新型大直径厚壁钢管铣头倒棱机结构设计

对现有的平头倒棱机设备及加工技术进行了分析,提出由于加工原理的限制导致设备加工能力不足,会出现刀具振动过大,切削稳定性差等问题。以此为参考将其加工原理改进为铣削加工,通过更换刀具以及增加过渡盘等方式,设计出具有创新结构的铣头倒棱机以提升对大直径厚壁钢管的加工能力。该设备使钢管在倒棱过程中的稳定性增强并扩大了加工范围,以此提升了钢管倒棱设备的加工能力和产品附加值,且对焊管和无缝钢管均适用,目前已在现场应用。     

The Effect of Some Soil Characteristics on Soil Radon Concentration and Radon Exhalation from Soil Surface

To find out the impacts of soil characters on radon concentrations in soil and radon exhalation from soil, field measurements on soil radon concentrations (60 cm under the soil surface) and radon exhalation rate from soil surface were carried out in totally 31 points with different types of soil in three cities in both South and North China. Soil radium contents, water contents, soil porosity and grain size were concretely analyzed in our laboratory. The linear simulation was used to analyze the above data. The results showed that radon exhalation rate from soil and radon concentrations in soil have direct proportion to soil radium contents. Rather high radium content and radon exhalation rate were measured in Guiyang area, 67±28Bq/kg and 40±59mBq/m²-s, however no high soil radon concentration was found due to the difficulties in the measurements on clay soils with high water saturation. Compared with soil radium contents, radon exhalation rate from soil and soil radon concentrations are more easily impacted by soil characters and change in a rather large range.     

钢管倒棱机新型液压夹紧装置的改造

倒棱工序是钢管制造中的重点工序，夹紧装置的夹紧效果意识风管管端的加工质量，本文就传统夹紧装置所存在的缺点和不足进行了分析，指出了新型液压夹紧装置的优点和良好的使用效果。     

孔口倒圆角的编程方法

加工孔口倒圆角时，通常可以用成型刀来加工。但是当倒角半径比较特殊时用传统的方法加工就比较困难。文章通过举例的方式介绍了如何用普通立铣刀、球头刀，借助宏程序完成孔口倒圆角几种方法，并对加工效果进行比较。     

The hydrochloric acid route for phosphate rock

When phosphate rock is leached with hydrochloric acid, radium can be removed by co-precipitation with Ba_0.4Ca_0.6SO₄ and uranium by extraction with a 5% solution of tributyl phosphate in hexane or Varsol. Phosphoric acid is then separated from calcium chloride solution and other impurities by extraction with undiluted tributyl phosphate. The lanthanides can be precipitated from the raffinate by NH₃, and CaSO₄.2H₂O by H₂SO₄ to regenerate HCl for recycle. The organic phase containing H₃PO₄ can be stripped by NH₃ to yield ammonium phosphate and to regenerate the tributyl phosphate for recycle. Fluorine can be precipitated from the initial leach solution as Na₂SiF₆.     

放射性废源的安全管理与处置

本文阐述了放射性废源的产生和安全问题;讨论了加强管理的必要性和国务院笫449号令提出的相关措施;给出了国际原子能机构和我国发布的有关密封源管理的法规和标准;介绍了放射性废源的安全处理和整备技术,重点介绍了现在国外废镭源的整备技术.     

基于改进模型的辽东湾东岸营口海域海底地下水排泄量计算

海底地下水排泄(SGD)是全球水循环的重要组成部分,也是向海洋输送营养盐等各类化学物质的必要途径之一。以辽东湾东部营口海域为研究对象,以天然镭同位素(²²⁴Ra、²²⁸Ra)作为示踪剂,建立镭质量平衡模型并加以改进,进而探讨再循环海水(RSGD)对研究区内水体刷新时间、SGD及携带氮磷营养盐通量的影响程度。结果表明:利用镭质量平衡模型计算水体刷新时间为9 d,改进后的镭质量平衡模型计算出的水体刷新时间为14.35~18.11 d;传统模型下SGD通量为(3.01~3.51)×10⁸ m³/d。改进模型评估的SGD通量为(3.55~4.39)×10⁸ m³/d,改进模型评估的水体刷新时间与SGD均明显高于初始模型,其中水体刷新时间增加了59.44%~101.22%;SGD通量增加了17.94%~25.07%。在此基础上,地下水向海输入的氮、磷营养盐通量在考虑RSGD的情况下分别为1.73×10⁸、1.52×10⁹ mol/d。研究结果证明了RSGD对SGD和营养盐通量存在较大影响,为营口海域生态环境评估提供了基础数据。     

Adsorption-desorption studies on the radium-silica system

Adsorption of radium-226 on quartz is investigated. Adsorption isotherms are obtained for crystalline and sulphuric and hydrochloric acid-treated quartz samples at pH 1 and 10. Desorption of radium-226 from silica with EDTA and an EDTA-KC1 mixture is also studied. It is found that radium-226 adsorbed on silica is difficult to desorb whereas radium deposited on silica as radium sulphate is easily removed in EDTA solutions.     

毫米波成像前端中H面电感膜片波导带通滤波器的精确设计

在H面电感膜片波导带通滤波器的设计中,考虑到加工产生倒角及其产生的频率偏移,总结出带倒角膜片滤波器的精确设计方法,并给出了修正公式。为了验证本文提出的设计方法,利用HFSS对具有不同的中心频率、不同的3 dB带宽(BW)和不同的倒角半径下对这种滤波器进行了仿真,其中心频率分别为18 GHz,26 GHz,34 GHz和42 GHz,对应的带宽对应为2.265%,2.5%,10%,15%和20%,仿真结果表现出了规律性偏移趋势。通过对中心频率和带宽分别为26 GHz、2.5%和34 GHz、2.265%的2种H面波导滤波器进行实测,测试结果与利用修正公式的仿真结果一致。     

Radium and Thorium Sorption by Monosodium Titanate (MST) and Modified MST (mMST)

To confirm performance assessment inputs for the Saltstone Facility at the Savannah River Site (SRS), a series of experiments were performed to examine the removal of Ra and Th by monosodium titanate (MST) and modified MST (mMST). The solubility of Th in the simulated high-level waste solutions was found to be extremely low; therefore, its removal by MST could not be measured. Radium was rapidly removed from the high-level waste simulant by both MST and mMST.