两项地方标准获批,塑料光纤市场“喜迎春”

近日,唐山市两项河北省地方标准《通信塑料光纤综合布线系统设计施工技术要求》、《通信塑料光纤综合布线系统测试验收方法》,通过了河北省标准审定委员会审定。这两项标准总结了河北省通信塑料光纤综合布线系统工程多年的设计施工和测试验收经验,预示着未来通信塑料光纤综合布线系统的设计、施工以及验收等方面将会有统一的标准。同时对促进未来中国塑料光纤产业的发展具有重要作用。     

关于发布国家标准《建筑与建筑群综合布线系统工程设计规范》和《建筑与建筑群综合布线系统工程验收规范》的通知

国务院各有关部门 ,各省、自治区、直辖市建委 (建设厅 )、有关计委 ,计划单列市建委 ,新疆生产建设兵团 :根据我部《关于印发一九九九年工程建设国家标准制订、修订计划的通知》(建标 [1 999] 30 8号 )的要求 ,由信息产业部会同有关部门共同制订的《建筑与建筑群综合布线系统工程设计规范》和《建筑与建筑群综合布线系统工程验收规范》 ,经有关部门会审 ,批准为推荐性国家标准 ,编号分别为ＧＢ/Ｔ50 31 1 -2 0 0 0和ＧＢ/Ｔ50 31 2 - 2 0 0 0 ,自 2 0 0 0年 8月 1日起施行。本规范由信息产业部负责管理 ,信息产业部北京邮电设计院负责具体…     

建筑综合布线工程系统的屏蔽与接地

本文阐述了综合布线系统中的屏蔽技术及综合布线系统接地的结构和应符合的规定,综合布线系统作为建筑智能化不可缺少的基础设施,其系统屏蔽及接地系统的好坏将直接影响到综合布线系统的运行质量,故而显得尤为重要。     

智能大厦综合布线系统

文章阐述了综合布线系统的需求和产生,着重论述了综合布线系统的组成、系统设计标准、规范和一般设计方法及最终达到的系统性能     

医院网络综合布线系统工程设计与实现

网络综合布线系统是现代高新技术应用的基础,同时信息化社会发展的趋势。进行结构化综合布线,对于提升信息服务质量和现代经济发展具有重大影响。以广州前海人寿医院项目为例,在阐述医院大楼综合布线必要性的基础上,就综合布线系统的内涵及特性进行分析,并指出网络综合布线工作区子系统、水平子系统、管理子系统、垂直干线子系统、设备间子系统的设置要点。期望有利于提升网络综合布线系统建设质量,进而为医院信息化管理与服务提供保证。     

网络光缆的敷设与测试

本文阐述了综合布线系统中的网络光缆的敷设及综合布线系统网络光缆的测试。介绍光缆敷设工艺、敷设经验及注意事项,对光缆测试原理及常用测试方法进行介绍。掌握这些将提高网络光缆的运行质量,所以显得尤为重要。     

智能建筑综合布线施工技术分析

智能建筑综合布线施工技术是当今建筑行业中的一个重要领域,其发展不仅全面覆盖了建筑物内部的信息通信系统,而且为建筑的安全性、舒适性和节能性提供了有效的解决方案。随着科技的不断进步,智能建筑综合布线施工技术不断改进和创新,文章全面分析、探讨智能建筑综合布线施工技术,旨在为相关人员提供该领域的实践经验。     

化工厂布线系统建设的研究

综合布线系统(Premises Distributed System,简称PDS)是一种集成化通用传输系统,它是利用双绞线或光缆来舆信息,可以连接工厂电话、计算机、会议电视和监视电视等设备的结构化信息传输系统.它是为了顺应发展需求而特别设计的一套布线系统.对于现代化的化工工厂来说,就如体内的神经,它采用了一系列高质量的标准材料,以模块化的组合方式,把语音、数据、图像和部分控制信号系统用统一的传输媒介进行综合,经过统一的规划设计,综合在一套标准的布线系统中,将现代建筑的三大子系统有机地连接起来.     

大气重金属在线监测系统验收及运行探讨

环境大气特征污染因子在线监测日益得到重视,重金属在线监测作为其中一项在冶金等工业园区得以推广,但是缺乏相应的技术验收规范和运行规范。通过分析宝钢股份一套重金属在线监测系统,讨论其满足监测需求的各项技术验收指标。分析结果得出主要的技术验收指标应满足:各元素测量精密度偏差≤5%、线性度0.99、准确度偏差≤15%、稳定度偏差≤10%。同时有必要进行检出限测试、空白滤膜验收、采样流量准确度和稳定性测试等。最后结合系统运行情况提出运行中的质量控制和维护要求,以满足监测质量规范化的要求。     

综合布线在某电话系统改造中的应用

随着科学技术的迅猛发展,以电话业务为主的通信网逐渐向综合业务数字网过渡,综合布线取代单一、昂贵、复杂的传统布线是科技发展的必然趋势。结合某院电话系统改造工程,分析了综合布线系统的特点、适用范围。指出应根据工程的实际情况和用户的客观需要,以及现场具体条件来确定综合布线系统的综合范围。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。