pp final state interaction in J/ψ →γpp

The phenomenon of the near ppˉ-threshold enhancement observed in the J/ψ→γ pp decay is studied by using the enhancement factor method with a simpler one-pion-exchange potential between p and p. The Jost function caused by the mentioned potential is perturbatively calculated in the zero-th order approximation, and the corresponding enhancement factor is obtained. It is found that such a final state interaction offers an important contribution to the decay width near the ppˉ-threshold, although it is not large enough. To explain the decay data, a phenomenological factor G(p) with the form of 285500/(m 2 π + p 2 ) should be introduced. A further calculation including the p-dependent bare T -matrix, a more realistic N ˉ N potential and the contribution from the higher-order wave functions would provide a better understanding of the decay data and even the existence of the baryonium ppˉ. The near ppˉ-threshold behavior of the decay width in the J/ψ→π 0 pp process is also discussed.     

硬件防火墙在电视台全台网络中的应用

本文介绍了如何实现办公网与业务生产网的融合,将信息浏览、稿件编审、节目编辑、媒资检索、非线性编辑、审片、设备申请、调度管理等工作放置在办公区域的桌面完成,使办公电脑成为真正的多业务、多功能的桌面终端,通过分析指出防火墙、防毒墙等具体产品、制定并执行合理的访问策略是保障系统安全的关键。     

二维无限深方势阱中粒子运动的路径积分解法

用路径积分的方法计算了二维无限深方势阱中粒子的传播子,并由传播函数推导出二维无限深方势阱中粒子的波函数和能量,进一步体现了路径积分与其他经典量子化方法的等价性,反映了路径积分应用于难以处理的量子力学问题的价值.     

热辐射型光纤高温传感器的理论与实验研究

从理论上分析了热辐射型光纤高温传感器的特性,给出了涉及探测器波长响应和光纤损耗谱响应的普朗克积分的数值计算。这种计算方法简单、适用并且精度很高,与所做的实验相比较,变化趋势一致。     

基于铕离子-四环素-草甘膦荧光增强体系结合分子印迹固相萃取测定环境样品中草甘膦的残留量

提出了基于铕离子-四环素-草甘膦荧光增强体系结合分子印迹固相萃取测定环境样品中草甘膦残留量的方法。以正硅酸乙酯为溶胶-凝胶功能单体,在pH 1.0的硅溶胶-凝胶体系中制备了草甘膦分子印迹固相萃取膜,用于环境水和土壤样品的前处理。将前处理后的样品溶液与1.5×10^-2 mol·L^-1 EuCl₃溶液、3.0×10^-3 mol·L^-1四环素溶液和100 mmol·L^-1硼酸盐缓冲溶液(pH 10.0)按照一定比例混合,静置反应3 min;以403 nm为激发波长,根据体系在615 nm发射波长处的荧光强度增加值ΔF计算草甘膦的含量。结果表明：在较强碱性条件下,草甘膦的加入使体系在615 nm处的荧光强度显著增强;草甘膦浓度的对数在5.0×10^-8～1.5×10^-4 mol·L^-1内与体系ΔF值呈线性关系,检出限(3s/k)为1.0×10^-8 mol·L^-1     

InAs/InxGa1－xSb二类超晶格红外探测器的吸收波长与电子-空穴波函数交叠的研究

运用包络函数模型和传输矩阵方法计算了二类超晶格的能级结构.考虑到InAs与In_xGa_1-xSb结合存在应变,在计算中InAs/In_xGa_1-xSb二类超晶格的带阶采用模型固体理论处理.因为吸收系数与电子-空穴波函数交叠成正比,所以研究了InAs/In_xGa_1-xSb二类超晶格红外探测器的吸收波 关键词： 二类超晶格 红外探测器 波函数的交叠 传输矩阵     

ICP-MS测定岩盐中痕量铷和铯

样品经水溶解后,选铑做内标,用ICP-MS测定岩盐中痕量铷和铯,回收率在96.0%—104.0%之间。     

池塘养殖条件下台湾泥鳅大规格鱼种的生长特性

为了解台湾泥鳅在池塘养殖条件下的生长特性, 于2017年9~12月对宁波市某水产养殖有限公司池塘养殖的台湾泥鳅(3~6月龄)进行生长及形态参数测定和统计学分析. 结果表明, 台湾泥鳅雌雄生长差异不显著(P>0.05). 体长(L)与体高(H)、体宽(D)、头长(E)的相关线性方程分别为L=6.3186H+0.0855(R2=0.9983), L=9.2335D+0.4164(R2=0.9988)及L=7.3853E-2.3784(R2=0.9963). 体重(W)、净体重(Wn)与体长的相关幂函数方程分别为W=0.087L3.037(R2=0.9647), Wn=0.0091L2.9606 (R2=0.9614). 以von Bertalanffy生长方程描述台湾泥鳅的生长, 得出体重和体长的生长方程分别为Wt=42.69[1-e-0.3119(t-0.204)]3.04及Lt=16.23[1-e-0.3119(t-0.204)]. 台湾泥鳅属快速生长型鱼类, 每年的9~10月养殖水温适宜, 生长较快; 11月后随着水温下降生长减慢. 肝体比、肥满度随水温下降呈先上升后下降趋势, 而性腺指数呈上升趋势.     

混合熔剂半熔ICP-AES测定天青石矿中的锶、钡、钙、镁和铁

在最佳仪器条件下,样品用混合熔剂半熔,于10%王水介质中测定天青石中的锶、钡、钙、镁、铁含量,其最终结果与现行国家标准方法测得结果一致。     

Attempt to generalize fractional-order electric elements to complex-order ones

The complex derivative D~(α±jβ), with α, β∈ R+ is a generalization of the concept of integer derivative, where α = 1,β = 0. Fractional-order electric elements and circuits are becoming more and more attractive. In this paper, the complexorder electric elements concept is proposed for the first time, and the complex-order elements are modeled and analyzed.Some interesting phenomena are found that the real part of the order affects the phase of output signal, and the imaginary part affects the amplitude for both the complex-order capacitor and complex-order memristor. More interesting is that the complex-order capacitor can do well at the time of fitting electrochemistry impedance spectra. The complex-order memristor is also analyzed. The area inside the hysteresis loops increases with the increasing of the imaginary part of the order and decreases with the increasing of the real part. Some complex case of complex-order memristors hysteresis loops are analyzed at last, whose loop has touching points beyond the origin of the coordinate system.