间接原子吸收光谱法测定水样中的痕量硼

本文研究了四氟硼酸根与邻二氮菲银形成的络合物由MIBK萃取后,用火焰原子吸收光谱法间接测定硼,其线性范围为0.002-1μg/mL,检出限为0.41μg/mL,回收率为93%-101%,且K^ 、Na^ 等10个种离子不干扰测定,本方法用于地下水中痕量硼的测定,结果令人满意。     

基于催化发光的高选择性的二甲醚传感器

研究了二甲醚气体通过石英加热管表面时的化学发光现象,利用此发光现象设计了检测二甲醚的传感器。此传感器由反应器、程序升温系统、单色器系统和光电检测及数据处理系统组成。化学发光强度与二甲醚浓度在0.59～118.6g/m3内呈良好的线性关系(r=0.9995);检出限为0.19g/m3。苯、甲醛等气体通过此传感器时,没有引起干扰。由于此传感器不涉及颗粒态催化剂的制备和固定过程,因此制造工艺简单、成本经济,且具有更好的稳定性和更长的寿命。应用本方法可方便快速地测定空气中的二甲醚气体。     

超声搅拌悬浮液进样石墨炉原子吸收测定海洋沉积物中的痕量镉

研究了一种使用超声搅拌悬浮液进样石墨炉原子吸收测定海洋沉积物中痕量镉的快速简便方法。使用丙三醇水溶液作为悬浮液介质,稳定时间可达７０ｍｉｎ,再用磷酸二氢铵作为基体改进剂,可使灰化温度大大提高,克服了基体干扰。用于海洋和澡流沉积物标准物质中镉的测定,对同一样品１０次平行测定的相对标准偏差为２．３％。标准曲线的线性范围为０－６．０μｇ．Ｌ＾－１,取得了较为满意的结果。     

类比法在电磁学教学中的运用

通过对电场、磁场的一般性质和规律进行对比、总结,给出了类比法在电磁学教学中的具体运用实例.     

A formula used to subtract the effect of gamma-ray of the others to that ofmeasured reaction in measurement of cross section of nuclear reaction andits application

According to the regulation of growing and decay of artificial radioactive nuclide, a formula used to subtract the effect of characteristic γ-ray of the others to that of measured reaction was deduced. And then the cross sections of ¹²⁰Te (n,2n)^119mTe reaction induced by neutrons around 14~MeV were measured by activation relative to the ⁹³Nb (n, 2n) ^92mNb. In the process of the cross sections measured to be calculated, it was subtracted that the effect of characteristic γ-ray of ¹²⁶Te (n, p) ¹²⁶Sb to that of measured ¹²⁰Te (n, 2n) ^119mTe reaction using the formula deduced. The experimental results were (689±37) and (750±41) mb at the neutron energies of (13.5±0.3) and (14.6±0.3)MeV, respectively. Measurements were carried out by γ-detection using a coaxial HPGe detector. As samples, spectroscopically pure tellurium powder has been used. The fast neutrons were produced by the T(d, n)⁴He reaction. The neutron energies in these measurements were determined by the method of cross-section ratios between ⁹⁰Zr (n, 2n) ^89m+gZr and ⁹³Nb (n, 2n) ^92mNb reactions.     

高斯定理在静电场中的应用问题

探讨了针对应用静电场高斯定理求解场强的一般条件、存在的误区以及对求解范围的扩展等问题,总结出高斯定理在静电场中应用的方法.