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141.
Gerald Rosen 《International Journal of Theoretical Physics》1988,27(11):1351-1353
It is observed that the magnitude relationma
2
l
P/c holds if the non-Euclidean incremental spatial volume associated with a fundamental particle of massm and radiusa is characteristically quantum gravitational in a Kaluza-Klein or superstringR
4×K
N
. HereR
4 is the four-dimensional Riemannian space-time of general relativity andK
N
is a small-scale, compact,N-dimensional space of characteristic quantum gravitational volumel
P
N
, withl
P (G/c
3)1/2= 1.61×10–33 cm denoting the Planck length. For the electron and electron neutrino (assumed to possess nonzero mass bounded empirically by
<30 eV) the derived magnitude relationa(l
P/mc)1/2 yields the estimatesa
e
2.5×10–22 cm and
3.3×10–20 cm, spatial extensions which may be detectable by way of fine-scale effects in SSC experiments. 相似文献
142.
143.
Armstrong TA Bettoni D Bharadwaj V Biino C Borreani G Broemmelsiek D Buzzo A Calabrese R Ceccucci A Cester R Church MD Dalpiaz P Dalpiaz PF Fast JE Ferroni S Ginsburg CM Gollwitzer KE Hahn AA Hasan MA Hsueh SY Lewis RA Luppi E Macr M Majewska A Mandelkern MA Marchetto F Marinelli M Marques JL Marsh W Martini M Masuzawa M Menichetti E Migliori A Mussa R Palestini S Pastrone N Patrignani C Peoples J Pesando L Petrucci F Pia MG Pordes S Rapidis PA Ray RE Reid JD Rinaudo G Rosen JL Santroni A 《Physical review letters》1992,68(10):1468-1471
144.
Antoniazzi L Arenton M Cao Z Chen T Conetti S Cox B Delchamps S Fortney L Guffey K Haire M Ioannou P Jenkins CM Judd DJ Kourkoumelis C Manousakis-Katsikakis A Kuzminski J LeCompte T Marchionni A He M Mazur PO Murphy CT Pramantiotis P Rameika R Resvanis LK Rosati M Rosen J Shen C Shen Q Simard A Smith RP Spiegel L Stairs DG Tan Y Tesarek RJ Turkington T Turnbull L Turkot F Tzamarias S Voulgaris G Wagoner DE Wang C Yang W Yao N Zhang N Zhang X Zioulas G Zou B 《Physical review D: Particles and fields》1992,46(11):4828-4835
145.
Måns Ekelöf Kenneth P. Garrard Rika Judd Elias P. Rosen De-Yu Xie Angela D. M. Kashuba David C. Muddiman 《Journal of the American Society for Mass Spectrometry》2018,29(12):2467-2470
Analyzing mass spectrometry imaging data can be laborious and time consuming, and as the size and complexity of datasets grow, so does the need for robust automated processing methods. We here present a method for comprehensive, semi-targeted discovery of molecular distributions of interest from mass spectrometry imaging data, using widely available image similarity scoring algorithms to rank images by spatial correlation. A fast and powerful batch search method using a MATLAB implementation of structural similarity (SSIM) index scoring with a pre-selected reference distribution is demonstrated for two sample imaging datasets, a plant metabolite study using Artemisia annua leaf, and a drug distribution study using maraviroc-dosed macaque tissue. 相似文献
146.
147.
Boussie TR Diamond GM Goh C Hall KA LaPointe AM Leclerc M Lund C Murphy V Shoemaker JA Tracht U Turner H Zhang J Uno T Rosen RK Stevens JC 《Journal of the American Chemical Society》2003,125(14):4306-4317
For the first time, new catalysts for olefin polymerization have been discovered through the application of fully integrated high-throughput primary and secondary screening techniques supported by rapid polymer characterization methods. Microscale 1-octene primary screening polymerization experiments combining arrays of ligands with reactive metal complexes M(CH(2)Ph)(4) (M = Zr, Hf) and multiple activation conditions represent a new high-throughput technique for discovering novel group (IV) polymerization catalysts. The primary screening methods described here have been validated using a commercially relevant polyolefin catalyst, and implemented rapidly to discover the new amide-ether based hafnium catalyst [eta(2)-(N,O)[bond](2-MeO[bond]C(6)H(4))(2,4,6-Me(3)C(6)H(2))N]Hf(CH(2)Ph)(3) (1), which is capable of polymerizing 1-octene to high conversion. The molecular structure of 1 has been determined by X-ray diffraction. Larger scale secondary screening experiments performed on a focused 96-member amine-ether library demonstrated the versatile high temperature ethylene-1-octene copolymerization capabilities of this catalyst class, and led to significant performance improvements over the initial primary screening discovery. Conventional one gallon batch reactor copolymerizations performed using selected amide-ether hafnium compounds confirmed the performance features of this new catalyst class, serving to fully validate the experimental results from the high-throughput approaches described herein. 相似文献
148.
Brands KM Payack JF Rosen JD Nelson TD Candelario A Huffman MA Zhao MM Li J Craig B Song ZJ Tschaen DM Hansen K Devine PN Pye PJ Rossen K Dormer PG Reamer RA Welch CJ Mathre DJ Tsou NN McNamara JM Reider PJ 《Journal of the American Chemical Society》2003,125(8):2129-2135
An efficient stereoselective synthesis of the orally active NK(1) receptor antagonist Aprepitant is described. A direct condensation of N-benzyl ethanolamine with glyoxylic acid yielded a 2-hydroxy-1,4-oxazin-3-one which was activated as the corresponding trifluoroacetate. A Lewis acid mediated coupling with enantiopure (R)-1-(3,5-bis(trifluoromethyl)phenyl)ethan-1-ol afforded a 1:1 mixture of acetal diastereomers which was converted into a single isomer via a novel crystallization-induced asymmetric transformation. The resulting 1,4-oxazin-3-one was converted via a unique and highly stereoselective one-pot process to the desired alpha-(fluorophenyl)morpholine derivative. Interesting and unexpected [1,2]-Wittig and [1,3]-sigmatropic rearrangements were identified during the optimization of these key steps. In the final step, a triazolinone side chain was appended to the morpholine core. The targeted clinical candidate was thus obtained in 55% overall yield over the longest linear sequence. 相似文献
149.
Thomas C. Rosen Ralf Feldmann Pascal Dünkelmann Thomas Daußmann 《Tetrahedron letters》2006,47(28):4803-4806
Perfluorinated chiral alcohols are interesting building blocks for pharmaceuticals and agrochemicals. Different chiral (R)- and (S)-configured perfluorinated alcohols were produced by asymmetric reduction of the corresponding ketones. Commercially available alcohol dehydrogenases were used as catalyst in combination with different cofactor regenerating systems. High selectivities of >99% were observed in most cases. The results also demonstrate the influence of the CF3 group on reactivity and enantioselectivity of alcohol dehydrogenases. 相似文献
150.
N-Heterocyclic carbenes, prepared in situ from diarylimidazolium salts, serve as highly effective catalysts for the generation of reactive homoenolates from alpha,beta-unsaturated aldehydes. The catalyst-bound homoenolate reacts with electrophilic aldehydes leading, via the key intermediacy of an activated carboxylate, to gamma-butyrolactones in good yields and stereoselectivities. Importantly, this process demonstrates an unprecedented reaction mode for the generation of nucleophilic carbanions with a multifunctional organocatalyst under exceptionally mild and convenient reaction conditions. 相似文献