针对航天器工作中的返回流污染问题,利用试验粒子Monte Carlo(Test Particle Monte Carlo,TPMC)方法对圆盘表面出气分子形成的环境散射返回流进行数值模拟,验证了计算结果与相关研究的一致性。结果表明:返回通量比随圆盘表面半径、来流...针对航天器工作中的返回流污染问题,利用试验粒子Monte Carlo(Test Particle Monte Carlo,TPMC)方法对圆盘表面出气分子形成的环境散射返回流进行数值模拟,验证了计算结果与相关研究的一致性。结果表明:返回通量比随圆盘表面半径、来流气体速度、来流气体分子数密度的增加呈线性增大;随出气分子质量、来流气体攻角的增加而先增大后减小;随出气表面温度的增加而减小并渐趋于稳定;随来流气体分子质量的增加而增大并渐趋于稳定;随来流气体温度的增加而增大。同时,采用分子动理学的观点,分析了这些因素影响返回通量比的物理机制。展开更多
Non-evaporable getter(NEG)films are an integral part of many particle accelerators.These films provide conductance-free evenly distributed pumping,a low thermal outgassing rate,and a low photon-and electron-stimulated...Non-evaporable getter(NEG)films are an integral part of many particle accelerators.These films provide conductance-free evenly distributed pumping,a low thermal outgassing rate,and a low photon-and electron-stimulated desorption.These characteristics make it an ideal solution for resolving the non-uniform pressure distribution in conductance-limited narrow vacuum tubes.In this study,ternary Ti-Zr-V films were deposited on Si substrates and Ag-Cu(Ag 0.085 wt%)tubes with an inner diameter of 22 mm.All Ti-Zr-V films were prepared from an alloy target using the same DC magnetron sputtering parameters.The compositions and corresponding chemical bonding states were analyzed by X-ray photoelectron spectroscopy after activation at different temperatures.The test particle Monte Carlo(TPMC)method was used to measure the sticking probability of the Ti-Zr-V film based on pressure readings during gas injection.The results indicate that activation commences at temperatures as low as 150℃and Ti~0,Zr~0,and V~0 exist on the surface after annealing at 180℃for 1 h.Ti-Zr-V films can be fully activated at 180℃for 24 h.The CO sticking probability reaches 0.15,with a pumping capacity of 1 monolayer.展开更多
In this study,a novel photosensitizer mesc-tetra(3-prrolidinomethyl-4-methoxyphenyl)chlorin(TPMC)was reported.It displays a characteristic long wavelength absorption peak at 656 nm and it shows a singlet oxygen quantu...In this study,a novel photosensitizer mesc-tetra(3-prrolidinomethyl-4-methoxyphenyl)chlorin(TPMC)was reported.It displays a characteristic long wavelength absorption peak at 656 nm and it shows a singlet oxygen quantum yield of 0.48.After light iradiation with 650 nm laser,it can kill Eca-109 and SMMC-7721 cells in vitro(25 mW/cm^(2),1.2 to 3.6J/cm^(2))and destroy Eca-109 tumor in nude mice(50 mW/cm^(2),90J/cm^(2)).It has the perspective to be developed as a new anti-tumor drug in photodynamic therapy(PDT)photodiagnosis,and deserves further investigation.展开更多
Third-Party Market Cooperation(TPMC)is good to promote the multilateral and intraregional cooperation,which means a lot for ASEAN Plus Three(APT)countries and has great potentials within the region.Despite its benefit...Third-Party Market Cooperation(TPMC)is good to promote the multilateral and intraregional cooperation,which means a lot for ASEAN Plus Three(APT)countries and has great potentials within the region.Despite its benefits,in practice TPMC still faces challenges including the lack of comprehensive and professional TPMC mechanism covering all APT countries,financing gap insufficient to satisfy diversified local demands,and differentiated business environments in need of coordination and facilitation.In order to maximize benefits of TPMC for all APT countries in both economic and social aspects,concrete actions should be carried out to cope with the mentioned challenges.展开更多
文摘针对航天器工作中的返回流污染问题,利用试验粒子Monte Carlo(Test Particle Monte Carlo,TPMC)方法对圆盘表面出气分子形成的环境散射返回流进行数值模拟,验证了计算结果与相关研究的一致性。结果表明:返回通量比随圆盘表面半径、来流气体速度、来流气体分子数密度的增加呈线性增大;随出气分子质量、来流气体攻角的增加而先增大后减小;随出气表面温度的增加而减小并渐趋于稳定;随来流气体分子质量的增加而增大并渐趋于稳定;随来流气体温度的增加而增大。同时,采用分子动理学的观点,分析了这些因素影响返回通量比的物理机制。
基金supported by the National Natural Science Foundation of China(Nos.11975226,11905219)the Fundamental Research Funds for the Central Universities(No.WK2310000071)the National Key Research and Development Program of China(2016YFA0402004).
文摘Non-evaporable getter(NEG)films are an integral part of many particle accelerators.These films provide conductance-free evenly distributed pumping,a low thermal outgassing rate,and a low photon-and electron-stimulated desorption.These characteristics make it an ideal solution for resolving the non-uniform pressure distribution in conductance-limited narrow vacuum tubes.In this study,ternary Ti-Zr-V films were deposited on Si substrates and Ag-Cu(Ag 0.085 wt%)tubes with an inner diameter of 22 mm.All Ti-Zr-V films were prepared from an alloy target using the same DC magnetron sputtering parameters.The compositions and corresponding chemical bonding states were analyzed by X-ray photoelectron spectroscopy after activation at different temperatures.The test particle Monte Carlo(TPMC)method was used to measure the sticking probability of the Ti-Zr-V film based on pressure readings during gas injection.The results indicate that activation commences at temperatures as low as 150℃and Ti~0,Zr~0,and V~0 exist on the surface after annealing at 180℃for 1 h.Ti-Zr-V films can be fully activated at 180℃for 24 h.The CO sticking probability reaches 0.15,with a pumping capacity of 1 monolayer.
基金supported by Chinese National Natural Science Foundation (21372042,81301878,81101298)Foundation of Shanghai government (13431900700,13430722300,13ZR1441000,13ZR1440900)+3 种基金Foundation of Donghua University (No.11D1050112D10515)Foundation of Yiwu Science and Technology Bureau (2011-G1-152012-G3-02).
文摘In this study,a novel photosensitizer mesc-tetra(3-prrolidinomethyl-4-methoxyphenyl)chlorin(TPMC)was reported.It displays a characteristic long wavelength absorption peak at 656 nm and it shows a singlet oxygen quantum yield of 0.48.After light iradiation with 650 nm laser,it can kill Eca-109 and SMMC-7721 cells in vitro(25 mW/cm^(2),1.2 to 3.6J/cm^(2))and destroy Eca-109 tumor in nude mice(50 mW/cm^(2),90J/cm^(2)).It has the perspective to be developed as a new anti-tumor drug in photodynamic therapy(PDT)photodiagnosis,and deserves further investigation.
基金Research Project funded by the Fundamental Research Funds for the Central Universities entitled New Pattern of China’s Opening-up Under the Background of Dual Circulation(3162022ZYQA02).
文摘Third-Party Market Cooperation(TPMC)is good to promote the multilateral and intraregional cooperation,which means a lot for ASEAN Plus Three(APT)countries and has great potentials within the region.Despite its benefits,in practice TPMC still faces challenges including the lack of comprehensive and professional TPMC mechanism covering all APT countries,financing gap insufficient to satisfy diversified local demands,and differentiated business environments in need of coordination and facilitation.In order to maximize benefits of TPMC for all APT countries in both economic and social aspects,concrete actions should be carried out to cope with the mentioned challenges.
