检索结果-南通市图书馆

Improved Harris Hawks Algorithm and Its Application in Feature Selection

Computers, Materials and Continua 2024年第1期81卷 1251-1273页

作者： Zhang Q. li y. Zhan J. Chen S. School of Computer Science and Information Engineering Harbin Normal University Harbin 150025 China College of Systems Engineering National University of Defense Technology Changsha 410073 China

This research focuses on improving the Harris' Hawks Optimization algorithm (HHO) by tackling several of its shortcomings, including insufficient population diversity, an imbalance in exploration vs. exploitation, and a lack of thorough exploitation depth. To tackle these shortcomings, it proposes enhancements from three distinct perspectives: an initialization technique for populations grounded in opposition-based learning, a strategy for updating escape energy factors to improve the equilibrium between exploitation and exploration, and a comprehensive exploitation approach that utilizes variable neighborhood search along with mutation operators. The effectiveness of the Improved Harris Hawks Optimization algorithm (IHHO) is assessed by comparing it to five leading algorithms across 23 benchmark test functions. Experimental findings indicate that the IHHO surpasses several contemporary algorithms its problem-solving capabilities. Additionally, this paper introduces a feature selection method leveraging the IHHOalgorithm(IHHO-FS) to address challenges such as lowefficiency in feature selection and high computational costs (time to find the optimal feature combination and model response time) associated with high-dimensional datasets. Comparative analyses between IHHO-FS and six other advanced feature selection methods are conducted across eight datasets. The results demonstrate that IHHO-FS significantly reduces the computational costs associated with classification models by lowering data dimensionality, while also enhancing the efficiency of feature selection. Furthermore, IHHO-FS shows strong competitiveness relative to numerous algorithms. © 2024 The Authors. Published by Tech Science Press.

关键词： deep exploitation strategy energy factor update strategy feature selection HHO IHHO population diversity

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

Greatly enhanced corrosion/wear resistances of epoxy coating for Mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

引用

Journal of Magnesium and Alloys 2024年第1期12卷 332-344页

作者： Z.y.Xue X.J.li J.H.Chu M.M.li D.N.Zou L.B.Tong School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China

The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various *** conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient *** the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly *** outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)*** FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier *** Ce film connects the outer layer with the substrate,showing the transition *** corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling *** synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.

关键词： Mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance Blocking layer

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

Microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

引用

Journal of Materials Science & Technology 2024年第4期171卷 80-93页

作者： y.H.Zhang H.li Z.W.yang X.liu Q.F.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

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

Effect of Al_(2)O_(3)on the Mechanical Properties of(B_(4)C+Al_(2)O_(3))/Al Neutron Absorbing Materials

引用

Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： J.X.Cai B.M.Shi N.li y.liu Z.G.Zhang y.N.Zan Q.Z.Wang B.L.Xiao Z.y.Ma Shi‑Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China Department of Materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

B_(4)C/Al composites are widely utilized as neutron absorbing materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of B_(4)C/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adjusted by utilizing spheroid Al powder with varying diameters,thereby investigating the impact of Al_(2)O_(3)content on the tensile properties of(B_(4)C+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain boundaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhibited a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional B_(4)C/Al composites.

关键词： Al matrix composites Neutron absorbing materials (B_(4)C+Al_(2)O_(3))/Al composites High-temperature strength

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

Tailored architecture of composite electrolyte for all-solid-state sodium batteries with superior rate performance and cycle life

引用

Nano Research 2024年第5期17卷 4171-4180页

作者： Xiang Guan Zhenhua Jian Xingan liao Wenchao liao yanfei Huang Dazhu Chen Robert K.y.li Chen liu Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518055China Department of Materials Science and Engineering City University of Hong KongHong KongChina

Seeking for composite electrolytes reinforced all-solid-state sodium ion batteries with superior long lifespan and rate performance remains a great ***,a unique strategy to tailor the architecture of composite electrolyte via inserting polymer chains into a small quantity of sulfate sodium grafted C_(48)0H_(28)O_(32)Zr_(6)(UIOSNa)is *** intimate contact between polymer segments and UIOSNa with limited pore size facilitates the anion immobilization of sodium salts and reduction of polymer crystallinity,thereby providing rapid ion conduction and reducing the adverse effect caused by the immigration of *** tNa+grafting of-SO_(3)Na groups on fillers allows the free movement of more sodium ions to further improve and ionic ***,even with the low content of UIOSNa fillers,a high ionic conductivity of 6.62×10^(-4) S·cm^(-1) at 60℃ and a transference number of 0.67 for the special designed composite electrolyte are *** assembled all-solid-state sodium cell exhibits a remarkable rate performance for 500 cycles with 95.96%capacity retention at a high current rate of 4 *** corresponding pouch cell can stably work for 1000 cycles with 97.03%capacity retention at 1 C,which is superior to most of the reported composite electrolytes in the literature.

关键词： solid state sodium battery composite electrolyte rate performance cycle life

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

Fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

引用

Matter and Radiation at Extremes 2024年第3期9卷 11-18页

作者： y.X.Wang X.L.Zhu S.M.Weng P.li X.F.li H.Ai H.R.Pan Z.M.Sheng Key Laboratory for Laser Plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghai 200240China Research Center of Laser Fusion of China Academy of Engineering Physics MianyangSichuan 621900China State key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-IR)to terahertz(THz)range is of interest for applications in a number of fields,from fundamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-IR or THz ***,we present a photon deceleration scheme for the efficient generation of ultrashort mid-IR or THz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake ***,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer *** greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength IR and THz spectral ranges.

关键词： laser ultrashort photon

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

Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft:a theoretical study

引用

Earth and Planetary Physics 2024年第1期8卷 204-214页

作者： A.M.Jorgensen TianRan Sun y.Huang L.li R.Xu L.Dai Chi Wang New Mexico Institute of Mining and Technology SocorroNMUSA National Space Science Center Chinese Academy of SciencesBeijing 100190China Tsinghua University Beijing 100084China

Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few *** work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch *** the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution *** this paper we explore the reconstruction using,two,three,and four *** show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.

关键词： magnetosheath tomography soft X-ray imaging SMILE

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

Game Theory based Optimal Defensive Resources Allocation with Incomplete Information in Cyber-physical Power Systems against False Data Injection Attacks

引用

Protection and Control of Modern Power Systems 2024年第2期9卷 115-127页

作者： Bingjing yan Zhenze Jiang Pengchao yao Qiang yang Wei li Albert y.Zomaya College of Electrical Engineering Zhejiang University College of Control Science and Engineering Zhejiang University College of Electrical Engineering Zhejiang UniversityHangzhou 310027China School of Information Technologies at The University of Sydney School of Information Technologies

Modern power grid is fast emerging as a complex cyber-physical power system(CPPS)integrating physical current-carrying components and processes with cyber-embedded computing,which faces increasing cy-berspace security threats and *** this paper,the state(i.e.,voltage)offsets resulting from false data injection(FDI)attacks and the bus safety characterization are applied to quantify the attack *** state offsets are obtained by the state estimation method,and the bus safety characterization considers the power net-work topology as well as the vulnerability and connection relationship of *** the indeterminacy of attacker’s resource consumption and reward,a zero-sum game-theoretical model from the defender’s perspective with incomplete information is explored for the optimal allocation of limited defensive *** attacker aims to falsify measurements without triggering threshold alarms to break through the protection,leading to load shedding,over-voltage or *** defender attempts to ensure the estimation results to be as close to the actual states as possible,and guarantee the system’s safety and efficient defensive resource *** proposed solution is extensively evaluated through simu-lations using the IEEE 33-bus test network and real-time digital simulator(RTDS)based testbed experiments of the IEEE 14-bus *** results demonstrate the effec-tiveness of the proposed game-theoretical approach for optimal defensive resource allocation in CPPS when lim-ited resources are available when under FDI *** Terms—Optimal strategy,game theory,Nash equilibrium,CPPS,FDI attack.

关键词： Optimal strategy game theory Nash equilibrium CPPS FDI attack

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

Trial characteristics and treatment effect estimates in randomized controlled trials of Chinese herbal medicine: A meta-epidemiological study

引用

Journal of Integrative Medicine 2024年第3期22卷 223-234页

作者： Betty H.Wang ya-li lin yin-yan Gao Jin-lu Song Lang Qin ling-qi li Wen-qi liu Claire C.W.Zhong Mary y.Jiang Chen Mao Xiao-bo yang Vincent C.H.Chung Irene X.y.Wu Jockey Club School of Public Health and Primary Care the Chinese University of Hong KongHong Kong 999077China Xiangya School of Public Health Central South UniversityChangsha 410006Hunan ProvinceChina School of Chinese Medicine the Chinese University of Hong KongHong Kong 999077China School of Public Health Southern Medical UniversityGuangzhou 510080Guangdong ProvinceChina State Key Laboratory of Dampness Syndrome of Chinese Medicine the Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou 510120Guangdong ProvinceChina Chinese Medicine Syndrome Research Team the Second Affiliated HospitalGuangzhou University of Chinese MedicineGuangzhou 510120Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Clinical Research on Traditional Chinese Medicine Syndrome Guangzhou 510120Guangdong ProvinceChina Hunan Provincial Key Laboratory of Clinical Epidemiology Central South UniversityChangsha 410006Hunan ProvinceChina

Background:Previously published meta-epidemiological studies focused on Western medicine have identified some trial characteristics that impact the treatment effect of randomized controlled trials(RCTs).Nevertheless,it remains unclear if similar associations exist in RCTs on Chinese herbal medicine(CHM).Further,Chinese medicine-related characteristics have not been explored ***:To investigate trial characteristics related to treatment effect estimates on CHM *** strategy:This meta-epidemiological study searched 5 databases for systematic reviews on CHM treatment published between January 2011 and July *** criteria:An eligible systematic review should only include RCTs of CHM and conduct at least one *** extraction and analysis:Two reviewers independently conducted data extraction on general characteristics of systematic reviews,meta-analyses and included *** also assessed the risk of bias of RCTs using the Cochrane risk of bias tool.A two-step approach was used for data *** ratio of odds ratios(ROR) and difference in standardized mean differences (dSMD) with 95%confidence interval (CI) were applied to present the difference in effect estimates for binary and continuous outcomes,***:Ninety-one systematic reviews,comprising 1338 RCTs were *** binary outcomes,RCTs incorporated with syndrome differentiation (ROR:1.23;95%CI:[1.07,1.39]),adopting Chinese medicine formula (ROR:1.19;95%CI:[1.03,1.34]),with low risk of bias on incomplete outcome data (ROR:1.29;95%CI:[1.06,1.52]) and selective outcome reporting (ROR:1.12;95%CI:[1.01,1.24]),as well as a trial size≥100 (ROR:1.23;95%CI:[1.04,1.42]) preferred to show larger effect *** for continuous outcomes,RCTs with Chinese medicine diagnostic criteria (dSMD:0.23;95%CI:[0.06,0.41]),judged as high/unclear risk of bias on allocation concealment (dSMD:-0.70;95%CI:[-0.99,-0.42]),with low risk of bias on incomplete outcome data (dSMD:0.30

关键词： Chinese herbal medicine Randomized controlled trial Risk of bias Meta-epidemiological study Effect estimates

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

Hole-Selective Contact with Molecularly Tailorable Reactivity for Passivating High-Performing Inverted Perovskite Solar Cells

引用

CCS Chemistry 2024年第7期6卷 1654-1661页

作者： Wenlin Jiang yingie Hu Fengzhu li Francis R.lin Alex K-y.Jen Department of Materials Science and Engineering City University of Hong KongKowloonHong Kong China 999077 Department of Chemistry City University of Hong KongKowloonHong Kong China 999077 Hong Kong Institute for Clean Energy City University of Hong KongKowloonHong Kong China 999077 State Key Laboratory of Marine Pollution City University of Hong KongKowloonHong Kong China 999077

The precisely customizable attributes of self-assembled monolayers(SAMs)molecules at the atomic level hold the potential to facilitate efficient hole selection and interface passivation ***,the correlation between the exposure of passivating groups on the surface and device performance remains ***,we introduce two newly designed SAM molecules,Cbz2S and Cbz2SMe,incorporating cyclic disulfide or two flanking thiomethyls by modifying the 4,5-position of carbazole to adjust the Lewis basicity of the SAM-modified *** possessing suitable energetic alignment,Cbz2S with more-exposed sulfur atoms exhibited inferior device performance due to excessive reactivity,leading to an overpopulation of PbI2 crystallites at the buried perovskite *** contrast,the screening effect from the methyl groups of Cbz2SMe optimized SAM reactivity,exquisitely integrating buried interface passivation and hole selection ***,the champion inverted perovskite solar cell(PSC)employing Cbz2SMe achieved an impressive power conversion efficiency of 24.42%,accompanied by prolonged *** work demonstrates the feasibility of incorporating Lewis-basic passivation groups into SAM molecules and elucidates the relationship between the reactivity of SAM passivation groups and device *** findings provide valuable insights for the design of novel multifunctional SAM molecules,further advancing the performance of PSCs.

关键词： self-assembled monolayer perovskite solar cell hole-selective layer carbazole derivatives defect passivation

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：