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Search Results: 1 - 10 of 87225 matches for " 周兴平 "
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水溶性分散剂的合成及其性能研究
刘安华,兴平
功能高分子学报 , 1997,
Abstract: 合成了苯乙烯-顺丁烯二酸酐共聚型水溶性分解剂,并讨论了这种分散剂对导电粉及炭黑等难分散颜料的分散稳定性作用。结果表明,在水介质中,该发散剂能明显改善导电粉和炭黑颜料的分散稳定性。
以疏水性Fe3O4纳米粒子为基的脂质体的制备及表
Preparation and Characterization of Liposomes Embedded with Hydrophobic Fe3O4 Nano-Particles
 [PDF]

韩利敏, 潘立志, 楚险峰, 兴平
Journal of Advances in Physical Chemistry (JAPC) , 2016, DOI: 10.12677/JAPC.2016.51001
Abstract:
磁性脂质体既有脂质体良好生物相容性的优势又具有磁性质而被广泛地用于肿瘤组织的MR增强造影,以实现对肿瘤的预防和早期诊断。本文运用经典的薄膜分散法制备出了一种结构较为新颖的磁性脂质体即负载疏水性Fe3O4纳米粒子的脂质体。研究了脂浓度、卵磷脂和胆固醇质量比等因素对磁性脂质体的性能影响,并通过TEM、DLS等手段进行形貌和粒径表征。另外,我们采用邻菲罗啉分光光度法测定Fe含量,以包封率为指标,对影响制备HMLs的因素进行正交实验。结果表明:当脂质体的浓度维持在0.5~2.0 mg/mL,卵磷脂和胆固醇的质量比在2:1~6:1之间时,所得脂质体复合体的稳定性良好,形貌及大小分布均匀,主要呈现夹心式形貌,粒径为125.3 ± 12.9 nm;当初始铁浓度为0.5~3.0 mg/mL时,HMLs的包封率为90%~71.0%。并且HMLs拥有很高的铁含量,这表明其作可潜在的用作肿瘤磁共振成像(MRI)造影剂以增强肿瘤造影的效果。
Magnetic liposomes not only have good biocompatibility but also have excellent magnetic proper-ties, so it is widely used in tumor tissue to enhance MR angiography in order to achieve prevention and early diagnosis of tumors. Here, we describe synthesis of magnetic nano-composite liposomes (HMLs) by a thin film dispersing method, based on hydrophobic magnetite (Fe3O4) nanoparticles. We studied the effect of lipid concentration, lecithin and cholesterol mass ratio for the properties of HMLs. The results showed that the size of the HMLs containing Fe3O4-OA NPs mainly in a sand-wich-structure is 125.3 ± 12.9 nm obtained by transmission electron microscopy (TEM) and dy-namic light scattering (DLS). The optimized prescription of HMLs has been obtained by orthogonal tests in which encapsulation efficiency of Fe is used as index and phenanthroline absorption spec-trophotometry is used to determine Fe content. The results showed that the best prescription pre- paration process of HMLs is: 0.5 - 2.0 mg/mL of lecithin, and [lecithin]:[cholesterol] = 2:1 - 6:1 (w/w). And while the initial Fe concentration in the solution varied from 0.25 to 3.0 mg/mL, an effective Fe3O4 NPs loading was achieved, with encapsulation efficiency (EE%) from 91.0% to 71.0%. In a word, the results affirm the HMLs possess high Fe concent and can be potentially used to enhance Magnetic Resonance Imaging (MRI) in tumor tissues.
微波对茶多酚浸出特性的影响研究
兴平,,张家年
食品科学 , 2001,
Abstract: ??以水为介质,对绿茶进行微波处理,结果表明,微波处理绿茶有利于茶多酚浸出,料液比(w/v)1∶20,时间3min,微波浸提2次,再50℃水浴浸提1次,10min,茶多酚浸出率达90.55%,高于乙醇水浸提;高效液相色谱分析结果显示,经微波处理的茶叶,茶多酚制品儿茶素组成略有变化,但酯型儿茶素egcg和ecg的含量下降不大。
微波对茶多酚结构及其儿茶素组成的影响
兴平,,张家年
食品科学 , 2002,
Abstract: ?以茶叶为原料,研究了微波对茶多酚结构及其儿茶素的影响,结果表明,微波短时处理茶叶,茶多酚的化学结构无明显变化,但其主要成分———儿茶素的组成发生了变化。egcg(表没食子儿茶素没食子酸酯)和ecg(表儿茶素没食子酸酯)两种组分有所下降,下降率分别达3.5%和3.4%,并出现gcg(没食子儿茶素没食子酸酯),增加量达5.2%,但与用沸水提取0.5h相比,儿茶素组分变化幅度小。
谷氨酸钠碳纳米颗粒的荧光光谱及量子产率测定
Measurement of Fluorescence Spectra and Quantum Yield of Carbon Nanoparticles Made from Monosodium Glutamate
 [PDF]

郑楠楠, 楚险峰, 潘立志, 毕森林, 丁莎, 兴平
Journal of Advances in Physical Chemistry (JAPC) , 2016, DOI: 10.12677/JAPC.2016.53008
Abstract:
本论文主要以高温热解谷氨酸钠得到的荧光碳纳米颗粒(Glu-FCN)为研究对象,对其荧光光谱及其量子产率进行研究。结果显示:一方面,Glu-FCN存在pH依赖性,当pH在3.0到9.0之间时它的荧光强度最强,而其他范围荧光较弱;另一方面,此荧光碳纳米颗粒水溶液发光位置稳定,最佳激发波长为338 nm和发射波长为391 nm,荧光稳定性极佳。在中性环境下,Glu-FCN水溶液的荧光强度和浓度之间存在很好的线性关系,线性范围在0.2~50 μg/mL,检出下限为0.2 μg/mL。最后,以硫酸奎宁溶液为参比,测量了Glu-FCN在不同激发波长下的荧光量子产率,在最佳激发波长338 nm处的荧光量子产率高达51.5%,适合作为荧光标记物使用。
In this article, fluorescent carbon nanoparticles (Glu-FCN), made by monosodium glutamate pyro-lysis, have been researched, mainly including measurements of Glu-FCN fluorescent spectra and quantum yields. On one hand, pH dependence has been shown to be present in Glu-FCN according to our works. The fluorescence intensity is pretty low when surrounding pH is less than 3.0 or over 12.0. In contrast, it will become quite high when the pH is between 3.0 and 9.0. On the other hand, luminous position of Glu-FCN is very fixed. Optimal excitation and emission wavelengths are respectively located at 338 nm and 391 nm in a stable state. Importantly, good linear relationship exists between fluorescence intensity and concentration of Glu-FCN neutral aqueous solutions. The linear range is 0.20 - 50.0 μg/mL, with 0.20 μg/mL limitation. Eventually, quantum yields of Glu-FCN have been determined using quinine sulfate as a reference under different excitations. And Glu-FCN quantum yield is concluded to be as high as 51.5% under the optimal excitation (338 nm), implying its feasibility for being a fluorescent marker.
含Zn生物玻璃、玻璃陶瓷与聚酯复合骨组织工程支架的制备及性能
杜瑞林,倪似愚,常江,兴平
复合材料学报 , 2008,
Abstract: 采用溶胶凝胶法在58S生物玻璃的基础上用氧化锌取代3mol%的氧化钙制备了含锌的生物玻璃粉体(58S3Z),对合成的粉体采用有机泡沫浸渍法在700℃及1200℃制备出58S3Z-700℃、58S3Z-1200℃玻璃及玻璃陶瓷多孔支架。在所得支架表面涂覆PLGA及PBS薄膜制备出58S3Z-1200℃-PLGA及58S3Z-1200℃-PBS复合支架。对其形貌、孔隙率、力学性能、体外降解性及细胞相容性进行了系统研究。复合后多孔支架仍然保持三维连通的多孔结构,孔隙率与复合前(86.9%±0.8%(58S3Z-700℃),80.1%±0.6%(58S3Z-1200℃))相比稍有下降,分别为75.9%±0.6%(58S3Z-1200℃-PLGA)和77.9%±0.9%(58S3Z-1200℃-PBS)。但复合多孔支架显示出较高的抗压强度,分别达到1509.4kPa±162.8kPa(PLGA)和901.6kPa±94.5kPa(PBS),与玻璃和玻璃陶瓷支架(258.4kPa±23.6kPa)相比具有较大的提高。体外降解实验表明58S3Z-1200℃-PLGA、58S3Z-1200℃-PBS复合多孔支架可降解,经过28天的浸泡其失重率分别达到13.3%和2.1%。体外研究结果表明:58S3Z玻璃陶瓷支架复合PBS或PLGA后支持成骨细胞黏附、铺展和生长。这种新型的复合支架具有三维的网状多孔结构,良好的力学性能、降解性和细胞相容性,有望成为一种较理想的骨组织工程支架。
SiO2-聚合物杂化微球改性聚丙烯的非等温结晶动力学
郑净植,兴平,解孝林
复合材料学报 , 2013,
Abstract: 将原位乳液聚合制得的SiO2-聚合物杂化微球与聚丙烯熔融共混制备了SiO2/聚丙烯(SiO2/PP)复合材料,利用差示扫描量热法(DSC)研究了SiO2/PP复合材料的非等温结晶动力学行为。结果表明,SiO2-聚合物杂化微球具有明显的异相成核效应,提高了PP的结晶温度和结晶速率,同时降低了PP的结晶度,提高了PP的结晶活化能。运用Mo法处理纯PP和SiO2/PP复合材料的非等温结晶动力学,结果显示SiO2-聚合物杂化粒子降低了聚丙烯在单位结晶时间内达到一定结晶度时所需的降温速率。
空间钢框架几何非线性分析的一种新单元
许红胜,绪红,兴平
工程力学 , 2003,
Abstract: 介绍了一种新的用于空间钢框架几何非线性分析用的单元,可有效考虑P-δ效应的影响,达到了一个单元模拟一根杆件的精度要求,用于非线性分析是行之有效的,并可使截断误差的影响得到满意的控制,计算实例证明,该单元是可靠和高效率的。
时效处理对FV520B马氏体时效钢的氢脆敏感性影响研究
倩青,兴平,翟玉春
腐蚀科学与防护技术 , 2008,
Abstract: 通过系列热处理和热充氢实验,采用光学显微镜、SEM和拉伸试验等研究了不同温度时效处理对沉淀硬化马氏体不锈钢FV520B的氢脆敏感性的影响.结果表明充氢后,FV520B钢表现出良好的抗氢脆性能;450℃低温时效后钢的氢脆敏感性较高,而630℃中温时效后,钢中由于析出较多的逆变奥氏体,阻碍氢扩散和裂纹扩展;充氢后表现出良好的抗氢脆性能.塑性损减率随钢中逆变奥氏体的增加而降低.
碱液和木瓜蛋白酶预处理对葛仙米多糖提取效果的影响
莫开菊,,兴平,谢笔均
食品科学 , 2007,
Abstract: ?多糖的保健功能日益得到学术界的重视与证实。葛仙米中含有丰富的多糖。以碱液和木瓜蛋白酶对葛仙米进行预处理,正交试验确定最佳预处理工艺。多糖提取条件为料水比1:300,于90℃水浴提取2次,2h/次。结果说明,以木瓜蛋白酶预处理葛仙米,按100mg葛仙米加入10ml水充分吸胀后,加入含1.5mg木瓜蛋白酶的缓冲液,在50℃的水浴条件下,经过10h预处理后,葛仙米多糖得率最高,为29.53%。以naoh溶液预处理葛仙米,最佳的条件是0.4mol/l的浓度,于40℃处理2h,多糖得率可高达35.15%。将碱与酶结合使用,则多糖的得率可以高达47.56%,比对照高出25.12%。
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