高效液相色谱法测定化妆品中林可霉素类药物

林可霉素类药物属抗菌药物中的小类别,临床上广泛用于除神经系统之外的敏感菌所致的各种感染,主要有以盐酸盐或磷酸酯形式存在的林可霉素和克林霉素类制剂。其不良反应也不容忽视[1],可引起胃肠道反应、肝脏损害、心血管反应等[2],我国在《化妆品卫生规范》中已将抗生素类药物列入化妆品禁用组分。近年来,祛痘或抑制粉刺化妆品中非     

AVS-P3音频解码器的算法优化

基于嵌入式系统应用中实时解码对速度和存储空间的要求，通过分析AVS—P3解码器原理及其技术特点，以AV3 release version1为蓝本对AVS音频解码器进行结构和算法上的优化．其中时频变换模块对intIMDCT算法进行分析与处理，量化模块定点化处理和AVS解码器熵解码模块的实现算法提出了新的方法．经过ARM9平台测试，在音乐质量没有受到损害的前提下，解码速度比原来提高10倍以上，存储空间也减少了一半以上．     

Ultrasound imaging and evaluation of lesion induced by High Intensity Focused Ultrasound

The present study was to investigate the differential imaging method for detecting HIFU (High Intensity Focused Ultrasound)-induced lesions and the estimation of variation of attenuation for lesion evaluation with log spectral difference algorithm. Experiment results of bovine muscle and liver in vitro were acquired. Several algorithms for lesion detection - Absolute Difference (AD), Sum Absolute Differences (SAD) and Sum Squared Differences (SSD) - were analyzed with several window sizes and threshold values. Then three attenuation parameters were compared to evaluate the degree of tissue damage. It was found that variation of the mean attenuation △α was an effective parameter to evaluate lesions.     

模糊数学在综合评价储层损害中的应用

依据现场统计资料，按照６类２０个项目建立了油气储层损害的综合评价指标体系，确定了各主要损害因素权重的分配原则并给定了权值，构造了体现储层损害因素及其关系的模糊关系矩阵。利用模糊数学综合评判的加权平均模型进行了二级评判，计算出了各作业环节及油田的地层损害程度     

贝雷砂岩射孔孔道流动效应正交计算分析

对射孔孔道流动效应进行了量纲分析,建立了轴向和径向流量与影响流量因素间的工程表达式。综合考虑影响流动效应的主要因素和取值范围,设计了数值模拟计算工况的正交计算方案,并利用ANSYS/FLOTRAN流体程序进行了带损伤区贝雷砂岩流量数值模拟研究,获得了各个计算方案的径向流量和轴向流量,用以确定出流量公式的系数。最终确定的流量公式表明,各要素对流量影响的重要顺序依次为固有渗透率、损害区厚度、孔深、渗透率剩余百分数和孔径。     

太空旅行会致盲吗

 宇航员巴拉特(Michael Barratt)在国际空间站度过200 天后,预计身体会出现一些不适。没有了地球引力,他的骨骼和肌肉将减轻,体内制造的红细胞也将减少,心脏则会萎缩。     

HOMOTOPY CONTINUATION ALGORITHM FOR STRUCTURAL DAMAGE IDENTIFICATION

I. INTRODUCTIONStructural damages due to the loss of sti?ness such as crack, localization bulking have remarkablein?uences on the physical properties of structure such as deformation, stress, frequency and modelshape. So the change of these properties can be used to identify the damage location and degree ofstructures. The damage identification techniques based on these properties’ changes have attractedmuch attention in recent years, and many approaches have been developed[1??5].Nowaday…     

镍与生物

镍是一种稀有金属元素，也是动植物和人的必需营养微量元素。本文对镍的生物学功能及对有机体可能造成的损害进行了详细地阐述。