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Journal of Computer Science & Technology 2023年第1期38卷 80-86页

作者： Kirk w.Cameron Computer Science Virginia TechWashington D.C.VA 24061U.S.A.

Amdahl’s Law painted a bleak picture for large-scale *** implication was that parallelism was limited and therefore so was potential *** Amdahl’s contribution was seminal and important,it drove others vested in parallel processing to define more clearly why large-scale systems are critical to our future and how they fundamentally provide opportunities for speedup beyond Amdahl’s *** the early 2000s,much like Amdahl,we predicted dire consequences for large-scale systems due to power *** our early work was often dismissed,the implications were clear to some:power would ultimately limit *** this retrospective,we discuss how power-performance measurement and modeling at scale led to contributions that have driven server and supercomputer design for more than a *** the influence of these techniques is now indisputable,we discuss their connections,limits and additional research directions necessary to continue the performance gains our industry is accustomed to.

关键词： Amdahl’s Law speedup power-aware computing power modeling performance modeling performance prediction power measurement

Depositional Environment of Sediments in Tonle Sap Sedimentary Basin, western Part of Cambodia: Insights from Field and Geochemical Studies

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Open Journal of Geology 2023年第7期13卷 651-666页

作者： Sopheap pech Chandoeun Eng Chanmoly Or Afikah Binti Rahim Ratha Heng Chitra Buth Sreymean Sio Research and Innovation Center Institute of Technology of Cambodia Phnom Penh Cambodia Faculty of Geo-Resources and Geotechnical Engineering Institute of Technology of Cambodia Phnom Penh Cambodia Faculty of Engineering Universiti Teknologi Malaysia Johor Malaysia Faculty of Engineering Chulalongkorn University Bangkok Thailand

Tonle Sap sedimentary basin was considered a favorable geological condition for hydrocarbon accumulation in the onshore Cambodia. Two exposure outcrops in Battambang province, called Somlout and Takream, were selected to represent sediments in this basin. The sedimentology and geochemistry studies provide insights into the depositional environment of sediments using field investigation, lithological, sedimentological, paleontological, and geochemical analysis. The redox condition, water column, and depositional setting were analyzed by plotting the ratio of V vs. Cr, Uauthigenic vs. V/Cr, Sr vs. Ba, Ca vs. (Fe + Ca), and Fe2O3/TiO2 vs. Al2O3/(Al2O3 + Fe2O3) diagram. Moreover, these diagrams can be used to predict depositional conditions as well. Based on the results, Somlout and Takream comprise calcareous shale and limestone facies. The geochemical analysis showed that Somlout calcareous shale samples were deposited in the dysoxic freshwater of the lake setting during the regression, while Somlout limestones and Takream were deposited in high salinity seawater, oxic condition of shallow-marine water. In addition, Somlout limestones consist of fragmental fusulinid foraminifera, bivalve shelve, and bryozoan, which suggest a barrier environment. Meanwhile, Teakream consists of fine-grained calcareous shale, and lime-mudstone, which are presented to form in the quiet marine setting of the lagoon environment. Therefore, the Tonle Sap basin sediments were deposited in the Somlout area’s barrier and lake environment, and the lagoon environment for Takream.

关键词： Depositional Environment Sedimentary Basin Geochemistry Paleontology Tonle Sap

Limits on light emission from silicon

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Chinese Optics Letters 2009年第4期7卷 268-270页

作者： Peter würfel Institut für Angewandte Physik Universitt KarlsruheD-76128 KarlsruheGermany

Although silicon is an indirect semiconductor, light emission from silicon is governed by the same gener- alized Planck＇s radiation law as the emission from direct semiconductors. The emission intensity is given by the absorptance of the volume in which there is a difference of the quasi Fermi energies. A difference of the Fermi energies may result h＇om the absorption of external light （photoluminescence） or from the injection of electrons and holes via selective contacts （electroluminescence）. The quantum efficiency may be larger than 0.5 for carrier densities below 10^15 cm^-3. At larger densities, non-radiative recombination, in particular Auger recombination dominates. At all carrier densities, the relation between emission intensity and difference of the quasi Fermi energies is maintained. Since this difference is equal to the voltage of a properly designed solar cell, luminescence is the key indicator of material quality for solar cells.

关键词： Carrier concentration Fermi level Light Light emission Photoluminescence Semiconducting silicon Silicon

PREDICTION OF CHARACTERISTICS FOR VERTICAL ROUND NEGATIVE BUOYANT JETS IN HOMOGENEOUS AMBIENT

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Journal of Hydrodynamics 2001年第1期13卷 103-110页

作者： Huai, w.X. Li, w. Dep. of River Eng. Coll. of Water Resource Eng. Wuhan 430072 China

The k-Ε turbulence model is used to establish a mathematical model of a vertical round jet with negative buoyancy in a static homogeneous ambient. The hybrid finite analytic method, with a non-uniform staggered grid, is used to calculate the whole flow field. The variations of centerline velocity, density and turbulent kinetic energy along the axial line for a given exit densimetric Froude number are found to converge to single curves under the unified scaling law derived by Chen and Rodi. The profiles of mean velocities, mean density difference and the half-width of negative buoyant jets for velocity and density are given. The calculation confirmed that the maximum height of rise is proportional to M03/4 B0-1/2, where M0 and B0 are the momentum flux and the buoyancy flux at the source, respectively.

关键词： Computer simulation Jets Mathematical models Numerical methods

Clinical features of chronic kidney disease in dogs with the serological presence of Leptospira spp.,Ehrlichia canis,and Anaplasma phagocytophilum

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Animal Diseases 2024年第3期4卷 224-230页

作者： Claire A.Vázquez‑Manzanilla María F.Cárdenas‑Marrufo Eduardo Gutiérrez‑Blanco Matilde Jiménez‑Coello Nelly R.pech‑Sosa Antonio Ortega‑Pacheco Departamento de Salud Animal y Medicina Preventiva Facultad de Medicina Veterinaria y ZootecniaCampus de Ciencias Biológicas y AgropecuariasUniversidad Autónoma de YucatánMéridaYucatán 97100México Unidad Interinstitucional de Investigación Clínica y Epidemiológica Facultad de MedicinaUniversidad Autónoma de YucatánMéridaYucatán 97000México

Chronic kidney disease is commonly diagnosed in dogs,and clinical signs may be aggravated when infected agents are *** this case report,33 dogs with chronic kidney disease were clinically evaluated and serologically tested for Leptospira spp.,Ehrlichia canis,and Anaplasma *** seroprevalence for Leptospira *** 39.4%.The most frequent serovars found were Pyrogenes,Canicola,Bratislava and Australis,with serological titers between 1:100 to 1:*** signs included fever,depression,decreased body condition,vomiting and hema‑*** laboratory fndings were anemia,leukocytosis,thrombocytopenia,increased liver enzymes,urea and creatinine,hyperbilirubinemia and *** leptospira seronegative dogs were positive for one or both monitored homoparasites(i.e.,*** and ***);only three leptospira seropositive dogs were positive for one or both *** also suggest that endemic hemoparasites of dogs should be moni‑tored in dogs with a kidney condition for a better clinical picture of the patients and therapeutic approach.

关键词： Anaplasma Chronic kidney disease Dog Ehrlichia Leptospira

Superexchange and charge transfer in the nickelate superconductor La_(3)Ni_(2)O_(7) under pressure

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 1-8页

作者： wéi wú Zhihui Luo Dao-Xin Yao Meng wang Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSchool of PhysicsSun Yat-sen UniversityGuangzhou 510275China

Recently, a bulk nickelate superconductor La_(3)Ni_(2)O_(7) is discovered at pressures with a remarkable high transition temperature T_(c)~ 80 K. Here, we study a Hubbard model with tight-binding parameters derived from ab initio calculations of La_(3)Ni_(2)O_(7),by employing large scale determinant quantum Monte Carlo and cellular dynamical mean-field theory. Our result suggests that the superexchange couplings in this system are comparable to that of cuprates. The system is a charge transfer insulator as the hole concentration becomes four per site at large Hubbard U. Upon hole doping, two low-energy spin-singlet bands emerge in the system exhibiting distinct correlation properties: while the one composed of the out-of-plane Ni-d_(3z^(2)-r^(2)) and O-p_(z) orbitals demonstrates strong antiferromagnetic correlations and narrow effective bandwidth, the in-plane singlet band consisting of the Ni-d_(x^(2)-y^(2)) and O-p_(x)/p_(y) orbitals is in general more itinerant. Over a broad range of hole doping, the doped holes occupy primarily the d_(x^(2)-y^(2)) and p_(x)/p_(y) orbitals, whereas the d_(3z^(2)-r^(2)) and p_(z) orbitals retain underdoped. we propose an effective t-J model to capture the relevant physics and discuss the implications of our result for comprehending the La_(3)Ni_(2)O_(7) superconductivity.

关键词： superconductivity nickelate superconductors Hubbard model superexchange charge transfer insulator quantum Monte Carlo

Effect of suction change on water content and total volume of an expansive clay

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 699-706页

作者： ZHAN Liang-tong CHEN Ping NG C.w.w. ~ Department of Civil Engineering Zhejiang University Hangzhou 310027 China Department of Civil Engineering Zhejiang Sci- Tech University Hangzhou 310018 China Department of Civil Engineering Hong Kong University of Science and Technology Hong Kong China

A laboratory study was carried out on both natural and compacted specimens to investigate the complex soil-water interaction in an unsaturated expansive clay. The laboratory study includes the measurement of soil-water characteristic curves, 1D free swelling tests, measurement of swelling pressure and shrinkage tests. The test results revealed that the air-entry value of the natural specimen was quite low due to cracks and fissures present. The hydraulic hysteresis of the natural specimen was relatively insignificant as compared with the compacted specimen. within a suction range 0 to 500 kPa, a bilinear relationship between free swelling strain (or swelling pressure) and initial soil suction was observed for both the natural and compacted specimens. As a result of over-consolidation and secondary structures such as cementation and cracks, the natural specimens exhibited significant lower swelling (or swelling pressure) than the compacted specimen. The change of matric suction exerts a more significant effect on the water phase than on the soil skeleton for this expansive clay.

关键词： Expansive soil water content Suction Swelling Shrinkage

开颅颅内肿瘤切除术后颅内血肿的危险因素分析

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开颅颅内肿瘤切除术后颅内血肿的危险因素分析

作者：冯伟志（pech Vichheka）广西医科大学

学位级别：硕士

目的:研究开颅颅内肿瘤切除术后颅内血肿的危险因素。方法:回顾性分析广西医科大学第一附属医院神经外科从2013年1月1日至2014年12月31日行开颅颅内肿瘤切除术的病例,共有1037例。根据综合文献[1-3]对开颅术后颅内血肿的定义,选取入院... 详细信息

目的:研究开颅颅内肿瘤切除术后颅内血肿的危险因素。方法:回顾性分析广西医科大学第一附属医院神经外科从2013年1月1日至2014年12月31日行开颅颅内肿瘤切除术的病例,共有1037例。根据综合文献[1-3]对开颅术后颅内血肿的定义,选取入院后行择期或限期开颅肿瘤切除术后发生颅内血肿的病例,共有32例。根据患者是否出现开颅颅内肿瘤切除术后颅内血肿,分为术后血肿组和术后无血肿组。比较两组间患者的一般资料(包括性别和年龄)、疾病特点(包括肿瘤类型、肿瘤位置、合并的重要基础疾病等)、手术相关信息(包括手术时间、术中出血量、术中行颅内外引流等)的分布差异。筛选出术后颅内血肿相关因素后,进一步通过多因素Logistic回归分析确定高危因素。结果:共有1037例开颅肿瘤切除手术患者纳入研究,术后颅内血肿组32例,无血肿组1005例。经比较后,两组间分布具有显著性差异(P值小于0.05)的有肿瘤类型、术中同时行颅内外引流、术中出血量、术前合并高血压病和糖尿病;将这些因素进一步通过多因素模型进行分析。Logistic多因素分析模型中,肿瘤类型(OR=5.876,95%CI:1.118～2.868)、术中出血量较多(OR=17.713,95%CI:1.743～4.589)、术前合并有高血压病(OR=8.792,95%CI:1.623～10.722)被认为是开颅颅内肿瘤切除术后颅内血肿的独立危险因素。结论:许多因素都可能增加开颅颅内肿瘤切除术后颅内血肿的风险,包括患者既往史、疾病特点、手术中的各种情况。在本研究的病例中,术前合并有高血压、肿瘤类型、术中出血量多的三个因素是开颅术后颅内血肿的独立危险因素。

关键词：开颅颅内肿瘤术后血肿危险因素

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Texas Helimak

Plasma Science and Technology 2008年第3期10卷 284-289页

作者： Kenneth w.GENTLE Fusion Research Center University of Texas at Austin Texas USA

Helimak is an experimental approximation to the ideal cylindrical slab, a onedimensional magnetized plasma with magnetic curvature and shear. The Texas Helimak realizes this approximation to a large degree; the finite size of the device can be neglected for many phenomena. Specifically, the drift-wave turbulence characteristic of a slab is observed with scale lengths small compared with the device size. The device and the general features of its behavior are described here. The device is capable of studying drift-wave turbulence, scrape-off layer （SOL） turbulence, and the stabilization of turbulence by imposing velocity shear.

关键词： plasma turbulence drift waves particle transport turbulence suppression

Effect of Equal Channel Angular Extrusion on the Microstructures and Properties of Two Extruded Al-Mg-Si Alloys

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Journal of Materials Science & Technology 2005年第5期21卷 623-629页

作者： G.w.Lorimer School of Materials The University of ManchesterGrosvenor StreetMl 7HS ManchesterUK

The effect of equal channel angular extrusion （ECAE） on the microstructure of two Al-Mg-Si extrusion alloys was investigated by high resolution electron backscattered diffraction （EBSD） using a field emission gun scanning electron microscope （FEG-SEM） and a transmission electron microscope （TEM）. Two contrasting alloys： a dilute alloy, based on alloy 6061 and a concentrated alloy, based on alloy 6069 were employed for this research. It has been found that prior ECAE to extrusion promotes high angle grain boundaries （HAGBs） in the extrusions, and the increase in HAGBs ratio is due to the large shear deformation involved in the process of ECAE. Tensile testing results show that a further ageing treatment strengthens the alloys after extrusion and the ECAE processed extrusions are more ductile than conventional extrusions.

关键词： Equal channel angular extrusion Electron backscattered diffraction Al-Mg-Si alloys