湖南汉族10对单基因遗传性状的调查分析

对300（男150,女150）例湖南汉族学生的10对遗传性状（上眼睑皱褶、耳垂、前额发际、耳盯聍、鼻孔形状、蒙古褶、达尔文节、鼻梁侧面观、折舌、卷舌）进行了调查分析.结果表明,上眼睑、蒙古褶、达尔文节、折舌、卷舌的显性频率超过50%,各性状基因频率无明显的性别差异;10对遗传性状中,前额发际同时与耳垂、耳盯聍、蒙古褶具...     

Intentional integration of diversity ideals in academic libraries: A literature review

Diversity is a cornerstone of the library profession and the Association of College and Research Libraries (ACRL) has recently announced a renewed emphasis on diversity and inclusion. In response to this initiative, this paper will review the current academic literature relating to diversity initiatives in academic libraries. Specifically, it will discuss diversity as it pertains to staffing, culture, collections, services and programming. These five areas are good starting points for libraries to reflect on the current state of diversity at their institutions and plan for meaningful change.     

多种方式实现以视频为媒介的听说课堂语言习得

视频材料凭借真实的语境和语言输入促进听说课堂上的语言习得。拟以输入假说、互动假说为理论基础,探索运用语音分离、视频暂停、分片段观看、正常观看四种方式使用视频材料开展听说教学活动,分析其如何促进学生听说课堂的语言习得过程,并简要指出教师在利用视频进行教学活动时应注意的问题。     

Cutting force and its frequency spectrum characteristics in high speed milling of titanium alloy with a polycrystalline diamond tool

In this paper, a series of experiments were performed by high speed milling of Ti-6.5Al-2Zr-1Mo-1V (TA15) by use of polycrystalline diamond (PCD) tools. The characteristics of high speed machining (HSM) dynamic milling forces were investigated. The effects of the parameters of the process, i.e., cutting speed, feed per tooth, and depth of axial cut, on cutting forces were studied. The cutting force signals under different cutting speed conditions and different cutting tool wear stages were analyzed by frequency spectrum analysis. The trend and frequency domain aspects of the dynamic forces were evaluated and discussed. The results indicate that a characteristic frequency in cutting force power spectrum does in fact exist. The amplitudes increase with the increase of cutting speed and tool wear level, which could be applied to the monitoring of the cutting process.     

循环相关在GPS信号捕获中的应用

研究了用循环相关理论来实现GPS信号的捕获。首先,介绍了循环相关的捕获理论;其次,具体分析了用循环相关法实现高动态信号的捕获过程,并给出了此方法的设计步骤;最后,对捕获结果进行了MATLAB仿真。结果表明:此方法可以准确快速地捕获信号。且设计简单,性能稳定,容易达到捕获的目的,可以作为一种常用方法。     

Sr3Tb2（BO3）4晶体生长原料的合成与表征

通过热重分析确定Sr3Tb2（BO3）4多晶原料的烧结工艺,并通过红外、XRD、磁化率等对合成出的多晶原料进行表征。结果表明,Sr3Tb2（BO3）4多晶原料为顺磁性,有可能成为紫外和可见光波段的磁光材料。     

高职高专大学英语听力策略训练的实证研究

以高职高专学生为研究对象,通过实验、调查问卷和访谈等形式进行听力策略的实证研究,旨在考察训练前后的高职学生听力策略使用的变化特征及其原因。研究表明．听力策略训练能够提高高职学生的听力水平,但三种听力策略的使用频率存在差异,而英语水平是影响听力策略训练效果的最重要因素。     

Henon系统动力学行为的MATLAB仿真研究

利用MATLAB对Henon系统的动力学行为的演变进行仿真与分析.通过对时域图、相图、功率谱和分岔图的分析,表明Henon系统可通过阵发性途径走向混沌,其间歇性与霍夫分岔和倍周期分岔密切相关.     

一类四阶微分方程第二广义谱的估计

考虑一类四阶微分方程第二广义谱的估计,利用方程谱理论、分部积分、Rayleigh定理和Cauchy-Schwarz不等式等估计方法,获得了用第一个谱来估计第二个谱的上界不等式,且其估计系数与所论区间的几何度量无关。     

基于混沌置乱的DWT域语音水印算法的研究

作为信息隐藏技术中的数字水印技术是信息时代的一个热门研究课题。语音水印技术由于受到人的听觉特性的限制,使得传统数字水印技术在实现上有一定难度。研究并实现了一种基于混沌置乱技术引入传统的DWT域语音水印算法,该算法可以实现向宿主语音信号嵌入具有特定意义的数字水印,且由于引入了混沌置乱技术极大地提高了水印的安全性和鲁棒性,并同时具有易于提取和高透明性的特点。