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91.
黄廷安 《湖南农机》2009,36(1):50-52
城市化是区域经济发展的重头戏,是解决农村剩余劳动力的重要渠道。近几年,铜仁地区城市化发展取得一定成绩,第二产业和第三产业比重接近60%,城镇化接近30%,但发展过程仍存在比较多制约因素。加快铜仁城市化进程,应调整产业结构,发展第三产业,重点要突出经济发展和产业聚集这个基础。  相似文献   
92.
Relatively few studies have so far investigated the hydrological impacts of urbanization in Mediterranean catchments, and particularly in peri‐urban catchments experiencing relatively rapid and large changes in their land‐use mosaic. This study uses data‐based model simulations to investigate such impacts, with the Ribeira dos Covões catchment in Portugal as a concrete Mediterranean peri‐urban catchment example. We distinguish the impacts of urbanization from those of climatic change on the water flux partitioning and connectivity in the catchment over the period 1958–2013. Decrease in precipitation over this period has primarily driven decreases in annual runoff and actual evapotranspiration, while the urbanization development has primarily changed the relative flux partitioning and connectivity pattern in the catchment. The relative contribution of overland flow to annual and seasonal runoff has increased, keeping the absolute overland flow more or less intact, while the baseflow contribution to the stream network has decreased. Methodologically, the present simulation approach provides a relevant means for distinguishing main drivers of change in hydrological flux partitioning and connectivity under concurrent urbanization and climatic changes. © 2017 The Authors. Land Degradation & Development Published by John Wiley & Sons Ltd.  相似文献   
93.
要夺取早稻生产的持续增产,扩大早稻种植面积,选择适宜品种,选准栽培方式,培育健壮秧苗,建立高产群体是五项关键措施。  相似文献   
94.
A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice.  相似文献   
95.
A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice.  相似文献   
96.
城市化是社会生产力发展的必然产物,是人类从传统的农业社会演变为现代工业社会必然要经历的历史过程。内蒙古自治区实施城市化战略已时机成熟、条件具备。本文全面论述了内蒙古自治区实施城市化战略的意义,详实分析了实施城市化的有利条件。并提出了切合实际的城市化战略措施。  相似文献   
97.
天津都市农业和农村城市化协调发展的战略问题   总被引:11,自引:3,他引:11  
从都市农业和农村城市化协调互动关系分析入手,提出天津城乡统筹一体化发展的路径选择。在天津都市农业和农村城市化发展现状分析的基础上,研究面临的重大战略问题,提出都市农业和农村城市化的战略走向以及总体发展思路。  相似文献   
98.
南京市城市化与土地生态系统服务耦合度分析   总被引:1,自引:0,他引:1  
在构建两个子系统指标体系-城市化与土地生态系统服务的基础上,通过信息熵法评价城市化子系统各评价指标的权重和综合城市化水平,及价值系数法计算各种土地利用类型的服务价值,并利用容量耦合度函数和耦合协调度模型来测定南京市2005-2014年城市化与土地生态系统服务之间的耦合度。结果表明,2005-2014年南京市城市化综合指数呈持续上升的趋势,且增长较快。土地生态系统服务综合指数两次呈现先下降后上升的趋势,波动幅度较大,其值介于0.2~0.8之间。研究期内南京市城市化与土地生态系统服务耦合度值均较大,介于0.6~1之间,2005年处于磨合阶段,2005年后进入高水平的耦合阶段。耦合协调度值变幅在0.53~0.73之间,研究期内南京市城市化与土地生态系统服务一直处于高度协调的状态,但呈现出明显的阶段性特征:2005-2009年呈上升趋势;2009-2012年呈下降趋势;2013-2014年协调度慢慢回升。  相似文献   
99.
我国人多地少、农村劳动力剩余现象严重。增加农民收入,必须将大量的农民从土地上解放出来,让他们进城务工或加入非农产业,从而达到减少农民,富裕农民之目的。  相似文献   
100.
闵捷  高魏 《农业现代化研究》2005,26(6):431-434,452
协调经济发展和农地保护之间的矛盾需要对农地非农化进行合理的调控.论文运用社会燃烧理论分析了农地非农化过程的发生,认为农地非农化是在“燃烧物质”——人口增长、资源禀赋、经济发展,“助燃剂”——农地比较经济效益低、农地非农化收益分配不合理、土地产权、权能模糊和地方政府的短期行为,“点火温度”——城市土地使用制度的第一次革命和快速城市化下共同作用的结果.其中,农地比较经济效益低、农地非农化收益分配不合理、土地产权、权能模糊和地方政府的短期行为是当前调控农地非农化应该重点解决的问题.  相似文献   
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