高阻尼黏弹性橡胶连梁阻尼器力学性能试验研究

黏弹性橡胶阻尼器是一种兼具黏滞性和弹性两种特性的阻尼器,耗能能力良好,可以同时为结构提供附加刚度和附加阻尼。通过对高阻尼黏弹性橡胶连梁阻尼器进行循环加载试验,研究了其基本力学性能,分析了该阻尼器在低周疲劳加载和高周疲劳加载下的基本力学特性。研究结果表明：高阻尼黏弹性橡胶连梁阻尼器的耗能能力优良;该阻尼器的储存刚度、损失刚度、损失系数受变形幅值的影响较大,受加载频率影响较小;等效阻尼系数与频率呈现反比例函数关系;该阻尼器的基本力学性能在低周和高周疲劳加载下呈现出较明显的衰减。     

A New Consistency Method for Tomato Products: The Precipitate Weight Ratio

The precipitate weight ratio (PPT) which refers to the weight ratio of precipitate to the initial sample weight after centrifugation was found to be highly correlated with the Bostwick consistency and the efflux viscosity of tomato products. Lower correlation coefficients were found for products containing added ingredients. However, the PPT may be a unique and reliable parameter to evaluate the consistency of tomato products before formulation.     

Tomato Products: A New Serum Separation Measurement

Previously developed methods to measure serum holding capacity of tomato products had either poor accuracy or were not adapted to the needs of industry. A new quick, reliable test that utilized an inexpensive apparatus was developed. This new test was highly correlated to serum viscosity and precipitate weight ratio. Strong correlation to these two consistency measurements indicated that both the viscosity of the soluble fraction as well as the quality and quantity of the insoluble material were involved in the serum holding capacity of the product.     

Phase Diagram of the System BaO-Fe2O3

The phase diagram of the system BaO-Fe₂0₃ was determined by X-ray diffraction, melting-point measurement, and microscopic methods. Since the reduction of Fe³⁺ to Fe²⁺ was observed by chemical analysis in the samples heated at high temperature, especially in molten samples, the samples were heated at 1 atmosphere pressure of oxygen in the temperature region in which the liquid was in equilibrium; 1 atmosphere pressure of oxygen was su5cient to restrain the reduction of Fe³⁺. In the temperature region of solid-solid equilibrium, the dissociation was not observed even when the samples were heated in air. BaO - 6Fe₂O₃ formed a solid solution with BaO.Fe₂0₃. The BaO:Fe₂0₃ ratio of the solid solution was BaO.4.5Fe₂0₃ at 1350°C. and BaO. 5.0Fe₂0_a at 800°C. The precipitation micro-structures of each primary solid solution were observed.     

大口径埋地钢管在地震断层作用下破坏模式的研究

利用壳有限元模型模拟了在土耳其地震和集集地震中埋地供水钢管在地震断层错动作用下的实际震害.从理论上得到一等效边界,引入到壳有限元模型的两端,因此只需对在断层附近发生大变形的管段进行壳分析.与梁有限元模型分析结果的比较,壳有限元模型能够更好地揭示断层作用下埋地钢管的各种屈曲破坏模式.通过区分断层两侧场地条件相同和相异这两种情况,很好地模拟了1999年土耳其地震中一根2.2m口径供水钢管在断层附近的三处破坏和集集地震中一根2.0m口径供水钢管在断层附近的二处破坏,探讨了断层两侧场地条件的分布形式对埋地管道破坏模式的影响.还详细地解释了土耳其地震供水钢管第三处破坏产生的原因.     

Evaluation of Inductive Contactless Power Transfer Outlet with Coaxial Coreless Transformer

A contactless outlet for dc distribution systems is proposed. It uses an inductive contactless power transfer circuit with a series/parallel compensation circuit to prevent voltage fluctuation. However, the output voltage of the circuit rises in light load conditions. In this paper, the main circuit and control method for reducing the rise in output voltage and a method of estimating the output voltage are presented. The proposed circuit and methods were verified and evaluated experimentally using feedback control.     

A circularly polarized conical beam spherical slot array antenna

This paper proposes a circularly polarized conical beam spherical slot array antenna which is suitable for a low elevation angle land mobile satellite communication subscriber. The structure of this antenna type is very simple to fabricate; i.e. a ring of perpendicular slot pairs is cut on an outer surface of a concentric conducting spherical cavity. From the assumption of weak coupling of the slots from the cavity, the conical beam pattern can be obtained. Experimental results that verify the conical beam radiation are in good agreement with the design.     

Precision nanometrology of a large areamicrostructured metrology surface

1 Introduction The authors have been working on a newsurface encoder for detecting multi-degree-of-freedom(MDOF) translational and tilt motionsof precision stages[1]. The surface encoder con-sists of two fundamental elements: a sinusoidalmicrostructured metrology surface, which is re-ferred to as the angle grid, and a two-dimension-al (2D) slope sensor[2-3].     

Pectin-Protein Interaction in Tomato Products

The pH influenced the viscosity of a model system of tomato product which consisted of citrus pectin and bovine serum albumin. The viscosity change was completely reversible depending on the pH. The same pH effect was observed in tomato products. Since the amino acid compositions of proteins suggest that the electrostatic property of water-soluble protein fraction from tomato juice can be similar to that of bovine serum albumin, the comparison of pH effects indicates that pectin-protein interaction may be involved in consistency of tomato products. Denaturation of protein may result in a decrease in the serum viscosity during processing.     

Dynamic Viscoelastic Behavior of Natural Actomyosin and Myosin during Thermal Gelation

The changes in viscoelasticity of natural actomyosin and myosin during thermal gelation were investigated by dynamic viscoelasticity measurements. Thermal gelation of natural actomyosin could be divided into four characteristic temperature ranges. The storage modulus increased considerably in the 32–43°C range, decreased sharply in the 43–52°C range, and then increased again in the 52–80°C range. For the thermal gelation of myosin, the storage modulus increased in two steps at two temperature ranges, i.e., 30–41°C and 51–80°C. An increase in the loss modulus was observed at an early stage of each of the two ranges.