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1.
为了研制用作温热治疗癌症的铁磁体微晶玻璃热种子材料,制备了一组化学组成为40Fe2O3xCaO(60-x)SiO23B2O33P2O5玻璃(x=20、25、30、35质量分数),用XRD、DTA、VSM对其核化与晶化过程进行了研究.研究发现,钙铁硅微晶玻璃在还原气氛下热处理后,除了磁铁矿和硅灰石及少量赤铁矿晶相外,还会出现钙铁辉石、方石英晶相.钙硅比较小的玻璃,热处理温度-时间相图中钙铁辉石相区范围较大;钙硅比较大的,钙铁辉石相区范围较小.另外,钙硅比不同,玻璃的成核机理、开始析出磁铁矿的温度也不同.  相似文献   

2.
钙硅比对钙铁硅铁磁体微晶玻璃核化与晶化的影响   总被引:1,自引:0,他引:1  
为了研制用作温热治疗癌症的铁磁体微晶玻璃热种子材料,制备了一组化学组成为40Fe2O3xCaO(60-x)SiO23B2O33P2O5玻璃(x=20、25、30、35质量分数),用XRD、DTA、VSM对其核化与晶化过程进行了研究.研究发现,钙铁硅微晶玻璃在还原气氛下热处理后,除了磁铁矿和硅灰石及少量赤铁矿晶相外,还会出现钙铁辉石、方石英晶相.钙硅比较小的玻璃,热处理温度-时间相图中钙铁辉石相区范围较大;钙硅比较大的,钙铁辉石相区范围较小.另外,钙硅比不同,玻璃的成核机理、开始析出磁铁矿的温度也不同.  相似文献   

3.
钙铁硅铁磁体微晶玻璃热处理气氛的研究   总被引:4,自引:0,他引:4  
使用XRD,DTA,VSM和穆斯堡尔谱等分析测试手段,对不同气氛下晶化热处理的含水量的B2O3,P2O5钙铁硅微晶玻璃的晶相结构和性质进行了比较深入的研究,研究结果表明,在氧化性气氛下热处理的钙铁硅微晶玻璃以赤铁矿为主;必须在还原性气氛下热处理才能得到以磁铁矿为主要晶相的铁磁体微晶玻璃。  相似文献   

4.
本文设计了Na2O-CaO-SiO2-MgO-Al2O3-ZnO体系,采用熔融法制备了以磷渣为主要原料的微晶玻璃,磷渣在微晶玻璃中的使用率达到67~75%,并利用XRD,SEM等确定了玻璃的最佳热处理制度,研究了Na2O对微晶玻璃析晶及特征的影响.结果发现经过 750 ℃核化4 h,850 ℃晶化2 h,得到主晶相为硅灰石(CaSiO3)和菱硅钙钠石(Na2Ca2Si3O9)的微晶玻璃.玻璃中表面析晶和整体析晶同时存在,其中Na2O可促进整体析晶和菱硅钙钠石的析出.  相似文献   

5.
采用高纯的SiO2、Al2O3、KNO3、Na2CO3、CaCO3及CaF2熔融制备了组成为8.4Na2O 1.3Al2O3 5K2O 10.8CaO 64SiO2 10.5 CaF2的硅碱钙石微晶玻璃,采用热力学计算及DTA,XRD和SEM等技术手段对其热处理过程中硅碱钙石和硬硅钙石晶相间的竞争和转变进行研究。经550℃热处理1h后,母体玻璃中有氟化钙晶相析出;在700℃下热处理1h后析出硬硅钙石晶相;在750~850℃下热处理1h后主晶相转变为硅碱钙石。经在700℃下延长微晶玻璃的热处理时间,观察到由硬硅钙石向硅碱钙石的晶相转变。这一转变趋势得到热力学计算的验证。  相似文献   

6.
在不同条件下对摩尔组分为 3Na2 O 12TiO2 5 7CaO 2 8P2 O5玻璃进行热处理 ,研究其热处理条件与微晶玻璃的 β Ca2 P2 O7晶相含量和生物活性的关系。实验结果表明 :该组成玻璃经热处理后 ,可以获得含有 β Ca2 P2 O7,CaTi4(PO4) 6 ,NaTi2 (PO4) 3和TiP2 O7晶相的微晶玻璃 ,β Ca2 P2 O7为主晶相。随着成核温度提高和成核时间的延长 ,β Ca2 P2 O7晶相在微晶玻璃中含量增加。含较多 β Ca2 P2 O7晶相的微晶玻璃有较强的生物活性 ,主要是由于 β Ca2 P2 O7晶相有较强的促进生物活性的能力 ,因而使微晶玻璃有较强的生物活性 ,其结果是改变微晶玻璃的热处理条件就改变了微晶玻璃的生物活性  相似文献   

7.
陈建  马鸿文  蒋周青  张盼 《硅酸盐通报》2016,35(9):2898-2903
以高铝粉煤灰提铝硅钙尾渣为主要原料,采用烧结法制备了硅灰石微晶玻璃。利用DTA、XRD和SEM分析方法研究了热处理制度、硅钙渣用量对微晶玻璃的晶化过程、显微结构及物化性能的影响。结果表明:核化时间与晶化时间的延长有助于硅灰石晶体的定向生长与紧密排列,对微晶玻璃的力学性能影响显著,而晶化温度与核化温度的影响则相对较小;随着硅钙渣的用量增加,微晶玻璃中硅灰石的析出能力增强,当其用量为70.98%,在800℃下核化热处理90 min,920℃晶化处理90 min时,可制备出单一晶相的硅灰石微晶玻璃。  相似文献   

8.
热处理对磷酸钙微晶玻璃中β-Ca2P2O7晶相含量的影响   总被引:3,自引:0,他引:3  
在不同条件下对摩尔组分为3Na2O-12TiO2-57CaO-28P2O5玻璃进行热处理,研究其热处理条件与微晶玻璃的β-Ca2P2O7晶相古量和生物活性的关系。实验结果表明:该组成玻璃经热处理后,可以获得含有β-Ca2P2O7,CaTi4(PO4)6,NaTi2(PO4)3和TiP2O7晶相的微晶玻璃,β-Ca2P2O7为主晶相。随着成核温度提高和成核时间的延长,β-Ca2P2O7晶相在微晶玻璃中含量增加。含较多β-Ca2P2O7晶相的微晶玻璃有较强的生物活性,主要是由于β-Ca2P2O7晶相有较强的促进生物活性的能力,因而使微晶玻璃有较强的生物活性,其结果是改变微晶玻璃的热处理条件就改变了向微晶玻璃的生物活性。  相似文献   

9.
通过两步法制备Li2O-Zn O-Al2O3-Si O2(LZAS)系微晶玻璃,并通过正交实验探究不同热处理工艺参数对微晶玻璃致密化的影响,使用P2O5作为晶核剂。结果表明;玻璃转化温度为492℃,析晶温度为560℃和714℃,材料软化点为685℃。各参数对微晶玻璃致密化的影响顺序为晶化温度晶化时间核化温度核化时间;析晶量主要受晶化温度和晶化时间影响;当温度为560℃时,开始有少量晶体析出,当温度超过580℃,主晶相为锂辉石,并且还有少量锂霞石;锂辉石的增多导致材料致密度下降。  相似文献   

10.
穆斯堡尔谱在钙铁硅铁磁体微晶玻璃研究中的应用   总被引:3,自引:0,他引:3  
应用穆斯堡尔谱来研究钙铁硅铁磁体微晶玻璃中氧化铁的适宜允许含量、熔制条件、热处理气氛和晶化过程。结果表明,穆斯堡尔谱对于准确地研究钙铁硅微晶玻璃形成、热处理过程中铁离子的价态、配位、结构情况具有重要价值,与XRD等其它方法的研究结果相比可以得到更多的信息。  相似文献   

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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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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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