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SHrIMP U-Pb dating for a K-bentonite bed in the Tieling formation,North China

Chinese Science Bulletin 2010年第29期55卷 3312-3323页

作者： SU WenBo LI HuaiKun HUff W D ettensohn f r ZHANG ShiHong ZHOU HongYing WAN YuSheng School of Earth Sciences and resources China University ofGeosciences (Beijing) Beijing 100083 China Tianjin Institute of Geology and Mineral resources China Geological Survey Tianjin 300170 China Department of Geology University of Cincinnati Cincinnati OH 45221-0013 USA Department of Earth and Environment Sciences University of Kentucky Lexington KY 40506-0053 USA Beijing SHrIMP Center Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China

A SHrIMP U-Pb zircon age of 1437±21 Ma was obtained for a recently discovered K-bentonite bed in the Tieling formation,situated northeast of Beijing at the boundary between Liaoning and Hebei provinces,on the northern margin of the North China Craton(NCC).The SHrIMP U-Pb age places Tieling formation near the end of the Calymmian Period of the early Mesoproterozoic *** addition,a SHrIMP U-Pb zircon date of 1372±18 Ma was acquired for K-bentonite beds in the overlying,dark-shale-dominated Xiamaling formation from the same location northeast of *** date assigns a similar Mid-Mesoproterozoic(Ectasian Period) age for the Xiamaling formation,as have previously determined dates from other sections northwest of *** dates indicate that the Tieling and Xiamaling formations,as well as the related succession in the eastern part of the Yanshan Mountains,represented by the well-known Meso-to Neoproterozoic standard section in Jixian,can be correlated well with sections northwest of Beijing in the western part of the Yanshan *** other words,the boundary between the Calymmian and Ectasian periods in the northern parts of the NCC is marked by the unconformity between the Tieling and Xiamaling formations in the northern *** boundary was previously ascribed to the "Qinyu Orogeny" and thought to be of Grenville *** this regard,the conventional "Qinyu Orogeny" should now be regarded as a short-lived regional uplift during Early Mesoproterozoic time,rather than a result from the Grenvillian assembly of the NCC to the rodinia Supercontinent(～1.0 Ga).

关键词： SHrIMP 铁岭组膨润土 Pb 锆石中国 rodinia超大陆中元古代早期

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铁岭组钾质斑脱岩锆石SHrIMP U-Pb年代学研究及其地质意义

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科学通报 2010年第22期55卷 2197-2206页

作者：苏文博李怀坤 HUff W D ettensohn f r 张世红周红英万渝生中国地质大学(北京)地球科学与资源学院北京100083 中国地质调查局天津地质矿产研究所天津300170 Department of Geology University of CincinnatiCincinnatiOH 45221-0013USA Department of Earth and Environment Sciences University of KentuckyLexingtonKY 40506-0053USA 北京离子探针中心中国地质科学院地质研究所北京100037

最近在冀北-辽西以碳酸盐岩为主的铁岭组内发现了钾质斑脱岩,并获得其锆石SHrIMP U-Pb年龄——(1437±21)Ma,这一进展将铁岭组的时代确定为中元古代早期盖层纪(Calymmian Period)末期.与此同时,还在同一剖面获得了铁岭组的上覆地层——... 详细信息

最近在冀北-辽西以碳酸盐岩为主的铁岭组内发现了钾质斑脱岩,并获得其锆石SHrIMP U-Pb年龄——(1437±21)Ma,这一进展将铁岭组的时代确定为中元古代早期盖层纪(Calymmian Period)末期.与此同时,还在同一剖面获得了铁岭组的上覆地层——下马岭组碳硅质页岩里钾质斑脱岩锆石SHrIMPU-Pb年龄——(1372±18)Ma,这与稍早前在北京西北及其附近地区所获得的定年结果(～1380Ma)是一致的.这在肯定了该地区下马岭组应归入中元古代中期延展纪(Ectasian Period)早期的同时,也表明以蓟县剖面为代表的燕山东部地区铁岭组-下马岭组等相关序列,可与北京西山及燕山西部进行良好对比.换言之,华北北部从高于庄组到铁岭组的巨厚碳酸盐岩序列都应视为中元古界盖层系沉积,而铁岭组与下马岭组之间的不整合面可作为中元古界盖层系与延展系之间的物理性分界标志;早先以该不整合面命名的"芹峪上升"(或"芹峪运动")应属于一个时限短暂的中元古代早期的区域抬升,不能再视为华北克拉通对新元古代罗迪尼亚超大陆聚合事件(～1.0Ga)的响应.

关键词：锆石U-Pb年龄钾质斑脱岩铁岭组华北克拉通盖层纪中元古代

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Inflow and outflow permeability tests in a very soft clay under low stresses

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Journal of rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： J.W.S.Vargas f.A.B.Danziger f.r.Lopes T.Lunne federal University of rio de Janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test Soft clay BAT probe Inflow and outflow tests

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Nonlinear corrections for the nuclear gluon distribution in eA processes

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Chinese Physics C 2024年第3期48卷 52-64页

作者： G.r.Boroun B.rezaei f.Abdi Department of Physics Razi UniversityKermanshah 67149Iran.

An analytical study with respect to the nonlinear corrections for the nuclear gluon distribution function in the next-to-leading order approximation at small x is *** consider the nonlinear corrections to the nuclear gluon distribution functions at low values of x and Q^(2) using the parametrization f_(2)(x,Q^(2))and the nuclear modification factors obtained from the Khanpour-Soleymaninia-Atashbar-Spiesberger-Guzey *** CT18 gluon distribution is used for the baseline proton gluon density at Q^(2)_(0)=*** discuss the behavior of the gluon densities in the next-to-leading order and the next-to-next-to-leading order approximations at the initial scale Q^(2)_(0),as well as the modifications due to the nonlinear *** find that the QCD nonlinear corrections are more significant for the next-to-leading order accuracy than the next-to-next-to-leading order for light and heavy *** results of the nonlinear GLr-MQ evolution equation are similar to those obtained with the rausch-Guzey-Klasen gluon upward and downward evolutions within the *** magnitude of the gluon distribution with the nonlinear corrections increases with a decrease in x and an increase in atomic number A.

关键词： gluon distribution nonlinear corrections light and heavy nuclei low x physics

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SnrK1a1, a new player in the sucrose-Opaque2 network during endosperm filling

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Molecular Plant 2024年第8期17卷 1172-1174页

作者： Kelly Mayrink Balmant Marcio f.r.resende Jr. Horticultural Sciences Department University of FloridaGainesvilleFLUSA

Maize(Zea mays)endosperm is an important food source for humans and *** addition,it is considered an excellent model for research on seed development because of its relatively large size for both embryo and endosperm compared to those of other crop species,such as rice(Oryza sativa)and wheat(Triticum aestivum).After double fertilization,early maize endosperm development includes three stages:(i)a multinucleate coenocyte stage;(i)a cellularization stage,in which the cellular endosperm is formed;and(ii)a stage of differentiation into distinct *** early differentiation,four major cell types with specific functions differentiate within the endosperm:starchy endosperm,aleurone layer,basal endosperm transfer layer(BETL),and embryo surrounding *** subaleurone,conducting zone,basal intermediate zone,and endosperm adjacent to scutellum arise in late differentiation(Sabelli and Larkins 2009).After the main cell types are established,maize endosperm undergoes intensive cell proliferation,which marks the transition to the endosperm-filling *** the endosperm-flling stage,the maternal sucrose products are transported to seeds through the BETL region,where they will act as the main carbon substrate for storage products such as starch and proteins(Chen et al.,2023).In fact,the endosperm of maize seeds accounts for approximately 90%of the total grain weight,serving as an important nutrient reservoir(flint-Garcia et al.,2009).

关键词： endosperm reservoir flint

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Effects of dust controls on respirable coal mine dust composition and particle sizes:case studies on auxiliary scrubbers and canopy air curtain

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International Journal of Coal Science & Technology 2024年第3期11卷 86-101页

作者： f.Animah C.Keles W.r.reed E.Sarver Department of Mining and Minerals Engineering Virginia Polytechnic Institute&State UniversityBlacksburgVAUSA National Institute of Occupational Safety and Health(NIOSH) PittsburghPAUSA

Control of dust in underground coal mines is critical for mitigating both safety and health *** decades,the National Institute of Occupational Safety and Health(NIOSH)has led research to evaluate the effectiveness of various dust control technologies in coal *** studies have included the evaluation of auxiliary scrubbers to reduce respirable dust downstream of active mining and the use of canopy air curtains(CACs)to reduce respirable dust in key operator *** detailed dust characterization was not a focus of such studies,this is a growing area of *** preserved filter samples from three previous NIOSH studies,the current work aims to explore the effect of two different scrubbers(one wet and one dry)and a roof bolter CAC on respirable dust composition and particle size *** this,the preserved filter samples were analyzed by thermogravimetric analysis and/or scanning electron microscopy with energy dispersive *** indicate that dust composition was not appreciably affected by either scrubber or the ***,the wet scrubber and CAC appeared to decrease the overall particle size *** an effect of the dry scrubber was not consistently observed,but this is probably related to the particular sampling location downstream of the scrubber which allowed for significant mixing of the scrubber exhaust and other return *** from the insights gained with respect to the three specific dust control case studies revisited here,this work demonstrates the value of preserved dust samples for follow-up investigation more broadly.

关键词： respirable dust Dust control SEM–EDX Scrubber Canopy air curtain Silica

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Uncovering the epidemiology of bladder cancer in the Arab world: A review of risk factors, molecular mechanisms, and clinical features

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Asian Journal of Urology 2024年第3期11卷 406-422页

作者： Noura f.Abbas Marc r.Aoude Hampig r.Kourie Humaid OAl-Shamsi Department of Hematology-Oncology Hotel Dieu De France HospitalSaint Joseph University of BeirutRiad El SolhLebanon Department of Oncology Burjeel Cancer InstituteBurjeel Medical CityAbu DhabiUnited Arab Emirates Innovation and research Center Burjeel Cancer InstituteBurjeel Medical CityAbu DhabiUnited Arab Emirates College of Medicine University of SharjahSharjahUnited Arab Emirates Emirates Oncology Society DubaiUnited Arab Emirates College of Medicine Gulf Medical UniversityAjmanUnited Arab Emirates

Objective:Bladder cancer(BC)is a significant public health concern in the Middle East and North Africa,but the epidemiology and clinicopathology of the disease and contributors to high mortality in this region remain poorly *** aim of this systematic review was to investigate the epidemiological features of BC in the Arab world and compare them to those in Western countries in order to improve the management of this ***:An extensive electronic search of the PubMed/PMC and Cochrane Library databases was conducted to identify all articles published until May 2022,following the Preferred reporting Items for Systematic reviews and Meta-Analyses guidelines.A total of 95 articles were included in the final analysis after title,abstract,and full-text screening,with additional data obtained from the GLOBOCAN and WHO 2020 databases.

关键词： Bladder cancer Epidemiology risk factor Biomarker Schistosomiasis Arab world Urology

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Application of novel constrained friction processing method to produce fine grained biomedical Mg-Zn-Ca alloy

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Journal of Magnesium and Alloys 2024年第2期12卷 516-529页

作者： Ting Chen Banglong fu Junjun Shen Uceu f.H.r.Suhuddin Björn Wiese Yuanding Huang Min Wang Jorge f.dos Santos Jean Pierre Bergmann Benjamin Klusemann Solid State Materials Processing Institute of Material MechanicsHelmholtz-Zentrum HereonMax-Planck-Str.1Geesthacht 21502Germany functional Magnesium Materials Institute of Metallic BiomaterialsHelmholtz-Zentrum HereonMax-Planck-Str.1Geesthacht 21502Germany Shanghai Key Laboratory of Materials Laser Processing and Modification Shanghai Jiao Tong UniversityDongchuan Road 800Shanghai 200240China Applied Materials and Manufacturing Energy and Environment DivisionPacific Northwest National LaboratoryPO Box 999RichlandWA 99352USA Production Technology Group Technisiche Universität IlmenauGustav-Kirchhoff-Platz 2Ilmenau 98693Germany Institute for Production Technology and Systems Leuphana University of LüneburgUniversitätsallee 1Lüneburg 21335Germany

In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CfP)”,was *** CfP,defect-free Mg-Zn-Ca rods with greatly refined grains and high mechanical properties were *** to the previous as-cast microstructure,the grain size was reduced from more than 1 mm to around 4μm within 3 s by a single process *** compressive yield strength was increased by 350%while the ultimate compressive strength by 53%.According to the established material flow behaviors by“tracer material”,the plastic material was transported by shear *** the base material to the rod,the material experienced three stages,*** by the tool,upward flow with additional tilt,followed by upward *** microstructural evolution was revealed by“stop-action”*** microstructural development at regions adjacent to the rod is mainly controlled by twinning,dynamic recrystallization(DrX)as well as particle stimulated nucleation,while that within the rod is related to DrX combined with grain growth.

关键词： Constrained friction processing Magnesium alloys Microstructure Mechanical properties Grain refinement Plastic deformation

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Control and vibration analyses of a sandwich doubly curved micro-composite shell with honeycomb, truss, and corrugated cores based on the fourth-order shear deformation theory

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1773-1790页

作者： f.SHIrDELAN M.MOHAMMADIMEHr f.BArGOZINI Department of Solid Mechanics Faculty of Mechanical Engineering University of Kashan

Curved shells are increasingly utilized in applied engineering due to their shared characteristics with other sandwich structures, flexibility, and attractive appearance. However, the inability of controlling and regulating vibrations and destroying them afterward is a challenge to scientists. In this paper, the curve shell equations and a linear quadratic regulator are adopted for the state feedback design to manage the structure vibrations in state space forms. A five-layer sandwich doubly curved micro-composite shell, comprising two piezoelectric layers for the sensor and actuator, is modeled by the fourth-order shear deformation theory. The core(honeycomb, truss, and corrugated) is analyzed for the bearing of transverse shear forces. The results show that the honeycomb core has a greater effect on the vibrations. When the parameters related to the core and the weight percentage of graphene increase, the frequency increases. The uniform distribution of graphene platelets results in the lowest natural frequency while the natural frequency increases. furthermore, without taking into account the piezoelectric layers,the third-order shear deformation theory(TSDT) and fourth-order shear deformation theory(fOSDT) align closely. However, when the piezoelectric layers are incorporated,these two theories diverge significantly, with the frequencies in the fOSDT being lower than those in the TSDT.

关键词： 74f15 corrugate core doubly curved shell honeycomb micro-composite O343 truss vibration and control

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MgO-attached graphene nanosheet(MgO@GNS)reinforced magnesium matrix nanocomposite with superior mechanical,corrosion and biological performance

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2062-2076页

作者： S.Abazari A.Shamsipur H.r.Bakhsheshi-rad M.S.Soheilirad f.Khorashadizade S.S.Mirhosseini Department of Materials and Metallurgical Engineering Amirkabir University of TechnologyTehran ***Iran Iranian National Standards Organization of Hormozgan HormozganIran Advanced Materials research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Department of Materials and Metallurgical Engineering Iran University of Science and TechnologyTehranIran

Magnesium(Mg)alloys are gaining great consideration as body implant materials due to their high biodegradability and ***,they suffer from low corrosion resistance and antibacterial *** this research,semi-powder metallurgy followed by hot extrusion was utilized to produce the magnesium oxide@graphene nanosheets/magnesium(MgO@GNS/Mg)composite to improve mechanical,corrosion and cytocompatibility *** have revealed that the incorporation of MgO@GNS nanohybrids into Mg-based composite enhanced microhardness and compressive *** vitro,osteoblast cell culture tests show that using MgO@GNS nanohybrid fillers enhances osteoblast adhesion and apatite *** presence of MgO@GNS nanoparticles in the composites decreased the opening defects,micro-cracks and micro-pores of the composites thus preventing the penetration of the corrosive solution into the *** demonstrated that the MgO@GNS/Mg composite possesses excellent antibacterial properties because of the combination of the release of MgO and physical damage to bacterium membranes caused by the sharp edges of graphene nanosheets that can effectively damage the cell wall thereby facilitating penetration into the bacterial lipid ***,the MgO@GNS/Mg composite with high mechanical strength,antibacterial activity and corrosion resistance is considered to be a promising material for load-bearing implant applications.

关键词： metal matrix composites MgO@GNS nanohybrid strengthening mechanisms antibacterial activity biocompatibility

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