12周有氧运动干预对运动员血浆压力激素的影响

为研究12周有氧运动干预对运动员血浆压力激素的影响,将某体育学院的30名运动员作为研究对象,随机将其划分成实验组与对照组,令实验组受试者进行12周的有氧训练,对照组受试者除了不参加有氧运动训练外,其余生活条件和实验组相同。实验发现12周有氧运动干预能够改变运动员的身体成分,运动员体重、体重指数、体脂百分比和体脂含量均较实验前有所降低,且具有统计学意义,说明长期有氧运动干预能够改变运动员的身体成分,使总体重与体重指数下降,体脂含量大大降低;同时可有效降低血浆压力,使身体成分趋于合理化。     

金属环境对HF频段RFID系统的影响

为实现HF频段RFID系统在金属环境下的正常工作,采用HFSS9.0为仿真工具,研究金属物体对HF频段RFID系统工作性能的影响,对中距离HF频段RFID系统在金属环境中的工作进行数值仿真分析,得出了读写器天线的磁场分布特性,根据仿真结果对铁氧体吸波材料标签和立体标签的设计方法进行了讨论,同时提出全向标签的概念.所得出的解决方法适用于在金属环境下工作的标签的设计.     

模仿在大学英语写作教学中的应用

模仿是人类重要的的认知行为。国内外许多研究语言习得和外语教学的学者都注意到了模仿在语言习得进程中的作用。本文试图以二语习得理论为依据阐述模仿是大学英语写作教学中一种行之有效的方法。     

一种降低弹翼RCS的技术方案研究

简述了弹翼电磁散射机理 ,阐述了电磁阻抗匹配的基本原理 ,设计了弹翼前缘阻抗匹配技术方案及其电磁模型。散射特性实验结果表明 ,在 8GHz～ 18GHz内 ,弹翼RCS可降低 6dB～ 12dB ,说明了所设计的电磁阻抗匹配技术方案对降低弹翼雷达截面 (RCS)具有明显的效果。     

变网格非协调有限元

本文主要讨论了一类抛物型方程边值问题的非协调变网格有限元法，得到了Ｌ_２模及能量模误差设计．     

抗菌肽A与抗菌肽B空间构象的喇曼光谱分析

通过抗菌肽Ａ与抗菌肽Ｂ两种分子的粉末固体状态、水溶液状态空间构象的喇曼光谱分析，表明这两种抗菌肽具有不同的主链构象，在固态中分别以无规卷曲、α螺旋为主，在水溶液中分别以α螺旋、β结构为主．两种分子在水溶液中Ｃ－Ｓ侧链构象分别为扭式与反式．但色氨酸侧链环境分析表明，两种分子在水溶液中均为色氨酸残基处于部分或完全暴露状态，这一结论为色氨酸具有使抗菌肽全分子与细胞膜发生密切接触的初级锚定作用直接提供了证明     

一种廉价的网络互联方式

本文提出了一种廉价的网络互联互联方式，并给出了这种方式的安装、配置、启动和连接操作的过程。     

Determination of lead isotope compositions of geological samples using femtosecond laser ablation MC-ICPMS

Lead isotopic compositions of international silicate glasses, feldspar and copper-based samples are obtained using femtosecond laser ablation multiple collector inductively coupled plasma mass spectrometry (fLA-MC-ICPMS). Some international glass standards for the microanalysis are applied to evaluate the method reported here. The Pb isotopic composition of these NIST glasses (SRM 610, 612, 614), USGS (BHVO-2G, BCR-2G, BIR-1G and GSD-1G) and MPI-DING glasses (GOR132-G, KL2-G, T1-G, StHs60/80-G) agree well with recommended values in 2 s error. One of 15 copper-based metals is found to have homogenized Pb isotope data and can be used as an external calibration standard and quality control sample for chalcopyrite, ancient coins, etc., to trace the genesis of metal deposit and culture exchange among different dynasties (GBW02137, ²⁰⁸Pb/²⁰⁴Pb = 37.9661 ± 0.0005 (2 s), ²⁰⁷Pb/²⁰⁴Pb = 15.5770 ± 0.0002 (2 s), ²⁰⁶Pb/²⁰⁴Pb = 17.7462 ± 0.0002 (2 s)). We also prepared a feldspar glass to serve as the external calibration standard/QC for Pb isotope analysis using fLA-MC-ICPMS.     

When central populations exhibit more genetic diversity than peripheral populations: A simulation study

The central-peripheral population hypothesis (CPH) predicts that peripheral populations have reduced genetic variability. Therefore, it is often assumed that they deserve higher conservation priority over central populations. We examined this hypothesis using computer simulations with the objective of determining the range of species properties (parameters) under which a species is likely to exhibit the CPH pattern. The interaction between migration, genetic drift, and time of population establishment was e...     

An adaptive spatial clustering method for automatic brain MR image segmentation

In this paper, an adaptive spatial clustering method is presented for automatic brain MR image segmentation, which is based on a competitive learning algorithm – self-organizing map (SOM). We use a pattern recognition approach in terms of feature generation and classifier design. Firstly, a multi-dimensional feature vector is constructed using local spatial information. Then, an adaptive spatial growing hierarchical SOM (ASGHSOM) is proposed as the classifier, which is an extension of SOM, fusing multi-scale segmentation with the competitive learning clustering algorithm to overcome the problem of overlapping grey-scale intensities on boundary regions. Furthermore, an adaptive spatial distance is integrated with ASGHSOM, in which local spatial information is considered in the clustering process to reduce the noise effect and the classification ambiguity. Our proposed method is validated by extensive experiments using both simulated and real MR data with varying noise level, and is compared with the state-of-the-art algorithms.