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Influence of long-period pesticide force on genetic polymorphism of wolf spider Pardosa pseudoannulata (Lycosidae: Araneae)

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Progress in Natural science:materials International 2007年第10期17卷 1161-1165页

作者： Sun Jiying, Fu Xiuqin, Peng Guangxu, Zhang Zhigang and Yan Hengmei(college of Life science, hunan Normal university, changsha 410081, china) college of Life science Hunan Normal University Changsha 410081 China

Wolf spiders are predators in large quantities in the fields. How wolf spiders keep their dominant species status under long-period pesticide force? To answer this question, eight geographical populations of Pardosa pseudoannulata were used as materials to test the influence of geographical habitats on their genomic DNA polymorphism. The RAPD pattern showed polymorphic variations among and within different populations. Total 84 bands amplified by 10 random primers, of which 62 (73.81%) are polymorphic, were generated from 55 individuals of eight geographical populations. Meanwhile, Shannon’s index (Ho= 0.5177) showed a rich genetic diversity of P. pseudoannulata, and most of the genetic variation (64.24%) was found within populations. Multiple regression analysis suggested that it is the climatic variation (such as annual average temperature etc.) that results in adaptive eco-geographic differentiation, and it is the long-period pesticide force that speeds up the genetic differentiation of P. pseudoannulata which changed the genetic diversity of the population.

关键词： pardosa pseudoannulata (Lycosidae: Araneae) eco-geography long-period pesticide force genetic differentiation.

New interpretation of laser gyro drifts

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science china(Technological sciences) 2010年第5期53卷 1168-1175页

作者： GAO BoLong,ZHANG Mei & ZHANG Wen college of Opto-electric science and engineering,National university of Defense Technology,changsha 410073,china 1. college of Opto-electric science and engineering National University of Defense Technology Changsha 410073 China

Discuss and develop some contents which are relevant to the IEEE Std 647TM-2006 in this paper. The IEEE Std only involves Allan variance, and decomposes it into five primary noise terms, in which, however, the noise nature of the so called "rate random walk noise" and the "rate ramp" is doubted by the IEEE Std editors. Here we use a mathematical identity to entirely affirm the first query and partially the second query as mentioned above. Besides, we argue that only the classical variance can be used in navigation, not the Allan variance. In order to seek the true nature of all drift terms in the variance, we adopt our original work that represents the noises as damped oscillations, to obtain the power spectral density (PSD) of the noises which is then transformed back into time domain. When the damped time constant is much longer than the sampling interval, the re-sulting slow variation term may be expanded into three terms: ordinary bias instability, rate random walk, and rate ramp. Therefore, these "noise terms" are not independent, and they are more of deterministic errors than random noises, and can be explained quantitatively. The resulting fast variation drift may be expanded into two terms. The first term is the same as angle random noise, while the second term adds to the true quantization noise term to form a new combined term called "quantiza-tion noise term". As the result of our research, not only the IEEE Std editors’ suspicions above are answered completely, but a new theory to analyze the laser gyro drifts is also presented, with several supporting examples to explain and verify the theory.

关键词： allan variance classical variance drift laser gyro

Microstructure and Mechanical Properties of Magnesium Alloy AZ31B Brazed Joint Using a Zn-Mg-Al Filler Metal

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Journal of materials science & Technology 2010年第8期26卷 743-746页

作者： Li Ma, Dingyong He, Xiaoyan Li and Jianmin Jiang college of materials science and engineering, Beijing university of Technology, Beijing 100124, china [a] college of materials science and engineering Beijing university of Technology Beijing 100124 china

In order to join the similar magnesium alloy, a novel Zn-Mg-Al filler metal was designed and applied to braze AZ31B plates by using high-frequency induction brazing technique. The microstructure, phase constitution and fracture morphology of the brazed joint were investigated. The experimental results show that MgZn2 phase in the original filler metal is completely consumed in the brazing process. Moreover, α-Mg solid solution and α-Mg＋MgZn eutectoid structure formed in the brazing region due to the intensive alloying between the molten filler metal and the base metal in the brazing process. Test results indicate that the shear strength of the brazed joint is 56 MPa. The fracture morphology of the brazed joint shows intergranular fracture mode, where crack originates from the hard α-Mg＋MgZn eutectoid structure.

关键词： Filler metal Brazing Microstructure Mechanical properties

Effect of surface nanocrystallization on the corrosion behavior of Zircaloy-4

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science china(Technological sciences) 2009年第8期52卷 2227-2231页

作者： ZHU YuTao1,2 & ZHANG XiYan1,2,3 1 college of materials science and engineering, Chongqing university, Chongqing 400045, china 2 National engineering Research Center for Magnesium Alloys, Chongqing university, Chongqing 400044, china 3 School of Physical science and engineering Technology, Guangxi university, Nanning 530004, china 1. college of materials science and engineering Chongqing University Chongqing 400045 China 2. National engineering Research Center for Magnesium Alloys Chongqing University Chongqing 400044 China 3. School of Physical science and engineering Technology Guangxi University Nanning 530004 China

The contrastive corrosion experiments between surface nanocrystallined Zircaloy-4 and coarse-grained Zircaloy-4 under the condition of 673 K/10.3 MPa in pure water are carried out, and the microstructure of oxide films has been studied. The results indicate that the growth rate of oxide films formed on the nanocrystalline Zircaloy-4 is lower than that of oxide films formed on the coarse-grained Zircaloy-4. Simultaneously, the oxide/metal interface of the former is more regular and glossy than that of the latter. For nanocrystalline Zircaloy-4, the low oxygen diffusion rate through the oxide/metal interface can hinder the reaction of oxygen ion with metal ion. Furthermore, more tetragonal ZrO2 are observed in the oxide films, which can delay the martensite phase transition from tetragonal to monoclinic phase in oxide films.

关键词： nanocrystalline Zircaloy oxide film microstructure

Screw dislocations interacting with two asymmetrical interfacial cracks emanating from an elliptical hole

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Chinese Physics B 2013年第1期22卷 356-362页

作者：曾鑫方棋洪刘又文 P. H. Wen State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University college of Mechanical and Vehicle engineering Hunan University School of engineering and Material sciences Queen Mary University of London

The interaction between screw dislocations and two asymmetrical interfacial cracks emanating from an elliptic hole under loads at infinity is studied. The closed-form solution is derived for complex potentials. The stress intensity factor and the critical applied stress for the dislocation emission are also calculated. In the limiting cases, well-known results can be obtained from the present solutions. Moreover, new exact solutions for a screw dislocation interacting with some complicated cracks are derived. The results show that the shielding effect increases with the increase in the length of the other cracks and the minor semi axis, but decreases with the increase of dislocation azimuth. The repulsion acting on the dislocation from the other phase and the other crack extend in the horizontal direction, which makes the dislocation emission at the crack tip take place more easily, but the minor semi axis of the elliptical hole extending in the vertical direction makes it more difficult.

关键词： interfacial crack elliptic hole shielding effect dislocation emission

An algorithm for high precision attitude determination when using low precision sensors

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science china(Information sciences) 2012年第3期55卷 626-637页

作者： CAO Lu , CHEN XiaoQian & SHENG Tao college of Aerospace and materials engineering National university of Defense Technology, changsha 410073, china 1. college of Aerospace and materials engineering National university of Defense Technology Changsha 410073 China

The technology for high precision attitude determination when using low precision sensors is a key requirement of a modern small satellite. This paper presents a new attitude determination algorithm termed preprocess EKF(PP-EKF) based on preprocessing of the sensor data. It can enhance the overall modeling accuracy by using the quadratic penalty function to correct the dynamic model error and angular velocity error in realtime, based on the information fusion of the current and the past measurement information. The measurement model of the EKF is linearized by introducing the q method. The solution error of this process is also corrected to further improve the accuracy of the measurement model and make better use of measurement data from the low precision sensors, to obtain good attitude determination results. Finally, the simulation results demonstrate the high reliability and other advantages of the proposed algorithm.

关键词： attitude determination EKF small satellite information fusion

Calculation and characteristics analysis of blade pitch loads for large scale wind turbines

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science china(Technological sciences) 2010年第5期53卷 1356-1363页

作者： DAI JuChuan1,2,HU YanPing1,LIU DeShun1,2 & LONG Xin3 1 School of Electromechanical engineering,hunan university of science and Technology,Xiangtan 411201,china 2 college of Mechanical and Electrical engineering,Central South university,changsha 410083,china 3 Hara XEMC Windpower Co.,Ltd.,Xiangtan 411000,china 1. School of Electromechanical engineering Hunan University of Science and Technology Xiangtan 411201 China2. College of Mechanical and Electrical Engineering Central South University Changsha 410083 China3. Hara XEMC Windpower Co. Ltd. Xiangtan 411000 China

Based on the electric pitch system of large scale horizontal-axis wind turbines,the blade pitch loads coming mainly from centrifugal force,aerodynamic force and gravity are analyzed,and the calculation models for them are established in this *** illustration,a 1.2 MW wind turbine is introduced as a practical sample,and its blade pitch loads from centrifugal force,aerodynamic force and gravity are calculated and analyzed separately and *** research results showed that in the process of rotor rotating 360o,the fluctuation of blade pitch loads is similar to cosine curve when the rotor rotational speed,in-flow wind speed and pitch angle are ***,the amplitude of blade pitch load presents quite a difference at a different pitch *** ways of calculation for blade pitch loads are of the universality,and are helpful for further research of the individual pitch control system.

关键词： blade pitch loads wind turbine individual variable-pitch pitch axis

A Series Piezoelectric Quartz Crystal Response Kinetics for *** Growth in the Presence of Cu(Ⅱ)

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Journal of Central South university 2000年第1期12卷 15-19页

作者： CHAI Li yuan 1,2 ,WEI Wan zhi 2,YAO Shou zhuo 2(1. Department of Metallurgical science and engineering, Central South university of Technology, changsha 410083, china 2. college of Chemistry and Chemical engineering, hunan university, changsha 1. Department of Metallurgical science and engineering Central South University of Technology 410083 Changsha China 2. college of Chemistry and Chemical engineering Hunan University 410082 Changsha China

The kinetics on the growth of *** in the presence of Cu(Ⅱ) was studied using of series piezoelectric quartz crystal (SPQC). Arsenic ion inhibits the growth of *** , which is consistent with the previous results by other measuring methods. This further demonstrates that the SPQC can monitor the chemical activity of *** growth. Cupric ion accelerates the growth of *** . The mechanism was discussed, i. e., copper promotes the protein enzyme of *** , rusticyanin, to form over the range of cupric ion concentration studied. The reaction order of cupric ion in accelerating the bacterial growth is 0.067. The growth of *** is dependent on temperature, the apparent reaction activation energy decreases from 25.56 kJ/mol to 18.32 kJ/mol because of the addition of 10 mg/L Cu(Ⅱ) to the bacterial growth solution of pH 2.0 at initial inoculum of 10%.

关键词： series piezoelectric quartz crystal T.ferrooxidans growth kinetics sigmoid curve cupric ion

s-ordering operator expansions of quantum-mechanical fundamental representations and their applications

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science china(Physics,Mechanics & Astronomy) 2011年第12期54卷 2150-2154页

作者： FAN HongYi 1,3 , XU YeJun 2 & YUAN HongChun 3,4 1 Department of materials science and engineering, university of science and Technology of china, Hefei 230026, china 2 Department of Physics Electronic and engineering, Chizhou university, Chizhou 247000, china 3 Department of Physics, Shanghai Jiao Tong university, Shanghai 200030, china 4 college of Optoelectronic engineering, Changzhou Institute of Technology, Changzhou 213002, china 1. Department of materials science and engineering University of Science and Technology of China Hefei 230026 China3. Department of Physics Shanghai Jiao Tong University Shanghai 200030 China2. Department of Physics Electronic and Engineering Chizhou University Chizhou 247000 China4. College of Optoelectronic Engineering Changzhou Institute of Technology Changzhou 213002 China

We show that the quantum-mechanical fundamental representations, say, the coordinate representation, the coherent state representation, the Fan-Klauder entangled state representation can be recast into s-ordering operator expansion, which is elegant in form and has many applications in deriving new operator identities. This demonstrates that Dirac's symbolic method can be merged into Newton-Leibniz integration theory in a broad way.

关键词： s-ordering operator expansion operator identities quantum mechanical representation