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951.
正1研究目的(Objective)中国南方下寒武统牛蹄塘组广泛发育暗色页岩,有机质含量丰富,沉积厚度大,但普遍存在有机质成熟度过高导致页岩气赋存不利等因素。贵州黄平地区牛蹄塘组为一套深水陆棚相沉积,以炭质页岩为主,具有页岩厚度大、有机质含量高、成熟度适中且构造保存较好等有利条件,目前尚未获得页岩气调查突破。在前期研究的基础上,为摸清牛蹄塘组在该区地层发育,力争获得页岩气发现,在武陵山褶皱带南部贵州黄平地区上塘复背斜东翼南段部署实施了黄地1井,钻遇牛蹄塘组见良好油气 相似文献
952.
953.
介绍了四川省雅安地区储量丰富、质地名贵的石材资源;论述了在石材开发中由于管理不善,采矿、加工工艺落后,存在资源破坏严重和地质环境恶化等问题;提出了合理开采石材资源和进行地质环境保护的建议 相似文献
954.
云南天文台高分辨率斑点成像的新进展 总被引:2,自引:0,他引:2
本文报道了对天文目标:双星ADS16800、ADS16173,三星Hu66(ADS11344)和Hld171(ADS16648)进行的斑点成像观测及测量结果。介绍了所用的二维光子计数斑点像探测系统的性能,分析了探测系统的光子噪声、附加噪声和其它更复杂的噪声对斑点图的平均功率谱和重谱的影响。在讨论了改正重谱中的噪声偏差项时提出了对重谱基底施加正性约束的算法。测量的结果表明,实现了高精度的微射受限天文 相似文献
955.
Yu Wei Liu Yimin Yang Xiu-Qun Wu Guoxiong He Bian Li Jinxiao Bao Qing 《Climate Dynamics》2021,56(1):559-579
Climate Dynamics - The South Asian circulation and precipitation in spring shows a clear seasonal transition and interannual variation. We investigate how the North Atlantic sea surface temperature... 相似文献
956.
957.
Evaporation loss from the saturated soil beneath drip irrigation emitters highly influences the irrigation efficiency of drip irrigation (DI). Subsurface drip irrigation (SDI) is one good approach to curb this inefficiency, but in a new irrigation method, straight tube irrigation (STI), the irrigation tubes do not need to be buried and thus STI is recommended to increase the irrigation efficiency under normal surface-applied DI. STI consists of only connectors and water-transference tubes that can directly transfer irrigation water from the lateral emitters in the drip line to the root zone of plants. Five-month field experiments were carried out in Aeolian sand soil in the forest-belts of the Taklimakan Desert, which have poor water storage capacity, to compare the potential water saving between STI and DI. The preliminary results showed that, compared with DI, STI (1) improved the soil water content in soil depths from 40 to 100 cm under the soil surface; (2) achieved the same irrigation effects in relatively shorter irrigation durations; (3) had very little water loss due to deep seepage; and (4) formed a layer of dry sand about 10 to 30 cm thick immediately below the soil surface, which lessened evaporation loss of soil water beneath the emitters on the soil surface. This demonstrates that STI can maximize the water-saving potential of DI through the reduction of wetted soil perimeters on the soil surface. This is valuable information for water-saving engineering applications and projects with STI in arid and semiarid regions. 相似文献
958.
959.
塔里木河流域土地利用监测适宜尺度选择方法 总被引:1,自引:0,他引:1
Optimal scale is one of the important issues in ecology and geography. Based on land-use data of the Tarim River Basin in
Xinjiang of China in the 1950s, regarding the area of land use types as the parameter in scale selecting, the histograms of
the patches in area are charted. Then, by reinforcing the normalized scale variances (NSV) with 3 landscape indices, the scale
characteristics of land use in the Tarim River Basin can be summarized. (1) NSV in the Tarim River up to a maximum at scale
of 1:50,000 which is considered appropriate for the Tarim River. (2) Diversity indices of saline land are consistent with
NSV’s. Diversity indices and NSV of sandy land showed that the appropriate scale is in the same scale domain. There is a significant
difference between diversity indices and NSV of forestland and shrubland. (3) Fractal dimension of sandy land and saline land
showed a hierarchical structure at a scale of 1:10,000. Fractal dimension of forestland and shrubland are distributed under
the same hierarchical structure in the region.
Foundation: National Natural Science Foundation of China, No.40571030; No.40730633
Author: Zhao Jin (1980–), Ph.D, specialized in study of scale effect. 相似文献
960.
The spatio-temporal pattern of the global water resource has significantly changed with climate change and intensified human activities. The regional economy and ecological environment are highly affected by terrestrial water storage (TWS), especially in arid areas. To investigate the variation of TWS and its influencing factors under changing environments, the response relationships between TWS and changing environments (climate change and human activities) in Central Asia have been analyzed based on the Gravity Recovery and Climate Experiment (GRACE) data, Climatic Research Unit (CRU) climate data and Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data products (MOD16A2, MOD13A3 and MCD12Q1) from 2003 to 2013. The slope and Pearson correlation analysis methods were used. Results indicate that: (1) TWS in about 77 % of the study area has decreased from 2003 to 2013. The total change volume of TWS is about 2915.6 × 108 m3. The areas of decreased TWS are mainly distributed in the middle of Central Asia, while the areas of increased TWS are concentrated in the middle-altitude regions of the Kazakhstan hills and Tarim Basin. (2) TWS in about 5.91% of areas, mainly distributed in the mountain and piedmont zones, is significantly positively correlated with precipitation, while only 3.78% of areas show significant correlation between TWS and temperature. If the response time was delayed by three months, there would be a very good correlation between temperature and TWS. (3) There is a significantly positive relationship between TWS and Normalized Difference Vegetation Index (NDVI) in 13.35% of the study area. (4) The area of significantly positive correlation between TWS and evapotranspiration is about 31.87%, mainly situated in mountainous areas and northwestern Kazakhstan. The reduction of regional TWS is related to precipitation more than evaporation. Increasing farmland area may explain why some areas show increasing precipitation and decreasing evapotranspiration. (5) The influences of land use on TWS are still not very clear. This study could provide scientific data useful for the estimation of changes in TWS with climate change and human activities. 相似文献