Scanning Analysis of REE in Bastnaesite with Synchrotron Radiation X－Ray Fluorescence Microprobe

ＳｃａｎｎｉｎｇＡｎａｌｙｓｉｓｏｆＲＥＥｉｎＢａｓｔｎａｅｓｉｔｅｗｉｔｈＳｙｎｃｈｒｏｔｒｏｎＲａｄｉａｔｉｏｎＸ－ＲａｙＦｌｕｏｒｅｓｃｅｎｃｅＭｉｃｒｏｐｒｏｂｅＡｎＱｉｎｇｘｉａｎｇ（安庆骧）；ＷａｎｇＲｕｉｂｉｎｇ（王锐兵）；ＤｅｎｇＳａ...     

Analysis of Stability and Large Deflection Buckle of Rolled Strip by Third Power B-Spline Function Method

ＡｎａｌｙｓｉｓｏｆＳｔａｂｉｌｉｔｙａｎｄＬａｒｇｅＤｅｆｌｅｃｔｉｏｎＢｕｃｋｌｅｏｆＲｏｌｅｄＳｔｒｉｐｂｙＴｈｉｒｄＰｏｗｅｒＢ┐ＳｐｌｉｎｅＦｕｎｃｔｉｏｎＭｅｔｈｏｄＢｉａｎＹｕｈｏｎｇ①ＡＢＳＴＲＡＣＴＡｎｅｗｍｅｔｈｏｄ——ｔｈｅｔｈ...     

Mobile Equilibrium Method for Determining Composition and Stability Constant of Coordination Compounds of the Form M_mR_n

ＭｏｂｉｌｅＥｑｕｉｌｉｂｒｉｕｍＭｅｔｈｏｄｆｏｒＤｅｔｅｒｍｉｎｉｎｇＣｏｍｐｏｓｉｔｉｏｎａｎｄＳｔａｂｉｌｉｔｙＣｏｎｓｔａｎｔｏｆＣｏｏｒｄｉｎａｔｉｏｎＣｏｍｐｏｕｎｄｓｏｆｔｈｅＦｏｒｍＭｍＲｎＺｈｏｕＺｈｉｍｉｎｇ（周执明），ＭａｏＤ...     

Kinetic Analysis of Isothermal Decomposition Process of Sodium Bicarbonate Using the Weibull Probability Function—Estimation of Density Distribution Functions of the Apparent Activation Energies

The decomposition process of sodium bicarbonate (NaHCO₃) has been studied by thermogravimetry in isothermal conditions at four different operating temperatures (380 K, 400 K, 420 K, and 440 K). It was found that the experimental integral and differential conversion curves at the different operating temperatures can be successfully described by the isothermal Weibull distribution function with a unique value of the shape parameter (β = 1.07). It was also established that the Weibull distribution parameters (β and η) show independent behavior on the operating temperature. Using the integral and differential (Friedman) isoconversional methods, in the conversion (α) range of 0.20 ≤ α ≤ 0.80, the apparent activation energy (E _a ) value was approximately constant (E _a,int  = 95.2 kJmol⁻¹ and E _a,diff  = 96.6 kJmol⁻¹, respectively). The values of E _a calculated by both isoconversional methods are in good agreement with the value of E _a evaluated from the Arrhenius equation (94.3 kJmol⁻¹), which was expressed through the scale distribution parameter (η). The Málek isothermal procedure was used for estimation of the kinetic model for the investigated decomposition process. It was found that the two-parameter Šesták-Berggren (SB) autocatalytic model best describes the NaHCO₃ decomposition process with the conversion function f(α) = α^0.18(1-α)^1.19. It was also concluded that the calculated density distribution functions of the apparent activation energies (ddfE _a ’s) are not dependent on the operating temperature, which exhibit the highly symmetrical behavior (shape factor = 1.00). The obtained isothermal decomposition results were compared with corresponding results of the nonisothermal decomposition process of NaHCO₃.     

Application of the Electrochemical Method for Stripping Eu~（3＋） after Extraction with Benzo－15－crown－5 in Dichloromethane

ＡｐｐｌｉｃａｔｉｏｎｏｆｔｈｅＥｌｅｃｔｒｏｃｈｅｍｉｃａｌＭｅｔｈｏｄｆｏｒＳｔｒｉｐｐｉｎｇＥｕ~（３＋）ａｆｔｅｒＥｘｔｒａｃｔｉｏｎｗｉｔｈＢｅｎｚｏ－１５－ｃｒｏｗｎ－５ｉｎＤｉｃｈｌｏｒｏｍｅｔｈａｎｅ￥ＫｏｎｇＦａｎｑｉ（孔繁岐），Ｙ?..     

Analysis of Rolling Pressure in Asymmetrical Rolling Process by Slab Method

 The plane strain asymmetrical rolling was analyzed using slab method. The contact arc was replaced by parabola, and the constant surface friction status was adopted during the analysis. The deformation area was divided into three zones according to the direction of the friction. Then, the three zones were studied, respectively. A rolling force model and a rolling torque model were developed based on the analysis, and they were used to analyze the influence of asymmetrical rolling factors on deformation area and unit pressure if they had good precision which was determined by comparing the calculated results with the measured ones.     

Grey Interrelation Analysis for the Use of Rare Earths and the Elements in Soil in Growing Cotton

ＧｒｅｙＩｎｔｅｒｒｅｌａｔｉｏｎＡｎａｌｙｓｉｓｆｏｒｔｈｅＵｓｅｏｆＲａｒｅ　ＥａｒｔｈｓａｎｄｔｈｅＥｌｅｍｅｎｔｓｉｎＳｏｉｌｉｎＧｒｏｗｉｎｇＣｏｔｔｏｎＺｈａｎｇＤｉａｎｘｉａｎｇ（张殿香）（ＡｇｒｉｃｕｌｔｕｒｅＣｅｎｔｅｒｏｆＫａｚｕ...     

Fluid–Solid Reaction Kinetics for Solids of Non-basic Geometries: Application of the Law of Additive Times in Combination with the Shape-Factor Method

Metallurgical and Materials Transactions B - Fluid–solid reactions often occur under the mixed rate control of chemical and mass transfer processes. The results of this work demonstrate that...     

An Application of the Inverse Solution for Electric Current Distribution From Magnetic Field Measurements in Aluminium Electrolysis Cells

A mathematical theory and the software application based on the full MHD model of the electrolysis cell is used to predict the electric current distribution over the anodes from the measurement of magnetic fields at specifically defined node points assumed to be available from the wireless sensors.The full 3d busbar configuration of two different commercial ceils are used for the model simulations.It is demonstrated that a unique solution for the electric current can be obtained when two sensors per each anode are used to detect the single component of magnetic field.The mathematical software is tested for the sensitivity to the busbar configuration complexity.The ability to monitor continuously the electric current distribution to high accuracy helps to control disturbances and deviations from a normal production process.     

Compilation of Q－data and Simulation of Q－spectra in Rare Earth Elements Analysis by Using ICP－AES

ＣｏｍｐｉｌａｔｉｏｎｏｆＱ－ｄａｔａａｎｄＳｉｍｕｌａｔｉｏｎｏｆＱ－ｓｐｅｃｔｒａｉｎＲａｒｅＥａｒｔｈＥｌｅｍｅｎｔｓＡｎａｌｙｓｉｓｂｙＵｓｉｎｇＩＣＰ－ＡＥＳＨｕｏＤｅｎｇ－Ｗｅｉ（霍登伟），ＹｉｎＸｉａｎｇ－Ｌｉａｎ（尹香莲），ＺｈａｏＧ...     

X光小角散射理论的研究

在改进原有实验条件的基础上，通过对原有X射线的小角散射理论进行修正及合理简化，从而建立了新的数学模型。并借助计算机进行数据处理，大大地提高了数据处理的效率。实验中通过接装角度显视仪，使我们能精确地测定出散射的角度，并在该角度下延时测量散射强度。有效地解决了样品薄所带来的散射强度弱的问题，提高了角度测量的精度。同时也为理论研究提供了可靠的依据。通过对比，新的数据处理方法与其它数据处理方法得到的结果吻合。这证明了该数字模型的可靠性和实用性。     

X射线小角散射法测量纳米粉末的粒度分布

在常规高分辨X射线衍射仪上应用小角散射法测量了ZnO、ZrO2、Fe和Al2O3纳米粉末的粒度分布。测量结果与专用X射线小角散射仪器的测量结果一致，并经TEM分析验证。证明在常规高分辨X射线衍射仪上应用小角散射法测量纳米粉末的粒度是可行的。与采用四狭缝系统或Kratky狭缝系统的专用小角散射仪相比，该方法的特点是操作简单，成本较低，易于推广。目前此法可测量1～300nm范围的粉末粒度。     

激光法测定稀土粉体粒度的影响因素研究

采用激光粒度分析仪对多种稀土粉体粒度测量中分散剂、分散时间、样品种类、样品浓度、折射率及测定误差等影响因素进行研究,分析在测量过程中影响稀土粉体粒度的因素,确定了激光法测定稀土粉体粒度的测量条件。并可由测定结果来推断粉体的球形状况。     

激光粒度分布仪检测细碳化钨粉方法

随着微细、超细甚至纳米级钨粉、碳化钨粉的生产,粉末粒度分布的检测方法也随之发生重大变革,从传统的沉降法、显微镜法等逐步演化成了现代的激光粒度分布仪检测方法,然而现在的激光粒度分布仪检测方法仍然存在一些问题,尤其是检测不稳定,检测出较多的粗大颗粒或团聚问题。笔者对激光粒度分布仪的检测方法进行了摸索,找到其检测不稳定的原因,并提出了检测稳定的方法。     

库尔特激光粒度分布仪在测定钽铌复合物粒度分布中的应用

文章介绍了应用库尔特激光粒度分布仪测定钽铌复合物粒度分布的方法。钽铌复合物颗粒均匀分散在二次去离子水中,以一定的流速通过激光束。衍射光经透镜被光电探测器接收转化为电信号,由此测出颗粒的粒度分布,并讨论了应用中的经验。该方法容易建立,精密度高,能够给出多种粒度分布结果以及参数,非常适合生产过程中的应用。     

传统流程生产优质超细碳化钨粉的质量控制及粒度检测

从原料、碳化工艺、粉碎分级等方面探讨了传统流程生产优质超细碳化钨粉的质量控制,并对几种检测超细碳化钨粉粒度的方法进行了比较,结果表明由BET法测定的结果与粉末颗粒的实际尺寸最为接近.     

关于Rosin—Rammler粒径分布函数的研究

罗辛－－拉姆勒分布函数Ｇ－１－ｅｘｐ「－ａｄ＾ｎ」是最常用的描述粉尘径分布的一种形式,本计分布函数进行分析得出系数ａ与指数ｎ不是相互独立的,而是由中位径决定的。     

重质MnCO3粉末的粒度分布和颗粒形貌

测定了不同视密度下ＭｎＣＯ３粉末的粒度分布，揭示了重质ＭｎＣＯ３粒度分布的特性，用ＳＥＭ展现了颗粒的形貌。     

粒度仪在巴润选矿厂的应用

在选矿工业中,粒度无疑是选矿作业较为重要的指标,粒度的测定也就显得尤为重要。粒度仪是用一定的自动控制方法测试固体颗粒的大小和分布的一种仪器,文章主要是对矿浆样品的指标进行化验分析,得出DFPSM超声波粒度仪在选矿作业中的准确性,并对其与粒度大小、料流稳定的关系做进一步分析。     

粉末粒度分布对烧结钕铁硼微观结构形成的影响

烧结钕铁硼永磁材料是用粉末冶金方法制造的,其生产环节中的每道工序对磁体的最终性能都有相当大的影响。从微观结构上看,磁性能的高低主要是由于具体的微观结构不同造成的。而其中制粉环节粉末的粒度分布对最终产品微观结构的形成具有非常大的影响。采取一组实验,以探讨不同的粉末粒度分布对产品微观结构形成的影响。