Alkynylstannanes 1 react with Cp2Zr(H)Cl (Cp=?-C5H5) giving (Z)--stannylvinyl- zirconium complexes 2, which are trapped with NBS or iodine in THF at 0C to stereoselectively afford (Z)-a-bromovinylstannanes and (E)- a-...Alkynylstannanes 1 react with Cp2Zr(H)Cl (Cp=?-C5H5) giving (Z)--stannylvinyl- zirconium complexes 2, which are trapped with NBS or iodine in THF at 0C to stereoselectively afford (Z)-a-bromovinylstannanes and (E)- a-iodovinylstannanes 3, respectively.展开更多
Two practical methods for highly stereoselective synthesis of (Z)-2-acylamido-4-phenylcrotonates 2a similar to b have been developed. The key step in the first route was how to control the acid-catalyzed isomerization...Two practical methods for highly stereoselective synthesis of (Z)-2-acylamido-4-phenylcrotonates 2a similar to b have been developed. The key step in the first route was how to control the acid-catalyzed isomerization of condensation mixtures of alpha-keto ester 5 with carbomite. In the second route the key step was reduction of oxime 8, derived from alpha-keto ester 5, with iron powder in the presence of acetic anhydride.展开更多
In this paper, a strong limit theorem on gambling strategy for binary Bernoulli sequence, (i.e.) irregularity theorem, is extended to random selection for dependent m-valued random variables, via using a new method-di...In this paper, a strong limit theorem on gambling strategy for binary Bernoulli sequence, (i.e.) irregularity theorem, is extended to random selection for dependent m-valued random variables, via using a new method-differentiability on net. Furthermore, by allowing the selection function to take value in finite interval [-M,M], the conception of random selection is generalized.展开更多
针对配电网中分布式电源渗透率提高导致的潮流倒送、电压波动和供电能力不足等问题,文中提出一种基于储能特性的三端智能软开关(three-terminal intelligent soft open point, E-SOP)有源配电台区优化控制策略。首先,深入分析E-SOP的拓...针对配电网中分布式电源渗透率提高导致的潮流倒送、电压波动和供电能力不足等问题,文中提出一种基于储能特性的三端智能软开关(three-terminal intelligent soft open point, E-SOP)有源配电台区优化控制策略。首先,深入分析E-SOP的拓扑,建立其数学模型,为后续优化控制奠定基础。其次,提出一种基于电压-功率灵敏度的ESOP选址规划模型,以确定其最佳安装位置。在此基础上,构建以综合费用和电压偏差最小化为目标的优化模型,实现E-SOP容量配置。该模型通过锥松弛技术转换为二阶锥规划模型,并采用粒子群算法求解。最后,通过IEEE33节点柔性互联系统的仿真验证所提策略的有效性,并在IEEE 69节点系统中进一步验证其适用性和优越性。结果表明,相比传统无E-SOP互联系统,所提策略可使电压偏差降低2.24%,日均损耗减少50.41%,综合成本下降21.74%,适用于不同规模的配电系统。展开更多
采用高效液相色谱/串联质谱技术建立了快速鉴定Z型盐酸头孢吡肟原料药中E型异构体杂质的新方法。以乙腈-醋酸盐缓冲溶液(4∶96)为流动相经C18柱分离,通过高分辨电喷雾串联质谱在线检测,获得了相关的色谱和质谱信息。在所建立条件下,Z型...采用高效液相色谱/串联质谱技术建立了快速鉴定Z型盐酸头孢吡肟原料药中E型异构体杂质的新方法。以乙腈-醋酸盐缓冲溶液(4∶96)为流动相经C18柱分离,通过高分辨电喷雾串联质谱在线检测,获得了相关的色谱和质谱信息。在所建立条件下,Z型盐酸头孢吡肟及其E型异构体杂质获得了有效分离,保留时间分别为5.22 m in和14.60 m in,同时它们的二级质谱及裂解方式呈现明显差异。本法能在无对照品情况下,快速、准确地分离鉴定盐酸头孢吡肟原料药中的Z/E异构体。展开更多
文摘Alkynylstannanes 1 react with Cp2Zr(H)Cl (Cp=?-C5H5) giving (Z)--stannylvinyl- zirconium complexes 2, which are trapped with NBS or iodine in THF at 0C to stereoselectively afford (Z)-a-bromovinylstannanes and (E)- a-iodovinylstannanes 3, respectively.
文摘Two practical methods for highly stereoselective synthesis of (Z)-2-acylamido-4-phenylcrotonates 2a similar to b have been developed. The key step in the first route was how to control the acid-catalyzed isomerization of condensation mixtures of alpha-keto ester 5 with carbomite. In the second route the key step was reduction of oxime 8, derived from alpha-keto ester 5, with iron powder in the presence of acetic anhydride.
文摘In this paper, a strong limit theorem on gambling strategy for binary Bernoulli sequence, (i.e.) irregularity theorem, is extended to random selection for dependent m-valued random variables, via using a new method-differentiability on net. Furthermore, by allowing the selection function to take value in finite interval [-M,M], the conception of random selection is generalized.
文摘针对配电网中分布式电源渗透率提高导致的潮流倒送、电压波动和供电能力不足等问题,文中提出一种基于储能特性的三端智能软开关(three-terminal intelligent soft open point, E-SOP)有源配电台区优化控制策略。首先,深入分析E-SOP的拓扑,建立其数学模型,为后续优化控制奠定基础。其次,提出一种基于电压-功率灵敏度的ESOP选址规划模型,以确定其最佳安装位置。在此基础上,构建以综合费用和电压偏差最小化为目标的优化模型,实现E-SOP容量配置。该模型通过锥松弛技术转换为二阶锥规划模型,并采用粒子群算法求解。最后,通过IEEE33节点柔性互联系统的仿真验证所提策略的有效性,并在IEEE 69节点系统中进一步验证其适用性和优越性。结果表明,相比传统无E-SOP互联系统,所提策略可使电压偏差降低2.24%,日均损耗减少50.41%,综合成本下降21.74%,适用于不同规模的配电系统。
文摘采用高效液相色谱/串联质谱技术建立了快速鉴定Z型盐酸头孢吡肟原料药中E型异构体杂质的新方法。以乙腈-醋酸盐缓冲溶液(4∶96)为流动相经C18柱分离,通过高分辨电喷雾串联质谱在线检测,获得了相关的色谱和质谱信息。在所建立条件下,Z型盐酸头孢吡肟及其E型异构体杂质获得了有效分离,保留时间分别为5.22 m in和14.60 m in,同时它们的二级质谱及裂解方式呈现明显差异。本法能在无对照品情况下,快速、准确地分离鉴定盐酸头孢吡肟原料药中的Z/E异构体。
