Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the su...Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the substantial pressures exerted by vehicles,trains,and other forms of transportation,but also efficiently transfer these loads to the underlying foundation,ensuring the stability and longevity of the roadway.In recent years,advancements in subgrade engineering technology have propelled the industry towards smarter,greener,and more sustainable practices,particularly in the areas of intelligent monitoring,disaster management,and innovative construction methods.This paper reviews the application and methodologies of intelligent testing equipment,including cone penetration testing(CPT)devices,soil resistivity testers,and intelligent rebound testers,in subgrade engineering.It examines the operating principles,advantages,limitations,and application ranges of these tools in subgrade testing.Additionally,the paper evaluates the practical use of advanced equipment from both domestic and international perspectives,addressing the challenges encountered by various instruments in realworld applications.These devices enable precise,comprehensive testing and evaluation of subgrade conditions at different stages,providing real-time data analysis and intelligent early warnings.This supports effective subgrade health management and maintenance.As intelligent technologies continue to evolve and integrate,these tools will increasingly enhance the accuracy,efficiency,and sustainability of subgrade monitoring.展开更多
The establishment of China’s forestry science and technology evaluation system is an important guarantee measure to improve the level of forestry science and technology management and promote forestry science and tec...The establishment of China’s forestry science and technology evaluation system is an important guarantee measure to improve the level of forestry science and technology management and promote forestry science and technology advancement. Based on the analysis of the current condition of forestry science and technology evaluation in China, the paper presents the suggestions to establish and improve forestry science and technology system, including the change in evaluation subject, the standardization of evaluation approaches and the implementation of classified evaluation, to solve the problems existing in the current forestry science and technology evaluation like non-standardization of evaluation methods, incomplete evaluation system and unsound evaluation indicator system.展开更多
In 2012,China's first national shale gas demonstrations areas were set up in the Sichuan Basin.After 10 years'construction and practice,the giant marine shale gas area of 10×10^(12) m^(3) level is built u...In 2012,China's first national shale gas demonstrations areas were set up in the Sichuan Basin.After 10 years'construction and practice,the giant marine shale gas area of 10×10^(12) m^(3) level is built up in the Sichuan Basin,and shale gas steps into a new stage of large-scale benefit exploration and development.In order to systematically summarize the achievements in shale gas exploration and development and provide guidance and reference for the exploration and development of deep shale gas and shale oil&gas in other areas,this paper systematically summarizes the main characteristics,development models and key identification and evaluation technologies for quality reservoirs of Wufeng Formation-Longmaxi Formation shale gas by analyzing the electric property,lithofacies,reservoir parameters and microscopic porosity of key wells in the basin.And the following research results are obtained.First,biogenetic siliceous shale,calcareous shale and mixed shale are main lithofacies types in quality shale gas reservoirs,and they are formed in the environment of semi-deep and deep water continental shelf.Their lateral distribution is controlled by the paleogeomorphology and their vertical development is influenced by provenance,redox condition and paleo productivity.They are 25-90 m thick.Second,in the quality shale gas reservoirs develop organic pores,inorganic pore and microfractures(including lamina/bedding fractures),among which,organic pore is one of the main reservoir spaces and microfracture is not only indispensable reservoir space,but also production pathway.The reservoir space of shale gas is overall micro-nano pore,and macropores play an important role in shale gas enrichment.Third,three development models of quality reservoir are established,including sedimentary type,diagenesis type and reworking type.The sedimentary type is the foundation.Multiple quality reservoirs are developed in the high U/Th interval of graptolite belt at the bottom of Longmaxi Formation,and their thickness is mainly controlled by paleogeomorphology and especially greater in the depression area.The diagenesis type is divided into three forms,i.e.,syngenetic-early diagenetic rigid support,middle-late diagenetic mineral-organic matter transformation,and overpressure relief compaction.The reworking type is dominated by quality reservoirs with microfractures.Fourth,the core technologies for identifying and evaluating quality shale gas reservoir include large-size core and rock slice observation,high-accuracy rock mineral identification,experimental gas content test and simulation,SEM microscopic characterization,3D microscopic pore reconstruction,comprehensive geophysical interpretation and prediction and big data analysis.In conclusion,nearly 10 years'research and practice achievements in demonstration area construction can deepen the understanding on domestic quality shale gas reservoirs,promote the effective development of the theories and technologies related to shale gas reservoirs,improve the prediction accuracy of shale gas sweet spot zones/intervals,and expand the shale gas exploration and development achievements of demonstration areas.展开更多
This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a signifi...This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs （about 20%）. This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field.展开更多
Driven by the rapid development of society, great changes have taken place in people's ideology, and more and more attention has been paid to environmental protection. In order to effectively solve the problems ex...Driven by the rapid development of society, great changes have taken place in people's ideology, and more and more attention has been paid to environmental protection. In order to effectively solve the problems existing in the governance of the environment, the environmental protection department must actively implement the environmental monitoring work, and use professional monitoring technology to evaluate the environmental pollution and improvement. After comprehensive analysis of the environmental monitoring data, the pollution situation in the environment can be judged. Only in this way can we make targeted plans to control environmental pollution and avoid the gradual expansion of the pollution problem. In view of this, this paper mainly focuses on the comprehensive analysis and evaluation technology of environmental monitoring data. It is hoped that it will be helpful to the future development of environmental monitoring in China.展开更多
In order to realize the impersonality, justness, impartiality and rationality in the awarding work of science ＆ technology, it is necessary to establish an evaluating model to make the evaluating course numeric as we...In order to realize the impersonality, justness, impartiality and rationality in the awarding work of science ＆ technology, it is necessary to establish an evaluating model to make the evaluating course numeric as well as a complete system of evaluating indexes. The theory of fuzzy mathematics is adopted in this paper to establish a multilevel fuzzy synthetical model to quantitate the evaluating index system for science ＆ technology awarding and to provide the scientific decision-making basis for science ＆ technology awarding.展开更多
The thesis analyzes risk factors of enterprise＇s technology innovation, adopts the undetermined measuring model to evaluate technology innovation risk and testifies it through an example.
Survivability is used to evaluate the ability of the satellite to complete the mission after failure,while the duration of maintaining performance is often ignored.An effective backup strategy can restore the constell...Survivability is used to evaluate the ability of the satellite to complete the mission after failure,while the duration of maintaining performance is often ignored.An effective backup strategy can restore the constellation performance timely,and maintain good network communication performance in case of satellite failure.From the perspective of network utility,the low Earth orbit(LEO)satellite constellation survivable graphical eva-luation and review technology(GERT)network with backup satel-lites is constructed.A network utility transfer function algorithm based on moment generating function and Mason formula is proposed,the network survivability evaluation models of on-orbit backup strategy and ground backup strategy are established.The survivable GERT model can deduce the expected mainte-nance time of LEO satellite constellation under different fault states and the network utility generated during the state mainte-nance period.The case analysis shows that the proposed surviv-able GERT model can consider the satellite failure rate,backup satellite replacement rate,maneuver control replacement ability and life requirement,and effectively determine the optimal sur-vivable backup strategy for LEO satellite constellation with limi-ted resources according to the expected network utility.展开更多
This Paper presents a valid innovation design method for electronic consuming products figures. Using the technology evaluation principle in TRIZ （theory of inventive problem solving） theory as a powerful tool, comb...This Paper presents a valid innovation design method for electronic consuming products figures. Using the technology evaluation principle in TRIZ （theory of inventive problem solving） theory as a powerful tool, combined with consumer psychology and relevant knowledge on products modeling methodology, evolution patterns and evolution paths of electronic consuming products figures have been explored. Moreover a set of regulations working for figures innovation design is established.展开更多
The sensitivity of collinear nonlinear nondestructive testing technique based on harmonic detection is high,but the results are vulnerable to interference from other nonlinear of experiment sources,which leads to this...The sensitivity of collinear nonlinear nondestructive testing technique based on harmonic detection is high,but the results are vulnerable to interference from other nonlinear of experiment sources,which leads to this technology limited in industrial applications.To solve this problem,a non-collinear nonlinear ultrasonic testing experimental system is established based on non-collinear beam mixing technology.The non-collinear nonlinear response is observed in the steel and LY12 aluminum alloy.The results show that:1 Based on the benefits of space selection,mode conversion,frequency and steerable optional of non-collinear beam mixing technology,the interference of system nonlinear effects can be suppressed effectively;2 Mode conversion and beam mixing are present in steel and LY12 aluminum alloy,and the non-collinear non-linear response of LY12 aluminum alloy is stronger than steel and the measurement results are more obvious;3 The technology has the feasibility to evaluate the uniformity of material internal.展开更多
UGS(underground gas storage)construction in China has stepped into a new development stage after years of exploration.The eleven UGSs that have been put into production play an important role in domestic natural gas p...UGS(underground gas storage)construction in China has stepped into a new development stage after years of exploration.The eleven UGSs that have been put into production play an important role in domestic natural gas peak shaving safety and supply guarantee,with designed working gas volume of 180×10^(8) m^(3),but there are still various difficulties in UGS construction in China.Firstly,the increasing speed of working gas volume is slower than that of peak shaving demand volume.Secondly,the UGS building engineering is difficult in technologies and high in investment costs.Thirdly,safe operation is under high pressure and it is hard to identify and control risks.Fourthly,there are fewer candidate UGS sites in China and UGS building conditions are complicated.And fifthly,it is difficult for those UGSs to realize economic benefits only based on their own operation under the existing natural gas price systems.To sum up,the currently available UGS operation modes and building technologies in China are not sufficient to cope with the challenges resulted from markets and complex geologic conditions.Facing all these challenges,it is necessary not only to explore market driven operation modes,but also to strengthen technology tackling and carry out core technological research and development,including geologic evaluation,gas reservoir engineering,drilling and completion engineering,UGS injection and gas recovery engineering,surface auxiliary technologies and UGS integrity evaluation,so that UGS building efficiency can be increased greatly.展开更多
Science and technology talent evaluation is an important part of the talent development system and mechanism,and the state's emphasis on science and technology talent evaluation is reflect-ed in the national polic...Science and technology talent evaluation is an important part of the talent development system and mechanism,and the state's emphasis on science and technology talent evaluation is reflect-ed in the national policy.This paper takes 49 policy documents on science and technology tal-ent evaluation issued by the state from 1978 to 2022 as the object,and uses policy text analysis,word frequency analysis and co-word network analysis to interpret the content of the policies.These policy texts are divided into four stages.200 high-frequency words were extracted from the policies in each stage after word segmentation was made,and the co-word matrixes and co-word networks were constructed for each stage.The research draws the following conclu-sions:1)The content of Chinese science and technology talent evaluation policies is gradually becoming concrete,and the concept of science and technology talent evaluation is gradually clear;2)The policies have transitioned from"scientific and technological development"to"sci-entific and technological innovation";3)The distribution of policies with different strengths is uneven;4)The cooperation between all departments involved in policy formulation is not e-nough.展开更多
According to the status of the northern rural architecture analysis, the prevalence of high energy consumption, low comfort features, it is essential to design energy-efficient buildings in rural areas. Article resear...According to the status of the northern rural architecture analysis, the prevalence of high energy consumption, low comfort features, it is essential to design energy-efficient buildings in rural areas. Article research and analyze the layout of rural buildings, a variety of energy-saving technologies and building design measures development and utilization of new energy sources and other issues that can make rural buildings to save energy and improve the environmental quality of living of farmers. It also put forward some reasonable suggestions for carrying out residential building energy efficiency in cold areas.展开更多
Global economic development and increasing human activities have brought great challenges to fragile ecosystems.In order to avoid,reduce,and reverse desertification,Chinese and foreign scientists and ecological govern...Global economic development and increasing human activities have brought great challenges to fragile ecosystems.In order to avoid,reduce,and reverse desertification,Chinese and foreign scientists and ecological governance institutions have developed a series of ecological restoration technologies(ERTs)and models in the past few decades.These technologies can improve residents’livelihoods,strengthen disaster resilience,and launch a comprehensive review of degraded ecosystems in desertification regions.However,some studies and practices have limited the selection and promotion of good technologies and the assessments of these technologies,resulting in the waste and loss of funds and manpower.The objective of this study is to identify desertification control and restoration technologies and models,summarize the evolutionary features and trends of these technologies under different natural conditions,and evaluate the various ERTs that are now available.The data sources of this study include the databases of international organizations,CNKI,related literature and reports,and questionnaires from institutions and experts.First,the three stages of ERTs evolution were summarized,and the key events and social-economic developments were identified as the driving forces of evolution.Then,the four categories of ERTs were identified as biological,engineering,agricultural,and management ERTs.Finally,the key ERTs were evaluated in the five dimensions of the degree of difficulty,the degree of maturity,effectiveness,suitability,and potential for transfer.The management ERTs scores for the degree of difficulty,the degree of maturity,and potential for transfer are higher.This study provides a reference for adapting to local conditions,the comprehensive management,rational development,and utilization of dryland resources,improving the application of ecological technologies,and promoting the export and import of the excellent technologies.展开更多
The influence of ecological technology measures on the annual sediment loads of rivers complies with the principles of statistics. In this paper, the annual sediment load of the Wuding River is taken as the dependent ...The influence of ecological technology measures on the annual sediment loads of rivers complies with the principles of statistics. In this paper, the annual sediment load of the Wuding River is taken as the dependent variable and the rainfall, rainstorms during the flood period of the Wuding River and areas of ecological technology measures are taken as the independent variables to analyze the influence of ecological technology measures on the annual sediment load of the Wuding River during the years 1956 to 2007. This research uses a stepwise regression method. The result shows that 1） the non-linear regression equation composed of three independent variables including 7–8 monthly rainfalls along the Wuding River, areas of ecological technology measures and maximum daily rainfall along the Wuding River has been calculated and set up; the correlation coefficient is R2=0.857 and the significance level is α=0.001. 2） R2=0.717 is adjusted and the regression equation reveals a change of annual sediment load exceeding 71.7% over 52 years; 3） The standardized regression coefficient for ecological technology measure area has the maximum absolute value of the three independent variables shows maximum influence on the change of annual sediment load; and 4） Because of implementing the ecological technology measures, until to year of 2007, when the 7–8 monthly rainfall and maximum daily rainfall are the maximum values in the research section, the annual sediment load is calculated as 149 million ton, which is 36% of the maximum value in the history.展开更多
China is one of the countries with the richest wildlife population.The large variety of widely distributed species act as natural or susceptible hosts for numerous infectious diseases.It is estimated that there are mo...China is one of the countries with the richest wildlife population.The large variety of widely distributed species act as natural or susceptible hosts for numerous infectious diseases.It is estimated that there are more than 1.2 million unknown virus species in China,and there might be 10,000–30,000 unknown bacteria in wild mammals on the Qinghai-Tibet Plateau alone.There are no less than 600,000 species of animal-borne parasites and approximately 2 million species of fungi worldwide.With rapid economic growth and globalization,humans and wildlife interact more frequently,which enhances the probability of wildlife-borne pathogens infecting humans.The occurrence of animal-borne infectious diseases will become the“new normal”we have to face in the future.Therefore,research should be carried out on wildlife-borne microorganisms and the prevention and control of emerging infectious diseases to establish an analytical framework and an evaluation technology system for risk assessment and early warning of potential animal-borne emerging infectious diseases.This will not only improve our understanding of wildlife-borne microbial communities but also enable in-depth analysis,discovery,early warning,and even prediction of major animal-borne emerging infectious diseases that might occur in the future.Furthermore,this research will reduce response times,minimize the social and economic impact and losses,enable interventions related to the emergence or spread of the disease as early as possible,and comprehensively improve our management of infectious disease outbreaks.展开更多
基金supported by the National Natural Science Foundation of China for Distinguished Young Scholars(Grant No.42225206)National Natural Science Foundation of China(42207180,42477209,42302320).
文摘Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the substantial pressures exerted by vehicles,trains,and other forms of transportation,but also efficiently transfer these loads to the underlying foundation,ensuring the stability and longevity of the roadway.In recent years,advancements in subgrade engineering technology have propelled the industry towards smarter,greener,and more sustainable practices,particularly in the areas of intelligent monitoring,disaster management,and innovative construction methods.This paper reviews the application and methodologies of intelligent testing equipment,including cone penetration testing(CPT)devices,soil resistivity testers,and intelligent rebound testers,in subgrade engineering.It examines the operating principles,advantages,limitations,and application ranges of these tools in subgrade testing.Additionally,the paper evaluates the practical use of advanced equipment from both domestic and international perspectives,addressing the challenges encountered by various instruments in realworld applications.These devices enable precise,comprehensive testing and evaluation of subgrade conditions at different stages,providing real-time data analysis and intelligent early warnings.This supports effective subgrade health management and maintenance.As intelligent technologies continue to evolve and integrate,these tools will increasingly enhance the accuracy,efficiency,and sustainability of subgrade monitoring.
文摘The establishment of China’s forestry science and technology evaluation system is an important guarantee measure to improve the level of forestry science and technology management and promote forestry science and technology advancement. Based on the analysis of the current condition of forestry science and technology evaluation in China, the paper presents the suggestions to establish and improve forestry science and technology system, including the change in evaluation subject, the standardization of evaluation approaches and the implementation of classified evaluation, to solve the problems existing in the current forestry science and technology evaluation like non-standardization of evaluation methods, incomplete evaluation system and unsound evaluation indicator system.
文摘In 2012,China's first national shale gas demonstrations areas were set up in the Sichuan Basin.After 10 years'construction and practice,the giant marine shale gas area of 10×10^(12) m^(3) level is built up in the Sichuan Basin,and shale gas steps into a new stage of large-scale benefit exploration and development.In order to systematically summarize the achievements in shale gas exploration and development and provide guidance and reference for the exploration and development of deep shale gas and shale oil&gas in other areas,this paper systematically summarizes the main characteristics,development models and key identification and evaluation technologies for quality reservoirs of Wufeng Formation-Longmaxi Formation shale gas by analyzing the electric property,lithofacies,reservoir parameters and microscopic porosity of key wells in the basin.And the following research results are obtained.First,biogenetic siliceous shale,calcareous shale and mixed shale are main lithofacies types in quality shale gas reservoirs,and they are formed in the environment of semi-deep and deep water continental shelf.Their lateral distribution is controlled by the paleogeomorphology and their vertical development is influenced by provenance,redox condition and paleo productivity.They are 25-90 m thick.Second,in the quality shale gas reservoirs develop organic pores,inorganic pore and microfractures(including lamina/bedding fractures),among which,organic pore is one of the main reservoir spaces and microfracture is not only indispensable reservoir space,but also production pathway.The reservoir space of shale gas is overall micro-nano pore,and macropores play an important role in shale gas enrichment.Third,three development models of quality reservoir are established,including sedimentary type,diagenesis type and reworking type.The sedimentary type is the foundation.Multiple quality reservoirs are developed in the high U/Th interval of graptolite belt at the bottom of Longmaxi Formation,and their thickness is mainly controlled by paleogeomorphology and especially greater in the depression area.The diagenesis type is divided into three forms,i.e.,syngenetic-early diagenetic rigid support,middle-late diagenetic mineral-organic matter transformation,and overpressure relief compaction.The reworking type is dominated by quality reservoirs with microfractures.Fourth,the core technologies for identifying and evaluating quality shale gas reservoir include large-size core and rock slice observation,high-accuracy rock mineral identification,experimental gas content test and simulation,SEM microscopic characterization,3D microscopic pore reconstruction,comprehensive geophysical interpretation and prediction and big data analysis.In conclusion,nearly 10 years'research and practice achievements in demonstration area construction can deepen the understanding on domestic quality shale gas reservoirs,promote the effective development of the theories and technologies related to shale gas reservoirs,improve the prediction accuracy of shale gas sweet spot zones/intervals,and expand the shale gas exploration and development achievements of demonstration areas.
文摘This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs （about 20%）. This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field.
文摘Driven by the rapid development of society, great changes have taken place in people's ideology, and more and more attention has been paid to environmental protection. In order to effectively solve the problems existing in the governance of the environment, the environmental protection department must actively implement the environmental monitoring work, and use professional monitoring technology to evaluate the environmental pollution and improvement. After comprehensive analysis of the environmental monitoring data, the pollution situation in the environment can be judged. Only in this way can we make targeted plans to control environmental pollution and avoid the gradual expansion of the pollution problem. In view of this, this paper mainly focuses on the comprehensive analysis and evaluation technology of environmental monitoring data. It is hoped that it will be helpful to the future development of environmental monitoring in China.
文摘In order to realize the impersonality, justness, impartiality and rationality in the awarding work of science ＆ technology, it is necessary to establish an evaluating model to make the evaluating course numeric as well as a complete system of evaluating indexes. The theory of fuzzy mathematics is adopted in this paper to establish a multilevel fuzzy synthetical model to quantitate the evaluating index system for science ＆ technology awarding and to provide the scientific decision-making basis for science ＆ technology awarding.
文摘The thesis analyzes risk factors of enterprise＇s technology innovation, adopts the undetermined measuring model to evaluate technology innovation risk and testifies it through an example.
基金This work was supported by the National Natural Science Foundation of China(72271124,52232014,72071111,71801127,71671091).
文摘Survivability is used to evaluate the ability of the satellite to complete the mission after failure,while the duration of maintaining performance is often ignored.An effective backup strategy can restore the constellation performance timely,and maintain good network communication performance in case of satellite failure.From the perspective of network utility,the low Earth orbit(LEO)satellite constellation survivable graphical eva-luation and review technology(GERT)network with backup satel-lites is constructed.A network utility transfer function algorithm based on moment generating function and Mason formula is proposed,the network survivability evaluation models of on-orbit backup strategy and ground backup strategy are established.The survivable GERT model can deduce the expected mainte-nance time of LEO satellite constellation under different fault states and the network utility generated during the state mainte-nance period.The case analysis shows that the proposed surviv-able GERT model can consider the satellite failure rate,backup satellite replacement rate,maneuver control replacement ability and life requirement,and effectively determine the optimal sur-vivable backup strategy for LEO satellite constellation with limi-ted resources according to the expected network utility.
基金Supported by Department of Science and Technology of Sichuan Province (No. 04JY029-001-2)
文摘This Paper presents a valid innovation design method for electronic consuming products figures. Using the technology evaluation principle in TRIZ （theory of inventive problem solving） theory as a powerful tool, combined with consumer psychology and relevant knowledge on products modeling methodology, evolution patterns and evolution paths of electronic consuming products figures have been explored. Moreover a set of regulations working for figures innovation design is established.
文摘The sensitivity of collinear nonlinear nondestructive testing technique based on harmonic detection is high,but the results are vulnerable to interference from other nonlinear of experiment sources,which leads to this technology limited in industrial applications.To solve this problem,a non-collinear nonlinear ultrasonic testing experimental system is established based on non-collinear beam mixing technology.The non-collinear nonlinear response is observed in the steel and LY12 aluminum alloy.The results show that:1 Based on the benefits of space selection,mode conversion,frequency and steerable optional of non-collinear beam mixing technology,the interference of system nonlinear effects can be suppressed effectively;2 Mode conversion and beam mixing are present in steel and LY12 aluminum alloy,and the non-collinear non-linear response of LY12 aluminum alloy is stronger than steel and the measurement results are more obvious;3 The technology has the feasibility to evaluate the uniformity of material internal.
文摘UGS(underground gas storage)construction in China has stepped into a new development stage after years of exploration.The eleven UGSs that have been put into production play an important role in domestic natural gas peak shaving safety and supply guarantee,with designed working gas volume of 180×10^(8) m^(3),but there are still various difficulties in UGS construction in China.Firstly,the increasing speed of working gas volume is slower than that of peak shaving demand volume.Secondly,the UGS building engineering is difficult in technologies and high in investment costs.Thirdly,safe operation is under high pressure and it is hard to identify and control risks.Fourthly,there are fewer candidate UGS sites in China and UGS building conditions are complicated.And fifthly,it is difficult for those UGSs to realize economic benefits only based on their own operation under the existing natural gas price systems.To sum up,the currently available UGS operation modes and building technologies in China are not sufficient to cope with the challenges resulted from markets and complex geologic conditions.Facing all these challenges,it is necessary not only to explore market driven operation modes,but also to strengthen technology tackling and carry out core technological research and development,including geologic evaluation,gas reservoir engineering,drilling and completion engineering,UGS injection and gas recovery engineering,surface auxiliary technologies and UGS integrity evaluation,so that UGS building efficiency can be increased greatly.
文摘Science and technology talent evaluation is an important part of the talent development system and mechanism,and the state's emphasis on science and technology talent evaluation is reflect-ed in the national policy.This paper takes 49 policy documents on science and technology tal-ent evaluation issued by the state from 1978 to 2022 as the object,and uses policy text analysis,word frequency analysis and co-word network analysis to interpret the content of the policies.These policy texts are divided into four stages.200 high-frequency words were extracted from the policies in each stage after word segmentation was made,and the co-word matrixes and co-word networks were constructed for each stage.The research draws the following conclu-sions:1)The content of Chinese science and technology talent evaluation policies is gradually becoming concrete,and the concept of science and technology talent evaluation is gradually clear;2)The policies have transitioned from"scientific and technological development"to"sci-entific and technological innovation";3)The distribution of policies with different strengths is uneven;4)The cooperation between all departments involved in policy formulation is not e-nough.
文摘According to the status of the northern rural architecture analysis, the prevalence of high energy consumption, low comfort features, it is essential to design energy-efficient buildings in rural areas. Article research and analyze the layout of rural buildings, a variety of energy-saving technologies and building design measures development and utilization of new energy sources and other issues that can make rural buildings to save energy and improve the environmental quality of living of farmers. It also put forward some reasonable suggestions for carrying out residential building energy efficiency in cold areas.
基金The National Science Fundation of China(41977421)The National Key Research and Development Program of China(2016YFC0503700)。
文摘Global economic development and increasing human activities have brought great challenges to fragile ecosystems.In order to avoid,reduce,and reverse desertification,Chinese and foreign scientists and ecological governance institutions have developed a series of ecological restoration technologies(ERTs)and models in the past few decades.These technologies can improve residents’livelihoods,strengthen disaster resilience,and launch a comprehensive review of degraded ecosystems in desertification regions.However,some studies and practices have limited the selection and promotion of good technologies and the assessments of these technologies,resulting in the waste and loss of funds and manpower.The objective of this study is to identify desertification control and restoration technologies and models,summarize the evolutionary features and trends of these technologies under different natural conditions,and evaluate the various ERTs that are now available.The data sources of this study include the databases of international organizations,CNKI,related literature and reports,and questionnaires from institutions and experts.First,the three stages of ERTs evolution were summarized,and the key events and social-economic developments were identified as the driving forces of evolution.Then,the four categories of ERTs were identified as biological,engineering,agricultural,and management ERTs.Finally,the key ERTs were evaluated in the five dimensions of the degree of difficulty,the degree of maturity,effectiveness,suitability,and potential for transfer.The management ERTs scores for the degree of difficulty,the degree of maturity,and potential for transfer are higher.This study provides a reference for adapting to local conditions,the comprehensive management,rational development,and utilization of dryland resources,improving the application of ecological technologies,and promoting the export and import of the excellent technologies.
基金National Key Research and Development Program of China(2016YFC0503700)
文摘The influence of ecological technology measures on the annual sediment loads of rivers complies with the principles of statistics. In this paper, the annual sediment load of the Wuding River is taken as the dependent variable and the rainfall, rainstorms during the flood period of the Wuding River and areas of ecological technology measures are taken as the independent variables to analyze the influence of ecological technology measures on the annual sediment load of the Wuding River during the years 1956 to 2007. This research uses a stepwise regression method. The result shows that 1） the non-linear regression equation composed of three independent variables including 7–8 monthly rainfalls along the Wuding River, areas of ecological technology measures and maximum daily rainfall along the Wuding River has been calculated and set up; the correlation coefficient is R2=0.857 and the significance level is α=0.001. 2） R2=0.717 is adjusted and the regression equation reveals a change of annual sediment load exceeding 71.7% over 52 years; 3） The standardized regression coefficient for ecological technology measure area has the maximum absolute value of the three independent variables shows maximum influence on the change of annual sediment load; and 4） Because of implementing the ecological technology measures, until to year of 2007, when the 7–8 monthly rainfall and maximum daily rainfall are the maximum values in the research section, the annual sediment load is calculated as 149 million ton, which is 36% of the maximum value in the history.
文摘China is one of the countries with the richest wildlife population.The large variety of widely distributed species act as natural or susceptible hosts for numerous infectious diseases.It is estimated that there are more than 1.2 million unknown virus species in China,and there might be 10,000–30,000 unknown bacteria in wild mammals on the Qinghai-Tibet Plateau alone.There are no less than 600,000 species of animal-borne parasites and approximately 2 million species of fungi worldwide.With rapid economic growth and globalization,humans and wildlife interact more frequently,which enhances the probability of wildlife-borne pathogens infecting humans.The occurrence of animal-borne infectious diseases will become the“new normal”we have to face in the future.Therefore,research should be carried out on wildlife-borne microorganisms and the prevention and control of emerging infectious diseases to establish an analytical framework and an evaluation technology system for risk assessment and early warning of potential animal-borne emerging infectious diseases.This will not only improve our understanding of wildlife-borne microbial communities but also enable in-depth analysis,discovery,early warning,and even prediction of major animal-borne emerging infectious diseases that might occur in the future.Furthermore,this research will reduce response times,minimize the social and economic impact and losses,enable interventions related to the emergence or spread of the disease as early as possible,and comprehensively improve our management of infectious disease outbreaks.
