Timing is everything.Nowhere is it truer than in the current global climatic conditions.As rainfall patterns change and temperature levels increase dramatically, water shortages,particularly in developing nations, hav...Timing is everything.Nowhere is it truer than in the current global climatic conditions.As rainfall patterns change and temperature levels increase dramatically, water shortages,particularly in developing nations, have reached record highs 20 years ahead of predictions and severe food shortage is the eventual result.Climate change may well exacerbate chronic hunger and malnutrition across much of展开更多
International environmental organizations propose voluntary eco-labeling as a market incentive to promote industry to operate in an ecologically sustainable and environmentally friendly manner,for instance,with the in...International environmental organizations propose voluntary eco-labeling as a market incentive to promote industry to operate in an ecologically sustainable and environmentally friendly manner,for instance,with the introduction of ISO 14000.These standards assist organizations to minimize their operations negatively affecting the environment and comply with applicable laws and regulations.Support for eco-labeling has been one of the ways that展开更多
Diversity indexes of current forestry view, such as dominance degree, fragmentation degree and overcast degree, were evaluated by the software ARCVIEWGIS. And developing strategies to improve diversity were put forwar...Diversity indexes of current forestry view, such as dominance degree, fragmentation degree and overcast degree, were evaluated by the software ARCVIEWGIS. And developing strategies to improve diversity were put forward in this paper, that is, combining with the items of forestry tour and enhancing scientific management, and choosing typical trees to change forestry structure on the basis of general conditions of dominance degree, fragmentation degree and overcast degree.展开更多
Compared with the stagnanteconomy of the rest world,Asian-Pa-cific economy has been experiencingthe hightest growth since the 1980s.Now,most researchers and officials,and even entrepreneurs believe
Shanghai,arelatlvely developed region ofChlna In economy andeducatlon;Isstill facing the critical problem ofhuman resources scarcity and low competence oflabourers In order to become a modern metropolis,one of the Int...Shanghai,arelatlvely developed region ofChlna In economy andeducatlon;Isstill facing the critical problem ofhuman resources scarcity and low competence oflabourers In order to become a modern metropolis,one of the Internatlonaleconomlc,nnanclal and trade centres.Statistics show thatthe city Is In need of600,000 highquahtled personnel by 2000.As Shanghai Is speeding up the adjustment ofindustrlalstructure,new and high tech Industries as well as knowledge-Intensive Industries areconstantly springing tip,and even In labourlntenslve Industries,the science andtechnology contentsbave also been Increasing,so It’s extremely urgent to trainurgently needed personnel and improve workers’competence universally.The municipal government of Shanghai thlllks highly of open education,andShanghai Education Commission（SEC）also sets It as one of＊thesion important tasks ofShanghai’s educational development. At present,SEC Is drafting the ninth nve、year plan for educational developmentandthe 2010’s target,ofwhich展开更多
The involvement of small RNAs in cotton fiber development is under explored.The objective of this work was to directly clone,annotate,and analyze small RNAs of developing ovules to reveal
Guo Bosheng, senior engineer/professor, is now a member of the Expert Group of the State Council Rare Earth Leading Group, PRC., director of Rare Earth Development Center for Agricultural Technique. He graduated from ...Guo Bosheng, senior engineer/professor, is now a member of the Expert Group of the State Council Rare Earth Leading Group, PRC., director of Rare Earth Development Center for Agricultural Technique. He graduated from Moscow Fine Chemical Industry University in the Sovi-展开更多
In the course of creating immense wealth, manufacturing industry has excessively consumed the resources and energy in the earth, and seriously polluted the environment. To take progress as the sustainable development ...In the course of creating immense wealth, manufacturing industry has excessively consumed the resources and energy in the earth, and seriously polluted the environment. To take progress as the sustainable development way, save resource and improve environment, our nation has been advocating to construct the cycle economy and saving-oriented society. Taking the remanufacturing engineering as the representative, the “4R” rule (Reduce, Reuse, Recycle and Remanufacture) is the important measure to get the goal. Remanufacturing engineering is the industrialization of high-tech maintenance of the waste and worn productions, and is one of the most active factors in “4R”. The development of high and new technology takes the important effect to promote the remanufacturing engineering.展开更多
For providing a correct and reasonable strategy to develop agricultural mechanization in developing countries, this paper took China as the representative to analyze the poor agricultural equipment service condition. ...For providing a correct and reasonable strategy to develop agricultural mechanization in developing countries, this paper took China as the representative to analyze the poor agricultural equipment service condition. It also put forward the ecology and social crisis brought out by the long-term and large-scale primary mechanization. According to the characteristics of national condition, this paper brought forward several certain policies and solutions, such as compelling to shorten the continuance cycle of traditional primary stage, seeking for new economic growth poles of high-added-value agricultural production by fully using the abundant labor force, etc. It is a feasible technical program to develop harmonious agricultural modernization in developing countries展开更多
Since the last half century,the world has been being in theme of peace and development,and passed through another glorious period with the rapid development of the economy,science and technology. In the energy field o...Since the last half century,the world has been being in theme of peace and development,and passed through another glorious period with the rapid development of the economy,science and technology. In the energy field of the globe,as the fuel with superior quality,the petroleum and gas gradually replaced the coal of the leading role in energy resources’ consumption,after the mineral energy replaced firewood.Moreover,various types of new energy are beginning to get application。展开更多
The histological characteristics,distribution and variability of epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) during development of skin in the goat fetus were studied with histological and ...The histological characteristics,distribution and variability of epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) during development of skin in the goat fetus were studied with histological and immunohistochemical methods.The results showed that the epidermis formed at the 6th gestational week,the thickness increased gradually because of transition from simple epithelium to stratified epithelium,and then decreased after the 15th week.The dermis was present at the 10th week,and the dermal derivatives appeared after the 11th week.All structures of the skin matured gradually during prenatal development.Low expression of EGF and EGFR could be observed at the 6th week and increased thereafter.Before the 11th week,EGF was mainly located in the cytoplasm of the basal layer of cells of epidermis,hair follicular epithelial cells and fibroblasts,and EGFR was mainly located on cell membranes of these cells.From the 11th to 16th week,the expression of EGF and EGFR extended from basal layer cells,prickle cells,hair follicular epithelial cells and fibroblasts to vascular endothelial cells,epithelial cells of sweat glands and arrector pili muscle.EGF was mainly detected cytoplasmically,and EGFR was located on membranes of these cells.From the 17th week to birth,EGF was mainly located in cells of the basal layer and hair follicular epithelial cells as the skin thinned and staining intensity continued to increase.The expressed amount of EGF and EGFR tended to increase throughout the whole development stage encompassed by gestational weeks 6 to 21 and the two components of the EGF signaling system were highly correlated.The results suggest that EGF and EGFR play important roles in the development of skin and its derivatives.展开更多
Climate change is becoming a serious issue nowadays.There are profound environmental,economic and political implications of global warming. Ecosystems,from mountains to oceans and from the poles to the tropics,are und...Climate change is becoming a serious issue nowadays.There are profound environmental,economic and political implications of global warming. Ecosystems,from mountains to oceans and from the poles to the tropics,are undergoing rapid change.The cost will be borne by all,but especially by the展开更多
Microsatellite marker （or Simple Sequence Repeate, SSR） is a marker technology based on DNA molecular length poly morphism. It is also one of the most commonly used molecular markers. Traditional SSR marker developm...Microsatellite marker （or Simple Sequence Repeate, SSR） is a marker technology based on DNA molecular length poly morphism. It is also one of the most commonly used molecular markers. Traditional SSR marker development methods are relatively time-consuming and mostly relying on the known genome sequence information while recently developed methods of SSR marker based on RAPD, ISSR-PCR SSR, the use of hybrid options, sequence tag SSR library access and screening EST-SSR have been widely used. This paper gave an overview of the methods mentioned above for the development of SSR markers.展开更多
At the 19th G20 Summit in Brazil in November 2024,China promoted the development of sustainable solutions to climate change,biodiversity loss,and environmental pollution.This continued the theme of the 2016 G20 Hangzh...At the 19th G20 Summit in Brazil in November 2024,China promoted the development of sustainable solutions to climate change,biodiversity loss,and environmental pollution.This continued the theme of the 2016 G20 Hangzhou Summit,at which China placed development at the center of the G20’s macroeconomic policy coordination for the first time,adopting the G20 Action Plan on the United Nations 2030 Agenda for Sustainable Development and the G20 Initiative on Supporting Industrialization in Africa and Least Developed Countries.In Brazil,China announced actions on advancing modernization in Africa over the next three years with a Chinese commitment of RMB360 billion yuan in financial support.In this article,we examine the potential role of geoscience research and practice in development,particularly in the sustainable use of natural resources,the prevention of climate change impacts,as well as mitigation of geo-hazards and their health implications,indicating the areas where China’s geoscience for Africa is strong and where it requires more effort.We find that although China is the world’s leading publisher of scientific papers,its contribution to geoscience in Africa(the globe’s fastest-growing economic area),as shown by bibliometric research,appears to be rather small and inconsistent with the research priorities of Africa.Amongst the priorities for geoscience research in Africa,which are not addressed substantially by the research conducted so far,are sustainable mineral and hydrocarbon development,hydrology and hydrogeology,climate change and resilience,natural hazards,medical geology,agrominerals,and geoscience education and training.A particular opportunity for African nations is the presence of critical minerals-minerals needed for the energy transition and for batteries for electric cars in particular.Africa is well-endowed with many of these critical materials,such as rare earth elements and platinum group metals.Several research groups stress the need for the agency on the part of African institutions to map out these valuable resources,understand their value and the economics and sustainability of their extraction,encourage local business,attract investment,and scrutinize proposals from potential international investors to get the best deals.A strong point of existing China-led geoscience development includes the Deep-time Digital Earth(DDE)program online computing platform and its artificial intelligence tool GeoGPT,which is being developed in partnership with Zhejiang Laboratory.These are being developed with strong China funding support for free and wide global access,with a particular focus on Africa.These advanced tools will help to place the agency of development squarely in the hands of African scientists and institutions.In summary,the following are recommended:(1)a more coordinated and strategic approach to China-led geoscience research in Africa;(2)an Africa-centered,geoscience funding initiative that concentrates on relevant topics to the continent such as critical minerals exploration and other geological resources,materials and processes and their health implications on the populations and ecosystems in general,as well as climate change and climate change resilience;and(3)continued support for China-led international initiatives that seek to increase the agency and capacity of Africa geoscience researchers,for example the Deep-time Digital Earth platform.展开更多
Currently,research on N^(6)-methyladenine(m^(6)A)is extensive in the field of oncology,while studies involving m^(6)A and skin diseases remain relatively limited.Based on existing reports,we searched PubMed and Web of...Currently,research on N^(6)-methyladenine(m^(6)A)is extensive in the field of oncology,while studies involving m^(6)A and skin diseases remain relatively limited.Based on existing reports,we searched PubMed and Web of Science for literature related to m^(6)A and dermatological conditions.Analysis of citation counts and journal impact factors revealed a significant upward trend in the volume of m^(6)A-related research.Term frequency analysis of titles and abstracts indicated that studies mainly focus on skin tumors and inflammatory or immune-related skin diseases,particularly melanoma,psoriasis,and skin development.Transcriptomic data from the Gene Expression Omnibus(GEO)were analyzed,revealing differential expression of m^(6)A-related genes in 4 types of skin tumors(including squamous cell carcinoma and basal cell carcinoma)as well as in inflammatory skin diseases such as psoriasis and atopic dermatitis,and potential mechanisms of action were also explored.Findings suggest that m^(6)A modifications exhibit heterogeneity between neoplastic and nonneoplastic skin diseases.However,the regulatory mechanisms of m^(6)A dynamic modifications on key genes involved in dermatological disorders remain unclear and warrant further investigation.展开更多
The cemented-gangue-fly-ash backfill(CGFB)prepared from coal-based solid waste materials commonly exhibits high brittleness,leading to an increased susceptibility to cracking.Uniaxial compressive strength(UCS),acousti...The cemented-gangue-fly-ash backfill(CGFB)prepared from coal-based solid waste materials commonly exhibits high brittleness,leading to an increased susceptibility to cracking.Uniaxial compressive strength(UCS),acoustic emission(AE),and scanning electron microscopy tests were conducted on CGFB samples with recycled steel fiber(RSF)contents of 0,0.5%,1.0%and 1.5%to assess the mechanical properties and damage evolution law of the CGFB.The research findings indicate that:1)When RSF contents were 0.5%,1%,and 1.5%,respectively,compared to samples without RSF,the UCS decreased by 3.86%,6.76%,and 15.59%,while toughness increased by 69%,98%,and 123%;2)The addition of RSFs reduced the post-peak stress energy activity and increased the fluctuations in the b-value;3)As the RSF dosage increased from 0 to 1.5%,the per unit dissipated strain energy increased from 5.84 to 21.51,and the post-peak released energy increased from 15.07 to 33.76,indicating that the external energy required for the CGFB sample to fail increased;4)The hydration products,such as C-S-H gel,ettringite,and micro-particle materials,were embedded in the damaged areas of the RSFs,increasing the frictional force at the interface between the RSF and CGFB matrix.The shape variability of the RSFs caused interlocking between the RSFs and the matrix.Both mechanisms strengthened the bridging effect of the RSFs in the CGFB,thereby improving the damage resistance capability of CGFB.The excellent damage resistance occurred at an RSF content of 0.5%;thus,this content is recommended for engineering applications.展开更多
With the aim of reducing the cost of developing internal combustion engines,while at the same time investigating different geometries,layouts and fuels,3D-CFD-CHT simulations represent an indispensable part for the de...With the aim of reducing the cost of developing internal combustion engines,while at the same time investigating different geometries,layouts and fuels,3D-CFD-CHT simulations represent an indispensable part for the development of new technologies.These tools are increasingly used by manufacturers,as a screening process before building the first prototype.This paper presents an innovative methodology for virtual engine development.The 3D-CFD tool QuickSim,developed at FKFS,allows both a significant reduction in computation time and an extension of the simulated domain for complete engine systems.This is possible thanks to a combination of coarse meshes and self-developed internal combustion engine models,which simultaneously ensure high predictability.The present work demonstrates the capabilities of this innovative methodology for the design and optimization of different engines and fuels with the goal of achieving the highest possible combustion efficiencies and pollutant reductions.The analysis focuses on the influence of different fuels such as hydrogen,methanol,synthetic gasolines and methane on different engine geometries,in combination with suitable injection and ignition systems,including passive and active pre-chambers.Lean operations as well as knock reduction are discussed,particularly for methane and hydrogen injection.Finally,it is shown how depending on the chosen fuel,an appropriate ad-hoc engine layout can be designed to increase the indicated efficiency of the respective engines.展开更多
文摘Timing is everything.Nowhere is it truer than in the current global climatic conditions.As rainfall patterns change and temperature levels increase dramatically, water shortages,particularly in developing nations, have reached record highs 20 years ahead of predictions and severe food shortage is the eventual result.Climate change may well exacerbate chronic hunger and malnutrition across much of
文摘International environmental organizations propose voluntary eco-labeling as a market incentive to promote industry to operate in an ecologically sustainable and environmentally friendly manner,for instance,with the introduction of ISO 14000.These standards assist organizations to minimize their operations negatively affecting the environment and comply with applicable laws and regulations.Support for eco-labeling has been one of the ways that
文摘Diversity indexes of current forestry view, such as dominance degree, fragmentation degree and overcast degree, were evaluated by the software ARCVIEWGIS. And developing strategies to improve diversity were put forward in this paper, that is, combining with the items of forestry tour and enhancing scientific management, and choosing typical trees to change forestry structure on the basis of general conditions of dominance degree, fragmentation degree and overcast degree.
文摘Compared with the stagnanteconomy of the rest world,Asian-Pa-cific economy has been experiencingthe hightest growth since the 1980s.Now,most researchers and officials,and even entrepreneurs believe
文摘Shanghai,arelatlvely developed region ofChlna In economy andeducatlon;Isstill facing the critical problem ofhuman resources scarcity and low competence oflabourers In order to become a modern metropolis,one of the Internatlonaleconomlc,nnanclal and trade centres.Statistics show thatthe city Is In need of600,000 highquahtled personnel by 2000.As Shanghai Is speeding up the adjustment ofindustrlalstructure,new and high tech Industries as well as knowledge-Intensive Industries areconstantly springing tip,and even In labourlntenslve Industries,the science andtechnology contentsbave also been Increasing,so It’s extremely urgent to trainurgently needed personnel and improve workers’competence universally.The municipal government of Shanghai thlllks highly of open education,andShanghai Education Commission（SEC）also sets It as one of＊thesion important tasks ofShanghai’s educational development. At present,SEC Is drafting the ninth nve、year plan for educational developmentandthe 2010’s target,ofwhich
文摘The involvement of small RNAs in cotton fiber development is under explored.The objective of this work was to directly clone,annotate,and analyze small RNAs of developing ovules to reveal
文摘Guo Bosheng, senior engineer/professor, is now a member of the Expert Group of the State Council Rare Earth Leading Group, PRC., director of Rare Earth Development Center for Agricultural Technique. He graduated from Moscow Fine Chemical Industry University in the Sovi-
文摘In the course of creating immense wealth, manufacturing industry has excessively consumed the resources and energy in the earth, and seriously polluted the environment. To take progress as the sustainable development way, save resource and improve environment, our nation has been advocating to construct the cycle economy and saving-oriented society. Taking the remanufacturing engineering as the representative, the “4R” rule (Reduce, Reuse, Recycle and Remanufacture) is the important measure to get the goal. Remanufacturing engineering is the industrialization of high-tech maintenance of the waste and worn productions, and is one of the most active factors in “4R”. The development of high and new technology takes the important effect to promote the remanufacturing engineering.
基金Supported by NEAU Doctor Research FundChinese National Science and Technology Subject (2006BAD11A05)
文摘For providing a correct and reasonable strategy to develop agricultural mechanization in developing countries, this paper took China as the representative to analyze the poor agricultural equipment service condition. It also put forward the ecology and social crisis brought out by the long-term and large-scale primary mechanization. According to the characteristics of national condition, this paper brought forward several certain policies and solutions, such as compelling to shorten the continuance cycle of traditional primary stage, seeking for new economic growth poles of high-added-value agricultural production by fully using the abundant labor force, etc. It is a feasible technical program to develop harmonious agricultural modernization in developing countries
文摘Since the last half century,the world has been being in theme of peace and development,and passed through another glorious period with the rapid development of the economy,science and technology. In the energy field of the globe,as the fuel with superior quality,the petroleum and gas gradually replaced the coal of the leading role in energy resources’ consumption,after the mineral energy replaced firewood.Moreover,various types of new energy are beginning to get application。
基金supported by Natural Science Foundation of Shanxi Province of China(2004C120)Talent Foundation of Northwest A&F University
文摘The histological characteristics,distribution and variability of epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) during development of skin in the goat fetus were studied with histological and immunohistochemical methods.The results showed that the epidermis formed at the 6th gestational week,the thickness increased gradually because of transition from simple epithelium to stratified epithelium,and then decreased after the 15th week.The dermis was present at the 10th week,and the dermal derivatives appeared after the 11th week.All structures of the skin matured gradually during prenatal development.Low expression of EGF and EGFR could be observed at the 6th week and increased thereafter.Before the 11th week,EGF was mainly located in the cytoplasm of the basal layer of cells of epidermis,hair follicular epithelial cells and fibroblasts,and EGFR was mainly located on cell membranes of these cells.From the 11th to 16th week,the expression of EGF and EGFR extended from basal layer cells,prickle cells,hair follicular epithelial cells and fibroblasts to vascular endothelial cells,epithelial cells of sweat glands and arrector pili muscle.EGF was mainly detected cytoplasmically,and EGFR was located on membranes of these cells.From the 17th week to birth,EGF was mainly located in cells of the basal layer and hair follicular epithelial cells as the skin thinned and staining intensity continued to increase.The expressed amount of EGF and EGFR tended to increase throughout the whole development stage encompassed by gestational weeks 6 to 21 and the two components of the EGF signaling system were highly correlated.The results suggest that EGF and EGFR play important roles in the development of skin and its derivatives.
文摘Climate change is becoming a serious issue nowadays.There are profound environmental,economic and political implications of global warming. Ecosystems,from mountains to oceans and from the poles to the tropics,are undergoing rapid change.The cost will be borne by all,but especially by the
文摘Microsatellite marker （or Simple Sequence Repeate, SSR） is a marker technology based on DNA molecular length poly morphism. It is also one of the most commonly used molecular markers. Traditional SSR marker development methods are relatively time-consuming and mostly relying on the known genome sequence information while recently developed methods of SSR marker based on RAPD, ISSR-PCR SSR, the use of hybrid options, sequence tag SSR library access and screening EST-SSR have been widely used. This paper gave an overview of the methods mentioned above for the development of SSR markers.
文摘At the 19th G20 Summit in Brazil in November 2024,China promoted the development of sustainable solutions to climate change,biodiversity loss,and environmental pollution.This continued the theme of the 2016 G20 Hangzhou Summit,at which China placed development at the center of the G20’s macroeconomic policy coordination for the first time,adopting the G20 Action Plan on the United Nations 2030 Agenda for Sustainable Development and the G20 Initiative on Supporting Industrialization in Africa and Least Developed Countries.In Brazil,China announced actions on advancing modernization in Africa over the next three years with a Chinese commitment of RMB360 billion yuan in financial support.In this article,we examine the potential role of geoscience research and practice in development,particularly in the sustainable use of natural resources,the prevention of climate change impacts,as well as mitigation of geo-hazards and their health implications,indicating the areas where China’s geoscience for Africa is strong and where it requires more effort.We find that although China is the world’s leading publisher of scientific papers,its contribution to geoscience in Africa(the globe’s fastest-growing economic area),as shown by bibliometric research,appears to be rather small and inconsistent with the research priorities of Africa.Amongst the priorities for geoscience research in Africa,which are not addressed substantially by the research conducted so far,are sustainable mineral and hydrocarbon development,hydrology and hydrogeology,climate change and resilience,natural hazards,medical geology,agrominerals,and geoscience education and training.A particular opportunity for African nations is the presence of critical minerals-minerals needed for the energy transition and for batteries for electric cars in particular.Africa is well-endowed with many of these critical materials,such as rare earth elements and platinum group metals.Several research groups stress the need for the agency on the part of African institutions to map out these valuable resources,understand their value and the economics and sustainability of their extraction,encourage local business,attract investment,and scrutinize proposals from potential international investors to get the best deals.A strong point of existing China-led geoscience development includes the Deep-time Digital Earth(DDE)program online computing platform and its artificial intelligence tool GeoGPT,which is being developed in partnership with Zhejiang Laboratory.These are being developed with strong China funding support for free and wide global access,with a particular focus on Africa.These advanced tools will help to place the agency of development squarely in the hands of African scientists and institutions.In summary,the following are recommended:(1)a more coordinated and strategic approach to China-led geoscience research in Africa;(2)an Africa-centered,geoscience funding initiative that concentrates on relevant topics to the continent such as critical minerals exploration and other geological resources,materials and processes and their health implications on the populations and ecosystems in general,as well as climate change and climate change resilience;and(3)continued support for China-led international initiatives that seek to increase the agency and capacity of Africa geoscience researchers,for example the Deep-time Digital Earth platform.
基金supported by the National Natural Science Foundation,China(82103704).
文摘Currently,research on N^(6)-methyladenine(m^(6)A)is extensive in the field of oncology,while studies involving m^(6)A and skin diseases remain relatively limited.Based on existing reports,we searched PubMed and Web of Science for literature related to m^(6)A and dermatological conditions.Analysis of citation counts and journal impact factors revealed a significant upward trend in the volume of m^(6)A-related research.Term frequency analysis of titles and abstracts indicated that studies mainly focus on skin tumors and inflammatory or immune-related skin diseases,particularly melanoma,psoriasis,and skin development.Transcriptomic data from the Gene Expression Omnibus(GEO)were analyzed,revealing differential expression of m^(6)A-related genes in 4 types of skin tumors(including squamous cell carcinoma and basal cell carcinoma)as well as in inflammatory skin diseases such as psoriasis and atopic dermatitis,and potential mechanisms of action were also explored.Findings suggest that m^(6)A modifications exhibit heterogeneity between neoplastic and nonneoplastic skin diseases.However,the regulatory mechanisms of m^(6)A dynamic modifications on key genes involved in dermatological disorders remain unclear and warrant further investigation.
基金Projects(52274143,51874284)supported by the National Natural Science Foundation of China。
文摘The cemented-gangue-fly-ash backfill(CGFB)prepared from coal-based solid waste materials commonly exhibits high brittleness,leading to an increased susceptibility to cracking.Uniaxial compressive strength(UCS),acoustic emission(AE),and scanning electron microscopy tests were conducted on CGFB samples with recycled steel fiber(RSF)contents of 0,0.5%,1.0%and 1.5%to assess the mechanical properties and damage evolution law of the CGFB.The research findings indicate that:1)When RSF contents were 0.5%,1%,and 1.5%,respectively,compared to samples without RSF,the UCS decreased by 3.86%,6.76%,and 15.59%,while toughness increased by 69%,98%,and 123%;2)The addition of RSFs reduced the post-peak stress energy activity and increased the fluctuations in the b-value;3)As the RSF dosage increased from 0 to 1.5%,the per unit dissipated strain energy increased from 5.84 to 21.51,and the post-peak released energy increased from 15.07 to 33.76,indicating that the external energy required for the CGFB sample to fail increased;4)The hydration products,such as C-S-H gel,ettringite,and micro-particle materials,were embedded in the damaged areas of the RSFs,increasing the frictional force at the interface between the RSF and CGFB matrix.The shape variability of the RSFs caused interlocking between the RSFs and the matrix.Both mechanisms strengthened the bridging effect of the RSFs in the CGFB,thereby improving the damage resistance capability of CGFB.The excellent damage resistance occurred at an RSF content of 0.5%;thus,this content is recommended for engineering applications.
文摘With the aim of reducing the cost of developing internal combustion engines,while at the same time investigating different geometries,layouts and fuels,3D-CFD-CHT simulations represent an indispensable part for the development of new technologies.These tools are increasingly used by manufacturers,as a screening process before building the first prototype.This paper presents an innovative methodology for virtual engine development.The 3D-CFD tool QuickSim,developed at FKFS,allows both a significant reduction in computation time and an extension of the simulated domain for complete engine systems.This is possible thanks to a combination of coarse meshes and self-developed internal combustion engine models,which simultaneously ensure high predictability.The present work demonstrates the capabilities of this innovative methodology for the design and optimization of different engines and fuels with the goal of achieving the highest possible combustion efficiencies and pollutant reductions.The analysis focuses on the influence of different fuels such as hydrogen,methanol,synthetic gasolines and methane on different engine geometries,in combination with suitable injection and ignition systems,including passive and active pre-chambers.Lean operations as well as knock reduction are discussed,particularly for methane and hydrogen injection.Finally,it is shown how depending on the chosen fuel,an appropriate ad-hoc engine layout can be designed to increase the indicated efficiency of the respective engines.
