Splitting and linearizing augmented Lagrangian algorithm for subspace recovery from corrupted observations

Given a set of corrupted data drawn from a union of multiple subspace, the subspace recovery problem is to segment the data into their respective subspace and to correct the possible noise simultaneously. Recently, it is discovered that the task can be characterized, both theoretically and numerically, by solving a matrix nuclear-norm and a ?_2,1-mixed norm involved convex minimization problems. The minimization model actually has separable structure in both the objective function and constraint; it thus falls into the framework of the augmented Lagrangian alternating direction approach. In this paper, we propose and investigate an augmented Lagrangian algorithm. We split the augmented Lagrangian function and minimize the subproblems alternatively with one variable by fixing the other one. Moreover, we linearize the subproblem and add a proximal point term to easily derive the closed-form solutions. Global convergence of the proposed algorithm is established under some technical conditions. Extensive experiments on the simulated and the real data verify that the proposed method is very effective and faster than the sate-of-the-art algorithm LRR.     

Adsorptive removal of uranium from aqueous solution using chitosan-coated attapulgite

Chitosan-coated attapulgite beads were prepared by coating chitosan on naturally and abundantly available attapulgite, and made into spherical beads to adsorb uranium from aqueous solutions. The beads were characterized by SEM, EDS and FT-IR. The characteristics of beads of adsorbing uranium(VI) from aqueous solutions were studied at different conditions of pH, initial uranium concentration, contact time, biomass dosage and temperature. The pseudo-second order rate equation was used to describe the kinetic data, and isotherm data were fitted to Langmuir and Freundlich adsorption models. Thermodynamic parameters (ΔG°, ΔH°, and ΔS°) of the biosorption were also calculated. Thermodynamic parameters of the CAAB, viz., ΔG°(308 K), ΔH°, and ΔS° were determined to be −21.59, 6.29l and 90.51 J/mol K, respectively. The experimental results demonstrate that the beads of chitosan coated onto attapulgite exhibit considerable potential for application in both adsorption and removal of uranium from aqueous solutions.     

过氧亚硝酸根对蛋白质损伤的研究进展

过氧亚硝酸根--一氧化氮和超氧根阴离子快速结合的产物,是生物体内产生的一种强氧化剂和细胞毒性物质,它可以介导生物大分子包括DNA、蛋白质和脂质的修饰和损伤。近年来,由于许多疾病条件下都发现大量过氧亚硝酸根诱导的蛋白质损伤产物,因此过氧亚硝酸根与蛋白质的相互作用引起了人们的广泛关注。本文详尽地介绍了过氧亚硝酸根介导蛋白质损伤对人体的病理作用和过氧亚硝酸根与蛋白质作用机制等方面的最新研究进展,并对未来过氧亚硝酸根与蛋白质相互作用的研究作了展望。