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排序方式: 共有270条查询结果,搜索用时 15 毫秒
41.
In this paper, we present a two-phase augmented Lagrangian method, called QSDPNAL, for solving convex quadratic semidefinite programming (QSDP) problems with constraints consisting of a large number of linear equality and inequality constraints, a simple convex polyhedral set constraint, and a positive semidefinite cone constraint. A first order algorithm which relies on the inexact Schur complement based decomposition technique is developed in QSDPNAL-Phase I with the aim of solving a QSDP problem to moderate accuracy or using it to generate a reasonably good initial point for the second phase. In QSDPNAL-Phase II, we design an augmented Lagrangian method (ALM) wherein the inner subproblem in each iteration is solved via inexact semismooth Newton based algorithms. Simple and implementable stopping criteria are designed for the ALM. Moreover, under mild conditions, we are able to establish the rate of convergence of the proposed algorithm and prove the R-(super)linear convergence of the KKT residual. In the implementation of QSDPNAL, we also develop efficient techniques for solving large scale linear systems of equations under certain subspace constraints. More specifically, simpler and yet better conditioned linear systems are carefully designed to replace the original linear systems and novel shadow sequences are constructed to alleviate the numerical difficulties brought about by the crucial subspace constraints. Extensive numerical results for various large scale QSDPs show that our two-phase algorithm is highly efficient and robust in obtaining accurate solutions. The software reviewed as part of this submission was given the DOI (Digital Object Identifier) https://doi.org/10.5281/zenodo.1206980. 相似文献
42.
LIU Yuan ZHOU Xiao-Hong ZHANG Yu-Hu ZHENG-Yong LIU Min-Liang GUO Ying-Xiang M. Oshima Y. Toh M. Koizumi A. Osa Y. Hatsukawa SUN Yang 《中国物理快报》2008,25(5):1633-1635
A standard in-beam γ-spectroscopy experiment for 188Pt is performed via the176Yb(18O, 6n) reaction at beam energies of 88 and 95MeV, and the level scheme for 188Pt is established. Prolate and oblate shape coexistence has been demonstrated to occur in 188Pt by applying the projected shell model. The rotation alignment of i13/2 neutrons drives the yrast sequence changingsuddenly from prolate to oblate shape at angular momentum 10h, indicating likely a new type of shape phase transition along the yrast line in 188Pt. 相似文献
43.
A. Kimura Y. Toh M. Oshima Y. Hatsukawa 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(2):521-525
Recycling steel products demands a new technique for determining tramp elements in steel. Tramp elements, As and Sb, in some
iron certified reference materials were determined by neutron activation analysis with multiple gamma-ray detection method
and reported in MTAA11. In MTAA12, the authors reported the lower limit of determination values (LDL) and the dispersion of
this method. The values of the LDLs for As and Sb in high purity iron were 0.002 and 0.0009 μg·g−1. The dispersion is small enough to satisfy the demand from materials science. 相似文献
44.
Hamasaki T Kashiwagi T Imada T Nakamichi N Aramaki S Toh K Morisawa S Shimakoshi H Hisaeda Y Shirahata S 《Langmuir : the ACS journal of surfaces and colloids》2008,24(14):7354-7364
There are few reports on the physiological effects of metal nanoparticles (nps), especially with respect to their functions as scavengers for superoxide anion radical (O2(.-)) and hydroxyl radical (.OH). We tried to detect the scavenging activity of Pt nps using a hypoxanthine-xanthine oxidase system for O2(.-) and using a Fenton and a UV/H2O2 system for .OH. Electron spin resonance analysis revealed that 2 nm particle size Pt nps have the ability to scavenge O2(.-) and .OH. The calculated rate constant for the O2(.-)-scavenging reaction was 5.03 +/- 0.03 x 10(7) M (-1) s (-1). However, the analysis of the Fenton and UV/H 2O 2 system in the presence of Pt nps suggested that the .OH-scavenging reaction cannot be determined in both systems. Among particle sizes tested from 1 to 5 nm, 1 nm Pt nps showed the highest O2(.-)-scavenging ability. Almost no cytotoxicity was observed even after adherent cells (TIG-1, HeLa, HepG2, WI-38, and MRC-5) were exposed to Pt nps at concentrations as high as 50 mg/L. Pt nps scavenged intrinsically generated reactive oxygen species (ROS) in HeLa cells. Additionally, Pt nps significantly reduced the levels of intracellular O2(.-) generated by UVA irradiation and subsequently protected HeLa cells from ROS damage-induced cell death. These findings suggest that Pt nps may be a new type of antioxidant capable of circumventing the paradoxical effects of conventional antioxidants. 相似文献
45.
We report the establishment of capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection as a common analytical platform for sensitive quantification of both phase I and II metabolism in various hepatic in vitro models. 相似文献
46.
Ultra-performance liquid chromatography/time-of-flight mass spectrometry based metabolomics of raw and steamed Panax notoginseng 总被引:4,自引:0,他引:4
Chan EC Yap SL Lau AJ Leow PC Toh DF Koh HL 《Rapid communications in mass spectrometry : RCM》2007,21(4):519-528
At present, metabolite profiling is of growing importance in herbal medicine fields such as breeding, formulation, quality control and clinical trials. This preliminary study indicated that ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOFMS)-based metabolomics allows direct detection of down-stream derivatives of metabolites, arising from the herbal formulation process. This analytical approach allows the discrimination and tentative authentication of unique biomarkers related to different herbal extracts using unsupervised multivariate principal component analysis (PCA). The tentative identification of biomarkers is complemented significantly by the accurate mass measurement of TOFMS and the high resolution and high retention time reproducibility rendered by UPLC. The application of this approach in herbal extract discrimination and ginsenoside biomarker discovery of raw and steamed Panax notoginseng (Burk.) F.H. Chen is demonstrated and discussed. 相似文献
47.
Y. Toh T. Czosnyka M. Oshima T. Hayakawa H. Kusakari M. Sugawara Y. Hatsukawa J. Katakura N. Shinohara M. Matsuda 《The European Physical Journal A - Hadrons and Nuclei》2000,9(3):353-356
74Ge beam was Coulomb-excited on a natPb target. Ten E2 matrix elements including diagonal matrix elements for 5 low-lying states have been determined using the least-squares search
code GOSIA. The expectation values of the rotational invariants 〈Q
2〉 and 〈cos3δ〉 show the small and triaxial deformation of the two lowest members of the ground-state band , while the 02
+ and 22
+ states are found to be almost spherical.
Received: 31 August 2000 / Accepted: 4 December 2000 相似文献
48.
C. Kloc K. J. Tan M. L. Toh K. K. Zhang Y. P. Xu 《Applied Physics A: Materials Science & Processing》2009,95(1):219-224
Liquid chromatography connected with mass spectroscopy reveals that the oxidized form of rubrene is the major impurity in
commercial powder of rubrene as well as in rubrene single crystals. One form of rubrene impurity can be transformed into the
other. In solution, rubrene undergoes photo-oxidation completely until the red color of the rubrene solution disappears. Single
crystals, due to compact packing of molecules and the required molecular shape change during oxidation, oxidize only on the
surface. 相似文献
49.
HUA Wei ZHOU Xiao-Hong ZHANG Yu-Hu GUO Ying-Xiang Oshima M. Toh Y. Koizumi M. Osa A. Hatsukawa Y. QI Bin ZHANG Shuang-Quan MENG Jie Sugawara M. 《中国物理C(英文版)》2009,33(9)
High-spin levels of 189Pt have been studied with the in-beam γ-spectroscopy method via the 176Yb(18O,5n) reaction at the beam energies of 88 and 95 MeV. The previously known vi13/2-1 band has been confirmed, and its unfavored signature branch extended up to the 31/2+ state. Within the framework of the triaxial particle-rotor model, the vi13/2-1 band is suggested to be associated with the 11/2[615] configuration, and to have triaxial deformation. 相似文献
50.
Julita K. Grzeskowiak Anne Tscheliessnig Poh Choo Toh Janet Chusainow Yih Yean Lee Niki Wong Alois Jungbauer 《Journal of chromatography. A》2009,1216(24):4902-4912
Although Staphylococcus Protein A (SpA) affinity chromatography is the state of the art capture step for antibody purification, non-affinity methods are more economical. We used two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) to evaluate the purification of a recombinant IgG1 antibody from cultured cells, with two different processes: (1) SpA capture followed by cation-exchange chromatography (CEX); and (2) CEX capture, followed by anion exchanger, then hydrophobic interaction chromatography. Efficiencies were similar in sodium dodecylsulphate polyacrylamide gel electrophoresis and size-exclusion chromatography; however, 2-D DIGE revealed higher efficiency with SpA than with CEX capture. Thus, 2-D DIGE is a valuable tool for downstream process development. 相似文献