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71.
Zhao H Shatruk M Prosvirin AV Dunbar KR 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(23):6573-6589
Reactions of [W(CN)(8)](3-/4-) anions with complexes of Mn(2+) ion with tridentate organic ligand 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) lead to a series of heterobimetallic complexes. The crystal structures of these compounds are derived from the same basic structural fragment, namely a W(2)Mn(2) square constructed of alternating cyanide-bridged W and Mn ions. In [Mn(II)(tptz)(OAc)(H(2)O)(2)](2){[Mn(II)(tptz)(MeOH)(1.58)(H(2)O)(0.42)](2)[W(V)(CN)(8)](2)}.5 MeOH.9.85 H(2)O (3), isolated molecular squares are co-crystallized with mononuclear cationic Mn(II) complexes. The structure of {[Mn(II)(tptz)(MeOH)](2)[W(IV)(CN)(8)].2 MeOH}(infinity) (4) is based on an infinite chain of vertex-sharing squares, while {[Mn(II) (2)(tptz)(2)(MeOH)(3)(OAc)][W(V)(CN)(8)].3.5 MeOH0.25 H(2)O}(infinity) (5) and {[Mn(II) (2)(tptz)(2)(MeOH)(3)W(V)(CN)(8)][Mn(II)(tptz)(MeOH)W(V)(CN)(8)].2 H(2).OMeOH}(8) (7) are derived from such an infinite chain by removing one of the W-C[triple bond]N-Mn linkages in each of the squares. The decanuclear cluster [Mn(II) (6)(tptz)(6)(MeOH)(4)(DMF)(2)W(V) (4)(CN)(32)].8.2 H(2)O.2.3 MeOH (6) is a truncated version of structure 4 and consists of three vertex-sharing W(2)Mn(2) squares. The structure of [Mn(II)(tptz)(MeOH)(NO(3))](2)[Mn(II)(tptz)(MeOH) (DMF)](2)[W(V)(CN)(8)](2).6 MeOH (8) consists of a hexanuclear cluster, in which the central W(2)Mn(2) square is extended by two Mn side-arms attached via CN(-) ligands to the W corners of the square. The magnetic behavior of these heterobimetallic complexes (except for 4) is dominated by antiferromagnetic coupling between Mn(II) and W(V) ions mediated by cyanide bridges. Compounds 3, 6, and 8 exhibit high spin ground states of S=4, 13, and 9, respectively, while 5 and 7 exhibit behavior typical of a ferrimagnetic chain with alternating spin centers. Complex 4 contains diamagnetic W(IV) centers but holds promise as a potential photomagnetic solid. 相似文献
72.
Zenkovets G. A. Shutilov A. A. Bondareva V. M. Sobolev V. I. Prosvirin I. P. Suprun E. A. Ishchenko A. V. Marchuk A. S. Tsybulya S. V. Gavrilov V. Yu. 《Kinetics and Catalysis》2022,63(6):732-746
Kinetics and Catalysis - The effect of gadolinium additives on the morphology, phase composition, and catalytic properties of MoVSbNbGdOx/SiO2 catalysts in the oxidative dehydrogenation of ethane... 相似文献
73.
Perevalov T. V. Iskhakzai R. M. Kh. Prosvirin I. P. Aliev V. Sh. Gritsenko V. A. 《JETP Letters》2022,115(2):79-83
JETP Letters - It is shown that the treatment of stoichiometric HfO2, which is synthesized by atomic layer deposition, in electron cyclotron resonance hydrogen plasma leads to a significant... 相似文献
74.
75.
A.V. Bukhtiyarov R.I. Kvon A.V. Nartova I.P. Prosvirin V.I. Bukhtiyarov 《Surface science》2012,606(3-4):559-563
Decomposition of nitric oxide on the flat (111) and stepped (310) and (533) faces of gold single crystals was investigated by in-situ X-Ray Photoelectron Spectroscopy at elevated NO pressures up to 7 Pa and temperatures between 300 K and 500 K. The adsorbed layer formed on the gold surfaces at these conditions was found to contain nitrogen adsorbed atomically and/or nitrous oxide. The population of these adspecies was found to be dependent upon the crystal structure of the Au face, as well as the sample temperature and NO pressure. Explanations for these phenomena are discussed. 相似文献
76.
Ouellette W Darling K Prosvirin A Whitenack K Dunbar KR Zubieta J 《Dalton transactions (Cambridge, England : 2003)》2011,40(45):12288-12300
The hydrothermal chemistry of a variety of M(II)SO(4) salts with the tetrazole (Ht) ligands 5,5'-(1,4-phenylene)bis(1H-tetrazole) (H(2)bdt), 5',5'-(1,1'-biphenyl)4,4'-diylbis(1H-tetrazole) (H(2)dbdt) and 5,5',5'-(1,3,5-phenylene)tris(1H-tetrazole) (H(3)btt) was investigated. In the case of Co(II), three phases were isolated, two of which incorporated sulfate: [Co(5)F(2)(dbdt)(4)(H(2)O)(6)]·2H(2)O (1·2H(2)O), [Co(4)(OH)(2)(SO(4))(bdt)(2)(H(2)O)(4)] (2) and [Co(3)(OH)(SO(4))(btt)(H(2)O)(4)]·3H(2)O (3·3H(2)O). The structures are three-dimensional and consist of cluster-based secondary building units: the pentanuclear {Co(5)F(2)(tetrazolate)(8)(H(2)O)(6)}, the tetranuclear {Co(4)(OH)(2)(SO(4))(2)(tetrazolate)(6)}(4-), and the trinuclear {Co(3)(μ(3)-OH)(SO(4))(2) (tetrazolate)(3)}(2-) for 1, 2, and 3, respectively. The Ni(II) analogue [Ni(2)(H(0.67)bdt)(3)]·10.5H(2)O (4·10.5H(2)O) is isomorphous with a fourth cobalt phase, the previously reported [Co(2)(H(0.67)bat)(3)]·20H(2)O and exhibits a {M(tetrazolate)(3/2)}(∞) chain as the fundamental building block. The dense three-dimensional structure of [Zn(bdt)] (5) consists of {ZnN(4)}tetrahedra linked through bdt ligands bonding through N1,N3 donors at either tetrazolate terminus. In contrast to the hydrothermal synthesis of 1-5, the Cd(II) material (Me(2)NH(2))(3)[Cd(12)Cl(3)(btt)(8)(DMF)(12)]·xDMF·yMeOH (DMF = dimethylformamide; x = ca. 12, y = ca. 5) was prepared in DMF/methanol. The structure is constructed from the linking of {Cd(4)Cl(tetrazolate)(8)(DMF)(4)}(1-) secondary building units to produce an open-framework material exhibiting 66.5% void volume. The magnetic properties of the Co(II) series are reflective of the structural building units. 相似文献
77.
A. S. Ivanova E. V. Korneeva G. A. Bukhtiyarova A. L. Nuzhdin A. A. Budneva I. P. Prosvirin V. I. Zaikovskii A. S. Noskov 《Kinetics and Catalysis》2011,52(3):446-458
The supports containing 70% Al2O3 and 30% β zeolite (AZ-1 and AZ-2), which differed in mixing procedures, and the Ni-W/AZ-1 and Ni-W/AZ-2 catalysts were characterized using an adsorption technique, high-resolution electron microscopy, IR spectroscopy, and X-ray photoelectron spectroscopy and tested in the hydrocracking reaction of vacuum gas oil (VGO). It was found that the supports differed in texture characteristics and surface Lewis acidity at the same composition and similar concentrations of Brønsted acid sites. The formation of Ni-W-S sulfide species on the surfaces of both of the supports occurred in different manners: multilayer Ni-W-S sulfide species were formed on AZ-1 (S sp = 220 m2/g), whereas single-layer species were mainly formed on AZ-2 (S sp = 380 m2/g). It was found that catalysts containing multilayer Ni-W-S sulfide species, which were characterized by a higher degree of sulfidation, provided a higher yield of diesel fuel upon the hydrocracking of VGO, whereas catalysts containing single-layer Ni-W-S sulfide species were more active in the reactions of VGO hydrodesulfurization and hydrodenitration. 相似文献
78.
A. A. Shutilov G. A. Zenkovets I. Yu. Pakharukov I. P. Prosvirin 《Kinetics and Catalysis》2014,55(1):111-116
The influence of CeO2 addition on the formation of the microstructure, electronic state, and catalytic properties of Pd/TiO2 supported catalysts in CO oxidation were investigated. It was shown that, when Pd is supported on titanium dioxide modified with cerium dioxide, annealing at 500°C results in the formation of Pd/(CeO2-TiO2) catalysts with a nanocrystalline structure composed of incoherently intergrown fine anatase crystals and interblock boundaries in which palladium and cerium are stabilized. The higher catalytic activity of Pd/(CeO2-TiO2) catalysts compared to Pd/TiO2 catalysts is explained by the smaller size of Pd particles and the higher proportion of palladium in the Pdδ+ state. 相似文献
79.
80.
High‐Resolution 3D Proton MRI of Hyperpolarized Gas Enabled by Parahydrogen and Rh/TiO2 Heterogeneous Catalyst 下载免费PDF全文
Dr. Kirill V. Kovtunov Danila A. Barskiy Aaron M. Coffey Dr. Milton L. Truong Oleg G. Salnikov Alexander K. Khudorozhkov Elizaveta A. Inozemtseva Dr. Igor P. Prosvirin Prof. Valery I. Bukhtiyarov Dr. Kevin W. Waddell Dr. Eduard Y. Chekmenev Prof. Igor V. Koptyug 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(37):11636-11639
Several supported metal catalysts were synthesized, characterized, and tested in heterogeneous hydrogenation of propene with parahydrogen to maximize nuclear spin hyperpolarization of propane gas using parahydrogen induced polarization (PHIP). The Rh/TiO2 catalyst with a metal particle size of 1.6 nm was found to be the most active and effective in the pairwise hydrogen addition and robust, demonstrating reproducible results with multiple hydrogenation experiments and stability for ≥1.5 years. 3D 1H magnetic resonance imaging (MRI) of 1 % hyperpolarized flowing gas with microscale spatial resolution (625×625×625 μm3) and large imaging matrix (128×128×32) was demonstrated by using a preclinical 4.7 T scanner and 17.4 s imaging scan time. 相似文献