The design and manufacture of spiral tap yet are in r esearch stage at present. This paper mainly introduces how to calculate its geom etric parameters and scientific selection of them with vector method. In additio n...The design and manufacture of spiral tap yet are in r esearch stage at present. This paper mainly introduces how to calculate its geom etric parameters and scientific selection of them with vector method. In additio n, an empiric formula of the tool life of spiral tap with large diameter is esta blished by method of correlation. The practice of design, manufacture and applying proves the advantage of spiral tap by the comparison between the spiral tap and common tap with same size. In the application of spiral tap has got better economic effect. The cutting fea ture and economic effect are obvious, that mean spiral tap greatly better than c ommon tap. The bright and wide prospect are going to come. No greatly increasing the ω can be effective to improve the cutting condition. Scientific selection of cutting speed V can increase the tool life of tapping and life of tapping too l.展开更多
Background Radiation protection and detection have been a main interest for researchers.The prepared glass samples were subjected to experimental investigations to evaluate their mechanical and attenuation properties....Background Radiation protection and detection have been a main interest for researchers.The prepared glass samples were subjected to experimental investigations to evaluate their mechanical and attenuation properties.As a consequence,the values of the mass attenuation coefficient,total electronic cross section,the effective atomic number and an effective electron number were determined and utilized to assess the shielding effectiveness of the investigated glass samples.The mass attenuation coefficients of these samples were calculated theoretically using WinXcom program.Purpose Preparation of glass of borate with zinc and barium can withstand shock,heat and corrosion to be used as a radiation shield.Methods Glass samples were prepared by melt quenching technique.Density and molar volume measurements were obtained by applying the Archimedes principle.The hardness was measured by using a microhardness tester(Leco AMH 100,USA)for sample indentation.The thermal behavior of the glass samples was investigated by differential scanning calorimetry(DSC).Also,by using a scintillator detector(1.5″×1.5″NaI(Tl))exposed to ^(232)Th,^(137)Cs and ^(60)Co gamma ray sources with accuracy range 0.12%.Results The investigated glasses have relatively good gamma ray attenuation properties,water resistance ability and thermal stability with increasing barium oxide.So,they can be used in containers for keeping radioactive waste and radioactive sources.Conclusion The changes in the molar volume and density show approximately opposite linear trends.Also,μm is dependent on the chemical compositions of glass samples and energy of gamma rays.Good agreement between the experimentally obtained mass attenuation coefficient values and the corresponding theoretical predictions based on the known WinXcom program was observed.Additionally,the effect of gamma irradiation on this glass is minor because its impact on the hardness values and dissolution rate is extremely small.展开更多
文摘The design and manufacture of spiral tap yet are in r esearch stage at present. This paper mainly introduces how to calculate its geom etric parameters and scientific selection of them with vector method. In additio n, an empiric formula of the tool life of spiral tap with large diameter is esta blished by method of correlation. The practice of design, manufacture and applying proves the advantage of spiral tap by the comparison between the spiral tap and common tap with same size. In the application of spiral tap has got better economic effect. The cutting fea ture and economic effect are obvious, that mean spiral tap greatly better than c ommon tap. The bright and wide prospect are going to come. No greatly increasing the ω can be effective to improve the cutting condition. Scientific selection of cutting speed V can increase the tool life of tapping and life of tapping too l.
文摘Background Radiation protection and detection have been a main interest for researchers.The prepared glass samples were subjected to experimental investigations to evaluate their mechanical and attenuation properties.As a consequence,the values of the mass attenuation coefficient,total electronic cross section,the effective atomic number and an effective electron number were determined and utilized to assess the shielding effectiveness of the investigated glass samples.The mass attenuation coefficients of these samples were calculated theoretically using WinXcom program.Purpose Preparation of glass of borate with zinc and barium can withstand shock,heat and corrosion to be used as a radiation shield.Methods Glass samples were prepared by melt quenching technique.Density and molar volume measurements were obtained by applying the Archimedes principle.The hardness was measured by using a microhardness tester(Leco AMH 100,USA)for sample indentation.The thermal behavior of the glass samples was investigated by differential scanning calorimetry(DSC).Also,by using a scintillator detector(1.5″×1.5″NaI(Tl))exposed to ^(232)Th,^(137)Cs and ^(60)Co gamma ray sources with accuracy range 0.12%.Results The investigated glasses have relatively good gamma ray attenuation properties,water resistance ability and thermal stability with increasing barium oxide.So,they can be used in containers for keeping radioactive waste and radioactive sources.Conclusion The changes in the molar volume and density show approximately opposite linear trends.Also,μm is dependent on the chemical compositions of glass samples and energy of gamma rays.Good agreement between the experimentally obtained mass attenuation coefficient values and the corresponding theoretical predictions based on the known WinXcom program was observed.Additionally,the effect of gamma irradiation on this glass is minor because its impact on the hardness values and dissolution rate is extremely small.
