检索结果-南通市图书馆

Monitoring and evaluation of the water quality of the Lower Neches River, Texas, USA

Water Science and Engineering 2024年第1期17卷 21-32页

作者： qin Qian Mengjie He Frank Sun Xinyu Liu Department of Civil and Environmental Engineering Lamar UniversityBeaumontTX 77710USA Department of Industry Engineering Lamar UniversityBeaumontTX 77710USA Department of Computer Science Lamar UniversityBeaumontTX 77710USA

Increasing bacteria levels in the Lower Neches River caused by Hurricane Harvey has been of a serious *** study is to analyze the historical water sampling measurements and real-time water quality data collected with wireless sensors to monitor and evaluate water quality under different hydrological and hydraulic *** statistical and Pearson correlation analysis on historical water samples determines that alkalinity,chloride,hardness,conductivity,and pH are highly correlated,and they decrease with increasing flow rate due to *** flow rate has positive correlations with Escherichia coli,total suspended solids,and turbidity,which demonstrates that runoff is one of the causes of the elevated bacteria and sediment loadings in the *** correlation between *** and turbidity indicates that turbidity greater than 45 nephelometric turbidity units in the Neches River can serve as a proxy for *** to indicate the bacterial outbreak.A series of statistical tools and an innovative two-layer data smoothing filter are developed to detect outliers,fill missing values,and filter spikes of the sensor *** correlation analysis on the sensor data illustrates that the elevated sediment/bacteria/algae in the river is either caused by the first flush rain and heavy rain events in December to March or practices of land use and land ***,utilizing sensor measurements along with rainfall and discharge data is recommended to monitor and evaluate water quality,then in turn to provide early alerts on water resources management decisions.

关键词： Water quality Pearson correlation analysis Lower Neches River YSI wireless sensors Non-point pollution

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

Associative Tasks Computing Offloading Scheme in Internet of Medical Things with Deep Reinforcement Learning

引用

China Communications 2024年第4期21卷 38-52页

作者： Jiang Fan qin Junwei Liu Lei Tian Hui School of Communications and Information Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

The Internet of Medical Things(Io MT) is regarded as a critical technology for intelligent healthcare in the foreseeable 6G era. Nevertheless, due to the limited computing power capability of edge devices and task-related coupling relationships, Io MT faces unprecedented challenges. Considering the associative connections among tasks, this paper proposes a computing offloading policy for multiple-user devices(UDs) considering device-to-device(D2D) communication and a multi-access edge computing(MEC)technique under the scenario of Io MT. Specifically,to minimize the total delay and energy consumption concerning the requirement of Io MT, we first analyze and model the detailed local execution, MEC execution, D2D execution, and associated tasks offloading exchange model. Consequently, the associated tasks’ offloading scheme of multi-UDs is formulated as a mixed-integer nonconvex optimization problem. Considering the advantages of deep reinforcement learning(DRL) in processing tasks related to coupling relationships, a Double DQN based associative tasks computing offloading(DDATO) algorithm is then proposed to obtain the optimal solution, which can make the best offloading decision under the condition that tasks of UDs are associative. Furthermore, to reduce the complexity of the DDATO algorithm, the cacheaided procedure is intentionally introduced before the data training process. This avoids redundant offloading and computing procedures concerning tasks that previously have already been cached by other UDs. In addition, we use a dynamic ε-greedy strategy in the action selection section of the algorithm, thus preventing the algorithm from falling into a locally optimal solution. Simulation results demonstrate that compared with other existing methods for associative task models concerning different structures in the Io MT network, the proposed algorithm can lower the total cost more effectively and efficiently while also providing a tradeoff between delay and energy co

关键词： associative tasks cache-aided procedure double deep Q-network Internet of Medical Things(IoMT) multi-access edge computing(MEC)

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 Certified Cubic B-Spline Interpolation Method with Tangential Direction Constraints

引用

Journal of Systems Science & Complexity 2024年第3期37卷 1271-1294页

作者： HE Shitao SHEN Liyong WU qin YUAN Chunming School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China KLMM Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

Curve interpolation with B-spline is widely used in various areas. This problem is classic and recently raised in application scenario with new requirements such as path planning following the tangential vector field under certified error in CNC machining. This paper proposes an algorithm framework to solve Hausdorff distance certified cubic B-spline interpolation problem with or without tangential direction constraints. The algorithm has two stages: The first stage is to find the initial cubic B-spine fitting curve which satisfies the Hausdorff distance constraint;the second stage is to set up and solve the optimization models with certain constraints. Especially, the sufficient conditions of the global Hausdorff distance control for any error bound are discussed, which can be expressed as a series of linear and quadratic constraints. A simple numerical algorithm to compute the Hausdorff distance between a polyline and its B-spline interpolation curve is proposed to reduce our *** results are presented to show the advantages of the proposed algorithms.

关键词： Cubic B-spline Hausdorff distance interpolation tangential direction

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 the yaw angle on turbulent flow structures around the submarine model

引用

Journal of Hydrodynamics 2024年第3期36卷 421-434页

作者： Yi-jing Hu Yi Qu qin Wu Biao Huang School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China Beijing Institute of Electronic System Engineering Beijing100854China

The objective of this paper is to investigate the turbulent flow structures around the submarine model and evaluate the effect of the yaw angle on the turbulent flow *** large eddy simulation based on the boundary data immersion method is used to *** computational domain consists of 1.2×10^(8)uniformly distributed Cartesian orthogonal grid nodes to capture the basic flow characteristics around the *** pressure coefficient,friction coefficient and wake velocity distribution are in good agreement with the experimental *** different types of vortex structures were mainly captured around the model,including horseshoe vortex,sail tip vortex and crossflow separation *** the increase of the yaw angle,the asymmetry of the horseshoe vortex and the tip vortex gradually increases,and the vortex strength of the vortex leg on the windward of the horseshoe vortex and the vortex strength of the tip vortex also increase *** the crossflow separation vortex,the flow separation zone gradually expands and migrates downstream with the increase of the yaw angle.

关键词： Vortex structure submarine model boundary data immersion method yaw angle

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

Empirical likelihood for spatial cross-sectional data models with matrix exponential spatial specification

引用

Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 125-139页

作者： LIU Yan RONG Jian-rong qin Yong-song Nanning University Nanning 530200China Center for Applied Mathematics of Guangxi and College of Mathematics and Statistics Guangxi Normal UniversityGuilin 541004China

In this paper,we study spatial cross-sectional data models in the form of matrix exponential spatial specification(MESS),where MESS appears in both dependent and error *** empirical likelihood(EL)ratio statistics are established for the parameters of the MESS *** is shown that the limiting distributions of EL ratio statistics follow chi-square distributions,which are used to construct the confidence regions of model *** experiments are conducted to compare the performances of confidence regions based on EL method and normal approximation method.

关键词： MESS empirical likelihood con dence region

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

Succinylation modification:a potential therapeutic target in stroke

引用

Neural Regeneration Research 2024年第4期19卷 781-787页

作者： Jie Lian Wenwu Liu qin Hu Xiaohua Zhang Department of Neurosurgery Ren Ji HospitalShanghai Jiao Tong University School of Medicine Department of Diving and Hyperbaric Medicine Naval Medical CenterNaval Medical University

Stroke is a leading cause of mortality and disability *** cell death triggered by the compromised supply of blood oxygen and glucose is one of the major pathophysiology of strokeinduced brain *** mitochondrial energy metabolism is observed minutes after stroke and is closely associated with the progression of ***,a new type of posttranslational modification,known as lysine succinylation,has been recognized to play a significant role in mitochondrial energy metabolism after ***,the role of succinylation modification in cell metabolism after stroke and its regulation are not well *** aimed to review the effects of succinylation on energy metabolism,reactive oxygen species generation,and neuroinflammation,as well as Sirtuin 5 mediated desuccinylation after *** also highlight the potential of targeting succinylation/desuccinylation as a promising strategy for the treatment of *** succinylation level is dynamically regulated by the nonenzymatic or enzymatic transfer of a succinyl group to a protein on lysine residues and the removal of succinyl catalyzed by *** evidence has suggested that succinylation can regulate the metabolic pathway through modulating the activity or stability of metabolic ***,especially Sirtuin 5,are characterized for their desuccinylation activity and have been recognized as a critical regulator of metabolism through desuccinylating numerous metabolic *** between succinylation and desuccinylation has been implicated in the pathophysiology of *** agents that enhance the activity of Sirtuin 5 have been employed to promote desuccinylation and improve mitochondrial metabolism,and neuroprotective effects of these agents have been observed in experimental stroke ***,their therapeutic efficacy in stroke patients should be validated.

关键词： mitochondria metabolism neuroprotection sirtuin 5 stroke succinylation modification

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 biosynthesis of alarm pheromone in the wheat aphid Rhopalosiphum padi is regulated by hormones via fatty acid metabolism

引用

Journal of Integrative Agriculture 2024年第7期23卷 2346-2361页

作者： Chengxian Sun Yaoguo qin Julian Chen Zhengxi Li Department of Entomology/Ministry of Agriculture Key Laboratory for Monitoring and Environment-friendly Control of Crop Pests College of Plant ProtectionChina Agricultural UniversityBeijing 100193China State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193China

Aphids are major insect pests in agriculture and forestry *** attacks by natural enemies,many aphids release an alarm pheromone to protect their *** most aphids,the main component of the aphid alarm pheromone(AAP)is the sesquiterpene hydrocarbon(E)-β-farnesene(EβF).However,the mechanisms behind its biosynthesis and regulation remain poorly *** this study,we used the bird cherry–oat aphid Rhopalosiphum padi,which is an important wheat aphid,to investigate the regulatory mechanisms of EβF *** results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st-and 2nd-instar *** provide the prerequisite material for EβF production and *** on transcriptome sequencing,RNAi analysis,hormone treatments,and quantitative measurements,we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation,which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid *** is the first systemic study on the modulation of EβF production in *** results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis,as well as valuable information for designing potential aphid control strategies.

关键词： (E)-β-farnesene critical period for biosynthesis fatty acid metabolism juvenile hormone 20-hydroxyecdysone

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

Reproductive biology of Hemitripterus villosus in the Bohai Strait,China

引用

Journal of Oceanology and Limnology 2024年第3期42卷 881-892页

作者： Ping SUN Song qin Zhengyi LIU Longchuan ZHUANG Key Laboratory of Coastal Biology and Biological Resource Utilization Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China University of Chinese Academy of Sciences Beijing 100049China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

To understand the reproductive biology of Hemitripterus villosus in the Bohai Strait,and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of this species,a year-round detail study was conducted for the first *** total,263 individuals were randomly sampled off the coasts of the Bohai *** show that and the overall female-to-male ratio(1.35:1)did not differ significantly from the 1:1 sex *** length and weight relationship for females and males were regressed,depicting an isometric growth for both *** reproductive phases of the complete gonadotropin dependent reproductive cycle in both sexes were *** monthly variations in the gonadosomatic and hepatosomatic indexes for both sexes further indicated that this species spawns a single batch of eggs per year and the peak spawning period is from October to *** average diameter of eggs ranged from 2.10 to 3.57 *** length at first sexual maturity was 224.87 mm for females and 241.26 mm for *** positive relationships between absolute fecundity and fish size,and also gonadal weight were *** from the Bohai Strait exhibited smaller body size,smaller egg diameter,lower gonadosomatic index,lower absolute fecundity,and higher population extinction risk than the other populations’studied *** findings contribute to understanding the status of this isolated westernmost population,and we emphasize that more efficient protection measures for the species and control measures are urgently required to improve the coastal environment in the Bohai Strait.

关键词： Hemitripterus villosus Bohai Strait fecundity length at first maturity reproductive seasonality

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

Transient state analysis of a rub-impact rotor system during maneuvering flight

引用

Chinese Journal of Aeronautics 2024年第7期37卷 236-251页

作者： Jun WANG Yunfei LIU Zhaoye qin Liang MA Fulei CHU Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-End Machinery Equipment Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China College of Aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

Maneuvering flight substantially affects the dynamic behavior of rotors;particularly,such flight may cause rubbing between a rotor and stator,which is one of the most serious damages in aircraft *** this paper,a nonlinear dynamic model for describing the dynamic characteristics of a rub-impact rotor system during maneuvering flight is established based on the Lagrange ***,numerical simulations employing the Newmark method are performed,delving into the detailed discussion of the influence of parameters such as rotational speed and maneuvering flight on the transient and steady-state responses of the rotor *** effect mechanism of maneuver load and its coupling with rub impact is *** results show that the impact response induced by maneuvering flight is more obvious in the subcritical state than in the supercritical *** additional stiffness and damping are also induced;in particular,the additional damping has a coupling ***,the rub impact imposes an additional constraint on the rotor system,thereby weakening the influence of the maneuver load and becoming the major factor that determines the dynamic behavior of the rotor system at high speeds.

关键词： Maneuvering flight Rub impact Rotor system Dynamic response Impact response

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

On Depolymerization

引用

CCS Chemistry 2024年第2期6卷 297-312页

作者： Bo qin Xi Zhang College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082 Department of Chemistry Tsinghua UniversityBeijing 100084

Polymers have become an essential part of modern life and the global economy on account of their costeffectiveness and versatile ***,most postconsumer polymer wastes are unrecycled,leading to environmental pollution and resource ***,as an efficient chemical recycling approach,holds great promise in establishing a circular polymer *** this review,we attempt to highlight recent and significant advancements in depolymerization *** key research topics are discussed:(1)depolymerization of commodity polymers to produce reusable monomers and high-value chemicals;(2)depolymerization of intrinsically depolymerizable *** is anticipated that this review will reflect the present status and future trends of this rapidly evolving realm of depolymerization.

关键词： depolymerization chemical recycling sustainable polymers circular polymer economy catalysis dynamic covalent chemistry

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：