-This paper first presents a new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater, i. e. , 1, 2, 4, 5-tetrahydroxybenzen -O, O' , O', O'''- tetraaceti...-This paper first presents a new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater, i. e. , 1, 2, 4, 5-tetrahydroxybenzen -O, O' , O', O'''- tetraacetic acid (TTAH4). The synthetic method of TTAH4, its enrichment behaviour for potassium ion in low concentration solution and seawater, and the chemical structure of its corresponding potassium salt have been investigated. A mechanism which caused the uptake of potassium ion is suggested. Elementary analysis and IR-spectrum determination of the potassium salt proved correct evidence for a polynuclear complex, i. e. , (TTAH3K)n. Thus, the mechanism which caused the uptake of potassium ion may be interpreted in terms of the formation of polynuclear chains as a continual sandwich type coordination complex.展开更多
Fine structure energy levels, wavelengths, log gf and allowed transition probabilities (E1) have been calculated for Lithium-like Ar XVI. The optimized electrostatic parameters by a least square approach, have been us...Fine structure energy levels, wavelengths, log gf and allowed transition probabilities (E1) have been calculated for Lithium-like Ar XVI. The optimized electrostatic parameters by a least square approach, have been used in the calculation to include the configuration interaction and relativistic effects. A total number of 69 Ar XVI levels having total angular momenta, 1/2 ≤ J ≤ 9/2 of even and odd parities, orbital angular momenta 2 ≤ l ≤ 4, with 546 E1 transitions for 6 ≤ n ≤ 10 are considered using the relativistic effect in the Breit-Pauli method, where n is the principal quantum number. A comparison is made with the available results in literature.展开更多
Chen Qingyun Majoring in chemistry, Prof. Chen obtained his BS degree in 1952 from Peking University and earned a Ph. D degree from the Institute of Elementary Organic Compounds under the Academy of Sciences of the fo...Chen Qingyun Majoring in chemistry, Prof. Chen obtained his BS degree in 1952 from Peking University and earned a Ph. D degree from the Institute of Elementary Organic Compounds under the Academy of Sciences of the former Soviet Union in 1960. Now he serves as pro-展开更多
Reaction of perfluoroalkyl iodides with a series of alkynes under sulfinatodehalogenation condition gave a mixture of E/Z adducts very readily in high yield, thus constituted a mild, convenient and effective new metho...Reaction of perfluoroalkyl iodides with a series of alkynes under sulfinatodehalogenation condition gave a mixture of E/Z adducts very readily in high yield, thus constituted a mild, convenient and effective new method for the addition of perfluoroalkyl iodides to alkynes. Under the same con- dition, in the presence of 1-hexyne perfluoroalkyl bromide and 1,1,1-trichlorotrifluoroethane reacted only to give sulfinates as the major products. A radical mechanism was proposed for the addition reaction.展开更多
目的:结合我院开展IGRT技术以来所做的质量保证和质量控制工作所积累的经验,分析和探讨IGRT系统的主要质控检测项目和实现方法,以保证系统安全、有效、稳定的进行。方法:检测图像系统的低对比度分辨力、空间分辨率、密度均匀性和几何失...目的:结合我院开展IGRT技术以来所做的质量保证和质量控制工作所积累的经验,分析和探讨IGRT系统的主要质控检测项目和实现方法,以保证系统安全、有效、稳定的进行。方法:检测图像系统的低对比度分辨力、空间分辨率、密度均匀性和几何失真度,测试系统的图像匹配精度,校准六自由度治疗床系统(HexaPODTM evo System)的等中心。结果:能分辨的图像低密度差异值小于2%,空间分辨率不小于7lp/cm,表征图像密度均一性的像素值差异小于2%,表征图像几何失真度的几何精度在X、Y、Z方向均小于1.04mm,XVI系统随机架运动时,旋转中心由于重力作用引起的位置变化范围在X、Y方向上小于1.04mm,KV级系统中心和MV级系统中心的位置差异在X、Y、Z方向上小于0.5mm。六自由度治疗床相对于等中心的偏差在0.2mm、0.2°以内。结论:相应的质控项目和方法保证了我院IGRT系统得以安全、稳定的运行,也有助于减小病人治疗过程中由于系统误差而引起的摆位误差。展开更多
目的:结合我院开展IGRT技术以来所做的质量保证和质量控制工作所积累的经验,分析和探讨IGRT系统的主要质控检测项目和实现方法,以保证系统安全、有效、稳定的进行。方法:检测图像系统的低对比度分辨力、空间分辨率、密度均匀性和几何失...目的:结合我院开展IGRT技术以来所做的质量保证和质量控制工作所积累的经验,分析和探讨IGRT系统的主要质控检测项目和实现方法,以保证系统安全、有效、稳定的进行。方法:检测图像系统的低对比度分辨力、空间分辨率、密度均匀性和几何失真度,测试系统的图像匹配精度,校准六自由度治疗床系统(HexaPODTM ev System)的等中心。结果:能分辨的图像低密度差异值小于2%,空间分辨率不小于7lp/cm,表征图像密度均一性的像素值差异小于2%,表征图像几何失真度的几何精度在X、Y、Z方向均小于1.04mm,XVI系统随机架运动时,旋转中心由于重力作用引起的位置变化范围在X、Y方向上小于1.04mm,KV级系统中心和MV级系统中心的位置差异在X、Y、Z方向上小于0.5mm。六自由度治疗床相对于等中心的偏差在0.2mm、0.2°以内。结论:相应的质控项目和方法保证了我院IGRT系统得以安全、稳定的运行,也有助于减小病人治疗过程中由于系统误差而引起的摆位误差。展开更多
文摘-This paper first presents a new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater, i. e. , 1, 2, 4, 5-tetrahydroxybenzen -O, O' , O', O'''- tetraacetic acid (TTAH4). The synthetic method of TTAH4, its enrichment behaviour for potassium ion in low concentration solution and seawater, and the chemical structure of its corresponding potassium salt have been investigated. A mechanism which caused the uptake of potassium ion is suggested. Elementary analysis and IR-spectrum determination of the potassium salt proved correct evidence for a polynuclear complex, i. e. , (TTAH3K)n. Thus, the mechanism which caused the uptake of potassium ion may be interpreted in terms of the formation of polynuclear chains as a continual sandwich type coordination complex.
文摘Fine structure energy levels, wavelengths, log gf and allowed transition probabilities (E1) have been calculated for Lithium-like Ar XVI. The optimized electrostatic parameters by a least square approach, have been used in the calculation to include the configuration interaction and relativistic effects. A total number of 69 Ar XVI levels having total angular momenta, 1/2 ≤ J ≤ 9/2 of even and odd parities, orbital angular momenta 2 ≤ l ≤ 4, with 546 E1 transitions for 6 ≤ n ≤ 10 are considered using the relativistic effect in the Breit-Pauli method, where n is the principal quantum number. A comparison is made with the available results in literature.
文摘Chen Qingyun Majoring in chemistry, Prof. Chen obtained his BS degree in 1952 from Peking University and earned a Ph. D degree from the Institute of Elementary Organic Compounds under the Academy of Sciences of the former Soviet Union in 1960. Now he serves as pro-
文摘Reaction of perfluoroalkyl iodides with a series of alkynes under sulfinatodehalogenation condition gave a mixture of E/Z adducts very readily in high yield, thus constituted a mild, convenient and effective new method for the addition of perfluoroalkyl iodides to alkynes. Under the same con- dition, in the presence of 1-hexyne perfluoroalkyl bromide and 1,1,1-trichlorotrifluoroethane reacted only to give sulfinates as the major products. A radical mechanism was proposed for the addition reaction.
文摘目的:结合我院开展IGRT技术以来所做的质量保证和质量控制工作所积累的经验,分析和探讨IGRT系统的主要质控检测项目和实现方法,以保证系统安全、有效、稳定的进行。方法:检测图像系统的低对比度分辨力、空间分辨率、密度均匀性和几何失真度,测试系统的图像匹配精度,校准六自由度治疗床系统(HexaPODTM evo System)的等中心。结果:能分辨的图像低密度差异值小于2%,空间分辨率不小于7lp/cm,表征图像密度均一性的像素值差异小于2%,表征图像几何失真度的几何精度在X、Y、Z方向均小于1.04mm,XVI系统随机架运动时,旋转中心由于重力作用引起的位置变化范围在X、Y方向上小于1.04mm,KV级系统中心和MV级系统中心的位置差异在X、Y、Z方向上小于0.5mm。六自由度治疗床相对于等中心的偏差在0.2mm、0.2°以内。结论:相应的质控项目和方法保证了我院IGRT系统得以安全、稳定的运行,也有助于减小病人治疗过程中由于系统误差而引起的摆位误差。
文摘目的:结合我院开展IGRT技术以来所做的质量保证和质量控制工作所积累的经验,分析和探讨IGRT系统的主要质控检测项目和实现方法,以保证系统安全、有效、稳定的进行。方法:检测图像系统的低对比度分辨力、空间分辨率、密度均匀性和几何失真度,测试系统的图像匹配精度,校准六自由度治疗床系统(HexaPODTM ev System)的等中心。结果:能分辨的图像低密度差异值小于2%,空间分辨率不小于7lp/cm,表征图像密度均一性的像素值差异小于2%,表征图像几何失真度的几何精度在X、Y、Z方向均小于1.04mm,XVI系统随机架运动时,旋转中心由于重力作用引起的位置变化范围在X、Y方向上小于1.04mm,KV级系统中心和MV级系统中心的位置差异在X、Y、Z方向上小于0.5mm。六自由度治疗床相对于等中心的偏差在0.2mm、0.2°以内。结论:相应的质控项目和方法保证了我院IGRT系统得以安全、稳定的运行,也有助于减小病人治疗过程中由于系统误差而引起的摆位误差。
