复配壳聚糖对废水中Cu~(2+)的动态吸附研究

将壳聚糖与活性炭复配,并进行交联和接枝改性,制得复配壳聚糖吸附剂,并用于动态吸附废水中的Cu~(2+),通过穿透曲线考察了主要操作条件对吸附性能的影响。结果表明,增大溶液初始浓度及溶液流量,吸附剂的穿透吸附量增加,穿透时间减少,穿透曲线前移;增加吸附剂填充量,穿透吸附量及穿透时间增加,穿透曲线更加平缓。采用Thomas模型对实验数据进行拟合分析,结果表明,复配壳聚糖对Cu~(2+)的动态吸附行为符合Thomas模型。     

基于改进型吸附等温线模型的空气预纯化TSA双层床模拟

为了掌握空气中CO2和水蒸气在空分装置双层床变温吸附(TSA)纯化器中的动态吸附特性,通过LDF传质假设及非绝热假设,建立了一维二元稀组分系统的双层床TSA过程数学模型。一种改进型的多组分等温线模型用于描述水蒸气的Ⅱ型吸附等温线以及水蒸气和CO2混合物的吸附平衡关系。通过对比模拟结果与TSA纯化器的现场监控数据发现,基于改进型等温线模型的模拟结果与现场数据吻合良好。最后对多种工况下的TSA纯化器中的温度、浓度及吸附量床层分布和穿透曲线进行了数值模拟和分析。     

Na2CO3/γ-Al2O3吸附剂对SO2吸附性能的研究

用浸渍法制备了 Na2 CO3 /γ- Al2 O3 吸附剂 ,考察了 Na2 CO3 含量、焙烧温度和吸附温度对 Na2 CO3 /γ- Al2 O3 吸附剂 SO2 吸附性能的影响 .结果表明 :Na2 CO3 含量从 4%增加到 2 0 %时 ,穿透时间和硫容在 1 6%时出现峰值 .未经焙烧的吸附剂穿透时间和硫容都比较低 ,较理想的焙烧温度为 30 0℃～ 40 0℃ .吸附温度对 SO2 吸附性能的影响明显 ,在室温下吸附时 ,穿透时间和硫容都较小 ,适宜的吸附温度为 1 2 0℃～ 1 60℃ .     

真空变压吸附提纯沼气的实验

以煤基碳分子筛为沼气净化吸附剂,借助扫描电镜观察了碳分子筛的表面形貌,并通过物理化学吸附仪表征了碳分子筛的孔径分布。基于静态容积法测定了CO2与CH4在碳分子筛的静态吸附量,并估算了CO2与CH4在碳分子筛的动力学扩散系数。单塔穿透实验考察了吸附压力与进料流量对原料气中CO2穿透曲线的影响,选取吸附压力为0.3 MPa,进料流量为4 L·min-1进行两塔六步真空变压吸附提纯沼气的实验研究,并考察了吸附步骤时长与产品气冲洗率对CH4富集效果的影响。实验结果表明,吸附步骤时长为140 s,冲洗率为0.05时,产品气中CH4纯度可达98%,收率可达82%。     

椰壳活性炭吸附纯化回收H_2的初步研究

测定了椰壳活性炭对多晶硅回收H_2中的HCl、Si HCl_3和Si Cl_4的吸附等温曲线,并用Freundlich方程进行了拟合。在此基础上运用ASPEN Adsorption软件对各组份的穿透曲线进行模拟和分析。根据HCl穿透曲线的形态和穿透点位置,可以确定活性炭吸附塔的装填量和吸附时间,模拟结果与实际运行情况较为吻合。     

CO在成型催化剂上脱除NOx的反应动力学模型

采用实验和模拟相结合的方法研究了NO_x在固定床反应器中的吸附还原过程。选取商业常用的堇青石和TiO₂为主要的成型催化剂基体材料，以铜铁铈复合型金属氧化物为活性成分，制备了蜂窝成型催化剂，对蜂窝催化剂的吸附性能和脱硝还原活性进行测定。建立了固定床反应器中CO脱除NO_x的反应动力学模型，由于CO法脱硝反应的解耦分解，脱硝反应模型也由吸附模型和还原模型组成。吸附模型由固相和气相的微分质量平衡方程建立，还原模型由一组微分方程组成。通过固定床NO_x吸附曲线和不同温度下NO_x的转化率对模型中的关键参数进行了拟合，得到了CO在成型催化剂上脱除NO_x的反应动力学模型，该模型与实验数据吻合较好。在此基础上，模拟了其他条件下吸附过程的穿透曲线和还原反应的转化率。此模型能较好地揭示CO在蜂窝催化剂上还原NO_x的反应动力学，为CO法成型催化剂脱除NO_x的实验或者工程提供理论指导。     

SO_2在活性焦固定床上的吸附性能

在120℃恒温条件下,在活性焦固定床上测定SO2的吸附等温线和动态吸附穿透曲线。采用Langmuir吸附方程拟合,得出饱和吸附量qm=0.072 g/g和Langmuir常数K=0.629 m3/g。根据穿透曲线的形状分析传质机制,建立了吸附过程的数学模型,并用COMSOL Multiphysics软件进行数值求解。模拟结果与试验值吻合良好,表明所建立的模型可用于预测其他条件下的穿透曲线。     

低浓度三氯乙烯活性炭吸附净化及数值模拟

对低浓度三氯乙烯在活性炭固定床中的吸附净化作了系统研究。测定了三氯乙烯-空气-活性炭系统吸附等温线及在40×120mm活性炭固定床中穿透曲线;建立了三氯乙烯活性炭固定床吸附数学模型并用此预测了穿透曲线,实验与计算结果对比表明模型预测与实验结果吻合良好。     

载金属离子的13X分子筛吸附噻吩的动态特性

采用13X分子筛及负载Cu2 、Zn2 、Ni2 、Ag 的13X分子筛等五种吸附剂,对噻吩进行动态吸附特性研究.在φ10.5 mm×200 mm的吸附柱测定了五种吸附剂吸附正己烷溶液中的噻吩的穿透曲线.采用加热法对Zn2 -13X、Ni2 -13X、Ag -13X三种吸附剂进行再生,测定了再生后吸附剂的穿透曲线,对吸附剂再生前后的吸附性能进行了比较.结果表明Ag -13X吸附性能优于其它吸附剂,其对噻吩的吸附容量为60.20 mg·g-1.再生后的Ag -13X对噻吩仍有很好的吸附能力,吸附容量相比新鲜吸附剂的仅下降了5%.穿透点以前出口噻吩含量为0.这些结果为工业吸附装置的设计提供了必要的吸附数据.     

5A分子筛分离工业异己烷中低含量正己烷

采用5A分子筛对工业异己烷进行吸附分离,既可纯化异己烷,又可得到高纯的正己烷。测定了吸附穿透曲线,分析了吸附温度对穿透吸附量、传质区长度以及床层利用率的影响,探讨了水置换法脱附再利用吸附剂的方法。试验结果表明:常压下,在60~90℃,5A分子筛对正己烷的吸附穿透曲线均为"S"型;70℃时正己烷的穿透吸附量及饱和吸附量最高;对于低浓度正己烷,温度对吸附传质区长度、床层利用率影响不大;采取水置换脱附法可以有效多次再生5A分子筛。5A分子筛对2-甲基戊烷、3-甲基戊烷吸附作用很小,吸附分离中异己烷的损失量小。     

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。