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81.
An often-exploited feature of the operator product expansion (OPE) is that it incorporates a splitting of ultraviolet and infrared physics. In this paper we use this feature of the OPE to perform simple, approximate computations of soft masses in gauge-mediated supersymmetry breaking. The approximation amounts to truncating the OPEs for hidden-sector current–current operator products. Our method yields visible-sector superpartner spectra in terms of vacuum expectation values of a few hidden-sector IR elementary fields. We manage to obtain reasonable approximations to soft masses, even when the hidden sector is strongly coupled. We demonstrate our techniques in several examples, including a new framework where supersymmetry breaking arises both from a hidden sector and dynamically. Our results suggest that strongly-coupled models of supersymmetry breaking are naturally split. 相似文献
82.
Thomas Michel Emilie Destandau Laëtitia Fougère Claire Elfakir 《Analytical and bioanalytical chemistry》2013,405(4):1431-1431
83.
Marine Rémy Dr. Iwona Nierengarten Boram Park Dr. Michel Holler Dr. Uwe Hahn Dr. Jean-François Nierengarten 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(33):8492-8499
Stable pillar[5]arene-containing [2]rotaxane building blocks with pentafluorophenyl ester stoppers have been efficiently prepared on a multi-gram scale. Reaction of these building blocks with various nucleophiles gave access to a wide range of [2]rotaxanes with amide, ester or thioester stoppers in good to excellent yields. The rotaxane structure is fully preserved during these chemical transformations. Actually, the addition-elimination mechanism at work during these transformations totally prevents the unthreading of the axle moiety of the mechanically interlocked system. The stopper exchange reactions were optimized both in solution and under mechanochemical solvent-free conditions. While amide formation is more efficient in solution, the solvent-free conditions are more powerful for the transesterification reactions. Starting from a fullerene-functionalized pillar[5]arene derivative, this new strategy gave easy access to a photoactive [2]rotaxane incorporating a C60 moiety and two Bodipy stoppers. Despite the absence of covalent connectivity between the Bodipy and the fullerene moieties in this photoactive molecular device, efficient through-space excited state interactions have been evidenced in this rotaxane. 相似文献
84.
The LDA-promoted addition of acetaldehyde on orsellinate gives (±) 6 -hydroxymellein, a fungal phytotoxin, with a 51% yield. 相似文献
85.
Par Michel Gros 《代数通讯》2013,41(11):2407-2420
86.
The successive steps of the computer analysis of a NMR spectrum are examined. Better results can be obtained by direct simulation of tentative model spectra. As an example the 1H-NMR spectrum of amphetamine is analysed. 相似文献
87.
Jean-Pierre Majoral René Mathieu Anne-Marie Caminade Serge Attali Michel Sanchez 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):443-446
Abstract A new entry to non classical phosphorus complexes is reported. 相似文献
88.
89.
Dr. Emilio Brunetti Dr. Lionel Marcelis Dr. Fedor E. Zhurkin Prof. Michel Luhmer Prof. Ivan Jabin Prof. Olivia Reinaud Prof. Kristin Bartik 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(55):13730-13738
In this study, the ligand exchange mechanism at a biomimetic ZnII centre, embedded in a pocket mimicking the possible constrains induced by a proteic structure, is explored. The residence time of different guest ligands (dimethylformamide, acetonitrile and ethanol) inside the cavity of a calix[6]arene-based tris(imidazole) tetrahedral zinc complex was probed using 1D EXchange SpectroscopY NMR experiments. A strong dependence of residence time on water content was observed with no exchange occurring under anhydrous conditions, even in the presence of a large excess of guest ligand. These results advocate for an associative exchange mechanism involving the transient exo-coordination of a water molecule, giving rise to 5-coordinate ZnII intermediates, and inversion of the pyramid at the ZnII centre. Theoretical modelling by DFT confirmed that the associative mechanism is at stake. These results are particularly relevant in the context of the understanding of kinetic stability/lability in Zn proteins and highlight the key role that a single water molecule can play in catalysing ligand exchange and controlling the lability of ZnII in proteins. 相似文献
90.
Alain Michel 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(3):361-371
4-Chloro-2-hexene can be considered a model compound for the chlorinated allylic structure appearing in PVC chains after dehydrochlorination. This model compound was used to elucidate the mechanism of reaction of primary or secondary stabilizers. 相似文献