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建立“量化劳动”管理,主要是解决公路养护管理和养护作业过程中存在的规范管理和效益管理的问题,它将克服存在养护管理体制中“凭感觉”管理的成份,为实现社会主义市场经济条件下养护管理和养护作业相剥离的养护体制改革的顺利进行创造条件。 相似文献
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Bacterial pore-forming toxins (PFTs) are essential virulence factors of many human pathogens. Knowl- edge of their structure within the membrane is critical for an understanding of their function in pathogenesis and for the development of useful therapy. Atomic force microscopy (AFM) has often been employed to structurally interrogate many membrane proteins, including PFTs, owing to its ability to produce sub-nanometer resolution images of samples under aqueous solution. However, an absolute prerequisite for AFM studies is that the samples are single-layered and closely-packed, which is frequently challenging with PFTs. Here, using the prototypical member of the cholesterol-dependent cytolysin family of PFTs, perfringolysin O (PFO), as a test sample, we have developed a simple, highly robust method that routinely produces clean, closely-packed samples across the entire specimen surface. In this approach, we first use a small Teflon well to prepare the supported lipid bilayer, remove the sample from the well, and then directly apply the proteins to the bilayer. For reasons that are not clear, bilayer preparation in the Teflon well is essential. We anticipate that this simple method will prove widely useful for the preparation of similar samples, and thereby enable AFM imaging of the greatest range of bacterial PFTs to the highest possible resolution. 相似文献
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介绍了上海轨道交通DC01型电动列车牵引控制单元及其插件板微机检测装置的检测原理和软硬件结构。阐述了工控主机、电气控制箱等硬件设计,以及检测装置软件的主程序模块设计、插件板检测程序设计、静态程序设计等软硬件方面所需要解决的关键技术及其实现方法。该装置的研制运用提高了牵引控制单元系统及其插件板的检修质量和检修效率。 相似文献
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Based on published reports and direct observation, the common resources of landscape plant species in the Shanghai area were
identified and studied in terms of the landscape characteristics of timing sequence changes over a one year time period. The
results showed that there were 199 common landscape plant species in Shanghai, distributed in 67 families and 129 genera.
These plants were categorized by three ornamental characteristics: flowers, foliage and fruits. The species were thus further
analyzed according to the time periods which these characteristics were present. The results showed that flower ornamental
distributed throughout the year, particularly from April to June, and plant species with colorful foliage could be seen every
month, and particularly in November and December. On the other hand, few plant species with fruit ornamentals were observed
in Shanghai area. The diversity of landscape timing sequence changes of the 199 plant species under examination was then analyzed
by using the Shannon-Weiner and Simpson index formulas. The results showed that the higher diversity was observed in January,
February and from August to October, while the lowest diversity was recorded from March to July and during November and December.
The diversity of landscape characteristics of these plants was ranked according to foliage, flowers and fruit. Using this
method, one park and one plant community were selected to evaluate the advantages and disadvantages of their time-changing
plant landscape, with the goal of assessing the validity of the chosen ranking method. These results in the present study
would be helpful to evaluate the plant landscape in a specified space and further enrich the diversity of plant and landscape
by a target-oriented way. 相似文献
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本文基于统计能量法分析了横向加筋板,纵向加筋板,斜加筋板,圆心在板角的圆弧形加筋板,圆心在板中轴的圆弧形加筋板,正交加筋板等六种不同加筋形式板在100Hz至1000Hz内的声辐射特性,研究表明正交加筋板的平均辐射声压级要低于另外五种形式的加筋板.研究了两类改变加强筋间距的横向加筋板的声辐射性能,研究表明对于固定左侧的一根加强筋改变加强筋间距,随着加强筋间距的增大,辐射声压级先增大后减小,而对于板中线为基准改变加强筋间距,对辐射声压级影响不大.最后,本文研究加筋板在主机舱中的实际应用,建立了三种主机舱模型,分析模型的声辐射特性,研究表明复合加筋形式的主机舱辐射声压级最小,相对于无加筋形式,要低4~5dB左右. 相似文献
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