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1.
Liew Seng  Fong 《科技资讯》2010,(32):232-232
论文注重于马来西亚从1970年开始实行经济改革以及以来所执行的相关政策。  相似文献   
2.
由聚合物稳定的铂纳米催化剂对环己烯催化加氢反应具有较高的催化活性,在铂纳米催化剂中引入第二金属元素钯,即在纳米铂颗粒上包裹一层钯,形成具有球壳结构Pt-Pd双金属催化剂,随引入钯的量不同,其催化能力的大小发生了变化.而且调节反应溶液的pH值,催化能力也发生变化.  相似文献   
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4.
F Y Liew  S M Russell 《Nature》1983,304(5926):541-543
Mice infected with an aerosol of influenza type A virus, or immunized with purified UV-inactivated whole virus or with viral subunits, develop a transient delayed-type hypersensitivity (DTH) which peaks 5-7 days after immunization. The intensity of DTH is greatly enhanced and sustained when mice are pretreated with cyclophosphamide. The reaction is maximal 24 h after elicitation, has classical tuberculin-type histology and is transferable by immune H-21 region restricted Lyt-1+2- T cells (Td) but not by immune serum. These Td cells not only fail to protect mice against influenza virus infection, but increase the mortality rate due to influenzal pneumonia following challenge with homologous lethal virus. On the other hand, antigen-specific suppressor T (Ts) cells which inhibit DTH are readily generated during influenza virus infection, and are detectable for at least 40 days thereafter. The ease with which they are induced and maintained during the infection may be of evolutionary advantage. In support of this, we now report that these Ts cells can reverse the pathogenic effect of Td cells thereby demonstrating a beneficial influence of Ts cells in a viral disease.  相似文献   
5.
棕榈油厂的倾析渣含较高有机物质.可将其用作吸附废水中金属离子吸附剂.倾析渣经105℃干燥后于500℃碳化,以碳化后的倾析渣去除Cd^2+,Cu^2+和Pb^2+.采用热重分析法分析碳化后的倾析渣表明:倾析渣湿度为4%,含挥发物21%、固定碳物23%、灰化物52%.运用朗格缪尔(Langmuir)等温模型和弗罗因德利奇(Freundlich)等温模型分析了含倾析渣1 g/100 mL离子水溶液,结果表明:碳化后的倾析渣对Cd,Cu,Pb的最大吸附量分别为24,23,97 mg/g,且吸附动力学遵循准二级反应动力学模型.测定了热力学参数标准生成焓(ΔH°)、标准熵(ΔS°)、标准自由能(ΔG°).  相似文献   
6.
微波法纳米镍的制备   总被引:1,自引:0,他引:1  
探索了微波法制备纳米镍的有效方法及反应条件.在微波辐射快速加热的条件下,以乙二醇为溶剂,PVP为保护剂,采用N2H4.H2O还原N iC l2.6H2O,通过改变PVP、N2H4.H2O、N a2CO3的用量,经60s制备了大小比较均匀、平均粒径在50~100nm的球状纳米镍.TEM结果表明:这些纳米N i是由许多平均粒径为6 nm的小颗粒的纳米N i组成的球状聚集体.N a2CO3与N iC l2的最佳摩尔比为1∶1,PVP与N iC l2的摩尔比控制在40,N2H4.H2O与N iC l2的摩尔比控制在5.  相似文献   
7.
Female fertility and offspring health are critically dependent on the maintenance of an adequate supply of high-quality oocytes. Like somatic cells, oocytes are subject to a variety of different types of DNA damage arising from endogenous cellular processes and exposure to exogenous genotoxic stressors. While the repair of intentionally induced DNA double strand breaks in gametes during meiotic recombination is well characterised, less is known about the ability of oocytes to repair pathological DNA damage and the relative contribution of DNA repair to oocyte quality is not well defined. This review will discuss emerging data suggesting that oocytes are in fact capable of efficient DNA repair and that DNA repair may be an important mechanism for ensuring female fertility, as well as the transmission of high-quality genetic material to subsequent generations.  相似文献   
8.
Surface pollen from various montane vegetations in Shalixian Mt.and Lepei Mt.of central and northern Taiwan have been explored and analyzed.The pollen data were used to simulate vegetation types by using the biomisation technique,Computing three matrixes of pollen taxa , plant functional types and combined biomes,vegetation types at each site have been finally defined through the fuzz selections of a tie-breaking rule.The results show that surface pollen data can simulate the subtropical Castanopsis and Cyclobalanopsis forests.alpine warm-temperate Quercus and Quercus-Pinus forests,and alpine temperate/cool-temperate conifers of Tsuge-Picea and Picea-Abies forests.Simulated elevations of the,forests are similar to actual locations of the forests.This study can add vertical surface pollen data for extending investigation of various vegetation types in China,provide PFT schemes and vegetation types in low-latitude and montane areas,and be applied as modern analogues for fossil pollen in order to reconstruct Quaternary vegetations.  相似文献   
9.
以柠檬酸钠直接还原氯铂酸制备出了平均粒径为1.3am的纳米铂微粒.在水溶液中,纳米铂粒子具有一个较弱的二级散射光谱,在牛血清白蛋白(BSA)存在下,其二级散射光谱大大增强并产生相应的散射光谱,最大波长位置位于516am.据此建立了一种灵敏快速简洁的测定蛋白质的分析方法.在酸性条件下,BSA在0~2.4mg/L范围内与散射峰强度的变化△I成正比,检测限为3.8μg/L.  相似文献   
10.
紫外-可见光谱分析在纳米颗粒超声分散中的应用   总被引:4,自引:0,他引:4  
探索了紫外-可见光谱分析在纳米颗粒超声分散中的应用;随着超声的进行,其紫外-可见光谱曲线上升;当超声时间达到某一值时,随着超声时问的增加其曲线反而下降.结合分散体系的TEM检测,从其粒径分布图可看到,随着时间的增加,其平均粒径先由大变小,然后再增大.定性地说明了紫外-可见光谱检测与透射电子显微镜检测是一致的.预测了紫外-可见光谱在纳米材料分散过程中的应用.  相似文献   
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