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Land cover change detection based on satellite data for an arid area to the south of Aksu in Taklimakan desert

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Journal of Arid Land 2010年第1期2卷 14-19页

作者： Kiyoshi TSUCHIYA Tamotsu IGARSHI Muhtar QONG Japan Meteorological consultant Association EORC Japan Aerospace Exploration Agency (JAEA) Space and Earth Information Technology School of EngineeringKyushu Tokai University

An experiment is made to detect the land-cover change in the area located to the south of Aksu in the northern Taklimakan desert through analyses of satellite data pixel by pixel basis. The analyzed data are those observed in the late summer and early autumn of 1973, 1977, 1993 and 1995. As a parameter of land-cover, SAVI (Soil Adjusted Vegetation Index) derived from the data of Landsat MSS and JERS-1 OPS (Optical Sensor) is used. The result indicates the increase of vegetation in the oasis areas, confluent area of the Yarkant and Kashgar Rivers and around reservoirs while little change occurs in the desert area. The 1973 satellite image shows the abundant flow in the Yarkant River while the river is almost dried up in the satellite images of later years. The trend of the decrease in the Hotan River flow is recognized although not so dramatic as that of the Yarkant River.

关键词： Taklimakan Desert SAVI Landsat MSS JERS-1 OPS vegetation false color landcover change

Ancient road transport devices： Developments from the Bronze Age to the Roman Empire

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Frontiers of Mechanical engineering 2016年第1期11卷 12-25页

作者： Cesare ROSSI Thomas G. CHONDROS Kypros F. MILIDONIS Sergio SAVINO Flavio RUSSO Department of Industrial engineering University of Naples 'Federico II' Naples 80125 Italy Mechanical engineering & Aeronautics Department University of Patras Patras 26500 Greece USSME consultant via Lamaria 137 Torte del Greco Napoli Italy

The development of transportation systems has significantly enhanced the welfare and modernization of society. Wooden vehicles pulled by animals have been used for land transportation since the early Bronze Age. Whole-body gharries with rigid wheels pulled by oxen appeared in Crete by 2000 BC or earlier. Horses originating from the East were depicted in early Cretan seal-rings of the same period. The two-wheeled horse- drawn chariot was one of the most important inventions in history. This vehicle provided humanity its first concept of personal transport and was the key technology of war for 2000 years. Chariots of Mycenaean and Archaic Greece with light and flexible four-spoked wheels acting as spring suspensions were depicted in vase paintings. The development of this vehicle incorporated the seeds of a primitive design activity and was important for engineering. The Trojan horse since 1194 BC and the helepolis since 700 BC were the first known machines on a wheeled base transported by horses or self-powered. Ancient engineers invented bearings lubricated with fat, and Romans introduced the ancestors of ball bearings for their wagons and carts. The historic evolution of wheeled transportation systems, along with early traction, suspension, and braking systems, is presented in this paper. Analytical and numerical methods are incorporated to analyze the most conceivable loading situations of typically reconstructed wheeled transportation systems in ancient times. Traction requirements both for horse-driven machines and the power for internal motors are also analyzed. This study can serve as a basis for further development of detailed reconstruction of transportation systems in antiquity.

关键词： transportation wheel spoke cart axle bearing

Prolog to the Section on Radar System engineering

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Journal of Systems engineering and Electronics 1995年第1期6卷 46-47页

作者： R. T. Hill Radar consultant USA November 1994 Beijing

ＰｒｏｌｏｇｔｏｔｈｅＳｅｃｔｉｏｎｏｎＲａｄａｒＳｙｓｔｅｍＥｎｇｉｎｅｅｒｉｎｇ￥／／ＩｎｔｈｅＥｎｇｌｉｓｈｌａｎｇｕａｇｅｗｅｈａｖｅａｎｅｘｐｒｅｓｓｉｏｎｔｈａｔｓａｙｓｉｔｉｓｐｏｓｓｉｂｌｅ＂ｔｏｌｏ... 详细信息

ＰｒｏｌｏｇｔｏｔｈｅＳｅｃｔｉｏｎｏｎＲａｄａｒＳｙｓｔｅｍＥｎｇｉｎｅｅｒｉｎｇ￥／／ＩｎｔｈｅＥｎｇｌｉｓｈｌａｎｇｕａｇｅｗｅｈａｖｅａｎｅｘｐｒｅｓｓｉｏｎｔｈａｔｓａｙｓｉｔｉｓｐｏｓｓｉｂｌｅ＂ｔｏｌｏｓｅｓｉｇｈｔｏｆｔｈｅｆｏｒｅｓ...

关键词： Prolog to the Section on Radar System engineering

基于LCEM-GFEM方法爆炸载荷作用下含缺陷岩体损伤机理研究（英文）

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Journal of Central South University 2024年第2期 496-510页

作者：陈勇王应朋杨玉贵孙文凯孟宁康 State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and Technology China Coal consultant International State Key Laboratory for Geomechanics and Deep Underground engineering China University of Mining and Technology

在爆破作业过程中，岩体缺陷对裂纹扩展具有显著影响。本研究基于全局有限元方法的局部黏结单元(LCEM-GFEM)方法构建数值模拟模型，研究爆破作用下含缺陷岩体的损伤演化和裂纹扩展模式。通过引入能量传递系数，定量分析了缺陷形态对应... 详细信息

在爆破作业过程中，岩体缺陷对裂纹扩展具有显著影响。本研究基于全局有限元方法的局部黏结单元(LCEM-GFEM)方法构建数值模拟模型，研究爆破作用下含缺陷岩体的损伤演化和裂纹扩展模式。通过引入能量传递系数，定量分析了缺陷形态对应力波传播和衰减的影响。结果表明，缺陷形态对岩体的损伤特性和裂纹扩展具有显著影响。随着平行缺陷夹角的增加，爆破诱发的裂缝与衍生裂缝的合并路径从缺陷末端转移到了缺陷中间，能量传递系数增加，分形维度减小。随着平行缺陷之间的水平距离增加，平行缺陷之间的裂缝数目和能量传递系数相应减少。随着垂直缺陷之间的垂直距离增加，穿过缺陷C的主水平裂缝长度增加，能量传递系数和分形维度也增加。研究结果可为受到爆破荷载作用下含缺陷岩体的损伤特征提供指导。

关键词：缺陷岩体 LCEM-GFEM方法裂纹扩展 Cohesive单元分形理论

Stabilized effects of L-S cement-mixed batter pile composite foundation for existed warm frozen soil subgrade

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Journal of Mountain Science 2023年第2期20卷 542-556页

作者： SUN Gao-chen YAO Gang ZHANG Jian-ming LI Bo LI Jun-qi LIAN Wei-ping WEI Yi School of Civil engineering Xi’an Shiyou UniversityXi’an 710065China China State Construction engineering Corporation AECOM consultant Co. Ltd.Lanzhou 730000China State Key Laboratory of Frozen Soil engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

In permafrost regions with warm frozen soil,subgrade thaw-collapse phenomenon commonly occurs,facing thaw collapse problems of the existed frozen soil subgrade,thus it is difficult to use traditional methods such as active cooling and passive protection technology to stabilize the existed warm frozen soil *** study derives a novel stabilizer method,a long-short(L-S)cement-mixed batter pile composite foundation to stabilize the existed warm frozen soil *** solve the thawcollapse problems in warm frozen soil subgrade,high water content and large compressibility characteristics were compared between soft soil and warm frozen *** analysis of heat conduction and numerical simulation of finite element model were used to study the freeze–thaw process and evaluate the stabilized effects of the L-S cement-mixed batter piles on the warm frozen soil foundation of the Qinghai-Tibet ***,the thaw process and mechanical properties of foundation and piles were analyzed by introducing the hydration heat factor in the thermodynamic control *** results indicate that the thawing displacement of the existed warm frozen soil subgrade was reduced owing to the“support”and“grasp”effects of the L-S cement-mixed batter piles on the surrounding *** composite ground formed by strengthening the warm frozen ground with batter piles could considerably improve the bearing capacity of the existed warm frozen ground,effectively restrain the deformation of the upper embankment,and improve the strength of the *** analysis can provide method for the construction design of cement mixing batter pile foundation in cold regions.

关键词： Warm frozen soil subgrade Thaw collapse Thermal disturbance Long-short cementmixed batter pile Existed frozen soil subgrade

Encounters & Responses Trade Protectionism——Export of Chinese Electronic Products

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China's Foreign Trade 2009年第11期 25-26页

作者： Cao Naicheng MBA and Master of engineering a consultant of Allpku

After several months' downtrend,the export market of Chinese flat-panel TV began to recover in the first quarter,with 5.815 million LCD TV sets exported to overseas,increasing by 17.7%from the same time of a year ago, and 132,000 plasma TV sets exported,up by 1.5%with the same comparison. Since the later half of 2008,export volume of color TV sets from China continued

关键词：美国产品出口市场经济危机等离子电视下降趋势平板电视液晶电视 30年代

Sediment storage and morphology of the Yalu Tsangpo valley due to uneven uplift of the Himalaya

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Science China Earth Sciences 2015年第8期58卷 1440-1445页

作者： WANG ZhaoYin YU Guo An WANG XuZhao Charles S. MELCHING LIU Le State Key Laboratory of Hydro-Science and engineering Tsinghua University Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences Beijing Institute of Geology for Mineral Resources Environmental consultant

The fluvial process of the Yalu Tsangpo River occurs concurrently with the uplift of the Qinghai-Tibet ***,the river exhibits unique features in morphology and sediment *** investigations were performed from 2009–2011and the depth of the interface between the sediment deposits and bed rock was detected with an electromagnetic imaging system(EH4)at 29 cross *** deposits were sampled along the Yalu Tsangpo valley from Xietongmen to the Yalu Tsangpo *** results show that a huge amount of sediment has been deposited in four wide valley sections because the uplift rate in these sections was lower than that in the downstream gorge sections over the past million *** 518 billion m3of gravel and sand have been stored in the high mountain river valleys,which has changed the V-shaped mountain river valley into a U-shaped wide river valley in the four *** the sections with high uplift rates the river bed is incised and has formed gorges and the Yalu Tsangpo Canyon.

关键词： Yalu Tsangpo River sediment deposits uneven uplift himalaya wide valley

Open cut resource optimisation as applied to coal

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Journal of Coal Science & engineering(China) 2007年第1期13卷 1-7页

作者： Martin L. Smith Principal Mining consultant AMC consultants Brisbane QLD

Pit optimisation is the earliest and most established application of its kind in the minerals industry, but this has been primarily driven by metal, not coal. Coal has the same financial drivers for resource optimisation as does the metalliferous industry, yet pit optimisation is not common practice. Why？ The following discussion presents the basics of pit optimisation as they relate to coal and illustrates how a technology developed for massive deposits is not suitable for thin, multi-seam deposits where mine planning is often driven more by product quality than by value drivers such as Net Present Value. An alternative methodology is presented that takes advantage of the data structure of bedded deposits to optimise resource recovery in terms of a production schedule that meets constraints on coal quality.

关键词： mixed integer programming coal reserve optimisation

Undrained Stability Analysis of Three-Dimensional Rectangular Trapdoor in Clay

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Journal of Donghua University(English Edition) 2020年第4期37卷 334-339页

作者： YIN Xiaojun XIE Jun College of Mining engineering Heilongjiang University of Science and TechnologyHarbin 150027China Independent Senior Geotechnical engineering consultant Toronto ON L4C 9G1Canada

A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface *** stability of 3DRT is examined with the upper bound method of plasticity limit analysis *** soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield *** analysis technique is employed to investigate the collapse of *** model is divided into five different block types and added up to ten rigid *** to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search *** results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square *** critical stability ratios can be used in the design of underground excavation and support force.

关键词： three-dimensional rectangular trapdoor upper bound solution stability ratio rigid block block analysis technique