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土地资源是人类社会赖以生存和发展的最基本的物质基础,是创造其他社会财富的主要源泉。随着可持续发展理论的兴起,土地资源可持续利用已成为人类社会可持续发展的重要依托和核心内容,土地资源可持续利用也成为国内外土地科学及相关学科研究的热门话题。本文以可持续发展理论、恢复生态学理论、自然资源学和生态经济学理论为基础,归纳概括了土地、土地资源、土地保护、土地资源的可持续利用的基本概念和内涵,回顾了国内外土地资源可持续利用的研究进展。选取了11个试验点(长武、安塞、米脂、淳化、乾县、准旗、定西、离石、隰县、西吉、固原)进行了初步研究,根据“十一.五”国民经济计划和远景目标,提出了促进土地资源可持续利用的基本对策。 相似文献
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土地资源是人类生产生活的重要物质基础，是社会发展的重要保障。实现土地资源的可持续利用，是缓解人地矛盾，促进资源、环境、人口、经济、社会可持续发展的重要保障。本文在土地可持续利用基本内涵的基础上，就目前土地可持续利用评价的指标体系构建、指标权重确定、评价方法选择等问题进行小结，为今后土地可持续利用研究工作的深入开展奠定基础。 相似文献
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煤炭是工农业生产和社会经济发展不可或缺的一种能源资源。煤炭资源的开发利用给人类带来巨大经济效益,同时也引起了一系列环境与社会经济问题。尤其是对土地资源的破坏,严重影响矿区经济发展以及人民正常的生产、生活。煤矿区土地利用研究逐渐成为社会焦点,这对于优化土地资源配置、提高土地利用效率、促进矿区城市经济可持续发展意义重大。本文基于生命周期理论分析了煤矿开采各个阶段矿区土地利用进程特点及其生态环境效应;论述了采后矿区土地可持续利用的含义及意义,并分析了采后矿区土地利用的特点。提出了矿区土地利用多元化发展的思路,使采后矿区土地资源得以可持续利用。以江苏省徐州市贾汪区作为试验区,通过对贾汪区土地利用变化情况及矿区生态环境效应展开研究,分析了试验区土地利用驱动力与土地利用变化的关系。研究结果不但对采后矿区土地利用可持续发展具有指导意义,而且对其它类型矿业城市的土地利用也有一定的参考价值。 相似文献
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土地问题已成为当今世界令人瞩目的重大社会经济问题.土地是人类赖以生存和发展的重要基础,围绕土地问题,我国也制定了基本国策,即“十分珍惜、合理利用土地和切实保护耕地”.所以,土地问题是关系经济和社会可持续发展的战略问题.在土地问题中,土地利用规划被公认为是必要的技术工具,可以实现土地资源的优化配置以及社会经济的可持续发展. 相似文献
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内蒙古草地资源现状及其可持续利用对策 总被引：2，自引：0，他引：2
草地资源及资源的可持续利用已经成为今天人类社会可持续发展关注的热点。本文概述了内蒙古草地资源现状,分析了造成退化的主要原因,提出了保护建设和实现草地资源可持续利用的几点措施与对策。 相似文献
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阿勒泰市草地面积辽阔,牧草种类丰富,草地类型多样,开发条件较好,既是发展畜牧业的物质基础,又是构建生态安全的重要屏障.但由于长期超载过牧、无序利用,资源过度消耗,环境普遍恶化,资源利用与人口、环境、社会经济协调发展的矛盾日益突出 ,成为阻碍社会经济可持续发展和生态安全的"瓶颈".本研究从可持续发展理论的经济学、生态学、社会学角度出发,论证阿勒泰市草地生态环境保护不但是生态环境建设的实际需要,而且关系到社会进步与牧区经济繁荣.关系到农业可持续发展. 相似文献
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Evidence for the non-involvement of the uterus in the lifespan of the corpus luteum in the cyclic dog 总被引：1，自引：0，他引：1
Progesterone levels in peripheral blood of dogs were analysed during the cycle in which hysterectomy (n = 5) or sham surgery (n = 3) was performed as well as during the cycle of dogs (n = 5) hysterectomized at least one year prior to this study; the data were compared with the findings in control dogs (n = 3). The averages of the duration of the luteal period observed in the three experimental groups were not significantly different from those of control dogs. Immediately after surgery, the progesterone level decreased from 25 to 50% of the presurgical level, but returned to presurgical level in about four days. Prolactin levels were elevated for about 30 h after surgery. Nevertheless, the averages of the mean prolactin levels for each animal during the luteal period of the experimental groups were not significantly different from those of control dogs. It is concluded that in the dog, the uterus is not involved in the lifespan of the cyclic corpus luteum. 相似文献
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Meschan EM Peham C Schobesberger H Licka TF 《Veterinary journal (London, England : 1997)》2007,173(3):578-584
As there is no statistical evidence that saddle fit influences the load exerted on a horse's back, this study was performed to assess the hypothesis that the width of the tree significantly alters the pressure distribution on the back beneath the saddle. Nineteen sound horses were ridden at walk and trot on a treadmill with three saddles differing only in tree width. Kinetic data were recorded by a sensor mat. A minimum of 14 motion cycles were used in each trial. The saddles were classified into four groups depending on fit. For each horse, the saddle with the lowest overall force (LOF) was determined. Saddles were classified as "too-narrow" if they were one size (2 cm) narrower than the LOF saddle, and "too-wide" if they were one size (2 cm) wider than the LOF saddle. Saddles two sizes wider than LOF saddles were classified as "very-wide". In the group of narrow saddles, the pressure in the caudal third (walk 0.63 N/cm(2)+/-0.10; trot 1.08 N/cm(2)+/-0.26) was significantly higher compared to the LOF saddles (walk 0.50 N/cm(2)+/-0.09; trot 0.86 N/cm(2)+/-0.28). In the middle transversal third, the pressure of the wide saddles (walk 0.73 N/cm(2)+/-0.06; trot 1.52 N/cm(2)+/-0.19) and very-wide saddles (walk 0.77 N/cm(2)+/-0.06; trot 1.57 N/cm(2)+/-0.19) was significantly higher compared to LOF saddles (walk 0.65 N/cm(2)+/-0.10/ 0.63 N/cm(2)+/-0.11; trot 1.33 N/cm(2)+/-0.22/1.27 N/cm(2)+/-0.20). This study demonstrates that the load under poorly fitting saddles is distributed over a smaller area than under properly fitting saddles, leading to potentially harmful pressures peaks. 相似文献
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嗅源是军犬嗅觉作业训练的依据.军犬鉴别中嗅源能力的培养在整个鉴别训练中占有重要地位,关系到鉴别训练的成败和鉴别能力的提高.所以,军犬在嗅认嗅源时必须按照训犬员的指令充分、细致地感受嗅源气味,并且对嗅源气味产生兴奋反应.如何培养军犬充分嗅认嗅源以及及时解决嗅认过程中出现的问题,成为我们进行鉴别训练的关键.…… 相似文献
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