期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
纳米氮化铝常压溶剂热合成及其光致发光 被引量:2
1
作者 于美燕 王立民 +3 位作者 郝霄鹏 董守义 徐现刚 王琪珑 《人工晶体学报》 EI CAS CSCD 北大核心 2002年第6期533-536,共4页
低温常压下 ,在有机溶剂中制备出了氮化铝纳米晶。通过XRD、FTIR和定域电子衍射分析 ,样品中立方相和六方相共存 ;经XRD和TEM分析 ,样品中颗粒的平均粒度约为 5 0nm ;在样品的PL谱中 ,在 475nm有一个非常强的由氮空位引起的发射峰 ,而在... 低温常压下 ,在有机溶剂中制备出了氮化铝纳米晶。通过XRD、FTIR和定域电子衍射分析 ,样品中立方相和六方相共存 ;经XRD和TEM分析 ,样品中颗粒的平均粒度约为 5 0nm ;在样品的PL谱中 ,在 475nm有一个非常强的由氮空位引起的发射峰 ,而在 5 5 0nm有一个由AlN的本征缺陷及纳米颗粒的表面效应引起的宽且弱的发射峰。 展开更多
关键词 纳米氮化铝 压溶剂热合成 光致发光
下载PDF
常压甘油有机溶剂预处理甘蔗渣的浓醪酶解 被引量:4
2
作者 洪嘉鹏 岳春 +4 位作者 赵晓琴 Marie Rose Mukasekuru 李祥 孙付保 孙海彦 《食品与发酵工业》 CAS CSCD 北大核心 2017年第10期36-42,共7页
为了实现木质纤维素浓醪酶解在低酶载量时的"三高"(高浓度、高转化率和高转化效率),通过利用常压甘油有机溶剂预处理甘蔗渣为底物,筛选合适的基质质量浓度(150 g/L)、纤维素酶添加量(6 FPU/g基质)和添加剂(吐温80,30 mg/g基质... 为了实现木质纤维素浓醪酶解在低酶载量时的"三高"(高浓度、高转化率和高转化效率),通过利用常压甘油有机溶剂预处理甘蔗渣为底物,筛选合适的基质质量浓度(150 g/L)、纤维素酶添加量(6 FPU/g基质)和添加剂(吐温80,30 mg/g基质)。接着采用分批补料策略使基质质量浓度达到350 g/L,考察了不同加酶方式对分批补料浓醪酶解的影响。酶解72 h酶解液葡萄糖质量浓度达到132 g/L,葡萄糖转化率达到了理论值的60%。结果表明,常压甘油有机溶剂预处理基质具有较好的可酶解性,添加吐温80可以显著提高酶解效率。常压甘油有机溶剂预处理甘蔗渣的分批补料浓醪酶解推动了纤维素乙醇浓醪发酵工业化进程。 展开更多
关键词 甘油有机溶剂预处理 甘蔗渣 浓醪酶解 分批补料 表面活性剂
下载PDF
利用溶剂热压方法制备羟基磷灰石多孔纳米固体
3
作者 刘秀琳 徐红燕 +5 位作者 孟宪平 李梅 崔得良 宋云京 白见强 李木森 《物理化学学报》 SCIE CAS CSCD 北大核心 2004年第6期608-611,共4页
利用溶剂热压方法,以羟基磷灰石(HAP)纳米颗粒为原料制备了一种介于纳米粉体和纳米陶瓷体之间的过渡态——体块HAP多孔纳米固体,并用X射线衍射(XRD)、扫描电子显微镜(SEM)、压汞仪和热分析(DSC和TGA)等方法对样品进行了表征,初步研究了... 利用溶剂热压方法,以羟基磷灰石(HAP)纳米颗粒为原料制备了一种介于纳米粉体和纳米陶瓷体之间的过渡态——体块HAP多孔纳米固体,并用X射线衍射(XRD)、扫描电子显微镜(SEM)、压汞仪和热分析(DSC和TGA)等方法对样品进行了表征,初步研究了溶剂的种类、分布均匀性等因素对HAP多孔纳米固体的孔容和孔径分布的影响,并对HAP多孔纳米固体的热稳定性进行了分析. 展开更多
关键词 溶剂方法 多孔纳米固体 羟基磷灰石纳米粉 孔容
下载PDF
提高溶剂压伸复合改性双基推进剂力学性能研究
4
作者 吴淑新 樊学忠 +2 位作者 邵重斌 李吉祯 陈亦斌 《化学推进剂与高分子材料》 CAS 2013年第1期83-85,共3页
力学性能是推进剂在固体发动机中应用的重要参数之一,为有效提高溶剂压伸复合改性双基(CMDB)推进剂力学性能,研究了吸收药种类、溶剂比、增强材料、黏合剂相对分子质量等对推进剂力学性能的影响。结果表明,吸收药种类对推进剂低温力学... 力学性能是推进剂在固体发动机中应用的重要参数之一,为有效提高溶剂压伸复合改性双基(CMDB)推进剂力学性能,研究了吸收药种类、溶剂比、增强材料、黏合剂相对分子质量等对推进剂力学性能的影响。结果表明,吸收药种类对推进剂低温力学性能影响较大,溶剂比对推进剂力学性能影响不明显,加入增强材料后CMDB推进剂-40℃冲击强度可达4.06 kJ/m2。 展开更多
关键词 CMDB 推进剂 溶剂 力学性能
下载PDF
共溶剂对ZnO多孔纳米块体孔径均匀性的影响 被引量:1
5
作者 李梅 孙海燕 +4 位作者 刘秀琳 徐红燕 王成建 崔得良 蒋民华 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2006年第3期414-418,共5页
以十二烷基硫酸钠(SDS)的水溶液为造孔剂,用溶剂热压方法制备了大孔径的ZnO多孔纳米块体,并进一步考察了添加聚乙二醇400(PEG400)对样品中孔道的影响.实验发现,向十二烷基硫酸钠(SDS)的水溶液中加入聚乙二醇400组成共溶剂后,制备的ZnO... 以十二烷基硫酸钠(SDS)的水溶液为造孔剂,用溶剂热压方法制备了大孔径的ZnO多孔纳米块体,并进一步考察了添加聚乙二醇400(PEG400)对样品中孔道的影响.实验发现,向十二烷基硫酸钠(SDS)的水溶液中加入聚乙二醇400组成共溶剂后,制备的ZnO多孔纳米块体的孔径大幅度减小,比表面积和孔隙率也明显降低,但孔径的均匀性显著提高. 展开更多
关键词 ZnO纳米颗粒 多孔纳米块体 溶剂方法 溶剂
下载PDF
Recent progress in ether-based electrolytes for high-voltage lithium metal batteries
6
作者 Hai-peng ZHU Qiang-feng ZHANG +4 位作者 Zhao CHEN Zi-yu PENG Lin MEI Chun-xiao ZHANG Wei-feng WEI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第11期3452-3470,共19页
Ether-based solvents generally show better affinity for lithium metal,and thus ether-based electrolytes(EBEs)are more inclined to form a uniform and thin solid electrolyte interface(SEI),ensuring the long cycle stabil... Ether-based solvents generally show better affinity for lithium metal,and thus ether-based electrolytes(EBEs)are more inclined to form a uniform and thin solid electrolyte interface(SEI),ensuring the long cycle stability of the lithium metal batteries(LMBs).Nonetheless,EBEs still face the challenge of oxidative decomposition under high voltage,which will corrode the structure of cathodes,destroy the stability of the electrode−electrolyte interface,and even cause safety risks.Herein,the types and challenges of EBEs are reviewed,the strategies for improving the high voltage stability of EBEs and constructing stable electrode−electrolyte interfaces are discussed in detail.Finally,the future perspectives and potential directions for composition optimization of EBEs and electrolyte−electrode interface regulation of high-voltage LMBs are explored. 展开更多
关键词 ether-based electrolyte lithium metal batteries high voltage solvation structure electrode−electrolyte interfaces
下载PDF
丙烷脱沥青装置的整改及应用 被引量:2
7
作者 王国华 李文典 +1 位作者 聂朋果 王建玲 《石油与天然气化工》 CAS CSCD 北大核心 2004年第3期168-171,192,共5页
南阳石蜡精细化工厂将 15× 10 4 t/a丁烷脱沥青装置改造成为 18× 10 4 t/a丙烷脱沥青装置 ,充分利用南阳原油含蜡量较高的资源优势 ,生产高附加值产品 ,可同时为该厂提供充足的微晶蜡原料、凡士林原料、催化原料、10 0 #道路... 南阳石蜡精细化工厂将 15× 10 4 t/a丁烷脱沥青装置改造成为 18× 10 4 t/a丙烷脱沥青装置 ,充分利用南阳原油含蜡量较高的资源优势 ,生产高附加值产品 ,可同时为该厂提供充足的微晶蜡原料、凡士林原料、催化原料、10 0 #道路沥青原料等多种特色产品的基础原料。主要介绍了该装置的整改内容、实施过程、实施后的效果及工程设计方面需注意的问题。 展开更多
关键词 丙烷脱沥青工艺 生产装置 沉降系统 抽提系统 抽提塔 压溶剂 系统
下载PDF
AP-CMDB推进剂微观结构及药形尺寸对低温力学性能的影响 被引量:3
8
作者 张正中 樊学忠 +3 位作者 李吉祯 刘晓军 党永战 张亚俊 《火炸药学报》 EI CAS CSCD 北大核心 2015年第6期91-94,共4页
为研究溶剂压伸法制备的AP-CMDB推进剂低温发动机试验易产生碎药的原因,采用扫描电子显微镜(SEM)和能谱仪(EDS)观察了AP-CMDB推进剂样品的微观结构;通过测试样品的线膨胀系数,研究了AP颗粒与黏合剂体系的线膨胀匹配性;讨论了药形尺寸对... 为研究溶剂压伸法制备的AP-CMDB推进剂低温发动机试验易产生碎药的原因,采用扫描电子显微镜(SEM)和能谱仪(EDS)观察了AP-CMDB推进剂样品的微观结构;通过测试样品的线膨胀系数,研究了AP颗粒与黏合剂体系的线膨胀匹配性;讨论了药形尺寸对推进剂低温抗冲强度的影响。结果表明,溶剂压伸法制备的APCMDB推进剂药柱中存在大量微孔和少量微裂纹,AP颗粒团聚明显,Al颗粒与黏合剂体系间出现严重的界面脱粘;AP颗粒与黏合剂体系间的线膨胀匹配性较差;壁厚1.5mm的单孔管状药柱的低温(-40℃)抗冲强度低于壁厚4.5mm的,套管结构药柱的低温(-40℃)抗冲强度低于单孔管状药柱的。AP-CMDB推进剂低温碎药的形成与其微观结构、力学性能及药形尺寸有关。 展开更多
关键词 AP-CMDB推进剂 低温力学性能 微观结构 线膨胀系数 抗冲强度 药形尺寸 溶剂伸法
下载PDF
SDS对ZnO多孔纳米块体孔道结构的影响 被引量:1
9
作者 李梅 孙海燕 +3 位作者 刘秀琳 徐红燕 崔得良 蒋民华 《山东大学学报(理学版)》 CAS CSCD 北大核心 2007年第3期47-51,共5页
以ZnO纳米颗粒为原料,十二烷基硫酸钠(SDS)水溶液作造孔剂,利用我们独有的液态溶剂热压方法制备了ZnO多孔纳米块体.实验结果表明,通过调控SDS溶液的浓度,可以调节ZnO多孔纳米块体的结构参数.当SDS的浓度达到4.34×10-1mol/L时,ZnO... 以ZnO纳米颗粒为原料,十二烷基硫酸钠(SDS)水溶液作造孔剂,利用我们独有的液态溶剂热压方法制备了ZnO多孔纳米块体.实验结果表明,通过调控SDS溶液的浓度,可以调节ZnO多孔纳米块体的结构参数.当SDS的浓度达到4.34×10-1mol/L时,ZnO多孔纳米块体的孔道空间分布均匀性最好,孔径分布也最窄.另外,红外分析结果表明,在液态溶剂热压制备ZnO多孔纳米块体过程中,SDS在ZnO多孔纳米块体的孔道中有微量残留. 展开更多
关键词 液态溶剂 SDS溶液 ZnO纳米颗粒 多孔纳米块体
下载PDF
水和辛胺对ZnO多孔纳米块体孔道结构的影响 被引量:3
10
作者 李梅 刘秀琳 +5 位作者 徐红燕 崔得良 任燕 孙海燕 陶绪堂 蒋民华 《化学学报》 SCIE CAS CSCD 北大核心 2005年第16期1510-1514,共5页
以ZnO纳米颗粒为原料,分别用水和辛胺水溶液作为造孔剂,利用溶剂热压方法制备了ZnO多孔纳米块体.实验结果表明,当以水作造孔剂时,随着ZnO纳米粉/水(质量比)比值的减小,ZnO多孔纳米块体的孔径分布变宽,比表面积和孔隙率增加;加入辛胺后,... 以ZnO纳米颗粒为原料,分别用水和辛胺水溶液作为造孔剂,利用溶剂热压方法制备了ZnO多孔纳米块体.实验结果表明,当以水作造孔剂时,随着ZnO纳米粉/水(质量比)比值的减小,ZnO多孔纳米块体的孔径分布变宽,比表面积和孔隙率增加;加入辛胺后,ZnO多孔纳米块体的孔径分布变窄,但比表面积和孔隙率略有减少.随着辛胺用量的增加,比表面积和孔隙率又同时呈上升趋势.对ZnO多孔纳米块体进行的红外吸收测试结果表明,在制备多孔纳米块体过程中,水及辛胺基本上都从样品中逸出,孔道中只有微量残留. 展开更多
关键词 ZnO纳米颗粒 多孔纳米块体 溶剂方法 孔隙率 纳米块体 孔道结构 ZNO 水溶液 多孔 胺基
下载PDF
溶液反应笼效应的改进 被引量:1
11
作者 刘国杰 黑恩成 《大学化学》 CAS 2012年第1期76-81,共6页
将溶剂压的概念引入溶液反应的笼效应中,不仅能用来说明溶剂的极性对溶液反应速率的影响,而且还能说明在何种溶剂下溶液反应速率会出现扩散控制和活化控制等动力学现象。
关键词 溶液反应 笼效应 溶剂 径向分布函数
下载PDF
A Method for Calculating Blast Pressure of Failed Lithium-Ion Cells with C-H-O Solvents
12
《Journal of Chemistry and Chemical Engineering》 2012年第3期268-271,共4页
Blast pressure of C-H-O solvents on failed lithium-ion cells at the voltage range between 3.8 V and 4.18 V may be calculated by means of the simple semi-empirical equation, y = (Ia + Jb)/(Ka + Lb + Me), p is th... Blast pressure of C-H-O solvents on failed lithium-ion cells at the voltage range between 3.8 V and 4.18 V may be calculated by means of the simple semi-empirical equation, y = (Ia + Jb)/(Ka + Lb + Me), p is the initial density of solvent, Q is the chemical energy of explosion, v is the voltage. The values of a, b, c depend on C-H-O composition. Value of I, J, K, L, Mmay be estimated from the H20-CO2 arbitrary decomposition assumption. Blast pressure derived in this manner can provide preliminary protective estimation and it is compared with experiment results by adiabatic calorimeter. 展开更多
关键词 SOLVENT blast pressure lithium-ion cells safety.
下载PDF
Analysis of Solvent Effect on Mechanical Properties of Poly(ether ether ketone) Using Nano-indentation
13
作者 Tanveer Iqbal Saima Yasin +3 位作者 Ahmad Shakeel Hamayoun Mahmood Fahad Nazir Paul F. Luckham 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第2期211-215,246,共6页
Poly(ether ether ketone) (PEEK) is a high-performance semi-crystalline thermoplastic polymer. Exposure of the polymeric surface to solvents can have a strong effect like softening/swelling of polymeric network or ... Poly(ether ether ketone) (PEEK) is a high-performance semi-crystalline thermoplastic polymer. Exposure of the polymeric surface to solvents can have a strong effect like softening/swelling of polymeric network or dissolution. In this study, nano-indentation analysis was performed to study the effect of acetone on the surface mechanical properties of PEEK using different exposure time. The experiments were performed with a constant loading rate (10 nrn/s) to a maximum indentation displacernent (1000 nrn). A 30-second hold segrnent was included at the maximum load to account for any creep eft)ors followed by an unloading segrnent to 80% unloading. The indentation hardness and the elastic modulus were corn- puted as a continuous function of the penetration displacernent in the continuous stiffness mode (CSM) indentation. The experirnental data showed that the peak load decreased from -5.2 mN to -1.7 mN as exposure tirne in solvent environrnent increased from 0 to 18 days. The elastic modulus and the hardness of PEEK samples also displayed a decreasing trend as a function of exposure tirne in the solvent environrnent. Two empirical models were used to fit the experirnental data of hardness as a function of exposure tirne which showed a good agreernent with the experirnental values. 展开更多
关键词 SOLVENT Nano-indentation Poly(ether ether ketone) MODULUS HARDNESS
下载PDF
Rheological behavior of Shengli coal-solvent slurry at low-temperatures and atmospheric pressure 被引量:4
14
作者 WANG Yong-gang YAN Yan GUO Xiang-kun Xu De-ping 《Mining Science and Technology》 EI CAS 2009年第6期779-783,共5页
We report the results from systematic studies of Shengli lignite coal-solvent slurries. Solvent type, temperature, coal to solvent ratio, particle granularity, shear rate and shear time were investigated. The viscosit... We report the results from systematic studies of Shengli lignite coal-solvent slurries. Solvent type, temperature, coal to solvent ratio, particle granularity, shear rate and shear time were investigated. The viscosity of the solvents is time independent. However, the slurries are thixotropic. A change from pseudo-plastic to Newtonian behavior occurs as the temperature, or as the solvent to coal ratio, increases. The solvent used in the slurry affects the point at which the rheology changes from pseudo-plastic to Newtonian. The REC slurry changes at 1:1.2 coal to solvent ratio and at 40 °C. The HAR slurry changes at a 1:1.5 ratio and at 60 °C. The rheology of the slurries is pseudo-plastic at low shear rates but Newtonian at high shear rates. 展开更多
关键词 direct liquefaction coal-solvent slurry rheological behaviors Shengli lignite
下载PDF
二氧化锆多孔纳米固体的制备与性质表征
15
作者 刘秀琳 徐红燕 +4 位作者 李梅 孟宪平 王琪珑 蒋民华 崔得良 《功能材料》 EI CAS CSCD 北大核心 2004年第z1期3119-3122,共4页
利用溶剂热压方法,以ZrO2(5%Y2O3)纳米粉和几种不同的溶剂为原料,制备了一种新型的体块ZrO2多孔纳米固体,利用X射线衍射(XRD)、透射电子显微镜(TEM)、压汞仪和差热-热重(DTA-TGA)分析方法对样品进行了表征.进一步地,我们研究了溶剂的种... 利用溶剂热压方法,以ZrO2(5%Y2O3)纳米粉和几种不同的溶剂为原料,制备了一种新型的体块ZrO2多孔纳米固体,利用X射线衍射(XRD)、透射电子显微镜(TEM)、压汞仪和差热-热重(DTA-TGA)分析方法对样品进行了表征.进一步地,我们研究了溶剂的种类、温度和压力对ZrO2多孔纳米固体的孔容及孔径分布的影响,并对ZrO2多孔纳米固体的热稳定性进行了初步分析.测试结果表明:制备的ZrO2多孔纳米固体的孔径分布范围很窄,孔容为0.1~0.2cc/g,比表面积为30~50m2/g,孔隙率为35%o~45%;另外,通过改变溶剂的种类、温度和压力可以在一定程度上调变多孔纳米固体的孔径、孔容及比表面积. 展开更多
关键词 溶剂方法 ZrO2(5%Y2O3)纳米粉 体块多孔纳米固体 孔容
下载PDF
Study on the rheology of coal-oil slurries during heating at high pressure 被引量:4
16
作者 Bingfeng Yan 《International Journal of Coal Science & Technology》 EI 2017年第3期274-280,共7页
Using the self-developed viscosity measuring device, the viscosity variations of coal-oil slurries with temperature increasing during coal-oil co-processing were studied. The results show that the viscosity of coal-oi... Using the self-developed viscosity measuring device, the viscosity variations of coal-oil slurries with temperature increasing during coal-oil co-processing were studied. The results show that the viscosity of coal-oil slurries prepared by different kinds of oil varies differently during heating. The viscosity of the coal-oil slurry prepared by the catalytic cracking slurry (FCC) generally decreases during heating. However, the viscosity of the coal-oil slurry prepared by the high-temperature coal tar (CT) will peak at 338 ℃ during heating. The differences in viscosity variations of coal-oil slurries are analyzed. In addition to the temperature, the properties of the solvents and coal are the main influencing factors. Because the used coal contains a large number of polar functional groups, the swelling behavior of the coal in polar solvent (CT) is stronger than that in non-polar solvent (FCC). The swelling effect of the coal can result in the appearance of the viscosity peak. Therefore, before 100 ~C, the solvent molecules entering into the coal pores is the main influencing factor of coal-oil slurries viscosity variations. After 100 ℃, the increasing of particle size of coal particles is the main influencing factor of coal-oil slurries viscosity variations. 展开更多
关键词 Coal-oil slurry · Rheology· Swelling · High temperature and pressure
下载PDF
Separation of Soybean Oil/n-hexane Miscellas Using Polymeric Membranes
17
作者 Marcus V. Tres Jéssica C. Racoski +4 位作者 Zuleica Novello Jonas R.M. de Melo Helen C. Ferraz Marco DiLuccio José Vladimir Oliveira: 《Journal of Food Science and Engineering》 2012年第11期616-624,共9页
Separation of refined soybean oil/n-hexane miscellas was studied using different commercial ultra- and nanofiltration membranes, with cut-oil's in the range of 1 to 5 kDa and salt rejection higher than 97% (MgSO4).... Separation of refined soybean oil/n-hexane miscellas was studied using different commercial ultra- and nanofiltration membranes, with cut-oil's in the range of 1 to 5 kDa and salt rejection higher than 97% (MgSO4). Commercial soybean oil and n-hexane miscellas with 1:3 and 1:1 mass ratios were permeated in a dead-end module. The effects of the feed pressure (2-25 bar) on oil and n-hexane fluxes and rejection were investigated. Oil rejection ranged from negative values to 30.8%, soybean oil flux from 28.9 to 617.8 g/m2 hl and n-hexane flux from 8.5 to 1,078.5 g m2 hl. Membrane fouling was observed at all experimental conditions studied. The membrane separation process has proven to be a promising alternative to solvent recovery in soybean oil extraction. 展开更多
关键词 Soybean oil N-HEXANE ULTRAFILTRATION NANOFILTRATION polymeric membranes.
下载PDF
LSER-based modeling vapor pressures of(solvent+salt) systems by application of Xiang-Tan equation
18
作者 Aynur Senol 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第8期1374-1383,共10页
The study deals with modeling the vapor pressures of(solvent + salt) systems depending on the linear solvation energy relation(LSER) principles. The LSER-based vapor pressure model clarifies the simultaneous impact of... The study deals with modeling the vapor pressures of(solvent + salt) systems depending on the linear solvation energy relation(LSER) principles. The LSER-based vapor pressure model clarifies the simultaneous impact of the vapor pressure of a pure solvent estimated by the Xiang-Tan equation, the solubility and solvatochromic parameters of the solvent and the physical properties of the ionic salt. It has been performed independently two structural forms of the generalized solvation model, i.e. the unified solvation model with the integrated properties(USMIP) containing nine physical descriptors and the reduced property-basis solvation model. The vapor pressure data of fourteen(solvent + salt) systems have been processed to analyze statistically the reliability of existing models in terms of a log-ratio objective function. The proposed vapor pressure approaches reproduce the observed performance relatively accurately, yielding the overall design factors of 1.0643 and1.0702 for the integrated property-basis and reduced property-basis solvation models. 展开更多
关键词 Vapor pressure Salt effect Modeling LSER Statistical analysis
下载PDF
Influence of Pressure and Temperature on the Velocity of a Turbulent Jet Flow 3D
19
作者 Flavia Aparecida Reitz Cardoso Regiani Aparecida de Almeida +4 位作者 Ricardo Vicente de Paula Rezende LucioCardozo-Filho Dirceu Norile Henry Franga Meier Vladimir Ferreira Cabral 《Journal of Chemistry and Chemical Engineering》 2014年第4期408-416,共9页
To investigate the influence of pressure and temperature on the jet velocity of a three-dimensional flow was the main goal of this study. Using a precipitation chamber with approximate capacity of 600 mL, it was studi... To investigate the influence of pressure and temperature on the jet velocity of a three-dimensional flow was the main goal of this study. Using a precipitation chamber with approximate capacity of 600 mL, it was studied the thermodynamic behavior of supercritical carbon dioxide mixture, dichloromethane and grape seed extract via SAS (supercritical antisolvent process). For the numerical solution, the Navier-Stokes equations were used along with the model of turbulence k-ε and Peng-Robinson equation of state with quadratic mixing rules of Van der Waals. The method of Chung was employed to determine the viscosity, thermal conductivity and mass diffusivity of the flow numerically solved through commercial code based on CFD (computational fluid dynamics). Simulations for pressures between 80 bar and 160 bar and temperatures between 308.15 K and 318.15 K showed large variations in the jet velocity, an important property in the dynamic mixing process that involves the size, size distribution and particle morphology. 展开更多
关键词 Supercritical fluid CFD mathematical modeling.
下载PDF
Optimization the Cell Wall Degrading Enzymes and Technique for Isolation of Protoplasts in Potato
20
作者 Le Minh Phuong Hana Vodickova +1 位作者 Brigitazamecnikova Jaromir Lachman 《Journal of Pharmacy and Pharmacology》 2016年第4期179-182,共4页
Plasma membrane of plant cells is surrounded by cellulose wall and adjacent cells are joined together by a thick pectin rich matrix. Separation of plant cells and removal of the cell wall experimentally, by either a m... Plasma membrane of plant cells is surrounded by cellulose wall and adjacent cells are joined together by a thick pectin rich matrix. Separation of plant cells and removal of the cell wall experimentally, by either a mechanical or an enzymatic process, results in the production ofprotoplast. Protoplasts are useful tools to study the uptake and transport ofmacromolecules and production of somatic hybrids. Protoplasts can be obtained from all types of actively growing young and healthy tissues. The most convenient and widely used source of plant protoplasts is leaf. Juvenile seedling tissues, cotyledons are other alternative tissues most frequently used for protoplasts isolation. All the environmental and genotypic factors, which affect the cell wall thickenings and compactness indirectly, influence the number of protoplasts recovered. Protoplasts are isolated by two methods, mechanical and enzymatic. The enzyme mixture solution of celluiose/macerozyme is used to digest the cell wall. The critical factors affecting the obtaning ofprotoplasts are the kinds of cell wall degrading enzymes, the physiological state of plant leaves, the type of osmotic stabilizers and the composition of reaction solution. With the improvement of technique and enzyme combination rate, the yield of collected protoplasts will be increased higher. 展开更多
关键词 Plasma membrane PROTOPLAST enzyme cell wall potato plant.
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部