Results 41 to 50 of about 20,406 (216)
Determination of Pseudostellarin B in Pseudostellaria heterophylla by HPCE and Study on Its Fingerprints Analysis [PDF]
, 2007 建立了测定太子参中环肽Pseudostellarin B含量的高效毛细管电泳(HPCE)分析方法,对10种不同产地太子参中环肽Pseudostellarin B的含量进行了测定。HPCE工作条件:采用未涂层熔融石英毛细管(内径75μm,有效长度50cm),分离电压为15kV,柱温20℃,二极管阵列检测器(DAD)检测波长为203nm,缓冲液为20mmol/L硼砂(pH=9.3)溶液。在选定的工作条件下,环肽Pseudostellarin B浓度与其响应信号值之间具有较好的线性相关性(Y=0.6357X ...
李文龙, 王小如, 陈军辉, 韩超
core
Rare Metals, EarlyView.ABSTRACT The limited osteogenic capacity of magnesium phosphate cement (MPC) has constrained its biomedical applications, underscoring the necessity to develop MPC with enhanced physical properties and bone‐forming capabilities. In this study, a multifunctional MPC system was developed by incorporating zoledronic acid‐loaded near‐infrared (NIR ...
Bin Wang +8 more
wiley +1 more source
Dianci bileiqi, 2018 外引接地是降低风机接地电阻的常用措施,必须详细研究雷电流作用下风机外引接地的有效长度及其影响因素。利用PSCAD软件建立风机叶片、塔筒和外引接地系统模型,考虑冲击电流作用下外引水平接地体的散流特性和火花效应。讨论土壤电阻率、波头时间对外引接地有效长度的影响,拟合出相应函数关系。分析结果表明:采用外引接地措施能够降低接地体的冲击接地阻抗,但外引接地体存在一个明显的有效长度,超过有效长度后对降低冲击接地阻抗几乎没有效果。外引接地的有效长度随着波头时间和土壤电阻率的增加而增大,三者之间存在一个幂函数关系 ...
武振宇, 张克勇, 李晓航
doaj
Dianci bileiqi, 2023 山区输电线路杆塔所处位置通常土壤电阻率高且空间有限，故散流效果差，降阻比较困难。针对这些问题，本研究使用CDEGS软件设计了立体均压环结构接地体，在不同激励电流类型、土壤电阻率、接地体深度和水平射线长度情况下，进行了冲击特性的分析。仿真结果表明：在工频电流和雷电流作用下，该接地体都能够具有良好的均压和散流效果。相同土壤电阻率下，立体均压环接地体冲击接地电阻比传统圆环形接地体冲击接地电阻至少可较低8.9%,最大跨步电压至少可降低16.0%,在高土壤电阻率下，降低幅度增大 ...
周西杰 +4 more
doaj
, 1988 本文研究了XP合成纤维制备Mn一纤维的条件。XP纤维与KMnO4在酸性条件下作用制得的Mn一纤维MnO2附着量高达30一38克/100克纤维而且附粉牢周不易脱落。在动态条件下研究了海水样品的流速、PH、温度、Mn一纤维用量对Mn一纤维吸附Ra的影响。结果表明，Mn一纤维对Ra有很高的富集系数和动态容量，当Mn一纤维用量为7.5克，水样体积不超过40升，水温低于500C,PH大于3,流速为300—500ml/min时，Ra的回收率大于95%。比较了Mn一纤维直接封闭射气法与酸沥取封闭射气法的测量结果 ...
邱晓辉
core
Rare Metals, EarlyView.ABSTRACT In recent years, the field of magnetic materials has witnessed a paradigm shift from single‐function applications to multifunctional integration, driven by the growing demand for smart materials in advanced technologies. Among various magnetic systems, La(Fe, Si/Al)13‐series materials have emerged as particularly promising candidates due to ...
Irfan Liaquat +2 more
wiley +1 more source
Determination of Gentiopicroside and Loganic Acid in Radix Gentianae by MEKC and MEEKC Mode [PDF]
, 2007 目的建立胶束电动毛细管色谱(MEKC)和微乳液毛细管电动色谱(MEEKC)分析龙胆药材中龙胆苦苷和马钱子苷酸含量的方法。方法采用加速溶剂萃取法(ASE)对龙胆药材进行提取,萃取温度:100℃,压力:9.65MPa,萃取时间:10min。采用未涂层熔融石英毛细管(内径75μm,有效长度50cm)。分别考察了两种分离模式下电泳介质的构成和电泳过程中的各操作参数对样品分离过程的影响,优化了MEKC和MEEKC的分析条件,在各自对应的缓冲液体系下,MEKC和MEEKC分离电压分别为30和22kV,柱温均为25℃,
吴凤琪 +6 more
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Layer-by-layer self-assembly preparation and performance of GO-ceramics composite nanofiltration membrane [PDF]
, 2017 氧化石墨烯(GO)的片层边缘含有COOH等含氧官能团,因而带负电荷,可以在带正电荷多孔基体上通过层层自组装实现快速沉积。以由3-氨丙基三乙氧基硅; 烷(APTES)修饰的多孔氧化铝管式陶瓷膜为基膜,令GO和聚乙烯亚胺(PEI)以溶液形态在其表面交替沉积实现自组装,继以环氧氯丙烷(ECH)交联; 之,制备新型氧化石墨烯-陶瓷复合纳滤膜。最佳制备工艺是,PEI浓度5 g·L~(-1)、pH=9,NaCl浓度0.3; mol·L~(-1),GO浓度0.6 mg·ml~(-1)、pH=4.5,层数2层 ...
丁马太 +5 more
core +1 more source
Rare Metals, EarlyView.ABSTRACT Although lithium metal has been regarded as an ideal anode material for high‐energy‐density batteries, its practical applications remain hindered by many serious challenges. Three‐dimensional (3D) porous Cu current collectors demonstrate potential in ensuring uniform Li deposition.
Meng‐Qi Zhu +7 more
wiley +1 more source
Dual‐Stage Heat Treatment for Enhanced Hydrogen Storage Properties of Mg−Ni−Y Alloys
Rare Metals, EarlyView.ABSTRACT Mg−Ni−Y alloy is considered to be one of the most promising hydrogen storage materials, but its high dehydrogenation energy barrier hinders its practical application. A dual‐stage heat treatment (490°C × 4 h + 550°C × 4 h) is applied to optimize the microstructure and hydrogen storage performance of a vacuum‐melted Mg94Ni3Y3 alloy.
You Lv +6 more
wiley +1 more source