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文章针对气压检定装置在使用中存在的一些问题,会同厂家对其进行了升级改造。介绍了改造后的气压检定装置的设计原理、软件和硬件设计以及技术指标等,新装置集成了目前先进的计量设备及技术,编写相应的程序软件升级改造而成。可广泛适用于气象部门空盒气压表、自动站气压传感器以及部分数字压力计的计量检定工作,实现气压检定工作的自动化,提高检定数据的准确性和可靠性,并有效提高检定的工作效率。 相似文献
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Yan Dai Shao-Ru Chen Ling Chai Jing Zhao 《Critical reviews in food science and nutrition》2019,59(11):S17-S29
AbstractAndrographis paniculata (A. paniculata) is a medicinal plant traditionally used as anti-inflammation and anti-bacteria herb. Andrographolide, the major active component of A. paniculata, exhibits diverse pharmacological activities, including anti-inflammation, anti-cancer, anti-obesity, anti-diabetes, and other activities. In this article, we comprehensively review the therapeutic potential of A. paniculata and andrographolide focusing on the mechanisms of action and clinical application. We systemically discuss the structure-activity relationship of andrographolide and derivatives. Despite the various pharmacological activities and formula of A. paniculata and andrographolide, we propose further development of more structural derivatives of andrographolide with reduced toxicity and increased therapeutic efficacy is still needed for the clinical application of this ancient mighty herb and its major component. 相似文献
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The thermodynamic properties of MgCaSi and its mother phase Ca2Si are comparatively investigated from ab initio calculations and quasi-harmonic Debye-Grüneisen model. At 0 K, MgCaSi is more thermodynamically stable. Under high temperature, the advantage of higher thermodynamically stability of MgCaSi is reduced, originating from the less negative entropy contribution because the thermodynamic entropy of MgCaSi increases more slowly with temperature and the entropy values are slightly smaller. With increasing temperature, the anti-softening ability for MgCaSi is slightly smaller due to the slightly faster decrease trend of bulk modulus than that of Ca2Si, although the bulk modulus of MgCaSi is higher in the whole temperature range considered. The thermal expansion behaviors of both MgCaSi and Ca2Si exhibit similar increase trend, although thermal expansion coefficient of MgCaSi is slightly lower and the increases is slightly slower at lower temperature. The isochoric heat capacity and isobaric heat capacity of MgCaSi and Ca2Si rise nonlinearly with temperature, and both are close to the Dulong–Petit limit at high temperature due to the negligibly small electronic contribution. The Debye temperature of both phases decrease with increasing temperature, and the downtrend for MgCaSi is slightly faster. However, MgCaSi possess slightly higher Debye temperature, implying the stronger chemical bonds and higher thermal conductivity than the mother phase Ca2Si. The Grüneisen parameter of MgCaSi and Ca2Si increase slightly with temperature, the values of MgCaSi are slightly larger. The investigation of electronic structures shows that with substitution of partial Ca by Mg in Ca2Si, the stronger MgSi, MgCa and SiSi covalent bonds are formed, and plays a very significant role for the structural stability and mechanical properties. 相似文献
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为创造良好的人居环境,针对近年来屡屡发生的城市内涝,分析了在规划设计中预防内涝的几种措施,比较了面积叠加法与流量叠加法的可靠性,提出应对城市绿地减少的几种措施,并指出低影响开发理念是雨水综合管理新思路,暴雨强度公式的修编及设计重现期的选择也是关系到排水迅速与安全的重要因素。 相似文献
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针对建筑结构设计要点进行了总结,分别阐述了剪力墙体系、框架—剪力墙体系、筒体体系的特点和优势,在此基础上对高层建筑结构分析的假定和分析方法作了具体介绍,指出不同建筑的结构构件及体系的尺寸和构成比例都需要科学合理的设计,从而保证其整体质量和使用性能。 相似文献
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HPLC法测定麻杏止咳糖浆中苦杏仁苷的含量 总被引:1,自引:0,他引:1
建立高效液相色谱法测定麻杏止咳糖浆中苦杏仁苷含量的方法。采用KromasilC18柱,乙腈-0.1%磷酸溶液(8∶92)为流动相,流速1.0mL·min-1,检测波长207nm。苦杏仁苷在0.0406~0.812μg范围内有良好的线性关系, r=0.9999,平均回收率为99.0%,RSD为0.25%。本方法简便、准确、重现性好,可用于麻杏止咳糖浆的质量控制。 相似文献