Y2O3/ZnO辅助空气鼓泡空化降解有机染料的研究

以Y2O3/ZnO鼓泡空化降解有机染料进行初步的探讨,研究了鼓泡时间,染料初始浓度,催化剂的量对降解刚果红的影响等,不同染料的降解率的对比及可能的降解过程。     

特殊离合器的设计

本文着重论述了一种特殊离合器的结构形式及它的特殊性,详细阐述了其工作原理和计算方法,并介绍了特殊离合器的应用场合和使用条件。这种特殊离合器在实际中已经得到成功的应用,设备运行情况良好,有效地提高了设备的控制精度,进而使生产效率和产品质量得到提高,产生了很好的经济效益和社会效益,具有良好的实际应用和市场推广价值。     

丝杠刚度受支撑方式影响的变化规律研究

滚珠丝杠螺母传动机构是机床的进给传动部件,其轴向刚度直接影响机床的定位精度,应用变形协调原理给出了滚珠丝杠螺母传动机构的轴向刚度计算方法。计算结果显示两端固定支撑的丝杠的轴向刚度随长度按抛物线规律变化,其变形最大值在丝杠的中点。     

氧化及平滑处理对DSC起始温度影响的研究

本文利用不同的三种方法对标准样品锌进行差示扫描量热法分析,讨论氧化对实验数据的影响。结果表明三种方法得出的起始温度数据相差很小,仅为0.2℃;从而进一步说明了氧化对起始温度的影响非常小。热分析软件功能日趋强大,但其中一些功能例如平滑处理,需要合理应用才能更好地发挥作用。     

低倍缺陷对38CrSi钢力学性能的影响

用酸蚀方法研究38CrSi钢的低倍缺陷与力学性能的关系。结果表明,低倍缺陷对钢的强度和塑性影响不大,而它对钢的冲击性能有明显作用,这种作用与钢中非金属夹杂物含量有关,夹杂物含量越高,钢的冲击韧性越低,通过电镜分析认为是α-MnS夹杂物。     

X60钢加热和冷却相变温度DSC法研究

采用差示扫描量热仪(DSC),分析了X60管线钢在加热与冷却过程中的相变温度.结果表明:在冷却时DSC曲线上出现三个峰值,除先共析铁素体析出和珠光体转变外,还有铌或钒的碳化物析出;相变温度随冷却速度的增大而降低;在加热至950℃时,DSC曲线上出现二个峰值,除先共析铁素体溶解和奥氏体转变外,没有明显的铌或钒的碳化物峰溶入奥氏体峰.     

Luminescent properties of YVO4·xTa2O5:Eu3+

The samples of YVO₄·xTa₂O₅:Eu³⁺ (x=0.45,0.35,0.25,0.15,0.05)were synthesized by the conventional solid state reaction. The structure of the prepared sample was checked by the X-ray diffraction. XRD measurements at room temperature were confirmed that the prepared YVO₄·xTa₂O₅:Eu³⁺ consisted of two phases. One phase was YVO₄, which is tetragonal according with the JCPDS-Card (17-0341); the other phase was YTaO₄, which is according with the JCPDS-Card (72-2018). The spectrum property of the sample was studied under the VUV. The effects of Ta doped on the luminescent properties of sample were investigated and it was found that some Ta doped could highlight the absorption of matrix in VUV region. The emission spectrum was dominated by the red peaks at 613 and 619 nm due to the electric dipole transition ⁵D₀→⁷F₂ of Eu³⁺. It indicated that Eu³⁺ occupied a site lacking inversion symmetry. There was one band peaked at 155 nm in the excitation spectrum of the sample, it could be assigned to the absorption of the host.     

Effects of the accumulation of the rare earth elements on soil macrofauna community

The accumulation of rare earth elements(REEs)in soil has occurred due to the pollution caused by the exploitation of rare earth resources and the wide rare earth fertilizers in agriculture.The accumulation of REEs has a toxic effect on the soil macrofauna community.12study samples were collected near a mine tailings dam with a large amount of REEs by distance gradient sample method.The total concentration of REEs was analyzed and the results were compared with that of the sample from a control site.The effects of the amount of REEs in the soil on the soil macrofauna community were also analyzed.The results showed that the accumulation of REEs in soil was significant in the study area and its concentration was strongly correlated with the distance from the pollution source.One-way ANOVA analysis indicated the significant differences in soil macrofauna communities among the different sites.The ordination obtained through the redundancy analysis demonstrated that the concentration of REEs and the total nitrogen,total potassium and pH,had affected the soil macrofauna community.A small amount of REEs in the soil can promote the diversity of soil macrofauna,but a large amount of REEs can reduce its diversity.The insect groups of Carabidae and Dermaptera were comparatively sensitive to the concentration of REEs in soil,and could be used as an indicator of soil pollution of REEs.However,the Formicidae and Stibaropus formosanus exhibited a high tolerance to REEs in soil.We believe that it is very important for the soil environment protection to strictly control the application of the rare earth fertilizers in agriculture in China.     

对苯乙炔苯丙二酮类稀土配体的理论研究

采用RHF法就对苯乙炔苯丙二酮类稀土配体进行了理论计算,得到了它们的结构、基态能量、原子电荷、原子间距、轨道能级等。结果表明,1-环戊二烯-3-(p-对苯乙炔苯基)-1,3-丙二酮和1-噻吩基-3-(p-对苯乙炔苯基)-1,3-丙二酮可与稀土离子形成更为稳定的发光配位化合物。     

包头稀土精矿浓硫酸低温焙烧工艺技术研究

采用浓硫酸低温动态焙烧方式分解包头稀土精矿,考察了焙烧温度、矿酸比、回转窑倾角、转速等因素对稀土精矿中稀土和钍分解率的影响。结果表明,包头稀土精矿浓硫酸低温焙烧工艺可行,稀土和钍的浸出率均大于95%,水浸渣的放射性总比放达到国家非放射性渣排放标准。具有推广应用前景。