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41.
Chandrasekhar V Athimoolam A Reddy ND Nagendran S Steiner A Zacchini S Butcher R 《Inorganic chemistry》2003,42(1):51-59
The reaction of the dicarbaphosphazene, [NC(NMe(2))](2)[NPCl(2)] (2), with the sodium salt of 4-hydroxy-4'-vinylbiphenyl afforded the vinyl group containing monomer [NC(NMe(2))](2)[NP(Cl)(O-C(6)H(4)-p-C(6)H(4)-p-CH=CH(2))] (3). Replacement of the lone chlorine atom of 3 by oxygen nucleophiles gave [NC(NMe(2))](2)[NP(OR)(O-C(6)H(4)-p-C(6)H(4)-p-CH=CH(2))] [R = CH(2)CF(3) (4); C(6)H(5) (5); C(6)H(4)-m-CH(3) (6); C(6)H(4)-p-Br(7)]. The X-ray crystal structures of 3-7 reveal that all the cyclodicarbaphosphazenes have a planar N(3)PC(2) ring; the ring carbons are completely planar, while the geometry around phosphorus is pseudotetrahedral. The presence of weak intermolecular hydrogen bonding [C-H---X(Cl or Br), C-H---N, or C-H---pi] interactions in 3-7 leads to the formation of polymeric architectures in the solid-state. The monomers 4-7 can be polymerized by a free-radical initiator to afford the corresponding air-stable homopolymers 8-11. These have moderate molecular weights with polydispersity indices ranging from 1.33 to 1.58. All of these polymers have high glass transition temperatures and have excellent thermal stability. 相似文献
42.
Phenylacetonitrile ( 2 ) (32%) and small amounts of benzyl methyl ether ( 3 ), benzonitrile ( 5 ) and methyl benzoate ( 6 ) were produced by irradiation of either 4-phenyl-1,2,3-triazole ( 1 ) or 4-phenyl-5-deutero-1,2,3-triazole ( 7 ) in methanol at 254 nm. In methylene chloride, irradiation of 1 produced 2 (15%) and small amounts of 3,6-diphenyl-1,2,4,5-tetrazine ( 8 ). Irradiation of 4,5-diphenyl-1,2,3-triazole ( 9 ) in methanol gave 2,4,5-triphenylimidazole ( 11 ) (4%) and trace amounts of diphenylacetonitrile ( 10 ), benzamide ( 12 ), and compounds 3 , 5 , and 6 . Irradiation of 2,3-diphenyl-2H-azirine ( 13 ) in methanol gave small amounts of 3 , benzaldehyde ( 4 ), and compounds 5 , 6 , 12 as well as 2,3,5,6-tetraphenylpyrazine ( 14 ) and in methylene chloride it gave 11 (16%) and small amounts of 4 , 5 , 14 , and acetophenone ( 15 ). On heating 4-phenyl-1,2,3-triazole ( 1 ) in n-hexadecane, elimination of nitrogen at 290° left phenylacetonitrile ( 2 ) as the only identified product. Similar pyrolysis of 4,5-diphenyl-1,2,3-triazole ( 9 ) produced 2,3,5,6-tetraphenylpyrazine ( 14 ) along with an intractable material. An efficient thermal isomerization of 2,3-diphenyl-2H-azirine ( 13 ) gave 2-phenylindole ( 17 ). 相似文献
43.
R. Ramasamy V. Selvarajan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(1):125-129
I–V characteristics of a non-transferred DC plasma spray torch operating on argon and argon + nitrogen mixtures are reported. Arc voltage is decreased with increase in arc current and increased with increase in electrode gap. Arc power is higher at higher percentage of nitrogen in argon. Nottingham co-efficients were calculated using numerical method. 相似文献
44.
Chandrasekhar V Gopal K Nagendran S Singh P Steiner A Zacchini S Bickley JF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(18):5437-5448
Organostannoxane-based multiredox assemblies containing ferrocenyl peripheries have been readily synthesized by a simple one-pot synthesis, either by a solution method or by room-temperature solid-state synthesis, in nearly quantitative yields. The number of ferrocenyl units in the multiredox assembly is readily varied by stoichiometric control as well as by the choice of the organotin precursors. Thus, the reaction of the diorganotin oxides, R2SnO (R = Ph, nBu and tBu) with ferrocene carboxylic acid affords tetra-, di-, and mononuclear derivatives [{Ph2Sn[OC(O)Fc]2}2] (1), [{[nBu2SnOC(O)Fc]2O}2] (2), [nBu2Sn{OC(O)Fc}2] (3), [{tBu2Sn(OH)OC(O)Fc}2] (4), and [tBu2Sn{OC(O)Fc}2] (5) (Fc = eta(5)C5H4-Fe-eta(5)C5H5). The reaction of triorganotin oxides, R3SnOSnR3 (R = nBu and Ph) with ferrocene carboxylic acid leads to the formation of the mono-nuclear derivatives [Ph3SnOC(O)Fc] (6) and [{nBu3SnOC(O)Fc}(n)] (7). Molecular structures of the compounds 1-4 and 6 have been determined by single-crystal X-ray analysis. The molecular structure of compound 1 is new among organotin carboxylates. In this compound, ferrocenyl carboxylates are involved in both chelating and bridging coordination modes to the tin atoms to form an eight-membered cyclic structure. In all of these compounds, the acidic protons of the cyclopentadienyl groups are hydrogen bonded to the carboxylate oxygens (C-HO) to form rich supramolecular assemblies. In addition to this, pi-pi, T-shaped, L-shaped, and side-to-face stacking interactions involving ferrocenyl groups also occur. Compound 6 shows an interesting and novel intermolecular CO2-pi stacking interaction. Electrochemical analysis of the compounds 1-4, 6, and 7 shows a single, quasi-reversible oxidation peak corresponding to the simultaneous oxidation of four, two, and one ferrocenyl substituents, respectively. Compound 5 shows two quasi-reversible oxidation peaks. This is attributed to the positional difference among the ferrocenyl substituents on the tin atom. Additionally, while compounds 2 and 4 are electrochemically quite robust and do not decompose even after ten continuous CV cycles, compounds 1, and 3, 5-7 start to show decomposition after five cycles. 相似文献
45.
Rose AS Selvarajan P Perumal S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,81(1):270-275
Phosphoric acid admixtured L-alanine (PLA) single crystals were grown successfully by solution method with slow evaporation technique at room temperature. Crystals of size 18 mm×12 mm×8 mm have been obtained in 28 days. The grown crystals were colorless and transparent. The solubility of the grown samples has been found out at various temperatures. The lattice parameters of the grown crystals were determined by X-ray diffraction technique. The reflection planes of the sample were confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. Fourier transform infrared (FTIR) studies were used to confirm the presence of various functional groups in the crystals. UV-visible transmittance spectrum was recorded to study the optical transparency of grown crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz-Perry powder technique and a study of its second harmonic generation efficiency in comparison with potassium dihydrogen phosphate (KDP) has been made. The mechanical strength of the crystal was estimated by Vickers hardness test. The grown crystals were subjected to thermo gravimetric and differential thermal analysis (TG/DTA). The dielectric behavior of the sample was also studied. 相似文献