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531.
532.
郗玉松 《邵阳高等专科学校学报》2011,(4):12-15
《海国图志》系魏源愤于鸦片战争失败,为了寻求抵抗西方侵略方策而编辑的一部名著,倾注在这部著作中的“师夷”、“制夷”的反侵略思想,集中反映了魏源的爱国主义情怀。这部书传播到日本后,引起日本社会的广泛共鸣,在介绍和传播“西洋情形与一般近代文化”、“关于国际法和立宪政治的知识”以及影响日本维新运动的发展上曾起过重要的作用。 相似文献
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534.
Characterization of chemical constituents in Zhi–Zi–Da–Huang decoction by ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry 下载免费PDF全文
Heyun Zhu Ran Yin Fei Han Jiao Guan Xiaoshu Zhang Xinjuan Mao Longshan Zhao Qing Li Xiaohong Hou Kaishun Bi 《Journal of separation science》2014,37(23):3489-3496
A sensitive and reliable ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method was established to separate and identify the chemical constituents of Zhi–Zi–Da–Huang decoction, a classic traditional Chinese medicine formula. The chromatographic separation was achieved on a Shim‐pack XR‐ODS C18 column (75 × 3.0 mm, 2.2 μm) using a gradient elution program. The detection was performed on a Waters Xevo G2 Q‐TOF mass spectrometer equipped with electrospray ionization source in both positive and negative modes. With the optimized conditions, a total of 82 compounds were identified or tentatively characterized. Of the 82 compounds, 21 compounds were identified by comparing the retention time and MS data with reference standards, the rest were characterized by analyzing MS data and retrieving the reference literature. In addition, 31 compounds were identified from Gardenia jasminoides Ellis, ten compounds were identified from Rheum palmatum L., 33 compounds were identified from Citrus aurantium L., and eight compounds were identified from Sojae Semen Praeparatum. Results indicated that iridoids, anthraquinones, flavonoids, isoflavonoids, coumarins, glycosides of crocetin, monoterpenoids, and organic acids were major constituents in Zhi–Zi–Da–Huang decoction. It is concluded that the developed ultra high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method with high sensitivity and resolution is suitable for identifying and characterizing the chemical constituents of Zhi–Zi–Da–Huang decoction, and the analysis provides a helpful chemical basis for further research on Zhi–Zi–Da–Huang decoction. 相似文献
535.
轴颈倾斜的径向轴承热弹性流体动力润滑分析 总被引:1,自引:0,他引:1
通过联立求解质量守恒的广义Reynolds方程、能量方程、固体热传导方程和固体变形方程,建立了轴颈倾斜的径向轴承三维热弹性流体动力润滑(TEHD)模型.在此基础上,深入研究了轴颈倾斜径向轴承的TEHD性能.结果表明,弹性变形和热变形都对轴颈倾斜径向轴承的性能具有显著影响.当只考虑弹性变形时,油膜厚度变化曲线出现了局部“凸”的形状,且最大油膜压力减小;当只考虑热变形时,油膜厚度变化曲线出现了局部“凹”的形状,且最小油膜厚度增大,但热变形对最大油膜压力的影响不大;当同时考虑弹性变形和热变形(即完整的TEHD模型)时,轴颈倾斜径向轴承的所有性能参数都发生了明显的变化,因此,对于重载高速的操作工况,有必要建立轴颈倾斜径向轴承的TEHD模型. 相似文献
536.
Chemical profiling approach to evaluate the influence of traditional and simplified decoction methods on the holistic quality of Da‐Huang‐Xiao‐Shi decoction using high‐performance liquid chromatography coupled with diode‐array detection and time‐of‐flight mass spectrometry 下载免费PDF全文
Da‐Huang‐Xiao‐Shi decoction, consisting of Rheum officinale Baill, Mirabilitum, Phellodendron amurense Rupr. and Gardenia jasminoides Ellis, is a traditional Chinese medicine used for the treatment of jaundice. As described in “Jin Kui Yao Lue”, a traditional multistep decoction of Da‐Huang‐Xiao‐Shi decoction was required while simplified one‐step decoction was used in recent repsorts. To investigate the chemical difference between the decoctions obtained by the traditional and simplified preparations, a sensitive and reliable approach of high‐performance liquid chromatography coupled with diode‐array detection and electrospray ionization time‐of‐flight mass spectrometry was established. As a result, a total of 105 compounds were detected and identified. Analysis of the chromatogram profiles of the two decoctions showed that many compounds in the decoction of simplified preparation had changed obviously compared with those in traditional preparation. The changes of constituents would be bound to cause the differences in the therapeutic effects of the two decoctions. The present study demonstrated that certain preparation methods significantly affect the holistic quality of traditional Chinese medicines and the use of a suitable preparation method is crucial for these medicines to produce special clinical curative effect. This research results elucidated the scientific basis of traditional preparation methods in Chinese medicines. 相似文献
537.
Identification and screening of chemical constituents with hepatoprotective effects from three traditional Chinese medicines for treating jaundice 下载免费PDF全文
Shufang Wang Xiaodong Li Yan Niu Yining Liu Yunxiang Zhu Xiaoyan Lu Xiaohui Fan Xingxian Zhang Yi Wang 《Journal of separation science》2016,39(19):3690-3699
The constituents with hepatoprotective activity were investigated in three traditional Chinese medicine formulae for treating jaundice, namely, Zhi‐Zi‐Da‐Huang‐Tang, Yin‐Chen‐Hao‐Tang, and Da‐Huang‐Xiao‐Shi‐Tang. By using liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry and liquid chromatography coupled with ion trap mass spectrometry, 79 chemical constituents were identified unambiguously or tentatively in three formulae based on the accurate molecular weight, mass spectrometric fragmentation behavior, and comparison with reference standards. Then the hepatoprotective activities of 27 constituents were evaluated on tert‐butylhydroperoxide‐injured BRL‐3A cells. The results indicated that 11 constituents, including protocatechic acid ( 19 ), epijasminoside A ( 56 ), rutin ( 71 ), tetrahydropalmatine ( 76 ), rhaponticin ( 80 ), 3,4‐dicaffeoylquinic acid ( 82 ), 3,5‐dicaffeoylquinic acid ( 85 ), diosmetin‐7‐O‐glucoside ( 90 ), jatrorrhizine ( 93 ), berberine ( 100 ), and daidzein ( 101 ) exerted hepatoprotective activities. Interestingly, most of the crude drugs in three formulae contained hepatoprotective active constituents, and the combinations of constituents from different crude drugs exhibited greater effects. This result provided evidence to the traditional Chinese medicine theory of combining several drugs together to exert synergistic efficacy. 相似文献
538.
【目的】研究广西近岸水下平原沉积物重金属分布和积累特征,促进对重金属自河口海湾向陆架扩散规律的对比与把握。【方法】从广西近岸水下平原采集表层沉积物和岩芯,通过实验测试的手段,分析表层沉积物重金属Pb、As、Hg的分布和积累特征。【结果】广西近岸水下平原表层沉积物中Pb含量为8.0×10-6~44.7×10-6,As含量为1.6×10-6~31.4×10-6,Hg含量为0.001×10-6~0.086×10-6,变化较大;Pb、As、Hg的分布受沉积环境和沉积物类型影响,As含量在水下平原北部水动力作用强烈之处出现局部高值,与含As的母岩风化有关;Pb、As、Hg有一定的共聚性,并显示亲Ni、Zn、Ga、Zr和疏Sr的特征;Pb、As、Hg与粒度参数有线性和聚类关系,对粒级响应性即斜率k的拐点在~0.125mm至~0.063mm之间,视沉积环境和沉积物的不同而有所移动;贫有机质站位由于水动力作用强烈,以自然风化的物理过程为主,重金属含量很低,而有机质积累成因为主的站位重金属含量积累增幅区间的频率,Pb的以40%~60%最高,As和Hg的均是60%~80%最高,增幅序列均遵循单增自然对数关系,曲线分段对应不同的沉积环境。【结论】广西近岸水下平原表层沉积物质量总体较好,但相对区域本底值来看,Pb积累性比较突出,As次之。 相似文献
539.
利用OpenSEES系统,基于Lazan材料阻尼与应力关系的研究理论,采用Hognestad混凝土本构关系模型及Karsan-Jirsa加卸载准则,计算素混凝土构件在轴向重复荷载作用下的滞回曲线包围面积,得到混凝土正应力作用下单位体积损耗能量.分析计算结果表明,素混凝土材料单位体积损耗能量随最大应力幅值的提高而增大,在相同最大应力幅值处混凝土强度越高,单位体积耗能越小.对结果非线性回归建立了素混凝土材料单位体积耗能与最大应力幅值及混凝土强度之间的关系式,在理论上为混凝土材料阻尼的计算提出了新的思路及方法,也为进一步准确分析其结构动力性能、进行安全经济合理的抗震设计打下基础. 相似文献
540.
硒是影响人体健康的重要生命元素,水中硒和氟含量具有较强的关联性,山东北部滨海平原区地下水氟含量较高,但硒含量地球化学特征尚未有详细的报道。本文选定卜庄镇为研究对象,系统分析了地下水硒含量,结果表明:地下水硒含量为1.43~15.60μg/L,平均值为6.23μg/L,仅王卢村硒含量超过地下水标准(10μg/L),有8个村庄地下水硒含量超过5μg/L。该区除金山村外,地下水氟含量超标,但硒和氟无显著相关性,表明该区地下水硒富集和氟富集动力存在差异。地球化学指标表明该区地下水受到海水入侵浸染,与未受浸染的参照样品相比,该区地下水硒含量明显升高。地下水硒含量与p H无显著相关性,与Fe、溶解固体总量、Cl~-、Br~-、Na~+、Mg~(2+)、SO_4~(2-)显著正相关,海水入侵引起的离子竞争吸附和高的Na-MgSO_4~(2-)矿物是影响该区地下水硒含量变化的重要动力。 相似文献