Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the ar...Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the artificial land is essential,yet challenging.Here,we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization.The system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and moisture.Yan’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench.Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess.Notably,the filling loess exhibits a stronger creep capability compared to underlying intact loess.The deformation along the profile is unevenly distributed,with a positive correlation with soil moisture.Water accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant deformation.Moreover,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,respectively.The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.展开更多
Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instr...Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instruction-brief and instruction-category, and constructing test suite. Consequently, this approach is adopted to test oven embedded system, and detail process is deeply discussed. As a result, the factual result indicates that the “instruction-category” approach can be effectively applied in embedded system testing as a black-box method for conformity testing.展开更多
In order to collect rainwater and resist drought to enhance the utilization rate of rainfall and water resources, through project rainwater harvesting measures, the total annual rainwater harvesting amount of the six ...In order to collect rainwater and resist drought to enhance the utilization rate of rainfall and water resources, through project rainwater harvesting measures, the total annual rainwater harvesting amount of the six greenhouses was calculated according to annual average precipitation 542.2 mm, up to 1 095.7 m^3. The upper natural slopes of cultivated land were as rainwater harvesting areas, and total annual rainwater harvesting amount was 49 242 m^3 on the mountain slopes with an area of 73.37 hm^2, while total water storage amount was 39 394 m^3 in theory, so it could meet water use for the irrigation of 26.28 hm^2 of T. sinensis land. To be convenient for rainwater harvesting, irrigation and supplying water to the water-saving cellars, one pert-cut and part-fill reservoir (which was 470 m^3 in volume) was built on the mountain slopes at the right rear of the greenhouses, and their altitude difference was 50 m. The reservoir was sealed and was built with reinforced concrete. Water-saving cellars were distributed in front and the middle and at the back of two rows of greenhouses, and they were connected with each other. The reservoir could supply water to the water-saving cellars and also collect water by mountain slopes, from the lower water-saving cellars or deep wells. Two rainwater hervesting ditches that were 1 650 m in length were at the lower edge of arable land in the upper reaches of slopes to intercept rainfall runoff and make it flow into channels and then the sedimentation tanks. The total annual rainwater harvesting amount of the reservoir and water-saving cellars was 1 222.5 m^3.展开更多
As Internet becomes largely used in the AEC (architecture, engineering andconstruction) industry, the main focus is in the area of information and project management. In thedynamic engineering consulting, less has bee...As Internet becomes largely used in the AEC (architecture, engineering andconstruction) industry, the main focus is in the area of information and project management. In thedynamic engineering consulting, less has been done so far. This research tries to find thepossibility and potential of the Internet application in design and consulting for the AEC industryby proposing a working model in specific area, steel construction. Several issues have beendiscussed: defining and formatting the typical procedure and character of the steel constructionconsulting, behavior approach based on activities among partners, and the model organization.展开更多
Wetland is one of the richest biodiversity areas in the earth. The main purpose of establishing wetland protected area is to protect biodiversity, and the protection of ecosystem diversity and landscape diversity is t...Wetland is one of the richest biodiversity areas in the earth. The main purpose of establishing wetland protected area is to protect biodiversity, and the protection of ecosystem diversity and landscape diversity is the key to protect biodiversity. In order to protect regional ecosystem and landscape, it is a good way to establish wetland comprehensive protected area which connected wetland nature reserves by habitat corridors. The Sanjiang Plain as a study area, its landscape evaluation index system on wetland protected area was studied, and some problems on landscape planning and ecology construction were further approached in this paper.It showed that establishing wetland comprehensive protected area is very important to protect regional wetlands, to maintain ecological balance, and to improve the sustainable development of agriculture and industry in this region.展开更多
According to the quality control needs of filling construction of the face rockfill dam, by means of the global satellite positioning technology, the wireless data communication technology, the computer technology and...According to the quality control needs of filling construction of the face rockfill dam, by means of the global satellite positioning technology, the wireless data communication technology, the computer technology and the data processing and analysis technology, and integrating with the roller compaction machine, the GPS real time supervisory system is developed in this paper. It can be used to real timely supervise the construction quality of the roller compaction for filling engineering. The composition and applied characteristics of GPS system, and the key technique problem and solution of the design are discussed. The height accuracy of GPS system is analyzed and the preliminary application is introduced.展开更多
A simplified full-depth precast concrete deck panel system for accelerating bridge construction (ABC) is introduced and a finite dement analysis (FEA) is con- ducted to investigate the static and dynamic responses...A simplified full-depth precast concrete deck panel system for accelerating bridge construction (ABC) is introduced and a finite dement analysis (FEA) is con- ducted to investigate the static and dynamic responses of this conceptual deck system. The FEA results are compared to those of the traditional full-depth precast concrete deck panel system. The comparison results show that the mechanical behavior of the new deck system is different from that of the traditional deck system. The concrete decks in the new system act as two-way slabs, instead of the one-way slab in the traditional system. Meanwhile, the connections in both the longitudinal and transverse direc- tions may need to accommodate the negative moments. Compared to those in the traditional system, the longitu- dinal nominal stress at middle span increases a lot in the new deck system and the effective flange width varies significantly. In addition, the dynamic results show that the impact factor is influenced by the spacing of connections. Finally, some design concerns of the new deck system are proposed.展开更多
The buildings construction safety problems contain various safety-hidden dangers that caused by the human unsafe behaviors, the substance unsafe conditions, operation environment unsafe factors and management defects....The buildings construction safety problems contain various safety-hidden dangers that caused by the human unsafe behaviors, the substance unsafe conditions, operation environment unsafe factors and management defects. The authors summarize comprehensively the problems of buildings construetion safety in China at present based on grasping the whole safety status of buildings construction, and the synthetic countermeasures including the systems about laws, management, technology and education civilization for buildings construction safety management are brought up based on the viewpoint of safety system theory. Then it is thought that huilding scientific management mechanisms and popularizing effective management methods and measures are the fundamental ways for improving further the level of safety management for buildings construction in China at present.展开更多
The theory and method of system integration for the real-time monitoring of core rock-fill dam filling con- struction quality are studied in this paper. First, the importance analysis of system integration factors is ...The theory and method of system integration for the real-time monitoring of core rock-fill dam filling con- struction quality are studied in this paper. First, the importance analysis of system integration factors is carried out with the analytic hierarchy process. Then, according to the analysis result of integration factors, the conceptual model of system integration is built based on function integration, index integration, technology integration and information integration, the index structure of core rock-fill dam filling construction quality control is constructed and the method of function integration and technology integration is studied. The mathematical model of process monitoring is built according to monitoring objective, process and indexes. Research results have been applied in Nuozhadu core rock-fill dam construction management, realizing system integration through building appropriate monitoring work flow and comprehensive information platform of digital dam.展开更多
The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM)...The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM).The bacterial communities of free,attached,weakly-attached,and strongly-attached microbes in the later bioleaching stage were investigated.In AM group,the addition of lump sulphide ore resulted in the low leachate pH,high ferric iron concentration,and rapid microbial adsorption,which obtained the maximum copper extraction(60.1%)compared with LM(54.6%)and PM(43.9%)groups.The relative abundance of dominant genera and microbial communities of different microbiota underwent changes in three heap construction methods.The alpha-diversity indexes of attached,weakly-attached,and strongly-attached microbes were different,while no significant change was observed in free bacteria.The variation of whole bacterial community was significantly associated with solution pH,total iron,and ferric iron concentrations.Pearson correlation analysis and partial least square path model both indicated that attached bacteria made larger contribution to the copper extraction of tailings.展开更多
Mutual influence may be driven by different models and operating mechanisms of grounding systems in multi-in-one substations.Even equipment damage and personal injury will occur in the event of a short-circuit or ligh...Mutual influence may be driven by different models and operating mechanisms of grounding systems in multi-in-one substations.Even equipment damage and personal injury will occur in the event of a short-circuit or lightning strike.To meet the construction requirements of different multi-in-one substations,two typical application modes of grounding systems in multi-in-one substations are analyzed in this paper:plane and longitudinal layout schemes.First,the safety index and withstand voltage of secondary equipment in multi-in-one substations are introduced.Second,the plane layout scheme of grounding grids is examined.Based on a 35-kV multi-in-one substations in Shanghai,it was verified that the overall grounding grid needs to be laid to meet the safety of secondary equipment in the station.Finally,considering that it is feasible to rebuild the upper layer of a substation,the longitudinal layout scheme of the grounding grid in multi-in-one substations is also examined.Safety assessment is carried out in terms of aspects such as short-circuits and lightning strikes,and relevant optimization construction methods are analyzed.In this study,a real 35-kV substation in Shanghai was selected as an example.Simulation and field tests based on Current Distribution,Electromagnetic Fields,Grounding and Soil Structure Analysis(CDEGS)software verified that the proposed construction scheme can achieve safe operation of multi-in-one substations.This construction idea can also serve as a reference for the future construction of multi-in-one substations.展开更多
To meet society’s needs for undergraduate students to have engineering skills and to develop students’ability to operate Linux and engage in network software development,this paper proposes the construction of a new...To meet society’s needs for undergraduate students to have engineering skills and to develop students’ability to operate Linux and engage in network software development,this paper proposes the construction of a new specialized course for network engineering major--Linux system and network programming.This paper analyzes the course’s advantages,presents the contents of this course,designs a series of teaching methods aimed at improving students’engineering ability,proposes a course assessment method that will encourage students to practice,lists the development requirements for an examination software designed for this course,and finally,presents the results of our practice in teaching this course.展开更多
The common topic the mankind faces in the 21^st century is to strengthen construction and support the ecological secure. It is also the needs of establlshing socialist harmonious society in China. It is an arduous sys...The common topic the mankind faces in the 21^st century is to strengthen construction and support the ecological secure. It is also the needs of establlshing socialist harmonious society in China. It is an arduous systematic project in ethnic group regions of China to realize economic and sodal sustainable development,promote the harmony between man and nature andrealize the coordination among the economic development population, natural resources and envinonment To develop ecosystem construction and the green indutry well is the basic path to realize the above goals. Huanren Manchu Autonomous County in Liaoning Province is abundant in forests, especially local products, medicinal materials, tourism resource, water resources and culotte resources. In order to develop its ecosystem, the strategies should be focused on enhancing protection consciousaess, brand consciousness, science and technology consciousoess and market consciousness. The ultimate purpose is to create the top-ranking ecosystem environment, industry system, policy systern and district civilization.展开更多
China’s Bei Dou-3 global positioning system has been officially initiated construction with four global networking satel ites to be launched by the end of this year,according to the announcement at the Sixth China An...China’s Bei Dou-3 global positioning system has been officially initiated construction with four global networking satel ites to be launched by the end of this year,according to the announcement at the Sixth China Annual Meeting of Satellite Navigation and Location Services in Shenzhen on September 16 and the First Satellite Application International Exposition held.展开更多
The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of it...The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and optimization.Thirteen types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial environment.Mechanical,thermal and optical,and radiation-shielding properties are considered.The influencing factors and optimization methods for these properties are analyzed.From the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction materials.Correspondingly,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.展开更多
On the basis of analyzing the function and restriction conditions of water features in residential community, the feasibility and specific strategies of using rain- water to construct the waterscape system in resident...On the basis of analyzing the function and restriction conditions of water features in residential community, the feasibility and specific strategies of using rain- water to construct the waterscape system in residential community were proposed, with the aim to deal with the problems of urban water shortage, urban waterlogging and initial rainwater non-point source pollution.展开更多
Recently, the increasing concern about the environmental quality of human settlements makes people realize that the attractive environment given by natural ecology also deficiently needs the feedback and protection of...Recently, the increasing concern about the environmental quality of human settlements makes people realize that the attractive environment given by natural ecology also deficiently needs the feedback and protection of nature in some forms so that the natural ecology can be endlessly cycled on its own. Taking the project of German Enterprise Center in Qingdao Sino-German Ecopark as an example, this paper discussed construction of outdoor environment water circulation system using the landscape building method.展开更多
To make full use of Chinese natural heritage resources and achieve their sustainable development, it is imperative and necessary to construct Chinese National Park System. Based on the theory of sustainable developmen...To make full use of Chinese natural heritage resources and achieve their sustainable development, it is imperative and necessary to construct Chinese National Park System. Based on the theory of sustainable development and the connotation of national park, this paper will discuss the signifi cance of establishing Chinese National Park System and then propose some measures. Chinese National Park System can be constructed from four levels, including policy, management, economic and social levels, and through such ways as reconstructing the national conservation system, making laws and regulations, establishing planning system, setting up independent and specialized regulatory agency, adopting way of franchising, innovating funding investment mechanisms and establishing mechanisms of public participation.展开更多
The vibratory roller is a piece of vital construction machinery in the field of road construction.The unmanned vibratory roller efficiently utilizes the automated driving technology in the vehicle engineering field,wh...The vibratory roller is a piece of vital construction machinery in the field of road construction.The unmanned vibratory roller efficiently utilizes the automated driving technology in the vehicle engineering field,which is innovative for the unmanned road construction.This paper develops and implements the autonomous construction system for the unmanned vibratory roller.Not only does the roller have the function of remote-controlled driving,but it also has the capability of autonomous road construction.The overall system design uses the Programmable Logic Controller(PLC)as the kernel controller.It establishes the communication network through multiple Input/Output(I/O)modules,Recommended Standard 232(RS232)serial port,Controller Area Network(CAN)bus,and wireless networks to control the roller vehicle completely.The locating information is obtained through the Global Navigation Satellite System(GNSS)satellite navigation equipment group to support the process of autonomous construction.According to the experimental results,the autonomous construction system can finally enable the roller to perform driving operations and construction independently,which was a significant step forward in engineering application.展开更多
The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission...The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission.Lunar lava tubes are special underground caves formed by volcanic eruptions and are considered as ideal natural shelters and scientific laboratories for lunar base construction.This paper begins with an in-depth overview of the geological origins,exploration history,and distribution locations of lunar lava tubes.Subsequently,it delves into the presentation of four distinctive advantages and typical concepts for constructing bases within lava tubes,summarizing the ground-based attempts made thus far in lunar lava tube base construction.Field studies conducted on a lava tube in Hainan revealed rock compositions similar to those found during the Apollo missions and clear lava tube structures,making it a promising analog site.Lastly,the challenges and opportunities encountered in the field of geotechnical engineering regarding the establishment of lunar lava tube bases are discussed,encompassing cave exploration technologies,in-situ testing methods,geomechanical properties under lunar extreme environments,base design and structural stability assessment,excavation and reinforcement techniques,and simulated Earth-based lava tube base.展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.4203070 and 41977217)the Key Research&Development Program of Shaanxi Province(Grant No.2020ZDLSF06-03).
文摘Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the artificial land is essential,yet challenging.Here,we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization.The system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and moisture.Yan’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench.Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess.Notably,the filling loess exhibits a stronger creep capability compared to underlying intact loess.The deformation along the profile is unevenly distributed,with a positive correlation with soil moisture.Water accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant deformation.Moreover,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,respectively.The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.
文摘Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instruction-brief and instruction-category, and constructing test suite. Consequently, this approach is adopted to test oven embedded system, and detail process is deeply discussed. As a result, the factual result indicates that the “instruction-category” approach can be effectively applied in embedded system testing as a black-box method for conformity testing.
基金Supported by Key Technology R&D Program Project of Shijiazhuang City(141520208A)~~
文摘In order to collect rainwater and resist drought to enhance the utilization rate of rainfall and water resources, through project rainwater harvesting measures, the total annual rainwater harvesting amount of the six greenhouses was calculated according to annual average precipitation 542.2 mm, up to 1 095.7 m^3. The upper natural slopes of cultivated land were as rainwater harvesting areas, and total annual rainwater harvesting amount was 49 242 m^3 on the mountain slopes with an area of 73.37 hm^2, while total water storage amount was 39 394 m^3 in theory, so it could meet water use for the irrigation of 26.28 hm^2 of T. sinensis land. To be convenient for rainwater harvesting, irrigation and supplying water to the water-saving cellars, one pert-cut and part-fill reservoir (which was 470 m^3 in volume) was built on the mountain slopes at the right rear of the greenhouses, and their altitude difference was 50 m. The reservoir was sealed and was built with reinforced concrete. Water-saving cellars were distributed in front and the middle and at the back of two rows of greenhouses, and they were connected with each other. The reservoir could supply water to the water-saving cellars and also collect water by mountain slopes, from the lower water-saving cellars or deep wells. Two rainwater hervesting ditches that were 1 650 m in length were at the lower edge of arable land in the upper reaches of slopes to intercept rainfall runoff and make it flow into channels and then the sedimentation tanks. The total annual rainwater harvesting amount of the reservoir and water-saving cellars was 1 222.5 m^3.
文摘As Internet becomes largely used in the AEC (architecture, engineering andconstruction) industry, the main focus is in the area of information and project management. In thedynamic engineering consulting, less has been done so far. This research tries to find thepossibility and potential of the Internet application in design and consulting for the AEC industryby proposing a working model in specific area, steel construction. Several issues have beendiscussed: defining and formatting the typical procedure and character of the steel constructionconsulting, behavior approach based on activities among partners, and the model organization.
文摘Wetland is one of the richest biodiversity areas in the earth. The main purpose of establishing wetland protected area is to protect biodiversity, and the protection of ecosystem diversity and landscape diversity is the key to protect biodiversity. In order to protect regional ecosystem and landscape, it is a good way to establish wetland comprehensive protected area which connected wetland nature reserves by habitat corridors. The Sanjiang Plain as a study area, its landscape evaluation index system on wetland protected area was studied, and some problems on landscape planning and ecology construction were further approached in this paper.It showed that establishing wetland comprehensive protected area is very important to protect regional wetlands, to maintain ecological balance, and to improve the sustainable development of agriculture and industry in this region.
文摘According to the quality control needs of filling construction of the face rockfill dam, by means of the global satellite positioning technology, the wireless data communication technology, the computer technology and the data processing and analysis technology, and integrating with the roller compaction machine, the GPS real time supervisory system is developed in this paper. It can be used to real timely supervise the construction quality of the roller compaction for filling engineering. The composition and applied characteristics of GPS system, and the key technique problem and solution of the design are discussed. The height accuracy of GPS system is analyzed and the preliminary application is introduced.
文摘A simplified full-depth precast concrete deck panel system for accelerating bridge construction (ABC) is introduced and a finite dement analysis (FEA) is con- ducted to investigate the static and dynamic responses of this conceptual deck system. The FEA results are compared to those of the traditional full-depth precast concrete deck panel system. The comparison results show that the mechanical behavior of the new deck system is different from that of the traditional deck system. The concrete decks in the new system act as two-way slabs, instead of the one-way slab in the traditional system. Meanwhile, the connections in both the longitudinal and transverse direc- tions may need to accommodate the negative moments. Compared to those in the traditional system, the longitu- dinal nominal stress at middle span increases a lot in the new deck system and the effective flange width varies significantly. In addition, the dynamic results show that the impact factor is influenced by the spacing of connections. Finally, some design concerns of the new deck system are proposed.
基金A Project Supported by Scientific Research Fund of Hunan Provincial Education Department(06C309)
文摘The buildings construction safety problems contain various safety-hidden dangers that caused by the human unsafe behaviors, the substance unsafe conditions, operation environment unsafe factors and management defects. The authors summarize comprehensively the problems of buildings construetion safety in China at present based on grasping the whole safety status of buildings construction, and the synthetic countermeasures including the systems about laws, management, technology and education civilization for buildings construction safety management are brought up based on the viewpoint of safety system theory. Then it is thought that huilding scientific management mechanisms and popularizing effective management methods and measures are the fundamental ways for improving further the level of safety management for buildings construction in China at present.
基金National Key Technology R&D Program in the 12th Five Year Plan of China (No. 2011BAB10B06)Independent Innovation Foundation of Tianjin University (No. 1102119)
文摘The theory and method of system integration for the real-time monitoring of core rock-fill dam filling con- struction quality are studied in this paper. First, the importance analysis of system integration factors is carried out with the analytic hierarchy process. Then, according to the analysis result of integration factors, the conceptual model of system integration is built based on function integration, index integration, technology integration and information integration, the index structure of core rock-fill dam filling construction quality control is constructed and the method of function integration and technology integration is studied. The mathematical model of process monitoring is built according to monitoring objective, process and indexes. Research results have been applied in Nuozhadu core rock-fill dam construction management, realizing system integration through building appropriate monitoring work flow and comprehensive information platform of digital dam.
基金financial supports from the National Key R&D Program of China(No.2018YFC1801804)the Shandong Provincial Natural Science Foundation,China(Nos.ZR2020QD120 and ZR2018LD001)Project of Introducing and Cultivating Young Talent in the Universities of Shandong Province,China(No.QC2019YY144)。
文摘The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM).The bacterial communities of free,attached,weakly-attached,and strongly-attached microbes in the later bioleaching stage were investigated.In AM group,the addition of lump sulphide ore resulted in the low leachate pH,high ferric iron concentration,and rapid microbial adsorption,which obtained the maximum copper extraction(60.1%)compared with LM(54.6%)and PM(43.9%)groups.The relative abundance of dominant genera and microbial communities of different microbiota underwent changes in three heap construction methods.The alpha-diversity indexes of attached,weakly-attached,and strongly-attached microbes were different,while no significant change was observed in free bacteria.The variation of whole bacterial community was significantly associated with solution pH,total iron,and ferric iron concentrations.Pearson correlation analysis and partial least square path model both indicated that attached bacteria made larger contribution to the copper extraction of tailings.
基金supported by National Natural Science Foundation of China(No.92067105)the science and technology project of State Grid Shanghai Municipal Electric Power Company(No.5209211900VD).
文摘Mutual influence may be driven by different models and operating mechanisms of grounding systems in multi-in-one substations.Even equipment damage and personal injury will occur in the event of a short-circuit or lightning strike.To meet the construction requirements of different multi-in-one substations,two typical application modes of grounding systems in multi-in-one substations are analyzed in this paper:plane and longitudinal layout schemes.First,the safety index and withstand voltage of secondary equipment in multi-in-one substations are introduced.Second,the plane layout scheme of grounding grids is examined.Based on a 35-kV multi-in-one substations in Shanghai,it was verified that the overall grounding grid needs to be laid to meet the safety of secondary equipment in the station.Finally,considering that it is feasible to rebuild the upper layer of a substation,the longitudinal layout scheme of the grounding grid in multi-in-one substations is also examined.Safety assessment is carried out in terms of aspects such as short-circuits and lightning strikes,and relevant optimization construction methods are analyzed.In this study,a real 35-kV substation in Shanghai was selected as an example.Simulation and field tests based on Current Distribution,Electromagnetic Fields,Grounding and Soil Structure Analysis(CDEGS)software verified that the proposed construction scheme can achieve safe operation of multi-in-one substations.This construction idea can also serve as a reference for the future construction of multi-in-one substations.
基金supported by the Teaching Research and Reform Project of Qingdao University of Technology under Grant 2024-10335040。
文摘To meet society’s needs for undergraduate students to have engineering skills and to develop students’ability to operate Linux and engage in network software development,this paper proposes the construction of a new specialized course for network engineering major--Linux system and network programming.This paper analyzes the course’s advantages,presents the contents of this course,designs a series of teaching methods aimed at improving students’engineering ability,proposes a course assessment method that will encourage students to practice,lists the development requirements for an examination software designed for this course,and finally,presents the results of our practice in teaching this course.
文摘The common topic the mankind faces in the 21^st century is to strengthen construction and support the ecological secure. It is also the needs of establlshing socialist harmonious society in China. It is an arduous systematic project in ethnic group regions of China to realize economic and sodal sustainable development,promote the harmony between man and nature andrealize the coordination among the economic development population, natural resources and envinonment To develop ecosystem construction and the green indutry well is the basic path to realize the above goals. Huanren Manchu Autonomous County in Liaoning Province is abundant in forests, especially local products, medicinal materials, tourism resource, water resources and culotte resources. In order to develop its ecosystem, the strategies should be focused on enhancing protection consciousaess, brand consciousness, science and technology consciousoess and market consciousness. The ultimate purpose is to create the top-ranking ecosystem environment, industry system, policy systern and district civilization.
文摘China’s Bei Dou-3 global positioning system has been officially initiated construction with four global networking satel ites to be launched by the end of this year,according to the announcement at the Sixth China Annual Meeting of Satellite Navigation and Location Services in Shenzhen on September 16 and the First Satellite Application International Exposition held.
基金supported by the National Key Research and Development Program of China(2023YFB3711300 and 2021YFF0500300)the Strategic Research and Consulting Project of the Chinese Academy of Engineering(2023-XZ-90 and 2023-JB-09-10)the National Key Research and Development Program of China(2021YFF0500300).
文摘The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and optimization.Thirteen types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial environment.Mechanical,thermal and optical,and radiation-shielding properties are considered.The influencing factors and optimization methods for these properties are analyzed.From the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction materials.Correspondingly,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.
文摘On the basis of analyzing the function and restriction conditions of water features in residential community, the feasibility and specific strategies of using rain- water to construct the waterscape system in residential community were proposed, with the aim to deal with the problems of urban water shortage, urban waterlogging and initial rainwater non-point source pollution.
基金Sponsored by the National Science and Technology Project in the Twelfth Five-Year Plan Period(2013BAJ02B04)
文摘Recently, the increasing concern about the environmental quality of human settlements makes people realize that the attractive environment given by natural ecology also deficiently needs the feedback and protection of nature in some forms so that the natural ecology can be endlessly cycled on its own. Taking the project of German Enterprise Center in Qingdao Sino-German Ecopark as an example, this paper discussed construction of outdoor environment water circulation system using the landscape building method.
基金Sponsored by National Social Science Fund(14CGL020)
文摘To make full use of Chinese natural heritage resources and achieve their sustainable development, it is imperative and necessary to construct Chinese National Park System. Based on the theory of sustainable development and the connotation of national park, this paper will discuss the signifi cance of establishing Chinese National Park System and then propose some measures. Chinese National Park System can be constructed from four levels, including policy, management, economic and social levels, and through such ways as reconstructing the national conservation system, making laws and regulations, establishing planning system, setting up independent and specialized regulatory agency, adopting way of franchising, innovating funding investment mechanisms and establishing mechanisms of public participation.
基金This work was supported by the Natural Science Foundation of Jiangsu Province(BK20170681,BK20180701)the National Natural Science Foundation of China(51675281).
文摘The vibratory roller is a piece of vital construction machinery in the field of road construction.The unmanned vibratory roller efficiently utilizes the automated driving technology in the vehicle engineering field,which is innovative for the unmanned road construction.This paper develops and implements the autonomous construction system for the unmanned vibratory roller.Not only does the roller have the function of remote-controlled driving,but it also has the capability of autonomous road construction.The overall system design uses the Programmable Logic Controller(PLC)as the kernel controller.It establishes the communication network through multiple Input/Output(I/O)modules,Recommended Standard 232(RS232)serial port,Controller Area Network(CAN)bus,and wireless networks to control the roller vehicle completely.The locating information is obtained through the Global Navigation Satellite System(GNSS)satellite navigation equipment group to support the process of autonomous construction.According to the experimental results,the autonomous construction system can finally enable the roller to perform driving operations and construction independently,which was a significant step forward in engineering application.
基金supported by the National Natural Science Foundation of China(Nos.52125903 and 52339001).
文摘The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission.Lunar lava tubes are special underground caves formed by volcanic eruptions and are considered as ideal natural shelters and scientific laboratories for lunar base construction.This paper begins with an in-depth overview of the geological origins,exploration history,and distribution locations of lunar lava tubes.Subsequently,it delves into the presentation of four distinctive advantages and typical concepts for constructing bases within lava tubes,summarizing the ground-based attempts made thus far in lunar lava tube base construction.Field studies conducted on a lava tube in Hainan revealed rock compositions similar to those found during the Apollo missions and clear lava tube structures,making it a promising analog site.Lastly,the challenges and opportunities encountered in the field of geotechnical engineering regarding the establishment of lunar lava tube bases are discussed,encompassing cave exploration technologies,in-situ testing methods,geomechanical properties under lunar extreme environments,base design and structural stability assessment,excavation and reinforcement techniques,and simulated Earth-based lava tube base.