青海城镇体系发展的历史轨迹与动力

青海城镇体系经历了发韧期、奠基期、转型期3个发展历程.在这一过程中,湟水谷地最先拉开了城镇发展的历史帏幕,随后逐步向西扩展进入青海湖地区.宏观上,从农耕区向农牧交错区渗透,进而向游牧区拓展,反映了社会历史进程和地域开发进程的调控作用,因此城镇分布数量和密度呈现出农耕区—农牧交错区—游牧区逐级递减的趋势.中观上,以河流为脉络,城镇发展或溯源而上伸入高原腹地,或向河谷两岸推进,进入山区,表现为从优势生存空间向劣势生存空间的时空转化,城镇数量与密度呈现出川水地区—浅山地区—脑山地区的递减趋势.微观上,河谷农耕区城镇选址多位于河流阶地上,土地肥沃,取水便利;而牧区城镇的选址却往往与水草丰美的牧场相关,映射出古代城镇对自然条件和自然物质基础的依赖性.总体而言,青海省城镇兴起和发展的动力,主要来自于外部中央行政建制和军事据点的设置,而非城镇内部社会经济自我发展.就单个城镇而言,民族文化、民族宗教与民族贸易的亲合关系和响应力,是城镇成长的主要推进剂.     

经济全球化背景下人的发展

阐述了经济全球化对人的发展既有使个人需要的相对丰富,可以提高人的文化品位等积极影响,也有受益不均,发展机会不平衡、贬抑人的价值等消极影响的论点.指出要趋利避害,为人的发展创造良好的环境.     

断续喷洒去溶电热雾化法在电感耦合等离子体原子发射光谱方法中的应用研究

本文所讨论的电热雾化法是采用继续喷洒去溶技术,使试样在石墨炉表面逐步积累的进样方法。文章简要介绍了实验条件的选择和控制以及石墨炉装置的结构,探讨了提高电热雾化法相对检测能力的途径。实验结果表明:谱线黑度值与试样积累时间的对数值之间具有较好的线性关系。     

流动注射-氢化物发生-原子吸收光谱法测定雪中的微量铅

建立了测定雪中微量铅的流动注射-氢化物发生-原子吸收光谱法。在优化条件下。测定铅的线性范围为0～52．0ng／mL，线性回归方程为A=0．018c 0．016，相关系数r=0．9995，检出限为0．2ng／mL。用于雪中微量铅的测定，加标回收率为94．2％～107．3％，相对标准偏差为1．47％～3．22％。该方法的测定结果与标准加入法基本一致。     

Novel flow injection-fluorometric method for the determination of trace silicate and its application to ultrapurified water analysis

A highly sensitive fluorescence quenching method for the determination of silicate based on the formation of an ion associate between molybdosilicate and Rhodamine B (RB) in nitric acid medium was developed. A flow injection system coupled with a fluorescence detector was used for the measurement of fluorescence intensity at 560 and 580 nm as excitation and emission wavelengths, respectively. The calibration graph for Si showed a linear range of 0.1–5 ng cm⁻³ with correlation coefficient of 0.9999, and the detection limit of 0.06 ng cm⁻³. The proposed method was successfully applied to the determination of silicate in ultrapurified water with satisfactory results.     

流动注入吸附溶出—催化极谱氢波分析痕量铂

本文叙述一种流动注入吸附溶出一催化极谱测定痕量铂的新技术,它集中了溶出法、催化波和流动注入的优点,达到非常高的灵敏度和分析速度。实验给出了最佳载液组成、流速、注入体积、吸附富集电位和吸附时间等因素。本方法成功地进行了多种铂络合物、矿样和生物样品分析。     

LC Packing Materials for Pharmaceutical and Biomedical Analysis

 The author has prepared novel liquid chromatography (LC) packing materials for pharmaceutical and biomedical analysis. Those include LC packing materials for direct serum injection assays of drugs and their metabolites, LC packing materials for resolution of enantiomeric drugs, and uniformly sized molecularly imprinted polymers for drugs and their metabolites.     

Extension of the measuring range of balances

The basic principle of comparing the sample mass with the mass of a reference body in equilibrium gives the equal-armed beam balance a unique accuracy. Main parameters characterising the suitability of the instrument are measuring range, resolution and relative sensitivity (resolution/maximum load). The historical development of the values of these parameters achieved depended strongly on the practical need in those times. Technically unfavourable scales of the oldest Egyptian dynasties (~3000 BC) could resolve mass differences of 1 g and had a relative sensitivity of at least 10^–3. More sophisticated instruments from the 18^th Dynasty (~1567–1320 BC) achieved a relative sensitivity of 10^–4 independent of the size of the instrument. In 350 BC Aristotle clarified the theory of the lever and at about 250 BC Archimedes used the balance for density determinations of solids. The masterpiece of a hydrological balance was Al Chazini’s 'Balance of Wisdom’ built about 1120. Its relative sensitivity was 2⋅10^–5. Real progress took place when scientists like Lavoisier (1743–1794) founded modern chemistry. At the end of the 19^th century metrological balances reached a relative sensitivity of 10^–9 with a maximum load of several kilogrammes. That seems to be the high end of sensitivity of the classical mechanical beam balance with knife edges. Improvements took place by electrodynamic compensation (Emich, Gast). In 1909 Ehrenhaft and Millikan could weigh particles of 10^–15 g by means of electrostatic suspension. In 1957 Sauerbrey invented the oscillating quartz crystal balance. By observing the frequency shift of oscillating carbon nanotubes or of silica nanorods, masses or mass changes in the attogram or zeptogram have been observed recently.     

壁喷电池在流动注射阳极溶出伏安法中的应用

在流动注射阳极溶出伏安法中应用壁喷电池,探讨了非稳定态电积过程的溶出峰电流理论方程,预言了峰电流正比于R~(3/4)(R为工作电极半径),并对有关参数进行了实验验证。对5×10~(-7)mol/L Cd(Ⅱ)连续测定40次,表明相对标准偏差为0.94％。