检索结果-南通市图书馆

An Improved Grasshopper Optimization Algorithm for Global Optimization

Chinese Journal of Electronics 2021年第3期30卷 451-459页

作者： yan yan MA Hongzhong LI zhendong College of Energy and Electrical Engineering Nanjing Hohai University Collaborative Innovation Center for Ningxia Big Data and Artificial Intelligence Co-founded by Ningxia Municipality and Ministry of Education Ningxia University School of Information Engineering Ningxia University

We proposes an improved grasshopper algorithm for global optimization problems. Grasshopper optimization algorithm(GOA) is a recently proposed meta-heuristic algorithm inspired by the swarming behavior of grasshoppers. The original GOA has some drawbacks,such as slow convergence speed, easily falling into local optimum, and so on. To overcome these shortcomings, we proposes a grasshopper optimization algorithm based on a logistic Chaos maps opposition-based learning strategy and cloud model inertia weight(CCGOA). CCGOA is divided into three stages. The chaos opposition learning initialization strategy is used to initialize the population,so that the population can be evenly distributed in the feasible solution space as much as possible, so as to improve the uniformity and diversity of the initial population distribution of the grasshopper algorithm. The inertia weight cloud model is introduced into the grasshopper algorithm, and different inertia weight strategies are used to adjust the convergence speed of the algorithm. Based on the principle of chaotic logistic maps, local depth search is carried out to reduce the probability of falling into local optimum. Fourteen benchmark functions and an engineering example are used for simulation verification.Experimental results show that the proposed CCGOA algorithm has superior performance in determining the optimal solution of the test function problem.

关键词： Optimisation techniques Learning in AI (theory) Combinatorial mathematics Cloud model inertia weight Grasshopper optimization algorithm Chaos logistic maps opposition based learning strategy Local depth search

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Deep Learning Based Channel Estimation in Fog Radio Access Networks

引用

China Communications 2019年第11期16卷 16-28页

作者： zhendong Mao Shi yan State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications

As a promising paradigm of the fifth generation networks,fog radio access network(F-RAN)has attracted lots of attention nowadays.To fully utilize the promising gain of F-RANs,the acquisition of accurate channel state information is significant.However,conventional channel estimation approaches are not suitable in F-RANs due to the large training and feedback overhead.In this paper,we consider the channel estimation in F-RANs with fog access point(F-AP)equipped with massive antennas.Thanks to the computing ability of F-AP and the sparsity of channel matrices in angular domain,Gated Recurrent Unit(GRU),a data-driven based channel estimation is proposed at F-AP to reduce the training and feedback overhead.The GRU-based method can capture the hidden sparsity structure automatically through the network training.Moreover,to further improve the channel estimation,a bidirectional GRU based method is proposed,whose target channel structure is decided by previous and subsequent structures.We compare the performance of our proposed channel estimation with traditional methods(Orthogonal Matching Pursuit(OMP)and Simultaneous OMP(SOMP)).Simulation results show that the proposed approaches have better performance compared with the traditional OMP and SOMP methods.

关键词： fog radio access network(F-RAN) massive MIMO compressive sensing deep learning gated recurrent unit(GRU)

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

Optimization of the Structural Parameters of a Plastic Centrifugal Pump in the Framework of a Flow Field Analysis

引用

Fluid Dynamics & Materials Processing 2022年第3期18卷 789-813页

作者： Wenbin Luo Youmin Wang Yuting yan Yifang Shi zhendong Zhang School of Mechanical Engineering Anhui Polytechnic UniversityWuhu241000China Hohai University Nanjing210098China Anhui Institute of Information Technology Wuhu241199China

In order to determine the optimal structural parameters of a plastic centrifugal pump in the framework of an orthogonal-experiment approach,a numerical study of the related flow field has been performed using CFX.The thickness S,outlet angleβ2,inlet angleβ1,wrap angle,and inlet diameter D1 of the splitter blades have been considered as the variable factors,using the shaft power and efficiency of the pump as evaluation indices.Through a parametric analysis,the relative importance of the influence of each structural parameter on each evaluation index has been obtained,leading to the following combinations:β119°,β235°,S 2 mm,wrap angle 154°,and D185 mm(corresponding to the maximum efficiency of 75.48%);β119°,β220°,S 6 mm,wrap angle 158°,and D181 mm(corresponding to the minimum shaft power of 75.48%).Moreover,the grey correlation method has been applied to re-optimize the shaft power and efficiency of the pump,leading to the following optimal combination:β119°,β215°,S 4 mm,D181 mm,and wrap angle 152°(corresponding to the maximum efficiency of 71.81%and minimum shaft power of 2.187 kW).

关键词： Plastic centrifugal pump splitter blade orthogonal experiment grey correlation method optimal combination

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

An alternative method to reduce process-induced deformation of CFRP by introducing prestresses

引用

Chinese Journal of Aeronautics 2022年第8期35卷 314-323页

作者： zhendong LIU Xitao ZHENG Wenjing FAN Fei WANG Sohail AHMED Leilei yan School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Unmanned System Research Institute Northwestern Polytechnical UniversityXi’an 710072China

Process-induced deformation is an important limiting factor to the application of high performance composite structures.An alternative method to reduce process-induced deformation is proposed by introducing prestress to a single layer or part of the layers instead of all the applicable layers.In this method,the necessary prestress level that applied to the single layer was in the reasonable range.Two kinds of unsymmetric laminates are manufactured at varying prestress levels.The experimental results described that the curing deformation is changed rapidly with the growing prestress level and flipped after a certain prestress level.Moreover,there is a good linear relationship between prestress level and final curing deformation,which gives a convenient way to calculate the prestress level that can fully counteract the curing deformation.The numerical model to predict the curing deformation was built.A good agreement between the numerical and the experimental results shows the effectiveness of the numerical model.To predict the prestress level that can fully counteract the curing deformation,an analytical model is also proposed.Theoretically,the prestress method can fully counteract the curing deformation of the specimens,while the experimental results show that the prestressing layer reduces more than 80%of the curing deformation.

关键词： Curing deformation Prestressing Pre-tension Process-induced deforamtion Residual stress

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

Tectonic analysis and petroleum significance of Cenozoic faults in Dongping-Niuzhong area in Altyn slope

引用

Petroleum Exploration and Development 2019年第5期46卷 983-990页

作者： DU Wei CHEN yan WANG zhendong BIAN Qing GUO Zhaojie Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of EducationBeijing 100871China School of Earth and Space Sciences Peking UniversityBeijing 100871China Qinghai Oilfield Company PetroChinaDunhuang 736202China

The evolution process and petroleum significance of two groups of fault structures,the NW-SE trending and near EW trending ones in the Cenozoic of Dongping-Niuzhong area of the Altyn slope,Qaidam Basin,were investigated using high precision 3-D seismic data.The NW-SE faults were generated in Oligocene,causing the formation of a series of folds related to transpression faults in the Niuzhong and Dongping area.After the Miocene,with the continuous extension of the Altyn Tagh strike-slip fault zone,the EW trending faults began to develop massively in Altyn slope.The activity of near EW trending faults and large-scale uplift of the bedrock in the northern Niuzhong area shared most of the compression torsion in Niuzhong and Dongping area,consequently,the activity of NW-SE trending faults weakened significantly after the Miocene.Then good hydrocarbon source rocks developed in the inherited Jurassic sags.The faults were effective pathways for oil and gas migration in Dongping and Niuzhong areas,and the oil and gas charging time matched well with the formation period of the NW-SE trending faults and their related structures,making the fault-related anticlines favorable targets for oil and gas accumulation.The Niuzhong area has been less affected by the Cenozoic movement after the Miocene,and thus has better conditions for gas reservoir preservation.

关键词： Qaidam Basin Altyn slope Cenozoic tectonic analysis strike-slip fault petroleum significance Dongping-Niuzhong area

来源：

维普期刊数据库

同方期刊数据库

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

Innovatively employing magnetic CuO nanosheet to activate peroxymonosulfate for the treatment of high-salinity organic wastewater

引用

Journal of Environmental Sciences 2020年第2期32卷 46-58页

作者： zhendong Li yanmei Sun Wenli Huang Cheng Xue yan Zhu Qianwen Wang Dongfang Liu Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution College of Environmental Science and EngineeringNankai UniversityTianjin 300350China Construction Management Department Tianjin Eco-City Water Investment and Construction Co.Ltd.Tianjin 300457China

Magnetic CuO nanosheet(Mag-CuO), as a cheap, stable, efficient and easily separated peroxymonosulfate(PMS) activator, was prepared by a simple one-step precipitation method for the removal of organic compounds from salt-containing wastewater.The experiments showed that the removal efficiencies of various organic pollutants including Acid Orange 7, Methylene Blue, Rhodamine B and atrazine in a high-salinity system(0.2 mol/L Na2SO4) with the Mag-CuO/PMS process were 95.81%, 74.57%, 100% and 100%,respectively.Meanwhile, Mag-CuO still maintained excellent catalytic activity in other salt systems including one or more salt components(NaCl, NaNO3, Na2HPO4, NaHCO3).A radical-quenching study and electron paramagnetic resonance analysis confirmed that singlet oxygen(1O2) was the dominant reactive oxygen species for the oxidation of organic pollutants in high-salinity systems, which is less susceptible to hindrance by background constituents in wastewater than radicals(·OH or SO4·-).The surface hydroxylation of the catalyst and catalytic redox cycle including Cu and Fe are responsible for the generation of1O2.The developed Mag-CuO catalyst shows good application prospects for the removal of organic pollutants from saline wastewater.

关键词： Singlet oxygen (1O2) CuO nanosheet Saline wastewater Peroxymonosulfate activation Magnetic separation

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

Development and Deformation Characteristics of Large Ancient Landslides in the Intensely Hazardous Xiongba-Sela Section of the Jinsha River， Eastern Tibetan Plateau， China

引用

Journal of Earth Science 2023年

作者： Yiqiu yan Changbao Guo yanan Zhang zhendong Qiu Caihong Li Xue Li Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural Resources Institute of Geomechanics Chinese Academy of Geological Sciences

The upstream Jinsha River， located in the eastern Tibetan Plateau， experiences intense geological hazard development， characterized by a high density of ancient landslides， significant deformation and reactivation challenges. In this study， we employed remote sensing interpretation， field investigations， and Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technology. Along a 17 km stretch of the Jinsha River， specifically in the Xiongba-Sela segment， we identified 16 large-scale ancient landslides， 9 of which are currently undergoing creeping deformation. Notably， the Sela and Xiongba ancient landslides exhibit significant deformation， with a maximum deformation rate of -192 mm/yr， indicating a high level of sliding activity. The volume of the Sela ancient landslide is estimated to be 1.8 × 108to 4.5 × 108m3， and characterized by extensive fissures and long-term creeping deformation. Our SBAS-InSAR result revealed significant spatial variations in the deformation of the Sela ancient landslide， generally displaying two secondary zones of intense deformation， and landslide deformation exhibits nonlinear behavior with time. Between January 2016 and February 2022， Zone III1on the southwest side of the Sela ancient landslide， experienced a maximum cumulative deformation of -857 mm， with a maximum deformation rate of -108 mm/yr. Zone III2， on the northeast side of the Sela ancient landslide， the maximum cumulative deformation was -456 mm， with a maximum deformation rate of -74 mm/yr; among these， the H2 and H4 secondary bodies on the south side of III1are in the accelerative deformation stage and at the Warn warning level. We propose that the large-scale flood and debris flow disasters triggered by the Baige landslide-dammed lake-dam broken disaster chain in Tibet during October and November 2018 caused severe erosion at the foot of downstream slopes. This far-field triggering effect accelerated the creep of the downstream ancient landslides. Consequently， the deformation rate of Zone III2of

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Significantly Enhanced Actuation Performance of IPMC by Surfactant-Assisted Processable MWCNT/Nafion Composite

引用

Journal of Bionic Engineering 2013年第3期10卷 359-367页

作者： Qingsong He Min Yu Dingshan Yu yan Ding zhendong Dai Institute of Bio-Inspired Structure and Surface Engineering Nanjing University of Aeronautics & Astronautics Nanjing 210016 P. R. China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics & Astronautics Nanjing 21 O016 P. R. China Department of Chemical Engineering Case Western Reserve University Cleveland 44106 USA

The performance of Ionic Polymer Metal Composite （IPMC） actuator was significantly enhanced by incorporating surfactant-assisted processable Multi-Walled Carbon Nanotubes （MWCNTs） into a Nation solution. Cationic surfactant Cetyl Trimethyl Ammonium Bromide （CTAB） was employed to disperse MWCNTs in the Nation matriX, forming a homogeneous and stable dispersion ofnanotubes. The processing did not involve any strong acid treatment and thus effectively preserved the excellent electronic properties associated with MWCNT. The as-obtained MWCNT/Nafion-IPMC actuator was tested in terms of conductivity, bulk and surface morphology, blocking force and electric current. It was shown that the blocking force and the current of the new IPMC are 2.4 times and 1.67 times higher compared with a pure Nation-based IPMC. Moreover, the MWCNT/IPMC performance is much better than previously reported Nafion-IPMC doped by acid-treated MWCNT. Such significantly improved performance should be attributed to the improvement of electrical property associated with the addition of MWCNTs without acid treatment.

关键词： ionic polymer metal composite homogeneous actuator conductivity cetyl trimethyl ammonium bromide multi-walled carbon nanotube

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

Morphology and multifractal features of a guyot in specific topographic vicinity in the Caroline Ridge,West Pacific

引用

Journal of Oceanology and Limnology 2021年第5期39卷 1591-1604页

作者： Yu GAN Xiaochuan MA zhendong LUAN Jun yan CAS Key Laboratory of Marine Geology and Environment Institute ofOceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Geology Pilot National Laboratory for MarineScience and Technology(Qingdao)Qingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao266071China

Massive seamounts have been surveyed and documented in the last decades.However,the morphologies of seamounts are usually described in qualitative manners,yet few quantitative detections have been carried out.Here,based on the high-re solution multi-beam bathymetric data,we report a recentlysurveyed guy ot on the Caroline Ridge in the West Pacific,and the large-scale volcanic structures and smallscale erosive-depositional landforms in the guyot area have been identified.The multifractal features of the guyot are characterized for the first time by applying multifractal detrended fluctuation analysis on the surveyed bathymetric data.The results indicate that the multifractal spectrum parameters of the seafloor have strong spatial dependency on the fluctuations of local landforms.Both small-and large-scale components contribute to the degree of asymmetry of the multifractal spectrum(B),while the fluctuations of B are mostly attributed to the changes in small-scale roughness.The maximum singularity strength(α0)correlates well with the roughness of large-scale landforms and likely reflects the large-scale topographic irregularity.Comparing to traditional roughness parameters or monofractal exponents,multifractal spectra are able to depict not only the multiscale characteristics of submarine landforms,but also the spatial variations of scaling behaviors.Although more comparative works are required for various seamounts,we hope this study,as a case of quantifying geomorphological characters and multiscale behaviors of seamounts,can encourage further studies on seamounts concerning geomorphological processes,ocean bottom circulations,and seamount ecosystems.

关键词： guyot morphology multifractal detrended fluctuation analysis(MFDFA) Caroline Ridge West Pacific Ocean

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

Large-area surface-enhanced Raman scattering-active substrates fabricated by femtosecond laser ablation

引用

Science China(Physics,Mechanics & Astronomy) 2013年第9期56卷 1806-1809页

作者： ZHU ZhiQing YAN ZhenDong ZHAN Peng WANG ZhenLin School of Physics and National Laboratory of Solid State Microstructures Nanjing University

A rapid and simple approach to fabricate large-area surface-enhanced Raman scattering-active(SERS-active) substrates is reported.The substrates are fabricated by using femtosecond laser(fs-laser) direct writing on Silicon wafers,followed by thin-film coating of metal such as gold.The substrates are demonstrated to exhibit signal homogeneity and good enhancement ability for SERS.The maximum enhancement factor(EF) up to 3×10 7 of such SERS substrates for rhodamine 6G(R6G) at 785 nm excitation wavelength was measured.This technique could demonstrate a functional microchip with SERS capability of signal homogeneity,high sensitivity and chemical stability.

关键词：表面增强拉曼散射 SERS活性飞秒激光激光烧蚀面积基底制备罗丹明6G

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

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：