检索结果-南通市图书馆

Acta Geologica Sinica(English Edition) 2012年第3期86卷 680-690页

作者： WANG Zhong XIAO Keyan SONG Chuanzhong School of Resources and Environmental Engineering Hefei University of TechnologyHefei 230009China Institute of Mineral Resource Chinese Academy of Geological SciencesBeijing 100037China

The authors have studied the statistical characteristics of China＇s molybdenum deposits to establish the grade-tonnage model based on the data updated to the end of 2010. The results showed that each type of China＇s molybdenum deposits complied with Lasky＇s law approximately and the characteristics of grade-tonnage model obey the lognormal distribution. However, there are poor correlations between grade and tonnage respectively. Ultimately, we aimed to fit the grade-tonnage model through the known distribution function, draw the cumulative probability curves, and evaluated undiscovered mineral resources of China＇s molybdenum deposits by means of Monte Carlo simulation integrated in MRAS.

关键词： molybdenum deposits grade-tonnage model probability statistics MRAS Monte Carlo simulation

Vertical temperature gradients of concrete box girder caused by solar radiation in Sichuan-Tibet railway

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第5期23卷 375-387页

作者： Tao SHI Xing-wang SHENG Wei-qi ZHENG Ping LOU School of Civil Engineering Central South UniversityChangsha 410075China National Engineering Research Center of High-Speed Railway Construction Technology Changsha 410075China MOE Key Laboratory of Engineering Structures of Heavy Haul Railway Central South UniversityChangsha 410075China

Spatial and temporal temperature variations are critical for concrete box girders,and non-uniform temperature distributions induced by solar radiation depend on the structural shapes and shadows cast on *** have been many studies of temperature distributions and temperature gradients of concrete box girders,but few have considered a high altitude plateau climatic *** this study,the nonlinear temperature distributions of concrete box girders in the Sichuan-Tibet railway caused by solar radiation were investigated based on experimental analysis,real-time shadow-selection algorithm,and finite element ***,a vertical temperature gradient model of the concrete box girders was *** vertical temperature gradient values first rise,then decrease,and finally rise again from Chengdu to Lhasa,with samples forming a normal *** recommended vertical temperature gradient value was 25℃with a confidence interval of 95%.This provides a reference for the design and maintenance of concrete box girders on the Sichuan-Tibet railway.

关键词： Concrete box girder Solar radiation Temperature gradient Sichuan-Tibet railway probability statistics

Theoretical Study on Stochastic Modeling of Combined Gravity-Magnetic-Electric-Seismic Inversion and Its Application

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Journal of China University of Geosciences 2003年第3期14卷 227-233页

作者： YanHanjie YanHong LiYunping ZhangXiaofeng ResearchInstituteofPetroleumExploration&Development SINOPECShengliOilfieldCo.Ltd.Dongying257022 CollegeofComputer&CommunicationEngineering UniversityofPetroleum(EastChina)Dongying257061

As gravity field, magnetic field, electric field and seismic wave field are all physical fields, their object function, reverse function and compound function are certainly infinite continuously differentiable functions which can be expanded into Taylor (Fourier) series within domain of definition and be further reduced into solving stochastic distribution function of series and statistic inference of optimal approximation. This is the basis of combined gravity-magnetic-electric-seismic inversion of stochastic modeling. It is an uncertainty modeling technology of combining gravity-magnetic-electric-seismic inversion built on the basis of separation of field and source gravity-magnetic difference-value (D-value) trend surface, taking distribution-independent fault system as its unit, depths of seismic and electric interfaces of interests as its corresponding bivariate compound reverse function of gravity-magnetic anomalies and using high order polynomial (high order trigonometric function) approximating to its series distribution. The difference from current dominant inversion techniques is that, first, it does not respectively create gravity-seismic, magnetic-seismic deterministic inversion model from theoretical model, but combines gravity-magnetic-electric-seismic stochastic inversion model from stochastic model; second, after the concept of equivalent geological body being introduced, using feature of independent variable of gravity-magnetic field functions, taking density and susceptibility related to gravity-magnetic function as default parameters of model, the deterministic model is established owing to better solution to the contradiction of difficulty in identifying strata and less test analytical data for density and susceptibility in newly explored area; third, under assumption of independent parent distribution, a real modeling by strata, the problem of difficult plane closure arising in profile modeling is avoided. This technology has richer and more de

关键词： gravity-magnetic compound reverse function stochastic geological model probability statistics gravity-magnetic D-value trend surface analysis.

Research on the Reliability Tolerance Analysis Method of Electromagnetic Relay in Aerospace

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Chinese Journal of Aeronautics 2005年第1期18卷 65-71页

作者：梁慧敏任万滨叶雪荣翟国富 Military Apparatus Research Institute Harbin Institute of Technology Harbin 150001 China

Electromagnetic relay in aerospace is one of the main electronic components in aerospace electronic systems for information transfer, control and power distribution, and its reliability will influence the reliability of the whole aerospace electronic systems. Reliability design is the key technique of electromagnetic relay reliability engineering. This paper synthetically analyzes the present reliability design methods, and presents the reliability tolerance analyzing mathematic models of electromagnetic force basing on orthogonal design, mechanical spring force basing on probability statistics theory, and matching characteristics of electromagnetic force and mechanical spring force basing on method of stressstrength interference. Some instructive conclusions are draw by researching on the reliability tolerance of some type electromagnetic relay in aerospace.

关键词： reliability electromagnetic relay in aerospace tolerance analysis orthogonal design probability statistics

Simulating the particle size distribution of rockfill materials based on its statistical regularity

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Journal of Chongqing University 2003年第2期2卷 20-23页

作者：阎宗岭 CollegeofResourceandEnvironmentalScience

The particle size distribution of rockfill is studied by using granular mechanics, mesomechanics and probability statistics to reveal the relationship of the distribution of particle size to that of the potential energy intensity before fragmentation, which finds out that the potential energy density has a linear relation to the logarithm of particle size and deduces that the distribution of the logarithm of particle size conforms to normal distribution because the distribution of the potential energy density does so. Based on this finding and by including the energy principle of rock fragmentation, the logarithm distribution model of particle size is formulated, which uncovers the natural characteristics of particle sizes on statistical distribution. Exploring the properties of the average value, the expectation, and the unbiased variance of particle size indicates that the expectation does notequal to the average value, but increases with increasing particle size and its ununiformity, and is always larger than the average value, and the unbiased variance increases as the ununiformity and geometric average value increase. A case study proves that the simulated results by the proposed logarithm distribution model accord with the actual data. It is concluded that the logarithm distribution model and Kuz-Ram model can be used to forecast the particle-size distribution of inartificial rockfill while for blasted rockfill, Kuz-Ram model is an option, and in combined application of the two models, it is necessary to do field tests to adjust some parameters of the model.

关键词： rockfill particle size probability statistics distribution characteristics