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Integrated HI emission in galaxy groups and clusters

Research in Astronomy and Astrophysics 2017年第10期17卷 15-26页

作者： Mei Ai ming Zhu jian Fu National Astronomical Observatories Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences

The integrated HI emission from hierarchical structures such as groups and clusters of galax- ies can be detected by FAST at intermediate redshifts. Here we propose to use FAST to study the evolution of the global HI content of clusters and groups over cosmic time by measuring their integrated HI emissions. We use the Virgo Cluster as an example to estimate the detection limit of FAST, and have estimated the integration time to detect a Virgo type cluster at different redshifts （from z = 0.1 to z ---- 1.5）. We have also employed a semi-analytic model （SAM） to simulate the evolution of HI contents in galaxy clusters. Our simulations suggest that the HI mass of a Virgo-like cluster could be 2-3 times higher and the physical size could be more than 50% smaller when redshift increases from z = 0.3 to z = 1. Thus the integration time could be reduced significantly and gas rich clusters at intermediate redshifts can be detected by FAST in less than 2 hours of integration time. For the local Universe, we have also used SAM simulations to create mock catalogs of clusters to predict the outcomes from FAST all sky surveys. Comparing with the optically selected catalogs derived by cross matching the galaxy catalogs from the SDSS survey and the ALFALFA survey, we find that the HI mass distribution of the mock catalog with 20 s of integration time agrees well with that of observations. However, the mock catalog with 120 s of integration time predicts many more groups and clusters that contain a population of low mass HI galaxies not detected by the ALFALFA survey. A future deep HI blind sky survey with FAST would be able to test such prediction and set constraints on the numerical simulation models. The observational strategy and sample selections for future FAST observations of galaxy clusters at high redshifts are also discussed.

关键词： galaxy clusters -- neutral hydrogen (HI) -- galaxy evolution

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Multi-stage Dynamic Post-disaster Recovery Strategy for Distribution Networks Considering Integrated Energy and Transportation Networks

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CSEE Journal of Power and Energy Systems 2021年第2期7卷 408-420页

作者： Xinyi jiang jian Chen ming Chen Zhen Wei Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan 250061China State Grid Qingdao Power Supply Company Qingdao 266002China

To improve the resilience of distribution networks(DNs),a multi-stage dynamic recovery strategy is proposed in this paper,which is designed for post-disaster DN considering an integrated energy system(IES)and transportation network(TN).First,the emergency response quickly increases the output of gas turbines(GTs)in the natural gas network(NGN),and responsively reconfigures the DN in microgrids,to maximize the amount of loads to be *** single-commodity flow model is adopted to construct spanning tree ***,in the second stage of energy storage recovery,mobile energy storage systems(MESSs)are deployed to cover the shortages of power demands,i.e.,to further restore the loads after evaluating the load recovery *** Floyd algorithm based dynamic traffic assignment(DTA)is selected to obtain the optimal path of the *** the third stage,the outputs of various post-disaster recovery measures are adjusted to achieve an economically optimized *** studies demonstrate the effectiveness of the proposed dynamic post-disaster recovery strategy.

关键词： Dynamic post-disaster recovery dynamic transportation network integrated energy system resilience distribution

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Prediction of nuclear charge density distribution with feedback neural network

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Nuclear Science and Techniques 2022年第12期33卷 24-35页

作者： Tian‑Shuai Shang jian Li Zhong‑ming Niu College of Physics Jilin UniversityChangchun 130012China School of Physics and Optoelectronic Engineering Anhui UniversityHefei 230601China

Nuclear charge density distribution plays an important role in both nuclear and atomic physics,for which the two-parameter Fermi(2pF)model has been widely applied as one of the most frequently used ***,the feedforward neural network has been employed to study the available 2pF model parameters for 86 nuclei,and the accuracy and precision of the parameter-learning effect are improved by introducing A^(1∕3)into the input parameter of the neural ***,the average result of multiple predictions is more reliable than the best result of a single prediction and there is no significant difference between the average result of the density and parameter values for the average charge density *** addition,the 2pF parameters of 284(near)stable nuclei are predicted in this study,which provides a reference for the experiment.

关键词： Charge density distribution Two-parameter Fermi model Feedforward neural network approach

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Pricing and Ordering Strategies of E-Retailers in Electronic Business Environments

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Tsinghua Science and Technology 2005年第Z1期10卷 778-789页

作者： XIE ming CHEN jian Research Center for Contemporary Management School of Economics and ManagementTsinghua University Beijing 100084 China Research Center for Contemporary Management School of Economics and ManagementTsinghua University Beijing 100084 China

It is becoming increasingly evident that in the future the Internet will host large numbers of software agents that aid or even act on behalf of companies and consumers to make decisions and carry out transactions. In this paper, we develop different pricing and ordering strategies with limited information requirements for e-retailers under the electronic business environment, and study the dynamics and performance of these strategies through multi-agent simulation. The results not only reproduce some phenomena in former literature, such as the "tacit collusion" and the cyclical price wars,but also generate new findings, for example, the "tacit collusion" does not always exist among hill-climbing e-retailers, and the cyclical price wars will be suppressed when e-retailers consider their competitors'strategies. The results show that in electronic business environments, to test different strategies and evaluate their performance by simulation before they are employed into practice is of great importance.

关键词： pricing strategy ordering strategy agent-based simulation electronic business

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Suppression of Rayleigh-Taylor instability by gyroviscosity and sheared axial flow in imploding plasma pinches

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核聚变与等离子体物理 2007年第2期27卷 87-94页

作者： HUANG Lin jian Guang-de QIU Xiao-ming Southwestern In stitute of Physics Chengdu 610041

The synergistic stabilizing effect of gyroviscosity and sheared axial flow on the Rayleigh-Taylor instability in Z-pinch implosions is studied by means of the incompressible viscid magneto-hydrodynamic *** gyroviscosity(or finite Larmor radius) effects are introduced in the momentum equation through an anisotropic ion stress *** relation with the effect of a density discontinuity is *** results indicate that the short-wavelength modes of the Rayleigh-Taylor instability are easily stabilized by the gyroviscosity *** long wavelength modes are stabilized by the sufficient sheared axial ***,the synergistic effects of the finite Larmor radius and sheared axial flow can heavily mitigate the Rayleigh-Taylor *** synergistic effect can compress the Rayleigh-Taylor instability to a narrow wave number *** with a sufficient gyroviscosity and large enough flow velocity,the synergistic effect can completely suppressed the Rayleigh-Taylor instability in whole wave number region.

关键词：雷利-泰勒不稳定性回转粘性内向爆炸等离子体箍缩增敏作用有限拉莫尔旋进半径增长比率

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Prediction of the Charpy V-notch impact energy of low carbon steel using a shallow neural network and deep learning

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International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1309-1320页

作者： Si-wei Wu jian Yang Guang-ming Cao State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

The impact energy prediction model of low carbon steel was investigated based on industrial data. A three-layer neural network, extreme learning machine, and deep neural network were compared with different activation functions, structure parameters, and training functions. Bayesian optimization was used to determine the optimal hyper-parameters of the deep neural network. The model with the best performance was applied to investigate the importance of process parameter variables on the impact energy of low carbon steel. The results show that the deep neural network obtains better prediction results than those of a shallow neural network because of the multiple hidden layers improving the learning ability of the model. Among the models, the Bayesian optimization deep neural network achieves the highest correlation coefficient of 0.9536, the lowest mean absolute relative error of 0.0843, and the lowest root mean square error of 17.34 J for predicting the impact energy of low carbon steel. Among the variables, the main factors affecting the impact energy of low carbon steel with a final thickness of7.5 mm are the thickness of the original slab, the thickness of intermediate slab, and the rough rolling exit temperature from the specific hot rolling production line.

关键词： prediction shallow neural network deep neural network impact energy low carbon steel

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A novel technology for quick acclimation of an anaerobic microbial consortia used for biodegrading teraphthalic acid (TA)

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Journal of Environmental Sciences 2002年第2期14卷 204-209页

作者： LI Xiao ming ZENG Guang-ming CHEN jian LUN Shi yi Department of Environmental Science and Engineering Hunan UniversityChangsha 410082China School of Biotechnology Wuxi University of Light IndustryWuxi 214036China

The seed sludge originated from a methane fermentation reactor was enriched and acclimated with TA as sole carbon source under nitrate respiration mode first for 6 week, and then can be turned to methane fermentation conditions. After 6 weeks processing, the specific rate of TA degradation under nitrate respiration mode reached 23.8 mgTA/(L·gVSS), more than two times of that under methane fermentation mode 11.4 mg TA/(L·gVSS). The TA reductive cleavers' population density increased about 6 times and 20 times after 30 days and 90 days acclimation. After a total of 90 days for the enrichment and acclimation, the fermentative bacteria which originally existed in the seed sludge nearly disappeared, and instead of them, the TA reductive and cleaving bacteria group was formed in the new consortia, which was confirmed by the MPN counts and roll tube counts. Compared with the control experiment, the acclimation period can be shortened by about 50%.

关键词： acclimation anaerobic sludge enrichment nitrate terephthalic acid (TA)

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Control of petroleum-hydrocarbon contaminated groundwater by intrinsic and enhanced bioremediation

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Journal of Environmental Sciences 2010年第6期22卷 864-871页

作者： Chih-ming Kao rao Y.Surampalli Mu-Sheng Lee Institute of Environmental Engineering "National" Sun Yat-Sen University U.S.Environmental Protection Agency Environmental Protection Bureau Kaohsiung City Government

In the first phase of this study, the effectiveness of intrinsic bioremediation on the containment of petroleum hydrocarbons was evaluated at a gasoline spill site. Evidences of the occurrence of intrinsic bioremediation within the BTEX （benzene, toluene, ethylbenzene, and xylenes） plume included （1） decreased BTEX concentrations; （2） depletion of dissolved oxygen （DO）, nitrate, and sulfate; （3） production of dissolved ferrous iron, methane, and CO2; （4） deceased pH and redox potential; and （5） increased methanogens, total heterotrophs, and total anaerobes, especially within the highly contaminated areas. In the second phase of this study, enhanced aerobic bioremediation process was applied at site to enhance the BTEX decay rates. Air was injected into the subsurface near the mid-plume area to biostimulate the naturally occurring microorganisms for BTEX biodegradation. Field results showed that enhanced bioremediation process caused the change of BTEX removal mechanisms from anaerobic biodegradation inside the plume to aerobic biodegradation. This variation could be confirmed by the following field observations inside the plume due to the enhanced aerobic bioremediation process：（1） increased in DO, CO2, redox potential, nitrate, and sulfate, （2） decreased in dissolved ferrous iron, sulfide, and methane, （3） increased total heterotrophs and decreased total anaerobes. Field results also showed that the percentage of total BTEX removal increased from 92% to 99%, and the calculated total BTEX first-order natural attenuation rates increased from 0.0092% to 0.0188% per day, respectively, after the application of enhanced bioremediation system from the spill area to the downgradient area （located approximately 300 m from the source area）.

关键词： petroleum hydrocarbon groundwater natural attenuation intrinsic bioremediation

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Statistical Characteristics of ENSO Events in CMIP5 Models

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Atmospheric and Oceanic Science Letters 2014年第6期7卷 546-552页

作者： rao jian REN Rong-Cai State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences

By applying the historical-run outputs from 24 Coupled Model Intercomparison Project Phase 5(CMIP5) models and the NOAA Extended Reconstructed SST V3 b dataset(ERSST), the characteristics of different types of ENSO in the selected CMIP5 models, including cold-season-matured Eastern Pacific(C-EP) ENSO, warmseason-matured EP(W-EP) ENSO, cold-season-matured Central Pacific(C-CP) ENSO, and warm-season-matured CP(W-CP) ENSO, were examined in comparison with those in the ERSST dataset. The results showed that, in general, consistent with observations, EP ENSO events in most of the model runs were relatively much stronger than CP ENSO events, and cold-season-matured ENSO events were relatively much more frequent than warm-season-matured ENSO events for both EP and CP ENSO events. The composite amplitudes of ENSO events in most of the models were generally weaker than in observations, particularly for EP El Ni?o and CP La Ni?a. Moreover, most of the models successfully reproduced the amplitude asymmetries between El Ni?o and La Ni?a for cold-season-matured EP and CP ENSO events, exhibiting an average stronger/weaker EP El Ni?o/La Ni?a regime and a weaker/stronger CP El Ni?o/La Ni?a regime. Most of the models, however, failed to reproduce the observed regimes of stronger/weaker W-EP El Ni?o/ La Ni?a and weaker/stronger W-CP El Ni?o/La Ni?a.

关键词： CMIP5 ENSO eastern Pacific central Pacific

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Redefined generalized fuzzy ideals of near-rings

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Applied Mathematics(A Journal of Chinese Universities) 2010年第3期25卷 341-348页

作者： ZHAN jian-ming YIN Yun-qiang Department of Mathematics Hubei Institute for Nationalities Enshi 445000 China College of Mathematics and Information Sciences East China Institute of Technology Fuzhou Jiangxi 344000 China

With a new idea, we redefine generalized fuzzy subnear-rings （ideals） of a near- ring and investigate some of its related properties. Some new characterizations are given. In particular, we introduce the concepts of strong prime （or semiprime）（∈, ∈∨ q）-fuzzy ideals of near-rings, and discuss the relationship between strong prime （or semiprime）（∈, ∈∨ q）-fuzzy ideals and prime （or semiprime）（∈, ∈∨ q）-fuzzy ideals of near-rings.

关键词： Near-ring subnear-ring (ideal) (∈^- ∈^-∨ q^-)-fuzzy subnear-ring (ideal) prime (semiprime) (∈ ∈∨ q)-fuzzy subnear-ring (ideal).

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