核酸适配体氯化血红素比色法检测牛奶中的氯霉素

利用一种基于适配体氯化血红素(hemin)比色分析法快速检测牛奶中的氯霉素(chloram-phenicol,CAP)含量.设计两条DNA链,其中一条为CAP的核酸适配体,在其3′端修饰氯化血红素;另一条为CAP核酸适配体的互补链(cDNA),在其5′端修饰hemin.当体系中无CAP时,两条DNA单链杂交形成DNA双...     

考虑压裂液流体特征的井筒多相流模型建立

针对页岩气井流体与常规气井流体的差异,基于页岩气井流体特征实验,对压裂液黏度、密度及表面张力与温度的变化关系进行研究。依据实验结果进行拟合得到返排液各物性的相关式,对常用压降模型及井筒温度预测模型进行修正并联立得到页岩气井筒温度压力耦合模型。利用F页岩气田气井真实数据进行实例计算,分析表明修正后的Gray模型精确度最高,验证了新温度压力耦合模型的科学性与合理性。     

Fuzzy子域及其点态刻划

利用集合套给出Fuzzy子域的又一定义,讨论了它的点态刻划及其有关性质。     

弱广义对角占优矩阵的新性质

给出了弱广义对角占优矩阵必有对角占优行这一结论,并证明当弱广义对角占优矩阵为不可约时,该结果还可以有更好的改进.     

疖痈康煎剂在抗菌及调节免疫功能方面的作用

疖痈康为临床验方,对由化脓性球菌（如金黄色葡萄球菌）引起的皮肤化脓性感染、疖、痈、蜂窝组织炎等有良好的防治效果。本文从抗菌及对免疫功能的调节两方面对疖痈康各组方与疖、痈、蜂窝组织炎等防治做一综述。     

低气压放电中的弧光放电发展及其抑制方法

在高频直流脉冲放电的条件下,对低气压放电过程中存在的弧光放电的发展过程进行了研究,揭示了脉冲放电频率的提高对抑制弧光放电的发展是有效的,而快速的弧光放电检测和保护电路是不可缺少的.为一种新型等离子体高频激励电源的研制提供了有效的依据.     

反模糊粗糙子群

提出群中的反模糊粗糙子群和反模糊粗糙正规子群的概念,证明反模糊子群的粗糙集是反模糊子群,反模糊正规子群的粗糙集是反模糊正规子群.     

Vertical distribution of liverwort communities and their relationship with environmental factors in a karst sinkhole in south-western China

ABSTRACT

Understanding the relationships between the vertical distribution of liverwort communities and associated environmental factors is vital for biodiversity conservation in karst sinkholes. The abundance index, α and β diversity indices were used to analyse the characteristics of liverwort communities in the Monkey-Ear Sinkhole (280 m deep, entrance diameter 300 m, width 280 m). A Generalised Linear Model was used to study the vertical distribution of liverwort communities, and the relationships between their vertical distribution and environmental factors were analysed with Canonical Correspondence Analysis. Forty-two liverwort taxa from 22 genera in 19 families were identified in the sinkhole. The liverwort assemblages were dominated by the families Plagiochilaceae and Lejeuneaceae. The α and β diversity appeared to fluctuate randomly among the four depths sampled. The highest degree of environmental heterogeneity was found at the lower-middle section of the sinkhole; liverwort community diversity at the base was much higher than that found at the upper, middle or lower-middle sections. The environment at the base of the sinkhole was more complex than at the other three depths, providing a range of habitats that facilitated the coexistence of multiple liverwort communities. The abundance of species, genera and families in liverwort communities followed the sequence: base > upper section > middle section > lower – middle section. There were significant differences in liverwort communities at the four depths. In the sinkhole, liverwort communities fell into three distribution groups: wide, moderate or narrow distribution along the vertical direction. The communities with a broad distribution, found from the upper section to the base, were affected by a combination of light, humidity and temperature, and were classified as mixed factor dependent; those with a moderate distribution found mostly in the mid and lower-middle sections were primarily dependent on temperature and humidity, and were classified as temperature and humidity dependent; and those with a narrow distribution found at the base of the sinkhole were mainly influenced by humidity, and were classified as humidity dependent.     

基于LBP和PCA特征提取的人脸识别

为有效解决局部二元模式(LBP)在人脸识别特征提取时维数过高的问题,提出了一种结合LBP特征和主成分分析(PCA)的人脸识别方法.首先,对人脸图像进行分块,提取其LBP直方图特征,然后使用PCA方法对特征向量进行降维,最后将降维后的特征向量用于识别.在FERET人脸库上的实验结果表明:相对于原始LBP表达方法,结合LBP和PCA的人脸表达能有效降低计算复杂度,同时也较好地保持了原有识别精度.     

关于强马氏过程的存在性

本文针对非时齐的情形给出了强马尔可夫过程存在的一些条件。这些条件是通过一个Ｒｉｃｓｚ锥给出的。