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Decomposition of Mongolian pine litter in the presence of understory species in semi-arid northeast China

Journal of Forestry Research 2016年第2期27卷 329-337页

作者： Bing mao Rong mao Yalin Hu Yue huang Dehui Zeng State Key Laboratory of Forest and Soil Ecology Institute of Applied EcologyChinese Academy of SciencesShenyang 110164China University of Chinese Academy of Sciences Beijing 100049China Daqinggou Ecological Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130012China

The effects of understory plant litter on domi- nant tree litter decomposition are not well documented especially in semi-arid forests. In this study, we used a microcosm experiment to examine the effects of two understory species （Artemisia scoparia and Setaria viridis） litter on the mass loss and N release of Mongolian pine （Pinus sylvestris var. mongolica） litter in Keerqin Sandy Lands, northeast China, and identified the influencing mechanism from the chemical quality of decomposing litter. Four litter combinations were set up： one monocul- ture of Mongolian pine and three mixtures of Mongolian pine and one or two understory species in equal mass proportions of each species. Total C, total N, lignin, cel- lulose and polyphenol concentrations, and mass loss of pine litter were analyzed at days 84 and 182 of *** chemistry of pine litter not only changed with the stages of decomposition, but was also strongly influenced by the presence of understory species during decomposition. Both understory species promoted mass loss of pine litter at 84 days, while only the simultaneous presence of two understory species promoted mass loss of pine litter at 182 days. Mass loss of pine litter was negatively correlated with initial ratios of C/N, lignin/N and polyphenol/N of litter combinations during the entire incubation period; at 182 days it was negatively correlated with polyphenol concentration and ratios of C/N and polyphenol/N of litter combinations at 84 days of incubation. Nitrogen release of pine litter was promoted in the presence of understory species. Nitrogen release at 84 days was negatively correlated with initial N concentration; at 182 days it was negatively correlated with initial polyphenol concentration of litter combinations and positively correlated with lignin concentration of litter com- binations at 84 days of incubation. Our results suggest that the presence ofunderstory species causes substantial changes in chemical components of pine litt

关键词： Litter chemistry Litter mixture Mass loss Nitrogen release Understory species

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Energy-information trade-off induces continuous and discontinuous phase transitions in lateral predictive coding

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 79-85页

作者： Zhen-Ye huang Ruyi Zhou Miao huang hai-Jun Zhou Key Laboratory for Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China Minjiang Collaborative Center for Theoretical Physics Minjiang UniversityFuzhou 350108China

Lateral predictive coding is a recurrent neural network that creates energy-efficient internal representations by exploiting statistical regularity in sensory ***,we analytically investigate the trade-off between information robustness and energy in a linear model of lateral predictive coding and numerically minimize a free energy *** observed several phase transitions in the synaptic weight matrix,particularly a continuous transition that breaks reciprocity and permutation symmetry and builds cyclic dominance and a discontinuous transition with the associated sudden emergence of tight balance between excitatory and inhibitory *** optimal network follows an ideal gas law over an extended temperature range and saturates the efficiency upper bound of energy *** results provide theoretical insights into the emergence and evolution of complex internal models in predictive processing systems.

关键词： predictive coding recurrent neural network phase transition internal model free energy

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Generation of mid-infrared supercontinuum by designing circular photonic crystal fiber

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Chinese Physics B 2022年第5期31卷 370-378页

作者： Ying huang Hua Yang Yucheng mao College of Computer Science and Electronic Engineering Hunan UniversityChangsha 410082China State Key Laboratory of Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

A circular photonic crystal fiber(C-PCF)based on As2 Se3 is designed,which has three zero dispersion wavelengths and flat *** this fiber,a wide mid-infrared supercontinuum(MIR-SC)can be generated by launching a femtosecond pulse in the first anomalous dispersion *** simulation results show that the MIR-SC is formed by soliton self-frequency shift and direct soliton spectrum tunneling on the long wavelength side and self-phase modulation,soliton fission on the short wavelength ***,optical shocking and four-wave mixing(FWM)are not conducive to the long-wavelength extension of MIR-SC,while the number and intensity of fundamental solitons have a greater effect on the short-wavelength extension of *** generation of optical shocking waves,FWM waves and fundamental solitons can be obviously affected by changing the fiber length and input pulse parameters,so that the spectrum range and flatness can be adjusted with great ***,under the conditions of 4000 W pulse peak power,30 fs pulse width,47 mm fiber length,and 0 initial chirp,a wide MIR-SC with a coverage range of 2.535μm-16.6μm is *** numerical results are encouraging because they demonstrate that the spread of MIR-SC towards the red and blue ends can be manipulated by choosing the appropriate incident pulse and designing optimized fiber parameters,which contributes to applications in such diverse areas as spectroscopy,metrology and tomography.

关键词： circular photonic crystal fiber chalcogenide glass direct soliton spectrum tunneling nonlinearity

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Self-assembly synthesis of SnNb2O6/amino-functionalized graphene nanocomposite as high-rate anode materials for sodium-ion batteries

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Rare Metals 2021年第2期40卷 425-432页

作者： Min huang Ji-Xin Liu Peng huang hai Hu Chao Lai Postdoctoral Innovation Practice Base Zhengzhou Normal UniversityZhengzhou450044China School of Chemistry and Material Science Jiangsu Normal UniversityXuzhou221116China Superconducting Materials Research Center Northwest Institute for Nonferrous Metal ResearchXi’an710016China

A two-dimensional(2 D)SnNb_(2)O_(6)/amino-functionalized graphene(En-RGO)nanocomposite with a representative 2 D-2 D architecture has been constructed by an easy self-assembly approach and firstly investigated as anode materials for secondary sodium-ion *** SnNb_(2)O_(6)nanosheets are evenly anchored with the aminofunctionalized graphene through electrostatic attractive interplay between the negatively charged SnNb_(2)O_(6)and positively charged En-RGO after *** a result,a remarkable reversible capacity of 300 mAh·g^(-1)was obtained at 50 mA·g^(-1),and significantly,the En-RGO electrode could also deliver ultra-long calendar life up to1900 cycles with a high reversible capacity of200 mAh·g^(-1)at current of 500 mA·g^(-1).Such excellent electrochemical characteristics can be mainly ascribed to its fast pseudo-capacitive energy storage mechanism,and the capacitive contribution can even reach up to 90%at1.2 mV·s^(-1).

关键词： SnNb2O6 Amino-functionalized graphene Anode material Sodium-ion batteries

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Single-phase Computational Fluid Dynamics Applicability for the Study of Three-dimensional Flow in 5×5 Rod Bundles with Spacer Grids

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Chinese Journal of Mechanical Engineering 2012年第4期25卷 738-744页

作者： TIAN Ruifeng mao Xiaohui GAO Puzhen huang Yanping College of Nuclear Science and Technology Harbin Engineering University Harbin 150001 China National Defense Key Discipline Laboratory of Nuclear Safety and Simulation Technology Harbin Engineering University Harbin 150001 China National Key Laboratory of Bubble Physics and Nature Circulation Nuclear Power Institute of China Chengdu 610041 China

Spacer grids play an important role in pressurized water reactor（PWR） fuel assembly in that they have significant influence on the thermal-hydraulic characteristics of the reactor *** so far,the numerical studies are performed without regarding dimple and spring of spacer grids,just considering mixing ***,these studies use k-ε turbulence model without considering the suitability of the other turbulence models upon the different spacer grids flow.A study is carried out to understand the 3-D single-phase flow in AFA-2G 5×5 rod bundles with spacer grids based on numerical *** order to investigate the suitability of different turbulence models,k-ε model and k-ω model,the influence of different parts of spacer grid on the fluid flow is also *** using second-order upwind scheme,hybrid grids technique,and improved SIMPLEC algorithm,the Reynolds averaged mass conservation and momentum conservation equations are solved,and the pressure and velocity field of flow are *** numerical simulation results are compared with experiment results and the agreement is *** simulation results show the influences of the spring,dimple and mixing vane,and the different characteristics of the k-ε model and k-ω *** with the experiment results,the simulation results suggest that the k-ω model is suitable for the simulation of the rod bundle flow with spacer grids;the spring and dimple are the main causes of the pressure loss in the spacer grid *** friction coefficient of the channel with spring and dimple is 1.5 times the coefficient of the channel with the *** results are beneficial to enhance the simulation ability of spacer grids flow and optimization design ability of spaces grid.

关键词： rod bundles spacer grids turbulence model SIMPLEC algorithm

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Primary resonance of traveling viscoelastic beam under internal resonance

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Applied Mathematics and Mechanics(English Edition) 2017年第1期38卷 1-14页

作者： Hu DING Linglu huang Xiaoye mao Liqun CHEN Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai UniversityShanghai 200072China Department of Mechanics College of ScienceShanghai UniversityShanghai 200444China

Under the 3：1 internal resonance condition, the steady-state periodic response of the forced vibration of a traveling viscoelastic beam is studied. The viscoelastic behaviors of the traveling beam are described by the standard linear solid model, and the material time derivative is adopted in the viscoelastic constitutive relation. The direct multi-scale method is used to derive the relationships between the excitation frequency and the response amplitudes. For the first time, the real modal functions are employed to analytically investigate the periodic response of the axially traveling beam. The unde- termined coefficient method is used to approximately establish the real modal functions. The approximate analytical results are confirmed by the Galerkin truncation. Numerical examples are presented to highlight the effects of the viscoelastic behaviors on the steady-state periodic responses. To illustrate the effect of the internal resonance, the energy transfer between the internal resonance modes and the saturation-like phenomena in the steady-state responses is presented.

关键词： traveling beam nonlinear vibration viscoelasticity primary resonance internal resonance

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Stable attenuation-compensated reverse time migration and its application to land seismic data

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Petroleum Science 2023年第5期20卷 2784-2795页

作者： Xin-Ru Mu Qiang mao Jian-Ping huang Geosciences Department China University of Petroleum(East China)QingdaoShandong266580China Pilot National Laboratory for Marine Science and Technology(Qingdao) QingdaoShandong266000China

Intrinsic attenuation of the earth causes energy loss and phase distortion in seismic wave *** obtain high-resolution imaging results,these negative effects must be considered during reverse time migration(RTM).We can easily implement attenuation-compensated RTM using the constant Q viscoacoustic wave equation with decoupled amplitude attenuation and phase dispersion ***,the nonphysical amplitude-compensation process will inevitably amplify the high-frequency noise in the wavefield in an exponential form,causing the numerical simulation to become *** is due to the fact that the amplitude of the compensation grows exponentially with *** order to achieve stable attenuation-compensated RTM,we modify the analytic expression of the attenuation compensation extrapolation operator and make it only compensate for amplitude loss within the effective frequency *** on this modified analytic formula,we then derive an explicit time-space domain attenuation compensation extrapolation ***,the implementation procedure of stable attenuation-compensated RTM is *** addition to being simple to implement,the newly proposed attenuation-compensated extrapolation operator is superior to the conventional low-pass filter in suppressing random noise,which will further improve the imaging *** use two synthetic and one land seismic datasets to verify the stability and effectiveness of the proposed attenuationcompensated RTM in improving imaging resolution in viscous media.

关键词： Seismic attenuation Reverse time migration Stability strategy Pseudospectral method

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A novel unsupervised method for new word extraction

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Science China(Information Sciences) 2016年第9期59卷 11-21页

作者： Lili MEI Heyan huang Xiaochi WEI Xianling mao Beijing Engineering Research Center of High Volume Language Information Processing and Cloud Computing Applications Department of Computer Science and TechnologyBeijing Institute of Technology

New words could benefit many NLP tasks such as sentence chunking and sentiment analysis. However, automatic new word extraction is a challenging task because new words usually have no fixed language pattern, and even appear with the new meanings of existing words. To tackle these problems, this paper proposes a novel method to extract new words. It not only considers domain specificity, but also combines with multiple statistical language knowledge. First, we perform a filtering algorithm to obtain a candidate list of new words. Then, we employ the statistical language knowledge to extract the top ranked new words. Experimental results show that our proposed method is able to extract a large number of new words both in Chinese and English corpus, and notably outperforms the state-of-the-art methods. Moreover, we also demonstrate our method increases the accuracy of Chinese word segmentation by 10% on corpus containing new words.

关键词： new word extraction word segmentation domain specificity statistical language knowledge domain word extraction

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Design optimization of a hexapod vibration isolation system for electro-optical payload

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Chinese Journal of Aeronautics 2024年第2期37卷 330-342页

作者： Jing LI Weipeng LI Xiaoyan ZHANG hai huang School of Astronautics Beihang UniversityBeijing 100191China

The electro-optical payloads on mobile platforms generally suffer undesirable vibrations generated by maneuvers and *** vibrations are in six degrees of freedom and cause line-of-sight jitters,resulting in image blurring and loss of tracking *** this paper,a Hexapod Vibration Isolation System(HVIS)is proposed and optimized to solve this *** optimization aims to centralize and minimize the natural frequencies of HVIS,for expanding the vibration isolation bandwidth and improving the vibration isolation in the higher frequency *** that the design space for HVIS is limited and interfered with the frames of the mobile platform,a non-collision algorithm is proposed and applied in the optimization to obtain the feasible optimal *** optimization result shows that the natural frequency bandwidth has been reduced by 42.9%,and the maximum natural frequency is reduced by 30.2%.The prototypes of initial and optimal designs are manufactured and *** simulated and experimental results demonstrate the validity of the optimization,and the optimal design provides a maximum of 15 dB more isolation in rotation direction than the initial design.

关键词： Electro-optical payload Vibrations Isolation system Hexapod Optimization Non-collision design

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Large-scale preparation of fernwort-like single-crystalline superstructures of CuSe as Fenton-like catalysts for dye decolorization

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Science China Chemistry 2016年第7期59卷 903-909页

作者： Yuting mao Hongyan Zou Qiang Wang Chengzhi huang Key Laboratory of Luminescent and Real-Time Analytical Chemistry Ministry of Education College of Chemistry and Chemical Engineering Southwest University College of Pharmaceutical Science Southwest University

A simple green hydrothermal template-free method was developed to prepare single-crystalline superstructures of fern- wort-like copper selenide （CuSe） in large-scale by using polyvinylpyrrolidone （PVP） as both reductant and surfactant for the first time. Time-dependent morphologic evolution was made in order to explore the formation mechanism of the as-prepared product. The copper selenides with different morphologies, phases and structural forms could be prepared by varying the synthesis parameters, such as precursor molar ratios, precursor combinations, and the molecular weight of PVP. The fernwort-like superstructures of CuSe show excellent Fenton-like catalytic activities in degrading malachite green （MG） and rhodamine B （RhB）. These catalysts play an important role in the degradation process of MG and RhB solution with the aid of H202 which can yield highly reactive hydroxyl radicals （HO.）. Besides, the as-prepared CuSe catalyst is stable and reusable, thus it could be applied to the treatment of the dye contaminated waste water.

关键词： CuSe fernwort-like hydrothermal method Fenton-like catalytic activity degradation

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