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51.
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Dr. Stefan K. Maier Georgiy Poluektov Dr. Stefan‐S. Jester Prof. Dr. Heiko M. Möller Prof. Dr. Sigurd Höger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(4):1379-1384
Macrocycles with quaterthiophene subunits were obtained by cyclooligomerization by direct oxidative coupling of unsubstituted dithiophene moieties. The rings were closed with high selectivity by an α,β′‐connection of the thiophenes as proven by NMR spectroscopy. The reaction of the precursor with terthiophene moieties yielded the symmetric α,α′‐linked macrocycle in low yield together with various differently connected isomers. Blocking of the β‐position of the half‐rings yielded selectively the α,α′‐linked macrocycle. Selected cyclothiophenes were investigated by scanning tunneling microscopy, which displayed the formation of highly ordered 2D crystalline monolayers. 相似文献
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MICROMECHANICS OF MACROELECTRONICS 总被引:2,自引:0,他引:2
Zhigang Suo Joost Vlassa Sigurd Wagner 《中国颗粒学报》2005,3(6):321-328
The advent of flat-panel displays has opened the era of macroelectronics. Enthusiasm is gathering to develop macroelectronics as a platform for many technologies, ranging from paper-like displays to thin-film solar cells, technologies that aim to address the essential societal needs for easily accessible information, renewable energy, and sustainable environment. The widespread use of these large structures will depend on their ruggedness, portability and low cost, attributes that will come from new material choices and new manufacturing processes. For example, thin-film devices on thin polymer substrates lend themselves to roll-to-roll fabrication, and impart flexibility to the products. These large structures will have diverse architectures, hybrid materials, and small features; their mechanical behavior during manufacturing and use poses significant challenges to the creation of the new technologies. This paper describes ongoing work in the emerging field of research - the mechanics of macroelectronics, with emphasis on the mechanical behavior at the scale of individual features, and over a long time. 相似文献
55.
Two 2D supramolecular structures of macrocycle 1 and 1/C60 have been obtained on HOPG by self-assembly under ambient conditions and investigated by high-resolution STM. The monolayers of 1 are characterized by structures with perfect ordering over relatively large areas. In the case of 1/C60, the size of the macrocycle 1 and the presence of two individual bithiophene units per ring lead in the final superstructure to a 1:2 stoichiometry. The fullerenes are not trapped at the graphite surface inside the macrocyclic holes but are located around the periphery of the bithiophene units. This clearly shows that the donor-acceptor interaction between C60 and the electron-rich units of the ring is the dominant factor for the structure formation. 相似文献
56.
Klyatskaya S Dingenouts N Rosenauer C Müller B Höger S 《Journal of the American Chemical Society》2006,128(10):3150-3151
Shape-persistent macrocycles with a rigid pyridyl core and a flexible oligo-alkyl corona aggregate to some extent in nonpolar solvents to form large (tubular) aggregates. To increase the assembling tendency, the intraannular pyridyl groups of the macrocycles were alkylated. Unexpectedly, the quarternized macrocycles show no tendency at all to form tubular micellar-like structures but form well-defined dimers, as determined by X-ray and dynamic light scattering. 相似文献
57.
Dr. Sigurd Øien-Ødegaard Dr. Calliope Bazioti Dr. Evgeniy A. Redekop Dr. Øystein Prytz Prof. Karl Petter Lillerud Prof. Unni Olsbye 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(48):21581-21586
Herein, we report the discovery of a toroidal inorganic cluster of zirconium(IV) oxysulfate of unprecedented size with the formula Zr70(SO4)58(O/OH)146⋅x(H2O) (Zr70), which displays different packing of ring units and thus several polymorphic crystal structures. The ring measures over 3 nm across, has an inner cavity of 1 nm and displays a pseudo-10-fold rotational symmetry of Zr6 octahedra bridged by an additional Zr in the outer rim of the ring. Depending on the co-crystallizing species, the rings form various crystalline phases in which the torus units are connected in extended chain and network structures. One phase, in which the ring units are arranged in layers and form one-dimensional channels, displays high permanent porosity (BET surface area: 241 m2 g−1), and thus demonstrates a functional property for potential use in, for example, adsorption or heterogeneous catalysis. 相似文献
58.
Jochen Ellermann Adolf Veit Ekkehard Lindner Sigurd Hoehne 《Journal of organometallic chemistry》1983,252(2):153-174
The reaction of N(CH2CH2Cl)3 (I) with KAs(C6H5)2·dioxane () in THF yields, as Sacconi et al. reported earlier, 80% of N[CH2CH2As(C6H5)2]3 (II). II is now obtained in a still higher quantity from the reaction of [HN(CH2CH2Cl)3]Cl (III) with NaAs(C6H5)2 in liquid ammonia. Treatment of II with gaseous HI in dry CH2Cl2 results in the formation of [HN(CH2CH2AsI2)3]I (IV), which is isolated by recrystallisation from THF as [HN(CH2CH2AsI2)3]I · THF () (IVa). IVa reacts with H2O/NH3 or H2S/N(C2H5)3 to give the novel cryptands [N(CH2CH2)3]8-(As4O4)6 (V) or [N(CH2CH2)3]8(As4S4)6 (VI), which also can be denoted as spherands. The reaction of V with dry gaseous HCl in benzene leads to [HN(CH2-CH2AsCl2)3]Cl (VII). All the new compounds are characterized, as far as possible, by their IR, FIR, Raman, 1H NMR and mass spectra. To determine the structure of V a single X-ray crystal study was carried out. Moreover II, which is already well-known but not completely characterized, is included in this discussion only for spectroscopic comparison. 相似文献
59.
Evaporation constants of acoustically levitated drops from the homologue series of n-alkanes and 1-alkanols in ambient air have been evaluated by size and temperature measurements. The size of the pure liquid drops, within a diameter range of 0.1 to 2.5 mm, was monitored using a CCD camera, while temperature measurements were carried out by IR thermography. During drop evaporation, water from a humid environment with a relative humidity between 5 and 80% was condensed on the drop surface and in the case of n-pentane, the condensed water froze as a result of the evaporative cooling. 相似文献
60.
Sigurd Höger Anne-Désirée Meckenstock 《Chemistry (Weinheim an der Bergstrasse, Germany)》1999,5(6):1686-1691
Macrocyclic structures such as 1 and rings with different polar substituents pointing inwards can be prepared by the intramolecular Glaser coupling of tetraacetylenes held covalently in position around a temporary template. 相似文献