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1. Quantum impurities in channel mixing baths

Author

Liu, J. G., Wang, D., and Wang, Q. H.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Superconductivity
Abstract

We propose a versatile strategy for numerical renormalization group solution of general channel-mixing Kondo and Anderson models beyond previous reach, opening the door toward broad applications in protocol non-perturbative machineries, such as dynamical cluster approximation and cluster dynamical mean field theory, for strongly correlated electron systems. We illustrate the strategy by investigating the quantum phase transitions in two quantum impurity models with cases untouched before., Comment: 5 pages, 4 figures, with separate supplementary materials

Published
2015
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2. Perforating characters of Zr-based bulk metallic glass fragment against thin steel target.

Author

Zhang, Y. F., Fang, L., Liu, J. G., Wei, X., Wu, K., Xu, C., and Liu, G. Q.

Subjects
METALLIC glasses, STEEL, CONSERVATION of energy, ENERGY conservation
Abstract

To investigate the perforating characteristics of Zr-based bulk metallic glass fragments against thin steel target, ballistic experiments were carried out to measure ballistic the limit velocities of fragments perforating against different thicknesses of targets. The fragments were driven by a 57 mm one-stage light gas gun to impact the thin steel target. The numerical model of Zr-based bulk metallic glass fragments perforating against thin steel target was established using Autodyn2D commercial software, and the perforating process and perforating mechanism were analyzed by numerical simulation. The semi-empirical model to predict the ballistic limit velocity was fitted. An energy model for calculating the residual velocity of a fragment was derived based on the conservation of energy. The theoretical results of the semi-empirical model and the energy model are in good agreement with experiment results and simulation results. And the energy model has good applicability without fitting the parameters for different target thicknesses. [ABSTRACT FROM AUTHOR]

Published
2024
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3. General Solution to Gradient Induced Transverse and Longitudinal Relaxation of Spins Undergoing Restricted Diffusion

Author

Zheng, W., Gao, H., Liu, J. -G., Zhang, Y., Ye, Q., and Swank, C.

Subjects
Physics - Atomic Physics, Condensed Matter - Other Condensed Matter
Abstract

We develop an approach, by calculating the autocorrelation function of spins, to derive the magnetic field gradient induced transverse ($T_2$) relaxation of spins undergoing restricted diffusion. This approach is an extension to the method adopted by McGregor. McGregor's approach solves the problem only in the fast diffusion limit; however, our approach yields a single analytical solution suitable in all diffusion regimes, including the intermediate regime. This establishes a direct connection between the well-known Torrey's slow diffusion result and the fast diffusion result. We also perform free induction decay measurements on spin-exchange optically polarized $^3$He gas with different diffusion constants. The transverse relaxation profiles are compared with the theory and satisfactory agreement has been found throughout all diffusion regimes. In addition to the transverse relaxation, this approach is also applicable to solving the longitudinal relaxation ($T_1$) regardless of the diffusion limits. It turns out that the longitudinal relaxation in the slow diffusion limit differs by a factor of two, compared with that in the fast diffusion limit.

Published
2012
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4. Fluctuation of the download network

Author

Han, D. D., Liu, J. G., and Ma, Y. G.

Subjects
Physics - Physics and Society, Condensed Matter - Statistical Mechanics, Nuclear Theory, Physics - Data Analysis, Statistics and Probability
Abstract

The scaling behavior of fluctuation for a download network which we have investigated a few years ago based upon Zhang's Encophysics web page has been presented. A power law scaling, namely $\sigma \sim < f> ^ \alpha $ exists between the dispersion $\sigma$ and average flux $$ of the download rates. The fluctuation exponent $\alpha$ is neither 1/2 nor 1 which was claimed as two universal fluctuation classes in previous publication, instead it varies from 1/2 to 1 with the time window in which the download data were accumulated. The crossover behavior of fluctuation exponents can be qualitatively understood by the external driving fluctuation model for a small-size system or a network traffic model which suggests congestion as the origin., Comment: 4 pages, 4 figures

Published
2007
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5. Network Topology of the Austrian Airline Flights

Author

Han, D. D., Qian, J. H., and Liu, J. G.

Subjects
Physics - Physics and Society, Physics - Popular Physics
Abstract

The information of the Austrian airline flights was collected and quantitatively analyzed by the concepts of complex network. It displays some features of small-world networks, namely large clustering coefficient and small average shortest-path length. The degree distributions of the networks reveal power law behavior with exponent value of 2 $\sim$ 3 for the small degree branch but a flat tail for the large degree branch. Similarly, the flight weight distributions show power-law behavior for the small weight branch. Furthermore, we found that the clustering coefficient $C$, 0.206, of this flight network is greatly larger than that of a random network, 0.01, which has the same numbers of the airports ($N$) and mean degree ($$), and the diameter $D$, 2.383, of the flight network is significantly smaller than the value of the same random network, 18.67. In addition, the degree-degree correlation analysis shows the network has disassortative behavior, i.e. the large airports are likely to link to smaller airports. Furthermore, the clustering coefficient analysis indicates that the large airports reveal the hierarchical organization., Comment: 6 page, 6 figures, 1 table

Published
2007

6. Scale-free download network for publications

Author

Han, D. D., Liu, J. G., Ma, Y. G., Cai, X. Z., and Shen, W. Q.

Subjects
Condensed Matter - Disordered Systems and Neural Networks, Condensed Matter - Statistical Mechanics, Nuclear Theory, Physics - Physics and Society
Abstract

The scale-free power-law behavior of the statistics of the download frequency of publications has been, for the first time, reported. The data of the download frequency of publications are taken from a well-constructed web page in the field of economic physics (http://www.unifr.ch/econophysics/). The Zipf-law analysis and the Tsallis entropy method were used to fit the download frequency. It was found that the power-law exponent of rank-ordered frequency distribution is $\gamma \sim 0.38 \pm 0.04$ which is consistent with the power-law exponent $\alpha \sim 3.37 \pm 0.45$ for the cumulated frequency distributions. Preferential attachment model of Barabasi and Albert network has been used to explain the download network., Comment: 3 pages, 2 figures

Published
2004
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7. Age-dependent aneuploidy in mammalian oocytes instigated at the second meiotic division

Author

Kouznetsova, A., Liu, J. G., Valentiniene, S., Brismar, Hjalmar, Höög, C., Kouznetsova, A., Liu, J. G., Valentiniene, S., Brismar, Hjalmar, and Höög, C.

Abstract

Ageing severely affects the chromosome segregation process in human oocytes resulting in aneuploidy, infertility and developmental disorders. A considerable amount of segregation errors in humans are introduced at the second meiotic division. We have here compared the chromosome segregation process in young adult and aged female mice during the second meiotic division. More than half of the oocytes in aged mice displayed chromosome segregation irregularities at anaphase II, resulting in dramatically increased level of aneuploidy in haploid gametes, from 4% in young adult mice to 30% in aged mice. We find that the post-metaphase II process that efficiently corrects aberrant kinetochore-microtubule attachments in oocytes in young adult mice is approximately 10-fold less efficient in aged mice, in particular affecting chromosomes that show small inter-centromere distances at the metaphase II stage in aged mice. Our results reveal that post-metaphase II processes have critical impact on age-dependent aneuploidy in mammalian eggs., QC 20230228

Published
2022
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16. Observations of SO2 and NO2 by mobile DOAS in the Guangzhou eastern area during the Asian Games 2010

Author

Wu, F. C., Xie, P. H., Li, A., Chan, K. L., Hartl, A., Wang, Y., Si, F. Q., Zeng, Y., Qin, M., Xu, J., Liu, J. G., Liu, W. Q., and Wenig, M.

Abstract

Mobile passive differential optical absorption spectroscopy measurements of SO2 and NO2 were performed in the Guangzhou eastern area (GEA) during the Guangzhou Asian Games 2010 from November 2010 to December 2010. The observations were carried out between 10:00 to 13:00 (local time, i.e., during daylight). Spatial and temporal distributions of SO2 and NO2 in this area were obtained and emission sources were determined using wind field data. The NO2 vertical column densities were found to agree with Ozone Monitoring Instrument values. The correlation coefficient (referred to as R2) was 0.88 after cloud filtering within a specific ground pixel. During the Guangzhou Asian Games and Asian Paralympics (Para) Games, the SO2 and NOx emissions in the area were quantified using averaged wind speed and wind direction. For times outside the games the average SO2 emission was estimated to be 9.50 ± 0.90 tons per hour and the average NOx emission was estimated to be 5.87 ± 3.46 tons per hour. During the phases of the Asian and Asian Para Games, the SO2 and NOx emissions were reduced by 53.50% and 43.50%, respectively, compared to the usual condition. We also investigated the influence of GEA on Guangzhou University Town, the main venue located northwest of the GEA, and found that SO2 concentrations here were about tripled by emissions from the GEA.

Published
2018

17. Erratum to: Effects of dietary botanical and synthetic astaxanthin on E/Z and R/S isomer composition, growth performance, and antioxidant capacity of white shrimp, Litopenaeus vannamei, in the nursery phase

Author

Liu, X H, Wang, B J, Li, Y F, Wang, L, and Liu, J G

Subjects
0301 basic medicine, 03 medical and health sciences, 030104 developmental biology, lcsh:Biology (General), education, 040102 fisheries, 0401 agriculture, forestry, and fisheries, 04 agricultural and veterinary sciences, lcsh:QH301-705.5, health care economics and organizations, humanities
Abstract

Invertebrate Survival Journal, Vol 15 No 1 (2018)

Published
2018

18. Effects of dietary botanical and synthetic astaxanthin on E/Z and R/S isomer composition, growth performance, and antioxidant capacity of white shrimp, Litopenaeus vannamei, in the nursery phase [For this article an Erratum has been published]

Author

Liu, X H, Wang, B J, Li, Y F, Wang, L, and Liu, J G

Subjects
0301 basic medicine, virus diseases, 04 agricultural and veterinary sciences, digestive system, digestive system diseases, astaxanthin, 03 medical and health sciences, 030104 developmental biology, fluids and secretions, lcsh:Biology (General), 040102 fisheries, polycyclic compounds, 0401 agriculture, forestry, and fisheries, L. vannamei postlarvae, lcsh:QH301-705.5, Vibrio
Abstract

Astaxanthin (AST) is a beneficial dietary supplement in shrimp farming. However, the different effects of synthetic AST (S-Ast) and natural AST (N-Ast) on the postlarvae is unclear. These effects were compared by supplementation with a gradient of AST (0, 50, 70, 90, 140 ppm) for 35 days. Growth parameters including weight and length gain, carotenoid content, AST content and isomer composition, antioxidant capacity (superoxide dismutase, catalase, glutathione peroxidase), survival rate and mRNA expression levels for antioxidant enzymes in Litopenaeus vannamei postlarvae were measured. The results indicated that postlarvae given N-Ast had significantly higher growth performance and AST content. Although there were different ratios of AST optical isomers in the diets, there was a similar optical isomer content in juvenile shrimp. The cis/trans AST ratio and antioxidant enzyme (SOD and GPx) activities in N-Ast90 were the highest among all groups. Cumulative mortality in N-Ast90, N-Ast140 and S-Ast70 were significantly lower than in the control and N-AST50. The mRNA expression levels for the antioxidant enzymes (cMnSOD and GPx) also increased for N-Ast90-fed shrimp under stress conditions. These results suggest that an epimerase may exist in vivo and that an appropriate level of botanical AST in diets was approximately 90 ppm for L. vannamei postlarvae., Invertebrate Survival Journal, Vol 15 No 1 (2018)

Published
2018

22. INVESTIGATION OF DEBRIS PARTICLES DISTRIBUTION IN ELECTRICAL DISCHARGE MACHINING OF MICRO-HOLES ARRAY.

Author

XIE, B. C., LIU, J. G., and CUI, H. X.

Subjects
*ELECTRIC metal-cutting, *MACHINING, *THREE-dimensional flow, *ABRASIVE machining, *ULTRASONIC effects, *METAL hardness, *ELECTRIC machines, *FLOW simulations
Abstract

Micro-holes array and micro-electrodes array are widely used in biomedical industry, aerospace industry and micro-electromechanical systems. The machining of micro-holes array is a difficult problem for traditional machining technology. Currently electrical discharge machining technology (EDM) is an alternative machining technology for the fabricating of micro-holes array in high strength and hardness of metal material because of it is free from mechanical force. However, distribution and concentration of debris particles in the discharge gap easily leads to the intensive distribution of discharge positions, which significantly influences machining performance of EDM of micro-holes array. In this study, a three-dimensional flow field simulation model of ultrasonic assisted EDM of micro-holes array is proposed by FLUENT software. The effect of ultrasonic vibration and the depth-to-diameter ratio on debris particles distribution in ultrasonic assisted EDM of micro-holes array will be investigated by numerical simulation. It is shown that reducing the depth-diameter ratio and increasing the ultrasonic amplitude and frequency are beneficial to enhance the exhaustion of debris particles out of the discharge gap and decrease the concentration of debris particles in the discharge gap. In addition, machining experiments are carried out. [ABSTRACT FROM AUTHOR]

Published
2020
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23. Efficacy of botanical pesticide for rotifer extermination during the cultivation of Nannochloropsis oculata probed by chlorophyll a fluorescence transient.

Author

ZHANG, L. T., XU, R., and LIU, J. G.

Subjects
CHLOROPHYLL spectra, BIOPESTICIDES, PESTICIDES, ALGAL cells, BRACHIONUS
Abstract

Nannochloropsis is widely used in aquaculture as a feed source. However, large-scale cultivation of Nannochloropsis usually fails due to rotifer contamination. In order to identify an effective technique for reducing rotifer contamination, the effect of Brachionus plicatilis contamination on photosynthetic characteristics in Nannochloropsis oculata and the efficacy of the celangulin (CA):toosendanin (TSN) (1:9) combination for rotifer extermination were investigated using chlorophyll a fluorescence transient. B. plicatilis could directly devour microalgal cells and sharply reduced N. oculata density to very low levels. B. plicatilis also inhibited activities of PSII reaction centers, both acceptor and donor side, thereby damaging the photosynthetic performance of surviving N. oculata cells. However, the CA:TSN (1:9) combination could completely eliminate B. plicatilis, thereby preventing rotifers from devouring microalgae cells and protecting the photosynthetic performance of the surviving algal cells against rotifers damage. Therefore, the binary combination of CA:TSN (1:9), is considered to be a good candidate of botanical pesticide for controlling rotifer contamination. [ABSTRACT FROM AUTHOR]

Published
2020
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30. Science for action at the local landscape scale

Author

Opdam, P., Nassauer, J. I., Wang, Z. F., Albert, C., Bentrup, G., Castella, Jean-Christophe, McAlpine, C., Liu, J. G., Sheppard, S., and Swaffield, S.

Subjects
Cross-disciplinary synthesis, Sustainability, Capacity building, Science-practice interface, Community-based landscape planning, Transdisciplinary science
Abstract

For landscape ecology to produce knowledge relevant to society, it must include considerations of human culture and behavior, extending beyond the natural sciences to synthesize with many other disciplines. Furthermore, it needs to be able to support landscape change processes which increasingly take the shape of deliberative and collaborative decision making by local stakeholder groups. Landscape ecology as described by Wu (Landscape Ecol 28:1-11, 2013) therefore needs three additional topics of investigation: (1) the local landscape as a boundary object that builds communication among disciplines and between science and local communities, (2) iterative and collaborative methods for generating transdisciplinary approaches to sustainable change, and (3) the effect of scientific knowledge and tools on local landscape policy and landscape change. Collectively, these topics could empower landscape ecology to be a science for action at the local scale.

Published
2013

31. The research on new technology and separation performance of wastewater treatment for offshore field.

Author

Zhao, Z. G., Feng, M. Q., Liu, J. G., Tao, Y. K., Wang, J. S., Wang, L., and Peng, G. Q.

Subjects
WASTEWATER treatment, TECHNOLOGICAL innovations, PETROLEUM in submerged lands
Abstract

Wastewater treatment and recycling for offshore oilfield can bring economic and social benefits. This paper produced wastewater treatment and recycling technological process for offshore oilfield combining with engineering practice. Considering the complexity of internal flow in disc separator, VOF model and RNG k-ε turbulence model were used to numerically simulate the process of separating oil-water in the separator then the law of distribution and the efficiency of separating oil-water such as flow velocity, pressure, turbulent kinetic energy, turbulent flow, laminar flow and so on were obtained. The discrete phase model (DPM) was used to simulate the motion of particles, then obtained the motion process and separation efficiency of discrete phase particles. The test results show that, the separation efficiency of the calculation and actual measurements both meet the design requirements with the separation efficiency calculated slightly higher than that in the actual measurements. The relative error of oil-water separation efficiency and particle separation efficiency are 1.5% and 1.4% respectively. The data indicate that the numerical simulation method is reliable for predicting the separation performance of the separator, so wastewater treatment and recycling technological process meet the requirements of engineering application. [ABSTRACT FROM AUTHOR]

Published
2018
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33. International Geoscience and Remote Sensing Symposium (IGARSS)

Author

Clerici, Nicola, Liang, L, Deng, H, Miao, F, Davis, A. M, Mason, P. J, and Liu, J. G.

Subjects
Ecology, Environment, Hydroelectrical power, Migration
Abstract

The Three Gorges Dam Project (TGP) has raised international attention because of its great potential for hydroelectrical power generation and flood control, as well as for its potentially hazardous effects on the environment and ecology, and for the migration and resettlement of local inhabitants. Slope instability is one common problem in the Three Gorges area and this paper reports a regional assessment of landslide hazard based on ASTER imagery and Digital Elevation Model (DEM), in combination with limited field investigation. A simple model based on the geometric mean and Boolean decision rules has been applied to a multi-criterion dataset to generate a map of landslide hazard.

Published
2003

34. Enantioselective binding of Lambda- and Delta-[Ru(bpy)(2)(HPIP)]Cl-2 (HPIP=2-(2-hydroxyphenyl)imidazo[4,5-f][1,10]phenanthroline) to the hexanucleotide [d(5 '-GTCGAC-3 ')2]

Author

Garoufis, A., Liu, J. G., Ji, L. N., and Hadjiliadis, N.

Subjects
oligonucleotide, h-1-nmr spectra, spectroscopy, ru(ii) enantiomers, ionization mass-spectrometry, nmr, nmr evidence, DNA-binding, d(gtcgac)(2), ruthenium(ii) complexes, esi-ms, minor-groove binding, sequential resonance assignments, intercalation, hpip
Abstract

Multidimensional NMR techniques (1D (HNMR)-H-1, 2D DQF (HH)-H-1-H-1 COSY and 2D (HH)-H-1-H-1 NOESY), electrospray ionization mass spectrometry (ESI-MS) and electronic spectroscopy, were performed to study the interactions of the enantiomers Lambda- and Delta-[Ru(bpy)(2)(HPIP)]Cl-2, (HPIP=2-(2-hydroxyphenyl)imidazo[4,5-f][1,10]phenanthro-line) with the self complementary hexanucleotide duplex d(5'-GTCGAC-3')(2). The results show that the Delta-[Ru(bpy)(2)(HPIP)]Cl-2 binds tightly to the oligonucleotide, by intercalation of the ligand HPIP, between the A5 and C6 base sequence of the same strand, probably through the minor groove. Lambda-enantiomer binds weakly, suggesting groove interactions with the hexanucleotide duplex. ESI-MS spectrometry and UV-vis spectroscopy also confirmed these observations. (C) 2002 Elsevier Science Inc. All rights reserved. J Inorg Biochem

Published
2003

42. Chronic Morphine Treatment Impaired Hippocampal Long-Term Potentiation and Spatial Memory via Accumulation of Extracellular Adenosine Acting on Adenosine A1 Receptors

Author

Lu, G., primary, Zhou, Q. X., additional, Kang, S., additional, Li, Q. L., additional, Zhao, L. C., additional, Chen, J. D., additional, Sun, J. F., additional, Cao, J., additional, Wang, Y. J., additional, Chen, J., additional, Chen, X. Y., additional, Zhong, D. F., additional, Chi, Z. Q., additional, Xu, L., additional, and Liu, J. G., additional

Published
2010
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47. Numerical methods for oscillatory solutions to hyperbolic problems

Author

Engquist, Björn, Liu, J.-G., Engquist, Björn, and Liu, J.-G.

Abstract

Difference approximations of hyperbolic partial differential equations with highly oscillatory coefficients and initial values are studied. Analysis of strong and weak convergence is carried out in the practically interesting case when the discretization step sizes are essentially independent of the oscillatory wave lengths, NR 20140805

Published
1993
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49. Observations of SO2 and NO2 by mobile DOAS in the Guangzhou Eastern Area during the Asian Games 2010.

Author

Wu, F. C., Xie, P. H., Li, A., Chan, K. L., Hartl, A., Wang, Y., Si, F. Q., Zeng, Y., Qin, M., Xu, J., Liu, J. G., Liu, W. Q., and Wenig, M.

Subjects
SULFUR oxides, LIGHT absorption, DISTRIBUTION (Probability theory), STATISTICAL correlation, ASIAN Games
Abstract

Mobile Differential Optical Absorption Spectroscopy measurements of SO2 and NO2 were performed in the Guangzhou Eastern Area (GEA) during the Guangzhou Asian Games 2010 from November 2010 to December 2010. Spatial and temporal distributions of SO2 and NO2 in this area were obtained and emission sources were determined by using wind field data. The NO2 vertical column densities were found to agree with OMI values. The correlation coefficient (R2) was 0.88 after cloud filtering. During the Guangzhou Asian Games and Asian Paralympics (Para) Games, the SO2 and NO2 emissions in the area were quantified using averaged wind speed and wind direction. For times outside the Games the average SO2 emission was estimated to be 9.50±0.90 tons per hour and the average NO2 emission was estimated to be 3.50±1.89 tons per hour. During the phases of the Asian and Asian Para Games, the SO2 and NO2 emissions were reduced by 53.5 and 46 %, respectively, compared to the usual condition. We also investigated the influence of GEA on Guangzhou University Town, the main venue located northwest of the GEA, and found that SO2 concentrations here were about tripled by emissions from the GEA. [ABSTRACT FROM AUTHOR]

Published
2013
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50. Fast Discrete W Transforms via Computation of Moments.

Author

Liu, J. G., Liu, Y. Z., and Wang, G. Y.

Subjects
*DISCRETE-time systems, *KERNEL functions, *COMPUTATIONAL complexity, *MACHINE theory, *ALGORITHMS, *STRUCTURED programming
Abstract

A novel approach to compute all four types of Discrete W transform (DWT) is proposed By using kernel transforms and Taylor expansions, a DWT is approximated by a linear sum of discrete moments. This enables us to use computational techniques developed for computing moments to compute DWTs efficiently. The amount of multiplications used in our method is O(N log2 N/log2 log2 N) and is superior to the O(N log2 N) in the conventional DWT. The proposed algorithm achieves a simple computational structure and naturally deals with any sequence lengths. [ABSTRACT FROM AUTHOR]

Published
2005
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