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Journal of Earth Science 2024年

作者： Zhijie Jia Pietro Sternai Jianbing Peng School of Geological Engineering and Geomatics， Chang'an University Department of Earth and Environmental Sciences， University of Milan-Bicocca chool of Geological Engineering and Geomatics， Chang'an University

Mantle plumes and surface erosion and sediment deposition affect the modes of continental lithospheric rupturing in extensional tectonic settings， modulating the evolution of rifting margins. However， their relative contributions to the overall evolution of rifting margins and possible roles in the formation of microcontinent are still elusive. Here， we use coupled geodynamic and surface processes numerical modeling to assess the extent to which surface processes may determine the formation of microcontinent during lithospheric stretching in presence or absence of a mantle plume underneath. Our modeling results indicate that fast extension rates and hillslope (i.e.， diffusion) erosion promote ridge jump events and therefore the formation of microcontinents. On the contrary， efficient fluvial erosion and far-reaching sediment transport (i.e.， stream power erosion) inhibits ridge jump events and the formation of microcontinents. The ridge jump event and overall evolution in our numerical models is consistent with the shift from the Mascarene Ridge to the Carlsberg Ridge that determined the formation of the Seychelles microcontinent. We therefore speculate that hillslope erosion， rather than fluvial erosion， was predominant during the formation of the Seychelles， a possible indication of overall dry local climate conditions.

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Expansion characteristics of twin combustion gas jets with high pressure in cylindrical filling liquid chamber

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Journal of Hydrodynamics 2013年第5期25卷 763-771页

作者：薛晓春余永刚张琦 chool of Energy and Power Engineering Nanjing University of Science and Technology

To deal with the problem of how to control the interior ballistic stability in the bulk-loaded liquid propellant gun, the expansion and mixing process of the twin combustion-gas jets with high temperature and pressure in a liquid medium is studied in the cylindrical filling liquid chamber. A series of the jet expansion shapes is obtained by using a high-speed photographic system. The influences of the jet pressure on the jet expansion shape are discussed. Based on the experiments, the three-dimensional mathematical model is established. The expansion processes of the twin gas jets in the liquid medium are simulated by means of fluent to get the pressure, density, temperature, velocity contours and evolutionary process of vortices. Results show that the jet external out-line and tops are all irregular. The Kelvin-Helmholtz instability is shown in the whole expansion process. The numerical simulation results of the axial displacement of the twin gas jets in liquid agree well with the experiment.

关键词： twin combustion gas jets with high pressure turbulent mixing jet expansion shape numerical simulation

Space radiation effect on fibre optical gyroscope control circuit and compensation algorithm

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Chinese Physics B 2008年第2期17卷 573-577页

作者：张春熹田海亭李敏金靖宋凝芳 chool of Instrumentation Science & Opto-electronics Engineering Beijing University of Aeronautics & Astronautics

The process of a γ-irradiation experiment of fibre optical gyroscope （FOG） control circuit was described, in which it is demonstrated that the FOG control circuit, except for D/A converter, could endure the dose of 10krad with the protection of cabin material. The distortion and drift in D/A converter due to radiation, which affect the performance of FOG seriously, was indicated based on the elemental analysis. Finally, a compensation network based on adaptive neuro-fuzzy inference system is proposed and its function is verified by simulation.

关键词： space radiation fibre optical gyroscope compensation network

Novel method for operating characteristics test of a hydraulic pump

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Journal of Beijing Institute of Technology 2015年第1期24卷 74-82页

作者：王向周陆叶郑戍华 chool of Automation Beijing Institute of Technology

The traditional testing method of a hydraulic pump requires a large amount of test data from a variety of pump working conditions. The test is usually time-consuming and energy-consu- ming. And the accurate characteristic curves of the pump were hardly obtained due to a limited a- mount and discreteness of the test data. In order to simplify the test procedure and improve the test accuracy, a novel method for measuring hydraulic pump operating characteristic based on multi-ele- ment nonlinear regression （NLMR） modeling is proposed in this paper. The main idea of this model- ing method is establishing a mathematical model to predict the performance parameters of the hy- draulic pump, only a small amount of test data is needed. Consequently, the pump operating charac- teristics in any working conditions are obtained. And the test results of the pump are easily charac- terized in the graphs, charts, tables and so on. The evaluations of the model are carried out and dis- cussed in this paper. The result shows that the test error of the novel method can be controlled to be about 0. 1%. Compared with the traditional test method, the proposed method reduces greatly the test time and the random error of the test data, and improves the efficiency and accuracy of the pump test.

关键词： hydraulic pump test model work characteristics

Host load prediction in cloud based on classification methods

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The Journal of China Universities of Posts and Telecommunications 2014年第4期21卷 40-46页

作者： TONG Jun-jie E Hai-hong SONG Mei-na SONG Jun-de chool of Computer Science Beijing University of Posts and Telecommunications

The host load prediction problem in cloud computing has also been received much attention. To solve this problem, we have to use the historical load data to predict the future load level. Accurate prediction methods are useful for host load balance and virtual machine migration. Although cloud is likely to grids at some extent, the length of tasks are much shorter and host loads change more frequently with higher noise. The above characteristics introduce challenges for host load prediction. In this paper, based on the proposed exponentially segmented pattern and the corresponding transformation, prediction problem is transformed into the traditional classification problem, This classification problem can be solved based on the traditional methods, and features are given for training the classification model. For achieving accurate prediction, a new feature periodical coefficient is introduced and some existed classification methods are implemented. Experiments on the real world dataset invalidate the efficiency of the new proposed feature, which is in the most effective combinations of features, it increases successful rate （SR） 1.33%-2.82% and decreases the mean square error （MSE） 1.37%-2.91%. And the results also show that support vector machine （SVM） method can achieve nearly the same performance as the Bayes methods and their performance is about 50% higher in successful rate and 17% better in the mean square error compared to the existed methods.

关键词： cloud computing host load exponentially segmented pattern load prediction classification

Crystal growth,structure and optical properties of Pr^(3+)-doped yttria-stabilized zirconia single crystals

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Chinese Physics B 2021年第7期30卷 583-590页

作者： Dai-Ni Wang Shou-Lei Xu Xiang-Yu Wang Si-Yao Li Xing Hong Bernard A.Goodman Wen Deng chool of Physical Science and Technology Guangxi UniversityNanning 53004China

The development of blue semiconductor light-emitting diodes(LEDs)has produced potential applications for Prdoped materials that can absorb blue light,especially crystals,and we now report structure and optical properties for high-quality Pr-doped single crystals of yttria-stabilized zirconia(YSZ)grown by the optical floating zone(FZ)method.X-ray diffraction(XRD)and Raman spectroscopy showed that all of the single crystal samples were in the cubic phase,whereas the corresponding ceramic samples contained a mixture of monoclinic and cubic phases.X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)spectroscopy showed that Pr was present as the Pr^(3+)ion in ceramic rods and single crystals after heating to high *** absorption and photoluminescence excitation(PLE)spectra of the Pr-doped YSZ crystals measured at room temperature showed strong absorption of blue light,while their photoluminescence(PL)spectra showed five emission peaks at 565 nm,588 nm,614 nm,638 nm,and 716 nm under450 nm *** optimum luminescence properties were obtained with the crystal prepared using 0.15 mol%Pr_(6)O_(11),and those with higher concentrations showed evidence of quenching of the luminescence *** addition,the color purity of Pr-doped YSZ single crystal reached 98.9%in the orange–red region.

关键词： yttria-stabilized zirconia(YSZ)single crystal praseodymium-doped optical floating zone method luminescence

Some new results for demimartingales

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Applied Mathematics(A Journal of Chinese Universities) 2011年第1期26卷 14-22页

作者： WANG Xue-jun HU Shu-he YANG Wen-zhi SHEN Yan chool of Mathematical Science Anhui University Hefei 230039 China

Harremoes obtained some new maximal inequalities for non-negative martingales. In this paper, we get some new maximal and minimal inequalities for non-negative demimartin- gales which generalize the results of Harremoes. We also obtain an inequality for non-negative demimartingales which generalizes the result of Iksanov and Marynych. Finally we obtain a strong law of large numbers, strong growth rate and integrability of supremum for demimartin- gales which generalize and improve the result of Chow.

关键词： Maximal inequality minimal inequality demimartingale strong law of large numbers.

Relighting multiple color textures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2005年第11期6卷 1284-1289页

作者：刁常宇鲁东明刘刚 chool of Computer Science Zhejiang University Conservation Institute Dunhuang Academy

With the development of digital library technology, library books made of paper can be digital released and read, and Endangered Cultural Heritages can be preserved. Traditional library＇s contents and functions can be greatly enhanced by digital technologies. For these new library objects, the primary key problem is precisely reconstructing their 3D models. When constructing complete 3D models, multiple color texture maps are often necessary. A commonly encountered problem uncounted during fusing of textures from multiple color images is color distortion. Each texture of a single 3D model may be obtained under possibly different lighting conditions and color response of the camera. To remove any visible seam and improve color consistency between the textures while avoiding color distortion, we propose a new efficient algorithm to relight all the texture images globally, spread residual light difference, and recolor each image by homogeneous transformation. A relative illumination model was adopted to obtain the relighting function. We choose lαβ color space with minimal correlation between channels for many natural scenes, for calculating the relighting result. Looking into two overlapped images A and B, we can pairwise relight B into A＇s luminosity condition in two steps. We first scale B＇s l channel by the lA/lB ratio of the overlapped region. We can assume A and B are in a same color plane now. Then a homogeneous transformation is applied to B＇s a and fl channels which moves B into A＇s hue and saturation condition. For multiple overlapped color textures, a patch based weighted global relighting method was proposed to minimize the total color difference. The pairwise relighting method was used between each two overlapped images, and the difference in every overlapped region after relighting was weighted and summed up to construct an energy value. We used Nelder-Mead method to find a minimal energy value and the relighting parameters for every image. After global r

关键词： Texture relighting Digitization Color correction Texture blending

Bound analysis of target displacement for seismic performance assessment of buildings

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Journal of Harbin Institute of Technology(New Series) 2008年第1期15卷 27-32页

作者：贾立哲段忠东陆钦年 chool of Civil Engineering Harbin Institute of Technology

The earthquake demand spectrum is often assumed as the average spectrum in the seismic design code or based upon probabilistic models to take into account the uncertainties of ground motion. The average spectrum can not deal with the uncertainty of earthquake excitation. Furthermore, results of probabilistic analysis are suspicious when information describing the uncertainty is inadequate. Considering the uncertainties of peak acceleration of ground motion and characteristic period of response spectra using a double bounded convex set model, the bounds of the design spectrum and the demand spectrum were obtained based on Chinese seismic code. Then the convex analysis method was integrated into the capacity spectrum procedure to study the bound characteristics of target displacement. Finally, the target displacement was derived with an interval, and it is more objective and robust with respect to probabilistic perspective.

关键词： convex set model capacity spectrum method uncertainty

Estimating stellar atmospheric parameters based on Lasso features

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Research in Astronomy and Astrophysics 2014年第4期14卷 423-432页

作者： Chuan-Xing Liu Pei-Ai Zhang Yu Lu Department of Mathematics Jinan University chool of Mathematical Sciences South China Normal University

With the rapid development of large scale sky surveys like the Sloan Digital Sky Survey （SDSS）, GAIA and LAMOST （Guoshoujing telescope）, stellar spectra can be obtained on an ever-increasing scale. Therefore, it is necessary to estimate stel- lar atmospheric parameters such as Teff, log g and [Fe/H] automatically to achieve the scientific goals and make full use of the potential value of these observations. Feature selection plays a key role in the automatic measurement of atmospheric parameters. We propose to use the least absolute shrinkage selection operator （Lasso） algorithm to select features from stellar spectra. Feature selection can reduce redundancy in spectra, alleviate the influence of noise, improve calculation speed and enhance the robustness of the estimation system. Based on the extracted features, stellar atmospheric param- eters are estimated by the support vector regression model. Three typical schemes are evaluated on spectral data from both the ELODIE library and SDSS. Experimental results show the potential performance to a certain degree. In addition, results show that our method is stable when applied to different spectra.

关键词： methods: data analysis -- stars: fundamental parameters -- techniques:spectroscopic -- surveys