Karst caves are among the most common and critical geological hazards in karst regions.Due to their marked differences in physical properties compared to the surrounding rock,they can be detected using various geophys...Karst caves are among the most common and critical geological hazards in karst regions.Due to their marked differences in physical properties compared to the surrounding rock,they can be detected using various geophysical techniques.Karsts have developed on the surface of the Qingshuitang Wollastonite Mining Area in Huangtian Town,Hezhou City,Guangxi Province.In line with mine safety production requirements,a professional assessment of the potential development of karst caves must be conducted within 150 m of the mining area’s surface.Following an on-site investiga-tion and comparison with traditional geophysical methods,seismic frequency resonance technology(Seismic FRT)was selected for detection due to its convenience,flexibility,cost-effectiveness,and rapid data acquisition capabilities.Contour maps of the apparent wave impedance and geological profiles along the survey lines were obtained through data collection and processing.In combination with surface karst and mining geology,32 karst caves(hidden danger points)and 15 karst development zones were identified.Drilling verification was conducted at the A428 and B122 anomalous points on the A1# and B1# survey lines.The verification results were consistent with the inferred depths and maximum apparent wave impedance anomalies,confirming that Seismic FRT is a feasible and effective method for detecting hid-den karst development areas in mines.展开更多
At present,AI is reshaping the global industrial landscape at an unprecedented depth.As the cornerstone suppor ting technological innovation and industrial development,metrology is radiating new vitality in the AI era...At present,AI is reshaping the global industrial landscape at an unprecedented depth.As the cornerstone suppor ting technological innovation and industrial development,metrology is radiating new vitality in the AI era.It is not only a verification scale for algorithm accuracy and a trust anchor for sensing systems,but also a strategic link for China and ASEAN to deepen industrial collaboration.Metrology runs through the entire innovation chain of AI,providing verifiable and reproducible scientific basis for technological innovation and industrial development.展开更多
Tiangong space station is a space station independently designed and developed by China.In order to build and operate the space station,it was necessary to make breakthroughs in many fields and master several key tech...Tiangong space station is a space station independently designed and developed by China.In order to build and operate the space station,it was necessary to make breakthroughs in many fields and master several key technologies,which were characterized over a long technological span and underwent difficult verifications.Therefore,in addition to ground verification,on-orbit flight tests of key technologies for the assembly,construction and operation of the space station were planned to be conducted used by the core module,taking into account the differences in the gravity environment between space and the Earth,in order to lay a foundation for the subsequent comprehensive assembly,construction and long-term on-orbit operation of the space station.In this paper,the mission characteristics of the space station are briefly introduced,along with the key technologies for the assembly and construction of the space station,and then the on-orbit verification tests are comprehensively introduced.展开更多
US military aircraft engine advanced technology programs were overviewed and analyzed from light weight gas generator(LWGG)program initiated in 1960 sthrough integrated high performance turbine engine technology(IHPTE...US military aircraft engine advanced technology programs were overviewed and analyzed from light weight gas generator(LWGG)program initiated in 1960 sthrough integrated high performance turbine engine technology(IHPTET)program started in 1980 s,then to versatile affordable advanced turbine engine(VAATE)program.Some features and trends were summarized and concluded by literature statistics method,such as teams based on closely corporation among government,industries and academics,goals oriented with national defence strategies and weapon system development requirements,engineering manufacture and development including all relative disciplines and areas,verification measured by technology readiness level,the application extending to military aircraft engine,civilian engine,gas turbine and space vehicle,etc.The experience and lessons obtained can provide reference and guide for technology research and engineering manufacture and development of military aircraft engines in the world.展开更多
Previous studies have proposed higher requirements for the transient characteristics of a DC transformer used in a flexible high-voltage direct current(HVDC) system to achieve faster sampling speed and meet wider band...Previous studies have proposed higher requirements for the transient characteristics of a DC transformer used in a flexible high-voltage direct current(HVDC) system to achieve faster sampling speed and meet wider bandwidth requirements of the control and protection signal, and to eventually suppress the large transient fault current. In this study, a transient characteristics verification method is proposed for transient characteristics verification of a DC transformer used in a flexible HVDC system based on resampling technology and LabVIEW measurement technology after analyzing the key technology for transient characteristics verification of a DC transformer. A laboratory experiment for the transient characteristics of a full-fiber electronic DC transformer is conducted, and experimental results show that such verification method can be employed for frequency response and step response verification of a DC transformer at 10% of the rated voltage and current, and can eventually improve the screening of a DC transformer.展开更多
Illegal logging of wood and its trade have become a global concern.Many governmental and private sectors have taken measures to ensure the legality of wood,and wood legality verification is becoming more and more comm...Illegal logging of wood and its trade have become a global concern.Many governmental and private sectors have taken measures to ensure the legality of wood,and wood legality verification is becoming more and more common.In this paper,a questionnaire survey is used to investigate the status of legality verification of wood processing enterprises in Jiangsu and Zhejiang.An investigation is also carried out by establishing a binary logistic regression model and multiplicative interaction analysis.The results show that applying for timber legality verification is conducive to improvement in technological innovation and management level of Jiangsu and Zhejiang wood processing enterprises.Based on this conclusion,this paper suggests some policies to promote the legality verification of Chinese wood processing enterprises.展开更多
With the continuous development of science and technolog ies in China,radiotherapy technology in medical field has been very significant ly developing,and intensity modulated radiation therapy(IMRT)technology has been...With the continuous development of science and technolog ies in China,radiotherapy technology in medical field has been very significant ly developing,and intensity modulated radiation therapy(IMRT)technology has been the most widely used.This paper first introduces the components and types of two-dimensional matrix detector,two-dimensional ionization chamber matrix detector and two-dimensional semiconductor matrix detector,then analyzes the dosimetric characteristics of the two-dimensional matrix detector.In the end,the various applications of the two-dimensional matrix detector are analyzed and discussed in detail.The paper aims to promote the two-dimensional matrix detector’s development in the field of radiotherapy in China.展开更多
基金supported by the General Project of Guangxi Natural Science Foundation grant number[2020GXNSFAA297088]the Hezhou Science Research and Development Plan Project grant number[2024143]the Basic Research Ability Enhancement Project for Young and Middle-aged Teachers at Guangxi Universities grant number[2024KY1877].
文摘Karst caves are among the most common and critical geological hazards in karst regions.Due to their marked differences in physical properties compared to the surrounding rock,they can be detected using various geophysical techniques.Karsts have developed on the surface of the Qingshuitang Wollastonite Mining Area in Huangtian Town,Hezhou City,Guangxi Province.In line with mine safety production requirements,a professional assessment of the potential development of karst caves must be conducted within 150 m of the mining area’s surface.Following an on-site investiga-tion and comparison with traditional geophysical methods,seismic frequency resonance technology(Seismic FRT)was selected for detection due to its convenience,flexibility,cost-effectiveness,and rapid data acquisition capabilities.Contour maps of the apparent wave impedance and geological profiles along the survey lines were obtained through data collection and processing.In combination with surface karst and mining geology,32 karst caves(hidden danger points)and 15 karst development zones were identified.Drilling verification was conducted at the A428 and B122 anomalous points on the A1# and B1# survey lines.The verification results were consistent with the inferred depths and maximum apparent wave impedance anomalies,confirming that Seismic FRT is a feasible and effective method for detecting hid-den karst development areas in mines.
文摘At present,AI is reshaping the global industrial landscape at an unprecedented depth.As the cornerstone suppor ting technological innovation and industrial development,metrology is radiating new vitality in the AI era.It is not only a verification scale for algorithm accuracy and a trust anchor for sensing systems,but also a strategic link for China and ASEAN to deepen industrial collaboration.Metrology runs through the entire innovation chain of AI,providing verifiable and reproducible scientific basis for technological innovation and industrial development.
文摘Tiangong space station is a space station independently designed and developed by China.In order to build and operate the space station,it was necessary to make breakthroughs in many fields and master several key technologies,which were characterized over a long technological span and underwent difficult verifications.Therefore,in addition to ground verification,on-orbit flight tests of key technologies for the assembly,construction and operation of the space station were planned to be conducted used by the core module,taking into account the differences in the gravity environment between space and the Earth,in order to lay a foundation for the subsequent comprehensive assembly,construction and long-term on-orbit operation of the space station.In this paper,the mission characteristics of the space station are briefly introduced,along with the key technologies for the assembly and construction of the space station,and then the on-orbit verification tests are comprehensively introduced.
文摘US military aircraft engine advanced technology programs were overviewed and analyzed from light weight gas generator(LWGG)program initiated in 1960 sthrough integrated high performance turbine engine technology(IHPTET)program started in 1980 s,then to versatile affordable advanced turbine engine(VAATE)program.Some features and trends were summarized and concluded by literature statistics method,such as teams based on closely corporation among government,industries and academics,goals oriented with national defence strategies and weapon system development requirements,engineering manufacture and development including all relative disciplines and areas,verification measured by technology readiness level,the application extending to military aircraft engine,civilian engine,gas turbine and space vehicle,etc.The experience and lessons obtained can provide reference and guide for technology research and engineering manufacture and development of military aircraft engines in the world.
基金supported by the State Grid Corporation Science and Technology Project(No.JL71-15-039)
文摘Previous studies have proposed higher requirements for the transient characteristics of a DC transformer used in a flexible high-voltage direct current(HVDC) system to achieve faster sampling speed and meet wider bandwidth requirements of the control and protection signal, and to eventually suppress the large transient fault current. In this study, a transient characteristics verification method is proposed for transient characteristics verification of a DC transformer used in a flexible HVDC system based on resampling technology and LabVIEW measurement technology after analyzing the key technology for transient characteristics verification of a DC transformer. A laboratory experiment for the transient characteristics of a full-fiber electronic DC transformer is conducted, and experimental results show that such verification method can be employed for frequency response and step response verification of a DC transformer at 10% of the rated voltage and current, and can eventually improve the screening of a DC transformer.
文摘Illegal logging of wood and its trade have become a global concern.Many governmental and private sectors have taken measures to ensure the legality of wood,and wood legality verification is becoming more and more common.In this paper,a questionnaire survey is used to investigate the status of legality verification of wood processing enterprises in Jiangsu and Zhejiang.An investigation is also carried out by establishing a binary logistic regression model and multiplicative interaction analysis.The results show that applying for timber legality verification is conducive to improvement in technological innovation and management level of Jiangsu and Zhejiang wood processing enterprises.Based on this conclusion,this paper suggests some policies to promote the legality verification of Chinese wood processing enterprises.
文摘With the continuous development of science and technolog ies in China,radiotherapy technology in medical field has been very significant ly developing,and intensity modulated radiation therapy(IMRT)technology has been the most widely used.This paper first introduces the components and types of two-dimensional matrix detector,two-dimensional ionization chamber matrix detector and two-dimensional semiconductor matrix detector,then analyzes the dosimetric characteristics of the two-dimensional matrix detector.In the end,the various applications of the two-dimensional matrix detector are analyzed and discussed in detail.The paper aims to promote the two-dimensional matrix detector’s development in the field of radiotherapy in China.
