火焰原子吸收法测定人参中的微量镁

通过干法灰化、混酸消化、硝酸溶解的方法处理样品,利用火焰原子吸收法测定人参中微量镁的含量。待测溶液在0.06～7.0μg.mL-1范围内有很好的线性关系,回归方程为A=0.0565C+0.0405,相关系数为0.9987,检出限为0.008μg.mL-1,特征浓度为0.017μg.mL-1/1%,回收率为97.7～103.2%。方法适用于测定各种中药材中的微量镁含量。     

辽宁省制造业FDI技术外溢效应实证分析

辽宁省要打造具有国际竞争力的装备制造业基地,不仅要靠自主创新,也要加大技术引进力度和提升FDI的技术外溢效应。对辽宁省制造业FDI技术外溢效应进行研究,在一定程度上衡量出制造业利用FDI的绩效并找出问题,进而提出相关对策建议,为引进外资政策的调整提供理论依据。实证分析的结论表明,辽宁省制造业FDI具有一定的技术外溢效应,但也存在一些问题,需要采取有效措施妥善解决。     

日本“吸收型”技术创新模式的再思考

从日本战后"赶超经济"取得巨大成功,20世纪90年代又陷入严重经济危机的强烈反差中,重新审视了日本战后"吸收型"技术创新模式的效应;在肯定日本"吸收型"技术创新模式取得成绩的前提下,剖析了日本"吸收型"技术创新模式造成的自主创新乏力、知识人才储备不足、经济发展与技术进步的脱节、科学技术体系的分割等弊端;探讨了在新的时代背景下我国技术创新可从中借鉴的经验。     

SrWO_4晶体中F型色心电子结构的研究

运用相对论的密度泛函离散变分法(DV-Xa)研究了SrWO4晶体中F型色心的电子结构.计算结果表明,F和F+心在禁带中引入了新的施主能级;从施主能级到导带底的电子跃迁能分别是1.858,2.14 eV,这分别与669,581 nm的吸收带相对应.由此说明SrWO4晶体中669,581 nm吸收带起源于晶体中的F和F+心.     

电热原子吸收中涂层石墨管、基体改进剂及酸对锗吸光度的影响

本文对电热原子吸收测定锗时石墨管的种类、基体改进剂及酸的影响进行了试验,确定了满足微量锗测试的条件,但该方法对分析条件要求苛刻,条件稍有改变即导致较大的偏差,为现有文献中锗分析数据有较大差异提供了一个解释依据。     

原子吸收分光光度法测试技术浅探

为普及和提高原子吸收分光光度法的测试技术,通过长期的测试实践,本文对该技术进行综述,可望能对原子吸收分光光度测试技术有所提高.但其中有些技术,如样品的分解,标准溶液的配制及仪器的灵敏度改善等尚有待更详尽的探讨.     

批判、借助和吸纳——对马克思主义经典作家关于民族主义论述的再认识

马克思主义经典作家在对民族主义持一般反对态度的同时,也对民族主义的进步性做了肯定,对不同性质的民族主义做了区别.根据经典作家的理论设想和世界历史的发展实践,民族主义是实现无产阶级革命和社会主义目标必需的"过渡"性途径.民族主义有着极为鲜明的两重性,既与民族本位、偏狭与排外倾向相通,又为反对压迫和不公提供动员手段,为社会进步提供有效的政治建构和认同.马克思主义经典作家对这个两重性有着清晰的辨别,对其消极性做了严厉的鞭挞和批判,而将它的积极因素在实践上加以借助,在理论上吸纳改造,使其成为马克思主义民族理论的重要内容.马克思主义经典作家对于民族主义的批判、借助和吸纳,既是矛盾的,又是统一的.     

Covariance analysis and associated spectra for classes of nonstationary processes

In 1951, Cramér introduced a class of nonstationary processes. This broad class of processes contains the important harmonizable and stationary classes of processes. The Cramér class can have additional structure imposed upon it through Cesàro summability considerations. These refined Cramér classes, termed (c,p)-summable Cramér, have recently been considered by Swift (in: M.M. Rao (Ed.), Real and Stochastic Analysis: Recent Advances, CRC Press, Boca Raton, FL, 1997, p. 303). In this paper, the relationship between the (c,p)-summable Cramér classes and the (KF,p) classes of processes introduced by Rao in 1985 is considered. The (KF,p) classes of processes are a generalization of the class of processes considered by Kampé de Feriet and Frenkiel. A continuity theorem for the (KF,p) classes is obtained. This result yields a spectral representation for the (KF,p) classes. Some (KF,p) class processes are shown to arise as the solution to a difference equation obtained from a linear model of a noisy communication channel.     

Probabilistic modeling of percutaneous absorption for risk-based exposure assessments and transdermal drug delivery

Chemical transport through human skin can play a significant role in human exposure to toxic chemicals in the workplace, as well as to chemical/biological warfare agents in the battlefield. The viability of transdermal drug delivery also relies on chemical transport processes through the skin. Models of percutaneous absorption are needed for risk-based exposure assessments and drug-delivery analyses, but previous mechanistic models have been largely deterministic. A probabilistic, transient, three-phase model of percutaneous absorption of chemicals has been developed to assess the relative importance of uncertain parameters and processes that may be important to risk-based assessments. Penetration routes through the skin that were modeled include the following: (1) intercellular diffusion through the multiphase stratum corneum; (2) aqueous-phase diffusion through sweat ducts; and (3) oil-phase diffusion through hair follicles. Uncertainty distributions were developed for the model parameters, and a Monte Carlo analysis was performed to simulate probability distributions of mass fluxes through each of the routes. Sensitivity analyses using stepwise linear regression were also performed to identify model parameters that were most important to the simulated mass fluxes at different times. This probabilistic analysis of percutaneous absorption (PAPA) method has been developed to improve risk-based exposure assessments and transdermal drug-delivery analyses, where parameters and processes can be highly uncertain.     

热电冷三联供系统能耗与经济性分析

对三联供溴化锂吸收式制冷与蒸汽压缩式制冷作了能耗分析，计算了汽轮机在不同的初始参数条件下三联供溴化锂制冷的节煤量，并对这两种制冷方案进行了经济比较，得出三联供溴化锂制冷节能所需的条件.