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Ecosystem carbon storage and sink/source of temperate forested wetlands in Xiaoxing’anling, northeast China

Journal of Forestry Research 2022年第3期33卷 839-849页

作者： Biao Wang Changcheng Mu Huicui Lu Na li Yan Zhang li Ma Center for Ecological Research Northeast Forestry UniversityHarbin150040People’s Republic of China Faculty of Forestry Qingdao Agricultural UniversityQingdao266000People’s Republic of China

Wetlands play an important role in the global carbon cycle, but there are still considerable uncertainties in the estimation of wetland carbon storage and a dispute on whether wetlands are carbon sources or carbon sinks. Xiaoxing’anling are one of several concentrated distribution areas of forested wetland in China, but the carbon storage and carbon sink/source of forested wetlands in this area is unclear. We measured the ecosystem carbon storage (vegetation and soil), annual net carbon sequestration of vegetation and annual carbon emissions of soil heterotrophic respiration of five typical forested wetland types (alder swamp, white birch swamp, larch swamp, larch fen, and larch bog) distributed along a moisture gradient in this area in order to reveal the spatial variations of their carbon storage and quantitatively evaluate their position as carbon sink or source according to the net carbon balance of the ecosystems. The results show that the larch fen had high carbon storage (448.8 t ha^(−1)) (6.8% higher than the larch bog and 10.5–30.1% significantly higher than other three wetlands (P < 0.05), the white birch swamp and larch bog were medium carbon storage ecosystems (406.3 and 420.1 t ha^(−1)) (12.4–21.8% significantly higher than the other two types (P < 0.0 5), while the alder swamp and larch swamp were low in carbon storage (345.0 and 361.5 t ha^(−1), respectively). The carbon pools of the five wetlands were dominated by their soil carbon pools (88.5–94.5%), and the vegetation carbon pool was secondary (5.5–11.5%). At the same time, their ecosystem net carbon balances were positive (0.1–0.6 t ha^(−1) a^(−1)) because the annual net carbon sequestration of vegetation (4.0–4.5 t ha^(−1) a^(−1)) were higher than the annual carbon emissions of soil heterotrophic respiration (CO_(2) and CH_(4)) (3.8–4.4 t ha^(−1) a^(−1)) in four wetlands, (the alder swamp being the exception), so all four were carbon sinks while only the alder swamp was a source of carbon emissio

关键词： Temperate forested wetlands Ecosystem carbon storage Carbon sink or source Xiaoxing’anling of China

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li-promoted C_(3)N_(4) catalyst for efficient isomerization of glucose into fructose at 50℃ in water

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Green Energy & Environment 2024年第9期9卷 1419-1426页

作者： Wang liu Yanfei Zhang Mengya Sun Xinpeng Zhao Shenggang li Xinqing Chen liangshu Zhong lingzhao Kong CAS Key Laboratory of Low-Carbon Conversion Science and Engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China University of Chinese Academy of Sciences Beijing100049China School of Physical Science and Technology Shanghai Tech UniversityShanghai201203China School of Environmental Science and Engineering Suzhou University of Science and TechnologySuzhouJiangsu215009China

Efficient and selective glucose-to-fructose isomerization is a crucial step for production of oxygenated chemicals derived from sugars,which is usually catalyzed by base or Lewis acid heterogeneous ***,high yield and selectivity of fructose cannot be simultaneously obtained under mild conditions which hamper the scale of application compared with enzymatic ***,a li-promoted C_(3)N_(4) catalyst was exploited which afforded an excellent fructose yield(40.3 wt%)and selectivity(99.5%)from glucose in water at 50℃,attributed to the formation of stable li–N bond to strengthen the basic sites of ***,the so-formed N_(6)–li–H_(2)O active site on li–C_(3)N_(4) catalyst in aqueous phase changes the local electronic structure and strengthens the deprotonation process during glucose isomerization into *** superior catalytic performance which is comparable to biological pathway suggests promising applications of lithium containing heterogeneous catalyst in biomass refinery.

关键词： Glucose Fructose Isomerization li–C_(3)N_(4) Density functional theory calculations

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Solution blow spinning mass production of mullite nanofiber from environment friendly aqueous Al–Si solutions

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Progress in Natural Science:Materials International 2023年第5期33卷 691-700页

作者： Xinpeng Jin Jiugang li Chi Zhang Keshuai liu Chong He Wenbin li School of Textile Science and Engineering Wuhan Textile University State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile University

Achieving large-scale production of high-performance mullite ceramic nanofibers posed a formidable ***, an air heating-solution blow spinning technique was designed for the mass fabrication of mullite nanofibers at high speeds, ranging from 6 to 60 ml/h. Spinnable aqueous Al–Si solution systems, employing various aluminum sources, were systematically investigated. The optimization of the solution blow spinning apparatus involved the incorporation of a hot air blow device capable of dispensing streams of hot, dry air. Comprehensive investigations were conducted to examine the impact of variables such as spinning solution viscosity, spinning rate, and spinning distance on the resulting mullite fiber diameter and morphology. Following sintering at 1200°C, mullite fiber cotton was successfully synthesized, exhibiting diameters spanning from 500 nm to 5 μm. These mullite nanofiber cotton demonstrated exceptional attributes, including robust temperature stability(up to 1300°C), remarkable thermal insulation properties and superior filtration efficiency.

关键词： Solution blow spinning Mullite nanofiber Aqueous solution Thermal insulation

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Absolute physical parameters of three poorly studied detached eclipsing binaries

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Research in Astronomy and Astrophysics 2021年第1期21卷 220-228页

作者： Dao-Ye Yang li-Fang li Quan-Wang Han Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100012China Key Lab of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 10101China School of Physics and Electronics Qiannan Normal University for NationalitiesDuyun 558000China

The photometric and spectroscopic data for three double-lined detached eclipsing binaries were collected from the photometric and spectral *** light and radial velocity curves of each binary system were simultaneously analyzed using Wilson-Devinney(WD)code,and the absolute physical and orbital parameters of these binaries were *** masses of both components of ASASSN-V J063123.82+192341.9 were found to be M1=1.088±0.016 and M20.883±0.016 M⊙;those of ASAS J011416+0426.4 were determined to be M1=0.934±0.046 and M2=0.754±0.043 M⊙;and those of MW Aur were derived to be M1=2.052±0.196 and M21.939±0.193 M⊙.Finally,the evolutionary status of these detached binaries was discussed based on their absolute parameters and the theoretical stellar models.

关键词： stars:binaries:eclipsing stars:fundamental parameters stars:evolution stars:individual:ASASSN-V J063123.82+192341.9,ASAS J011416+0426.4 and MW Aur

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Micromixing performance of the teethed high shear mixer under semi-batch operation

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Frontiers of Chemical Science and Engineering 2022年第4期16卷 546-559页

作者： Xiaoning li lin Yang Junheng Guo Wei li Mingliang Zhou Jinli Zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China School of Chemistry and Chemical Engineering Shihezi UniversityShihezi 832003China

Semi-batch operated reaction processes are necessary for some competitive reaction systems to achieve a desirable process selectivity and productivity of fine chemical *** the structural and operating parameters of the teethed high shear mixers were adjusted to study the micromixing performance in the semi-batch operated system,using the Villermaux/Dushman reaction *** results indicate that the rising of the rotor speed and the number of rotor teeth,the decrease of the width of the shear gap and the radial distance between the feed position and the inner wall of stator can enhance the micromixing level and lead to the decrease of the segregation ***,computational fluid dynamics calculations were carried out to disclose the evolution of the flow pattern and turbulent energy dissipation rate of the semi-batch operated high shear ***,the correlation was established with a mean relative error of 8.05%and R^(2)of 0.955 to fit the segregation index and the parameters studied in this work,which can provide valuable guidance on the design and optimization of the semi-batch operated high shear mixers in practical applications.

关键词： high shear mixer semi-batch operation micromixing performance Villermaux Dushman system segregation index

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Research on the intermediate phase of 40CrMnSiB steel shell under different heat treatments

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Defence Technology（防务技术） 2021年第3期17卷 1032-1041页

作者： Wei-bing li Zhi-chuang Chen Xiao-ming Wang Wen-bin li ZNDY of Ministerial Key Laboratory Nanjing University of Science and TechnologyNanjing210094China

In this study, 40 Cr Mn Si B steel cylindrical shells were tempered at 350, 500 and 600 ℃ to study the effect of tempering temperature on the dynamic process of expansion and fracture of the metal shell. A midexplosion recovery experiment for the metal cylinder under internal explosive loading was designed, and the wreckage of the casings at the intermediate phase was obtained. The effects of different tempering temperatures on the macroscopic and microscopic fracture characteristics of 40 Cr Mn Si B steel were studied. The influence of tempering temperatures on the fracture characteristic parameters of the recovered wreckage were measured and analyzed, including the circumferential divide size, the thickness and the number of the circumferential divisions. The results show that as the tempering temperature was increased from 350 to 600 ℃, at first, the degree of fragmentation and the fracture characteristic parameters of the recovered wreckage changed significantly and then became essentially consistent. Scanning electron microscopy analysis revealed flow-like structure characteristics caused by adiabatic shear on different fracture surfaces. At the detonation initiation end of the casing, fracturing was formed by tearing along the crack, which existed a distance from the initiation end and propagated along the axis direction. In contrast, the fracturing near the middle position consists of a plurality of radial shear fracture units. The amount of alloy carbide that was precipitated during the tempering process increased continuously with tempering temperature, leading to an increasing number of spherical carbide particles scattered around the fracture surface.

关键词： Explosive mechanics Mid-explosion recovery experiment Explosion and fracture Heat treatment SEM(Scanning electron microscope)fracture analysis

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Existence,Orbital Stability and Instability of Solitary Waves for Coupled BBM Equations

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Acta Mathematicae Applicatae Sinica 2009年第1期25卷 1-10页

作者： li-wei Cui Fundamental Department The Academy of Armored Force Engineering Beijing 100072 China

This paper is concerned with the orbital stability/instability of solitary waves for coupled BBM equations which have Hamiltonian form. The explicit solitary wave solutions will be worked out first. Then by detailed spectral analysis and decaying estimates of solutions for the initial value problem, we obtain the orbital stability/instability of solitary waves.

关键词： Solitary wave orbital stability/instability spectral analysis decaying estimate

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Landslide prediction based on improved principal component analysis and mixed kernel function least squares support vector regression model

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Journal of Mountain Science 2021年第8期18卷 2130-2142页

作者： li li-min CHENG Shao-kang WEN Zong-zhou School of Electronics and Information Xi’an Polytechnic UniversityXi’an710048China School of Automation Northwestern Polytechnical UniversityXi’an710072China

Landslide probability prediction plays an important role in understanding landslide information in advance and taking preventive *** factors can influence the occurrence of landslides,which is easy to have a curse of dimensionality and thus lead to reduce prediction *** the generalization ability of the model will also decline sharply when there are only small *** reduce the dimension of calculation and balance the model’s generalization and learning ability,this study proposed a landslide prediction method based on improved principal component analysis(PCA)and mixed kernel function least squares support vector regression(LSSVR)***,the traditional PCA was introduced with the idea of linear discrimination,and the dimensions of initial influencing factors were reduced from 8 to *** improved PCA can not only weight variables but also extract the original ***,combined with global and local kernel function,the mixed kernel function LSSVR model was framed to improve the generalization *** optimization algorithm(WOA)was used to optimize the ***,Root Mean Square Error(RMSE),the sum of squared errors(SSE),Mean Absolute Error(MAE),Mean Absolute Precentage Error(MAPE),and reliability were employed to verify the performance of the *** with radial basis function(RBF)LSSVR model,Elman neural network model,and fuzzy decision model,the proposed method has a smaller ***,the landslide warning level obtained from the landslide probability can also provide references for relevant decision-making departments in emergency response.

关键词： Landslide probability LSSVR Mixed kernel function Improved PCA Warning level

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Towards universal neural network interatomic potential

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Journal of Materiomics 2023年第3期9卷 447-454页

作者： So Takamoto Daisuke Okanohara Qing-Jie li Ju li Preferred Networks Inc.100-00041-6-1 OtemachiChiyoda-kuTokyoJapan Department of Nuclear Science and Engineering and Department of Materials Science and Engineering MITCambridgeMA02139USA

The universal gravitational force law f=-Gm_(1)m_(2)/r^(2)enabled Newton to predict the trajectory of celestial bodies in 1686,pro-pelling human civilization into the modern *** and ions underlie chemistry,biology and materials *** their interaction potential U(r1,r2,…,rN),where r1,r2,…,rN are the positions and types of atoms/ions.

关键词： potential positions interaction

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Boosting polysulfide redox conversion of li-S batteries by one-step-synthesized Co-Mo bimetallic nitride

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Journal of Energy Chemistry 2021年第10期30卷 336-346,I0010页

作者： Yingying Yan Hongtai li Chen Cheng Tianran Yan Wenping Gao Jing Mao Kehua Dai liang Zhang Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou 215123JiangsuChina School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001HenanChina College of Chemistry Tianjin Normal UniversityTianjin 300387China

lithium-sulfur(li-S)batteries are considered as one of the most promising next generation energy storage systems due to the high theoretical specific capacity,low cost,and environmental ***,the notorious shuttle effect of polysulfides hinders the practical application of li-S ***,we have rationally designed and synthesized sea urchin-like Co-Mo bimetallic nitride(Co_(3) MO_(3) N)in the absence of additional nitrogen sources with only one step,which was applied as the sulfur host materials for li-S *** results indicate that Co_(3) Mo_(3) N can efficiently anchor and catalyze the conversion of polysulfides,thus accelerating the electrochemical reaction kinetics and enabling prominent electrochemical *** a consequence,the S@Co_(3) Mo_(3) N cathode exhibits a high rate performance of 705 mAh g^(-1) at 3 C rate and an excellent cycling stability with a low capacity fading rate of 0.08%per cycle at 1 C over 600 *** at a high sulfur loading of 5.4 cmg cm^(-2),it delivers a high initial areal capacity of 4.50 mAh cm^(-2) which is still retained at 3.64 mAh cm^(-2) after 120 ***,the catalytic mechanism and structural stability of Co_(3) Mo_(3) N during cycling were elucidated by a combination of X-ray photoelectron spectroscopy and X-ray absorption fine *** work highlights the strategy of structure-catalysis engineering of bimetallic nitride,which is expected to have a wide application in li-S batteries.

关键词： lithium-sulfur batteries Co3Mo3N Shuttle effect Catalytic effect XAFS

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