A novel ternary borate, sodium strontium pentaborate, NaSrB5O9, has been prepared by solid-state reaction below 800 ℃. The single-crystal X-ray structural analysis showed that NaSrB5O9 crystallizes in monoclinic, spa...A novel ternary borate, sodium strontium pentaborate, NaSrB5O9, has been prepared by solid-state reaction below 800 ℃. The single-crystal X-ray structural analysis showed that NaSrB5O9 crystallizes in monoclinic, space group P21/c with a = 6.499（2）, b = 13.979（3）, c = 8.045（2）A, β = 106.92（2）°, V = 699.2（3）A^3, Z = 4, Mr = 308.66, Dc = 2.932 g/cm^3, μ = 7.804 mm^-1, F（000） = 584, R = 0.0264 and wR = 0.0621 for 2426 observed reflections and 146 variables. NaSrB5O9 is a layered compound containing double ring B5O11 building units composed of two BO4 tetrahedra and three BO3 triangles. Each B5O11 unit is connected to four other equivalent units through exocyclic oxygen atoms to form a two-dimensional ∞^2 [B5O9]^3- layer. Symmetry-center related layers are stacked along the b axis and held together by Na^＋ and Sr^2＋ cations via electrostatic interactions.展开更多
SIS(Strategic Information System)在日本通译为“战略信息系统”,它不是一个单纯的软件开发系统,而是一种由美、日企业创造的、目前在世界各国有巨大影响的企业经营管理思路和管理经验。在美国,这种经营策略有多种不同的名称:IT(Infor...SIS(Strategic Information System)在日本通译为“战略信息系统”,它不是一个单纯的软件开发系统,而是一种由美、日企业创造的、目前在世界各国有巨大影响的企业经营管理思路和管理经验。在美国,这种经营策略有多种不同的名称:IT(Information Tech-nology),IST(Information System Techolo-gy),哈佛商业学院则定名为SUIS(StrategicUse of Information System),其中最常用的为IT。展开更多
基金Supported by the Talent Training Funds of Beijing (20051D0501501)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality, and the Natural Science Foundation of Beijing (No. 2073021)
文摘A novel ternary borate, sodium strontium pentaborate, NaSrB5O9, has been prepared by solid-state reaction below 800 ℃. The single-crystal X-ray structural analysis showed that NaSrB5O9 crystallizes in monoclinic, space group P21/c with a = 6.499（2）, b = 13.979（3）, c = 8.045（2）A, β = 106.92（2）°, V = 699.2（3）A^3, Z = 4, Mr = 308.66, Dc = 2.932 g/cm^3, μ = 7.804 mm^-1, F（000） = 584, R = 0.0264 and wR = 0.0621 for 2426 observed reflections and 146 variables. NaSrB5O9 is a layered compound containing double ring B5O11 building units composed of two BO4 tetrahedra and three BO3 triangles. Each B5O11 unit is connected to four other equivalent units through exocyclic oxygen atoms to form a two-dimensional ∞^2 [B5O9]^3- layer. Symmetry-center related layers are stacked along the b axis and held together by Na^＋ and Sr^2＋ cations via electrostatic interactions.
文摘SIS(Strategic Information System)在日本通译为“战略信息系统”,它不是一个单纯的软件开发系统,而是一种由美、日企业创造的、目前在世界各国有巨大影响的企业经营管理思路和管理经验。在美国,这种经营策略有多种不同的名称:IT(Information Tech-nology),IST(Information System Techolo-gy),哈佛商业学院则定名为SUIS(StrategicUse of Information System),其中最常用的为IT。
