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排序方式: 共有253条查询结果,搜索用时 0 毫秒
51.
HPLC法测定太和春胶囊中淫羊藿苷的含量 总被引:2,自引:0,他引:2
建立了HPLC法测定太和春胶囊中淫羊藿苷含量的方法。采用KromasilC1 8(1 50mm× 4 .6mm ,5μm)色谱柱 ,以乙腈 水 (30∶70 )为流动相 ,流速 1 .0ml/min ,检测波长 2 70nm。结果表明 ,该法线性范围为3 .656mg/L~1 8.2 80mg/L,且相关系数良好 (r=0 .9999) ,平均回收率为 99.3 % ,RSD =1 .6 % (n =6)。本法快速、准确、简便 ,适用于太和春胶囊中淫羊藿苷的含量测定。 相似文献
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Supramolecular chemistry research is focused on the study of weak non-covalent intermolecular — that is, supramolecular — interactions as the driving force in self-assembly and molecular recognition. Dimeric resorcin[4]arenes capsules have been a focus of our research for the last 15 years. This review describes the solid state complexation studies of unsubstituted phenolic resorcin[4]arenes and pyrogall[4]arenes towards the formation of dimeric capsules and assemblies using ionic and neutral species as guest molecules and templates. The multitude of different crystal structures obtained during these studies demonstrates the versatile nature of resorcin[4]arenes and pyrogall[4]arenes (2-hydroxy-resorcin[4]arenes) as supramolecular hosts in crystal engineering. 相似文献
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Inclusion of guests inside molecular capsules may have pronounced effects on their chemical reactivity. This article provides a quick summary of research on the electrochemical reactivity of encapsulated redox-active guests. A brief account of the results obtained with simple hosts, such as cyclodextrins and cucurbiturils, starts the article. However, these hosts can only provide partial encapsulation. Most of the article is devoted to the results obtained by the authors’ group on the inclusion of ferrocene, cobaltocenium, and tetrathiafulvalene in molecular capsules formed by cavitand-type ligands, which give rise to supramolecular assemblies that provide full encapsulation. In general terms, trapping of redox-active centers inside molecular capsules leads to a substantial attenuation of their electrochemical kinetics, which results in electrochemically silent properties in extreme cases. However, the magnitude of this kinetic attenuation cannot be rationalized by simple criteria based on the overall size of the supramolecular assembly. 相似文献
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The dynamic charging performance of a solar heat storage system involving a packed bed containing spherical capsules is studied. The dynamic charging process of the solar heat storage system is simulated according to the energy balance equations. Paraffin is used as the phase change material (PCM) and water is used as the heat transfer fluid (HTF). The temperatures of the PCM and HTF, melting fraction and solar heat storage capacity are illustrated and analyzed. The influences of inlet temperature, initial temperature and flow rate of HTF, and the porosity of the packed bed on the charging time and heat storage capacity during the heat storage process are also discussed. 相似文献
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本文建立了描述蓄冷平板堆积床动态蓄冷性能的数理模型,并与实验结果进行了比较,两者吻合得较好。分析了载冷剂流量对充冷时间的影响,得到了载冷剂出口温度和蓄冷剂温度随时间的变化规律。该模型可为蓄冷平板堆积床的设计和优化提供依据 相似文献
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Caging Nb2O5 Nanowires in PECVD‐Derived Graphene Capsules toward Bendable Sodium‐Ion Hybrid Supercapacitors 下载免费PDF全文
Xiangguo Wang Qiucheng Li Li Zhang Zhongli Hu Lianghao Yu Tao Jiang Chen Lu Chenglin Yan Jingyu Sun Zhongfan Liu 《Advanced materials (Deerfield Beach, Fla.)》2018,30(26)
Sodium‐ion hybrid supercapacitors (Na‐HSCs) by virtue of synergizing the merits of batteries and supercapacitors have attracted considerable attention for high‐energy and high‐power energy‐storage applications. Orthorhombic Nb2O5 (T‐Nb2O5) has recently been recognized as a promising anode material for Na‐HSCs due to its typical pseudocapacitive feature, but it suffers from intrinsically low electrical conductivity. Reasonably high electrochemical performance of T‐Nb2O5‐based electrodes could merely be gained to date when sufficient carbon content was introduced. In addition, flexible Na‐HSC devices have scarcely been demonstrated by far. Herein, an in situ encapsulation strategy is devised to directly grow ultrathin graphene shells over T‐Nb2O5 nanowires (denoted as Gr‐Nb2O5 composites) by plasma‐enhanced chemical vapor deposition, targeting a highly conductive anode material for Na‐HSCs. The few‐layered graphene capsules with ample topological defects would enable facile electron and Na+ ion transport, guaranteeing rapid pseudocapacitive processes at the Nb2O5/electrolyte interface. The Na‐HSC full‐cell comprising a Gr‐Nb2O5 anode and an activated carbon cathode delivers high energy/power densities (112.9 Wh kg?1/80.1 W kg?1 and 62.2 Wh kg?1/5330 W kg?1), outperforming those of recently reported Na‐HSC counterparts. Proof‐of‐concept Na‐HSC devices with favorable mechanical robustness manifest stable electrochemical performances under different bending conditions and after various bending–release cycles. 相似文献
58.
建立一种用高效液相色谱(high performance liquid chromatography,HPLC)同时测定明胶胶囊中的11种合成色素的分析方法。样品经木瓜蛋白酶60℃水解30 min后,以CAPCELL PAK C18柱(4.6 mm×250 mm,5 μm)为分析柱,甲醇-乙腈(1:1)和15 mmol/L乙酸铵为流动相,梯度洗脱进行分离,以二极管阵列检测器检测,检测波长450(柠檬黄、喹啉黄)、520(新红、苋菜红、胭脂红、日落黄、诱惑红、偶氮玉红、赤藓红)和620 nm(靛蓝、亮蓝)。结果表明:11种合成色素在0~100 μg/mL浓度范围内线性关系良好,相关系数均大于0.999,方法检出限为0.3~2.5 mg/kg,回收率在79.1%~119.3%之间。该方法操作简便,灵敏度高,分离效果好,能实现11种色素的同步测定,适用于明胶胶囊中合成色素的检测分析。 相似文献
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Olga Kulygin Andrew D. Price Siow‐Feng Chong Brigitte Städler Alexander N. Zelikin Frank Caruso 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(14):1558-1564
Subcompartmentalized hydrogel capsules (SHCs) with selectively degradable carriers and subunits are designed for potential applications in drug delivery and microencapsulated biocatalysis. Thiolated poly(methacrylic acid) and poly(N‐vinyl pyrrolidone) are used to assemble 3‐µm‐diameter carrier capsules and 300‐nm‐diameter subunits, independently stabilized by a diverse range of covalent linkages. This paper presents examples of SHCs with tens of subcompartments and their successful drug loading, as well as selective degradation of the SHC carrier and/or subunits in response to multiple chemical stimuli. 相似文献