渗流井合理竖井降深确定

通过采用单位面积河流在单位水头差作用下的渗漏量来表征河流渗漏能力,建立渗流井取水理想模型,分别计算了在不同河流渗漏能力和含水层渗透性能条件下,竖井降深对渗流井出水量的影响.建立渗流井取水非稳定流模型,计算了在前期稳定竖井降深不同条件下,河流断流后渗流井出水量衰减过程及竖井降深发展过程.提出渗流井合理竖井降深应根据河流与地下水是否脱节以及含水层渗透性能,在岸边渗流井中部及一侧各布设一个观测孔,根据观测孔水位进行确定.对于含水层渗透性能较强地区,渗流井竖井降深应使得渗流井范围内地下水位与河流脱节,但高于辐射孔顶面;对于含水层渗透性能较差地区,渗流井竖井降深应使得侧部观测孔水位接近河床底面或刚出现脱节.     

2005年1月18日乳山ML4.3地震序列

对2005年1月18日乳山ML4.3地震序列特征及烈度分布进行了介绍, 认为乳山ML4.3地震序列是一次能量衰减较快、频度起伏衰减的主-余型地震序列, 序列本身不具有明显的前兆意义.     

A new approach of selecting real input ground motions for seismic design: The most unfavourable real seismic design ground motions

This paper presents a new way of selecting real input ground motions for seismic design and analysis of structures based on a comprehensive method for estimating the damage potential of ground motions, which takes into consideration of various ground motion parameters and structural seismic damage criteria in terms of strength, deformation, hysteretic energy and dual damage of Park & Ang damage index. The proposed comprehensive method fully involves the effects of the intensity, frequency content and duration of ground motions and the dynamic characteristics of structures. Then, the concept of the most unfavourable real seismic design ground motion is introduced. Based on the concept, the most unfavourable real seismic design ground motions for rock, stiff soil, medium soil and soft soil site conditions are selected in terms of three typical period ranges of structures. The selected real strong motion records are suitable for seismic analysis of important structures whose failure or collapse will be avoided at a higher level of confidence during the strong earthquake, as they can cause the greatest damage to structures and thereby result in the highest damage potential from an extended real ground motion database for a given site. In addition, this paper also presents the real input design ground motions with medium damage potential, which can be used for the seismic analysis of structures located at the area with low and moderate seismicity. The most unfavourable real seismic design ground motions are verified by analysing the seismic response of structures. It is concluded that the most unfavourable real seismic design ground motion approach can select the real ground motions that can result in the highest damage potential for a given structure and site condition, and the real ground motions can be mainly used for structures whose failure or collapse will be avoided at a higher level of confidence during the strong earthquake. Copyright © 2007 John Wiley & Sons, Ltd.     

Ensemble retrieval of atmospheric temperature profiles from AIRS

ABSTRACT Satellite-based observations provide great opportunities for improving weather forecasting. Physical retrieval of atmo spheric profiles from satellite observations is sensitive to the uncertainty of the first guess and other factors. In order to improve the accuracy of the physical retrieval, an ensemble methodology was developed with an emphasis on perturbing the first guess. In the methodology, a normal probability density function （PDF） is used to select the optimal profile from the ensemble retrievals. The ensemble retrieval algorithm contains four steps： （1） regression retrieval for original first guess; （2） perturbation of the original first guess to generate new first guesses （ensemble first guesses）; （3） using the ensemble first guesses and nonlinear iterative physical retrieval to generate ensemble physical results; and （4） the final optimal profile is selected from the ensemble physical results by using PDE Temperature eigenvectors （EVs） were used to generate the pertur- bation and generate the ensemble first guess. Compared with the regular temperature profile retrievals from the Atmospheric InfraRed Sounder （AIRS）, the ensemble retrievals RMSE of temperature profiles selected by the PDF was reduced between 150 and 320 hPa and below 400 hPa, with a maximum improvement of 0.3 K at 400 hPa. The bias was also reduced in many layers, with a maximum improvement of 0.69 K at 460 hPa. The combined optimal （CombOpt） profile and a mean optimal （MeanOpt） profile of all ensemble physical results were improved below 150 hPa. The MeanOpt profile was better than the CombOpt profile, and was regarded as the final optimal （FinOpt） profile. This study lays the foundation for improving temperature retrievals from hyper-spectral infrared radiance measurements.     

班怒带西段尕尔穷铜金矿两套侵入岩源区及其地质意义——来自Hf同位素特征的指示

尕尔穷铜金矿位于班公湖—怒江缝合带西段南缘的措勤—申扎火山岩浆弧内,为与侵入岩有关的矽卡岩型-破碎带型铜金(铁)矿床。在已有石英闪长岩LA-ICP-MS锆石U-Pb测年的基础上,进一步对其进行锆石Hf同位素研究,同时对最新勘查成果显示具有一定成矿潜力的花岗斑岩进行LA-ICP-MS锆石U-Pb定年和Hf同位素研究,确定了两套侵入岩的形成顺序;结合前人总结的岩石地球化学特征,利用Hf同位素对其岩浆源区进行示踪。结果显示:花岗斑岩锆石206Pb/238U年龄加权平均值为(83.2±0.7)Ma,较石英闪长岩晚4 Ma左右,其初始176Hf/177Hf值为0.282 235～0.283 073,εHf(t)值为-17.2～12.5;石英闪长岩锆石初始176Hf/177Hf值为0.282 800～0.283 015,εHf(t)值为3.5～10.5。结合二者地球化学特征显示:石英闪长岩和花岗斑岩可能是同一岩浆系统不同分异阶段的产物,前者主要起源于具有幔源印记的初生地壳,而花岗斑岩具有和石英闪长岩相似的岩浆源区,但明显混入上地壳基底物质;暗示晚白垩世班怒带西段南缘内随着南羌塘—三江复合板片与冈底斯—念青唐古拉板片之间的弧-陆碰撞,先成的具有幔源印记的初生地壳重熔形成岩浆,随着碰撞的继续和岩浆的上涌分异,部分上地壳受挤压或热效应进一步重熔并参与岩浆系统中,由早至晚形成了由幔源特征向幔-壳混合源特征源区逐渐转变的花岗岩演化系列。尕尔穷铜金矿是起源于具有幔源印记的初生地壳的花岗岩的成矿专属性表现。     

邻近算法在微地震震源位置和一维速度模型同时反演中的应用

微地震事件的空间分布可以用来监测水力压裂过程中裂缝的发育情况.因此,震源定位是微震监测中重要的环节.震源定位依赖准确的速度模型,而震源位置和速度模型的耦合易导致线性迭代的同时反演方法陷入局部极小值.邻近算法作为一种非线性全局优化算法,能够最大程度地避免陷入局部最优解.本文将邻近算法应用于单井监测的微震定位和一维速度模型...     

扬子地块北缘武当山岩群与耀岭河岩群不整合接触关系的地质意义

鄂西北南化塘地区中元古界武当山岩群由三个岩段组成，其原岩分别以火山角砾岩、岩屑凝灰岩及晶屑凝灰岩为主。它们的空间展布与上覆上元古界耀岭河岩群高角度相交，三岩段所显示出早期褶皱也只限于武当山岩群内部，与上覆岩群的构造轮廓极不谐调，耀岭河岩群没有经历过这一期变形。因此，武当山岩群与耀岭河岩群之间最初存在着明显的角度不整合接触。该区域不整合面的厘定和早晋宁运动的确认将改变以往关于扬子地块北缘构造层的划分及构造演化历史的认识，对研究秦岭造山带的造山过程具有重要意义。     

松辽盆地西部斜坡英台地区姚二、三段辫状河三角洲沉积特征研究

松辽地区西部斜坡英台地区姚家组二、三段,是在干旱一半干旱、源近流短、东倾陡坡背景下,在洪积扇前,由辫状河入湖形成的辫状河三角洲沉积。可明显区分出狭窄的辫状河三角洲平原,河口坝不太发育的辫状河三角洲前缘和夹浊积砂的辫状河前三角洲三种沉积亚相。辫状河三角洲平原由灰色含砾砂岩,粗、中砂岩,少量细砂岩,粉砂岩夹紫红色泥岩组成。具有明显的正韵律为特征。辫状河三角洲前缘沉积为灰色-绿灰色中、粗砂岩、细砂岩、少量的含砾砂岩,成正韵律或反韵律夹在灰绿色、灰黑色泥质岩中。辫状河前三角洲沉积多为灰绿色、灰黑色泥质岩,可夹少量砂质浊积岩。上述沉积特征明显地区别于正常河流三角洲沉积和扇三角洲沉积。     

Study of Influence of Regional Geodynamic Background on Strata Behaviors in China's Tongxin Mine

Strata behaviors are mainly affected by regional geodynamic background. The influence of rock mass stress and energy distribution on strata behaviors in the Tongxin mine is studied in terms of regional tectonic movement, seismic activity and tectonic stress field. The results show that the extrusion lifting movement of Kouquan fault adjacent to the Tongxin mine results in the stress concentration in the rock of the Carboniferous coal bed and accumulation of a large amount of elastic energy and forms structural background of Tongxin mine. Due to various seismic activities in the mine area, the strain energy is known to reach much higher levels, up to 0.5×10⁸ J^1/2. Since the stratigraphic structure is sensitive to the mining operation, the strain energy could cause strong strata behaviors. A special geological structure model of the Tongxin mine is established based on the geodynamic division method. The distribution of regional structure stress field is determined by the rock mass stress analysis system. Based on this model, Tongxin mine is divided into five areas with high stress, eight areas with low stress and eight areas with gradient stress. The strong strata behaviors mostly occur in high stress areas. These results could provide guidance to predict the strength of regional or mine pressure and control strata behavior in different areas.     

区域矿产资源技术经济评价方法的研究

矿产资源是国民经济发展的重要物质基础。因此,一个区域经济发展战略或规划的制定,都把矿产资源技术经济评价成果作为重要的依据。但国内、外在这方面的研究和实践多只限于某一单矿种或某一矿组;多矿种综合性的定量评价实例尚未见到。本文以区域内所有矿种的矿床、矿点、矿化点构成的整体,在地质评价的基础上,于技术可行的条件下对探明的矿产可利用储量在未来一定时期内进行工业开发的经济评价的理论和方法进行了研究。先以区内大量地质勘查和开发利用的实际资料,对矿产资源优劣类型进行定量评判,论述矿产资源经济价值,以其为基础对矿产资源经济区进行划分。再按区内优势矿产资源进行开发系统评价,并分别提出开发对策意见。最后论述矿产资源技术经济评价的主要结论,总结矿产资源开发中的主要问题,提出切实可行的措施和建议。