A Search for Solar Axions and Anomalous Neutrino Magnetic Moment with the Complete Panda X-Ⅱ Data

We report a search for new physics signals using the low energy electron recoil events in the complete data set from PandaX-Ⅱ,in light of the recent event excess reported by XENON1 T.The data correspond to a total exposure of 100.7 ton·day with liquid xenon.With robust estimates of the dominant background spectra,we perform sensitive searches on solar axions and neutrinos with enhanced magnetic moment.It is found that the axionelectron coupling gAe<4.6×10^-12 for an axion mass less than 0.1 keV/c² and the neutrino magnetic moment μv<4.9×10^-11μB at 90%confidence level.The observed excess from XENON1 T is within our experimental constraints.     

Jet Radius and Momentum Splitting Fraction with Dynamical Grooming in Heavy-Ion Collisions

We investigate the medium modifications of momentum splitting fraction and groomed jet radius with both dynamical grooming and soft drop algorithms in heavy-ion collisions.In the calculation,the partonic spectrum of initial hard scattering in p+p collisions is provided by the event generator PYTHIA8,and the energy loss of fast parton traversing in a hot/dense quantum-chromodynamic medium is simulated with the linear Boltzmann transport model.We predict the normalized distributions of the groomed...     

原子吸收限附近Bragg情况的衍射波和透射波的观测

在Ｇａ的Ｋ吸收限附近的强反常散射条件下，测定了ＧａＡｓ（６００）对称Ｂｒａｇｇ情况的衍射波和透射波的摇摆曲线，并将其和Ｘ射线衍射动力学理论的相应计算结果作了比较，指出了原子吸收限附近Ｂｒａｇｇ情况的透射波在研究反常散射中的应用价值 关键词：     

掺Gd~(3 ),Y~(3 )对PbWO_4低温热释光的影响

通过热释光方法研究了PbWO4 (PWO), PWO:Y3+, PWO:Gd3+多晶粉末及PWO,PWO:Y单晶的低温(<300K)热释光现象.多晶粉末中，掺杂Y3+或Gd3+都会大大降低甚至消除200K附近的热释光峰，同时产生新的热释光峰，分别位于125和150K（掺Y掺Gd）.这表明掺三价离子除了起到电荷补偿作用以减少Pb3+，O-浓度外，还可以产生新的陷阱能级.对于PWO:Y单晶，掺杂Y3+可以消除253K的热释光峰，即消除较深(～0.89eV)的陷阱,但PWO单晶中较浅的陷阱(～0.42eV)对应130K热释光峰仍然存在，对此进行讨论，它最可能源于氧空位缺陷.根据Pb3+，Gd3+，Y3+的电子库仑势不同，在PWO晶体中替代Pb2+后形成的电子陷阱深度有别（EPb>EGd>EY），从而解释了相应的热释光峰值温度的不同.     

法布里－珀罗腔压缩啁啾光脉冲的最佳调谐

法布里－珀罗腔对啁啾光脉冲的压缩存在滤波和色散（谱相位均衡）双重机制；后者根据腔体谐振波长与光载波中心波长之差可呈现为正常或反常色散。证明了最佳调谐区为一系列间隔约几纳米的不连续区。首次解释了Ｍ．Ｎａｋａｚａｗａ等人的实验结果     

关于作图法有效数字的一些讨论

在物理实验中,常常用拟合直线的方法求出某些待测物理量的数值.拟合直线的诸方法中,作图法和最小二乘法都是被普遍采用的.众所周知,在诸方法中,最小二乘法拟合的直线的不确定度是最小的.由于其所求得的物理量误差最小,物理量的有效数字位     

CRYSTAL STRUCTURES OF 1,2-BENZO[2.2]PARACYCLOPHANE AND 1,2-BENZO[2.2]PARACYCLOPHANE-1,7-DIENE

<正> C20H16 (1) Mr = 256.34 and C20H14 (2), Mr = 254.32 are isomorphous, orthorhombic, P212121, Z = 4. For (?), ?a= 7.116(1), b =7.874(2), c = 24.564(4) A, V = 1376.4(3) A3, Dx = 1.237 g cm-3, μ(Mo-K α) =0.65 cm-1 , final R = 0.047 for 1152 observed reflections; for 2, a=6.963(2), b = 7.985(4), c = 24.315(8) A, V = 1351.9(8) A3, Dx = 1.250 g cm-3,μ(Mo-Kα) = 0.66 cm-1 , final R = 0.076 for 886 observed data. Structuralfeatures are similar to those of the parent [2.2]paracyclophane and related derivatives.     

用二维色谱技术直接定量测定白酒中氨基甲酸乙酯

建立了一个利用二维色谱技术直接定量测定白酒中氨基甲酸乙酯的方法。在本方法中，利用二维色谱技术的出色分离能力，免除了以往复杂的化学前处理步骤；应用对含氮化合物具有选择性响应的ＮＰＤ，提高了定性的可靠性和分析灵敏度；选用氨基甲酸异丙酯做内标物，克服了二维色谱技术中应用内标法定量的困难。直接进酒样２μＬ，最低检测限１３μｇ／Ｌ。方法的相对标准偏差为７．７％。     

Hydrothermal Synthesis,Crystal Structure and Luminescence Property of a 2D Manganese(Ⅱ) Coordination Polymer

Solvothermal reactions of MnCl_2·4H_2O with(pyridin-2-yl)methyl 4-(2-(4-((pyridin-2-yl)methoxy)phenyl)diazenyl)benzoate(L1) via an in situ ligand transformation reaction produced a new coordination polymer, {[Mn_(2.5)Cl_3L_2(H_2O)]·H_2O}_n(1, where HL = 4-(2-(4-((pyridin-2-yl)methoxy)phenyl)diazenyl)benzoic acid). The L1 ligand was decomposed in situ to L~- which was coordinated with Mn(Ⅱ) to form compound 1 in the solvothermal synthesis process. Complex 1 was characterized by IR spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction.Compound 1 possesses a 2D network. In addition, stability and photoluminescent property of 1 were also investigated.