Detection of dryland degradation using Landsat spectral unmixing remote sensing with syndrome concept in Minqin County,China

This study was to detect dryland degradation coupling linear spectral unmixing model of Landsat images with syndrome concept in temperate dryland system, Minqin, China. The phenological contrast and complementation between green vegetation fraction in summer, sandland fraction and saline land fraction in spring, was firstly structured to quantify degradation characteristics by simple correlation analysis with ground data. The spatiotemporal patterns of the three degradation indicators were interpreted with the help “dust bowl” syndrome, qualitatively deciphered the degradation causal clusters, loops and important consequences in the study area. The results indicate water-using and distribution pattern was changed, agricultural intensity and productivity increased, salinization lessened in oasis, whereas sandification risk heightened. This approach developed in this study, has the potentially broad applicability, for dryland system monitoring and modelling.     

城市地下管线信息管理系统的设计

数字管网和数字城市是信息时代的重要标志,该文探讨了城市地下管线信息管理系统的设计与建设,从而为数字管网的建设与完善提供借鉴。     

Tectono-Metallogenic System in the Altay Orogenic Belt, China

The Altay erogenic belt of China is an important metallogenic belt of base metals, rare metals and gold. The main orogenic-metallogenic epoch is the Hercynian (Late Palaeozoic). Hercynian orogeny underwent two tectonic stages: the early volcano-passive continental margin extension (D1-D2) and late subduction-collision (D3-P). There correspondingly developed two different metallogenic systems. One is the stratabound massive sulphide and iron metallogenic system related to volcano-passive continental margin, and the other is the epigenetic gold and granite-associated rare metals system formed by collision. Very few mineralizations were formed during the subduc-tion time.     

EH-4系统观测资料的非远区场校正研究

EH－4系统实测的卡尼亚视电阻率在非远区场时应作必要的校正。基于导出的EH－4系统的卡尼亚电阻率ρxy和ρyx的表达式,采用多项式分段逼近的方法,建立EH－4系统测深数据的全频域的视电阻率算法。根据建立的算法对均匀大地、二层大地和三层大地模型的EH－4系统测深数据进行非远区场校正的结果表明：均匀大地时,全频域的视电阻率与真电阻率吻合很好,D型、K型和Q型断面的视电阻率曲线与MT法的接近,G型、H型和A型的视电阻率曲线得到很大改善。     

Carbonate platform evolution: from a bioconstructed platform margin to a sand-shoal system (Devonian, Guilin, South China)

ABSTRACT The depositional organization and architecture of the middle–late Devonian Yangdi rimmed carbonate platform margin in the Guilin area of South China were related to oblique, extensional faulting in a strike‐slip setting. The platform margin shows two main stages of construction in the late Givetian to Frasnian, with a bioconstructed margin evolving into a sand‐shoal system. In the late Givetian, the platform margin was rimmed with microbial buildups composed mainly of cyanobacterial colonies (mostly Renalcis and Epiphyton). These grew upwards and produced an aggradational (locally slightly retrogradational) architecture with steep foreslope clinoforms. Three depositional sequences (S3–S5) are recognized in the upper Givetian strata, which are dominated by extensive microbialites. Metre‐scale depositional cyclicity occurs in most facies associations, except in the platform‐margin buildups and upper foreslope facies. In the latest Givetian (at the top of sequence S5), relative platform uplift (± subaerial exposure) and associated rapid basin subsidence (probably a block‐tilting effect) caused large‐scale platform collapse and slope erosion to give local scalloped embayments along the platform margin and the synchronous demise of microbial buildups. Subsequently, sand shoals and banks composed of ooids and peloids and, a little later, stromatoporoid buildups on the palaeohighs, developed along the platform margin, from which abundant loose sediment was transported downslope to form gravity‐flow deposits. Another strong tectonic episode caused further platform collapse in the early Frasnian (at the top of sequence S6), leading to large‐scale breccia release and the death of the stromatoporoid buildups. Siliceous facies (banded cherts and siliceous shales) were then deposited extensively in the basin centre as a result of the influx of hydrothermal fluids. The platform‐margin sand‐shoal/bank system, possibly with gullies on the slope, persisted into the latest Frasnian until the restoration of microbial buildups. Four sequences (S6–S9), characterized by abundant sand‐shoal deposits on the margin and gravity‐flow and hemipelagic deposits on the slope, are distinguished in the Frasnian strata. Smaller‐scale depositional cyclicity is evident in all facies associations across the platform–slope–basin transect. The distinctive depositional architecture and evolution of this Yangdi Platform are interpreted as having been controlled mainly by regional tectonics with contributions from eustasy, environmental factors, oceanographic setting, biotic and sedimentary fabrics.     

新地球观

One of the most important achivements on science in 20th century is the new recognition on the Earth:the Earth,out of the other planets, exhibits very peculiar features because it has an extremely complex and active periphery part (surfacial layers). This periphery part is an open system sustained by inputting solar energe , which is captured , transfered and stored by life. Through the system , cyclings of matters and energe flow are driven and regulated by life activities. This system is self-equilibrated,self-controlled and far away from astrophysical and thermodynamic equilibria mainly because of life and life activities.
Development of human calture influences increasingly on流Earth's periphery system , at last , the natural biosphere that has existed for 3 billion years on the Earth's surface will inavoidably be replaced by so called "noosphere",which is man一reconstructed,man-controlled and unstable system. Thus the fate of the Earth,to a great extent,will be determined by the direction of human calture evolution.
     

五酸溶样-电感耦合等离子体质谱法同时测定地质样品中的稀土等28种金属元素

电感耦合等离子体质谱法(ICP-MS)测定大批量地质样品中的稀土和钴铪铟锰铌钽铊铬镉镓锗钒锡等金属元素,主要采用三酸或四酸溶解样品.由于地质样品组分复杂,稀土等金属元素含量低,各元素性质差异大,三酸或四酸溶样经常出现易挥发元素如钒铬镉镓锡的测定结果不稳定、镧铈镨钕等稀土元素溶解不完全的问题.本文在盐酸-硝酸-氢氟酸-高...     

1997～1998年伽师强震群小地震震源机制解系统聚类分析

用P、S波最大振幅比法计算1997~1998年伽师强震群MS2.5~3.7小地震震源机制解,对小地震震源机制解进行系统聚类分析。结果表明,伽师小地震主要以走滑和正断层为主,与该时段发生的伽师6级强震具有相似的断错性质。1997年伽师小地震主压应力P轴方位为北东或近南北向,与1997~1998年6级强震主压应力P轴方位一致。1997年4月6日6.4级和1998年8月2日6.1级两次6级正断层地震前出现地震空段现象。     

浅水环境中垂向圆形纯射流的试验研究

对静止均匀浅水水域中的铅垂圆形单孔射流进行了试验研究,试验是在实验室的自制恒定水流循环系统中进行的。得到了水面的隆起高度与射流出口单位能量和相对水深的函数关系;验证了隆起高度分布具有自相似性,并给出其统一表达式;借助于三维测速仪,得到了射流流速的横断面分布、射流中线流速的衰减规律和流场的流函数等值线。     

地下工程围岩分类模糊推理系统设计

将现场获取的影响地下工程围岩分类的几种主要因素视为判别围岩类别论域上的模糊子集,利用建立的地下工程围岩分类模糊逻辑推理系统对围岩类别进行模糊逻辑推理运算,获得与实际情况相一致的围岩类别的判定,直接为地下工程的信息化设计和施工提供依据。