广西蔗区红尾白螟分布区域及危害程度调查          下载免费PDF全文

魏吉利  黄诚华  潘雪红  商显坤  王丹  韦喜  罗荣森 《南方农业学报》2016,47(4):594-598

[目的]了解红尾白螟在广西甘蔗主产区的分布及危害程度,掌握其生活习性及发生规律,为制定甘蔗红尾白螟防治措施提供科学依据.[方法]2014年调查红尾白螟在广西甘蔗主产区(百色、来宾、北海、崇左、南宁、河池、柳州)的分布,并定时定点调查甘蔗苗期、伸长期和成熟期红尾白螟发生程度.[结果]红尾白螟主要分布在百色、来宾、北海、崇左和南宁蔗区,其中以百色蔗区危害最重,年平均为害率为(9.00±2.797)%,其次为来宾、北海、崇左、南宁,为害率分别为(2.66±1.094)%、(1.94±0.923)%、(1.44±0.383)%和(0.80±0.283)%,各蔗区间无显著性差异(P<0.05).甘蔗成熟期较苗期受红尾白螟危害重,百色蔗区苗期的红尾白螟为害率为(1.72±0.367)%,而成熟期达(20.00±5.088)%,极显著高于其他蔗区(P<0.01).[结论]甘蔗红尾白螟在广西百色、来宾、北海、崇左、南宁等蔗区均有分布,其中为害最重的是百色蔗区,且甘蔗成熟期受害最重.  相似文献   

Functional modification of wool fabric by thiol-epoxy click chemistry     

Yi Hu  Wei Wang  Dan Yu 《Fibers and Polymers》2016,17(1):30-35

The paper reports modification and characterization of wool fabrics achieved through thiol-epoxy click chemistry. A pretreatment with tris (2-carboxyethyl) phosphine (TCEP) as an effective reducing agent was carried out to produce thiol groups on wool surface. Glycidyl trimethyl ammonium chloride (GTAC) was later covalently bonded with wool fibers via thiol-epoxy reaction. The reaction was confirmed by SEM, FTIR, Raman and TG analysis. Antibacterial activity, antistatic property, hydrophilicity and dyeability of treated wool fabric were assessed. The results demonstrated that TCEP-GTAC treatment can endow wool fabric good antibacterial and antistatic properties as well as improved hydrophilicity. Tensile strength studies indicated fiber strength loss of ~12 % on modification.  相似文献   

Chondrogenic differentiation of rat mesenchymal stem cells on silk fibroin/chondroitin sulfate/hyaluronic acid ternary scaffolds     

Ying Yu  Yafei Wang  Chen Lu  Dan Long  Qiang Zhang  Shuqin Yan  Renchuan You  Mingzhong Li 《Fibers and Polymers》2016,17(3):324-332

Cartilage repair is a challenge in bone tissue reconstruction. In this study, silk fibroin (SF), chondroitin sulfate (CS) and hyaluronic acid (HA) were employed to fabricate scaffolds for tissue engineered cartilage by freeze drying technique. The secondary pores were formed in the main pores of SF/CS/HA scaffold which improved the pore connectivity and equilibrium swelling of the scaffold. Furthermore, rat bone marrow mesenchymal stem cells were seeded on the scaffolds to evaluate the cell adhesion and proliferation. Results of hematoxylin/eosin staining and cell counting kit-8 assay showed that the cells migration and differentiation of SF/CS/HA (80/15/5) scaffold were better than that of SF/CS/HA scaffolds with different ratios after 7 days culture. Moreover, immunohistochemistry and scanning electron microscope demonstrated that large amounts of collagen II and proteoglycans of the cells were expressed in the SF/CS/HA 3D scaffold, while the expression of collagen I was barely visible by immunohistochemistry. Abound of extracellular matrix was formed to morphologically round and distributed uniformly throughout the scaffolds. The 3D ternary scaffold could promote the cells chondrogenic differentiation without using any inductive agent and offer potential for cartilage tissue regeneration.  相似文献   

湖北引种黄金茶1号主要生化特性及绿茶适制性分析     

马林龙  金孝芳  曹丹  刘艳丽  王胜鹏  刘盼盼 《茶叶科学技术》2016,(1):34-41

以湖北茶区主栽品种鄂茶1号为对照,研究引种的茶树品种黄金茶1号鲜叶以及春梢所制绿茶的主要生化成分含量变化,并进行感官审评.结果表明,黄金茶1号春梢鲜叶氨基酸、咖啡碱显著高于对照,而水浸出物、茶多酚、儿茶素、酚氨比低于对照;夏、秋梢鲜叶内含物质丰富,各生化成分含量相对高于春梢.春梢所制绿茶水浸出物、茶多酚、儿茶素、酚氨比低于对照,茶氨酸、天冬氨酸、谷氨酸、精氨酸以及氨基酸总量高于对照;共检测出香气成分37种,各香气类别、组分所占比例均与鄂茶1号有明显差异;感官审评表明,黄金茶1号所制绿茶苦涩味低、嫩香浓郁、滋味鲜醇淡爽,品质优于鄂茶1号.  相似文献   

Progress in research on acute hepatopancreatic necrosis disease (AHPND)     

Xupeng Hong  Liqun Lu  Dan Xu 《Aquaculture International》2016,24(2):577-593

Acute hepatopancreatic necrosis disease (AHPND) of shrimps is an important disease, first appeared in China in 2009. Since then, AHPND has caused serious drops in shrimp production (up to 20 % worldwide). Although AHPND [originally termed as acute hepatopancreatic necrosis syndrome (AHPNS)] first appeared in 2009, it was not until 2013 that a laboratory infection model was devised and the causative agent identified as certain strains of Vibrio parahaemolyticus. AHPND has caused mortality from 40 to 100 % which usually occurs early (within approximately 35 days) after stocking shrimp fry in shrimp ponds; therefore, it was initially referred to as early mortality syndrome (EMS). Confusingly, other pathogens and environmental factors also cause EMS and are often attributed to AHPND by shrimp farmers. Frequently, farmers do not send samples for confirmatory tests requiring detection of the unique histopathology at the acute stage of disease (massive sloughing of hepatopancreatic epithelial cells without any accompanying signs of a pathogen). The gross signs presumptive of AHPND (lethargy, slow growth, empty stomach and midgut, and a pale to white, atrophied hepatopancreas) are insufficient for confirmatory diagnosis. Recently, molecular detection of AHPND bacteria using PCR has been developed, which has sped up diagnosis and increased research on the causative agent, alternative detection methods, and possible therapies. We hope that this review of research progress on AHPND will serve as a useful introduction for researchers who are currently unfamiliar with AHPND, but have backgrounds in bacterial virulence, detection, and epidemiology, and may be encouraged to participate in the research effort to reduce AHPND’s impact on shrimp cultivation.  相似文献   

U、Cd单一及复合污染对水芹生长和生理特性影响   总被引：1，自引：0，他引：1  

姚天月  王丹  李泽华 《农业环境科学学报》2016,35(5):871-877

通过土壤盆栽试验研究不同浓度的U、Cd单一及其复合污染对水芹的生长、叶绿素含量、根系活力、细胞膜透性和MDA含量的影响。结果表明:与对照相比,随U、Cd单一及其复合污染处理浓度的增加,水芹的生长受到显著抑制(P0.05);水芹叶绿素含量逐渐减少,其中以Cd元素对水芹叶绿素b胁迫作用最显著;水芹根系活力在低浓度(15 mg·kg~(-1))时受到促进,而在高浓度(150mg·kg~(-1))时受到抑制;叶片相对电导率处理组数据均显著高于对照组,U胁迫作用强于Cd;叶片丙二醛含量与对照相比随处理浓度的增加呈上升趋势。比较U、Cd单一及其复合处理对水芹的胁迫效应表明,高U高Cd(U150 mg·kg~(-1)+Cd150 mg·kg~(-1))对水芹生长和生理影响最显著,水芹在低浓度U、Cd胁迫下具有较好的抗逆性,因此,其在低浓度U、Cd单一及其复合污染的土壤修复方面具有潜在应用价值。  相似文献   

农地信托中信托财产性质及归属谜题：困局与出路     

朱庆  王丹 《安徽农业大学学报》2016,(4):80-83

农地信托中信托财产的性质为何,农地信托设定后信托财产所有权是否发生变动,已困扰我国学界多年。目前既有的承包权—权利转移说、承包权—权利不转移说、租赁权—权利转移说等多种学说均未能完美解决农地信托的理论谜题。农地“三权分置”政策的提出,为解决上述谜题提供了新的机遇。将农地信托中信托财产界定为农地经营权,并将这项权利配置为“高度物权化的债权”,有利于彻底解决农地信托的理论谜题。  相似文献   

基于农民增收视角下甘肃农村人力资源开发研究     

闫丹  韩旭峰 《安徽农业大学学报》2016,(2):9-19

农民收入始终是我国“三农”问题的核心,也是农业农村经济社会发展的晴雨表,更是衡量“三农”工作力度的试金石。以农民增收为视角,应用格兰杰检验探索人力资本投资和经济发展的计量关系,得出加大人力资本投资,可以促进农民收入增长的结论。通过问卷调查、实地访谈、查阅年鉴等方式获取有关资料,采用实证分析、定量和定性相结合的分析方法对甘肃省人力资源开发现状进行纵向和横向的分析,在此基础上提出政府要注重人力开发工作,实施人力反哺机制;要推进双基教育,狠抓农业教育;要合理规划“新农合”,打好农民健康盾牌;要优化配置人力资源,动态匹配人与岗位。  相似文献   

基于ArcGIS的上海社区人行道使用频度分析——以莘庄为例     

迟娇娇  陈丹  李志刚  车生泉 《上海交通大学学报(农业科学版)》2016,(6):78-85

城市人行道是市民日常行为活动的重要发生场所,合理的人行道建设对完善城市公共空间和建设宜居社区有重要意义。为分析社区人行道的使用频度,本文以上海莘庄社区为例,利用ArcGIS最短路径分析方法,从交通、休闲两个层面对人行道使用频度进行叠加模拟分析,并通过现场调研对模拟结果进行对比验证。研究发现,人行道使用频度与目的地、小区出入口及户数、街道出入口数量、两种使用频度的相对权重等因素有关;ArcGIS最短路径分析法能快速、定量的分析人行道使用频度,可应用于社区尺度人行道的前期规划中。本文还针对不同使用频度人行道在交通、休闲、景观层面存在的问题提出优化对策,对上海社区人行道建设具有一定的指导意义。  相似文献   

海南本地野生维管植物区系研究   总被引：1，自引：0，他引：1  

林泽钦  杨小波  陈玉凯  李东海  黄瑾  龙成  李丹  张萱蓉  刘子金 《热带作物学报》2016,37(2):351-358

为全面了解海南本地野生维管植物区系基本特征,以《海南植物物种多样性编目》、《海南植物图志》等文献为基础,并通过野外考查、标本考证,从野生维管植物区系组成、成分等方面开展海南本地野生维管植物区系研究。结果表明:(1)海南维管植物共243科1 895属6 036种,其中本地野生维管植物有4 579种,隶属于225科1 429属,具有较高的物种多样性,但特有种占总种数的10.55%,仅483种;(2)在海南本地野生维管植物种类组成中,重要科有樟科(Lauraceae)、楝科(Meliaceae)、壳斗科(Fagaceae)、棕榈科(Palmae)、龙脑香科(Dipterocarpaceae)、五加科(Araliaceae)、漆树科(Anacardiaceae)等;(3)海南本地野生维管植物区系主要由以热带分布为主的科(占科数82.63%)和属(占属数84.40%)组成,其中,科以泛热带分布及其变型为主(57.49%),属以热带亚洲分布及其变型为主(27.09%),属马来西亚亚区的一部分,不仅呈现出热带性,而且呈现出与中国华南大陆的共源性,带有明显的热带边缘性质,为中国华南植物区系与亚洲热带雨林的过渡类型。  相似文献