Geopolymer formation and its unique properties   总被引：3，自引：0，他引：3  

Daeik Kim  Hsuan-Ting Lai  George V. Chilingar  Teh Fu Yen 《Environmental Geology》2006,51(1):103-111

The characteristic property of naturally-occurring geopolymers is a high content of humic materials that are recognized by the nitrogen function. Through a simulated geopolymerization, biopolymers with non-nitrogen function, such as xanthan gum, were found to have the characteristics of humic acid by means of UV–Vis spectrometry. This fact ascertains that any kind of biopolymer may naturally transform to a geopolymer. A geopolymer is a type of crosslinked long-chain compound, built in three-dimensional structures whose property is immune to microbial degradation. A crosslinked biopolymer was shown to have the same characterization as a geopolymer that has a long life due to its crosslinking capacity and anti-microbial properties. In this study, the formation of petroleum-based geopolymers (e.g., kerogen) was introduced. This study may elucidate the structure of geomacromolecules and the mechanism of their formation, closely related with crosslink reaction between inorganic and organic molecules. This will further change the conventional definition of geopolymer that involves only the inorganic geopolymer.  相似文献   

Sulfur electronic environments in α-NiS and β-NiS: examination of the relationship between coordination number and core electron binding energies     

Siew Wei Goh  Alan N. Buckley  Robert N. Lamb  William M. Skinner  Allan Pring  Haipeng Wang  Liang-Jen Fan  Ling-Yun Jang  Lee-Jene Lai  Yaw-wen Yang 《Physics and Chemistry of Minerals》2006,33(2):98-105

X-ray photoelectron spectra have been obtained under the same experimental conditions for synthetic α-NiS and natural β-NiS in order to establish any difference in S electronic environment, and to test the proposition that S core electron binding energies increase measurably with coordination number when the same metal is in different sulfide structures or lattice sites. The Ni and S electronic environments in the two NiS structures have been further probed by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, and the NEXAFS spectra interpreted by reference to spectra simulated by ab initio calculations. The photoelectron and NEXAFS spectra for freshly prepared surfaces of α-NiS and β-NiS were found to be similar, with only subtle differences in electronic environment evident in the experimental and simulated NEXAFS spectra. The measured and calculated core electron binding energies did not support the previously postulated relationship between S coordination number and electron binding energies.  相似文献   

Further Study on Geochemical Characteristics and Genesis of the Boninitic Rocks from Bikou Group, Northern Yangtze Plate     

李永飞赖绍聪  秦江锋 《中国地质大学学报(英文版)》2006,17(2):126-131

INTRODUCTIONCompositionally ,the term“boninite”refers to alarge variety of pri mary or near-pri mary ( Mg#=0 .60 -0 .85) magmas with a wide variation of CaO/Al2O3(most range from0 .55 to 0 .75) (Crawford etal .,1989) . With regard to its definition as recom-mended bythe I UGS (Deng et al .,1993) and Hickeyand Frey (1982) ,the classification of boninitic rocksis still a matter of petrological debate ( Qiu et al .,2004) .In general ,rock with some typical geochemi-cal features of bon…  相似文献   

Geology and Mineralogy of the Baolun Hydrothermal Gold Deposit in the Hainan Island, South China     

Ping'an Wang    Hiroaki Kaneda    Shijiang Ding  Xiaowen Zhang  Xiangjun Liao  Faxian Dong    Zhongjian Li    Xiaochun Liu  Yong Lai 《Resource Geology》2006,56(2):157-166

Abstract. The Baolun quartz vein type Au deposit, is located at the southwestern Hainan Island. It occurs next to a Triassic ilmenite-series/S-type syenogranite complex. A ⁴⁰Ar/³⁹Ar plateau age for muscovite from the master orebody is dated to be 219.4±0.6 Ma, suggesting that the gold deposit genetically related to the granite pluton. In the Baolun mining area, orebodies of auriferous quartz vein and wall rock alteration occur in NNW-striking fracture zones hosted by weakly metamorphosed turbidite of the Lower Silurian age. Eight fracture zones, 400∼1300 m long and 10∼30 m wide, have been identified. The five fracture zones of them form orebodies. The ores are mainly of quartz vein type. More than 20 orebodies in shapes of vein and lens of 195∼751 m in length and 0.20∼7.49 m in thickness are known, and 14 of them occur in the No. 1 vein belt. Silicification, sericitization and pyritization are closely related to the Au mineralization. The ores exhibit commonly 1.54∼29.48 g/t in Au grade, partially >98 g/t. The master orebody is 720 m long and 2.62 m thick in average, with 9.53∼29.27 g/t Au. Gold reserves of more than 70 t have been proven by geological exploration. More than 20 metallic minerals including native gold and sulfides such as pyrite, pyrrhotite, chalcopyrite, and others are identified to be formed in four ore-forming stages: (1) Au-coarse grain quartz stage, (2) Au-fine grained quartz stage, (3) Au-bismuthide-bismuth sulfosalt-sulfide-quartz stage, and (4) calcite-sulfide-quartz stage. The Au mineralization in this deposit occurred mainly in the first three stages. A variety of Bi- and Te-bearing minerals is closely associated with native gold suggesting that the mineralization may take place in a relatively high temperature.  相似文献   

A deterministic linearized recurrent neural network for recognizing the transition of rainfall–runoff processes     

Tsung-yi Pan  Ru-yih Wang  Jihn-sung Lai 《Advances in water resources》2007

Characterizing the dynamic relationship between rainfall and runoff is a highly interesting modeling problem in hydrology. This study develops a deterministic linearized recurrent neural network (denoted as DLRNN) that deals with the system’s nonlinearity by recalibration at each time interval, and relates the weights of DLRNN to unit hydrographs in order to describe the transition of the rainfall–runoff processes. Case studies of 38 events, from 1966 to 1997, are implemented in the Wu-Tu watershed of Taiwan, where the runoff path-lines are short and steep. A comparison between the DLRNN and a feed-forward neural network demonstrates the advantage of DLRNN as a dynamic system model. It is concluded that DLRNN shows superiority in the performance of rainfall–runoff simulations and the ability to recognize transitions in hydrological processes.  相似文献   

浙江嵊泗海域第四纪沉积层序及承压水层位特征初探   总被引：1，自引：0，他引：1  

李珍  李杰  李贞  张莱  骆祖江 《上海国土资源》2008,(2):7-14

通过对“嵊泗二井”地层层序和孢粉层序分析结果与前人研究成果及数据进行对比,同时参考长江三角洲、东海内陆架的第四纪沉积环境演化的总体框架,对嵊泗二井进行了第四纪地层的划分,并初步探讨了各含水层和隔水层的地层特征,为今后对东海陆架区地下水的开采和利用提供研究基础。  相似文献   

Behaviour of the crushed zone in rock indentation     

Per-Arne Lindqvist  Lai Hai-Hui 《Rock Mechanics and Rock Engineering》1983,16(3):199-207

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基于Meta分析的中国森林生态系统生态服务功能价值转移研究   总被引：1，自引：0，他引：1  

漆信贤  黄贤金  赖力 《地理科学》2018,38(4):522-530

构建中国森林生态系统生态服务功能价值的数据库和Meta模型,分析价值评估的影响因素,检验模型的有效性。研究表明：①研究方法、生态系统生态服务功能、植被类型、所处植被区域、受益人口数量及集聚程度是影响森林生态系统生态服务功能价值变化的主要影响因素;②有效性检验证明将基于Meta分析的价值转移运用在森林生态系统生态服务功能价值评估上是一种快速且有效的方法;③中国森林生态系统生态服务功能价值呈现东高西低、南高北低的特征,价值随时间推移而增加,涵养水源功能价值最高,提供林果产品功能价值最低。  相似文献   

Analyzing vegetation dynamic trend on the Mongolian Plateau based on the Hurst exponent and influencing factors from 1982–2013     

Siqin Tong  Jiquan Zhang  Yuhai Bao  Quan Lai  Xiao Lian  Na Li  Yongbin Bao 《地理学报(英文版)》2018,28(5):595-610

This study analyzed the spatial and temporal variations in the Normalized Difference Vegetation Index (NDVI) on the Mongolian Plateau from 1982–2013 using Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g data and explored the effects of climate factors and human activities on vegetation. The results indicate that NDVI has slight upward trend in the Mongolian Plateau over the last 32 years. The area in which NDVI increased was much larger than that in which it decreased. Increased NDVI was primarily distributed in the southern part of the plateau, especially in the agro-pastoral ecotone of Inner Mongolia. Improvement in the vegetative cover is predicted for a larger area compared to that in which degradation is predicted based on Hurst exponent analysis. The NDVI-indicated vegetation growth in the Mongolian Plateau is a combined result of climate variations and human activities. Specifically, the precipitation has been the dominant factor and the recent human effort in protecting the ecological environments has left readily detectable imprints in the NDVI data series.  相似文献   

多普勒雷达产品对南宁冰雹天气的应用分析   总被引：1，自引：0，他引：1  

赖雨薇  黄磊  周惠文 《气象研究与应用》2014,35(4):36-39

利用南宁多普勒天气雷达产品结合天气图资料,对2013年3月13日凌晨和夜间发生在南宁冰雹过程的天气背景、多普勒雷达产品进行分析,找出了相应的天气气候特征,为日后冰雹天气的临近预报提供一定的指导依据。  相似文献