检索结果-南通市图书馆

Effect of Air Injector on the Performance of an Air-lift for Conveying River Sand

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2010年第1期23卷 122-128页

作者： TANG Chuanlin hu dong PEI Jianghong YANG Lin College of Mechanical Engineering Hunan University of Technology Zhuzhou 412008 China Department of Mechanical Engineering Chongqing Jiaotong University Chongqing 400044 China

An air-lift has been more recently applied in the dredging, deep-seated beach placer mining and underground mining engineering. However, the influence and mechanism of various parameters on the air-lift performance are not quite clear, especially the influence of flow pattern on lifting efficiency. Focusing on the problems mentioned above, the key part of the air-lift （namely, the air injector） was proposed aimed to reduce friction loss in the inner pipe according to improving flow field performance, thus increase the lifting efficiency. The study of relative factors of the performance of an air-lift is performed and the river sand is used as simulation of underground ore bed. The total lifting height of the experimental system is 3 m, the water flux, mass flow of solid particles, concentration of particles and lifting efficiency are measured under the same submergence ratios by changing the air injector, which is divided into nine specifications of air injection in this research. The experimental results indicate that the optimal air flow rate corresponding to excellent performance of the air-lift can be obtained in the range of 35-40 m3/h. The air injection method has a great effect on the performance of the air-lift, the air injector with three nozzles is better than that in the case of one or two nozzles. Further more, the air injection angle and arrangement of air injection pipes also have great effect on the performance of an air-lift. The proposed research results have guiding significance for engineering application.

关键词： air-lift submergence ratio air flow rate air injector lifting efficiency

Efficacy and adverse effects of oral propranolol in infantile hemangioma:a meta-analysis of comparative studies

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2019年第6期15卷 546-558页

作者： Hao Yang dong-Lai hu Qiang Shu Xiao-dong Guo Department of Pediatrics Surgery Jinhua Central HospitalNo.365 Renmindong RoadWucheng DistrictJinhua 321000China Children's Hospital Zhejiang University School of MedicineNo.3333 Binsheng RoadBinjiang DistrictHangzhou 310052China

Background A number of clinical trials evaluated the efficacy and adverse effects of oral propranolol in the treatment of infantile hemangioma(IH),but the treatment has not yet been *** meta-analysis aims to reevaluate the efficacy and adverse effects of oral propranolol in comparative studies and to provide a reliable basis for clinical administration in the therapy for *** Data were obtained from PubMed,Embase,Cochrane Library,Web of Science,China National Knowledge Infra-structure and Wanfang database,from inception to December 1st,*** pooled risk ratios(RR)with 95%confidence intervals(95%CI)were calculated and used to evaluate the effect *** meta-analysis was performed using the random-effects model due to heterogeneity between the *** Cochrane Collaboration 6 aspects of bias,methodological index for non-randomized studies and the Newcastle-Ottawa Scale were used to assess the risk for *** analysis,publication bias and subgroup analysis were *** Eighteen unique studies involving 2701 unique children were included in the *** response rate was reported in 18 trials,which compared oral propranolol with other *** heterogeneity was statistically significant(P<0.00001,P=95%).The difference in the response rate was statistically significant(RR=1.40,95%CI 1.13-1.75)while compared with the ***,no significant difference in the adverse events rate(RR=0.78,95%CI 0.45-1.34)and relapse rate(RR=1.45,95%CI 0.66-3.16)were ***,the subgroup analysis indicated that the RR was 1.64(95%CI 0.24-11.36)for low-dose propranolol(1 mg/kg/day),1.42(95%CI 1.12-1.80)for medium dose(2 mg/kg/day)and 1.46(95%CI 1.17-1.82)for high dose(3 mg/kg/day),but the high dose had higher adverse events rate than medium dose,with 3.60%and 86.22%,*** effectiveness of propranolol therapy among cases of treatment duration less than 6 months(RR=1.24,95%CI 1.05-1.47)was inferior to that of t

关键词： Hemangioma Meta-analysis Propranolol

Influence of dynamic tissue properties on temperature elevation and lesions during HIFU scanning therapy:Numerical simulation

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

Chinese Physics B 2020年第3期29卷 277-284页

作者： Xiao Zou hu dong Sheng-You Qian School of Physics and Electronics Hunan Normal UniversityChangsha 410081China

When large tumors are treated,ablation of the entire volume of tumors requires multiple treatment spots formed by high intensity-focused ultrasound(HIFU)scanning *** heating effect of HIFU on biological tissue is mainly reflected in temperature elevation and tissue *** property parameters vary with temperature and,in turn,the distribution of temperature as well as the heating effects change *** this study,an HIFU scanning therapy model considering dynamic tissue properties is *** acoustic fields and temperature fields are solved combining the Helmholtz wave equation with Pennes bio-heat transfer equation based on the finite element method(FEM)to investigate the effects of various tissue properties(i.e.,the attenuation coefficient,acoustic velocity,thermal conductivity,specific heat capacity,density,and blood perfusion rate)on heating *** of the temperature distribution and thermal lesions under static and dynamic properties are made based on the data of tissue property parameters varying with *** results show that the dynamic changes of thermal conductivity,specific heat capacity,and acoustic velocity may account for the decrease of temperature elevation in HIFU treatment,while the dynamic changes of attenuation coefficient,density,and blood perfusion rate aggravate the increase of temperature on treatment *** with other properties,the dynamic change of attenuation coefficient has a greater impact on tissue temperature *** HIFU scanning therapy,the temperature elevation and tissue lesions of the first treatment spot are smaller than those of the subsequent treatment spots,but the temperature on the last treatment spot drops faster during the cooling *** ellipsoidal tissue lesion is not symmetrical;specifically,the part facing toward the previous treatment spot tends to be *** the condition of the same doses,the temperature elevation and the size of tissue l

关键词： high intensity-focused ultrasound(HIFU) temperature elevation tissue lesions dynamic tissue properties

Dedication on the Occasion of the Thirtieth Anniversary of the Founding of Institute of Applied Mathematics

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2009年第3期25卷 353-354页

作者： Fu-zhou Gong Xiao-dong hu Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

In March of 1979, Chinese Academy of Sciences （CAS） established, with the approval of the State Council of China, an office for promoting the application of mathematics and Interdisciplinary studies in practice. Later in October of 1979, based on this office CAS established the Institute of Applied Mathematics （IAM）. The first director of IAM was the world-wide famous mathematician, Professor huA Loo-Keng, and most faculty members of IAM came from Institute of Mathematics within CAS, which was founded in July of 1952 and was also directed by Prof. huA.

关键词： Applied Mathematics IAM,CAS Dedication

A survey on heavy metal concentrations in residential neighborhoods: The influence of secondary water supply systems

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 37-45页

作者： dong hu Jie Zeng Yue hu Xiali Fei Xinyan Xiao Mingbao Feng Xin Yu Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Freshwater Fishery Research Institute of Jiangsu Province Nanjing 210017China Xiamen Municipal Water Group.Ltd. Xiamen 361000China College of the Environment and Ecology Xiamen UniversityXiamen 361005China

Water quality deterioration often occurs in secondary water supply systems(SWSSs), and increased heavy metal concentrations can be a serious problem. In this survey, twelve residential neighborhoods were selected to investigate the influence of SWSSs on the seasonal changes in heavy metal concentrations from input water to tank and tap water. The concentrations of nine evaluated heavy metals in all groups of water samples were found to be far below the specified standard levels in China. The concentrations of Fe, Mn, and Zn increased significantly from the input water samples to the tank and tap water samples in spring and summer( p < 0.05), especially for the water samples that had been stagnant for a long time. Negative correlations were found between most of the heavy metals and residual chlorine(Fe, Cu, Zn, and As, r =-0.186 to-0.519, p < 0.05). In particular, a high negative correlation was observed between Fe and residual chlorine( r =-0.489 to-0.519, p < 0.01) in spring and summer. Fe and Mn displayed positive correlations with turbidity( r = 0.672 and 0.328, respectively;p < 0.05). In addition, Cr and As were found to be positively associated with some nutrients(NO, TN, and SO;r = 0.420-0.786, p < 0.01). The material of the storage tanks had little influence on the difference in heavy metal concentrations. Overall, this survey illustrated that SWSSs may pose a chronic threat to water quality and could provide useful information for practitioners.

关键词： Residential neighborhoods Secondary water supply systems Tank materials Water stagnation Residual chlorine Heavy metals

Fast-armored target detection based on multi-scale representation and guided anchor

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第4期16卷 922-932页

作者： Fan-jie Meng Xin-qing Wang Fa-ming Shao dong Wang Xiao-dong hu Department of Mechanical Engineering College of Field EngineeringArmy Engineering University of PLANanjing210007China

Focused on the task of fast and accurate armored target detection in ground battlefield,a detection method based on multi-scale representation network(MS-RN) and shape-fixed Guided Anchor(SF-GA)scheme is ***,considering the large-scale variation and camouflage of armored target,a new MS-RN integrating contextual information in battlefield environment is *** MS-RN extracts deep features from templates with different scales and strengthens the detection ability of small *** targets of different sizes are detected on different representation ***,aiming at the accuracy and real-time detection requirements,improved shape-fixed Guided Anchor is used on feature maps of different scales to recommend regions of interests(ROIs).Different from sliding or random anchor,the SF-GA can filter out 80% of the regions while still improving the recall.A special detection dataset for armored target,named Armored Target Dataset(ARTD),is constructed,based on which the comparable experiments with state-of-art detection methods are *** results show that the proposed method achieves outstanding performance in detection accuracy and efficiency,especially when small armored targets are involved.

关键词： red image RPN Fast-armored target detection based on multi-scale representation and guided anchor

Recent Advances and Perspectives in the Synthesis and Applications of Tetrahydrocarbazol-4-ones

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2020年第7期38卷 737-752页

作者： Muhammad Usman Xu-dong hu Wen-Bo Liu Sauvage Center for Molecular Sciences Engineering Research Center of Organosilicon Compounds&Materials(Ministry of Education)College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei 430072China

Tetrahydrocarbazol-4-one represents a prevalent framework of numerous natural products and *** review summaries the recent synthetic progresses of this core structure,including Fischer indoliation,oxidative and reductive coupling,a-arylative cyclization by means of transition-metal catalysis or under metal-free conditions,and other *** recently emerged enantioselective catalytic methods of tetrahydrocarba20l-4-ones are also *** mechanistic insights and applications of these strategies as a key step in the total(formal)synthesis of complex alkaloids are highlighted as well.

关键词： methods. oxidative catalysis

Determination of berberine in Phellodendron amurense from different sites of Changbai Mountain

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

Journal of Forestry Research 2015年第1期26卷 201-207页

作者： Lin Ma Jun-qing Li Yuan-dong hu Key Laboratory for Silviculture and Conservation of Ministry of Education Forest CollegeBeijing Forestry University Landscape Architecture School Northeast Forestry University

Phellodendron amurense has been used for many years as a medical plant in traditional Chinese medicine and has shown great prospect in recent clinical trials for future applications. Berberine is an essential active compound contained in P. amurense. Our objective in this study was to quantify the content of berberine in *** from sites at different elevations on Changbai Mountain. We collected samples of P. amurense from five different elevations on Changbai Mountain. Berberine in samples was extracted by ultrahigh pressure extraction（UPE）. And the quantity was measured by high performance liquid chromatography（HPLC）. First, the optimal HPLC conditions for berberine were identified with satisfactory precision（relative standard deviation, R SD／5.6 %）, good accuracy（relative error, R E／ 3.6 %） and good linear relation（R2= 0.9998） in the range of 6.576–328.8 mg L-1. Second, the combination of UPE and HPLC methods in quantitative analysis of berberine showed high repeatability（R SD= 3.28 %）, reproducibility（R SD= 4.72 %）,stability（R SD／ 1.27 %） and good recovery（99.54 %） for real plant materials. Samples from Heilongjiang Province at the lowest elevation contained the highest amount of ***, the lowest amount of berberine was recorded in samples from Changbai Forest Bureau of Jilin Province collected at the highest elevation in this paper. The proposed UPE–HPLC method is simple, reliable and low-cost for quantitative analysis of berberine. Content of berberine in *** varied significantly by site on Changbai Mountain.

关键词： Phellodendron amurense Berberine Changbai Mountain Altitudes Ultrahigh pressure extraction High performance liquid chromatography

Thermodynamic analysis and simulation for gas baffle entrance collimator of EAST-NBI system based on thermo-fluid coupled method

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2018年第1期29卷 90-95页

作者： Ling Tao Chun-dong hu Yuan-Lai Xie Institute of Plasma Physics Chinese Academy of Sciences

The world's first full Experimental Advanced Superconducting Tokamak(EAST) is designed with the auxiliary heating method of neutral beam injection(NBI)system. Beam collimators are arranged on both sides of the beam channel for absorbing the divergence beam during the beam transmission process in the EAST-NBI *** gas baffle entrance collimator(GBEC) is a typical high-heat-flux component located at the entrance of gas baffle. An efficient and accurate analysis of its thermodynamic performance is of great significance to explore the working limit and to ensure safe operation of the system under a high-parameter steady-state condition. Based on the thermo-fluid coupled method, thermodynamic analysis and simulation of GBEC is performed to get the working states and corresponding operating limits at different beam extraction conditions. This study provides a theoretical guidance for the next step to achieve long pulse with highpower experimental operation and has an important reference to ensure the safe operation of the system.

关键词： Neutral beam injection High-heat-flux component Beam collimator Thermo-fluid coupled method Thermodynamic analysis