Study on extraction technology of volatile oil from cortex phellodendri by supercritical carbon dioxide

使用超临界二氧化碳技术对经过超声-微波处理过的黄柏中的挥发油进行萃取,并对萃取工艺进行响应面优化。在单因素预实验的基础上,以萃取压力、萃取温度、萃取时间为响应因素,黄柏挥发油的萃取量为响应值,根据中心组合(bOX-bEHnkEn)实验设计原理,采用三因素三水平的响应面分析法,确定各工艺条件对萃取量的影响,并用扫描电子显微镜(SEM)对萃取前、未超声-微波处理超临界萃取后及超声-微波处理超临界萃取后的黄柏进行比较观察,对萃取效果进行了微观解释。结果表明,经过超声-微波处理过的黄柏中的挥发油超临界二氧化碳萃取最佳工艺条件为:萃取压力为34MPA,萃取温度为41℃,萃取时间为66MIn,萃取率达6.03%。The supercritical carbon dioxide extraction of volatile oil from processed cortex phellodendri was optimized by response surface methodology(RSM).According to the principle of Box-Behnken central composite design,extraction pressure,extraction temperature,extraction time were chosen as response factors,extraction mass was chosen as response value,and a three-factor and three level central composite design was adopted to determine the influence of various technological conditions.Using SEM observed the cortex phellodendri before and after extraction,and explained the extraction effects from microcosmic aspect.The results showed that the optimum extraction conditions were as follows:extraction pressure 34MPa,extraction temperature 41℃,extraction time 66min,extraction yield was 6.03%.湖南省科技厅重大专项(2008FJ1007);2010年吉首大学大学生研究性学习与创新性实验计划项目(JSU-CX-2010-49

LSNCCP:A Clustering Algorithm Based on the Largest Set of Not-Covered Core Points

聚类在数据挖掘、模式识别等许多领域有着重要的应用 提出了一种新颖的聚类算法 :一种基于最大不相含核心点集的聚类算法LSNCCP(aclusteringalgorithmbasedonthelargestsetofnot coveredcorepoints) 在密度定义的基础上 ,考察核心点之间的距离关系 ,定义相含、相交、相离这 3种核心点之间的关系 ,最后找出一个最大不相含核心点集 ,在此基础上进行聚类 ,并且找到解决丢失点问题的快速方法 该最大不相含核心点集只是全部核心点集合的一个很小的子集 ,因此有效地缩减了同类算法中搜寻核心点的时间 理论和实验上证明了这种算法的可行性和优越性Clustering is an important application area for many fields including data mining, pattern recognition, etc. In this paper, a novel clustering algorithm LSNCCP(a clustering algorithm based on the largest set of not-covered core points) is proposed. On the basis of the definition of density, the distance between the core points is discussed. And then, the three essential distance relation: covered core points, intersectant core points, and separate core points. Finally, the largest set of not-covered core points is found and based on the set the data can cluster very well. Because the largest set of not-covered core points is a lesser subset of the all core points, the new algorithm cuts short the time of searching all core points in the similar algorithms. The feasibility and the advantage or the new algorithm are proved in theory and experiment.福建省自然科学基金项目 (A0 3 10 0 0 8) ;; 福建省高新技术研究开放计划重点项目 (2 0 0 3H0 43

知母皂苷元对体外培养皮层神经元树突发育的影响及信号转导机制

目的探讨知母皂苷元(Sarsasapogenin,SAR)对大脑皮层神经元树突发育的促进作用及其信号转导机制。方法选用出生0～24 h的Sprague-Dawley(SD)大鼠乳鼠,取皮层神经元进行体外细胞培养,4 d后用于实验。倒置相差显微镜测量培养神经元树突分支总长度(TDBL)、一级树突数目(PDN)、最大分支级数(MBO)和神经元胞体面积。West-ern blot法观察神经元p-PDK1、p-Akt473及p-mTOR蛋白表达。结果形态学观察结果显示SAR(10、30、100μmol.L-1)可明显促进树突发育,表现为树突分支总长度增加、一级树突数目增多、最大分支级数增大及胞体面积增大,并呈明显浓度依赖。SAR 30+LY组、SAR 30+TCBN组、SAR 30+Rapa组的神经元树突总长度、一级树突数目、最大分支级数及胞体面积较SAR30μmol.L-1组明显降低。Westernblot结果显示SAR 30也可明显增加p-PDK1、p-Akt473及p-mTOR蛋白表达水平。SAR 30+LY组明显降低神经元p-PDK1、p-Akt473及p-mTOR的蛋白表达水平。SAR 30+TCBN组明显降低神经元p-Akt473及p-mTOR的蛋白表达水平。SAR 30+Rapa组明显降低神经元p-mTOR的蛋白表达水平。结论 SAR对体外培养皮层神经元树突的发育有促进作用,这种作用可能与PI3K/Akt/mTOR信号转导通路有关

Anticorrosion Properties of Modified Nano-TiO_2 Films Prepared by Sol-Gel Method

应用溶胶-凝胶法和浸渍提拉技术在316l不锈钢表面分别制备TIO2纳米膜和 b-fE-CE改性的TIO2纳米膜. 采用场发射扫描电子显微镜(fE-SEM)、原子力显微镜(AfM)、拉曼光谱法和能量分散谱(EdS)对薄膜进行表征,通过电化学阻抗谱(EIS)和动电位阳极极化曲线的测试考察薄膜的耐蚀性及对不锈钢的保护性能. 结果表明:两种纳米薄膜均含锐钛矿型的TIO2纳米颗粒,纯TIO2纳米膜与改性后的纳米膜中颗粒直径分别约为15和10 nM. TIO2/316l不锈钢和 b-fE-CE-TIO2/316l不锈钢膜电极浸泡在0.5 MO.ll-1 nACl溶液后,后者的电化学反应电阻较大,动电位阳极极化曲线的稳定钝化区较宽,击穿电位更高,说明改性的纳米膜的耐蚀性及其保护性能更好.TiO2 and B-Fe-Ce-modified TiO2 films were synthesized on the surfaces of 316L stainless steel(316L SS) substrates using a sol-gel and dip-coating method.The properties of the films were characterized by field emission scanning electron microscopy,atomic force microscopy,Raman spectroscopy and energy dispersive spectrometry.The corrosion resistance of the films and their ability to protect stainless steel were investigated by electrochemical impedance spectroscopy and potentiodynamic polarization curves.Both TiO2 and B-Fe-Ce-modified TiO2 films were composed of anatase nanoparticles about 15 and 10 nm in diameter,respectively.Impedance spectra of the stainless steel substrates coated TiO2 films contained semicircles for capacitive reactance in 0.5 mol.L-1 NaCl solution,but the charge transfer resistance of the B-Fe-Ce-TiO2/316L SS electrode was higher than that of the TiO2/316L SS electrode.The potentiodynamic anodic polarization curve of the B-Fe-Ce-TiO2/316L SS electrode showed a larger stable passive region and a higher breakdown potential than the TiO2/316L SS electrode,indicating that the modified film had better corrosion resistance and protective properties for 316L SS.国家高技术研究发展计划项目(863)(2009AA03Z327);国家自然科学基金(21073151和21173177)资助---

三种检测方法对样品中沙门氏菌的检测结果比较

本实验采用VIDAS、API20E和SN0170-92三种不同的检测方法对CNCA举行的食品中常见致病菌能力验证计划中提供的一份盲样进行检验,总结对比了3种不同检验方法对沙门氏菌检测的各自优缺点

用HPLC-MS-MS快速分析和鉴定三尖杉植物内生真菌发酵液中的Brefeldin A

采用HPLC -MS -MS联用技术 ,分析了C56和C65两株具有抗肿瘤活性的三尖杉植物内生真菌发酵液抽提物 ,首次报道了这两株真菌都能产生BrefeldinA(BFA)。采用ESI-MS总离子流跟踪分析HPLC的洗脱液 ,并用低能量的CID -MS -MS(碰撞诱导裂解方式 )进一步确定目标离子峰为BFA分子离子峰 ,这为植物内生真菌发酵液中的有效成分的早期鉴别奠定了基

A preliminary study on the induction of spawning by sex pheromones in Bostrichthys sinensis

在陶瓷人工产卵管道内吊挂性外激素的研究表明,卵巢提取液对雄鱼的吸引作用大于雌鱼,而精巢和贮精囊提取液对雌鱼的吸引作用则大于雄鱼,17α-P、17α,20β-P和PGE2对雌鱼和雄鱼均具有相似的吸引作用。雌鱼在管道内的产卵次数、产卵量以及成熟卵的受精率均与产卵管道内吊挂的性外激素种类有关,17α,20β-P和PGE2两个实验组产卵次数最多,其中PGE2实验组的产卵量和受精率最高。17α-P在贮精囊和精巢提取液中的含量显著高于卵巢提取液(P精巢提取液>卵巢提取液。卵巢提取液刺激雄鱼所引起的平均EOG高于雌鱼,而精巢和贮精囊提取液刺激雌鱼所引起的平均EOG高于雄鱼,雌鱼和雄鱼对17α-P、17α,20β-P、PGE2和PGF2α刺激所产生的平均EOG,以PGE2为最高。The results obtained from fixing sex pheromones to the inside surface of the artificial ceramic spawning nests showed that ovarian extract attracted more males than females to enter the nests, while testis extract and seminal vesicle extract attracted more females than males. 17α-P, 17α, 20β-P and PGE_2 were equally effective in attracting both females and males. Spawning frequencies and the spawned egg number of females as well as fertilization rates were related to different kinds of sex pheromones. The most spawning frequencies were found in both 17α, 20β-P and PGE_2 treated groups. The greatest spawned egg number and the highest fertilization rate were observed in PGE_2 group. The levels of 17α-P in seminal vesicle extract and testis extract were significantly higher (Ptestis extract>ovarian extract. The mean EOG, stimulated by ovarian extract, was higher in males than in females, whereas the mean EOGs, stimulated by testis or seminal vesicle extract, were higher in females than in males. The mean highest EOG of both females and males in response to 17α-P,17α, 20β-P,PGE_2 and PGF_(2α) was observed in PGE_2 group.国家自然科学基金资助项目(40276040

驾驶行为理论模型研究概述

通过回顾驾驶行为的研究概况,重点介绍了4种理论模型:计划行为理论、威慑理论、事故原因模型、情境中介模型。在此基础上,分析了我国驾驶行为研究现状,并提出开展我国驾驶行为研究的初步建议和未来的研究方向:发展适用于我国的驾驶行为模型,并进一步研究在我国文化背景和道路环境下,不安全驾驶行为与示范性规范、文化因素以及情境变量等因素之间的关系,从心理学角度减少不安全驾驶行为和事故卷入,改善交通安全,提高交通效率

一种富锂锰基正极材料及其制备方法

本发明提供一种富锂锰基正极材料及其制备方法，所述富锂锰基正极材料包括如式（Ⅰ）所示的富锂化合物和如式（Ⅱ）所示的包覆层。所述富锂锰基正极材料的制备方法包括以下步骤：将络合剂、第一分散剂与如式（Ⅰ）所示的富锂化合物混合后进行第一次热处理；将第一次热处理的产物与锂源化合物、第二分散剂混合后进行第二次热处理，得到富锂锰基正极材料。实验结果表明，本发明所述的富锂锰基正极材料具有较高的首次效率和循环性能；xLi2MnO3·（1-x）Li（MaM′b）O2（Ⅰ）；yLiMn2O4·（1-y）Li（MaM′b）O2????（Ⅱ）

Overview on Theoretical Models of Driving Behaviors

通过回顾驾驶行为的研究概况,重点介绍了4种理论模型：计划行为理论、威慑理论、事故原因模型、情境中介模型。在此基础上,分析了我国驾驶行为研究现状,并提出开展我国驾驶行为研究的初步建议和未来的研究方向：发展适用于我国的驾驶行为模型,并进一步研究在我国文化背景和道路环境下,不安全驾驶行为与示范性规范、文化因素以及情境变量等因素之间的关系,从心理学角度减少不安全驾驶行为和事故卷入,改善交通安全,提高交通效率