碳酸钙含量对泡沫玻璃结构与性能的影响

以废玻璃为主要原料,CaCO_3为发泡剂,烧结制备了泡沫玻璃材料。利用DTA、XRD、电子万能试验机等分析测试手段,研究了CaCO_3含量对泡沫玻璃结构与性能的影响。结果表明:随着CaCO_3添加量的增加,孔径由小变大,形貌从均匀的单峰孔转变成复杂的双峰孔结构,力学性能趋向于开孔结构;750℃下保温15 min可制得体积密度0.23~0.35 g/cm~3、抗压强度0.76~5.09 MPa、气孔率84.05~90.73%的泡沫玻璃材料。     

工艺参数对煤矿废弃物泡沫隔热陶瓷孔结构和力学性能的影响

以煤矿固体废弃物煤矸石和煤炭伴生页岩为主要原材料,抛光渣为造孔剂、滑石为助熔剂,制备泡沫陶瓷.研究烧成温度、保温时间和球磨时间等工艺参数对泡沫隔热陶瓷孔结构、表观密度、孔隙率和力学性能的影响.研究结果表明,随着烧成温度升高,泡沫陶瓷的孔径和孔隙率增大,材料的致密度和孔密度降低,抗压强度减小.并随着保温时间的延长,泡沫陶瓷的孔径和孔隙率先增大而后趋于平缓,发泡状况更加完善.当烧成温度、保温时间和球磨时间等工艺参数分别为1200℃、30 min和40 min时,泡沫陶瓷的孔径小且孔分布均匀,在0.6～0.8 mm孔径区间集聚度达80.6％,孔隙率大于70％,抗压强度大于12 MPa.     

保温隔热墙体材料的研究现状

保温隔热材料近年来发展迅速,目前已在墙体方面得到大量应用。本文主要概述了有机、无机以及复合保温隔热墙体材料的研究现状,国内有机保温隔热材料主要采用聚苯乙烯泡沫板(EPS)、聚氨酯材料(PU)、挤塑聚苯乙烯泡沫板(XPS)等,无机保温材料主要有泡沫玻璃、泡沫混凝土、岩棉和无机保温砂浆等,有机保温材料和无机保温材料各有优缺点,对比分析表明：复合保温隔热墙体材料将成为一种发展趋势。最后分析了我国保温隔热墙体材料的应用现状。     

发泡剂含量和发泡温度对无碱玻璃纤维废丝制备泡沫玻璃的性能影响

以无碱玻璃纤维废丝为主要原料,SiC为发泡剂,用烧结发泡法制备了高强度低密度保温泡沫玻璃。研究了发泡剂含量及发泡温度对泡沫玻璃气孔率、孔结构、表观密度、抗压强度和导热率的影响。研究结果表明,随着发泡剂含量的增加,孔径逐渐增大,表观密度和抗压强度降低,过多的发泡剂会导致大气孔的出现;随着发泡温度的提高,泡沫玻璃的气孔逐渐增大,表观密度呈现下降趋势,当发泡温度过高会导致大孔和连通孔的出现;当发泡剂含量为3wt%,发泡温度为950℃,保温时间为30min时制得的泡沫玻璃综合性能最佳,表观密度为0.216g/cm~3,抗压强度为8MPa,抗折强度为4MPa,吸水率为0.28%,导热系数为0.061W/(m·k)。     

矿渣微粉-糊精灰浆复合胶凝材料的试验研究

用矿渣微粉代替部分石灰,并对36组不同组分的矿渣微粉-糊精灰浆复合胶凝材料的力学性能和耐水性能进行试验研究.结果 表明,添加激发剂和砂含量为900 g时都可提高复合胶凝材料强度,且抗压强度随糊精浓度的增加而提高,矿渣微粉替代率为35％时28 d抗压强度较高,矿渣微粉替代率为25％时90 d抗压强度提高显著,当矿渣微粉替代率为25％、糊精浓度为16％、砂含量为900 g并添加激发剂时复合胶凝材料强度最好,其28 d抗折和抗压强度分别为0.62 MPa和3.95 MPa,90 d抗折和抗压强度分别为1.21MPa和8.31 MPa,且耐水性能达到27 d.用矿渣微粉代替部分石灰,可以提高糊精灰浆力学强度和改善耐水性能.     

聚丙烯纤维添加量对发泡水泥性能影响研究

研究了聚丙烯纤维添加量对发泡水泥力学性能、保温性能及泡孔结构的影响。结果表明聚丙烯纤维的添加改善发泡水泥的泡孔结构。在聚丙烯纤维添加量为0.55 g,养护28 d时试样抗折强度最大为1.7 MPa。当聚丙烯纤维添加量为0.55 g,养护28 d时发泡水泥的抗压强度最大1.18 MPa。当聚丙烯纤维添加量为0.5 g时发泡水泥导热系数最小为1.124 W/(m·K),保温性能最好。     

多排陶粒混凝土复合砌块结构优化设计分析

随着我国建筑节能工作的全面推进和不断深化,促进了新型墙体材料的研究和应用.参考相关规范,选取砌块主规格:长×宽×高=390 mm×240 mm×190 mm,根据空心砌块不同孔排数、交错程度和孔洞率,设计12种内部结构不同的空心砌块.通过有限元软件ABAQUS和加权求和法对混凝土自保温空心砌块进行结构优化设计,将优化后的砌块结构浇制成陶粒混凝土空心砌块,空心砌块孔洞由正交试验优化后的泡沫混凝土填充,定量分析不同配比条件下各种材料对泡沫混凝土热工和力学性能影响程度的大小,得到最优配比:水灰比41％,粉煤灰20％,碳酸锂0.16％,聚羧酸减水剂0.075％,微硅粉含量4％和硬质酸钙0.2％,泡沫混凝土的导热系数和抗压强度分别为0.0602 W/(m·K)和5.2 MPa.结合有限元数值模拟和试验研究,制得优化后的陶粒混凝土复合砌块,平均传热系数▉KC3=0.61 W/(m2·K),平均抗压强度10.11 MPa,强度等级达到MU10,同时满足节能65％的要求.     

微晶泡沫玻璃的制备及力学性能研究

以废旧阴极射线管为主要原料,SiC为发泡剂,采用烧结法制备了微晶泡沫玻璃。通过DTA,XRD,SEM等分析手段,研究了发泡剂用量,升温速率,降温速率,保温时间对试样力学性能的影响。结果表明,所制备的微晶泡沫玻璃的主晶相为Pb,次晶相为Pb3O4,Al6Si2O13,抗压强度为6.28MPa,抗折强度为2.1MPa。     

异氰酸酯交联聚氯乙烯泡沫发泡工艺研究

采用模压及高温高湿发泡的方法，在PVC糊状树脂中添加改性MDI、偶氮类复配发泡剂，制备了异氰酸酯交联发泡聚氯乙烯硬质泡沫。考察了升温速率、塑化温度及时间、膨胀温度及时间等对泡孔结构及泡沫力学性能的影响。结果表明，模压工艺的升温时间为30 min、模压温度为170℃、保温时间为30 min,膨胀工艺参数为96℃(4 h),此工艺条件下泡孔结构最佳同时具有最佳力学性能，即压缩强度0.92 MPa、压缩模量79 MPa、剪切强度0.78 MPa、剪切模量24 MPa。     

磷石膏基复合胶凝材料早期强度和体积稳定性研究

针对磷石膏基复合胶凝材料(PGF)早期强度低、易膨胀开裂等缺点,通过加入适量活化剂(Y-l)来改善早期强度和体积稳定性,并且通过pH值、X射线衍射分析、微观形貌和孔隙率等测试方法分析PGF硬化体的水化产物和孔结构.结果表明:当Y-1掺量为3％(质量分数)时,可有效提高PGF硬化体早期抗压强度和抑制过度膨胀,其中3d和28 d湿抗压强度分别为7.5 MPa和37.9 MPa,线膨胀率较参比样(未掺Y-1)分别降低了69.6％和71.6％,总孔隙率降低了2.3％和18.0％,有效改善了PGF硬化体的力学性能和体积稳定性.     

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.     

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。     

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.