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排序方式: 共有343条查询结果,搜索用时 62 毫秒
1.
Yingchun Wu Haipeng Li Xuecheng Wu Gérard Gréhan Lutz Mädler Cyril Crua 《Proceedings of the Combustion Institute》2019,37(3):3211-3218
Droplet evaporation characterization, although of great significance, is still challenging. The recently developed phase rainbow refractometry (PRR) is proposed as an approach to measuring the droplet temperature, size as well as evaporation rate simultaneously, and is applied to a single flowing n-heptane droplet produced by a droplet-on-demand generator. The changes of droplet temperature and evaporation rate after a transient spark heating are reflected in the time-resolved PRR image. Results show that droplet evaporation rate increases with temperature, from ?1.28 m2/s at atmospheric 293 K to a range of (?1.5, ?8) m2/s when heated to (294, 315) K, agreeing well with the Maxwell and Stefan–Fuchs model predictions. Uncertainty analysis suggests that the main source is the indeterminate gradient inside droplet, resulting in an underestimation of droplet temperature and evaporation rate. With the demonstration on simultaneous measurements of droplet refractive index as well as droplet transient and local evaporation rate in this work, PRR is a promising tool to investigate single droplet evaporation in real engine conditions. 相似文献
2.
Reversibly light‐responsive biodegradable poly(carbonate) micelles constructed via CuAAC reaction 下载免费PDF全文
Ding Hu Hua Peng Yile Niu Yefei Li Yingchun Xia Ling Li Jingwen He Xiangyu Liu Xinnian Xia Yanbing Lu Weijian Xu 《Journal of polymer science. Part A, Polymer chemistry》2015,53(6):750-760
Light‐responsive poly(carbonate)s PEG113‐b‐PMPCn‐SP were synthesized via copper catalyzed azide‐alkyne cycloaddition reaction between azide‐modified spiropyran (SP‐N3) and amphiphilic copolymer PEG113‐b‐PMPCn. PEG113‐b‐PMPC25‐SP can self‐assemble to biocompatible micelles with an average diameter of ~96 nm and a critical aggregation concentration of 0.0148 mg mL?1. Under 365 nm UV light irradiation, the characteristic absorption intensity of merocyanine (MC) progressively increased and most of the micellar aggregations were disrupted within 10 min, suggesting the completion of the transformation of hydrophobic SP to hydrophilic MC. Subsequent exposuring the micelles to 620 nm visible light, spherical micelles aggregated again. The light‐controlled release and re‐encapsulation behaviors of coumarin 102‐loaded micelles were further investigated by fluorescence spectroscopy. This study provides a convenient way to construct smart poly(carbonate)s nanocarriers for controlled release and re‐encapsulation of hydrophobic drugs. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 750–760 相似文献
3.
Tyrosine nitration of human ERK1 introduces an intra-hydrogen bond by molecular dynamics simulations
Xu Wu Zhang Yuanya Achi Oliver Y. Knierim Kathleen D. Hanks Justin G. Wang Yingchun 《Structural chemistry》2019,30(4):1459-1470
Structural Chemistry - ERK1 is an important kinase in Ras–Raf–MEK signaling. We have recently demonstrated by mass spectrometry that Tyr210 of ERK1 can be nitrated, and the nitration... 相似文献
4.
Monitoring the quality consistency of Weibizhi tablets by micellar electrokinetic chromatography fingerprints combined with multivariate statistical analyses,the simple quantified ratio fingerprint method,and the fingerprint–efficacy relationship 下载免费PDF全文
Yingchun Liu Guoxiang Sun Yan Wang Lanping Yang Fangliang Yang 《Journal of separation science》2015,38(12):2174-2181
Micellar electrokinetic chromatography fingerprinting combined with quantification was successfully developed and applied to monitor the quality consistency of Weibizhi tablets, which is a classical compound preparation used to treat gastric ulcers. A background electrolyte composed of 57 mmol/L sodium borate, 21 mmol/L sodium dodecylsulfate and 100 mmol/L sodium hydroxide was used to separate compounds. To optimize capillary electrophoresis conditions, multivariate statistical analyses were applied. First, the most important factors influencing sample electrophoretic behavior were identified as background electrolyte concentrations. Then, a Box–Benhnken design response surface strategy using resolution index RF as an integrated response was set up to correlate factors with response. RF reflects the effective signal amount, resolution, and signal homogenization in an electropherogram, thus, it was regarded as an excellent indicator. In fingerprint assessments, simple quantified ratio fingerprint method was established for comprehensive quality discrimination of traditional Chinese medicines/herbal medicines from qualitative and quantitative perspectives, by which the quality of 27 samples from the same manufacturer were well differentiated. In addition, the fingerprint–efficacy relationship between fingerprints and antioxidant activities was established using partial least squares regression, which provided important medicinal efficacy information for quality control. The present study offered an efficient means for monitoring Weibizhi tablet quality consistency. 相似文献
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光学目标模拟器是光学成像制导仿真系统中的关键设备之一。本文在介绍圆弧导轨式和框架式两种光学目标模拟器机械结构方案的基础上,详细分析了框架式机械结构的诸多优点。最后,总结了框架式目标模拟器研制中的一些关键技术 相似文献
7.
惯性系统三轴综合测试转台总体设计若干问题的探讨 总被引:3,自引:0,他引:3
本文从框架形式、总体布局、轴承的种类和布置方式等方面,讨论了惯性系统三轴综合测试转台总体设计中的若干问题,从设计、制造和使用等方面阐述了各种总体布局形式的优缺点,并提出了自己的相应看法,最后讨论了目前惯导测试设备研究领域需要研究的关键技术。 相似文献
8.
—本文提出了一种新的轴系相交度误差测试方法。该方法不存在测量基准安装偏心问题,更适合于大型转台轴系相交度误差的测量 相似文献
9.
Palladium Nanotubes Formed by Lipid Tubule Templating and Their Application in Ethanol Electrocatalysis 下载免费PDF全文
Yinan Wang Shenghua Ma Yingchun Su Prof. Xiaojun Han 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(16):6084-6089
Palladium nanotubes were fabricated by using lipid tubules as templates for the first time in a controlled manner. The positively charged lipid 1,2‐dioleoyl‐3‐trimethylammoniumpropane (DOTAP) was doped into lipid tubules to adsorb PdCl42? on the tubule surfaces for further reduction. The lipid tubule formation was optimized by studying the growing dynamics and ethanol/water ratio. The DOTAP‐doped tubules showed pH stability from 0 to 14, which makes them ideal templates for metal plating. The Pd nanotubes are open‐ended with a tunable wall thickness. They exhibited good electrocatalytic performance in ethanol. Their electrochemically active surface areas were 6.5, 10.6, and 83.2 m2 g?1 for Pd nanotubes with 77, 101, and 150 nm wall thickness, respectively. These Pd nanotubes have great potential in fuel cells. The method demonstrated also opens up a way to synthesize hollow metal nanotubes. 相似文献
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