硅碱钙石微晶玻璃中析晶过程的研究

通过烧结法制备了硅碱钙石微晶玻璃,并结合XRD,DJA、SEM等测试方法对其晶化过程中的晶相与显微结构演变进行了探索.结果表明,基础玻璃中CaF2晶体的成核自568℃开始.当热处理温度达到650℃时,以CaF2为晶核.析出的晶体以Frankanlenite为主,以及硅碱钙石和少量的石英、氟化钙晶体.750℃硬硅钙石开始形成,在850℃以上,硬硅钙石成为主晶相.     

柠檬酸法合成SrFe12O19磁铅石型铁氧体的晶化过程研究

采用柠蒙酸法合成具有热稳定性的SrFe1 2 O1 9磁铅石型铁氧体。IR ,TG和DSC分析表明 :化学计量SrFe1 2 O1 9干凝胶为具有吸水性的柠檬酸盐。不同煅烧温度下的产物XRD分析表明 ,该干凝胶在 45 0℃和 5 5 0℃分解时并不直接形成SrFe1 2 O1 9磁铅石型铁氧体。结果表明 :60 0℃左右形成的低温SrFe1 2 O1 9磁铅石型铁氧体在热力学上并不稳定 ,当温度升高时将被分解成斜方晶系SrFeO2 .5和四方晶系Fe2 O3,分解温度为 688.6℃左右。热稳定的SrFe1 2 O1 9磁铅石型铁氧体的形成温度需高于 80 0℃。当温度升至 10 0 0℃时 ,产物由α -Fe2 O3和SrFe1 2 O1 9组成 ,斜方晶系SrFeO2 .5和四方晶系Fe2 O3消失。 12 0 0℃时煅烧产物的组成和含量特征指出 ,温度升至 10 0 0℃后 ,升高温度已不再对SrFe1 2 O1 9的纯度产生影响。给出了粉末XRD法鉴别γ -Fe2 O3和四方晶系Fe2 O3的方法 ,证实在热稳定性SrFe1 2 O1 9磁铅石型铁氧体结晶之前有四方晶系Fe2 O3中间相结晶     

准东煤高温燃烧过程中含钙矿物质的转化规律

采用3种萃取液（水、醋酸铵和盐酸）对准东煤进行逐级萃取实验,使用高温气氛炉对准东原煤及萃取后的煤样进行燃烧实验,使用电感耦合等离子体原子发射光谱仪和X射线衍射物相分析仪对萃取前后的固体煤样及燃烧后煤灰样品分别进行Ca元素分析和矿物检测。研究结果表明,准东煤中的钙元素主要以醋酸铵溶钙和盐酸溶钙形式存在。在燃烧过程中,准东煤中含钙矿物质与含硅、含铝矿物质反应生成硅钙石、斜硅钙石与钙铝石等;其中经水萃取后碱酸比减小,灰熔融温度升高,盐酸溶钙与含硅、含铝矿物质反应生成硅钙石、硅铝石等,不溶钙主要以稳定的硅铝酸盐形式存在。     

硅碱钙石微晶玻璃中晶相相变

采用高纯的SiO2、Al2O3、KNO3、Na2CO3、CaCO3及CaF2熔融制备了组成为8.4Na2O 1.3Al2O3 5K2O 10.8CaO 64SiO2 10.5 CaF2的硅碱钙石微晶玻璃,采用热力学计算及DTA,XRD和SEM等技术手段对其热处理过程中硅碱钙石和硬硅钙石晶相间的竞争和转变进行研究。经550℃热处理1h后,母体玻璃中有氟化钙晶相析出;在700℃下热处理1h后析出硬硅钙石晶相;在750～850℃下热处理1h后主晶相转变为硅碱钙石。经在700℃下延长微晶玻璃的热处理时间,观察到由硬硅钙石向硅碱钙石的晶相转变。这一转变趋势得到热力学计算的验证。     

生物可降解共聚物PBST和PBS的结构与结晶性能

利用核磁共振氢谱和广角X射线衍射法研究了生物可降解共聚物聚对苯二甲酸-共-丁二酸丁二醇酯(PBST)的结构及结晶性能,并与聚丁二酸丁二醇酯(PBS)进行比较。结果表明:PBST为无规共聚物,其晶体结构为三斜晶系,PBS为均聚物,为单斜晶系,PBST的结晶度和结晶尺寸均比PBS的小。     

硬硅钙石晶须的水热合成

采用动态水热法,以硅酸钠钙为原料合成硬硅钙石晶须,通过搅拌使晶须形成高孔隙率的球形颗粒. 考察了温度、时间和原料CaO/SiO2摩尔比等反应条件对硬硅钙石晶须及其球形颗粒孔隙率的影响. 结果表明,将CaO和SiO2按摩尔比0.90~1.15溶于Na2O浓度为20 g/L的NaOH溶液中,控制液固比为30 mL/g,以300 r/min的转速在220℃下水热反应7 h以上,可制备出直径约200 nm、长径比大于20的硬硅钙石晶须,晶须相互缠绕形成的球形颗粒孔隙率最高可达93%.     

Na2O-CaO-SiO2-MgO-Al2O3-ZnO微晶玻璃制备及晶化行为的研究

本文设计了Na2O-CaO-SiO2-MgO-Al2O3-ZnO体系,采用熔融法制备了以磷渣为主要原料的微晶玻璃,磷渣在微晶玻璃中的使用率达到67～75%,并利用XRD,SEM等确定了玻璃的最佳热处理制度,研究了Na2O对微晶玻璃析晶及特征的影响.结果发现经过 750 ℃核化4 h,850 ℃晶化2 h,得到主晶相为硅灰石(CaSiO3)和菱硅钙钠石(Na2Ca2Si3O9)的微晶玻璃.玻璃中表面析晶和整体析晶同时存在,其中Na2O可促进整体析晶和菱硅钙钠石的析出.     

SO42-/C3A对单矿C3S水泥浆体中碳硫硅钙石形成的影响

碳硫硅钙石型硫酸盐侵蚀是一种以碳硫硅钙石为生成产物的硫酸盐侵蚀,碳硫硅钙石的形成过程与水泥基材料中铝源及外界环境中硫酸盐密切相关。以铝酸三钙(C₃A)为铝源,Na₂SO₄溶液为侵蚀介质,采用单矿硅酸三钙(C₃S)制备水泥浆体,通过XRD、FTIR、SEM/EDS等测试技术表征不同SO^2-₄与C₃A摩尔比(S/Al比)对单矿C₃S水泥浆体中碳硫硅钙石形成的影响,旨在揭示碳硫硅钙石形成机理并探讨抑制其形成的方法。结果表明:当S/Al比为3时,侵蚀14个月后在侵蚀产物中依然没有检测到碳硫硅钙石;当S/Al比为6和9时,侵蚀3个月即可检测到碳硫硅钙石,这表明外部硫酸根离子浓度越高越有利于碳硫硅钙石的形成。     

不同硅质原料水热合成水化硅酸钙物相及其反应效率的研究

为探究不同硅质原料对水热合成水化硅酸钙物相的影响，研究了温度和硅钙比对产物的影响。采用X射线衍射(XRD)分析了水化硅酸钙物相，并探究了不同硅质原料与Ca(OH)₂的反应效率。结果表明，不同硅质原料与Ca(OH)₂的反应效率由高到低依次为硅藻土、石英、珍珠岩；在硅藻土-石灰体系中，硅藻土中非晶态二氧化硅的Si—O更易被破坏，具有不稳定性，致使硅藻土反应效率更高。在石英-石灰体系中，随着钙硅比的提高，空气中的CO₂参与反应，生成碳硅钙石与片柱钙石，且托贝莫来石与硬硅钙石会逐渐消失，通过合理调控硅钙比和水热温度可有效地控制反应产物，这对于不同硅质原料的选择、水热合成水化硅酸钙中产物的控制及水热合成水化硅酸钙应用领域具有重大意义。     

水热法解聚钠硼解石制备硼酸钙

以钠硼解石天然矿粉为原料，经水热解聚和相转化制备出硼酸钙产品。通过化学分析、XRD及TG—DTG分析表明：产品中的物相主要是白硼钙石（4CaO·5B2O3-7H2O）、硬硼钙石（2CaO·3B2O3·5H2O）和羟硼钙石（3CaO·2B2O3·9H2O）。实验确定了适宜的工艺条件，即：反应体系液固体积质量比为2．5mL／g左右；解聚温度120℃；解聚时间8h左右；干燥温度在200℃左右。在此工艺条件下制得的硼酸钙产品的氧化钠质量分数在0．5％以下，很好地满足了无碱玻璃纤维工业对含硼原料的要求。     

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。