检索结果-南通市图书馆

Numerical Investigation on Vortex-Induced Rotations of A Triangular Cylinder Using An Immersed Boundary Method

China Ocean Engineering 2019年第6期33卷 723-733页

作者： WANG Hua-kun YAN Yu-hao chen can-ming JI Chun-ning ZHAI Qiu Jiangsu Key Laboratory of Coast Ocean Resources Development and Environment Security College of HarbourCoastal and Offshore EngineeringHohai UniversityNanjing 210098China State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China Key Laboratory of Water Science and Water Engineering of Ministry of Water Resources Nanjing Hydraulic Research InstituteNanjing 210029China

A numerical study of vortex-induced rotations(VIRs) of an equivalent triangular cylinder, which is free to rotate in the azimuthal direction in a uniform flow, is presented. Based on an immersed boundary method, the numerical model is established, and is verified through the benchmark problem of flow past a freely rotating rectangular *** computation is performed for a fixed reduced mass of m~*=2.0 and the structural stiffness and damping ratio are set to zero. The effects of Reynolds number(Re=25-180) on the characteristics of VIR are studied. It is found that the dynamic response of the triangular cylinder exhibits four distinct modes with increasing Re: a rest position,periodic rotational oscillation, random rotation and autorotation. For the rotational oscillation mode, the cylinder undergoes a periodic vibration around an equilibrium position with one side facing the incoming flow. Since the rotation effect, the outset of vortex shedding from cylinder shifts to a much lower Reynolds number. Further increase in Re leads to 2 P and P+S vortex shedding modes besides the typical 2 S pattern. Our simulation results also elucidate that the free rotation significantly changes the drag and lift forces. Inspired by these facts, the effect of free rotation on flow-induced vibration of a triangular cylinder in the in-line and transverse directions is investigated. The results show that when the translational vibration is coupled with rotation, the triangular cylinder presents a galloping response instead of vortex-induced vibration(VIV).

关键词： vortex-induced rotation triangular cylinder dynamic response vortex shedding mode immersed boundary method

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

Activation of peroxymonosulfate by sustainable biomass-based carbon nanotubes for controlling the spread of plant viruses in water environments

引用

Journal of Environmental Sciences 2025年第3期149卷 99-112页

作者： Jian Tang Yujie Wang JunMa Yujie chen ming chen College of Resources and Environment Yangtze UniversityWuhan 430100China Key Laboratory of Reservoir Aquatic Environment Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China Chongqing School University of Chinese Academy of SciencesChongqing 400714China School of Geography and Tourism Chongqing Normal UniversityChongqing 400714China

With the increasing demand for water in hydroponic systems and agricultural irrigation,viral diseases have seriously affected the yield and quality of *** removing plant viruses in water environments,virus transmission can be prevented and agricultural production and ecosystems can be *** so far,there have been few reports on the removal of plant viruses in water ***,in this study,easily recyclable biomass-based carbon nanotubes catalysts were synthesized with varying metal activities to activate peroxymonosulfate(PMS).Among them,the magnetic 0.125Fe@NCNTs-1/PMS system showed the best overall removal performance against pepper mild mottle virus,with a 5.9 log_(10)removal within 1 ***,the key reactive species in the 0.125Fe@NCNTs-1/PMS system is^(1)O_(2),which can maintain good removal effect in real water matrices(river water and tap water).Through RNA fragment analyses and label free analysis,it was found that this system could effectively cleave virus particles,destroy viral proteins and expose their *** capsid protein of pepper mild mottle virus was effectively decomposed where serine may be the main attacking sites by^(1)O_(2).Long viral RNA fragments(3349 and 1642 nt)were cut into smaller fragments(∼160 nt)and caused their *** summary,this study contributes to controlling the spread of plant viruses in real water environment,which will potentially help protect agricultural production and food safety,and improve the health and sustainability of ecosystems.

关键词： Pepper mild mottle virus Removal Plant virus spread Biomass-based carbon nanotubes Water environments

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

江西省征地补偿标准与区域经济时空耦合关系研究

引用

中国人口·资源与环境 2018年第S1期28卷 140-142页

作者：陈灿明何春博江西师范大学地理与环境学院江西南昌330022

研究目的:通过构建耦合模型,揭示江西省征地补偿标准与区域经济系统间的耦合关系,并从时空角度对耦合关系的分布规律进行分析。研究方法:本文运用灰色关联分析法,构建耦合模型,测算耦合度系数,并通过arcgis10.1进行可视化。研究结果:江... 详细信息

研究目的:通过构建耦合模型,揭示江西省征地补偿标准与区域经济系统间的耦合关系,并从时空角度对耦合关系的分布规律进行分析。研究方法:本文运用灰色关联分析法,构建耦合模型,测算耦合度系数,并通过arcgis10.1进行可视化。研究结果:江西省征地补偿标准与区域经济之间关联程度较高;空间分布基本以拮抗类型为主、低水平耦合次之;耦合度分布符合南、北空间分异的规律,同时以浙赣线为横轴,昌九线为纵轴,交汇于南昌;时序上,两者关联度呈现出平稳上升趋势。

关键词：征地补偿标准区域经济耦合江西省

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

New classification of gastric polyps:An in-depth analysis and critical evaluation

引用

World Journal of Gastroenterology 2025年第7期31卷 149-155页

作者： Xiao-Hui Liao Ying-ming Sun Hong-Bin chen Department of Gastroenterology The First Hospital of Sanming Affiliated to Fujian Medical UniversityFujian Medical UniversitySanming 365000Fujian ProvinceChina Department of Medical and Radiation Oncology Sanming First HospitalFujian Medical UniversitySanming 365000Fujian ProvinceChina Department of Gastroenterology I Sanming First HospitalFujian Medical UniversitySanming 365000Fujian ProvinceChina

With the widespread use of upper gastrointestinal endoscopy,more and more gastric polyps(GPs)are being *** management strategies often rely on histopathologic examination,which can be time-consuming and may not guide immediate clinical *** paper aims to introduce a novel classification system for GPs based on their potential risk of malignant transformation,categorizing them as"good","bad",and"ugly".A review of the literature and clinical case analysis were conducted to explore the clinical implications,management strategies,and the system's application in endoscopic *** polyps,mainly including fundic gland polyps and inflammatory fibrous polyps,have a low risk of malignancy and typically require minimal or no *** polyps,mainly including hyperplastic polyps and adenomas,pose an intermediate risk of malignancy,necessitating closer monitoring or *** polyps,mainly including type 3 neuroendocrine tumors and early gastric cancer,indicate a high potential for malignancy and require urgent and comprehensive *** new classification system provides a simplified and practical framework for diagnosing and managing GPs,improving diagnostic accuracy,guiding individualized treatment,and promoting advancements in endoscopic *** some challenges,such as the risk of misclassification due to similar endoscopic appearances,this system is essential for the standardized management of *** also lays the foundation for future research into biomarkers and the development of personalized medicine.

关键词： Gastric polyps Classification Fundic gland polyps Inflammatory fibroid polyps Hyperplastic polyps Adenomas Neuroendocrine tumors Early gastric cancer Patient management

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

Deciphering environmental factors influencing phytoplankton community structure in a polluted urban river

引用

Journal of Environmental Sciences 2025年第2期148卷 375-386页

作者： Xiaxia Li Kai chen Chao Wang Tianyu Zhuo Hongtao Li Yong Wu Xiaohui Lei ming Li Bin chen Beibei Chai School of Water Conservancy and Hydroelectric Power Hebei University of EngineeringHandan 056038China Collaborative Innovation Center for Intelligent Regulation and Comprehensive Management of Water Resources School of Water Conservancy and HydroelectricHebei University of EngineeringHandan 056038China Hebei Key Laboratory of Intelligent Water Conservancy Hebei University of EngineeringHandan 056038China Tianjin Water Group Binhai Water Co. Ltd.Tianjin 300308China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100038China School of Architecture and Civil Engineering Xi’an University of Science and TechnologyXi’an 710054China chengdu University of Technology Chengdu 610059China College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentBeijing Normal UniversityBeijing 100875China

Tuojiang River Basin is a first-class tributary of the upper reaches of the Yangtze River—which is the longest river in *** phytoplankton are sensitive indicators of trophic changes inwater bodies,characterizing phytoplankton communities and their growth influencing factors in polluted urban rivers can provide new ideas for pollution ***,we used direct microscopic count and environmental DNA(eDNA)metabarcoding methods to investigate phytoplankton community structure in Tuojiang River Basin(chengdu,Sichuan Province,China).The association between phytoplankton community structure and water environmental factors was evaluated by Mantel *** environmental monitoring data were used to pinpoint major factors that influenced phytoplankton growth based on structural equation *** the phylum level,the dominant phytoplankton taxa identified by the conventional microscopic method mainly belonged to Bacillariophyta,Chlorophyta,and Cyanophyta,in contrast with Chlorophyta,Dinophyceae,and Bacillariophyta identified by eDNA ***α-diversity analysis,eDNA metabarcoding detected greater species diversity and achieved higher precision than the microscopic *** growth was largely limited by phosphorus based on the nitrogen-to-phosphorus ratios>16:1 in all water *** analysis and structural equation modeling also confirmed that the nitrogen-to-phosphorus ratio was the principal factor influencing phytoplankton *** results could be useful for implementing comprehensive management of the river basin *** is recommended to control the discharge of point-and surface-source pollutants and the concentration of dissolved oxygen in areas with excessive nutrients(e.g.,Jianyang-Ziyang).Algae monitoring techniques and removal strategies should be improved in 201 Hospital,Hongrihe Bridge and Colmar Town areas.

关键词： Environmental DNA Microscopic count Phytoplankton growth Structural equation modeling Tuojiang River Basin

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

Alpha-decay properties of nuclei around neutron magic numbers

引用

Nuclear Science and Techniques 2025年第1期36卷 140-149页

作者： ming Li Chu-Xin chen Lan-Fang Xiao Yi Zhang Song Luo Xiao-Hua Li School of Nuclear Science and Technology University of South ChinaHengyang 421001China PET‑CT Center Chenzhou First People’s HospitalChenzhou 423000China Hengyang Ecological Environment Monitor Center Hengyang 421001China China Certification and Inspection Group Hefei 230000China National Exemplary Base for International Science and Technology Collaboration of Nuclear Energy and Nuclear Safety University of South ChinaHengyang 421001China Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment University of South ChinaHengyang 421001China Key Laboratory of Low Dimensional Quantum Structures and Quantum Control Hunan Normal UniversityChangsha 410081China

By combining experimental α-decay energies and half-lives, the α-particle preformation factor for nuclei around neutron magic numbers N of 126, 152, and 162 were extracted using the two-potential approach. The nuclei around the shell closure were more tightly bound than adjacent nuclei. Additionally, based on the WS4 mass model (Wang et al., Phys. Lett.B 734, 215 (2014)), we extended the two-potential approach to predict the α-decay half-lives of nuclei around N values of178 and 184 with Z of 119 and 120. We believe that our findings will serve as guidelines for future experimental studies.

关键词： adecay Preformation factor Neutron magic number Heavy and superheavy nuclei

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

Long-term trends and response of wet ammonia deposition to changes in anthropogenic emissions in the Pearl River delta of China

引用

Journal of Environmental Sciences 2025年第5期151卷 373-386页

作者： mingyue Li Lyumeng Ye ming Chang Weihua chen Shuidi He Buqing Zhong Xuemei Wang Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Institute for Environmental and Climate ResearchJinan UniversityGuangzhou 511443China South China Institute of Environmental Sciences The Ministry of Ecology and Environment of PRCGuangzhou 510530China Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China

The Pearl River Delta(PRD)region has been identified as a significant hotspot of wet ammonium ***,the absence of long-term monitoring data in the area hinders the comprehension of the historical trends and changes in wet NH_(4)^(+)-N deposition in response to emissions,which interferes with the ability to make effective *** study has analyzed the long-term trends of wet NH_(4)^(+)-N deposition flux and has quantified the effect of anthropogenic emissions and meteorological factors at a typical urban site and a typical forest site in the PRD region from 2009 to *** revealed a significant decreasing trend in wet NH_(4)^(+)-N flux in both the typical urban and forest areas of the PRD region,at-6.2%/year(p<0.001)and-3.3%/year(p<0.001),*** emissions are thought to have contributed 47%–57%of the wet NH_(4)^(+)-N deposition trend over the past 12 years compared to meteorological *** conditions dominated the interannual fluctuations in wet NH_(4)^(+)-N deposition with an absolute contribution of 46%–52%,while anthropogenic emissions change alone explained 10%–31%.NH_(3)emissions have the greatest impact on the urban area among anthropogenic emission factors,while SO_(2)emissions have the greatest impact on the forest ***,precipitation was identified as the primary meteorological driver for both *** findings also imply that the benefits of NH_(3)emissions reductions might not immediately emerge due to interference from weather-related factors.

关键词： Long-term trends Inter-annual variation Wet ammonium deposition Anthropogenic emission change Meteorological condition The Pearl River Delta region

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

Least Square Estimation for Multiple Functional Linear Model with Autoregressive Errors

引用

Acta Mathematicae Applicatae Sinica 2025年第1期41卷 84-98页

作者： Meng WANG ming-liang SHU Jian-jun ZHOU Si-xin WU Min chen School of Management University of Science and Technology of ChinaHefei 230026China Academy of Mathematics and System Science Chinese Academy of SciencesBeijing 100190China Yunnan Key Laboratory of Statistical Modeling and Data Analysis Yunnan UniversityKunming 650091China

As an extension of linear regression in functional data analysis, functional linear regression has been studied by many researchers and applied in various fields. However, in many cases, data is collected sequentially over time, for example the financial series, so it is necessary to consider the autocorrelated structure of errors in functional regression background. To this end, this paper considers a multiple functional linear model with autoregressive errors. Based on the functional principal component analysis, we apply the least square procedure to estimate the functional coefficients and autoregression coefficients. Under some regular conditions, we establish the asymptotic properties of the proposed estimators. A simulation study is conducted to investigate the finite sample performance of our estimators. A real example on China's weather data is applied to illustrate the validity of our model.

关键词： multiple functional linear model autoregressive errors principal component analysis consistency

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

枣粮间作生态系统土壤氮空间分布特性

引用

生态学报 2009年第1期29卷 325-331页

作者：尹飞毛任钊傅伯杰陈明灿中国科学院生态环境研究中心城市与区域生态国家重点实验室北京100085 中国科学院遗传与发育生物学研究所农业资源研究中心石家庄050021 河南科技大学洛阳471003

基于枣粮间作复合生态系统内部异质性,通过在不同位置采样测定,探讨了枣粮间作系统内土壤氮素空间分布特性。结果表明:(1)枣粮间作生态系统中,在小麦收获期和玉米收获期两个时期,土壤全氮和硝态氮含量均存在明显的垂直和水平两个方向空... 详细信息

基于枣粮间作复合生态系统内部异质性,通过在不同位置采样测定,探讨了枣粮间作系统内土壤氮素空间分布特性。结果表明:(1)枣粮间作生态系统中,在小麦收获期和玉米收获期两个时期,土壤全氮和硝态氮含量均存在明显的垂直和水平两个方向空间变异性。而土壤铵态氮含量极低且没有明显的空间变异;(2)与全氮相比,枣粮间作系统中硝态氮空间变异性更强,且随着时间变化其空间分布特性有明显变化;(3)氮素施用量对土壤全氮和硝态氮空间变异有正向作用,而植株对氮的吸收利用可以降低土壤氮素分布空间差异程度。各因子对土壤全氮空间变异影响强弱顺序为氮吸收量>氮素施用量>土壤含水量;对土壤硝态氮空间变异影响强弱顺序为氮素施用量>土壤全氮含量>氮素吸收量>土壤含水量。

关键词：枣粮间作全氮硝态氮分布空间异质性

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

Masking quantum information in multipartite systems via Fourier and Hadamard matrices

引用

Communications in Theoretical Physics 2025年第2期77卷 101-111页

作者： chen-ming Bai Meng-Ya Wang Su-Juan Zhang Lu Liu Department of Mathematics and Physics Shijiazhuang Tiedao University

Quantum information masking（QIM） is a crucial technique for protecting quantum data from being accessed by local subsystems. In this paper, we introduce a novel method for achieving1-uniform QIM in multipartite systems utilizing a Fourier matrix. We further extend this approach to construct an orthogonal array with the aid of a Hadamard matrix, which is a specific type of Fourier matrix. This allows us to explore the relationship between 2-uniform QIM and orthogonal arrays. Through this framework, we derive two distinct 2-uniform quantum states,enabling the 2-uniform masking of original information within multipartite ***, we prove that the maximum number of quantum bits required for achieving a2-uniformly masked state is 2~n-1, and the minimum is 2n-1+ 3. Moreover, our scheme effectively demonstrates the rich quantum correlations between multipartite systems and has potential application value in quantum secret sharing.

关键词： multipartite systems quantum information masking Fourier matrix orthogonal arrays

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

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：