基于GIS的农用地定级研究──以新疆五家渠垦区为例

农用地定级是土地质量评价的重要内容,可实现可持续的土地利用,提高土地的利用效益。以五家渠垦区农用地为例,采用因素法,根据《农用地定级规程》选取自然、社会经济和区位因素为定级因素。运用层次分析法并结合专家建议确定各因素因子的权重,选择适当的模型对因子进行量化,利用GIS软件生成定级因子分值图,采用加权求和法计算定级指数。依据定级指数结合实际情况将五家渠垦区农用地最终划分成6个级别,并得到了五家渠垦区农用地级别图。五家渠垦区农用地质量总体较好,以三、四、五级地为主。质量好的农田,限制因素为经济和区位条件,质量差的条田,限制因素为自然条件。空间上农用地质量级别呈相互交错的态势。农用地质量由自然因素与社会经济因素共同决定,但自然因素占主导地位。     

基于空间技术的农用地质量等别与经济耦合性研究

为了进一步丰富资源环境与经济社会发展相关性的研究,探讨农用地质量等别与经济的关联特点和耦合机制,按照农用地分等定级的基本思想与方法,测算各监测控制点的农用地自然等别、利用等别和经济等别,以镇为单位,以面积为权重,聚类监控点的自然等别、利用等别和经济等别。运用空间自相关方法,分析Moran散点图,研究农用地等别之间的关系,探讨农用地质量等别与经济耦合性。结果表明,农用地质量等别在空间上无序,而利用等别与经济等别较高的农用地主要分布在平原的水田,农用地利用等别与经济等别在空间分布上较吻合,经济耦合性强。通过聚类分析和空间技术模型,可以确定经济发展水平与耕地质量等别的空间耦合关系。     

石河子垦区农田土壤重金属含量调查及评价

本文对新疆石河子垦区16个团场耕地土壤重金属含量进行调查．并对研究区土壤重金属环境质量进行评价。结果表明：垦区土壤6种重金属的平均含量均低于国家土壤环境质量二级标准值。以国家土壤环境质量为评价标准，各元素单因子污染指数为Cd〉As〉Cu〉Cr〉Hg〉Pb，16个团场的综合污染指数均小于1．土壤环境质量属于安全、警戒限级别；以绿色食品土壤环境质量要求为评价标准，垦区土壤综合污染指数为0．98．土壤环境质量为尚清洁级别．农田土壤能满足绿色食品土壤环境质量要求。     

基于MapGIS地价系统的城镇土地定级研究——以德州市城区商服用地定级为例

为了全面掌握德州市城镇土地质量和利用状况,为政府土地利用决策提供技术支持,以德州市城区作为定级区域,采用特尔菲法确定定级因素因子体系和因子权重,应用MapGIS 6.7进行单因子层量化,确定各因子层的衰减方式、要素级别、各级别的功能分和服务半径;在此基础上,基于MapGIS地价系统,输入专家信息、因素因子体系和权重以及因素因子信息,设定单元格大小和障碍物通行点、通行线,进行因素因子分值计算;根据生成的单元总分值频率直方图并经过检验和修正,确定最终土地级别界线。结果表明,德州市城区一、二、三、四、五级地面积分别占总面积的2.82%、11.08%、15.70%、31.93%和38.47%,土地级别呈现由中心向外围逐级降低的趋势,京沪铁路、岔河、京福高速公路和减河成为各级别划分的主要界线。与上一轮商服用地定级结果相比,一级和二级商服用地的面积明显增加,土地质量有较大提高;其原因主要是近年来对经济开发区投入加强,进行了商业设施和基础设施建设。     

气象因子与五家渠地区玉米产量的关联分析

利用垦区主栽品种郑单958在同一地区不同年份进行种植,采用灰色关联分析方法对产量与生育期气象因子进行相关性分析,研究五家渠地区气候条件对玉米产量的影响。分析表明：对产量影响最大的是≥25℃的积温,其它依次为≥20℃的积温、日照时数、≥15℃的积温、≥10℃的积温、总降水量。     

基于GIS的重庆市耕地质量评价模型建立与检验

借助GIS空间数据获取、分析与管理能力,基于农用地分等方法的应用和改进,建立了包括自然质量等和利用等指数模型的重庆市耕地质量评价模型。评价对象为2003年末39个区县更新调查的耕地,总面积2347627.48hm^2,通过各区县1：5万土地利用现状图共获取142319个评价单元。评价模型通过分功能模块从机理上实现评价质量控制,以实现指标区之间和标准耕作制度间指数的可比性。就光温/气候潜力指数加和算法,采用以能值为基础确定标准产量折算系数β,引入光温潜力协调系数γ;就自然质量分模型,指标区之间因素-分级-分值进行了统一,但保留了因素权重的区域差异性,体现了指标区间共性和个性的统一。采用2004-2005年重庆市分区县统计平均粮食播面单产对平均自然质量等和利用等进行独立检验,线性相关系数分别达83%和87%,相关性极显著。研究得出结论,评价模型有效实现了重庆市跨区域耕地质量评价指数的可比性。     

农用地定级估价中基础资料收集整理及相关问题探讨

科学有效地开展农用地定级估价,对于促进土地资源管理从数量管理向质量与生态环境综合管理方面转化具有重要的基础支撑作用。本文结合当前国家有关农用地定级估价规程和地方农用地定级估价项目的具体实施,从基础资料收集整理的实践出发,初步探讨分析了目前农用地定级估价中资料收集整理途径及资料收集整理过程中应注意的问题,以期为类似项目的开展提供一定的参考与指导。     

甘肃省耕地集约利用及其驱动力研究

为探索甘肃省近十年来耕地集约利用的驱动力,运用综合分析法、聚类分析法以及因子分析法,分析影响其耕地集约利用时空差异的各种因素。研究结果表明：(1)甘肃省耕地集约利用虽在逐年提高,但总体水平较低,增长速度缓慢,时间特征不明显;(2)受到降雨、地形等因素的限制,甘肃省耕地集约利用空间特征较为显著,尤其是以黄河为界,河东和河西的差异比较明显。以2008年为例,集约度最高的是嘉峪关市达到了0.12,而最低的甘南州只有0.05,相差一倍多;(3)通过因子分析法,确定甘肃省耕地集约利用的驱动力主要有社会经济因素、耕作条件及自然因素三类。通过研究发现,甘肃省的耕地集约利用主要受到人口、科学技术水平、政策制度、经济发展、自然灾害的限制。相关部门应该从上述五方面着手提高甘肃省耕地集约利用水平。     

农用地分等国家级汇总等别转换方法研究——以河北省为例

通过理论研究和实证分析,研究农用地分等国家级汇总中农用地自然质量等别平衡转换的方法,为国家级的农用地分等成果汇总奠定基础。在全国的农用地分等汇总中,用标准粮单产及相应的转换函数,实现农用地自然质量等别的平衡转换。研究结果表明,全国的标准粮产量分别与省级和国家级的自然质量等指数呈显著相关,可以通过这一衔接手段完成农用地自然质量等别的国家级汇总。     

永城市陈四楼煤矿土地复垦适宜性评价研究

为了采取指数和法和极限条件法对陈四楼煤矿土地复垦适宜性进行评价。以GIS软件为平台,利用河南省永城市土壤图、地形图、土地利用现状图进行空间叠加分析最终确定4个评价单元。依据研究区的自然、经济、社会现状和相关技术标准,确定了宜农、宜林、宜渔3个复垦方向的评价指标,然后采用指数和法和极限条件法对矿区复垦土地进行适宜性评价。结果表明：评价总面积为73.7 hm2,其中适宜农业种植用地面积为25 hm2,适宜林业种植用地面积为20 hm2,适宜渔业养殖用地面积为28.7 hm2。通过评价研究建立矿区土地复垦适宜性评价等级体系。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.     

Genetic variation for disease and nematode resistances and forage quality in perennial diploid and tetraploid lucerne populations (Medicago sativa L.)

Summary Twenty-five lucerne populations of the Medicago sativa complex, which were either diploid or tetraploid and wild or cultivated, were analysed for their resistance to four different fungal diseases and to stem nematode. Forage quality, including stem digestibility and saponin content, was also tested.Populations varied in susceptibility to the diseases caused by Colletotrichum trifolii, Verticillium albo-atrum, Sclerotinia trifoliorum and Pseudopezizza medicaginis, and to the nematode Ditylenchus dipsaci. Except for Sclerotinia rot, sativa and falcata subspecies differed in susceptibility, but this grouping of populations did not account for the full range of variation among them. However, the resistance to P. medicaginis was much lower in the sativa than in the falcata populations.Populations also varied significantly in stem fiber content and digestibility. Stem digestibility was negatively correlated to forage yield. Wild sativa and falcata populations had lower fiber content and higher digestibility than cultivated sativa populations. The medicagenic acid was the sapogenin responsible for the anti-nutritional effect of the lucerne measured by the yellow mealworm larvae Tenebrio molitor. The medicagenic acid content was lowest for the pure sativa populations, highest for the pure falcata populations, and intermediate for the French sativa varieties that have some traits originating from falcata germplasm. Some populations could be used in breeding programs to improve disease and nematode resistance, and forage quality.     

Review of Effects of Active Components of Gastrodiae Rhizoma on Central Nervous System

In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,...     

Effects of Pb on Rhizosphere Soil Enzyme Activity and Chemical Constituents of Achyranthes bidentata Blume

[Objectives]The purpose of this study was to investigate the effects of Pb on rhizosphere soil enzyme activity and chemical constituents of Achyranthes bidentat...     

不同P-Zn配比对小麦幼苗微量元素营养的影响

采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应.     

Isozyme variation between diploid and tetraploid cytotypes of Glycine tabacina (Labill.) Benth.

Summary Glycine tabacina (Labill.) Benth. is a wild perennial species related to the cultivated soybean, G. max (L.) Merr. It is composed of diploid (2n=40) and tetraploid (2n=80) cytotypes. Currently, to differentiate the cytotypes, plants are grown out in the greenhouse and chromosome counts made on pollen mother cells. It is a laborious and time consuming process. The objective of this study was to determine whether electrophoretic techniques could be utilized to separate the cytotypes. Electrophoretic examination of seven isozyme systems from seed of 67 G. tabacina accessions revealed banding patterns that could be used to differentiate between diploid and tetraploid cytotypes in the species. Among the tetraploid accessions, the number of bands observed were always greater than the diploids. Some tetraploid banding patterns consisted of bands similar to the diploid tabacina and/or additional bands previously identified in other Glycine species. The patterns of isozyme multiplicity and variation in the tetraploid tabacinas suggests more than one mode of origin for the tetraploids.     

Some physiological and photosynthetic characters of rice × sorghum and rice × wheat hybrids

Summary Some photosynthetic characters as-leaf anatomy, leaf photosynthetic rate and CO₂ compensation pointdistinguishing C₃ and C₄ plants and physiological characters as leaf area ratio, nitrogen content, leaf stem ratio and total shoot-to-root and deep root-to-shoot ratios have been studied in rice × sorghum and rice × wheat hybrids. Rice × sorghum 1. has lower values of photosynthetic rate, leaf nitrogen, total root and deep root-to-shoot ratio and CO₂ compensation point as of rice parent where as, rice × sorghym 2. is superior in all these characters. Both hybrids lack kranz anatomy. Though both rice × sorghum hybrids show characters of C₃ rice plant but rice × sorghum 2. has improved drought tolerance and leaf characters in relation to yield. Rice × wheat hybrid have higher assimilatory area and higher total root-to-shoot ratio. Grains of rice × wheat hybrids are identical to rice grain. However, as grains of rice × wheat hybrid does not contain seed coat, it could be exploited as novel rice germplasm after improvement.Abbreviations T CO₂ compensation point - T21 CO₂ compensation point at 21% O₂ - T2 CO₂ compensation point at 2% O₂ - dR/sR deep Root-to-shoot Ratio - LAR Leaf Area Ratio - CER photosynthetic rate - TR/SR Total Root-to-Shoot Ratio