Possible light bosonic dark matter interactions with the Standard Model photon have been searched using microwave resonant cavities.In this paper,we describe the cryogenic readout system calibration of a 7.138 GHz cop...Possible light bosonic dark matter interactions with the Standard Model photon have been searched using microwave resonant cavities.In this paper,we describe the cryogenic readout system calibration of a 7.138 GHz copper cavity with a loaded quality factorQ1=10^(4)whose operation at a temperature of 22 mK is based on a dilution refrigerator.Our readout system consists of High Electron Mobility Transistors working as cryogenic amplifiers at 4 K,plus room-temperature amplifiers and a spectrum analyzer for signal power detection.We tested the system with a superconducting two-level system based on a single-photon source in the microwave frequency regime.We obtained an overall 95.6 dB system gain and–71.4 dB attenuation in the cavity's input channel.The effective noise temperature of the measurement system is 7.5 K.展开更多
Producing sufficient food with finite resources to feed the growing global population while having a smaller impact on the environment has always been a great challenge.Here,we review the concept and practices of Gree...Producing sufficient food with finite resources to feed the growing global population while having a smaller impact on the environment has always been a great challenge.Here,we review the concept and practices of Green Super Rice(GSR)that have led to a paradigm shift in goals for crop genetic improvement and models of food production for promoting sustainable agriculture.The momentous achievements and global deliveries of GSR have been fueled by the integration of abundant genetic resources,functional gene discoveries,and innovative breeding techniques with precise gene and whole-genome selection and efficient agronomic management to promote resource-saving,environmentally friendly crop production systems.We also provide perspectives on new horizons in genomic breeding technologies geared toward delivering green and nutritious crop varieties to further enhance the development of green agricul-ture and better nourish the world population.展开更多
It is well known that a primordial black hole(PBH)can be generated in the inflation process of the early universe,especially when the inflation field has a number of non-trivial features that could break the slow-roll...It is well known that a primordial black hole(PBH)can be generated in the inflation process of the early universe,especially when the inflation field has a number of non-trivial features that could break the slow-roll condition.In this study,we investigate a toy model of inflation with bumpy potential,which has one or several bumps.We determined that the potential with multi-bump can generate power spectra with multi-peaks in small-scale region,which can in turn predict the generation of primordial black holes in various mass ranges.We also consider the two possibilities of PBH formation by spherical and elliptical collapses.Finally,we discuss the scalar-induced gravitational waves(SIGWs)generated by linear scalar perturbations at second-order.展开更多
基金supported in part by the Scientific Instrument Developing Project of the Chinese Academy of Sciences(YJKYYQ20190049)the International Partnership Program of Chinese Academy of Sciences for Grand Challenges(112311KYSB20210012)+1 种基金the National Natural Science Foundation of China(12074117,92365209,12150010,11875062,11947302,12047503,12074117,61833010,12061131011,12150410317,11905149,12275333)the Beijing Natural Science Foundation(IS23025)。
文摘Possible light bosonic dark matter interactions with the Standard Model photon have been searched using microwave resonant cavities.In this paper,we describe the cryogenic readout system calibration of a 7.138 GHz copper cavity with a loaded quality factorQ1=10^(4)whose operation at a temperature of 22 mK is based on a dilution refrigerator.Our readout system consists of High Electron Mobility Transistors working as cryogenic amplifiers at 4 K,plus room-temperature amplifiers and a spectrum analyzer for signal power detection.We tested the system with a superconducting two-level system based on a single-photon source in the microwave frequency regime.We obtained an overall 95.6 dB system gain and–71.4 dB attenuation in the cavity's input channel.The effective noise temperature of the measurement system is 7.5 K.
基金the National High Technology Research and Development Program of China(2014AA10A604)the Bill&Melinda Gates Foundation(OPP1130530)+1 种基金the Earmarked Fund for the China Agricultural Research System of China(CARS-01-06)Hubei Special Major Projects for Technological Innovation(2019ABA104,2020ABA016).
文摘Producing sufficient food with finite resources to feed the growing global population while having a smaller impact on the environment has always been a great challenge.Here,we review the concept and practices of Green Super Rice(GSR)that have led to a paradigm shift in goals for crop genetic improvement and models of food production for promoting sustainable agriculture.The momentous achievements and global deliveries of GSR have been fueled by the integration of abundant genetic resources,functional gene discoveries,and innovative breeding techniques with precise gene and whole-genome selection and efficient agronomic management to promote resource-saving,environmentally friendly crop production systems.We also provide perspectives on new horizons in genomic breeding technologies geared toward delivering green and nutritious crop varieties to further enhance the development of green agricul-ture and better nourish the world population.
基金Supported by the National Natural Science Foundation of China(11653002,11875141),partially the Fundamental Research Funds for the Central Universities(Innovation Funded Projects)(2020CXZZ105)。
文摘It is well known that a primordial black hole(PBH)can be generated in the inflation process of the early universe,especially when the inflation field has a number of non-trivial features that could break the slow-roll condition.In this study,we investigate a toy model of inflation with bumpy potential,which has one or several bumps.We determined that the potential with multi-bump can generate power spectra with multi-peaks in small-scale region,which can in turn predict the generation of primordial black holes in various mass ranges.We also consider the two possibilities of PBH formation by spherical and elliptical collapses.Finally,we discuss the scalar-induced gravitational waves(SIGWs)generated by linear scalar perturbations at second-order.
