甜樱桃光合作用研究进展

作者综述了甜樱桃光合作用的基本特性,以及甜樱桃品种间的差异、叶片内部叶绿素含量、不同节位、不同冠层、环境条件(光照、温度、水分和空气)等内、外因素对甜樱桃光合作用的影响,并对今后甜樱桃光合作用研究进行了展望,旨为甜樱桃科研与生产提供参考。     

云南中亚热带禾本科高产饲草引种试验

在云南中亚热带试验点,对8个禾本科饲草栽培种进行引种栽培试验,结果表明墨西哥类玉米、8493墨西哥类玉米、大力士甜高粱、先锋高丹草和M-8IE甜高粱5个栽培种干物质产量高,适应性强,适宜在相似气候条件地区推广种植.     

白音阿扁叶蜂老龄幼虫化学防治试验

对白音阿扁叶蜂防治试验,表明采用2.5%的功夫乳油5000倍液、4.5%的高效氯氰聚酯乳油5000倍液、50%的辛硫磷乳油2000倍液、80%的敌敌畏乳油2000倍液,都能达到理想的防治效果.两种菊酯类药剂成本相对较低,对环境污染也相对较小,在防治中可以推广应用.     

几种因素对培养小鼠精原干细胞的影响

探讨了小鼠胚胎成纤维细胞饲养层及干细胞因子(SCF)、白血病抑制因子(LIF)、碱性成纤维细胞生长因子(bFGF)等对体外培养小鼠精原干细胞的作用.结果显示,在饲养层上,精原干细胞贴壁时间缩至8～12 h,饲养层具有促进其分裂增殖的作用;培养液中加入不同浓度的SCF、LIF及bFGF,可延长精原干细胞在体外的存活时间,其中加入30μg/LSCF后,其体外存活时间与对照组相比差异显著(P<0.05).     

中国草原生态旅游资源及可持续开发利用

从草原生态旅游本质与内涵出发,论述了草原开展生态旅游的可行性和必要性,分析了草原生态旅游开发的资源基础、开发现状及存在问题;从草原生态旅游资源开发的特点出发,提出了促进保护与发展目标相统一的生态旅游资源开发原则和管理措施.     

A formation mechanism for catalytically grown helix-shaped graphite nanotubes

The concept of a spatial-velocity hodograph is introduced to describe quantitatively the extrusion of a carbon tubule from a catalytic particle. The conditions under which a continuous tubular surface can be generated are discussed in terms of this hodograph, the shape of which determines the geometry of the initial nanotube. The model is consistent with all observed tubular shapes and explains why the formation process induces stresses that may lead to "spontaneous" plastic deformation of the tubule. This result is due to the violation of the continuity condition, that is, to the mismatch between the extrusion velocity by the catalytic particle, required to generate a continuous tubular surface, and the rate of carbon deposition.     

Biological control in Hungary: present situation and possibilities1

Biological control has already achieved certain results in Hungary, especially against soil-borne fungi and glasshouse pests. Nevertheless, experience has shown that locally found biological agents, however effective, could not be developed into registered, ready-for-sale plant protection products because of the lack of companies willing to invest. Biological control in Hungary is therefore limited to the conservation of natural antagonistic flora and fauna and to the application of imported biopesticides and bioagents, which are subject in Hungary to a registration procedure similar to that for chemical plant protection products. Current work includes the development of an anti-nematode product from a local strain of Arthrobotrys oligospora, application techniques for a local mirid Dicyphus hyalinipennis against insect pests, studies with native and imported strains of the nematodes Steinernema and Heterorhabditis against soil-borne insect pests, and introduction techniques for the chrysomelid Zygogramma sutularis against the weed Ambrosia elatior.     

散养湘黄鸡常见病的临床表现特点及其防制

湘黄鸡进行专业户(场)散养时，由于生产方式不同于舍饲群养，其生产环境、食物结构和易感病种类都必然发生变化。对此，笔者结合临床所遇病例进行了研究总结，对散养湘黄鸡的几种常发病的病因、病理、临床表现及防治特点等方面进行了介绍。     

基于VBA的云南省基层林业工作站信息管理系统的设计与构建

为全面掌握全省各级林业站管理机构、各县(市、区)基层林业工作站的基本情况,基于云南省基层林业工作站情况调查的要求,结合乡镇林业工作站工程建设标准需要,以林业工作站调查信息数据为基础,利用VBA语言在Access 2007下开发具有形象直观的统计图功能、智能查询功能、数据导出至电子表格模板等功能特点的云南省基层林业工作站信息管理系统,文中阐述了系统开发方案、开发环境及系统主要功能。