检索结果-南通市图书馆

Resistance of the flow over rough surfaces

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2021年第3期33卷 593-601页

作者： Yu Han Shi-yu Wang Jian Chen Shuqing Yang Liu-chao qiu Nadeesha Dharmasir College of Water Resources and Civil Engineering China Agricultural UniversityBeijing100083China College of Engineering China Agricultural UniversityBeijing100083China School of Civil Mining and Environmental EngineeringUniversity of WollongongWollongongAustralia

The mechanism of the flow resistance in open channels and pipelines is of vital importance for various critical issues related to the water *** Nikurade’s method of calculating the friction factor is not applicable in some *** is necessary to consider the influence of the vortex volume surrounding the vegetation and to study the hydrodynamic characteristics of the vegetated *** paper analyzes the variation of the vortices created by the surface roughness of different types and different sizes and proposes new definitions of the hydraulic radius and the equivalent roughness *** consideration of the skin friction and the form drag,on the basis of the force balance equation,a novel calculation method is used for the friction factor,and this method is verified by experimental *** hydrodynamic mechanism of the flow resistance revealed in this study may serve as a theoretical basis for hydraulic engineers to calculate the friction factor.

关键词： Hydraulic radius skin friction form drag friction factor separation zone dead fluid volume

Design,synthesis of novel antifungal triazole derivatives with high activities against Aspergillus fumigatus

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 2007年第4期18卷 421-423页

作者： qiu Qin He chao Mei Liu Ke Li Yong Bing Cao School of Pharmacy Second Military Medical University Shanghai 200433 China

Based on the active site of Aspergillus fumigatus lanosterol 14α-demethylase （AF-CYP51）, novel triazole compounds were designed. Their chemical synthesis and the antifungal activities were reported. The results showed that all the target compounds exhibited excellent activities with broad spectrum; in which compounds 4, 12 and 15 showed comparable activities against A. fumigatus to the control drug itraconazole.

关键词： CYP51 Antifungal Triazole Synthesis Aspergillus fumigatus

Modeling Non-aqueous Phase Liquid Displacement Process

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2007年第3期4卷 40-46页

作者： Yang Zhenqing Shao Changjin Zhou Guanggang qiu chao Physics Department China University of Petroleum Beijing 102249 China

A pore-network model physically based on pore level multiphase flow was used to study the water-non-aqueous phase liquid （NAPL） displacement process, especially the effects of wettability, water-NAPL interracial tension, the fraction of NAPL-wet pores, and initial water saturation on the displacement. The computed data show that with the wettability of the mineral surfaces changing from strongly water-wet to NAPL-wet, capillary pressure and the NAPL relative permeability gradually decrease, while water-NAPL interfacial tension has little effect on water relative permeability, but initial water saturation has a strong effect on water and NAPL relative permeabilities. The analytical results may help to understand the micro-structure displacement process of non-aqueous phase liquid and to provide the theoretical basis for controlling NAPL migration.

关键词： Non-aqueous phase liquid pore-network model capillary pressure relative permeability

One-step approach for full-thickness skin defect reconstruction in rats using minced split-thickness skin grafts with Pelnac overlay

在线全文

学校读者我要写书评

暂无评论

Burns & Trauma 2019年第1期7卷 167-179页

作者： Tong Liu chao qiu Chi Ben Haihang Li Shihui Zhu Department of Burn Surgery Institute of BurnsThe First Affiliated HospitalNaval Medical UniversityShanghai 200433China Emergency Department The First Affiliated HospitalNaval Medical UniversityShanghai 200433China

Background:Split-thickness skin grafting is the current gold standard for the treatment of traumatic skin ***,for patients with extensive burns,split-thickness skin grafting is limited by donor skin *** split-thickness skin minced into micrografts increases the expansion ratio but may reduce wound repair *** substitutes such as Pelnac can enhance the healing of full-thickness skin wounds,but their application currently requires two *** present study investigated whether it is possible to repair full-thickness skin defects and improve wound healing quality in a single surgery using Pelnac as an overlay of minced split-thickness skin grafts in a rat ***:A full-thickness skin defect model was established using male Sprague-Dawley rats of 10 weeks *** animals were randomly divided into control and experimental groups in which Vaseline gauze and Pelnac,respectively,were overlaid on minced split-thickness skin grafts to repair the *** healing rate and quality were compared between the two *** better illustration of the quality of wound healing,some results were compared with those obtained for normal skin of ***:We found that using Pelnac as an overlay for minced split-thickness skin grafts accelerated wound closure and stimulated cell proliferation and tissue *** addition,this approach enhanced collagen synthesis and increased the formation of basement membrane and dermis as well as the expression of growth factors related to wound healing while reducing scar ***:Using minced split-thickness skin grafts overlaid with Pelnac enables the reconstruction of fullthickness skin defects in a single step and can increase the healing rate while improving the quality of wound healing.

关键词： Skin wound healing Full-thickness skin defect Minced skin graft Pelnac Split-thickness skin grafts Reconstruction

Sediment transport in pure acceleration-skewed oscillatory sheet flow

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 2018年第6期30卷 1045-1054页

作者： Xin Chen Fu-jun Wang Gen-fa Chen Liu-chao qiu College of Water Resources and Civil Engineering China Agricultural University Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural University China Institute of Water Resources and Hydropower Research

In the present study, an analytical concept model is built, using a two-phase model for the sediment transport in a pure acceleration-skewed oscillatory sheet flow. The analytical model is based on the asymmetric wave theory, the irregular boundary layer theory and the exponential concentration distribution theory, to be used for analyzing the phase lag and the boundary layer development related to the acceleration skewness. The two-phase model is applied for the calculations of the instantaneous erosion depth, the sediment flux, the boundary layer thickness and the sediment transport rate, as well as the differences between the positive acceleration stage and the negative acceleration stage caused by the acceleration skewness, as very important in the net current and sediment transport. The effects of the sediment diameter and the phase lag are explained by a comparison with the instantaneous type empirical formula, as is closely related to the acceleration skewness. With the analytical concept model and the two-phase model, the generation of the net sediment transport in the pure acceleration-skewed flows is clearly explained. The phase lag effect is important for the instantaneous sediment transport in the pure acceleration-skewed flow, whereas the boundary layer development difference between the positive acceleration stage and the negative acceleration stage plays a major role in the determination of the net sediment transport.

关键词： Acceleration skewness analytical concept model boundary layer thickness two-phase model sediment transport rate

Can the Prior Cathodic Polarisation Treatment Remove the Air-Formed Surface Film and Is It Necessary for the Potentiodynamic Polarisation Test?

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2020年第6期33卷 839-845页

作者： Zheng-Rong Ye Zhi-chao qiu Zheng-Bin Wang Yu-Gui Zheng Ran Yi Xiang Zhou Research Institute of Petroleum Exploration and Development PetroChinaBeijing 100083China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

This paper clarifies two issues related to the prior cathodic polarisation treatment(PCPT) for the potentiodynamic polarisation test: whether PCPT can(1) remove the air-formed surface film and(2) affect the polarisation test results. X-ray photoelectron spectroscopy analyses of fluoride ion-labelled samples show that PCPT cannot remove the surface film completely due to the low reaction rate. Potentiodynamic polarisation tests demonstrate that PCPT with proper operating parameters,-1.0 V SCE for 5 min with subsequent open circuit potential(OCP) stabilisation in this study, is necessary because it can improve the test reproducibility without affecting the corrosion parameters by unifying the initial surface state. However, PCPT with lower potentials, longer time or no OCP stabilisation has significant effects on the electrochemical corrosion parameters due to the hydrogen absorption under the conditions of this study.

关键词： Stainless steel Prior cathodic polarisation treatment Surface film Potentiodynamic polarisation

基于不可压缩光滑粒子动力学的黏性液滴变形过程仿真

在线全文

学校读者我要写书评

暂无评论

物理学报 2013年第12期62卷 328-333页

作者：邱流潮中国农业大学应用力学系北京100083

应用基于投影算法的不可压缩光滑粒子动力学(incompressible smoothed particle hydrodynamics,ISPH)法对黏性液滴变形过程进行了数值仿真.对于张力失稳导致的粒子非物理簇集问题,采用粒子移位技术加以解决.为了验证本文ISPH算法的精度... 详细信息

应用基于投影算法的不可压缩光滑粒子动力学(incompressible smoothed particle hydrodynamics,ISPH)法对黏性液滴变形过程进行了数值仿真.对于张力失稳导致的粒子非物理簇集问题,采用粒子移位技术加以解决.为了验证本文ISPH算法的精度和稳定性,分别模拟了圆形黏性液滴的拉伸变形过程以及方形液滴的旋转变形过程,得到了不同时刻液滴内部的压力变化特征,准确地捕捉了液滴自由面演化过程,并将数值计算结果与文献中的解析解进行了比较.分析结果表明,基于投影算法的不可压缩光滑粒子动力学方法结合粒子移位技术,能够有效地模拟黏性液滴变形过程,可以得到精确和稳定的结果.

关键词：不可压缩光滑粒子动力学黏性液滴自由面流动数值仿真

HIV-1/AIDS vaccine development： are we in the darkness before the dawn？

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2008年第10期121卷 939-945页

作者： qiu chao XU Jian-qing The Institute of Biomedical Sciences Fudan University Shanghai 201508 China

The pandemic of human immunodeficiency virus type 1 （HIV-I） has been devastating for the last two decades in a number of developing countries and constituting a grand challenge to the public health. WHO/UNAIDS estimates that approximately 33.2 million people were living with HIV-1 infection by the end of 2007 and almost 2.5 million new infections occurred in 2007. An unprecedented scientific challenge for the AIDS vaccine community is how to develop an effective HIV vaccine that can block HIV transmission and consequently stop the continuing spread of HIV-1. The recent failure of Merck Phase II B trial alerted the HIV vaccine community that new vaccine strategies need to be more exclusively explored. In this review, we outline the basics of HIV vaccine and retrospect the history of the road to HIV vaccine in last two decades, and highlight the challenges we are currently facing and new strategies to develop HIV vaccines in this field.

关键词： human immunodeficiency virus vaccine T cell immunity neutralization antibody

Recent progress in porous Mg-based foam preparation approaches:effect of processing parameters on structure and mechanical property

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 Iron and Steel Research International 2022年第3期29卷 371-402页

作者： Solomon-Oshioke Agbedor Dong-hui Yang Jing Cao Jian-qing Chen Bassiouny Saleh chao qiu Lei Wang Jing-hua Jiang Ai-bin Ma College of Mechanics and Materials Hohai UniversityNanjing211100JiangsuChina Suqian Research Institute of Hohai University Suqian223814JiangsuChina Ocean and Offshore Engineering Research Institute of Hohai University Nantong226019JiangsuChina

Porous metals are a class of cellular materials with lightweight and unique mechanical,electrical,thermal,physical and acoustic *** and magnesium alloy foams have exhibited excellent *** particular,open-cell Mg-based foams(porous Mg/Mg alloy foams)have been used for bioresorbable implants,CO_(2)trapping systems,filters,heat exchangers,absorbent panels and many other *** significant progress has been taken in producing porous Mg-based foams with good structure-property relations,but with a large number of different processing parameters,different mechanical properties and pore morphologies of each porous Mg-based foam,it is essential to understand the individual effects of each aspect of the ***,the present article summarized the effects of available processing parameters on the structure and mechanical properties of the porous Mg-based ***,the future perspectives to enhance the structure and properties of porous Mg/Mg alloy foams were discussed.

关键词： Porous Mg alloy Powder processing Sintering Liquid metal infiltration Mechanical property