In conjunction with the working characteristics of the high-clearance wheeled sprayer and the benefits of the closed hydraulic system,a series of reasonable working parameters should be established,and a hydraulic sys...In conjunction with the working characteristics of the high-clearance wheeled sprayer and the benefits of the closed hydraulic system,a series of reasonable working parameters should be established,and a hydraulic system that fulfills the requisite specifications should be designed.The AMESim software model is employed to construct a closed hydraulic transmission system,and the simulation analysis is then performed according to the data of hydraulic components.According to analysis results,the prototype can be optimized and upgraded,and a verification test is further carried out.The test results demonstrate that the designed closed hydraulic transmission system meets the actual working requirements of the high-clearance wheeled sprayer and provides a stable experimental platform for intelligent control of agricultural machinery.展开更多
In view of the imbalanced distribution of power load and resources, including the status of “electric shortage” in some cities in our country, the article discusses the long-distance transmission technology. It main...In view of the imbalanced distribution of power load and resources, including the status of “electric shortage” in some cities in our country, the article discusses the long-distance transmission technology. It mainly analyzed two ways of the long-distance transmission: UHV AC transmission and UHV DC transmission. The fractional frequency transmission technology and half wavelength AC transmission technology of AC transmission are introduced. Some key technologies of long-distance transmission are described. It has a guess for long-distance transmission future direction.展开更多
Objective To investigate the relationship between maternal peripheral blood mononuclear cells (PBMC) hepatitis B virus(HBV) covalenty closed circular deoxyribonucleic acid(cccDNA) and other HBV serological markers and...Objective To investigate the relationship between maternal peripheral blood mononuclear cells (PBMC) hepatitis B virus(HBV) covalenty closed circular deoxyribonucleic acid(cccDNA) and other HBV serological markers and its effects on HBV intrauterine transmission. Methods We enrolled 290 newborns and their hepatitis B surface antigen(HBsAg) positive mothers. HBV cccDNA in PBMC and HBV DNA in serum were detected by a real‐time PCR‐TaqM an probe while HBV serological markers were detected with an electrochemiluminescence immunoassay. Results There was a positive correlation between the levels of PBMC HBV cccD NA and serum HBV DNA and HBeA g(r = 0.436 and 0.403, P < 0.001). The detection rate of pattern A [‘HBsA g(+), HBeA g(+), and anti‐HBc(+)’] was significantly higher in the PBMC HBV cccD NA positive group than in the control group(χ^2 = 48.48, P < 0.001). There was a significant association between HBV intrauterine transmission and PBMC HBV cccD NA(χ^2 = 9.28, P = 0.002). In the presence of serum HBV DNA, HBeA g, and PBMC HBV cccD NA, the risk of HBV intrauterine transmission was three times higher(OR = 3.69, 95% CI: 1.30‐10.42) than that observed in their absence. The risk of HBV intrauterine transmission was the greatest(OR = 5.89, 95% CI: 2.35‐14.72) when both PBMC HBV cccD NA and pattern A were present. A Bayesian network model showed that maternal PBMC HBV cccD NA was directly related to HBV intrauterine transmission. Conclusion PBMC HBV cccDNA may be a direct risk factor for HBV intrauterine transmission. Our study suggests that serological markers could be combined with PBMC‐related markers in prenatal testing.展开更多
The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, ...The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, it would be necessary to establish a system of information management for the pipeline. The monitoring, calculating and analyzing functions of the system serve to give controlling instructions and safe operating rules to the automatic equipment and technician, making sure the resistance coefficient distribution along the pipeline is reasonable; the hydraulic state transition is smooth when operating conditions change or water supply accidents occur, avoiding the damage of water hammer. This paper covered the composition structures of the information management system of long-distance water transmission pipelines and the functions of the subsystems, and finally elaborated on the approaches and steps of building a mathematics model for the analysis of dynamic hydraulic status.展开更多
Excess wind power produced in wind-inten- sive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has ga...Excess wind power produced in wind-inten- sive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has gained popularity, and local energy consumption, in which a fraction of the generated wind power can be locally consumed by energy-intensive industries. First, the challenges and solutions to the long-distance transmission and local consumption of wind power are presented. Then, the two approaches to the utilization of wind power are compared in terms of system security, reliability, cost, and capability to utilize wind energy. Finally, the economic feasibility and technical feasibility of the local consumption of wind power are demonstrated by a large and isolated industrial power system, or supermicrogrid, in China. The coal-fired generators together with the shortterm interruptible electrolytic aluminum load in the supermicrogrid are able to compensate for the intermit- tency of wind power. In the long term, the transfer of high- energy-consumption industries to wind-rich areas and their local consumption of the available wind power are beneficial.展开更多
We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division mul...We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication.展开更多
随着航空航天技术的快速发展,封闭腔体内的无线能量传输(Wireless Power Transmission,WPT)技术开始受到广泛关注.基于频率控制的WPT技术,可实现对电大封闭腔体(103×λ3)内的多方位传感器进行可控和高效的无线充电.电大腔体内的电...随着航空航天技术的快速发展,封闭腔体内的无线能量传输(Wireless Power Transmission,WPT)技术开始受到广泛关注.基于频率控制的WPT技术,可实现对电大封闭腔体(103×λ3)内的多方位传感器进行可控和高效的无线充电.电大腔体内的电场分布对频率的变化敏感,利用频率变化实现对封闭腔体场分布控制.实验结果表明,在S波段的1 m3腔体最高WPT传输效率为96.6%.设计的宽带整流电路实测整流效率最高为80%,整流效率高于50%的带宽为1.65 GHz.在2.401~2.495 GHz频段实现控制双接收机的不同工作状态,展现其在航空航天器等封闭空间中为传感器无线供电的应用前景.展开更多
Images and videos provide a wealth of information for people in production and life.Although most digital information is transmitted via optical fiber,the image acquisition and transmission processes still rely heavil...Images and videos provide a wealth of information for people in production and life.Although most digital information is transmitted via optical fiber,the image acquisition and transmission processes still rely heavily on electronic circuits.The development of all-optical transmission networks and optical computing frameworks has pointed to the direction for the next generation of data transmission and information processing.Here,we propose a high-speed,low-cost,multiplexed parallel and one-piece all-fiber architecture for image acquisition,encoding,and transmission,called the Multicore Fiber Acquisition and Transmission Image System(MFAT).Based on different spatial and modal channels of the multicore fiber,fiber-coupled self-encoding,and digital aperture decoding technology,scenes can be observed directly from up to 1 km away.The expansion of capacity provides the possibility of parallel coded transmission of multimodal high-quality data.MFAT requires no additional signal transmitting and receiving equipment.The all-fiber processing saves the time traditionally spent on signal conversion and image pre-processing(compression,encoding,and modulation).Additionally,it provides an effective solution for 2D information acquisition and transmission tasks in extreme environments such as high temperatures and electromagnetic interference.展开更多
基金Supported by 2023 Xinjiang Uygur Autonomous Region R&D and Promotion and Application of Key Technologies of CNC Sprayer for Seed Corn(2023NC010).
文摘In conjunction with the working characteristics of the high-clearance wheeled sprayer and the benefits of the closed hydraulic system,a series of reasonable working parameters should be established,and a hydraulic system that fulfills the requisite specifications should be designed.The AMESim software model is employed to construct a closed hydraulic transmission system,and the simulation analysis is then performed according to the data of hydraulic components.According to analysis results,the prototype can be optimized and upgraded,and a verification test is further carried out.The test results demonstrate that the designed closed hydraulic transmission system meets the actual working requirements of the high-clearance wheeled sprayer and provides a stable experimental platform for intelligent control of agricultural machinery.
文摘In view of the imbalanced distribution of power load and resources, including the status of “electric shortage” in some cities in our country, the article discusses the long-distance transmission technology. It mainly analyzed two ways of the long-distance transmission: UHV AC transmission and UHV DC transmission. The fractional frequency transmission technology and half wavelength AC transmission technology of AC transmission are introduced. Some key technologies of long-distance transmission are described. It has a guess for long-distance transmission future direction.
基金supported by grants from the National Natural Science Foundation of China [81573212,81872677]Open Project Support by the State Key Laboratory of Infectious Disease Prevention and Control [2017SKLID306,2018SKLID310]
文摘Objective To investigate the relationship between maternal peripheral blood mononuclear cells (PBMC) hepatitis B virus(HBV) covalenty closed circular deoxyribonucleic acid(cccDNA) and other HBV serological markers and its effects on HBV intrauterine transmission. Methods We enrolled 290 newborns and their hepatitis B surface antigen(HBsAg) positive mothers. HBV cccDNA in PBMC and HBV DNA in serum were detected by a real‐time PCR‐TaqM an probe while HBV serological markers were detected with an electrochemiluminescence immunoassay. Results There was a positive correlation between the levels of PBMC HBV cccD NA and serum HBV DNA and HBeA g(r = 0.436 and 0.403, P < 0.001). The detection rate of pattern A [‘HBsA g(+), HBeA g(+), and anti‐HBc(+)’] was significantly higher in the PBMC HBV cccD NA positive group than in the control group(χ^2 = 48.48, P < 0.001). There was a significant association between HBV intrauterine transmission and PBMC HBV cccD NA(χ^2 = 9.28, P = 0.002). In the presence of serum HBV DNA, HBeA g, and PBMC HBV cccD NA, the risk of HBV intrauterine transmission was three times higher(OR = 3.69, 95% CI: 1.30‐10.42) than that observed in their absence. The risk of HBV intrauterine transmission was the greatest(OR = 5.89, 95% CI: 2.35‐14.72) when both PBMC HBV cccD NA and pattern A were present. A Bayesian network model showed that maternal PBMC HBV cccD NA was directly related to HBV intrauterine transmission. Conclusion PBMC HBV cccDNA may be a direct risk factor for HBV intrauterine transmission. Our study suggests that serological markers could be combined with PBMC‐related markers in prenatal testing.
基金Hi-Tech Research and Development Program of China (863 Program)(2002AA601140)
文摘The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, it would be necessary to establish a system of information management for the pipeline. The monitoring, calculating and analyzing functions of the system serve to give controlling instructions and safe operating rules to the automatic equipment and technician, making sure the resistance coefficient distribution along the pipeline is reasonable; the hydraulic state transition is smooth when operating conditions change or water supply accidents occur, avoiding the damage of water hammer. This paper covered the composition structures of the information management system of long-distance water transmission pipelines and the functions of the subsystems, and finally elaborated on the approaches and steps of building a mathematics model for the analysis of dynamic hydraulic status.
基金This work was supported in part by the Ministry of Science and Technology of China （Grant No. 2016YFB0900105） and the National Natural Science Foundation of China （Grant Nos. 51190105 and 51477122）.
文摘Excess wind power produced in wind-inten- sive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has gained popularity, and local energy consumption, in which a fraction of the generated wind power can be locally consumed by energy-intensive industries. First, the challenges and solutions to the long-distance transmission and local consumption of wind power are presented. Then, the two approaches to the utilization of wind power are compared in terms of system security, reliability, cost, and capability to utilize wind energy. Finally, the economic feasibility and technical feasibility of the local consumption of wind power are demonstrated by a large and isolated industrial power system, or supermicrogrid, in China. The coal-fired generators together with the shortterm interruptible electrolytic aluminum load in the supermicrogrid are able to compensate for the intermit- tency of wind power. In the long term, the transfer of high- energy-consumption industries to wind-rich areas and their local consumption of the available wind power are beneficial.
基金supported by the National Key R&D Program of China(No.2018YFB1800905)the National Natural Science Foundation of China(Nos.61935005,61720106015,61835002,and 62127802)。
文摘We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication.
基金financial supports from the National Key R&D Program of China (2021YFA1401103)the National Natural Science Foundation of China (61925502 and 51772145)
文摘Images and videos provide a wealth of information for people in production and life.Although most digital information is transmitted via optical fiber,the image acquisition and transmission processes still rely heavily on electronic circuits.The development of all-optical transmission networks and optical computing frameworks has pointed to the direction for the next generation of data transmission and information processing.Here,we propose a high-speed,low-cost,multiplexed parallel and one-piece all-fiber architecture for image acquisition,encoding,and transmission,called the Multicore Fiber Acquisition and Transmission Image System(MFAT).Based on different spatial and modal channels of the multicore fiber,fiber-coupled self-encoding,and digital aperture decoding technology,scenes can be observed directly from up to 1 km away.The expansion of capacity provides the possibility of parallel coded transmission of multimodal high-quality data.MFAT requires no additional signal transmitting and receiving equipment.The all-fiber processing saves the time traditionally spent on signal conversion and image pre-processing(compression,encoding,and modulation).Additionally,it provides an effective solution for 2D information acquisition and transmission tasks in extreme environments such as high temperatures and electromagnetic interference.
