On-line pretreatment and determination of Pb, Cu and Cd at the μg l level in drinking water by chelation ion chromatography

A novel, highly sensitive method for the simultaneous separation and determination of lead, copper, cadmium and other transition metals in drinking water was achieved by on-line sample pretreatment of chelation ion chromatography. Manganese, which coeluted with cadmium, was oxidized to permanganate by ammonium persulfate before injection. Permanganate, with bulk quantity of alkali, alkaline earth metals, iron and aluminum, was eliminated by pyrophosphoric acid–ammonium acetate buffer solution (pH 5.5), while retaining heavy and transition metals on a selective chelating resin (MetPac CC-1 column). Then, they were disabsorbed and transferred to a sulfonated cation exchanger (TMC-1 column). Finally, the concentrated trace metals were separated on a bifunctional ion-exchange column (CS5A) by a concentration gradient of oxalic acid and sodium nitrate eluents, coupled with post-column spectrophotometric detection with 2-[(5-bromo-2-pyridyl)azo]-5-diethylaminophenol (5-Br-PADAP) at 560 nm. The separation and color-development conditions were optimized. The detection limits for the method (signal-to-noise ratio=3:1) were at or below the μg l⁻¹ level. The results of drinking water analyses were satisfactory.     

Thermal, pressure and light switchable spin-crossover materials

This article reviews the most relevant chemical and structural aspects that influence the spin-crossover phenomenon (SCO). Special attention is focussed on the recent development of SCO coordination polymers. The different approaches currently being explored in order to achieve multifunctionality in SCO materials are discussed.     

Synthesis and fungicidal activity of novel strobilurin analogues containing substituted N-phenylpyrimidin-2-amines

A number of novel strobilurin analogues containing substituted N-phenylpyrimidin-2-amines were synthesized.The structures of these new compounds were confirmed by ~1H NMR,IR and elemental analysis.Biological evaluation in the greenhouse showed several compounds have good fungicidal activities at 25 mg/L.     

Two new secoiridoid glucosides from Syringa velutina Kom

Chemical investigation of Syringa velutina Kom. led to the isolation of two new secoiridoid glucosides. Their structures were identified as 6'-0-(6, 7-dihyrofoliamenthoyl)-8-epi-kingisidic acid (syrveoside A, 1) and 6'-O-menthiafoloyl-8-epi-kingisidic acid (syrveoside B, 2) on the basis of chemical and physicochemical evidence.     

苏北与苏南地区中小学生体质比较分析

江苏省地处我国东南沿海经济发达地区,由于历史原因,苏北、苏南在诸多方面存在着发展不平衡。根据调查数据,从身体形态、身体机能、身体素质等方面分析苏北与苏南地区中小学生体质存在的差异,为全面了解苏北地区中小学生体质健康状况、提高中小学体育水平提供参考依据。     

故障诊断专家系统学习机制

根据机器学习的特点，提出并设计了一种能在故障诊断过程中进行参数修正学习、知识扩充，并在诊断结束后能对知识进行归纳的专家系统学习机制。这一系统在可视化工程环境（ＶＥＥ）平台下实现，能有效地运行，使用方便。     

国内生产总值变化的趋势及其稳定性的研究

由消费、投资、进口、出口４个出数及均衡条件导出了国内生产总值所满足的一阶线性非齐次差分方程，并求出了国内生产总值ｙ１随时间ｔ的变化规律，给出了ｙ１稳定性的主分条件及单调条件，指目前宏观经济政策中出台的各项措施正是由ｙ１的规律所制约 。     

用无波函数微扰论和Padè近似方法计算双原子分子振动能级

本文不仅利用无波函数微扰论推导出了双原子分子的非谐振动能级的理论公式，而且还利用双变量 Ｐａｄè近似对 Ｈ Ｃｌ３５ 分子的振动能级做了具体的数值计算，通过选取适当的势参数，理论计算值和实验结果符合得很好     

嘧啶氧磷毒性和解毒试验研究

本文报道了嘧啶氧磷的急性经口，经皮毒性和解毒试验研究结果。嘧啶氧磷对小白鼠经口ＬＤ５０为８７ｍｇ／ｋｇ，大白鼠经口ＬＤ５０为１８３ｍｇ／ｋｇ，大白鼠经皮ＬＤ５０为１０６２ｍｇ／ｋｇ，氯磷定对嘧啶氧磷中毒有良好的解毒效果。     

BorlandC＋＋和汇编语言的接口技术

本文论述了ＢｏｒｌａｎｄＣ＋＋和汇编语言混合编程的方法，文中详细讨论混合编程中编程模式的选择，过程的调用，参数的传递，以及工程文件的制作和编译等内容。