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免耕措施对土壤水分及利用效率的影响
作者: 彭文英   来源: 土壤通报 年份: 2016 文献类型 : 期刊 关键词: 免耕   动态变化   土壤水分   水分利用效率  
描述: 免耕覆盖能有效地控制土壤侵蚀,抑制地表起沙,防治土壤退化,将是我国北方地区代替传统农耕的最好办法之一。针对土壤水分往往是我国北方地区农作物生长重要的限制性因子,本文选择国内外免耕措施的土壤水分试验
新疆加工番茄抗黄瓜花叶病毒转基因技术的研究
作者: 张瑜   来源: 石河子大学 年份: 2010 文献类型 : 学位论文 关键词: RNA干扰   系统进化树   黄瓜花叶病毒  
描述: bution, one of the pathogenicity impaired crops. It has three genomic RNAs. So it is one of RNA virus model strains to investigate pathogenicity mechanism in host.
全文:上,同时也是研究RNA病毒在寄主上致病机制的模式病毒之一。 黄瓜花叶病毒是造成新疆加工番茄减产甚至绝产的重要病原,对于传统的抗病毒育种以及农药防治等方法不仅造成了环境污染,而且费时费力。但是RNAi
中国古代农业灾害防减体系研究
作者: 邵侃   来源: 西北农林科技大学 年份: 2009 文献类型 : 学位论文 关键词: 农业灾害史   农业灾荒文献   减灾技术   灾荒赈救   灾害预防  
描述: n the 1920s when China was called “the Land of Famine” by an American relief worker, the phrase immediately gained currency.
全文:民在承受各种灾害打击的同时,也开始了认识灾害、防治灾害的探索和实践,采取了各种积极的措施防灾抗灾,取得了巨大的成就,主要表现在救荒制度建设和减灾技术进步两个方面。本文以历史时期的抗灾救荒活动为基本
中国古代农业灾害防减体系研究
作者: 邵侃   来源: 西北农林科技大学 年份: 2009 文献类型 : 学位论文 关键词: 农业灾害史   农业灾荒文献   减灾技术   灾荒赈救   灾害预防  
描述: n the 1920s when China was called “the Land of Famine” by an American relief worker, the phrase immediately gained currency.
全文:民在承受各种灾害打击的同时,也开始了认识灾害、防治灾害的探索和实践,采取了各种积极的措施防灾抗灾,取得了巨大的成就,主要表现在救荒制度建设和减灾技术进步两个方面。本文以历史时期的抗灾救荒活动为基本
中国古代农业灾害防减体系研究
作者: 邵侃   来源: 西北农林科技大学 年份: 2009 文献类型 : 学位论文 关键词: 农业灾害史   农业灾荒文献   减灾技术   灾荒赈救   灾害预防  
描述: n the 1920s when China was called “the Land of Famine” by an American relief worker, the phrase immediately gained currency.
全文:民在承受各种灾害打击的同时,也开始了认识灾害、防治灾害的探索和实践,采取了各种积极的措施防灾抗灾,取得了巨大的成就,主要表现在救荒制度建设和减灾技术进步两个方面。本文以历史时期的抗灾救荒活动为基本
历史时期青海地区自然灾害与区域社会经济发展研究
作者: 刘雯   来源: 西北农林科技大学 年份: 2009 文献类型 : 学位论文 关键词: 青海地区   自然灾害   历史时期   社会效应  
描述: e distinctive features in Western and Eastern of Qinghai's natural disaster in history which based on the historical materials and studied the Interaction Relationship Between the natural disasters and social-economic development, we used the theory and analysis method from the research area of disaster history and agricultural history, try to have a comprehensive investigation between the natural disasters and social-economic development in the history of Qinghai. Firstly, we divided Qinghai into two parts: the eastern and the western, under the study of the geographical features of Qinghai. We summarized the natural disaster of the eastern part mainly as flood, drought, hailstone and frost with distinctive features of variety, continuity and growth accompany while the western is mainly as earthquake and snow disaster with distinctive features of unexpected and severity. Secondly , as the great influence on agriculture and the resulting changement in agriculture is most profound, so the progress in agriculture sciences is related to withstand the natural disaster in some ways. The paper discussed the natural disasters affected Qinghai's agriculture in history, from the aspect of seed selection 、 production 、 processing and storage to invest the development of mitigation techniques in this area. And for the livestock we investigated in two sides bred of livestock and prevention of livestock, furthermore we invested the mitigation techniques which full of geographical characteristics. Thirdly, the article investigated the relationship between natural disasters and the economic fluctuation in Qinghai from the perspective of the change in population and grain price. And then, we analyzed the influence on regional industrial structure from the aspect of expansion in rural areas, the relationship between agriculture and animal husbandry, disaster-relief crop introduction and the structure of animal species. In the view of pastoral economic exchange, we studied the interaction relationship between the natural disasters and economic development. Finally, we studied the interaction relationship between the natural disasters and social development in Qinghai. What is more, we analyzed the policy which includes grain storage, relieved and help the people in disaster , reduced taxes to control the disaster in history. We wish these could be helpful to the prevention and control of natural disasters in Qinghai today.
全文:很大程度上与抵御自然灾害相联系。文章探讨了历史时期青海地区的农业灾害情况,从选种、生产、加工、储藏的角度对该地区种植业减灾技术的发展进行了考察,对畜牧业则从畜种选育和畜疫防治的角度进行了分析,此外还
植物河道水流特性和稳定河相关系研究
作者: 王燕   来源: 中国海洋大学 年份: 2009 文献类型 : 学位论文 关键词: 仙农熵   水流特性   生态河流   根系加固   河相关系  
描述: made for economic prosperity. At the same time, some man-made natural disasters have been paid more and more attentions , so the research on hydraulic characteristics of the river in recent years has been put on the agenda. Considering the ecological environment, flood control, pollution prevention and control method, and in view of the perspective of the urban landscape as well as the national strategic plan for sustainable development, the research the hydraulic characteristics of river and making river reasonably repair and ecological reconstruction will become a general trend, because that is a kind of remediation measure for human to be done unreasonable exploitation, and it also will be the strong protection of river resources and sustainable model for better using river resources in the future.
全文:河流的开发利用带来了一定的经济效益,为经济的繁荣做出了很大的贡献。但与此同时,人为造成的自然灾害不得不越来越引起人们的广泛关注,于是近年来河道的水力特性的研究已提上日程。无论是从生态、防洪、防治
小麦蓝矮病植原体β-1,4-内切葡聚糖酶基因的分离、序列分析与致病性测定
作者: 张珏   来源: 西北农林科技大学 年份: 2010 文献类型 : 学位论文 关键词: 致病性   1   植物病毒表达载体   β   4   原核表达   小麦蓝矮病植原体   内切葡聚糖酶  
描述: Northwest China, this disease was transmitted by Psammotettix striatus in a distinct way.
全文:持久方式专化性传播。表现病症的叶片多为黄化,植株矮缩,叶片厚硬,造成减产,严重时全田发病绝收,极大威胁小麦产量。因此,小麦蓝矮病的研究和防治意义重大。β-1,4-内切葡聚糖酶(FrvX)是一类由真菌
兰州市古树名木调查及保护研究
作者: 刘秀琴   来源: 兰州大学 年份: 2009 文献类型 : 学位论文 关键词: 古树养护与复壮技术   古树后续资源   保护性开发建议   兰州市   古树名木  
描述: e are scarce are one of the and nonrenewable of city devel engrave epoch stamp, They are often named "Green Antique" and "Live opment, Cultural relic" by having high ecological, social, economic value, scientific research, high ornamental and tourist, and historical memorial meaning.
全文:与复壮技术要点。 古树养护管理措施主要包括:(1)修建树池与设置围栏;(2)水分调节与灌水;(3)养分补充与合理施肥;(4)整理地面环境与松土;(5)树皮、枯枝落叶覆地保护;(6)防治病虫害;(7)修剪
清代洮河中下游地区农业开发初探
作者: 孛鹏旭   来源: 西北师范大学 年份: 2010 文献类型 : 学位论文 关键词: 清代   洮河流域   农业开发   生态环境变迁  
描述: 本文从地域上选取自然环境较完整、经济文化交流较密切、同属农耕区的洮河中下游地区为探讨对象,选取时代性鲜明、农业开发成果显著、环境压力较大、前后期对比较为明显的清代为探讨时段。从历史地理学的角度研究农业开发,并探讨生态环境变迁过程,在方法论上力求以区域历史地理学的综合方法来进行研究。 全文包括三部分,
全文:农业开发的技术选择,系统探讨清代本区水利工程及灌溉技术;以玉米与马铃薯为例,探讨农作物品种的引进及改良;探讨清代本区农业耕作技术;探讨影响本区农业生产的自然灾害及其防治。第五章从农业开发的集中体现
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