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1.
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
2.
Landslide risk: some issues that determine societal acceptance 总被引：2，自引：1，他引：1
This paper illustrates approaches to landslide risk acceptance in various parts of the world in the context of the willingness to accept that risk, the willingness to pay to reduce the risk, and the willingness to alter the environment in the process. These factors are interlinked using the ternary ??willingness diagram?? which is also used to demonstrate how such willingness may change over time and to compare a range of generic approaches to landslide remediation as well as different conceptual approaches to landslide risk management. The willingness construct is intended to provide a readily understood framework for infrastructure owners and operators, amongst others, to understand how their approach to risk management compares with those in other regions, countries and contexts. Issues relevant to the response of society and groups of individuals to landslide risk, its acceptance and management include cultural factors, regulation and planning, budgetary constraints, vehicular vulnerability, and the often limited size of the event footprint compared to the vulnerability shadow that is cast are also discussed. 相似文献
3.
《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
4.
软土型水泥土掺砂试验研究 总被引：4，自引：0，他引：4
考虑到土性对水泥土强度的影响，提出了在软土中掺砂以改进水泥土抗压强度性能的方法。选取深港西部通道填海区含有机质的淤泥，采用均匀设计法来考察水泥掺入比、砂的掺入比、龄期和水泥土抗压强度的关系；建立了其回归模型，研究了3个因素对强度的影响情况，给出了优化配比的方法；最后提出了改进机具以实现水泥土掺砂的设想。 相似文献
5.
Benjamin R. Jordan Haraldur Sigurdsson Robert Rogers 《Geochimica et cosmochimica acta》2007,71(14):3581-3591
An analysis of 70 samples, collected from Miocene-age ignimbrites in 68 locations in Nicaragua and Honduras, indicates that geochemical processes and a subduction zone geometry similar to those in the modern arc were also present in the paleoarc. Samples were plotted along two transects, parallel and perpendicular to the inferred paleoarc. Most of the oxide plots exhibit flat profiles along the arc from NW to SE, except for SiO2, which decreases. FeO, CaO, TiO2, and MgO increase from NW to SE. There are no clear trends in the oxides from SW to NE, except K2O. K2O increases to the SW. Most trace elements show little to no variation along the province from NW to SE, with the exception of La, Ce, Rb, Ba, Th, Nb, Ta, Pb, and Sr, which all appear to decrease in abundance from NW to SE. While Ba increases to the SW, toward the paleotrench, it also shows remarkable variation parallel to the arc, with highs in Nicaragua, and decreasing concentrations to the NW and SE. This trend is especially apparent in Ba/La with lows near 1 in the NW and highs approaching 80 in Nicaragua. This trend is similar to that of the modern arc, which suggests that the geometry of the arc in the Miocene was very similar to that of the modern arc. In addition, the data also becomes more scattered to the southeast as a basement boundary is crossed (determined by gravity-anomaly mapping), probably due to a higher degree of contamination by continental crust. 相似文献
6.
Most laboratories aim to produce data of the highest quality. Trying to lower uncertainties to infinitesimal figures and push detection limits even lower are valid goals. However, is it possible to overachieve? Are old data still of good enough quality to be usable? In a geochemical context, the main goal of producing analytical results is to answer geological or environmental questions. Not all scientific problems require the same data quality. What is really required are data of adequate quality – i.e., ‘fit-for-purpose’– to ensure that the geological problem at hand can be solved. Furthermore, it is doubtful that uncertainties and reproducibilities associated with field sampling are better than those from laboratories. It is thus proposed that, as geoanalysts, we encourage data users (students, colleagues or referees) to ensure that their analytical results are of sufficient quality to solve the problem. However, authors have to demonstrate, through the use of reproducibility testing, reference and quality control materials, that the quality of their results is sufficient to solve the problem. Uncertainties and detection limits in publications should not only be evaluated with respect to a set value, such as 10%, but also with regard to the geological problem to be solved. 相似文献
7.
LI Chao-lin TIAN Ya-jing LI Hai-yan QU Xue-xian DU Xing-feng Coalfield Geological Geophysical Exploration Company of Jilin Province Changchun China 《吉林大学学报(地球科学版)》2006,(Z2)
在陆相煤系地层地震勘查中,由于地层的岩石类型不稳定,给采集和解释工作带来很大不便,大大的影响了勘查效果,为取得良好的勘查效果,提高采集效果和地震解释人员的综合解释能力是非常重要的。在此,就合理的施工设计、最佳的采集方法、高精度的资料处理和资料的综合解释等进行了分析,并较好地解决了上述问题。 相似文献
8.
According to the latest International Chronostratigraphic Scheme (ICS, 2000), the Permian in the Middle-Lower Yangtze region of South China can e divided into three series and nine stages relevant to the traditional six stages of South China. From Assellian to Changxingian of Permian, 44 Main age range, the strata are composed of 14 third-order sequences, each of which is 3.14 Ma in average age range. There is one third-order sequence of Zisongian, equivalent to middle and upper Chuanshan Formation or equal to Asselian and two thirds of Sakmarian. There are two third-order sequences, corresponding to Liang-shan Formation or Zhenjiang Formation and upper Chuanshan Formation, which are assigned to Longlingian, coinciding with Artinskian and one third of Sakmarian. In addition, three third-order sequences, equal to Qixia Formation, are attributed to Chhsian, corresponding to Kubergandian and one third of Roadian. Four third-order sequences, comprising Gufeng, Maokou, Yanqiao,Yinping and Wuxue formations, are assigned to Maokouan, equivalent to two thirds of Roadian, Wordian and Capitanian. Two third-order sequences, equal to Longtan Formation or Wujiaping Formation, are included in Wuchiapingian. Other two third-order sequences, corresponding to changxing Formation or Dalong Formation, are assigned to Changhsingian. In brief, these above third-order sequences can be incorporated into 4 sequences sets. 相似文献
9.
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
10.
11.
《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
12.
Tornadoes are the most destructive winds created by nature. Sometimes tornadoes are strong enough to destroy most things in their path. These types of tornadoes are few compared to all tornadoes confirmed/reported. Currently, existing scales describe severity levels in terms of intensity/magnitude, and they are not sufficient to clearly distinguish the severity level. Several discrepancies between various sources of information complicate the interpretation of trends in tornado data. As a solution to these inconsistencies, a technique is required to compare the severity level of tornadoes. Impact factors, such as the number of fatalities, number of injuries, number of homeless, affected population, affected area, and cost of damage, can be considered to evaluate the severity levels. Prior experience, preparedness, awareness, evolving technology, mitigation methods, and early warning systems may minimize the number of fatalities and injuries. Models are used to identify which of the above factors should be considered in a severity scale to indicate the seriousness of tornadoes. However, the lack of data prevents an in-depth analysis of tornado severity. Extreme value theory is used to study potential severity levels of tornadoes. This paper attempts to develop an initial severity scale for tornadoes, which is a primary stage to develop a multi-dimensional severity scale. This common scale provides the criteria to rank tornadoes and allows the impact of one tornado to be compared to the impact of another tornado. Further, the scale allows the impact of a tornado to be compared to any type of natural disaster that occurs. 相似文献
13.
以松辽盆地北部高分辨率勘探试验资料为基础,对其精细构造勘探中需注意的几个重要环节进行了系统的研究,并在某些环节上得出了与常规地震相悖的观点,如：应兼顾激发能量和频带宽度确定激发层位与药量;应根据勘探目的层的深浅,选择不同自振频率的检波器,检波器以多串少并方式连接,更有利于记录高频信号;在信号记录方面,提出应根据模/数转换器位数对频宽的影响程度选择低切;另外指出是否采用高分辨率地震勘探的依据是高频信息在浅层的衰减程度、目的层的物性条件及目的层的层数。针对施工中容易出现问题的环节,提出了应采取的措施,根据目前高分辨率地震勘探现状,提出未来需进一步攻关的方向。 相似文献
14.
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
15.
近来,为缓解北京市日趋紧张的供水情况,需启用1995年建成的北京某应急备用地下水源地。该水源地建有30眼水井,属第四系河旁非承压含水层,当时静水位埋深为4m,单井平均出水量超过4000m3h。近年来由于各种原因,尤其是2003年该水源井出水量大幅减少的主要原因是含铁碳质化合物附着对井壁的堵塞。针对这一情况,通过试验确定了以强力正反冲洗活塞洗井工艺为核心的复合洗井方案,对17眼水井实施洗井处理,使井群出水量恢复到了建井初期的水平,取得了良好的效果。 相似文献
16.
中下扬子区二叠系露头层序地层研究 总被引：15，自引：1，他引：15
按新近国际年代地层划分方案（ICS，2000），下扬子区二叠纪地层自下向上分为3统，9阶和相对应的华南传统6阶划分。二叠系从阿瑟尔阶至长兴阶（44Ma)共划分出14个三级层序，每个三级层序平均时限约为3.14Ma，其中“紫松阶”）相当阿瑟尔＋2／3萨克马尔阶）1个（船山组中上部）、“隆林阶、（相当1／3萨克马尔阶＋阿丁斯克阶）2个（分别对应船山组上部和梁山组或镇江组）、“栖霞阶”（相当库班甘德阶＋1／3罗德阶）3个（栖霞组），“茅口阶”（相当于2／3罗德阶＋沃德阶＋卡皮丹阶）4个（孤峰组，茅口组，堰桥组，银屏组和武穴组），吴家坪阶2个（龙潭组或吴家坪组），长兴阶2个（长兴组或大隆组）；共归并为4个层序组（sequence set)。 相似文献
17.
河南省地震活动趋势分析 总被引：1，自引：0，他引：1
张立汉 《大地构造与成矿学》1991,15(3):217-224
河南省东北部属华北地洼区烈震区南延部分,西南部属华中地洼区中强震区。历史上发生5级及5级以上的地震18次,依规律可分淅川-南阳、信阳-商城、菏泽-许昌、安阳-新乡,洛阳-灵宝5个构造地震带,空间分布规律:长期隆起强烈坳陷区;不同构造单元交接处地貌反差明显的下降一侧:新生代后大面积沉降背景下差异下降显著部位;上述部位几组断裂交叉处是发震有利场所。时空迁移规律:南阳、信阳-商城地震活动动向有待进一步研究;菏泽-许昌构造中强震线,地震活动以双震形式跳跃式往返迁移;安阳-新乡构造中强震线。有南北往返递迁规律;豫北不同地震线间有由东向西波浪状转化递迁规律。许昌、安阳-新乡、洛阳-灵宝一带,存在着发生中强地震危险性。 相似文献
18.
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
19.
封闭体系有机质与有机碳氢氮恢复动力学研究 总被引：3，自引：0，他引：3
在封闭体系的条件下,对典型的Ⅰ、Ⅱ、Ⅲ型干酪根在热演化过程中的损失进行生烃动力学研究,获得了Ⅰ、Ⅱ、Ⅲ型干酪根的总量、有机碳、氢以及氮质量损失动力学参数。用Kinetics软件计算了封闭体系干酪根有机碳丰度、氢碳原子比和氮碳原子比的恢复系数。认为在对高成熟—过成熟干酪根进行生烃评价时,Ⅰ、Ⅲ型干酪根残余有机碳丰度需要进行恢复,而Ⅱ型干酪根残余有机碳丰度不需要恢复。三种类型干酪根的氢碳原子比均需要进行恢复。 相似文献
20.
对付金刚石绳索取芯钻进复杂地层施工中的两个突出问题,有两项比较有效的技术措施。一是在易塌、漏水、水敏地层钻进时,使用加大外径的金刚石钻头以增大钻孔环状间隙,减小孔内阻力,并改善对低固相泥浆的配制和管理。二是在跑斜地层设置初级定向孔,提高钻具在动态条件下的稳定性,并在弯曲孔段采用套管楔纠斜。 相似文献