An α-expansin, VfEXPA1, is involved in regulation of stomatal movement in Vicia faba L.

The wall loosening of guard cells differs from other types of plant cells. However, the regulation of wall loosening during stomatal movement is poorly understood. VfEXPA1 is an α-expansin gene cloned from Vicia faba epidermal strips. Expression of VfEXPA1 is regulated by darkness and submergence, and is not affected by light and abscisic acid (ABA). In situ hybridization showed that VfEXPA1 is expressed primarily in the guard cells. Overexpression of VfEXPA1 in transgenic tobacco accelerated light-induced ...     

异型框架柱在住宅设计中的应用

中高层住宅使用空间的凸出柱子，不仅减少了使用面积，也破坏了房间美观。本文论述了异型柱框架在住宅设计中的优点并介绍了方便的施工方法。     

γ-MnFe合金内耗的振幅效应

采用低频内耗仪研究原子分数分别为86.4%Mn和80.8%Mn的γ-MnFe合金在相变过程中内耗和模量的变化情况。结果表明，从高温到低温，γ-MnFe合金经历了反铁磁转变和马氏体相变，依次出现了反铁磁转变、马氏体相变和孪晶3个内耗峰，且均出现了振幅效应。这是由于反铁磁转变和马氏体相变所产生孪晶的结果。     

The law of refraction and Kepler’s heuristics

Archive for History of Exact Sciences - Johannes Kepler dedicated much of his work to discover a law for the refraction of light. Unfortunately, he formulated an incorrect law. Nevertheless, it was...     

小清河底泥沉积物的形态分析(Ⅰ)——主成分及次要成分分析方法研究

采用透射电镜 ,红外光谱 ,X ray粉末衍射光谱 ,原子吸收光谱等现代技术对小清河底泥沉积物复杂化合物的形貌及其中无机化合物的物种进行了综合分析 ,结合相应样区的水质分析进一步确认了底泥沉积物中主、次成份的物种以及痕量重金属污染物的分子存在状态 .     

对一个物理实验的改进及讨论

本文对物理学中自感现象的演示实验进行了讨论,并对实验进行了改进,使得实验效果更明显.     

基于OFDMA多系统共享的一种半静态资源分配策略

现有的OFDMA资源分配算法大都以提高单系统内的频谱利用率为目标,而对于同一区域内多系统间的资源共享问题未加考虑.针对这一问题提出了一种适用于双无线系统的半静态的资源分配策略.首先划分一定的频谱共享区并设置系统间的优先级,然后引入一种泊松评判机制来控制不同系统接入频谱共享区的概率,从而降低系统间的互干扰.结合几种分配算...     

浅析酒店个性化服务

随着我国酒店业的发展,消费者对酒店业的服务要求越来越高,尤其对个性化服务的要求比较突出.现代酒店必须以个性化服务的理念面对需求时刻变化的消费者,不能只把个性化服务当作一种口号、一种形式,一定要落实到酒店日常运营中.只有这样,酒店才能在激烈的市场竞争中立于不败之地.本文系统阐释了酒店个性化服务的内涵、特点及其作用,并详细分析了个性化服务的实际应用,对个性化服务的发展趋势做出展望.     

Face Live Detection Method Based on Physiological Motion Analysis

In recent years, face recognition has often been proposed for personal identification. However, there are many difficulties with face recognition systems. For example, an imposter could login the face recognition system by stealing the facial photograph of a person registered on the facial recognition system. The security of the face recognition system requires a live detection system to prevent system login using photographs of a human face. This paper describes an effective, efficient face live detection method which uses physiological motion detected by estimating the eye blinks from a captured video sequence and an eye contour extraction algorithm. This technique uses the conventional active shape model with a random forest classifier trained to recognize the local appearance around each landmark. This local match provides more robustness for optimizing the fitting procedure. Tests show that this face live detection approach successfully discriminates a live human face from a photograph of the registered person's face to increase the face recognition system reliability.     

关于F.Smarandache的一个问题

设n是一个正整数,a(n)表示n的平方补数,即a(n)表示使nk为一完全平方数的最小正整数k.本文的主要目的是研究a(n)的均值性质,并利用初等方法给出两个有趣的渐近公式.