排序方式: 共有56条查询结果,搜索用时 15 毫秒
21.
Tarasov IS Pikhtin NA Slipchenko SO Sokolova ZN Vinokurov DA Borschev KS Kapitonov VA Khomylev MA Leshko AY Lyutetskiy AV Stankevich AL 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,66(4-5):819-823
We suggested and experimentally confirmed the effective method of internal optical loss reduction by high order mode suppression in a separate confinement quantum well laser heterostructure with asymmetric ultra thick waveguide. Manufacturing of InGaAs/GaAs/AlGaAs laser heterostructure with a 1.7 microm-thick asymmetric waveguide allowed attaining super low value of internal optical loss alphai=0.34 cm-1 preserving high efficiency and fundamental transverse mode operation. Record-high 16 W continuous wave (CW) and 145 W pulse room temperature front facet output optical power and 74% wallplug efficiency were attained in 100-microm-aperture 1.06-microm-emitting laser diodes with 3 mm cavity length. 相似文献
22.
Cover Picture: The Chemical Basis of Fungal Bioluminescence (Angew. Chem. Int. Ed. 28/2015)
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Dr. Konstantin V. Purtov Dr. Valentin N. Petushkov Dr. Mikhail S. Baranov Dr. Konstantin S. Mineev Dr. Natalja S. Rodionova Zinaida M. Kaskova Aleksandra S. Tsarkova Dr. Alexei I. Petunin Dr. Vladimir S. Bondar Dr. Emma K. Rodicheva Dr. Svetlana E. Medvedeva Prof. Yuichi Oba Yumiko Oba Prof. Alexander S. Arseniev Prof. Sergey Lukyanov Prof. Josef I. Gitelson Dr. Ilia V. Yampolsky 《Angewandte Chemie (International ed. in English)》2015,54(28):8001-8001
23.
Optical Properties and Model of the Electronic and Spatial Structure of Hypercrosslinked Polystyrene
Davankov V. A. Klimova T. P. Tsyurupa M. P. Blinnikova Z. K. 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2018,92(12):2507-2512
Russian Journal of Physical Chemistry A - A number of hypercrosslinked polystyrene networks are studied. The networks are obtained via additional crosslinking of granules of styrene copolymer with... 相似文献
24.
A. S. Morozov M. N. Kopitsyna I. V. Bessonov N. V. Karelina A. V. Nuzhdina I. Yu. Sarkisov L. A. Pavlova M. P. Tsyurupa Z. K. Blinnikova V. A. Davankov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(12):2465-2470
Synthetic ligands carrying a positive charge and capable of selective binding of bacterial endotoxins are covalently immobilized on surfaces of domestic hemosorbent Styrosorb-514 based on hypercrosslinked polystyrene. It is shown that the resulting sorbent aimed at treating sepsis exceeds imported specific hemosorbent in Toraymyxin? columns in removing lipopolysaccharides, and can be used in domestically-produced Desepta columns. 相似文献
25.
Zinaida A. Lykova 《代数通讯》2013,41(6):1779-1793
We prove that, for every natural number n, there exists a unital semisimple Banach star algebra Aand a closed star subalgebra Bof the centre of A, different from C, such that the global B-homological dimension and the B-homological bidimension of Aare both equal to n. The algebras Aand Bcan be taken to be function algebras. 相似文献
26.
Ekaterina V. Matveeva Pavel V. Petrovskii Zinaida S. Klemenkova Natalya A. Bondarenko Irina L. Odinets 《Comptes Rendus Chimie》2010,13(8-9):964-970
Biphasic systems room temperature imidazolium ionic liquid (RTIL)/water or water as a solvent significantly accelerate the addition of amines to vinylphosphoryl compounds hence opening green and effective synthesis of β-aminophosphoryl compounds in excellent yields over short reaction times. The application of water, being the cheapest and most non-toxic solvent, without any catalyst or co-solvent, is more advantageous as it provides a simple isolation procedure for products having high purity (> 95% according to the NMR data) via simple freeze-drying and does not require extraction with organic solvents. The solubility of the starting phosphorus substrate in water does not play crucial role in the reaction as it was demonstrated using water insoluble diphenylvinylphosphine oxide. In contrast to typical procedures, using a reactant ratio (vinylphosphoryl compound: amine) of 2:1 readily resulted in double phosphorylation of primary amines, including polyamines, in water. 相似文献
27.
Sergii Demchenko Roman Lesyk Oleh Yadlovskyi Johannes Zuegg Alysha G. Elliott Iryna Drapak Yuliia Fedchenkova Zinaida Suvorova Anatolii Demchenko 《Molecules (Basel, Switzerland)》2021,26(14)
A series of novel 3-aryl-5H-pyrrolo[1,2-a]imidazole and 5H-imidazo[1,2-a]azepine quaternary salts were synthesized in 58–85% yields via the reaction of 3-aryl-6, 7-dihydro-5H-pyrrolo[1,2-a]imidazoles or 3-aryl-6,7,8,9-tetrahydro-5H-imidazo[1,2-a]azepines and various alkylating reagents. All compounds were characterized by 1H NMR, 13C NMR, and LC-MS. The conducted screening studies of the in vitro antimicrobial activity of the new quaternary salts derivatives established that 15 of the 18 newly synthesized compounds show antibacterial and antifungal activity. Synthesized 3-(3,4-dichlorohenyl)-1-[(4-phenoxyphenylcarbamoyl)-methyl]-6,7-dihydro-5H-pyrrolo[1,2-a]imidazol-1-ium chloride 6c possessed a broad activity spectrum towards Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Cryptococcus neoformans, with a high hemolytic activity against human red blood cells and cytotoxicity against HEK-293. However, compound 6c is characterized by a low in vivo toxicity in mice (LD50 > 2000 mg/kg). 相似文献
28.
Ananda Rama Krishnan S Weissflog W Pelzl G Diele S Kresse H Vakhovskaya Z Friedemann R 《Physical chemistry chemical physics : PCCP》2006,8(10):1170-1177
The influence of the direction of ester linkage groups on the structural and electronic properties of five-ring banana-shaped molecules with a central 1,3-phenylene unit has been investigated including hexyloxy and dodecyloxy terminal chains. DFT studies on the B3LYP/6-31G(d) level were performed on the conformational behaviour of the ten isomers in a systematic way. The one- and two-fold potential energy scans show that the flexibility of the wings significantly depends on the orientation of the carboxyl linkage groups. Moreover, the different directions of the carboxyl groups between the aromatic rings cause remarkable changes on the dipole moment and its components of the molecules. These findings are supported by investigations on the global charge pattern of the molecules calculated from electrostatic potential group charges. The bending angle alpha obtained from a simple model for the five-ring bent-core molecules is a characteristic structural parameter which can be correlated with experimental findings. Calculations on the bent-core molecules in an external electric dipole field related to the direction of their polar axis show remarkable effects with respect to the flexibility and polarity of the isomers. First molecular dynamics simulations on the banana-shaped molecules were carried out within the AMBER 7 package. The trajectories of relevant structural parameters support the findings of the DFT studies. The results concerning the structure and polarity revealed from the DFT and MD calculations of the ten isomers can be correlated with data from dielectric measurements and mesophase properties. 相似文献
29.
Zinaida A. Lykova 《Journal of Pure and Applied Algebra》2006,205(3):471-497
We present methods for the computation of the Hochschild and cyclic-type continuous homology and cohomology of some locally convex strict inductive limits of Fréchet algebras Am. In the pure algebraic case it is known that, for the cyclic homology of A, for all n?0 [Cyclic Homology, Springer, Berlin, 1992, E.2.1.1]. We show that, for a locally convex strict inductive system of Fréchet algebras such that
0→Am→Am+1→Am+1/Am→0 相似文献
30.
Nataliya A. Vlasenko Pavel F. Oleksenko Miroslav A. Mukhlyo Zinaida L. Denisova Ludmila I. Veligura 《Annalen der Physik》2013,525(12):889-905
ZnS:Cr and ZnSe:Cr are the focus of studies as media for broadly tunable optically pumped lasers operating in the near‐ and mid‐IR regions. It is of great interest to obtain such lasers electrically pumped. The effective electrical excitation of Cr2+ ions was demonstrated only in the case of the impact mechanism for thin‐film structures with insulator layers between an electroluminescent film and electrodes, which prevent avalanche breakdown at high electric field (≥ 1 MV/cm). To obtain lasing, the waveguide electroluminescent structures were used. For the first time, the stimulated emission and the laser oscillation were demonstrated in the ZnS:Cr waveguide structures. Although the lasing is unstable as yet, these results lay the foundations of a new direction in laser physics aimed at creation of electrically pumped lasers by dint of impact excitation. Published results concerning various aspects of ZnS:Cr and ZnSe:Cr thin films and waveguide structures as promising electrically pumped laser media are reviewed. The causes of the instability of the laser oscillation and means of improving their characteristics are also considered. 相似文献