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Morphological and molecular identification of Panus conchatus(Polyporaceae,Polyporales)from Yunnan Province,China

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Studies in Fungi 2019年第1期4卷 253-262页

作者： Luangharn T Karunarathna SC Mortimer pe Hyde KD Xu j Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnanChina University of Chinese Academy of Sciences Beijing 100049China East and central Asia Regional Office World Agroforestry Centre(ICRAF)KunmingYunnanChina centre for Mountain Ecosystem Studies(CMES) Kunming Institute of BotanyKunmingYunnanChina center of Excellence in Fungal Research Mae Fah Luang UniversityChiang RaiThailand

Panus conchatus is a species of lentinoid fungi in the family *** species is characterized by its concave,smooth,deeply decurrent gills,with distinctive purple grey to greyish magenta *** fungus is widely distributed in both tropical and temperate ***,we report a specimen of *** collected from a temperate region in Yunnan Province,*** specimen is described and illustrated based on macro-and micro-morphological *** analyses were done based on the sequence data of ITS and LSU,and the placement of the taxon was *** is the first time *** has been reported with molecular phylogenetic data from *** description,illustrations,color photographs,and a phylogenetic tree to show the placement of *** are provided.

关键词： agaricoid form hymenophoral trama lentinoid mushroom polyporales

Arc erosion of AgSnO_2 electrical contacts at different stages of a break operation

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Rare Metals 2010年第3期29卷 248-254页

作者： j. Swingler A. Sumption School of Engineering Sciences University of Southampton

Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation. A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity. The arc current is terminated at different stages as the arc is drawn between the contacts enabling a study of the arcing phenomena up to that point. Surface profiling of the contacts is conducted to determine the extent of erosion at the different stages as the arc is drawn. Spectral analysis is also conducted on the arc and then related to the extent of erosion. The results show that particular features occur at different stages as the arc is drawn. As the arc is initially established, it goes through an ＂Arc Generation＂ regime where the arc roots are small and immobile on both the anode and the cathode. Material transfer occurs mainly from anode to cathode. The spectral analysis indicates that Sn and O species dominate the arc followed by the Ag species. As the arc is drawn further and enters the ＂Arc Degeneration＂ regime, the anode undergoes significantly larger erosion than the cathode. Also, both contacts indicate that multiple arc roots have formed, which are highly mobile in the later stages of the discharge. The spectral analysis indicates that Ag and N species are in high concentrations compared to other species. The mechanisms of erosion and deposition are discussed in relation to the species within the arc discharge. For the complete break operation, it is found that the anode undergoes maj.r erosion, and it is thought that the gaseous ions species do not dominate the arc under these conditions of short arcs and voltage 〈42 V to cause cathode erosion.

关键词： contact materials electrical contacts arc erosion 3D surface profiles spectral analysis

Small Zeros of Additive Forms in Several Variables

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Acta Mathematica Sinica,English Series 1998年第1期14卷 57-66页

作者： j. S. Hwang Institute of Mathematics Academia Sinica Taipei Taiwan 11529 China

Let f（X） be an additive form defined by f（X）=f（x1. x2,…,xs）=σ1α1x1k+σα2x2k+…+σsαsxsk, where αo≠0 is integer, i=1, 2,…, s. In 1979, Schmidt proved that if ε>0 then there is a large constant C（k, ε） such that for s≥C（k, ε） the equation f（X）=0 has a nontrivial integer solution in σ1. σ2,…σs, x1, x2…,xs satisfying σi=±1 and |xi|≤Aε, i=1, 2.…,s where A=max|ai|. Schmidt did not estimate this constant C（k. ε） since it would be extremely large. In this paper, we prove the following result: Theorem 1 If log A≤1/ε,then C（k,ε）≤max （2/ε,20）; if log A>1/ε,A is sufficiently larye and 1/2A≤5≤|ai|≤A,i=1. 2,…, s, then C（k,ε）≤c1c2p and if the last condition is omitted, then C（k. ε）≤[4/ε]c1c2,where c1={2k+1 for≤k≤11 [5k2log k] for k≥12, c2=100c1k22k+c12 and p=2[log 2c1/ε]. We note that the inequality in the first case is sharp but not in the second case.

关键词： Additive form Subset sums Small zeros

ON THE ALGORITHMIC COMPLEXITY OF STATIC STRUCTURES

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j.urnal of Systems Science & Complexity 2010年第6期23卷 1037-1053页

作者： j.el RATSABY j. CHASKALOVIC j.el RATSABY Dept. of Electrical and Electronics Engineering Ariel University Center of Samaria Ariel Israel Department of Mathematics Ariel University Center of Samaria Ariel Israel and IJLRDA University Pierre and Marie Curie-Paris VI France.

This paper provides a first indication that this is true for a system comprised of a static structure described by hyperbolic partial differential equations and is subj.cted to an external random input force. The system deforms the randomness of an input force sequence in proportion to its algorithmic complexity. The authors demonstrate this by numerical analysis of a one-dimensional vibrating elastic solid （the system） on which we apply a maximally-random force sequence （input）. The level of complexity of the system is controlled via external parameters. The output response is the field of displacements observed at several positions on the body. The algorithmic complexity and stochasticity of the resulting output displacement sequence is measured and compared against the complexity of the system. The results show that the higher the system complexity, the more random-deficient the output sequence.

关键词： Data compression descriptional complexity randomness static structure.

Topology optimization of turbine disk considering maximum stress prediction and constraints

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Chinese j.urnal of Aeronautics 2023年第8期36卷 182-206页

作者： Cheng YAN ce LIU Han DU Cunfu WANG Zeyong YIN School of Aerospace Engineering Xiamen UniversityXiamen 361102China National Key Laboratory of Science and Technology on Helicopter Transmission AECC Hunan Aviation Powerplant Research InstituteZhuzhou 412002China Aero Engine Academy of China Beijing 101304China

For the stress-constrained topology optimization of a turbine disk under centrifugal loads,the j.gged boundaries of the mesh and the gray densities on the solid/void interfaces could make the calculated stress field inconsistent with the actual *** may result in overestimating the maximum stress and thus affect the effectiveness of stress *** paper proposes a new method for predicting the maximum stress to overcome the *** the process,a predicted density is newly defined to obtain stable boundaries with thin layers of gray elements,a transition factor is innovatively proposed to evaluate the effects of intermediate-density elements,two different stiffness penalty schemes are flexibly used to calculate the elastic modulus of elements,and a linear stress penalty is further adopted to relax the stress field of the *** proposed approach for predicting the maximum stress value is verified by the analysis of a structure with smooth boundaries and the topology optimization of a turbine *** updating scheme of the stress constraint in the topology optimization is also developed using the predicted maximum *** key ingredients affecting the optimization results are discussed in *** results prove the effectiveness and efficacy of the proposed maximum stress prediction and developed stress constraint methods.

关键词： centrifugal loads Maximum stress prediction Stress constraints Topology optimization Turbinedisk

Conservation laws for energy and momentum in curved spaces

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j.urnal of Zhej.ang University-Science A(Applied Physics & Engineering) 2007年第4期8卷 665-668页

作者： LópeZ-BONILLA j. MORALES j. OVANDO G. Section of Postgraduate Studies and Research Superior School of Mechanical and Electrical EngineeringNational Polytechnic InstituteCP 07738Mexico Division of Basic Sciences and Engineering Autonomous Metropolitan UniversityCP 02200Mexico

In arbitrary Riemannian 4-spaces, continuity equations are constructed which could be interpreted as conservation laws for the energy and momentum of the gravitational field. Special attention is given to general relativity to obtain, of natural manner, the pseudotensors of Einstein, Landau-Lifshitz, Moeller, Goldberg and Stachel, and also the conservation equations of Komar, Trautman, DuPlessis and Moss.

关键词： Noether theorem Lagrangians in curved spaces Energy and momentum in Riemannian spaces Rund-Lovelock identities

Multifractal filtering method for extraction of ocean eddies from remotely sensed imagery

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Acta Oceanologica Sinica 2006年第5期25卷 27-38页

作者： GE Yong DU Yunyan CHENG Qiuming LI ce State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences ＆ Natural Re-sources Research Chinese Academy of Sciences Beijing 100101 China Department of Earth and Space Science and Engineering York University Toronto M3J 1P3 Canada State Key Laboratory of Geo-Processes and Mineral Resources China University of Geosciences Beijing 100083 China

Traditional methods of extracting the ocean wave eddy information from remotely sensed imagery mainly use the edge detection technology such as Canny and Hough operators. However, due to the complexities of ocean eddies and image itself, it is sometimes difficult to successfully detect ocean eddies using these methods. A mnltifractal filtering technology is proposed for extraction of ocean eddies and demonstrated using NASA MODIS, SeaWiFS and NOAA satellite data set in the typical area, such as ocean west boundary current. Results showed that the new method has a superior performance over the traditional methods.

关键词： remotely sensed imagery extraction of ocean eddies multifractal filtering

Acoustic Measurements for Determination of the Materials Damping Using A Sound Source Localisation System

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Acta Metallurgica Sinica(English Letters) 2013年第2期26卷 113-121页

作者： j. Gken j. Swiostek H. Hurdelbrink U. Keil Faculty of Maritime Studies University of Applied Sciences Emden/Leer Bergmannstr. 36 26789 LeerGermany Stalomax TM Company of High-Precision Mechanics ul. Parkingowa 45 37450 Stalowa WolaPoland

Noise measurements are especially a problem when the obj.ct under investigation is largely dimensioned and can only be measured from the distance. To obtain information about the location of noise generation, a measurement technique which makes sound visible in order to introduce further specific technical measures is advantageous. The question is if the time dependence of the signal got from such a non touching and non destructive acoustic method has the potential to calculate the materials damping from. Using a small sound source localization system （Microflown^TM probe）, specimens of magnesium alloys with different grain sizes obtained by hydrostatic extrusion were investigated. It has been demonstrated that the fine grained microstructure led to a lower damping and its dependence on the strain was reduced. In this context, acoustic measurements by a sound source localisation system which makes materials characterization possible could be used as a quality tool to detect changes in highly stressed components. This approach allows to promote a selective substitution of conventional materials by more innovative ones. The offshore sector is considered to be a field of application： Wind turbines produce noise emission which stems mainly from turbulences at the tips of the rotor blades and vibrations of components inside the nacelle （e.9. gearbox, generator, ...）. If the vibration amplitudes are too high, microcracks of components can lead to failure over the long term. The monitoring of microstructural changes using a larger type of a sound source localisation system is considered as an innovative technical approach with respect to maintenance activities.

关键词： Magnesium Noise measurements MicroflownTM Damping

Contribution of point defects and nano-grains to thermal transport behaviours of oxide-based thermoelectrics

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npj.Computational Materials 2016年第1期2卷 84-92页

作者： Guang-Kun Ren j.n-Le Lan Kyle j.Ventura Xing Tan Yuan-Hua Lin ce-Wen Nan State Key Laboratory of New ceramics and Fine Processing Department of Materials Science and EngineeringTsinghua UniversityBeijingChina State Key Laboratory of Organic-inorganic Composite College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijingChina School of Engineering Clarkson UniversityPotsdamNYUSA

Point defects and nano-grains are very effective ways to control the thermal conductivity in oxide-based *** we use the optimised Debye–Callaway model to understand how the effect of point defects and nano-grains to reduce the thermal conductivity by inducing normal process and oxygen vacancy in oxide-based *** results reveal that this model can be effective to fit the experimental data of thermal conductivity in ZnO-,CaMnO_(3)-,BiCuSeO-,SrTiO_(3)^(-)and In_(2)O_(3)-based systems,which indicate that the normal scattering process and the oxygen vacancy will make obvious contribution to the thermal conductivity as compared with alloy compounds *** calculations also propose that it could be desirable to obtain higher ZT by controlling the concentration of oxygen vacancy in the nano-grained thermoelectric oxides.

关键词： alloy grain thermal