共查询到20条相似文献，搜索用时 78 毫秒
1.
针对剩余静校正问题,讨论了统计方法中的蒙特卡罗法用于反射波能量最大化剩余静校正的方法。分别论述了反射波叠加能量最大化法和蒙特卡罗方法,以及蒙特卡罗方法如何应用于剩余静校正的计算中,并用实例说明了该方法的效果。通过实际应用蒙特卡罗剩余静校正方法,解决了经野外静校正后残留的剩余静校正问题,并通过与其他剩余静校正方法的实际应用对比,说明了蒙特卡罗剩余静校正方法的优势。对于大剩余量的静校正问题,蒙特卡罗剩余静校正方法仍然可以很好的解决,并且不会产生串相位问题,说明蒙特卡罗剩余静校正方法是可靠的。 相似文献
2.
3.
静校正是深地震反射资料处理的关键技术之一,深反射剖面通常跨越多种不同的地质构造单元,地震地质条件复杂且变化较大,单一的静校正方法通常不能很好地解决深反射的静校正问题,针对兴蒙造山带西南段深反射地震数据进行静校正测试,最终选取多种静校正方法组合静校正技术,即针对不同地质条件分别应用折射和层析相结合来解决静校正问题。对于剩余静校正,采用模拟退火法解决,较好地解决了研究区的静校正问题,为资料后续处理提供借鉴。 相似文献
4.
复杂地区静校正技术应用研究 总被引：1，自引：0，他引：1
在地震勘探中,静校正问题一直是一个难题,尤其在复杂地表地区静校正问题更为严重.静校正问题影响地震反射波的成像,导致地震剖面出现假构造,在解释过程中给地质人员带来错误的认识.本文认为在解决静校正问题上,折射波静校正方法优于传统的野外静校正算法. 相似文献
5.
随着地震勘探的不断深入,探区地表条件日趋复杂化,静校正问题突出,对常用静校正方法的基本原理以及适应性进行系统的分析显得尤其重要。基于对高程静校正、折射波静校正、层析反演静校正以及初至波剩余静校正4种常用方法基本原理进行的分析,比较其优缺点,并探讨各方法在油气勘探中的适用范围。认为:随着油气地震勘探不断深入,地震采集面临复杂地表情况更加频繁,要因地制宜地选择静校正方法,如基于初至时间的层析静校正能较好地解决复杂地区由于地形和低降速带变化引起的长波长静校正问题。 相似文献
6.
7.
塔里木盆地沙漠地区静校正技术方法的应用 总被引：1，自引：4，他引：1
在地震勘探中,尤其在复杂地表的地区,静校正问题一直是一个难题。通过全面系统地分析塔里木沙漠地区其静校正产生的原因、原始地震资料的特点及老资料处理存在的问题,对该区严重的静校正问题提出了3种静校正方法,即野外静校正方法、折射波静校正方法以及反射波自动剩余静校正方法联合使用的观点。通过在塔里木地区地震资料的处理应用,取得了一定效果。认为解决复杂地表地区静校正问题是一个综合的过程,它取决于对所在工区静校正问题的分析、有效的折射波初至拾取和静校正量的准确计算及应用。对实际地震资料的处理证明,在处理流程中所采用的静校正联合使用的方法在本工区是切实可行的,并在生产中得到了广泛应用。 相似文献
8.
9.
10.
11.
Nutrient loading to estuaries with heavily populated watersheds can have profound ecological consequences. In evaluating policy
options for managing nitrogen (N), it is helpful to understand current and historic spatial loading patterns to the system.
We modeled N inputs to Narragansett Bay from 1850 to 2000, using data on population, human waste disposal, livestock, fertilizer,
and atmospheric deposition. We found that total N loading to the bay increased 250% from 1850 to 2000, and 80% from 1900 to
2000. Loading to the upper bay increased far more than that to the lower bay, and the most important source shifted from non-point
animal waste to human waste concentrated at sewage treatment facilities. We also modeled future N loads in 2015 under four
management scenarios. Planned improvements in sewage treatment would reduce N loads 9% below business-as-usual, to the 1990
loading rate. Greater reductions, to circa 1900 rates of loading, may be possible. 相似文献
12.
地勘单位要吸引和留住人才,就要在事业、感情、待遇留人上下功夫.即营造鼓励人才干成事业、帮助人才干好事业、创造施展才华的社会氛围和环境;用来自领导的关心爱护之情,同事的团结友爱之情来拴住人心;为人才提供与其创新能力和贡献相适应的物质待遇,使人才充分享有实现自身价值的自豪感、贡献社会的成就感、得到社会承认的荣誉感. 相似文献
13.
基岩裂隙水探寻是一项意义重大的研究课题,富水优势断裂的确定是其中的关键。文章详细论述了运用层次分析法寻找富水优势断裂并进行分级的实施方法。这一方法的实施可归纳为"两个前题条件,五个分析步骤,一个结果判断",两个前题条件为富水性功能分类和构建优势指标体系,五个分析步骤为构建层次分析结构模型、构造判断矩阵、层次单排序及其一致性检验、层次总排序、对象层权重总排序;一个结果判断为利用层次分析的结果进行断裂富水性分级,从而最终确定出富水优势断裂。此法为富水优势断裂的定量化评价提供了一种简洁、实用的新方法。 相似文献
14.
《International Geology Review》2012,54(11):1042-1050
Minerals of the stibnite-antimonselite series, in close association with tiemannite, clausthalite, kullerudite, Se-bearing stibioluzonite, native gold, quartz, and barite, were discovered in Cambrian stratabound gold deposits at La'erma and Qiongmo, western Qinling, China. Based on S/(S + Se) ratios of microprobe analyses, the binary stibnite-antimonselite system is divided into four series: stibnite, Se-stibnite, S-antimonselite, and antimonselite. Micro-hardness of the stibnite series (Sb = 58.47 to 72.99 wt%, S = 11.86 to 28.76, and Se = 0.00 to 29.12) and the antimonselite series (Sb = 48.94 to 59.13 wt%, Se = 29.20 to 46.86, S = 1.99 to 11.43) is 101.26 and 103 kg/mm2, respectively. Representative reflectivities of the four series are (470 nm) Rg'= 42.62 to 47.62%, Rp' = 30.83 to 40.55%; (550 nm) Rg' = 41.84 to 46.75%, Rp'= 31.48 to 38.85%; (590 nm) Rg' = 42.25 to 46.63%, Rp' = 30.73 to 39.46%; (650 nm) Rg' = 43.30 to 46.48%, Rp' = 30.01 to 41.56%. Cell parameters obtained from two stibnite samples (containing 3 to 5% Se) are a = 1.1209 to 1.1212 nm, b = 1.1299 to 1.1303 nm, c = 0.3847 to 0.3849 nm; and those of S-antimonselite and antimonselite are a = 1.1591 to 1.1593 nm, b = 1.1724 to 1.1747 nm, and c = 0.3941 to 0.3984 nm. 相似文献
15.
湿陷性黄土增湿和减湿效应的探讨 总被引：1，自引：0，他引：1
湿陷性黄土的湿陷性不是一成不变的。土中含水率的变化产生的增湿和减湿效应,对黄土湿陷性影响很大。进行黄土湿陷性评价时,应注意以动态的观点和方法综合分析、预测增湿和减湿效应的不利影响,以便采取有效的处理措施,消除工程事故隐患。 相似文献
16.
文章以金川和红原两组泥炭纤维素Δδ13C时间序列值的反向变化来指示西太平洋副热带高压活动变化.结果表明,在过去5000年中,西太平洋副热带高压的活动可分为4个阶段,即西太平洋副热带高压位置在2800～2200B.C.期间持续偏北,2200～600B.C.期间持续偏南,600B.C.～1200A.D.期间在北进与南移之间频繁波动,以及1200～1900A.D.期间再次持续偏北,它们导致降雨量在中国大陆上不同的分布.从约1900A.D.起西太平洋副热带高压的活动似乎又开始一个新的偏南阶段,值得进一步加强研究. 相似文献
17.
Mangrove forest stores large organic carbon stocks in a setting that is highly vulnerable to climate change and direct anthropogenic influences. As such there is a need to elucidate the causes and consequences of land use change on these ecosystems that have high value in terms of ecosystem services. We examine the areal pattern of land types in a coastal region located in southern Iran over a period of 14 years to predict future loss and gain in land types to the year 2025. We applied a CA–Markov model to simulate and predict mangrove forest change. Landsat satellite images from 2000 to 2014 were used to analyze the land cover changes between soil, open water and mangroves. Major changes during this period were observed in soil and water which could be attributed to rising sea level. Furthermore, the mangrove area in the more seaward position was converted to open water due to sea-level rise. A cellular automata model was then used to predict the land cover changes that would occur by the year 2025. Results demonstrated that approximately 21 ha of mangrove area will be converted to open water, while mangroves are projected to expand by approximately 28 ha in landward direction. These changes need to be delineated to better inform precise mitigation and adaptation measures. 相似文献
18.
《Quaternary Research》2014,81(3):513-519
We developed a tree-ring chronology (AD 1446–2008) based on 75 cores from 37 Abies squamata Mast. trees from the Shaluli Mountains, southeastern Tibet Plateau, China, using signal-free methods, which are ideally suited to remove or reduce the distortion introduced during traditional standardization. This chronology correlates best with regional temperatures in June–July, which allowed us to develop a June–July temperature reconstruction that explained 51.2% of the variance in the instrumental record. The reconstruction showed seven cold periods and five warm periods. Cold periods were identified from AD 1472 to 1524, 1599 to 1653, 1661 to 1715, 1732 to 1828, 1837 to 1847, 1865 to 1876 and 1907 to 1926. Warm intervals occurred from AD 1446 to 1471, 1525 to 1598, 1716 to 1731, 1848 to 1864, 1877 to 1906 and 1927 to present. The reconstruction agrees well with nearby tree-ring-based temperature reconstructions. Spatial correlation analyses suggest that our reconstructions provide information on June–July temperature variability for the southeastern Tibetan Plateau and its vicinity. Spectral analyses revealed significant peaks at 2–6, 10.7, 51.2, 102.2 and 204.8 yr. The temperature variability in this area may be affected by ENSO, the Pacific Decadal Oscillation and solar activity. 相似文献
19.
《International Geology Review》2012,54(11):1028-1032
The purpose of this paper is to provide a guide to research results and published literature on stable-isotope geochemistry of UHP rocks for the period from 1993 to 1998. Although some articles on blueschist- and lower-eclogite-facies rocks are included, the predominant focus is on coesite-and diamond-bearing rocks of the eclogite facies. Attention is called to a number of studies of fluid inclusions in UHP rocks. Even though stable-isotope geochemistry may not play a direct role in fluid-inclusion research, the link between the two methods is too strongly complementary to be ignored. A number of references are made to works in press and to abstracts presented at the 1998 International Workshop on UHP Metamorphism and Exhumation, Stanford University. These informal references to abstracted research are made in order to alert the reader to ongoing projects that are likely to be published in the near future. 相似文献
20.
本文据东海五口探井的559个碎屑矿物样资料,用主要重矿物的含量及其组合特征编绘了含量变化图,试图进行分层比较。位于西湖凹陷的平湖一井和玉泉1井重矿组合特征可比性较好;龙井2井三潭组以下与上两井缺少可比特点;灵峰1井除东海群外,其余地层与上列3井相比,差异是大的。 相似文献