Multi-source seismic technology is an efficient seismic acquisition method that requires a group of blended seismic data to be separated into single-source seismic data for subsequent processing. The separation of ble...Multi-source seismic technology is an efficient seismic acquisition method that requires a group of blended seismic data to be separated into single-source seismic data for subsequent processing. The separation of blended seismic data is a linear inverse problem. According to the relationship between the shooting number and the simultaneous source number of the acquisition system, this separation of blended seismic data is divided into an easily determined or overdetermined linear inverse problem and an underdetermined linear inverse problem that is difficult to solve. For the latter, this paper presents an optimization method that imposes the sparsity constraint on wavefields to construct the object function of inversion, and the problem is solved by using the iterative thresholding method. For the most extremely underdetermined separation problem with single-shooting and multiple sources, this paper presents a method of pseudo-deblending with random noise filtering. In this method, approximate common shot gathers are received through the pseudo-deblending process, and the random noises that appear when the approximate common shot gathers are sorted into common receiver gathers are eliminated through filtering methods. The separation methods proposed in this paper are applied to three types of numerical simulation data, including pure data without noise, data with random noise, and data with linear regular noise to obtain satisfactory results. The noise suppression effects of these methods are sufficient, particularly with single-shooting blended seismic data, which verifies the effectiveness of the proposed methods.展开更多
火山岩成分的多样性是岩浆物理和化学过程在其产生、运移、存储和喷发过程中的综合反映。长白山火山区自上新世以来喷发了大量的玄武质火山岩,其成分变化范围较大（Mg O 3.2%~7.8%）。以往研究认为其成分的变化主要受地幔不均一、部分...火山岩成分的多样性是岩浆物理和化学过程在其产生、运移、存储和喷发过程中的综合反映。长白山火山区自上新世以来喷发了大量的玄武质火山岩,其成分变化范围较大（Mg O 3.2%~7.8%）。以往研究认为其成分的变化主要受地幔不均一、部分熔融程度和分离结晶的影响,没有明显地壳混染。本研究发现这些玄武岩经历了不同程度的上、下地壳的混染。同时,结合火山岩的年龄发现玄武岩地球化学成分和同位素比值随时间呈现脉动式的变化。根据87Sr/86Sr和Mg O的突变点可以分为3段：5~2Ma,2~1Ma,1~0Ma。通过定性和定量的模拟发现地幔不均一性和部分熔融程度差异造成玄武岩成分的变化有限,而分离结晶、地壳混染和岩浆补给的岩浆作用是形成玄武岩成分随时间脉动变化的主要原因。并结合能量约束-补给-混染-分离结晶算法（ECRAFC）模拟得出以下结论：天池和望天鹅喷发中心的玄武质岩浆最初都存储于同一下地壳岩浆房,可能由于上地壳构造差异导致岩浆迁移路径和存储区不同;长白山岩浆房迁移有从5~2Ma阶段由下地壳向上地壳逐渐变浅,2~1Ma阶段由上地壳向下地壳快速变深的规律,而1~0Ma阶段的玄武岩由岩浆从下地壳直接快速喷出地表形成;长白山玄武质岩浆的活动与本区的构造断裂活动密切的关系,5Ma以来,火山岩成分随时间的周期性波动可能与本区构造应力的周期性的强拉张-弱拉张过程有关。展开更多
Stable transmission of genetic information during cell division requires faithful mitotic spindle assembly and chromosome segregation. The Ran GTPase plays a key role in mitotic spindle assembly. However, how the gene...Stable transmission of genetic information during cell division requires faithful mitotic spindle assembly and chromosome segregation. The Ran GTPase plays a key role in mitotic spindle assembly. However, how the generation of a chemical gradient of Ran-GTP at the spindle is coupled to mitotic post-translational modifications has never been characterized. Here, we solved the complex structure of Ran with the nucleotide release factor Mogl and delineated a novel mitosis-specific acetylation-regulated Ran-Mogl interaction dur- ing chromosome segregation. Our structure-guided functional analyses revealed that Mogl compotes with RCCl for Ran binding in a GTP/GDP-dependent manner. Biochemical characterization demonstrated that Mogl-bound Ran prevents RCCl binding and subse- quent GTP loading. Surprisingly, Ran is a bono fide substrate of TIP60, and the acetylation of Lys134 by TIP60 liberates Mogl from Ran binding during mitosis. Importantly, this acetylation-elicited switch of Ran binding to RCC1 promotes high level of Ran-GTP, which is essential for chromosome alignment. These results establish a previously uncharacterized regulatory mechanism in which TIP60 pro- vides a homeostatic control of Ran-GTP level by tuning Ran effector binding for chromosome segregation in mitosis.展开更多
Y99-61532-372 9916333不确定多变量模糊数字控制系统的稳定性和鲁棒性分析:Stability and robustness analysis of uncertain multi-variable fuzzy digital control systems[会,英]/Leung,F.H.F.& Lam,H.K.//1998 IEEE Internatio...Y99-61532-372 9916333不确定多变量模糊数字控制系统的稳定性和鲁棒性分析:Stability and robustness analysis of uncertain multi-variable fuzzy digital control systems[会,英]/Leung,F.H.F.& Lam,H.K.//1998 IEEE International Con-ference on Fuzzy Systems,Vol.1.—372～377(NiG)本文分析了具有参数不确定性数字模糊控制系统的稳定性和鲁棒性,为进行分析,文中首先采用模糊模型精确描述了一种具有参数不确定性的数字非线性系统,然后将数字模糊控制器与被控对象组成闭环系统。本文给出了三种设计方法,并针对每种设计方法给出了相应的稳定性条件,最后举例揭示了提出方法的应用。展开更多
The diffusion behavior of particles in the chromatography is a fundamental issue of chromatographic dynamics. The understanding of the diffusion behaviors is particularly critical to optimize the operation conditions,...The diffusion behavior of particles in the chromatography is a fundamental issue of chromatographic dynamics. The understanding of the diffusion behaviors is particularly critical to optimize the operation conditions, improve the chromatographic performance and design a new separation device. Many of the present simulations focus on chromatographic thermodynamics, and very few aim at the overall diffusion and separation process. In order to dynamically trace the trajectory of the diffusing particles and to perform simulations of the whole chromatographic process, we have developed a model based on the framework of random walk in the restricted space and performed the simulation of a single particle diffusion in the gas chromatography. The simulation parameters were determined by comparing with the experimental data. The elution profiles of n-alkanes under different flow rates were accurately simulated with the method. The results show that the relative difference between the measures and the simulations are less than 2% and 10% for the retention time and the peak width, respectively. The simulation method shows great significance for the optimization of separation conditions and the development of novel technologies of chromatographic separation.展开更多
文摘Multi-source seismic technology is an efficient seismic acquisition method that requires a group of blended seismic data to be separated into single-source seismic data for subsequent processing. The separation of blended seismic data is a linear inverse problem. According to the relationship between the shooting number and the simultaneous source number of the acquisition system, this separation of blended seismic data is divided into an easily determined or overdetermined linear inverse problem and an underdetermined linear inverse problem that is difficult to solve. For the latter, this paper presents an optimization method that imposes the sparsity constraint on wavefields to construct the object function of inversion, and the problem is solved by using the iterative thresholding method. For the most extremely underdetermined separation problem with single-shooting and multiple sources, this paper presents a method of pseudo-deblending with random noise filtering. In this method, approximate common shot gathers are received through the pseudo-deblending process, and the random noises that appear when the approximate common shot gathers are sorted into common receiver gathers are eliminated through filtering methods. The separation methods proposed in this paper are applied to three types of numerical simulation data, including pure data without noise, data with random noise, and data with linear regular noise to obtain satisfactory results. The noise suppression effects of these methods are sufficient, particularly with single-shooting blended seismic data, which verifies the effectiveness of the proposed methods.
文摘火山岩成分的多样性是岩浆物理和化学过程在其产生、运移、存储和喷发过程中的综合反映。长白山火山区自上新世以来喷发了大量的玄武质火山岩,其成分变化范围较大（Mg O 3.2%~7.8%）。以往研究认为其成分的变化主要受地幔不均一、部分熔融程度和分离结晶的影响,没有明显地壳混染。本研究发现这些玄武岩经历了不同程度的上、下地壳的混染。同时,结合火山岩的年龄发现玄武岩地球化学成分和同位素比值随时间呈现脉动式的变化。根据87Sr/86Sr和Mg O的突变点可以分为3段：5~2Ma,2~1Ma,1~0Ma。通过定性和定量的模拟发现地幔不均一性和部分熔融程度差异造成玄武岩成分的变化有限,而分离结晶、地壳混染和岩浆补给的岩浆作用是形成玄武岩成分随时间脉动变化的主要原因。并结合能量约束-补给-混染-分离结晶算法（ECRAFC）模拟得出以下结论：天池和望天鹅喷发中心的玄武质岩浆最初都存储于同一下地壳岩浆房,可能由于上地壳构造差异导致岩浆迁移路径和存储区不同;长白山岩浆房迁移有从5~2Ma阶段由下地壳向上地壳逐渐变浅,2~1Ma阶段由上地壳向下地壳快速变深的规律,而1~0Ma阶段的玄武岩由岩浆从下地壳直接快速喷出地表形成;长白山玄武质岩浆的活动与本区的构造断裂活动密切的关系,5Ma以来,火山岩成分随时间的周期性波动可能与本区构造应力的周期性的强拉张-弱拉张过程有关。
文摘Stable transmission of genetic information during cell division requires faithful mitotic spindle assembly and chromosome segregation. The Ran GTPase plays a key role in mitotic spindle assembly. However, how the generation of a chemical gradient of Ran-GTP at the spindle is coupled to mitotic post-translational modifications has never been characterized. Here, we solved the complex structure of Ran with the nucleotide release factor Mogl and delineated a novel mitosis-specific acetylation-regulated Ran-Mogl interaction dur- ing chromosome segregation. Our structure-guided functional analyses revealed that Mogl compotes with RCCl for Ran binding in a GTP/GDP-dependent manner. Biochemical characterization demonstrated that Mogl-bound Ran prevents RCCl binding and subse- quent GTP loading. Surprisingly, Ran is a bono fide substrate of TIP60, and the acetylation of Lys134 by TIP60 liberates Mogl from Ran binding during mitosis. Importantly, this acetylation-elicited switch of Ran binding to RCC1 promotes high level of Ran-GTP, which is essential for chromosome alignment. These results establish a previously uncharacterized regulatory mechanism in which TIP60 pro- vides a homeostatic control of Ran-GTP level by tuning Ran effector binding for chromosome segregation in mitosis.
文摘Y99-61532-372 9916333不确定多变量模糊数字控制系统的稳定性和鲁棒性分析:Stability and robustness analysis of uncertain multi-variable fuzzy digital control systems[会,英]/Leung,F.H.F.& Lam,H.K.//1998 IEEE International Con-ference on Fuzzy Systems,Vol.1.—372～377(NiG)本文分析了具有参数不确定性数字模糊控制系统的稳定性和鲁棒性,为进行分析,文中首先采用模糊模型精确描述了一种具有参数不确定性的数字非线性系统,然后将数字模糊控制器与被控对象组成闭环系统。本文给出了三种设计方法,并针对每种设计方法给出了相应的稳定性条件,最后举例揭示了提出方法的应用。
基金supported by the National Natural Science Foundation of China (21273113)
文摘The diffusion behavior of particles in the chromatography is a fundamental issue of chromatographic dynamics. The understanding of the diffusion behaviors is particularly critical to optimize the operation conditions, improve the chromatographic performance and design a new separation device. Many of the present simulations focus on chromatographic thermodynamics, and very few aim at the overall diffusion and separation process. In order to dynamically trace the trajectory of the diffusing particles and to perform simulations of the whole chromatographic process, we have developed a model based on the framework of random walk in the restricted space and performed the simulation of a single particle diffusion in the gas chromatography. The simulation parameters were determined by comparing with the experimental data. The elution profiles of n-alkanes under different flow rates were accurately simulated with the method. The results show that the relative difference between the measures and the simulations are less than 2% and 10% for the retention time and the peak width, respectively. The simulation method shows great significance for the optimization of separation conditions and the development of novel technologies of chromatographic separation.
