The goal of Collaborative Research Centre(SFB) 561 "thermally highly loaded,porous and cooled multi-layer systems for combined cycle power plants" is to expand the current technological and scientific knowle...The goal of Collaborative Research Centre(SFB) 561 "thermally highly loaded,porous and cooled multi-layer systems for combined cycle power plants" is to expand the current technological and scientific knowledge on power plants in order to achieve total efficiencies of 65% in a combined cycle power plant in the year 2025.Therefore,the aero-thermomechanical,structural-mechanical,materials' scientific and production fundamentals for the development of steam and gas turbine components that are able to withstand highest thermal loads are being worked out within this SFB.This means for the gas turbine that combustion chamber outlet temperatures of 1520℃ at 1.7MPa are to be attained.In order to control these high temperatures,it is not only required to develop new materials' solutions,including thermal barrier coatings,but also to apply improved cooling techniques,as for example effusion cooling.This novel cooling concept is to be realised through open-porous structures.These structures can consist of drilled open-porous multi-layer systems or open-porous metallic foams.The development of graded multi-layer systems is also extremely important,as the grading will enable the use of coolant in dependence of the requirements.The live steam parameters in the high pressure turbine are expected to be increased up to approximately 700℃ with pressure of 30MPa.These elevated steam parameters can be encountered with Ni-base alloys,but this is a costly alternative,associated with many manufacturing difficulties.Therefore,the SFB proposes cooling the highly loaded turbines instead,as this would necessitate the application of far less Ni-base alloys.To protect the thermally highly loaded casing,a sandwich material consisting of two thin face sheets with a core of a woven wire mesh is used to cover the walls of the steam turbine casing.The current state of the research shows that by utilising innovative cooling technologies a total efficiency of 65% can be reached without exceeding the maximum allowable material temperature,thereb展开更多
Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential...Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential to understand root functions and root turnover in ecosystems,and at the same time such researches are the most difficult because roots are hidden underground. Therefore, how to investigate efficiently root functions and root dynamics is the core aspect in underground ecology. In this article, we reviewed some experimental methods used in root researches on root development and root system architecture, and summarized the advantages and shortages of these methods. Based on the analyses, we proposed three new ways to more understand root processes：（1） new experimental materials for root development;（2） a new observatory system comprised of multiple components, including many observatory windows installed in field, analysis software,and automatic data transport devices;（3） new techniques used to analyze quantitatively functional roots.展开更多
文摘The goal of Collaborative Research Centre(SFB) 561 "thermally highly loaded,porous and cooled multi-layer systems for combined cycle power plants" is to expand the current technological and scientific knowledge on power plants in order to achieve total efficiencies of 65% in a combined cycle power plant in the year 2025.Therefore,the aero-thermomechanical,structural-mechanical,materials' scientific and production fundamentals for the development of steam and gas turbine components that are able to withstand highest thermal loads are being worked out within this SFB.This means for the gas turbine that combustion chamber outlet temperatures of 1520℃ at 1.7MPa are to be attained.In order to control these high temperatures,it is not only required to develop new materials' solutions,including thermal barrier coatings,but also to apply improved cooling techniques,as for example effusion cooling.This novel cooling concept is to be realised through open-porous structures.These structures can consist of drilled open-porous multi-layer systems or open-porous metallic foams.The development of graded multi-layer systems is also extremely important,as the grading will enable the use of coolant in dependence of the requirements.The live steam parameters in the high pressure turbine are expected to be increased up to approximately 700℃ with pressure of 30MPa.These elevated steam parameters can be encountered with Ni-base alloys,but this is a costly alternative,associated with many manufacturing difficulties.Therefore,the SFB proposes cooling the highly loaded turbines instead,as this would necessitate the application of far less Ni-base alloys.To protect the thermally highly loaded casing,a sandwich material consisting of two thin face sheets with a core of a woven wire mesh is used to cover the walls of the steam turbine casing.The current state of the research shows that by utilising innovative cooling technologies a total efficiency of 65% can be reached without exceeding the maximum allowable material temperature,thereb
基金supported by the project of public benefits in China(No.201503221)the open fund in the Institute of Root Biology,Yangtze University
文摘Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential to understand root functions and root turnover in ecosystems,and at the same time such researches are the most difficult because roots are hidden underground. Therefore, how to investigate efficiently root functions and root dynamics is the core aspect in underground ecology. In this article, we reviewed some experimental methods used in root researches on root development and root system architecture, and summarized the advantages and shortages of these methods. Based on the analyses, we proposed three new ways to more understand root processes：（1） new experimental materials for root development;（2） a new observatory system comprised of multiple components, including many observatory windows installed in field, analysis software,and automatic data transport devices;（3） new techniques used to analyze quantitatively functional roots.
