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1.
用铝铬渣和转炉用后镁碳砖细粉为主要原料,通过固相烧结反应合成MgAl2O4材料.用X射线衍射、扫描电镜及X'Pert plus软件对材料中主晶相进行表征.结果表明:当烧成温度为1 400℃,镁碳砖与铝铬渣摩尔比为5∶1时,生成的镁铝尖晶石晶粒发育完整清晰,排列致密,外貌呈典型的八面体形貌.镁铝尖晶石质量百分数达到92%.  相似文献   

2.
采用水热法在180℃下合成纳米级的尖晶石相的Ni0.6Zn0.4Fe2O4铁氧体材料,在空气中退火温度分别为600、800、1000℃.使用X射线衍射(XRD)、红外光谱(FTIR)、扫描电镜(SEM)和振动样品磁强计(VSM)分别表征NiZn铁氧体纳米粉体的相组成、微结构以及磁性能.XRD衍射谱和FTIR谱表明:未退火和退火的纳米晶NiZn铁氧体皆为单一尖晶石相;退火温度对晶格常数基本无影响,主要提高了致密度以及使晶粒尺寸得到长大;样品的饱和磁化强度随着退火温度的提高逐渐增大到1 000℃时的58.75 emu/g;样品的矫顽力与未退火的样品相比,先增加后减小,其矫顽力主要取决于样品的微结构.  相似文献   

3.
采用拉曼光谱和红外光谱结合X线衍射和透射电子显微镜等技术探讨SiO2-Al2O3-ZrO2(SAZ)玻璃的热相转变过程。研究结果表明:SAZ玻璃经900℃热处理2 h后仍为典型非晶,其拉曼峰位于460,600和800 cm-1左右,峰形宽,强度弱,从900~920℃开始分相,形成富Si区和富Zr和Al区,拉曼峰强度随温度升高而增大,且在148 cm-1和300 cm-1附近出现2个峰值;当温度升高至1 000℃时,四方氧化锆拉曼特征峰已很明显,表明四方氧化锆已形成,且在XRD谱中观察到Al-Si尖晶石相并有莫来石晶相开始生成;当温度进一步升高时,四方氧化锆的拉曼峰更明显,同时在180~270,350~440和970~1 020 cm-1区域间出现拉曼峰,峰形尖锐,强度大,表明结晶完好;XRD谱中Al-Si尖晶石相消失,四方氧化锆、莫来石成为主晶相,同时生成了少量方石英。  相似文献   

4.
以电熔镁砂、铁粉、氧化铁粉和α-Al2O3粉为原料,制备方镁石-铁铝尖晶石砖,研究了烧结温度和铁加入量对方镁石-铁铝尖晶石砖性能的影响,采用XRD和SEM对试样的物相组成和显微结构进行了分析和表征.结果表明,提高烧结温度有利于方镁石-铁铝尖晶石砖性能的提高,1500℃烧成的试样最致密,综合性能较好,增大铁加入量不利于方镁石-铁铝尖晶石砖性能的提高.与直接结合镁铬砖相比,方镁石-铁铝尖晶石砖的常温耐压强度、抗折强度和热震稳定性较好,挂窑皮性和抗侵蚀性与其相近.  相似文献   

5.
以高纯镁砂、高铁镁砂、铁铝尖晶石砂、镁铝尖晶石为原料,于1600℃烧成制备了方镁石-复合尖晶石试样,研究不同镁铝尖晶石对试样性能的影响,采用SEM观察和分析了V2O5气氛侵蚀后试样的微观形貌。结果表明:添加75MA和90MA的试样,显气孔率随着尖晶石含量的增加先增加后降低;添加66MA的试样,显气孔率随着尖晶石含量增加而增加;添加三种尖晶石的试样,耐压强度、高温抗折强度均随着尖晶石含量增加而降低;添加12%75MA和90MA试样的热震稳定性好于添加66MA的试样;添加90MA的试样,尖晶石含量越高,试样的抗侵蚀性越好;添加66MA尖晶石的试样,尖晶石含量越高,试样的抗侵蚀性越差;当试样中MA含量相同时,Al2O3含量越高,试样的抗V2O5侵蚀性越好。  相似文献   

6.
采用射频等离子体增强化学气相沉积系统(RF-PECVD)以高纯SiH4为气源在P型〈100〉晶向单晶硅片上、衬底温度600℃、射频(13.56MHz)电源功率50W时沉积非晶硅薄膜,利用高温真空退火制作纳米晶粒多晶硅薄膜。采用X射线衍射仪(XRD)、Raman光谱、AFM测量和分析薄膜微结构及表面形貌,实验结果表明,退火温度为800℃时非晶硅薄膜晶化,形成择优取向为〈111〉晶向的多晶硅薄膜;退火温度增加,Raman谱TO模和TA模强度逐渐减弱;AFM给出800℃退火后薄膜晶粒明显细化,形成由20~40nm大小晶粒组成的多晶硅薄膜,薄膜晶粒起伏程度明显减弱。  相似文献   

7.
晶化温度对堇青石玻璃陶瓷结构及性能的影响   总被引:2,自引:0,他引:2  
采用DTA、XRD、SEM以及红外光谱等先进的测试技术,结合样品性能的测试,分析了晶化温度对堇青石玻璃陶瓷结构及性能的影响. 结果表明,样品主晶相为α-堇青石相,随晶化温度的提高,α-堇青石相析出量增加,样品强度增大,热膨胀系数减小,但当温度超过1 000 ℃后,晶化温度对样品结构和性能的影响较小;本实验确定堇青石玻璃陶瓷最佳晶化温度为1 000 ℃;低温下钛离子以四配位状态存在,随晶化温度升高,四配位钛离子消失,主要以镁铝钛酸盐相存在;含钛晶相的析出,促进玻璃系统分相,有利于主晶相的析出.  相似文献   

8.
采用水热合成工艺,以钛酸丁酯(Ti(OC4H9)4)为前驱体,通过改变水热合成反应的温度,合成了不同晶型和形貌的二氧化钛(TiO2)微粒。使用扫描电子显微镜和X射线衍射仪对产物进行表征。结果表明:水热反应的温度对TiO2微粒的晶型、晶粒尺寸和形貌有较大影响。随着水热反应温度的增加,二氧化钛微粒的晶粒粒径越来越大,结晶程度越来越完整,形貌也越来越规则。当水热反应温度较低时(80℃),晶型以锐钛矿为主,衍射峰峰宽较宽,峰强也较弱,晶粒刚开始发育;随着反应温度增加,开始出现金红石晶型,衍射峰锐化,峰的强度增强,晶粒粒径增大,晶粒逐渐发育完全;当反应温度达到160℃时,以金红石晶型为主,晶粒发育完全,结晶完善。  相似文献   

9.
以NaOH为沉淀剂,通过一种简单的低温回流法制备了MnFe2O4纳米晶.采用XRD、SEM、FESEM、FTIR和VSM等手段对MnFe2O4纳米晶尺寸、晶相结构和磁性能进行了分析表征.结果表明,所制备的MnFe2O4纳米晶为尖晶石相结构,晶粒尺寸随着反应温度的升高而增大,从50℃的10 nm增大到90℃的22 nm;样品的饱和磁化度随温度的升高而增大.  相似文献   

10.
用铝型材厂阳极氧化废渣和碱式碳酸镁((MgCO3)4·Mg(OH)2·5H2O)为主要原料固相烧结合成镁铝尖晶石(MgAl2O4),探讨氟化铝(AlF3)矿化剂对合成的MgAl2O4晶相结构、晶胞参数及微观形貌的影响.用X射线衍射(XRD),扫描电镜(SEM)及相关分析软件等表征得到MgAl2O4.结果表明,添加AlF3的各样品都形成2种晶相:镁铝尖晶石固溶体(Mg0.68Al0.32)(Al0.84Mg0.16)2O4和镁橄榄石固溶体Mg1.81Fe0.19(SiO4).确定2%(质量分数)为最佳添加量,此时试样中MgAl2O4固溶体含量最高为95%,体积密度最高为3.44g·cm-3,显气孔率最小为1.89%,抗弯强度达到151.9 MPa.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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