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Revisiting rock classification to estimate rock mass properties

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第3期11卷 494-510页

作者： robert Bertuzzi Pells Sullivan Meynink North RydeNSW 2113Australia

This paper presents the results of ongoing research carried out by the author exploring methods to provide a more robust estimate of rock mass properties specifically for use in tunnel *** from various large-scale rock mass failures are introduced,including coal *** damage-initiation,spalling-limit approach is compared to the coal pillar *** comparisons of estimating the geological strength index(GSI)and relationships to estimate the Hoek-Brown failure criterion parameters,mb,s and a,are presented.

关键词： Rock mass properties HoekeBrown strength criterion Geological strength index(GSI) Tunnelling

Aquatic molluscs in high mountain lakes of the Eastern Alps (Austria): Species-environment relationships and specific colonization behaviour

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Chinese Journal of Oceanology and Limnology 2012年第1期30卷 59-70页

作者： STURM robert Brunnleitenweg 41 A-5061 Elsbethen Salzburg Austria

Mountain lakes represent essential stages for aquatic species on their way colonizing habitats of more elevated regions. Despite extensive biological and chemical study, only little has been reported about the species number and density of freshwater molluscs in these waters. The article presented here elucidates the dispersal of aquatic gastropods and bivalves in 12 mountain lakes that are commonly situated in the Eastern Alps, Austria. Molluscs were recorded at 120 sample points, where a total of 13 species （8 gastropods and 5 bivalves） could be determined. Species distribution data as well as results from contemporarily conducted physico-chemical factor recording were subject to weighted average analysis. In addition, a global marginality coefficient indicating the particularity of a habitat inhabited by a focal species as well as a global tolerance coefficient expressing the width of a niche occupied by this species were computed. Species-environment relationships exhibited that species number and specific density decrease with increasing geographic altitude, declining water temperature, and decreasing amount of submerged vegetation. Whilst waters of the montane altitude level are partly charcterized by high number of mollusc species （〉 10）, lakes of the subalpine altitude level commonly bear 1 or 2 species with 〈〈1 ind./mz. As proposed by the results of statistics, 9 of the 13 mollusc species are characterized by a pronounced behaviour as specialists with respect to most environmental factors. The four remaining species, Pisidium casertanum, Galba truncatula, Radix labiata, and Radix balthica, act as generalists which increases their pioneering role in the long-term occupation of the Central-alpine region.

关键词： aquatic invertebrates species abundance weighted average analysis global marginality coefficient global tolerance coefficient Eastern Alps

The Impact of Climate Change on Agriculture in Asia

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Journal of Integrative Agriculture 2014年第4期13卷 660-665页

作者： robert Mendelsohn School of Forestry and Environmental Studies Yale University

Asian agriculture is responsible for two thirds of global agricultural GDP. There have been numerous studies exploring the impact of climate change on crops in specific locations in Asia but no study has yet analyzed crops across the entire continent. This study relies on a Ricardian study of China that estimated climate coefficients for Chinese crops. These coefficients are then used to interpolate potential climate damages across the continent. With carbon fertilization, the model predicts small aggregate effects with a 1.5℃ warming but damages of about USS84 billion with 3℃ warming. India is predicted to be especially vulnerable.

关键词： agriculture climate change Asia Rieardian

On the Chow Groups of Certain Cubic Fourfolds

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Acta Mathematica Sinica,English Series 2017年第7期33卷 887-898页

作者： robert LATERVEER Institut de Recherche Mathématique Avancée CNRS-Universitd de Strasbourg7 Rue Rene Descartes67084 Strasbourg CedexFrance

This note is about the Chow groups of a certain family of smooth cubic fourfolds. This family is characterized by the property that each cubic fourfold X in the family has an involution such that the induced involution on the Fano variety F of lines in X is symplectic and has a K3 surface S in the fixed locus. The main result establishes a relation between X and S on the level of Chow motives. As a consequence, we can prove finite-dimensionality of the motive of certain members of the family. Keywords Algebraic cycles, Chow groups, motives, cubic fourfolds, hyperkiihler varieties, K3 sur- faces, finite-dimensional motive

关键词： Algebraic cycles Chow groups motives cubic fourfolds hyperk?hler varieties K3 surfaces finite-dimensional motive

Some new pre-warning criteria for creep slope failure

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Science China(Technological Sciences) 2011年第S1期54卷 210-220页

作者： HACK robert The International Institute for Geo-information Science and Earth Observation(ITC) Enschedethe Netherlands

The forecasting of the failure time of a slope remains a worldwide problem because of many different possibilities of geological conditions in combination with many varying external factors such as climate and vegetation,and not well-defined or unknown time effects in deformation and failure *** aim of this paper is to suggest a new method to carry out the phase division and to explore tangential angular features of the displacement-time curve of creep slopes as well as the acceleration characteristics in the process of slope deformation and the pre-warning criteria for critical *** imminent failure is pro-ceeded with usually three basic deformation phases,namely primary creep("decelerated") ,secondary creep("steadystate") and tertiary creep("accelerated") .Mostly,only during the accelerated phase the imminence of a possible slope failure is *** analysis of displacement data from a series of landslides allowed to recognize different evolutionary patterns of displacement.A quantitative approach was proposed to describe the tangential angle of the displacement-time curve and a new criterion based on the angle was put forward to divide the accelerated phase into three sub-phases:initial acceleration,medium acceleration,and the critical failure.A pre-warning criterion for critical failure is also proposed consequently. Changes of acceleration showed completely different characteristics from those of cumulative displacement and displacement in the process of slope *** values of acceleration usually oscillate around 0 prior to the critical failure phase,whereas the acceleration increases abruptly when the deformation moves into the critical failure *** allows,therefore,for a method to forecast the time of the *** it is possible to define different alert acceleration threshold values to be used for emergency management.

关键词： creep slope displacement-time curve tangential angle alert acceleration threshold pre-warning of critical failure

Back-analysing rock mass modulus from monitoring data of two tunnels in Sydney, Australia

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第5期9卷 877-891页

作者： robert Bertuzzi Pells Sullivan Meynink North Ryde NSW 2113 Australia School of Civil and Environmental Engineering University of New South Wales Kensington NSW 2052 Australia

This paper presents two case studies where the rock mass modulus and in situ stress are estimated from the monitoring data obtained during the construction of underground excavations in Sydney,*** case studies comprise the widening of existing twin road tunnels within Hawkesbury sandstone and the excavation of a large cavern within Ashfield *** back-analysis from detailed systematic monitoring has been previously published,this paper presents a relatively simple methodology to derive rock mass modulus and in situ stress from the relatively simple displacement data routinely recorded during tunnelling.

关键词： Back-analysis Rock mass modulus In situ stress Sydney tunnels

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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维普期刊数据库

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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