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Distribution of fatty acids in the alpine grassland soils of the Qinghai-Tibetan Plateau

Science China Earth Sciences 2016年第7期59卷 1329-1338页

作者： DAI guo Hua ZHU shan shan LIU Zong Guang CHEN Li Tong HE Jin Sheng FENG xiao Juan State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Key Laboratory of Adaptation and Evolution of Plateau Biota Northwest Institute of Plateau Biology Chinese Academy of Sciences Department of Ecology College of Urban and Environmental Sciences Peking University

As an important biomarker, fatty acids(FAs) have been extensively used to trace the origin of organic matter in sediments and soils. However, studies of the distribution and abundance of FAs in alpine grassland soils are still rare, especially on the Qinghai-Tibetan Plateau(QTP), the highest plateau in the world, which contributes sediments to many large rivers in Asia. This study investigates the composition, distribution and source of FAs with increasing soil depths from 17 typical alpine grassland sites in the QTP. The most abundant FAs included the ubiquitous C16 FA and even-numbered long-chain FAs(C20–C30), indicating mixed inputs from microbial and higher plant sources. Source apportionment showed that higher plants were the dominant contributor of FAs(approximately 40%) in QTP soils. The abundance of FAs decreased with soil depth, with the highest value(1.08±0.09 mg/g C) at a 0–10 cm depth and the lowest value(0.46±0.12 mg/g C) at a 50–70 cm depth, due to much lower plant inputs into the deeper horizons. The total concentration of FAs was negatively correlated to the mean annual temperature(MAT; P<0.05) and soil p H(P<0.01), suggesting that the preservation of FAs was favored in low-MAT and low-p H soils on the QTP. The abundance of fresh C source FAs increased significantly with the mean annual precipitation(MAP; P<0.05), indicating that high MAP facilitates the accumulation of fresh FAs in QTP soils. Other environmental parameters, such as the soil mineral content(aluminum and iron oxide), microbial community composition as well as litter quality and quantity, may also exert a strong control on the preservation of FAs in QTP soils and warrant further research to better understand the mechanisms responsible for the preservation of FAs in QTP soils.

关键词： Qinghai-Tibetan Plateau Soil organic matter Biomarker Fatty acids Distribution sources

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A Novel Model of the H Radical in Hot-Filament Chemical Vapor Deposition

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Chinese Physics Letters 2011年第2期28卷 216-219页

作者： guo xiao-Song BAO Zhong ZHANG shan-shan XIE Er-Qing Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education Physical Science and Technology SchoolLanzhou UniversityLanzhou 730000

Amorphous hydrogenated and crystalline silicon thin films were prepared by hot-filament chemical vapor deposition.A structural transformation from amorphous phase to crystalline phase by increasing the filament temperature Tfil from 1600℃ to 1650℃ was *** phenomenon may result from the associated abundance of H radicals participating in the growth of the Silms.A probability distribution model of the H radical is proposed to elucidate this *** to this model,the phase transition is due to a distinct difference in the probability distribution of the H radicals,which seems to be dependent upon Tfil.

关键词： deposition transformation crystalline

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SsRSS1 mediates salicylic acid tolerance and contributes to virulence in sugarcane smut fungus

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Journal of Integrative Agriculture 2023年第7期22卷 2126-2137页

作者： ZHANG Hao-yang YANG Yan-fang guo Feng SHEN xiao-rui LU shan CHEN Bao-shan College of Agriculture/Guangxi Key Laboratory of Sugarcane Biology Guangxi UniversityNanning 530004P.R.China State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources/College of Life Science and Technology Guangxi UniversityNanning 530004P.R.China Ministry and Province Co-sponsored Collaborative Innovation Center for Sugarcane and Sugar Industry Guangxi UniversityNanning 530004P.R.China

Sugarcane smut caused by Sporisorium scitamineum is a destructive disease responsible for significant losses in sugarcane production ***,the mechanisms underlying the pathogenicity of this fungus remain largely *** this study,we found that the disruption of the SsRSS1 gene,which encodes a salicylic acid(SA)sensing regulator,does not affect phenotypic traits such as the morphology,growth rate,and sexual mating ability of haploid basidiospores,but rather reduces the tolerance of basidiospores to SA stress by blocking the induction of SsSRG1,a gene encoding a SA response protein in ***1 deletion resulted in the attenuation of the virulence of the *** addition to a significant reduction in whip formation,a portion of plantlets(18.3%)inoculated with theΔSsRSS1 strains were found to be infected but failed to produce whips for up to 90 days ***,the development of hyphae and teliospore from theΔSsRSS1-infected plants that formed whips seemed indistinguishable from that in the wild-type-infected ***,our findings suggested that SsRss1 is required for maintaining fungal fitness in planta by counteracting SA stress.

关键词： Sporisorium scitamineum SsRSS1 pathogenicity salicylic acid response

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BOUNDS ON AVERAGE CONTROLLED DIRECT EFFECTS WITH AN UNOBSERVED RESPONSE VARIABLE

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Journal of Systems Science & Complexity 2011年第6期24卷 1154-1164页

作者： Na shan Jianhua guo Key Laboratory for Applied Statistics of Ministry of Education School of Mathematics and Statistics Northeast Normal University Changchun 130024 China School of Basic Science Changchun University of Technology Changchun 130012 China

This paper considers the problem of estimating the bounds on the average controlled direct effects （ACDEs） of a treatment variable on an unobserved response variable in the presence of unobserved confounders between an intermediate variable and the response variable. When the response variable is observed, Cai, et al.（2008） derived the formulas for the sharp bounds on the ACDEs. When the response variable is unobserved, the authors propose a graphical criterion for selecting variables affected by the response variable to derive the formulas for the bounds on the ACDEs, which is an extension of the result of Kuroki（2005） to ACDEs. The results enable us not only to judge from the graph structure whether the bounds on the ACDEs can be expressed through observed variables when the response variable is unobserved, but also to provide their formulas when the answer is affirmative.

关键词： Average controlled direct effect causal network d-separation

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Improve Robustness and Accuracy of Deep Neural Network with L_(2,∞) Normalization

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Journal of Systems Science & Complexity 2023年第1期36卷 3-28页

作者： YU Lijia GAO xiao-shan Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

In this paper,the L_(2,∞)normalization of the weight matrices is used to enhance the robustness and accuracy of the deep neural network(DNN)with Relu as activation *** is shown that the L_(2,∞)normalization leads to large dihedral angles between two adjacent faces of the DNN function graph and hence smoother DNN functions,which reduces over-fitting of the DNN.A global measure is proposed for the robustness of a classification DNN,which is the average radius of the maximal robust spheres with the training samples as centers.A lower bound for the robustness measure in terms of the L_(2,∞)norm is ***,an upper bound for the Rademacher complexity of DNNs with L_(2,∞)normalization is *** algorithm is given to train DNNs with the L_(2,∞)normalization and numerical experimental results are used to show that the L_(2,∞)normalization is effective in terms of improving the robustness and accuracy.

关键词： Deep neural network global robustness measure L_(2,∞)normalization over-fitting Rademacher complexity smooth DNN

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Internal limiting membrane peeling with different dyes in the surgery of idiopathic macular hole: a systematic review of literature and network Meta-analysis

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International Journal of Ophthalmology(English edition) 2019年第12期12卷 1917-1928页

作者： shan-shan Li Ran You Min Li xiao-xiao guo Lu Zhao Yan-Ling Wang Xi Chen Department of Ophthalmology Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Clinical Epidemiology and EBM Unit National Clinical Research Center for Digestive DiseaseBeijing 100050China

AIM: To evaluate the effect of internal limiting membrane(ILM) peeling with indocyanine green(ICG), brilliant blue G(BBG), triamcinolone acetonide(TA), trypan blue(TB), or without dye for the treatment of idiopathic macular hole(IMH). METHODS: A search was conducted using Pub Med, EMBASE, and CENTRAL(Cochrane Central Register of Controlled Trials) for related studies published before October 2018. RESULTS: A total of 29 studies and 2514 eyes were included in this network Meta-analysis. For IMH closure, the rank from the best to the worse treatment was: BBG, TB, TA, ICG, and no dye. There was a significant difference in postoperative IMH closure rate between BBG and no dye. The rank of the best to the worse treatment to improve visual acuity was: BBG, TB, no dye, TA, and ICG. The improvement rate of visual acuity after using BBG was significantly higher than ICG. The improvement rate of visual acuity was more favorable with TB than ICG, TA, and no dye. CONCLUSION: BBG can contribute to better anatomical and functional outcomes compared to other dyes for ILM peeling in patients with IMH. The results show that the best treatment of ILM peeling with dyes is BBG.

关键词： idiopathic macular hole brilliant blue G trypan blue internal limiting membrane peeling network Meta-analysis

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The coninvolutory decomposition and its computation for a complex matrix

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Applied Mathematics(A Journal of Chinese Universities) 2013年第3期28卷 303-310页

作者： CHEN xiao-shan School of Mathematics South China Normal University

A complex, square matrix E is called coninvolutory if EE = I, where E denotes complex conjugate of the matrix E and I is an identity matrix. In this paper we introduce the coninvolutory decomposition of a complex matrix and investigate a Newton iteration for computing the coninvolutory factor. A simple numerical example illustrates our results.

关键词： coninvolutory decomposition Newton iteration spectral norm.

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Influence of low ambient pressure on the performance of a high-energy array surface arc plasma actuator

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Chinese Physics B 2020年第10期29卷 380-387页

作者： Bing-Liang Tang shan-Guang guo Hua Liang Meng-xiao Tang Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi'an 710038China

In order to solve the problem of single arc plasma actuator's failure to suppress the boundary layer separation, the effectiveness of the array surface arc plasma actuator to enhance the excitation intensity is verified by experiment. In this study, an electrical parameter measurement system and high-speed schlieren technology were adopted to delve into the electrical, flow field, and excitation characteristics of the high-energy array surface arc plasma actuator under low ambient pressure. The high-energy array surface arc discharge released considerable heat rapidly;as a result, two characteristic structures were generated, i.e., the precursor shock wave and thermal deposition area. The duration increased with the increase in environmental pressure. The lower the pressure, the wider the thermal deposition area's influence range. The precursor shock wave exhibited a higher propagation speed at the initial phase of discharge;it tended to decay over time and finally remained at 340 m/s. The lower the environmental pressure, the higher the speed would be at the initial phase. High-energy array surface arc plasma actuator can be employed to achieve effective high-speed aircraft flow control.

关键词： low ambient pressure high-energy array surface arc plasma actuator

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Novel approach for determining the optimal axial preload of a simulating rotary table spindle system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 812-817页

作者： shan xiao-biao XIE Tao CHEN Wei-shan School of Mechatronics Engineering Harbin Institute of Technology Harbin 15001 China

This paper presents a new theoretical model to determine the optimal axial preload of a spindle system, for challenging the traditional method which relies heavily on experience of engineers. The axial preloading stiffness was treated as the sum of the spindle modal stiffness and the framework elastic stiffness, based on a novel concept that magnitude of preloads can be controlled by measuring the resonant frequency of a spindle system. By employing an example of a certain type of aircraft simulating rotary table, the modal stiffness was measured on the Agilent 35670A Dynamic Signal Analyzer by experimental modal analysis. The equivalent elastic stiffness was simulated by both finite element analysis in ANSYS? and a curve fitting in MATLAB?. Results showed that the static preloading stiffness of the spindle was 7.2125×107 N/m, and that the optimal preloading force was 120.0848 N. Practical application proved the feasibility of our method.

关键词： Three-axis simulating rotary table Axial position preload Stiffness Experimental modal analysis Finite elementanalysis

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Progress on elliptical magnetic skyrmions

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Rare Metals 2023年第2期42卷 359-367页

作者： Bao-shan Cui Yong-Qiang Yang xiao-Bin guo Shi-Heng Liang Hao Wu guo-Qiang Yu Songshan Lake Materials Laboratory Dongguan523808China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing100190China Faculty of Physics and Electronic Science Hubei UniversityWuhan430062China School of Physics&Optoelectric Engineering Guangdong University of TechnologyGuangzhou510006China

Magnetic skyrmions,the topological spin textures firstly observed in chiral magnets,have aroused huge interest due to their emergent electromagnetism and potential applications in *** the last decade,significant efforts have been devoted to skyrmion generation,stabilization,and *** most cases,the theoretical and experimental investigations have been performed in the materials where the skyrmions have a circular *** we know,magnetic anisotropy(K_(u))and Dzyaloshinskii-Moriya interaction(DMI)play key roles in the stabilization of the skyrmions in chiral ***,modifying the Kand DMI provide new degrees of freedom for studying the related physics and applications of skyrmions in addition to engineering their energetics and *** this review,the latest progress on the study of the anisotropic deformation of magnetic skyrmions(i.e.,elliptical magnetic skyrmions)is *** physical origins and important advantages of elliptical magnetic skyrmions are mainly focused *** review gives an insight into the understanding of the physical mechanisms of elliptical magnetic skyrmion-hosting systems.

关键词： Dzyaloshinskii-Moriya interaction(DMI) Elliptical magnetic skyrmion Magnetic anisotropy(K_(u)) Skyrmion Hall effect

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