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81.
Aihara H Alston-Garnjost M Avery RE Barbaro-Galtieri A Barker AR Barnes AV Barnett BA Bauer DA Bengtsson H Bintinger DL Bobbink GJ Bolognese TS Bross AD Buchanan CD Buijs A Caldwell DO Clark AR Cowan GD Crane DA Dahl OI Derby KA Eastman JJ Eberhard PH Edberg TK Eisner AM Enomoto R Erné FC Fujii T Gary JW Gorn W Hauptman JM Hofmann W Huth JE Hylen J Kamae T Kaye HS Kees KH Kenney RW Kerth LT Ko W Koda RI Kofler RR Kwong KK Lander RL Langeveld WG Layter JG Linde FL Lindsey CS Loken SC Lu A Lu X 《Physical review letters》1986,57(25):3140-3143
82.
Aihara H Alston-Garnjost M Avery RE Barbaro-Galtieri A Barker AR Barnes AV Barnett BA Bauer DA Bengtsson H Bintinger DL Bobbink GJ Bolognese TS Bross AD Buchanan CD Buijs A Caldwell DO Clark AR Cowan GD Crane DA Dahl OI Derby KA Eastman JJ Eberhard PH Edberg TK Eisner AM Enomoto R Erné FC Fujii T Gary JW Gorn W Hauptman JM Hofmann W Huth JE Hylen J Kamae T Kaye HS Kees KH Kenney RW Kerth LT Ko W Koda RI Kofler RR Kwong KK Lander RL Langeveld WG Layter JG Linde FL Lindsey CS Loken SC Lu A Lu XQ 《Physical review letters》1986,57(20):2500-2503
83.
Belmares M Blanco M Goddard WA Ross RB Caldwell G Chou SH Pham J Olofson PM Thomas C 《Journal of computational chemistry》2004,25(15):1814-1826
We introduce the Cohesive Energy Density (CED) method, a multiple sampling Molecular Dynamics computer simulation procedure that may offer higher consistency in the estimation of Hildebrand and Hansen solubility parameters. The use of a multiple sampling technique, combined with a simple but consistent molecular force field and quantum mechanically determined atomic charges, allows for the precise determination of solubility parameters in a systematic way (sigma = 0.4 hildebrands). The CED method yields first-principles Hildebrand parameter predictions in good agreement with experiment [root-mean-square (rms) = 1.1 hildebrands]. We apply the CED method to model the Caltech electronic nose, an array of 20 polymer sensors. Sensors are built with conducting leads connected through thin-film polymers loaded with carbon black. Odorant detection relies on a change in electric resistivity of the polymer film as function of the amount of swelling caused by the odorant compound. The amount of swelling depends upon the chemical composition of the polymer and the odorant molecule. The pattern is unique, and unambiguously identifies the compound. Experimentally determined changes in relative resistivity of seven polymer sensors upon exposure to 24 solvent vapors were modeled with the CED estimated Hansen solubility components. Predictions of polymer sensor responses result in Pearson R2 coefficients between 0.82 and 0.99. 相似文献
84.
Steven R. Caldwell James C. Turley Gary E. Martin 《Journal of heterocyclic chemistry》1980,17(6):1153-1162
The synthesis of the first diazaphenoxathiins, 1,9-diazaphenoxathiin and 1,7-diazaphenoxathiin, are described. Complete assignments are made for the 13C-nmr spectra of these compounds based on additivity correlation and 1H-13C spin-coupling constants. The isolation and confirmation of the structure of 2-[2′(-3′-nitropyridylthio)]-3-[2″-(3″-nitropyridyloxy)] pyridine using 13C-nmr and appropriate model compounds is also discussed. A preliminary evaluation of spontaneous motor depression in mice showed a substantial difference between the observed activities of the two diazaphenoxathiins reported. The possibility of the observed difference being associated with the relative positions of the annular aza-substitutions is discussed. 相似文献
85.
86.
Ohne Zusammenfassung 相似文献
87.
88.
A high-throughput monoamine oxidase inhibition assay using liquid chromatography with tandem mass spectrometry 总被引:1,自引:0,他引:1
Yan Z Caldwell GW Zhao B Reitz AB 《Rapid communications in mass spectrometry : RCM》2004,18(8):834-840
A highly efficient method utilizing liquid chromatography with tandem mass spectrometry (LC/MS/MS) was developed and employed for high-throughput screening of compounds for monoamine oxidase (MAO) inhibition. The method used kynuramine as a common substrate for both MAO-A and MAO-B in incubations, and the 4-hydroxyquinoline (4-HQ) resulting from deamination of kynuramine followed by intramolecular condensation was analyzed using LC/MS/MS; formation of 4-HQ was used as the marker of MAO activity to evaluate the effects of test compounds. Isocratic liquid chromatography was applied to reduce the run time to 2 min. Because of the high specificity and sensitivity of detection of 4-HQ by LC/MS/MS, this method was able to use MAO enzymes at very low concentrations and to perform short incubations; as a result, consumable cost was minimized, and sample preparations were completely avoided. The inhibition data are highly reproducible, and the IC(50) values determined by the method are in good agreement with literature values. The results suggest that this method is very robust and can be used as a generic approach to screen for MAO inhibitors in drug discovery. 相似文献
89.
Conventional operation of field-flow fractionation (FFF) systems involves carrying out the analysis at a constant flow of carrier; the flow is temporarily interrupted after injection of a sample in order to permit its equilibration under the applied field. Retention is calculated as the ratio of elution times for a non-retained species and the sample of interest, respectively. Such time-based retentions are only valid if the flow-rate is precisely known at all times during the run. The peristaltic pumps often used with FFF equipment are shown to have an output which varies unpredictably in time. Furthermore, initiation of flow after relaxation is shown to result in significant periods of transient behaviour while the system adjusts to the operating pressure. These and other variations in flow-rate can be eliminated as sources of error by basing the retention measurement on effluent weight, rather than on time. For this purpose, an electronic balance is interfaced with the system's computer, so that detector response/effluent weight data pairs are continuously monitored during the course of the FFF analysis. 相似文献
90.
Lei Shi Carrie Miller Karin D. Caldwell Paul Valint 《Colloids and surfaces. B, Biointerfaces》1999,15(3-4):303-312
In this work, bovine submaxillary gland mucin (BSM) was used as an emulsifier to stabilize oil–water emulsion systems. Prior to use, commercial BSM was purified by jacalin affinity chromatography. Emulsions consisting of 5% mineral oil in phosphate buffered saline (PBS) were prepared through the addition of different amounts of purified mucin followed by sonication using either of two methods: (1) low energy input for a long time (2 h), or (2) high energy input for a short time (20 s). The surfactancy property of mucin was investigated by surface tension measurements, which showed the BSM to greatly reduce the surface tension of PBS. Compared to several synthetic surfactants of the Pluronic® type, mucin showed comparable or better surface activity than F68, F88 and F108 products in dilute solutions. The formed emulsions had a mean droplet size that decreased monotonically with increasing concentration of mucin until a plateau was reached at concentrations around 0.1% by weight. The stability of these emulsions was evaluated by monitoring their average droplet size during a 33-day period. Emulsions with more than 0.25% mucin showed a constant mean size throughout the period. Specifically, an emulsion produced with 0.95% mucin showed a stable mean droplet size of about 300 nm. The stability of the mucin-emulsified systems was also evaluated by measuring turbidity changes with time, which allowed a comparison with similar emulsions stabilized by the Pluronic® surfactants in the same concentration. Thus, mucin showed its ability to establish more stable and more efficient oil–water emulsion systems. Since mucin is a glycoprotein, and hence biodegradable, our results suggest that mucin might serve as an ideal biological surfactant for the stabilization of emulsion systems intended for biomedical and pharmaceutical applications. 相似文献