检索结果-南通市图书馆

Acta Geologica sinica(English Edition) 2021年第6期95卷 2045-2062页

作者： Waleed s.IBRAhIM Nuclear Materials Authority El MaadiCairoEgypt

The Wadi Ibib area is situated in the northern part of the Neoproterozoic hamisana shear Zone(hsZ), which is a high strain zone evolved during the late stages of the Pan-African orogeny, likely as a tectonic escape structure. Amphibolite facies pelitic metasedimentary windows crop out in the axial parts of the hsZ and are noticeably associated with numerous N-trending pegmatite dikes. Whole-rock geochemistry of the pegmatites reveals a peraluminous(s-type) affinity, with low K/Rb ratios and elevated concentrations of U, Th, REE, Rb, Li, Cs, Y, Nb and Ta. structurally, the pegmatite sets intrude along the shear plane of the hsZ, corresponding to the regional N-trending tectonic fabrics, such as axial planar foliation and dextral-shearing in the metasedimentary host rock. Field relationships, including structural context, coupled with geochemical characteristics of the Wadi Ibib pegmatites, do not support their formation as a complementary part of evolved granitic magmas. space-localized decompression-induced partial melting of peraluminous garnet-bearing metapelites was alternatively the underlying process for formation of these pegmatites. such decompression was associated with regional escape tectonics and stress axes permutations during the late deformation stage(D3) in the evolution of the south Eastern Desert terrane, due to end-orogeny system pressure-release.

关键词： U-Th-REE mineralization anataxis pegmatite origin hamisana shear Zone Wadi Ibib Egypt

The tectonics and mineral systems of Proterozoic Western Australia:Relationships with supercontinents and global secular change

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2018年第2期9卷 295-316页

作者： A.R.A.Aitken s.A.Occhipinti M.D.Lindsay A.Joly h.M.howard s.P.Johnson J.A.hollis C.V.spaggiari I.M.Tyler T.C.McCuaig M.C.Dentith Centre for Exploration Targeting The University of Western AustraliaPerthWestern AustraliaAustralia The Geological survey of Western Australia Department of Mines and PetroleumPerthWestern AustraliaAustralia BhP Billiton 125 St Georges TerracePerthAustralia ARC Centre of Excellence for Core to Crust Fluid systems Centre for Exploration TargetingSchool of Earth SciencesThe University of Western AustraliaAustralia Resource Potentials PerthAustralia Department of Geology The Ministry of Mineral ResourcesGreenland GovernmentGreenland

The cratonisation of Western Australia during the Proterozoic overlapped with several key events in the evolution of Earth. These include global oxidation events and glaciations, as well as the assembly,accretionary growth, and breakup of the supercontinents Columbia and Rodinia, culminating in the assembly of Gondwana. Globally, Proterozoic mineral systems evolved in response to the coupled evolution of the atmosphere, hydrosphere, biosphere and lithosphere. Consequently, mineral deposits form preferentially in certain times, but they also require a favourable tectonic setting. For Western Australia a distinct plate-margin mineralisation trend is associated with Columbia, whereas an intraplate mineralisation trend is associated with Rodinia and Gondwana, each with associated deposit types. We compare the current Proterozoic record of ore deposits in Western Australia to the estimated likelihood of oredeposit formation. Overall likelihood is estimated with a simple matrix-based approach that considers two components: The "global secular likelihood" and the "tectonic setting likelihood". This comparative study shows that at least for the studied ore-deposit types, deposits within Western Australia developed at times, and in tectonic settings compatible with global databases. Nevertheless, several deposit types are either absent or poorly-represented relative to the overall likelihood models. Insufficient exploration may partly explain this, but a genuine lack of deposits is also suggested for some deposit types. This may relate either to systemic inadequacies that inhibited ore-deposit formation, or to poor preservation. The systematic understanding on the record of Western Australia helps to understand mineralisation processes within Western Australia and its past connections in Columbia, Rodinia and Gondwana and aids to identify regions of high exploration potential.

关键词： Mineral systems Tectonics Australia

Magnetic moments and g-factors in odd-A ho isotopes

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2017年第7期41卷 52-60页

作者： E.Tabar h.Yakut A.A.Kuliev h.Quliyev G.hosgor Physics Department Sakarya University 54187 Sakarya Turkey Biomedical magnetic and semiconductor materials research center (BIMAYAM) Sakarya University 54187 Sakarya Turkey Azerbaijan National Academy of Aviation Baku Azerbaijan

The ground-state magnetic moment, g K factor and quenching spin gyromagnetic ratio have been calculated using the microscopic method based on the Quasiparticle Phonon Nuclear Model（QPNM） for ^155-169 ho nuclei for the first time. It is shown that the residual spin-spin interactions are responsible for the core polarization,and because of the core polarization the spin gyromagnetic factors are quenched. By considering the core polarization effects, a satisfactory agreement is obtained for the computed ground state g K factor, which gives an intrinsic contribution to the magnetic moments. In order to assess the collective contribution to the magnetic moments, the rotational gyromagnetic factors g R have been also calculated within the cranking approximation using the single particle wave function of the axially symmetric Woods-saxon potential. For the ground-state magnetic moments of odd-proton ^155-165 ho nuclei, a good description of the experimental data is obtained with an accuracy of 0.01–0.1μN. From systematic trends, the quenching spin gyromagnetic factor, g K factor and magnetic moment have also been theoretically predicted for167,169 ho where there is no existing experimental data.

关键词： deformed odd-A ho isotopes magnetic moment magnetic g-factors core-polarization QRPA

Adaptive Learning Video streaming with QoE in Multi-home heterogeneous Networks

在线全文

学校读者我要写书评

暂无评论

Computer systems science & Engineering 2023年第9期46卷 2881-2897页

作者： s.Vijayashaarathi s.NithyaKalyani Department of Electronics and Communication Sona College of TechnologySalem636005Tamil NaduIndia Department of Information Technology K.S.R.College of EngineeringTiruchengode637215Tamil NaduIndia

In recent years,real-time video streaming has grown in *** growing popularity of the Internet of Things(IoT)and other wireless heterogeneous networks mandates that network resources be carefully apportioned among versatile users in order to achieve the best Quality of Experience(QoE)and performance *** researchers focused on Forward Error Correction(FEC)techniques when attempting to strike a balance between QoE and ***,as network capacity increases,the performance degrades,impacting the live visual ***,Deep Learning(DL)algorithms have been successfully integrated with FEC to stream videos across multiple heterogeneous *** these algorithms need to be changed to make the experience better without sacrificing packet loss and delay *** address the previous challenge,this paper proposes a novel intelligent algorithm that streams video in multi-home heterogeneous networks based on network-centric *** proposed framework contains modules such as Intelligent Content Extraction Module(ICEM),Channel status Monitor(CsM),and Adaptive FEC(AFEC).This framework adopts the Cognitive Learning-based scheduling(CLs)Module,which works on the deep Reinforced Gated Recurrent Networks(RGRN)principle and embeds them along with the FEC to achieve better *** complete framework was developed using the Objective Modular Network Testbed in C++(OMNET++),Internet networking(INET),and Python 3.10,with Keras as the front end and Tensorflow 2.10 as the back *** extensive experimentation,the proposed model outperforms the other existing intelligentmodels in terms of improving the QoE,minimizing the End-to-End Delay(EED),and maintaining the highest accuracy(98%)and a lower Root Mean square Error(RMsE)value of 0.001.

关键词： Real-time video streaming IoT multi-home heterogeneous networks forward error coding deep reinforced gated recurrent networks QoE prediction accuracy RMsE

hYDROGEN PULVERIZATION OF Nb_3Al AND NbCr_2 ALLOYs

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1999年第S1期9卷 13-20页

作者： h. hosoda and s. hanada Institute for Materials Research, Tohoku University, sendai 980 8577, Japan

Measurements of hydrogen absorption desorption behavior of Nb Al alloys, Nb ss (Nb solid sloution), Nb ss +Nb 3Al, Nb 3Al, Nb 3Al+Nb 2Al, were carried out under hydrogen pressure from 0 to 3.4 MPa at 353 and 357 K, along with mircostructural observation and X ray diffraction analysis. It was found that single phase alloys of Nb ss and Nb 3Al are not pulverized regardless of a considerable amount of hydrogen absorption, while two phase alloys of Nb ss +Nb 3Al and Nb 3Al+Nb 2Al are readily pulverized. X ray diffraction analysis indicated that no hydride with crystal structure different from constituent phases is formed by hydrogen absorption, but lattice parameters of Nb ss and Nb 3Al are increased. Pulverization of Nb Cr alloys was investigated under a hydrogen atmosphere of 0.1 MPa in an arc melting chamber without exposure to air after arc melting. similarly, hydrogen pulverization occurs only in two phase alloys consisting of Nb ss and NbCr 2. Based on the measured lattice parameters of Nb ss and Nb 3Al(NbCr 2) in the hydrogenated two phase alloys and the microstructural observations, a mechanism for hydrogen pulverization is discussed.

关键词： Nb 3Al NbCr 2 hydrogen pulverization hydrogen adsorption hydrogen desorption microstructural observations lattice parameters mechanism

在线全文

学校读者我要写书评

暂无评论

提问的技巧、算法及其应用

软件学报 1993年第6期4卷 7-15页

作者：邵维忠 h.s.soon 北京大学计算机系北京100871 新加坡国立大学系统科学院

巧妙的提问是人类的智能之一,本文讨论如何让机器模仿人的这种智能,给出一系列提高提问效率的策略和算法,这些技巧可以改善一些咨询系统,特别是专家系统的提问机制,使系统在为用户服务时,向用户提出的问题尽可能的简练贴切,从而降低系... 详细信息

巧妙的提问是人类的智能之一,本文讨论如何让机器模仿人的这种智能,给出一系列提高提问效率的策略和算法,这些技巧可以改善一些咨询系统,特别是专家系统的提问机制,使系统在为用户服务时,向用户提出的问题尽可能的简练贴切,从而降低系统的提问开销。

关键词：技巧算法应用专家系统

Cardiovascular surgery in the elderly: an update

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2005年第2期2卷 123-128页

作者： Ahmed A. ARIFI Calvin s. h. NG Anthony P. C. YIM Division of Cardiothoracic surgery The Chinese University of hong Kong Prince of Wales hospital Hong KongPeople's Republic of China

The aging of the population and improvements in outcomes after cardiovascular surgery have resulted in a worldwide growing demand of complex surgical intervention for elderly patients. We briefly review the up-to-date English-language literature with particular focus on cardiovascular surgery in elderly patients. With earlier referral, careful preoperative evaluation, strategic planning, and the continuing efforts in optimizing surgical techniques, operative mortality and morbidity following primary or reoperative coronary artery bypass grafting and valvular interventions are expected to fall in this high-risk patient subset. Importantly, accumulating evidence indicates that elderly patients may benefit from improved functional status and quality of life after cardiovascular surgical therapy(J Geriatr Cardiol 2005,2(2): 123-128).

关键词： cardiovascular surgery coronary artery bypass grafting elderly reoperation risk factor valve replacementIntroduction

Comparative Analysis of Velocity Decomposition Methods for Internal Combustion Engines

在线全文

学校读者我要写书评

暂无评论

Open Journal of Fluid Dynamics 2012年第3期2卷 70-90页

作者： semih Olcmen Marcus Ashford philip schinestsky Mebougna Drabo Department of Aerospace Engineering and Mechanics The University of AlabamaTuscaloosaUSA Department of Mechanical Engineering The University of AlabamaTuscaloosaUSA

Different signal processing technique performances are compared to each other with regard to separating the mean and fluctuating velocity components of a simulated one-dimensional unsteady velocity signal comparable to signals observed in internal combustion engines. A simulation signal with known mean and fluctuating components was generated using experimental data and generic turbulence spectral information. The simulation signal was generated based on observations on the measured velocity data obtained using LDV in a motored Briggs-and-stratton engine at about 600 RPM. Experimental data was used as a guide to shape the simulated signal mean velocity variation;fluctuating velocity variations with specified spectrum and standard deviation was used to mimic the turbulence. Cyclic variations were added both to the mean and the fluctuating velocity signals to simulate prescribed cyclic variations. The simulated signal was introduced as input to the following algorithms: ensemble averaging;high-pass filtering;Proper-Orthogonal Decomposition (POD);Wavelet Decomposition (WD) and Wavelet Decomposition/Principal Component Analysis (WD/PCA). The results were analyzed to determine the best method in correctly separating the mean and the fluctuating velocity information, indicating that the WD/PCA performs better compared to other techniques.

关键词： Proper-Orthogonal Decomposition Wavelet Decomposition Principal Component Analysis LDV signal Processing

Enhancing recovery of uranium column bioleaching by process optimization and kinetic modeling

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals society of China 2017年第12期27卷 2691-2703页

作者： h. ZARE TAVAKOLI M. ABDOLLAhY s. J. AhMADI A. KhODADADI DARBAN Mining Engineering Department Tarbiat Modares University Tehran 14115116 Iran Nuclear science and Technology Research Institute Tehran 113658486 Iran

This research aimed to enhance the column bioleaching recovery of uranium ore by Acidithiobacillus *** factors were examined for their significance on bioleaching using a Plackett-Burman factorial *** significant variables([Fe2+]initial,ph,aeration rate and inoculation percent)were selected for the optimization *** effect of these variables on uranium bioleaching was studied using a central composite design(CCD).The optimal values of the variables for the maximum uranium bioleaching recovery(90.27±0.98)%were as follows:[Fe2+]initial=2.89g/L,aeration rate420mL/min,ph1.45and inoculation6%(v/v).[Fe2+]initial was found to be the most effective *** maximum uranium recovery from the predicted models was92.01%.This value was in agreement with the actual experimental *** analysis of bioleaching residue of uranium ore under optimum conditions confirmed the formation of K-jarosite on the surface of *** using optimal conditions,uranium bioleaching recovery is increased at column and jarosite precipitation is *** kinetic model showed that uranium recovery has a direct relation with ferric ion concentration.

关键词： column bioleaching uranium ore screening optimization kinetic model Acidithiobacillus ferrooxidans

Antitumor effect of thymoquinone combined with resveratrol on mice transplanted with breast cancer

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2017年第4期10卷 378-386页

作者： Omar h.Alobaedi Wamidh h.Talib Iman A.Basheti Department of Clinical Pharmacy&Therapeutics Facuty of PharmacyApplied Science Private UniversityAmmanJordan

Objective:To test the anticancer potential activity of the combination of thymoquinone(TQ)and resveratrol(REs) against breast cancer in ***:The antiproliferative activity of *** and their combination was assessed against three breast cancer cell lines and one normal cells using MTT *** combination index was calculated using isobolographic ***/C mice were inoculated with EMT6/P cells and in vivo antitumor activity was ***:The combination therapy caused significant decrease in tumor size with a percentage cure of 60%.The combination therapy induced geographic necrosis,enhanced apoptosis,and decreased VEGF *** levels of IFN-y were elevated in mice treated with combination therapy with no liver and kidney ***:The combination of TQ and REs against breast cancer in mice can work *** anticancer effect of this combination is mediated by apoptosis induction,angiogenesis inhibition and immune modulation.

关键词： Combination therapy Natural products Breast cancer Apoptosis