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Nitrogen release and re-adsorption dynamics on crop straw residue during straw decomposition in an Alfisol

Journal of Integrative Agriculture 2021年第1期20卷 248-259页

作者： LI Ji-fu zhong fang-fang Engineering Research Center of Ecology and Agricultural Use of Wetland Ministry of Education/College of AgricultureYangtze UniversityJingzhou 434025P.R.China

Returning crop straw to the field not only improves the nitrogen(N) supplying capacity and N retention of soil but also decreases the amount of rural organic waste and prevents air pollution. Therefore, understanding the mechanisms of the N release and re-adsorption dynamics on crop straw residue during straw decomposition in agricultural soil is important, and this understanding can help us strengthen N fertilizer management during the crop growth period. An on-farm incubation experiment was conducted in the Jianghan Plain in Central China under flooded conditions using the nylon mesh bag method. Results showed that the decomposition rate of crop straw was much faster at the beginning of the incubation stage, whereas it was steady during the later stage with no observed differences among the three types of crop straw. After 120 d of incubation, the cumulative decomposition proportion of rice straw, wheat straw and rape straw was 72.9, 56.2, and 66.9%, respectively. The proportion of N that released from the three crop straws was 52.0, 54.4 and 54.9%, respectively. The zeta potentials and Brunauer, Emmett and Teller(BET) surface area of the rice, wheat and rape straw residues increased gradually as the decomposition period progressed. The water adsorption capacity of the rice straw was significantly affected during the decomposition period. The saturated water adsorption capacity of rice straw was the highest at 30 d of decomposition(4.17 g g^–1) and then decreased slightly. The saturated water adsorption of wheat and rape straws reached the lowest value at 30 d and then gradually increased and became stable. All the results demonstrated that crop straw and straw residue can re-adsorb NH4^+ ions from the surrounding solution. The re-adsorption was affected by the decomposition period and concentration of exogenous NH4^+ and was independent of the crop species via the combined efforts of physical and chemical adsorption, ion exchange and water retention on residue su

关键词： adsorption decomposition nitrogen(N) Alfisol straw substrate

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A k⋅p Effective Hamiltonian Generator

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Chinese Physics Letters 2021年第7期38卷 85-89页

作者： Yi Jiang zhong fang Chen fang Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China Kavli Institute for Theoretical Sciences Chinese Academy of SciencesBeijing 100190China

A k⋅p effective Hamiltonian is important for theoretical analysis in condensed matter *** on the kdotp-symmetry package,we develop an upgraded package named as *** generator takes in arbitrary magnetic symmetries with their representations and returns symmetry-allowed k⋅p *** this package,we calculate k⋅p Hamiltonians for irreducible co-representations in 1651 magnetic space groups up to the third order,and their linear coupling to external fields including the electromagnetic field and the strain *** hope that the package will facilitate related research in the future.

关键词： Hamiltonian symmetry allowed

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Xanthones from the bark of Garcinia Xanthochymus

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Chinese Chemical Letters 2007年第7期18卷 849-851页

作者： fang fang zhong Yu Chen Zhi Nan Mei Guang zhong Yang Laboratory for Natural Product Chemistry College of Life Sciences South Central University for Nationalities Wuhan 430074 China College of Chemistry and Material Sciences South Central University for Nationalities Wuhan 430074 China

Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone （1） and 1,5,6-trihydroxy-7,8-di（3-methyl-2-butenyl）-6＇,6＇-dimethylpyrano（2＇,3＇：3,4）xanthone （2） were isolated from the bark of Garcinia xanthochymus by normal phase and reverse phase silica gel column chromatography. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.

关键词： Garcinia Garcinia xanthochymus Xanthones

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Exact Confidence Limits for the Parameter of an Exponential Distribution in the Accelerated Life Tests under Type-ⅠCensoring

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Acta Mathematicae Applicatae Sinica 2021年第2期37卷 393-408页

作者： De-qiang ZHENG Xiang-zhong fang School of Mathematical Sciences Peking UniversityBejing 100871China

Life data frequently arise in many reliability studies,such as accelerated life tests *** paper considers the part of life data where failure and censoring observations may *** develop statistical methods and theory for the analysis of these data,a new approach was proposed to obtain the exact lower and upper confidence limits for the mean life of the exponential distribution with Type-I censoring *** is assumed that the acceleration factor is a random variable,and that the distribution of the acceleration factor is known from some empirical information or the meta analysis.A method for constructing the lower and upper confidence limits for the parameter based on an ordering relation among the sample space was *** studies and analyses of two examples suggest that the proposed method performed well.

关键词： mean life confidence limit acceleration factor sample space ordering relation

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A maximum a posteriori super resolution algorithm based on multidimensional Lorentzian distribution

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第12期10卷 1705-1713页

作者： Wen CHEN Xiang-zhong fang Yan CHENG Shanghai Key Lab of Digital Media Processing and Transmissions Institute of Image Communication and Information Processing Shanghai Jiao Tong University Shanghai 200240 China College of Information Technology East China University of Political Science and Law Shanghai 201620 China

This paper presents a threshold-free maximum a posteriori (MAP) super resolution (SR) algorithm to reconstruct high resolution (HR) images with sharp edges. The joint distribution of directional edge images is modeled as a multidimensional Lorentzian (MDL) function and regarded as a new image prior. This model makes full use of gradient information to restrict the solution space and yields an edge-preserving SR algorithm. The Lorentzian parameters in the cost function are replaced with a tunable variable, and graduated nonconvexity (GNC) optimization is used to guarantee that the proposed multidimensional Lorentzian SR (MDLSR) algorithm converges to the global minimum. Simulation results show the effectiveness of the MDLSR algorithm as well as its superiority over conventional SR methods.

关键词： Edge preservation Multidimensional Lorentzian distribution (MDL) Super resolution Threshold

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Generalized braided Hopf algebras

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Applied Mathematics(A Journal of Chinese Universities) 2009年第1期24卷 105-113页

作者： LU zhong-jian fang Xiao-li Department of Mathematics Shaoxing College of Arts and Sciences Shaoxing 312000 China

The concept of （f, σ）-pair （B, H）is introduced, where B and H are Hopf algebras. A braided tensor category which is a tensor subcategory of the category ^HM of left H-comodules through an （f, σ）-pair is constructed. In particularly, a Yang-Baxter equation is got. A Hopf algebra is constructed as well in the Yetter-Drinfel＇d category H^HYD by twisting the multiplication of B.

关键词： (f, σ )-pair Yetter-Drinfel’d modules category braided Hopf algebra

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Evaluation of tourism climate comfort in the Grand Shangri-La region

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Journal of Mountain Science 2019年第6期16卷 1452-1469页

作者： CHENG Qing-ping zhong fang-lei Northwest Institute of Eco-Environmental and Resources Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China School of Economics Lanzhou UniversityLanzhou 730000China

The Grand Shangri-La(GSL) region has strong international tourist appeal. GSL has considerable international eco-tourist potential as well as being attractive for leisure, vacation, health, explorative, and scientific research activities in addition to high-end tourism experiences. These factors could promote the development of its regional tourism. GSL has been identified as a key area for tourism development in China. In this study, we investigated tourism climate conditions in GSL from 1980 to 2016 using a tourism climate index(TCI). We found that through global warming, the number of annual and monthly good-weather days, as assessed with the TCI, showed an increase over most of GSL;that trend was especially true for very good, excellent, and ideal days. The optimal travel period was May–October. We obtained the same result using cluster heat maps, in which we categorized 31 studied meteorological stations into eight types. However, heavy rainfall tended to occur during that optimal period, and it was concentrated at certain times. The annual total number of comfortable days greater than 300 was mainly located in southern GSL. We observed significant correlations between monthly and annual excellent and ideal days with latitude and elevation;in particular, we identified a significant nonlinear correlation between excellent(and ideal) days and elevation.

关键词： Grand Shangri-La region Evaluation Tourism climate comfort Cluster heat maps Temperature Precipitation

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FLUID DYNAMIC PERFORMANCE OF GROOVED PLANING BOAT AND ITS EFFECT ON RESISTANCE

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Journal of Hydrodynamics 2005年第5期17卷 571-579页

作者： SHI zhong-kun WU fang-liang ZHOU Feng College of Traffic Science and Engineering Huazhong University of Science and Technology Wuhan430074 China

In this paper, the fluid dynamic performance for a new boat form grooved planing boats is analyzed, and the results of resistance tests for seven grooved planing boat models of different types are presented in the form of curves of attack angle and resistance-weight ratio versus Froude number. According to these curves, the effect of some parameters of the boat type on the resistance is analyzed.

关键词： grooved planing boat fluid dynamic performanee resistanee

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Hinge Majorana flat band in type-Ⅱ Dirac semimetals

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Science China(Physics,Mechanics & Astronomy) 2024年第12期67卷 127-132页

作者： Yue Xie Xianxin Wu zhong fang Zhijun Wang Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing100190China

Type-Ⅱ Dirac semimetals exhibit a unique Fermi surface topology,which allows them to host novel topological superconductivity(TSC).We reveal a novel inter-orbital superconducting state,corresponding to the B_(1u) and B_(2u) pairings under the D_(4h) point ***,we find that both first-and second-order TSC coexist in this novel *** is induced by a dominant inter-orbital attraction and possesses surface helical Majorana cones and hinge Majorana flat bands,spanning the entire z-directed hinge Brillouin *** investigation uncovers that these higher-order hinge modes are robust against the C_(4z) symmetry-breaking perturbation.

关键词： topological superconductivity Majorana fermions higher-order topology type-II Dirac semimetals

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The roles of cysteines in the heme domain of human soluble guanylate cyclase

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Chinese Chemical Letters 2012年第8期23卷 973-976页

作者： fang fang zhong Xiao Xiao Liu Jie Pan zhong Xian Huang Xiang Shi Tan Department of Chemistry Fudan UniversityShanghai 200433China Institutes of Biomedical Sciences Fudan UniversityShanghai 200433China

Soluble guanylate cyclase（sGC） is a critical heme-containing enzyme involved in NO *** dimerization of sGC subunits is necessary for its bioactivity and its mechanism is a striking and an indistinct *** roles of heme domain cysteines of the sGC on the dimerization and heme binding were investigated *** site-directed mutations of three conserved cysteines（C78A,C122A and C174S） were studied systematically and the three mutants were characterized by gel filtration analysis,UV-vis spectroscopy and heme transfer ***78 was involved in heme binding but not referred to the dimerization,while Cys174 was demonstrated to be involved in the *** results provide new insights into the cysteine-related dimerization regulation of sGC.

关键词： Human soluble guanylate cyclase sGC Heine domain Cysteine Dimerization

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