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Effect of Activator and Curing Mode on Fly Ash-based Geopolymers

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Journal of Wuhan university of technology(Materials Science) 2009年第5期24卷 711-715页

作者：侯云芬 Institute of Civil Engineering and Traffic Beijing Institute of Civil Engineering and Architecture Department of Material China University of Mining and Technology

The influences of concentration and modulus of sodium silicate solution and curing mode on the phase composition, microstructure and strength development in the geopolymers prepared using Class F fly ash were investigated. X-ray diffraction （XRD）, Fourier transform infrared spec-troscopy （FTIR） and MAS NMR were utilized. Results show that the compressive strength increases as sodium silicate solution modulus increases, but when modulus exceeds 1.4, the compressive strength decreases, and it decreases markedly while the modulus is greater than 2.0. The compressive strength was improved by the increase of sodium silicate solution concentration. When the concentration is 32., the compressive strength reaches the maximum, then it reduces as concentration increasing. Elevated temperature can increase the strength of samples that synthesized from sodium silicate solution with 32. concentration and modulus 1.2. Compared to the strength of the sample cured at 50 ℃, the strength of the samples cured at 65 ℃ and 80 ℃ are higher at 1 d and 3 d, but the same at 7 d. At high temperature, prolonged curing time will decrease the strength. Long precuring at room temperature before application of heat is beneficial for strength development, and there is about 50% increase in strength of the samples cured at 1 d precuring and 2.d elevated temperature as compared to the strengths of the samples cured for 3 d at elevated temperatures or cured for 2. d at room temperature. The main product of reaction in the geopolymeric material is amorphous alkali aluminosilicate gel.

关键词： geopolymers fly ash activator elevated temperature

Quantitative analysis on soil erosion based on 3S technology

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中国有色金属学会会刊：英文版 2005年第S1期15卷 82-85页

作者： JING Hai-tao~1, XIE Hong-quan~(2. 3), FU Mei-chen~2. FENG Zhong-ke~4 (1. Xuzhou Normal university, Xuzhou 2.1009, china {2.(beijing Campus), beijing 100083, china 3. Hebei Polytechnic university, Tangshan 063009, china 4. beijing Forestry university, beijing 100083, china Xuzhou Normal Univ Xuzhou 221009 Peoples R China china Univ Min & Technol Beijing 100083 Peoples R China Hebei Polytech Univ Tangshan 063009 Peoples R China beijing Forestry Univ Beijing 100083 Peoples R China

The quantitative analysis on soil erosion is very significant for macro-decision of soil loss, for quick control of natural disasters and for system of periodical report. Based on the research of 3S(GPS, GIS and RS), the special information can be obtained by GPS or RS. Digital elevation model can be formed by GIS software, and at the same time, we can get some vector graph, such as landuse, vegetation type and soil type. Then the soil erosion of research area was calculated by USLE. The methods and techniques were discussed, including how to carve up polygons, how to capture the values of factors and how to differentiate the erosion intensity.

关键词： soil erosion USLE GPS GIS RS

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我国油气资源评价现状与存在问题

新疆石油地质 2004年第5期25卷 554-556页

作者：周总瑛唐跃刚中国石油化工股份有限公司石油勘探开发科学研究院中国矿业大学北京100083 中国矿业大学

简要介绍了我国历次油气资源评价概况及特点,指出了我国油气资源评价与国际惯例相比,在评价方法、评价结果、资源量的构成和资源量的时效性四个方面上存在的差异。为了更加客观评价我国油气资源潜力,建议以新一轮全国油气资源评价工作... 详细信息

简要介绍了我国历次油气资源评价概况及特点,指出了我国油气资源评价与国际惯例相比,在评价方法、评价结果、资源量的构成和资源量的时效性四个方面上存在的差异。为了更加客观评价我国油气资源潜力,建议以新一轮全国油气资源评价工作为契机,加强统计法、地质类比法及油气资源经济性评价等薄弱环节的研究,进一步完善我国油气资源评价方法,建立一套既能符合我国油气地质特点、又能与国际接轨的油气资源评价方法体系。

关键词：油气资源评价资源量构成时效性资源潜力

巴楚寒武—奥陶系碳酸盐岩微量元素及沉积环境

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新疆石油地质 2004年第6期25卷 631-633页

作者：何宏彭苏萍邵龙义中石化石油勘探开发科学研究院北京100083 中国矿业大学北京100083

研究了塔里木盆地巴楚地区寒武-奥陶系海相碳酸盐岩的微量元素特征,探讨了微量元素的富集机制。分析表明,微量元素的富集与原始沉积环境有着极为密切的关系押微量元素K、Na、Al、Fe等含量在开阔台地和台地边缘浅滩均较低,而在台地斜坡... 详细信息

研究了塔里木盆地巴楚地区寒武-奥陶系海相碳酸盐岩的微量元素特征,探讨了微量元素的富集机制。分析表明,微量元素的富集与原始沉积环境有着极为密切的关系押微量元素K、Na、Al、Fe等含量在开阔台地和台地边缘浅滩均较低,而在台地斜坡带较高;Mn、Cr、Ni、V等元素的含量从浅水到深水总体呈增加之势,因此可以指示古水深的变化。常量元素w(Ca)/w(Mg)比值在以白云岩为主的蒸发台地、局限台地相中最低,在潮下开阔台地、台地边缘浅滩沉积中则由于白云岩不发育而比较高。开阔台地相w(Sr)/w(Ba)比值较高,而局限台地相、蒸发台地相则相对较低。碳酸盐岩的微量元素结合常量元素分析可以作为沉积环境判别的有效的标志。

关键词：台地沉积环境碳酸盐岩奥陶系巴楚富集机制古水深白云岩塔里木盆地斜坡带

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沙坝沟滑坡成因分析与稳定性评价

土工基础 2008年第6期22卷 29-32页

作者：陈书生易武三峡大学三峡库区地质灾害教育部重点实验室中国矿业大学北京校区

分析了滑坡体的物质组成、结构特征及复合滑动的变形特征,认为滑坡的坡体特性、坡体前缘局部崩塌、水体入渗为滑坡的形成提供了条件;持续降雨、河流长期冲刷、人类工程活动是影响滑坡稳定性的主要因素。据岩土物理力学试验及不同工况下... 详细信息

分析了滑坡体的物质组成、结构特征及复合滑动的变形特征,认为滑坡的坡体特性、坡体前缘局部崩塌、水体入渗为滑坡的形成提供了条件;持续降雨、河流长期冲刷、人类工程活动是影响滑坡稳定性的主要因素。据岩土物理力学试验及不同工况下稳定性计算结果,对滑坡进行稳定性评价。结果表明在一定条件下,滑坡体存在潜在的不稳定滑面,应采取必要的防治措施。

关键词：滑坡成因机制稳定性评价

A MODIFIED ALGORITHM OF FINDING AN ELEMENT OF CLARKE GENERALIZED GRADIENT FOR A SMOOTH COMPOSITION OF MAX-TYPE FUNCTIONS A MODIFIED ALGORITHM OF FINDING AN ELEMENT OF CLARKE GENERALIZED GRADIENT FOR A SMOOTH COMPOSITION OF MAX-TYPE FUNCTIONS

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Journal of Computational Mathematics 2000年第5期18卷 513-520页

作者： Yan Gao (Department of Basic Science, china university of {2. and technology-beijing, beijing 100083, china) （北京）中国矿业大学北京 100083

This paper refers to Clarke generalized gradient for a smooth composition of max-type functions of the form: f(x) = g(x, maxj∈J1 f1j(x),''', maxj∈Jm fmj(x)), where x ∈Rn, Ji, i = 1,''',m are finite index sets, g and fij,j ∈ Ji, i = 1,... )m, are continuously differentiable on Rm+n and Rn, respectively. In a previous paper) we proposed an algorithm of finding an element of Clarke generalized gradient for f, at a point. In that paper, finding an element of Clarke generalized gradient for f, at a point, is implemented by determining the compatibilities of systems of linear inequalities many times. So its computational amount is very expensive. In this paper) we will modify the algorithm to reduce the times that the compatibilities of systems of linear inequalities have to be determined.

关键词： Nonsmooth optimization Clarke generalized gradient Max-type function.

On three-dimensional geological modeling and visualization

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Science china Earth Sciences 2004年第8期47卷 739-748页

作者： WU Qiang1 & XU Hua2.1. Department of Resource Exploitation Engineering, china university of {2. and technology, beijing 100083, china 2. beijing Institute of Petrochemical technology, beijing 102.17, china Department of Resource Exploitation Engineering China University of Mining and Technology Beijing China beijing Institute of Petrochemical technology Beijing China

The technology of 3D geological modeling will bring about great changes in the methods of geological data acquiring, storing, processing and displaying. However, no perfect or convenient software systems have been developed up to now since the geologic data which re-flect geological entities bear the feature of diversity, uncertainty and complexity. Some supervoxel models, mathematical models of fault and geometrical models of fold have been contrived so as to show the space geometric configuration of the complicated geologic structures. The application-oriented system architecture for 3D geological modeling is established; and a novel design concept based on spatial data processing is also proposed with the technology of solid modeling as its core and the application of models as its objective. Theories and methods for 3D geological modeling will hopefully be enriched and developed. In the light of these theories and methods, a feature-based navigation visualization technique is also put forward in the paper. By integrating geo-database, graphics libraries and KBS with 3D dynamic simulation systems, geologists will be able to capture the partial characteristics and whole structure embodied in the geological data in a direct-viewing, figurative and accurate manner.

关键词： 3D geological modeling,geometrical model,system architecture,visualization

The evolution model of the earth's limited expanding

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Chinese Science Bulletin 2000年第4期45卷 304-313页

作者： CHEN Zhigengchina university of {2. and technology, beijing 100083, china china university of {2. and technology Beijing China

Based on the prerequisite that the earliest acid rock formed because of the initial global expanding tectonic processes, by combining it with other geological limitation conditions, and starting from the lithosphere elastic mechanics, the following is defined : the earth expansion started at about 4300 Ma ago, the average increasing rate of the earth radius is 0.40 mm/a, the initial expanding earth radius is 4651 km, and the initial global expansion of tectonic processes happened at 4183.7 Ma ago. From the natural and attenuation evolution condition of the earth and terrestrial planets, through the limit condition got from the combination of the mathematics logic and the geological significance, the limited expanding earth evolution model is established as follows:in which R0= 4.651×106 m, A =1.86×106 m, β = -6.01?10-10 a and ts=3×10 a. From this model the maximum radius Rmax of the limited expanding earth evolution should be 6511 km. The earth’s radius increasing rate is about 0.1 mm/a at present.

关键词： limited earth expansion evolution model start time of expansion start time of expanding tectonism stage character of tectonism .

On some tests-based projection pursuit for elliptical symmetry of a high-dimensional distribution

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Chinese Science Bulletin 1998年第6期43卷 450-458页

作者： JING Ping 1 and ZHU Lixing 2.1. Mathematics Lab, china university of {2. & technology, beijing 100083, china 2. Probability Lab, Institute of Applied Mathematics, Chinese Academy of Sciences, beijing 100080, china Mathematics Lab China University of Mining & Technology Beijing China Probability Lab Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

Some test statistics of Kolmogorov type and Cramér-von Mises type based on projection pursuit technique are proposed for the testing problem of sphericity of a high-dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis and under any fixed alternative. The asymptotic properties of bootstrap approximation are investigated. Furthermore, for computational reasons, an approximation for the statistics, based on the number theoretic method, is suggested.

关键词： bootstrap approximation projection pursuit type statistic elliptical symmetry.