The rapid uncertainty prediction of the ocean-acoustic coupled model

Focusing on the rapid prediction of acoustic field uncertainty in environment with temporal and spatial sound speed perturbation, evolvement of sound speed structure over time is predicted based on the ocean-acoustic coupled model to obtain the uncertainty distribution of the vertical structure of sound speed. Further, a method combining the arbitrary polynomial chaos expansion with the empirical orthogonal function is proposed to reduce the dimensionality of uncertain parameters and to obtain the uncertainty distribution of the acoustic field. Simulations have shown that the computational complexity can be reduced by 2 orders of magnitude compared to the conventional polynomial chaos expansion while ensures the same precision.Moreover, the computational complexity is not influenced by the complexity of the sound speed profile. The acoustic field and uncertainty predicted in uncertain environment by proposed method also have been tested with the experimental data.     

新大线同沟敷设热力分析

针对新大线同沟敷设管道,采用非结构化有限容积法,分析了不同的物性条件下,常温输送原油对加热输送原油的热力影响.     

荞麦花多糖的提取及含量测定

采用热水提取、乙醇沉淀的方法从荞麦花中提取出了水溶性多糖,采用硫酸-苯酚法在波长为497nm处进行了糖含量的测定,求得其校准曲线的回归方程为y=0.00508x 0.0294,相关系数为r=0.9978.平均回收率为99%-103%,RSD为0.74%.结果显示:荞麦花多糖的产率为2.5%.糖含量为41.63%.     

Peculiarities of the phase composition and structure of the high-entropy FeWMoCrVSiMnC multicomponent steel

We report on the results of analysis of the phase composition, structure, and hardness of high-entropy FeWMoCrVSiMnC multicomponent steel subjected to synthesis and subsequent thermal treatment. Analysis is carried out using the methods of analytic transmission and scanning structural and orientational electron microscopy, optical metallography, X-ray energy-dispersive spectroscopy, X-ray phase and structural analyses, and Rockwell measurements of hardness. It is found that steel has a high hardness (62 HRC) and is in ultra-fine-disperse composite martensite-multicarbide state. All carbides are distributed uniformly over the steel volume and have nano- and submicrometer scales depending on the carbide type.

     

离子交换色谱法分离测定磷霉素的研究

分别采用全多孔型硅胶基键合强阴离子交换柱与氨丙基键合硅胶柱,在低波长 ２００ ｎｍ 处检测,分离测定了磷霉素 探讨了流动相条件,如ｐ Ｈ 值、离子强度等对磷霉素保留及分离选择性的影响,优化分离条件,建立了一种测定磷霉素的高效液相色谱新方法方法简便、快速     

Benzoid-quinoid tautomerism of Schiff bases and their structural analogs: LV. Crown-containing N-phenylimines derived from ortho-hydroxycarbaldehydes of the coumarin series

Schiff bases were synthesized from 3-hydroxy-6-oxo-6H-benzo[c]chromene-4-carbaldehyde, 5-hydroxy-4,7-dimethyl-2-oxo-2H-chromene-6-carbaldehyde, 6,7-dihydroxy-4-methyl-2-oxo-2H-chromene-8-carbaldehyde, 5,7-dihydroxy-4-methyl-2-oxo-2H-chromene-6,8-dicarbaldehyde, and 5-hydroxy-4,7-dimethyl-2-oxo-2H-chromene-6,8-dicarbaldehyde and (¹⁵N)aniline or aminobenzo-15-crown-5 (2,3,5,6,8,9,11,12-octahydrobenzo[b][1,4,7,10,13]pentaoxacyclopentadecin-15-amine), and tautomeric equilibrium between the hydroxy enimino and keto enamino forms of the 4- and 8-iminomethyl derivatives in solution was revealed by 1H NMR and electronic spectroscopy. Addition of alkaline earth cations to their solutions in acetonitrile displaced the tautomeric equilibrium toward the hydroxy enimino structure due to complex formation with the crown ether fragment.     

Three-Dimensional Structure of Thermostable D-Amino Acid Transaminase from the Archaeon Methanocaldococcus jannaschii DSM 2661

Crystallography Reports - Pyridoxal 5′-phosphate (PLP)-dependent transaminases catalyze the stereospecific amino-group transfer from an amino acid or amine to ketone or keto acid....     

Passive ranging of a moving sound source using three-dimensional measured information

To solve the problem of passive ranging of a moving sound source,a method of estimating the initial distance of target is presented by using the measured inform...     

The Effect of Supports of Glassy–Carbon and Activated Graphite Foil on the Electrochemical Behavior of Composite Coatings Based on Polyaniline and Its N-Substituted Derivatives

Russian Journal of Electrochemistry - Abstract—Hybrid polymer nanomaterials are synthesized based on polyaniline (PAni) and its N-substituted derivative...     

Synthesis and Investigation of Copolymers of Glycidyl Methacrylate and Methyl Pheophorbide a in a Solution

Russian Journal of General Chemistry - Copolymers of glycidyl methacrylate and methyl pheophorbide a of different compositions were synthesized by radical copolymerization in toluene and THF...