M2M产业与中间件解析

M2M就在我们身边但却不为大家所熟知,不过这并不妨碍这个市场从幼年期渐渐迎来成熟发展的时期。     

复杂地质条件下导流洞塌方的离散元法模拟研究

锦屏一级水电站左岸导流洞地质条件非常复杂,地应力极高,节理、断层发育,施工过程中发生了较大规模的塌方。基于离散元法模拟主要节理和断层,建立计算模型,通过计算和分析,得到导流洞围岩的变形破坏规律。导流洞开挖后,围岩应力释放,结构面松弛、滑移,导致围岩边墙首先产生纵向裂缝,拱顶出现掉块;随着结构面变形加剧,边墙沿结构面进一步滑移张开,拱顶的支撑作用减弱导致坍塌,计算模拟和实际塌方情况基本一致。     

双重预防机制在乙烯厂常全压装置罐区中的应用

双重预防机制是指风险分级防控和隐患排查治理机制的双重管控。某乙烯厂将双重预防机制在常全压装置罐区中进行了应用。实践表明：风险分级防控可提高罐区风险管控能力,落实风险分级防控层级,加强隐患排查治理力度,为夯实罐区本质安全生产运行打好基础。     

基于异常与误用的入侵检测系统

入侵检测系统近年来得到长足的发展,但功能都不够完善.为此将基于误用的入侵检测与基于异常的检测结合为一体.在误用检测上,将检测规则进行分类排序,从而极大地提高了检测效率.异常检测则采用人工免疫技术,使系统对已知的攻击和新型攻击均有较强检测能力.     

神经工程系统中的微电极技术

神经工程系统对人们揭示神经系统的工作机理以及探索神经疾病治疗和康复的有效手段具有重要意义,而微电极是神经工程系统中最关键的部件。从微电极的形式、材料和性能评价等几个方面对国际上应用于神经工程系统的微电极技术进行了较为全面的综述。     

M2M网络新生活畅想曲

21世纪是一个网络化时代,网络技术的不断发展和创新不断给社会的生产、生活带来惊喜和变化。然而,网络社会中的机器设备(包括IT机器设备和非IT机器设备)和人口在日益膨胀,应用者和管理者的负担在不断加重。     

Phenotypic and genetic characterization of a novel strain of Acidithiobacillus ferrooxidans （AF2）

A comparative study on the phenotypic and genetic characteristics among Acidithiobacillus ferrooxidans (AF2), a typic strain ATCC23270 and a previously isolated strain AF3 was performed. AF2 can use ferrous ion (Fe²⁺) or elemental sulfur (S⁰) as sole energy source, but oxidizes S⁰ more effectively than Fe²⁺, which is different from ATCC23270 and AF3. The G+C content of AF2 is 51.8% (molar fraction), however, ATCC23270 and AF3 strains have G+C content of 63.7% and 64.8% (molar fraction), respectively. The DNA-DNA hybridization results show that AF2 has 41.53% and 52.38% genome similarity to ATCC 23270 and AF3, respectively, but AF3 has a high genome similarity of 89.86% to ATCC 23270 strain. Rusticyanin (rus) and subunit III of aa₃-type cytochrome oxidase (coxC) genes are not detected in AF2, but Fe²⁺ oxidase (iro) gene can be detected. To understand the genomic organization of iro gene, a cosmid library of AF2 genome was constructed and iro gene-containing clone was screened. The sequencing result shows that although the nucleotide sequence of iro gene in AF2 is completely identical to that of ATCC 23270 strain, its genomic organization is different from that of ATCC 23270. In AF2, iro is located at downstream of purA gene, while it is located at downstream of petC-2 gene in ATCC 23270 strain. These results indicate that AF2 is a novel strain of A. ferrooxidans, and that phenotypic differences among the strains of A. ferrooxidans are closely correlated with their genetic polymorphisms.     

Aerobic biodegradation of di-n-butyl phthalate by Xiangjiang River sediment and microflora analysis

Di-n-butyl phthalate (DBP), one of phthalate acid esters (PAEs), was investigated to determine its biodegradation rate using Xiangjiang River sediment and find potential DBP degraders in the enrichment culture of the sediment. The sediment sample was incubated with an initial concentration of DBP of 100 mg/L for 5 d. The biodegradation rate of DBP was detected using HPLC and the degraded products were analyzed by GC/MS. Subsequently, the microbial diversity of the enrichment culture was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results reveal that almost 100% of DBP is degraded after merely 3 d, generating two main degraded products: mono-butyl phthalate (MBP) and 9-octadecenoic acid. After a six-month enrichment period under the pressure of DBP, the dominant family in the final enrichment culture is clustered with the Comamonas sp., the remaining are affiliated with Sphingomonas sp., Hydrogenophaga sp., Rhizobium sp., and Acidovorax sp. The results show the potential of these bacteria to be used in the bioremediation of DBP in the environment.     

爆破作业中防静电事故的研究

静电是威胁爆破作业中运用电力起爆网路安全的因素之一。本文列举了一起药包早爆事故,在对静电产生的原因及可能侵入电爆网路的途径进行分析研究的基础上,提出了采用"抑制、泄漏、中和"法解决防静电的基本原则,并结合工程爆破作业的具体实际,提出了爆破作业中防静电事故的五条具体措施。以供爆破工作者借鉴与参考。