboratory of Heavy Ion Accelerator of Lanzhou Center of Theoretical Nuclear PhysicsLanzhou 730000China

Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental *** synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 *** influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in *** reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.

关键词： Superheavy nuclei Dinuclear system model Fusion reaction Evaporation residue cross section

在线全文

学校读者我要写书评

暂无评论

32例儿童心肌病基因检测与临床特征分析

临床心血管病杂志 2022年第7期38卷 566-571页

作者：郑奎张英谦刘露武菲娄美娜郝京霞李博河北省儿童医院心内科河北省小儿心血管重点实验室石家庄050031 河北医科大学研究生学院河北北方学院研究生学院

目的:探讨基因检测对儿童心肌病遗传病因的诊断价值,并分析其临床特征及基因型-表型的关系。方法:回顾性分析2018年1月—2020年12月收治的32例心肌病患儿临床资料及基因结果。根据患儿基因结果分为基因突变阳性(A组)17例和基因突变阴性(... 详细信息

目的:探讨基因检测对儿童心肌病遗传病因的诊断价值,并分析其临床特征及基因型-表型的关系。方法:回顾性分析2018年1月—2020年12月收治的32例心肌病患儿临床资料及基因结果。根据患儿基因结果分为基因突变阳性(A组)17例和基因突变阴性(B组)15例,并对比两组首诊左心室射血分数(LVEF)、随诊1年结局(是否死亡)之间的差异。结果:基因突变阳性率为53.1%(17/32),其中新生突变约占35.3%(6/17),临床意义不明(VUS)者46.9%(15/32)。随诊1年死亡率为28.1%(9/32),其中A组47.1%(8/17),B组6.7%(1/15),差异有统计学意义(P=0.018)。9例死亡患儿的突变基因为GAA4例、TTN3例、LMNA和TAZ各1例,其中1例GAA(c.875A>G)基因的致病性目前被分类为VUS。32例心肌病患儿以腹胀、食欲欠佳等症状最常见,仅少部分(6.2%)患儿以晕厥、休克等症状就诊。32例患儿LVEF为(49.9±18.1)%,A组LVEF为(50.8±17)%,B组LVEF为(48.9±19.8)%,差异无统计学意义(P>0.05)。结论:儿童心肌病缺乏特异性临床表现。基因突变阳性患儿近期预后相对较差。特别是GAA、LMNA、TAZ、TTN基因变异相关心肌病患儿,大多近期预后不良。

关键词：儿童心肌病遗传基因检测

Degradable magnesium alloy suture promotes fibrocartilaginous interface regeneration in a rat rotator cuff transosseous repair model

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第1期12卷 384-393页

作者： Baoxiang zhang Wen zhang Fei zhang Chao Ning Mingyang An Ke Yang Lili Tan Qiang zhang Department of Sports Medicine Chinese PLA General HospitalBeijing 100853China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Medical School of PLA Beijing 100853China Institute of Orthopedics Chinese PLA General HospitalBeijing Key Lab of Regenerative Medicine in OrthopedicsKey Lab of Musculoskeletal Trauma&War Injuries of Chinese PLABeijing 100853China

Despite transosseous rotator cuff tear repair using sutures is widely accepted for tendon-bone fixation,the fibrocartilaginous enthesis regeneration is still hardly achieved with the traditional *** the present work,degradable magnesium(Mg)alloy wire was applied to suture supraspinatus tendon in a rat acute rotator cuff tear model with Vicryl Plus 4±0 absorbable suture as *** shoulder joint humerus-supraspinatus tendon complex specimens were retrieved at 4,8,and 12 weeks after *** Mg alloy suture groups showed better biomechanical properties in terms of ultimate load to *** observation showed that hyperplastic response of the scar tissue at the tendon-bone interface is progressively alleviated over time in the both Mg alloy suture and Vicryl suture *** the histological analysis,for Mg alloy suture groups,chondrocytes appear to proliferate at 4 weeks postoperatively,and the tendon-bone interface showed an orderly structural transition zone at 8 weeks *** collagenous fiber tended to be aligned and the tendon-bone interlocking structures apparently formed,where transitional structure from unmineralized fibrocartilage to mineralized fibrocartilage was closer to the native fibrocartilaginous *** vivo degradation of the magnesium alloy wire was completed within 12 *** results indicated that Mg alloy wire was promising as degradable suture with the potential to promotes fibrocartilaginous interface regeneration in rotator cuff repair.

关键词： Rotator cuff repair Mg alloy wire Tendon-bone healing Fibrocartilaginous interface

Road map for, and technical challenges of, carbon-nanotube integrated circuit technology

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 14-16页

作者： Jia Si Panpan zhang Zhiyong zhang Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics School of Electronics Peking University State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

The past decade has witnessed an explosion of research on carbon-nanotube(CNT) electronics due to their outstanding properties, including an ultrathin body, a high carrier mobility and a high saturation velocity.

关键词： TRANSISTORS