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通过对丘陵山区土地整治技术与农业机械化现状的思考,分析了当前丘陵山区土地整治技术不利于推进农业机械化的一些因素,即水平梯田田面宽度确定、田间道路的平纵线型设计、机械下田与田间转移设施设置等,之后提出了有针对性的建议。 相似文献
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陈海 《资源导刊(河南)》2015,(7)
<正>进入汛期,汝阳县政府多措并举,标本兼治,扎实做好地质灾害防治工作,"不留死角",确保地质灾害防治工作有效开展,切实保障人民群众生命财产安全。汝阳县位于豫西伏牛山区,北汝河上游,地形复杂。南部崇山峻岭连绵不断,北部为平原丘陵。全县山地面积900余平方千米,占总面积的70.2%,丘陵占总面积的19.6%,平川仅占10.2%。地貌基本上分为南部深山区、中南部浅山区、平川区和丘陵区。平川区主要在汝河等河流两岸,进入 相似文献
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济宁南部优质大米产地土壤地球化学特征 总被引：2，自引：0，他引：2
对济宁南部优质大米产地的不同层位土壤样品的分析结果进行统计，分析了土壤元素的分布特征，证实除P的含量稍低于山东省平均值外，其他元素含量均高于山东省平均值，土壤质量良好，营养水平较高。但Cu，F，As，cd，Pb，Hg，cr在土壤中原始含量偏高，是潜在污染源和引发地方病的隐患。通过土壤环境质量评价和土壤肥力评价，结果表明该区土壤环境质量较好，大部分地区肥力优良或尚可，但个别地段因重金属污染超标成为质量较差区，应引起人们的重视，以确保粮食生产安全。 相似文献
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平邑县境内属于丘陵山区,进行地形三维显示不仅便于用户直观地了解平邑的地形地貌,而且便于用户查询相关信息进行土地利用分析。该文主要介绍利用ArcView3.2进行数字高程模型(DEM)的建立及其三维显示,以及道路、水系等各主要要素的三维显示。 相似文献
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2015年3月19日,浙江省国土2资源厅科技与教育处和地质环境处组织专家对浙江省国土资源厅信息中心完成的"浙江省丘陵山区县(市、区)级区域引发滑坡(泥石流)的降雨阈值研究"成果进行了评审,评审专家委员会一致认为该项成果在同类研究中处于国际领先水平。浙江陆域面积的70%为丘陵山区,具有复杂的地质、地形和独特 相似文献
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枣庄市山亭区位于枣庄市东北部，泰沂山区西南部，属低山丘陵区，全区大小山头1000多座，地形条件复杂，土地总面积1018．64km^2，山地丘陵占全区总面积的80％以上。山亭区的土地利用现状更新调查工作始于2004年，经过1年多的艰苦调查，查清了全区各类土地利用的现状，绘制了山亭区土地利用现状图，建成了山亭区土地利用数据库。2007年7月，山东省国土资源厅对山亭区的土地利用调查更新工作进行了验收。经验收，山亭区土地利用更新调查技术路线正确、方法先进，各项成果符合土地更新调查技术要求。 相似文献
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开展农村土地整治是为了增加有效耕地面积,实现耕地占补平衡,促进新农村经济发展的有效途径。
一、当前丘陵山区土地整治面临的问题
随着城市、农村经济发展,耕地后备资源已严重不足,特别是丘陵山区耕地资源分布零散,远离居民点,开发难度大,利用条件差,垦殖成本高,经济效益低。林地、草地和坡地开荒受限制。原有耕地中,坡耕地多,水土流失严重。耕地质量下降,地力减退,进城农民房屋闲置成废弃地,这些将给农业可持续发展带来潜在危害。针对存在的问题,积极开展农村土地整治,在增加有效耕地面积的同时实现耕地占补平衡,也是加强新农村建设的有效途径。 相似文献
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根据 2 0 0 1年 11至 2 0 0 2年 1月间北部湾海域秋、冬季 2个航次的底拖网渔业资源调查资料 ,对北部湾海域甲壳类的种类组成及分布进行研究。本次调查共渔获虾类 2 4种 ,隶属于 6科 11属 ;蟹类 30种 ,隶属 9科 19属 ;虾蛄 9种 ,隶属 2科 6属。各种类沿水深和地理分布有明显变化 ,主要集中分布于湾中部水深 2 1～ 80m海域。 相似文献
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Pak-TaoLeung CarlH.Gibson 《中国海洋湖沼学报》2004,22(1):1-23
Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than any of the other forces that tend to damp the eddies out. Energy cascades of irrotational flows from large scales to small are non-turbulent, even if they supply energy to turbulence. Turbulent flows are rotational and cascade from small scales to large, with feedback. Viscous forces limit the smallest turbulent eddy size to the Kolmogorov scale. In stratified fluids, buoyancy forces limit large vertical overturns to the Ozmidov scale and convert the largest turbulent eddies into a unique class of saturated, non-propagating, internal waves, termed fossil-vorticity-turbulence. These waves have the same energy but different properties and spectral forms than the original turbulence patch. The Gibson (1980, 1986) theory of fossil turbulence applies universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as its growth is constrained and fossilized by buoyancy forces. Quantitative hydrodynamic-phase-diagrams (HPDs) from the theory are used to classify microstructure patches according to their hydrodynamic states. When analyzed in HPD space, previously published oceanic datasets showed their dominant microstructure patches are fossilized at large scales in all layers. Laboratory and field measurements suggested phytoplankton species with different swimming abilities adjust their growth strategies by pattern recognition of tur-bulence-fossil-turbulence dissipation and persistence times that predict survival-relevant surface layer sea changes. New data collected near a Honolulu waste-water outfall showed the small-to-large evolution of oceanic turbulence microstructure from active to fossil states, and revealed the ability of fossil-density-turbulence patches to absorb, and vertically radiate, internal wave energy, information, and enhanced turbulent-mixing-rates toward the sea surface so that the submerged waste-field could be detected from a space satellite (Bondur and Filatov, 2003). 相似文献
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Mollisols properties and changes in Ukraine and China 总被引：4，自引：2，他引：2
Soils are the foundation of civilizations and the basis for human food production.Mollisols in Ukraine and Northeast China are two out of the four major Mollisol regions in the world.The natural areas from which Mollisols developed are the prairies and steppes that experience temperate and freezing conditions.This review paper introduces the general climate,vegetation,and topography of Mollisols regions in Ukraine and Northeast China,analyzes their properties,including soil texture,soil organic matter content,soil bulk density,pH,cation exchange capacity and other chemical properties,and compares the property changes and management practices of Mollisols in relation to sustainable grain production. 相似文献
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王有春 《广东海洋大学学报》2002,22(5):49-52
我国的民主党派既不同于执政党 ,也不同于反对党 ,它们是接受中国共产党领导、致力于社会主义现代化建设的参政党。所谓参政 ,首先是参加国家政权 ,其次是参与国家大政方和国家领导人人选的协商 ,其三是参与国家事务的管理。民主党派不仅要参政 ,还要对执政的中国共产党进行有效的监督 ,因为执政党 .的状况如何 ,路线、方、政策正确与否 ,直接关系到社会主义事业的兴衰成败。所以 ,作为执政党的中国共产党 ,一定要充分认识并切实发挥各民主党派的监督作用。 相似文献
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以章丘地区土壤为对象,系统分析了表层、深层土壤及8条剖面土壤中Se元素的含量水平,研究了土壤中Se的分布特征及其与土壤类型、成土母质、地形地貌和土壤理化性质及组分的关系。结果表明：章丘地区表层土壤中Se含量在0.1～0.8mg/kg之间,以中硒土壤为主,富硒土壤面积173km2。土壤类型中,水稻土Se平均含量水平最高,为0.55mg/kg;成土母质中以石炭—二叠纪泥页岩发育的土壤Se含量最高;剖面土壤中的Se主要在表层富集。影响章丘地区土壤Se含量分布的主要因素是成土母质、地形地貌、土壤pH、有机质及土壤中硫、铁铝氧化物等组分。 相似文献
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Selected trace metals(Pb, Cd, Cu, Hg) and arsenic in seawater and surface sediments of Laizhou Bay were determined, to evaluate their spatial distribution, pollution risk and potential ecological risk. Concentrations of the elements were 0.56–2.07, 0.14–0.38, 12.70–18.40, 0.014–0.094, and 1.13–2.37 μg/L in the seawater and 8.94–32.2, 0.18–0.67, 4.51–30.5, 0.006–0.058, and 5.75–15.3 mg/kg in sediments for Pb, Cd, Cu, Hg and As, respectively. High concentrations of the trace metals and arsenic in seawater and surface sediments were generally observed near the river estuary. The pollution risk result of the elements showed that Cu was the prominent trace metal pollutant in seawater, followed by Hg, Pb, Cd and As. The metal complex pollution index in seawater was at a medium level. The most important trace metal pollutant in sediments was Cd, followed by As, Cu, Pb, and Hg. Our pollution assessment suggests that trace metal pollution in Laizhou Bay sediments was at a low level. The potential ecological risk was also low in surface sediment. 相似文献
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Evaluation and analysis of provincial differences in resources and environment carrying capacity in China 总被引：2，自引：0，他引：2
Resources and environment carrying capacity is central to not only regional sustainable development but also major function-oriented zoning. This paper presents an evaluation index system for resources and environment carrying capacity based on four aspects of carrying capacity(i.e., water resources, land resources, the environment, and ecosystems) by using a square deviation decision-making method, and on the basis of above effort evaluates the resources and environment carrying capacity across 31 provincial regions in China(not including Hong Kong, Macau and Taiwan regions of China). In addition, this paper evaluates the current state of socio-economic development, and analyzes the spatial distribution of resources and environment pressure. The results showed that distinct spatial differences in resources and environment carrying capacity and pressure across provincial regions. Resources and environment pressure is affected by both comprehensive resources and environment carrying capacity and socio-economic development. Regions subjected to lower degrees of resources and environment pressure will be restricted by resources and environmental problems through future courses of development owing to excessively low carrying capacities. By contrast, regions with higher comprehensive resources and environment carrying capacity will be subjected to excessively high levels of resources and environment pressure because of rapid socio-economic development. Both of resources and environment carrying capacity and pressure must therefore be considered in the allocation of country-binding targets to provincial regions. 相似文献
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Toxic cyanobacteria(TCB) are well-known worldwide for their adverse impacts on humans. Species compositions and seasonal variations of TCB in reservoirs depend on interactions between physical and chemical factors. This study was conducted to evaluate the water quality in the Aha Reservoir, Southwest China, focusing on cyanobacteria and cyanotoxins. Water samples were collected weekly or biweekly from May to September of 2015 and used to delineate temporal variations in density and distribution of toxic cyanobacteria and cyanotoxins in the reservoir. Toxic cyanobacteria identified consisted of Aphanizomenon flos-aquae, Pseudanabaena limnetica, Cylindrospermopsis sp., and Microcystis sp., with Aphanizomenon flos-aquae and Pseudanabaena limnetica being the most common and significant toxic genera. The total biomass of cyanobacteria was 17.0 mg/L. Identification and quantification of microcystin variants were conducted by high performance liquid chromatography(HPLC) using a system equipped with a photodiode array detector. Microcystin levels were between 0–3.0 μg/L, MC-RR was around 0–3.0 μg/L and MC-LR was approximately 0–0.9 μg/L. Overall, the results of this study indicate that the investigated reservoirs should be monitored regularly to minimize potential health risks to the human population. 相似文献
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Distribution of Aluminum and Fluoride in Tea Plant and Soil of Tea Garden in Central and Southwest China 总被引：4，自引：0，他引：4
The distribution of Al and F contents and the relationship between Al and F in tea plants and soils of 12 tea gardens in Central and Southwest China were investigated from October 31 to November 14, 2006. The results show that there were differences in pH, CEC, the contents of organic matter (OM), Al and F in the different soils of the tea gardens. The Al content ranged from 1196 to 7976mg/kg for old leaf, 370 to 2681mg/kg for young leaf and 285 to 525mg/kg for stem, whereas the content of F ranged from 221 to 1504mg/kg for old leaf, 49 to 602mg/kg for young leaf and 13.5 to 77.5mg/kg for stem. The concentrations of labile Al varied obviously in the different soils, but the distribution law of labile Al content for the same garden was Alexchangeable≈AlFe-Mn oxide>Alorganic>Alwater-soluble. The contents of different labile F fractions varied slightly in the different soils and the different soil layers, though the exchangeable F content was lowest among the labile F in the soils. The concentrations of Al and F in tea plants increased with increasing amount of water-soluble Al or F, especially the amount of water-soluble fractions in the soil layer of 0-20cm.The correlation between Al content and F content in the tea leaf was more significant than that in the tea stem. Furthermore, the correlation between Al content and F content in whole tea plant was strongly significant (r=0.8763, p<0.01, n=36). There were evident tendency that Al concentration increased with the increase of F concentration in different soil layers. The correlation of water-soluble Al with water-soluble F in all soils was also strongly significant (r=0.7029, p<0.01, n=34). The results may provide a proof that Al and F are jointly taken up by tea plants to some extent in natural tea gardens. 相似文献