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1.
A novel series of glass, consisting of B2O3, Bi2O3, TeO2, and TiO2 (BBTT) containing rare earth oxide RE2O3, where RE is La, Ce, Sm, Er, and Yb, was prepared. We investigated the structural, optical, and gamma attenuation properties of the resultant glass. The optical energy bands, the linear refractive indices, the molar refractions, the metallization criteria, and the optical basicity were all determined for the prepared glass. Furthermore, physical parameters such as the density, the molar volume, the oxygen molar volume, and the oxygen packing density of the prepared glass, were computed. Both the values of density and optical energy of the prepared glass increased in the order of La2O3, Ce2O3, Sm2O3, Er2O3, and then Yb2O3. In addition, the glass doped with Yb2O3 had the lowest refractive index, electronic polarizability, and optical basicity values compared with the other prepared glass. The structures of the prepared glass were investigated by the deconvolution of infrared spectroscopy, which determined that TeO4, TeO3, BO4, BO3, BiO6, and TiO4 units had formed. Furthermore, the structural changes in glass are related to the ratio of the intensity of TeO4/TeO3, depending on the type of rare earth. It is also clarified that the resultant glass samples are good attenuators against low-energy radiation, especially those that modified by Yb2O3, which exhibited superior shielding efficiency at energies of 622, 1170, and 1330 keV. The optical and gamma ray spectroscopy results of the prepared glass show that it is a good candidate for nonlinear optical fibers, laser solid material, and optical shielding protection.  相似文献   
2.
In the present study, the extraction of rare earth elements (REEs) from waste neodymium magnets using phosphorus ionic liquid Cyphos IL 104 was investigated. The objective was to recover and separate the heavy REE (Dy) from light REEs (Nd and Pr). Therefore, the experimental parameters of ionic liquid extraction, including contacting time, the initial pH value, extractant concentration, and O/A ratio, have been optimized. The highest separation factor αDy/Nd of 45.18 and αDy/Pr of 47.93 has been achieved. Following the ionic liquid extraction, the comparison of different stripping agents and the stripping parameters (the concentration of stripping agent and A/O ratio) were also explored. In short terms, this research demonstrates the optimal parameters of Cyphos IL 104 for selectively extracting high REE (Dy) and reveals its potential for recovering and separating REEs in real waste.  相似文献   
3.
In this experiment, the rare earth Gd element was added to Finemet alloy to observe the microstructure and soft magnetic properties. The experimental results showed that the samples with the addition of 0.5% Gd and 1.0% Gd can be quenched and cast normally, and the MS of Fe73Cu1Nb3Si13.5B9Gd0.5 alloy was 10.41% higher than that of Finemet. After annealing, crystal grains of about 10 nm were formed. The μi and μm values of Fe73Cu1Nb3Si13.5B9Gd0.5 alloy were 25.51% and 22.23% higher, respectively, and the coercivity HC was reduced by 12.19% compared to Finemet. At 1 kHz, the μe value of Fe73Cu1Nb3Si13.5B9Gd0.5 alloy at room temperature was 14.57% higher than that of Finemet, while the μe reached 162.34 k and 142.42 k at 90 °C and 150 °C (24% and 29.51% higher, respectively). The Fe72.5Cu1Nb3Si13.5B9Gd1.0 alloy had the best performance at 100 kHz, with higher μe values than Finemet across the ambient temperature range of 30 °C to 150 °C. After tension annealing, the μe values of Fe72.5Cu1Nb3Si13.5B9Gd1.0 alloy were 20–30% higher than those of Finemet.  相似文献   
4.
结合历代治疗水湿病证名方的用药配伍特点,对祛湿方剂的组方配伍规律进行探析。其治疗重在调理脾肺肾功能,配伍健脾药,以培土制水;配伍宣肺药,以通调水道;配伍温肾药,助阳化气以行水,使津液输布正常则湿邪不生。在临床诊疗中应辨证论治,正虚为主者或健脾升阳或养阴祛湿,或温肾以助运化;邪实盛者当配伍利尿、活血化瘀、清热等药物,助邪外出。湿热宜清宜利,寒湿宜温宜燥。外湿宜表散,内湿宜淡渗芳化。临床应根据具体病证,注重辨证论治,随证用药,以期取得满意疗效。  相似文献   
5.
稀土元素La、Gd和Ce对培养大鼠细胞生物学效应的研究   总被引:27,自引:0,他引:27  
目的 在细胞水平上研究稀土元素(REE)La,Gd和Ce对培养大鼠细胞的生物学作用及机。方法 采用同位素示踪、质子激发X荧光分析(PIXE)结合生化及细胞学等技术观察La对细胞的生物学作用,La,Gd及Ce的亚细胞分布及Gd,Ce对细胞钙含量及钙内流的影响。结果 La^3 在10^-10(或10^-9)-10^-6mol/L时促进细胞蛋白质合成、线粒体琥珀酸脱氢酶活性增加、DNA合成以及S期细胞比率增加,但La^2 在高剂量时(10^-4-10^-3mol/L)降低平滑肌细胞总蛋白质含量、抑制线粒体琥珀酸脱氢酶酸活性以及S期细胞比率减少。通过PIXE发现La,Gd,Ce可进入细胞,且在核内含量最高,其次为胞膜。Gd和Ce使细胞内钙含量增加,促进细胞钙内流。结论(1)La^3 对细胞有明显剂量-效应关系,在10^-10(或10^-19)-10^-6mol/L剂量范围内有促进细胞增殖作用。在10^-4-10^-3mol/L时有细胞毒性作用。(2)REE可进入细胞,且在核内富集。(3)REE可促进细胞外钙进入细胞。  相似文献   
6.
五步推拿法辅治小儿腹泻经验   总被引:1,自引:0,他引:1  
运用五步推拿法加减辅助内服中药治疗小儿腹泻,据证之虚实运用相应的补泻手法,有促进药物吸收、增强疗效、缩短疗程的作用,而且无痛苦,无毒副作用,患儿容易接受,更宜于服药困难的小儿,并举验案五则以证之。  相似文献   
7.
在稀土三元催化体系(三氯乙酸钇-二乙基锌-甘油)中加入相转移剂四甲基氟化铵(TMAF),并用于催化二氧化碳和环氧丙烷交替共聚。采用核磁共振(1H-NMR)、凝胶渗透色谱(GPC)、差示扫描量热(DSC)、热重分析(TG)和原位傅里叶转换红外光谱(in situ FT-IR)等对聚合过程和产物结构性能进行表征分析。采用基于密度泛函理论(DFT)的分子模拟方法对聚合起始步骤链增长机理进行探究。研究结果表明:稀土三元/TMAF催化体系可以在不改变聚合特征和共聚物结构性能的情况下,得到高达4 740.6 g/mol(1 mol Zn催化得到聚合物的质量)的催化活性,且将催化剂诱导期从100 min缩短至20 min。机理研究表明:环氧丙烷的插入步骤为反应的速控步骤,且该步骤所需克服的吉布斯自由能能垒随模型催化剂活性锌中心的自然成键轨道电荷的增加而降低,环状链增长机理中二氧化碳的插入并“返咬”成环所需克服的吉布斯自由能能垒很高,进一步证实了二氧化碳和环氧丙烷共聚反应更倾向于遵循链状链增长聚合机理形成聚碳酸亚丙酯。  相似文献   
8.
Because of the almost total lack of geological record on the Earth''s surface before 4 billion years ago, the history of the Earth during this period is still enigmatic. Here we describe a practical approach to tackle the formidable problems caused by this lack. We propose that examinations of lunar soils for light elements such as He, N, O, Ne, and Ar would shed a new light on this dark age in the Earth''s history and resolve three of the most fundamental questions in earth science: the onset time of the geomagnetic field, the appearance of an oxygen atmosphere, and the secular variation of an Earth–Moon dynamical system.  相似文献   
9.
Rare earth elements (REE) are a group of chemical elements that include lanthanoids (lanthanum to lutetium), scandium and yttrium. In the last decades, the REE demand in the industry and other areas has increased significantly. In general, REE have shown low concentrations in soils, plants, water and atmosphere, but they may accumulate in such environments due to anthropogenic inputs. In areas where there is REE contamination, the slow accumulation of these elements in the environment could become problematic. Many studies have shown environmental areas contaminated with REE and their toxic effects. Thus, it is important to review, in order to improve the current understanding of these elements in the environment, showing the effects of REE exposure in mining, soil, water, plants and food. Besides, there are few suppliers and a limited quantity of these elements in the world. This paper suggests options to improve the sustainability management of REE chain.  相似文献   
10.
背景与目的:研究三氯化镧(LaCl3)对大鼠肝癌细胞CyclinD1和CDK4蛋白表达的影响.材料与方法:采用体外培养大鼠肝癌细胞株CBRH-7919,分别加入0.01、0.10、1.00 mmol/L LaCl3培养1、3、5 d后观察CBRH-7919细胞生长变化;运用流式细胞术、MTF实验和免疫细胞化学检测与G1期调控有关的CyclinD1和CDK4的变化情况,以培养液中不加LaCl3体外培养CBRH-7919作为对照.结果:0.10、1.00 mmol/L LaCl3组培养后3、5 d对细胞的生长均具有抑制作用,与对照组比差异具有统计学意义(P<0.01);G0/G1期细胞百分数均有显著性增加,与对照组比差异均具有统计学意义(P<0.01);CyclinD1、CDK4阳性表达均显著减弱,与对照组比差异具有统计学意义(P<0.01).结论:LaCl3可通过下调CyclinD1和CDK4,使肿瘤细胞从G1期进入S期受阻,从而抑制CBRH-7919细胞的生长.  相似文献   
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