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Fiducial intervals of restricted parameters and their applications

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Science china Mathematics 2005年第11期48卷 1567-1583页

作者： LI Xinmin, LI Guoying & XU Xingzhong College of Mathematics and Information Sciences, Shandong University of technology, Zibo 255049, china academy of Mathematics and System Sciences, Chinese academy of Sciences, beijing 100800, china Department of Mathematics, beijing Institute of technology, beijing 100801, china College of Mathematics and Information Sciences Shandong University of Technology Zibo China academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China Department of Mathematics Beijing Institute of Technology Beijing China

In practice, the unknown parameters are often restricted. This paper provides a general method for constructing the fiducial intervals of the restricted parameters. Applying the general method, the fiducial intervals are constructed for the location (scale)parameters and the difference (ratio) of two locations (scales) in a location (scale) family of distributions. The frequency properties of these intervals are verified. For a variance components model, the fiducial intervals for the three parameters of common interest are obtained. Their frequency properties are investigated theoretically and computationally.

关键词： restricted parameter space,fiducial interval,frequency property,variance components

Revision of seismic design codes corresponding to building damagesin the “5.12” Wenchuan earthquake

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Earthquake Engineering and Engineering Vibration 2010年第2期9卷 147-155页

作者： Wang Yayong Institute of Earthquake Engineering, china academy of Building Research, beijing 100013, china Institute of Earthquake Engineering China Academy of Building Research Beijing China

A large number of buildings were seriously damaged or collapsed in the "5.12" Wenchuan earthquake. Based on field surveys and studies of damage to different types of buildings, seismic design codes have been updated. This paper briefly summarizes some of the major revisions that have been incorporated into the "Standard for classification of seismic protection of building constructions GB50223-2008" and "Code for Seismic Design of Buildings GB50011-2001." The definition of seismic fortification class for buildings has been revisited, and as a result, the seismic classifications for schools, hospitals and other buildings that hold large populations such as evacuation shelters and information centers have been upgraded in the GB50223-2008 Code. The main aspects of the revised GB50011-2001 code include: (a) modification of the seismic intensity specified for the Provinces of Sichuan, Shanxi and Gansu; (b) basic conceptual design for retaining walls and building foundations in mountainous areas; (c) regularity of building configuration; (d) integration of masonry structures and precast RC floors; (e) requirements for calculating and detailing stair shafts; and (f) limiting the use of single-bay RC frame structures. Some significant examples of damage in the epicenter areas are provided as a reference in the discussion on the consequences of collapse, the importance of duplicate structural systems, and the integration of RC and masonry structures.

关键词： Wenchuan earthquake earthquake damage to buildings revision of seismic design codes

The gravity wave instability induced by photochemistry in summer polar mesopause region

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Chinese Science Bulletin 2000年第3期45卷 267-272页

作者： Center for space Science and Applied Research, Chinese academy of Sciences, beijing 100080, china Laboratory of Numeric Study of Heliospheric Physics, Chinese academy of Sciences, beijing 100080, china Center for space Science and Applied Research Chinese Academy of Sciences Beijing China Laboratory of Numeric Study of Heliospheric Physics Chinese Academy of Sciences Beijing China

The effect of diabatic process due to the photochemical heating and cooling on the gravity wave propagation in middle atmosphere is studied. A linear gravity wave model which considers the diabatic process is established. The unstable region and the growth rate of the gravity wave caused by photochemistry are calculated. And the comparison between the model and the adiabatic gravity wave theory of pure dynamics is made. The results indicate that the photochemical heating process can induce the instability of gravity wave at mesopause. The intensity of the instability becomes stronger as the temperature decreases. The temperature feature and the altitude characteristics of the instability are consistent with the observation. Therefore, the instability of the gravity wave induced by photochemistry may be an important mechanism in polar mesopause region in summer.

关键词： photochemistry instability gravity wave growth rate.

Study on Sulfide-melt Inclusions in Mantle Xenoliths of Xinchang, Zhejiang

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 5-9页

作者： Jiuhua Xu Xuelei Chu YulingXie Fenglei Bie Dayi Qian University of Science and technology beijing, beijing 100083, china china University of Geosciences, beijing 100083, china The Research Center of Mineral Resources Exploration, Chinese academy University of Science and technology beijing Beijing 100083 China Research Center of Mineral Resources Exploration Chinese Academy of Sciences Beijing 100101 China Institute of Geology Chinese Academy of Sciences Beijing 100029 China china University of Geosciences Beijing 100083 China

In minerals of mantle xenoliths captured within Tertiary alkali-basalt from Xinchang, Zhejiang province, china, many sulfidemelt inclusions were found by the observation of polished thin section. Electron microprobe analysis has been applied to detect the components of sulfide-melt inclusions. The result shows that the sulfide phases of inclusions are mainly pentlandite, and secondarily pyrrho- tite, The molar ratio of Ni to Fe, r_Ni,/r_Fe, of mineral phases in sulfide inclusions is related to olivine contents in host mantle xenoliths. The r_Ni/r_Ni, of sulfides from Xinchang samples has a possitive correlation to r_(Fe+Ni),/r_S. The r_(Fe+Ni),/r_S, becomes higher with the increasing of r_Ni/r_Fe In single sulfide-melt inclusions, r_Ni,/r_Fe, r_(Fe+Ni),/r, and Ni contents increase from the center to edge, reflecting a result of different cooling speed in an inclusion. A comparison between the data from Hannuoba, West Eifel of Germany and Nograd-Gomor of east Europe suggests that the composition of the inclusions is different for each area, which indicated that a regional differentiation of sulfide in mantle fluids.

关键词： mantle xenolith sulfide-melt inclusion electron microprobe analysis, Xinchang

Cleaning of Chromate Manufacture Process

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 132-134页

作者： Xing Zou Yi Zhang(Applied Science School, University of Science and technology beijing, beijing 100083, china)(Institute of Engineering Chemistry and Metallurgy, Chinese academy of Sciences, beijing 100080, china) Applied Science School University of Science and Technology Beijing Beijing 100083 China Institute of Engineering Chemistry and Metallurgy Chinese Academy of Sciences Beijing 100080 China

Sodium chromate solubility is determined in the range of NaOH concentrations from 450 to 810 g/L andsolution temperatUres from 30 to 110℃. The optimized conditions to separate sodium chromate from NaOH inleached solution are resolved. It is first found the method to efficiently separate sbdium chromate from NaOH andsodium altuninate in crude sodium chromate. Bench-scale studies on the separating are performed. Finally, goodseparation results are achieved.

关键词： chromate separation clean process

THERMAL CRACK AND WEAR OF RAIL WHEEL AND DEVELOPMENT OF THERMAL CRACKING PROOF WHEELS

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Acta Metallurgica Sinica(English Letters) 1990年第4期3卷 287-292页

作者： DONG Renze china academy of Railway Sciences,beijing,china Associate Professor,Dept.of Science and technology Development,china academy of Railway Sciences,Beiiing 100081,china

The thermal cracking and wear mechanism of rail wheel tread have been *** results showed that the thermal cracking of rail wheel tread is related to the chemical composition (mainly the carbon content)and the hardness of the *** the composite braking shoes are used,the rate of wear of the wheel tread is related to the fracture toughness of the newly-formed“white layer”*** *** thermal cracking proof wheels(55SiMn) so far developed has achieved significant operating results in practical use.

关键词： thermal cracking wear fracture toughness composite braking shoe

Convergence of the Vlasov-Poisson-Fokker-Planck system to the incompressible Euler equations

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Science china Mathematics 2006年第2期49卷 255-266页

作者： XIAO Ling, LI Fucai & WANG Shu academy of Mathematics and Systems Science, Chinese academy of Sciences, beijing 100080, china Department of Mathematics, Nanjing University, Nanjing 210093, china College of Applied Sciences, beijing University of technology, beijing 100022, china academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China Department of Mathematics Nanjing University Nanjing China College of Applied Sciences Beijing University of Technology Beijing China

We establish the convergence of the Vlasov-Poisson-Fokker-Planck system to the incompressible Euler equations in this paper. The convergence is rigorously proved on the time interval where the smooth solution to the incompressible Euler equations exists. The proof relies on the compactness argument and the so-called relative-entropy method.

关键词： Vlasov-Poisson-Fokker-Planck system incompressible Euler equations relative-entropy method.

Responses of plant rhizosphere to atmospheric CO_2 enrichment

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Chinese Science Bulletin 2000年第2期45卷 97-101页

作者： LIN Weihong, ZHANG Fusuo & BAI Kezhi Institule of Bolany, Chinese academy of Sciences, beijing 100093, china: Department of Plant Nutrition, china AgriculturaI University, beijing 100094, china Institute of Botany Chinese Academy of Sciences Beijing China Department of Plant Nutrition China Agricultural University Beijing China

Plant root growth is generally stimulated under elevated CO2. This will bring more carbon to the below-ground through root death and exudate. This potential increase in below-ground carbon sink may lead to changes in long-term soil sequestration and relationship between host plants and symbions. On the other hand, changes in litter components due to the changes in plant chemical composition may also affect soil processes, such as litter decomposition, soil organic matter sequestration and hetero-nutritional bacteria activities. These issues are discussed.

关键词： CO2 eurichment rhizosphere microorganism.

Direct Optimization of Low-thrust Many-revolution Earth-orbit Transfers

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Chinese Journal of Aeronautics 2009年第4期22卷 426-433页

作者： Gao Yang academy of Opto-Electronics,Chinese academy of Sciences,beijing 100190,china academy of Opto-Electronics Chinese Academy of Sciences Beijing 100190 China

Low-thrust Earth-orbit transfers with 10^- 5-order thrust-to-weight ratios involve a large number of orbital revolutions which poses a real challenge to trajectory optimization. This article develops a direct method to optimize minimum-time low-thrust many-revolution Earth-orbit transfers. A parameterized control law in each orbit, in the form of the true optimal control, is proposed, and the time history of the parameters governing the control law is interpolated through a finite number of nodal values. The orbital averaging method is used to significantly reduce the computational workload and the trajectory optimization is conducted based on the orbital averaging dynamics expressed by nonsingular equinoctial elements. Furthermore, Earth＇s shadowing and perturbation effects are taken into account. The optimal transfer problem is thus converted to the parameter optimization problem that can be solved by nonlinear programming. Taking advantage of the mapping between the parameterized control law and the Lyapunov control law, a technique is proposed to acquire good initial guesses for optimization variables, which results in enlarged convergence domain of the direct optimization method. Numerical examples of optimal Earth-orbit transfers are presented.

关键词： low thrust orbital transfer optimization direct method orbital averaging Lyapunov method