The breakthrough of key core technology is a theoretical and practical strategic issue to realize the rise of the country.This paper analyzes the concept of key core technology and its breakthrough and analyzes its ch...The breakthrough of key core technology is a theoretical and practical strategic issue to realize the rise of the country.This paper analyzes the concept of key core technology and its breakthrough and analyzes its characteristics.Based on the perspective of participants,this paper summarizes the influencing factors of key core technology breakthroughs in enterprises:internal and external enterprises,universities and scientific research institutions,and government.This paper expands the relevant research on key core technology breakthroughs and provides inspiration for enterprises to carry out key core technology research and breakthrough practices.展开更多
Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biot...Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biotechnology and its applications in the field of neuropsychiatry.Available evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin deficit.In vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric diseases.Although the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic applications.However,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical applications.This review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.展开更多
The key technology of semi-continuous conveyor system decides the successful using of this system. The key technology includes optimal initial building depth of this system,the crusher moving step and the layout of co...The key technology of semi-continuous conveyor system decides the successful using of this system. The key technology includes optimal initial building depth of this system,the crusher moving step and the layout of conveyor system are studied, and their calculating models are built up.展开更多
In order to develop green good, reduce the use of chemical fertilizer and pesticide, realize "double reduction" and synergism, improve safety and quality of products, protect the ecological environment and promote t...In order to develop green good, reduce the use of chemical fertilizer and pesticide, realize "double reduction" and synergism, improve safety and quality of products, protect the ecological environment and promote the healthy and steady development of strawberry industry, the goals and key technology of fertilizer-pesticide "double reduction" and synergism for greenhouse strawberry are summed up in this paper targeting at the current situation of strawberry production and combined with the new technology achievements at home and abroad. The key technology includes six items: healthy seedling cultivating technique, soil improvement and continuous cropping obstacle treatment technique, agricultural ecological prevention tech- nique, physicochemical trap of pest control technique, biological control technique and low residual risk chemical control technique.展开更多
A low-power environmental monitoring system based on WSN technology is proposed to effectively monitor the environmental status and ensure the healthy growth of greenhouse crops in the greenhouse. The system performs ...A low-power environmental monitoring system based on WSN technology is proposed to effectively monitor the environmental status and ensure the healthy growth of greenhouse crops in the greenhouse. The system performs dynamic mon- itoring on the environmental data of temperature, humidity, illumination, soil tempera- ture and humidity of the greenhouse, and it reduces the energy consumption by us- ing solar energy and lithium battery as the power supply mode and dynamic power management algorithm combined with improved routing protocol. Stable and reliable, the system could effectively monitor the key environmental factors in the green- house, making it of certain promotion value.展开更多
To understand the resource features and geology in the deep Jinchuan nickel deposit, difficult geological conditions were systematically analyzed, including high stress, fragmentized ore rock, prevalent deformation, d...To understand the resource features and geology in the deep Jinchuan nickel deposit, difficult geological conditions were systematically analyzed, including high stress, fragmentized ore rock, prevalent deformation, difficult tunnel support, complicated rock mechanics, and low mining recovery. An integrated technology package was built for safe, efficient, and continuous mining in a deep, massive, and complex nickel and cobalt mine. This was done by the invention of a large-area continuous mining method with honeycomb drives; the establishment of ground control theory and a technology package for high-stress and fragmented ore rock: and the development of a new type of backfilling cement material, along with a deep backfilling technology that comprises the pipeline transport of high-density slurry with coarse aggregates. In this way, good solutions to existing problems were found to permit the efficient exploitation and comprehensive utilization of the resources in the deep Jinchuan nickel mine. In addition, a technological demonstration in an underground mine was performed using the cemented undercut-and-fill mining method for stressful, frag- mented, and rheological rock.展开更多
Evacuated tube transportation (ETT) will be one of the ultra-large-scale vacuum application areas. This paper lists some key vacuum technology issues in ETT: (1) how to construct ultra-large-scale vacuum chamber ...Evacuated tube transportation (ETT) will be one of the ultra-large-scale vacuum application areas. This paper lists some key vacuum technology issues in ETT: (1) how to construct ultra-large-scale vacuum chamber with lower cost and high reliability, (2) how to evacuate gas out of the ETT tube in short time, (3) how to release heat or reduce temperature in the vacuum tube, (4) how to avoid vacuum discharge, (5) how to make vehicles with airproof shells and life support system, and (6) how to detect leaks and find leak positions efficiently. At the same time, some solutions are proposed.展开更多
Quantum key distribution(QKD) generates information-theoretical secure keys between two parties based on the physical laws of quantum mechanics. The phase-matching(PM) QKD protocol allows the key rate to break the qua...Quantum key distribution(QKD) generates information-theoretical secure keys between two parties based on the physical laws of quantum mechanics. The phase-matching(PM) QKD protocol allows the key rate to break the quantum channel secret key capacity limit without quantum repeaters, and the security of the protocol is demonstrated by using equivalent entanglement. In this paper, the wavelength division multiplexing(WDM) technique is applied to the PM-QKD protocol considering the effect of crosstalk noise on the secret key rate. The performance of PM-QKD protocol based on WDM with the influence of adjacent classical channels and Raman scattering is analyzed by numerical simulations to maximize the total secret key rate of the QKD, providing a reference for future implementations of QKD based on WDM techniques.展开更多
A new business management mode-agile & convenient management mode (ACM) was proposed because of large scale mobile computing and mobile business. As an efficient approach to ACM, Mobile ERP (MERP), including its c...A new business management mode-agile & convenient management mode (ACM) was proposed because of large scale mobile computing and mobile business. As an efficient approach to ACM, Mobile ERP (MERP), including its concept and four-tier architecture was introduced firstly. Then, the two key technologies of implementing MERP about message service and wireless WAP service were developed. Meanwhile, an official MERP system was also implemented based on our CERP software system by aglets. And it was applied by Henan Tongli Cement Group in China. In comparison with the traditional ERP system, the new system could improve the efficiency and level of management, and reduce the management cost of enterprise.展开更多
Sutong Bridge is a cable-stayed bridge across Yangtze River with the main span of 1 088 m. This article outlines technical challenges,key technology and innovation in the design and construction such as scour protecti...Sutong Bridge is a cable-stayed bridge across Yangtze River with the main span of 1 088 m. This article outlines technical challenges,key technology and innovation in the design and construction such as scour protection,lowering steel cofferdam,construction platform establishment,construction and control of pylons,fabrication and damping of long cables,erection and control of steel box girders.展开更多
Quantum key distribution(QKD) generates information-theoretical secret keys between two parties based on the physical laws of quantum mechanics. Following the advancement in quantum communication networks, it becomes ...Quantum key distribution(QKD) generates information-theoretical secret keys between two parties based on the physical laws of quantum mechanics. Following the advancement in quantum communication networks, it becomes feasible and economical to combine QKD with classical optical communication through the same fiber using dense wavelength division multiplexing(DWDM) technology. This study proposes a detailed scheme of TF-QKD protocol with DWDM technology and analyzes its performance, considering the influence of quantum channel number and adjacent quantum crosstalk on the secret key rates. The simulation results show that the scheme further increases the secret key rate of TF-QKD and its variants. Therefore, this scheme provides a method for improving the secret key rate for practical quantum networks.展开更多
In recent years,great efforts have been made on the geoparks’ application and construction,but there is a shortage of research on the theories and methodologies of geoheritage investigation and assessment. Based on t...In recent years,great efforts have been made on the geoparks’ application and construction,but there is a shortage of research on the theories and methodologies of geoheritage investigation and assessment. Based on the summaries of having finished geoheritage investtigation and assessment and geopark construction projects,some key technologic methods analyzed in this paper are as follows:(1)展开更多
An integrated monitoring system for running parameters of key mining equipmenton the basis of condition monitoring technology and modern communication networktechnology was developed.The system consists of a client co...An integrated monitoring system for running parameters of key mining equipmenton the basis of condition monitoring technology and modern communication networktechnology was developed.The system consists of a client computer with functions ofsignal acquisition and processing, and a host computer in the central control room.Thesignal acquisition module of the client computer can collect the running parameters fromvarious monitoring terminals in real-time.The DSP high-speed data processing system ofthe main control module can quickly achieve the numerical calculation for the collectedsignal.The signal modulation and signal demodulation are completed by the frequencyshift keying circuit and phase-locked loop frequency circuit, respectively.Finally, the signalis sent to the host computer for logic estimation and diagnostic analysis using the networkcommunication technology, which is helpful for technicians and managers to control therunning state of equipment.展开更多
Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control (CNC) system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical cont...Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control (CNC) system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical control (HITCNC), is researched and manufactured based on the interface standards. The system's external interfaces are coincident with the corresponding international standards, and the internal interfaces follow the open modular architecture controller (OMAC) agreement. In the research and manufacturing process, object-oriented technology is used to ensure the openness of the HITCNC, and static programming is applied in the CNC system according to the idea of modularization disassembly. The HITCNC also actualizes real-time and unreal-time modules adopting real-time dynamical linked library (RTDLL) and component object model (COM). Finite state ma- chine (FSM) is adopted to do dynamically modeling of HITCNC. The complete separation between the software and the hardware is achieved in the HITCNC by applying the SoftSERCANS technique. The application of the above key techniques decreases the programming workload greatly, and uses software programs replacing hardware functions, which offers plenty technique ensures for the openness of HITCNC. Finally, based on the HITCNC, a three-dimensional milling system is established. On the system, series experiments are done to validate the expandability and interchangeability of HITCNC. The results of the experiments show that the established open architecture CNC system HITCNC is correct and feasible, and has good openness.展开更多
The forestry is the main department of the national economy. During forty years development of the forestry , it has made a lot of contribution for the national economic construction and society development. However, ...The forestry is the main department of the national economy. During forty years development of the forestry , it has made a lot of contribution for the national economic construction and society development. However, paying more attention to the logging than to the silviculture for a long time lead that the felling amount has been more than the growth in volume of forest. And the forest resources have much decreased. The forestry is now faced to many difficulties. The forestry problems should be tackled by relying on the progress of science and technology. The achievements of science and technology should be first spread in forest zone. And the second task is that the step of the progress of science and technology in forestry enterprises should be quicken. In order to raise the economic benefits of forestry enterprises. The key problems of science and technology in forestry should be tackled by cooperation. Raising, the level of forestry science and technology and enlarging the international exchange are the other important aspect of vigorously developing the forestry.展开更多
On October 14, two satellites SJ-9A/B were sent into their preset orbits by a LM-2C/SMA launch vehicle, which is the first flight of a series of China's civilian technology experimental satellites. SJ-9A and B are...On October 14, two satellites SJ-9A/B were sent into their preset orbits by a LM-2C/SMA launch vehicle, which is the first flight of a series of China's civilian technology experimental satellites. SJ-9A and B are the first two satellites in the series of civilian technology experimental satellites designed for tests such as long lifetime and high reliability, high precision and high performance of satellite, domestically developed core components, satellite formation展开更多
Three clock synchronization schemes for a quantum key distribution system are compared experimentally through the outdoor fibre and the interaction physical model of the the clock signal and the the quantum signal in ...Three clock synchronization schemes for a quantum key distribution system are compared experimentally through the outdoor fibre and the interaction physical model of the the clock signal and the the quantum signal in the quantum key distribution system is analysed to propose a new synchronization scheme based on time division multiplexing and wavelength division multiplexing technology to reduce quantum bits error rates under some transmission rate conditions, The proposed synchronization scheme can not only completely eliminate noise photons from the bright background light of the the clock signal, but also suppress the fibre nonlinear crosstalk.展开更多
The paper summarizes the development of mobile communication of domestic and foreign railways,and proposes the priorities for tackling key technological problems of railway 5G private network according to the technica...The paper summarizes the development of mobile communication of domestic and foreign railways,and proposes the priorities for tackling key technological problems of railway 5G private network according to the technical routes of railway next-generation mobile communication determined by China State Railway Group Co.,Ltd.From the aspects of work objectives,principles,technical routes and innovative working methods,the paper elaborates the ideas of railway 5G scientific and technological research,puts forward the contents and plans of scientific and technological research on railway 5G private network,systematically organizes the achievements in the scientific and technological research stage of railway 5G private network,and sets forth the key contents of next-step scientific and technological research.展开更多
A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL...A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.展开更多
文摘The breakthrough of key core technology is a theoretical and practical strategic issue to realize the rise of the country.This paper analyzes the concept of key core technology and its breakthrough and analyzes its characteristics.Based on the perspective of participants,this paper summarizes the influencing factors of key core technology breakthroughs in enterprises:internal and external enterprises,universities and scientific research institutions,and government.This paper expands the relevant research on key core technology breakthroughs and provides inspiration for enterprises to carry out key core technology research and breakthrough practices.
基金supported by grants from the National Key R&D Program of China,No.2017YFC0909200(to DC)the National Natural Science Foundation of China,No.62075225(to HZ)+1 种基金Zhejiang Provincial Medical Health Science and Technology Project,No.2023XY053(to ZP)Zhejiang Provincial Traditional Chinese Medical Science and Technology Project,No.2023ZL703(to ZP).
文摘Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biotechnology and its applications in the field of neuropsychiatry.Available evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin deficit.In vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric diseases.Although the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic applications.However,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical applications.This review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.
文摘The key technology of semi-continuous conveyor system decides the successful using of this system. The key technology includes optimal initial building depth of this system,the crusher moving step and the layout of conveyor system are studied, and their calculating models are built up.
基金Supported by Demonstration and Promotion Project of Shanghai Municipal Committee of Agriculture[HNKT(2015)2-7]Jiangsu Agricultural"Three New Engineering"Project[SXGC(2017)208]Jiangsu Agricultural Science and Technology Innovation Fund[CX(15)1029]~~
文摘In order to develop green good, reduce the use of chemical fertilizer and pesticide, realize "double reduction" and synergism, improve safety and quality of products, protect the ecological environment and promote the healthy and steady development of strawberry industry, the goals and key technology of fertilizer-pesticide "double reduction" and synergism for greenhouse strawberry are summed up in this paper targeting at the current situation of strawberry production and combined with the new technology achievements at home and abroad. The key technology includes six items: healthy seedling cultivating technique, soil improvement and continuous cropping obstacle treatment technique, agricultural ecological prevention tech- nique, physicochemical trap of pest control technique, biological control technique and low residual risk chemical control technique.
基金Supported by the Fund for Independent Innovation of Agricultural Sciences in Jiangsu Province(CX(14)2108&CX(13)5066)~~
文摘A low-power environmental monitoring system based on WSN technology is proposed to effectively monitor the environmental status and ensure the healthy growth of greenhouse crops in the greenhouse. The system performs dynamic mon- itoring on the environmental data of temperature, humidity, illumination, soil tempera- ture and humidity of the greenhouse, and it reduces the energy consumption by us- ing solar energy and lithium battery as the power supply mode and dynamic power management algorithm combined with improved routing protocol. Stable and reliable, the system could effectively monitor the key environmental factors in the green- house, making it of certain promotion value.
文摘To understand the resource features and geology in the deep Jinchuan nickel deposit, difficult geological conditions were systematically analyzed, including high stress, fragmentized ore rock, prevalent deformation, difficult tunnel support, complicated rock mechanics, and low mining recovery. An integrated technology package was built for safe, efficient, and continuous mining in a deep, massive, and complex nickel and cobalt mine. This was done by the invention of a large-area continuous mining method with honeycomb drives; the establishment of ground control theory and a technology package for high-stress and fragmented ore rock: and the development of a new type of backfilling cement material, along with a deep backfilling technology that comprises the pipeline transport of high-density slurry with coarse aggregates. In this way, good solutions to existing problems were found to permit the efficient exploitation and comprehensive utilization of the resources in the deep Jinchuan nickel mine. In addition, a technological demonstration in an underground mine was performed using the cemented undercut-and-fill mining method for stressful, frag- mented, and rheological rock.
基金provided by National Natural Science Foundation of China (No.50678152)Scientific Plan Fund of Shaanxi Province (No.2009K09-24)
文摘Evacuated tube transportation (ETT) will be one of the ultra-large-scale vacuum application areas. This paper lists some key vacuum technology issues in ETT: (1) how to construct ultra-large-scale vacuum chamber with lower cost and high reliability, (2) how to evacuate gas out of the ETT tube in short time, (3) how to release heat or reduce temperature in the vacuum tube, (4) how to avoid vacuum discharge, (5) how to make vehicles with airproof shells and life support system, and (6) how to detect leaks and find leak positions efficiently. At the same time, some solutions are proposed.
基金supported by the State Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications) (Grant No. IPOC2021ZT10)the National Natural Science Foundation of China (Grant No. 11904333)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No. 2019XDA02)BUPT Innovation and Entrepreneurship Support Program (Grant No. 2022-YC-T051)。
文摘Quantum key distribution(QKD) generates information-theoretical secure keys between two parties based on the physical laws of quantum mechanics. The phase-matching(PM) QKD protocol allows the key rate to break the quantum channel secret key capacity limit without quantum repeaters, and the security of the protocol is demonstrated by using equivalent entanglement. In this paper, the wavelength division multiplexing(WDM) technique is applied to the PM-QKD protocol considering the effect of crosstalk noise on the secret key rate. The performance of PM-QKD protocol based on WDM with the influence of adjacent classical channels and Raman scattering is analyzed by numerical simulations to maximize the total secret key rate of the QKD, providing a reference for future implementations of QKD based on WDM techniques.
基金Sponsored by the Project Supported by the National High-Technology R&D Program for CIMS of China (Grant No2006AA04Z165)
文摘A new business management mode-agile & convenient management mode (ACM) was proposed because of large scale mobile computing and mobile business. As an efficient approach to ACM, Mobile ERP (MERP), including its concept and four-tier architecture was introduced firstly. Then, the two key technologies of implementing MERP about message service and wireless WAP service were developed. Meanwhile, an official MERP system was also implemented based on our CERP software system by aglets. And it was applied by Henan Tongli Cement Group in China. In comparison with the traditional ERP system, the new system could improve the efficiency and level of management, and reduce the management cost of enterprise.
文摘Sutong Bridge is a cable-stayed bridge across Yangtze River with the main span of 1 088 m. This article outlines technical challenges,key technology and innovation in the design and construction such as scour protection,lowering steel cofferdam,construction platform establishment,construction and control of pylons,fabrication and damping of long cables,erection and control of steel box girders.
基金supported by the State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications (Grant No. IPOC2021ZT10)the National Natural Science Foundation of China (Grant No. 11904333)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No. 2019XD-A02)BUPT Innovation and Entrepreneurship Support Program (Grant No. 2022YC-T051)。
文摘Quantum key distribution(QKD) generates information-theoretical secret keys between two parties based on the physical laws of quantum mechanics. Following the advancement in quantum communication networks, it becomes feasible and economical to combine QKD with classical optical communication through the same fiber using dense wavelength division multiplexing(DWDM) technology. This study proposes a detailed scheme of TF-QKD protocol with DWDM technology and analyzes its performance, considering the influence of quantum channel number and adjacent quantum crosstalk on the secret key rates. The simulation results show that the scheme further increases the secret key rate of TF-QKD and its variants. Therefore, this scheme provides a method for improving the secret key rate for practical quantum networks.
文摘In recent years,great efforts have been made on the geoparks’ application and construction,but there is a shortage of research on the theories and methodologies of geoheritage investigation and assessment. Based on the summaries of having finished geoheritage investtigation and assessment and geopark construction projects,some key technologic methods analyzed in this paper are as follows:(1)
基金Supported by the National Hi-tech Research and Development Program of China(2007AA04Z415)the Hunan Province and Xiangtan City Natural Science Joint Foundation(09JJ8005)the Torch Program Project of Hunan Province(2008SH044)
文摘An integrated monitoring system for running parameters of key mining equipmenton the basis of condition monitoring technology and modern communication networktechnology was developed.The system consists of a client computer with functions ofsignal acquisition and processing, and a host computer in the central control room.Thesignal acquisition module of the client computer can collect the running parameters fromvarious monitoring terminals in real-time.The DSP high-speed data processing system ofthe main control module can quickly achieve the numerical calculation for the collectedsignal.The signal modulation and signal demodulation are completed by the frequencyshift keying circuit and phase-locked loop frequency circuit, respectively.Finally, the signalis sent to the host computer for logic estimation and diagnostic analysis using the networkcommunication technology, which is helpful for technicians and managers to control therunning state of equipment.
基金This project is supported by Provincial Science & Technology Projoct of Heilongjiang, China (No. GB05A501).
文摘Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control (CNC) system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical control (HITCNC), is researched and manufactured based on the interface standards. The system's external interfaces are coincident with the corresponding international standards, and the internal interfaces follow the open modular architecture controller (OMAC) agreement. In the research and manufacturing process, object-oriented technology is used to ensure the openness of the HITCNC, and static programming is applied in the CNC system according to the idea of modularization disassembly. The HITCNC also actualizes real-time and unreal-time modules adopting real-time dynamical linked library (RTDLL) and component object model (COM). Finite state ma- chine (FSM) is adopted to do dynamically modeling of HITCNC. The complete separation between the software and the hardware is achieved in the HITCNC by applying the SoftSERCANS technique. The application of the above key techniques decreases the programming workload greatly, and uses software programs replacing hardware functions, which offers plenty technique ensures for the openness of HITCNC. Finally, based on the HITCNC, a three-dimensional milling system is established. On the system, series experiments are done to validate the expandability and interchangeability of HITCNC. The results of the experiments show that the established open architecture CNC system HITCNC is correct and feasible, and has good openness.
文摘The forestry is the main department of the national economy. During forty years development of the forestry , it has made a lot of contribution for the national economic construction and society development. However, paying more attention to the logging than to the silviculture for a long time lead that the felling amount has been more than the growth in volume of forest. And the forest resources have much decreased. The forestry is now faced to many difficulties. The forestry problems should be tackled by relying on the progress of science and technology. The achievements of science and technology should be first spread in forest zone. And the second task is that the step of the progress of science and technology in forestry enterprises should be quicken. In order to raise the economic benefits of forestry enterprises. The key problems of science and technology in forestry should be tackled by cooperation. Raising, the level of forestry science and technology and enlarging the international exchange are the other important aspect of vigorously developing the forestry.
文摘On October 14, two satellites SJ-9A/B were sent into their preset orbits by a LM-2C/SMA launch vehicle, which is the first flight of a series of China's civilian technology experimental satellites. SJ-9A and B are the first two satellites in the series of civilian technology experimental satellites designed for tests such as long lifetime and high reliability, high precision and high performance of satellite, domestically developed core components, satellite formation
基金Project supported by the Key Projects in the Guangzhou Science & Technology Pillar Program of China(Grant No.2008Z1-D501)the Guangdong Key Technologies Research & Development Program of China(Grant No.2007B010400009)+1 种基金the Guangdong Polytechnic Institute Scientific Research Fund,China(Grant No.0901)the Key Laboratory Program of Quantum Information of Chinese Academy of Sciences
文摘Three clock synchronization schemes for a quantum key distribution system are compared experimentally through the outdoor fibre and the interaction physical model of the the clock signal and the the quantum signal in the quantum key distribution system is analysed to propose a new synchronization scheme based on time division multiplexing and wavelength division multiplexing technology to reduce quantum bits error rates under some transmission rate conditions, The proposed synchronization scheme can not only completely eliminate noise photons from the bright background light of the the clock signal, but also suppress the fibre nonlinear crosstalk.
文摘The paper summarizes the development of mobile communication of domestic and foreign railways,and proposes the priorities for tackling key technological problems of railway 5G private network according to the technical routes of railway next-generation mobile communication determined by China State Railway Group Co.,Ltd.From the aspects of work objectives,principles,technical routes and innovative working methods,the paper elaborates the ideas of railway 5G scientific and technological research,puts forward the contents and plans of scientific and technological research on railway 5G private network,systematically organizes the achievements in the scientific and technological research stage of railway 5G private network,and sets forth the key contents of next-step scientific and technological research.
基金supported by the National Natural Science Foundation of China under Grant 62034002 and 62374026.
文摘A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.