Field Static Load Test on Kao-Ping-Hsi Cable-Stayed Bridge

Field load testing is an effective method for understanding the behavior and fundamental characteristics of a cable-stayed bridge. This paper presents the results of field static load tests on the Kao-Ping-Hsi cable-stayed bridge, the longest cable-stayed bridge in Taiwan, before it was open to traffic. A total of 40 loading cases, including the unit and distributed bending and torsion loading effects, were conducted to investigate the bridge behavior. The atmospheric temperature effect on the variations of the main girder deflections was also monitored. The results of static load testing include the main girder deflections, the flexural strains of the prestressed concrete girder, and the variations of the cable forces. A three-dimensional finite-element model was developed. The results show that the bridge under the planned load test conditions has linear superposition characteristics and the analytical model shows a very good agreement with the bridge responses. Further discussion of deflection and cable forces of the design specifications for a cable-stayed bridge is also presented.     

Recrystallization/precipitation behaviour in microalloyed steels

Microalloyed high-strength low-alloy (HSLA) steels contain additions of Nb, V, Ti, or in combination, in amounts of 0.01 to 0.1 weight percent to improve mechanical properties, which are strongly dependent on the thermomechanical interaction taking place in the course of rolling mill processes. The recrystallizatian of hat-twisted austenite has been investigated in a cylindrical specimen (f 6×50 mm) machined from hat rolled plates of 0,052 wt % Niobium microalloyed steel. Continuous and interrupted torsion test were carried out in the temperature range 1123 K to 1173 K after a solution treatment of 1.5 minutes at 1423 K and torque-twist data were analysed. The various methods were discussed for obtaining results from torsion tests. The effect of precipitation kinetics was appreciated by way of connection t_p/t_p(red), where t_p is the experimental measured time for the peak stress and t_p(red) is the newly defined reduced time. The softening ratio X and time t_0.05R for start of static recrystallization were established.

The correlation between precipitation and recrystallization is presented as a graphs for chosen requirements (temperature of austenitization, carbon and niobium content and strain rate). If temperature goes below 850°C, the restoration processes are hardly suppressed, both are limited by diffusion and Nb(CN) precipitation, which are extended dynamically in the range of strains rates 10⁻² to 1 s⁻¹.

In the present paper, an attempt is made to derive the PRTT diagram and to define all mathematical equations for describing recrystallization times t_0.05R, t_0.5R, t_0.95R and t_0.05P for the start of precipitation. In real metal forming processes such as the hot rolling of plates or strips the knowledge of these parameters and results is extremely important for the the correct microstructure and sheet quality to be obtained.     

结构陶瓷的高温疲劳强度衰减理论

提出了陶瓷材料疲劳强度衰减理论并由此导出了各种疲劳关系式。建立了疲劳基本方程ｄσ＿ｒ／ｄ＿ｉ＝一Ａσ（ｔ）￣ｎｔ￣（－ｍ），得出了疲劳寿命公式Ｔ＝Ｍ（σ＿０－σ）／Ａσ￣ｎ（静疲劳时Ｍ＝１，连续增载疲劳时Ｍ＝ｎ＋１，循环疲劳时Ｍ＝（ｎ＋１）／（１＋Ｒ＋Ｒ￣２＋……＋Ｒ￣ｎ），逐级加载时，并导出不同疲劳方式下疲劳寿命间的关系。同时，用多种Ｓｉ＿３Ｎ＿４材料在高温中作了论证试验，结果与理论一致。     

转炉炼钢静态模型的初步探讨

根据转炉炼钢的物理化学反应机理，从质量平衡和能量平衡的计算出发，通过小参数变动，导出了增量式静态模型中矿石方程和供氧方程的系数。所得结论与新日铁资料基本相符。同时，还进行了炉料和产物的计算，分析了改变废钢比对生产的影响。     

Ensuring primary realization of pressure unit in the vacuum range without typically utilized static expansion system

After the break-up of Czechoslovakia in 1993 the primary metrological standards authority almost fully remained in Slovakia. So we had to build our primary vacuum metrology anew. But we could do it using uptodate techniques that are more effective and they enable us to fulfil our task more effectively and in a shorter time.The steady demand to widen the lower pressure range and a steady demand for maximal accuracy collide with the financial possibilities open to a small country. So it is impossible to follow the classical pattern for the vacuum standards: liquid columns, static expansion system and dynamic expansion system. But it is possible to utilize contemporary progress in construction of piston manometers. This enables us to discard liquid column and static expansion techniques in favour of piston technique [Tesar J, Prazak D. Vacuum 2002; 67: 311, Tesar J, Prazak D, Krajicek Z. In:Proceedings of international symposium on Pressure and Vacuum, 2003. p. 169, Tesar J, Repa P, Prazak D, Krajicek Z, Peksa L. Vacuum 2004; 76: 491.]. Such system fulfils all the needs of a little industrial country and is economically acceptable.     

从催化裂化柴油中分离高纯度2,6-二甲基萘

以大庆石油化工总厂炼油厂催化柴油为原料 ,通过精馏分离得到二甲基萘 (DMN)窄馏分 (2 5 8～ 2 70℃ ) ,经糠醛溶剂抽提 ,减压蒸馏后 ,在 -10～ -2 5℃冷冻 2～ 5h ,离心分离制得纯度约 80 %的粗 2 ,6 DMN ,再经无水乙醇在 -10～ -2 5℃重结晶 ,得到纯度大于等于 98%的 2 ,6 DMN。     

The Effect of Ozone Gas-Liquid Contacting Conditions in a Static Mixer on Microorganism Reduction

The effect of gas-liquid contacting conditions in a static mixer on ozone transfer efficiency and reduction of Bacillus subtilis spores was studied in an experimental ozone contactor. An empirical mathematical model was developed that related the transfer efficiency in the experimental system to the superficial liquid velocity in the mixer, the gas-liquid flow rate ratio and the height of the down-stream bubble column. Spore reduction was determined primarily by the dissolved ozone concentration-time (C_avgt_m) product in the reactive flow segment and was independent of the gas-liquid contacting conditions in the static mixer. In an integrated ozone contacting system, the static mixer should be designed to maximize ozone mass transfer while the reactive flow segment should be designed for efficient microorganism reduction.     

Design development of a static sunshade using small scale modeling technique

The rising global demand for energy has triggered emphasis on conservation of energy. Buildings are one of the important energy consuming sectors. Passive solar architecture encompasses a wide range of strategies and options resulting in energy efficient building design and increased occupant's comfort. Passive solar design, aiming at increasing direct solar gains during winter period and to avoid overheating during summer period should make use of specific shading devices over energy efficient window. The static sunshades are most effective for solar control inside the buildings.Countries like India have composite climate, which can be classified under summer, winter and rainy season. Depending on the seasonal requirements, this paper introduces a new geometry of a static sunshade, designed by calculating the sun angles for the two dates. The static sun shading design methodology is validated with the help of small scale modeling experimentation technique, carried out in Pilani, Rajasthan (India). Although insulating materials can be used as a part of a building structure, its feasibility should be checked before particular application. In the present paper, the two small-scale experimental models of actual construction material with varying static sunshades, i.e. horizontal and the proposed one have been constructed and analyzed with the models of insulating material (Polyurethane Foam [PUF]). Depending upon the solar intersection over south facade wall, sunlit area and shaded area have been correlated with temperature inside the models to decide the effectiveness of the proposed sunshade.     

溶质原子在再结晶运动晶界上偏聚的研究

Ｂ~（１０）（ｎ，α）Ｌｉ~７裂变反应的径迹显微照相技术被用来研究含硼Ｆｅ－３０％Ｎｉ合金高温热变形再结晶过程中硼在晶界上的偏聚行为，实验表明，含硼Ｆｅ－３０％Ｎｉ合金１０００℃热变形２０％再结晶过程中，运动晶界前方发生硼偏聚而后方发生贫硼现象，而在静止晶界上看不到硼偏聚，随着再结晶新晶粒的长大，运动晶界上的硼偏聚变弱。本文提出，可以用晶界对溶质原子热运动散射的量子理论来解释溶质原子在运动晶界上的偏聚现象。     

Recrystallization in Model Ice Cream Solutions as Affected by Stabilizer Concentration

Ice recrystallization rates in simple aqueous solutions comprising fructose and a hydrocolloid stabilizer were measured. The stabilizers were an enzyme-modified guar and a non-gelling high methoxy pectin. The stabilizer concentration dependence of the recrystallization rates for both materials was similar in that increasing the concentration resulted in decreasing rates until a point is reached where further addition had no additional effect. That recrystallization rates were reduced by both gelling and non-gelling stabilizers was strongly suggestive that gelation was not a requirement for recrystallization inhibition and another more specific mechanism applies, for example a weak interfacial effect such as adsorption or blocking. This behavior was also seen with locust bean gum and guar and provided further empirical evidence to support the hypothesis that stabilizers adsorb to ice crystal surfaces.