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331.
在电动自行车电池使用过程中,需要定期对电池充电以满足用户需求,此文分别对温度与电动自行车电池的材料、容量、寿命、充电电压及存储时间的关系进行研究。结果表明电动自行车电池最宜使用温度为25℃左右,温度过高或过低,都会降低电池使用寿命。 相似文献
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Fungal infection remains a major problem worldwide, yet treatment options are limited owing to the lack of effective drugs, the significant toxicity of available compounds, and the emergence of drug resistance. The low toxicity of calcofluor white (CFW) is an attractive antifungal compound for its known inhibitive effects on trichophyton rubrum and candida albicans growth. However, the efficacy of CFW is limited in most cases. In order to search for effective means to improve its efficacy, using saccharomyces cerevisiae as a model, we have used microarrays to examine the cell's response when treated with CFW on the genome scale. We found that both the PKC-SLT2 (i.e, protein kinase C-mitogen activated protein kinase) and the glycogen metabolic pathways are activated upon CFW treatment. These results suggest that the key components in these pathways could be targeted by other drugs to counter the cell's compensative response, thus to further substantiate the inhibitive effect of CFW on fungal growth, which may lead to treatment regimens with improved efficacy of this compound in clinical applications. 相似文献
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结合桥梁冬季施工中存在的问题,对水泥水化热的影响和混凝土早期受冻的影响等问题进行详细介绍.以贵阳某桥段冬季施工为例,针对所出现的问题采取了材料保温与养护保温的改善措施,可为同类工程提供参考借鉴. 相似文献
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Scrap leather fibers (SLFs) modified with active silane containing epoxide groups were incorporated into poly(lactic acid) (PLA) modified by vinyl trimethoxysilane, i.e., the PLA/SLF composites were prepared for bio-composites by solvent compounding technology in this article. The effects of silane coupling agents on the structures of PLA and SLF molecules were examined, and the mechanical properties and thermal stability of PLA/SLF composites were also measured. The results of Fourier-transform infrared spectroscopy (FTIR) had proved that silane had been incorporated successfully to PLA and SLF molecules by means of the solvent technology. Scanning electric microscopy (SEM) was used to investigate both the changes in shapes between the pristine SLFs and the treated SLFs and the microscopic structures of composites. According to SEM results, it was shown that there were some significant differences between the untreated and treated SLFs, and a double continuous phase structure had occurred in PLA/SLF composites due to the excellent dispersion of SLFs in matrix. The addition of the treated SLFs into PLA resulted in a distinct improvement of the impact and tensile strengths. When the mass fraction of the treated SLFs was 15%, the notched impact strength and tensile strength of PLA/SLF bio-composites were improved by 34.4% and 21.2% compared with the pristine PLA, respectively. Additionally, with the increase of the modified SLFs content, the thermal stability of PLA/SLF bi-composites was apparently improved. The macroscopic properties of bio-composites were found to be strongly dependent on their components, concentration, dispersion and resulted morphological structures. 相似文献
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1 AutoCAD使用中的问题及解决方法AutoCAD作为设计行业的绘图软件,其操作简单易用,应用面之广泛在诸多软件中可以说是首屈一指的。AutoCAD版本也由原先AutoCAD R14升级至AutoCAD R2007,版本的升级带来了诸多新功能和便利,但是R14这 相似文献
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结合北京市典型信号控制交叉口实际情况,现场调查高峰时段7个保护相位下专用双左转车道的车头时距、周期流量、大型车比例等数据,对双左转车道使用特性和调头车辆影响特性进行分析。结果表明,左转车辆的内、外侧车道利用率为50%,大型客车倾向于选择外侧左转车道行驶,给出双左转饱和流率的范围为1587~1818pcu/h/ln,平均值为1665pcu/h/ln,并且得到内、外侧左转饱和车头时距均值无显著性差异的结论。考虑到内侧车道特有的调头行为对左转车辆运行的影响,用数学方法确定了调头行为带来影响的范围,给出左转调头车辆相对于左转标准小型车的当量值为1.39。 相似文献