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1.
电感耦合等离子体发射光谱法测定水中微量磷的研究   总被引:1,自引:0,他引:1  
用ICP-AES法测定水中磷,讨论并确定了试验的最佳测定条件,在选定的最佳条件下测磷的检出限为0.02mg/L,回收率为96.5%-102.1%,RSD为1.65%-2.83%。该法准确、快速、简便,应用于水中磷的测定,结果满意。  相似文献   

2.
微波加热法测定土壤中有机质含量   总被引:2,自引:0,他引:2  
应用微波加热法对土壤中有机质含量进行测定。分析了分析测定条件,方法简便、快速。应用于土壤样品测定,结果的相对偏差为1.20%,加标回收率为95.45%-101.01%。  相似文献   

3.
应用氢化物发生一原子荧光光谱(HGAFS)法,用L-半胱氨酸预还原法,对石材中砷进行了分析。讨论并确定了实验的最佳测定条件,结果表明,砷的检出限为0.058μg/g,回收率为92.67%~104.88%,相对标准偏差为0.6%。该法准确、快速、简便,应用于石材中砷的测定.结果满意。  相似文献   

4.
谢华林 《佛山陶瓷》2003,13(10):39-40
采用高频熔样、电感耦合等离子体原子发射光谱(ICP—AES)法实现了对陶瓷中的Mg、Ca、Fe、Al、Ti和Zr的同时测定。对影响其光谱测量的各种因素进行了较为详细的研究,确定了实验的最佳测定条件。结果表明,方法的检出限为0.008—0.255μg/mL,回收率为95.14%--107.72%,RSD小于3.40%。该法准确、快速、简便,应用于陶瓷的测定,结果满意。  相似文献   

5.
ICP-MS法测定陶瓷容器中重金属元素的研究   总被引:2,自引:0,他引:2  
采用电感耦合等离子体—质谱(ICP—MS)法同时测定了陶瓷容器中重金属元素PB、CA、Cr、Ni,对影响其测量的各种因素进行了较为详细的研究,确定了实验的最佳测定条件。结果表明,方法的检出限为0.002—0.008μg/L,回收率为90.0%-110.0%,RSD小于9.21%。该法准确、快速、简便,应用于陶瓷容器中重金属元素的测定,结果满意。  相似文献   

6.
ICP-AES法同时测定陶瓷样品中镁钙铁铝钛锆的研究   总被引:2,自引:0,他引:2  
谢华林 《山东陶瓷》2003,26(5):20-22
采用高频熔样,电感耦合等离子体原子发射光谱(ICP—AES)法实现了对陶瓷中的Mg、Ca、Fe、Al、Ti和Zr的同时测定。对影响其光谱测量的各种因素进行了较为详细的研究,确定了实验的最佳测定条件。结果表明,该方法的检出限为0.008-0.255μg/mL,回收率为95.14%-107.72%,RSD小于3.40%。该法准确、快速、简便,应用于陶瓷的测定,结果满意。  相似文献   

7.
原子荧光光谱法测定涂料中痕量砷和锑   总被引:3,自引:1,他引:2  
谢华林  刘宏伟 《涂料工业》2003,33(10):50-51
采用氢化物发生-原子荧光光谱法,用L-半胱氨酸预还原法,测定了涂料中痕量砷和锑。讨论并确定了最佳的测定条件。试验结果表明,砷和锑的检出限分别为0.058μg/L和0.075μg/L,回收率为98.5%~100.3%,相对偏差分别为0.6%和0.9%。该方法准确、快速、简便,结果令人满意。  相似文献   

8.
采用高频熔样,电感耦合等离子体原子发射光谱(ICP-AES)法实现了对陶瓷中的Mg、Ca、Fe、Ti和Zr的同时测定。对影响其光谱测量的各种因素进行了较为详细的研究,确定了实验的最佳测定条件。结果表明,方法的检出限为0.008—0.255μg/ml,回收率为95.14—107.72%,RSD小于3.40%。该法准确、快速、简便,应用于陶瓷的测定,结果满意。  相似文献   

9.
氯化亚锡-甲基橙容量法测定硫铁矿和硫精矿中全铁含量   总被引:1,自引:0,他引:1  
周成洪  杨清群 《当代化工》2010,39(1):98-99,114
确定了用氯化亚锡一甲基橙容量法测定硫铁矿和硫精矿中全铁含量的最佳测定条件,操作简便,条件易控制,对环境无汞污染。RSD为0.65%,结果稳定可靠。经大量试验证明,采用此法测定,方便快速,结果令人满意。  相似文献   

10.
粉煤灰全组分化学元素同时测定的研究   总被引:1,自引:0,他引:1  
采用偏硼酸锂熔样,电感耦合等离子体原子发射光谱法对粉煤灰实现了一次熔样,全组分同时分析。对影响其光谱测量的各种因素进行了较为详细的研究,确定了实验的最佳测定条件,结果表明,方法的检出限为0.009~0.831μg/mL^1,回收率为91.54%~104.45%,相对标准偏差小于3.22%。该法准确、快速、简便,应用于粉煤灰中全组分的测定,结果满意。  相似文献   

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Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.  相似文献   

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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   

15.
2008~2009年世界塑料工业进展   总被引:4,自引:1,他引:3  
收集了2008年7月~2009年6月世界塑料工业的相关资料,介绍了2008~2009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、环氧树脂、不饱和聚酯树脂)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   

16.
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   

17.
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   

18.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  相似文献   

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