HIV-1 gp160截短蛋白在酿酒酵母中的表达

利用PCR技术从pNL-43上扩增出截短的编码gp160蛋白的基因片断,克隆到酿酒酵母表达载体YEpFLAG-1上构建表达质粒YEp-gp160Δ12,电转化到酿酒酵母中,用缺色氨酸的SC培养基筛选出阳性克隆,重组子经YP培养基诱导后进行全菌蛋白的SDS-PAGE和Western Blotting分析,筛选出高表达菌株.纯化后的重组gp160Δ12(rgp160Δ12)蛋白经ELISA鉴定显示具有良好的生物活性

Molecular phylogenetic analysis of floating Sargassum horneriassociated with green tides in coastal area of Qingdao

2013年6月份,我国黄海连续第7年暴发绿潮灾害,同时出现了漂浮褐藻规模聚集现象,进一步增大了山东半岛绿潮防控工作的难度。为了对漂浮褐藻进行分子鉴定,采用PCR扩增和序列测定的方法,获得了漂浮褐藻的5.8S r DNA-ITS序列。通过与已经报道的其他马尾藻属5.8S r DNA-ITS序列比对及系统发育分析,对绿潮暴发期间山东青岛近海出现的漂浮褐藻样品进行了分子鉴定。结果表明:该漂浮褐藻的5.8S r DNA-ITS基因序列全长1366 bp,其中ITS1序列长度为647 bp,5.8S r DNA序列长度为155 bp,ITS2序列长度为717 bp。序列比对分析显示,2013年绿潮暴发期..

Texture discrimination of different kinds of green tea based on multi-spectral imaging technique

为了提高茶叶加工的智能化水平,提出一种基于多光谱图像纹理分析的快速识别不同品种绿茶的方法.通过3CCD成像仪同时获得绿茶样本的红光、绿光和近红外三个通道的图像,采用灰度共生矩阵和纹理滤波相结合来提取图像纹理特征,分析了不同品种绿茶的各个通道图像的纹理特征.非监督聚类分析表明,基于组合方法提取的纹理特征优于仅依靠灰度共生矩阵得到的纹理特征.优化和筛选后得到10个特征参数作为支持向量机模型的输入,建立模式识别模型.结果表明,对于126个建模样本的识别正确率达到94.4%,对于未知64个预测样本的识别正确率达到93.8%,说明提出的组合纹理特征提取和模式识别方法能够较好地识别不同品种的绿茶.For enhancing the intelligence level of tea processing,a method for discriminating images of four different kinds of green tea was put forward based on texture analysis.First,green tea images were obtained from three charged coupled device camera,which could simultaneously obtain three images from green,red and near-infrared channels.The statistical information derived from the combination of gray level co-occurrence matrix(GLCM) and texture filtering was used to describe the textural features of image.The results of unsupervised cluster analysis indicated that the combined textural features were more optimal than those from GLCM.Then ten optimized texture parameters were selected as input for least squares support vector machine(LS-SVM) classifier.This classifier got high recognition rate(94.4%) for 126 samples in calibration set,and same excellent performance was obtained for discrimination of 64 unknown samples in prediction set with 93.8%.The result indicated that it is feasible to discriminate tea images of different kinds of green tea based on combined textural feature extraction and LS-SVM classifier.国家“863”高技术研究发展计划资助项目(2007AA10Z210);; 国家自然科学基金资助项目(30671213,60605011);; 高等学校优秀青年教师教学科研奖励计划资助项目(02411

A Pilot Plant on Study of Solvent Dewaxing

建立了一套酮苯脱蜡连续化中试装置,该装置吸收并采纳了工业实际情况,包括结晶系统、过滤系统、溶剂回收系统、冷冻系统以及仪表显示和控制系统.运用该装置对阿曼减三和阿曼减四精制油进行脱蜡试验研究,探讨脱蜡过程中溶剂加入位置、溶剂混合比和溶剂/油料稀释比对脱蜡效果的影响.试验结果表明,所建立的装置运行平稳,所获得的石蜡晶体以片状为主,所得到的脱蜡油的倾点和收率数据具有规律性和合理性.该研究工作为进一步利用该套装置对油料脱蜡进行系统研究以指导工业生产奠定了基础.A continuous pilot plant was established to study the dewaxing process by butanone and toluene mixture solvents for different refined oils.Considered and adopted some features from industry equipments,this plant consists of the crystallization system,the filtration system,the solvent recovery system,the cooling system and the control system with a capacity of 1~2 L/h feeding oils,and some important parameters can be flexibly varied.Using this plant,two refined oils were investigated under various operation conditions.The effects of the solvent-adding position,the butanone/toluene ratio,and the ratio of solvent over oil on the experimental results were explored.The pouring point and the recovery of the dewaxing oil were analyzed,and the paraffin crystals were detected by the scanning electron microscopy (SEM).The running of the experiments showed that the plant can be operated steadily,the experimental results indicated mainly the plate paraffin crystals formed,high ratio of solvent/oil and large amount of butanone in the mixed solvent were benefit to the paraffin crystallization for the studied oils and the dewaxed oil yields had a reasonable trend

样线法和标志重捕法在鳄蜥种群数量调查中的应用比较

2015年7～8月,分别采用样线法和标志重捕法对广西大桂山自然保护区主要分布点的鳄蜥(Shinisaurus crocodilurus)种群数量进行调查。结果显示,利用样线法共发现鳄蜥58只,种群密度5.0只/km; 标志重捕法共发现鳄蜥129只(其中有26只重复),估算的种群数量为(162±59)只,种群密度(13.9±5.08)只/km,表明标志重捕法的调查结果优于样线法。由于鳄蜥的尾纹可以作为无损伤的个体标记,适合于开展标志重捕法调查,在鳄蜥的种群资源调查中,为得到更为准确的结果,应使用标记重捕法进行调查

电缆橡胶包皮冻雨灾害实验研究

冻雨是较为严重的自然灾害之一，短时间内就可以在物体表面结附大量的冰，尤其对输电线路和塔架，可造成输电线路断裂，导致严重的冰冻灾害。实验在已有的过冷水动态制冰系统的基础上，成功实现人工环境下的冻雨模拟，同时对不同材料的管材进行对比实验，观察其表面结冰情况，分析不同管材的抗冻雨性能，结果表明：在相同的条件下，表面结附冰层的厚度从厚到薄依次为天然橡胶、氯丁橡胶、丁腈橡胶、硅橡胶（壁厚为3mm）、硅橡胶（壁厚6mm）；表面结冰的粘附性强弱排序同上；表面最先出现结冰附着的为天然橡胶，其次为丁腈橡胶和氯丁橡胶，最后为硅橡胶。抗冻雨性能最佳的为硅橡胶（壁厚6mm），最差的是天然橡胶

节点约束对单面连接角钢受压承载力影响试验研究

为了研究节点约束对单面连接角钢受压承载力的影响，设计了一种弹簧支座刀口铰，通过试验研究了120根等边角钢的偏心受压稳定承载力。分析了其最小轴、平行轴布置时的破坏模式、承载力及变形形态，研究了不同节点约束、构造形式对其承载力的影响，并与国内规范进行了比较。研究结果表明：最小轴布置时，构件的失效模式为弯曲失稳，旋转轴介于最小轴和平行轴之间；平行轴布置时，构件失效模式为绕与刀口铰平行的主轴的弯曲失稳；构件长细比小于120时，其承载力主要受偏心控制，偏心越大，承载力越低；构件长细比大于120时，其承载力主要受约束刚度控制，约束刚度越大，承载力越高；采用A、C类连接时，在不同长细比下二者各具优势，但采用B类连接时构件的承载力始终低于采用A、C类连接时的承载力；与规范的对比表明，规范GB 50017—2017和DL/T 5486—2020均未考虑节点构造形式对斜材受压承载力的影响，计算结果存在一定的局限性，研究结论对于工程设计具有一定的指导意义