检索结果-南通市图书馆

Ecological effects of co-culturing the sea cucumber Apostichopus japonicus with the Chinese white shrimp Fenneropenaeus chinensis in an earthen pond

引用

Chinese Journal of Oceanology and Limnology 2017年第1期35卷 122-131页

作者：周顺任贻超 christopher m.pearce 董双林田相利高勤峰王芳 Key Laboratory of mariculture Ministry of Education Ocean University of China marine Science and Engineering College Qingdao Agricultural University Fisheries and Oceans Canada Pacific Biological Station

Using net enclosures in an earthen pond, we established three culture treatments with the sea cucumber Apostichopus japonicus and the Chinese white shrimp Fenneropenaeus chinensis : monoculture of sea cucumbers(C), monoculture of shrimp(S), and co-culture of the two species(CS). We measured levels of suspended particulate matter in the water column; total organic matter, total organic carbon, total nitrogen, and carbon/nitrogen ratios in both settling particles and the sediment; and chlorophyll a levels in the sediment. We then compared these variables between the three treatments. We also examined growth, survival, and yield of the two species in the different treatments. From June to September, the mean monthly suspended particulate matter sedimentation rates in the CS and S treatments were significantly( P ment. From August to November, the mean monthly total organic matter, total organic carbon, total nitrogen, and chlorophyll a contents in the sediment in the CS and S treatments were significantly( P ment. Final wet weight, specific growth rate, survival rate, and total yield of sea cucumbers in co-culture were all significantly greater than those of sea cucumbers in monoculture. There were no significant differences among any of these variables for shrimp reared in the two systems. The bioturbation of the sediment and fecal production of the shrimp likely supplied natural food for the sea cucumbers. Co-culture of the two species is a viable option for increasing yield per unit area, maximizing use of the water body, and diversifying crop production.

关键词： Apostichopus japonicus co-culture Fenneropenaeus chinensis sea cucumber sediment sedimentation

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

Cost-Effectiveness of Interventions for Alternate Food to Address Agricultural Catastrophes Globally

引用

International Journal of Disaster Risk Science 2016年第3期7卷 205-215页

作者： David C.Denkenberger Joshua m.pearce Global Catastrophic Risk Institute Department of Civil and Architectural Engineering Tennessee State University Department of materials Science and Engineering Michigan Technological University Department of Electrical and Computer Engineering Michigan Technological University

The literature suggests there is about a 1 % risk per year of a 10 % global agricultural shortfall due to catastrophes such as a large volcanic eruption, a medium asteroid or comet impact, regional nuclear war, abrupt climate change, and extreme weather causing multiple breadbasket failures. This shortfall has an expected mortality of about 500 million people. To prevent such mass starvation, alternate foods can be deployed that utilize stored biomass. This study developed a model with literature values for variables and, where no values existed,used large error bounds to recognize uncertainty. Then monte Carlo analysis was performed on three interventions: planning, research, and development. The results show that even the upper bound of USD 400 per life saved by these interventions is far lower than what is typically paid to save a life in a less-developed country. Furthermore, every day of delay on the implementation of these interventions costs 100–40,000 expected lives(number of lives saved multiplied by the probability that alternate foods would be required). These interventions plus training would save 1–300 million expected lives. In general, these solutions would reduce the possibility of civilization collapse, could assist in providing food outside of catastrophic situations, and would result in billions of dollars per year of return.

关键词： Agricultural catastrophe Alternate food Global catastrophic risk Intervention cost-effectiveness

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

Chronic disease in a digital health environment

引用

Family medicine and Community Health 2018年第1期6卷 20-25页

作者： christopher pearce Australasian College of Health Informatics Outcome Health Department of Health Informatics University of Melbourne Department of General Practice Monash University Digital Health Committee of the Australian College of Rural and Remote medicine

Although we know that there are benefits to individual patients from electronic data,the next potential,and potentially the biggest,benefit will come from the technologies known as big data,machine learning,and artificial *** the potential of computers to sift through large amounts of data will result in the possibility of generating insights into individual patients,and into whole populations,predicting the risk of hospital admission for an individual,or track-ing influenza epidemics to prepare adequate *** the data are reliable,recorded in a computer-interpretable way,new horizons will open.

关键词： Ehealth digital health chronic disease patient centred medicine health systems

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

Assessing risks from mining-induced ground movements near gas wells

引用

International Journal of mining Science and Technology 2020年第1期30卷 11-16页

作者： christopher mark Gregory m.Rumbaugh mine Safety and Health Administration PittsburghPAUSA

The proliferation of unconventional gas well development in the Northern Appalachian coalfields has raised a number of mine safety *** wells,which extract gas from deep shale formations,are characterized by gas volumes and pressures that are significantly higher than those observed at many conventional *** gas is composed largely of methane as well as other *** of planned and actively producing wells penetrate protective coal pillars or barriers within active mine boundaries,including chain pillars located between longwall *** released from a well damaged by mining-induced ground movements could pose a risk to miners by flowing into the mine *** mining-induced ground movements that may cause well damage include conventional subsidence,non-conventional subsidence(*** plane slip),pillar failure,and floor *** paper describes the known risk factors for each of the four failure *** includes a framework that can guide the risk assessment process when mining takes place near gas or oil wells.

关键词： Gas well Subsidence Coal protection pillar Risk matrix Longwall mining

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

Influence of residual stresses on failure pressure of cylindrical pressure vessels

引用

Chinese Journal of Aeronautics 2013年第6期26卷 1415-1421页

作者： m.Jeyakumar T.christopher Department of mechanical Engineering Sardar Raja College of EngineeringAlangulamTirunelveli 627 808India Department of mechanical Engineering Government College of EngineeringTirunelveli 627 007India

The utilization of pressure vessels in aerospace applications is *** this work,fnite element analysis（FEA）has been carried out using ANSYS software package with 2D axisymmetric model to access the failure pressure of cylindrical pressure vessel made of ASTm A36 carbon steel having weld-induced residual *** fnd out the effect of residual stresses on failure pressure,frst an elasto-plastic analysis is performed to fnd out the failure pressure of pressure vessel not having residual *** a thermo-mechanical fnite element analysis is performed to assess the residual stresses developed in the pressure vessel during *** one more elasto-plastic analysis is performed to assess the effect of residual stresses on failure pressure of the pressure vessel having residual *** analysis indicates reduction in the failure pressure due to unfavorable residual stresses.

关键词： Aerospace engineering ASTm A36 Finite element analysis Pressure vessels Welding residual stress

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

Jet flows from bubbles during subcooled pool boiling on micro wires

引用

Science China(Technological Sciences) 2005年第4期48卷 385-402页

作者： D. m. christopher Laboratory of Phase Change and Interfacial Transport Phenomena Department of Thermal Engineering Tsinghua University Beijing 100084 China

An experimental investigation was conducted on subcooled nucleate boiling on ultra-small wires having diameters of 25―100 μm. High-speed photography and laser PIV (Particle Image Velocimetry) technology were used to visually observe the bubble dynamics. For highly subcooled boiling at moderate heat fluxes, the bubbles generally remained attached to the micro heating wires and bubble-top jet flows were clearly observed. Smaller bubbles usually had stronger bubble-top jet flows, while larger bubbles seemed to produce multi-jet flows. The structures of the bubble-top jet flows, as well as multi-jet flows, were proposed from the experimental observation. A model was developed to describe jet flow phenomena from bubbles on micro wires. Numerical simulations for bubbles having diameter of 0.03 and 0.06 mm showed that both the bubble-top and multi-jet flows were induced by a strong marangoni effect due to high temperature gradients near the wire. The predicted velocity magnitudes and flow structures agreed very well with experimental measurements. The bubble size relative to the wire is an important factor affecting the jet flow structure. For a 0.03 mm bubble on a 0.1 mm wire, only a bubble-top jet flow forms, while a complex multi-jet flow pattern forms around the bubble with a weak bubble-top jet and two side jet flows for a 0.06 mm bubble.

关键词： subcooled boiling, bubble, multi-jet, jet flow, PIV, marangoni, CFD.

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

Updates on treatment of irritable bowel syndrome

引用

World Journal of Gastroenterology 2008年第17期14卷 2639-2649页

作者： christopher W Hammerle Christina m Surawicz Department of medicine University of Colorado Health Sciences Center Harborview medical Center University of Washington

Irritable bowel syndrome （IBS） is a highly prevalent gastrointestinal disorder characterized by abdominal pain and discomfort in association with altered bowel habits. It is estimated tD affect 10%-15% of the Western population, and has a large impact on quality of life and （in）direct healthcare costs. IBS is a multifactorial disorder involving dysregulation within the brain-gut axis, and it is frequently associated with gastrointestinal motor and sensory dysfunction, enteric and central nervous system irregularities, neuroimmune dysregulation, and postinfectious inflammation. As with other functional medical disorders, the treatment for IBS can be challenging. Conventional therapy for those with moderate to severe symptoms is largely unsatisfactory, and the development of new and effective drugs is made difficult by the complex pathogenesis, variety of symptoms, and lack of objective clinical findings that are the hallmark of this disorder. Fortunately, research advances over the past several decades have provided insight into potential mechanisms responsible for the pathogenesis of IBS, and have led to the development of several promising pharmaceutical agents. In recent years there has been much publicity over several of these new IBS medications （alosetron and tegaserod） because of their reported association with ischemic colitis and cardiovascular disease. While these agents remain available for use under restricted prescribing programs, this highlights the need for continued development of safe and effective medication for IBS. This article provides a physiologicallybased overview of recently developed and frequently employed pharmaceutical agents used to treat IBS, and discusses some non-pharmaceutical options that may be beneficial in this disorder.

关键词： Irritable bowel syndrome Treatment Pharmacotherapy Challenges Opportunities

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

CO2 degassing and melting of metasomatized mantle lithosphere during rifting-Numerical study

引用

Geoscience Frontiers 2019年第4期10卷 1409-1420页

作者： Weronika Gorczyk christopher m. Gonzalez University of Western Australia Centre for Exploration TargetingSchool of Earth SciencesARC Centre of Excellence for Core to Crust Fluid SystemsPerthWestern AustraliaAustralia School of Earth Atmosphere and EnvironmentMonash University ClaytonMelbourneVICAustralia

:Reactivation of metasomatized mantle lithosphere may occur during continental extension,which is an important component of plate *** lower most part of the metasomatized domains in the subcontinental mantle lithosphere can be locally enriched in ***,partial melting of these metasomatized domains may play a crucial role in the global carbon ***,little is known about this process and up until now few numerical constraints are *** we address this knowledge gap and use a 2-D high resolution petrological-thermomechanical model to assess lithospheric ***2 degassing and *** test 4 lithospheric thicknesses:90,110,130 and 200 km with a 10 km thick metasomatized layer at the base using CO2 of 2 wt.%in the bulk *** carbonate enriched layer is stable below^3 GPa(>110 km)for a temperature of 1300℃;therefore,we only observe degassing patterns for lithospheric models that are 130 km and 200 km *** metasomatized layer for the 130 km thick lithosphere mostly comprises carbonatite melting,whereas in the 200 km thick scenario propagation of melt development from kimberlites to carbonatites occurs as the metasomatic mantle is exhumed during *** numerical models fit well into natural rifting zones of the European Cenozoic Rift System for young(shallow)and of the North Atlantic Rift for old(thick)lithosphere.

关键词： Rifting mantle CO2 degassing Carbonate melting

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

Heat Transfer in the microlayer Under a Bubble During Nucleate Boiling

引用

Tsinghua Science and Technology 2010年第4期15卷 404-413页

作者： David m.christopher 张璐 Key Laboratory for Thermal Science and Power Engineering of ministry of Education Department of Thermal Engineering Tsinghua University

many studies have shown that a very thin liquid microlayer forms under vapor bubbles during nucleate boiling. The heat transfer from the surface to the bubble is then significantly affected by this mi- crolayer and the curved region leading into the microlayer. Various models have been developed to predict the microlayer shape and the heat transfer along the curved interfacial region, but they tend to have incon- sistent boundary conditions or unrealistic results. This paper presents a theoretical model to predict the mi- crolayer thickness and the heat transfer rates for a variety of conditions. The results show how the wall su- perheat, the Hamaker constant, the bubble radius, and the accommodation coefficient at the interface affect the evaporation heat transfer rates and the microlayer shape for a large range of conditions for water and FC 72. The microlayer results are then shown to compare well with predictions made by solving the Na- vier-Stokes equations in the microlayer.

关键词： nucleate boiling bubble growth heat transfer microlayer

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

Experimental Study of High moisture Content Gas Flow Across a Cylinder at moderate Reynolds Numbers

引用

Tsinghua Science and Technology 2003年第5期8卷 598-604页

作者： D.m.christopher 郭亮 Department of Thermal Engineering

The Nusselt number for cross flow of a mixture of air and vapor over a cylinder was measured at moderate Reynolds numbers (30007000) for temperatures from 300℃ to 700℃ and for vapor mass fractions of 0.180.35. Results are also presented for a set of three cylinders aligned perpendicular to the flow for the same range of conditions. The effect of the vapor concentration and temperature on the convection coefficients was investigated to develop a modified Zhukauskas correlation. The results show that the Nusselt number increases as the moisture content increases and that the increase is more than could be accounted for by typical models for the property variations of mixtures. The exponent of the vapor concentration term in the modified correlation is 0.145 for the entire data set indicating the importance of the property variation due to the moisture content.

关键词： high moisture content cross flow convection coefficients heat exchangers

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：