检索结果-南通市图书馆

Bifurcation analysis and control study of improved full-speed differential model in connected vehicle environment

Chinese Physics B 2024年第7期33卷 245-266页

作者：艾文欢雷正清李丹洋方栋梁刘大为 College of Computer Science and Engineering Northwest Normal UniversityLanzhou 730070China College of Electrical Engineering Lanzhou Institute of TechnologyLanzhou 730050China

In recent years, the traffic congestion problem has become more and more serious, and the research on traffic system control has become a new hot spot. Studying the bifurcation characteristics of traffic flow systems and designing control schemes for unstable pivots can alleviate the traffic congestion problem from a new perspective. In this work, the full-speed differential model considering the vehicle network environment is improved in order to adjust the traffic flow from the perspective of bifurcation control, the existence conditions of Hopf bifurcation and saddle-node bifurcation in the model are proved theoretically, and the stability mutation point for the stability of the transportation system is found. For the unstable bifurcation point, a nonlinear system feedback controller is designed by using Chebyshev polynomial approximation and stochastic feedback control method. The advancement, postponement, and elimination of Hopf bifurcation are achieved without changing the system equilibrium point, and the mutation behavior of the transportation system is controlled so as to alleviate the traffic congestion. The changes in the stability of complex traffic systems are explained through the bifurcation analysis, which can better capture the characteristics of the traffic flow. By adjusting the control parameters in the feedback controllers, the influence of the boundary conditions on the stability of the traffic system is adequately described, and the effects of the unstable focuses and saddle points on the system are suppressed to slow down the traffic flow. In addition, the unstable bifurcation points can be eliminated and the Hopf bifurcation can be controlled to advance, delay, and disappear,so as to realize the control of the stability behavior of the traffic system, which can help to alleviate the traffic congestion and describe the actual traffic phenomena as well.

关键词： bifurcation analysis vehicle queuing bifurcation control Hopf bifurcation

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

Deconvolution with hybrid parameterizations for radio emission reconstruction

引用

Research in Astronomy and Astrophysics 2021年第4期21卷 287-296页

作者： li Zhang Long Xu li-Gong Mi Ming Zhang Xiang liu Feng Wang Yun-Jun Ruan dan-yang li College of Big Data and Information Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesUrumqi 830011China Center for Astrophysics Guangzhou UniversityGuangzhou 510006China

Deconvolution is used to eliminate imperfections in the point spread function,such as sidelobes caused by incomplete sampling of radio telescopes,and is a key technology for radio synthesis *** telescopes have such high sensitivities that the observed celestial images may contain both compact and diffuse *** essentially requires deconvolution technology to have the ability to model *** this paper,a deconvolution algorithm based on hybrid parameterization is proposed for the rapid reconstruction of complex celestial *** this algorithm,scale-free parameterization is utilized to reconstruct compact emission,while multi-scale parameterization is employed to reconstruct diffuse *** data representing Square Kilometre Array(SKA)observations with realistic celestial brightness distributions are applied to test the performance of the *** experiments show that,compared with other state-of-the-art deconvolution algorithms,the algorithm proposed in this paper can reconstruct complex celestial structures well and provide competitive reconstruction results while greatly improving the reconstruction speed.

关键词： methods:data analysis techniques:image processing techniques:interferometric

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

Application of Optical Hydrogels in Environmental Sensing

引用

Energy & Environmental Materials 2024年第3期7卷 311-336页

作者： Shuo yang Shruti Sarkar Xing Xie dan li Jianmin Chen Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3) Department of Environmental Science and EngineeringFudan UniversityShanghai 200438China School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlanta Georgia 30332USA

The ever-increasing complexity of environmental pollutants urgently warrants the development of new detection *** based on the optical properties of hydrogels enabling fast and easy in situ detection are attracting increasing *** this paper,the data from 138 papers about different optical hydrogels(OHs)are extracted for statistical *** detection performance and potential of various types of OHs in different environmental pollutant detection scenarios were evaluated and compared to those obtained using the standard detection *** on this analysis,the target recognition and sensing mechanisms of two main types of OHs are reviewed and discussed:photonic crystal hydrogels(PCHs)and fluorescent hydrogels(FHs).For PCHs,the environmental stimulus response,target receptors,inverse opal structures,and molecular imprinting techniques related to PCHs are reviewed and ***,the different types of fluorophores(i.e.,compound probes,biomacromolecules,quantum dots,and luminescent microbes)of FHs are ***,the potential academic research directions to address the challenges of applying and developing OHs in environmental sensing are proposed,including the fusion of various OHs,introduction of the latest technologies in various fields to the construction of OHs,and development of multifunctional sensor arrays.

关键词： environmental sensors fluorescent hydrogel optical hydrogel photonic crystal hydrogel pollution detection

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

Adaptive scale model reconstruction for radio synthesis imaging

引用

Research in Astronomy and Astrophysics 2021年第3期21卷 117-127页

作者： li Zhang li-Gong Mi Long Xu Ming Zhang dan-yang li Xiang liu Feng Wang Yi-Fan Xiao Zhong-Zu Wu College of Big Data and Information Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesUrumqi 830011China Center for Astrophysics Guangzhou UniversityGuangzhou 510006China College of Physics Guizhou UniversityGuiyang 550025China

A sky model from CLEAN deconvolution is a particularly effective high dynamic range reconstruction in radio astronomy,which can effectively model the sky and remove the sidelobes of the point spread function(PSF)caused by incomplete sampling in the spatial frequency *** to scale-free and multi-scale sky models,adaptive-scale sky modeling,which can model both compact and diffuse features,has been proven to have better sky modeling capabilities in narrowband simulated data,especially for large-scale features in high-sensitivity observations which are exactly one of the challenges of data processing for the Square Kilometre Array(SKA).However,adaptive scale CLEAN algorithms have not been verified by real observation data and allow negative components in the *** this paper,we propose an adaptive scale model algorithm with non-negative constraint and wideband imaging capacities,and it is applied to simulated SKA data and real observation data from the Karl *** Very Large Array(JVLA),an SKA *** show that the new algorithm can reconstruct more physical models with rich *** work is a step forward for future SKA image reconstruction and developing SKA imaging pipelines.

关键词： methods:data analysis techniques:image processing techniques:interferometric

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

Carbon storage of the forest and its spatial pattern in Tibet,China

引用

Journal of Mountain Science 2021年第7期18卷 1748-1761页

作者： JIA Long-yu WANG Gen-xu LUO Ji RAN Fei li Wei ZHOU Jun yang dan-li SHI Wen-bo XU Qian ZHU Kun Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China College of Tourism and Urban-Rural Planning Chengdu University of TechnologyChengdu 610059China

The raising concentration of atmospheric CO_2 resulted in global *** forest ecosystem in Tibet played an irreplaceable role in maintaining global carbon balance and mitigating climate change for its abundant original forest resources with powerful action of carbon *** the present study,the samples of soil and vegetation were collected at a total of 137 sites from 2001 to 2018 in *** on the field survey of Tibet's forest resources and 8^(th) forest inventory data,we estimated the carbon storage and carbon density of forest vegetation(tree layer,shrub,grass,litter and dead wood) and soil(0-50 cm) in *** methods combined with Kriging spatial interpolation and Moran's I were applied to reveal their spatial distribution patterns and variation *** carbon density of forest vegetation and soil in Tibet were 74.57 t ha^(-1) and 96.24 t ha^(-1),*** carbon storage of forest vegetation and soil in Tibet were 344.35 Tg C and 440.53 Tg C,*** density of fir(Abies forest) was 144.80 t ha^(-1) with the highest value among all the forest *** storage of spruce(Picea forest) was the highest with 99.09 Tg C compared with other forest *** carbon density of fir forest and spruce forest both increased with the rising temperature and *** was the main influential *** spatial distribution of carbon density of forest vegetation,soil,and ecosystem in Tibet generally showed declining trends from western Tibet to eastern *** results facilitated the understanding of the carbon sequestration role of forest ecosystem in the *** also implied that as the carbon storage potential of Tibet's forests are expected to increase,these forests are likely to serve as huge carbon sinks in the current era of global warming and climate change.

关键词： Carbon storage Carbon density Spatial distribution Forest ecosystems Climate factors Tibet

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

A phase-field model for simulating the propagation behavior of mixed-mode cracks during the hydraulic fracturing process in fractured reservoirs

引用

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 911-930页

作者： dan ZHANG liangping YI Zhaozhong yang Jingqiang ZHANG Gang CHEN Ruoyu yang Xiaogang li State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059China Tarim Oilfield Company PetroChinaBayingolin Mongolian Autonomous Prefecture 841000Xinjiang Uygur Autonomous RegionChina Wuqi Oil Production Plant Shaanxi Yanchang PetroleumXi'an 716000China Exploration Division of PetroChina Southwest Oil and Gasfield Company Chengdu 610041China

A novel phase-field model for the propagation of mixed-mode hydraulic fractures,characterized by the formation of mixed-mode fractures due to the interactions between fluids and solids,is *** this model,the driving force for the phase field consists of both tensile and shear components,with the fluid contribution primarily manifesting in the tension driving *** displacement and pressure are solved simultaneously by an implicit *** numerical solution's iterative format is established by the finite element discretization and Newton-Raphson(NR)iterative *** correctness of the model is verified through the uniaxial compression physical experiments on fluid-pressurized rocks,and the limitations of the hydraulic fracture expansion phase-field model,which only considers mode I fractures,are *** addition,the influence of matrix mode II fracture toughness value,natural fracture mode II toughness value,and fracturing fluid injection rate on the hydraulic fracture propagation in porous media with natural fractures is studied.

关键词： mixed-mode crack hydraulic fracturing poro-elasticity phase-field method(PFM)

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

The changes in soil organic carbon stock and quality across a subalpine forest successional series

引用

Forest Ecosystems 2024年第4期11卷 423-433页

作者： Fei li Zhihui Wang Jianfeng Hou Xuqing li dan Wang Wanqin yang Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation School of Life SciencesTaizhou UniversityTaizhou 318000China linhai Station of Zhejiang Provincial Forest Ecological Research Taizhou UniversityTaizhou 318000China Taizhou Key Laboratory of Mountain Ecological Restoration and Special Industry Cultivation Taizhou UniversityTaizhou 318000China Hawkesbury Institute for the Environment Western Sydney UniversityPenrithNew South WalesAustralia

Soil organic carbon(SOC)affects the function of terrestrial ecosystem and plays a vital role in global carbon ***,large uncertainty still existed regarding the changes in SOC stock and quality with forest ***,the stock and quality of SOC at 1-m soil profile were investigated across a subalpine forest series,including shrub,deciduous broad-leaved forest,broadleaf-conifer mixed forest,middle-age coniferous forest and mature coniferous forest,which located at southeast of Tibetan *** results showed that SOC stock ranged from 9.8 to29.9 kg·m^(-2),and exhibited a hump-shaped response pattern across the forest successional *** highest and lowest SOC stock was observed in the mixed forest and shrub forest,*** SOC stock had no significant relationships with soil temperature and litter stock,but was positively correlated with wood debris ***,the average percentages of polysaccharides,lignins,aromatics and aliphatics based on FTIR spectroscopy were 79.89%,0.94%,18.87%and 0.29%,***,the percentage of polysaccharides exhibited an increasing pattern across the forest successional series except for the sudden decreasing in the mixed forest,while the proportions of lignins,aromatics and aliphatics exhibited a decreasing pattern across the forest successional series except for the sudden increasing in the mixed ***,the humification indices(HIs)were highest in the mixed forest compared to the other four successional stages,which means that the SOC quality in mixed forest was worse than other successional *** addition,the SOC stock,recalcitrant fractions and HIs decreased with increasing soil depth,while the polysaccharides exhibited an increasing *** findings demonstrate that the mixed forest had higher SOC stock and worse SOC quality than other successional *** high proportion of SOC stock(66%at depth of 20-100 cm)and better SOC quality(lower HIs)indicate that deep s

关键词： Forest successional series Soil organic cubon stock Molecular composition Humification indices Soil organic carbon quality

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

Migration pattern of a population of Barn Swallows(Hirundo rustica)breeding in East Asian tropical region

引用

Avian Research 2024年第3期15卷 299-307页

作者： li Tian Yu liu yang Wu Zimei Feng dan Hu Zhengwang Zhang Key Laboratory for Biodiversity Sciences and Ecological Engineering Ministry of EducationCollege of Life SciencesBeijing Normal UniversityBeijing100875China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing100107China life Science and Technology School Lingnan Normal UniversityZhanjiang524048China

Birds exhibit a high degree of migratory diversity,which is influenced by various ecological factors and life history *** studies on tropical bird migration,of which research is scarce,and comparing it with temperate birds can enhance our understanding of bird migration behaviour and its underlying *** this study,we explored the migration behaviour of a breeding population of the Barn Swallow(Hirundo rustica)in Zhanjiang,southern China,a region located in the northern tropics,using light-level *** 2021 to 2023,we deployed geolocators on 92 breeding swallows and retrieved geolocators successfully from 23 *** swallows all exhibited migratory behaviour,and wintering on various islands in Southeast *** displayed sex differences in their wintering *** males concentrated in Borneo,while females primarily chose Borneo but also dispersed to the Philippines,South China Sea,and Vietnam for *** studied swallow population adopted a seasonal migration pattern of“indirect in autumn,direct in spring”,bypassing the ecological barrier of the South China Sea in autumn and tending to directly cross it in spring ***,the distance and duration of autumn migration was significantly longer than those of the spring *** to temperate Barn Swallows,the Barn Swallow population breeding in Zhanjiang adopts a pattern of“intra-tropical migration”and initiates autumn migration *** formation of their migration pattern may be limited by ecological and physiological factors.

关键词： Asia Chain migration light-level geolocators Migration Northern tropics

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

Effect of Artificial Cooling Extrusion on Microstructure and Mechanical Properties of Mg–Zn–Y Alloys

引用

Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1115-1127页

作者： Qi-Yu liao Da-Zhi Zhao Qi-Chi Le Wen-Xin Hu Yan-Chao Jiang Wei-yang Zhou liang Ren dan-dan li Zhao-yang Yin School of Materials Science and Engineering Northeastern UniversityShenyang110819China Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang110819China Key Laboratory of lightweight Structural Materials Liaoning ProvinceNortheastern UniversityShenyang110819China Baotou Research Institute of Rare Earths Baotou014000China

Microstructure and mechanical properties of Mg–Zn–Y alloys with different Zn/Y atomic ratios with or without artificial cooling (AC) extrusion were systematically investigated in this work. The results show that bimodal microstructure consisting of submicron dynamic recrystallized (DRXed) grains with high fraction of low-angle grain boundaries (LAGBs) and elongated unDRXed grains was formed in Mg_(98.7)Zn_(1)Y_(0.3) alloy with AC extrusion. The AC process effectively limits the growth of precipitated phases, and large amount of nanoscale precipitates were dynamically precipitated during the extrusion process. AC extrusion could effectually refine the lamellar 14H LPSO phases and inhibit the transition from stacking faults to LSPO phases in Mg_(98)Zn_(1)Y_(1) alloy and the narrow LPSO phase in Mg_(98)Zn_(1)Y_(1)-AC alloy which could promote the nucleation of DRXed grains. The AC extrusion significantly improves the strength of Mg–Zn–Y alloys. Owing to AC extrusion, the strength improvement of Mg_(98.7)Zn_(1)Y_(0.3) alloy is mainly attributed to fine grain strengthening, dislocation strengthening, and nano-phases precipitation strengthening. After AC process, more fine grains and nano-phases jointly strengthen the Mg_(98)Zn_(1)Y_(1) alloy. The Mg_(98)Zn_(1)Y_(1) alloy obtains optimal mechanical properties after extrusion at 623 K, with ultimate tensile strength (UTS) of 406 MPa, yield strength (YS) of 388 MPa, and elongation (EL) of 5.6%.

关键词： Mg-Zn-Y Artificial cooling Extrusion Microstructure Mechanical properties

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

Mitochondria-targeted nano-AIEgens as a powerful inducer for evoking immunogenic cell death

引用

Chinese Chemical Letters 2024年第5期35卷 338-343页

作者： Kun-Heng li Hong-yang Zhao dan-dan Wang Ming-Hui Qi Zi-Jian Xu Jia-Mi li Zhi-li Zhang Shi-Wen Huang Key Laboratory of Biomedical Polymers of Ministry of Education Department of ChemistryWuhan UniversityWuhan 430072China

AIEgens can serve as an effective platform for the construction of photosensitizer-based immunogenic cell death(ICD)*** date,several mitochondria or endoplasmic reticulum(ER)-targeted aggregationinduced emission(AIE)molecules have been developed and have evoked massive ICD in ***,due to the complex physicochemical environment in cells,these small AIE molecules cannot maintain a stable aggregate state,which not only affects the fluorescence intensity of the photosensitizer but also decreases the generation of reactive oxygen species(ROS),and thus reducing the effect of the photosensitizer to elicit ***-based nanomicelles,which maintain a stable micellar structure,can prevent defects of AIE molecules in photodynamic therapy(PDT)***,in this study,a mitochondria-targeted AIE nanophotosensitizer was synthesized and used as a highly potent ICD inducer for vaccine preparation and tumor prevention.

关键词： Aggregation induced emission Photodynamic therapy Immunogenic cell death Reactive oxygen species Nanophotosensitizer Mitochondria

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：