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中国北方盆地大规模铀成矿作用:地层篇

地质学报 2024年第7期98卷 1953-1976页

作者：程银行金若时 Michel CUneY v.A.PeTROv 苗培森中国地质调查局天津地质调查中心(华北地质科技创新中心) 天津300170 中国地质调查局铀矿地质重点实验室天津300170 法国洛林大学资源学院法国NancyF54500 俄罗斯科学院矿床地质、岩石学、矿物学和地球化学研究所俄罗斯Moscow119017

“红黑”耦合沉积建造是中国北方中—新生代盆地(简称北方盆地)砂岩型铀矿的重要控矿要素之一,在勘查实践中得到了广泛证实和应用,指导发现找矿靶区和矿产地300余处,在成矿理论方面取得重要进展。本文系统总结了北方产铀盆地的60万余米... 详细信息

“红黑”耦合沉积建造是中国北方中—新生代盆地(简称北方盆地)砂岩型铀矿的重要控矿要素之一,在勘查实践中得到了广泛证实和应用,指导发现找矿靶区和矿产地300余处,在成矿理论方面取得重要进展。本文系统总结了北方产铀盆地的60万余米铀矿岩芯钻探成果,通过典型矿床赋矿层沉积学、地球化学等对比研究,系统分析了北方盆地侏罗系、白垩系、新近系等赋矿层形成的沉积环境、物质组成等,进一步明确了制约成矿流体运移、铀矿物沉淀的赋矿层条件。结果显示:①北方盆地自侏罗纪以来,发育了Ⅰ中侏罗世—晚侏罗世早期(Bathonian-Oxfordian)、Ⅱ早白垩世早期(valanginian)、Ⅲ早白垩世晚期(Aptian)、Ⅳ晚白垩世早期(Cenomanian)、Ⅴ晚白垩世晚期—早古近纪(Campanian-Thanetian)、Ⅵ早新近纪(Aquitanian-Burdigalian)和Ⅶ晚新近纪(ZancleanPiacenzian)7期红层,与下伏富还原性组分的黑色层构成了典型的对偶沉积建造,为北方盆地大规模成矿奠定了赋矿层基础。②地球化学指标显示:红层中fe^(2+)/fe^(3+)比值介于0.29~1.47(n=78),黑层fe^(2+)/fe^(3+)比值介于0.57~53.96(n=223),赋矿层fe^(2+)/fe^(3+)比值介于1.00~26.45(n=52)。赋矿层、黑层fe^(2+)/fe^(3+)比值一般大于1,以发育黄铁矿、炭屑、油斑为特征,为相对较还原的环境。红层fe^(2+)/fe^(3+)比值一般小于1,以发育钙质结核为特征,为相对较强氧化的环境。③总有机碳含量显示红层为0~0.16%(n=107),含矿层为0.01%~2.65%(n=137),黑层为0.01%~2.66%(n=339),含矿层总有机碳含量略低于黑层,与铀矿的富集沉淀有密切关系。④砂岩型铀矿体呈“板状”或“楔状”产出于黑层顶部的灰色、灰绿色砂岩和细砂岩,甚至泥岩,红层为含氧含铀流体的运移通道,黑层为含氧含铀流体的富集沉淀的化学屏障。因此,北方盆地红层和黑层对偶沉积、旋回充填是大规模铀成矿必要的地层条件,这些认识打破常规思维,“红黑”旋回叠加导致了北方盆地多层成矿的现象,矿体一般呈板状就位于红层和黑层的过渡带,这对深入理解砂岩型铀矿成矿环境、成矿规律及成矿机理等工作和勘查工作部署具有重要实践意义。

关键词：北方中—新生代盆地砂岩型铀矿大规模成矿沉积环境赋矿层

How to fill the biodiversity data gap:Is it better to invest in fieldwork or curation?

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Plant diversity 2024年第1期46卷 39-48页

作者： Carlos A.vargas Marius Bottin Tiina Sarkinen James e.Richardson Marcela Celis Boris villanueva Adriana Sanchez Programa de Biología Facultad de Ciencias NaturalesUniversidad del RosarioBogotaD.C.Colombia Subdireccion Científica Jardín Botanico de Bogota“Jose Celestino Mutis”BogotaD.C.Colombia Independent Researcher BogotaD.C.Colombia Tropical diversity Section Royal Botanic Garden EdinburghUK School of Biological Earth and Environmental SciencesUniversity College CorkCorkIreland departamento de Química y Biología Universidad del NorteKm.5 Vía Puerto ColombiaArea Metropolitana de Barranquilla 081007Colombia

data gaps and biases are two important issues that affect the quality of biodiversity information and downstream *** how best to fill existing gaps and account for biases is necessary to improve our current information most *** current main approaches for obtaining and improving data include(1)curation of biological collections,and(2)***,the comparative effectiveness of these approaches in improving biodiversity data remains little *** used the flora de Bogota project to study the magnitude of change in species richness,spatial coverage,and sample coverage of plant records based on curation versus *** process of curation resulted in a decrease in species richness(synonym and error removal),but it significantly increased the number of records per *** contributed to a slight increase in species richness,via accumulation of new ***,curation led to increases in spatial coverage,species observed by locality,the number of plant records by species,and localities by species compared to ***,curationwas more efficient in producing new information compared to fieldwork,mainly because of the large number of records available in *** recommend intensive curatorial work as the first step in increasing biodiversity data quality and quantity,to identify bias and gaps at the regional scale that can then be targeted with *** stepwise strategy would enable fieldwork to be planned more costeffectively given the limited resources for biodiversity exploration and characterization.

关键词： Colombia flora de Bogota Sample coverage Species richness Tropical Andes

On Charged Black Hole in Multidimensional Theory with Ricci-flat Internal Spaces

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Chinese Physics Letters 1991年第9期8卷 439-441页

作者： S.B.fadeev v.d.Ivashchuk v.n.Melnikov USSR State Committee for Standards 9 Leninski Prospect117049MoscowUSSR

A generalization of the Reissner-nordstrom solution for the case of n internal Ricci-flat spaces is obtained.

关键词： Ricci generalization Reissner

direct modulation characteristics of microdisk lasers with InGaAs/GaAs quantum well-dots

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Photonics Research 2019年第6期7卷 664-668页

作者： n.v.KRYZHAnOvSKAYA e.I.MOISeev f.I.ZUBOv A.M.MOZHAROv M.v.MAXIMOv n.A.KALYUZHnYY S.A.MInTAIROv M.M.KULAGInA S.A.BLOKHIn K.e.KUdRYAvTSev A.n.YABLOnSKIY S.v.MOROZOv YU.BeRdnIKOv S.ROUvIMOv A.e.ZHUKOv St.Petersburg Academic University Khlopina 8/3 S t Petersburg 194021 Russia Ioffe Institute of RAS Politehnicheskaya 26 St. Petersburg 194021 Russia Institute for Physics of Microstuctures of RAS Nizhny Novgorod 603950 Russia ITMO University Kronverkskiy prospekt 49 St. Petersburg 197101 Russia University of notre dame Notre Dame Indiana 46556 USA

GaAs-based microdisk lasers with an active region representing a dense array of indium-rich islands(InGaAs quantum well-dots) were studied using direct small-signal modulation. We demonstrate that using dense arrays of InGaAs quantum well-dots enables uncooled high-frequency applications with a GHz-range bandwidth for microdisk lasers. A maximum 3 dB modulation frequency of 5.9 GHz was found in the microdisk with a radius of 13.5 μm operating without a heatsink for cooling. A modulation current efficiency factor of 1.5 GHz∕mA1∕2 was estimated.

关键词： direct modulation characteristics quantum well-dots

Microtubule as a Transmission Line for Ionic Currents

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Chinese Physics Letters 2009年第7期26卷 97-99页

作者： IliC d.I. SatariC M.v RaleviC n. faculty of Technical Sciences University of Novi SadTrg D.Obradovica 621000 Novi SadSerbia

We establish a new model for ionic waves along microtubules based on polyelectrolyte features of cylindrical biopolymers. The nonlinear transmission line described by a nonlinear differential equation is obtained with stable kink solution pertinent to the shape of the front of accompanying potential. The localized ionic wave could be used to explain the behavior of microtubules as biomolecular transistors capable of amplifying electrical information in neurons.

关键词： MICROTUBULeS eLeCTRIC lines IOn acoustic waves POLYeLeCTROLYTeS BIOPOLYMeRS nOnLIneAR differential equations

Glass and cellulose acetate fibers-supported boehmite nanosheets for bacteria adsorption

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Progress in natural Science:Materials International 2017年第2期27卷 268-274页

作者： n.v.Svarovskaya O.v.Bakina e.A.Glazkova A.n.fomenko M.I.Lerner Institute of Strength Physics and Materials Sciences of the Siberian Branch of the Russian Academy of Sciences national Research Tomsk Polytechnic University

In this work, in situ method of producing hybrid fibrous adsorbents in which boehmite nanosheets with high sorption properties formed on the surface of hydrophilic microfibres, such as cellulose acetate and glass fibre,was described. The boehmite nanosheets were fabricated by the reaction of composite Al n/Al nanoparticles with water at 60 °C. The synthesized samples were characterized by X-ray diffractometer, scanning, transmission electron microscopy, fourier transform infrared spectrometer(fT-IR), zeta-potential and specific surface area analyzers. The introduction of microfibres into a diluted aqueous suspension of nanopowders causes heteroadagulation of the nanoparticles and accelerates their further transformation. This effect is most substantial with the glass microfibre, which is thought to have a higher concentration of surface groups capable of generating hydrogen bonds that act as heteroadagulation and nucleation centres. The experimental results showed that the morphology of the resultant hybrid fibrous adsorbents differed accordingly: the nanosheets were attached on-edge to the glass microfibre surface, while on the surface of the cellulose acetate microfibre,they were secured in the form of spherical "nanoflowers" of agglomerated nanosheets. The effect of the morphology of hybrid fibrous adsorbents on adsorption bacteria escherichia coli was also investigated.

关键词： nanosheets Microfibres Hybrid materials Bacterial adsorption

Tribological behavior of ultra-high molecular weight polyethylene in a hip joint simulator

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frontiers of Materials Science 2012年第4期6卷 358-365页

作者： n.MOHAMAd RAffI d.KAnAGARAJAn v.SRInIvASAn department of Manufacturing engineering Annamalai UniversityAnnamalai Nagar-608002TamilnaduIndia

In this paper effects of various injection molding parameters on tribological properties of ultra-high molecular weight polyethylene （UHMWPe） were investigated. The tribological properties like coefficient of friction and wear rate were obtained from the experimental results of hip simulator which was designed and fabricated in the laboratory. Bovine serum was used as a lubricant in this study. In addition, the hardness of the specimen was also investigated as well. The injection molding parameters that varied for this study are melt temperature, injection velocity and compaction time. The results show that contact loads and melt temperature were mostly influenced the tribological behavior of UHMWPe. A wear mechanism map was developed to study the dominant wear mechanism that influences the wear behavior of UHMWPe. SeM was employed to study the worn out morphologies of UHMWPe. The dominant wear mechanisms that are dominated through our study are ironing, scratching, ploughing, plastic deformation, and fatigue wear.

关键词： UHMWPe injection molding parameter wear tribological property hipsimulator

Contrasting arthropod communities associated with dwarf mistletoes Arceuthobium globosum and A. vaginatum and their host Pinus hartwegii

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Journal of forestry Research 2018年第5期29卷 1351-1364页

作者： León f.Chávez-Salcedo Mónica e.Queijeiro-Bolanos víctor López-Gómez Zenón Cano-Santana Blanca e.Mejía-Recamier Aurea Mojica-Guzmán Laboratorio de Interacciones y Procesos ecologicos Departamento de Ecología y Recursos Naturales Facultad de Ciencias Universidad Nacional Autonoma de Moico Av.Universidad 3000 04510 Mexico City Mexico Laboratorio de ecología y Sistemática de Microartr dpodos Departamento de Ecología y Recursos Naturales Facultad de Ciencias Universidad Nacional Autónoma de M4xico Av.Universidad 3000 04510 Mexico City Mexico Instituto de Biologia Universidad Nacional Autdnoma de Mexico Av. Universidad 3000 04510 Mexico City Mexico departamento de ecologia Facultad de Ciencias Naturales Universidad Autdnoma de Quer6taro Av.de las Ciencias s/n 76230 Queretaro Queretaro Mexico

Arthropod communities and epiphytic plants associated with tree canopies have been widely studied and have revealed a great diversity of organisms; however,the community hosted by parasitic plants,such as dwarf mistletoes,remains poorly *** the coniferous forests of north America,dwarf mistletoe infection（Arceuthobium spp.） significantly damages the health of the forest,causing large financial losses for the forest industry,but it also positively affects diversity,especially of mammals and *** study examined the attributes of the arthropod communities associated with two species of dwarf mistletoe [Arceuthobium globosum Hawksw.＆ Wiens and ***（Humb.＆ *** Willd.） ***] and their host Pinus hartwegii *** 2010,in five sites located in Zoquiapan（Central Mexico）,we collected plant tissue from the three species *** were separated from the plant tissue and identified to the finest level *** collected 32,059 individuals,for which51 morphospecies were identified,belonging to 15 taxonomic orders; the most abundant orders for the three plants were Prostigmata,Thysanoptera and *** community associated with *** had the highest value of diversity（H＇= 1.47; ***,H＇= 0.64; ***,H＇= 0.68） and species richness（S = 40; ***,S = 30; ***,S = 35）; while abundance was significantly higher for the mistletoes（***,n = 407 individuals/sample; ***,n = 536 individuals/sample; ***,n = 134 individuals/sample）.Species richness,abundance and diversity were significantly different for the three studied plants,as well for sampling month and the interaction of these two factors（except for diversity）.The results suggest that the canopy of *** is an important element in the ecosystem,providing a mosaic of resources and conditions to the associated *** also propose that mistletoes are key species within the forest canopy,as they greatly influence the establishment of d

关键词： Arceuthobium spp Pinus hartwegii Arthropod community Thrips Mites Hemiparasitic plants

Synthesis,structure and magnetic properties of Sm_(1.2)Ho_(0.8)fe_(17)Hx(X=0;4.4)

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Journal of Rare earths 2021年第9期39卷 1089-1094页

作者： S.v.veselova M.A.Paukov I.S.Tereshina v.n.verbetsky K.v.Zakharov d.I.Gorbunov A.n.vasiPev faculty of Physics M.V.Lomonosov Moscow State UniversityMoscow 119991Russia nuclear fuel Cycle department.Centrum vyzkumu Rez Hlavni 130Husinec-Rez 25068.Czech Republic Immanuel Kant Baltic federal University Kaliningrad 236004Russia faculty of Mathematics and Physics Charles UniversityPrague 12116Czech Republic Hochfeld-Magnetlabor dresden(HLd-eMfL) Helmholtz-Zentrum Dresden-RossendorfDresden 07328Germany f National Research South Ural State UniversityChelyabinsk 454080Russia

Intermetallic compounds based on rare-earth metals and iron are by far the most promising materials for permanent mag *** this work,the multicomponent compound Sm_(1.2)Ho_(0.8)fe_(17)was prepared by in duction *** hydride Sm_(1.2)Ho_(0.8)fe_(17)H_(4.4)with a high hydrogen content was obtained by direct hydrogenation of the intermetallic *** rhombohedral Th2Zn17-type of structure(space group R3^(-)m)is inhere nt to parent compound and hydride as *** effect of hydrogenation on the magneric properties of Sm_(1.2)Ho_(0.8)fe_(17)was *** temperature of the hydride Sm_(1.2)Ho_(0.8)-fe_(17)H_(4.4)is higher than that of parent compound by△Tc=138 *** hydrogen embedded in Sm_(1.2)Ho_(0.8)fe_(17)crystal lattice in creases the saturation magnetization(σs)at T=300 K,but does not significantly affect%at T=4.2 *** ferrimagnetic structure is retained in magnetic fields up to 58 T in the parent compound,while,in the hydride,there is a spin-reorie ntatio n phase transitio n observed at 55 *** is found that the parameter of the in tersublattice exchange interaction decreases significantly in the hydride Sm_(1.2)Ho_(0.8)fe_(17)Hg_(4.4)(and in the nitride Sm_(1.2)Ho_(0.8)fe_(17)n_(2.4))which is associated with boosting of the unit-cell volume and distances between magnetic ions.

关键词： Intermetallic compound Hydride Crystal structure Magnetization Magnetic phase transition exchange interaction