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1.
The crop estimates by remote sensing, developing quickly in recent decades, is a up-to-date technique. Regionalization for large area crop estimates by remote sensing, a special applied regionalization, is the foundation of crop estimates in a large area by remote sensing. According to the actual demands of wheat yield estimation by remote sensing and wheat agroclimatic demarcation of China, this paper first puts forward some principles upheld in this regionalization and analyses its main bases. Secondly, it works out the classificatory schemes about the optimum temporal for estimating wheat yield by remote sensing, information sources of space remote sensing and landuse structure in China. Finally, According to the regionalization indices, this study divides the wheat plantable region of China into 14 regions of crop yield estimates and 31 subregions of crop yield estimates.  相似文献   
2.
成生于冰碛扇内,经一定的生物、物理、化学成矿作用,以砂金形态分布而富集成矿的金矿称为冰碛扇型砂金矿床。它具有沿造山带一定标高范围成群、成带分布,沉积物为近源且半胶结,砂金呈面状分布,并以粒金、块金为主,具胶状、浑圆状、包块状构造形态,分布极不均匀等特征。冰碛扇型砂金矿床的成矿作用与河成砂金矿床有本质的区别。它的成矿作用模式是:造山带下地壳富含的活化金通过新构造运动活化的断裂运移地表,经地下流体和地表流体的迁移聚集到冰碛扇这一封闭稳定的生物、物理、化学障环境中,主要经高效聚金微生物有机胶体成矿作用沉淀、再生加大形成砂金,逐步富集成矿床。而红色磨拉石建造中风化离解的Fe,Mn物质对沉淀环境pH值起着一定的调节作用。冰碛扇型砂金矿床在我国西部造山带内广泛分布,具有一定的工业价值,是砂金矿床中一重要类型,应予以重视  相似文献   
3.
上扬子地台震旦系铅锌矿床类型及找矿方向   总被引:13,自引:0,他引:13  
上扬子地台含铅锌矿地层主要为震旦系。震旦系在上扬子地台主要发育上统灯影组,次有下统陡山沱组。将上扬子地台震旦系铅锌矿床成因划分为一级为叠生矿床,二级为层控矿床,三级为热水沉积改造矿床和热水沉积再造矿床四级类型,该类型按铅锌比例进一步划分为富铅型、富锌型、铅锌共生型。研究区内最重要的铅锌矿床成因类型为南郑马元、会东大梁子铅锌矿为代表的富锌型。陕西南郑、紫阳—镇坪地区,湖北武当、神农架、黄陵地区,以及地台西缘的安宁河、甘洛—小江、峨边—寻甸等地区的震旦系是寻找铅锌矿的最有利地段。  相似文献   
4.
5.
In order to understand the process of surface erosion and acquire basic data of conditions on hillslope without vege tation, a sprinkling experiment is conducted on a bare slope in Mt. Tanakami in the central part of Japan. Based on the mea surements of runoff, mean soil erosion depth, and sediment yield, etc. , the results suggest the following characteristics in the process of surface erosion in the experimental area. (1) The occurrence of sediment discharge is interrupted; (2) Surface runoff is a saturated overland flow; (3) The mean soil erosion depth is thick compared with other areas in Mt. Tanakami;(4) Sediment discharge process is detachment- limited.  相似文献   
6.
This paper examines the effect of ploughing depths (A -- 60 cm, B -- 45 cm and C -- 30 cm) on the growth and yield of Heracleum candicans Wall (Apiaceae), a threatened medicinal herb of the Himalayan region. This less-explored plant is being suggested as a potential crop for the mountain agriculture. The study was carried out in an orchard in Himachal Pradesh, India at 2500 m altitude, for two successive growth years. During the first year, all plants remained in juvenile state; in the second year, nearly 65 % plants produced flowers only under 60cm ploughing depth. Among its morphological traits, plant height, collar diameter and aboveground flesh weight were found to be strongly correlated (P 〈 0.01) with the belowground biomass during the first year (r =0.968, 0.925 and 0.973, respectively) and during the second year (r=0.945, 0.928 and 0.775, respectively). Increase in the ploughing depth was significantly correlated (P〈0.01) with all growth parameters, including the belowground dry weight, marketable portion of the produce. The belowground biomass (commercial yield; 16.28 Qt/hec) at depth A was about 2.6 and 4.7 times higher than those recorded at depths B and C, respectively. The results clearly justify the importance of deep ploughing and this paper strongly recommends it for economically sustainable cropping.  相似文献   
7.
STUDY ON GIS FOR YIELD ESTIMATION BY REMOTE SENSING IN JILIN MAIZE BELTSTUDYONGISFORYIELDESTIMATIONBYREMOTESENSINGINJILINMAIZ...  相似文献   
8.
通过杂质对导电类型的影响的研究,得出了同种矿物的不同导电类型与矿物形成温度的规律:电子型(n型)导电矿物的形成温度大于电子与空穴混合型导电矿物的形成温度,又大于空穴型(p型)导电矿物的形成温度,绝缘体矿物的形成温度低于上述三种导电类型矿物。应用矿物热电图谱仪,天然金刚石半导体测试仪对闪锌矿、黄铁矿、金刚石等矿物的导电类型进行了测试,并探讨了导电类型成因,证实了上述规律的正确性。  相似文献   
9.
Isolated protoplasts from thalli ofPorphyra haitanensis andPorphyra yezoensis were treated with colchicine or irradiated by ultraviolet (UV). Several types of color variants were observed among the protoplast offspring. After treatment with colchicine: (1) 0.04–0.09% of red type variants inP. haitanensis were obtained; (2) The rate of red type variants and the variegated chimeral thalli composed of red type and wild type of sectors were 0.31–1.11% inP. yezoensis. After irradiation with UV: (1) 3.5–10.5% of red type variants inP. yezoensis were obtained: (2) 0.5–2.0% of red type variants and the variegated chimeral thalli composed of red type and wild type of sectors were obtained inP. haitanensis. Colchicine and UV’s mutangenic effects onP. yezoensis protoplasts were stronger than those onP. haitanensis protoplasts. The most efficient concentration of colchicine was 0.05%. The optimal length of UV-radiation was 1/2 min (radiation distance 5 cm). The red type variants induced by colchicine treatment grew faster than the wild type thalli. The clones of vegetative propagation from protoplasts of red type variants were still red type thalli. The red type variants will be good materials for genetic studies and improvement ofPorphyra strains.  相似文献   
10.
Keck's Long Wavelength Spectrometer (LWS), is the facility instrument used for imaging and spectroscopy in the wavelength range of 3–28 μm at the Keck Observatory. LWS uses an 128 × 128 Si:As blocked impurity band (BIB) array manufactured by the Boeing Corporation. This paper discusses the method used for optimizing the detector's operating parameters at a temperature of 8.5 K and bias voltage of 1.2 V. A process for characterizing detective quantum efficiency of BIB detectors is also presented. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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