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Effects of Wetland Vegetation on Soil Microbial Composition:A Case Study in Tumen River Basin,Northeast China

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Chinese Geographical Science 2017年第2期27卷 239-247页

作者： qin Lei jianG Ming TIAN wei ZHANG jian ZHU weihong Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China Geography Department of Sciences Yanbian UniversityYanji 133002China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Natural Resources of Changbai Mountain&Functional Molecules Yanji 133002China State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration Northeast Normal UniversityChangchun 130117China

Hydrology plays a dominant role in wetland plant distribution and microbial composition, but few studies explicitly attempted to relate the linkage between wetland vegetation and microbial community. The present study consisted of five wetland plant communities along three adjacent flood gradients zones(zone 1 dominated by Carex appendiculat, zone 2 dominated by Eleocharis ovate, and zone 3 dominated by Phragmites australis/Bidens pilosa/Calamagrostis angustifolia, which formed separate, monoculture patches). Gram negative and arbuscular mycorrhizal fungal phospholipid fatty acid(PLFA) are more abundant in the site with short flooding period(zone 3) than in the site with long flooding period(zone 1), and they are also different in the P. australis, B. spilosa and C. angustifolia of zone 3. Principle Component Analysis(PCA) showed that the flooding period could explain 92.4% of variance in microbial composition. Redundancy Analysis(RDA) showed that available nitrogen(AN), total nitrogen(TN) and soil organic matter(SOM) could explain the 79.5% of variance in microbial composition among E. ovata, P. australis, B. pilosa and C. angustifolia. Results demonstrated that flooding period was the main factor in driving the microbial composition and plant-derived resources could influence soil microbial composition in the seasonally flooded zones.

关键词： plant soil feedback redundancy analysis phospholipid fatty acid (PLFA) soil property flooding period

An object correlation and maneuver detection approach for space surveillance

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Research in Astronomy and Astrophysics 2012年第10期12卷 1402-1416页

作者： jian Huang wei-Dong Hu qin xin Xiao-Yong Du ATR Key Lab. College of Electronic Science and Engineering National University of DefenseTechnology Changsha 410073 China Faculty of Science and Technology University of the Faroe Islands Torshavn FO100 FaroeIslands

Object correlation and maneuver detection are persistent problems in space surveillance and maintenance of a space object catalog. We integrate these two prob- lems into one interrelated problem, and consider them simultaneously under a sce- nario where space objects only perform a single in-track orbital maneuver during the time intervals between observations. We mathematically formulate this integrated sce- nario as a maximum a posteriori （MAP） estimation. In this work, we propose a novel approach to solve the MAP estimation. More precisely, the corresponding posterior probability of an orbital maneuver and a joint association event can be approximated by the Joint Probabilistic Data Association （JPDA） algorithm. Subsequently, the ma- neuvering parameters are estimated by optimally solving the constrained non-linear least squares iterative process based on the second-order cone programming （SOCP） algorithm. The desired solution is derived according to the MAP criterions. The per- formance and advantages of the proposed approach have been shown by both theoret- ical analysis and simulation results. We hope that our work will stimulate future work on space surveillance and maintenance of a space object catalog.

关键词： celestial mechanics -- methods: analytical -- techniques: miscellaneous-- surveys

Evolution of interfacial microstructure and mechanical properties of Nb521/GH99 brazed joints using Ti-35Ni filler alloy

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Journal of Iron and Steel Research International 2024年第10期31卷 2577-2589页

作者： Shuo Su Xiao-guo Song Sheng-peng Hu Wen Zhang jian Cao jian qin wei-min Long State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001HeilongjiangChina Shandong Institute of Shipbuilding Technology Weihai264209ShandongChina Northwest Institute for Nonferrous Metal Research Xi’an710016ShaanxiChina China Machinery Intelligent Equipment Innovation Research Institute(Ningbo)Co. Ltd.Ningbo315700ZhejiangChina

The dissimilar brazing of Nb521 niobium alloy to GH99 superalloy was achieved successfully using Ti–35Ni brazing filler under *** effects of brazing temperature and holding time were systematically analyzed on the interfacial microstructure evolution and mechanical properties of *** joints brazed at 1120℃ for 10 min exhibited a typical interfacial structure composed of Nb521/β-(Nb,Ti)+TiNi/TiNi+Ti_(2)Ni/TiNi+TiNi_(3)/Cr-rich TiNi/Ti-rich(Ni,Cr)_(ss)/(Ni,Cr)_(ss)/*** findings indicated that as the brazing temperature or holding time increased,the presence of brittle Ti_(2)Ni compounds decreased while the formation of TiNi_(3) gradually increased and tended to *** shear strength of joints exhibited variations corresponding to changes in interfacial brittle compound,and reached the highest value of 121 MPa at 1120℃ for 10 *** the context of shear testing,all joints displayed clear brittle fracture patterns,with fractures predominantly occurring at the brittle compounds,namely,Ti_(2)Ni and TiNi_(3) phases.

关键词： Nb521 alloy GH99 alloy Brazing Microstructure Shear strength

A pruning algorithm with L_(1/2) regularizer for extreme learning machine

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第2期15卷 119-125页

作者： Ye-tian FAN wei WU Wen-yu YANG qin-wei FAN jian WANG School of Mathematical Sciences Dalian University of Technology College of Science Huazhong Agricultural University

Compared with traditional learning methods such as the back propagation(BP)method,extreme learning machine provides much faster learning speed and needs less human intervention,and thus has been widely *** this paper we combine the L1/2regularization method with extreme learning machine to prune extreme learning machine.A variable learning coefcient is employed to prevent too large a learning increment.A numerical experiment demonstrates that a network pruned by L1/2regularization has fewer hidden nodes but provides better performance than both the original network and the network pruned by L2regularization.

关键词： Extreme learning machine(ELM) L1/2 regularizer Network pruning

Analytic calculation of magnetic force between two current-carrying coils

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Applied Mathematics and Mechanics(English Edition) 2015年第4期36卷 475-486页

作者： Xiaofan GOU jian qin College of Mechanics and Materials Hohai University

Current-carrying coils are basic elements in electromagnetic equipments, for example, in high field magnets from high temperature superconducting wires or tapes. In the assembly of these systems and their current-carrying operation, unavoidable mis- alignment and shift from the original position can be induced by disturbances such as the imbalance of magnetic force due to safety problems. For two current-carrying coils with non-coplanar axes, the analytic expression of the magnetic force between the two coils is presented according to the rule of Ampere circulation and the Biot-Savart law. Based on the expression, the dependence of the magnetic force on the size and the relative position of each other is further investigated, and the variation of the magnetic force is obtained with the above parameters.

关键词： current-carrying coil non-coplanar axis magnetic force analytic calcula-tion

New constraint of the Hubble constant by proper motions of radio components observed in AGN twin-jets

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Research in Astronomy and Astrophysics 2021年第10期21卷 209-212页

作者： wei-jian Lu Yi-Ping qin School of Information Engineering Baise UniversityBaise 533000China Center for Astrophysics School of Physics and Materials ScienceGuangzhou UniversityGuangzhou 510006China

As the advent of precision cosmology,the Hubble constant(H0)inferred from the Lambda Cold Dark Matter fit to the Cosmic Microwave Background data is increasingly in tension with the measurements from the local distance *** approach its real value,we need more independent methods to measure,or to make constraint of,the Hubble *** this paper,we apply a plain method,which is merely based on the Friedman-Lema??tre-Robertson-Walker cosmology together with geometrical relations,to constrain the Hubble constant by proper motions of radio components observed in AGN *** the assumption that the ultimate ejection strengths in both sides of the twin-jet concerned are intrinsically the same,we obtain a lower limit of H0,min=51.5±2.3 km s^(-1)Mpc^(-1) from the measured maximum proper motions of the radio components observed in the twin-jet of NGC 1052.

关键词： (cosmology:)cosmological parameters cosmology:observations galaxies:active galaxies:jets

Procreating Tiles of Double Commutative-Step Digraphs

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Acta Mathematicae Applicatae Sinica 2008年第2期24卷 185-194页

作者： jian-qin Zhou Telecommunication School Hangzhou Dianzi University Hangzhou 310018 China Department of Computer Science Anhui University of Technology Ma'anshan 243002 China

Double commutative-step digraph generalizes the double-loop digraph. A double commutative-step digraph can be represented by an L-shaped tile, which periodically tessellates the plane. Given an initial tile L（l, h, x, y）, Aguil5 et al. define a discrete iteration L（p） = L（l ＋ 2p, h ＋ 2p, x ＋ p, y ＋ p）, p = 0, 1, 2,..., over L-shapes （equivalently over double commutative-step digraphs）, and obtain an orbit generated by L（l, h, x,y）, which is said to be a procreating k-tight tile if L（p）（p = 0, 1, 2, ~ ~ ~ ） are all k-tight tiles. They classify the set of L-shaped tiles by its behavior under the above-mentioned discrete dynamics and obtain some procreating tiles of double commutative-step digraphs. In this work, with an approach proposed by Li and Xu et al., we define some new discrete iteration over L-shapes and classify the set of tiles by the procreating condition. We also propose some approaches to find infinite families of realizable k-tight tiles starting from any realizable k-tight L-shaped tile L（l, h, x, y）, 0 ≤ y - x ≤ 2k ＋ 2. As an example, we present an infinite family of 3-tight optimal double-loop networks to illustrate our approaches.

关键词： Double-loop digraph double commutative-step digraph L-shaped tile procreate infinite family

Research status of crack problem in laser brazing diamond

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Journal of Iron and Steel Research International 2024年第10期31卷 2329-2343页

作者： Hong-tao Zhu jian qin wei-min Long Xin-yi Song Pei-yao Jing State Key Laboratory of Advanced Brazing Filler Metals&Technology Zhengzhou Research Institute of Mechanical Engineering Co.Ltd.Zhengzhou450001HenanChina

Diamond tools have been widely used in national defense military,automobile manufacturing,resource exploitation and other *** brazing diamond technology is often applied to the preparation of diamond ***,the formation and expansion of cracks in the process of laser brazing diamond seriously affect the mechanical properties of diamond *** order to solve the crack problem of laser brazing diamond,many scholars are committed to the research on improving the solder,optimizing the laser process parameters,improving the laser brazing equipment,optimizing the design of joint form,and developing ultrasonic-assisted laser brazing technology,*** studies have achieved certain *** at the research status of laser brazing diamond crack problem,the crack characteristics of brazing diamond are firstly introduced,and the formation reasons of laser brazing diamond crack are ***,the elemental characteristics of brazing filler metals used in brazing diamond are *** influences of Ni-Cr and Ag-Cu-Ti alloy solder and laser process parameters on the crack problem are ***,the solutions to the crack problem by scholars at home and abroad in recent years are summarized,and the future research directions to solve crack problem are prospected.

关键词： Diamond tool Laser brazing Crack problem Process parameter Solder alloy Crack characteristics

Hemorrhagic transformation in patients with large-artery atherosclerotic stroke is associated with the gut microbiota and lipopolysaccharide

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Neural Regeneration Research 2024年第7期19卷 1532-1540页

作者： qin Huang Minping wei Xianjing Feng Yunfang Luo Yunhai Liu jian Xia Department of Neurology Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina Department of Neurology Peking University People’s HospitalBeijingChina Clinical Research Center for Cerebrovascular Disease of Hunan Province Central South UniversityChangshaHunan ProvinceChina National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina

Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases *** of the gut microbiota is an important feature of stroke,and some specific bacteria and bacterial metabolites may contribute to hemorrhagic transformation *** aimed to investigate the relationship between the gut microbiota and hemorrhagic transformation in largearte ry atheroscle rotic stro *** observational retrospective study was *** May 2020 to September 2021,blood and fecal samples were obtained upon admission from 32 patients with first-ever acute ischemic stroke and not undergoing intravenous thrombolysis or endovascular thrombectomy,as well as 16 healthy *** with stro ke who developed hemorrhagic transfo rmation(n=15)were compared to those who did not develop hemorrhagic transformation(n=17)and with healthy *** gut microbiota was assessed through 16S ribosomal ribonucleic acid *** also examined key components of the lipopolysaccharide pathway:lipopolysaccharide,lipopolysaccharide-binding protein,and soluble *** observed that bacterial diversity was decreased in both the hemorrhagic transformation and non-hemorrhagic transfo rmation group compared with the healthy *** patients with ischemic stro ke who developed hemorrhagic transfo rmation exhibited altered gut micro biota composition,in particular an increase in the relative abundance and dive rsity of members belonging to the Enterobacteriaceae *** lipopolysaccharide and lipopolysaccharide-binding protein levels were higher in the hemorrhagic transformation group compared with the non-hemorrhagic transfo rmation ***,lipopolysaccharide-binding protein,and soluble CD14 concentrations were associated with increased abundance of Enterobacte ***,the role of the gut microbiota in hemorrhagic transformation was evaluated using

关键词： gut microbiota hemorrhagic transformation inflammation lipopolysaccharide stroke