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Evaluation of the azoospermic male

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Asian Journal of Andrology 2012年第1期14卷 82-87,177页

作者： robert Oates Boston University School of Medicine Boston MA 02118 USA

When presented with an azoospermic patient, a thorough history and careful, considered physical examination often leads to a definite or presumptive diagnosis. An algorithmic, logical thought process is important to have in mind when embarking on the evaluation. Adjunctive laboratory tests, such as hormonal assays or genetic studies, are often complementary and/or additive and allow a very precise determination to be made as to the etiologies, either genetic or acquired. It is only with this information that a therapeutic plan can be made for the patient. As will be discussed, a targeted approach to testing is far more satisfying and cost-effective than a blind, shotgun approach.

关键词： azoospermia congenital bilateral absence of the vas deferens male infertility Y chromosomal microdeletion

Energy consumption for creep fracture of metallic materials

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Acta Mechanica Sinica 2008年第4期24卷 469-472页

作者： robert A.Arutyunyan Universitetskii pr.28 Faculty of Mathematics and Mechanics Sankt-Petersburg State University Petrodvoretz Sankt-Petersburg 198504 Russia

The energy conservation law is applied to formulate the ductile and brittle creep fracture criterion for metallic materials. The criterion contains a summary of heat and latent energies. Assuming that the heat energy is given out so it has no effect on the fracture process, the ductile creep fracture criterion is simplified. To take into account the evaluation of the damage state of materials the compressibility condition is introduced and the brittle creep fracture law is formulated.

关键词： Ductile and brittle fracture criterion Energy conservation law Heat and latent energies

On-line non-intrusive particle size measurement of pulverised fuel through digital imaging

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仪器仪表学报 2007年第11期28卷 1942-1946页

作者： Carter robert M Department of Electronics University of Kent

This paper presents the basic principles of particle size measurement and latest industrial results recorded using an innovative optical instrumentation system designed to measure the size distribution of particles in a pneumatic *** system is non-intrusive and cost-effective.A low-cost CCD camera is used to capture images of the particulate flow field,which is illuminated by a low-cost pulsed laser sheet *** particle size distribution is then determined by processing the particle images through the use of novel processing *** results obtained in the past on a small scale particle flow test rig have demonstrated that the system is capable of measuring the size distribution of pneumatically conveyed particles with an accuracy of a few *** the present paper results obtained when testing the system at a 4 MW industrial test facility are *** are made with both off-line reference data achieved through sieving and on-line laser diffraction data recorded using an intrusive,extractive,Malvern Instruments *** general there is good agreement between results when considering the characteristics and limitations of the individual *** novel imaging system shows itself to be rugged,practical and useful under genuine industrial conditions.

关键词：粒子测量方法数字成像数码

Modelling of the Process of Coal Dust Combustion in a Cyclone Furnace

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Journal of Thermal Science 2017年第2期26卷 192-198页

作者： robert Zarzycki Zbigniew Bis Czestochowa University of Technology Department of Energy Engineering Brzeznicka 60a42-201 CzestochowaPoland

This study presents the concept of a cyclone furnace for coal dust oxy-fuel combustion and gasification. The results of numerical calculations for the combustion and gasification processes were also presented.

关键词： oxy-fuel combustion numerical simulations coal dust gasification cyclone furnace

Discrete scale invariance and ln(B) periodic quantum oscillations in topological semimetals

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Science China(Physics,Mechanics & Astronomy) 2019年第3期62卷 114-116页

作者： robert Joynt Physics Department University of Wisconsin-Madison Kavli Institute for Theoretical Sciences University of Chinese Academy of Sciences

Quantum oscillations have played a major role in the history of condensed matter physics—and indeed in physics as a *** 1930,Shubnikov and de Haas(SdH)[1]discovered oscillations in the resistance of bismuth as a function of magnetic field,R(B).Because of theoretical work of Landau[2]in the same year,it was soon realized that the oscillations were periodic in 1/B:if a peak in R is observed at B=1T and another at B=0.5T,then we should see one at B=0.33 T,B=0.25T and so *** work is famous,but maybe not as much as it should be:it was the first discovery of a macroscopic effect that depends for its existence on the fact that an electron has a phase.

关键词： Discrete scale invariance In(B)periodic quantum oscillations topological semimetals

Solar surface magnetoconvection simulations: A brief review of solar dermatology

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Science China(Physics,Mechanics & Astronomy) 2009年第11期52卷 1665-1669页

作者： CAMERON robert Max-Planck-Institute fr Sonnensystemforschung Katlenburg-Lindau

Rapid improvement in the speed of computers has enabled realistic simulations of magnetoconvective processes in the surface layers of the Sun. The simulations now cover a wide range of features found in observations. In many cases a direct comparison with the observations is justified, and in all cases our understanding and interpretation of the observations is being improved. Current and future opportunities and difficulties will be discussed.

关键词： Sun photosphere magnetohydrodynamics

Demand response:a strategy to address residential air-conditioning peak load in Australia

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Journal of Modern Power Systems and Clean Energy 2013年第3期1卷 223-230页

作者： robert SMITH Ke MENG Zhaoyang DONG robert SIMPSON Ausgrid SydneyNSW 2000Australia enter for Intelligent Electricity Networks(CIEN) The University of NewcastleNewcastleNSWAustralia

Rapid growth in electricity network peak demand is increasing pressure for new investment which may be used for only a few hours a *** airconditioning is widely believed to be the prime cause of the rise in peak demand but,in the absence of detailed residential demand research,there is no bottom-up empirical evidence to support this supposition or to estimate its *** paper first examines the developments in network peak demand,at a national,network distribution,and local distribution feeder level to show recent trends in peak ***,this paper applies analytics to the half-hourly consumption data of a sample of Ausgrid’s interval metered customers,combined with local weather data,to develop an algorithm which can recognize air-conditioner use and can identify consumption patterns and peak *** estimate is then compared to system peaks to determine residential airconditioning’s impact on overall ***,this paper considers the future impacts of air-conditioning load on peak demand as penetration rates reaches saturation levels and new minimum energy performance standards take effect reducing new units peak impacts.

关键词： Air conditioner Demand response Peak load

How TP53 (almost) became an oncogene

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Journal of Molecular Cell Biology 2019年第7期11卷 531-533页

作者： robert A.Weinberg Whitehead Institute for Biomedical Research Ludwig/MIT Center for Molecular OncologyMIT Department of BiologyCambridgeMA 02142USA

Like the histories of many other genes,the discovery and characterization of p53 are associated with some false leads,dead ends,and major *** chronicle of p53,s early years is no *** is now well known,the protein was ... 详细信息

关键词： histories characterization Old

A mechanistic study of CO removal on a small H-saturated platinum cluster

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Science China Chemistry 2008年第12期51卷 1187-1196页

作者： FORREY robert C Department of Physics Pennsylvania State University Berks Campus Reading PA 19610 USA

CO poisoning to platinum catalysts has long been recognized as one of the major technical obstacles in heterogeneous catalysis and its successful removal represents a significant challenge to a wide variety of applications. Using density functional theory (DFT), we performed systematic theoretical calcula-tions to explore the CO removal mechanisms, in the presence of hydrogen, via oxidation by oxygen to form CO2 or reduction by hydrogen to form formaldehyde using a subnano Pt cluster as a model for catalyst nanoparticles. We show that CO oxidation is both thermochemically and kinetically difficult at low H coverage but becomes very exothermic with a moderate activation barrier at high H coverage, suggesting that the oxidation can be carried out readily at elevated temperatures. Doping the Pt cluster with Ru can significantly improve the oxidation thermochemical energy and moderately reduce the activation barrier. The results are consistent with experimental observations. We found that CO reduction by hydrogen to form formaldehyde is moderately endothermic. However, the reaction is predicted to be kinetically difficult due to the relatively high activation barriers associated with the sequential H attacks to the CO molecule.

关键词： cluster Pt-Au alloy full H-saturation CO oxidation CO hydrogenation density functional theory