Interaction Rule between Rare Earths and LowMelting Point Elements in Fe-,Cu-,AI-,Ni-Base Liquid Solutions

Interaction rule between representative RE and Sn, Sb, Pb, Cu, S, P low melting point elements respectively in Fe , Cu , Al , Ni base liquid solutions including totally 34 ternary and quarternary systems was investigated. For each system some thermodynamic properties were obtained, such as the standard free energies of equilibrium reactions, activity interaction coefficients etc ..

A Generalized Point Conforming Rectangular Plate Element

A generalized point conforming rectangular element for plate bending is proposed. The present element displacement field can not only satisfy the continuity of normal displacement and its derivative at the element node, but also satisfy the generalized continuity at the middle point of each element boundary, where the generalized conforming condition is to make the non-conforming residual to be minimum. Numerical results show that the proposed element is more accurate than the ordinary 4-node non-conforming rectangular plate element (ACM element).

Element-free Galerkin method for free vibration of rectangular plates with interior elastic point supports and elastically restrained edges

The element-free Galerkin method is proposed to solve free vibration of rectangular plates with finite interior elastic point supports and elastically restrained edges.Based on the extended Hamilton＇s principle for the elastic dynamics system,the dimensionless equations of motion of rectangular plates with finite interior elastic point supports and the edge elastically restrained are established using the element-free Galerkin method.Through numerical calculation,curves of the natural frequency of thin plates with three edges simply supported and one edge elastically restrained,and three edges clamped and the other edge elastically restrained versus the spring constant,locations of elastic point support and the elastic stiffness of edge elastically restrained are obtained.Effects of elastic point supports and edge elastically restrained on the free vibration characteristics of the thin plates are analyzed.

HIGH ACCURACY FINITE VOLUME ELEMENT METHOD FOR TWO-POINT BOUNDARY VALUE PROBLEM OF SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS

In this paper, a high accuracy finite volume element method is presented for two-point boundary value problem of second order ordinary differential equation, which differs from the high order generalized difference methods. It is proved that the method has optimal order error estimate O(h3) in H1 norm. Finally, two examples show that the method is effective.

Incremental Static Analysis of 2D Flow by Inter-Colliding Point-Particles and Use of Incompressible Rhombic Element

A simple method is proposed, for incremental static analysis of a set of inter-colliding particles, simulating 2D flow. Within each step of proposed algorithm, the particles perform small displacements, proportional to the out-of-balance forces, acting on them. Numerical experiments show that if the liquid is confined within boundaries of a set of inter-communicating vessels, then the proposed method converges to a final equilibrium state. This incremental static analysis approximates dynamic behavior with strong damping and can provide information, as a first approximation to 2D movement of a liquid. In the initial arrangement of particles, a rhombic element is proposed, which assures satisfactory incompressibility of the fluid. Based on the proposed algorithm, a simple and short computer program (a “pocket” program) has been developed, with only about 120 Fortran instructions. This program is first applied to an amount of liquid, contained in a single vessel. A coarse and refined discretization is tried. In final equilibrium state of liquid, the distribution on hydro-static pressure on vessel boundaries, obtained by proposed computational model, is found in satisfactory approximation with corresponding theoretical data. Then, an opening is formed, at the bottom of a vertical boundary of initial vessel, and the liquid is allowed to flow gradually to an adjacent vessel. Almost whole amount of liquid is transferred, from first to second vessel, except of few drops-particles, which remain, in equilibrium, at the bottom of initial vessel. In the final equilibrium state of liquid, in the second vessel, the free surface level of the liquid confirms that the proposed rhombing element assures a satisfactory incompressibility of the fluid.

A New Fixed Point Theorem in L-Convex Spaces with Applications

In this paper, we present a new fixed point theorem in L-convex spaces and apply it to obtain a maximal element theorem, a variational inequality and a saddle point theorem in L-convex spaces.

Application of finite element method to design of reinforced concrete

Structural safety against collapse will be ensured on the condition that stresses and strains in each element of concrete and reinforcement do not exceed the set limits. Different from the general design method, the required amounts of longitudinal and stirrup reinforcements in reinforced concrete beam under certain loads by the finite element design method are interactive. There is an approximate hyperbolic relation between them. Considering economy and the design principle that beam should be stronger for shear and weaker for bending, even the yield point of longitudinal reinforcement is taken as reference point for design. According to this point, a real-life beam is designed and the design steps of the finite element method are discussed.

Mathematical analysis of EEP method for one-dimensional finite element postprocessing

For a class of two-point boundary value problems, by virtue of onedimensional projection interpolation, it is proved that the nodal recovery derivative obtained by Yuan＇s element energy projection （EEP） method has the accuracy O（h^min{2k,k＋4}） The theoretical analysis coincides the reported numerical results.

Finite Element Modeling and Design of Rectangular Patch Antenna with Different Feeding Techniques

The finite element modeling of three dimensional structures is important for researchers especially in the field of antennas and other domains of electromagnetic waves. This paper presents a finite element calculations and numerical analysis for the microstrip patch antennas. In this paper, two different designs have been modelled and analyzed and both designs are based on the rectangular patches. The feeding point of one design is inside the patch while the other design contains feeding point outside the patch is T shaped. The computational analysis showed some interesting results for radiation pattern and far field domain. For these designs, the characteristic impedance taken is 50 Ω and the operating frequency domain is 1.4 to 1.7 GHz. The microstrip patch antennas are encapsulated in the inert spherical atmosphere of 20 mm thickness containing air inside it.

三维有限元中奇异点源的简化分析方法

减压井是渗流控制的重要手段,减压浅井井底的入渗量不可忽略。在渗流场有限元有关井的计算中,含水层与井半径有巨大尺寸差异,只有将井周围的网格尺寸限制在厘米级或更少,才能达到合理的精度,但效率过低。为提高效率,分析时通常将井底简化为点源。由于点源附近的水头梯度极大,是奇异点,有限元中通常要进行等效处理才能保证全局的精度。提出了以零体积点元模拟点源的方法,该方法基于修正井水位法,利用点源解析解及四面体渗流单元,推导了点元单元的显式解。使用该点元单元模拟井底,可以在不失全局精度的条件下用大网格对点源进行模拟,避免了迭代计算,极大提高了利用三维有限元模拟点源的效率。详细介绍了该点元显式解的推导过程,验证其计算精度,并探究出简化计算方法的适用范围。最后介绍了该方法在实际排水减压抗浮工程中的应用。

MAXIMAL ELEMENTS OF A FAMILY OF G_B-MAJORIZED MAPPINGS IN PRODUCT FC-SPACES AND APPLICATIONS

A new family of GB-majorized mappings from a topological space into a finite continuous topological spaces （in short, FC-space） involving a better admissible set-valued mapping is introduced. Some existence theorems of maximal elements for the family of GB-majorized mappings are proved under noncompact setting of product FCspaces. Some applications to fixed point and system of minimax inequalities are given in product FC-spaces. These theorems improve, unify and generalize many important results in recent literature.

Stress Distribution in Maxillary Central Incisors without Ferrules: A Finite Element Analysis of Post and Core Systems

Purpose: The purpose of this study was to identify optimal post and core materials for central incisors without ferrules using three-dimensional finite element analysis and three-point bending tests. Methods: Stress analyses were performed with six models: cast metal post and core (MP), composite resin core alone, straight fiber-reinforced post-composite resin core (FSR), tapered fiber-reinforced post-composite resin core, straight titanium post-composite resin core (TSR), and tapered titanium post-composite resin core (TTR). A 100-N load was applied to the lingual surface at a 45° angle to the long axis of the tooth. Maximum von Mises stress distributions were calculated with finite element analysis software. Five samples each of composite resin, straight fiber-reinforced post, straight titanium post, straight fiber-reinforced post and composite resin, and straight titanium post and composite resin were subjected to three-point bending tests, followed by analysis of variance and Tukey’s multiple comparison test. Results: Stress distribution was optimal on TTR. Maximum von Mises stress on the cervical side of the post was greatest in TSR (693 MPa) and TTR (556 MPa). Maximum stress on the apical side of the post was greatest in MP (110 MPa). Maximum stress in surrounding dentin was lowest in MP (203 MPa) and TTR (250 MPa). Gap distance was smallest in MP (0.09 mm) and largest in FSR (0.26 mm). Mean maximum three-point bending force was lowest in composite resin (26.9 N/mm) and highest in titanium post and composite resin (97.1 N/mm). Titanium post bending strength was consistently greater than that of the fiber-reinforced post (p < 0.01). Conclusion: These results revealed optimal stress distribution and high bending strength with the tapered titanium post and resin combination, suggesting that this combination can most effectively prevent root or post fracture in an anterior tooth without a ferrule.

Superconvergence of Continuous Finite Elements with Interpolated Coeffcients for Initial Value Problems of Nonlinear Ordinary Differential Equation

In this paper, n-degree continuous finite element method with interpolated coefficients for nonlinear initial value problem of ordinary differential equation is introduced and analyzed. An optimal superconvergence u-uh = O(hn+2), n ≥ 2, at (n + 1)-order Lobatto points in each element respectively is proved. Finally the theoretical results are tested by a numerical example.

Fitting on elements of exterior orientation utilizing SPOT-5 raw data file

In traditional pattern, the calculation of elements of exterior orientation is to calculate the elements of image forming moment by using fundamental ground control points. Utilizing satellite raw data file directly, which holds abundant information and using the numerical analysis methods of modern mathematics, the parameter equations about each element of exterior orientation are adjused and the elements of image forming moment under some precision are calculated.

海洋科考船码头设计要素和要点研究及应用

随着国内海洋开发、海洋科考及海洋维权等需求的日益增加,现有的科考船码头普遍无法适应大型及新型科考船的实际需求。为了更好地推进海洋科考船码头的规划建设,通过对海洋科考船码头营运模式和功能需求两大功能要素、船型要素分析总结,提出了海洋科考船码头设计过程中的选址、水域布置、装卸工艺、水工结构、后方陆域及配套工程等要点,可为后续类似海洋科考船码头工程设计提供参考。

低熔点亲铜元素(LMCE)在金成矿中的作用及促进金富集的机理

低熔点亲铜元素(LMCE),包含As、Sb、Bi、Hg、Pb、Se、Te、Tl、Sn等,在戈尔德斯密特(V·M·Goldschmidt)元素地球化学分类中均属于亲铜元素。它们具有亲铜性、电负性大、低熔点、半金属的特性。在金成矿过程中,这些元素与硫的亲和力强,多形成LMCE的硫化物、硫盐矿物、硒化物、碲化物和金属互化物,甚至形成LMCE与金的互化物和金的化合物。同时,它们在成矿流体中可以形成LMCE熔体,并对金矿床中Au的高效富集沉淀起到一种重要的桥梁作用。作者针对LMCE在金矿床中的赋存状态,总结了金矿床中LMCE富集金的特点,综合归纳了LMCE对金富集的成矿机理,认为在一些大型金矿床中,除了人们熟知的水-岩反应、硫化作用、流体沸腾、流体混合、有机成矿、岩浆脱气、叠加成矿等对热液金矿床的成矿起到重要作用外,流体-熔体分离、溶解-再沉淀、矿物重结晶、矿物表面吸附和元素替代等地质作用,也是LMCE在成矿过程中对金的富集重要机制。

Multivariate Analyses of Potentially Toxic Elements along an Industrialized Urban River in Northern Taiwan

The Ker-Ya River flows through the high-tech industrial park and urban residential areas of Hsin-Chu in northern Taiwan. Major and trace element concentrations of waste effluents, river water, and sediment samples collected during 2017 along the Ker-Ya River were analyzed to elucidate the distribution pattern of potential pollutants. Principal component analyses were applied, and four major contaminant associations were recognized: 1) Ce, Co, Fe, La, V, and Cr;2) Cu and Ni associated with Hg, Ni, P, Ga, W, In, and Ti;3) B, Li, Ba, Ca, and Ag;and 4) Sn with Zn, In, and Cd. All associations are considered to be mainly anthropogenic. Although the element associations recognized from the water samples are not exactly the same as those from the sediment samples but nevertheless, they are similar, suggesting that the short-term and long-term distribution patterns are consistent. The A association accounts for the most variance in the data and exhibits the widest distribution, suggesting the existence of contaminant sources in the upper and lower reaches, respectively. The sediments near the outlet of the city sewage plant also contain association A elements, signaling incomplete processing of the diverged waters sent to the plant at the river mouth. The B association (mainly Cu and Ni) appeared mainly in the upper and middle reaches, indicative of sources from industries in the upper reaches and the tributary Nan-Men Creek. The C association (B, Ba, Ca, and Li) was limited to the center part of the river, probably attributable to a nearby paper mill. The D association (primarily Sn, In, and Zn) was present in the top point of the middle reaches, suggesting the presence of other contaminant sources in the upper reaches. Although a total of four concomitant associations were recognized, none of the elements exceeded the drinking water standard, suggesting that there was no severe pollution present.

五行针灸联合耳穴压丸治疗卒中后抑郁症临床研究

目的:观察五行针灸联合耳穴压丸治疗卒中后抑郁症的效果。方法:80例以随机数字表法分为对照组和研究组各40例,对照组给予常规针灸治疗、研究组用五行针灸联合耳穴压丸治疗。结果:治疗后研究组HADS-A、HADS-D低于对照组(P<0.05)。治疗后研究组Cor水平低于对照组(P<0.05)而神经肽Y水平高于对照组(P<0.05)。治疗后研究NIHSS低于对照组(P<0.05)而Brathel指数高于对照组(P<0.05)。结论:五行针灸配合耳穴压丸治疗卒中后抑郁症可有效缓解焦虑、抑郁情绪,增强信心,改善神经功能缺损,促进日常生活能力提高。

五行音乐联合穴位按摩在肝阳上亢型中青年高血压患者中的应用研究

目的:探讨五行音乐联合穴位按摩对肝阳上亢型中青年高血压患者的应用效果。方法:选择在我院就诊的符合标准的病例纳入研究,以集团化、同质化管理的两个院区的两个病区随机分为两组,试验组和对照组各70例。对照组参照《中国高血压防治指南》(2018年修订版)进行常规治疗和护理,试验组在常规治疗和护理的基础上给予五行音乐联合穴位按摩疗法,在干预前、干预4个疗程后比较两组患者PSQI得分、HAMA得分、HAMD得分以及SF-36生活质量量表得分和血压情况。结果:治疗后,试验组患者降压疗效、睡眠质量、生活质量及焦虑状态的改善效果明显优于对照组,差异有统计学意义(P<0.05),但抑郁状态比较差异无统计学意义(P>0.05)。结论:五行音乐联合穴位按摩治疗肝阳上亢型中青年高血压患者,不仅能降低其血压水平,还能显著改善患者睡眠质量,减轻焦虑,进而提高其生活质量,临床效果显著,值得推广。

武安州塔动力特性与抗震性能分析

为给赤峰市武安州塔的加固保护工作提供依据,对古塔动力特性开展测试和数值模拟分析。首先对武安州塔的塔体材料力学参数进行测试;然后在考虑栣木构造措施基础上建立武安州塔的数值分析模型,对模型进行模态分析并通过经验公式进行验证;之后用该模型进行反应谱分析。研究结果表明,塔身周围4个正方位的券洞是塔体的薄弱部位,塔身和1~4层束腰部位出现拉应力,超出了砌体材料的抗拉强度极限值;塔体3层及以上已产生轻微破坏,存在较大安全隐患,需采取相应加固保护措施。