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Average Unit Pressure Formula for ThreeRoll Tube Rolling

SUN Binyu , YUAN Shijian

钢铁研究学报(英文版)

According to the deformation characteristics of threeroll tube rolling, the existent disadvantages of traditional A Geleiyi and A Tselikov′s formulas were objectively analyzed. An assumption approximate to actual situation was put forward. After suitable simplification, the energy method was adopted to establish velocity fields for permissive movement in deformed areas, and the calculation formula of average unit pressure for threeroll tube rolling was deduced. The values of theoretical calculation are basically consistent with the measured values of largescale aluminum tube during onsite rolling process. The results proved that the formula is reasonable.

关键词: energy method;unit pressure;velocity field

DL-EPR法评价2205双相不锈钢晶间腐蚀敏感性

徐菊良 , 邓博 , 孙涛 , 李劲 , 蒋益明

金属学报 doi:10.3724/SP.J.1037.2009.00598

利用Thermo-Calc软件并结合金相显微镜,定性研究了2205双相不锈钢在800℃下敏化不同时间后的微观组织演变过程.通过研究扫描速率、介质成分、介质温度和试样表面状态优化了双环电化学动电位再活化法(DL-EPR),并用该优化方法研究了2205双相不锈钢晶间腐蚀敏感性.结果表明:DL-EPR法能定量评价σ相对2205双相不锈钢晶间腐蚀敏感性的影响,随敏化时间延长,σ相含量增多,晶jian 腐蚀敏感性也随之增加.腐蚀形貌的观测验证了这一规律,

关键词: 2205双相不锈钢 , DL-EPR , 晶间腐蚀敏感性 , σ相

Intensified alkaline leaching pretreatment of refractory gold concentrates at common temperature and pressure

Transactions of Nonferrous Metals Society of China

A new process for the hydrometallurgy of refractory gold concentrates was presented. The process comprises grinding-leaching, intensified alkaline leaching (IAL), cyanidation and adsorption. In a stirring-type pulverizing-leaching tower mill, the concentrate is ground to <35. 6 μm of 95. 5 % while simultaneously leached by NaOH of 12 kg/t, then carried out intensified alkaline leaching for 48 h by NaOH of 108 kg/t in enhanced agitation tanks with the pulp concentration of 40% solids at the environmental temperature of 9. 5 &SIM; 13. 5 &DEG;C and the environmental pressure of 10(5) Pa. The oxidation rate of As is 94. 9%, and 47. 6% for S. The total consumption of NaOH is only 20% of that theoretically calculated under the conditions of full oxidation at the same oxidation rates of arsenic to arsenate and sulfur to sulfate. The gold leaching rate by NaCN in 24 h is increased from 9. 2% before pretreatment to 94. 2%. The consumption of NaCN is 7. 5 kg/t, which is one times less than that before pretreatment. The extraction cost of gold is about 422 Yuan/t.

关键词: refractory gold concentrates;grinding-leaching;intensified alkaline;leaching (IAL);pretreatment;common temperature and pressure

Improving glass-forming ability of Mg-Cu-Y via substitutional alloying: Effects of Ag versus Ni

Journal of Materials Research

Based on the best bulk metallic glass (BMG) forming alloy in the Mg-Cu-Y ternary system, we introduced Ag (or Ni) to partially substitute for Cu to improve the glass-forming ability (GFA). The objective of this paper is twofold. First, we illustrate in detail a recently developed search strategy, which was proposed but only briefly outlined in our previous publication [H. Ma, L.L. Shi, J. Xu, Y. Li, and E. Ma: Discovering inch-diameter metallic glasses in three-dimensional composition space. Appl. Phys. Lett. 87, 181915 (2005)]. The protocol to navigate in three-dimensional composition space to land large BMGs is spelled out step-by-step using the pseudo-ternary Mg-(Cu,Ag)-Y as the model system. Second, our ability to locate the best BMG former in the composition tetrahedron allows us to systematically examine, and conclude on, the effects of a given alloying element. The large improvement in glass-forming ability in the Mg-(Cu,Ag)-Y system relative to the based ternary will be contrasted with the reduced glass-forming ability in the Mg-(Cu,Ni)-Y pseudo ternary system. It is demonstrated that the improvement of glass-forming ability requires judicious choice of substitutional alloying elements and concentrations, rather than simple additions of multiple elements assuming the "confusion principle."

关键词: bulk metallic-glass;shaped copper mold;amorphous-alloys;thermal-stability;ternary-system;casting method;p system;diameter;zr;mm

基于角点增强改进的TL D目标跟踪算法

孙保基 , 张葆 , 宋策 , 龙思源

液晶与显示 doi:10.3788/YJYXS20163109.0921

针对TLD算法的特征点无法有效表述目标问题,提出了一种基于角点增强改进的TLD目标跟踪算法。改进算法在跟踪模块加入了对目标表述能力更强,具有光照不敏感性和旋转不变性的 Shi-Tomas 角点作为跟踪特征点。跟踪器运行时,在角点经光流法跟踪和双向误差检测后,利用剩余的稳定角点定位目标窗口。对照结果表明,改进算法在面对目标抖动和形变时可以稳定跟踪;有效抑制因跟踪平滑点造成的漂移现象;提高了跟踪的稳定性。针对 TLD算法跟踪过程中因在线模板积累造成的计算量持续增大、实时性持续降低的问题,提出了一种依据相似度中值的模板判断删除机制。该删除机制在模板积累到设定阈值时运行,根据模板与当前目标的相似度,删除不再具备代表性的模板;调整模板空间并更新模板数目。实验表明,该删除机制在应对模板更新快、持续时间长的跟踪情景时有效降低算法计算量,实时性可提高约20%。

关键词: 目标跟踪 , TLD , 角点特征 , 在线模板

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