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Distribution of Soil Enzyme Activities and Microbial Biomass Along a Latitudinal Gradient in Farmlands of Songliao Plain,Northeast China

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Pedosphere 2008年第4期18卷 431-440页

作者： liU Xiu-Mei li Qi liANG wen-Ju JIANG Yong Key Laboratory of Terrestrial Ecological Process Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 （China） Graduate School of the Chinese Academy of Sciences Beijing 10004g （China）

Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in farmlands of Songliao Plain, Northeast China to assess the impact of climatic changes along the latitudinal transect on nutrient cycling in agroecosystems. Top soils （0-20 cm depth） were sampled in fields at 7 locations from north （Hallun） to south （Dashiqiao） in the end of October 2005 after maize harvest. The contents of total C, N, and P, C/N, available N, and available P increased with the latitude. The activities of invertase and acid phosphatase, microbial biomass （MB） C and N, and MBC/MBN were significantly correlated with latitude （P 〈 0.05, r^2 = 0.198, 0.635, 0.558, 0.211 and 0.317, respectively）, that is, increasing with the latitude. Significant positive correlations （P 〈 0.05） were observed between invertase activity and the total N and available P, and between acid phosphatase activity and the total C, C/N, available N, total P and available P. The urease, acid phosphatase, and dehydrogenase activities were significantly correlated with the soil pH and electrical conductivity （EC）（P 〈 0.05）. MBC and MBN were positively correlated with the total C, C/N, and available P （P 〈 0.05）. The MBC/MBN ratio was positively correlated with the total C, total N, C/N, and available N （P 〈 0.05）. The spatial distribution of soil enzyme activities and microbial biomass resulted from the changes in soil properties such as soil organic matter, soil pH, and EC, partially owing to variations in temperature and rainfall along the latitudinal gradient.

关键词： farmlands hydrolases latitudinal gradient microbial biomass soil organic matter

Dynamics of a dengue epidemic model with class-age structure

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International Journal of Biomathematics 2017年第8期10卷 63-85页

作者： wen-Jing Feng li-Ming Cai Kaihui liu Department of Mathematics and StatisticsXinyang Normal University Xinyang 464000 P. R. China Department of Applied MathematicsThe Hong Kong Polytechnic University Hong Kong SAR P. R. China

We introduce the class-age-dependent rates of the infected and vaccinated class in the compartmental model of dengue transmission. An age-structured host-vector interac- tion model incorporating vaccination effects is formulated and analyzed for the spread of dengue. Moreover, the basic reproduction number is derived, which serves as a thresh- old value determining the stability of the equilibrium points. By constructing suitable Lyapunov functional, the global asymptotic stability of the equilibria of the model is established in terms of the basic reproduction number. In particular, the disease-free equilibrium of the model is globally asymptotically stable if the basic reproduction num- ber is less than one, while the disease persists and the unique endemic equilibrium is globally asymptotically stable if the basic reproduction number is greater than one. The analysis of our model indicates that our model is realistic to give a hint to control the transmission of dengue. Furthermore, it follows from the formulation of the infection-free equilibrium of susceptible humans So and the basic reproduction number R0 that both of them are decreasing with respect to the vaccination parameter ~bh, which indicates that appropriate vaccinating program may contribute to prevent the transmission of Dengue disease.

关键词： Dengue epidemic model basic reproduction number global stability Lyapu-nov functional class-age structure.

Bacterial Community Structure and Diversity in a Black Soil as Affected by Long-Term Fertilization

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Pedosphere 2008年第5期18卷 582-592页

作者： wei Dan YANG Qian ZHANG Jun-Zheng WANG Shuang CHEN Xue-li ZHANG Xi-lin li wei-Qun Harbin Institute of Technology Harbin 150001 （China）. The Institute of Soil Fertility and Environmental Sources Heilongjiang Academy of Agricultural Sciences Harbin 150086（China）

Black soil （Mollisol） is one of the main soil types in northeastern China. Biolog and polymerase chain reactiondenaturing gradient gel electrophoresis （PCR-DGGE） methods were used to examine the influence of various fertilizer combinations on the structure and function of the bacterial community in a black soil collected from Harbin, Heilongjiang Province. Biolog results showed that substrate richness and catabolic diversity of the soil bacterial community were the greatest in the chemical fertilizer and chemical fertilizer＋manure treatments. The metabolic ability of the bacterial community in the manure treatment was similar to the control. DGGE fingerprinting indicated similarity in the distribution of most 16S rDNA bands among all treatments, suggesting that microorganisms with those bands were stable and not influenced by fertilization. However, chemical fertilizer increased the diversity of soil bacterial community. Principal com- ponent analysis of Biolog and DGGE data revealed that the structure and function of the bacterial community were similar in the control and manure treatments, suggesting that the application of manure increased the soil microbial population, but had no effect on the bacterial community structure. Catabolic function was similar in the chemical fertilizer and chemical fertilizer＋manure treatments, but the composition structure of the soil microbes differed between them. The use of chemical fertilizers could result in a decline in the catabolic activity of fast-growing or eutrophic bacteria.

关键词： bacteria community black soil chemical fertilizer diversity manure

Preintercalation of Layered γ-Zirconium Phosphate for Preparation of Immobilized Hemoglobin

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Chinese Chemical Letters 2002年第8期13卷 801-804页

作者： li Na GENG Na li Xiao Fan wen Nan DAI Feng lin ZHAO Ke An li College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871

Layeredγ-Zirconium phosphate (γ-ZrP) preintercalated with butylamine, tetra (n-butylammonium)hydroxide, dimethylamine respectively, or only ultrasonificated, for preparation of immobilized hemoglobin were investigat... 详细信息

关键词： Zirconium phosphate preintercalation exfoliation hemoglobin immobilization.

Analytical Result on the Supercurrent Through a Superconductor/Quantum-Dot/Superconductor Junction

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Communications in Theoretical Physics 2002年第7期38卷 103-106页

作者： li wei ZHU Yu liN Tsung-Han State Key Laboratory for Mesoscopic Physics and Department of Physics Peking University Beijing 100871 China State Key Laboratory for Mesoscopic Physics and Department of Physics Peking University Beijing 100871 China State Key Laboratory for Mesoscopic Physics and Department of Physics Peking University Beijing 100871 China

We present an analytical result for the supercurrent across a superconductor/quantum-dot/superconductor junction. By converting the current integration into a special contour integral, we can express the current as a sum of the residues of poles. These poles are real and give a natural definition of the Andreev bound states. We also use the exact result to explain some features of the supercurrent transport behavior.

关键词： supercurrent, superconductor/quantum-dot/superconductor junction

Synaptic transistor with multiple biological functions based on metal-organic frameworks combined with the liF model of a spiking neural network to recognize temporal information

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Microsystems & Nanoengineering 2023年第4期9卷 107-118页

作者： Qinan Wang Chun Zhao Yi Sun Rongxuan Xu Chenran li Chengbo Wang wen liu Jiangmin Gu Yingli Shi li Yang Xin Tu Hao Gao Zhen wen School of Advanced Technology Xi’an Jiaotong-Liverpool UniversitySuzhou 215123P.R.China Department of Electrical Engineering and Electronics University of LiverpoolLiverpool L693GJUK School of Science Xi’an Jiaotong-Liverpool UniversitySuzhou 215123P.R.China Department of Electrical Engineering Eindhoven University of TechnologyDen Dolech 25612 AZ EindhovenThe Netherlands Institute of Functional Nano and Soft Materials(FUNSOM) Joint International Research Laboratory of Carbon-Based Functional Materials and DevicesSoochow UniversitySuzhou 215123P.R.China

Spiking neural networks(SNNs)have immense potential due to their utilization of synaptic plasticity and ability to take advantage of temporal correlation and low power *** leaky integration and firing(liF)model and spike-timing-dependent plasticity(STDP)are the fundamental components of ***,a neural device is first demonstrated by zeolitic imidazolate frameworks(ZIFs)as an essential part of the synaptic transistor to simulate ***,three kinds of typical functions between neurons,the memory function achieved through the hippocampus,synaptic weight regulation and membrane potential triggered by ion migration,are effectively described through short-term memory/long-term memory(STM/LTM),long-term depression/long-term potentiation(LTD/LTP)and liF,***,the update rule of iteration weight in the backpropagation based on the time interval between presynaptic and postsynaptic pulses is extracted and fitted from the *** addition,the postsynaptic currents of the channel directly connect to the very large scale integration(VLSI)implementation of the liF mode that can convert high-frequency information into spare pulses based on the threshold of membrane *** leaky integrator block,firing/detector block and frequency adaptation block instantaneously release the accumulated voltage to form ***,we recode the steadystate visual evoked potentials(SSVEPs)belonging to the electroencephalogram(EEG)with filter characteristics of *** deeply fused by synaptic transistors are designed to recognize the 40 different frequencies of EEG and improve accuracy to 95.1%.This work represents an advanced contribution to brain-like chips and promotes the systematization and diversification of artificial intelligence.

关键词： transistor network neural

Transcription factor GLK1 promotes anthocyanin biosynthesis via an MBW complex-dependent pathway in Arabidopsis thaliana

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Journal of Integrative Plant Biology 2023年第6期65卷 1521-1535页

作者： Yan li wei Lei Zuxu Zhou Yanlin li Dawei Zhang Honghui lin Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment State Key Laboratory of Hydraulics and Mountain River EngineeringCollege of Life ScienceSichuan UniversityChengdu 610064China Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation SWU-TAAHC Medicinal Plant Joint R&D CentreSchool of Life SciencesSouthwest UniversityChongqing 400715China

Anthocyanins are important natural plant pigments and play diverse roles in plant growth and *** function as screens to protect photosynthetic tissues from ***,the regulatory mechanisms underlying the biosynthesis and spatial accumulation pattern of anthocyanins remain some unresolved ***,we demonstrate that the GARP-type transcription factor GOLDEN2-liKE 1(GLK1)functions as a positive factor in anthocyanin ***1 enhances the transcriptional activation activities of MYB75,MYB90,and MYB113 via direct proteinprotein interactions to increase the expression of anthocyanin-specific biosynthetic *** accumulate in an acropetal manner in *** also found that the expression pattern of GLK1 overall mimicked the accumulation pattern of anthocyanin from the base of the main stem to the shoot *** on these findings,we established a working model for the role of GLK1 in anthocyanin accumulation and propose that GLK1mediates the spatial distribution pattern of anthocyanins by affecting the transcriptional activation activities of MYB75,MYB90,and MYB113.

关键词： anthocyanin biosynthesis GLK1 MYB75 transcriptional activation activity

An[Fe-Fe]-Hydrogenase Mimic Immobilized on MCM-41 for the Photochemical Production of Hydrogen in Pure Water

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Chinese Journal of Chemistry 2014年第6期32卷 479-484页

作者： wen Wang Tianjun Yu Yi Zeng Jinping Chen Yi li Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

A composite proton-reducing catalyst Hy@MCM-41 was created by using a hydrophobic[Fe-Fe]-hydrogenase mimic(Hy)incorporated into the K^(+)-exchanged molecular sieve *** acts as the active site to generate H_(2) by reducing H^(+),and MCM-41 provide a large surface area to maintain the dispersion of Hy and to prevent aggrega-tion and ***@MCM-41 was successfully applied to the light-induced hydrogen production in pure water with an iridium compound[Ir(ppy)_(2)bpy]Cl and triethylamine(TEA)as the photosensitizer and the sacrificial electron donor,respectively,exhibiting good stability and catalytic *** present study provides a general strategy for the application of water-insoluble catalysts in pure water by using mesoporous molecular sieves.

关键词： energy conversion hydrogen hydrogenase MCM-41 immobilization photochemistry

Spatial Channel Sounding Based on Bistatic Synthetic Aperture Radar Principles

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Journal of Electronic Science and Technology 2018年第3期16卷 251-268页

作者： lin-li Cui David G.Michelson wen-Qin Wang the University of Electronic Science and Technology of China Chengdu 611731 the Radio Science Laboratory University of British ColumbiaVancouver V6T 1Z4

In this paper, we propose a simplified spatial channel sounding method by utilizing bistatic synthetic aperture radar(BiSAR) principles. Despite the different deployment geometries compared with a conventional BiSAR system, the feasibility of the approach is established by 1) the proposed method achieves a better spatial resolution than conventional directional channel sounders and 2) reconstruction algorithms based on time-domain backprojection in conjunction with a digital elevation model provide a good imaging performance and are suitable for reconstructing the spatial distribution of scatterers. Simulations of a high-speed rail(HSR) scenario demonstrate that the estimated power delay profiles(PDPs) and power angle profiles(PAPs) are close to the actual values.

关键词： Bistatic synthetic aperture radar(bistatic SAR) channel sounding spatial channel modeling