This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction an...This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction and built up notable contributions to the flourish of this field. Keeping pace with international development and participating international cooperation in the field of IVF, Chinese scientists have now focused on the investigation of basic mechanism relevant to possible gamete interaction, egg cell activation and early embryogenesis by IVF. In vitro manipulation techniques are combined with cytological and molecular biological approaches to unveil the double fertilization mysteries.展开更多
A new kind of electron source, the photoemissive monoenergetic electron source has been invented for calibrating the beta--magnetic spectrometer. It produceselectrons in the form of simulating a radioactive monoenerge...A new kind of electron source, the photoemissive monoenergetic electron source has been invented for calibrating the beta--magnetic spectrometer. It produceselectrons in the form of simulating a radioactive monoenergetic electron source andcan be made in any shape and size according tO the demands of experimentS. In thispaper, the principles and basic constructions of the photoemissive monoenergeticelectron source are described, the resultS of calibrating our 2’l’x bead--magneticspectrometer with a single strip arc shaped photoemissive monoenergetic electronsource are listed, a new way for determining resolution function of experimentslsystem in the research of neutrino rest mass has been posed and one of its actualapplications is also given.展开更多
The work of Chinese scientists conducted at the Joint Institute for Nuclear Research(JINR)(1956–1965)was inextricably linked to the Sino-Soviet relations in the 1950 s–1960 s.During the early stage of the JINR,with ...The work of Chinese scientists conducted at the Joint Institute for Nuclear Research(JINR)(1956–1965)was inextricably linked to the Sino-Soviet relations in the 1950 s–1960 s.During the early stage of the JINR,with the aid of advanced equipment and the international cooperation mechanism,Chinese scientists yielded significant results,such as the discovery of the antisigma-minus hyperon and the proof of the law of partial conservation of axial current(PCAC).After the Sino-Soviet split,Chinese scientists’activities at the institute were hampered by political tensions,eventually resulting in China’s withdrawal from the JINR in 1965.But through the involvement at the JINR,Chinese scientists were trained in scientific practices and participated in international exchange and cooperation which turned them into a new force in China’s nuclear industry,boosting its nuclear weapons,particle physics theory,and accelerator technology.In the meantime,the scientists’activities extended the international influence of the JINR.The withdrawal of China from the institute impacted both the JINR and the development of science in China.展开更多
The study of hadron properties in dense medium created in relativistic heavy ion collision is a subject of considerable current interest. Of particular importance is the in-medium modification of kaon properties. The ...The study of hadron properties in dense medium created in relativistic heavy ion collision is a subject of considerable current interest. Of particular importance is the in-medium modification of kaon properties. The knowledge is useful for our understanding of both chiral symmetry restoration in dense matter and the properties of the dense nuclear matter existing in neutron stars.展开更多
At the CERN large hadron collider (LHC), production of the Higgs boson in association with Z or W bosons provides a dramatic experimental signal for detecting the standard model (SM) Higgs boson. In this paper, we...At the CERN large hadron collider (LHC), production of the Higgs boson in association with Z or W bosons provides a dramatic experimental signal for detecting the standard model (SM) Higgs boson. In this paper, we consider the contributions of the left-right twin Higgs (LRTH) model to the processes qq' --~ Z(W)H. Our numerical results show that, in the favorable parameter spaces, the cross sections deviate distinctly from the predictions of the SM. The possible signals of the LRTH model can be detected via these processes at the LHC experiments.展开更多
During the past five decades, the TRIGA reactor Vienna has reached a top place in utilization among low power research reactors. This paper discussed the highlights of the major neutron physics experiments in the fiel...During the past five decades, the TRIGA reactor Vienna has reached a top place in utilization among low power research reactors. This paper discussed the highlights of the major neutron physics experiments in the field of neutron interferometry and ultra-small angle neutron scattering as well as in the field of radiochemistry, education and training and research in the field of nuclear safeguards and nuclear security. Potential further directions of research are outlined where the Atominstitut of Vienna might concentrate in future.展开更多
Many theoretical methods have predicted that the low density nuclear matter can encounter chemical instability. However, for high density nuclear matter, very little knowledge is known to people. In this work, the che...Many theoretical methods have predicted that the low density nuclear matter can encounter chemical instability. However, for high density nuclear matter, very little knowledge is known to people. In this work, the chemical instability at high density nuclear matter and its dependence on the symmetry potential are investigated.Fig.l(a) and (b) show (μn/δ)|p versus density p at zero temperature and relative neutron excesses展开更多
The design of a lead slowing down spectrometer is being developed at KAERI (Korea Atomic Energy Research Institute) for an analysis of isotopic fissile content in spent and recycled fuel. The lead spectrometer has a...The design of a lead slowing down spectrometer is being developed at KAERI (Korea Atomic Energy Research Institute) for an analysis of isotopic fissile content in spent and recycled fuel. The lead spectrometer has an advantage to assay fissile content directly from spent fuel. Accurate fissile material data must be fed back to the spent fuel design and management. For reutilization of PWR spent fuel, an isotopic fissile content analysis is required to obtain safety and economics in the fuel cycle. The LSDS (lead slowing down spectrometer) uses the different fission signatures of each fissile with respect to the interrogation neutron energy. Several simulations were done and parameter was obtained for the system working. Energy between 1 keV to 0.1 eV is very sensitive to isotopic fissile material fission with good energy resolution. An external source neutron is necessary to induce enough fissile fission. A neutron production methodology is being developed for cost effectiveness, easy maintenance and high neutron yield rate. The threshold fission detector screens the prompt fast fission neutrons from an intense radiation background. The detection of a fission signature has a direct relationship with the isotopic fissile content.展开更多
文摘This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction and built up notable contributions to the flourish of this field. Keeping pace with international development and participating international cooperation in the field of IVF, Chinese scientists have now focused on the investigation of basic mechanism relevant to possible gamete interaction, egg cell activation and early embryogenesis by IVF. In vitro manipulation techniques are combined with cytological and molecular biological approaches to unveil the double fertilization mysteries.
文摘A new kind of electron source, the photoemissive monoenergetic electron source has been invented for calibrating the beta--magnetic spectrometer. It produceselectrons in the form of simulating a radioactive monoenergetic electron source andcan be made in any shape and size according tO the demands of experimentS. In thispaper, the principles and basic constructions of the photoemissive monoenergeticelectron source are described, the resultS of calibrating our 2’l’x bead--magneticspectrometer with a single strip arc shaped photoemissive monoenergetic electronsource are listed, a new way for determining resolution function of experimentslsystem in the research of neutrino rest mass has been posed and one of its actualapplications is also given.
基金supported in part by the Youth Innovation Promotion Association CAS(2018186)the National Science Foundation of China(NSFC)under Grant No.11775207。
文摘The work of Chinese scientists conducted at the Joint Institute for Nuclear Research(JINR)(1956–1965)was inextricably linked to the Sino-Soviet relations in the 1950 s–1960 s.During the early stage of the JINR,with the aid of advanced equipment and the international cooperation mechanism,Chinese scientists yielded significant results,such as the discovery of the antisigma-minus hyperon and the proof of the law of partial conservation of axial current(PCAC).After the Sino-Soviet split,Chinese scientists’activities at the institute were hampered by political tensions,eventually resulting in China’s withdrawal from the JINR in 1965.But through the involvement at the JINR,Chinese scientists were trained in scientific practices and participated in international exchange and cooperation which turned them into a new force in China’s nuclear industry,boosting its nuclear weapons,particle physics theory,and accelerator technology.In the meantime,the scientists’activities extended the international influence of the JINR.The withdrawal of China from the institute impacted both the JINR and the development of science in China.
基金Supported by the CAS knowledge innovation project ( No.KJcx2-sw-N02) and Ministry of Science and Technology of the People's Republic of China (No. 2002ccb00200).
文摘The study of hadron properties in dense medium created in relativistic heavy ion collision is a subject of considerable current interest. Of particular importance is the in-medium modification of kaon properties. The knowledge is useful for our understanding of both chiral symmetry restoration in dense matter and the properties of the dense nuclear matter existing in neutron stars.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10975047 and 10979008
文摘At the CERN large hadron collider (LHC), production of the Higgs boson in association with Z or W bosons provides a dramatic experimental signal for detecting the standard model (SM) Higgs boson. In this paper, we consider the contributions of the left-right twin Higgs (LRTH) model to the processes qq' --~ Z(W)H. Our numerical results show that, in the favorable parameter spaces, the cross sections deviate distinctly from the predictions of the SM. The possible signals of the LRTH model can be detected via these processes at the LHC experiments.
文摘During the past five decades, the TRIGA reactor Vienna has reached a top place in utilization among low power research reactors. This paper discussed the highlights of the major neutron physics experiments in the field of neutron interferometry and ultra-small angle neutron scattering as well as in the field of radiochemistry, education and training and research in the field of nuclear safeguards and nuclear security. Potential further directions of research are outlined where the Atominstitut of Vienna might concentrate in future.
文摘Many theoretical methods have predicted that the low density nuclear matter can encounter chemical instability. However, for high density nuclear matter, very little knowledge is known to people. In this work, the chemical instability at high density nuclear matter and its dependence on the symmetry potential are investigated.Fig.l(a) and (b) show (μn/δ)|p versus density p at zero temperature and relative neutron excesses
文摘The design of a lead slowing down spectrometer is being developed at KAERI (Korea Atomic Energy Research Institute) for an analysis of isotopic fissile content in spent and recycled fuel. The lead spectrometer has an advantage to assay fissile content directly from spent fuel. Accurate fissile material data must be fed back to the spent fuel design and management. For reutilization of PWR spent fuel, an isotopic fissile content analysis is required to obtain safety and economics in the fuel cycle. The LSDS (lead slowing down spectrometer) uses the different fission signatures of each fissile with respect to the interrogation neutron energy. Several simulations were done and parameter was obtained for the system working. Energy between 1 keV to 0.1 eV is very sensitive to isotopic fissile material fission with good energy resolution. An external source neutron is necessary to induce enough fissile fission. A neutron production methodology is being developed for cost effectiveness, easy maintenance and high neutron yield rate. The threshold fission detector screens the prompt fast fission neutrons from an intense radiation background. The detection of a fission signature has a direct relationship with the isotopic fissile content.