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1.
以甲酸废水为原料,考察不同工艺条件对氢氧化钙法和碳酸钙法制取甲酸钙的影响。以废水中甲酸的去除率、产品产率、产品甲酸钙的含量为考察指标,确定了制取甲酸钙的最佳工艺条件。采用单因素条件实验法,氢氧化钙法分别考察了浓缩方式、反应时间、浓缩比例、结晶时间对实验结果的影响,碳酸钙法分别考察了投料比、反应温度、反应时间对实验结果的影响。  相似文献   

2.
采用油酸和氢氧化钙通过一步法直接合成了油酸钙皂,考察了油酸与氢氧化钙质量比、矿物油用量、反应温度、反应时间等因素对合成的油酸钙中钙质量分数和体系黏度的影响。同时采用红外光谱对合成的油酸钙结构进行了表征。结果表明:在油酸与氢氧化钙质量比为1.14∶1、矿物油用量为油酸的37%、加热温度90℃、加热时间3 h的工艺条件下,得到的油酸钙中钙的质量分数为3.73%,黏度为186.5 mPa·s。合成的油酸钙能够作为钙锌稳定剂原料,通过与有机助剂复配,制备出钙锌热稳定剂,用于PVC树脂加工成型过程中,以替代对环境和人体有害的铅、镉盐类稳定剂。  相似文献   

3.
饲料级磷酸氢钙中钙含量偏高的原因   总被引:1,自引:0,他引:1  
通过不同温度下的烘干、灼烧实验 ,分析饲料级磷酸氢钙中钙含量偏高的主要原因是产品结晶水含量少 ,仅 0 .3个结晶水。取消中和槽蒸汽加热 ,保持常温反应 ;改闪蒸干燥为气流干燥 ;用氢氧化钙作中和剂 ;使饲钙产品中钙含量由平均约 2 8%降至 2 2 %。  相似文献   

4.
目前,多数分析方法难以计算工业氢氧化钙中氧化钙、氢氧化钙和碳酸钙的含量。将蔗糖滴定法和热重分析相结合,对工业氢氧化钙中的氧化钙、氢氧化钙和碳酸钙做了分析。采用GB/T 5762—2012《建材用石灰石、生石灰和熟石灰化学分析方法》测定氢氧化钙中有效钙的含量。根据氢氧化钙和碳酸钙分解温度的差异,使用热重分析测定工业氢氧化钙中氢氧化钙和碳酸钙的含量。之后,将有效钙中的氢氧化钙部分扣除并换算,得到氧化钙的含量。实验得到氧化钙、氢氧化钙和碳酸钙这3种物质的含量,其余部分为杂质。该方法具有操作相对简单、测定成分种类较多的优点。  相似文献   

5.
过氧化钙的常温制备   总被引:2,自引:0,他引:2  
选用氢氧化钙法制备过氧化钙,即采用氢氧化钙过量的方法,在常温下,以氢氧化钙和双氧水为原料,以磷酸二氢钠为稳定剂.选用高锰酸钾法检测产物中过氧化钙的含量.考察单因素对产物过氧化钙含量和产率的影响,得出最佳的制备条件是:氢氧化钙的过量系数为15%,反应时间为15min,加水量是45mL,稳定剂的用量为0.40g,此时,过氧化钙的含量可达到73%,产率达到77%.  相似文献   

6.
煤热解特性研究   总被引:17,自引:7,他引:17  
对大雁、协庄和昔阳3个不同煤化程度的煤样,在N2,CO2和水蒸气3种不同气氛及不同温度下进行了热解研究,考察了煤化程度、热解气氛和热解温度对煤热解产物产率和热解气性质的影响规律.研究表明,对上述3个煤样,随煤化程度加深,焦产率增加,油和气产率一般随煤中挥发分增加而增加,但又与煤的大分子结构、热解温度和加热速率等有密切关系;干馏气组成H2和CH4含量协庄煤样最高,而(CO CO2)含量因煤中氧含量的降低而下降.与N2气氛相比,CO2和水蒸气气氛中半焦产率下降,气产率增加;油产率水蒸气气氛下最高.H2组分含量在水蒸气气氛下最高,而CO,CH4和烃类C2~C5组分则最低.LHV在N2,CO2和水蒸气气氛下逐次降低.  相似文献   

7.
张宁 《陕西化工》2013,(11):1997-2001
采用沉淀.浸渍法制备了复合不同Ce摩尔含量的稀土固体超强酸Sz0827ZrO2-CeO2,研究了其在花生壳水解制备乙酰丙酸反应中的催化效果,考察了水解温度、水解时间、固体酸用量和液固比(mL/g)对乙酰丙酸产率的影响。实验发现,ce含量为4%的固体酸催化性能最佳,最佳工艺条件为:水解温度243℃,水解时间35min,固体酸用量5.2%。在此条件下,乙酰丙酸产率为35.86%。  相似文献   

8.
混凝剂复配处理山梨酸废水的实验研究   总被引:1,自引:0,他引:1  
选用氢氧化钙复配聚丙烯酰胺对山梨酸废水进行了预处理,考察了混凝剂用量、温度、搅拌时间等因素对CODcr去除率的影响。结果表明:在氢氧化钙用量为16g/L、聚丙烯酰胺用量为5mg/L、混凝温度50℃、搅拌时间3min时,CODcr去除率可达43.1%。氢氧化钙复配聚丙烯酰胺的混凝效果明显优于氢氧化钙和聚丙烯酰胺单独使用时的效果,并且可显著缩短絮体沉降时间。  相似文献   

9.
张育民  仲剑初  王洪志 《硅酸盐通报》2011,30(3):705-709,713
以硼酸和氢氧化钙为原料,在硼酸和氢氧化钙物质的量比为4:1和反应温度160℃的条件下,水热反应4 h合成出一种硼酸钙.对合成产物进行了化学成分、X射线衍射、粒度、热重、扫描电镜等表征,结果表明产物为单一物相的白硼钙石(4CaO·5B2O3·7H2O).以硬脂酸钠为改性剂对白硼钙石进行湿法改性,考察了硬脂酸钠的用量等因素...  相似文献   

10.
以双氧水和甘油为复合催化剂,实现了硬脂酸与氢氧化钙在水介质中一步合成硬脂酸钙。固定双氧水和甘油用量,考察反应温度、固液比和反应时间等对反应的影响。结果表明,在双氧水用量8%、甘油用量10%、反应温度60℃、固液比1:10、反应时间2.5 h的优化条件下,产品的游离酸含量为0.20%。  相似文献   

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12.
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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14.
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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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.
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   

19.
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   

20.
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   

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