首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
采用特殊液相沉淀法制备了掺杂纳米TiO2粉体,用XRD和TEM对其进行表征.用它做催化剂在日光作用下对亚甲基蓝进行了光催化实验,研究了掺杂量、焙烧温度及焙烧时间对光催化性能的影响,结果表明,掺镧纳米TiO2比纯TiO2光催化效果好.在同等条件下,掺镧纳米TiO2对亚甲苯蓝的降解率最多要比纯TiO2提高30%左右.其中掺镧2%的纳米TiO2在焙烧温度600 ℃,焙烧时间30 min时,效果最佳.  相似文献   

2.
采用特殊液相沉淀法制备了双元素镧和铁掺杂纳米二氧化钛粉体,通过TG-DTA对其前驱体进行分析,用XRD和TEM对其进行表征.用它做催化剂在日光作用下对亚甲基蓝进行了光催化实验,结果表明双元素镧和铁掺杂纳米二氧化钛比纯纳米TiO2粉体光催化效果好.其中掺铁1%、镧0.5%的纳米TiO2在焙烧温度650℃焙烧时间30 min时效果最佳.  相似文献   

3.
采用特殊液相沉淀法制备了双元素镧和铁掺杂纳米二氧化钛粉体,通过TG-DTA对其前驱体进行分析,用XRD和TEM对其进行表征.用它做催化剂在日光作用下对亚甲基蓝进行了光催化实验,结果表明双元素镧和铁掺杂纳米二氧化钛比纯纳米TiO2粉体光催化效果好.其中掺铁1%、镧0.5%的纳米TiO2在焙烧温度650℃焙烧时间30 min时效果最佳.  相似文献   

4.
采用特殊液相沉淀法制备了双元素镧和铁掺杂纳米二氧化钛粉体,通过TG-DTA对其前驱体进行分析,用XRD和TEM对其进行表征。用它做催化剂在日光作用下对亚甲基蓝进行了光催化实验,结果表明双元素镧和铁掺杂纳米二氧化钛比纯纳米TiO2粉体光催化效果好。其中掺铁1%、镧0.5%的纳米TiO2在焙烧温度650℃焙烧时间30 min时效果最佳。  相似文献   

5.
采用特殊液相沉淀法制备了双元素镧和铁掺杂纳米二氧化钛粉体,通过TG-DTA对其前驱体进行分析,用XRD和TEM对其进行表征。用它做催化剂在日光作用下对亚甲基蓝进行了光催化实验,结果表明双元素镧和铁掺杂纳米二氧化钛比纯纳米Ti02粉体光催化效果好。其中掺铁1%、镧0.5%的纳米TiO2在焙烧温度650℃焙烧时间30min时效果最佳。  相似文献   

6.
采用特殊液相沉淀法制备了掺杂纳米二氧化钛粉体,通过TG-DTA对其前驱体进行分析,用XRD和TEM对其进行表征.用它做催化剂在日光作用下对亚甲基蓝进行了光催化实验,研究了掺杂量对光催化性能的影响,结果表明掺铁纳米二氧化钛比纯二氧化钛光催化效果好.其中掺铁1.25%的纳米二氧化钛在焙烧温度600 ℃,焙烧时间30 min时效果最佳,最多比纯二氧化钛的降解率提高47%.  相似文献   

7.
掺铁纳米TiO2粉体的制备及其光催化活性的研究   总被引:1,自引:0,他引:1  
采用特殊液相沉淀法制备了掺杂纳米二氧化钛粉体,通过TG-DTA对其前驱体进行分析,用XRD和TEM对其进行表征。用它做催化剂在日光作用下对亚甲基蓝进行了光催化实验,研究了掺杂量对光催化性能的影响,结果表明掺铁纳米二氧化钛比纯二氧化钛光催化效果好。其中掺铁1.25%的纳米二氧化钛在焙烧温度600℃,焙烧时间30 min时效果最佳,最多比纯二氧化钛的降解率提高47%。  相似文献   

8.
用溶胶-凝胶法在石英玻璃衬底上制备了纯的和掺杂Ce(1%、2%、5%)的TiO2纳米薄膜。用X射线衍射仪、原子力显微镜和紫外-可见分光光度计对薄膜的结构、形貌和光学性能进行了表征。通过紫外光下降解亚甲基蓝的实验,考察了Ce掺杂对TiO2纳米薄膜光催化性能的影响。结果表明,掺杂适量的Ce能有效提高TiO2纳米薄膜的光催化活性,当Ce的掺杂量为2%时,TiO2纳米薄膜的光催化活性最佳。  相似文献   

9.
La掺杂对纳米TiO2薄膜晶体结构和光催化性能的影响   总被引:3,自引:0,他引:3  
采用溶胶一凝胶法在玻璃表面制备La掺杂纳米TiO2薄膜;利用X射线衍射仪(XRD)和原子力显微镜(AFM)对其结构和形貌进行表征;通过对紫外光照射下亚甲基蓝溶液的光催化降解率评价其光催化性能;研究不同掺杂量、热处理温度以及pH值对La掺杂纳米TiO2薄膜光催化性能的影响,并对其光催化的影响机制进行探讨.研究结果表明:适量La掺杂能抑制TiO2由锐钛矿相向金红石相的转变,引起晶格膨胀,导致晶格畸变;La掺杂使TiO2的吸收光谱发生红移,扩展TiO2的光谱吸收范围,有效地提高纳米TiO2薄膜的光催化性能,且光催化反应符合一级动力学方程:La掺杂量(摩尔分数)为0.5%的纳米TiO2薄膜在400℃热处理2 h后具有最大的光催化效率98.2%,其光催化效率比纯TiO2薄膜的光催化效率提高约40%.  相似文献   

10.
掺杂Zn2+纳米TiO2光催化降解亚甲基蓝   总被引:1,自引:0,他引:1  
印染废水治理是水系环境治理的重点,而亚甲基蓝是印染废水中典型的有机污染物。本研究选用掺杂Zn2+的纳米TiO2作为光催化剂对亚甲基蓝进行降解研究。XRD谱图分析表明,Zn2+的掺入可改变纳米TiO2锐钛矿型和金红石型的组成。制备工艺参数对样品光催化降解亚甲基蓝的活性具有很大影响,纯TiO2样品在450℃焙烧时的活性较其他温度的高;而掺杂Zn2+的样品则在500℃焙烧时的光催化活性相对最佳。催化剂的加入量过高或过低都不利于光催化活性的提高,催化剂的加入量为1g/L时,光催化剂对亚甲基蓝的降解效果最好;Zn2+掺入量为0.5%时,掺杂粉体的光催化活性相对较高。随着掺杂量的进一步增加,光催化活性降低。被降解有机物浓度过高时,紫外光较难到达催化剂表面,光的利用率降低,导致催化剂活性降低。亚甲基蓝的初始浓度为5mg/L时的降解速率较快。  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号