广东省青少年跆拳道运动员损伤特点研究

通过对青少年跆拳道运动员训练、比赛期间运动损伤特点的调查,分析该项目在青少年群体中运动损伤发生的机制、原因,运用Kazemi M的损伤调查问卷,对123名青少年跆拳道运动员（男运动员70名,女运动员53名）进行问卷调查为青少年业余跆拳道运动员训练、比赛过程中预防损伤发生提供重要的理论参考依据。     

青杄类伸展蛋白基因PwELP1的克隆及表达分析

【目的】克隆青杄类伸展蛋白(extensin-like proteins,ELPs)基因PwELP1并分析该基因的表达特性,为研究ELP基因家族的功能奠定基础。【方法】以青杄cDNA文库为模板,用RACE-PCR方法克隆青杄类伸展蛋白编码基因PwELP1的cDNA全长,利用DNAMAN确定PwELP1的编码框及蛋白氨基酸的翻译,运用clustalx软件与Espript工具进行多序列比对,利用MEGA 5软件的邻位相连法构建系统树,并对编码蛋白进行生物信息学分析;利用RT-qPCR检测PwELP1基因在青杄不同组织中表达的特异性、花粉和种子不同萌发时期及幼苗受到不同逆境处理时的表达差异,分析该基因的组织发育及逆境响应表达特点。【结果】PwELP1基因全长832bp,其编码一个由159个氨基酸组成的蛋白,该蛋白的N端与C端均有比较保守的结构域;此蛋白二级结构由1个α-螺旋、5个β-折叠与3个β-转角结构构成,对其三级结构的预测印证了这一结果,同时发现该蛋白中还存在部分无规则卷曲。其分子质量为17.03ku,理论等电点为5.81。PwELP1在青杄花粉中的表达量较高,且在花粉萌发后期(30~36h)以及种子萌发初期(第2天)表达量高;PwELP1的表达不同程度地受低温、高温、茉莉酸甲酯(MeJA)、H_2O_2、脱水以及脱落酸(ABA)等非生物逆境胁迫处理的诱导,尤其是H_2O_2、高温和ABA,处理初期表达量就显著升高。【结论】PwELP1在青杄花粉和种子萌发过程中可能发挥重要功能,并可参与青杄对非生物逆境胁迫的响应过程。     

我国全民健身志愿服务现状及发展策略研究*

利用文献资料、经验总结和逻辑分析等研究方法对我国近年来的全民健身志愿服务活动进行全面总结与梳理。结果表明：全民健身志愿服务活动有效促成了群众体育发展的社会化,成为全民健身的重要纽带与桥梁;多种形式与内容丰富的全民健身志愿服务活动带动了社会力量参与到群众体育发展中,科学健身与全民健身深入人心;单一化的志愿服务人群、间断性的活动开展、匮乏的群众体育健身实施、注重城市与农村滞后等问题也同时出现。建议坚持以人为本,全民参与的服务宗旨,加大宣传力度,拓宽志愿服务群体,建立有效的常态志愿服务机制,依托高校体育专业与地方体育管理机构实施全民健身的可持续化与深入化。     

甜玉米LCYE等位基因多态性及功能分析

【目的】鉴定甜玉米材料中LCYE基因的多态性和β-胡萝卜素和类胡萝卜素含量的变异,为了解甜玉米LCYE基因的等位基因功能及维生素A源强化育种提供参考和依据.【方法】以47份甜玉米自交系为材料,用高效液相色谱法检测β-胡萝卜素和总类胡萝卜素的含量,扩增LCYE基因并测序,结合LCYE基因的测序结果和β-胡萝卜素、总类胡萝卜素含量的表型值作关联分析.【结果和结论】在47份甜玉米自交系的LCYE基因的测序结果中共发现75个多态性位点,其中49个多态性位点分布在非编码区,26个多态性位点分布于LCYE基因的外显子区,且均为SNP,第5外显子区多态性位点最丰富,第4和第9外显子区未检测到多态性位点,其保守程度较高.关联分析检测到与β-胡萝卜素相关联的位点3个,与总类胡萝卜素含量关联的位点6个,位点exon1-2和exon5-6与2种表型极显著相关.本研究证明在甜玉米中LCYE基因与β-胡萝卜素和类胡萝卜素的合成显著相关,为甜玉米的维生素A源强化育种提供了理论基础.     

闽江流域生态公益林林型对水源涵养的影响

【目的】分析林型与降雨量、径流量的关系,为合理调整闽江流域内生态公益林林型结构布局,充分发挥公益林的水源涵养功能提供参考。【方法】以闽江流域为研究对象,借助遥感(Remote sensing,RS)和地理信息系统(Geographic information system,GIS)技术手段,对闽江流域HJ-1A/B CCD遥感影像进行处理,在提取生态公益林资源信息的基础上,结合水文数据,采用灰色关联分析法,研究流域内不同林型与年降雨量、年径流量之间的关系。【结果】经过遥感影像处理和森林资源信息提取,获得了闽江流域30个县市的多年平均径流深和降雨量栅格图及生态公益林森林资源分布图。灰色关联分析结果表明,流域内6种林型阔叶林、杉木林、马尾松林、针阔混交林、竹林、经济林与年径流量的关联度分别为0.599 6,0.544 1,0.529 8,0.546 9,0.501 5,0.457 3;与年降雨量的关联度分别为0.574 3,0.757 1,0.783 0,0.729 1,0.853 8,0.882 1。各县市生态公益林的涵养水源能力以大田、闽清、三明、沙县、尤溪等较强,德化、仙游、古田和福州、建瓯、明溪等表现为从一般到较强,光泽和武夷山最差。【结论】流域内不同林型的水源涵养能力大小依次为阔叶林针阔混交林杉木林马尾松林竹林经济林;当阔叶林、杉木林、针阔混交林面积分别约占有林地面积的20%,18%和26%时,森林涵养水源的能力较强。     

不同氮素利用效率基因型油菜氮素营养性状的差异

【目的】研究盆栽条件下不同氮素利用效率基因型油菜氮素营养性状的差异,为揭示植物高效利用氮素的机理和氮高效基因型油菜品种的选育提供依据。【方法】在低氮(施N 0.1g/kg)和高氮(施N 0.3g/kg)条件下,采用土培盆栽试验对50份不同基因型甘蓝型油菜的氮利用效率进行分析,从中筛选氮高效基因型和氮低效基因型油菜,研究不同氮利用效率基因型油菜各器官及其不同生长阶段的氮含量、氮素累积量及各器官氮累积量占植株总氮素累积量的比例的差异。【结果】1)油菜氮利用效率与籽粒、果荚皮壳、茎叶氮含量均呈显著或极显著负相关,无论氮素供应水平高低,氮高效基因型各器官氮含量均低于氮低效基因型。2)高氮条件下,油菜氮利用效率与果荚皮壳、茎叶、根系氮素累积量和植株总氮累积量均呈显著或极显著负相关;成熟期氮高效基因型油菜果荚皮壳、茎叶、根系氮素累积量和总氮素累积量均显著低于氮低效基因型。低氮条件下,油菜氮利用效率与成熟期果荚皮壳、茎叶氮素累积量均呈显著或极显著负相关,而与成熟期籽粒氮素累积量和植株总氮累积量呈显著正相关;氮高效基因型油菜的籽粒氮素累积量显著高于氮低效基因型,果荚皮壳和茎叶氮素累积量均低于氮低效基因型,总氮素累积量高于氮低效基因型。3)高氮条件下,油菜氮利用效率与茎叶和根系氮素累积量占总氮素累积量的比例均呈显著或极显著负相关,而与籽粒氮素累积量占植株总氮素累积量的比例呈极显著正相关;氮高效基因型油菜籽粒氮素累积量占总氮素累积量的比例明显高于氮低效基因型,而茎叶和根系氮素累积量占植株总氮素累积量的比例均明显低于氮低效基因型。在低氮条件下,油菜氮利用效率与果荚皮壳、茎叶和根系氮素累积量占植株总氮素累积量的比例均呈显著或极显著负相关,而与籽粒氮素累积量占植株总氮素累积量的比例呈正相关;氮高效基因型籽粒氮素累积量占总氮素累积量的比例明显高于氮低效基因型,而果荚皮壳和茎叶氮素累积量占总氮素累积量的比例则明显低于氮低效基因型。4)相对于氮低效基因型,氮高效基因型油菜氮含量对氮素反应更敏感;氮低效基因型油菜氮素累积量对氮素供应水平的敏感性较氮高效基因型油菜高。无论是氮高效基因型还是氮低效基因型,茎叶和果荚皮壳氮含量及氮素累积量对氮素的反应均较籽粒和根系敏感。【结论】不同氮素利用效率油菜的氮含量、氮素累积量和氮素分配比例以及对供氮水平的敏感性存在明显差异。     

Ultimate Bearing Capacity Analysis of High Strength Single Angle Compression Member Eccentrically at One End

To analyze mechanical behavior of Q460 high strength single angle steel struts with an eccentric load at one end in transmission towers, experimental analysis and theoretical calculation were carried out to study the overall stability and local buckling of members. Spherical hinge bearing and double knife edge bearing were applied at axial end of specimens. Influence of some factors on bearing capacity of compression members with eccentricities at both ends was analyzed, such as the end supporting conditions and residual stresses. It was shown that whether spherical hinge bearing or double knife edge bearing was used at axial end, the mechanical behavior can be accurately presented and the residual stresses affected the ultimate load carrying capacity by about 5％ or less. Compared with different methods, such as experiment method、finite element method, method in the Guide for American Design of Latticed Steel Transmission Structure（ASCE101997）and method in Chinese Technical Regulation of Design for Tower and Pole Structure of Overhead Transmission Line (DL/T51542002), it was found that the calculated strength of high strength steel member by standard calculation method in DL/T51542000 was over conservative. According to the research results, the revised formulas of ASCE were proposed with dividing actual material strength by the resistance coefficient of rR=1.111. Therefore, the experimental results can provide reference for designing high strength Q460 single angle steel members compressed eccentrically at one end.     

Dynamic analysis and optimization of gear trains in a megawatt level wind turbine

Through coupling vibration analysis of the transmission system of a 1.5 MW wind turbine gearbox, a torsional vibration model of a gear drive system in wind turbines is established. The fourth order Runge Kutta integration method is applied to calculate the dynamic response of a gear system caused by wind loads, time varying meshing stiffness, and system damping. The harmonic balance method is used to find the analytic solution. Based on the solution, a mathematical model for optimum gear system design is established. The model aims at minimizing the vibration acceleration of the planet gear and the total mass of the gear transmission system. The optimization toolbox in MATLAB program is adopted to obtain the optimal solution. A calculated example shows that the primary natural frequency of the gear system has been raised, the dynamic properties of the gear train have been improved remarkably, and the total mass of the gear train has been decreased.     

Numerical analysis on the performance of spiral antennas

The surfaces of the Planar Spiral Antennas and Conical Spiral Antennas are analyzed with planar triangle. The surface currents of the antennas are solved by using the Method of Moment (MoM) based on the RWG basis function. The input impedance, directivity, gain, radiated power and radiation field of the antenna can be found. The results indicate that, in very wide frequency band, the value of the input impedance equals to the theoretical value of Self-Compensated antennas (in agreement with Babinet-booker' principle), which is,188.5 ohm , the half of the wave impedance of free space, while the directivity, gain and radiated power are stable within the frequency band. When the antenna is driven by the signal of derivative Gaussian pulse, the radiating electric field waveform is obtained by the Fourier transform. When the spiral antenna is used as the pulse radiation antenna, the waveform of the radiation electric field shows the characteristics of the Gaussian quadratic differential.     

Numerical analysis of noise radiation from motorcycle engine shell

FEM/BEM (Finite Element Method/Boundary Element Method) mode analysis of the noise radiation from motorcycle engine shell is conducted. The natural frequency is compared between FEM/BEM analysis and experimental analysis. The FEM/BEM results are agreed with the experiment results, which proves that the finite element model is correct. The frequency response is analyzed and the structure’s noise radiation is simulated by means of FEM/BEM, in order to predict the noise radiation from the motorcycle engine shell and gain the sound field characteristic outside the structure. The calculation data is compared with the experiment data in different frequency bands. The result shows high accordance, which indicates that this method is effective.