三维地理信息数据在移动通信网络规划和优化系统中的应用

随着移动通信的迅猛发展,网络规模不断扩大,借助数字地图,尤其是三维地理信息数据进行网络规划和优化已变得越来越重要。本文主要介绍三维地理信息数据在建立移动通信网络规划和优化系统中的应用。     

昌化鸡血石的成矿构造背景及成因探讨

通过应用地球化学方法对昌化鸡血石的成矿构造背景进行了分析研究，并在此基础上对成因进行了初步探讨，进而指出找矿的方向和找矿标志。     

Managing rice pests with less chemicals

Losses caused by pests remain an important constraint to achieving high rice yields. Potentials of protecting these losses have stimulated innovations in pesticide development. Today the rice pesticide market is valued at US $ 3.0 billion per year. With reducing land available for rice production and increasing demand for food production, attention is turning towards intensification through higher fertilizer inputs and cropping. Such intensifications may in turn increase pest intensities and demand for more pesticides.A large proportion of insecticide sprays administered by rice farmers in Asia is influenced by misperceptions and overestimations of damages. Most farmers apply their first sprays in the first 40 days after crop establishment to control leaf feeding insects. However, these pests do not occur in sufficiently high densities to cause yield loss. Instead, such early season sprays may contribute towards development of secondary pests, such as the brown planthopper. Strategies to reduce insecticide use need to focus on enhancing naturally occurring biological control and understanding farmers' decision making behavior.Most fungicides used in rice are in the sub-tropical countries, like Japan, Korea, Taiwan and Vietnam. An important strategy towards reduction in fungicide use is through host plant resistance and gene deployment strategies. With biotechnology, tools may be used to characterize population structures in order to enhance these strategies. Cultural practices, such as rotations, cultivar mixtures, crop mosaics and planting times are being investigated.As cost of labor increases, farmers are likely to resort to using herbicides. The best way to accomplish weed control is the simultanous application of a variety of practices. These will include cultural, mechanical and chemical methods. The potentials of using naturally occurring enemies, such as plant pathogens, and the use of allelopathy are also being explored.     

高分辨率光学遥感卫星反射点源像点提取方法

像点提取精度是高分辨光学遥感卫星几何定标精度的关键因素之一。本文提出一种基于轻小型、自动化反射点源的像点提取方法,以参数化高斯模型拟合获取点源影像的像点坐标。在轨试验结果初步表明,反射点源法所提取的像点坐标的共线误差小于0.001像素,比例常量的相对标准偏差优于5‰,与质心法等常用方法提取的点源像点坐标相比较,精度优于0.05像素。反射点源不仅能够实现高精度的像点提取,而且还能够实现高分辨率光学遥感卫星的高精度几何定标与像质评价,对提高我国航天遥感立体测绘精度具有重要意义。     

CLDAS和GLDAS土壤温度数据在陕西省的适用性评估

利用陕西省2016年97站逐日5cm土壤温度观测数据,结合相关系数、平均偏差和均方根误差等统计参数,评估了中国气象局陆面数据同化系统CLDAS2.0和美国全球陆面数据同化系统不同陆面模式(Noah-GLDAS2.1,Noah-GLDAS1,CLM-GLDAS1)土壤温度数据在陕西省的适用性。结果表明:(1)CLDAS2.0在陕西省的相关系数最高,均方根误差最小,Noah-GLDAS2.1次之,Noah-GLDAS1最差。(2)从陕西省3个区域的时间演变序列的分析可以看到,CLDAS2.0和Noah-GLDAS2.1能很好模拟出土壤温度的季节变化以及日变化,Noah-GLDAS1、CLMGLDAS1对于日变化的模拟较差,且前两者偏差也明显小于后两者。(3)Noah-GLDAS2.1在陕北与关中地区土壤温度模拟能力与CLDAS2.0相差无几,但在陕南地区CLDAS2.0要好于Noah-GLDAS2.1。总体来看,CLDAS2.0对陕西省土壤温度模拟能力最好,在陕西省有着更好的适用性。     

青藏高原物质东流的岩石层力学背景探讨

利用地表大地热流观测资料、岩石生热率及热导率数据研究了三江和四川盆地 6个地区的岩石层平均温度结构及强度分布。结果表明 ,整个三江地区岩石层温度较高 ,而四川盆地温度较低 ;在岩石层强度分布上 ,四川盆地为高强度区 ,而三江地区则为低强度区 ;整个三江地区构成了一条青藏高原物质东流的低强度通道 ;由于四川盆地高强度块体的阻挡 ,青藏高原向东的物质流在此转向近南向 ,沿三江地区流逸 ;不同岩石层块体的强度差异可能是控制高原物质流动态势的重要力学背景之一。     

生态足迹分析的资源产量法研究

提出以资源生产量作为生态足迹分析中生态容量计算依据的资源产量法。该方法更全面地考虑了林地、可耕地、水域等具有的多重生态生产性功能，扩大了生态容量的内涵，将可再生能源、可回收利用废物等作为生态容量的供给，使生态容量与生态足迹的计算依据更为协调。以湖北省襄樊市2001年的生态容量计算为实例，说明了资源产量法的合理性。     

金川软岩蠕变破坏机理电镜实验研究

为探讨金川矿岩石蠕变破坏机理,应用微观扫描电镜(SEM)对蠕变受力情况下岩石破坏断口微观形态进行了观察研究,并分析了其产生的微观破坏机制。结果表明:岩石蠕变断裂的微观机制主要是拉伸、剪切作用下岩石发生脆性断裂,从岩石断裂微观形态研究岩石蠕变断裂,可以更好的揭示岩石断口微观形貌特征、裂纹生核、扩展、及断裂方式与岩石蠕变演进过程的联系。     

A numerical study on 2-D compressive wave propagation in rock masses with a set of joints along the radial direction normal to the joints

An explosion in a borehole or an accidental explosion in a tunnel will generate a two-dimensional (2-D) compressive wave that travels through the surrounding rock mass. For the problem of 2-D compressive wave propagation in a rock mass with parallel joints in the radial direction normal to the joints, parametric studies on the transmission ratio and the maximum rebound ratio are performed in universal distinct element code. The variation of the transmission ratio with the ratio of joint spacing to wavelength is generalized into a characteristic curve, which can be used as a prediction model for estimating the transmission ratio. The relationship between the maximum rebound ratio and the influence factors is obtained in charts. The charts can be used as a prediction model for estimating the maximum rebound ratio. The proposed prediction models for estimating the transmission ratio and the maximum rebound ratio are applied to a field explosion test, Mandai test in Singapore. The minimum possible values of peak particle velocity (PPV) at the monitoring points are estimated by using the proposed prediction model for estimating the transmission ratio along the radial direction normal to the joints. On the other hand, the maximum possible values of PPV are estimated by using the proposed prediction model for estimating the maximum rebound ratio along the same radial direction. The comparison shows a good agreement between the field-recorded PPVs and the estimated range of PPVs given by the minimum possible PPVs and the maximum possible PPVs at the monitoring points in Mandai test. The good agreement between the estimated and field-recorded values validates the proposed prediction models for estimating peak particle velocity in a rock mass with a set of joints due to application of a compressive wave at the boundary of a tunnel or a borehole.     

盐井二次定向对接连通施工工艺

新汶矿业集团泰山盐化工ZJ03-PJ03井组为一对定向连通采卤井井组，采用二次定向钻井连通施工工艺，技术套管下入深度907．6m（8矿层顶板），有效地阻隔了上部含较多杂质的岩盐矿层，确保了卤水质量能满足盐化工的需要。本对接连通井组，采用随钻测量井斜、方位及钻进轨迹控制技术，为该井组的顺利对接提供了技术保障。