检索结果-南通市图书馆

基于水体交换能力的调水工程对底栖动物群落影响研究

在线全文

学校读者我要写书评

暂无评论

水力发电学报 2024年第4期43卷 62-72页

作者：方青青王国强张尚弘王运涛张思远华北电力大学水利与水电工程学院北京102206 北京师范大学地理科学学部地理数据与应用分析中心北京100875

水文条件的改变会引起水生态系统的波动变化,大型调水工程的实施会改变水生生物群落结构。本研究分别调研了南四湖和东平湖在调水工程实施前后一段时间的大型底栖动物群落结构,模拟分析了调水工程引起的湖泊水龄变化特征,从水体交换能... 详细信息

水文条件的改变会引起水生态系统的波动变化,大型调水工程的实施会改变水生生物群落结构。本研究分别调研了南四湖和东平湖在调水工程实施前后一段时间的大型底栖动物群落结构,模拟分析了调水工程引起的湖泊水龄变化特征,从水体交换能力的角度探讨了大型调水工程对湖泊中大型底栖动物群落的影响。结果显示,调水工程运行一段时间后,东平湖中大型底栖动物群落在年尺度上从由小体型的水生昆虫类主导转变为由大体型的软体动物主导,南四湖中软体动物的优势在调水工程实施之后更加凸显。在季节尺度上,软体动物占比通常在调水期(非雨季)减小,而在非调水期(雨季)增大。调水工程的实施改变了湖泊水动力场特征,在年尺度上增强了湖泊水体交换能力,调水入流与入湖径流的叠加使湖泊水体的高流速时间变长,这不利于小体型物种稳定生长,进而导致在年尺度上大体型软体动物的占比逐渐增大。此外,调水工程的实施主要是提升了非雨季湖泊的水体交换能力,但增加调水后的非雨季湖泊水体交换能力仍然小于雨季,这也导致软体动物占比在调水工程实施前后均呈现在雨季减小在非雨季增加的规律。

关键词：水动力大型底栖动物南水北调南四湖东平湖水龄

小浪底水库运行下花园口河段黄河鲤生态流量研究

在线全文

学校读者我要写书评

暂无评论

水利水电技术（中英文） 2024年第4期55卷 151-162页

作者：张尚弘姜琪唐彩红岳子琪华北电力大学水利与水电工程学院北京102206

【目的】大坝和水库等水利工程的修建在带来防洪减灾效益的同时,也给所在区域的水生生物栖息繁衍带来了一定影响,诊断关键水生生物的生态流量对大坝下游的生态环境修复工作具有重要意义。【方法】以黄河下游花园口河段为例,探讨了小浪... 详细信息

【目的】大坝和水库等水利工程的修建在带来防洪减灾效益的同时,也给所在区域的水生生物栖息繁衍带来了一定影响,诊断关键水生生物的生态流量对大坝下游的生态环境修复工作具有重要意义。【方法】以黄河下游花园口河段为例,探讨了小浪底水库运行下不同流量情景下的黄河鲤栖息地质量情况,并由此推求黄河鲤的生态流量。基于栖息地模拟法,通过构建耦合栖息地适宜度模型的二维水动力模型,分析了黄河鲤鱼苗期、亲鱼期的栖息地适宜度指数空间分布,分别建立了黄河鲤两个生命阶段流量与栖息地加权可用面积关系曲线。【结果】结果表明:随着模拟流量的增大,黄河鲤不同生命阶段的栖息地适宜度指数空间分布及栖息地加权可用面积呈现先增加,达到峰值后逐渐减小的变化规律。【结论】黄河下游花园口河段的最小生态流量为1 150 m~3/s,适宜生态流量为1 450 m~3/s,最适宜生态流量为3 000 m~3/s,研究成果加深了对大流量情景下黄河鲤栖息地质量的认识,对黄河下游生态保护与修复具有重要意义。

关键词：生态流量栖息地模型黄河流域黄河鲤小浪底水库

基于水文水力学水生态结合法的大渡河生态流量研究

在线全文

学校读者我要写书评

暂无评论

生态学报 2024年第15期44卷 6487-6498页

作者：薛笑薇苗蔚欧延静张尚弘尹世洋林小楠华北电力大学水利与水电工程学院北京102206 福建省水利水电勘测设计研究院有限公司福州350001

大渡河是长江上游重要支流,水电资源丰富,流域内现存大量特有物种和珍惜物种,具有较高的生态及经济价值。生态流量是保障河道生态环境不退化、维持河道健康的重要指标,开展对大渡河生态流量的计算,对大渡河水生态环境保护和水资源合理... 详细信息

大渡河是长江上游重要支流,水电资源丰富,流域内现存大量特有物种和珍惜物种,具有较高的生态及经济价值。生态流量是保障河道生态环境不退化、维持河道健康的重要指标,开展对大渡河生态流量的计算,对大渡河水生态环境保护和水资源合理利用具有重要意义。当前对生态流量的研究众多,本文基于大渡河中下游2008—2017年天然来水情况,分别选取水文学方法中的Tennant法、改进Tennant法,水力学法中的湿周法,以及鱼类生境适宜度法,提出了水文-水力学-水生态的结合法(下称结合法)。将结合法计算的生态流量与多年实测流量对比,确定需要进行生态补水的月份,并根据水利部印发的第四批重点河湖生态流量保障目标对大渡河生态流量进行满足程度分析。研究结果表明:结合法考虑了水文学、水力学以及不同月份鱼类繁殖的需求,满足年内不同时段河道生态需求。大渡河中下游泸定站2—4月、沙湾站2月的来流量无法满足生态需水,应进行生态补水,使河道流量满足鱼类繁殖要求。与水利部制定的大渡河生态流量保障目标相比,本文计算的生态流量在鱼类繁殖期高于保障目标,在非鱼类繁殖期低于保障目标。本文提出的结合法考虑了河道生态需水的年内差异,且计算方法简便,实用性较强,大渡河生态流量的计算能够为年内生态补水提供科学依据。

关键词：生态流量大渡河水文学法水力学法结合法

Analysis of the sediment sources of flood driven erosion and deposition in the river channel of the Fu River Basin

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2023年第5期38卷 653-661页

作者： shanghong zhang Xujian Hu Wei Miao Zan Xu School of Water Resources and Hydropower Engineering North China Electric Power University

Studying the characteristics of runoff and sediment processes and revealing the sources of sediment provide key guidance for the scientific formulation of relevant soil erosion protection measures and water conservancy development plans. In the current study, the flow and sediment data of five hydrological stations on the main stream of the Fu River Basin(FRB) from 2007 to 2018 were selected to identify flood events, explore the variation of sediment transport along the FRB, and clarify the sediment sources. The results found that the Jiangyou—Fujiangqiao section is the main source of sediment in the FRB during the flood season. The runoff volume and sediment load during flood events in the Jiangyou—Fujiangqiao section accounted for 35% and 145% respectively of that of Xiaoheba station. These results combined with the change of the sediment load before and after the 2008 Wenchuan Earthquake(May12) show that the sediment in this section mainly comes from the Fu River tributary—the Tongkou River watershed. The calculation results for the sediment carrying capacity of the Fu River show that the main stream was in a state of erosion in theory. However, according to the calculation results for the interval sediment yield during flood events, the sediment load at the Xiaoheba station was smaller than that at the Shehong station upstream. The analysis indicates that this was not because of sediment deposition in the river channel, but because of sand mining in the river channel and sediment interception by water conservancy projects. If heavy rainfall occurs in the FRB, the sediment accumulated upstream will move downstream with the resulting flood, and the sediment yield in the FRB may further increase. These research conclusions can provide reference information for improving the prediction and management ability of soil and water loss in the FRB and scientific regulation of the Three Gorges Reservoir.

关键词： Flood event Fu River Basin (FRB) Sediment source Channel erosion and deposition Sediment carrying capacity

Joint Computing and Communication Resource Allocation for Satellite Communication Networks with Edge Computing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Communications 2021年第7期18卷 236-252页

作者： shanghong zhang Gaofeng Cui Yating Long Weidong Wang School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Key Laboratory of Universal Wireless Communications(Beijing University of Posts and Telecommunications) Beijing 100876China Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory Hebei 050000China

Benefit from the enhanced onboard processing capacities and high-speed satellite-terrestrial links,satellite edge computing has been regarded as a promising technique to facilitate the execution of the computation-intensive applications for satellite communication networks(SCNs).By deploying edge computing servers in satellite and gateway stations,SCNs can achieve significant performance gains of the computing capacities at the expense of extending the dimensions and complexity of resource ***,in this paper,we investigate the joint computing and communication resource management problem for SCNs to minimize the execution latency of the computation-intensive applications,while two different satellite edge computing scenarios and local execution are ***,the joint computing and communication resource allocation problem for the computation-intensive services is formulated as a mixed-integer programming problem.A game-theoretic and many-to-one matching theorybased scheme(JCCRA-GM)is proposed to achieve an approximate optimal *** results show that the proposed method with low complexity can achieve almost the same weight-sum latency as the Brute-force method.

关键词： satellite communication networks edge computing resource allocation matching theory

Statistical characteristics of eukaryotic intron database

在线全文

学校读者我要写书评

暂无评论

Frontiers in Biology 2006年第4期1卷 362-366页

作者： HE Miao LI Jidong zhang shanghong School of Life Sciences Sun Yat-Sen UniversityGuangzhou 510275China The Key Laboratory of Gene Engineering of Ministry of Education and Biotechnology Research CenterSun Yat-Sen UniversityGuangzhou 510275China

A database called eukaryotic intron database(EID)was developed based on the data from *** on the statistical characteristics of EID show that there were 103,848 genes,478,484 introns,and 582,332 exons,with an average of 4.61 introns and 5.61 exons per *** of 40−120 nt in length were abundant in the *** of the statistical analysis on the data from nine model species showed that in eukaryotes,higher species do not necessarily have more introns or exons in a gene than lower ***,characteristics of EID,such as intron phase,distribution of different splice sites,and the relationship between genome size and intron proportion or intron density,have been studied.

关键词： eukaryote intron database statistical characteristics

国内外雪崩试验、流变模型与动力模拟进展综述

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

力学与实践 2024年第5期46卷 907-918页

作者：徐小蓉田园诗孙其诚孙玉科张尚弘华北电力大学水利与水电工程学院北京102206 清华大学水圈科学与水利工程全国重点实验室北京100084

高海拔地区水电建设面临雪崩、冰崩等地质灾害的挑战。本文以雪崩为研究对象，阐述关于雪崩试验技术、流变模型及动力学数值模拟的研究进展。国内外通过开展全尺寸雪崩试验或缩尺雪槽试验，结合先进测量技术积累雪崩案例数据;雪崩常被... 详细信息

高海拔地区水电建设面临雪崩、冰崩等地质灾害的挑战。本文以雪崩为研究对象，阐述关于雪崩试验技术、流变模型及动力学数值模拟的研究进展。国内外通过开展全尺寸雪崩试验或缩尺雪槽试验，结合先进测量技术积累雪崩案例数据;雪崩常被视作复杂流体或颗粒流，采用Voellmy双参数模型、多孔黏弹塑性模型、颗粒流流变模型等描述其流变行为;基于流体动力学和基于连续介质力学的雪崩动态模拟已逐步发展成熟。该研究可为雪崩运动路径的科学预测与灾害风险评估奠定基础。

关键词：雪崩灾害高海拔水电建设雪崩动力学雪崩流动试验流变模型

Impact of anthropogenic activities on the sediment microbial communities of Baiyangdian shallow lake

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2020年第2期35卷 180-192页

作者： Wenjun Wang YujunYi Yufeng Yang Yang Zhou shanghong zhang Xuan Wang Zhifeng Yang State Key Laboratory of Water Environmental Simulation School of EnvironmentBeijing Normal University Ministry of Education Key Laboratory of Water and Sediment Science School of EnvironmentBeijing Normal University Renewable Energy School North China Electric Power University

Microorganisms are recognized as sensors of external disturbance in freshwater *** this study,sediment samples from regions with strong human activity interference(four sites),moderate human activity interference(five sites) and minor human activity interference(five sites) in Baiyangdian Lake were collected;and their physiological and chemical properties and heavy metals contents were *** structures of bacterial and fungal communities were tested using 16 S ribosomal Ribonucleic Acid(rRNA) and Internal Transcribed Spacer 2(ITS2) high-throughput sequencing *** results indicated that Proteobacteria was the most abundant bacterial ***,Basidiomycota and Ciliophora were the dominant phyla of *** differences of microbial genera among the three regions we re obse rved,especially fungal *** intensified disturbance by human activities,the Simpson and Shannon indices of bacteria significantly *** fungal communities were clustered into three groups in accordance with the different human disturbance *** bacterial communities of sediment samples under moderate and minor human disturbance appeared similar,but different from those under strong human *** analysis indicated that zinc,total phosphorus,copper,and lead were the dominant factors that influenced the bacterial *** and sulfate-reducing bacteria were influenced by pH,nitrate(NO3),and total *** fungal community was significantly affected by total *** study reveals that sediment microbial community structures among different regions of a shallow lake are mainly impacted by human activities.

关键词： Bacterial community Fungal community Human activity interference Environmental factors

Synthesis of waterborne polyurethane-humic acid cross-linked biomass porous materials for the adsorption of methylene blue

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第3期67卷 27-38页

作者： shanghong Ma Jianbo Qu Haitao zhang Xiubin Cui Peng Ye Qingfei Hu Mingzhen Chao State Key Laboratory of Biobased Material and Green Papermaking Qilu University of TechnologyShandong Academy of SciencesJinan 250353China Faculty of Light Industry Qilu University of TechnologyShandong Academy of SciencesJinan 250353China

A series of adsorbent materials(WPU-HAx-y)with a three-dimensional porous structure,green sustainability,and excellent performance were prepared and evaluated for the removal of methylene blue using nontoxic and environmentally friendly waterborne polyurethane as the matrix material and humic acid,a biomass material,as the functional *** newly synthesized adsorbents were characterized by infrared spectroscopy,scanning electron microscopy,specific surface area,and *** effects of contact time(0-8 h),starting concentration(10-100 mg·L^(-1)),pH(3-11),solution temperature(30-60℃),and coexisting ions(Ca2+,Na+,K+,Mg2+)on the performance were ***-first-order,pseudo-second-order,elovich,and intra-particle diffusion models were used to analyze the adsorption kinetics;the Langmuir,Freundlich,Temkin,and Dubin-Radushkovich adsorption isotherms were evaluated;and the adsorption behavior of the adsorbent materials was found to be more appropriate for the pseudo-second-order model for chemical pollutant removal than the Langmuir model,which depends on monolayer ***-HA2-3 stood out with a maximum adsorption capacity of 813.0081 mg·g^(-1) fitted to the pseudo-second-order and 309.2832 mg·g^(-1) fitted to the Langmuir model,showing superior adsorption performance and regenerability.

关键词： Porous media Bioenergy Sustainability Waste water