检索结果-南通市图书馆

Experimental study of non-uniform bubbles in a plume

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2022年第1期34卷 116-124页

作者： xin-wei ye Hao-jie Zhou Dong-dong Shao Xiao-jing Niu State Key laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing100084China State Key laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing100875China

The bubble plume is an important flow phenomenon, ubiquitous in many fields. The non-uniform bubbles in a plume are often simply considered as uniform and moving with a same slip velocity in an integral model. This study aims to have a better understanding of the behavior of the non-uniform bubbles in a plume. A set of experiments are conducted in a transparent water tank, in which the air plumes are generated through different injectors to vary the spectrum of the bubble size. The shadow images of the bubbles are simultaneously recorded with the illumination of a plane backlight. The algorithm used in the image analysis for tracing the bubbles is a newly developed multi-frame method based on the predictor-corrector method, with a good accuracy in estimating the size and the velocity of the overlapped bubbles based on the bubble shadow images. The bubbles are divided into several groups by their equivalent diameters with an interval of 0.5 mm. The spectrums of the bubble size and the void fraction are measured. It is found that the bubbles of different sizes show different dynamics features, resulting in a difference in the radial distribution. It is shown that the large bubbles gather in the center of the plume, while the medium bubbles spread the widest and even wider than the small bubbles. The difference can be explained by the effects of the transverse lift force and the amplitude of the bubble oscillation.

关键词： Bubble plume experiment image analysis bubble size transverse lift force

Solvent extraction of U(Ⅵ) by N,N-dimethyl-N',N'-dioctylsuccinylamide and N,N-dimethyl-N',N'-didecylsuccinylamide in cyclohexane

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2016年第3期27卷 68-73页

作者： Yu Cui Xiao-Feng Yang Cheng Yang ye-xin li Guo-Zhu Chen Guo-xin Sun School of Chemistry and Chemical Engineering University of Jinan

The extraction of uranyl nitrate by novel extractants of N,N-dimethyl-N',N'-dioctylsuccinylamide(DMDOSA)and N,N-dimethyl-N',N'-didecylsuccinylamide(DMDDSA) from aqueous nitric/nitrate solutions was *** was found both the concentration of HNO_3 and extractants had an effect on the U(Ⅵ) extraction *** extraction mechanism was established,and stoichiometry of the main extracted species was confirmed to be UO_2(NO_3)_2·2DMDOSA and UO_2(NO_3)_2·2DMDDSA,*** of the extraction reactions are *** spectral study of the U(Ⅵ) extracted species was also made.

关键词：溶剂萃取二甲基环己烷 ftir光谱硝酸铀酰化学计量比 O3浓度萃取反应

Sampling Methods for Efficient Training of Graph Convolutional Networks:A Survey

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2022年第2期9卷 205-234页

作者： xin liu Mingyu Yan lei Deng Guoqi li Xiaochun ye Dongrui Fan State Key laboratory of Computer Architecture Institute of Computing TechnologyChinese Academy of SciencesBeijing 100086 School of Computer Science and Technology University of Chinese Academy of SciencesBeijing 100049 IEEE Department of Precision Instrument Center for Brain Inspired Computing ResearchTsinghua UniversityBeijing 100084China

Graph convolutional networks(GCNs)have received significant attention from various research fields due to the excellent performance in learning graph *** GCN performs well compared with other methods,it still faces *** a GCN model for large-scale graphs in a conventional way requires high computation and storage ***,motivated by an urgent need in terms of efficiency and scalability in training GCN,sampling methods have been proposed and achieved a significant *** this paper,we categorize sampling methods based on the sampling mechanisms and provide a comprehensive survey of sampling methods for efficient training of *** highlight the characteristics and differences of sampling methods,we present a detailed comparison within each category and further give an overall comparative analysis for the sampling methods in all ***,we discuss some challenges and future research directions of the sampling methods.

关键词： Efficient training graph convolutional networks(GCNs) graph neural networks(GNNs) sampling method

A Comparative Study on the Post-Buckling Behavior of Reinforced Thermoplastic Pipes(RTPs)Under External Pressure Considering Progressive Failure

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第2期38卷 233-246页

作者： DING xin-dong WANG Shu-qing lIU Wen-cheng ye Xiao-han College of Engineering Ocean University of ChinaQingdao 266100China Shandong Provincial Key laboratory of Ocean Engineering Ocean University of ChinaQingdao 266100China Department of Marine Technology Norwegian University of Science and Technology(NTNU)Trondheim NO-7491Norway

The collapse pressure is a key parameter when RTPs are applied in harsh deep-water *** investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are *** the numerical simulations,the eigenvalue analysis and Riks analysis are combined,in which the Hashin failure criterion and fracture energy stiffness degradation model are used to simulate the progressive failure of composites,and the“infinite”boundary conditions are applied to eliminate the boundary *** for the hydrostatic pressure tests,RTP specimens were placed in a hydrostatic chamber after filled with *** has been observed that the cross-section of the middle part collapses when it reaches the maximum *** collapse pressure obtained from the numerical simulations agrees well with that in the ***,the applicability of NASA SP-8007 formula on the collapse pressure prediction was also *** has a relatively greater difference because of the ignorance of the progressive failure of *** the parametric study,it is found that RTPs have much higher first-ply-failure pressure when the winding angles are between 50°and 70°.Besides,the effect of debonding and initial ovality,and the contribution of the liner and coating are also discussed.

关键词： reinforced thermoplastic pipes post-buckling behavior progressive failure of composites debonding initial ovality

Intensified inactivation of model and environmental bacteria by an atmospheric-pressure air-liquid discharge plasma compared with chlorination

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第7期34卷 80-90页

作者： Mingli Shao Chengsong ye Ting li Jiaming Gan xin Yu lei Wang School of Environmental Science&Engineering Xiamen University of TechnologyXiamen 361024China College of the Environment&Ecology Xiamen UniversityXiamen 361102China

Water-borne pathogenic bacteria are always the top priority to be removed through disinfection process in water treatment due to their threat to human health. It was necessary to develop novel disinfection methods since the conventional chlorine disinfection was inefficient in inactivating chlorine-resistant bacteria, inducing the viable but non-culturable(VBNC) bacteria and forming disinfection by-products(DBPs). In this study, the inactivation of four model strains including Gram-negative(G), Gram-positive(G) and environmental samples by atmospheric-pressure air-liquid discharge plasma(AlDP) was assessed systematically. The results showed that AlDP was superior in inactivating all of the samples compared with chlorination. During 10 min AlDP treatment, the Gbacteria were completely inactivated, and the Gone was inactivated by more than 4.61 logs. The inactivation of bacteria from a campus lake and a wastewater treatment plant effluent exceeded 99.82% and 97.78%, respectively. For G-bacteria, AlDP resulted in a much lower(10~2~10~3 times) levels of VBNC cells than chlorination. AlDP could effectively remove the chlorine-resistant bacteria. More than 96.41% of the intracellular DNA and 99.99% of the extracellular DNA were removed, whereas it was only 56.35% and 12.82% for chlorination. AlDP had a stronger ability to destroy cell structure than chlorination, presumably due to the existence of ROS( ·OH, ~1Oand O). GC-MS analysis showed that AlDP produced less DBPs than chlorination. These findings provided new insights for the application of discharge plasma in water disinfection, which could be complemental or alternative to the conventional disinfection methods.

关键词： Air-liquid discharge plasma Pathogenic bacteria Viable but non-culturable state Intracellular-and extracellular genes Disinfection mechanism

Climate change and Chinese farmers: Perceptions and determinants of adaptive strategies

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2018年第4期17卷 949-963页

作者： ZHAI Shi-yan SONG Gen-xin QIN Yao-chen ye xin-yue Mark leipnik College of Environment and Planning/laboratory of Geospatial Technology for the Middle and lower yellow River Regions/Key Research Institute of yellow River Civilization and Sustainable Development & Collaborative Innovation Center on yellow River Civilization of Henan Province Henan University Key laboratory of Geographic Information Science Ministry of Education East China Normal University Department of Geography Kent State University Department of Geography & Geology Sam Houston State University

Farmers’ perceptions, beliefs, adaptive strategies, and barriers regarding climate change are critical to promoting sustainable ecosystems and societal stability. This paper is based on an extensive survey of 1 500 farmers and their households in Henan Province in China during 2013–2014. Henan is the largest agricultural province in China with over 51 million farmers. The survey results showed that approximately 57% of the respondents perceived the direct impact of climate change during the past 10 years, with 70.3% believing that climate change posed a risk to their livelihood. Not surprisingly, most farmers reported that they have adopted new measures to mitigate the negative impacts of climate change. The main barriers hindering farmers’ adopting adaptation measures were lack of funds and timely information. A multinomial logit model revealed that land ownership, knowledge of crop variety and the causes of climate change, as well as the belief of climate change, were all positively related to the likelihood of employing adaptive strategies. Moreover, the percentage of households engaging in agriculture activity, and years of engaging in farming were both negatively correlated with famer’s likelihood of adopting adaptation strategies. More importantly, farmers with high incomes were less likely to adopt adaptive strategies and more willing to engage in other business activities. In conclusion, it is important to communicate climate change related information and government policies in rural areas, promote farmer associations and other educational outreach efforts to assist Chinese farmers to deal with climate change.

关键词： climate change Chinese farmers adaptive strategies Henan Province

Prediction model for cost data of a power transmission and transformation project based on Pearson correlation coefficient-IPSO-ElM

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2021年第4期5卷 756-764页

作者： Ju xin liu ShangKe Xiao Yanli Wan ye State Grid Ningxia Electric Power Co.ltd Eco-Tech Research Institute NingXia Yinchuan750004P.R.China

In view of the difficulty in predicting the cost data of power transmission and transformation projects at present,a method based on Pearson correlation coefficient-improved particle swarm optimization(IPSO)-extreme learning machine(ElM)is *** this paper,the Pearson correlation coefficient is used to screen out the main influencing factors as the input-independent variables of the ElM algorithm and IPSO based on a ladder-structure coding method is used to optimize the number of hidden-layer nodes,input weights and bias values of the ***,the prediction model for the cost data of power transmission and transformation projects based on the Pearson correlation coefficient-IPSO-ElM algorithm is *** the analysis of calculation examples,it is proved that the prediction accuracy of the proposed method is higher than that of other algorithms,which verifies the effectiveness of the model.

关键词： cost data of power transmission and transformation project Pearson correlation coefficient IPSO-ElM algorithm project-cost prediction

Inverted Y ureteral duplication with an ectopic ureter and multiple urinary calculi:A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第4期10卷 1326-1332页

作者： Wen-xin ye li-Gang Ren li Chen Department of Urology Tongde Hospital of Zhejiang ProvinceHangzhou 310000Zhejiang ProvinceChina

BACKGROUND In the clinical treatment of diseases related to ureteral duplication,it is very important to make a clear diagnosis before surgery because different types of ureteral duplication correspond to different treatment *** Y ureteral duplication with ectopic ureters and multiple urinary calculi is clinically *** case can help clinicians increase their understanding of this disease and gain some experience in its diagnosis and *** SUMMARY A 36-year-old male who was previously healthy presented to the hospital with lumbar *** of the right kidney area showed the patient had *** tomography scans revealed multiple urinary calculi in the right urinary *** tomography urography revealed a duplicated ureteral malformation with an ectopic ureter.A transurethral ureteroscopic holmium laser lithotripsy was performed *** retrograde ureterography was performed,and the ectopic ureter was *** informed the family of the intraoperative findings and suggested laparoscopic ectopic ureterectomy for the ectopic ureteral ***,the family temporarily refused laparoscopic *** patient did not feel any discomfort after one year of *** Inverted Y ureteral duplication with an ectopic ureter and multiple urinary calculi is *** must be highly vigilant,make a correct diagnosis before surgery,determine the type of ureteral duplication and the distribution of urinary calculi,and then draw up a reasonable treatment plan to avoid unnecessary complications.

关键词： Ureteral duplication Inverted Y Ectopic ureter Urinary calculi Case report

Copper-mediated O-arylation of lactols with aryl boronic acids

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical letters 2019年第8期30卷 1533-1537页

作者： Jing-Jing Sui De-Cai Xiong xin-Shan ye National Research Center for Carbohydrate Synthesis Jiangxi Normal UniversityNanchang 330022China State Key laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191China State Key laboratory of Drug Research Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China

An efficient and novel methodology to access phenolic glycosides has been established by using coppermediated coupling reaction of aryl boronic acids with *** reaction takes place normally in the presence of Cu(OAc)_2(1.0 equiv.)and pyridine(2.0 equiv.)at 40℃.This protocol distinguishes itself by wide substrate scope,operational simplicity and giving rise to a myriad of phenolic glycosides in good to excellent yields.

关键词： Phenolic glycoside O-Arylation lactol Aryl boronic acid