H2S燃料电池用质子传导膜及电池性能

研究了H2S燃料电池用的质子传导膜的制备及性能,考察了不同的Li2SO4与填充物Al2O3的匹配、微量元素B(H2BO3)的掺杂对膜及电池性能影响.研究了由H2S、(MoS2+NiS)/Li2SO4-Al2O3/pt、air构成的燃料电池在101.13kPa和600～700℃C时的电化学特性.在实验温度范围内,质子传导膜Li2SO4-Al2O3及整个电池系统在H2S气流下具有较好的化学稳定性.温度提高,质子传导膜的内阻减小,膜及电池性能变好.微量元素B的掺杂提高了膜的机械强度及膜的致密性,从而改善了电池的性能.在实验条件下,较适宜的B的掺杂量为2%～5%(质量百分数),较适宜的Li2SO4Al2O3(质量比)为(3～5)1,电池最大输出电流密度和功率密度在700℃时分别达到200mA.cm-2和55mW.cm-2.     

电纺EVOH磺酸锂/TiO_2聚合物电解质电性能的研究

将纳米二氧化钛加入到EVOH-SO3Li中制备纺丝液,利用高压静电纺丝法制备EVOH-SO3Li/TiO2复合膜。组装扣式电池,测试EVOH-SO3Li/TiO2聚合物电解质的电化学稳定窗口及离子电导率。结果表明:复合薄膜的电化学性能稳定,离子电导率达到0.96×10-3s/cm。     

含氟聚芴醚噁二唑质子交换膜的性能

将十氟噁二唑和双酚芴作为聚合物单体制备了一种新型的偏氟聚芴醚噁二唑质子交换膜。通过加入4-羟基磺酸钠进攻十氟噁二唑邻位的C—F键引入官能基团探究了膜的制备方法。研究了膜的物理、电化学性能并组装了燃料电池单电池。实验结果表明:该膜具有较高的离子传导率、较强的机械性能及低的甲醇渗透率。30℃时,传导率为58mS·cm-1,70℃,传导率达到了137 mS·cm-1。甲醇渗透率是Nafion117膜的1/2,在100℃时,单电池的功率达到85mW·cm-2。     

高性能PVDF/SiO_2@HPA复合膜在全钒液流电池中的应用

以聚偏氟乙烯(PVDF)多孔膜为基质,采用原位凝胶溶胶合成二氧化硅负载磷钨酸(Si O2@HPA)纳米粒子的方法对多孔膜进行修饰。分别用扫描电子显微镜、电化学工作站、充放电测试仪等仪器对膜的结构、电化学性能进行表征。结果表明:与空白的PVDF相比,经过纳米粒子修饰的复合膜的钒离子选择性得到明显提高。在不同的电流密度下,修饰后的复合膜的充放电效率都高于未修饰PVDF多孔膜,并且在40m A·cm-2的电流密度下,复合膜的能量效率提高了17.6%。在80 m A·cm-2的电流密度下,用PVDF/Si O2@HPA组装的电池在100圈的循环测试中保持较好的稳定性。     

微/纳多级结构LiMn2O4微米球在水系锂离子电池中的应用

通过750℃煅烧由共沉淀法制得的碳酸盐前驱物,制备出由粒径为30~40 nm的纳米粒子组装的直径为600~900 nm的微/纳多级结构LiMn2O4微米球。将这种LiMn2O4多孔微米球作为水系锂离子电池电极材料,在2M Li2SO4水溶液中具有优良的倍率性能,在1 A g-1,1.5 A g-1,2 A g-1和2.5 A g-1的电流密度下,其放电容量均在110 mAh g-1左右,当电流密度增至5 A g-1,其放电容量还能保持在71 mAh g-1。     

Al_2O_3包覆锂电池正极材料LiMn_2O_4的合成及电化学性能研究

研究了在锂离子电池尖晶石Li Mn2O4正极材料上包覆Al2O3来改善材料在循环过程中的容量衰减问题。通过SEM和X射线衍射研究材料的表观形貌和晶体结构。在电化学性能测试中,发现包覆Al2O3可以减少材料与电解液的直接接触,阻止了电解液对尖晶石的侵蚀,最终有效地改进锂电池正极材料Li Mn2O4的电化学性能。     

五氧化二钒电解制备全钒液流电池V3+电解液

电解液的质量直接决定了全钒液流电池的储电能力。为了降低全钒液流电池的生产成本,在国内首次采用流动型电解槽电解还原法,研究了采用相对廉价的五氧化二钒(V2O5)代替价格昂贵的硫酸氧钒(VOSO4)为原料制备全钒液流电池电解液的制备技术;研究了阳极电极材料、电解电流密度等对制备电解液的影响因素;并通过循环伏安、交流阻抗和充放电测试分析和比较由两种原料制备的电解液的电化学性能。实验结果表明:以Ru Ir/Ti为阳极,多孔铅板为阴极,3 mol·L-1 H2SO4为阳极电解液,1.5 mol·L-1 V2O5+3 mol·L-1 H2SO4粉末混合溶液为阴极电解液,40 m A·cm-2恒流电解得到的电解液不但具有良好的电化学活性和可逆性,且电流效率高和电能损耗低,完全可以满足全钒液流电池的工作需求。     

表面包覆对LiNi0.5Mn1.5O4电极材料循环性能改善研究

能量密度是判断锂离子电池技术用于混合动力汽车(HEV)和插电式混合动力汽车(PHEV)应用的关键参数,因此增加锂离子电池中的插层化合物的容量有利于提高锂电池的能量密度.采用氧化物涂层来抑制电解质与LiNi0.5Mn1.5O4正极材料的氧化副反应.由于纳米Al2 O3不活泼且不能插入或提取锂离子,Al2O3导致LiNi0.5Mn1.5O4电极容量降低.在1 C下经过40次充放电循环后,涂覆有5％纳米Al2O3的LiNi0.5Mn1.5O4具有72.94％容量保持率,结果表明纳米Al2O3涂层对于改善LiNi0.5Mn1.5O4材料的循环性能没有显著影响.     

复合电解质SrCe0.9 Yb0.1 O3-α-LiCl-KCl的制备及其中温电性能研究

选择具有优良质子导电性的SrCe0.9 Yb0.1 O3-α与碱金属盐共熔体LiCl-KCl进行复合.制备复合电解质SrCe0.9 Yb0.1 O3-α-LiCl-KCl所用的温度(420℃)比制备SrCe0.9 Yb0.1 O3-α的温度(1500℃)显著降低.X射线衍射结果表明SrCe0.9 Yb0.1 O3-α和LiCl-KCl复合没有发生反应生成新物质.采用电化学工作站研究了单一SCYb电解质和复合SCYb-LK电解质在各种气氛中400~600℃下的电导率.结果表明,温度为600℃时,复合SCYb-LK电解质在湿润氮气气氛中的电导率为8.6×10-2 S·cm-1,复合SCYb-LK电解质的活化能远低于单一SCYb电解质.H2/O2燃料电池性能测试表明SrCe0.9 Yb0.1 O3-α-LiCl-KCl在600℃最大输出功率密度为113 mW·cm-2,是SrCe0.9 Yb0.1 O3-α在700℃相同条件下的7倍.     

钠离子电池Fe2O3/CNF负极材料的制备与研究

为了获得具有一定柔性和较好电化学性能的钠离子电池负极材料,采用静电纺丝和碳化工艺制备Fe2O3/碳纳米纤维(Fe2O3/CNF)纳米纤维膜,用于钠离子电池(SIBs)柔性负极材料.通过扫描电镜、TGA测试、元素分析、Raman测试、XRD测试、电池充放电性能测试研究碳化前后Fe2O3/CNF纳米纤维膜的形貌结构及电化学...     

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。