肾脏和股骨铅蓄积多元素综合指标探讨

目的:通过对血液中多元素与肾铅、股骨铅关系的分析,探讨能够准确反映肾脏、股骨铅蓄积的综合指标。方法:选取健康的4周龄雄性SD大鼠75只,随机分成25组,采取大剂量范围,小浓度间隔的染毒方法。实验开始后,于第40、80、120天分别从各组随机选取1只大鼠,经乙醚麻醉后股动脉取血,并收集肾脏、股骨,用电感耦合等离子体质谱法(ICP-MS)测定元素含量。结果:血铅、肾铅、股骨铅浓度随染毒剂量的增加而发生变化,但变化趋势各不相同;血铅浓度与肾铅、股骨铅浓度之间的相关性随染毒周期而变化;血液中其他元素的浓度或浓度比值与肾铅、股骨铅之间的相关有统计学意义,且相关系数均高于单一元素与肾铅、股骨铅间的相关系数。结论:单一血铅指标在反映脏器铅蓄积水平有一定的局限性;多元素综合指标则有可能成为估算脏器铅蓄积水平的有力工具。     

热镀锌板钝化膜的电感耦合等离子体原子发射光谱法测定

建立了电感耦合等离子体发射光谱法测定热镀锌板钝化膜的方法。优化了仪器工作条件,通过对机体匹配消除了无机酸基体干扰。方法检出限为0.148mg/L,对10.000mg/L铬标准溶液测定的相对标准偏差(RSD)为0.507%(n=10),加标回收率为94%～116%,方法精密度通过在优化条件下测定标样得到了验证,方法准确可靠。     

基于改进型脉冲耦合神经网络的空间X射线星图分割

为进行空间X射线星图分割及在X射线背景噪声中提取目标源,提出了改进的脉冲耦合神经网络图像分割算法.改进算法将图像分割成小区域,不同区域中设置不同的参数;将内部行为的调制参数设计成邻域像素灰度值分布的负耦合函数,强制降低强X射线目标源附近的强X射线背景噪声的点火频率,以提取X射线辐射点目标源.分别利用改进型PCNN模型、普通PCNN模型进行了空间X射线星图分割实验,结果表明改进型PCNN模型具有更优的分割效果.     

克尔介质腔中耦合三能级原子与光场相互作用系统的动力学行为

The Hamiltonian of coupled three-level atoms interacting with light field in the cavity filled with Kerr-like medium is derived. A simplified analytic solution to the Schrodinger equation of the system is obtained. The case of A type atom with degenerate lower levels is discussed in detail. It is shown that the coupling strength between atoms and Kerr coefficient affect the system＇s dynamic behaviors, especially the modulation period and oscillation frequency of the squeezing parameters of the field and the collective dipole moment. Dynamic behaviors of the system are sensitive to the initial state of atoms.     

耦合谐振子的初等求解

本文用代数的方法求出了耦合谐振子的简正模,过程简单且物理意义清晰。     

Neutrinos and our Sun — Part 3

In the concluding part of the article on Neutrinos and our Sun we discuss the detection of atmospheric neutrinos, their fluxes and zenith angle distributions. Here too one finds discrepancies with theoretical predictions. We discuss how the idea of neutrino oscillations helps resolve both the solar neutrino puzzle (discussed in Part 2) and the discrepancy observed in atmospheric neutrino fluxes. This is followed by a discussion of neutrino masses and the recent confirmation of the neutrino oscillations in the KamLAND experiment.     

混合型微分求积法对求解联立的二维不可压Navier-Stokes方程和热方程的应用

1　Introduction　Variousnumericaltechniques,suchasthefinitedifferencemethodandfiniteelementsmethod ,havebeenusedinthepasttosolvetheincompressibleflowproblemnumerically .Usually ,thesemethodsrequirealargenumberofdiscretizedpointsinthecomputa tionaldomainforaccurateresults .Becausetheinfor mationonallgridpointsisusedtofitderivativesatgrid pointsinthedifferential quadrature (DQ )method ,itisenoughtouseonlyfewgridpointstoob tainhigh accuracynumericalsolutions .Therefore ,thenumberofgridpointscanb…     

一类半线性耦合Schrdinger方程组解的存在唯一性

利用Galerkin方法证明了一类半线性耦合Schro¨dinger方程组解的存在唯一性.     

非线性耦合标量场方程的Jacobi椭圆函数求解

推广了Jacobi椭圆函数展开方法，研究了非线性耦合标量场方程组的求解问题。得到了更多更新的非线性耦合标量场方程组的解释解。     

Electrochemical Oscillations Induced by Surfactants

HeZhanbopointedout[1] thatsurfactantscanbeusedtomakenewchemicaloscillatorsinaqueoussolution ,suchasbromateoscillator[2 ] andpermanganateoscillator[3] .Untilnow ,however,thereisnotanyelectrochemicaloscillatorre latedwithsurfactant.　　Anelectrochemicaloscillatorisoneofthefirstdisco veriesofchemicaloscillators .Todayhundredsofarticleshavebeenpublished[4— 6 ] aboutelectrochemicaloscillators.Theyprovidematerialstoenrichmaturetheoriesandmecha nisms[7— 8] .InourexperimentsweusedaDaniellcellasele…