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Geochemistry,Petrogenesis and Alteration of Rare-Metal-Bearing Granitoids and Mineralized Silexite of the Al-Ghurayyah Stock,Arabian Shield,Saudi Arabia

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地球科学学刊:英文版 2023年第5期34卷 1488-1510页

作者： hisham A.Gahlan Mokhles K.Azer Paul D.Asimow Mansour h.Al-hashim Department of Geology and Geophysics College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia Geological Sciences Department National Research CentreCairoEgypt Division of Geological&Planetary Sciences California Institute of TechnologyPasadena CA 91125USA

New data are presented for the rare-metal bearing A-type granitoids of the AlGhurayyah stock in the northwestern segment of the Arabian Shield, a composite pluton intruding metamorphosed volcano-sedimentary successions of the Silasia Formation. Metals in the granitoids are variably enriched, with up to 1 990 μg/g Zn, 7 680 μg/g Zr, 2 316 μg/g Nb, 232 μg/g Ta, 485 μg/g hf, 670 μg/g Th, 137 μg/g U and 1 647 μg/g total rare earth elements(REE). The silexite is highly mineralized and yields higher maximum concentrations of several metals than the granitoids, including up to 1 860 μg/g Y, 9 400 μg/g Zr, 878 μg/g hf, 1 000 μg/g Th, and 2 029 μg/g total REE. The Al-Ghurayyah stock has been assigned to an intraplate setting. Lithospheric delamination led to generation of mantle melts that supplied heat to melt the juvenile crust of the ANS. The fluorine and rare-metal enriched parental magma evolved by fractional crystallization. The quartz-rich silexite, distinct in character from ordinary hydrothermal vein quartz, is inferred to be co-genetic with the granitoids on the basis of their similar REE patterns;it is interpreted as a small volume of residual magma enriched in SiO2, volatiles, and trace metals. Mineralization took place both at the magmatic stage and later during a hydrothermal stage that concentrated these elements to economic grades.

关键词： Arabian Shield Al-Ghurayyah rare metals silexite peralkaline granite hydrothermal metasomatism

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Design and implementation of a leader-follower cooperative control system for unmanned helicopters

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控制理论与应用（英文版） 2010年第1期8卷 61-68页

作者： Ben YUN Ben M. ChEN Kai Yew LUM Tong h. LEE Department of Electrical & Computer Engineering National University of Singapore Singapore 117576 Temasek Laboratories National University of Singapore Singapore 117508

In this paper, we present a full scheme for the cooperative control of multiple unmanned aerial vehicle （UAV） helicopters. We adopt the leader-follower pattern to maintain a fixed geometrical formation while navigating the UAVs following certain trajectories. More specifically, the leader is commanded to fly on some predefined trajectories, and each follower is controlled to maintain its position in formation using the measurement of its inertial position and the information of the leader position and velocity, obtained through a wireless modem. More specifications are made for multiple UAV formation flight. In order to avoid possible collisions of UAV helicopters in the actual formation flight test, a collision avoidance scheme based on some predefined alert zones and protected zones is employed. Simulations and experimental results are presented to verify our design.

关键词： Unmanned aerialvehicles Cooperative control Flight formation Collision avoidance

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Sexual differences in weaponry and defensive behavior in a neotropical harvestman

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Current Zoology 2019年第5期65卷 553-558页

作者： Julio M.G.SEGOVIA Gabriel P.MURAYAMA Rodrigo h.WILLEMART Laboratorio de Ecologia Sensorial e Comportamento de Artropodes Escolade ArtesCiencias e Humanidades da Universidade de Sao PauloSao PauloBrazil Programa de Pos-Graduaqao em Zoologia Instituto de BiocienciasUniversidade de Sao PauloSao PauloBrazil Programa de Pos-Graduaqao em Ecologia e Evoluqao Universidade Federal de Sao PauloSao PauloBrazil

Sexual differences in morphology can evolve by sexual selection and/or natural *** some species,only males have morphological structures that are used as *** some weapons may also be used for defensive purposes,males and females may behave differently towards *** some species of harvestmen(Arachnida and Opiliones),males have sharp apophyses("spines")on their 4th pair of legs whereas females lack *** apophyses are used in malemale fights and in antipredatory *** harvestmen antipredatory repertory also encompasses passive defenses such as thanatosis(death feigning),retaliation(attack on predators),and chemical *** to the sexual differences on weaponry,we hypothesized that males and females of Mischonyx cuspidatus(Gonyleptidae)rely on different defensive *** experimentally induced males and females to perform 3 defensive behaviors:thanatosis,pinching with legs,and chemical *** predicted that females would engage more in passive and chemical defenses than males,whereas males would rely more on retaliation than *** expected,females performed thanatosis more often than ***,males performed retaliation more often than *** did not find differences in the rate of chemical defense use between the *** study provides evidence that due to sexual dimorphism,alternative antipredatory behaviors may have been selected in the different sexes in ***.

关键词： Arachnida death feigning nipping thanatosis weapon Opiliones

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Industrial and Small-Scale Biomass Dryers:An Overview

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Energy Engineering 2021年第3期118卷 435-446页

作者： P.Murugan S.Dhanushkodi K.Sudhakar Vincent h.Wilson Department of Mechanical Engineering St.Anne’s College of Engineering and Technology(Affiliated to Anna University)Tamilnadu607106India School of Engineering and Technology PRIST UniversityPuducherry605007India Faculty of Mechanical and Automotive Engineering Technology University Malaysia PahangPahang26600Malaysia Automotive Engineering Centre University Malaysia PahangPahang26600Malaysia Department of Technology Management School of Mechanical EngineeringVellore Institute of TechnologyVellore632014India

The quality of the drying process depends mainly on the efficient use of thermal *** systems based on solar energy takes a leading role in the drying of agro-products because of low operating ***,they are limited in use during off–sun *** dryer is one of the simplest ways of drying because of its potential to dry products regardless of time and climate *** other benefit is that crop residues could be used as fuel in these ***,the major limitation of the dryer is unequal drying because of poor airflow distribution in the drying medium,which can be improved by integrating some design changes in the *** review analyses the two types of biomass dryers:industrial biomass dryers and small biomass dryers for food product,along with their ***,studies on technical,sustainability and economic aspects are expected to provide a greater understanding of biomass drying.

关键词： Biomass dryer sustainable energy biomass direct indirect drying time

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Survival and an overview of decision-making in patients with cholangiocarcinoma

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hepatobiliary & Pancreatic Diseases International 2008年第4期7卷 412-417页

作者： hvard Mjφrud Forsmo Arild horn Asgaut Viste Dag hoem Kjell φvrebφ Department of Surgery Haukeland University HospitalBergenNorway Department of Surgical Sciences Haukeland University HospitalBergenNorway

BACKGROUND:Cholangiocarcinoma is rare,accounting for approximately 3%of all gastrointestinal *** study aimed to identify the survival rate among surgically treated and palliated patients,and secondly to identify parameters that could predict a curative resection. METhODS:A total of 121 patients,55 men and 66 women, median age 70 years(range 31-91),who had been treated for cholangiocarcinoma in the period of 1990-2005 were evaluated retrospectively. RESULTS:Curative resection was performed in 40 patients (33%),whereas 81 received palliative treatment(67%).16% (19 of 121)of the patients had an explorative laparotomy without tumour *** above 65 years(OR 3.4;95% CI 1.4-8.4;P=0.008),weight loss(OR 8.5;95%CI 1.5-46; P=0.01)or tumour location(The resection rate of hilar cholangiocarcinoma was lower than that of intrapancreatic cancer.)(OR 2.7;95%CI 1.7-4.5;P=0.001)predicted palliative *** adjusted 5-year survival rate of patients who received tumour resection and palliative treatment was 30%and 1.2%,respectively(Phe survival rate of patients who were subjected to hepatectomy (70%)was better than that of patients who had a local or distal resection(20%)(P=0.02). CONCLUSIONS:In few patients with a resectable cholangiocarcinoma,an explorative laparotomy is often necessary to evaluate ***,long-term survival is significantly better in patients who received radical surgical resection.

关键词： cholangiocarcinoma survival treatment surgery

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Seroprevalence of celiac disease among United Arab Emirates healthy adult nationals: A gender disparity

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World Journal of Gastroenterology 2014年第42期20卷 15830-15836页

作者： Yousif A Abu-Zeid Waheeba S Jasem Benjamin Lebwohl Peter h Green Gehad ElGhazali Department of Biology College of Science United Arab Emirates University Ambulatory healthcare Services Abu Dhabi Health Services Company Celiac Disease Center at Columbia University Department of Medicine Columbia University College of Physicians and Surgeons Mafraq hospital and Sheikh Khalifa Medical City

AIM: To determine celiac disease (CD) prevalence and associated manifestations or risk factors in healthy adult Emiratis.

关键词： Celiac disease Epidemiology Serology Prevalence Gender United Arab Emirates

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Oxygen redox chemistry in lithium-rich cathode materials for Li-ion batteries:Understanding from atomic structure to nano-engineering

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Nano Materials Science 2022年第4期4卷 322-338页

作者： Majid Farahmandjou Shuoqing Zhao Wei-hong Lai Bing Sun Peter.h.L.Notten Guoxiu Wang Centre for Clean Energy Technology School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneySydneyNSW2007Australia Department of Chemical Engineering and Chemistry Eindhoven University of Technology5600MBEindhoventhe Netherlands Fundamental Electrochemistry(IEK9) Forschungszentrum JülichD-52425JülichGermany

Lithium-rich oxide compounds have been recognized as promising cathode materials for high performance Li-ion batteries,owing to their high specific ***,it remains a great challenge to achieve the fully reversible anionic redox reactions to realize high capacity,high stability,and low voltage hysteresis for lithiumrich cathode ***,it is critically important to comprehensively understand and control the anionic redox chemistry of lithium-rich cathode materials,including atomic structure design,and nano-scale materials engineering ***,we summarize the recent research progress of lithium-rich cathode materials with a focus on redox ***,we highlight the oxygen-based redox reactions in lithium-rich metal oxides,with critical views of designing next generation oxygen redox lithium cathode ***,we purposed the most promising strategies for improving the performances of lithium-rich cathode materials with a technology-spectrum from the atomic scale to nano-scale.

关键词： Oxygen redox chemistry Lithium-rich cathode Li-ion batteries Atomic structure Nano-engineering

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Crack initiation of granite under uniaxial compression tests:A comparison study

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 656-666页

作者： G.K.Zhang h.B.Li M.Y.Wang X.F.Li State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China University of Chinese Academy of Sciences Beijing100049China

In this study,a combination of acoustic emission(AE)method(AEM)and wave transmission method(WTM)is used to investigate the behaviors of AE and ultrasonic properties corresponding to initial fracturing in granitic *** relationships of AE characteristics,frequency spectra,and spatial locations with crack initiation(CI)are *** anisotropic ultrasonic characteristics,velocity distributions in different ray paths,wave amplitudes,and spectral characters of transmitted waves are *** identify CI stress,damage initiations characterized by strain-based method(SBM),AEM and WTM are *** granite samples,it shows that the ratio of CI stress to peak strength estimated by SBM ranges from 0.4 to 0.55,and 0.49-0.6 by WTM,which are higher than that of AEM(0.38-0.46).The CI stress identified by AEM indicates the onset of microcracking,and the combination of AEM and WTM provides an insight into the detection of rock damage initiation and anisotropy.

关键词： Crack initiation(CI)stress Acoustic emission(AE) Ultrasonic transmission Wave velocity Granite

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Dynamic Modeling of the Feed Drive System of a CNC Metal Cutting Machine

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Sound & Vibration 2021年第1期55卷 19-30页

作者： h.heydarnia I.A.Kiselev M.M.Ermolaev S.Nikolaev Department of Applied Mechanics Bauman Moscow State Technical UniversityMoscowRussia Department of Bases of Machine Designing Bauman Moscow State Technical UniversityMoscowRussia Skolkovo Institute of Science and Technology MoscowRussia

Studying the vibrational behavior of feed drive systems is important for enhancing the structural performance of computer numerical control(CNC)*** preload on the screw and nut position have a great influence on the vibration characteristics of the feed drive as two very important operational *** acceleration of the screw also affects the performance of the CNC feed drive when machining small *** paper investigates the influence of preload and nut position on the vibration characteristics of the feed drive system of a CNC metal cutting machine in order to be able to eliminate an observed resonance occurred at high rotational speeds of the screw,corresponding to high feed ***,rational structural parameters of the feed drive system are selected in order to increase the rotational acceleration for improving the performance of the CNC *** and analyses showed that by selecting specific parameters of feed drive system and simultaneously applying a certain value of preload,a 97%increase in rotational acceleration and 30%time reduction considering the vibration resistance at high rotational speeds can be achieved.

关键词： Machining performance CNC machine tools vibration characteristics machine tool dynamic modeling

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Expansion of GARP-Expressing CD4^(+)CD25^(-)FoxP3^(+)T Cells and SATB1Association with Activation and Coagulation in Immune Compromised hIV-1-Infected Individuals in South Africa

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Virologica Sinica 2021年第5期36卷 1133-1143页

作者： Eman Teer Danzil E.Joseph Leanne Dominick Richard h.Glashoff M.Faadiel Essop Centre for Cardio-Metabolic Research in Africa(CARMA) Department of Physiological SciencesStellenbosch UniversityStellenbosch 7600South Africa Division of Medical Microbiology and Immunology Department of PathologyStellenbosch University and NHLSCape Town 7505South Africa

Although antiretroviral treatment lowers the burden of human immunodeficiency virus(hIV)-related disease,it does not always result in immunological *** manifests as persistent chronic inflammation,immune activation or exhaustion that can promote the onset of *** the exact function of regulatory T(Treg)cells in hIV remains unclear,this cross-sectional study investigated three expression markers(Forkhead box protein P3[FOXP3],glycoprotein A repetitions predominant[GARP],special AT-rich sequence binding protein 1[SATB1])and compared their expansion between CD4^(+)CD25^(-)and CD4^(+)CD25^(++)T ***-matched study subjects were recruited(Western Cape,South Africa)and sub-divided:hIV-negative subjects(n=12),hIV-positive na(i|")ve treated(n=22),hIV-positive treated based on CD4 count cells/μL(CD4>500 and CD4hIV-treated based on viral load(VL)copies/mL(VL1000)(n=34).Markers of immune activation(CD38)and coagulation(CD142)on T cells(CD8)were assessed by flow cytometry together with FOXP3,GARP and SATB1 expression on CD4^(+)CD25^(-)and CD4^(+)CD25^(++)T *** levels of interleukin-10(IL-10;anti-inflammatory marker),IL-6(inflammatory marker)and D-dimer(coagulation marker)were *** study revealed three major findings in immuno-compromised patients with virological failure(CD41000):(1)the expansion of the unconventional Treg cell subset(CD4^(+)CD25^(-)FOXP3^(+))is linked with disease progression markers;(2)increased GARP expression in the CD4^(+)CD25^(-)and CD4^(+)CD25^(++)subsets;and(3)the identification of a strong link between CD4^(+)CD25^(-)SATB1+cells and markers of immune activation(CD8^(+)CD38^(+))and coagulation(CD8^(+)CD142^(+)and D-dimer).

关键词： human immunodeficiency virus(hIV) Regulatory T cells(Treg) Immune activation Progression markers Glycoprotein A repetitions predominant(GARP) Forkhead box protein P3(FOXP3)

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