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1.
过去5000年西太平洋副热带高压活动的泥炭纤维素碳同位素记录 总被引:10,自引:2,他引:8
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
2.
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
3.
《Applied Geochemistry》1998,13(4):415-420
The European Communities Bureau of Reference (BCR) and Chunguo sequential extraction procedures were employed to evaluate the retention of U and As by a soil contaminated with low level radioactive waste. Modifications were made to both procedures to optimize the measurement of soil and extractant samples using epithermal neutron activation analysis. Based on the BCR procedure, approximately 20% of the U appeared to be bound to the carbonate fraction, 10% to the mineral oxide fraction and 20% to the organic fraction. In the case of As, the majority was strongly bound in the residue fraction. The results obtained with the Chunguo procedure supported these conclusions to some extent, in that the majority of the U and As was found to be strongly bound to the soil in a manner consistent with its presence in the residue fraction. 相似文献
4.
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
5.
通过对不同生态补偿方式的对比分析, 可知生态补偿能够在一定程度上提升农户的生活水平, 促进农户五种生计资本的合理均衡分布. 而资金支持的补偿方式对于农户生活的提升最为有效, 技术支持的补偿方式对促进农户生计资本的合理分布更为有效. 从对农户人力资本的影响来看, 政府可以通过对农户给予资金支持, 从而有效促进农户人力资本的提高; 从对农户物质资本的影响来看, 政府可以通过对农户给予技术支持, 从而有效促进农户物质资本的提高; 从对农户金融资本的影响来看, 政府可以通过对农户给予资金和技术支持, 从而有效促进农户金融资本的提高, 弥补农户由于实施生态补偿后所损失的利益, 提高农户的生计水平. 相似文献
6.
Based on the questionnaire survey, this paper analyzes China’s public perception of climate change in terms of several influence factors and some empirical findings are obtained. We find that some respondents are willing to take individual actions to address climate change, and they pay more attention to climate change or approve that climate change does harm to residents and society; meanwhile, they tend to have confidence in the government to deal with climate change or believe that fiscal and taxation policies are the effective policy measures. However, there are also other respondents unwilling to take actions and argue that climate change proves the natural consequences. Thus, in order to motivate the public to take actions, the paper suggests that the government should widespreadly disseminate relevant knowledge about climate change to the public and guide the work to address climate change and adopt proper fiscal and taxation policies. 相似文献
7.
公路桥涵台背回填及处治技术研究 总被引:1,自引:0,他引:1
“桥头跳车”现象,已成为高速公路的多发常见病害,分析其主要原因是桥头与路基的沉降差所致。通过对在建垫(江)邻(水)高速公路“桥、涵背”回填及处治技术研究,提出合理设置过渡台阶,使用级配碎石作回填材料,铺设土工格栅加强整体性等工程措施,经现场试验检验,处治效果较好。 相似文献
8.
典型岩溶流域土地整理的生态评价——以云南小江流域为例 总被引:2,自引:0,他引:2
以云南小江典型岩溶流域为例,在GIS支持下,通过选择评价因子和建立评价模型对岩溶区的土地整理进行了生态评价。结果表明: 流域生态评价分值较高的土地面积较少,而生态评价分值较低的土地面积较大。分值在80~ 100的土地整理主要任务是在保护生态环境质量和耕地数量的前提下,加快流域经济结构的调整,提高土地利用的经济效益;分值在70~ 80的土地整理主要任务是耕地数量保护和质量保护并重,提高土地的生产能力,提高经济效益,同时防止水土流失及化肥、农药施用对地下水造成的非点源污染; 分值在60~ 70的土地整理主要任务是着重于生态环境的保护和重建以及立体农业的综合开发; 分值在60以下的土地整理主要任务是土地石漠化的治理。 相似文献
9.
Akira IMAI 《Resource Geology》2002,52(2):147-161
Abstract: K–Ar ages of the following porphyry Cu deposits in the western Luzon arc are determined: Lobo-Boneng (10.50.4 Ma), Santo Niño (9.50.3 Ma), Black Mountain (2.10.1 Ma), Dizon (2.50.2 Ma) and Taysan (7.30.2 Ma). Microphenocrys-tic apatite in the late Cenozoic intermediate to silicic intrusions associated with porphyry Cu deposits in the western Luzon arc contains sulfur as SO3 detectable by electron probe microanalyzer. Sulfur is supposed to have been accommodated dominantly as oxidized species in oxidizing hydrous magmas that generated porphyry Cu deposits. Likewise, such high SO3 contents in microphenocrystic apatite are common characteristics of the intermediate to silicic magmatism of the western Luzon arc, from tonalitic rocks of the Luzon Central Cordillera of about 15 Ma to an active magmatism at Mount Pinatubo. Thus, the western Luzon arc has been generating porphyry Cu mineralization associated with oxidizing hydrous intermediate to silicic magmatism related to eastward subduction, since Miocene to the present day. Intermediate to silicic rocks since 15 Ma to present-day western Luzon arc generally show high whole-rock Sr/Y ratio ranging from 20 to 184. However, porphyry Cu deposit is not necessarily related to the rocks that show higher Sr/Y ratios compared to the other barren rocks in the western Luzon arc. The characteristics of the intermediate to silicic magma associated with porphyry Cu deposit are not attributed to the composition of the source material of the magma, but to the properties defined by the high activity of oxidized species of sulfur in the fluid phase that is encountered during the generation of intermediate to silicic magmas. 相似文献
10.
Prediction criteria for groundwater potential zones in Kemuning District,Indonesia using the integration of geoelectrical and physical parameters
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The presence of groundwater is strongly related to its geological and geohydrological conditions.It is,however,important to study the groundwater potential in an area before it is utilized to provide clean water.Werner-Schlumberger’s method was used to analyze the groundwater potential while hydraulic properties such as soil porosity and hydraulic conductivity were used to determine the quality and ability of the soil to allow water’s movement in the aquifer.The results show that the aquifer in the Sekara and Kemuning Muda is at a depth of more than 6 meters below the ground level with moderate groundwater potential.It is also found that the aquifer at depths of over 60 m have high groundwater potential.Moreover,soil porosity in Kemuning is found to be average while the ability to conduct water was moderate.This makes it possible for some surface water to seep into the soil while the remaining flows to the rivers and ditches. 相似文献
11.
湖南省探矿权、采矿权市场现状与发展对策 总被引:1,自引:0,他引:1
探矿权、采矿权市场是社会主义市场经济的重要组成部分.培育和规范探矿权、采矿权市场不仅是实现矿产资源利用方式和管理方式转变的根本途径,更是推动矿业经济全面开放。走向健康有序发展的强大动力.湖南省的探矿权、采矿权市场还不发育,与我国市场体制的发展进程和其他各类市场的建设进程相比,很难适应入世的需要.在对湖南省探矿权、采矿权市场现状进行深入分析的基础上,提出了解放思想、整顿秩序、明确政策、加强勘探。严格规划、加强领导等项措施来培育和规范我省探矿权、采矿权市场. 相似文献
12.
我国喜马拉雅地区适应气候变化能力建设的需求调查与分析 总被引:4,自引:3,他引:1
喜马拉雅地区是全球潜在关键区,过去几十年的气候变化已导致该地区冰川消融,与冰川有关的灾害风险与日俱增,随着气候的持续变暖,冰川消融将对该地区水资源供给产生负面影响.基于社会调查和实地考察,分析了我国喜马拉雅山地区冰川消融对灾害的可能影响,对水电发展的现实和潜在影响,并详细分析了气候变化对农业、牧业和林业的影响.根据调查问卷,分析了当地在适应冰川消融方面的迫切需求,社会经济不同部门适应气候变化的需求.以位于珠峰北坡朋曲河流域的定日县为典型区,探讨了在该县增强适应气候变化能力建设问题.当地应首先加强气候防护基础设施建设,以应对目前强降水增加引发的山洪、冰川加速消融导致的冰川洪水和泥石流危害、气候暖干化导致的农牧业干旱;开展以水能为主,多能互补,能源多样化建设,既可加快当地社会经济发展,又可促进当地居民适应气候变化能力的提高;吸引本地人才回流,加强各级岗位人才培训,提高管理水平和技术水平;大力开展科普宣传,提高农牧民对气候变化及其影响的了解和认识,增强其防御和应对能力. 相似文献
13.
钻进过程状态监测旨在实时描述钻进工况,判断运行性能优劣程度进行非优追溯,及时指导司钻人员调整作业操作,保证钻进过程安全、高效、稳定开展。钻进工况是钻进系统运行状态的反映,因此开展面向状态监测技术的钻进工况识别研究具有重要的理论和应用价值。本文针对钻进工况识别问题,基于状态监测数据,建立基于支持向量机的钻进工况识别模型,对钻进工况进行识别。综合工况识别结果,对钻进效率进行评估,并对影响钻进效率的因素进行讨论,寻找提升钻进效率的手段。最后,采用钻进现场实钻数据进行仿真实验,验证所提方法的可行性和有效性。 相似文献
14.
ZHUANG Yi-ming LIU Ying-xin LI Hai-yan SUN Pei-lin ZHAO Fu-you Coal Field Geology Bureau of Jilin Province Changchun China 《吉林大学学报(地球科学版)》2006,(Z2)
高分辨率地震采集数据是构造解释和砂体预测的基础资料,其保真程度的高低直接影响到小构造和砂体预测的准确性。震源的激发、波的传播、检波器的接收和仪器记录各个环节对地震信息的保真度都有影响,地震采集每个环节的分析、研究对提高地震信息的保真度具有重要意义。 相似文献
15.
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
16.
选取某一支护面上的任意一根桩为研究对象,设置一道支撑(或锚索或锚杆)及开挖至坑底,建立其受力平衡方程和位移协调方程。通过圈梁的协调作用,将研究对象扩大到整个支护面,推导出能够同时考虑开挖过程、支撑设置以及桩-土-圈梁共同作用的支护面位移和受力方程组,利用FORTRAN语言编制的程序求解,可计算出开挖至坑底工况下圈梁、桩身任一截面的内力、水平位移。通过算例计算圈梁(桩顶)的位移与监测位移及部分桩的内力,与文献[1]方法计算的内力进行对比分析,验证文中方法的合理与可行性。 相似文献
17.
M. Dolores Petit-Dominguez M. Isabel Rucandio Almudena Galan-Saulnier Rosario Garcia-Gimenez 《Journal of Geochemical Exploration》2008
Due to the high number of variables involved in mine profitability studies, it is often very difficult to establish connections among them in order to provide a blend of market saleable quality products. In this sense, analytical chemistry together with chemometry are essential and indispensable disciplines to tackle these studies. The aim of this work was to demonstrate the utility of these disciplines to carry out optimization studies of iron mines. For this purpose, one of the most important iron mines of the Iberian Peninsula was chosen, sited in the mountain range of Sierra Menera, near the location of Ojos Negros (Teruel, Spain). Geological, mineralogical and chemical composition of 148 samples was analyzed, corresponding to different depths of three drill holes (named TE1, TE2 and TE3). In particular, aspects concerning to chemical composition are very important, since the mean contents of certain elements, such as phosphorus, sodium and potassium, should be restricted to the established limits to prevent that companies can drive back the raw material if they do not fulfil the necessary requirements. On the other hand, the large number of analysed samples drove us to use a statistical processing of the data. Among other aspects, it provides a way to find possible connections among a high number of variables and classify samples into compositional groups sharing similar composition, in order to limit the mineralised area and to obtain enough information about the amount of those chemical elements associated to iron ores. Data obtained from all these analytical techniques were in good agreement and provide a methodology that can be of wide interest applied to different geological studies. 相似文献
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19.
中国铬矿资源形势及其找矿方向 总被引:3,自引:0,他引:3
我国铬矿资源贫乏,具有区域分布差异明显、矿床规模小、分布零散、矿床成因类型单一以及冶金级矿石所占比例不高的特点.上述特点造成我国当前铬矿资源形势非常严峻,一方面探明储量逐年减少,将面临枯竭的危险,另一方面铬铁合金的产量逐年增加,但铬铁矿产量却难以满足国内市场的需求,只能不断增加进口来缓解市场压力.因此,为了摆脱当前的不利局面,今后我国铬铁矿的找矿方向包括:①找寻新的铬铁矿产地.②探究新的铬铁矿类型.③加强已知铬铁矿的外围以及深部的找矿.④利用新技术新方法的进行间接找矿.⑤深入开展成矿理论的研究,为找矿以及成矿潜力评价提供指导. 相似文献