检索结果-南通市图书馆

Computer Modeling in Engineering & Sciences 2024年第5期139卷 1935-1960页

作者： Yu Cheng Yajun Huang Shuai Li zhongbin zhou Xiaohui Yuan Yanming Xu College of Architecture and Civil Engineering Xinyang Normal UniversityXinyang464000China Henan Unsaturated Soil and Special Soil Engineering Technology Research Center Xinyang Normal UniversityXinyang464000China College of Intelligent Construction Wuchang University of TechnologyWuhan430223China College of Civil Engineering and Architecture Dalian UniversityDalian116622China Henan International Joint Laboratory of Structural Mechanics and Computational Simulation School of Architecture and Civil EngineeringHuanghuai UniversityZhumadian463000China

A new approach for flexoelectricmaterial shape optimization is proposed in this *** this work,a proxymodel based on artificial neural network(ANN)is used to solve the parameter optimization and shape optimization *** improve the fitting ability of the neural network,we use the idea of pre-training to determine the structure of the neural network and combine different optimizers for *** isogeometric analysis-finite element method(IGA-FEM)is used to discretize the flexural theoretical formulas and obtain samples,which helps ANN to build a proxy model from the model shape to the target *** effectiveness of the proposed method is verified through two numerical examples of parameter optimization and one numerical example of shape optimization.

关键词： Shape optimization deep learning flexoelectric structure finite element method isogeometric

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

煤矿采空区智能充填深度神经网络算法

太原理工大学学报 2024年第2期55卷 223-230页

作者：周忠斌梁卫国郭凤岐阎雾龙太原理工大学矿业工程学院太原030024 太原理工大学原位改性采矿教育部重点实验室太原030024

【目的】采空区智能充填是煤炭资源绿色安全智能高效开采的重要方向,其关键在于对井下采空区矸石充填过程进行智能决策与控制。【方法】为实现该目标,以采空区充填后围岩应力及变形作为监测指标,建立了一种采空区智能充填深度神经网络算... 详细信息

【目的】采空区智能充填是煤炭资源绿色安全智能高效开采的重要方向,其关键在于对井下采空区矸石充填过程进行智能决策与控制。【方法】为实现该目标,以采空区充填后围岩应力及变形作为监测指标,建立了一种采空区智能充填深度神经网络算法,该算法可以通过输入煤层埋深、厚度、工作面长度、直接顶厚度等关键基本参数,进行相应条件下不同充填方案的采场应力及围岩变形计算分析。将FLAC3D模拟400种不同条件下的充填开采结果作为数据集,对建立的智能充填深度神经网络算法进行训练测试,并和其余3种不同算法进行对比分析。【结果】结果表明:建立的智能充填深度神经网络算法总体优于随机森林、决策树和多元线性回归算法,每组数据运算平均速度仅为0.013 s;智能充填深度神经网络算法计算的顶板最大变形、工作面煤壁压力峰值、巷道超前支护距离等关键参数误差均值介于2%~8%之间;应用该算法针对现场实际条件进行测试,结果与现场实际结果基本吻合,表明该算法科学可行。【结论】本研究对煤矿绿色智能开采具有重要意义与价值。

关键词：采空区充填绿色开采智能充填深度神经网络算法

医务工作者体成分现况及各指标对营养状况的评估效果

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

中华健康管理学杂志 2024年第3期18卷 199-203页

作者：黄月周忠彬陈延丽吴瑛李颖赵敏解放军总医院第六医学中心营养科北京100048 解放军总医院第六医学中心质量管理科北京100048

目的:分析医务工作者体成分现况及各指标对营养状况的评估效果。方法:本研究为横断面研究,于2021年5月21日至6月22日招募北京某医院313例医务工作者为研究对象进行体成分测量,采用方差分析比较其体脂肪总量、去脂体重、体脂率、骨骼肌... 详细信息

目的:分析医务工作者体成分现况及各指标对营养状况的评估效果。方法:本研究为横断面研究,于2021年5月21日至6月22日招募北京某医院313例医务工作者为研究对象进行体成分测量,采用方差分析比较其体脂肪总量、去脂体重、体脂率、骨骼肌、蛋白质、水分、矿物质、基础代谢率指标的年龄、性别分布差异,分别用蛋白质含量、体脂率和体重指数评价医务工作者的营养状况,并分析其评估效果。结果:纳入分析的313例医务工作者中,女性221例,男性92例;女性体脂肪总量、去脂体重、骨骼肌及基础代谢率均与年龄呈正相关( F=19.823、6.745、6.561、6.707)(均 P0.05)。女性医务工作者体脂肪总量显著高于男性(17.58 kg比17.08 kg),总水分、蛋白质、矿物质、去脂体重、骨骼肌及基础代谢率均显著低于男性[30.40 kg比41.78 kg、8.07 kg比11.26 kg、2.96 kg比3.88 kg、41.43 kg比56.92 kg、22.37 kg比31.98 kg、1 264.86 kcal(1 kcal=4.184 kJ)比1 599.39 kcal](均 P<0.05)。医务工作者蛋白质含量正常190例(60.7%),蛋白质含量缺乏103例(32.9%),蛋白质含量超标20例(6.3%);体脂率正常110例(35.1%),体脂率超标193例(61.6%),体脂率不足10例(3.2%);体重指数正常198例(63.2%),其中体脂率正常145例(73.2%),体脂率超标53例(26.7%),蛋白质含量正常108例(54.5%),蛋白质含量不足89例(44.9%),蛋白质含量超标1例(0.5%);体重指数超标103例(32.9%),其中体脂率正常20例(19.4%),属于肌肉/骨骼强壮型,蛋白质含量正常83例(80.6%),属于肌肉良好型;体重指数不足12例(3.8%),其中体脂率正常6例(50.0%)。结论:医务工作者体成分分布存在明显性别差异,女性体脂肪总量、去脂体重、骨骼肌及基础代谢率与年龄相关,仅根据体重指数进行个体营养状况评价会低估肥胖率,蛋白质/肌肉含量低于或高于正常者均不宜用体重指数评价。

关键词：医务工作者体成分营养状况评估蛋白质肥胖

在线全文

学校读者我要写书评

暂无评论

多段式变形翼技术发展现状分析

战术导弹技术 2024年第1期 75-84,112页

作者：马航宋笔锋周忠彬张丁山西安近代化学研究所西安710065 西北工业大学航空学院西安710072

多段式变形翼通过内、外翼段的协同偏转,为提高飞机在飞行包线内的综合气动性能、平衡飞机的机动性及稳定性需求提供了新的解决途径。针对多段式变形翼可提供多种组合变形模式的特点,基于典型的变形结构分析,总结了多段式变形翼在智能... 详细信息

多段式变形翼通过内、外翼段的协同偏转,为提高飞机在飞行包线内的综合气动性能、平衡飞机的机动性及稳定性需求提供了新的解决途径。针对多段式变形翼可提供多种组合变形模式的特点,基于典型的变形结构分析,总结了多段式变形翼在智能材料结构设计、气动特性分析、稳定性分析与飞行控制系统设计等关键技术领域的研究现状与成果,指出了多段式变形翼在大尺寸无人机工程化应用中的技术难点及亟需解决的关键问题,为多段式变形翼关键技术的研究提供了参考。

关键词：多段式变形翼结构设计气动特性分析稳定性分析飞行控制系统设计

Necessity and feasibility of improving the residual resistance factor of polymer flooding in heavy oil reservoirs

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2010年第2期7卷 251-256页

作者： Shi Leiting Ye zhongbin Zhang Zhuo zhou Changjiang Zhu Shanshan Guo Zhidong State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University ChengduSichuan 610500 China

The efficiency of water flooding in heavy oil reservoirs would be improved by increasing the viscosity of the displacing phase, but the sweep efficiency is not of significance due to the low mobility of the vicious oil. On the basis of mobility control theory, increasing the residual resistance factor not only reduces the water-oil mobility ratio but also decreases the requirement for viscosity enhancement of the polymer solution. The residual resistance factor caused by hydrophobic associating polymer solution is higher than that caused by polyacrylamide solution in brine containing high concentrations of calcium and magnesium ions. The results of numerical simulations show that the polymer flooding efficiency improved by increasing the residual resistance factor is far better than that by only increasing solution viscosity. The recovery factor of heavy oil reservoirs （70 mPa·s） can be enhanced by hydrophobic associating polymer solution of high residual resistance factor （more than 3） and high effective viscosity （24 mPa·s）. Therefore, increasing the residual resistance factor of the polymer solution not only decreases the requirement for the viscosity of polymer solution injected into heavy oil reservoirs but also is favorable to enhanced oil recovery during polymer flooding.

关键词： Heavy oil reservoir polymer flooding mobility control residual resistance factor viscosity

The influence of patterned microporous layer on the proton exchange membrane fuel cell performances

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 6095-6101页

作者： Shunzhong Wang Kadi Hu Wei Chen Yali Cao Linan Wang Zhichang Wang Lirui Cui Mingzheng zhou Wei Zhu Hui Li zhongbin Zhuang State Key Lab of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China State Power Investment Corporation Hydrogen Energy Company Ltd.Beijing 102600China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory of Energy Environmental Catalysis Beijing University of Chemical TechnologyBeijing 100029China

The ordered membrane electrode assembly(MEA)has gained much attention because of its potential in improving mass ***,a comprehensive study was conducted on the influence of the patterned microporous layer(MPL)on the proton exchange membrane fuel cell *** patterned MPL is employed,grooves are generated between the catalyst layer and the gas diffusion *** is found that the grooves do not increase the contact resistance,and it is beneficial for water *** the MEA works under low humidity scenarios,the MEA with patterned MPL illustrated higher performance,due to the reduced inner resistance caused by improved water retention,leading to increased ionic ***,when the humidity is higher than 80%or working under high current density,the generated water accumulated in the grooves and hindered the oxygen mass transport,leading to a reduced MEA performance.

关键词： microporous layer patterned proton exchange membrane fuel cell mass transport humidity water reduction

Influence and optimization of swirler parameters on elbow wear of deep coal fluidization pipeline transportation system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第7期12卷 1408-1433页

作者： Shaodi ZHAO Jiusheng BAO Shirong GE zhongbin WANG Yan YIN Congguang HUANG School of Mechanical and Electrical Engineering China University of Mining and TechnologyXuzhou 221116China School of Mechanical Electronic and Information Engineering China University of Mining and Technology-BeijingBeijing 100083China Frontier Scientific Research Center for Fluided Mining of Deep Underground Resources China University of Mining and TechnologyXuzhou 221008China

Elbow wear is a major threat to the multiphase pipeline transportation industry,which has a negative impact on the stable operation of the transportation *** order to find the wear reduction methods of elbows in the fluidization pipeline transportation system for 2000-meter-deep coal resources,the swirler was installed upstream of the elbows,and wear simulations and tests of three kinds of elbows were carried *** results showed that the maximum wear rate(MWR)of elbows increased and then decreased along the elbow *** to the different directions of gravity,the heavy wear position(HWP)of the horizontal-vertical(H-V)elbow was in front of the vertical-horizontal(V-H)*** the downstream portion of the horizontal-horizontal(H-H)elbow was still a horizontal pipe,the HWP of the H-H elbow almost covered the whole *** swirler placed upstream of the elbows could make the particles at the elbow move to the intrados of the elbows,resulting in less collision between the particles and the extrados of the elbows,thus reducing the wear of the *** wear reduction effects of swirlers on three different elbows were favorably connected with the guide vane angle(GVA)and negatively correlated with the guide vane length(GVL),decreased first and then increased as the guide vane height(GVH)increased,and were little affected by the guide vane number(GVN)and the guide vane thickness(GVT).The mathematical models between the MWR of the elbows and guide vane parameters were *** bench tests,the wear reduction effect of three kinds of elbows under the optimal guide vane parameters was 58.4%,76.9%,and 78.6%,*** errors between the bench test results and the simulation results were around 10%.

关键词： pipe elbow erosion wear spiral flow swirler guide vane parameters particle collision

Boosting MA-based two-dimensional Ruddlesden-Popper perovskite solar cells by incorporating a binary spacer

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 Energy Chemistry 2024年第8期95卷 348-356,I0008页

作者： Xue Dong Yinhao Tang Yiqun Li Xin Li Yuzhen Zhao Wenqi Song Fangmin Wang Shudong Xu Yipeng zhou Chenxin Ran Zongcheng Miao Lin Song zhongbin Wu Xi’an Key Laboratory of Advanced Photo-Electronics Materials and Energy Conversion Device Technological Institute of Materials&Energy Science(TIMES)Xijing UniversityXi’an 710123ShaanxiChina Frontiers Science Center for Flexible Electronics Xi’an Institute of Flexible Electronics(IFE)Northwestern Polytechnical UniversityXi'an 710072ShaanxiChina School of Artificial Intelligence Optics and Electronics(iOPEN) Northwestern Polytechnical UniversityXi'an 710072ShaanxiChina

Two-dimensional Ruddlesden-Popper(2DRP)perovskite exhibits excellent stability in perovskite solar cells(PSCs)due to introducing hydrophobic long-chain organic ***,the poor charge transporting property of bulky organic cation spacers limits the performance of 2DRP *** by the Asite cation alloying strategy in 3D perovskites,2DRP perovskites with a binary spacer can promote charge transporting compared to the unary spacer ***,the superior MA-based 2DRP perovskite films with a binary spacer,including 3-guanidinopropanoic acid(GPA)and 4-fluorophenethylamine(FPEA)are *** films(GPA_(0.85)FPEA_(0.15))_(2)MA_(4)Pb_5I_(16)show good morphology,large grain size,decreased trap state density,and preferential orientation of the as-prepared ***,the present 2DRP-based PSC with the binary spacer achieves a remarkable efficiency of 18.37%with a V_(OC)of1.15 V,a J_(SC)of 20.13 mA cm^(-2),and an FF of 79.23%.To our knowledge,the PCE value should be the highest for binary spacer MA-based 2DRP(n≤5)PSCs to ***,owing to the hydrophobic fluorine group of FPEA and the enhanced interlayer interaction by FPEA,the unencapsulated 2DRP PSCs based on binary spacers exhibit much excellent humidity stability and thermal stability than the unary spacer counterparts.

关键词： Perovskite solar cells Two-dimensional Ruddlesden-Popper perovskite Binary spacers Stability

Pore shrinkage capacity of Shajiang black soils(Vertisols)on the North China Plain and its influencing factors

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2024年第3期34卷 620-630页

作者： Yueming CHEN zhongbin ZHANG Lei GAO Zichun GUO Peng XIONG Fahui JIANG Xinhua PENG State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) University of Chinese Academy of Sciences Beijing 100049(China) Jiangxi Agricultural University Nanchang 330045(China)

Different pore sizes present different pore shrinkage capacities in a nonrigid ***,the shrinkage capacities of different pore sizes and their influencing factors are not *** aimed to quantify the shrinkage capacities of different pore sizes(large pores,>50μm;medium pores,0.2-50μm;fine pores,<0.2μm)and determine how soil properties impact soil shrinkage capacity at the regional *** sampling transects from west to east(360 km long,35 samples)and from north to south(190 km long,29 samples)were selected to investigate soil shrinkage capacity and physicochemical properties of at0-20 cm depth in the Vertisol(locally known as Shajiang black soil)region of the North China *** results showed that soil total shrinkage capacity,indicated by the coefficient of linear extensibility(COLE),had a mean value of 0.041-0.051 in the west-east and north-south *** pores had higher pore shrinkage index(PSI)values(0.103-0.109)than medium(0.077-0.096)and fine(0.087-0.091)*** PSI of fine pores showed a fluctuating increasing trend from northwest to southeast,and the fine pore shrinkage capacity determined the COLE(r^(2)=0.789,P<0.001).The PSI of large pores had a significant relationship with soil bulk density(r=0.281,P<0.05)and organic carbon(r=-0.311,P<0.05),whereas those of medium and fine pores were correlated with soil clay content(r=0.381 and 0.687,respectively,P<0.001).In addition,the PSI of fine pores was also correlated with montmorillonite content(r=0.387,P<0.01).It can be concluded that the PSI of large pores is related to anthropogenically influenced soil properties with low stability,whereas those of medium and fine pores are related to pedogenic *** high variability in anthropogenic and pedogenic factors explains the spatial pattern of Vertisol shrinkage capacity on the North China Plain.

关键词： clay content coefficient of linear extensibility pore shrinkage index soil structure spatial distribution swelling

A general and facile calcination method to synthesize single-site catalysts for highly efficient electrochemical CO_(2) reduction

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 3895-3901页

作者： Rui Sui Bingyan Wang Yongsheng Wang Jiajing Pei Wei Zhu Wenxing Chen Chunhui Li Ailing Sun zhongbin Zhuang Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084China College of Chemistry and Green Catalysis Center Zhengzhou UniversityZhengzhou 450001China State Key Lab of Organic-Inorganic Composites and Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Energy&Catalysis Center School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China

The electrochemical CO_(2) reduction reaction(CO_(2)RR)has received widespread attention as a promising method for producing sustainable chemicals and mitigating the global ***,we demonstrate a general and facile synthetic route for the metal-nitrogen-carbon(M-N-C)type catalyst by simply calcinating metal acetate and urea with commercial carbon black,which have potential application in CO_(2)*** synthesized Ni-NC-600 catalyst has the structure of single Ni atom coordinated with one N atom and three C atoms(Ni-N_(1)C_(3)),which is suggested by X-ray absorption *** Ni-NC-600 catalyst exhibits high CO_(2)RR catalytic performance and a high CO Faraday efficiency above 98%in a wide potential range from-0.7 to-1.3 V(*** hydrogen electrode(RHE)),superior to most of the reported Ni-N-C *** work has developed a facile strategy to synthesize high performance CO_(2)RR catalyst.

关键词： nickel single atom catalyst CO_(2)reduction reaction CO production electrocatalyst