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281.
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283.
Experimental characterization of a two-photon memory 总被引:2,自引:0,他引:2
Wang MM Esener SC McCormick FB Cokgör I Dvornikov AS Rentzepis PM 《Optics letters》1997,22(8):558-560
We demonstrate the recording of 100 planes of digital images in a page-oriented two-photon memory and characterize the images in terms of signal-to-noise ratio and bit error rate. Possible error sources in the recording are discussed, and methods for compensating for some of these effects are presented. Looking at the distributions of the normalized bit intensities, we are able to estimate the minimum achievable bit error rate for this system. 相似文献
284.
Erckmann V Wagner F Baldzuhn J Brakel R Burhenn R Gasparino U Grigull P Hartfuss HJ Hofmann JV Jaenicke R Niedermeyer H Ohlendorf W Rudyj A Weller A Bogdanov SD Bomba B Borschegovsky AA Cattanei G Dodhy A Dorst D Elsner A Endler M Geist T Giannone L Hacker H Heinrich O Herre G Hildebrandt D Hiznyak VI Il'in VI Kasparek W Karger F Kick M Kubo S Kuftin AN Kurbatov VI Lazaros A Malygin SA Malygin VI McCormick K Müller GA Orlov VB Pech P Roi IN Sardei F Sattler S Schneider F Schneider U Schüller PG 《Physical review letters》1993,70(14):2086-2089
285.
286.
Alp H. Alidedeoglu Adam W. York Charles L. McCormick Sarah E. Morgan 《Journal of polymer science. Part A, Polymer chemistry》2009,47(20):5405-5415
We report the direct homopolymerization and block copolymerization of 2‐aminoethyl methacrylate (AEMA) via aqueous reversible addition‐fragmentation chain transfer (RAFT) polymerization. The controlled “living” polymerization of AEMA was carried out directly in aqueous buffer using 4‐cyanopentanoic acid dithiobenzoate (CTP) as the chain transfer agent (CTA), and 2,2′‐azobis(2‐imidazolinylpropane) dihydrochloride (VA‐044) as the initiator at 50 °C. The controlled “living” character of the polymerization was verified with pseudo‐first order kinetic plots, a linear increase of the molecular weight with conversion, and low polydispersities (PDIs) (<1.2). In addition, well‐defined copolymers of poly(AEMA‐b‐HPMA) have been prepared through chain extension of poly(AEMA) macroCTA with N‐(2‐hydroxypropyl)methacrylamide (HPMA) in water. It is shown that the macroCTA can be extended in a controlled fashion resulting in near monodisperse block copolymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5405–5415, 2009 相似文献
287.
We establish some asymptotic expansions for infinite weighted convolutions of distributions having rapidly varying subexponential
tails. Examples are presented, some showing that in order to obtain an expansion with two significant terms, one needs to
have a general way to calculate higher order expansions, due to possible cancellations of terms. An algebraic methodology
is employed to obtain the results.
相似文献
288.
Michael E. Sigman C. Douglas Clark Kimberly Painter Chatham Milton Ekaterina Simatos Jessica L. Frisch Meghan McCormick Julie L. Bitter 《Rapid communications in mass spectrometry : RCM》2009,23(3):349-356
Oligomeric peroxides formed in the synthesis of triacetone triperoxide (TATP) have been analyzed by mass spectrometry utilizing both electrospray ionization (ESI) and chemical ionization (CI) to form sodiated adducts (by ESI) and ammonium adducts (by CI and ESI). Tandem mass spectrometry and deuterium isotopic labeling experiments have been used to elucidate the collision‐induced dissociation (CID) mechanisms for the adducts. The CID mechanisms differ for the sodium and ammonium adducts and vary with the size of the oligoperoxide. The sodium adducts of the oligoperoxides, H[OOC(CH3)2]nOOH, do not cyclize under CID, whereas the ammonium adducts of the smaller oligoperoides (n < 6) do form the cyclic peroxides under CID. Larger oligoperoxide adducts with both sodium and ammonium undergo dissociation through cleavage of the backbone under CID to form acyl‐ and hydroperoxy‐terminated oligomers of the general form CH3C(O)[OOC(CH3)2]xOOH, where x is an integer less than the original oligoperoxide degree of oligomerization. The oligoperoxide distribution is shown to vary batch‐to‐batch in the synthesis of TATP and the post‐blast distribution differs slightly from the distribution in the uninitiated material. The oligoperoxides are shown to be decomposed under gentle heating. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
289.
McCormick MS Sazinsky MH Condon KL Lippard SJ 《Journal of the American Chemical Society》2006,128(47):15108-15110
We report the X-ray crystal structures of native and manganese(II)-reconstituted toluene/o-xylene monooxygenase hydroxylase (ToMOH) from Pseudomonas stutzeri OX1 to 1.85 and 2.20 A resolution, respectively. The structures reveal that reduction of the dimetallic active site is accompanied by a carboxylate shift and alteration of the coordination environment for dioxygen binding and activation. A rotamer shift in a strategically placed asparagine 202 accompanies dimetallic center reduction and is proposed to influence protein component interactions. This rotamer shift is conserved between ToMOH and the corresponding residue in methane monooxygenase hydroxylase (MMOH). Previously unidentified hydrophobic pockets similar to those present in MMOH are assigned. 相似文献
290.
Copper foils have been widely used in microelectronic devices. Adequate adhesion between copper foils to various substrates, such as Si, SiO2, polyimide, is crucial to high performance of these devices. The adhesion between a new high temperature adhesive, aromatic thermosetting copolyester (ATSP), and various copper foils, namely, zinc(Zn)‐coated copper foil, copper foil and nickel (Ni)‐coated copper foil was characterized by a 90° peel strength test. It was found that the peel strength of Zn‐coated copper foil to ATSP was 1050 N/m, which was more than three times higher than copper foil and five times that of Ni‐coated copper foil. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS) studies indicated that this higher adhesion results from the stronger mechanical interlocking due to the rougher surface of Zn‐coated copper foil, and from chemical reactions at the interface which occur during the curing process of ATSP on the Zn‐coated copper surface. In contract to the adhesive failure at the ATSP/Cu and ATSP/Ni interfaces, the failure mechanism of ATSP/Zn is both cohesive and adhesive. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献