微波辅助萃取煤的实验研究

在微波辅助下,以神府煤为主要研究对象,四氢呋喃、丙酮、甲醇为溶剂,考察了萃取温度、时间、溶剂量及煤粒度对萃取率的影响,结果显示:使上述3种沸点接近的不同溶剂萃取率达到最佳值,所需要的萃取温度、溶剂量及煤粒度相差大;同时探讨了以四氢呋喃、丙酮、N,N-二甲基甲酰胺为溶剂,对不同变质程度煤的微波辅助萃取效果,结果是变质程度相似的煤在相同萃取条件下萃取率不同。运用红外光谱现代分析技术,对神府脱灰煤和四氢呋喃抽提残煤的结构进行对比分析,结果表明萃取并没有破坏煤的大分子结构。     

溶剂类型对煤微波辅助抽提率及组成的影响

以神府煤和攀枝花煤为对象进行煤微波辅助抽提研究,所用溶剂有甲醇、乙醇、丙酮、乙酸、四氢呋喃、乙二胺和DMF等.结果表明,前四种溶剂对攀枝花煤的抽提率较高,后三种溶剂对神府煤的抽提率较高,其中乙二胺对神府煤的抽提率可达70.76%.抽提残煤的元素分析、官能团测定及FT-IR分析表明,各残煤H/C和O/C比略有降低而N/C明显升高;含氧官能团含量较脱灰煤有所增加,总酸性基及羟基含量提高;另外,利用GC/MS检测脱灰神府煤四氢呋喃抽提物,正己烷可溶物含较多的脂肪烷烃,甲苯可溶物中则含各种芳香族化合物,四氢呋喃可溶物中只检测到一种含氧杂原子化合物.     

微波条件下氯化锌对乙醇抽提神府煤的影响

微波条件下,研究了在乙醇抽提神府煤中加入氯化锌对其结果的影响。采用气相色谱/质谱联用的方法分析了乙醇和乙醇-氯化锌抽提物的组成;利用傅里叶红外光谱技术分析了神府脱矿物质煤、乙醇抽余煤和乙醇-氯化锌抽余煤的结构。分析结果显示:在乙醇溶剂中添加少量的氯化锌,其抽提物的组成发生了改变;乙醇-氯化锌抽余煤与原脱矿物质煤和乙醇抽余煤相比,芳环吸收强度降低,表明在抽提过程中可能伴随着烷基化反应的发生。     

微波辅助低温煤焦油馏分萃取-热解耦合神府煤的作用研究

为提高煤在萃取过程中的转化率,考察微波辅助萃取煤的工业化可行性。以低温煤焦油馏分为溶剂,研究了神府煤在微波辅助萃取-热解耦合新工艺下的特性,考察了溶剂类型、萃取温度、溶煤比、萃取时间对转化率的影响。结果表明：当溶剂为200～360℃馏分油,萃取温度为200℃、萃取时间为30 min、溶煤比为3∶1时,微波辅助过程煤的转化率最高为34.75%。最后,通过对比常规萃取与微波辅助萃取的工艺条件及反应结果发现：微波辅助萃取-热解过程较常规萃取-热解过程略占优势,但其产业化仍需进一步验证。     

微波辅助下从泥炭中提取黄腐酸类物质的研究

在微波辅助下,以泥炭为研究对象,水为抽提溶剂,采用正交试验考察了抽提温度、时间、固液比及压力对黄腐酸类物质（泥炭水溶酸性抽提物）提取率的影响。结果显示,影响抽提率最主要的因素是压力。较佳的抽提条件为压力0.6MPa、抽提温度150℃、固液比1：10g／ml）、抽提时间20min,并采用红外光谱、元素分析及官能团测定的方法分析了抽提物的组成。采用微波辅助法从泥炭中提取医用黄腐酸可能为一种有效的环境友好的方法。     

神府煤的液化性能及其重质产物结构表征

利用管式高压反应釜,以四氢萘为溶剂、FeS和S为催化剂,对神府煤进行了加氢液化研究,考察了催化剂、反应温度和反应气氛等因素对煤液化性能和产物组成分布的影响,同时对液化产物进行了红外光谱、元素分析以及酸性含氧官能团等结构表征。结果表明,FeS+S催化神府煤液化的最高四氢呋喃(THF)抽提率和油+气收率分别为69.5%和35.9%;未加催化剂时,神府煤液化THF抽提率和油+气收率都是最低的。     

煤的溶剂抽提研究进展

介绍了影响煤溶剂抽提的因素及提高煤溶剂抽提效率的一些主要的辅助方法(超声辐照,微波辐射,水热处理),并通过对比多种煤溶剂抽提的实验室研究进展和溶剂抽提技术在工业化应用的情况,提出了今后关于煤溶剂抽提的发展方向。     

神府镜煤光氧化产物的组成和结构研究

在紫外光照射下,用氧气对神府镜煤进行了光催化氧化研究。探讨了氧化时间对氧化煤中腐植酸含量的影响。通过溶剂抽提,FTIR分析及GC/MS分析对神府镜煤光氧化产物进行了组成和结构分析。研究表明:控制光氧化时间,可以获得不同腐植酸含量的光氧化产物,在光氧化4 h时,镜煤中腐植酸含量最高;镜煤在光氧化产物过程中,芳香结构较难打开,主要是醚键等含氧官能团发生反应,生成羧基和甲基等。     

一种低变质煤微波热解过程分析

微波闪速热解是低变质煤转化的一种新工艺.研究了微波加热条件下原煤粒度变化对热解产品质量和收率的影响.结果表明,微波加热条件下,10min左右煤料温度可达到750℃,22min焦油收率就可达到12%左右,比常规加热提高4%;热解煤气中氢气、一氧化碳和甲烷含量大幅度提高;原料煤粒度对各种产品的收率影响不大.因此该工艺可用于粉煤的快速热解,为煤气的进一步综合利用奠定了基础.     

煤的CS2/NMP混合溶剂抽提研究进展

综述了 CS2 /NMP混合溶剂用于煤抽提的研究进展 ,着重介绍了煤阶、煤岩组分、添加物和各种辅助手段对抽提率的影响 ,并对添加物的增溶机理、混合溶剂的抽提机理、抽提动力学以及抽提物的表征等问题进行了讨论 ,指出高抽提率的溶剂抽提不仅对于煤结构的研究有着重要的意义 ,而且可望成为获取高附加值产品和煤净化的新途径     

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。