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A Middle Triassic stem-neopterygian fish from China sheds new light on the peltopleuriform phylogeny and internal fertilization

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Science Bulletin 2016年第22期61卷 1766-1774页

作者： Guang-Hui Xu xin-ying Ma Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences

Internal fertilization and viviparity are easily observed and well studied in living neopterygian fishes(14teleostean families), but they are difficult to identify in extinct taxa due to the limitation of the fossil record. The Peltopleuriformes from the Middle to Late Triassic of Europe and South China are a stem group of Neopterygii that may have first evolved internal fertilization and viviparity in this clade because they show a highly modified anal fin in presumed males resembling the intromittent organ in living viviparous teleosts. Until recently, Peltopleurus lissocephalus and P. rugosus from the Ladinian/Anisian boundary(*242 Ma) of Monte San Giorgio area in Switzerland and Italy represent the oldest record of Peltopleuriformes, and the phylogenetic interrelationships of this group remain controversial. Here, we report the discovery of a new peltopleuriform, Peltopleurus nitidus sp. nov., based on eleven well-preserved specimens from the early Middle Triassic(Pelsonian, Anisian, *244 Ma)of Luoping, eastern Yunnan, China. The discovery documents the oldest convincing peltopleuriform, extending the geological range of this clade by proximately two million years. Results of the phylogenetic analysis recover *** at the base of Peltopleuridae, and provide robust support for the sister-group relationships of Peltopleuridae with Thoracopteridae within the Peltopleuriformes. The male anal fin of P. nitidus shows a primitive condition unknown in other peltopleuriforms. Comparative studies of the male anal fin in P. nitidus and other peltopleuriforms shed new light on the internal fertilization in this group.

关键词： Sexual dimorphism Viviparity Peltopleuridae Thoracopteridae Triassic

Changes in and evaluation of surface soil quality in Populus×xiaohei shelterbelts in midwestern Heilongjiang province,China

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Journal of Forestry Research 2021年第3期32卷 1221-1233页

作者： Jun Zhang Yusen Zhao ying xin School of Forestry Northeast Forestry UniversityHarbin 150040People’s Republic of China Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta Binzhou UniversityBinzhou 256603People’s Republic of China

To examine changes in surface soil quality over time in Populus×xiaohei shelterbelts,we collected soil samples from five shelterbelts of different ages and also from former cropland left fallow for 25 ***-one surface soil(0–20 cm)properties were measured,and variation in soil quality was assessed using one-way ANOVAs and multiple comparison *** on this analysis,16 soil indexes were used in a model evaluating soil quality,with each index given weight as determined by the correlation *** with the control,the postmature forest had greater soil moisture content but lower bulk density(P<0.05).The mature forest also had higher soil pH,total organic carbon,alkali-hydrolyzed nitrogen,available phosphorus,and biomass nitrogen content,but reduced nitrate-nitrogen and total phosphorus content than the control(P<0.05).Total porosity was highly positively correlated with aeration,nitrate-nitrogen,alkali-hydrolyzed nitrogen,available phosphorus,microbial biomass carbon and microbial biomass *** total organic carbon,ammonium nitrogen,nitrate-nitrogen,alkali-hydrolyzed nitrogen,total nitrogen,available phosphorus,microbial biomass carbon and microbial biomass nitrogen were all strongly *** the soil quality evaluation model,total organic carbon was assigned the highest weight and total potassium content the *** soil quality index was lowest in the near-mature forest and greatest in the postmature ***,soil quality in P opulus×xiaohei shelterbelts varied with age and was higher in the 10–20 cm versus 0–10 cm soil *** a single forest generation,surface soil quality was significantly improved.

关键词： Populus×xiaohei Shelterbelts Black soil area Soil quality Evaluation

An efficient and green preparation of 5-aminophosphonate substituted pyrimidine nucleosides under solvent-free conditions

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Chinese Chemical Letters 2010年第10期21卷 1191-1194页

作者： xin ying Zhang ying ying Qu Xue Sen Fan School of Chemistry and Environmental Sciences Henan Key Laboratory for Environmental Pollution Control Henan Normal University Xinxiang 453007 China

An environmentally benign and highly efficient one-pot preparation of α-aminophosphonates under solvent-free conditions was developed. By employing this method, 5-aminophosphonate substituted pyrimidine nucleosides were synthesized in good to excellent yields starting from 5-forrnyl-2＇-deoxyuridine, aniline and dimethylphosphite.

关键词： Aminophosphonate 5-Substituted pyrimidine nucleoside Solvent-free reaction Green synthesis

Grain boundary segregation and relaxation in nano-grained polycrystalline alloys

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Science China(Physics,Mechanics & Astronomy) 2021年第2期64卷 72-90页

作者： Tong-Yi Zhang ying-xin Gao Sheng Sun Materials Genome Institute Shanghai UniversityShanghai200444China

The present study carries out systematic thermodynamics analysis of Grain Boundary(GB)segregation and relaxation in NanoGrained(NG)polycrystalline *** segregation and relaxation is an internal process towards thermodynamic equilibrium,which occurs naturally in NG alloys without any applied loads,causes deformation and generates internal *** analysis comprehensively investigates the multiple coupling effects among chemical concentrations and mechanical stresses in GBs and grains.A hybrid approach of eigenstress and eigenstrain is developed herein to solve the multiple coupling *** analysis results indicate that the GB stress and grain stress induced by GB segregation and relaxation can be extremely high in NG alloys,reaching the GPa level,which play an important role in the thermal stability of NG alloys,especially via the coupling terms between stress and *** present theoretic analysis proposes a novel criterion of thermal stability for NG alloys,which is determined by the difference in molar free energy between a NG alloy and its reference single crystal with the same nominal chemical *** the difference at a temperature is negative or zero,the NG alloy is thermal stable at that temperature,otherwise unstable.

关键词： nano-grained alloys thermal stability grain boundary segregation eigenstress eigenstrain

On the Global Existence and Uniqueness of Solutions to Prandtl's System

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Acta Mathematica Sinica,English Series 2009年第1期25卷 109-132页

作者： xin ying XU Jun Ning ZHAO Department of Mathematics Xiamen University Xiamen Fujian 361005 P. R. China

In this paper, we consider the Prandtl system for the non-stationary boundary layer in the vicinity of a point where the outer flow has zero velocity. It is assumed that U（t, x, y） = x^mU1（t, x）, where 0 〈 x 〈 L and m 〉 1. We establish the global existence of the weak solution to this problem. Moreover the uniqueness of the weak solution is proved.

关键词： boundary layer global solution uniqueness

Arsenic uptake, accumulation and phytofiltration by duckweed (Spirodela polyrhiza L.)

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Journal of Environmental Sciences 2011年第4期23卷 601-606页

作者： xin Zhang ying Hu Yunxia Liu Baodong Chen State key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

This study investigates arsenic （As） accumulation and tolerance of duckweed Spirodela polyrhiza L. and its potential for As phytofiltration. S. polyrhiza was able to survive in high concentration of As（V） solution. The EC 50 values （± SE） based on the external As（V） were （181.66 ± 20.12） μmol/L. It accumulated （999 ± 95） mg As/kg dw when exposed in 320 μmol/L As（V） solution for one week, and was able to take up appropriately 400 mg As/kg dw in tissues without a significant biomass loss. The EC 50 values （the effective concentration of As（V） in the nutrient solution that caused a 50% inhibition on biomass production） was （866 ± 68） mg/kg dw for the tissues, indicating that S. polyrhiza had a high capability of As accumulation and tolerance. The uptake kinetic parameters V max was （55.33 ± 2.24） nmol/（g dw·min） and K m was （0.144 ± 0.011） mmol/L. Within 72 hr, S. polyrhiza decreased As concentration in the solution from 190 to 113 ng/mL with a removal rate of 41%. The study suggested that this floating aquatic plant has some potential for As phytofiltration in contaminated water bodies or paddy soils.

关键词： arsenic duckweed phytofiltration Spirodela polyrhiza L.

Resource optimization in distributed cooperative multi-relay system based on STBC-OFDM

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The Journal of China Universities of Posts and Telecommunications 2007年第2期14卷 1-6页

作者： WU Tong QU xin-chun WANG ying Key laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

On the basis of the amplify-and-forward relaying mode, a two-hop distributed cooperative multi-relay system is proposed combining with the space-time block coding OFDM （STBC-OFDM） technique. Taking the maximum end-to-end data rate as optimization criterion, the signal-to-noise ratio （SNR） of receiving terminal is deduced. On the basis of the water-filling theory, the optimal power allocation （OPA） is achieved for each subcarrier in each antenna and each relay node （RN） of the two-hop, to realize the resource optimization. Monte Carlo method is adopted in simulation. The simulation results show that compared with the uniform resource allocation scheme, the proposed OPA strategy *** the system capacity. And the energy consumption of each transmission bit will be decreased, indicating the improvement of resource efficiency. In the scenario that the total power is limited, the system performance can be enhanced further by the distributed cooperative multi-relay through the diversity gain.

关键词： STBC-OFDM distributed multi-relay water-filling theory OPA Monte Carlo

Application of kernel methods in signals modulation classification

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The Journal of China Universities of Posts and Telecommunications 2011年第1期18卷 84-90页

作者： ZHOU xin WU ying WANG Da-lei Institute of Engineering Information Engineering University Zhengzhou 450002 China

A new approach to common signals classification of relevance vector machine （RVM） was presented and two signal classifiers based on kernel methods of support vector machine （SVM） and RVM were compared and analyzed. First several robust features of signals were extracted as the input of classifiers, then the kernel thought was used to map feature vectors impliedly to the high dimensional feature space, and multi-class RVM and SVM classifiers were designed to complete AM, CW, SSB, MFSK and MPSK signals recognition. Simulation result showed that when chose proper parameter, RVM and SVM had comparable accuracy but RVM had less learning time and basis functions. The classification speed of RVM is much faster than SVM.

关键词： kernel function sparse Bayesian model RVM SVM

Transitions to Equilibrium State in Classical φ4 Lattice

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Communications in Theoretical Physics 2002年第8期38卷 157-162页

作者： WANG xin-Gang ZHANG ying HU Gang Department of Physics Beijing Normal University Beijing 100875 China The Abdus Salam International Centre for Theoretical Physics (ICTP) P.O. Box 586 34100 Trieste Italy Department of Physics Beijing Normal University Beijing 100875 China

Statistical behavior of a classical φ4 Hamiltonian lattice is investigated from microscopic dynamics. Thelargest Lyapunov exponent and entropies are considered for manifesting chaos and equipartition behaviors of the *** is found, for the first time, that for any large while finite system size there exist two critical couplings for the transitionsto equipartitions, and the scaling behaviors of these lower and upper critical couplings vs. the system size are numericallyobtained.

关键词： Hamiltonian system, measure synchronization, equilibrium, equipartition