Notch Effect and Frequency Compensation of Dual-Sensor OBC Data in Shallow Water

Reverberation is significant in shallow water and produces obvious notches in OBC spec-tra. It also degrades the quality of sections and increases the difficulty of processing and interpretation. This ...     

基于信噪比的投资组合策略研究

采用收益率的协方差矩阵的特征根刻划投资的风险;用主成分综合反映证券市场的信息;用主成分的信噪比反映投资组合的期望收益率与风险之间的均衡关系,并以此作为投资组合收益极大化的指标;得到了不同与H.Markowitz的投资组合模型,并给出了具体的投资组合策略-卖空与非卖空条件下的投资组合的比例,文章最后给出了一个实例.     

"数字电路与系统"多媒体双语教学的体会

“数字电路与系统”具有实践性和离散性等特点;采用多媒体与板书相结合的方法克服多媒体的局限性,发扬板书的优势,取长补短;加强与学生的交流,创建和谐、有序、兴趣盎然的教学氛围。     

CHARACTERISTICS OF QUATERNARY AMMONIUM RESISTANT BACTERIA FROM A FINE PAPERMACHINE SYSTEM

To evaluate the biocide effect of quaternary ammonium chloride (QAC), a whitewater sample was taken from a fine papermachine headbox. By plate spreading method, 51 strains of facultative anaerobe were isolated morphologically. Then the strains were separately transferred to basal medium and were incubated before the beginning of log phase. To identify strains with different QAC resistance, 30-120 ppm of N-Alkyl-benzyl-dimethyl ammonium chloride were added to basal medium.Biocide effect was investigated by comparison of bacterial growth, which can be monitored by 600 nm light absorbance of basal medium suspension. Among 51 strains, only 2 strains can Survive for QAC concentration up to 120 ppm. API20E aud 16S rRNA gene sequencing technique were applied to identify two strains with highest (120 ppm)QAC resistance. One strain (HB22)was identified as Morganella morganii. HB22 can resist QAC concentration up to 150 ppm. HB22 is Gram-negative rod, motile with flagella, catalase positive, oxidase negative, Indole positive, H2S production negative, facultative anaerobe. HB22 has optimum growth condition of 35℃ and pH 7.0.HB22 can catabolize only glucose and D (+)-Mannose.The other (HB45) was identified with high similarity among Pseudomonas cf. monteili or Pseudomonas mosselii or Pseudomonas putida. HB45 can resist QAC concentration up to 200 ppm.HB45 is Gram-negative rod, motile with flagella,catalase positive, oxidase negative, Indole negative,H2S production negative, aerobe. HB45 has optimum growth condition of 30℃ and pH 7.4. HB45 can catabolize L-Arabinose, L(+)-Rhanmose, D (+)-Mannose, Glucose, Glycerol, Lactose, Maltose,Raffmose, Xylose, Cellulose and Xylan. The implication of this work to paper industry is also discussed.     

Empirical Test for Earnings Management of Top Managers＇ Change in Listed Companies

Top managers play a significant role on business decision in listed companies. The frequency of top managers＇ change is rather high all along. Whether those listed companies which top managers changed can really improve performances？ In this paper, we will discuss whether listed companies improve the financial index through earning management and give some advice on top managers＇ change in listed companies in China.     

美国USNews学科评估指标体系的剖析及其启示

通过学科评估指标体系的比较分析与研究,阐述了评估指标体系的客观性、可行性,分析了《美国新闻与世界报道》中多元学科评估指标体系的特点及对我国大学学科评估的启示。     

PIC系列单片机片内定时器实时时钟的实现

针对直接用单片机片内定时器作实时计时不准问题，本文提出了一种可以获取与秒成整数倍关系的定时器溢出信号的方法，同时克服定量溢出中信号被其它中断暂停所受的计时影响，实验表明，在4MHz晶振下，计时误差可控制在每天14s以下，本方法也适用于一般的单片机，在PIC87系列上的实验结果表明效果很好。     

Research on Tracing Evaluation System in Virtual Enterprise Based on Neural Network

The tracing evaluation index system was designed to be used in virtual enterprise and established neural network trace evaluation model. As a result, it was more simple and nicer than the traditional method, so it had wider application foreground.     

如何做好桩基工程旁站监理

文章介绍了桩基工程旁站监理的过程和实效及保证监理目标实现的具体措施。