10TeV宇宙线的太阳阴影与太阳活动的关联

利用1990年6月至1993年10月间采集的数据,西藏空气簇射阵列(海拔高度4300m)以5.7σ、7.1σ的显著性观测到了10TeV宇宙线的太阳阴影和月亮阴影;研究发现,行星际磁场效应使太阳阴影偏向西0.62°,南0.22°:仔细研究了太阳阴影与太阳活动及其不对称性的关联,对太阳阴影位置的偏转发其变化行为给出了新的定性解释.     

养殖容器颜色对拟穴青蟹幼蟹生长、应激和甲壳颜色的影响

研究评估了6种养殖容器颜色(红、黄、绿、蓝、黑和白)对拟穴青蟹幼蟹生长、应激及甲壳颜色的影响. 结果表明, 黄色和蓝色容器中幼蟹存活率和生长率较高, 红色存活率最低. 在应激方面, 红色和黄色组的皮质醇水平较高(P＜0.05); 黄色组的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)水平、红色组的丙二醛(MDA)水平较高(P＜0.05); 蓝色组的己糖激酶(HK)水平较低(P＜0.05). 养殖容器颜色还显著影响了幼蟹的甲壳颜色, 幼蟹壳色会趋近养殖容器颜色. 线性回归方程表明养殖容器颜色对壳色的L*、a*、b*值的贡献分别为80.17%、41.28%、19.13%. 本研究的结果表明, 蓝色容器能够提高拟穴青蟹幼蟹的存活率和生长率, 且其应激较低, 因此蓝色容器更适合于拟穴青蟹幼蟹的中间培育.     

Nonreciprocal Single Photon Frequency Conversion via Chiral Coupling between a V-Type System and a Pair of Waveguides

The single photon frequency conversion is investigated theoretically in the system composed of a V-type system chiral coupling to a pair of waveguides. The single photon scattering amplitudes are obtained using the real-space Hamiltonian. The calculated results show that the probability of single photon frequency down-or up-conversion can reach a unit by choosing appropriate parameters in the non-dissipative system with perfect chiral coupling.We present a nonreciprocal single photon beam splitter whose frequency of the output photon is different from that of the input photon. The influences of dissipations and non-perfect chiral coupling on the single frequency conversion are also shown. Our results may be useful in designing quantum devices at the single-photon level.