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1.
锆钛酸铅(PZT)纳米陶瓷粉体的液相制备技术   总被引:1,自引:0,他引:1  
评述了Sol-gel法、共沉淀法和水热法制备锆钛酸铅(PZT)纳米陶瓷粉体的原理、工艺过程、技术特点及其优缺点。重点论述了水热合成PZT纳米陶瓷粉体的dissolution/precipitation和in-situ两种合成机制,详细分析了锆、钛、铅等反应物离子在水热条件下的存在形式、反应机理以及碱度、温度、干燥技术和铅含量等条件对水热合成PZT纳米陶瓷粉体的影响。讨论了液相法合成PZT纳米陶瓷粉体的研究热点与发展方向。  相似文献   

2.
利用超声雾化设备制备超细陶瓷粉体,确定该制备粉末的工艺参数和考查所制粉末的特性。  相似文献   

3.
目的研究水热法合成超细陶瓷粉体的工艺方法及影响因素。方法从温度,pH值,前驱物等方面对水热法工艺过程中存在的问题进行了分析,提出了一些改进意见。结果在合适的反应温度和烧结温度,反应体系的pH值控制在远离等电点(PZC)的pH,选用活性较大的前驱物有利于提高合成陶瓷粉体的性能。结论水热法是最适合于规模生产超细粉体的一种湿化学合成法,把它应用到功能陶瓷的制备中,可得到性能比常规固相法优越的陶瓷材料。  相似文献   

4.
PEG在ZrO2前驱体表面的吸附及改性作用   总被引:13,自引:2,他引:13  
以粘度法测定了高分子型表面活性剂聚乙二醇(PEG)在ZrO2前驱体表面上的吸附量和水洗后的残留量,结合粉体改性效果和IR,XPS技术对前驱体表面-OH,PEG在加热过程中分解脱除情况的测定结果,分析了PEG大分子在前驱体表面上的吸附状态及其对前驱体表面性能的影响,有助于了解PEG大分子对湿化学法制备超细ZrO2陶瓷粉体的改性作用,为进一步优化表面改性工艺条件提供实能依据。  相似文献   

5.
随着电子工业的高速发展,对半导体陶瓷材料性能的要求越来越高。制备工艺是决定其质量的关键技术之一。章对半导体陶瓷粉末制备方法如机械粉碎法、喷雾热解法、沉淀法、溶胶——凝胶法、水热合成法、水解法、气相化学反应法等进行了综合评述。比较和分析了各工艺方法的优缺点,并提出制备性能优异的陶瓷粉体的发展趋势。  相似文献   

6.
采用化学共沉淀法制得了BaTiO3陶瓷粉体.借助热分析仪(DSC)分析了共沉淀产物的热分解过程,确定了共沉淀产物的煅烧温度范围,采用三个不同煅烧温度煅烧得到BaTiO3粉体.并借助扫描电镜(SEM)观察粉体形貌,研究了不同煅烧温度对粉体形貌的影响.结果表明,通过控制工艺条件成功地制备了粒度不超过250nm的球形BaTiO3粉体,且随煅烧温度升高粉体粒度增大。  相似文献   

7.
张占新 《科技信息》2010,(16):20-21
在料浆的制备过程中,研究了料浆的固相含量、pH值、分散剂等因素对料浆的性能影响。结果表明,在pH值约为9时,有机单体占陶瓷粉体的4wt%,料浆分散性和稳定性最好;在此基础上,研究了固相含量对悬浮液流变性的影响,制备了固相含量高达54vol%的分散性和稳定性好的浓悬浮体,完全满足胶冻成型的要求。  相似文献   

8.
钛酸铝陶瓷粉体的制备研究   总被引:3,自引:0,他引:3  
以NH4HCO3作沉淀剂的共沉淀法制备了钛酸铝(Al2TiO5)陶瓷粉体.实验发现,此反应体系的pH值对钛、铝元素的沉淀量有重要的影响,只有在pH6.0~6.5左右极小范围内能保证钛、铝完全沉淀.采用FT-IR、XRD、DTA-TG等分析手段确定了前驱体的组成.通过XRD、DTA-TG等分析表明,前驱体在热处理形成Al2TiO5的过程中,物相的变化情况是:碳酸铝铵→无定形Al2O3→α-Al2O3;无定形TiO2→锐钛型TiO2→金红石型TiO2;在1000℃左右α-A12O3和金红石TiO2开始形成Al2TiO5,然后在1350℃完全形成Al2TiO5.同时,TEM分析显示Al2TiO5粉体的形貌为球形,粒径为70~100nm.  相似文献   

9.
简要介绍了纳米陶瓷及其独特的性能、纳米陶瓷粉体的制备以及纳米陶瓷的最新发展,重点介绍了在轴承工业领域中,纳米陶瓷的广泛应用。  相似文献   

10.
增韧补强是现代技术陶瓷研究的重要领域。ZTA纳米复相陶瓷借助于ZrO2的相变特性能够显著改善陶瓷的韧性。首先从断裂力学的角度分析了影响陶瓷增韧的显微结构因素,在此基础上,介绍了ZTA增韧陶瓷复合粉体的几种制备工艺,分析比较了各种工艺的特点,指出了ZTA陶瓷粉体制备的发展方向。  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.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
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   

17.
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   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
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   

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