全文获取类型
收费全文 | 73篇 |
免费 | 1篇 |
专业分类
化学 | 47篇 |
力学 | 21篇 |
数学 | 4篇 |
物理学 | 2篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 5篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 7篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1993年 | 1篇 |
1988年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有74条查询结果,搜索用时 31 毫秒
51.
E. V. Gracheva A. V. Vologzhanina E. S. Smirnova S. P. Tunik 《Russian Journal of Inorganic Chemistry》2011,56(7):1046-1049
Synthesis was carried out, and structure solved for the new dinuclear erbium(III) complex having a composition of Na4[Er2(EDTA)2(C2O4)] · 8H2O (where EDTA stands for ethylenediamine-N,N′-tetraacetate). The compound was characterized by IR and UV spectroscopy, mass
spectrometry, and X-ray crystallography. In the structure of the compound, erbium(III) has C.N. 8 and a coordination polyhedron
shaped as a square antiprism. The EDTA and oxalate ions manifest their characteristic coordination modes: N,O-chelate hexadentate
and bridge-cyclic tetradentate, respectively. 相似文献
52.
Koshevoy IO Lin CL Karttunen AJ Jänis J Haukka M Tunik SP Chou PT Pakkanen TA 《Inorganic chemistry》2011,50(6):2395-2403
Reactions between the diphosphino-gold cationic complexes [Au(2)(PPh(2)-C(2)-(C(6)H(4))(n)-C(2)-PPh(2))(2)](2+) (n = 0, 1, 2, 3) and polymeric acetylides (AuC(2)Ph)(n) and (AgC(2)Ph)(n) lead to the formation of a new family of heterometallic clusters with the general formula [Au(8+2n)Ag(6+2n)(C(2)Ph)(8+4n)(PPh(2)C(2)(C(6)H(4))(n)C(2)PPh(2))(2)](2+), n = 0 (1), 1 (2), 2 (3), 3 (4). Compounds 1-4 were characterized in detail by NMR and ESI-MS spectroscopy. Complex 1 (n = 0) crystallizes in two forms (orange (1a) and yellow (1b)), one of which (1a) has been analyzed by X-ray crystallography. The luminescence behavior of 1-4 has been studied. Compounds 2 and 3 exhibited orange-red phosphorescence with quantitative quantum efficiency in both aerated and degassed CH(2)Cl(2), implying O(2)-independent phosphorescence due to efficient protection of the emitting chromophore center by the organic ligands. Complex 3 exhibits reasonable two-photon absorption (TPA) property with a cross section of σ ≈ 45 GM (800 nm), which is comparable to the value of commercially available TPA dyes such as coumarin 151. Computational studies have been performed to correlate the structural and photophysical features of the complexes studied. The metal-centered triplet emission within the heterometallic core is suggested to play a key role in the observed phosphorescence. The luminescence spectrum of 1 in CH(2)Cl(2) shows dual phosphorescence maximized at 575 nm (the P(1) band) and 770 nm (the P(2) band). Both P(1) and P(2) bands possess identical excitation spectra, i.e., the same ground-state origin, and the same relaxation dynamics throughout the temperature range of 298-200 K. The dual emission of 1 arises from fast structural fluctuation upon excitation, perhaps forming two geometry isomers, which exhibit distinctly different P(1) and P(2) bands. The scrambling dynamics might require large-amplitude motion and, hence, is hampered in rigid media, as evidenced by the single emission for 1a (610 nm) and 1b (570 nm) observed in solid. 相似文献
53.
Yu. V. Tunik 《Fluid Dynamics》2008,43(6):954-959
The flow of a hydrogen-oxygen mixture diluted with argon in a supersonic axisymmetric nozzle consisting of an inlet cylinder, a convergent region, a cylindrical throat, and a divergent region is considered. The supersonic flow enters the channel along the axis of symmetry. The flow structure is calculated with allowance for hydrogen ignition. A possibility of stabilizing the combustion zone is studied and the forces acting on the nozzle from the flow are determined. The problem is solved in the two-dimensional approximation with account for detailed combustion kinetics. 相似文献
54.
55.
Koshevoy IO Haukka M Pakkanen TA Tunik SP 《Dalton transactions (Cambridge, England : 2003)》2006,(47):5641-5647
A novel trimetallic cluster [Ru5CRh2Pt2(CO)16(dppm)2] was synthesized via coupling of two neutral clusters-[Ru5C(CO)15] and [Rh2Pt2(CO)6(dppm)2]. The structure of this mixed metal complex was established using X-ray crystallography and 31P NMR spectroscopy. It was found that the reaction between [Ru6C(CO)17] and [Pt2(CO)3(dppm)2] leads to spontaneous electron transfer between these polynuclear complexes and results in the formation of an unusually stable cluster "salt" {[Ru6(CO)16]2-[Pt2(CO)2(dppm)2]2+}, which was characterized by crystallographic and spectroscopic methods. Heating of the Ru6-Pt2 ion pair in an autoclave (145 degrees C, 15 atm N2) results in fusion of the metal frameworks to give a nonanuclear mixed metal [Ru6C(CO)16Pt3(dppm)2] cluster in a good yield. The latter complex was obtained earlier as a minor product of another thermal reaction and now has been additionally characterized by 31P NMR spectroscopy. 相似文献
56.
A.A. Manshina A.V. Povolotskiy T.Y. Ivanova Y.S. Tver’yanovich S.P. Tunik D. Kim M. Kim S.C. Kwon 《Applied Physics A: Materials Science & Processing》2007,89(3):755-759
Continuous copper structures were precipitated on microscope cover glasses by the laser-induced chemical liquid phase deposition
(LCLD) method. The deposition of copper was realized from both CuSO4- and CuCl2-based electrolyte solutions. The surface morphology and the chemical composition of the deposits were analyzed with a scanning
electron microscope and energy dispersive X-ray spectrometer (EDX). The dependence of the characteristics (width and resistance)
of the copper deposits on the laser power, temperature and the salt precursor was examined. The observed strong influence
of the solution temperature and the salt precursor on the deposits characteristics was explained by the specific chemical
features of the Cu(II)→Cu(0) reduction process.
PACS 42.62.-b 相似文献
57.
Halogen Bonding to Amplify Luminescence: A Case Study Using a Platinum Cyclometalated Complex
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Vasily V. Sivchik Anastasia I. Solomatina Yi‐Ting Chen Prof. Antti J. Karttunen Prof. Sergey P. Tunik Prof. Pi‐Tai Chou Prof. Igor O. Koshevoy 《Angewandte Chemie (International ed. in English)》2015,54(47):14057-14060
The cocrystallization of a weakly luminescent platinum complex [Pt(btpy)(PPh3)Cl] ( 1 ) (Hbtpy=2‐(2benzothienyl)pyridine; emission quantum yield Φem=0.03) with fluorinated bromo‐ and iodoarenes C6F6‐nXn (X=Br, I; n=1, 2) results in the formation of efficient halogen‐bonding (XB) interactions Pt? Cl???X? R. An up to 22‐fold enhancement (Φem=0.65) in the luminescence intensity of the cocrystallized compound is detected, without a substantial change of the emission energy. Based on crystallographic, photophysical, and theoretical investigations, the contribution of the XB donors C6F6‐nXn to the amplification of luminescence intensity is attributed to the enhancement of spin–orbit coupling through the heavy‐atom effect, and simultaneously to the suppression of the nonradiative relaxation pathways by increasing the rigidity of the chromophore center. 相似文献
58.
Kristina S. Kisel Vadim A. Baigildin Anastasia I. Solomatina Alexey I. Gostev Eugene V. Sivtsov Julia R. Shakirova Sergey P. Tunik 《Molecules (Basel, Switzerland)》2023,28(1)
A series of diphosphine Re(I) complexes Re1–Re4 have been designed via decoration of the archetypal core {Re(CO)2(N^N)} through the installations of the phosphines P0 and P1 bearing the terminal double bond, where N^N = 2,2′-bipyridine (N^N1), 4,4′-di-tert-butyl-2,2′-bipyridine (N^N2) or 2,9-dimethyl-1,10-phenanthroline (N^N3) and P0 = diphenylvinylphosphine, and P1 = 4-(diphenylphosphino)styrene. These complexes were copolymerized with the corresponding N-vinylpyrrolidone-based Macro-RAFT agents of different polymer chain lengths to give water-soluble copolymers of low-molecular p(VP-l-Re) and high-molecular p(VP-h-Re) block-copolymers containing rhenium complexes. Compounds Re1–Re4, as well as the copolymers p(VP-l-Re) and p(VP-h-Re), demonstrate phosphorescence from a 3MLCT excited state typical for this type of chromophores. The copolymers p(VP-l-Re#) and p(VP-h-Re#) display weak sensitivity to molecular oxygen in aqueous and buffered media, which becomes almost negligible in the model physiological media. In cell experiments with CHO-K1 cell line, p(VP-l-Re2) and p(VP-h-Re2) displayed significantly reduced toxicity compared to the initial Re2 complex and internalized into cells presumably by endocytic pathways, being eventually accumulated in endosomes. The sensitivity of the copolymers to oxygen examined in CHO-K1 cells via phosphorescence lifetime imaging microscopy (PLIM) proved to be inessential. 相似文献
59.
Dr. Anastasia I. Solomatina Dr. Ekaterina E. Galenko Daria O. Kozina Alexey A. Kalinichev Dr. Vadim A. Baigildin Natalia A. Prudovskaya Dr. Julia R. Shakirova Dr. Alexander F. Khlebnikov Dr. Vitaly V. Porsev Dr. Robert A. Evarestov Dr. Sergey P. Tunik 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(64):e202202207
Five square-planar [Pt(C^N*N′^C′)] complexes ( Pt1 – Pt5 ) with novel nonsymmetric tetradentate ligands ( L1 – L5 ) were synthesized and characterized. Varying the structure of the metalating aromatic systems result in substantial changes in photophysical properties and intermolecular interaction mode of the complexes in solution and in solid state. The complexes are strongly emissive in tetrahydrofuran solution, with the band maxima ranging from 560 to 690 nm. Three of these complexes ( Pt1 , Pt2 , Pt4 ) afford nanospecies upon injection of their solution into water, which show aggregation-induced emission (AIE) with a strong red shift of emission bands. In the solid state, crystalline samples of these complexes demonstrate mechanochromism upon grinding with a bathochromic shift of the emission. DFT and TD-DFT computational analysis of monomeric Pt1 – Pt5 in solution and model dimeric emitters formed through intermolecular interaction of Pt1 , Pt2 , Pt4 molecules allowed assignment of observed AIE to the 3MMLCT excited states of Pt-Pt bonded aggregates of these complexes. 相似文献
60.
International Applied Mechanics - The synthesis of control laws for an inertial stabilized platform (ISP) designed for stabilizing the image of an observed target in observer’s field of view... 相似文献