弹性力学平面问题的精确元法

本文在阶梯折算法和精确解析法的基础上,提出构造有限元的新方法——精确元法.该方法不用一般变分原理,可适用于任意变系数正定和非正定偏微分方程.利用该方法得到弹性力学平面问题的一个非协调任意四边形单元.它具有八个自由度.由于没有采用雅可比变换,该单元可以蜕化为三角形单元,在工程中使用起来较为方便.文中给出收敛性证明.文末给出算例,位移和应力均给出较好的结果,在单元的节点上有较好的数值精度.

由可精确测量元控制的弱可换的伪效应代数

主要研究了由可精确测量元控制的弱可换的伪效应代数中可精确测量元。证明了可精确测量元控制的弱可换的伪效应代数中可精确测量元是弱可换的伪正交代数代数。讨论了弱可换的伪效应代数与BZ-偏序集之间的关系。讨论了弱可换的伪效应代数商代数中可精确测量元与正规Riesz理想之间的关系。

基于“情景模型线索假设”的外语阅读元理解监测精确性研究

在"情景模型线索假设"的基础上,本文通过两项实证研究对外语篇章阅读元理解监测精确性及其内部机制进行了考察。93名二年级英语专业本科生参加了测试。研究一对不同阅读能力外语学习者元理解监测精确水平及其线索使用情况进行了比较。结果发现:高阅读能力组元理解监测精确水平显著高于低能力组;与后者相比,前者在元理解判断时更多地使用了与情景模型相关的线索。研究二在研究一基础上,从线索干预角度进一步探讨了"延迟关键词效应"以及关键词质量在外语阅读元理解监测中的作用,结果表明:"延迟写关键词"仅对高阅读能力组元理解监测精确水平具有促进作用,而对低能力组的影响不显著;然而,无论阅读能力如何,关键词产出质量对于监测水平的提高均具有显著作用。

线索编码和提取时间间隔对外语阅读元理解监测精确性的影响

本文分别在分段延迟与即时判断两种模式下,探讨了元记忆线索编码和提取时间间隔对外语学习者元理解监测准确性的影响。60名英语专业一年级本科生参加了实验。研究结果表明:线索加工时间间隔对外语阅读元理解监测精确性具有显著影响,并且这种影响会依据阅读水平的不同而表现出差异。上述研究结果印证了线索加工的外部条件以及目的语阅读能力在外语元理解监测中的作用。

甘蔗糖厂多次元精准配比低温新型燃硫炉系统的开发与应用

本研究开发并介绍了新型低温燃硫炉系统,分析了该系统在亚硫酸法甘蔗糖厂实际生产中的应用效果。结果表明:新型燃硫炉系统能够显著提升清混汁纯度差,澄清效果明显改善。同时,白砂糖质量明显提升,其中色值降低10%以上,AA级白砂糖产率提升20%左右。该应用对于提高亚硫酸法甘蔗糖厂生产澄清效果,提升产品质量,降低生产成本,促进生产向自动化、智能化发展具有重要的意义。

外语听力的元理解监测精确性研究

本研究采用标准化语篇听力测试任务,对66名英语专业学生的听力元理解监测精确性及其监测线索使用特点进行了考察,并结合"情景模型线索理论"从教育干预角度探讨了延迟关键词效应对外语听力元理解监测精确性的影响。研究结果表明:(1)外语学习者倾向于采用非情景模型类线索对听力理解程度进行判断,导致其元理解监测精确性较低;(2)延迟关键词组与即时、无关键词组之间的元理解监测精确性差异仅达到边际显著水平,表明延迟写关键词对听力元理解监测的促进作用有限;(3)无论在即时还是延时条件下,关键词质量与听力元理解监测精确性均呈显著正相关。

由可精确测量元控制的效应代数上的态

证明了由可精确测量元控制的Archimedes原子格效应代数能被所谓的元素基本分解性质所刻画.做为应用,证明了这类效应代数的态弥漫定理.

Simulation and Design Optimization of Novel Microelectromechanical Digital-to-Analog Converter

A microelectromechanical Digital to Analog Converter (DAC) based on Weighted Gap (WG) principle is described,which is analogous to the weighed resistor DAC in electronic circuits.To convert the input of binary voltage to the output of analog displacement,the gaps are proposed to be employed as a scale factor.A finite element method is used to simulate the performance of the DAC.To reduce the error,the structure design is optimized and the maximum error of 0 002μm is obtained.

The Habitus Made Me Do It： Bourdieu＇s Key Concept as a Substruction of the Monad

My claim is that Bourdieu＇s concept of habitus is not consistent and its ambiguities conceal an imprecision concerning the subject of social action. Indeed, Bourdieu defines habitus in three different ways： as a capacity, as a set of dispositions, and as a scheme for practice. That is why he cannot solve the problem of the duality of agent and habitus and produces a problem offundamentation, as we can see in his troubles to determine which is the substratum of social actions. Though Bourdieu claims he borrows the concept of habitus from Husserl and other phenomenologists, many divergences can be stated in the way they conceive it. Unlike Bourdieu, phenomenology can establish precise relations of fundamentation between agent, habitus, and the ego because it avoids the fallacy of the wrong level involved in the attribution of systemic properties to personal eogic structures. Accordingly, it provides a consistent and precise concept of the habitus,

Regression analysis of major parameters affecting the intensity of coal and gas outbursts in laboratory

Estimating the intensity of outbursts of coal and gas is important as the intensity and frequency of outbursts of coal and gas tend to increase in deep mining. Fully understanding the major factors contributing to coal and gas outbursts is significant in the evaluation of the intensity of the outburst. In this paper, we discuss the correlation between these major factors and the intensity of the outburst using Analysis of Variance(ANOVA) and Contingency Table Analysis(CTA). Regression analysis is used to evaluate the impact of these major factors on the intensity of outbursts based on physical experiments. Based on the evaluation, two simple models in terms of multiple linear and nonlinear regression were constructed for the prediction of the intensity of the outburst. The results show that the gas pressure and initial moisture in the coal mass could be the most significant factors compared to the weakest factor-porosity. The P values from Fisher's exact test in CTA are: moisture(0.019), geostress(0.290), porosity(0.650), and gas pressure(0.031). P values from ANOVA are moisture(0.094), geostress(0.077), porosity(0.420), and gas pressure(0.051). Furthermore, the multiple nonlinear regression model(RMSE: 3.870) is more accurate than the linear regression model(RMSE: 4.091).

THE SUPERCONVERGENCE ANALYSIS OF AN ANISOTROPIC FINITE ELEMENT

This paper deals with the high accuracy analysis of bilinear finite element on the class of anisotropic rectangular meshes. The inverse inequalities on anisotropic meshes are established. The superclose and the superconvergence are obtained for the second order elliptic problem. A numerical test is given, which coincides with our theoretical analysis.

High accuracy nonconforming finite elements for fourth order problems

The approach of nonconforming finite element method admits users to solve the partial differential equations with lower complexity,but the accuracy is usually low.In this paper,we present a family of highaccuracy nonconforming finite element methods for fourth order problems in arbitrary dimensions.The finite element methods are given in a unified way with respect to the dimension.This is an effort to reveal the balance between the accuracy and the complexity of finite element methods.

An efficient rectangular plate element

A new 12-parameter rectangular plate element is presented by useof the double set parameter method. The error in the energy norm is of order O(h2), one order higher than the commonly used Adini nonconforming element.

Pulling growth technique towards rare earth single crystals

Pulling growth technique serves as a popular method to grow congruent melting single crystals with multiscale sizes ranging from micrometers to centimeters.In order to obtain high quality single crystals,the crystal constituents would be arranged at the lattice sites by precisely controlling the crystal growth process.Growing interface is the position where the phase transition of crystal constituents occurs during pulling growth process.The precise control of energy at the growing interface becomes a key technique in pulling growth.In this work,we review some recent advances of pulling technique towards rare earth single crystal growth.In Czochralski pulling growth,the optimized growth parameters were designed for rare earth ions doped Y_3Al_5O_(12)and Ce:(Lu_(1-x)Y_x)_2Si O_5on the basis of anisotropic chemical bonding and isotropic mass transfer calculations at the growing interface.The fast growth of high quality rare earth single crystals is realized by controlling crystallization thermodynamics and kinetics in different size zones.On the other hand,the micro pulling down technique can be used for high throughput screening novel rare earth optical crystals.The growth interface control is realized by improving the crucible bottom and temperature field,which favors the growth of rare earth crystal fibers.The rare earth laser crystal fiber can serve as another kind of laser gain medium between conventional bulk single crystal and glass fiber.The future work on pulling technique might focus on the mass production of rare earth single crystals with extreme size and with the size near that of devices.

Simple and cost-effective methods for precise analysis of trace element abundances in geological materials with ICP-MS

Inductively coupled plasma mass spectrometry （ICP-MS） is the most commonly used technique to deter- mine the abundances of trace elements in a wide range of geological materials. However, incomplete sample digestion, isobaric interferences and instrumental drift remain obvious problems that must be overcome in order to obtain precise and accurate results, For this reason, we have done many experi- ments and developed a set of simple, cost-effective and practical methods widely applicable for precise and rapid determination of trace element abundances in geological materials using ICP-MS. Commonly used high-pressure digestion technique is indeed effective in decomposing refractory phases, but this inevitably produces fluoride complexes that create new problems. We demonstrate that the fluoride complexes formed during high-pressure digestion can be readily re-dissolved using high-pressure vessel at 190 ℃ for only 2 h for 50 mg sample. In the case of isobaric interferences, although oxide （e.g., MO^＋/M^＋） and hydroxide （e.g., MO^＋/M^＋） productivity is variable between runs, the （MO^＋/M^＋）/（CeO^＋/Ce^＋） and （MOH^＋/M^＋）/（CeO^＋/Ce^＋） ratios remain constant, making isobaric interference correction for all other elements of interest straightforward, for which we provide an easy-to-use off-line procedure. We also show that mass-time-intensity drift curve is smooth as recognized previously, for which the correction can be readily done by analyzing a quality-control （QC） solution and using off-line Excel VBA procedure without internal standards. With these methods, we can produce data in reasonable agreement with rec- ommended values of international rock reference standards with a relative error of 〈8% and precision generally better than 5%. Importantly, compared to the widely used analytical practice, we can effectively save 〉60% of time （e.g., 〈24 h vs. 〉60 h）.