等离子体发射光谱法同时测定铬铁矿中铬、铁、镁和铝

铬铁矿属难熔矿种之一，经典分析方法在铂金坩埚内过氧化钠半熔，容量法测定铬、铁离子交换分离富集后，再用容量法或比色法测定其它元素，分离手续繁杂，耗费试剂多，周期长。等离子光谱（ICP）技术具有稳定性好、灵敏度高、线性范围宽、化学干扰少、多元素同时测定等优点，但由于仪器进样量和雾化效率受测定溶液含盐量的限制，试样前处理通常用酸分解，或碱熔后经沉淀分离除去大量可溶性盐类，用酸溶液沉淀，定容，待测。本文利用ICP上述优点对碱熔试样不经分离直接酸化，对高倍稀释试液测定铬铁矿中的主量元素进行了探讨。试验表明，此设想是可行的。本文还就试样的分解条件、酸度、元素间的光谱干扰作了研究，拟出了同时测定铬铁矿中铬、铁、镁、铝的分析方法。本法 质矿产部标准试样的结果与推荐值对照，符合要求。本法称取试样量少，试剂用量少，用银坩埚代替昂贵的铂坩埚，不经分离直接酸化后同时测定4种主量元素，大大简化了操作手续，为分析铬铁矿中主量元素的含量寻找了一条准、快、省的途径。     

浅谈油田开发钕铁硼永磁体温度和环境对其性能的影响

本文简述了工作温度和环境对油田开发用钕铁硼永磁体磁性能的影响，并探讨了改善钕铁硼永磁体耐热、耐蚀性的方法。     

Brick Walls for Nonstationary Black Holes

The validity condition of the brick-wall model is analysed in nonstationary space-time.It is shown that the model holds only in thin regions,only by using tortoise coordinates near the event horizon of a slowly varying(quasistationary)black hole.The reason for the use of tortoise cooridnates is that the stationary state solutions of quantum field equations in other coordinates do not exist for any region in nonstationary space-time.Meanwhile,the quantum corrections to the entropy of the Vaidya-Bonner black hole due to the spin fields are calculated in terms of the brick-wall model.     

大型爆轰实验示波器组群控制系统

针对爆轰实验中示波器的应用特点，介绍大型爆轰实验示波器组群控制系统。分析了基于GPIB接口的示波器组群的硬件连接方式，控制软件的组成，示波器的实验过程控制方式，数据存储格式和示波器组群控制系统的安全措施。     

D—Wave Kondo Problem in a Square Tight—Bounding Lattice

A Kondo model in a square tight-bonding lattice of conduction electrons is considered.The Kondo interaction takes a d-wave.Using mean-field theory and numerical simulations,it is found that there is a pseudo-gap for the impurity density of states at the Fermi level.Numerical results also show that the exponents of the lowtemperature thermodynamic quantities are non-universal but dependent on the interaction.     

Nonlocality Property of Three—Mode Correlated Fields

Four three-mode correlated states are generated by two beam splitters.We show that,by means of parity measurement,those light fields exhibit the nonlocality represented by the violation of the Bell inequality.The conditions fo the maximum violation are also studied.     

A New Method for the Raman Spectra Calculation of Vitreous or Molten Silicate

A new method is deduced to calculated the Raman spectra of vitreous or molten silicate.This method includes five steps:(i) molecular dynamics simulation to generate thousands of vitreous or molten configurations in equilibrium;(ii)decomposing the configurations into five kinds of defined tetrahedral units;(iii) normal vibrational analysis with Wilson‘s GF matrix method for the eigenfrequencies and eigenvectors of each tetrahedral unit;(iV) Raman intensity calculations for each vibrational mode by utilizing the electro-optical parameter method and bond polarizability model;(v)accumulating the data of frequencies and corresponding intensities to form the prtial Raman spectral line of each defined tetrahedral unit and finally the envelope.     

Theoretical Study of the Opacity for Mixture Materials at High Temperatures

Using a detailed configuration accounting model with term structures treated by the umresolved transition array model,we have extensively investigated the opacitiesof mixture materials.For plasmas at the temperature of 250 eV and density of 1 g/cm^3,our calculated Rosseland mean opacities are in good agreement with other theoretical results.A high increase in the Rosseland mean opacity to 2944cm^2/g is achieved for a multi-element mixture compared to the value of 1729cm^2/g for pure gold.Various mixtures at other plasma conditions are also studied.     

Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques.It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes.The aggregates are not solvolyzed in acetone,and do not take part n any chemical reactions either.It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone.The aggregation is reversible,and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.