检索结果-南通市图书馆

现代信息技术 2000年第4期 70-72页

作者： andre.,D

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

由可见光发光二极管激励的光纤温度传感器

国外计量 1989年第3期 25-26页

作者： andre.,T 王莉

DEM parameter calibration of cohesive bulk materials using a simple angle of repose test

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2019年第4期17卷 105-115页

作者： Thomas Roessler andre.Katterfeld Chair of Material Handling Institute of Logistics and Material Handling Systems University of Magdeburg Universitatsplatz 239106 Magdeburg Germany

The numerical effort of discrete element method (DEM) simulations results in a general idealisation of DEM models that makes the calibration crucial to obtaining realistic simulation results. The angle of repose test has become a standard test for the calibration of DEM parameters of cohesionless bulk materials and is extensively discussed in the literature. One of the most used test methods is the pull-up test of a hollow cylinder filled with bulk material. This paper presents how this basic pull-up test can also be used for the calibration of DEM parameters of cohesive materials by changing the analysis criteria. In contrast to analysing the static angle of repose, the focus lies on the macroscopic flow behaviour during the lifting of the cylinder. Reproducible phases of flow are identified in experiments: the build-up of a stable bulk material column, the convex bending of the column, and the beginning of collapse of the column. Furthermore, the phases are independent of the size and lifting velocity. The convex bending of the bulk-material column combined with the moment of first collapse are introduced as new measurable calibration criteria. These experimental results of wet sand are used for the calibration of related DEM parameters using a simplified JKR cohesion model. The DEM calibration including an analysis algorithm that fits the experimental flow behaviour and the final selection of the relevant parameters (i.e., sliding friction coefficient, rolling friction coefficient, and cohesion energy density) is presented in detail.

关键词： Discrete element method Angle of repose Cohesive bulk material Calibration

Performance-based seismic design of nonstructural building components:The next frontier of earthquake engineering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2014年第S1期13卷 17-46页

作者： andre.Filiatrault Timothy Sullivan Dept.of Civil Structural and Environmental Engineering University at BuffaloState University of New York Dept.of Civil Engineering & Architecture University of Pavia Assistant Professor

With the development and implementation of performance-based earthquake engineering,harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event,failure of architectural,mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover,nonstructural damage has limited the functionality of critical facilities,such as hospitals,following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore,it is not surprising that in many past earthquakes,losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore,the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings,or of rescue workers entering buildings. In comparison to structural components and systems,there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse,and the available codes and guidelines are usually,for the most part,based on past experiences,engineering judgment and intuition,rather than on objective experimental and analytical results. Often,design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components,identifying major knowledge gaps that w

关键词： nonstructural building components performance-based earthquake engineering seismic design and analysis

Subsidence over room and pillar retreat mining in a low coal seam

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第1期29卷 51-57页

作者： andre.Zingano Anderson Weiss Mining Engineering Department University Federal of Rio Grande do Sul Carb.Do CambuíInc.

The objective of this paper is to study the behavior of a low thick and low depth coal seam and the overburden rock mass. The mining method is room and pillar in retreat and partial pillar recovery. The excavation method is conventional drill and blast because of the small production. The partial pillar recovery is about 30% of the previous pillar size, 7 m × 7 m. The roof displacement was monitored during retreat operation; the surface movement was also monitored. The effect of the blasting vibration on the final pillar strength had been considered. Due to blasting, the pillar reduced about 20%. The consequence is more pillar deformation and roof vertical displacement. The pillar retreat and ground movement were simulated in a three-dimensional numerical model. This model was created to predict the surface subsidence and compare to the subsidence measured. This study showed that the remaining pillar and low seam reduce the subsidence that was predicted with conventional methods.

关键词： Subsidence Room-and-pillar mining Retreat mining Coal

Automatic route planning for GPS art generation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Computational Visual Media 2019年第3期5卷 303-310页

作者： andre.Waschk Jens Krüger University of Duisburg-Essen

In this paper, we present a novel approach to automated route generation of global positioning system(GPS) artwork. The term GPS artwork describes the generation of drawings by leaving virtual traces on digital maps. Until now, the creation of these images has required a manual planning phase in which an artist designs the route by hand. Once the route for this artwork has been planned, GPS devices have been used to track the movement. Using our solution, the lengthy planning phase can be significantly shortened,thereby opening art creation to a broader public.

关键词： GPS art walking routing shape detection navigation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

先进的地形跟踪高度计

空间电子技术 1990年第2期 13-20页

作者： andre.,R 共田

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

C—26A井的钻井经验

国外钻井技术 1996年第5期11卷 14-21页

作者： andre.,S 李春楼

Various phases in surface movements linked to deep coal longwall mining:from start-up till the period after closure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2021年第3期8卷 412-426页

作者： andre.Vervoort Department of Civil Engineering KU LeuvenLeuvenBelgium

This paper covers the entire lifetime of an underground coal mine,including the start-up of the mining operations and the period after the closure and sealing of the underground *** of the vertical surface movement are presented for three neighbouring mines in the Belgian Campine coal basin,where the longwall mining method was ***,the monitoring of the initial phase showed that the impact of the first panel was smaller than the impacts of the following two neighbouring *** the second panel was mined,a change in the induced surface tilt was observed in the immediate proximity of the ***,data for a transect with a length of about 2.5 km were presented,covering a total time of 54 years,of which the first 31 years were during the active life of the *** subsidence rates of up to-0.3 m/year were *** the mine was closed and the pumping facilities were stopped,the average uplift rate was situated mostly between 4 and 16 mm/year,but a value of 141 mm/year also was *** years after closure,the upward movements are still ***,the phase of uplift is analyzed in more detail over a full north–south transect.A clear narrow maximum was observed for the uplift,corresponding to a total vertical movement of 0.2 m over approximately an 18-year *** these phases are relevant,for example when analysing damage to buildings and *** becomes visible when the cumulative movement and loading exceed critical limits and not necessarily when the largest rate of movement is observed,for example.

关键词： Longwall Ground control Subsidence Uplift Surface movement Radar-interferometry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

吸烟过度所致红细胞增多症的急性心肌梗塞

德国医学 1990年第4期7卷 247-248页

作者： andre.,S 李茜首都医学院