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Controlled flight of a self-powered micro blimp driven by insect-sized flapping-wing thrusters

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Chinese journal of Aeronautics 2024年第6期37卷 127-136页

作者： Xian YU Zhiwei LIU Jiaming LENG Mingjing QI Xiaojun YAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100191China National Key Laboratory of science and technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijng 100191China beijing Key Laboratory of Aero-Engine Structure and Strength Beihang UniversityBeijing 100191China

Micro aerial platforms face significant challenges in achieving long controlled endurance as most of the energy is consumed to overcome the weight of the *** this study,we present a controllable micro blimp that addresses this issue through the use of a helium-filled *** micro blimp has a long axis of 23 cm and is propelled by four insect-sized flapping-wing thrusters,each weighing 80 mg and with a wingspan of 3.5 *** distributed thrusters enable controlled motions and provide the micro blimp with an advantage in flight endurance compared to multirotors or flapping-wing micro aerial vehicles at the same size *** enhance the performance of the controlled flight,we propose a wireless control module that enables manipulation from a distance of up to 100 ***,a smartphone application is developed to send instructions to the circuit board,allowing the blimp to turn left and right,ascend and descend,and achieve a combination of these movements *** findings demonstrate that this micro blimp is one of the smallest controlled self-powered micro blimps to date.

关键词： Microairvehicle Aircraft control Self-powered micro blimp Flapping-wing thruster Wireless flight

Emergency management capacity assessment for urban rail transit-an example of beijing Metro Line 13

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Transportation Safety and Environment 2024年第1期6卷 109-115页

作者： Jiao Liu Yun Qi Wei Wang School of Emergency Management and Safety Engineering China University of Mining&Technology(Beijing)Beijing 100083China China Safety science journal editorial Department China Occupational Safety and Health AssociationBeijing 100011China College of mechanical engineering and automation Liaoning University of TechnologyJinzhou 121001LiaoningChina

In order to improve the emergency management capability of urban rail transit system and reduce accidents during metro operation,an emergency management capability evaluation method combining analytic hierarchy process(AHP)and technique for order preference by similarity to ideal solution(TOPSIS)is *** on the Prevention Preparation Response Recovery(PPRR)model,factors influencing the emergency management capability of the urban rail transit system are summarized from the perspective of‘human,machine,environment and management’.Then,an emergency management capability evaluation index system containing of 20 secondary indicators is constructed in four stages:emergency prevention,emergency preparation,emergency response and emergency *** weights of indicators are calculated using the AHP method,and the closeness of each indicator to the optimal solution is analysed with the TOPSIS ***,take the beijing Metro Line 13 as an example to investigate the level of emergency management capability of urban rail *** results show that the emergency management capability of beijing’s urban rail transit system is‘well’,among which hazard prevention measures(0.31)and emergency response team(0.34)have a greater weight on the emergency management capability of rail *** model can more accurately assess the emergency management capability of urban rail transit and provide a basis for emergency management.

关键词： urban rail transit emergency management capability analytic hierarchy process(AHP) technique for order preference by similarity to ideal solution(TOPSIS) prevention preparation response recovery(PPRR)model

editorial A Scholar of Dignity:Remembering Peter

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IEEE/CAA journal of Automatica Sinica 2024年第9期11卷 1895-1897页

作者： Fei-Yue Wang Macao university of science and technology Macao 999078China beijing Engineering Research Center of Intelligent Systems and technology Chinese Academy of SciencesBeijing 100190China State Key Laboratory for Management and Control of Complex Systems Chinese Academy of SciencesBeijing 100190China

It was a shock and disbelief to learn of Peter's death last *** me,he was so fit in his figure,so healthy in his lifestyle,so mild and mindful in his social behavior,and so devout in his religious belief,......,I had ... 详细信息

关键词： religious Scholar belief

Launch of the transdisciplinary health science journal hLife

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Biosafety and Health 2024年第1期6卷 1-2页

作者： Qun Yan Kieran Gary Thow editorial office of hLife Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China The university of Chinese Academy of sciences Beijing 101408China

The launch ceremony of the health science journal hLife was held at the Institute of Microbiology,Chinese Academy of sciences(CAS)on 15 November *** 100 guests attended the event,including the editors-in-chief of hLife and editorial board members,representatives from sister journals,regulatory agency leaders,and leaders of the Institute of Microbiology,CAs,and other related departments(Fig.1).

关键词： journal editorial sister

Numerical Study on Heat Transfer and Frictional Resistance of Two Types of Molten Salts in Straight Channels and Supercritical Carbon Dioxide in Airfoil Channels

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journal of Thermal science 2024年第4期33卷 1443-1457页

作者： WANG Yanquan LU Yuanwei GAO Qi LI Feng MA Yancheng WANG Yuanyuan WU Yuting MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation Beijing Key Laboratory of Heat Transfer and Energy ConversionBeijing University of TechnologyBeijing100124China

Molten salt and supercritical carbon dioxide(sCO_(2))are considered to be one of the most promising combined heat transfer refrigerants for third-generation solar thermal power *** evaluate the potential of chloride salts and carbonates in third-generation solar thermal power generation,this paper uses molten salts and sCO_(2)as the working media of printed circuit board heat exchangers(PCHE),and uses numerical simulation to study the heat transfer and friction of PCHE channels with different molten salts and sCO_(2),and establishes predictive correlations respectively.A local heat transfer and friction study was conducted on the sCO_(2)side of the airfoil channel,and it was found that the inlet mass flow rate has a significant impact on it,while the inlet temperature has a relatively small impact.A comprehensive comparison was made between the heat transfer and friction of two molten salts,and the comprehensive performance of chloride salts was 70%-80%higher than that of *** results indicate that the potential of chloride salts in third-generation solar thermal power generation is much greater than that of carbonates.

关键词： third generation solar thermal power generation sCO_(2) PCHE molten salt

Structural Optimization of the Inlet Header of Supercritical Carbon Dioxide Printed Circuit board Heat Exchanger

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journal of Thermal science 2024年第4期33卷 1458-1467页

作者： WANG Yanquan LU Yuanwei WANG Yuanyuan HAN Xinlong WU Yuting GAO Qi MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation Beijing Key Laboratory of Heat Transfer and Energy ConversionBeijing University of TechnologyBeijing100124China

Supercritical carbon dioxide printed circuit board heat exchangers are expected to be applied in third-generation solar thermal power ***,the uniformity of supercritical carbon dioxide entering the heat exchanger has a significant impact on the overall performance of the heat *** order to improve the uniformity of flow distribution in the inlet header,this article studies and optimizes the inlet header of a printed circuit board heat exchanger through numerical *** results indicate that when supercritical carbon dioxide flows through the header cavity,eddy currents will be generated,which will increase the uneven distribution of flow rate,while reducing the generation of eddy currents will improve the uniform distribution of flow *** the dimensionless factor of the inlet header is 6,the hyperbolic configuration is the optimal *** also reduced the eddy current region by adding transition segments,and the results showed that the structure was the best when the dilation angle was 10°,which reduced the non-uniformity by 21%compared to the hyperbolic configuration,providing guidance for engineering practice.

关键词： third-generation solar thermal power generation inlet header PCHE numerical simulation

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editorial

The journal of China Universities of Posts and Telecommunications 2024年第2期31卷 1-2页

作者： Zhang Jie beijing university of Posts and Telecommunications Beijing 100876China

Integrated circuits(ICs)have become the cornerstone of the information age,driving scientific and technological revolutions and symbolizing strategic national *** the continuous adjustment of economic structure and the changing of international relationships,the pivotal role of ICs and related sectors has become increasingly *** address Chinese critical“bottleneck”challenges in this domain,it is necessary to strengthen the research on semiconductor devices,IC design,and manufacturing technologies.

关键词： corners driving symbol

Spatial Dynamics of Chickenpox Outbreaks in Rapidly Developing Regions: Implications for Global Public Health*

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Biomedical and Environmental sciences 2024年第7期37卷 687-697页

作者： Wang L. Wang M. Xu C. Wang P. You M. Li Z. Chen X. Liu X. Li X. Wang Y. Hu Y. Yin D. College of Geography and Environmental science Henan University Henan Kaifeng 475001 China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Science and Natural Resource Research Chinese Academy of Sciences Beijing Beijing 100101 China Key Laboratory of Geospatial technology for the Middle and Lower Yellow River Regions (Henan university) Ministry of Education Henan Kaifeng 475001 China Office of Epidemiology Chinese Center for Disease Control and Prevention Beijing Beijing 102206 China university of Chinese Academy of sciences (UCAS) Beijing Beijing 100101 China Weifang Municipal Center for Disease Control and Prevention Shandong Weifang 261061 China Hainan Center for Disease Control and Prevention Hainan Haikou 570203 China

Objective: The occurrence of chickenpox in rapidly developing areas poses substantial seasonal risk to children. However, certain factors influencing local chickenpox outbreaks have not been studied. Here, we examined the relationship between spatial clustering, heterogeneity of chickenpox outbreaks, and socioeconomic factors in Southern China. Methods: We assessed chickenpox outbreak data from Southern China between 2006 and 2021, comprising both relatively fast-growing parts and slower sub-regions, and provides a representative sample of many developing regions. We analyzed the spatial clustering attributes associated with chickenpox outbreaks using Moran's I and local indicators of spatial association and quantified their socioeconomic determinants using Geodetector q statistics. Results: There were significant spatial heterogeneity in the risk of chickenpox outbreaks, with strong correlations between chickenpox risk and various factors, particularly demographics and living environment. Furthermore, interactive effects among specific are factors, such as population density and per capita residential building area, percentage of households with toilets, percentage of rental housing, exhibited q statistics of 0.28, 0.25, and 0.24, respectively. Conclusion: This study provides valuable insights into the spatial dynamics of chickenpox outbreaks in rapidly developing regions, revealing the socioeconomic factors affecting disease transmission. These implications extend the formulation of effective public health strategies and interventions to prevent and control chickenpox outbreaks in similar global contexts. © 2024 The editorial board of Biomedical and Environmental sciences

关键词： Chickenpox Socioeconomic factors Spatial dynamics

Fast Fourier transform convolution neural network accelerator based on overlap addition

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The journal of China Universities of Posts and Telecommunications 2024年

作者： You Chen Li Dejian Feng Xi Shen Chongfei Wei Jizeng Liu Yu School of Microelectronics Tianjin university College of Intelligence and Computing Tianjin university beijing Smart-Chip Microelectronics technology Company Limited

In convolutional neural networks（CNNs）， the floating point computation in the traditional convolution layer is enormous， and the execution speed of the network is limited by intensive computing， which makes it challenging to meet the real-time response requirements of complex applications. This work is based on the principle that the time domain convolution result equals the frequency domain dot multiplication result to reduce the amount of floating-point calculations for convolution. The input feature map and the convolution kernel are converted to the frequency domain by the fast Fourier transform（FFT）， and the corresponding dot multiplication is performed. Then the frequency domain result is converted back to the time domain， and the output result of the convolution is obtained. In the shared CNN， the input feature map is much larger than the convolution kernel， resulting in many invalid operations. The overlap addition method is proposed to reduce invalid calculations and speed up network execution better. This work designs a hardware accelerator for frequency domain convolution and verifies its efficiency on the Xilinx ZYNQ UltraScale+MPSoC ZCU102 board: comparing the calculation time of Visual Geometry Group16(VGG16) under the ImageNet dataset， compared to traditional convolution accelerators， the hardware acceleration of frequency-domain convolution has improved performance by 8.5 times.

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