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1.
比较不同NaCl、Ca2+、PO3-4等离子浓度对嗜盐隐杆藻(Aphanothecehalophytica)细胞生长及胞外多糖(Exopolysac-charideEPS)产量的影响。在各影响因子不同浓度的培养条件下,0.5mol/L的NaCl、1.0g/L的Ca(NO3)2·4H2O、0.1g/L的KH2PO4分别是其最佳生长浓度。EPS的产量在0.5mol/LNaCl、,0.5g/LCa(NO3)2·4H2O、0.5g/L的KH2PO4培养条件下最高。在较低的Ca2+、Mg2+、PO3-4浓度下可提高EPS产率。 相似文献
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液膜分离富集汞与测量痕量汞 总被引:4,自引:0,他引:4
有D2EHPA,TOA,兰13A和煤油乳状液膜体系,研究了Hg^2+的迁移富行为,适宜条件下,Hg^2+,的迁移率达99.7%以上,在此条件下,许多共存离子如Cu^2+,Pb^2+,Zn^2+,Sn^4+,Co^2+,Ni^2+,Cd^2+,∑RE^3+,Ca^2+,Mg^2+,Al^3+,Fe^3+和Mn^2+等都不被迁移,只有Hg^2+能与这些离子得到很好的分离。已成功地应用于测定水和工业废水 相似文献
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金—钼酸盐—丁基罗丹明B体系显色反应研究 总被引:4,自引:0,他引:4
研究了在高氯酸和聚乙烯醇(PVA)存在下,金与钼酸盐和丁基罗丹明B(BRB)的显色反应。其适宜条件CHClO4=1.5mol/L,CMoO2-4=9.1×10-4mol/L,CBRB=3.8×10-5mol/L及0.08%PVA。金钼杂多酸—丁基罗丹明B离子缔合物的最大吸收位于570nm,表观摩尔吸光系数为3.36×106L·mol-1·cm-1,金量在0~40μg/L范围内服从比尔定律,测定极限(S/N=3)0.90μg/L(n=10),对于28μgAu(Ⅲ)/L测定的相对标准偏差2.1%(n=7)。缔合物至少可稳定5h,摩尔比Au∶BRB=1∶3。考察了44种共存离子的影响,大多数常见离子不干扰,用活性炭分离富集金,对砂矿和炭粉中金的测定,结果满意。 相似文献
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在聚乙烯醇(PVA)存在下,耐尔蓝(NB)与铈钼、钪钼杂多酸络阴离子形成离子缔合物,其最大吸收均位于585nm,表观摩尔吸光度分别为εcw=3.52×106和εSc=3.59×10_5L·molˉ1·cmˉ1,铈和钪服从比耳定律的浓度范围分别为0~0.8μg/25ml和0~2.0μg/25ml,测定极限分别为1.3ngCe/ml(n=10)和3.0ngSc/ml(n=7),对于0.02μgCe/ml或0.04μgSc/ml测定的相对标准偏差分别为2.7%(n=9)和2.8%(n=10),离子缔合物的摩尔比分别为Ce:Mo:NB=1:6:4和Sc:Mo:NB=1:12:3。本法用于地质标样分析,结果满意。 相似文献
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以AS4A-SC为色谱柱,2.0mmol/L碳酸钠为淋洗液,流速为2.00mL/min,检测器量程为30μs,进样体积为50μL,对洗涤剂中乙二胺四乙酸(EDTA)、磷酸盐(PO3-4)及氯离子(Cl-)、硝酸根(NO-3)、硫酸根(SO2-4)同时测定,它们的线性关系比较好,相关系数大于0.9965,9次平行测定的相对标准偏差为0.51%~2.95%,对EDTA和PO3-4的测定回收率分别为106.5%和98.5%。 相似文献
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王新德 《陶瓷研究与职业教育》1994,(2)
在合成的(Ba0.65Pb0.35)TiO3中分别掺入了Al2O3,SiO2,La2O3,MnO2和TiO2.讨论了每种掺杂物与烧成气氛和升温制度对常温电阻率的影响,找出了PTC陶瓷的最佳组成;1mol(Ba0.65Pb0.35)TiO3,0.002molAl2O3,0.004molSiO2,0.01molTiO2,0.003molLa2O3,0.0002molMnO2.这种PTC陶瓷的表面温度为270℃,常温电阻率为5~8×103Ω·cm,时任性为240v/mm. 相似文献
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在氯酸锂电解液中,用硫酸亚铁使氯酸盐还原,当pH=3~4时,用苯萃取LiClO4灿烂绿络合物,测定了高氯酸锂。在25mL萃取液中,LiClO4于2~100μg范围内遵守比尔定律。大量Na+,K+,Mg2+,Pb2+,Mn2+,Fe3+,F-,Cl-,SO2-4,CH3COO-和少量的CrO2-4不影响测定。该法也可用于氯酸盐产品中微量高氯酸根的测定 相似文献
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采用硫酸作溶剂,高压密封溶解99.99%Al2O3,以电感偶合等离子体发射光谱(ICP/AES)测定高纯Al2O3中痕量杂质元素(Ca,Mg,Fe,Mn,Cu,Si,Na)含量。方法加标回收率89%~107%,相对标准偏差4.6%~8.4%。该法具用溶样简便、无污染、基体干扰小、数据可靠、能同时测定多种元素等优点。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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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. 相似文献
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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. 相似文献
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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. 相似文献
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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。 相似文献