ZDY25000LDK智能化定向钻进装备关键技术研究

利用顺煤层、顶板高位钻孔抽采煤层气是当前煤矿井下煤层气综合治理最直接、有效的方法。提高定向钻孔钻进速度和起伏变化大、薄厚不均煤层中的钻遇率,降低施工人员劳动强度,提高钻孔事故预防能力,适应煤矿智能化发展需求,满足煤矿井下长距离定向钻孔施工的智能化钻进装备是当前煤矿井下钻探领域亟待解决的重要问题。基于地质导向和旋转导向钻进施工对钻机精确控制的实际需求,以及煤矿智能化发展的迫切需要,提出了基于防爆电液控制技术的煤矿井下长距离定向钻进装备自动化控制和分体紧凑布局设计的集成化解决方案。重点解决总体紧凑布局设计、关键执行部件设计、自动装卸钻杆技术、防爆电液控制技术、大流量泥浆泵单元设计等设计和技术。研制的ZDY25000LDK智能化定向钻进装备,实现了长距离定向钻进施工过程中自动化装卸钻杆控制、智能化定向钻进施工、参数实时监测以及典型故障智能诊断与预警等功能,使定向钻进装备的智能化水平得到全面提升,为旋转导向和地质导向施工,以及“以孔代巷”大直径定向钻孔高效施工提供了可靠装备保障。      

基于不同参考点选取的导弹脱靶量处理精度分析

在研究战术导弹试验中脱靶量数据处理方法基础上,提出了脱靶量处理的靶位坐标系参考点选取方法。阐述了传统的参考点与新的靶位参考点选取方法对导弹脱靶量精度的影响,通过外弹道轨迹处理得到的脱靶量结果与检靶结果的比对分析,验证了选取以靶标为原点的坐标系下处理得到的脱靶量结果精度较高。为考核导弹试验鉴定提供了准确合理的处理结果,取得了很好的应用效果。     

Comparing terrain and vegetation-based visibility for explaining sable flight behaviour in a Southern African savanna

In this study, we tested whether terrain-based visibility modelled from a remotely sensed ASTER Digital Elevation Model (DEM) explains sable flight initiation distance (FID) better than vegetation-based visibility measured in the field. We also tested whether the effect of hunting on sable FID varies with spatial scale. We first performed a linear regression analysis relating FID to standardized coefficients of both vegetation- and terrain-based visibility where the variable with the larger coefficient was the better predictor of FID. We latter performed an analysis of covariance (ANCOVA) comparing the slopes relating FID to both measures of visibility, first at the large scale and later at the small scale within the hunting area. Our results suggest that remotely sensed terrain-based visibility predicts the FID of sable better than vegetation-based visibility. We also found that the effect of hunting on sable FID varies with spatial scale.     

Field survey and modelling of irrigation water quality indices in a Mediterranean island catchment: a comparison between spatial interpolation methods

ABSTRACT

A biannual survey of physico-chemical quality indices of 104 irrigation-water wells located in a cultivated plain of a Mediterranean island catchment was conducted using a multi-parameter probe. The campaign was planned so as to differentiate between the dry and wet seasons. The acquired data constituted the test bed for evaluating the results and the features of four spatial interpolation methods, i.e. ordinary kriging, universal kriging, inverse distance weighted and nearest neighbours, against those of the recently introduced bilinear surface smoothing (BSS). In several cases, BSS outperformed the other interpolation methods, especially during the two-fold cross-validation procedure. The study emphasizes the fact that both in situ measurements and good mathematical techniques for studying the spatial distribution of water quality indices are pivotal to agricultural practice management. In the specific case studied, the spatio-temporal variability of water quality parameters and the need for monitoring were evident, as low irrigation water quality was encountered throughout the study area.     

浅层弯线地震勘探采集与处理技术

在浅层地震勘探中,测线常常由于场地的限制而不能沿直线布设.而弯线地震勘探施工过程中炮检中点比较分散,影响共面元道集的叠加和最终剖面的真实性.加之浅层地震资料又有其自身的特殊性,所以选择合理有效的浅层弯线采集与处理技术非常必要.本文以甘肃陇南山区新文县一中测线为例,结合弯线共中心点面元叠加的时间、空间条件,在采集和处理两个环节分析控制炮检中点分散范围的具体方法,获得了真实且高品质的地震剖面.剖面有效波的能量较好,同向轴连续清晰,各种干扰波得到了压制,说明浅层弯线地震勘探的方法在理论上和技术上都是可行的.     

采用sPn震相确定甘肃岷县M>4.0地震震源深度

通过对甘肃岷县2013年7月3个M>4.0地震震相的细致分析,认为在震中距大于250km时四川数字地震台网部分台站可记录到较为清晰的sPn震相。采用sPn和Pn震相确定震源深度的方法分别对岷县3个地震的震源深度进行了重新计算,得到了较为精确的地震震源深度。     

CLOUD BAND MORPHOMETRY: AN ALTERNATIVE APPROACH TO SATELLITE IMAGE ANALYSIS

This research assesses the use of Cold Front Cloud Band (CFCB) morphometry as an indicator of the characteristics of air masses at cold fronts. Measurements of the configuration of the CFCB (i.e., length, width, length/width ratio, and radius of curvature) are made using GOES/SMS satellite imagery. CFCB height and air mass characteristics of temperature, specific humidity, 500 mb wind velocity, and 500 mb vorticity are derived from NWS surface and upper air charts. Nonparametric correlations are utilized to relate CFCB morphometric variables to the selected characteristics of maritime tropical (mT) and continental polar (cP) air masses as they meet to form cold fronts over the eastern United States.

CFCB-Air Mass relationships resulting in higher correlations are examined through two series of interpretive tests. The stronger correlations imply a direct relationship between CFCB height and 500 mb vorticity and between CFCB length and cP specific humidity; and inverse relationships between both the CFCB length/width ratio and mT specific humidity and between CFCB radius of curvature and 500 mb vorticity. Preliminary investigation suggests that the cloud band morphometric approach to weather satellite image interpretation is a viable point of departure for future research.     

Modeling Near-Surface Air Temperature From Solar Radiation and Lapse Rate: New Development on Short-Term Monthly and Daily Approach

Short-term monthly mean temperature (T_m ) and short-term daily mean temperature (T_d ) rather than long-term monthly and daily mean temperature (T_m and T_d ) are preferred for some ecosystem studies such as carbon source and sink, pine beetle mortality, and snow melting. The recent progress of modeling T_m and T_d (based on the previous work on T_m ) supported by climatologically aided interpolation (CAI) is reported over the mountainous Yellowstone National Park. With the spatial scale of a 30 m digital elevation model (DEM), the slope, aspect, and shadows cast by surrounding topography, which could not be well captured by very coarse DEM, could be taken into account. Data from 12 months (Jan-Dec 2008) and 12 dates (25 Jan-Dec 2008) were used to demonstrate the approach. Inverse distance weighting (IDW) interpolations of limited temperature anomalies were adopted to represent the deviations from normality. T_m , as a preexisting climatology surface, was added to deviations in order to model T_m . Linear temporal interpolation of adjacent T_m was used to create a climatology surface, which was then added to deviations in order to model T_d . Results show the mean absolute errors (MAEs) for T_m ranged from 0.75° C to 1.78° C, while the MAEs for T_d ranged from 1.14° C to 2.02° C. The four factors of elevation, seasonal change of lapse rate, temperature difference caused by variation in solar radiation, and preexisting climatology surface for the CAI approach were comprehensively considered in this approach.     

A cell-based algorithm for evaluating directional distances in GIS

Directional distance is commonly used in geographical information systems as a measure of openness. In previous works, the sweep line method and the interval tree method have been employed to evaluate the directional distances on vector maps. Both methods require rotating original maps and study points in every direction of interest. In this article, we propose a cell-based algorithm that pre-processes a map only once; that is, it subdivides the map into a group of uniform-sized cells and records each borderline of the map into the cells traversed by its corresponding line segment. Based on the pre-processing result, the neighbouring borderlines of a study point can be directly obtained through the neighbouring cells of the point, and the borderlines in a definite direction can be simply acquired through the cells traversed by the half line as well. As a result, the processing step does not need to enumerate all the borderlines of the map when determining whether a point is on a borderline or finding the nearest intersection between a half line and the borderlines. Furthermore, we implement the algorithm for determining fetch length in coastal environment. Once the pre-processing is done, the algorithm can work in a complex archipelago environment such as to calculate the fetch lengths in multiple directions, to determine the inclusion property of a point, and to deal with the singularity of a study point on a borderline.     

Inferring properties and revealing geographical impacts of intercity mobile communication network of China using a subnet data set

This article provides a novel and practical approach for investigating the characteristics of intercity telecommunication network whose overall and complete information is unavailable. Using a mobile phone call data set covering 4.39 million subscribers registered in a particular region, we construct two intercity mobile communication subnets and infer characteristics of the whole intercity mobile communication network of China. Results confirm that intercity communication intensity is characterized by the gravity model. The communication intensity based on mobile call number decreases along the distance with a scaling exponent 0.5, whereas the scaling exponent for the communication intensity based on mobile call duration is 0.4. Moreover, we uncover the rank-size distribution of tie strength (mobile call number and duration) between a city and its neighbours. The rank-size law of tie strengths between cities is mainly determined by the rank-size distribution of cities. The distance between cities plays a less decisive role than the size distribution in the network, but significantly impacts mobile communication patterns. The call duration of individual intercity mobile communication is generally positively correlated to the communication distance, explaining why the distance decay of communication intensity based on call durations is slower than that based on call numbers. The contribution of this research is twofold. First, we identify the distance decay effect in intercity mobile communications of China and uncover the dominant impact of the rank-size distribution of cities. Second, a method for estimating the properties of the whole network according to the observed interactions of its subnets is developed.