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1.
Using common phosphate as a check, we studied the growth and yield of potato by new rare earth agro-materials including rare earth phosphate (base fertilizer), rare earth whole plant nutrient fertilizer, and amino acid chelated rare earth ( top dressing), which were used in a single or mixed way in Dingxi city, Gansu Province.The results are as follows that ( 1 ) After using new rare earth materials, the plant height increases by 0.4 ~ 5.6 cm and the ripen period is delayed by 4 ~ 9 d.(2) They can improve the potato economic characteristics, enhance productivity, decrease black leg and late blight.The disease index is decreased by 1.6% ~ 10.6%, single plant potato number increases by 0.3 ~ 0.5, and single plant yield increases by 80 g ~ 130 g.(3) The effect of increased yield is significant, and mixed use is better than single use.In the single material treatments, rare earth phosphate is the best, rare earth whole plant nutrient fertilizer and amino acid chelated rare earth are the second, and the increased rate are 14.5%, 8.4%, 9.2% so the material mixture-rare earth phosphate mixed of rare earth whole plant nutrient fertilizer or with amino acid chelated rare earth is economically useable, and increase rate are 25.2% and 24.4% compared with common phosphate.  相似文献   

2.
Inrecentyears ,rareearthelements (REEs)havebeenwidelyusedinfunctionalmaterials ,cata lystsandotherproductsinindustry ,diagnosisreagentsofmagneticresonanceimaging (MRI)inmedicineandsomefertilizersinagricultureespeciallyinChina .However,asaresultoftheirusage ,moreandmoreREEsaregettingintotheenvironment,andalsointohumanbodyviafoodchain[1,2 ] .Itisnotclearwhetherrareearthelementsareessentialforman ,soitisveryurgenttostudythebiologicaleffectofrareearthelementsinhumanhealthandenvironment .Inthes…  相似文献   

3.
Reactive bright blue rare earth dyestuffs were prepared by using reactive bright blue and lanthanum oxide,praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, dysprosium oxide, erbium oxide, lutetium oxide, yttrium oxide respectively for dyeing silk cloth.The degree of dyeing of reactive bright blue praseodymium and the degree of fixation of reactive bright blue gadolinium are the biggest, and 22.9% and 7 %are increased with that of reactive bright blue respectively.The spectra of reactive bright blue rare earth and reactive bright blue were studied by UV-VIS.In 200.00 ~ 800.00 nm, reactive bright blue has four absorption peaks, reactive bright blue rare earth has three absorption peaks; in 420.00 ~ 760.00 nm, reactive bright blue has two absorption peaks at 661.50 nm and 625.50 nm, respectively, and λmax is 661.50 nm; reactive bright blue rare earth has one absorption peak at 620.50, 618.00, 622.00, 623.00, 622.50, 619.50, 619.00, 621.00, 624.00, 620.00 nm adding La3 ,Pr3 , Nd3 , Sm3 , Eu3 , Gd3 , Dy3 , Er3 , Lu3 , Y3 respectively.  相似文献   

4.
RoleofREandMgonGraphitizationofSpheroidalGraphiteMalleableCastIron¥LiuJin-Hai(HebeiInstituteofTechnotogy,Mianjin300130,China)...  相似文献   

5.
摘 要:对显色剂2,4-二氯-6-溴偶氮氟膦与稀土元素在微波催化下的显色反应进行了研究。在硝酸及少量吡啶介质中,于40℃的微波水浴中加热催化8 min,试剂与各稀土发生显色反应,形成稳定的蓝色配合物。典型稀土元素La、Ce与显色剂的配合比均为1︰3,各稀土配合物的最大吸收波长位于632~636 nm,表观摩尔吸光系数相近,ε为 0.89~1.15×105 L?mol-1?cm-1。以634 nm作为测定波长,改变混合稀土的配分进行试验,结果表明,La、Ce、Y的比例对稀土总量测定的影响不显著。加入四元混合掩蔽剂,采用本方法对岩石等实际样品中稀土总量进行测定,相对标准偏差(RSD, n=5)为2.0%~2.4%,回收率为 93%~98%。  相似文献   

6.
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   

7.
论述了我国钕铁硼磁性材料的发展历程,总结了赣州近年来钕铁硼磁体产业的生产和发展情况,同时指出赣州是中国南方离子型稀土矿供应基地,但不是钕铁硼生产的基地;近年来,赣州已形成一条从稀土开采-合金冶炼-钕铁硼磁体生产完整的产业链,钕铁硼磁体相关企业正在逐年增加,企业自身的竞争力也在逐年增强。  相似文献   

8.
稀土功能材料综述   总被引:2,自引:1,他引:2  
稀土元素被誉为二十一世纪新材料的宝库,因其在电、光、磁等方面具有独特性质,故在功能材料领域获得了广泛的应用.文章介绍了稀土磁性材料、稀土发光材料、稀土催化材料、稀土贮氢材料、稀土超导材料的研究及其应用进展.  相似文献   

9.
Effects of processing technology on the properties such as relative density, flexural strength, fracture toughness, hardness, etc. and the microstructure of rare earth yttrium containing Al2O3/(W, Ti)C ceramic composite were experimentally investigated. It suggests that different processing parameters can undoubtedly result in different microstructures and different mechanical properties of the material. Under the experimental conditions, the suitable hot pressing temperature is 1720 ~ 1780 ℃, the time duration is 10 ~ 30 min and the hot pressing pressure is 30 ~ 35 MPa. The corresponding relative density can even be higher than 98 %. With SEM and TEM observation, each phases in the ceramic material is found to be in fine grains and distribute homogeneously. Typical fracture feature of the material is the mixture of both intergranular and introgranular fracture. Additionally, the existence of rare earth yttrium containing nanometer or sub-micron meter sized ceramic grains, dislocations and spontaneous microcracks can also contribute to the further improvement of the mechanical properties of the ceramic composite.  相似文献   

10.
张建新  高爱华 《稀有金属》2005,29(3):289-292
讨论了晶粒细化、热处理制度、合金元素及稀土添加剂对6063铝合金导热性能的影响,在分析实验数据的基础上,阐述了各影响因素的作用机制。结果表明良好的铸态组织、适宜的时效制度、合理的合金元素配比与适量稀土处理剂均能不同程度的提高材料的导热系数。  相似文献   

11.
稀土产品的物性控制与稀土产业的发展   总被引:12,自引:3,他引:9  
本文讨论了稀土材料性能与稀土产品物性间的相关关系,认为稀土产品的物性控制对于发展未来稀土产业将起重要作用,因此建议在现阶段的稀土产业的发展计划中应当体现出物性控制的攻关目标,并就当前国内稀土新产品开发中的问题和大家关注的热点作了相应的介绍  相似文献   

12.
简述了三明稀土产业的现状,分析了开发三明稀土资源的重要性,提出要编制稀土产业发展规划,增强宏观调控和政策引导力度,促进稀土深加工、新材料和应用产业发展等对策建议,利用三明丰富的离子型稀土资源,打造稀土优势产业.  相似文献   

13.
The effects of rare earths with different contents on anti-degradation of Y base heavy rare earths-magnesium and cerium base light rare earths-magnesium nodular cast iron were studied. Curves of the relationship between the spheroidization grade of liguid iron treated by different nodulizers and holding time were obtained. The results show that the more the remains of the rare earth, the longer the anti-degradation time, the liquid iron was treated either by Y-Mg-Si or by Ce-Mg-Si nodulizer. When the rare earth remains are above certain quantity, the spheroidization grade starts to decline. When liquid iron treated by either Y-Mg-Si or Ce-Mg-Si nodulizer with proper remains of rare earths about 0.04% 0.06%(mass fraction), the anti-degradation is the best, and the remains of Mg being about 0.04% -0.07% (mass fraction). Rare earths-Mg nodulizer with moderate RE remains is better than that of Mg-Si nodulizer in anti-degradation property. However, Y-Mg-Si nodulizer with moderate remins of Re is better than Ce-Mg-Si nodulizer. Sometimes Ce-Mg- Si nodulizer can be used for the production of heavy section nodular cast iron.  相似文献   

14.
The effect of Y-base rare earth alloy in ultra-high hardfacing was observed by means of OM, SEM and XRD. Precipitated carbide can be metamorphosed and spheroidized in surfacing by adding Y-base rare earth alloy, which contributes to the increase of precipitated carbide. Rare earth combined with oxygen and sulfur can improve the morphology of slag inclusion as well as purify surfacing. The result shows proper rare earth alloy in surfacing can fine its microstmcture, improve hardness and impact toughness.  相似文献   

15.
利用气相色谱技术研究混合稀土精矿焙烧过程中氟的逸出规律,分别对混合稀土精矿在400℃~750℃下焙烧30min~120min的各个条件进行实验,测出不同条件下焙烧气体中的氟总量、逸出率、混合稀土精矿的分解率以及焙烧产物的物相组成,分析了氟的逸出率与焙烧温度、焙烧时间和环境湿度等因素间的关系,揭示了氟逸出的化学反应机制,为控制环境污染、优化处理工艺提供依据.  相似文献   

16.
The intermetallic compounds formation at interface between rare earth elements and clad material were investigated to demonstrate the effects of rare earth elements on fuel-cladding chemical interaction(FCCI)behavior.Mischmetal(70Ce-30La)and Nd were prepared as rare earth elements.Diffusion couple testing was performed on the rare earth elements and cladding(9Cr2W steel)near the operation temperature of(sodium-cooled fast reactor)SFR fuel.The performance of a diffusion barrier consisting of Zr and V metallic foil against the rare earth elements was also evaluated.Our results showed that Ce and Nd in the rare earth elements and Fe in the clad material interdiffused and reacted to form intermetallic species according to the parabolic rate law,describing the migration of the rare earth element.The diffusion of Fe limited the reaction progress such that the entire process was governed by the cubic rate law.Rare earth materials could be used as a surrogate for high burnup metallic fuels,and the performance of the barrier material was demonstrated to be effective.  相似文献   

17.
The luminescence properties of CdSiO3:RE^3 phosphors doped with various rare earth ions are reported. The series of rare earth ions doped CdSiO3 phosphors are prepared by the conventional high-temperature solid-state method, and characterized by XRD and photoluminescence (PL) spectra. The results of XRD measurement indicate that the products fired under 1050 ~C for 3 h have a good crystallization without any detectable amount of impure phase. The PL spectra measurement results show that CdSiO3 is a novel self-activated luminescent matrix. When rare earth ions such as Y^3 ,La^3 , Gd^3 , Lu^3 , Ce^3 , Nd^3 , Ho^3 , Er^3 , Tm^3 and Yb^3 are introduced into the CdSiO3 host, one broadband centered at about 420 nm resulted from traps can be observed. In the case of other earth ions which show emissions at the visible spectrum region, such as Pr^3 , Sm^3 , Eu^3 , Tb^3 and Dy3 , the mixture of their characteristic line emissions with the ~420 nm strong broadband luminescence results in various emitting colors. As a consequence, different emitting colors can be attairied via introducing certain appropriate active ions into the CdSiO3 matrix. In additional, this kind of phosphors shows good long-lasting properties when excited by UV light. All the results show that CdSiO3 is a potential luminance matrix.  相似文献   

18.
文中研究了微量稀土元素Ce在金合金中的分布情况,观察了稀土元素Ce不同添加量对金合金铸态组织及其硬度的影响.研究发现:在添加Ce的金合金中,Ce部分固溶,部分作为异质点Ce-Si化合物存在,基本没有Ce的偏聚;添加0.075?金合金铸态组织就可以达到较好的晶粒细化效果,分析其作用机理是添加Ce的金合金以高熔点的Ce-Si化合物和氧化物作为异质点,起到异质晶核的作用而细化组织;在低于Ce的金合金固溶度时,铸态合金的硬度随Ce含量增加而升高,过量Ce对金合金的铸态硬度影响不大;利用时效处理,能显著地提高金合金的硬度,Ce主要强化机制在于固溶强化.  相似文献   

19.
Fracture appearance, surface and nanomechanics properties of antibacterial ceramics contairing rare earth phosphate composite antibacterial materials were characterized and measured by SEM, AFM and Nanoindenter, respectively. Results show that grain of fracture surface of antibacterial ceramics grows uniform refinement topography of bubble break-up appears at the surface, which is flat and has liquid character, by adding the phosphate composite containing rare earth, nevertheless needle-like crystal and granular outgrowth form at fracture surface and surface of common ceramics, respectively. Young's modulus of antibacterial ceramic film is 74. 397 GPa and hardness is 8. 134 GPa, which increses by 4.4% and 1.6% comparing with common ceramics, respectively. Loading curves of two kind of ceramics have obvious nonlinear character under 700 nm and linear character between 700 ~ 1000 nm, and unloading curve have obvious linear character.  相似文献   

20.
LaCe-based sintered magnets with different microstructural features and distinct rare earth elemental distribution were designed by dual-alloy method.The sample prepared by fine LaCe-containing powder and coarse LaCe-free powder possesses higher remanence(~13.41 kGs),whereas another sample prepared by fine LaCe-free powder and coarse LaCe-containing powder possesses higher coercivity(~5.67 kOe).Additionally,these samples are with the same nominal compositions and their elemental distribution features are obviously different in matrix grains respectively.Their remanence difference is mainly affected by the saturation magnetization difference caused by the distribution variation of the rare earth elements at the matrix phase.The coercivity difference is affected by the component of the grain boundary phase between the adjacent grains and the distribution variation of the rare earth elements at the matrix phase.These findings may provide a new prospect for the utilization of LaCe mischmetal in 2:14:1-type permanent magnets.  相似文献   

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