检索结果-南通市图书馆

Numerical Approach to Film Cooling Effectiveness Over a plate Surface with Coolant Impingement

Journal of Thermal Science 2004年第1期13卷 67-74页

作者： Chang-Hsien Tai jr-Ming Miao A-Fu Kao Department of Vehicles Engineering National Pingtung University of Science and TechnologyPingtungTaiwanChinaDepartment of Mechanical EngineeringChung Cheng Institute of TechnologyNational Defense UniversityTaoyuanTaiwanChinaGraduate School of Defense Science StudiesChung Cheng Institute of TechnologyNational Defense UniversityTaoyuanTaiwanChina

The aim of the present study is conducting the numerical approach to a combination of internal jet impingement and external film cooling over a flat plate. A multi-block three-dimensional Navier-Stokes code, CFX 4.4, with k-e turbulence model is used to simulate this complicated thermal-flow structure induced by the interaction of coolant jet and hot cross mainstream. By assuming the adiabatic wall boundary condition on the tested film-cooled plate, both the local and the spanwise-averaged adiabatic film cooling effectiveness are evaluated for comparison of the cooling performance at blowing ratios of Br=0.5, 1.0, and 1.5. Film flow data were obtained from a row of five cylindrical film cooling holes, inclined in angle of 35?and 0?in direction of streamwise and spanwise, respectively. The film cooling hole spacing between adjacent holes is 15 mm for all the holes. Before the coolant flow being injected through individual cooling hole then encountered with the mainstream, an impingement chamber containing an impingement plate with 43 holes is located on the path of coolant flow. present study also focused on the effect of impingement spacing, 10mm, 20mm, and 30mm. Compare the results, we find the impingement jet has a significant effect on the adiabatic film cooling effectiveness. As the coolant impingement spacing is fixed, results indicated that higher blowing ratio would enhance the local and the spanwise-averaged adiabatic film cooling effectiveness. Moreover, neither uniform nor parabolic distribution of pressure distribution are observed within the coolant hole-pipe.

关键词： film cooling impingement cooling CFD turbulence model.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of in-situ formed Al hydrates through long-term aging on enhanced particle destabilization by pACl coagulation

引用

Journal of Environmental Sciences 2020年第6期32卷 200-210页

作者： jr Lin Lin Aldeno Rachmad Ika Chun Chen Tseng Department of Environmental Engineering Chung Yuan Christian UniversityChinese Taipei

Aging of polyaluminum chloride(pACl) coagulants could significantly influence hydrolyzed Al speciation ruling coagulation *** goal of this study was to investigate Al species transformation through long-term aging and its impact on coagulation *** kinds of commercial coagulants(pACl-1 and pACl-2) were stored for in-situ aging tests in six months to evaluate Al species variation with time and the performance of coagulation with natural turbid *** results showed that CaSO4 precipitation easily occur in a commercial pACl coagulant with time as it contains SO4^2- and Ca^2+.It also activates the precipitation of gibbsite Al(OH)3 in pACl with *** 180 days aging,both monomeric Al(Ala) and polymeric Al(Alb) substantially transform into colloidal Al(Alc) and precipitated for both pACl *** low turbidity(10 NTU),pACl-1 has a superior turbidity reduction rate than pACl-2,while pACl-2 performs a little better turbidity re duction at high turbidity(1000 NTU) regardless of aging *** aging time,an obvious decrease in turbidity reduction for pACl-1 coagulation is observed at low turbidity of 10 NTU,while the improvement in turbidity reduction for pACl-2 coagulation by enhanced sweep flocculation can be achieved as Alb mostly transform into Alc after 150 days *** is concluded that dominant in-situ formed Alc after a long time hydrolysis can improve pACl coagulation efficiency in turbidity reduction by enhanced sweep flocculation,especially for low turbidity water,but the increase in preformed Alc in pACl would worsen particle destabilization after aging.

关键词： Coagulation pACl Aging Al hydrates

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Review of endoscopic techniques in the diagnosis and management of cholangiocarcinoma

引用

World Journal of Gastroenterology 2008年第19期14卷 2995-2999页

作者： Katherine Nguyen James T Sing jr Scott & White Clinic Texas A&M University Health Science Center College of Medicine

Cholangiocarcinoma is a rare malignancy of the biliary tract. Key factors in determining therapeutic options include knowledge of tumor extent, anatomy and obtaining tissue diagnosis. Endoscopically, there are three modalities available to make the diagnosis of cholangiocarcinoma. These include endoscopic retrograde cholangiopancreatography, endoscopic ultrasound with fine needle aspiration and cholangioscopy. Management of cholangiocarcinoma endoscopically is typically confined to stent placement for palliative purposes or as a bridge to surgery. In this article, we will review the endoscopic techniques available for the diagnosis and management of cholangiocarcinoma.

关键词： Cholangiocarcinoma Endoscopic ultrasound Endoscopic cholangiopancreatography Cholangioscopy Diagnosis Hanagement

来源：

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

Deadlock-free dynamic resource assignment in multi-robot systems with multiple missions:application in wireless sensor networks

引用

控制理论与应用（英文版） 2010年第1期8卷 12-19页

作者： p.M.BALLAL A.C.TRIVEDI V.GIORDANO J.MIRELES jr. F.L.LEWIS Automation & Robotics Research Institute University of Texas at Arlington

In unstructured environments, dynamic resource assignment is required for effective cooperation of robot teams. In some scenarios, robots are in charge of executing multiple missions simultaneously. This creates risks of deadlock due to the presence of shared resources among various missions. The main contribution of this paper is the development of a novel approach that combines the one-step look-ahead deadlock avoidance policy with dynamic resource assignment. The dynamicresource assignment is achieved using greedy resource assignment for multi-mission robot teams in the framework of a matrix-based discrete event controller. Simulation results are presented in MATLAB to discuss in detail the proposed control strategy. The paper also discusses the toolkit developed in LabVIEW which is used to implement this control framework using a suitable example.

关键词： Discrete event systems Wireless sensor networks Deadlock avoidance petri nets

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

polymer-virus core-shell structures prepared via co-assembly and template synthesis methods

引用

Science China Chemistry 2010年第1期53卷 71-77页

作者： SUTHIWANGCHAROEN Nisaraporn pREVELIGE peter E.jr Department of Chemistry and Biochemistry and Nanocenter University of South CarolinaColumbiaSouth Carolina 29208USA Department of Microbiology University of Alabama at BirminghamBirminghamAL 35294USA

Bionanoparticles(BNps),consisting of virus and virus-like assemblies,have attracted much attention in the biomedical field for their applications such as imaging and targeted drug delivery,owing to their well-defined structures and well-controlled ***-based core-shell structures provide a unique system for the investigation of biological interactions such as protein-protein and protein-carbohydrate ***,it is still a challenge to prepare the BNps-based core-shell ***,we describe(i) co-assembly method and(ii) template synthesis method in the development of polymer-BNps core-shell *** two methods can be divided into three different *** system A,different polymers including poly(2-vinylpyridine)(p2Vp),poly(4-vinylpyridine)(p4Vp) and poly(ε-caprolactone)-block-poly(2-vinylpyridine)(pCL-b-p2Vp) can form a raspberry-like structure with *** system B,polystyrene(pS) spheres end capped with free amine and BNps can form a core-shell *** System C,layer-by-layer(LBL) method is used to prepare positive charged pS particles,which can be used as a template to form the core-shell structures with *** two methods may open a new way for preparing novel protein-based functional materials for potential applications in the biomedical field.

关键词： core-shell structures bionanoparticles virus polymers co-assembly template synthesis layer-by-layer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact of a physician-supervised exercise-nutrition program with testosterone substitution in partial androgen-deficient middle-aged obese men

引用

Journal of Geriatric Cardiology 2011年第4期8卷 201-206页

作者： Ernst R Schwarz Robert D Willix jr Cenegenics Education and Research Foundation Las Vegas and Heart Institute of Southern CaliforniaBeverly Hills348 S Oakhurst DrBeverly HillsCA 90212USA

Background partial androgen deficiency syndrome in the aging male is associated with signs of aging such as a development of abdominal obesity,sexual dysfunction,increase body fat,weight gain and the development of cardiac *** We assessed the outcome of a commercially available physician supervised nutrition and exercise program with concomitant testosterone replacement therapy in middle age obese men with partial androgen deficiency in order to reduce cardiac risks *** Fifty-six self referred men without diabetes mellitus,hypertension,or cardiovascular disease(ages 52.3±7.8 years)were randomly selected from a large *** weight,body fat composition,fasting glucose,hemoglobin A1c and fasting lipid levels,as well as free and total testosterone levels were *** patients were assessed and followed 6–18 months after initiation of the *** program consisted of a low glycemic load balanced nutrition diet,a recommended structured daily exercise program of 30–60 minutes,as well as once to twice weekly intramuscular testosterone injections(113.0±27.8 mg).Results At follow up,weight was reduced from 233.9±30.0 pounds(lbs)to 221.3±25.1 lbs(pppppplacement therapy in middle aged obese men with partial androgen deficiency appeared safe and might have promoted the effects of a weight reduction diet and daily exercise program as long as an adequate physician supervision and follow up was *** combination therapy significantly reduced coronary risk factors such as glucose intolerance and hyperlipidemia.

关键词： aging heart disease androgen deficiency testosterone

来源：

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

3D printed millireactors for process intensification

引用

Chinese Journal of Chemical Engineering 2020年第1期28卷 180-190页

作者： Harrson S.Santana Alan C.Rodrigues Mariana G.M.Lopes Felipe N.Russo Joao L.Silva jr Osvaldir p.Taranto School of Chemical Engineering University of CampinasBrazil Federal Institute of Education Science and Technology of South of Minas GeraisBrazil

The scope of the present research aims at demonstrating the 3D printing use in the manufacturing of microchannels for chemical process applications. A comparison among digital model processing applications for 3D print(slicers) and a print layer thickness analysis were performed. The 3D print fidelity was verified in several devices, including the microchannels’ printing with and without micromixer zones. In order to highlight the 3D print potential in Chemical Engineering, the biodiesel synthesis was also carried out in a millireactor manufactured by 3D printing. The millireactor operated under laminar flow regime with a total flow rate of 75.25 ml·min^-1(increment of about 130 times over traditional microdevices used for biodiesel production).The printed millireactor provided a maximum yield of Ethyl Esters of 73.51% at 40 ℃, ethanol:oil molar ratio of7 and catalyst concentration of 1.25 wt% and residence time about 10 s. As a result of flow rate increment attained in the millireactor, the number of required units for scaling-up the chemical processes is reduced. Using the approach described in the present research, anyone could produce their own millireactor for chemical process in a simple way with the aid of a 3D printer.

关键词： process intensification 3D printer Millireactors Micromixers Microdevices Biodiesel

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Roles of Financial Innovation and Information Technology:Lessons from US Sub-prime Mortgage Crisis and Its Implications for China

引用

Chinese Geographical Science 2012年第3期22卷 343-355页

作者： James H LENZER jr Simon Xiaobin ZHAO International Center for China Development Studies & Department of Geography Faculty of Social Sciencesthe University of Hong KongHong KongChina

The mortgage loan has evolved from a local lending instrument into a major global security and its role is unparallel to other financial instruments in the process of financial globalization. This paper explains how technology and financial innovation transformed the mortgage loan from a local security into a premier global security traded worldwide. It examines the fundamental flaws of this process and why it does not work in regards to mortgage lending and the re-securitization products that were created through financial innovation. The findings show that regulation was unable to keep pace with financial innovation, which created an environment where actors in the financial service sector were able to behave geographically irresponsibly by using information asymmetries to their advantage by par- ticipating in moral hazard activities and engaging in other immoral and unethical business practices that were centered around localized geography, which ultimately contributed to the global financial crisis. It also examines the roll of financial innovation in regard to the Lehman Brothers Mini-Bond in Hung and its role as a driving force behind China＇s newly emerging shadow banking sector. It concludes with a policy recommendation and its implication for China＇s continued economic development.

关键词： shadow banking US sub-prime mortgage crisis financial tsunami global financial crisis wealth man- agement vehicle China asset bubble

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

predator-prey distance and latency to flee from an immobile predator： functional relationship and importance

引用

Current Zoology 2016年第2期62卷 117-122页

作者： William E. COOpER jr Jose MARTIN Department of Biology Indiana University Purdue University Fort Wayne Fort Wayne IN 46805 USA Departamento de Ecologia Evolutiva Museo Nacional de Ciencias Naturales CSIC Madrid Spain

When an immobile prey has detected an immobile predator nearby, predation risk is greater when the predator is closer. Consequently, prey flee with shorter latency as standing distance （predator-prey distance when both are still） decreases. Since it was first reported in 2009, this relationship has been confirmed in the few species studied. However, little is known about the functional relationship between standing distance and latency to flee （LF）. We hypothesized that LF increases as standing distance increases at short distances, but reaches a plateau at longer distances where prey can escape reliably if attacked. We simulated immobile predators by moving slowly into positions near striped plateau lizards Sceloporus virgatus, stopping and then remaining immobile, and recording LF from the stopping time. LF increased from shorter to longer standing distances in a decelerating manner. The relationship was concave downward, and LF was indistinguishable among the longer standing distance groups. Latency to flee appears to reach a plateau or approach an asymptotic value as stand- ing distance increases. The effect size of standing distance was large, indicating that S. virgatus sensi- tively adjusts LF to the level of risk associated with standing distance. Relationships between risk assessment and theoretical zones associated with risk, its assessment by prey, and escape decisions are discussed. Effect sizes of standing distance were substantial to large in all studies to date, indicating that standing distance is an important predation risk factor when both predator and prey are immobile.

关键词： antipredatory behavior escape behavior latency to flee squamata standing distance.

来源：

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

Biomarkers of Neurotoxicity: An Overview

引用

Biomedical and Environmental Sciences 1991年第1期4卷 192-196页

作者： WILLIAM SLIKKER jr Chief pharmacodynamics Branch Division of Reproductive and Developmental Toxicology National Center for Toxicological Research JeffersonDepartments of Pharmacology and Toxicology and Pediatrics University of Arkansas for Medical Sciences and Arkansas Children's Hospital Little Rock Arkansas 72079 Arkansas 72205

Neurotoxicity may be defined as any adverse effect on the structure or function of the central and/or peripheral nervous system by a biological, chemical, or physical agent. Neurotoxic effects may be permanent or reversible, produced by neuropharmacological or neurodegenerative properties of a neurotoxicant, or the result of direct or indirect actions on the nervous system (ICON, 1990). Adverse effects include side effects (unwanted effects) or effects due to overdosing; functional or structural responses that promote compensation to restore normal function; or any

关键词： An Overview Biomarkers of Neurotoxicity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：