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991.
Liaoran Cao Xinyu Zhang Alix Grimley Anna R. Lomasney Michael G. Roper 《Analytical and bioanalytical chemistry》2010,398(5):1985-1991
A microfluidic device was developed to produce temporal concentration gradients of multiple analytes. Four on-chip pumps delivered
pulses of three analytes and buffer to a 14-cm channel where the pulses were mixed to homogeneity. The final concentration
of each analyte was dependent on the temporal density of the pulses from each pump. The concentration of each analyte was
varied by changing the number of pump cycles from each reservoir while maintaining the total number of pump cycles per unit
time to ensure a constant total flow rate in the device. To gauge the independent nature of each pump, sinusoidal waves of
fluorescein concentration were produced from each pump with independent frequencies and amplitudes. The resulting fluorescence
intensity was compared with a theoretical summation of the waves and the experimental data matched the theoretical waves within
1%, indicating that the pumps were operating independently and outputting the correct frequency and amplitude. The device
was used to demonstrate the role of adenosine triphosphate-sensitive K+ channels in glucose-stimulated increases in intracellular [Ca2+] in islets of Langerhans. Perfusion of single islets of Langerhans with combinations of glucose, diazoxide, and K+ resulted in intracellular Ca2+ patterns similar to what has been observed using conventional perfusion devices. The system will be useful in other studies
with islets of Langerhans, as well as other assays that require the modulation of multiple analytes in time. 相似文献
992.
993.
Anna M. Maj Isabelle Suisse Catherine Méliet Francine Agbossou-Niedercorn 《Tetrahedron: Asymmetry》2010,21(16):2010-2014
The enantioselective hydrogenation of indole esters has been carried out efficiently in the presence of a rhodium catalyst modified by Walphos-type chiral ligands. The addition of a base can be beneficial in some catalytic conditions. 相似文献
994.
Anna Goldberg Vitali Grinberg Irina Utepova Oleg Chupakhin Igor Eremenko 《Journal of organometallic chemistry》2011,696(13):2607-2610
New ionic complexes [ML2(MeCN)2]?2Otf (M = Co or Ni; L = 6-ferrocenyl-2,2′-bipyridyl) were synthesized and characterized by single-crystal X-ray diffraction. Cyclic voltammograms of the compounds [ML2(MeCN)2]?2Otf in CH2Cl2 show good cycle stability over 100 cycles in the quasi-reversible oxidation potential range (from −0.25 to 0.5 V). 相似文献
995.
996.
Jan P. Weyrauch Dr. A. Stephen K. Hashmi Prof. Dr. Andreas Schuster Dipl.‐Chem. Tobias Hengst Dipl.‐Chem. Stefanie Schetter Anna Littmann Dipl.‐Chem. Matthias Rudolph Dr. Melissa Hamzic Dr. Jorge Visus Jan W. Bats Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(3):956-963
The substrate scope, the mechanistic aspects of the gold‐catalyzed oxazole synthesis, and substrates with different aliphatic, aromatic, and functional groups in the side chain were investigated. Even molecules with several propargyl amide groups could easily be converted, delivering di‐ and trioxazoles with interesting optical properties. Furthermore, the scope of the gold(I)‐catalyzed alkylidene synthesis was investigated. Further functionalizations of these isolable intermediates of the oxazole synthesis were developed and chelate ligands can be obtained. The use of Barluenga’s reagent offers a new and mild access to the synthetically valuable iodoalkylideneoxazoles from propargylic amides, this reagent being superior to other sources of halogens. 相似文献
997.
Semenishchev Vladimir S. Voronina Anna V. Titova Svetlana M. Tomashova Lyubov A. Nasonova Yulia I. 《Journal of Radioanalytical and Nuclear Chemistry》2021,329(2):857-863
Journal of Radioanalytical and Nuclear Chemistry - Activity concentrations of natural radionuclides were determined in water from 31 springs of Sverdlovsk region, Middle Urals, Russia. Activity... 相似文献
998.
Anna Andreou 《Tetrahedron letters》2010,51(52):6935-6938
(4RS,5RS)-4,5-Diphenylimidazolidine-2-thione is resolved efficiently by treatment with NaHMDS and an enantiomerically pure pentafluorophenyl active ester. The levels of diastereocontrol were excellent (up to 90% de). 相似文献
999.
Sebastian A. Suarez Ana Foi Shawn Eady Anna Larsen Fabio Doctorovich 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(10):o417-o420
The title compound, C9H14N+·CHB11Cl11−, was obtained in the course of our continuing studies of the low‐melting salts of closo‐ and nido‐carborane cage anions with alkylpyridinium and dialkylimidazolium cations. The title compound is the first example of a pyridinium salt of a perchlorinated carborane anion. The structure consists of one N‐butylpyridinium cation counterbalanced by one perchlorinated carborane cage anion per asymmetric unit. By changing the counter‐ion, different packings are observed, and to try to understand this the new structure is compared with five similar compounds. 相似文献
1000.