济宁市耕地质量评价与保护对策研究          下载免费PDF全文

刘良  张祖陆  于成  张光凤 《山东国土资源》2013,29(4):49-53

耕地资源作为一种非常重要的土地资源,对其质量的研究评价越来越受到人们的重视。该文综合选取了13个可能导致耕地质量发生变化的因素作为基础指标,运用基于AHP的模糊综合评价方法对山东省济宁市耕地资源的质量进行了综合评价。结果表明,济宁市耕地的质量等级为"一般",评价结果符合实际。针对评价结果,对可能导致耕地质量变化的驱动力因子进行了分析,并提出优化建议和措施。  相似文献   

内蒙迪彦庙地区寿山沟组地层研究          下载免费PDF全文

宋鹏  王丰翔  李英杰  张红晨  贺秋利  于灵艳 《山东国土资源》2013,29(10)

内蒙迪彦庙地区早二叠世寿山沟组地层发育良好,岩性相对稳定,变质、变形程度较低,是研究区范围内早二叠世地层层序研究的理想地区。该课题逐层实测了寿山沟组剖面,从剖面的岩性地层入手,着重分析了迪彦庙地区早二叠世的岩性组合特征、基本层序、沉积旋回特征;同时根据古生物化石类型和组合,推断该区域形成的地质时代和沉积环境。研究表明：寿山沟组剖面厚度为9598.98m,根据岩性和粒度的大小,可分3个岩段：一段为滨浅海浅海陆棚沉积;二段、三段为一套浊流沉积岩系,发育特征性浊流沉积构造,为典型的复理石建造。  相似文献   

复合linex对称损失下Lomax分布参数的Bayes估计     

余慧敏 《广东海洋大学学报》2013,(4)

研究了在复合linex对称损失下,两参数Lomax分布当刻度参数已知时,其形状参数的Bayes估计及其容许性,并给出了其多层Bayes估计的一般形式。  相似文献   

山东石炭二叠纪地层沉积环境分析     

杨恩秀  张春池  宁振国  于得芹  王巧云  彭观峰  王世进 《山东国土资源》2013,29(12):1-10

山东是华北地区较早接受晚古生代地层沉积的地区,分布于沂沭断裂带以西地区,自下而上划分为月门沟群和石盒子群,富含动植物化石和煤炭、铝土矿等矿产资源。该套地层不整合于奥陶系之上,顶部遭受风化剥蚀,被三叠系不整合覆盖,在不同地区地层厚度、岩性及含矿性特征差别较大。沉积环境由海相-海陆交互相向陆相演化,主要分为海洋环境、海陆过渡环境、湖泊环境、沼泽环境和河流环境。  相似文献   

分段量化门牌编码方法研究     

于焕菊  李云岭  蔡永宁 《测绘通报》2013,(4):37-41

首先介绍国内外主要门牌系统优缺点,在对门牌号空间特征进行分析的基础上,通过比较街区编码法和街道编码法各自优缺点,指出街道是适合我国门牌系统的空间参考框架;然后在街道框架下,通过剖析门牌的指位特征,指出传统序号法的不足及距离编号法的缺陷;最后提出在街道中以街区为分段的量化门牌编码方法,并针对每个街区100个号码的特殊情况,给出分段量化编码的效果。  相似文献   

基于局部化转换规则的元胞自动机土地利用模型   总被引：3，自引：1，他引：2  

宇林军  孙丹峰  彭仲仁  李红 《地理研究》2013,32(4):671-682

传统土地利用元胞自动机(Cellular automata,CA)模型基于空间同质性假设,使用全局性模型建立元胞转换规则,忽略了土地利用变化驱动因素的驱动作用在空间上的变化。以美国佛罗里达州的橙县(Orange County)2003-2009年土地利用变化为例,提出了基于局部化转化规则的CA土地利用模型,其中元胞的土地利用类型适宜性由地理加权多项logit模型(Geographically weighted multinomial logit,GWML)获得。结果表明:GWML模型较传统全局性多项logit(Multinomial logit,MNL)模型有更高的数据解释能力。基于GWML模型的土地利用CA模型能反映局部土地利用变化模式,因而较基于MNL模型的CA模型具有更高的模拟精度。所得结论对未来国内地区的研究有借鉴意义。  相似文献   

Pond culture of seaweed Sargassum hemiphyllum in southern China     

于宗赫  胡超群  孙红岩  李海鹏  彭鹏飞 《中国海洋湖沼学报》2013,31(2):300-305

The seaweed Sargassum hemiphyllum is widely distributed throughout the coastal waters of Asia and has high commercial value.In recent years,its natural biomass has declined due to over-exploitation and environmental pollution.To seek for a feasible way to culture this seaweed efficiently,we designed a simple long-line system in a shrimp pond for the culture during winter,and the growth and nutritional composition of the seaweed were examined.Results show that the culture system was durable and flexible allowing S.hemiphyllum to grow vertically off the muddy bottom of the pond.Although the length of pondcultured S.hemiphyllum was inhibited by water depth,the weight-specific growth rate((1.65±0.17)%/d) was nearly three times higher than that of wild plants((0.62±0.19)%/d).The crude protein(6.92%±0.88%) and ash content(21.52%±0.07%) of the pond-cultured seaweed were significantly lower than those of the wild plants(9.38%±0.43% and 26.93%±0.07%,respectively);however,crude fat(1.01%±0.04%) was significantly higher than that of the wild plants(0.87%±0.02%).In addition,the nutritional composition of both pond-cultured and wild S.hemiphyllum was comparable to or even higher than those of other common seaweeds being used as food and/or aquaculture fodder.Future studies shall be focused on the impact of environmental parameters on its growth and nutritional composition.  相似文献   

Mechanisms and factors affecting the adsorption of sodium alginate onto modified clays     

林勇新  曹西华  宋秀贤  王楠  俞志明 《中国海洋湖沼学报》2013,31(4):867-875

Algal organic materials (AOMs) are one critical factor affecting the efficiency of modified clays used for the mitigation of harmful algal blooms (HABs). This study was conducted to develop a deeper understanding of the mechanisms and factors affecting the adsorption of AOMs onto modified clays. Sodium alginate (polysaccharide) and kaolinite modified with polyaluminium chloride (PACl) were used as AOMs and modified clay model substances, respectively, and the effects of modifier dosage, contact time, solution pH and ionic strength were investigated through batch adsorption experiments. Kinetics revealed that the alginate adsorption rate was described well by a pseudo-second order model. PACl effectively enhanced the adsorption capacity of kaolinite and increased the adsorption rate, and the optimum additive amount of PACl was 5%. The experimental data fitted both the Freundlich and Langmuir adsorption equations well. The adsorption thermodynamics for alginate onto modified clays suggests that alginate adsorption is a spontaneous process. The adsorption of alginate onto modified clays was highly dependent on pH, with a decrease in adsorption observed with increased pH to 9.48, but the opposite was true above pH 9.48. Finally, adsorption increased with increasing ionic strength.  相似文献   

Population genetics of Sargassum horneri (Fucales, Phaeophyta) in China revealed by ISSR and SRAP markers     

于深辉  崇卓  赵凤娟  姚建亭  段德麟 《中国海洋湖沼学报》2013,31(3):609-616

Sargassum horneri is a common brown macro-alga that is found in the inter-tidal ecosystems of China. To investigate the current status of seaweed resources and provide basic data for its sustainable development, ISSR (inter simple sequence repeat) and SRAP (sequence related amplified polymorphism) markers were used to analyze the population genetics among nine natural populations of S. horneri. The nine studied populations were distributed over 2 000 km from northeast to south China. The percentage of polymorphic loci P% (ISSR, 99.44%; SRAP, 100.00%), Nei’s genetic diversity H (ISSR, 0.107-0.199; SRAP, 0.100-0.153), and Shannon’s information index I (ISSR, 0.157-0.291; SRAP, 0.148-0.219) indicated a fair amount of genetic variability among the nine populations. Moreover, the high degree of gene differentiation G st (ISSR, 0.654; SRAP, 0.718) and low gene flow N m (ISSR, 0.265; SRAP, 0.196) implied that there was significant among-population differentiation, possibly as a result of habitat fragmentation. The matrices of genetic distances and fixation indices (F st ) among the populations correlated well with their geographical distribution (Mantel test R=0.541 5, 0.541 8; P=0.005 0, 0.002 0 and R=0.728 6, 0.641 2; P=0.001 0, 0.001 0, respectively); the Rongcheng population in the Shandong peninsula was the only exception. Overall, the genetic differentiation agreed with the geographic isolation. The fair amount of genetic diversity that was revealed in the S. horneri populations in China indicated that the seaweed resources had not been seriously affected by external factors.  相似文献   

Near-surface structure and energy characteristics of the Antarctic Circumpolar Current     

GAO Libao  YU Weidong  WANG Haiyuan  LIU Yanliang 《极地研究(英文版)》2013,(4):265-272

Historical surface drifter observations collected from the Southern Ocean are used to study the near-surface structure, variability, and energy characteristics of the Antarctic Circumpolar Current （ACC）. A strong, nearly zonal ACC combined with complex fronts dominates the circulation system in the Southern Ocean. Standard variance ellipses indicate that both the Agulhas Return Current and the East Australian Warm Current are stable supplements of the near-surface ACC, and that the anticyclonic gyre formed by the Brazil warm current and the Malvinas cold current is stable throughout the year. During austral winter, the current velocity increases because of the enhanced westerly wind. Aroused by the meridional motion of the ACC, the meridional velocity shows greater instability characteristics than the zonal velocity does over the core current. Additionally, the ACC exhibits an eastward declining trend in the core current velocity from southern Africa. The characteristics of the ACC are also argued from the perspective of energy. The energy distribution suggests that the mean kinetic energy （MKE）, eddy kinetic energy （EKE）, and are strong over the core currents of the ACC. However, in contrast, EKE/MKE suggests there is much less （more） eddy dissipation in regions with strong （weak） energy distribution. Both meridional and zonal energy variations are studied to illustrate additional details of the ACC energy characteristics. Generally, all the energy forms except EKE/MKE present west-east reducing trends, which coincide with the velocity statistics. Eddy dissipation has a much greater effect on MKE in the northern part of the Southern Ocean.  相似文献