首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 685 毫秒
1.
Nanometer Ce/TiO2 functional materials with photocatalystic antibacterial properties were prepared by dipping TiO2 nanometer powders into RE( NO3 )·nH2O solutions, filtrating, drying and heat treatment, and the enhancement mechanisms of Ce on the nanometer TiO2 were studied by electronic spin resonance(ESR) The results show that TiO2 for photocatalystic antibacterial properties is strengthened evidently by adding Ce, which has a high efficiency of photocatalystic antibacterial properties with the light extent of visible light and ultraviolet radiation. The basic reason for obtaining the strengthened result is that the effective wave length of photocatalystic properties of TiO2 can be expanded to visible light area with the induction of the rare earth elements, whether or not ultraviolet light exists, nanometer TiO2 can produce a great deal of hydroxylic radical(·OH) by treating with rare earth elements.  相似文献   

2.
赣南离子吸附型稀土矿富含中、重稀土元素,具有极高的经济价值及重要的战略意义.在对大量文献资料进行查阅及分析的基础上,介绍铝在离子吸附型稀土矿中的赋存形态、浸出行为以及对稀土工业生产的影响,系统地阐述离子吸附型稀土矿浸取过程中除铝技术的研究和实践进展,并对现有技术进行分析总结,提出未来离子吸附型稀土矿除铝技术应向环境友好型发展,并实现除铝产物资源化、商品化.   相似文献   

3.
采用浸渍法制备了纳米TiO2负载钯催化剂,以乙炔选择催化加氢制备乙烯为反应模型考察了稀土元素La、空速对纳米Pd/TiO2催化剂性能的影响,并与纳米SiO2为载体的Pd—La/SiO2催化剂的性能做了比较。实验结果表明,纳米Pd/TiO2催化剂具有良好的催化活性和性能稳定性,La的加入显著提高了乙烯的选择性、增幅达加%左右。与Pd—La/SiO2催化剂相比,Pd—La/TiO2催化剂具有更高的选择性。  相似文献   

4.
复杂稀有金属矿综合利用新工艺   总被引:2,自引:1,他引:1  
研究一种从复杂稀有金属矿中综合回收稀土、铌、钛的新工艺。按6∶5的酸矿质量比添加浓硫酸混匀后在400℃酸化,酸化渣浸出后,浸出液按1∶1的体积比加水在100℃水解60min得到水解沉淀,浸出渣采用强磁选分离得到磁性物及非磁性物。将水解沉淀与磁性物混匀在1 800℃还原熔炼,获得Nb2O5含量22.38%、铁品位52.32%的铌铁合金和TiO2含量35.12%的钛渣,铌、钛回收率分别为66.89%和50.38%。水解液在通入空气的条件下用氨水调节至pH=3进行固液分离,按理论量1.2倍添加草酸沉淀稀土,最后将该稀土沉淀在950℃煅烧60min,可得到REO含量92.4%的稀土氧化物,稀土总回收率71.32%。  相似文献   

5.
采用水热合成法制备稀土掺杂金红石型纳米二氧化钛,并通过XRD,TEM等对其进行了表征。结果表明,稀土离子的掺杂使得二氧化钛(110)晶面衍射峰位置发生了漂移,并且出现了不同程度的宽化,但并没有改变纳米TiO2的晶型,也没有出现稀土氧化物的特征衍射峰。稀土掺杂后的二氧化钛形貌为棒状,长径比约为110 nm∶20 nm。利用硅烷偶联剂KH-570对稀土掺杂纳米TiO2表面修饰,与乙烯硅油发生接枝反应制备新型电流变液,并通过旋转流变仪测试了该电流变液的稳态电流变性能。通过红外吸收光谱发现,乙烯基硅油与KH-570-TiO2发生了一定程度的接枝共聚反应。由于无机纳米粒子与聚硅氧烷连续相形成化学键体系,电流变液的抗沉降稳定性得到了很大的提高;稀土离子的掺杂增大了体系的极性,随着电场强度的增大,电流变液的线性平台区也随之变长,表现出典型的类固态响应行为,其中以Sm3+的掺杂效果最为显著。  相似文献   

6.
赵莉萍  钦祥斗  张慧敏  贺建新 《钢铁》2014,49(10):71-75
 以加入不同含量稀土元素镧的节镍铬锰氮不锈钢为对象,采用交流阻抗和极化曲线分析技术,对节镍铬锰氮不锈钢在周浸腐蚀环境下的电化学行为进行了研究。通过试验结果分析得出:加入质量分数为0~0.014%镧元素,随着镧含量增加,基体的电极电位提高;在体积分数3.5%NaCl溶液中模拟海洋大气腐蚀的48天内,节镍铬锰氮不锈钢的耐蚀性随稀土镧含量增加,耐蚀性先增加后减小,含稀土镧质量分数为0.004 9%的节镍铬锰氮不锈钢的耐蚀性最好。  相似文献   

7.
王文华  杨天林  丁玲  李寒玉 《稀土》2012,33(3):90-95
合成了一种新型三足席夫碱和它的四种稀土配合物,通过元素分析、红外光谱、紫外光谱、差热-热重、核磁共振和摩尔电导率对配合物进行了表征,推测了配合物的可能结构。应用紫外可见光谱法和电化学方法对配合物与ct-DNA之间的相互作用进行了研究,结果表明,配合物与ct-DNA之间存在插入作用;配合物CV测试随扫描速度增加,其氧化峰电位Ep发生正移,氧化峰电流Ip随扫描速度的增加呈线性增加趋势,并且Ip与扫描速率平方根(v1/2)呈良好线性关系,表明配合物在GCE上的电化学氧化反应是一个受扩散步骤所控制的过程。  相似文献   

8.
改性粉煤灰吸附稀土氨氮废水的机理研究   总被引:1,自引:1,他引:0       下载免费PDF全文
分别用氢氧化钠、硫酸和稀土镧对粉煤灰进行改性,然后用对比法研究了粉煤灰改性前后对稀土氨氮废水的吸附行为。结果表明,碱改性粉煤灰对稀土氨氮废水的吸附效果最佳。在室温下,pH为11.7,投加量5g,吸附达到平衡时,碱改性粉煤灰的吸附效率可以达到81.56%。碱改性粉煤灰吸附稀土氨氮废水的吸附过程符合Elovich吸附方程,属于良性吸附,吸附容量达到1.72mg/g。  相似文献   

9.
陈祖义  朱旭东  米恩富 《稀土》2006,27(1):73-75
基于稀土厂废水的放射性,吸取水质放射性污染净化原理与多种粘土矿物和土壤对稀土的吸附性,探讨稀土厂废水放射性的净化技术。建议稀土厂在现有废水处理的基础上,建吸附滤池,通过混合吸附剂对水中放射性元素的吸附,净化废水放射性,确保环境辐射安全性。  相似文献   

10.
采用等离子光谱法测定碳酸稀土、氯化稀土中氧化铕含量,系统考察了不同试样浓度、不同基体配分下共存元素对测定元素的影响,并进行了加料回收及精密度实验,结果稳定可靠,与ICP-MS的对照结果令人满意。测定范围0.01%~0.30%。  相似文献   

11.
用稀土定量络合氟,EDTA测定剩余稀土,从而间接测定氟。研究了酸度、缓冲液对测定结果的影响.杂质元素干扰的消除条件。方法回收率在98.67%~100.45%之间,相对标准偏差小于0.21%。  相似文献   

12.
The adsorption-desorption behavior of the mixed rare earth elements(RE)on the main types ofsoils of China,kaolinite and synthetic oxides was studied.The isothermal adsorption of RE was fitted toLangmuir.Freundlich and Temkin equations.The main factors determining the RE adsorption capacity ofthe soils are the type of clay mineral and the content of amorphous iron oxide in the soils.The above two fac-tors and the pH of soil determine the RE adsorption ability of the soils.The soil and synthetic iron,manga-nese oxides strongly adsorb RE specifically.  相似文献   

13.
Effect of Rare Earth on Microstructure of γ-TiAl Intermetallics   总被引:3,自引:0,他引:3  
The rare earth (RE) elements (Ce, La) were added to binary Ti-47% Al alloys (atomic fraction) by Induction Skull Melting. The element Ce of 1.0 atomic percent was added individually, and La of 0.2 atomic percent was added individually. This article studied the influences of rare earth metal (Ce, La) on microstructure of as-cast TiA1 based alloy by XRD, SEM, EMPA and TEM measurement methodology. The results show that most of rare earth-rich phases (AlCe, Al-La) are uniformly distributed in grain boundary in the shape of discontinuous network, and some particles of rare earthrich phases within the grains are mainly ellipsoids. In addition, rare earth element can obviously refine the grain size and the lamellar thickness of as-cast TiAl based alloy samples. The grain size of Ti-47Al-1.0Ce-0.2La alloy reaches about 30~80μm, and the lameUar thickness of its γ phase and α2 phase are less than 200 and 20nm, respectively.  相似文献   

14.
稀土铈对化学沉积Co-Ni-B合金镀层结构和性能的影响   总被引:8,自引:3,他引:5  
宣天鹏  章磊  黄芹华 《稀有金属》2003,27(3):399-402
研究了稀土铈对化学沉积Co-Ni-B合金层化学组成、结构和性能的影响。结果表明:微量稀土铈的加入提高了镀层中钴的含量,降低了镍和硼的含量;使镀层由非晶态转变为品态;稀土铈也明显地提高了镀层的显微硬度,在一定的范围内,镀液中稀土铈添加量越多,镀层的铈含量和显微硬度也越高;稀土铈还提高了镀层的饱和磁化强度,降低了剩余磁化强度和娇顽力,含铈镀层显示出了良好的软磁性能。  相似文献   

15.
2 mercaptobenzothiazolewasfirstreportedbyHofmann[1 ] in 1 887.Ithasbeenusedasanacceleratorinthevulcanizationofrubberformanyyears .Todayitisstillbeingusedasamainacidicacceleratorinrubberindustry .Butithasdisadvantagesofvulcanizationreversionandeasyscorch[2 ] whe…  相似文献   

16.
以邻苯二胺、乳酸、二乙三胺为原料合成双苯并咪唑甲基酮缩二乙三胺Schiff碱化合物,在无水乙醇溶剂中,所得的化合物与稀土离子(Ce3 、Nd3 、Sm3 )配合,合成了三种新型稀土配合物,并对其进行了元素分析、红外光谱测试、差热热重及生物活性研究。钕与苯并咪唑甲基酮缩二乙三胺Schiff碱的配合物对大肠杆菌和霉菌均有较好的杀菌活性;钐与苯并咪唑甲基酮缩二乙三胺Schiff碱的配合物对大肠杆菌有较好的杀菌活性,而对霉菌无活性;铈的配合物对所考察的菌种均无抑制作用。  相似文献   

17.
The effect of rare earth element Ce on mechanical performance and electrical conductivity of aluminum rod for electrical purpose were studied under industrial production condition. Using optical microscope, SEM, TEM, EDS and X-ray diffractometer, the microstructure and phase composition of aluminum rod were measured and analyzed. The results indicate that the content of rare earth element Ce is between 0.05%~0.16% in the aluminum rod for electrical purpose. Its tensile strength is enhanced to some extent. The research also discovers that the tensile strength is enhanced remarkably with impurity element Si content increases. Because influence of Si is big to the conductivity, the Si content should be controlled continuously strictly in the aluminum for electrical purpose. Adding rare earth element Ce reduces the solid solubility of Si in the aluminum matrix, and the negative effect of Si on the aluminum conductor reduces effectively. So the limit of in Si content in aluminum rod for electrical purpose can be relaxed moderately.  相似文献   

18.
微生物吸附法作为一种高效、廉价、环境友好的生物技术,已在稀土离子分离回收中逐渐被开发利用。实验通过固定化微生物技术,使用海藻酸钠包埋活性炭与枯草芽孢杆菌芽孢制备成固定化颗粒,处理含稀土离子的废水。对比了固定化芽孢加活性炭、固定化芽孢以及固定化活性炭对铽离子的吸附效果,并探究了不同条件对几种固定化吸附剂吸附铽离子的影响。结果表明:固定化芽孢加活性炭兼具包埋法与吸附法的优点,对铽离子的吸附效果更好; 在包炭量为1:100(活性炭质量:溶液总质量)、芽孢悬液浓度为OD600(菌液在600 nm波长处的吸光值)=2、铽离子浓度为100 μmol/L、温度为15~25 ℃、pH=4.5~8.5的条件下吸附60 min,铽去除率可达90%以上。固定化芽孢加活性炭对铽离子的吸附更符合准一级动力学、Langmuir吸附等温线模型。   相似文献   

19.
A novel polystyrene-poly(hydroxamic acid)interpenetrating network resin(PS-PHA IPNs)was successfully synthesized by suspension polymerization and interpenetrating network technology.The effects of various experimental parameters,including pH,contact time and initial concentrations of rare earth ions on the adsorption capacity were discussed in detail.Under the condition of pH 4.0(La3+),1.0(Ce3+)and 3.0(Y3+),respectively,PS-PHA IPNs can reach equilibrium adsorption in 6 h and get maximum adsorption capacities(1.08,1.43 and 1.36 mmol/g).The adsorption process of PS-PHA IPNs for La(Ⅲ),Ce(Ⅲ)and Y(Ⅲ)ions can be described by liquid membrane diffusion,particle diffusion and chemical reaction.The adsorption process is a spontaneous and endothermic process and can be better simulated by Langmuir adsorption isotherm.The studies of SEM-EDS indicate that rare earth ions are adsorbed on the surface of PS-PHA IPNs.Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS)analysis further prove that rare earth ions are chemisorbed on the surface of PS-PHA IPNs.These results reveal that the as-prepared PS-PHA IPNs is a promising adsorbent for adsorption of rare earth ions due to their higher adsorption capacity than other adsorbents.  相似文献   

20.
Geochemical behaviors of the rare earth elements(REEs)in river and lake water bodies are dependentmainly on water chemistry and other factors,andhence their variationsin concentration and compositionreflect changes of various environmental variables.There…  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-23

京公网安备 11010802026262号