检索结果-南通市图书馆

Multi-Label Feature Selection Based on Improved Ant Colony Optimization Algorithm with Dynamic Redundancy and Label Dependence

在线全文

学校读者我要写书评

暂无评论

Computers, Materials and Continua 2024年第1期81卷 1157-1175页

作者： Cai, Ting Ye, Chun Ye, Zhiwei Chen, Ziyuan mei, Mengqing zhang, Haichao Bai, Wanfang zhang, Peng school of Computer Hubei University of Technology Wuhan 430068 China Xining Big Data Service Administration Xining 810000 China Wuhan Fiberhome Technical Services Co. Ltd Wuhan 430205 China

The world produces vast quantities of high-dimensional multi-semantic data. However, extracting valuable information fromsuch a largeamount of high-dimensional andmulti-label data is undoubtedly arduous and challenging. Feature selection aims to mitigate the adverse impacts of high dimensionality in multi-label data by eliminating redundant and irrelevant features. The ant colony optimization algorithmhas demonstrated encouraging outcomes in multi-label feature selection, because of its simplicity, efficiency, and similarity to reinforcement learning. Nevertheless, existing methods do not consider crucial correlation information, such as dynamic redundancy and label correlation. To tackle these concerns, the paper proposes a multi-label feature selection technique based on ant colony optimization algorithm (MFACO), focusing on dynamic redundancy and label correlation. Initially, the dynamic redundancy is assessed between the selected feature subset and potential ***, the ant colony optimization algorithmextracts label correlation fromthe label set,which is then combined into the heuristic factor as label weights. Experimental results demonstrate that our proposed strategies can effectively enhance the optimal search ability of ant colony, outperforming the other algorithms involved in the paper. © 2024 The Authors. Published by Tech Science Press.

关键词： Ant colony optimization

A New Analytical Model for the Flow Stress of Twin-roll Casting Magnesium Sheet at Elevated Temperatures

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 Materials Science & Technology 2010年第5期26卷 461-466页

作者： Zhimin Liu,Shuming Xing ,Peiwei Bao,Nan Li,Shuqing Yao and Milan zhang school of Mechanical,Electronic and Control Engineering,beijing Jiaotong {3.,beijing 100044,china [a] school of Mechanical Electronic and Control Engineering beijing Jiaotong university beijing 100044 china

To evaluate the flow stress of the twin-roll casting magnesium sheet in high temperature forming processes,a new analytical model was proposed by analyzing stress-strain curves measured under various temperatures and strain *** model can be parameterized to reflect the volume fraction of semi-sold grain and sold grains undergoing *** applying the new model,the result showed that the simulated stress-strain curves fit the experiment data very *** curve fitting can be employed for any magnesium sheet when the deformation conditions are *** evolution indicated that it affected the stress-strain curves *** mechanisms of dynamic recrystallization（DRX） depended on the operating deformation mechanisms,which changed with *** the volume fraction and grain size of DRX changed with the Zener-Hollomon parameter and temperatures.

关键词： Twin-roll casting Semi-sold grains Twinning

Cisplatin-induced premature senescence with concomitant reduction of gap junctions in human fibroblasts

在线全文

学校读者我要写书评

暂无评论

Cell Research 2004年第1期14卷 60-66页

作者： Wei ZHAO, Zhong Xiang LIN, Zhi Qian zhang Peking university school of Oncology, and {3. Institute for Cancer Research, {3. 10003., china. Lin ZX Peking Univ Sch Oncol Beijing 100034 Peoples R China

To examine the role of gap junctions in cell senescence, the changes of gap junctions in cisplatin-induced premature senescence of primary cultured fibroblasts were studied and compared with the replicative senescent human fibroblasts. Dye transfer assay for gap junction function and immunofluorescent staining for connexin 43.protein distribution were done respectively. Furthermore, cytofluorimetry and DAPI fluorescence staining were performed for cell cycle and apoptosis analysis, p53.gene expression level was detected with indirect immunofluorescence. We found that cisplatin (10 mM) treatment could block cell growth cycle at G1 and induced premature senescence. The premature senescence changes included high frequency of apoptosis, elevation of p53.expression, loss of membranous gap junctions and reduction of dye-transfer capacity. These changes were comparable to the changes of replicative senescence of human fibroblasts. It was also concluded that cisplatin could induce premature senescence concomita

关键词： cisplatin premature senescence gap junction intercellular communication connexin 43 fibroblasts.

Dynamic membrane filtration accelerates electroactive biofilms in bioelectrochemical systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Environmental Science and Ecotechnology 2024年第4期20卷 208-217页

作者： Jinning Wang mei Chen Jiayao zhang Xinyi Sun Nan Li Xin Wang MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringNankai UniversityNo.38 Tongyan RoadJinnan DistrictTianjin300350China school of Environmental Science and Engineering Tianjin UniversityNo.35 Yaguan RoadJinnan DistrictTianjin300350China

Bioelectrochemical systems(BES)have emerged as a dual-function technology for treating wastewater and recovering energy.A vital element of BES is the rapid formation and maintenance of electroactive biofilms(EABs).Previous attempts to accelerate EAB formation and improve electroactivities focused on enhancing the bacterial adhesion process while neglecting the rate-limiting step of the bacterial transport ***,we introduce membrane filtration into BES,establishing a dynamic membrane filtration system that enhances overall *** observed that optimal membrane flux considerably reduced the startup time for EAB ***,EABs established under a 25 L m^(-2)h^(-1)flux(EAB_(25)LMH)had a formation time of 43.8±1.3.h,notably faster than the 51.4±1.6 h in the static state(EAB_(0)LMH).Additionally,EAB_(25)LMH exhibited a significant increase in maximum current density,approximately 2.2 times higher than EAB_(0)*** correlation analysis indicated a positive relationship between current densities and biomass quantities and an inverse correlation with startup *** analysis revealed two critical findings:(i)variations in maximum current densities across different filtration conditions were associated with redox-active substances and biomass accumulation,and(ii)the incorporation of a filtration process in EAB formation enhanced the proportion of viable cells and encouraged a more diverse range of electroactive ***,the novel electroactive membrane demonstrated sustained current production and effective solid-liquid separation during prolonged operation,indicating its potential as a viable alternative in membrane-based *** approach not only provides a new operational model for BES but also holds promise for expanding its application in future wastewater treatment solutions.

关键词： Electroactive biofilm Membrane filtration Spatial structure Mass transfer Microbial community

Effects of binders on the performance of electric double-layer capacitors of carbon nanotube electrodes

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

Progress in Natural Science:Materials International 2005年第5期15卷 453-457页

作者： LI Chensha1*, WANG Dazhi1, zhang Baoyou2, WANG Xiaofeng1, CAO Maosheng3. and LIANG Ji1(1. Department of Mechanical Engineering, Tsinghua university, beijing 100084,{3. 2. Center for Analysis and Measurement, Harbin Institute of Technology, Harbin 150001,{3. 3. school of Material Science and Engineering, Tsinghua university, beijing 100084,{3.) Department of Mechanical Engineering Tsinghua University Beijing 100084 China Center for Analysis and Measurement Harbin Institute of Technology Harbin 150001 China school of Material Science and Engineering Tsinghua University Beijing 100084 China

Polarizable electrodes of electric double layer capacitor (EDLCs) were made from carbon nanotubes. Effects of different binders, which are phenolic resin (PF) and polytetrafluoroethylene (PTFE), on the properties of polarizable electrodes are studied. Results indicate that the microstructure, pore size distribution and specific capacitance of the electrodes with PTFE binder are superior to those electrodes with PF binder after carbonization. The suitable binder (PTFE) for carbon nanotubes electrodes is proposed.

关键词： carbon nanotubes electric double-layer capacitors phenolic resin polytetrafluoroethylene.

Bone marrow mesenchymal stem cells in treatment of peripheral nerve injury

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 Stem Cells 2024年第8期16卷 799-810页

作者： Xiong-Fei Zou Bao-Zhong zhang Wen-Wei Qian Florence mei Cheng Department of Orthopedic Surgery Peking Union Medical College HospitalBeijing 100730China College of Nursing The Ohio State UniversityOhioOH 43210United States

Peripheral nerve injury(PNI)is a common neurological disorder and complete functional recovery is difficult to *** recent years,bone marrow mesenchymal stem cells(BMSCs)have emerged as ideal seed cells for PNI treatment due to their strong differentiation potential and autologous trans-plantation *** review aims to summarize the molecular mechanisms by which BMSCs mediate nerve repair in *** key mechanisms discussed include the differentiation of BMSCs into multiple types of nerve cells to promote repair of nerve *** also create a microenvironment suitable for neuronal survival and regeneration through the secretion of neurotrophic factors,extracellular matrix molecules,and adhesion ***,BMSCs release pro-angiogenic factors to promote the formation of new blood *** modulate cytokine expression and regulate macrophage polarization,leading to ***,BMSCs synthesize and release proteins related to myelin sheath formation and axonal regeneration,thereby promoting neuronal repair and ***,this review explores methods of applying BMSCs in PNI treatment,including direct cell trans-plantation into the injured neural tissue,implantation of BMSCs into nerve conduits providing support,and the application of genetically modified BMSCs,among *** findings confirm the potential of BMSCs in treating ***,with the development of this field,it is crucial to address issues related to BMSC therapy,including establishing standards for extracting,identifying,and cultivating BMSCs,as well as selecting application methods for BMSCs in PNI such as direct transplantation,tissue engineering,and genetic *** these issues will help translate current preclinical research results into clinical practice,providing new and effective treatment strategies for patients with PNI.

关键词： Bone marrow mesenchymal stem cells Peripheral nerve injury Schwann cells Myelin sheath Tissue engineering

Particle modulations to turbulence in two-phase round jets

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

Acta Mechanica Sinica 2009年第5期25卷 611-617页

作者： Bing Wang Huiqiang zhang Yi Liu Xiaofen Yan Xilin Wang school of Aerospace, Tsinghua university, 100084 {3., china school of Aerospace Tsinghua University 100084 Beijing China

The particle modulations to turbulence in round jets were experimentally studied by means of two-phase velocity measurements with Phase Doppler Anemometer （PDA）. Laden with very large particles, no significant attenuations of turbulence intensities were measured in the farfields, due to small two-phase slip velocities and particle Reynolds number. The gas-phase turbulence is enhanced by particles in the near-fields, but it is significantly attenuated by the small particles in the far-fields. The smaller particles have a more profound effect on the attenuation of turbulence intensities. The enhancements or attenuations of turbulence intensities in the far-fields depends on the energy production, transport and dissipation mechanisms between the two phases, which are determined by the particle prop- erties and two-phase velocity slips. The non-dimensional parameter CTI is introduced to represent the change of turbulence intensity.

关键词： Particle modulations Turbulence intensity Particle sizes Two-phase slip velocity Particle-laden round turbulent jet

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2004年第10期47卷 896-911页

作者： zhang Changhou1,2, WU Ganguo1,2, WANG Genhou2, zhang Weijie2 & SONG Honglin2 1. Key Laboratory of Lithospheric Tectonics and Lithoprobing Technology, china {3. of Geosciences, Ministry of Education of china, beijing 100083. china 2. school of Earth sciences and Mineral Resources, china {3. of Geosciences, beijing 100083. china 1. Key Laboratory of Lithospheric Tectonics and Lithoprobing Technology China University of Geosciences Ministry of Education of China 100083 Beijing China 2. school of Earth sciences and Mineral Resources China University of Geosciences 100083 Beijing China

The northwest trending tectonic belt in the middle part of the Mesozoic intraplate Yanshan Orogenic Belt, northeast Hebei Province, is composed of thrusts, extensional faults, strike-slip faults and syntectonic sedimentations as well. The northeastward basement-involved major thrusting deformation occurred between 174Ma and 168MaBP and was followed by an intrusion of the granitic plutonic rocks. As a part of the post-thrusting extensional deformations a northwest extending volcano-sedimentation system of Late Jurassic and Early Cretaceous formed in the southwest side of the belt. These volcano-sedimentary sequences are divided into Tuchengzi Formation, zhangjiakou Formation, Yixian Formation and Jiufotang Formation re- spectively. They are characterized by southeastward migration as a result of the increasing down-dip slip displacement along the major extensional fault toward the southeast of the belt. The provenance area of the Jiufotang Formation north to it experienced southwestward thrusting during and after its later sedimentation. The thrusting in this stage resulted in the formation of an asymmetric footwall syncline with vergence to SW in the Jiufotang Formation in the NE side of the basin. Finally a dextral strike-slip deformation occurred along the NW tectonic belt. The striking tectono-geomorphological features and present seismic activities along this belt indicate that it has been being active since Cenozoic era and is still in the active state at present. This northwest extending tectonic belt was following the same direction and location as the existing fault systems within the basement as revealed by former geological and geophysical studies. So it is reasonable to infer the Mesozoic deformation along this belt to be a result of reactivation of the basement structures in a favorable tectonic stress field. The reactivation of basement struc- tures might be taken as one of the mechanisms of intraplate deformation and orogeny.

关键词： Yanshan Orogenic Belt, northwest extending tectonic complex, thrust system, geochronology.

Joint source channel VL coding/decoding for deep space communication networks based on a space trellis

在线全文

学校读者我要写书评

暂无评论

Science china(Information sciences) 2011年第9期54卷 1883-1894页

作者： WU WeiRen 1,TU Juan 2,TU GuoFang 1,GAO ShaoShuai 1 & zhang Can 1,3.1 school of Information Science and Engineering,Graduate university of Chinese Academy of {3.,beijing 100049,china 2 beijing Institute of Electronic System Engineering,china Aerospace Science & Industry Corp.,beijing 100854,china 3.State Key Laboratory of Information Security,Graduate university of Chinese Academy of Science,beijing 100049,china 1. school of Information Science and Engineering Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Beijing Institute of Electronic System Engineering China Aerospace Science & Industry Corp. Beijing 100854 China3. State Key Laboratory of Information Security Graduate University of Chinese Academy of Science Beijing 100049 China

This paper presents joint source channel variable length (VL) coding/decoding based on a space *** constructing a joint decoding plane trellis,better decoding performance can be achieved than by using the bit-level decoding ***,the plane trellis is complicated,which results in high decoding complexity for decoding VL turbo *** solve this problem,we construct a space trellis and design a low-complexity joint decoding algorithm with a variable length symbol-a posteriori probability (VLS-APP) algorithm in resource constrained deep space communication *** results show that the proposed approach reduces the decoding complexity by 10% compared with the plane trellis,and the gain of Eb/N0 is about 0.2 dB at SER=***,it provides substantial error protection for variable-length encoded image data.

关键词： joint coding/decoding VL turbo codes space trellis VLS-APP