Ethics and governance are vital to the healthy and sustainable development of artificial intelligence(AI).With the long-term goal of keeping AI beneficial to human society,governments,research organizations,and compan...Ethics and governance are vital to the healthy and sustainable development of artificial intelligence(AI).With the long-term goal of keeping AI beneficial to human society,governments,research organizations,and companies in China have published ethical guidelines and principles for AI,and have launched projects to develop AI governance technologies.This paper presents a survey of these efforts and highlights the preliminary outcomes in China.It also describes the major research challenges in AI governance research and discusses future research directions.展开更多
In this paper,the application strategy of ultrasonic detection technology in the detection of concrete foundation piles is analyzed using a construction project as an example.It includes a basic overview of the projec...In this paper,the application strategy of ultrasonic detection technology in the detection of concrete foundation piles is analyzed using a construction project as an example.It includes a basic overview of the project,an overview of ultrasonic testing technology in bridge concrete pile foundation testing,and an analysis of its practical application in the concrete pile foundation testing of this project.The objective of this analysis is to provide some reference for the application of ultrasonic testing technology and the improvement of the quality of bridge concrete pile foundation testing.展开更多
The merging of optical communication and wireless communication is a tendency in the development of future communication.Orthogonal Frequency Division Multiplexing (OFDM) technology is becoming a core technology in th...The merging of optical communication and wireless communication is a tendency in the development of future communication.Orthogonal Frequency Division Multiplexing (OFDM) technology is becoming a core technology in the physical layer of next generation wireless communication system.Taking advantages of both wireless communication and optical communication,OFDM Radio over Fiber (OFDM-RoF) system is characterized by high speed,large capacity and high spectral efficiency.However,it still has some problems to be addressed,including dispersion and nonlinearity effects.The nonlinearity effect of fiber and modulator can be mitigated by PAPR reduction algorithms,the dispersion effect can be eliminated using Cyclic Prefix (CP) and channel estimation,and the fiber nonlinearity can be reduced by techniques such as digital phase conjugation,Partial Carrier Filling (PCF),nonlinearity precompensation and serial correlation reduction.展开更多
With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration bo...With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas.Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained.The practice in the Panyi coal mine has shown that, after mining the C11coal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated.The result was that we achieved a safe and highly efficient mining operation of the C13 coal seam.展开更多
In the traditional mining technology,the coal resources trapped beneath surface buildings,railways,and water bodies cannot be mined massively,thereby causing the lower coal recovery and dynamic disasters.In order to s...In the traditional mining technology,the coal resources trapped beneath surface buildings,railways,and water bodies cannot be mined massively,thereby causing the lower coal recovery and dynamic disasters.In order to solve the aforementioned problems,the roadway backfilling mining technology is developed and the joint bearing mechanism of coal pillar and backfilling body is presented in this paper.The mechanical model of bearing system of coal pillar and backfilling body is established,by analyzing the basic characteristics of overlying strata deformation in roadway backfilling mining technology.According to the Ritz method in energy variation principle,the elastic solution expression of coal pillar deformation is deduced in roadway backfilling mining technology.Based on elastic-viscoelastic correspondence principle,combining with the burgers rheological constitutive model and Laplace transform theory,the viscoelastic solution expression of coal pillar deformation is obtained in roadway backfilling mining technology.By analyzing the compressive mechanical property of backfilling body,the time formula required for coal pillar and backfilling body to play the joint bearing function in roadway backfilling mining technology is obtained.The example analysis indicates that the time is 140 days.The results can be treated as an important basis for theoretical research and process design in roadway backfilling mining technology.展开更多
This paper introduces the development,compositions and characteristics of the domestic and foreign blowing-carding technique,discusses the technology of blowing-carding machines and the structures and functions of the...This paper introduces the development,compositions and characteristics of the domestic and foreign blowing-carding technique,discusses the technology of blowing-carding machines and the structures and functions of the main machines,analyses the production experiments of three types of blowing-carding flow lines in detail,and puts forward the effective measures to control the main quality index of blowing-carding sliver and the trend of blowing-carding technique development.展开更多
Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market p...Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market price of power coal. The GCP （green coal power） is the power generated in coal-combustion with zero emission. The author indicates that it is possible to make coal-fired power plants emission free based on thermodynamic analysis and purposely designed experiments using SFG （simulated flue gases）. It is concluded in the study that all SO_2 and NOx in the post-combustion flue gas are reduced to inoffensive substances at temperature lower than 750 ℃ when contacting carbon and elemental sulfur is separated in succeeded cooling of flue gas at temperatures 200-400 ℃, and the ultrafine dusts are trapped in condensed water at temperature blow 100 ℃. Based on chemical engineering expertise the author is sure that the cost for removing acid gases is much lower than any clean coal technologies known to today. Instead of capture, the remained CO_2 is converted to CO in the second time contact with carbon at 900-950 ℃. CO is the raw material of chemical synthesis and, thus, CO_2 is stored in chemical products such as methanol, fertilizer, plastics, etc. The simple and low-cost processing allows GCP utilized in practice easily.展开更多
English for Science and Technology （EST）, as one branch of English for Special Purposes, has its own distinctive features and plays a significant role in today＇s English education. In language teaching, teaching ma...English for Science and Technology （EST）, as one branch of English for Special Purposes, has its own distinctive features and plays a significant role in today＇s English education. In language teaching, teaching materials play an important role. To a great extent, they determine the content and approaches of teaching and learning and affect the quality of language education. The author of this paper makes a tentative analysis of the compilation principles of EST teaching materials, from the perspective of students, scientific and technological discipline, and the English language, highlighting the content of teaching and the motivation of students. This paper proposes the Principles of Interest, Life-Long Development, Appropriateness, Systematization, Cognitive Scientificalness, Illumination, Integration of Abstract Knowledge and Specific Cases, Authenticity, Timeliness, and Comprehensive Improvement, so as to improve both subject competence and linguistic ability展开更多
文摘Ethics and governance are vital to the healthy and sustainable development of artificial intelligence(AI).With the long-term goal of keeping AI beneficial to human society,governments,research organizations,and companies in China have published ethical guidelines and principles for AI,and have launched projects to develop AI governance technologies.This paper presents a survey of these efforts and highlights the preliminary outcomes in China.It also describes the major research challenges in AI governance research and discusses future research directions.
文摘In this paper,the application strategy of ultrasonic detection technology in the detection of concrete foundation piles is analyzed using a construction project as an example.It includes a basic overview of the project,an overview of ultrasonic testing technology in bridge concrete pile foundation testing,and an analysis of its practical application in the concrete pile foundation testing of this project.The objective of this analysis is to provide some reference for the application of ultrasonic testing technology and the improvement of the quality of bridge concrete pile foundation testing.
基金funded by the National Natural Science Foundation of China under Grant No.60877052by the National High Technology Research and Development Program of China("863" program)under Grant No.2009AA01Z220
文摘The merging of optical communication and wireless communication is a tendency in the development of future communication.Orthogonal Frequency Division Multiplexing (OFDM) technology is becoming a core technology in the physical layer of next generation wireless communication system.Taking advantages of both wireless communication and optical communication,OFDM Radio over Fiber (OFDM-RoF) system is characterized by high speed,large capacity and high spectral efficiency.However,it still has some problems to be addressed,including dispersion and nonlinearity effects.The nonlinearity effect of fiber and modulator can be mitigated by PAPR reduction algorithms,the dispersion effect can be eliminated using Cyclic Prefix (CP) and channel estimation,and the fiber nonlinearity can be reduced by techniques such as digital phase conjugation,Partial Carrier Filling (PCF),nonlinearity precompensation and serial correlation reduction.
基金Projects 2005CB221503 supported by the National Basic Research Program of China70533050 and 50674089 by the National Natural Science Foundationof China
文摘With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas.Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained.The practice in the Panyi coal mine has shown that, after mining the C11coal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated.The result was that we achieved a safe and highly efficient mining operation of the C13 coal seam.
基金This work was supported by the National Natural Science Foundation of China(51504081,51774110,51508166,U1404527)the Science and Technology Breakthrough Project by Henan Province(162102210221,162102310427)+1 种基金the Foundation for Higher Education Key Research Project by Henan Province(15A440013)the Ph.D.Programs Foundation of Henan Polytechnic University(B2018-65,B2018-4,B2016-67).
文摘In the traditional mining technology,the coal resources trapped beneath surface buildings,railways,and water bodies cannot be mined massively,thereby causing the lower coal recovery and dynamic disasters.In order to solve the aforementioned problems,the roadway backfilling mining technology is developed and the joint bearing mechanism of coal pillar and backfilling body is presented in this paper.The mechanical model of bearing system of coal pillar and backfilling body is established,by analyzing the basic characteristics of overlying strata deformation in roadway backfilling mining technology.According to the Ritz method in energy variation principle,the elastic solution expression of coal pillar deformation is deduced in roadway backfilling mining technology.Based on elastic-viscoelastic correspondence principle,combining with the burgers rheological constitutive model and Laplace transform theory,the viscoelastic solution expression of coal pillar deformation is obtained in roadway backfilling mining technology.By analyzing the compressive mechanical property of backfilling body,the time formula required for coal pillar and backfilling body to play the joint bearing function in roadway backfilling mining technology is obtained.The example analysis indicates that the time is 140 days.The results can be treated as an important basis for theoretical research and process design in roadway backfilling mining technology.
文摘This paper introduces the development,compositions and characteristics of the domestic and foreign blowing-carding technique,discusses the technology of blowing-carding machines and the structures and functions of the main machines,analyses the production experiments of three types of blowing-carding flow lines in detail,and puts forward the effective measures to control the main quality index of blowing-carding sliver and the trend of blowing-carding technique development.
文摘Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market price of power coal. The GCP （green coal power） is the power generated in coal-combustion with zero emission. The author indicates that it is possible to make coal-fired power plants emission free based on thermodynamic analysis and purposely designed experiments using SFG （simulated flue gases）. It is concluded in the study that all SO_2 and NOx in the post-combustion flue gas are reduced to inoffensive substances at temperature lower than 750 ℃ when contacting carbon and elemental sulfur is separated in succeeded cooling of flue gas at temperatures 200-400 ℃, and the ultrafine dusts are trapped in condensed water at temperature blow 100 ℃. Based on chemical engineering expertise the author is sure that the cost for removing acid gases is much lower than any clean coal technologies known to today. Instead of capture, the remained CO_2 is converted to CO in the second time contact with carbon at 900-950 ℃. CO is the raw material of chemical synthesis and, thus, CO_2 is stored in chemical products such as methanol, fertilizer, plastics, etc. The simple and low-cost processing allows GCP utilized in practice easily.
文摘English for Science and Technology （EST）, as one branch of English for Special Purposes, has its own distinctive features and plays a significant role in today＇s English education. In language teaching, teaching materials play an important role. To a great extent, they determine the content and approaches of teaching and learning and affect the quality of language education. The author of this paper makes a tentative analysis of the compilation principles of EST teaching materials, from the perspective of students, scientific and technological discipline, and the English language, highlighting the content of teaching and the motivation of students. This paper proposes the Principles of Interest, Life-Long Development, Appropriateness, Systematization, Cognitive Scientificalness, Illumination, Integration of Abstract Knowledge and Specific Cases, Authenticity, Timeliness, and Comprehensive Improvement, so as to improve both subject competence and linguistic ability
