负风压下结构密封胶对隐框幕墙力学行为的影响

采用负风压加载的方式,研究了均布荷载下隐框幕墙玻璃面板应力和挠度随载荷变化的规律,隐框幕墙玻璃面板为1000mill×1000mm,厚度为6mm的单片钢化玻璃,结构密封胶几何尺寸为9mm x8mm、12mm×8mm和15mm×8mm.实验结果表明:核心结构玻璃面板-结构密封胶-铝合金副框决定了隐框幕墙在承受负风雎时承载能力和抗弯能力的下降;结构密封胶的粘接宽度不能影响隐框玻璃幕墙在负风压条件下的根本力学行为,但是支承条件的不同决定了隐框玻璃幕墙承载能力和抗弯能力不同;负风压下隐框玻璃幕墙的力学性能同结构密封胶粘接宽度之间的关系并非简单的线性关系,粘接宽度存在一个最优值.     

基于动测法的隐框玻璃幕墙硅酮结构胶粘结强度检测方法

隐框玻璃幕墙硅酮结构胶粘结强度是评价幕墙可靠性的重要指标,该文提出了基于动测法的隐框玻璃幕墙结构胶粘结强度检测方法。以结构胶的固化过程模拟幕墙玻璃面板的约束变化,发现玻璃面板的一阶和二阶自振频率随结构胶约束的增强而线性增大,采用多元线性回归方法建立了隐框玻璃幕墙结构胶拉伸粘结强度与面板前二阶自振频率的定量关系,指出可以采用幕墙玻璃面板的自振频率表征结构胶的粘结强度。     

谈高速公路隧道施工监控量测技术

为了研究高速公路隧道施工监控量测技术,本文以监控量测的重要作用为出发点,主要介绍了监控量测技术的优点。然后详细的介绍了高速公路隧道施工监控量测技术的目的和监控量测的具体项目,然后从监控量测的流程和方法上介绍了监控量测技术的应用。监控量测技术能够通过对现场隧道围岩动态的检测来指导隧道的施工过程,进而对整个施工过程进行优化,尽可能的保证隧道施工的稳定性和安全性。本文的研究可以作为高速公路隧道施工过程中的参考。     

隐框玻璃幕墙粘结可靠性检测评估的困境与对策

隐框玻璃幕墙在荷载、紫外辐射、冷热循环等多因素耦合作用下性能逐渐下降,存在支撑体系松动、连接件锈蚀、硅酮结构胶老化等安全隐患.本文深入分析了幕墙结构不同的风险类型,明确硅酮结构胶老化是导致玻璃面板脱落的重要原因.在综述结构胶固化机理、设计方法、可靠性检测评价方法的基础上,指出现有的隐框玻璃幕墙粘结可靠性检测评估存在检测方法会对幕墙造成损伤、检测效率低且成本高、缺少专用设备等问题.为此,本文探索表面硬度法、动测法和化学分析法评价结构胶的粘接性能,详述了各方法的研究思路.拟开展的研究将为"无损、快速、实时"评价硅酮结构胶粘接可靠性提供新路径.     

微晶玻璃应力测量与退火实验研究

应力大小是玻璃光学性能的重要指标之一。介绍了玻璃应力的分类、计算方法、测量方法和先进测试设备。退火是消除应力的有效手段。采用最高575℃的温度曲线对微晶玻璃块(40mm×50 mm×30 mm)进行退火实验,退火前后采用高精度数字应力仪进行应力测量。退火前实验件的应力分布不均匀,应力最小值0.85 nm/cm,最大值25.06 nm/cm;退火后实验件的应力分布均匀,应力最小值为0.75 nm/cm,最大值2.39 nm/cm。实验结果表明此退火能够明显减小微晶玻璃应力值并大幅提高应力分布均匀性。     

MgO加入量对刚玉尖晶石浇注料性能的影响

以致密电熔白刚玉、刚玉微粉、电熔白刚玉细粉、电熔镁砂细粉为原料,研究了5种不同加入量的镁砂对同配比刚玉尖晶石浇注料性能和理化指标的影响。实验结果表明:1.7%的MgO加入量的刚玉尖晶石浇注综合性能最佳,加入量超过7%后,材料的性能降低;2.MgO加入量的增加有利于提高110℃×24h烘干后刚玉尖晶石浇注料的致密度,体积密度逐渐增大,气孔率逐渐减小,并提高常温强度;3.随着MgO加入量的增加,1500℃×3h处理后刚玉尖晶石浇注料尖晶石化剧烈,材料体积膨胀大,结构疏松,材料的气孔率逐渐增大,体积密度和强度降低。     

中高速冲击下PVB夹层玻璃开裂及碎片特性研究

研究表明玻璃幕墙、汽车风挡等夹层玻璃受冲击破坏时,玻璃碎片是造成次生伤害的主要因素.采用空气炮冲击试验结合高速摄影及数字图像处理技术,进行夹层玻璃开裂及碎片特性的研究,分析了玻璃和PVB厚度及冲击能量对碎片特性的影响.采用金相显微系统从介观尺度(10-3 mm)观测开裂及碎片产生过程.结果 表明,中高速冲击下PVB夹层玻璃碎片破坏模式具有五个阶段;碎片飞溅速度呈现两个阶段,其主导因素为正面玻璃的抗侵彻强度;扇形碎片飞溅能量具有一个明显的峰值,对于优化夹层玻璃防护性能具有重要意义.     

应用于管道测径清管器的涡流检测方法

管道测径清管器已成为新建管线验收的重要手段之一。针对传统的测径清管器不能准确定量管径变形的具体位置问题,本文提出利用涡流检测技术,使无损检测技术与传统的测径清管器有效结合,准确定量管径变形的具体位置。文中重点介绍了涡流检测技术原理以及涡流位移传感器对于曲面管径检测的可行性。对传感器进行的仿真和实验结果验证了涡流位移传感器对曲面钢板进行检测方法的可行性和准确性,为新型通径器所应用的涡流位移传感器方案提供理论依据;实现精准确认管道变形的具体位置,提高测径清管器的检测效率。     

渗锡量的定性检测及降低玻璃表面渗锡量的措施研究

浮法工艺生产平板玻璃,由于玻璃在锡槽内成形,玻璃下表面必然会引入一定的渗锡量,当渗锡量达到一定程度时,如果玻璃进行钢化加工,就会出现钢化彩虹,从而影响到玻璃的外观质量.分析了浮法玻璃钢化彩虹的形成与渗锡量的关系,提出了浮法玻璃生产中渗锡量的定性快速检测方法,可以避免玻璃在后续加工中造成损失;论述了降低玻璃渗锡量的措施,可用于指导浮法玻璃生产.     

爆破动荷载作用下巷道群的稳定性研究

以某铁矿-430~-500m阶段为研究对象,利用数值模拟手段研究上分段爆破动荷载对下分段巷道群稳定性的影响,分析巷道围岩应力、位移、塑性区分布、监测点峰值振速及安全系数。研究结果表明:爆破动荷载作用后,2号巷道拱顶围岩最大拉应力从0.33 MPa增至0.53 MPa,增加了0.61倍;巷道拱顶最大沉降位移从4.43mm增至13.79mm,增加了2.11倍,底板最大鼓起位移从3.57mm增至6.21mm,增加了0.74倍;巷道周边塑性区分布区域较静力作用有所增大,拱顶区域破坏明显;拱顶峰值振速43.62cm/s,安全系数1.05,底板峰值振速32.19cm/s,安全系数1.24。应对巷道顶板加强支护。     

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。