Modulation of hypertensive heart disease by estrogen

During pharmaceutical production the quality of the air in manufacturing areas is monitored by volumetric samplers and settle plates. Settle plates are often assigned a secondary role, their usefulness in predicting airborne contamination of containers not being fully recognised. In this paper criticisms of settle plates are answered and the advantages of settle plates explained. It is concluded that using settle plates is the best method of quantifying the likely airborne microbial contamination of containers filled in pharmaceutical production areas.     

Plastic Buckling of Simply Supported, Polygonal Mindlin Plates

This paper is concerned with the plastic buckling of Mindlin plates of polygonal plan shape and whose straight edges are simply supported. The plates are subjected to a uniform in-plane compressive stress. Two well-known competing theories of plasticity are considered here: the incremental theory of plasticity (with the Prandtl–Reuss constitutive relations) and the deformation theory of plasticity (with the Hencky constitutive relation). Based on an analogy approach, the plastic buckling stresses of such Mindlin plates are expressed in terms of their corresponding elastic buckling stresses of Kirchhoff (classical thin) plates, albeit in a transcendental form. Using this buckling stress relationship and the readily available elastic buckling solutions, one may deduce the plastic buckling stresses of the corresponding Mindlin plates. Tabulated herein are some buckling stress factors for various polygonal shaped plates with material properties defined by the Ramberg–Osgood relation.     

IC Debonding of FRP NSM and EB Retrofitted Concrete: Plate and Cover Interaction Tests

The use of fiber-reinforced polymer (FRP) externally bonded (EB) plates is widely accepted as an efficient and unobtrusive retrofitting technique. FRP near-surface mounted plates are now also gradually gaining acceptance due to their substantial increase in debonding strains over EB plates. However tests have shown that the intermediate crack (IC) debonding resistances of FRP plates can be reduced by their interaction with adjacent parallel plates and with parallel free surfaces, that is the cover; this is often reflected in design rules where the IC debonding resistance of individual plates depends on the width of the plate as a proportion of the width of the concrete specimen and on the cover. In this paper, 22 new pull tests are reported that study the IC debonding interaction with adjacent plates and cover. The results are encouraging as they show that there is little reduction in the IC debonding resistance until the lateral cover or gap between plates is relatively small.     

大冶铁矿回转烘干机导料板的改进设计

通过分析烘干机筒体与导料板的截交关系。提出了一种新型设计方法：将空间曲面导料板改成平面结构导料板。并应用于大冶铁矿的生产实际。这种平面结构导料板具有制作简单、安装方便等优点。还可以避免因为积料导致烘干机驱动电机电流的增大。     

Membrane Analogy of Buckling and Vibration of Inhomogeneous Plates

Exact explicit eigenvalues are found for compression buckling, hygrothermal buckling, and vibration of sandwich plates with dissimilar facings and functionally graded plates via analogy with membrane vibration. These results apply to simply supported polygonal plates using the first-order shear deformation theory and the classical theory. A Winkler-Pasternak elastic foundation, a hydrostatic inplane force, hygrothermal effects, and rotary inertias are incorporated. Bridged by the vibrating membrane, exact correspondence is readily established between any pairs of eigenvalues associated with buckling and vibration of sandwich plates, functionally graded plates, and homogeneous plates. Positive definiteness is proved for the critical buckling hydrostatic pressure and, in the range of either tension loading or compression loading prior to occurrence of buckling, for the natural vibration frequency.     

Analytical and Numerical Models of Postbuckling of Orthotropic Symmetric Plates

Two analytical perturbation methods which give approximate solutions of postbuckling behavior of orthotropic simply supported plates are considered in this work: the method of Chandra and Raju and the method of Shen and Zhang. The reproduction of the algebraic developments of these methods by the Mathematica symbolic manipulator program has revealed that there are errors in the formulas included in the original paper by Chandra and Raju. After a revision and correction of these errors, the analytical results of both methods for a set of 23 orthotropic plates are compared, an excellent agreement being found for a wide range of values of geometrical and mechanical parameters in which many actual plates lie. A numerical simulation performed on a reduced sample of six plates using finite-element code ABAQUS has validated analytical results. The present work is intended as a first step in the investigation of the possibility of using reliable analytical formulas in the design of composite plates.     

电力机车受电弓滑板的现状

概述了影响电力机车受电弓滑板寿命的主要原因,阐述了国内一些不同材质滑板的特点和应用,分析了受电弓滑板的发展趋势,指出碳基复合材料是今后电力机车滑动集电材料的主要发展方向.     

Martensite plate arrangements in 01 tool steel

In a commercial 01 tool steel austenitized at 1200°C, martensite plates form in small clusters within austenite which has been partitioned by grain boundaries and preexisting martensite plates. But the surface of martensite plate mid-planes increases only about one fourth as rapidly and the plates are about six times as long as would be expected from random formation in austenite randomly partitioned by preexisting plates. Martensite plates maintain a constant thickness until their radius is restricted to approximately the distance which is tip affected, about 10 μm. The plate thickness to radius ratio is not constant.     

Martensite plate arrangements in 01 tool steel

In a commercial 01 tool steel austenitized at 1200°C, martensite plates form in small clusters within austenite which has been partitioned by grain boundaries and preexisting martensite plates. But the surface of martensite plate mid-planes increases only about one fourth as rapidly and the plates are about six times as long as would be expected from random formation in austenite randomly partitioned by preexisting plates. Martensite plates maintain a constant thickness until their radius is restricted to approximately the distance which is tip affected, about 10 μm. The plate thickness to radius ratio is not constant.     

Study of the mechanical characteristics of low-carbon plate steels

The Azovstal’ Metallurgical Combine has conducted tests of the production of plates of low-carbon (0.06–0.08% C) low-alloy steels 06GBD and 06G2B. The plates, ranging up to 45 mm in thickness and having yield points ≥390 and ≥440 N/mm², respectively, are intended for use in structures employed for critical applications. Both steels are microalloyed with niobium, vanadium, molybdenum, and additions of copper. It is shown that in the quenched-and-tempered state the two steels fully conform to the specifications. The plates are characterized by excellent cold resistance, impact toughness, and weldability (C_e = 0.34–0.37 for steel 06GBD and C_e = 0.38–0.41 for steel 06G2B) and satisfactory values of the ratio σ _y/σ _u (≤0.90 for plates with a thickness ≤20 mm and ≤0.85 for plates with a thickness >20 mm). The construction of serial curves describing impact work and the percentage of the ductile component in the fracture of Charpy specimens prepared from plates of steel 06GBD showed that the plates have a high resistance to brittle fracture (impact work was at least 145 J at ?70°C, and the percentage of ductile fracture was 100% for 14-mm-thick plates and 80% for 32-mm-thick plates).     

Keep the nail plate on with Histoacryl

Sutures are commonly used to secure nail plates after nail-bed repair. Here we describe a technique to secure nail plates using an adhesive--Histoacryl blue (n-butyl-2-cyanoacrylate). We report a series of 16 avulsed nail plates secured with Histoacryl after nail bed repair with a satisfactory end result.     

Effect of Longitudinal Stress Gradients on Elastic Buckling of Thin Plates

This paper analyzes the effect of longitudinal stress gradients on the elastic buckling of thin isotropic plates. Two types of thin plates are considered: (1) a plate simply supported on all four edges and rotationally restrained on two longitudinal edges; and (2) a plate simply supported on three edges with one longitudinal edge free and the opposite longitudinal edge rotationally restrained. These two cases illustrate the influence of longitudinal stress gradient on stiffened and unstiffened elements, respectively. A semianalytical method is derived and presented herein to calculate the elastic-buckling stress of both types of rectangular thin plates subjected to nonuniform applied longitudinal stresses. Finite-element analysis using ABAQUS is employed to validate the semianalytical model for plates with fixed and/or simple supports. Empirical formulas are produced to calculate the buckling coefficients of plates with fixed and/or simple supports under longitudinal stress gradients. The results help establish a better understanding of the effect of longitudinal stress gradients on the elastic buckling of thin plates and are intended to aid in the development of design provisions to include these effects in the strength prediction of thin-walled beams under moment gradients.     

Study on the heat resistance of 55％ Al-Zn steel plates

Post-treated 55% Al-Zn steel plates,which have adequate mechanical properties and corrosion resistance,are widely used for automobiles,household appliances,and other products. The heat resistance of 55% Al-Zn steel plates is slightly lower than that of aluminum plates or hot-dip aluminized steel plates,but their corrosion resistance is better. Herein,by testing at different baking temperatures and for different periods,the trends of color,gloss,and loss weight have been analyzed. The heat-resistant properties of differently post-treated 55% Al-Zn steel plates,aluminum plates,and hot-dip aluminized steel plates have been studied.     

Q345B连铸坯内部质量对钢板力学性能的影响

文章研究了Q345B连铸坯低倍组织、碳偏析和钢板常规力学性能,从而找出Q345B连铸坯低倍组织对钢板常规性能的影响,为中厚板连铸坯轧制成的钢板力学性能预测提供依据。     

Analysis of Thick Circular Plates Undergoing Large Deflections

This investigation considers the effect of transverse shear deformation on bending of the axisymmetrically loaded isotropic and orthotropic circular and annular plates undergoing large deflection. The analysis treats the nonlinear terms of lateral displacement as fictitious loads acting on the plate. The solution of a von Kármán‐type plate is, therefore, reduced to a plane problem in elasticity and a linear plate‐bending problem. Results are presented for simply supported and clamped plates and are in good agreement with the available solutions. For plates considered in this study, the influence of shear deformation on lateral displacement becomes more significant as the orthotropic parameter increases. The linear and nonlinear solutions for orthotropic plates deviate at a low value of the maximum deflection‐to‐thickness ratio (w/h). Consequently, the extent of w/h within which the small‐deflection theory is applicable to orthotropic plates is much lower than the value of about 0.4 typically used for isotropic plates, and it depends, in general, on the degree of orthotropy. The technique employed in this study is well suited for the analysis of nonlinear plate problems.     

Analysis of Hybrid Laminated Composite Plates

Hybrid laminated composite plates are analyzed using a nine‐noded isoparametric plate finite element based on Mindlin's theory. The shear flexibility is included in the finite element modeling. Shear flexibility is of importance, especially when different materials are used in the laminate design. Hybrid laminates consisting of graphite∕epoxy and kevlar∕epoxy plies are considered for illustration. The study indicates that hybrid laminates provide stiffnesses that are intermediate to the values obtained for single‐material laminates. The minimum deflection is achieved at different fiber orientation for thick plates compared to thin plates. The deflection behavior of hybrid laminates seems to be less affected by outer‐ply stiffness in the case of thick plates. Thick plates show less variation in the first natural frequency with fiber orientation but hybridization changes the natural frequency considerably. The first natural frequency of the hybrid laminate can be made higher than the stiffer single‐material laminate.     

Exact Buckling Solutions For Rectangular Plates Under Intermediate and End Uniaxial Loads

This paper is concerned with the elastic buckling of rectangular plates subjected to both intermediate and end uniaxial loads. The rectangular plates have two simply supported opposite edges that are perpendicular to the in-plane load direction, while the other two plate edges can have free, simply supported, or clamped edges. The solution procedure involves the use of the Levy approach, the domain decomposition technique, and the state-space concept. The method furnishes exact stability criteria; samples of which are presented in a graphical form for plates with various boundary conditions. These results will be useful to engineers who design plates (or walls) that support intermediate floors.     

Response of RC T-Beams Strengthened for Flexure with Staggered CFRP Plates

The results of an analytical and experimental study on the behavior of reinforced concrete T-beams retrofitted with carbon-fiber-reinforced polymer (CFRP) plates are discussed in this paper. CFRP plates were bonded to the underside of the beams with the main objective of increasing the service life load capacity. A test series comprising a prototype beam and six 5-m-long simply supported beams were tested under repeated cyclic and monotonic load conditions to failure. Particular emphasis was given to the development of the CFRP plates and to the behavior of the service and ultimate load ranges. This paper examines variables that have not previously been considered such as the use of staggered plates and the use of plates on beam with curtailed longitudinal steel reinforcement. The effect of diagonal tension cracking is also considered in this study by adapting a simple version of the modified compression field theory into the discrete element method. An important conclusion in this paper is that staggered CFRP plates can be used in lieu of full-length plates when considering flexural strengthening of beams.     

碳基复合材料模压双极板研究进展

双极板作为质子交换膜燃料电池（PEMFCs）的重要组成部件,对电池堆的重量、体积、效率、耐久度、成本起着决定性作用。目前,金属板与石墨板电堆制备技术相对成熟,已经广泛应用于商用车、乘用车领域,但复合双极板的生产制造因原料配方未完全实现国产化、无法大批量流水线生产、成本较高等在我国仍未大批量投入市场,寻找低成本的原材料、优化原料配比及加工条件、缩短加工周期对复合双极板的产业化具有重要意义。本文首先比较了金属双极板、石墨双极板和复合双极板的特点,介绍了复合双极板的模压工艺及优点,然后概述了碳基复合材料模压双极板的研究进展,包括以酚醛树脂、环氧树脂和乙烯基酯树脂等热固性树脂为黏结剂的树脂/石墨复合双极板和炭黑、碳纤维、碳纳米管增强复合双极板,重点总结了原料种类、配比和成型工艺条件对双极板性能的影响,最后梳理了复合双极板的产业化现状,提出国内外主要双极板研发企业面临的问题,并对复合双极板的发展方向进行了展望。      

Moment-Inelastic Rotation Behavior of Longitudinally Stiffened Beams

The significance for inelastic design of moment-inelastic rotation behavior with respect to interior pier sections of steel girder bridges is experimentally investigated. Under center span loading conditions, 12 welded, built-up, simply supported beams with various slenderness ratios of the flange and web plates are tested. In this test, lengths and locations for partial longitudinal stiffeners on the web plates are varied, and the results are then compared with the inelastic deformation capacity of beams without longitudinally stiffened web plates. The results are also compared with the inelastic design code in AASHTO LRFD bridge design specifications. It is concluded that (1) the ultimate strength of stiffened beams is governed by the local buckling at the compression flange of the far end from the loading point due to the presence of a partial longitudinal stiffener; and (2) the inelastic rotation capacity and ultimate strength of a beam with a stiffened web plate are remarkably improved. The optimum length and location of stiffeners on the plates are given.