Silicon neutron transmutation doping remains one of the most viable nuclear applications for research reactors.Providing this kind of product involves an irradiation method capable of fulfilling the quality requiremen...Silicon neutron transmutation doping remains one of the most viable nuclear applications for research reactors.Providing this kind of product involves an irradiation method capable of fulfilling the quality requirements of doping and alleviating the challenges related to the design and safety of the irradiation device.In this paper,we propose an irradiation device prototype for neutron transmutation doping of silicon ingots with diameters of 2 to 3 in.based on the Es-Salam research reactor.The thermal hydraulic analysis of the proposed irradiation device was performed to determine the optimum conditions for cooling.The effect of the mechanical vibrations induced by the circulation of coolant in the device was quantified via experimental measurements under different flow rates.The results show that the maximum temperature reached by the silicon ingots is below the temperature limit,effectively validating the design of the irradiation device.Other investigations are prospected to further optimize the design and the irradiation conditions.The irradiation of silicon ingots with a large diameter will be considered.展开更多
A series of events relating to inferior medical devices has brought about changes in the legal requirements regarding quality control on the part of regulators. Apart from clinical studies, register and routine data w...A series of events relating to inferior medical devices has brought about changes in the legal requirements regarding quality control on the part of regulators. Apart from clinical studies, register and routine data will play an essential role in this context. To ensure adequate use of these data, adapted methodologies are required as register data in fact represent a new scientific entity. For the interpretation of register and routine data several limitations of published data should be taken into account. In many cases essential parameters of study cohorts- such as age, comorbidities, the patients' risk profiles or the hospital profile- are not presented. Required data and evaluation procedures differ significantly, for example, between hip and spine implants. A "one fits for all" methodology is quite unlikely to exist and vigorous efforts will be required to develop suitable standards in the next future. The new legislation will affect all high-risk products, besides joint implants also contact lenses, cardiac pacemakers or stents, for example, the new regulations can markedly enhance product quality monitoring. Register data and clinical studies should not be considered as competitors, they complement each other when used responsibly. In the future follow-up studies should increasingly focus on specific questions, while global follow-up investigations regarding product complication rates and surgical methods will increasingly be covered by registers.展开更多
750 kV substation of Riyue Mountain, Qinghai is a substation that annual average thunderstorm days are the maximum at the same volt- age level and altitude in the wodd. We detailedly described testing methods and step...750 kV substation of Riyue Mountain, Qinghai is a substation that annual average thunderstorm days are the maximum at the same volt- age level and altitude in the wodd. We detailedly described testing methods and steps of 6 characteristic parameters for grounding device of 750 kV substation by using 8000S comprehensive test system, and scientifically judged overall performance of the grounding device. Moreover, we espe- cially emphasized key and difficult points in testing process, providing reference for the majority of grounding test workers.展开更多
Device physics research for submicron and deep submicron space microelectronics devices and integrated circuits will be described in three topics.1.Thin film submicron and deep submicron SOS / CMOS devices and integra...Device physics research for submicron and deep submicron space microelectronics devices and integrated circuits will be described in three topics.1.Thin film submicron and deep submicron SOS / CMOS devices and integrated circuits.2.Deep submicron LDD CMOS devices and integrated circuits.3.C band and Ku band microwave GaAs MESFET and III-V compound hetrojunction HEM T and HBT devices and integrated circuits.展开更多
Ferroelectric materials have many interesting physical properties such as ferroelectricity, pyroelectricity, piezoelectricity, and opto-electricity, and applying ferroelectric materials in the forms of thin and thick ...Ferroelectric materials have many interesting physical properties such as ferroelectricity, pyroelectricity, piezoelectricity, and opto-electricity, and applying ferroelectric materials in the forms of thin and thick films and integrating them on the silicon substrate as electronic and MEMS devices is a very attractive research area and challenging. In this paper, we report our research works on ferroelectric MEMS and ferroelectric films for electronic device applications. Pyroelectric thin film infrared sensors have been made, characterized, and a 32×32 array with its size of 1cm×1cm has been obtained on Si membrane. Ferroelectric thin films in amorphous phase have been applied to make silicon based hydrogen gas sensors with the metal/amorphous ferroelectric film/metal device structure, and its turn-on voltage of about 4.5V at ～1000 ppm in air is about 7 times of the best value reported in the literature. For the application of electron emission flat panel display, ferroelectric BST thin films with excess Ti concentrations have been coated on Si tips, the threshold voltage of those ferroelectric film coated tips has been reduced about one order from ～70 V/μm to 4～10 V/μm for different Ti concentrations, and however, the electron emission current density has been increased at least 3～4 order for those coated tips compared to that of the bare Si tips. To fulfill in the thickness gap between thin film of typical ～1 μm made by PVD/CVD and polished ceramic wafer of ～50 μm from the bulk, piezoelectric films with thickness in a range of 1～30 μm have been successfully deposited on Si substrate at a low temperature of 650oC by a novel hybridized deposition technique, and piezoelectric MEMS ultrasonic arrays have been very recently obtained with the sound pressure level up to ～120 dB. More detailed results will be presented and mechanisms will be discussed.展开更多
Users, especially the non-expert users, commonly experience problems when connecting multiple devices with interoperability. While studies on multiple device connections are mostly concentrated on spontaneous device a...Users, especially the non-expert users, commonly experience problems when connecting multiple devices with interoperability. While studies on multiple device connections are mostly concentrated on spontaneous device association techniques with a focus on security aspects, the research on user interaction for device connection is still limited. More research into understanding people is needed for designers to devise usable techniques. This research applies the Research-through-Design method and studies the non-expert users＇ interactions in establishing wireless connections between devices. The ＂Learning from Examples＂ concept is adopted to develop a study focus line by learning from the expert users＇ interaction with devices. This focus line is then used for guiding researchers to explore the non-expert users＇ difficulties at each stage of the focus line. Finally, the Research-through-Design approach is used to understand the users＇ difficulties, gain insights to design problems and suggest usable solutions. When connecting a device, the user is required to manage not only the device＇s functionality but also the interaction between devices. Based on learning from failures, an important insight is found that the existing design approach to improve single-device interaction issues, such as improvements to graphical user interfaces or computer guidance, cannot help users to handle problems between multiple devices. This study finally proposes a desirable user-device interaction in which images of two devices function together with a system image to provide the user with feedback on the status of the connection, which allows them to infer any required actions.展开更多
[Objective] To design a safety device set for fishing vessel net hauler, in order to reduce the severe potential safety hazards in offshore operation. [Method] In view of the operation and structure of net hauler on t...[Objective] To design a safety device set for fishing vessel net hauler, in order to reduce the severe potential safety hazards in offshore operation. [Method] In view of the operation and structure of net hauler on the fishing trawler, this paper investigated the existing safety protection devices and designed a new set of purely mechanical structure without changing the original structures of the vessel significantly. [Result] Using the easily-adjustable functions of the main shaft of CNC lathe, and simulating the operation performance of different hauling line speeds and testing the safety device, the results showed that the new device could protect the crew from safety accidents caused by net hauler. [Conclusion] The result provides references for the design and application of mechanical protection devices for net haulers on other fishing trawlers.展开更多
The clearance of the hemisphere dynamic pressure motor is small and difficult to measure, the measurement method of micro clearance is studied. The shortcomings of the original measurement method are analyzed, and a c...The clearance of the hemisphere dynamic pressure motor is small and difficult to measure, the measurement method of micro clearance is studied. The shortcomings of the original measurement method are analyzed, and a clearance measuring device for the hemisphere dynamic pressure motor is designed, which improves the measurement efficiency and stability.展开更多
Since 1990,China has made considerable progress in resolving the problem of“treatment difficulty”of cardiovascular diseases(CVD).The prevalent unhealthy lifestyle among Chinese residents has exposed a massive propor...Since 1990,China has made considerable progress in resolving the problem of“treatment difficulty”of cardiovascular diseases(CVD).The prevalent unhealthy lifestyle among Chinese residents has exposed a massive proportion of the population to CVD risk factors,and this situation is further worsened due to the accelerated aging population in China.CVD remains one of the greatest threats to the health of Chinese residents.In terms of the proportions of disease mortality among urban and rural residents in China,CVD has persistently ranked first.In 2021,CVD accounted for 48.98%and 47.35%of deaths in rural and urban areas,respectively.Two out of every five deaths can be attributed to CVD.To implement a national policy“focusing on the primary health institute and emphasizing prevention”and truly achieve a shift of CVD prevention and treatment from hospitals to communities,the National Center for Cardiovascular Diseases has organized experts from relevant fields across China to compile the“Report on Cardiovascular Health and Diseases in China”annually since 2005.The 2024 report is established based on representative,published,and high-quality big-data research results from cross-sectional and cohort population epidemiological surveys,randomized controlled clinical trials,large sample registry studies,and typical community prevention and treatment cases,along with data from some projects undertaken by the National Center for Cardiovascular Diseases.These firsthand data not only enrich the content of the current report but also provide a more timely and comprehensive reflection of the status of CVD prevention and treatment in China.展开更多
基金supported by the Nuclear Research Centre of Birine of Algerian Atomic Energy Commission.
文摘Silicon neutron transmutation doping remains one of the most viable nuclear applications for research reactors.Providing this kind of product involves an irradiation method capable of fulfilling the quality requirements of doping and alleviating the challenges related to the design and safety of the irradiation device.In this paper,we propose an irradiation device prototype for neutron transmutation doping of silicon ingots with diameters of 2 to 3 in.based on the Es-Salam research reactor.The thermal hydraulic analysis of the proposed irradiation device was performed to determine the optimum conditions for cooling.The effect of the mechanical vibrations induced by the circulation of coolant in the device was quantified via experimental measurements under different flow rates.The results show that the maximum temperature reached by the silicon ingots is below the temperature limit,effectively validating the design of the irradiation device.Other investigations are prospected to further optimize the design and the irradiation conditions.The irradiation of silicon ingots with a large diameter will be considered.
文摘A series of events relating to inferior medical devices has brought about changes in the legal requirements regarding quality control on the part of regulators. Apart from clinical studies, register and routine data will play an essential role in this context. To ensure adequate use of these data, adapted methodologies are required as register data in fact represent a new scientific entity. For the interpretation of register and routine data several limitations of published data should be taken into account. In many cases essential parameters of study cohorts- such as age, comorbidities, the patients' risk profiles or the hospital profile- are not presented. Required data and evaluation procedures differ significantly, for example, between hip and spine implants. A "one fits for all" methodology is quite unlikely to exist and vigorous efforts will be required to develop suitable standards in the next future. The new legislation will affect all high-risk products, besides joint implants also contact lenses, cardiac pacemakers or stents, for example, the new regulations can markedly enhance product quality monitoring. Register data and clinical studies should not be considered as competitors, they complement each other when used responsibly. In the future follow-up studies should increasingly focus on specific questions, while global follow-up investigations regarding product complication rates and surgical methods will increasingly be covered by registers.
文摘750 kV substation of Riyue Mountain, Qinghai is a substation that annual average thunderstorm days are the maximum at the same volt- age level and altitude in the wodd. We detailedly described testing methods and steps of 6 characteristic parameters for grounding device of 750 kV substation by using 8000S comprehensive test system, and scientifically judged overall performance of the grounding device. Moreover, we espe- cially emphasized key and difficult points in testing process, providing reference for the majority of grounding test workers.
文摘Device physics research for submicron and deep submicron space microelectronics devices and integrated circuits will be described in three topics.1.Thin film submicron and deep submicron SOS / CMOS devices and integrated circuits.2.Deep submicron LDD CMOS devices and integrated circuits.3.C band and Ku band microwave GaAs MESFET and III-V compound hetrojunction HEM T and HBT devices and integrated circuits.
文摘Ferroelectric materials have many interesting physical properties such as ferroelectricity, pyroelectricity, piezoelectricity, and opto-electricity, and applying ferroelectric materials in the forms of thin and thick films and integrating them on the silicon substrate as electronic and MEMS devices is a very attractive research area and challenging. In this paper, we report our research works on ferroelectric MEMS and ferroelectric films for electronic device applications. Pyroelectric thin film infrared sensors have been made, characterized, and a 32×32 array with its size of 1cm×1cm has been obtained on Si membrane. Ferroelectric thin films in amorphous phase have been applied to make silicon based hydrogen gas sensors with the metal/amorphous ferroelectric film/metal device structure, and its turn-on voltage of about 4.5V at ～1000 ppm in air is about 7 times of the best value reported in the literature. For the application of electron emission flat panel display, ferroelectric BST thin films with excess Ti concentrations have been coated on Si tips, the threshold voltage of those ferroelectric film coated tips has been reduced about one order from ～70 V/μm to 4～10 V/μm for different Ti concentrations, and however, the electron emission current density has been increased at least 3～4 order for those coated tips compared to that of the bare Si tips. To fulfill in the thickness gap between thin film of typical ～1 μm made by PVD/CVD and polished ceramic wafer of ～50 μm from the bulk, piezoelectric films with thickness in a range of 1～30 μm have been successfully deposited on Si substrate at a low temperature of 650oC by a novel hybridized deposition technique, and piezoelectric MEMS ultrasonic arrays have been very recently obtained with the sound pressure level up to ～120 dB. More detailed results will be presented and mechanisms will be discussed.
文摘Users, especially the non-expert users, commonly experience problems when connecting multiple devices with interoperability. While studies on multiple device connections are mostly concentrated on spontaneous device association techniques with a focus on security aspects, the research on user interaction for device connection is still limited. More research into understanding people is needed for designers to devise usable techniques. This research applies the Research-through-Design method and studies the non-expert users＇ interactions in establishing wireless connections between devices. The ＂Learning from Examples＂ concept is adopted to develop a study focus line by learning from the expert users＇ interaction with devices. This focus line is then used for guiding researchers to explore the non-expert users＇ difficulties at each stage of the focus line. Finally, the Research-through-Design approach is used to understand the users＇ difficulties, gain insights to design problems and suggest usable solutions. When connecting a device, the user is required to manage not only the device＇s functionality but also the interaction between devices. Based on learning from failures, an important insight is found that the existing design approach to improve single-device interaction issues, such as improvements to graphical user interfaces or computer guidance, cannot help users to handle problems between multiple devices. This study finally proposes a desirable user-device interaction in which images of two devices function together with a system image to provide the user with feedback on the status of the connection, which allows them to infer any required actions.
基金Supported by Zhoushan Scientific and Technological Plan Program "Exploration of Net Hauler Safety Device for Fishing Trawler"(2016C32021)
文摘[Objective] To design a safety device set for fishing vessel net hauler, in order to reduce the severe potential safety hazards in offshore operation. [Method] In view of the operation and structure of net hauler on the fishing trawler, this paper investigated the existing safety protection devices and designed a new set of purely mechanical structure without changing the original structures of the vessel significantly. [Result] Using the easily-adjustable functions of the main shaft of CNC lathe, and simulating the operation performance of different hauling line speeds and testing the safety device, the results showed that the new device could protect the crew from safety accidents caused by net hauler. [Conclusion] The result provides references for the design and application of mechanical protection devices for net haulers on other fishing trawlers.
文摘The clearance of the hemisphere dynamic pressure motor is small and difficult to measure, the measurement method of micro clearance is studied. The shortcomings of the original measurement method are analyzed, and a clearance measuring device for the hemisphere dynamic pressure motor is designed, which improves the measurement efficiency and stability.
文摘Since 1990,China has made considerable progress in resolving the problem of“treatment difficulty”of cardiovascular diseases(CVD).The prevalent unhealthy lifestyle among Chinese residents has exposed a massive proportion of the population to CVD risk factors,and this situation is further worsened due to the accelerated aging population in China.CVD remains one of the greatest threats to the health of Chinese residents.In terms of the proportions of disease mortality among urban and rural residents in China,CVD has persistently ranked first.In 2021,CVD accounted for 48.98%and 47.35%of deaths in rural and urban areas,respectively.Two out of every five deaths can be attributed to CVD.To implement a national policy“focusing on the primary health institute and emphasizing prevention”and truly achieve a shift of CVD prevention and treatment from hospitals to communities,the National Center for Cardiovascular Diseases has organized experts from relevant fields across China to compile the“Report on Cardiovascular Health and Diseases in China”annually since 2005.The 2024 report is established based on representative,published,and high-quality big-data research results from cross-sectional and cohort population epidemiological surveys,randomized controlled clinical trials,large sample registry studies,and typical community prevention and treatment cases,along with data from some projects undertaken by the National Center for Cardiovascular Diseases.These firsthand data not only enrich the content of the current report but also provide a more timely and comprehensive reflection of the status of CVD prevention and treatment in China.
