48 research outputs found
Preliminary studies on the scale insect pest of Pseudaulacaspis cockerelli in mangrove
首次发现陆生考氏白盾蚧严重为害潮间带红树植物秋茄。通过野外定位调查和室内饲养观察,研究其危害特征、种群分布、生殖力和自然死亡率。结果表明,考氏白盾蚧主要分布在秋茄叶片主脉两侧,叶背虫口数显著多于叶面(P<0.01),单叶虫口数多为1-50头,平均25.65头,最高418头;秋茄植株不同垂直空间层次的虫口密度无显著差异,但聚集度随垂直空间下降而增大;种群平均产卵量每雌52.22粒,自然死亡率69.35%,寄生蜂寄生是最主要的死亡因子,寄生率达34.23%;与几种陆生寄主植物相比,红树林考氏白盾蚧的种群密度、生殖力、叶最高虫口数均较高,该虫对潮间带生境及寄主秋茄具有适应性。The scale insect,Pseudaulacaspis cockerelli is an important pest for many kinds of plants for a long time in the land.In 2006,it was found firstly attacking the mangrove plant of Kandelia obovata in the tideland in Xiamen City,and had led to badly damages.Based on the field surveys and lab feeding,this paper dealed with its damage characteristic,population distribution,fecundity and natural mortality etc.The results showed that the scale insect mainly distributed on both sides of the midvien of K.obovata leaves,but the individual on the abaxial surface was significantly more than those on the adaxial surface(P<0.01).The individual number of one leaf mostly fluctuated from 1 to 50,and the average and tiptop numbers were 25.65 and 418,respectively.The pest population density had no remarkable discrepancies among different vertical spatial layer of K.obovata,however,its aggregating degree increased with falling of the layer.The population had an avarage fecundity of 52.22 each female and a high natural mortality of 69.53%.The main natural death factor were two species of parasites(Hymenoptera: Chalcididae),and their total parasitical ratio reached 34.23%.In the mass,the pest population density,fecundity and tiptop individual number of a leaf in the mongrove were all more than those in serval other host plants on land,which implied that this scale insect had a high adaptability to the habitat of tideland and the plant of K.obovata
Hyperspectral image classification based on spectral-spatial combination features and graph cut
高光谱图像中存在着特征维度高而训练集小的问题。为解决该问题,提出了一种2步走的分类方法:1)通过支持向量机对图像进行初步分类,根据分类结果计算出每个类别的均值特征;2)使用1)计算出来的均值特征作为能量函数的数据项,然后利用图割原理对图像做二次分类。实验中发现:空间上相近的像素点往往具有相似的特征,且属于同一个类别。针对这种现象,提取一个将谱域特征和空域特征相结合的新特征。该特征既包含了光谱信息也包含了空间信息,具有较好的分类性能和鲁棒性。在IndIAn PInE数据集和PAVIA unIVErSITy数据集进行实验,实验结果表明了本文提出方法的有效性。The high-dimension of the feature vs.small-size of training set is an unsolved problem in the hyperspectral image classification task.To solve this problem a two-step classification method is proposed.Firstly,a preliminary classification is performed by the support vector machine( SVM) and the classification results are used to calculate the mean feature( MF) of each class.Secondly,a classification based on the graph cut theory is applied with the MFs as an input of the energy function.The experimental results showed that spatially nearby pixels have large possibilities of having the same label and similar features.Therefore,a new feature called spectral-spatial combination( SSC) is extracted that combines the spectral-based feature and spatial-based feature.The SSC feature contains the related spectral and spatial information of each pixel and provides better classification performance and robustness.Experiment results on the Indian Pine dataset and the Pavia University dataset demonstrated the effectiveness of the proposed method.国家自然科学基金资助项目(61202143); 福建省自然科学基金资助项目(2013J05100;2010J01345;2011J01367); 湖南省自然科学基金资助项目(12JJ2040
Non-cyanide copper plating on steel substrate in alkaline citrate bath
以柠檬酸盐为配位剂,结合胺化合物为辅助配位剂,研究了钢铁基体上无氰镀铜工艺。探索了搅拌方式、温度、PH、铜离子质量浓度和添加剂质量浓度对镀层质量的影响以及该工艺抗fE2+、fE3+、zn2+、Sn4+等杂质的能力。试验结果表明,电流效率在90%左右,并随电流密度、温度和PH的提高而增大;镀液深镀能力达100%。通过极化曲线,解释了配位剂和添加剂的作用。The process of alkaline non-cyanide copper electroplating on steel substrate was studied using citrate as complexing agent and amine compound as assistant complexing agent.The effects of agitation mode, temperature, pH, copper ions concentration and additive content on deposit quality were discussed.The ability of bath to resist impurities such as Fe2+, Fe3+, Zn2+ and Sn4+ was revealed.The test results showed that the current efficiency is about 90% and is increased with increasing current density, temperature and pH.The throwing power of the bath is 100%.The action mechanisms of the complexing agents and additive were explained based on polarization curves.广东省教育部产学研结合专项资金项目(2006D90404019);福建省科技计划重点项目(2008H0086);国家自然科学基金项目(20873114
A Novel Co-training Object Tracking Algorithm Based on Online Semi-supervised Boosting
基于自训练的判别式目标跟踪算法使用分类器的预测结果更新分类器自身,容易累积分类错误,从而导致漂移问题。为了克服自训练跟踪算法的不足,该文提出一种基于在线半监督bOOSTIng的协同训练目标跟踪算法(简称CO-SEMIbOOST),其采用一种新的在线协同训练框架,利用未标记样本协同训练两个特征视图中的分类器,同时结合先验模型和在线分类器迭代预测未标记样本的类标记和权重。该算法能够有效提高分类器的判别能力,鲁棒地处理遮挡、光照变化等问题,从而较好地适应目标外观的变化。在若干个视频序列的实验结果表明,该算法具有良好的跟踪性能。The self-training based discriminative tracking methods use the classification results to update the classifier itself.However,these methods easily suffer from the drifting issue because the classification errors are accumulated during tracking.To overcome the disadvantages of self-training based tracking methods,a novel co-training tracking algorithm,termed Co-SemiBoost,is proposed based on online semi-supervised boosting.The proposed algorithm employs a new online co-training framework,where unlabeled samples are used to collaboratively train the classifiers respectively built on two feature views.Moreover,the pseudo-labels and weights of unlabeled samples are iteratively predicted by combining the decisions of a prior model and an online classifier.The proposed algorithm can effectively improve the discriminative ability of the classifier,and is robust to occlusions,illumination changes,etc.Thus the algorithm can better adapt to object appearance changes.Experimental results on several challenging video sequences show that the proposed algorithm achieves promising tracking performance.国家自然科学基金(61201359;61202143); 福建省自然科学基金(2011J01367;2012J05126); 高等学校博士学科点专项科研基金(20090121110032)资助课
Tannin Content of Different Casuarina Species and Its Distribution Law
探讨了几种木麻黄单宁含量与种类、年龄、部位、生态环境的关系。结果表明:8种木麻黄小枝总多酚含量排序为:细枝木麻黄(CASuArInA CunnIngHAMInA)>山地木麻黄(C.JungHuHnIAnA)>山神木麻黄(C.COllIA)>短枝木麻黄(C.EQuISETIfOlIA)>鸡冠木麻黄(C.CrISTATA)>粗枝木麻黄(C.glAuCA)>肥木木麻黄(C.ObESA)>滨海木麻黄(AllOCASuArI-nA lITTOrAlIS);不同年龄木麻黄小枝总多酚含量随着年龄的增加而增大。短枝木麻黄和细枝木麻黄总多酚、可溶性单宁、蛋白质结合缩合单宁以及纤维素结合缩合单宁含量大体上以细根>树皮>小枝。随着离海岸带距离的增加,木麻黄小枝总多酚含量降低。木麻黄小枝蛋白质结合态缩合单宁含量非常低,而纤维素结合态缩合单宁含量较高,这可能与木麻黄鳞片叶退化为小枝,纤维素含量高有关。Tannin contents of different Casuarina species and tannin distribution rules of species,ages,position and ecological environment were studied.The results showed that the total phenol of branchlet of Casuarina was under the order as follows:Casuarina cunninghamina>C.junghuhniana>C.collia>C.equisetifolia>C.cristata>C.glauca>C.obesa>Allocasuarina littoralis.The total phenol contents of branchlets of different years old of Casuarina increased with ages.The total phenol,solubility tannins,protein binding condensing tannins,fibrin binding condensing tannins contents of short and thin Casuarina branchlets were under the following order wholly:thin root>bark>branchlet.With the increasing of the distance from coastal belt,the total phenol of branchlet declined.The protein binding condensing tannin of Casuarina branchlet was very low,whereas fibrin binding condenseing tannins content was highest.The reason could be the high fibrin content after Casuarina scale leaf degenerated to branchlet国家“十一五”科技支撑计划(2006BAD01A1605);福建省林业厅科研项目“木麻黄单宁生化活性与提取利用技术研究”资
结肠镜对急性不全肠梗阻的诊断及治疗作用探讨
目的 探讨结肠镜在急性不全肠梗阻患者中的诊断与治疗作用。方法 对我院 1994年 5月~ 2 0 0 3年 4月共 5 933例肠镜检查中的 12 2例 (占 2 .0 6 % )急性不全肠梗阻患者进行回顾性分析 ,就其发病年龄分布、梗阻病因及内镜下诊断进行分析探讨。结果 本组 12 2例急性不全肠梗阻的原因包括肠癌、息肉、粪块、炎症性肠病等多种 ,其中结直肠癌共 5 0例 ,发病率最高 ,占 4 0 .98% ,且以左半结肠癌为主。肠粪石梗阻在高龄患者中发病率仅次于结肠癌。全部患者的肠镜检查结果中无假阴性或假阳性。同时结肠镜可解除非肿瘤病变如粪石、肠粘连等所致的肠梗阻。结论 结肠镜检查对急性不全肠梗阻有重要的诊断价值并可对治疗起积极指导作用
第十八届美国理论与应用力学大会总结
1会议概况2018年6月5—9日,第18届美国理论与应用力学大会(18th U.S. National Congress of Theoretical and Applied Mechanics, USNCTAM2018)在美国芝加哥召开.本次大会由美国力学国家委员会和中国力学学会联合主办,旨在探讨和交流近四年世界范围内在理论和应用力学领域的基础研究、创新技术的最新进展,吸引了来自世界各地的近千名专家学
关于“经济发展方式转变进程中的财税政策”的探讨(笔谈)
转变经济发展方式是当前中国的热门话题,而上海在城市发展中又肩负着率先转变的重要任务,在这一意义和背景下,2010年4月24日由上海金融学院学院主办、上海金融学院公共经济管理学院承办的“《中国城市财政发展报告2009/2010:促进‘两个中心’建设的上海城市财政》首发式暨‘经济发展方式转变进程中的财税政策’论坛“在我校举行。与会专家围绕经济发展方式转变进程中的财税政策的“趋势与目标“、“机遇和挑战“、“实施方略“和“地方实践“等四个专题进行研讨,各抒己见,智慧交锋。现将其真知灼见整理摘要与读者分享,以期待更多学者共同关注当前经济发展方式转变进程中的财税政策
Preliminary study on the genetic diversity and differentiation of three Chinese Bruguiera gymnorrhiza populations
研究了我国红树林分布区内3个木榄种群的遗传变异和遗传分化.在种水平和种群水平上,期望杂合度分别为0.293和0.268,观察杂合度分别为0.2745和0.2705.种群间遗传多样性为0.0830,表明总的遗传变异中有8.3%来自种群间.基因流较为顺畅,为3.34.The genetic diversity and differentiation of three Chinese Bruguiera gymnorrhiza populations are ex-amined. Expected heterozygosity at species and population levels is 0. 293 and 0. 268, observed heterozygosity is 0. 274 5 and 0.270 5, respectively. The genetic diversity between population is 0. 083 0, which shows that among total heterozygositios, 8. 3 % come from inter - population. Gene now is smooth, which is 3. 34.国家自然科学基金!3967013