氯偏共聚物的应用及工艺技术

介绍氯偏共聚物的特性、用途和生产方法；比较国内外生产技术的差异及市场的需求情况。     

Early fault feature extraction of bearings based on Teager energy operator and optimal VMD

As the fault shock component in vibration signals is extremely sparse and weak, it is difficult to extract the fault features when large-scale, low-speed and heavy-duty mechanical equipment is in the early stage of failure. To solve this problem, an early fault feature extraction method based on the Teager energy operator, combined with optimal variational mode decomposition (VMD) is presented in this study. First, the Teager energy operator was used to strengthen the weak shock component of the original signal. Next, a logistic–sine complex chaotic mapping with variable dimensions was constructed to enhance the global search ability and convergence speed of the pigeon-inspired optimization (PIO) algorithm, which is named the variable dimension chaotic pigeon-inspired optimization (VDCPIO) algorithm. Then, the VDCPIO algorithm is used to search for the optimal combination value of key parameters of VMD. The enhanced vibration signal is decomposed into a set of intrinsic mode functions (IMFs) by the optimized VMD, and then kurtosis for every IMF and mean kurtosis of all IMFs are extracted. According to the average kurtosis, several IMFs, whose kurtosis value is greater than the average kurtosis value, are selected to reconstruct a new signal. Then, envelope spectrum analysis of the reconstructed signal is carried out to extract the early fault features. Finally, experimental verification of the method was performed using the simulated signal and measured signal from a rolling bearing; the experimental results indicate that the method presented in this paper is more effective to extract the early fault features of this kind of mechanical equipment.     

VDC-VC悬浮共聚树脂的颗粒特性研究

合成了偏氯乙烯(VDC)-氯乙烯(VC)悬浮共聚树脂，研究了聚合时间分散剂用量和搅拌器转速等对共聚树脂颗粒特性的影响。结果表明：树脂粒径随聚合时间延长而增大，并趋于定值；增加分散剂用量，粒径先减小后增大，当分散剂用量为0．12％时，平均粒径最小；平均粒径随搅拌器转速提高呈马鞍形变化，在130r／min时粒径最小，树脂颗粒形态规整。     

1,1-二氟-1-氯乙烷合成研究进展

介绍了1,1-二氟-1-氯乙烷(HCFC-142b)的基本性质、用途和合成研究进展,比较了直接氟代法、偏氯乙烯加成氟代法和光氯化法的研究概况和不同方法的优缺点.采用在催化剂存在下,用偏氯乙烯和氟化氢在液相中加成氟化的方法生产HCFC-142b是最具工业前景的合成路线,该工艺路线的关键是氟化催化剂的选择,选择一种助催化剂...     

从传统数据中心到VDC

本文分析了传统数据中心面临的挑战,从市场及技术角度分析了云计算对传统数据中心的改变,重点阐述了基于云计算的VDC解决的具体问题以及VDC系统的优势,揭示了数据中心云化的必然趋势。     

大型超高层项目BIM技术应用的POPi数字化集成框架研究——以苏州中南中心为例

本论文基于VDC/BIM的产品—组织—流程研究模型,增加软硬件的基础设施这一核心要素提出了POPi数字化集成框架。并针对大型超高层项目BIM应用及软件多样性和跨组织任务互依性的实践特征论述了POPi框架的要素模型和相应关系。论文结合苏州中南中心项目从实践的角度分析了POPi框架的四个核心要素模型,并基于要素模型分析了项目设计和施工前期阶段的典型应用。     

VDC/BIM技术在浦东美术馆项目的应用实践

伴随着BIM技术的推广,建设项目VDC理念也逐渐得到实践。本文阐述了VDC框架下的POP模型,并且结合浦东美术馆项目中的案例实践,论述了VDC/BIM技术在项目设计和施工过程中的应用价值。     

数据中心网络发展简析

从数据中心整体承载网络出发,阐述了数据中心的链路协议、内部组网方式、外部组网连接等方面如何发展的问题,提出了数据中心的扁平化胖树模型以解决扩展性问题,最后总结出网络发展的主要变化点.     

探讨Honeywell TDC3000系统APM柜24VDC电源的改造

针对DCS系统24VDC电源模块损坏较多,更换费用昂贵的缺陷,我们提出引进24VDC至原损坏电源内部的新思路,不但使损坏电源还能继续利用,而且节约了大量备件采购资金,目前该改造已经成功运用于某化工企业的Honeywell TDC3000系统APM柜。     

VDC实现联通云服务落地

VDC(Virtual Data Center,虚拟数据中心)是中国联通重点打造的云计算服务体系。文章阐述中国联通如何通过VDC实现云服务落地,介绍VDC的管理平台的总体架构、功能模块,同时描述VDC商业模式、具体的产品及规划等,使读者能对中国联通VDC有全面的了解。