North East Asian countries are facing to rapid increase in aged population ratio.The most recent values of aged population ratios are 19.5%,8.7%,and 6.9%,for Japan,Korea and China,respectively.One of the welfare servi...North East Asian countries are facing to rapid increase in aged population ratio.The most recent values of aged population ratios are 19.5%,8.7%,and 6.9%,for Japan,Korea and China,respectively.One of the welfare services in the aged society is provision of assistive products.Electronic control systems are commonly adopted in modern assistive products and sensors are indispensable for control units.Alarm systems,such as fire alarm,smoke detectors,and gas leak detectors,have been regarded as indispensable to safety of elderly persons and persons with disability.Main application of chemical sensors in home care of elderly persons is in the field of personal care and personal medical treatment.Products for personal medical treatment include that for medical treatment in home care and that to keep elderly persons healthy.Large market is expected in the latter one.展开更多
By solving the quantum Vlasov equation, the dynamically assisted pair production for scalar quantum electrodynamics （QED） is investigated. It is verified that this mechanism still holds true for boson pair productio...By solving the quantum Vlasov equation, the dynamically assisted pair production for scalar quantum electrodynamics （QED） is investigated. It is verified that this mechanism still holds true for boson pair production. Two combinations of two electric fields having different time scales under various time delays are considered; it is found that the oscillations of the momentum spectrum and the number density of created bosons decrease with increasing time delay, and the latter has a maximum value when the time delay equals zero. Furthermore, the differences in vacuum pair production between bosons and fermions are also studied, and they are helpful for distinguishing the created bosons from fermions.展开更多
文摘North East Asian countries are facing to rapid increase in aged population ratio.The most recent values of aged population ratios are 19.5%,8.7%,and 6.9%,for Japan,Korea and China,respectively.One of the welfare services in the aged society is provision of assistive products.Electronic control systems are commonly adopted in modern assistive products and sensors are indispensable for control units.Alarm systems,such as fire alarm,smoke detectors,and gas leak detectors,have been regarded as indispensable to safety of elderly persons and persons with disability.Main application of chemical sensors in home care of elderly persons is in the field of personal care and personal medical treatment.Products for personal medical treatment include that for medical treatment in home care and that to keep elderly persons healthy.Large market is expected in the latter one.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （NSFC） （Grant Nos. 11475026 and 11335013） and partially by the Open Fund of National Laboratory of Science and Technology on Computational Physics at IAPCM and the Fundamental Research Funds for the Central Universities （FRFCU）.
文摘By solving the quantum Vlasov equation, the dynamically assisted pair production for scalar quantum electrodynamics （QED） is investigated. It is verified that this mechanism still holds true for boson pair production. Two combinations of two electric fields having different time scales under various time delays are considered; it is found that the oscillations of the momentum spectrum and the number density of created bosons decrease with increasing time delay, and the latter has a maximum value when the time delay equals zero. Furthermore, the differences in vacuum pair production between bosons and fermions are also studied, and they are helpful for distinguishing the created bosons from fermions.
