四川盆地中二叠统栖霞组层序——岩相古地理

随着对四川盆地碳酸盐岩储集层的重视和大力勘探,中二叠统栖霞组发育的滩相储集层成为盆地内寻找新气源的有利层位之一。文中根据岩心观察、野外剖面实测和室内镜下岩石薄片鉴定分析,并结合各种沉积相标志研究,确定研究区栖霞组主要发育浅水型碳酸盐岩台地沉积,其可进一步划分为碳酸盐岩台地相及若干亚相和微相。以Vail的层序地层学理论为指导,通过以岩性—岩相转换界面为主的层序界面识别,确定栖霞组发育2个Ⅱ型三级层序,每个层序划分出TST和HST两个沉积体系域。在沉积相和层序地层学分析的基础上,以层序格架内体系域为编图单元,用"单因素分析多因素综合作图法"编制了各体系域的岩相古地理图并对其演化特征进行了分析。结合各相带储集物性特征,认为台缘滩和台内滩为最有利储集相带,尤以SQ2-HST滩相颗粒灰岩经过白云岩化改造后更具储集意义。     

内蒙古赤峰市鸭鸡山钼铜矿成矿流体特征及矿床成因

鸭鸡山钼铜矿床所处大地构造位置为蒙古—鄂霍次克造山带的温都尔庙—翁牛特旗褶皱带,该带是我国重要的有色金属成矿带之一。鸭鸡山钼铜矿床分布受控于区域EW向深断裂,矿体产于EW向主断裂F1上盘的二长花岗岩体中,严格受东西向F1断裂和北东向断裂控制。该矿床矿石自然类型为石英脉型和蚀变岩型,矿石中硫化物主要有黄铁矿、辉钼矿和黄铜矿。石英流体包裹体有气液两相、含子矿物三相和纯气相3种类型。流体盐度(w(NaCl))为2.06%～44.00%,集中在40%～44%和4%～8%;流体密度为0.85～1.25 g/cm3,集中在1.20～1.24 g/cm3和0.88～0.92 g/cm3;成矿温度为167～380℃,集中在320～360℃和200～220℃;流体盐度、密度、成矿温度在直方图上均表现为双峰特征。研究表明:成矿早阶段流体为高盐度、高密度和高温的岩浆流体,气相包裹体与含子晶三相包裹体共存,表明该阶段发生过强烈的沸腾或不混溶;成矿晚阶段为低盐度、低密度和中温的混合流体。通过等容线图解法估算成矿压力为274.7～368.5 MPa,用静岩压力梯度估算成矿深度为8.32～11.2 km。矿床成因类型为中成、中高温热液脉型...     

Grass cover density and metal speciation in profiles of a tailings-pile from a mining zones in Zacatecas,North-Central Mexico

The 7-year-old mine tailings pile P2 from Concepción del Oro has been revegetated spontaneously by xerophyte grasses, covering about the 30% of its surface. To elucidate the effect of the grass cover in the geochemical behavior of the sulfide minerals (SM) and metals, the strata of four selected profiles (P2-I, P2-II, P2-III and P2-IV, with high, middle, low, and null grass cover, respectively) were analyzed mineralogically and chemically, using scanner electron microscopy, X-ray diffractometer and performing a six-step sequential extraction method. An older (50-year-old) and uncovered (without grass cover) profile of the tailings pile P3 was also analyzed. In all the profiles from P2, the SM oxidation is not yet an extended process; however, the samples from the uncovered profile P2-IV showed evidences of SM (pyrite and chalcocite) oxidation, as well as the presence of gypsum and Fe oxides, as the major secondary phases resulted from the SM oxidation. Additionally, the carbonate content and pH values in P2-IV were lower than in the covered profiles from P2. The oldest and uncovered P3-I profile showed an extensive oxidation of sulfurs which resulted in the depletion of carbonates and a pH 2. Another distinctive characteristics of the covered profiles was that Pb, Cu, and Zn were mainly associated with the reducible fractions (carbonates and/or amorphous oxides); meanwhile, in the uncovered (P2-IV and P3-I) such metals were mainly associated with the oxidizable fraction (crystalline oxides). The results suggest that the mineralogical transformations control metal stability in plant-covered impoundments (phytostabilization): the occurrence of a thick grass cover, with an efficient water usage and retention, seems to shun both the acidic dissolution of carbonates and the reductive dissociation of the formerly present oxyhydroxides, which is desired for remediation tasks. This is the first report about the effects of grass cover for a carbonaceous and unsaturated mine tailings from a semiarid region, that can help in a better understanding of the scope of phytoremediation in such conditions.     

Construction of deep tunnel shafts in Mexico city soft clays by the flotation method

The drainage system of Mexico City, one of the largest metropolitan areas in the world, is formed by a large network of interceptors and collectors leading to the main outlet: a 49.3-km-long tunnel with a 6.5 m diameter. To build the access shafts to the tunnels of the system and the deep sumps of the pumping stations in the very soft clays of the lacustrine area of Mexico valley, a technique known as “flotation method” has been commonly used since 1969. The paper presents the main construction steps followed and some aspects of the analysis and design of shafts constructed by this technique. The experience gained obtained after more than 30 shafts have been constructed by this method, and the actual trends in its application are also discussed.     

Spatial patterns and environmental associations of deep scattering layers in the northwestern subtropical Pacific Ocean

The mesopelagic communities are important for food web and carbon pump in ocean, but the large-scale studies of them are still limited until now because of the difficulties on sampling and analyzing of mesopelagic organisms. Mesopelagic organisms, especially micronekton, can form acoustic deep scattering layers (DSLs) and DSLs are widely observed. To explore the spatial patterns of DSLs and their possible influencing factors, the DSLs during daytime (10:00–14:00) were investigated in the subtropical northwestern Pacific Ocean (13°–23.5°N, 153°–163°E) using a shipboard acoustic Doppler current profiler at 38 kHz. The study area was divided into three parts using k-means cluster analysis: the northern part (NP, 22°–24°N), the central part (CP, 17°–22°N), and the southern part (SP, 12°–17°N). The characteristics of DSLs varied widely with latitudinal gradient. Deepest core DSLs (523.5 m±17.4 m), largest nautical area scattering coefficient (NASC) (130.8 m2/n mile2±41.0 m2/n mile2), and most concentrated DSLs (mesopelagic organisms gathering level, 6.7%±0.7%) were observed in NP. The proportion of migration was also stronger in NP (39.7%) than those in other parts (18.6% in CP and 21.5% in SP) for mesopelagic organisms. The latitudinal variation of DSLs was probably caused by changes in oxygen concentration and light intensity of mesopelagic zones. A positive relationship between NASC and primary productivity was identified. A four-months lag was seemed to exist. This study provides the first basin-scale baselines information of mesopelagic communities in the northwest Pacific with acoustic approach. Further researches are suggested to gain understandings of seasonal and annual variations of DSLs in the region.     

基于数据挖掘探讨中药治疗肝豆状核变性的用药规律

目的：基于数据挖掘探讨中药治疗肝豆状核变性的用药规律。方法：计算机检索1990年1月至2020年1月中国知网（CNKI）、万方数据（WANFANG DATA）、维普中文科技期刊数据库（VIP）中中药治疗肝豆状核变性的相关文献,利用Microsoft Excel 2010 进行频次分析,通过 SPSS Modeler 18.0、SPSS Statistics 23.0 对处方药物进行关联规则、复杂网络、系统聚类分析。结果：最终纳入文献161篇,筛选出处方151首,中药70味。中药频次排前5位的依次是泽泻、姜黄、大黄、黄连、丹参;功效排前5位的依次是利水渗湿、活血化瘀、清热、补虚、泻下药。二项关联多为利水渗湿、活血化瘀、清热、泻下药的组合,三项关联多为活血化瘀、清热、利水渗湿药的组合。聚类分析得到新方聚类的中药组合3类。结论：中医药治疗肝豆状核变性以清热化湿、活血化瘀为主,常用利水渗湿、活血化瘀、清热药,可配伍补虚及泻下药等。     

生血通便颗粒治疗血虚肠燥型脓毒症胃肠功能损伤的临床研究

目的：观察生血通便颗粒治疗血虚肠燥型脓毒症胃肠功能损伤的临床疗效。方法：将60 例血虚肠燥型脓毒症胃肠功能损伤患者随机分为治疗组和对照组,每组各30 例。2组均予西医常规基础治疗,对照组在此基础上加用马来酸曲美布汀治疗,治疗组在对照组基础上再加生血通便颗粒治疗,疗程均为14 d。观察2组综合疗效和治疗前后炎症指标［白细胞计数（WBC）、C-反应蛋白（CRP）、降钙素原（PCT）］水平、序贯性器官衰竭（SOFA）积分、胃肠功能损伤积分、腹内压、血清二胺氧化酶(DAO)水平及中医证候积分。结果：总有效率治疗组为86.67%（26/30）,明显高于对照组的60.00%（18/30）,差异有统计学意义（P<0.05）。治疗后2组炎症指标(WBC、CRP、PCT)水平、SOFA积分、胃肠功能损伤积分、腹内压、DAO水平及中医证候积分较治疗前均有所下降,且治疗组下降幅度均大于对照组,差异有统计学意义（P<0.05或P<0.01)。结论：生血通便颗粒治疗血虚肠燥型脓毒症胃肠功能损伤,能减轻患者炎症反应、降低SOFA和胃肠功能损伤积分、降低腹内压及血清DAO水平、改善中医证候,值得临床推广运用。     

Uncovering spatiotemporal micromobility patterns through the lens of space–time cubes and GIS tools

Journal of Geographical Systems - In the past ten years, cities have experienced a burst of micromobility services as they offer a flexible transport option that allows users to cover short trips...     

Soil and vegetation seasonal changes in the grazing Andean Mountain grasslands

Andean grasslands ecosystems are fragile environments with rigorous climatologic conditions and low and variable food for the grazing. The Apolobamba area is located in the Bolivian Andean Mountains. Its high grasslands provide a natural habitat for wild and domestic camelids such as vicuna（Vicugna vicugna） and alpaca（Lama pacos）. The botanical diversity plays an essential role in maintaining vital ecosystem functions. The objectives of this research were to determine the seasonal changes in soil properties, to study the vegetation changes during the wet and dry seasons and the influence of soil properties and camelid densities on the vegetation in the Apolobamba grasslands. Four zones with different vicuna populations were selected to be studied. The following soil parameters were determined： total organic carbon, total nitrogen, available phosphorous, cation exchange capacity, exchangeable cations, pH and texture. The vegetation season changes were studied through botanical identification, above-ground biomass, plant cover and species richness. Results showed that some soil properties such as C/N ratio, CEC, silt and clay percentages kept stable against the seasonal changes. Generally, soil nutrients were relatively higher during the dry season in the surface and subsurface. The results did not point out the predominant vegetation growth during the wet season. The seasonal vegetation growth depended on each species. Thegood soil fertility corresponded to the highest plant cover. Soil fertility presented no influence on the above-ground biomass of the collected species. The negative influence of camelid grazing on soil properties could not be assessed. However, overgrazing could affect some plant species. Therefore, protection is needed in order to preserve the biodiversity in the Andean mountain grasslands.