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the hot compressive deformation behavior of cast Mg-Gd-Y-Zn-Zr alloys with and without LPSO phase in their initial microstructures

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journal of Magnesium and Alloys 2022年第10期10卷 2901-2917页

作者： H.t.jeong W.j.Kim Departmentof Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

Samples of Mg-8.2Gd-3.8Y-1.1Zn-0.4Zr alloy with and without an intragranular lamellae-shaped long period stacking ordered(LPSO)phase were prepared through heat treatment and a series of hot compression tests on these materials were conducted to examine and evaluate the influence of LPSO on the hot compressive deformation behavior and deformation mechanisms at a given alloy *** values of activation energy for plastic flow(Qc)of the solution treated(without LPSO phase)and annealed alloys(with intragranular LPSO phase)were larger than that for pure Mg,indicating that the presence of a high amount of rare earth(RE)elements and LPSO in the Mg matrix significantly increases *** Qcvalue of the annealed alloy was larger than that of the solution treated alloy at all the strain levels(223.3 vs.195.5 k j/mol in average)and the largest difference in Qcbetween the two alloys was recorded at the smallest strain of 0.1 where precipitation of LPSO during deformation was limited in the solution treated *** observations imply that the formation of LPSO phase out of the RE-rich solid solution matrix during deformation increases Qc,but the increment is not so *** of the hot compressive data of the alloys with LPSO phase and the alloys with RE-rich solid solution matrix in literatures indicates the similarity of the effect of the LPSO and RE-rich solid solution matrix phases on Qcand high-temperature strength.

关键词： Magnesium alloys LPSO Deformation mechanism Dynamic recrystallization Activation energy for plastic flow Processing maps

the effects of gonadal hormones on learning and memory in male mammals： A review

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Current Zoology 2011年第4期57卷 543-558页

作者： Stuart t. LEONARD Peter j. WINSAUER Department of Pharmacology and Experimental therapeutics Louisiana State University Health Sciences Center 1901 Perdido Street New Orleans LA 70112-1393

the primary role of the gonadal steroid hormones in mammals is to regulate reproduction and related behaviors; however, both androgens and estrogens are also integrally involved in mediating higher brain function and processes including cognition, neural development, and neural plasticity. In particular, a number of studies show that estradiol modulates dendritic spine growth and synapse density （synaptic plasticity） in the hippocampus of females, and that increased estradiol levels are generally associated with improvements on a variety of learning and memory tasks. While the majority of research has focused on the beneficial effects of estradiol in females, much less attention has been given to testosterone and its effects on learning and memory in males. Similar to estradiol titers in females, testosterone titers in males decline with age, albeit more gradually, and this decline has been correlated with impairment of certain cognitive tasks. Moreover, studies involving both humans and animals indicate that testosterone and its metabolites can augment responding on certain behavioral tasks, depending on the subject＇s current hormonal state, the response required, and the stimuli involved （e.g., those involving spatial or nonspatial stimuli）. While the exact mechanisms by which testosterone exerts its effects on learning and memory are not fully understood, recent findings suggest that testosterone modulates learning and memory in males through an interaction with the cholinergic system. the overall objective of this review is to discuss studies investigating the role of the gonadal hormones in mediating learning and memory processes in male mammals [Current Zoology 57 （4）： 543-558, 2011].

关键词： testosterone Learning and memory Cholinergic system Mammals Cognition Androgens

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提高线材质量的途径

唐钢科技 1990年第1期 66-72页

作者： Pik.,t.j 刘贵富

AGWO-CNN Classification for Computer-Assisted Diagnosis of Brain tumors

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Computers, Materials & Continua 2022年第4期71卷 171-182页

作者： t.jeslin j.Arul Linsely Department of Electronics and Communication Engineering Universal College of Engineering and TechnologyVallioor627117India Department of Electrical and Electronics Engineering Noorul Islam Centre for Higher EducationKumarakovil629180India

Brain cancer is the premier reason for cancer deaths all over the *** diagnosis of brain cancer at an initial stage is mediocre,as the radiologist is *** experiments have been conducted and demonstrated clearly that the algorithms for nodule segmentation are ***,the research has consolidated incremental clustering focused on superpixel segmentation as an appropriate optimization approach for the accurate segmentation of pulmonary *** key aim of the research is to refine brain Ct images to accurately distinguish tumors and the segmentation of small-scale anomalous nodules in the brain *** the beginning stage,an anisotropic diffusion filters(ADF)method with un-sharp intensification masking is utilized to eliminate the noise discernment in *** the following stage,within the improved nodule image sequence,a Superpixel Segmentation Based Iterative Clustering(SSBIC)algorithm is proposed for irregular brain tissue ***,the brain nodule samples are captured using deep learning methods:Advanced Grey Wolf Optimization(AGWO)with ONN(AGWO-ONN)and Advanced GWO with CNN-based(AGWOCNN).the proposed technique indicates that the sensitivity is increased and the calculation time is ***,the proposed methodology manifests that the advanced Computer-Assisted Diagnosis(CAD)system has outstanding potential for automatic brain tumor *** average segmentation time of the nodule slice order is 1.06s,and 97%of AGWO-ONN and 97.6%of AGWO-CNN achieve the best classification reliability.

关键词： Advanced GWO with ONN(AGWO-ONN) Advanced GWO with CNN(AGWO-CNN) brain cancer superpixel segmentation based iterative clustering(SSBIC)algorithm

trace element characteristics of partial melts produced by melting of metabasalts at high pressures: Constraints on the formation condition of adakitic melts

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Science China Earth Sciences 2006年第9期49卷 915-925页

作者： j. Adam t.H. Green GEMOC National Key Centre Department of Earth and Planetary Sciences Macquarie University Sydney NSW 2109 Australia GEMOC National Key Centre Department of Earth and Planetary Sciences Macquarie University Sydney NSW 2109 Australia

Experiments were conducted on a natural basalt (with 5 wt.% added H2O) at 1.0―2.5 GPa and 900―1100℃. Experimental products include partial melts (quenched glasses) + residual mineral assemblages of amphibolite or eclogite. Electron microprobe and LAM-ICP-MS were used to determine major and trace element compositions of these quenched melts, respectively. Major ele- ment compositions of all the melts are tonalitic- trondhjemitic, similar to adakite. their trace element characteristics are controlled by coexisting residual minerals. Signatures of adakite such as high Sr/Y, low HREE and negative Nb-ta anomaly, etc. are present only in the melts coexisting with residual assemblages containing rutile and garnet (rutile-bearing eclogite or rutile-bearing amphibole-eclogite). Garnet leads to HREE depletion in melts, whereas rutile controls Nb and ta partitioning during the partial melting and causes negative Nb-ta anomaly in melts. therefore, in addition to garnet, rutile is also a necessary residual phase during the generation of adakite or ttG magmas to account for the negative Nb-ta anomaly of the magmas. the depth for the generation of adakite/ttG magmas via melting of metabasalt must be more than about 50 km based on the approximate 1.5 GPa mini- mum-pressure for rutile stability in the partial melting field of hydrous basalt.

关键词： trace element adakite/ttG magmas partial melting of metabasalt negativeNb-ta anomaly rutile

tsallis holographic dark energy under complex form of quintessence model

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Communications in theoretical Physics 2023年第2期75卷 157-167页

作者： j Sadeghi S Noori Gashti t Azizi Department of Physics Faculty of Basic SciencesUniversity of Mazandaran P.O.Box 47416-95447BabolsarIran

In this paper,we use a tsallis holographic dark energy model in two forms,interacting and noninteracting cases,to acquire some parameters as the equation of state for the energy density of the tsallis model in the FRW Universe concerning the complex form of quintessence *** will study the cosmology of complex quintessence by revamping the potential and investigating the scalar field *** we analyze(w-w’)and stability in two cases,*** and *** will explore whether these cases describe a real Universe by calculating fractional energy densityΩ_(D)and concerning two parts of the quintessence field effect(complex and real part)by considering the real part of this field to be a slow-roll *** know that the part in which the fractional energy density(Ω_(D)>1)does not describe a real ***,we specified an interacting coupling parameter b2that depends on the constant parameter of the tsallis holographic model(δ)with respect to fractional energy density(0.73).Unlike independence between the fractional energy density and interacting coupling in the real quintessence model,we determine a relationship among these parameters in this ***,by plotting some figures,we specify the features of(w-w’)and(ν^(2)_(s))in two cases and compare the result with each other.

关键词： tsallis holographic model complex form of quintessence model stability

Combinatorial synthesis and high-throughput characterization of copper-oxide superconductors

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Chinese Physics B 2018年第11期27卷 126-129页

作者： j Wu A t Bollinger X He I Bozovic Brookhaven National Laboratory Upton New York 11973-5000 USA Applied Physics Department Yale University New Haven CT 06520 USA

Fast synthesis and screening of materials are vital to the advance of materials science and are an essential component of the Materials Genome Initiative. Here we use copper-oxide superconductors as an example to demonstrate the power of integrating combinatorial molecular beam epitaxy synthesis with high-throughput electric transport measurements. Leveraging this method, we have generated a phase diagram with more than 800 compositions in order to unravel the doping dependence of interface superconductivity. In another application of the same method, we have studied the superconductorto-insulator quantum phase transition with unprecedented accuracy in tuning the chemical doping level.

关键词： Materials Genome Initiative combinatorial growth high-throughput characterization copperoxide superconductors

Computational and Experimental Study of Pinch on the Performance of a Vaneless Diffuser in a Centrifugal Compressor

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journal of thermal Science 2006年第4期15卷 306-313页

作者： t.turunen-Saaresti A.Reunanen j.Larjola Lappeenranta University of technology Department of Energy and Environmental TechnologyLappeenrantaFinland teemu

this study focuses on the vaneless diffuser of a centrifugal compressor. the examined stage consists of an unshrouded impeller, a parallel wall vaneless diffuser and a volute. the walls of the diffuser were movable allowing different pinch configurations to be investigated. the baseline geometry had no pinch i.e. the height of the diffuser was equal to the height of the impeller flow channel plus the axial running clearance. the work consists of both numerical and experimental parts. Quasi-steady, turbulent, fully 3D numerical simulations were conducted. the inlet cone, rotor and diffuser were modelled. Six different configurations were studied. the height of the pinch was altered and the pinch made to different walls was tested. two of the numerically studied cases were also experimentally investigated. the overall performance of the compressor, the circumferential static and total pressure and the spanwise total pressure distribution before and after the diffuser were measured. the numerical and experimental studies showed that the pinch improved the efficiency of the compressor.

关键词： Centrifugal compressor vaneless diffuser pinch

Biological records of paleoclimate and paleoenvironment changes from Guanzhong area, Shaanxi Province during the last glacial maximum

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Chinese Science Bulletin 2000年第9期45卷 853-857页

作者： j.Head A.j.t.jull State Key Laboratory of Loess and Quaternary Geology Xi'an 710054ChinaNSF-AMS Facility Department of PhysicsUniversity of ArizonaAZ 85721USA

We have collected a suite of Paleoloxodon naumanni-Coelodonta antiquitatis fossils from a river terrace profile between Xi’an and Xianyang cities in Guanzhong Area, Shaanxi Province. A detailed examination of the fossils, together with 14C determinations and pollen analyses, have enabled us to reconstruct preliminary features of climate and environment changes and their evolutionary processes, within the last glacial maximum (LGM): about 20 ka ago, the climate was basically cool and wet, and was favourable for the existence of Paleoloxodon naumanni-Coelodonta antiquitatis fauna. this was followed by a cold, dry phase which was no longer suitable for this type of faunal suite, causing the death of a large number of mammalian assemblages. the available evidence indicates the existence of cold-dry and cool-wet climate and environment fluctuations during the LGM. the cool-wet stage within the LGM reflects a Heinrich event occurring in the high latitude areas, proving the existence of a teleconnection

关键词： Guanzhong of Shaanxi Province Paleoloxodon naumanni-Coelodonta antiguitatis fauna last glacial maximum paleomonsoon precipitation.