基于互联网的地图标注系统设计与实现

基于互联网的地图标注系统涉及到点、线和面的标注,对解决地图数据生产所面临的现势性、完备性、正确性以及准确性问题具有积极的意义。系统是在Oracle数据库、POI搜索引擎和瓦片地图数据服务的基础上,采用Ajax技术、NHibernate技术设计开发而成的,文章给出了系统的设计和实现。     

Inferring the global mean sea level from a global tide gauge network

An attempt is made to infer the global mean sea level(GMSL) from a global tide gauge network and frame the problem in terms of the limitations of the network. The network,owing to its limited number of gauges and poor geographical distribution complicated further by unknown vertical land movements,is ill suited for measuring the GMSL. Yet it remains the only available source for deciphering the sea level rise over the last 100 a. The poor sampling characteristics of the tide gauge network have necessitated the usage of statistical inference. A linear optimal estimator based on the Gauss-Markov theorem seems well suited for the job. This still leaves a great deal of freedom in choosing the estimator. GMSL is poorly correlated with tide gauge measurements because the small uniform rise and fall of sea level are masked by the far larger regional signals. On the other hand,a regional mean sea level(RMSL) is much better correlated with the corresponding regional tide gauge measurements. Since the GMSL is simply the sum of RMSLs,the problem is transformed to one of estimating the RMSLs from regional tide gauge measurements. Specifically for the annual heating and cooling cycle,we separate the global ocean into 10-latitude bands and compute for each 10-latitude band the estimator that predicts its RMSL from tide gauges within. In the future,the statistical correlations are to be computed using satellite altimetry. However,as a first attempt,we have used numerical model outputs instead to isolate the problem so as not to get distracted by altimetry or tide gauge errors. That is,model outputs for sea level at tide gauge locations of the GLOSS network are taken as tide gauge measurements,and the RMSLs are computed from the model outputs. The results show an estimation error of approximately 2 mm versus an error of 2.7 cm if we simply average the tide gauge measurements to estimate the GMSL,caused by the much larger regional seasonal cycle and mesoscale variation plaguing the individual tide gauges. The numerical model,Los Alamos POP model Run 11 lasting 3 1/4 a,is one of the best eddy-resolving models and does a good job simulating the annual heating and cooling cycle,but it has no global or regional trend. Thus it has basically succeeded in estimating the seasonal cycle of the GMSL. This is still going to be the case even if we use the altimetry data because the RMSLs are dominated by the seasonal cycle in relatively short periods. For estimating the GMSL trend,longer records and low-pass filtering to isolate the statistical relations that are of interest. Here we have managed to avoid the much larger regional seasonal cycle plaguing individual tide gauges to get a fairly accurate estimate of the much smaller seasonal cycle in the GMSL so as to enhance the prospect of an accurate estimate of GMSL trend in short periods. One should reasonably expect to be able to do the same for longer periods during which tide gauges are plagued by much larger regional interannual(e. g.,ENSO events) and decadal sea level variations. In the future,with the availability of the satellite altimeter data,we could use the same approach adopted here to estimate the seasonal variations of GMSL and RMSL accurately and remove these seasonal variations accordingly so as to get a more accurate statistical inference between the tide gauge data and the RMSLs(therefore the GMSL) at periods longer than 1 a,i. e.,the long-term trend.     

Sampling errors of the global mean sea level derived from TOPEX/Poseidon altimetry

Sampling errors of the global mean sea level derived from TOPEX/Poseidon (T/P) altimetry are explored using 31/ 4a of eddy-resolving numerical model outputs for sea level. By definition, the sampling errors would not exist if data were available everywhere at all times. Four problems with increasing and progressively added complexities are examined to understand the causes of the sampling errors. The first problem (P1) explores the error incurred because T/P with turning latitudes near 66° latitudes does not cover the entire globe. The second problem (P2) examines, in addition, the spatial sampling issue because samples are only available along T/P ground tracks. The third problem (P3) adds the additional complexity that sea level at any along track location is sampled only once every 10 d versus every 3 d for the model (i.e., the temporal sampling issue). The fourth problem (P4) incorporates the full complexity with the addition of real T/P data outages. The numerical model (Los Alamos POP model Run 11) conserves the total water volume, thus generating no global mean sea level variation. Yet when the model sea level is sampled in the four problems (with P4 using the real T/P sampling), variations occur as manifestations of the sampling errors. The results show root-mean-squares (rms) sampling errors for P1 of 0.67 (0.75) mm for 10 d (3 d) global mean sea level, 0.78 (0.86) mm for P2, 0.79 mm for P3, and 1.07 mm for P4, whereas the amplitudes of the sampling errors can be as large as 2.0 (2.7) mm for P1, 2.1 (2.7) mm for P2, 2.2 mm for P3, and 2.5 mm for P4. The results clearly show the largest source of the sampling errors to be the lack of global coverage (i.e., P1), which the model has actually underestimated due to its own less-than-global coverage (between latitudes about 77° latitudes). We have extrapolated that a truly global model would show the rms sampling error to be 1.14 (1.28) mm for P1, thus implying a substantially larger sampling error for P4.     

河北省张家口地区膨润土资源特点、开发利用现状及前景分析

张家口地区膨润土以钙基土为主,其成因是处于侵蚀基准面以上的膨润土中钠离子往往被钙离子交换,而处于深部重碳酸钠型水中的膨润土却仍然保留了钠基土的原始特性。由于易采、易选的特殊条件,多年来该区膨润土开发一直旺而不衰,其原因之一就是随着工业化进程加快,膨润土开发利用已上升到重要地位。     

基于Grab Cut和二维熵的SAR图像目标分割方法

传统的Grab cut算法需要人工交互操作,无法实现SAR图像的自动分割;且SAR图像的斑点噪声干扰容易降低图像的分割质量。针对以上问题,文中以Grab Cut图像分割算法为基础,首先利用FCM算法对SAR图像进行预分割,根据预分割结果标记SAR图像中的前景与背景集合,得到两组较为准确的GMM初始化参数,迭代求得能量函数的最小化,实现SAR图像前景区域与背景区域的自动分割;并结合二维熵算法滤除SAR图像中的阴影,分割出目标区域。实验表明,利用该方法可自动分割出SAR图像中的目标,且分割质量良好。     

宁夏固原市原州区高氟地区氟对人体健康的影响

近年来随着人们生活质量的提升,对健康的关注度也不断提高,氟中毒性地方病越来越受到人们的重视。在关注氟污染源分析及暴露途径研究的同时,开展氟暴露途径评价健康风险研究也十分必要。据调查,固原市原州区彭堡镇地区表层土壤氟含量高于当地区域背景值,本文针对当地存在氟超标导致地方病的实际情况,重点采集了固原市原州区彭堡镇地区表层土壤、地层岩石、农作物、地下水等样品,主要采用电感耦合等离子体发射光谱法（ICP-OES）、原子荧光光谱法（AFS）等分析方法对相关元素进行分析测试,研究固原市原州区彭堡镇高氟区氟超标对人体健康的影响,并运用健康风险评价模型对人体健康风险进行评价。评价结果表明：谷物和蔬菜氟暴露途径健康风险指数HQ<1,没有非致癌风险。当地人体氟暴露风险主要途径为饮用地下水摄入,相关的健康风险指数HQ>1,这表明通过饮用氟超标的地下水,可能具有潜在的非致癌风险。年度总健康风险为1.69×10^-8,低于国际辐射防护委员会（ICRP）建议的最大可接受年健康风险水平5.0×10^-5,属于人类可接受的风险水平。根据氟健康风险评价结果,本文提出该地区饮用水安全性方面还需多给予关注。     

微波消解电感耦合等离子体质谱法测定黑色页岩中稀有稀土元素

采用硝酸-氢氟酸-过氧化氢于微波消解仪中分解样品,电感耦合等离子体质谱法测定贵州遵义地区某黑色页岩中稀有稀土元素的含量。对页岩标准物质(GBW 07107)和水系沉积物地球化学成分分析标准物质(GBW07305、GBW 07310)的分析,测定值与标准值相一致。对黑色页岩的分析结果较好,方法精密度(RSD,n=6)各元素均小于4%,加标回收率为97.9%~100.1%。方法准确度高、简单、快捷,一次溶样可同时测定多种元素。     

沈阳市地铁二号线GPS控制网的建立与数据处理

介绍了沈阳市地铁二号线北延工程平面控制网的建立与数据处理过程,通过对精度指标的分析,总结了本次控制网工程的特点,对日后施工作业提供参考作用。     

应用GAMIT-GLOBK软件进行高精度GPS控制网解算

介绍了作为高精度的GPS基线处理软件GAMIT-GLOBK的构成及使用方法,通过算例说明在高精度网内利用GAMIT-GLOBK软件进行基线解算精度完全可以达到要求,从而满足城市级控制网的需要。     

沈阳市桃仙机场改扩建GPS控制网的建立与数据处理

介绍了沈阳市桃仙机场改扩建GPS控制网的建立与数据处理过程,通过对精度指标的分析,总结了本次控制网工程的特点。