Browsing by Author "Zhou, Bin"

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  • Capture efficiency and thermal comfort in Chinese residential kitchen with push-pull ventilation system in winter-a field study
    (2019-02-01) Zhou, Bin; Wei, Peng; Tan, Meilan; Xu, Yang; Ding, Lili; Mao, Xinyue; Zhao, Yongkun; Kosonen, Risto
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The IAQ and thermal comfort in residential kitchen are two major concerns in built environment. The ventilation effectiveness is closely related to the IAQ of the residential kitchen. Therefore, it is necessary to design a cost-effective kitchen ventilation system. In this study, a field experimental study was conducted on a push-pull kitchen ventilation system. The experiment was divided into two parts. The first part was to test the capture efficiency of the push-pull ventilation system under various working conditions. The second part was to investigate the thermal comfort of the human body during cooking process with and without air curtain in winter. The results show that the push-pull ventilation system can effectively improve the capture efficiency of the range hood, and the low-momentum make-up air and the reasonable air distribution around the stove are important to obtain good performance. The optimal working condition of the push-pull ventilation system is a range hood mid gear plus an air curtain velocity of 0.5 m/s when the kitchen window is closed. In winter, when people enter the non-air-conditioned kitchen from the air-conditioned room, the thermal sensation and thermal comfort of people were all decreased significantly. However, they can be improved during cooking processes. The prediction results show that models which used skin temperature as input parameter can predict the thermal sensation of most parts of human body in kitchen. However, the prediction correction model is still needed for the body parts with movement or exposure to severe heat radiation.
  • CORBES: radiation belt survey with international small satellite constellation
    (2025-04-17) Wu, Ji; Deng, Li; Praks, Jaan; Anger, Marius; Oleynik, Philipp; Hajdas, Wojciech; Wang, Jin-Dong; Zhang, Shen-Yi; Zhou, Bin; Zeng, Li; Cao, Jinbin; Fischer, David; Liu, Shuang; Chen, Wen; Wu, Fan; Xi, Rui-Chen; Li, Xinlin; Abrahao, Dos-Santos Walter; Denardini, Clezio Marcos; Li, Yulun; Yang, Xiao-Chao; Dai, Lei; Ma, Ying-Qi; Yu, Tian; Cai, Ming-hui; Yang, Hao-Liang; Ebrahimi, Mohammad; Maurizio, Falanga; Kalegaev, Vladimir; Li, Wen; Miyoshi, Yoshizumi; Nakamura, Rumi; Petrukovich, Anatoli; Baker, Daniel N.; Worms, Jean-Claude
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The COnstellation of Radiation BElt Survey program (CORBES) is designed to deploy small satellites into a highly elliptic orbit for multi-point exploration of the Earth's radiation belts. Its scientific objective is to achieve unprecedented high-time-resolution dynamics measurements within the regions of Earth's outer radiation belts. The CORBES program initiative comprises satellites equipped with three types of payloads: the Magnetometer (MAG), the Search Coil Wave Detector (SCWD), and the High Energy Electron Detector (HEED). The energy interval of HEED is suggested as 0.1–4 MeV, logarithmically divided into 12 channels. To ensure extensive coverage of the outer radiation belts, a highly eccentric and inclined orbit is suggested, featuring a perigee of 280 km, an apogee of 7 Earth-Radius (Re), and an inclination of approximately 11°, resulting in an orbital period of approximately 13.5 h. Within a single orbital period, it takes roughly 10 h to traverse the outer radiation belts (3 Re to 7Re). All satellites are expected to operate within the same orbit, maintaining a spin-stabilized with sun-pointing spinning axis, and a spinning speed of approximately 8 RPM. Each satellite's mass should not exceed 30 kg. For telecommand, either S-band or X-band will be utilized, while X-band is designated for data downlink. The satellites are scheduled for launch by one or two rockets, with the equipped upper stage placing them into the target orbit, and the attached dispenser releasing them individually according to the required separation sequence. Key aspects of the program include cross-calibration, radiation shielding, assembly integration and testing (AIT). Prior to launch, the cross-calibration is optional for the payloads. The payloads will be tested in the same environment to calibrate the technical specifications. Post-launch, in orbit cross-calibration becomes necessary to maintain data consistency and comparability. Specifically for HEED, this involves selecting electrons with the same energy range during the magnetospheric quiet period (Kp < 3), and comparing the observation results of different HEEDs under the same L,B conditions. A similar method applies to MAG and SCWD comparing observations during selected quiet period. Given that the satellites will operate within radiation belts characterized by high-energy protons at low altitudes and electrons at high altitudes, all on-board electronic components must meet fundamental requirements, including shielding geometry structure design, and thickness calculation to mitigate the Total Ionizing Dose Effect (TID) to a level of 200 krad [Si] over a one-year mission cycle. Lastly, system-level AIT before launch could be performed.
  • Experimental study of thermal comfort by variable temperature and velocity air supply system in operating room
    (2025-06-01) Zhou, Bin; Wang, Ang; Ren, Hui; Xia, Jie; Peng, Fan; Wang, Shao Cong; Wang, Yi Chu; Zhao, Hao Yi; Li, Wen Jie; Tan, Mei Lan; Kosonen, Risto
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    In operating room, conventional unidirectional air supply system with constant supply temperature and velocity cannot satisfy the thermal comfort need of the surgical team. Therefore, a novel variable temperature and velocity air supply system is introduced. Indoor thermal environment and thermal comfort parameters through simulated surgical experiments were tested, where thermal sensation changes, skin temperature and thermal comfort of medical staff with different duties under different air supply conditions were analyzed. Thirty-five experimental personnel were recruited as medical staffs with five different roles. It is shown that there are significant differences in the perception of thermal comfort of medical staff under the conventional unidirectional air supply system. The thermal comfort of medical staff can be improved with variable temperature and velocity air supply system. Especially the comfort conditions of the surgeon and the anesthesiologist has been significantly improved. The proportion of medical staff feeling comfortable with variable temperature and velocity air supply system reaches 64.0%, while it is only 42.7% with conventional unidirectional air supply system. By adjusting the air supply temperature and velocity in different zones, the thermal sensation of the personnel in the critical operating zone tends to be moderate, which reduces the occurrence of local discomfort. This study shows that enough attention should paid on the thermal comfort condition of medical staff during the design and operation of the operating room. The variable temperature and velocity air supply system could be a promising solution to improve thermal comfort level in operating room.
  • A multi-satellite survey scheme for addressing open questions on the Earth’s outer radiation belt dynamics
    (2025-04-17) Yang, Xiaochao; Li, Xinlin; Dai, Lei; Wu, Ji; Kalegaev, Vladimir; Li, Wen; Miyoshi, Yoshizumi; Liu, Wenlong; Xiang, Zheng; Ni, Binbin; Liu, Si; Baker, Daniel N.; Wang, Chi; Deng, Li; Li, Yulun; Praks, Jaan; Anger, Marius; Wang, Jingdong; Zhou, Bin; Zhang, Shengyi; Santos, Walter; Ma, Yingqi
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The Earth’s outer radiation belt is highly dynamic, containing relativistic electron fluxes that can increase by several orders of magnitude during magnetospheric disturbances. This greatly increases the likelihood of spacecraft malfunction or failure and significantly influences the solar-terrestrial system’s energy and mass coupling, highlighting the importance of fully understanding the mechanisms governing these dynamics from both theoretical and practical perspectives. Although many theories have been proposed, further research is essential to quantify the specific contributions of different dynamic mechanisms for improving space weather forecasting. To address this, observations of the outer radiation belt with high spatial–temporal resolution to distinguish the spatial and temporal variations are essential. We introduce a 10-CubeSat constellation survey scheme in the geosynchronous transfer orbit (GTO) to achieve this required observation. Three baseline instruments are proposed to be employed: the high energy electron detector (HEED), the search coil wave detector (SCWD), and the magnetometer (MAG). Two groups of physical processes will be investigated: wave-particle interactions involving charged particles interacting with whistler-mode waves, electromagnetic ion cyclotron (EMIC) waves, and ultra-low frequency (ULF) waves; and radial transport encompassing shock-induced injections, substorm injections, storm convection and magnetopause shadowing. The performance parameters of instruments and platform of the constellation are presented. Additionally, aligned with the concept of constellation survey, we outline the COSPAR-coordinated space program, COnstellation of Radiation BElt Survey (CORBES), which will provide a crucial scientific contribution in the absence of the Van Allen Probes. The program’s excellent observational capability enables a comprehensive understanding of the underlying physical mechanisms governing the outer radiation belt dynamics and improved space weather forecasting.
  • The nature and nurture of network evolution
    (2023-12) Zhou, Bin; Holme, Petter; Giong, Zaiwu; Zhan, Choujun; Huang, Yao; Lu, Xin; Meng, Xiangyi
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Although the origin of the fat-tail characteristic of the degree distribution in complex networks has been extensively researched, the underlying cause of the degree distribution characteristic across the complete range of degrees remains obscure. Here, we propose an evolution model that incorporates only two factors: the node’s weight, reflecting its innate attractiveness (nature), and the node’s degree, reflecting the external influences (nurture). The proposed model provides a good fit for degree distributions and degree ratio distributions of numerous real-world networks and reproduces their evolution processes. Our results indicate that the nurture factor plays a dominant role in the evolution of social networks. In contrast, the nature factor plays a dominant role in the evolution of non-social networks, suggesting that whether nodes are people determines the dominant factor influencing the evolution of real-world networks.