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41.
42.
Andrew D. Kligerman Garret B. Nelson Jeffrey A. Ross Gregory L. Erexson 《Polycyclic Aromatic Compounds》2013,33(3-4):841-851
Experiments were designed to investigate how the route of exposure to polycyclic aromatic hydrocarbons (PAHs) in mice and rats affects the induction of cytogenetic end points and DNA adduction. Both mice and rats were exposed to 100 mg/kg of benz[ a ]anthracene (B[ a ]A), benzo[ b ]fluoranthene (B[ b ]F), benzo[ a ]pyrene (B[ a ]P), or chrysene (Chr) by gavage or by intraperitoneal injection (i.p.). Peripheral blood was removed by cardiac puncture 7 days after PAH administration. Blood samples were analyzed in parallel for sister chromatid exchange (SCE) frequency, the frequency of micronuclei in cytochalasin B-induced binucleate cells (MN bn ), and DNA adduction using 32P-postlabeling. The i.p. route of exposure produced both the highest levels of cytogenetic damage and DNA adducts for each PAH. The mouse was more sensitive than the rat to PAH exposure as measured by SCE induction and the total amount of DNA adducts/ w g DNA. 相似文献
43.
Selvaraj?Rengaraj Younghun?Kim Cheol?Kyun?Joo Kyunghee?Choi Jongheop?YiEmail author 《Korean Journal of Chemical Engineering》2004,21(1):187-194
The removal of copper from aqueous solution by ion exchange resins, such as 1200H and IRN97H, is described. Effect of initial
metal ion concentration, agitation time and pH on adsorption capacities of ion exchange resins was investigated in a batch
mode. The adsorption process, which is pH dependent, shows maximum removal of copper in the pH range 2–7 for an initial copper
concentration of 10 mg/L. The experimental data have been analyzed by using the Freundlich, Langmuir, Redlich-Peterson, Temkin
and Dubinin-Radushkevich isotherm models. The batch sorption kinetics have been tested for a first-order, pseudo-first order
and pseudo-second order kinetic reaction models. The rate constants of adsorption for all these kinetic models have been calculated.
Results showed that the intraparticle diffusion and initial sorption into resins of Cu(II) in the ion exchange resins was
the main rate limiting step. The uptake of copper by the ion exchange resins was reversible and thus has good potential for
the removal/recovery of copper from aqueous solutions. We conclude that such ion exchange resins can be used for the efficient
removal of copper from water and wastewater.
This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University. 相似文献
44.
在化工系统实际运行中,调度自动化实时系统与管理信息系统间存在数据交换的技术开发问题。以华鲁恒升集团调度自动化OASYS的系统的工程实际为基础,介绍一种实时SCADA系统与管理信息MIS系统间交换数据的实现方式。 相似文献
45.
Urban environmental mercury in Changchun, a metropolitan city in Northeastern China: source, cycle, and fate 总被引:10,自引:0,他引:10
Mercury concentrations in each environmental compartment in Changchun City had obvious spatial and temporal trends. Particulate Hg (HgP) and total gaseous mercury (TGM) concentrations in air, total Hg (HgT) concentrations in precipitation and ratios of HgP to HgT (total Hg in air) in the atmosphere in heating season were higher than those in non-heating season, which resulted from civil heating. In contrast, reactive Hg (HgR) concentrations in precipitation were higher in non-heating season than those in heating season. TGM and SO2 in air had good agreement. HgP concentrations in the atmosphere were correlated with HgT concentrations in precipitation. Based on Hg concentrations in each environmental compartment, Hg exchange fluxes between environmental interfaces were estimated. Only 11.6% of Hg, emitted from coal combustion, deposited into land surface in urban district and the rest part participated in regional or global cycle, so urban district was the source of Hg global and regional cycle. Net fluxes of Hg into land surface and water were 34.26 kg year(-1) and 0.051 kg year(-1), respectively, which were clearly accumulated in the water and soil. Therefore considering urban local Hg cycle, each environmental compartment of urban ecosystem (water, air and soil) was the sink of Hg. 相似文献
46.
文章依据石油企业管控一体化网络的开发过程,首先介绍LON网络中上位机与智能节点之间的通信方式,即LNSDDE Server在工业实时控制中的应用,然后介绍建立采油站管控一体化网络体系中的一些核心技术以及系统监控过程。 相似文献
47.
48.
R. S. Meghwal T. C. Loya S. L. Kakani 《Journal of Superconductivity and Novel Magnetism》2009,22(7):659-665
We consider the extended two-band s–f model with additional terms, describing intersite Cooper pairs’ interaction between
4f (5f) and conduction electrons. Following Green’s function technique and equation of motion method, self-consistent equations
for superconducting order parameter (Δ) and magnetic order parameter (m
f
) are derived. The expressions for specific heat, density of states, and free energy are also derived. The theory has been
applied to explain the coexistence of superconductivity and ferromagnetism in hybrid rutheno-cuprate superconductors RuSr2RECu2O8 (RE = Gd, Eu). The theory shows that it is possible to become superconducting if the system is already ferromagnetic. A study
of specific heat, density of states and free energy is also presented. The agreement between theory and experimental observations
is quite satisfactory.
相似文献
49.
分析了WEB网站的现状,提出了基于对象池的数据访问层技术,通过对象池技术的设计与实现,很好的解决了多用户并发访问网站的瓶颈.巧妙的设计了对象池页面置换算法,解决了缓存不够的问题.通过多个企业网站的稳定运行,验证了该方法的可靠性与可行性. 相似文献
50.