利用Arnol'd的Legendrian理论,对三维Anti de Sitter空间中Lorentzian曲面进行了研究.引入光维高度函数概念研究了三维Anti de Sitter空间Lorentzian曲面的S1t×S1s-值、光锥Gauss映射的奇点,进行了奇点分类,揭示了类光Causs-kr...利用Arnol'd的Legendrian理论,对三维Anti de Sitter空间中Lorentzian曲面进行了研究.引入光维高度函数概念研究了三维Anti de Sitter空间Lorentzian曲面的S1t×S1s-值、光锥Gauss映射的奇点,进行了奇点分类,揭示了类光Causs-kronecker曲率之间的关系;并研究了Lorentzian曲面的一些基本几何性质.展开更多
为了提升永磁直线同步电机(permanent magnet linear synchronous motor,PMLSM)在负载变化、参数摄动和其他不确定因素下的抗扰性能和速度跟踪性能,提出一种基于级联线性-非线性自抗扰控制器的PMLSM速度控制策略。首先,建立考虑负载扰...为了提升永磁直线同步电机(permanent magnet linear synchronous motor,PMLSM)在负载变化、参数摄动和其他不确定因素下的抗扰性能和速度跟踪性能,提出一种基于级联线性-非线性自抗扰控制器的PMLSM速度控制策略。首先,建立考虑负载扰动和参数失配的PMLSM数学模型;其次,设计级联线性-非线性扩张状态观测器来实时估计和补偿系统所受的不确定扰动,前级线性扩张状态观测器保证系统在大扰动下保持稳定,后级非线性扩张状态观测器利用非线性机制进一步提高系统对扰动的估计精度,从而将线性自抗扰控制和非线性自抗扰控制的优势相结合,以此提升系统的速度跟踪性能和抗扰动能力;并且,对所提控制器提出基于劳斯判据的稳定性分析方法,并对系统的抗扰性能和噪声抑制性能进行了频域分析;最后,对基于PI控制、级联线性自抗扰控制、非线性自抗扰控制和级联线性-非线性自抗扰控制的永磁直线同步电机系统进行仿真和实验对比,验证所提方法的优越性。展开更多
It needs the foundation of system and the guarantee of organizational system for anti-corruption,but it is more necessary to build and form an effective anti-corruption mechanism,so that the anti-corruption can be rea...It needs the foundation of system and the guarantee of organizational system for anti-corruption,but it is more necessary to build and form an effective anti-corruption mechanism,so that the anti-corruption can be really put into practice. Anti-corruption mechanism refers to a organic operation system of the interaction,interconnection and constraint between the constituent elements( parts) and elements of national anti-corruption,and as a system,anti-corruption mechanism should have the characteristics of system aticness,comprehensiveness,transparency,legalization,public participation,scientific dynam ic,and internationalism. The construction of deepening anti-corruption mechanism is the need for reconstructing the ruling legitimacy of the party and the governm ent. Adhering to the principle of treating both root causes and symptoms is necessary in the construction of anti-corruption m echanism,com bating and punishing corruption is an important part of anti-corruption,and the prevention and control of corruption is the basic project of anti-corruption. Therefore,the construction of prevention and control mechanism in the anti-corruption mechanism has a more far-reaching significance.展开更多
为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用...为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用 GC-MS 在选择离子监测（ SIM）模式下测定水产品中的痕量二甲苯麝香和酮麝香，以基质匹配标准溶液外标法定量。选用 DB-5 MS 石英毛细管柱（30 m×0.25 mm×0.25μm），采用电子轰击电离源，二甲苯麝香的选择监测离子为 m / z 282、297、265，酮麝香为 m / z 279、294、191。结果表明：在优化条件下，二甲苯麝香和酮麝香在1～100μg / kg 范围内线性良好，相关系数不低于0.999，检出限（S / N =3）为0.30μg / kg。明虾、花蛤和鳗鱼空白样品中1.0、2.0、10.0μg / kg 3个添加水平下二甲苯麝香和酮麝香的加标回收率为79％～104％，相对标准偏差（RSD）为1.6％～13.3％。本方法具有操作简便、快速、准确的特点，可用于水产品中痕量二甲苯麝香和酮麝香的日常检测。展开更多
文摘利用Arnol'd的Legendrian理论,对三维Anti de Sitter空间中Lorentzian曲面进行了研究.引入光维高度函数概念研究了三维Anti de Sitter空间Lorentzian曲面的S1t×S1s-值、光锥Gauss映射的奇点,进行了奇点分类,揭示了类光Causs-kronecker曲率之间的关系;并研究了Lorentzian曲面的一些基本几何性质.
文摘为了提升永磁直线同步电机(permanent magnet linear synchronous motor,PMLSM)在负载变化、参数摄动和其他不确定因素下的抗扰性能和速度跟踪性能,提出一种基于级联线性-非线性自抗扰控制器的PMLSM速度控制策略。首先,建立考虑负载扰动和参数失配的PMLSM数学模型;其次,设计级联线性-非线性扩张状态观测器来实时估计和补偿系统所受的不确定扰动,前级线性扩张状态观测器保证系统在大扰动下保持稳定,后级非线性扩张状态观测器利用非线性机制进一步提高系统对扰动的估计精度,从而将线性自抗扰控制和非线性自抗扰控制的优势相结合,以此提升系统的速度跟踪性能和抗扰动能力;并且,对所提控制器提出基于劳斯判据的稳定性分析方法,并对系统的抗扰性能和噪声抑制性能进行了频域分析;最后,对基于PI控制、级联线性自抗扰控制、非线性自抗扰控制和级联线性-非线性自抗扰控制的永磁直线同步电机系统进行仿真和实验对比,验证所提方法的优越性。
文摘It needs the foundation of system and the guarantee of organizational system for anti-corruption,but it is more necessary to build and form an effective anti-corruption mechanism,so that the anti-corruption can be really put into practice. Anti-corruption mechanism refers to a organic operation system of the interaction,interconnection and constraint between the constituent elements( parts) and elements of national anti-corruption,and as a system,anti-corruption mechanism should have the characteristics of system aticness,comprehensiveness,transparency,legalization,public participation,scientific dynam ic,and internationalism. The construction of deepening anti-corruption mechanism is the need for reconstructing the ruling legitimacy of the party and the governm ent. Adhering to the principle of treating both root causes and symptoms is necessary in the construction of anti-corruption m echanism,com bating and punishing corruption is an important part of anti-corruption,and the prevention and control of corruption is the basic project of anti-corruption. Therefore,the construction of prevention and control mechanism in the anti-corruption mechanism has a more far-reaching significance.
文摘为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用 GC-MS 在选择离子监测（ SIM）模式下测定水产品中的痕量二甲苯麝香和酮麝香，以基质匹配标准溶液外标法定量。选用 DB-5 MS 石英毛细管柱（30 m×0.25 mm×0.25μm），采用电子轰击电离源，二甲苯麝香的选择监测离子为 m / z 282、297、265，酮麝香为 m / z 279、294、191。结果表明：在优化条件下，二甲苯麝香和酮麝香在1～100μg / kg 范围内线性良好，相关系数不低于0.999，检出限（S / N =3）为0.30μg / kg。明虾、花蛤和鳗鱼空白样品中1.0、2.0、10.0μg / kg 3个添加水平下二甲苯麝香和酮麝香的加标回收率为79％～104％，相对标准偏差（RSD）为1.6％～13.3％。本方法具有操作简便、快速、准确的特点，可用于水产品中痕量二甲苯麝香和酮麝香的日常检测。
