oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 6 )

2018 ( 352 )

2017 ( 417 )

2016 ( 398 )

Custom range...

Search Results: 1 - 10 of 29992 matches for " Hua Ning "
All listed articles are free for downloading (OA Articles)
Page 1 /29992
Display every page Item
Extended Variational Cluster Approximation
Ning-Hua Tong
Physics , 2005, DOI: 10.1103/PhysRevB.72.115104
Abstract: The variational cluster approximation (VCA) proposed by M. Potthoff {\it et al.} [Phys. Rev. Lett. {\bf 91}, 206402 (2003)] is extended to electron or spin systems with nonlocal interactions. By introducing more than one source field in the action and employing the Legendre transformation, we derive a generalized self-energy functional with stationary properties. Applying this functional to a proper reference system, we construct the extended VCA (EVCA). In the limit of continuous degrees of freedom for the reference system, EVCA can recover the cluster extension of the extended dynamical mean-field theory (EDMFT). For a system with correlated hopping, the EVCA recovers the cluster extension of the dynamical mean-field theory for correlated hopping. Using a discrete reference system composed of decoupled three-site single impurities, we test the theory for the extended Hubbard model. Quantitatively good results as compared with EDMFT are obtained. We also propose VCA (EVCA) based on clusters with periodic boundary conditions. It has the (extended) dynamical cluster approximation as the continuous limit. A number of related issues are discussed.
Structural heterogeneity and its role in determining properties of disordered solids
Hua Tong,Ning Xu
Physics , 2014, DOI: 10.1103/PhysRevE.90.010401
Abstract: We construct a new order parameter from the normal modes of vibration, based on the consideration of energy equipartition, to quantify the structural heterogeneity in disordered solids. The order parameter exhibits strong spatial correlations with low-temperature single particle dynamics and local structural entropy. To characterize the role of particles with the most defective local structures identified by the order parameter, we pin them and study how properties of disordered solids respond to the pinning. It turns out that these particles are responsible to the quasilocalized low-frequency vibration, instability, softening, and nonaffinity of disordered solids.
Equation of Motion Series Expansion of Double Time Green's Functions
Ning-Hua Tong
Physics , 2015, DOI: 10.1103/PhysRevB.92.165126
Abstract: Based on the Green's function (GF) equation-of-motion formalism, we develop a method to expand the double time Green's function into Taylor series of the parameter $\lambda$ in the Hamiltonian $H=H_0 + \lambda H_1$. Here $H_0$ is the exactly solvable part and $H_1$ is regarded as the perturbation. To restore the analytical structure of GF, we use the continued fraction to do resummation for the obtained series. The problem of zero-temperature divergence is identified and remedied by the self-consistent series expansion. To demonstrate the implementation of this method, we carry out the weak- as well as the strong-coupling expansion for the Anderson impurity model to order $\lambda^2$. Improved result for the local density of states is obtained by self-consistent second-order strong-coupling expansion and continued fraction resummation.
AFLP-SSCP: A Useful AFLP-Based Method for Informative SNPs Discovery in Non-Model Organisms  [PDF]
Te-Hua Hsu, Yue Ning, Jin-Chywan Gwo
Advances in Biological Chemistry (ABC) , 2014, DOI: 10.4236/abc.2014.46042
Abstract: Single nucleotide polymorphisms (SNPs) are the most common type of genetic variation among individuals of a species. Recently, in spite of the development of high-throughput genotyping technologies, SNPs have been applied as markers for population genetic and high-density genetic mapping. However, the high costs of SNPs discovery and genotyping assay limit the applications of SNP markers in non-model organisms. In this study, we present a cheap and convenient AFLP-based (Amplified fragment length polymorphism) strategy that is highly efficient for developing informative SNP markers without any prior information. We developed SNP markers in a non-model and economic aquaculture species Asian Seabass (Lates calcarifer), and discussed the potential use of the combinations of AFLP and AFLP-SSCP.
A Highly Compatible Circular-Shifting Network for Partially Parallel QC-LDPC Decoder  [PDF]
Yanzhi Wang, Zhenzhi Wu, Peipei Liu, Ning Guan, Hua Wang
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2017, DOI: 10.4236/ijcns.2017.105B003
Abstract:
The conventional methodology for designing QC-LDPC decoders is applied for fixed configurations used in wireless communication standards, and the supported largest expansion factor Z (the parallelism of the layered decoding) is a fixed number. In this paper, we study the circular-shifting network for decoding LDPC codes with arbitrary Z factor, especially for decoding large Z (Z P) codes, where P is the decoder parallelism. By buffering the P-length slices from the memory, and assembling the shifted slices in a fixed routine, the P-parallelism shift network can process Z-parallelism circular-shifting tasks. The implementation results show that the proposed network for arbitrary sized data shifting consumes only one times of additional resource cost compared to the traditional solution for only maximum P sized data shifting, and achieves significant saving on area and routing complexity.
AN EXTENSION ON MOBIUS INVERSE FORMULAR
关于Mobius反转公式的一个推广

Hua Ning LIU,
刘华宁

系统科学与数学 , 2004,
Abstract: This paper studied the M\"{o}bius transform, and gave an extended inverse formula on it.
Power Efficiency Improvements through Peak-to-Average Power Ratio Reduction and Power Amplifier Linearization
Chen Ning,Zhou G Tong,Qian Hua
EURASIP Journal on Advances in Signal Processing , 2007,
Abstract: Many modern communication signal formats, such as orthogonal frequency-division multiplexing (OFDM) and code-division multiple access (CDMA), have high peak-to-average power ratios (PARs). A signal with a high PAR not only is vulnerable in the presence of nonlinear components such as power amplifiers (PAs), but also leads to low transmission power efficiency. Selected mapping (SLM) and clipping are well-known PAR reduction techniques. We propose to combine SLM with threshold clipping and digital baseband predistortion to improve the overall efficiency of the transmission system. Testbed experiments demonstrate the effectiveness of the proposed approach.
Power Efficiency Improvements through Peak-to-Average Power Ratio Reduction and Power Amplifier Linearization
Ning Chen,G. Tong Zhou,Hua Qian
EURASIP Journal on Advances in Signal Processing , 2007, DOI: 10.1155/2007/20463
Abstract: Many modern communication signal formats, such as orthogonal frequency-division multiplexing (OFDM) and code-division multiple access (CDMA), have high peak-to-average power ratios (PARs). A signal with a high PAR not only is vulnerable in the presence of nonlinear components such as power amplifiers (PAs), but also leads to low transmission power efficiency. Selected mapping (SLM) and clipping are well-known PAR reduction techniques. We propose to combine SLM with threshold clipping and digital baseband predistortion to improve the overall efficiency of the transmission system. Testbed experiments demonstrate the effectiveness of the proposed approach.
Three-Phase Fuel Deposition in a Long-Distance Migrant, the Red Knot (Calidris canutus piersmai), before the Flight to High Arctic Breeding Grounds
Ning Hua, Theunis Piersma, Zhijun Ma
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0062551
Abstract: Refuelling by migratory birds before take-off on long flights is generally considered a two-phase process, with protein accumulation preceding rapid fat deposition. The first phase expresses the demands for a large digestive system for nutrient storage after shrinkage during previous flights, the second phase the demands for fat stores to fuel the subsequent flight. At the last staging site in northward migration, this process may include expression of selection pressures both en route to and after arrival at the breeding grounds, which remains unascertained. Here we investigated changes in body composition during refuelling of High Arctic breeding red knots (Calidris canutus piersmai) in the northern Yellow Sea, before their flight to the tundra. These red knots followed a three-phase fuel deposition pattern, with protein being stored in the first and last phases, and fat being deposited mainly in the second phase. Thus, they did not shrink nutritional organs before take-off, and even showed hypertrophy of the nutritional organs. These suggest the build up of strategic protein stores before departure to cope with a protein shortage upon arrival on the breeding grounds. Further comparative studies are warranted to examine the degree to which the deposition of stores by migrant birds generally reflects a balance between concurrent and upcoming environmental selection pressures.
Pseudogap, non-Fermi-liquid behavior, and particle-hole asymmetry in the 2D Hubbard model
Ansgar Liebsch,Ning-Hua Tong
Physics , 2009,
Abstract: The effect of doping in the two-dimensional Hubbard model is studied within finite temperature exact diagonalization combined with cluster dynamical mean field theory. By employing a mixed basis involving cluster sites and bath molecular orbitals for the projection of the lattice Green's function onto 2x2 clusters, a considerably more accurate description of the low frequency properties of the self-energy is achieved than in a pure site picture. The transition from Fermi-liquid to non-Fermi-liquid behavior for decreasing hole doping is studied as a function of Coulomb energy, next-nearest neighbor hopping, and temperature. In particular, the self-energy component Sigma_X associated with X=(pi,0) is shown to exhibit an onset of non-Fermi-liquid behavior as the hole doping decreases below a critical value delta_c. The imaginary part of Sigma_X(omega) then develops a collective mode above E_F, which exhibits a distinct dispersion with doping. Accordingly, the real part of Sigma_X(omega) has a positive slope above E_F, giving rise to an increasing particle-hole asymmetry as the system approaches the Mott transition. This behavior is consistent with the removal of spectral weight from electron states close to E_F and the opening of a pseudogap which increases with decreasing doping. The phase diagram reveals that delta_c = 0.15 ... 0.20 for various system parameters. For electron doping, the collective mode of Sigma_X(omega) and the concomitant pseudogap are located below the Fermi energy which is consistent the removal of spectral weight from hole states just below E_F. The critical doping which marks the onset of non-Fermi-liquid behavior, is systematically smaller than for hole doping.
Page 1 /29992
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.