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Effects of Serum Concentration, Synchronization Time and Confluence on the Cell-Cycle Synchronization Efficiency of Goat Fibroblasts
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作者 Van Khanh Nguyen Huong Thu Thi Vu +4 位作者 Au Thi Hoang Yen Kim Thi Pham Giang Thi Thanh Nhan Hung Phu Lai Lan Doan Pham 《Open Journal of Animal Sciences》 2024年第3期194-203,共10页
This study aims to evaluate the effect of serum concentration, synchronization time, and confluence degree on the synchronisation efficiency of goat fibroblast cycle. The results indicated that there was no difference... This study aims to evaluate the effect of serum concentration, synchronization time, and confluence degree on the synchronisation efficiency of goat fibroblast cycle. The results indicated that there was no difference in the percentage of nucleated fibroblasts in the G0/G1 stage between serum concentrations of 0.3% and 0.4% (83.89% and 82.69%, respectively, P > 0.05) as well as between serum concentrations of 0.2% and 0.5% (76.95% and 75.46%, respectively, P > 0.05). The percentage of nucleated fibroblasts in the G0/G1 stage was highest at the concentration of 0.3% and lowest in the control group (83.89% vs. 62.67%, P 0.05). The beneficial effect of high confluence was confirmed by the large percentage of nucleated fibroblasts at the G0/G1 stage. The 60% confluency was significantly lower than the 80% and 100% confluency (73.44%, 86.63%, and 87.17%, respectively, P < 0.05). The results indicate that the goat fibroblast cycle synchronization is the most effective at the serum concentration of 0.3%, 72 hours of synchronization and 100% confluency. 展开更多
关键词 Goat Fibroblast Cycle Synchronisation Serum Concentration Synchronization Time confluence
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Pollution control of outfall of rainwater-sewage confluence in old town
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作者 黄勇强 史凯 +1 位作者 朱艳 刘荣平 《Journal of Southeast University(English Edition)》 EI CAS 2014年第2期230-233,共4页
In order to improve water quality of middle ancient canal in Zhenjiang city a pollution control project was carried out.The research area is the middle catchment area of the ancient canal river system in the old town ... In order to improve water quality of middle ancient canal in Zhenjiang city a pollution control project was carried out.The research area is the middle catchment area of the ancient canal river system in the old town of Zhenjiang. The specific research object is the runoff of the outfall of rainwater-sewage confluence in the area. On the basis of detecting and analyzing the water yield and water quality of the runoff of rainwater-sewage confluence a combined technology which contains four independent continuous processes for lowering pollution load was developed and system equipment was established and put into operation. The processing effects of the project were monitored and analyzed.The results show that the pollution control project of outfall runoff is efficient which decreases the pollution load including chemical oxygen demand COD total phosphorus TP suspended solids SS and ammonia-nitrogen NH3-N .As a result the water environment of the ancient canal is protected. 展开更多
关键词 urban rainwater confluence of rainwater and sewage outfall rainwater runoff pollution load processing equipment
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Influence of bed elevation discordance on flow patterns and head losses in an open-channel confluence 被引量:4
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作者 Pedro Xavier Ramos Laurent Schindfessel +1 位作者 Joao Pedro Pego Tom De Mulder 《Water Science and Engineering》 EI CAS CSCD 2019年第3期235-243,共9页
Confluences play a major role in the dynamics of networks of natural and man-made open channels, and field measurements on river confluences reveal that discordance in bed elevation is common.Studies of schematized co... Confluences play a major role in the dynamics of networks of natural and man-made open channels, and field measurements on river confluences reveal that discordance in bed elevation is common.Studies of schematized confluences with a step at the interface between the tributary and the main channel bed reveal that bed elevation discordance is an important additional control for the confluence hydrodynamics.This study aimed to improve understanding of the influence of bed elevation discordance on the flow patterns and head losses in a right-angled confluence of an open channel with rectangular cross-sections.A large eddy simulation (LES)-based numerical model was set up and validated with experiments by others.Four configurations with different bed discordance ratios were investigated.The results confirm that, with increasing bed elevation discordance, the tributary streamlines at the confluence interface deviate less from the geometrical confluence angle, the extent of the recirculation zone (RZ) gets smaller, the ratio of the water depth upstream to that downstream of the confluence decreases, and the water level depression reduces.The bed elevation discordance also leads to the development of a large-scale structure in the lee of the step.Despite the appearance of the large-scale structure, the reduced extent of the RZ and associated changes in flow deflection/contraction reduce total head losses experienced by the main channel with an increase of the bed discordance ratio.It turns out that bed elevation discordance converts the lateral momentum from the tributary to streamwise momentum in the main channel more efficiently. 展开更多
关键词 Open channel confluence BED ELEVATION DISCORDANCE Three-dimensional numerical modelling Large EDDY simulation Recirculation ZONE
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Confluence and cold shut computation based on time field in casting simulation 被引量:4
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作者 Yong-shuai Feng Dun-ming Liao Tao Chen 《China Foundry》 SCIE CAS 2021年第2期101-109,共9页
Numerical simulation technology has been widely used in the foundry industry to analyze and improve casting processes.During the casting filling process,many filling-related defects form easily at the confluences of l... Numerical simulation technology has been widely used in the foundry industry to analyze and improve casting processes.During the casting filling process,many filling-related defects form easily at the confluences of liquid metal streams.The main filling-related defects are cold shut defects.To calculate the positions of casting defects,the characteristics of liquid metal confluences were analyzed.The flow front of liquid metal was captured by the volume-of-fluid algorithm to obtain a time field,which was used to calculate the time derivatives of the liquid front position and the confluences of liquid metal streams.To distinguish small confluences from the main confluences,the concept of confluent scale was developed,which was used to filter the small confluences based on a threshold.The calculation process was demonstrated through the post-processing of numerical simulation.A "W" shaped casting and a steering wheel casting were calculated to validate the accuracy of the method developed in this study.The positions of cold shut defects were predicted by calculating the confluences of liquid metal streams.The method was proved to be practical by comparing the calculation results with the positions of cold shut defects in an end cover casting.The computation of confluences and cold shut defects can improve the analysis efficiency and provide assurance for the optimization of a casting process plan. 展开更多
关键词 numerical simulation casting defects flow front time field confluence cold shut
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Managing injuries of hepatic duct confluence variants after major hepatobiliary surgery:An algorithmic approach 被引量:4
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作者 Georgios Fragulidis Athanasios Marinis +5 位作者 Andreas Polydorou Christos Konstantinidis Georgios Anastasopoulos John Contis Dionysios Voros Vassilios Smyrniotis 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第19期3049-3053,共5页
AIM:To investigate injuries of anatomy variants of hepatic duct confluence during hepatobiliary surgery and their impact on morbidity and mortality of these procedures. An algorithmic approach for the management of th... AIM:To investigate injuries of anatomy variants of hepatic duct confluence during hepatobiliary surgery and their impact on morbidity and mortality of these procedures. An algorithmic approach for the management of these injuries is proposed. METHODS:During a 6-year period 234 patients who had undergone major hepatobiliary surgery were retrospectively reviewed in order to study postoperative bile leakage. Diagnostic workup included endoscopic and magnetic retrograde cholangiopancreatography (E/MRCP), scintigraphy and fistulography. RESULTS:Thirty (12.8%) patients who developed postoperative bile leaks were identified. Endoscopic stenting and percutaneous drainage were successful in 23 patients with bile leaks from the liver cut surface. In the rest seven patients with injuries of hepatic duct confluence, biliary variations were recognized and a stepwise therapeutic approach was considered. Conservative management was successful only in 2 patients. Volume of the liver remnant and functional liver reserve as well as local sepsis were used as criteria for either resection of the corresponding liver segment or construction of a biliary-enteric anastomosis. Two deaths occurred in this group of patients with hepatic duct confluence variants (mortality rate 28.5%). CONCLUSION:Management of major biliary fistulaethat are disconnected from the mainstream of the biliary tree and related to injury of variants of the hepatic duct confluence is extremely challenging. These patients have a grave prognosis and an early surgical procedure has to be considered. 展开更多
关键词 Biliary aberrations Bile duct injury Postope-rative bile leakage Hepatic duct confluence HEPATECTOMY
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An Empirical Formula for Suspended Sediment Delivery Ratio of Main River after Confluence of Debris flow 被引量:1
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作者 ZHANG Jin-shan CUI Peng 《Journal of Mountain Science》 SCIE CSCD 2013年第2期326-336,共11页
In order to calculate the suspended sediment discharge of the flood debris flows into the main river,a small scale flume test was designed to simulate the process of confluence of Jiangjia Ravine and Xiangjiang River ... In order to calculate the suspended sediment discharge of the flood debris flows into the main river,a small scale flume test was designed to simulate the process of confluence of Jiangjia Ravine and Xiangjiang River in Yunnan province,China.By test observation and data analysis,suspended sediment discharge of Debris flow after its entry into the main river was found to have a close relation with the bulk density,the confluence angle of the Debris flow and the main river,the ratio between per unit width discharge of Debris flow and main river.Based on the measured and simulated results,and statistical analysis,an empirical formula was proposed for the suspended SDR(Sediment Delivery Ratio) of the main river after the confluence of Debris flow.Compared with the observed results of Debris flow in 2009,the error between the data calculated by the empirical formula and the monitored data is only about 10%. 展开更多
关键词 Debris flow confluence SuspendedSediment Delivery Ratio (SDR) Jiangjia Ravine Xiaojiang River Model
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Intermittent portal triad clamping in resection of liver tumors involving the hepatocaval confluence
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《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2002年第2期276-280,共5页
Objective: To review our experience in and the re-sults of resecting liver tumors involving the hepatoca-val confluence under intermittent portal triad clam-ping (PTC).Methods: Sixty-eight consecutive patients with li... Objective: To review our experience in and the re-sults of resecting liver tumors involving the hepatoca-val confluence under intermittent portal triad clam-ping (PTC).Methods: Sixty-eight consecutive patients with livertumors involving the hepatocaval confluence under-went hepatectomies with liver parenchymal transec-tions under intermittent PTC.Results: All the tumors were successfully resected un-der PTC, except for one in which the infrahepatic in-ferior vena cava was concomitantly occluded in addi-tion to PTC. There was neither operative death noruncontrollable massive bleeding or air embolism oc-curred in our patients. The bleedings from the mainand short hepatic veins and right adrenal veins wereproperly managed during the operation, with a meanintraoperative blood loss of 1400 ml. Of the 68tumors resected, 65 were hepatocellular carcinomas(HCC). Their 1-, 2-, 3- and 4-year suvival rateswere 64.11%, 52. 82%, 44.90% and 36.98%, re-spectively, and the patients with HCC with capsulessurvived significantly longer than those with HCCwithout capsules.Conclusions: The liver tumors involving the hepato-caval confluence could be safely resected simply un-der PTC, without routine use of total hepatic vascu-lar exclusion. As for HCCs in this area, the tumorwith capsule is a better indicator for surgical resec-tion than that without capsule. 展开更多
关键词 HEPATECTOMY hepatocval confluence PORTAL TRIAD CLAMPING hepatic vascular EXCLUSION liver neoplasmas
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Liver tumors invading the hepatocaval confluence:treatment improvements still not completed
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作者 Isidoro Di Carlo 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2016年第6期570-571,共2页
Also if rarely, hepatocellular carcinoma, cholangiocarcinoma, and metastatic carcinoma can invade the retrohepatic portion of the inferior vena cava (IVC), because of the proximity of this vessel to the liver.
关键词 IVC Liver tumors invading the hepatocaval confluence
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Foshan:Confluence of Tradition and Modernity
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《China Today》 2017年第12期68-72,共5页
FOSHAN is an ancient city endowed with a bountiful culture.Located in the heartland of the vibrant Pearl River Delta,Foshan is west of Guangzhou,the capital of Guangdong Province,and gazes upon Hong Kong and Macao fro... FOSHAN is an ancient city endowed with a bountiful culture.Located in the heartland of the vibrant Pearl River Delta,Foshan is west of Guangzhou,the capital of Guangdong Province,and gazes upon Hong Kong and Macao from the north.For centuries,Foshan has been the economic and trade center in this region,and known for its high-quality ceramic products throughout the country.In modern times,it has witnessed a growth 展开更多
关键词 Foshan:confluence of Tradition and Modernity
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胆囊管汇入部微切开技术行腹腔镜胆总管探查取石术267例报告
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作者 刘楠 刘奇 +2 位作者 李晓勇 王婷婷 陈德兴 《中国微创外科杂志》 CSCD 北大核心 2024年第4期245-249,共5页
目的总结胆囊管汇入部微切开技术行腹腔镜胆总管探查(laparoscopic common bile duct exploration,LCBDE)的经验。方法2020年1月~2023年3月,对267例胆囊结石胆囊炎合并胆总管结石采用胆囊管汇入部微切开技术行LCBDE,沿胆囊管下壁切开至... 目的总结胆囊管汇入部微切开技术行腹腔镜胆总管探查(laparoscopic common bile duct exploration,LCBDE)的经验。方法2020年1月~2023年3月,对267例胆囊结石胆囊炎合并胆总管结石采用胆囊管汇入部微切开技术行LCBDE,沿胆囊管下壁切开至胆总管汇入部,纵行切开胆总管外侧壁3~5 mm,胆道镜完成胆道探查取石,一期缝合,留置腹腔引流管。结果267例均完成手术,取净胆总管结石。手术时间45~128 min,(96.5±9.7)min;术后腹腔引流管留置时间3~13 d,(5.1±1.2)d;术后住院5~13 d,(6.8±1.1)d。胆漏4例,腹腔引流9~11 d;术后发热11例,抗炎治疗1~3 d;腹腔脓肿形成2例,腹腔引流治愈。242例(90.6%)随访6~39个月,中位时间11个月,其中66例随访≥36个月,结石残留2例,结石复发2例,未发生胆总管狭窄。结论经胆囊管汇入部微切开技术行LCBDE治疗胆总管结石临床效果良好。 展开更多
关键词 胆囊管汇入部 腹腔镜手术 胆总管探查取石术 胆总管结石
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钢渣在自愈合路面中的应用
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作者 李超 涂亮亮 +2 位作者 谢君 吴少鹏 刘全涛 《现代交通与冶金材料》 CAS 2024年第4期9-17,共9页
钢渣是炼钢过程中产生的副产品,中国钢渣存量和年产量都很大,利用率却很低。钢渣的物理力学性能优良,在道路建设方面有很大应用潜力。路面出现裂纹时,传统路面修补技术存在修复不彻底和成本高等问题,热诱导自愈合技术修复速率快且方便,... 钢渣是炼钢过程中产生的副产品,中国钢渣存量和年产量都很大,利用率却很低。钢渣的物理力学性能优良,在道路建设方面有很大应用潜力。路面出现裂纹时,传统路面修补技术存在修复不彻底和成本高等问题,热诱导自愈合技术修复速率快且方便,是一种国际公认的先进养护技术。本文对钢渣组成、电磁感应特性及具有电磁感应和微波加热自愈合功能的钢渣沥青混凝土相关研究进行综述。钢渣中含有单质Fe,Fe_(2)O_(3)等电磁参数较高的金属及金属氧化物,使钢渣具有感应发热和微波发热特性。钢渣沥青混合料的加热性能和愈合性能优于普通愈合型沥青混合料,微波愈合的效率低于电磁感应愈合,但加热均匀度和有效加热深度高于后者。在自愈合钢渣沥青混合料组成设计中,需先确定钢渣掺量和加热参数以综合考虑加热的效率和均匀度。 展开更多
关键词 钢渣 道路工程 自愈合
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砂岩型铀矿“源-汇”系统
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作者 贺锋 张字龙 +3 位作者 武正乾 刘鑫扬 刘持恒 李西得 《世界核地质科学》 CAS 2024年第3期419-433,共15页
把从“源”到“汇”的分析方法应用到我国北方盆地砂岩型铀矿成矿作用研究中来,确定不同时期含铀物质的汇流路径,有利于砂岩型铀矿的富集机理和成矿规律的研究和总结。砂岩型铀矿“源—汇”系统是富铀物质从蚀源区风化剥蚀或从盆地深部... 把从“源”到“汇”的分析方法应用到我国北方盆地砂岩型铀矿成矿作用研究中来,确定不同时期含铀物质的汇流路径,有利于砂岩型铀矿的富集机理和成矿规律的研究和总结。砂岩型铀矿“源—汇”系统是富铀物质从蚀源区风化剥蚀或从盆地深部富铀烃源岩活化,经汇流体系运移,再到盆地有利赋矿砂体聚集成矿的物理、化学和生物作用的过程,主要包括铀源、汇流体系和富集体系三部分。铀源外源是指在产铀盆地边缘大面积出露的富铀基底和岩石;内源是指含矿目的层本身的含铀建造,是在沉积成岩过程中形成的铀预富集;盆地深部富铀烃源岩在高温-高压条件下排烃,通过活动断裂可为浅部砂岩铀矿提供铀源。富铀物质从铀源区风化或活化搬运迁移到赋矿砂体并在砂体中运移的统一过程称为铀成矿汇流体系,沉积盆地的含铀物质主要在沉积期和成矿期通过汇流体系进入赋矿层位中。铀富集体系是砂岩中还原性物质或微生物等将含铀流体还原沉淀富集成矿的相关整体。鄂尔多斯盆地西南部具有浅部渗入、深部渗出汇流体系特点,渗入与渗出汇流体系的相互叠加改造对铀成矿也起到了比较重要的作用。 展开更多
关键词 砂岩型铀矿 “源—汇”系统 铀源 汇流体系 铀富集体系
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北方地区公交港湾停靠站路段低影响开发研究
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作者 孙宝芸 汪子皿 +1 位作者 鲁泓麟 董雷 《沈阳建筑大学学报(社会科学版)》 2024年第2期185-190,共6页
降雨条件下公交港湾式停靠站区域易产生积水,不仅会损害停靠区域路面健康,而且严重影响乘客出行体验与道路通行效率。北方地区城市有其独特的自然地理气候特征,低影响开发措施的设置具有局限性。以分隔带类型的港湾停靠站路段为研究对象... 降雨条件下公交港湾式停靠站区域易产生积水,不仅会损害停靠区域路面健康,而且严重影响乘客出行体验与道路通行效率。北方地区城市有其独特的自然地理气候特征,低影响开发措施的设置具有局限性。以分隔带类型的港湾停靠站路段为研究对象,分析了传统港湾停靠站路段雨水处理模式及其存在的问题,结合北方地区道路适用的低影响开发措施,提出了港湾停靠站路段低影响开发设施布局方案,并分析了雨水径流排放机制。通过暴雨洪水管理模型(Storm Water Management Model, SWMM)软件模拟研究路段海绵模式下雨水径流的调控效果,发现研究区域低影响开发设计对雨水径流具有明显的削减和延迟作用。 展开更多
关键词 港湾停靠站 低影响开发 产汇流机制 调控效果
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竹枝词的“诗体汇流”现象与“广竹枝”概念的生成——兼谈“历代竹枝词全编”之构想
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作者 马大勇 《浙江社会科学》 北大核心 2024年第6期131-146,F0003,共17页
竹枝词是中国诗歌长河中一个非常复杂的体式概念,它既向外散射分流,又向内吸纳汇流,形成了密如织网的水系结构。这是自宋代至晚清的诗人们有意将各种诗体向竹枝词附丽追认而形成的结果。其中,竹枝词记讽功能大幅上升的现象尤其值得关注... 竹枝词是中国诗歌长河中一个非常复杂的体式概念,它既向外散射分流,又向内吸纳汇流,形成了密如织网的水系结构。这是自宋代至晚清的诗人们有意将各种诗体向竹枝词附丽追认而形成的结果。其中,竹枝词记讽功能大幅上升的现象尤其值得关注,它在一定程度上改变了竹枝词作为风土诗歌的属性。鉴于这一判断,我们有必要重新厘定竹枝词的边界,并以“遵实归名”为原则,提出一个“广竹枝”概念,辨体从严,收录从宽,站到今人的文体立场上去动态地认识符合文学史事实的“竹枝词”内涵与外延。由此而言,编纂一部全、新、精、善兼备的“历代竹枝词全编”已经具有了良好的基础与契机。 展开更多
关键词 竹枝词 诗体汇流 记讽功能 广竹枝 历代竹枝词全编
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长江中游通江湖泊对干流顶托作用变化规律 被引量:1
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作者 杨春瑞 邓金运 +2 位作者 陈立 郑柠辉 赵晋 《水科学进展》 EI CAS CSCD 北大核心 2024年第1期98-111,共14页
长江中游通江湖泊(洞庭湖和鄱阳湖)对干流的顶托作用直接关系到区域防洪安全。通过构造支流顶托强度指标并结合Copula函数,分析三峡水库蓄水前后两湖出流对长江干流顶托强度的变化和异同,讨论干支流流量分布和地形变化对两湖顶托强度变... 长江中游通江湖泊(洞庭湖和鄱阳湖)对干流的顶托作用直接关系到区域防洪安全。通过构造支流顶托强度指标并结合Copula函数,分析三峡水库蓄水前后两湖出流对长江干流顶托强度的变化和异同,讨论干支流流量分布和地形变化对两湖顶托强度变化的贡献。研究结果表明:①三峡水库蓄水后,对干流顶托强度变化方面,汛期洞庭湖变化不大、鄱阳湖明显减弱;枯水期洞庭湖略有增强、鄱阳湖变化不大。②干支流流量分布导致的汇流比变化和江湖交汇区地形调整综合影响导致了两湖蓄水后顶托强度变化的差异;三峡水库蓄水后,干支流流量分布变化使洞庭湖、鄱阳湖对干流平均顶托强度分别减弱5.11%和13.45%;干流河床冲刷加剧导致的交汇区干支流河床高程差增大使洞庭湖、鄱阳湖对干流平均顶托强度分别增强6%和0.9%。 展开更多
关键词 顶托作用 汇流比 COPULA函数 长江中游 洞庭湖 鄱阳湖
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湟水与黄河交汇区水力特性数值模拟 被引量:1
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作者 刘晓雁 王凯 +3 位作者 谌霞 魏子淳 李昇 杨天啸 《水利水运工程学报》 CSCD 北大核心 2024年第2期62-71,共10页
河流交汇区在流域系统治理中发挥着控制节点作用。为探究中国西北地区典型Y型天然河流交汇区的水动力特性,以湟水与黄河交汇区为例,构建交汇区紊动水流二维水动力数学模型进行数值模拟研究。结果表明:湟水与黄河交汇区存在典型的高流速... 河流交汇区在流域系统治理中发挥着控制节点作用。为探究中国西北地区典型Y型天然河流交汇区的水动力特性,以湟水与黄河交汇区为例,构建交汇区紊动水流二维水动力数学模型进行数值模拟研究。结果表明:湟水与黄河交汇区存在典型的高流速区,且其位置和大小与汇流比有关;交汇区在各水文条件下均未形成明显的水流分离区;受干流顶托影响,支流入汇口左右岸会出现反方向回流区,沿水流方向呈翼状贴合壁面分布,其形态随汇流比发生变化。交汇区水流紊动能较大的区域分布在水流剪切层和下游右岸,在各水文时期,随着汇流比增大,剪切层紊动能减小;随着干流流速增大,交汇区下游右岸紊动能增大。本研究可为该交汇区及下游的河道治理、水环境保护及防洪减灾等提供理论基础。 展开更多
关键词 河流交汇区 水动力特性 汇流比 湟水 黄河
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海底峡谷浊流汇流后含沙量与速度变化研究
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作者 张子涵 任宇鹏 +2 位作者 陶威 许国辉 靳梓堃 《海洋地质与第四纪地质》 CAS CSCD 北大核心 2024年第4期78-87,共10页
高速的浊流具有强大的破坏力,威胁着海底结构物的安全。海底峡谷是浊流向深海运动的重要通道,其中许多海底峡谷具有多条分支峡谷,而分支峡谷与主干峡谷浊流发生汇流后,含沙量、速度可能会增加,进而破坏力增强。本文通过室内水槽试验和... 高速的浊流具有强大的破坏力,威胁着海底结构物的安全。海底峡谷是浊流向深海运动的重要通道,其中许多海底峡谷具有多条分支峡谷,而分支峡谷与主干峡谷浊流发生汇流后,含沙量、速度可能会增加,进而破坏力增强。本文通过室内水槽试验和数值模拟,研究了分支峡谷中的浊流汇流到主干峡谷中含沙量和速度的变化,并与仅有主干峡谷浊流的情景进行了对比。研究发现,发生汇流时,浊流的高度、含沙量和速度在头部均有增加,在汇流发生过后会有所减小,但含沙量和速度仍大于不发生汇流时的情况。本文试验结果可为有分支峡谷发生浊流汇流的现场监测位置及项目、速度推算提供指引。 展开更多
关键词 海底峡谷 浊流 汇流 速度 含沙量
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黄河-渭河交汇处水流结构与河道演变实测结果分析
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作者 林昊 张汇明 +4 位作者 张同强 徐磊 王平 万安 凌宇翔 《水电能源科学》 北大核心 2024年第6期68-72,共5页
黄河-渭河交汇处是黄河流域典型的大型河道交汇处之一,亦是中下游水动力和泥沙输移的重要控制节点。为进一步认识该处大宽深比、高含沙、复杂地形条件下的三维水流结构及河道演变规律,运用声学多普勒流速剖面仪(ADCP)对该交汇处15个横... 黄河-渭河交汇处是黄河流域典型的大型河道交汇处之一,亦是中下游水动力和泥沙输移的重要控制节点。为进一步认识该处大宽深比、高含沙、复杂地形条件下的三维水流结构及河道演变规律,运用声学多普勒流速剖面仪(ADCP)对该交汇处15个横断面的流场进行现场测量,采用动能校正系数(α)和动量校正系数(β)分析水动力调整过程。通过遥感影像数据提取河道平面形态,分析交汇处及上下游的河道演变规律。结果表明,黄河-渭河交汇处可观测到明显的停滞区、最大流速区、流速恢复区等水动力特征区;拐角处未发现明显分离区,主要是因为该处河道过渡平顺。黄河与渭河交汇初期,由于流速差异大和河道缩窄导致流速不均匀性较强,α、β分别约为1.5、1.2,随着河道向下游展宽,流速不均匀性迅速减小。交汇处断面内存在较强的二次流,其流速可达主流流速的1/8,并向下游衰减。遥感研究表明交汇处所属黄河河段不稳定,且存在顶点的岸线淤长和对岸的岸线后退现象。 展开更多
关键词 黄河-渭河 河流交汇 ADCP 水流结构 二次流 河道演变
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上游来水来沙与洞庭湖入汇顶托对荆江河段冲淤的影响
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作者 尚海鑫 胡春宏 +1 位作者 夏军强 周美蓉 《水科学进展》 EI CAS CSCD 北大核心 2024年第3期485-495,共11页
三峡工程运用后荆江河段处于持续冲刷状态,分析上游来水来沙与洞庭湖入汇顶托对荆江河段冲淤的影响,对掌握坝下游河道演变规律具有重要意义。本研究基于2003—2020年荆江河段实测水沙及冲淤量资料,建立河段累计冲淤量与河段上下游边界... 三峡工程运用后荆江河段处于持续冲刷状态,分析上游来水来沙与洞庭湖入汇顶托对荆江河段冲淤的影响,对掌握坝下游河道演变规律具有重要意义。本研究基于2003—2020年荆江河段实测水沙及冲淤量资料,建立河段累计冲淤量与河段上下游边界条件之间的函数关系,并重点分析顶托作用对荆江河段冲淤的影响。结果表明:(1)荆江河段累计冲淤量与河段进口水流冲刷强度呈正相关,与进出口水位落差呈负相关,河段冲淤过程是二者共同作用的结果;(2)建立进口水流冲刷强度、进出口水位落差与荆江河段累计冲淤量的函数关系,能较好反映上下游边界条件对河段冲淤过程的影响(R^(2)>0.92);(3) 2003—2020年荆江河段累计冲刷量为12.3亿m^(3),在假设无洞庭湖入汇顶托的情况下比实测值增加0.67亿m^(3),即入汇顶托能使荆江河段冲刷量减少约5%;同期上、下荆江累计冲刷量分别为7.3亿和5.0亿m^(3),入汇顶托能使冲刷量分别减少约1%和16%。洞庭湖入汇顶托会导致荆江河段的冲刷量减少,对下荆江冲淤影响更显著。 展开更多
关键词 顶托作用 河床冲淤 水流冲刷强度 洞庭湖入汇 荆江河段
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150 t单水口钢包出钢过程汇流旋涡影响因素研究
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作者 贾星宇 赵烁 +4 位作者 汤群伟 陈刚 李伟涛 唐海燕 张家泉 《炼钢》 CAS 北大核心 2024年第4期65-73,共9页
钢包浇注末期,钢液在科氏力和自身初始状态的作用下会产生汇流旋涡,其成为控制钢包下渣和提高钢水收得率的瓶颈问题。以某钢厂150 t单水口钢包为原型,基于相似原理,制作了相似比为1∶3.5的钢包物理模型,首先探究了水口偏心率对浇注末期... 钢包浇注末期,钢液在科氏力和自身初始状态的作用下会产生汇流旋涡,其成为控制钢包下渣和提高钢水收得率的瓶颈问题。以某钢厂150 t单水口钢包为原型,基于相似原理,制作了相似比为1∶3.5的钢包物理模型,首先探究了水口偏心率对浇注末期汇流旋涡的影响程度与机制,获得了适宜的水口位置后研究了钢包静置时间、阻旋装置、底搅拌工艺等控流措施对偏心率为0.83的钢包汇流旋涡的作用效果。结果表明,让钢包内形成非对称流场可以抑制旋涡的发展。当钢包静置时间小于45 min时,旋涡产生和贯通高度随静置时间的延长变化不明显;但当静置时间超过45 min时,旋涡起旋高度明显增加、贯通高度明显降低。另外,在此偏心率下,设置阻旋装置和增添底吹搅拌操作均不能抑制旋涡,但在旋涡起旋时短暂关闭水口会延缓旋涡的进一步发展。 展开更多
关键词 钢包 汇流旋涡 偏心率 底吹搅拌 水口关闭
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