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Search Results: 1 - 10 of 40274 matches for " Qing Yuan "
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Generative Potential of Carboniferous-Permian Coal-Bearing Source Rocks in Ordos Basin  [PDF]
Cheng Li, Qing Yuan, Min Zhang
Open Journal of Yangtze Oil and Gas (OJOGas) , 2017, DOI: 10.4236/ojogas.2017.24021
Abstract: The organic matter abundance, type and maturity have been studied along with their generative potential in coals, carbonaceous mudstones and mudstones from Carboniferous-Permian in Ordos Basin, revealing that the coal-bearing source rocks in the study area have the stronger generative potential. The source rocks are typically humic gas source rocks with the main source rock dominated by the coals. There are significant diversities in the generative potential in different lithological source rocks. The generative potential decreases in the following order: coals, carbonaceous mudstones, mudstones. The desmocollinite in vitrinite group shows a positive correlation with hydrogen index (IH) or S1 + S2 values, indicating the desmocollinite in coal may be the major contributor to hydrocarbon generation. On the whole, the hydrogen index and S1 + S2 values both exhibit a good relationship with the desmocollinite in carbonaceous mudstones or mudstones, whereas they have a poor correlation with the pristane/phytane ratios. The hydrogen index and S1 + S2 values in coal with the increased pristane/phytane ratios in coal both increase at first and then decrease, whereas they both have a poor correlation with the desmocollinite. These results show that the generative potential in coal is mainly related with the sedimentary environment, while the hydrocarbon generation matter is the main factor influencing the generative potential in carbonaceous mudstones or mudstones.
A New Filled Function method for Smooth Clustering
Qing Wu,Lixing Yuan
Journal of Computers , 2012, DOI: 10.4304/jcp.7.2.491-498
Abstract: The mathematical modeling of the clustering centers problem leads to a min-sum-min formulation which, has the significant characteristic of being strongly nondifferentiable. To overcome this difficulty, a new filled function method is proposed to find centers of clusters based on entropy technique. A completely differentiable non-convex optimization model for the clustering center problem is constructed. A parameter free filled function method is adopted to search for a global optimal solution of the optimization model. For the purpose of illustrating both the reliability and the efficiency of the method, a set of computational experiments was performed. Numerical results illustrate that the proposed algorithm can effectively hunt centers of clusters and especially improve the accuracy of the clustering even with a relatively small entropy factor.
A Tentative Study on Differences and Integration of Sino-Western Filial Piety Culture
Xinrui Yuan,Qing Wang
Asian Social Science , 2011, DOI: 10.5539/ass.v7n8p97
Abstract: Filial piety has become an important cultural symbol of civilization in Chinese national vitality which is different with others’. For thousands of years, it has been regarded as a traditional virtue and permeated into the national blood and bone. The Chinese filial piety culture and thought are limited to the nature and influenced by the Confucian ideology. There is also filial idea in the Western culture, which is lean to surpass the nature, and is affected by the Christianity; however, due to various reasons they are in obviously different forms. In the wave of globalization, a large-scale importation of Western thoughts and culture has collided with traditional Chinese thoughts and culture, filial piety is no exception. The paper focuses on exploring the differences and integration of filial piety between Chinese and Western cultures, and the factors contributing to this dissimilarity would be identified. The paper indicates that there are huge differences of the Sino-Western filial morality culture due to their diverse social and historical backgrounds as well as the reasons lie behind geography, nature and values. Bearing these differences in mind can not only reduce unnecessary conflict and clash but enhance mutual understanding and respect in cross-cultural communication, hence seek to the possibility of narrowing the cultural gap. Meanwhile, the two filial ideas could find ways to form the complementarities and coexist harmoniously.
Comments on the Rate of Convergence between Mann and Ishikawa Iterations Applied to Zamfirescu Operators
Qing Yuan,Rhoades BE
Fixed Point Theory and Applications , 2008,
Abstract: In the work of Babu and Vara Prasad (2006), the claim is made that Mann iteration converges faster than Ishikawa iteration when applied to Zamfirescu operators. We provide an example to demonstrate that this claim is false.
-Stability of Picard Iteration in Metric Spaces
Qing Yuan,Rhoades BE
Fixed Point Theory and Applications , 2008,
Abstract: We establish a general result for the stability of Picard's iteration. Several theorems in the literature are obtained as special cases.
A note on static spaces and related problems
Jie Qing,Wei Yuan
Mathematics , 2012, DOI: 10.1016/j.geomphys.2013.07.003
Abstract: We solve the classifying problem raised by Fischer and Marsden for Bach flat static spaces. We also prove the conjecture about critical point equations proposed by Besse for Bach flat manifolds. Particularly in dimension 3, we derive an integral identity that allows us to obtain conformal flatness from the vanish of the full divergence of the Cotton tensor for static metrics and metrics satisfying the critical point equation.
On scalar curvature rigidity of Vacuum Static Spaces
Jie Qing,Wei Yuan
Mathematics , 2014,
Abstract: In this paper we extend the local scalar curvature rigidity result in [6] to a small domain on general vacuum static spaces, which confirms the interesting dichotomy of local surjectivity and local rigidity about the scalar curvature in general in the light of the paper [10]. We obtain the local scalar curvature rigidity of bounded domains in hyperbolic spaces. We also obtain the global scalar curvature rigidity for conformal deformations of metrics in the domains, where the lapse functions are positive, on vacuum static spaces with positive scalar curvature, and show such domains are maximal, which generalizes the work in [15].
Design and Simulation of a Fully Digitized GNSS Receiver Front-End
Yuan Yu,Qing Chang,Yuan Chen
Discrete Dynamics in Nature and Society , 2011, DOI: 10.1155/2011/329535
Abstract: In the near future, RF front-ends of GNSS receivers may become very complicated when multifrequency signals are available from at least four global navigation systems. Based on the direct RF sampling technique, fully digitized receiver front-ends may solve the problem. In this paper, a direct digitization RF front-end scheme is presented. At first, a simplified sampling rate selection method is adopted to determine the optimal value. Then, the entire spectrum of GNSS signal is directly digitized through RF sampling at a very fast sampling rate. After that, the decimation and filtering network is designed to lower the sampling rate efficiently. It also realizes the digital downconversion of the signal of interest and the separation of narrow band signals from different navigation systems. The scheme can be flexibly implemented in software. Its effectiveness is proved through the experiment using simulated and true signals. 1. Introduction With the development of global navigation satellite system (GNSS) including GPS, GLONASS, GALILEO, and COMPASS, multi-constellation signals will be available in the future. These signals mainly concentrate in 1164~1300?MHz and 1559~1610?MHz (referred as “Band I” and “Band II” below). In order to receive all of the GNSS signals, conventional RF front-end may not fit for future multisystem receivers. From the theory of software radio, A/D needs to be set as close to the antenna as possible, thus a single hardware configuration could operate as multiple receivers simply by changing the software programming [1]. Based on such idea, the direct RF sampling offers several advantages for GNSS RF front-end design. First, it reduces the parts count and eliminates the need to design and fabricate a mixing chip with a specially tailored frequency plan. Second, it simplifies the design of new receivers for the new signals that will become available as GPS gets modernized and as Galileo comes on line. Third, it is possible to make a single RF front-end for multiple frequency bands. This approach to multifrequency GNSS receiver front-end design eliminates the need for multiple front-ends, which reduces the parts count and eliminates some potential sources of inter channel line bias. Therefore, the digitized RF front-end is becoming a hot research area. Although software radio is not a novel concept, most studies on direct RF sampling nowadays are still conducted in labs. Brown and Wolt [2] are the first to report on the use of direct RF sampling for the design of GPS receiver front-ends. They concentrated on a system that used a very
The Diagonal Tensor Approximation (Dta) for Objects in a Non-Canonical Inhomogeneous Background
Mengqing Yuan;Qing Huo Liu
PIER , 2011, DOI: 10.2528/PIER10110804
Abstract: A non-canonical inhomogeneous background medium is one whose Green's function cannot be obtained by an analytical method. Electromagnetic scattering from objects embedded in a non-canonical inhomogeneous background medium is very challenging because of the computational complexity with the calculation of its Green's function and the multiple scattering between objects and the background. This work applies the Diagonal Tensor Approximation (DTA) to calculate the scattering from arbitrary objects in a noncanonical inhomogeneous background. Previously, the DTA has only been applied to a canonical background such as a homogeneous or layered background media. This approach employs a numerical method to obtain all Green's functions required in the calculation; an accurate DTA is used to calculate the scattering properties. In order to reduce the large number of simulations, we employ the symmetry and reciprocity in the Green's function calculation. Furthermore, considering that most realistic imaging measurements are made through a voltage probe usually represented by a wave port, we develop a method to convert the scattered field on the probe (the antenna) to the measured wave port voltage. Numerical results show that this method can obtain accurate scattering characteristics from arbitrary objects in a non-canonical inhomogeneous background medium in a microwave imaging system.
Comments on the Rate of Convergence between Mann and Ishikawa Iterations Applied to Zamfirescu Operators
Yuan Qing,B. E. Rhoades
Fixed Point Theory and Applications , 2008, DOI: 10.1155/2008/387504
Abstract: In the work of Babu and Vara Prasad (2006), the claim is made that Mann iteration converges faster than Ishikawa iteration when applied to Zamfirescu operators. We provide an example to demonstrate that this claim is false.
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