油田开发后期低效井经济评价方法

应用盈亏平衡原理,确定了油由开发后期低效生产井最低经济产量界限的计算方法及图版,为优化单井产量、提高开发效益提供了一种经济评价手段。     

Optimum thickness of carbon stripper foils in tandem accelerator in view of transmission and lifetime

Optimum thickness of charge stripper foils installed at the terminal of a tandem accelerator has been investigated from the view of (1) charge stripping effect, (2) transmission of ions through accelerator, (3) lifetime of foils for the irradiation of ions. For this purpose, measurements have been done for (a) transmission of H, Li, O, Br and Au ions, passing through 12 UD Pelletron tandem accelerator for carbon stripper foils of 1.8–19.5 μg/cm² thickness, at terminal voltages of 5 and 10 MV, and (b) lifetime of 2–15 μg/cm² thick Tanashi foils developed by Sugai by irradiating Au ions at the terminal voltage of 10 MV. The results obtained are as follows: (a) From the view of above items (1) and (2), the optimum thickness of foils is 10 μg/cm² for ions of Z=1, several μg/cm² for Z=8, and less than a few μg/cm² for heavier ions. (b) From the view of item (3), the lifetime of Tanashi foils by means of new arc-discharge method is demonstrated to be much longer than that of commercial foils for foils thicker than about 5 μg/cm² thick. This superiority rapidly decreases with decreasing foil thickness, and at around 2 μg/cm², the lifetime of Tanashi foils is at the most 2.4 times longer than that of commercial foils.     

脱锭起重机主梁结构通风改造技术分析

空腹箱型结构是现在冶金起重机普遍采用的结构形式之一,采用该结构可以改善桥箱内光照度及通风条件,便于使用维修。因此,笔者认为除非对箱型结构有特殊密闭要求外,该结构是较合理的结构形式,在副腹板中性层处开适当的孔,对主梁主腹板应力没有明显增加。     

多型芯径向抽芯注塑模设计

轴套塑件上有12个周向均布的圆孔,注塑生产时需要多型芯径向抽芯。为此设计了一种特殊的轴套注塑模具,论述了模具结构特点和工作原理。该模具利用异型弯销、转盘及滑块完成多型芯径向抽芯,而未采用一般的齿轮-齿条机构或连杆机构,简化了模具结构。采用三脚推管推出塑件,解决了轴套塑件脱模难的问题。模具结构简单紧凑,工作可靠,操作方便,成型塑件质量好。     

Carbon stripper foils held in place with carbon fibers

The Spallation Neutron Source (SNS) currently under construction at Oak Ridge National Laboratory, Oak Ridge, Tennessee, is planned to initially utilize carbon stripper foils having areal densities approximately 260 μg/cm². The projected design requires that each foil be supported by only one fixed edge. For stability of the foil, additional support is to be provided by carbon fibers. The feasibility of manufacturing and shipping such mounted carbon foils produced by arc evaporation was studied using two prototypes. Production of the foils is described. Fibers were chosen for satisfactory mechanical strength consistent with minimal interference with the SNS beam. Mounting of the fibers, and packaging of the assemblies for shipping are described. Ten completed assemblies were shipped to SNS for further testing. Preliminary evaluation of the survivability of the foils in the SNS foil changer is described.     

The charge state distribution of B,C, Si,Ni, Cu and Au ions on 5 MV pelletron accelerator

Stripper gas and terminal potential play a key role for the charge state distribution in a tandem pelletron accelerator. The knowledge of this distribution is important for experiments performed on tandem accelerators. The charge state distribution of B, C, Si, Ni, Cu and Au beams is measured by using Ar as stripper gas, and terminal potential is varied from 0.3 to 3.0 MV on 5UDH-2 tandem pelletron accelerator installed at the National Centre for Physics, Islamabad. The individual charge state is measured after the switching magnet at 15° in high-energy portion. It is observed that the higher charge states are stable in the range of lower and middle atomic masses of periodic table, whereas higher atomic mass(Au) shows beam current instability in higher charge states. For carbon,the charge distribution at 1.7 MV terminal potential by varying stripper gas pressure is also studied, which resulted in decreased overall transmission with good current value for higher charge states.     

高精度冷冲模的卸料

高精度冷冲模冲裁时，为避免凸模受侧向力的影响产生损伤，而采用特殊的卸料装置。本文介绍了带导向与防护的卸料装置，以及弹压卸料板导条卸料装置两种设计形式。     

Simulation of the Condensate Treatment Process in a Kraft Pulp Mill

A simulation program has been developed and used to study the condensate treatment process in a kraft pulp mill consisting of a stripper, a methanol column and a decanter. The simulations require rigorous models for vapor‐liquid and liquid‐liquid equilibrium calculations. The Wilson equation and the NRTL equation (non random two liquids) have been used for these calculations. New data were included in the flowsheeting program Aspen Plus for seven volatile compounds, to perform accurate calculations of both vapor‐liquid and liquid‐liquid equilibria. Simulations were compared with measurements on the industrial condensate treatment process and the results of the simulations were used to improve the process. By changing the position of the decanter in the process, the COD (chemical oxygen demand) content in the stripped condensate was decreased from 700 to 300 mg O₂/l. The effect of various process parameters, such as the vapor fraction after the stripper and the flow rate of secondary steam to both the stripper and the methanol column, on the quality of clean condensate were investigated. The design of the stripper and the methanol column was studied by calculating the optimal feed location for various numbers of trays in the columns. The results showed that the feed location in the methanol column would be more optimal if it were located higher up in the column (above tray 5–7) instead of above tray 10, which was the case in the industrial process investigated.     

基于最小二乘支持向量机的聚氯乙烯汽提过程预测模型

聚氯乙烯(PVC)汽提过程最显著的特点为具有非线性和时变性,属于复杂的非线性工业控制过程,而支持向量机对于非线性系统控制过程表现出了良好的性能。研究基于最小二乘支持向量机建立了(PVC)汽提过程的温度预测模型,将统计学习理论和结构风险最小化理论应用到PVC生产过程中,对汽提塔温度进行建模和仿真实验,仿真结果表明建模方法有效。     

移轴法计算解吸塔效率

在分析解吸塔效率基础上,采用移轴法推导出解吸塔效率公式。该法具有误差小,应用范围广的特点,且能方便地确定全塔效率,板效率和塔板数之间的关系。应用工厂实例进行计算、分析、证实了该法具有一定的实用性。