二连浩特市水资源与经济社会和谐度评价

以二连浩特市人水关系为研究对象,从取水总量和谐度、用水效率和谐度、水生态环境保护和谐度三个方面构建了二连浩特市水资源与经济社会和谐度评价体系。从评价结果可以看出,二连浩特市开展节水型社会建设以来,水资源与经济社会和谐度发生了较显著的改善。评价体系较好地反映了二连浩特市水资源与经济社会和谐度,对北方干旱缺水地区节水型社会建设具有借鉴意义。     

汶川地震断裂带多次地震活动新证据

虹口乡八角庙出露完整的映秀—北川断裂带剖面断层岩,高分辨率磁化率测试揭示出多个具有高磁化率特征的断层岩带。系统的岩石磁学分析证明一层褐色断层岩相对围岩具有最大的磁化率值,存在新生成的磁铁矿和拥有相似的天然剩磁(NRM)和非磁滞剩磁(ARM)强度衰减过程。高磁化率特征是含铁顺磁性矿物受到断层滑移过程产生摩擦生热作用生成磁铁矿所致。同时断层岩还获得了热剩磁,记录了地震活动磁学信息。结合汶川地震科学钻探项目1号孔(WFSD-1)磁化率和岩石磁学研究结果,说明映秀—北川断裂带包含多层具有高磁化率特征的断层岩,暗示了多次强震的发生。具有高磁化率特征的断层岩可以作为判定地震活动的标志之一。     

若尔盖铀矿田漏失层空心微珠泥浆试验研究

若尔盖铀矿是我国四大基本类型铀矿田之一,矿层为灰岩、硅灰岩,圈团状纵向裂隙发育,长孔段失返性全漏失,泥浆性能难以维护,孔壁失稳,堵漏花费大量的人力、物力。为提高钻进效率,针对地层漏失机理,通过降低漏失压力实现平衡钻进,分别开展了空气泡沫、微泡沫泥浆以及空心微珠等低密度泥浆体系的研究和试验。实践表明,空心微珠低密度泥浆体系是一种适合若尔盖铀矿田漏失层钻进的泥浆体系。     

北方某经济开发区地下水污染调查评价

本文应用污染指数法,对北方某经济开发区及周边地下水水质进行了污染评价,结果表明研究区地下水水质以轻污染和中污染为主,局部地区出现较重污染,主要指标为硝酸盐氮、三氯甲烷和三氯乙烯。通过对工业废水、再生水、河水水质的检测,发现研究区地表水水质与污水处理厂再生水排放密切相关,地下水污染很可能与开发区企业排污有关。由于开发区所处位置的环境敏感性和脆弱性,建议今后在开发区及附近继续开展相关研究,进一步查明地下水的硝酸盐氮及有机污染物来源、污染途径,建立完善的监测体系,以便及时切断污染源,保障城市及当地供水安全。     

Development of a new method for efficiently calculating of evaporation from the phreatic aquifer in variably saturated flow modeling

In this paper, we proposed a new method that has been developed based on the surface soil moisture content (SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this method, the empirical formula to calculate evaporation was modified and the value of the formula varies from zero to one as a closed interval. In addition, the simulation code for calculating the groundwater evaporation based on the SSMC method was incorporated into the EOS9 module of Tough2, a variably saturated flow modeling code. Finally, two numerical tests and a case simulation were conducted to verify the feasibility and accuracy of the SSMC method. Simulation results indicate that the SSMC method is capable of appropriately simulating the characteristics of water flow in vadose zone and the amount of evaporation with the variable water table. And such results are in coincidence with the value calculated by the logistic function method, and fit well with the measured data globally rather than locally.     

Fracture characteristics in Cretaceous platform and overlying ramp carbonates: An outcrop study from Maiella Mountain (central Italy)

This article focuses on field- and laboratory-based characterization of vertically persistent fractures that are part of oblique-slip normal fault zones and crosscut the Cretaceous platform and overlaying ramp carbonates outcropping at Maiella Mountain (central Italy). The achieved results show that: (i) fault damage zones are wider and more densely fractured in the platform carbonates than in the ramp ones; (ii) joints and sheared joints composing the fault damage zones are taller, better connected and less spaced within the former rocks than in the ramp carbonates. The aforementioned structural differences are interpreted to be a consequence of the different mechanical properties of the platform and ramp carbonates during failure. At Maiella Mountain, platform carbonates are, indeed, made up of overall stiffer (higher Uniaxial Compressive Strength values) and less porous rocks, due to more abundant intergranular void-filling cement and presence of matrix.In terms of hydrocarbon flow and recovery, geometric and dimensional attributes of fractures suggest that the well-connected network of closely spaced fractures cutting across the platform carbonates may form efficient pathways for both vertical and horizontal hydrocarbon flow. In contrast, the relatively poorly connected and low-density fracture network affecting the ramp carbonates is likely less efficient in providing fairways for flowing hydrocarbons.     

基于高效生态农业布局导向性的资源环境承载力评价—以黄河三角洲高效生态经济区为例

该文在对研究区资源环境本底基本了解的基础上,建立了包括耕地资源、水资源、社会经济资源、土壤环境、极端气候发生率和地质环境6个二级指标的资源环境承载力评价指标体系,采用定性和定量相结合的方法,利用层次分析法确定相关指标权重,分别对6个要素进行承载力评价。在各单元要素评价基础上,结合黄河三角洲高效生态经济区农业发展要求,划分出了沿海湿地生态系统保护带、北部盐渍化土质特色种植区、南部优质粮食生产区和果蔬集中种植区4个生态农业布局适宜区,并提出发展建议。     

西藏改则县多龙矿集区发现岩墙岭蛇绿岩残片

西藏班公湖-怒江缝合带北缘多龙矿集区是青藏高原新近发现的具有超大型远景的、典型的富金斑岩型铜矿集区,其成岩成矿地质背景是解决班公湖-怒江洋构造演化的关键问题之一。近年来的区域地质调查研究发现,多龙矿集区南侧出露岩墙岭蛇绿岩残片,应该是班公湖-怒江蛇绿岩带的重要组成部分。岩墙岭蛇绿岩主要由席状岩墙群、枕状玄武岩和硅质岩组成,整体呈棱形或透镜体状断续分布于侏罗系复理石沉积内,构成典型的网结状构造。糜棱岩普遍发育在岩墙岭蛇绿岩和围岩的接触部位。综合前人研究成果,初步认为多龙矿集区早白垩世成岩成矿作用应该形成于增生楔之上伸展拉张的构造环境。岩墙岭蛇绿岩的发现和确定进一步约束了多龙矿集区成岩成矿地质背景,同时为班公湖-怒江缝合带的延伸及其构造演化的研究提供了新的线索。     

Petrological and Os Isotopic Characteristics of Zedong Peridotites in the Eastern Yarlung–Zangbo Suture in Tibet

The Zedong ophiolites in the eastern Yarlung–Zangbo suture zone of Tibet represent a mantle slice of more than 45 km~2. This massif consists mainly of mantle peridotites, with lesser gabbros, diabases and volcanic rocks. The mantle peridotites are mostly harzburgite, lherzolite; a few dike-like bodies of dunite are also present. Mineral structures show that the peridotites experienced plastic deformation and partial melting. Olivine(Fo89.7–91.2), orthopyroxene(En_(88–92)), clinopyroxene(En_(45–49) Wo_(47–51) Fs_(2–4)) and spinel [Mg~#=100×Mg/(Mg+Fe)]=49.1–70.7; Cr~#=(100×Cr/(Cr+Al)=18.8–76.5] are the major minerals. The degree of partial melting of mantle peridotites is 10%–40%, indicating that the Zedong mantle peridotites may experience a multi–stage process. The peridotites are characterized by depleted major element compositions and low REE content(0.08–0.62 ppm). Their "spoon–shaped" primitive–mantle normalized REE patterns with(La/Sm)_N being 0.50–6.00 indicate that the Zedong ultramafic rocks belong to depleted residual mantle rocks. The PGE content of Zedong peridotites(18.19–50.74 ppb) is similar with primary mantle with Pd/Ir being 0.54–0.60 and Pt/Pd being 1.09–1.66. The Zedong peridotites have variable, unradiogenic Os isotopic compositions with ~(187)Os/~(188)Os=0.1228 to 0.1282. A corollary to this interpretation is that the convecting upper mantle is heterogeneous in Os isotopes. All data of the Zedong peridotites suggest that they formed originally at a mid-ocean ridge(MOR) and were later modified in supra–subduction zone(SSZ) environment.     

基于稳态碎岩方式的PDC钻头设计分析研究

自从20世纪80年代PDC复合片研发成功以来,PDC钻头由于其钻进性能强和耐磨性能好,在世界许多国家的石油钻井和地质勘探中得到了广泛应用,取得了很好的效果。但是,如何进一步提高其在钻探工程中的技术经济指标是一个很迫切的问题。俄罗斯博士Скоромных В. В.教授等对此进行多年研究,提出了稳态破碎岩石方式的思想,即在轴载和扭矩切力形成的合力R与切削面成垂直角度条件下,切入深度h不变时形成的一种碎岩方式。并在此基础上提出了一些设计PDC钻头方面的建议。