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61.
Summary 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-ylidene)-propene, ab-vinylogous verdin, was synthesized by condensation of 3-(dipyrrinon-9-yl)-propenal with a dipyrrinone unsubstituted in position 9. By condensing the latter with dimedone or squaric acid,b-vinylogous verdin pigments with restricted configurational and conformational degrees of freedom were obtained. The chemical and spectroscopic properties of these novel systems are discussed.
Zur Chemie von Pyrrolpigmenten, 94. Mitt.: 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-yliden)-1-propen — Ein neuerb-vinyloger Verdinchromophor
Zusammenfassung 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-yliden)-propen, einb-vinyloges Verdin, wurde durch Kondensation von 3-(Dipyrrinon-9-yl)-propenal mit einem in Position 9 unsubstituierten Dipyrrinon dargestellt. Kondensation des Letzteren mit Dimedon oder Quadratsäure lieferte vinyloge Pigmente, welche in ihren konfigurationellen und konformationellen Freiheiten eingeschränkt sind. Die chemischen und spektroskopischen Eigenschaften dieser neuen Systeme werden diskutiert.相似文献
62.
63.
Falk M. Hante Günter Leugering Thomas I. Seidman 《Applied Mathematics and Optimization》2009,59(2):275-292
We consider networked transport systems defined on directed graphs: the dynamics on the edges correspond to solutions of transport
equations with space dimension one. In addition to the graph setting, a major consideration is the introduction and propagation
of discontinuities in the solutions when the system may discontinuously switch modes, naturally or as a hybrid control. This
kind of switching has been extensively studied for ordinary differential equations, but not much so far for systems governed
by partial differential equations. In particular, we give well-posedness results for switching as a control, both in finite
horizon open loop operation and as feedback based on sensor measurements in the system. 相似文献
64.
Summary An ,-appended eighteen carbon chains hypercin derivative (2) was synthesized starting from emodin. The overall yield of the seven step synthesis was 12%. The1H and13C NMR, absorption, and emission spectroscopic properties were measured;2 can be dissolved even in apolar solvents and polyethylene.
Synthese und Eigenschaften eines mit C18-Ketten ,-substituierten Hypericinderivats
Zusammenfassung Ein in den Positionen , mit zwei C18-Ketten substituiertes Derivat des Hypericins (2) wurde ausgehend von Emodin synthetisiert. Die Gesamtausbeute der siebenstufigen Synthese betrug 12%. Die1H- und13C-NMR, absorptions- und emissionsspektroskopischen Eigenschaften wurden gemessen;2 kann sogar in apolaren Lösungsmitteln und Polyethylen gelöst werden.相似文献
65.
Drexler D Barlow DJ Falk P Cantone J Hernandez D Ranasinghe A Sanders M Warrack B McPhee F 《Analytical and bioanalytical chemistry》2006,384(5):1145-1154
Fluorescence detection has been a method of choice in industry for screening assays, including identification of enzyme inhibitors,
owing to its high-throughput capabilities, excellent reproducibility, and sensitivity. Occasionally, inhibitors are identified
that challenge the fluorescence assay limit, necessitating the development of more sensitive detection methods to assess these
compounds. For data mining purposes, however, original assay conditions may be required. A direct method transfer to highly
sensitive and specific LC-MS-based methods has not always been possible due to the presence of MS-incompatible neutral detergents
and non-volatile salts in the assay matrix. Utilizing an in vitro proteolytic screening assay for the serine protease hepatitis C virus (HCV) nonstructural (NS) 3 protease as a test case,
we report the development of an automated sample clean-up procedure implemented on-line with liquid chromatography–tandem
mass spectrometry (LC-MS/MS) analysis to complement fluorescence detection. Ion exchange and peptide microtraps were employed
to remove MS-incompatible assay matrix components. Three protease inhibitors were used to validate the MS/MS method. Comparable
potencies were achieved for these compounds when assessed by fluorescence and MS/MS detection. Furthermore, four-fold less
enzyme could be utilized when employing the MS/MS method compared to fluorescence detection. The longer analysis time, however,
resulted in reduced sample capacity. The potency of our designed HCV NS3 protease inhibitors are thus routinely evaluated
using a continuous fluorescence-based assay. Only pertinent inhibitors approaching the fluorescence assay sensitivity limit
are subsequently analyzed further by LC-MS/MS. This methodology allows us to maintain a database and to compare results independent
of the detection method. Despite the relatively slow sample turnaround time of this LC-MS approach, the versatility of the
automated on-line clean-up procedure and sample analysis can be applied to assays containing reagents which were historically
considered to be MS incompatible. 相似文献
66.
Boca R Boca M Dlhán L Falk K Fuess H Haase W Jarosciak R Papánková B Renz F Vrbová M Werner R 《Inorganic chemistry》2001,40(13):3025-3033
The spin crossover system, [Fe(bzimpy)(2)](ClO(4))(2).0.25H(2)O, was reinvestigated above room temperature (bzimpy = 2,6-bis(benzimidazol-2-yl)pyridine). The system exhibits an abrupt low-spin to high-spin transition at T(c) = 403 K. Liberation of a fractional amount of water does not affect the spin crossover: the system is perfectly reversible with a hysteresis width of DeltaT = 12 K. The existence of the hysteresis at such high temperature determines that the lowest limit of the solid-state cooperativity parameter is J/k > 403 K despite long iron(II) separations (10 A). The high cooperativeness has been assigned to a perfect pi-stacking of the benzimidazole rings in the crystal lattice at a distance as short as 3.6 A. Variable-temperature IR data and the heat capacity measurements match well the magnetic data. The thermodynamic properties are DeltaH = 17 kJ mol(-)(1), DeltaS = 43 J K(-)(1) mol(-)(1), so that the entropy of the spin transition shows a considerable contribution from the molecular vibrations. A theoretical model has been applied in fitting the magnetic data along the whole hysteresis path. A statistical distribution of the cooperativity parameter led to the feature that angled walls of the hysteresis loop are well reproduced. 相似文献
67.
Zoltan Bajko Dietrich Gudat Falk Lissner Martin Nieger Thomas Schleid 《无机化学与普通化学杂志》2004,630(12):1969-1976
Phosphonio‐benzo[c]phospholides with an additional phosphonium ylide substituent in 3‐position were synthesized by deprotonation of appropriately substituted 1, 3‐bis‐phosphonio benzophospholide cations and characterized by spectroscopic and analytical data. The ability of these molecules to act as bidentate P, C‐chelating ligands to transition metal atoms was demonstrated in the reactions with [W(CO)4(norbornadiene)] and [MCl2(cyclooctadiene)] (M = Pd, Pt). The PdII and PtII complexes are distinguished by a strong inclination towards addition of H2O to the 10π‐electron system of the ligand. The molecular structures of a W0 complex with a P, C‐chelating ylidyl‐phosphonio‐benzophospholide ligand and of the product resulting from H2O‐addition to a corresponding PtII complex were determined. The structural parameters of the W0 complex provide evidence for the presence of substantial steric strain around the metal atom. 相似文献
68.
Summary The acid promoted decomposition of 2-(10-diazo-10H-anthracen-9-ylidene)-malonodinitrile in the presence of water, methanol, ethanol, acetic and propionic acid, ethyl thioglycolate,p-thiocresole, and acetyl acetone yielding 9,10-disubstituted 9,10-dihydroanthracenes was investigated. Treatment of the reaction products with tri-ethyl amine followed by hydrochloric acid caused their tautomerization to the corresponding 9,10-disubstituted anthracenes. A mechanism for this reaction is proposed. The first example of an intermolecular C-C-bond formation during the protic acid promoted decomposition of a diazo compound in the presence of CH-acids was found. An improved procedure for the preparation of the starting diazo compound, which may serve as a convenient precursor of 9,10-disubstituted anthracenes, is described.Cordially dedicated to Prof. Dr.K. Winsauer on the occasion of his 70th birthday 相似文献
69.
70.
Zusammenfassung Ringschluß von -bzw. -Phenyl--ferrocenyl-buttersäure liefert die homoannular überbrückten Ketone (- bzw. -Phenyl--ketotetramethylen)-ferrocen (VI, VII, XIV). Die Ermittlung der Absolutkonfiguration dieser Ketone gelang durch Korrelation des Asymmetriezentrums der optisch aktiven -Phenyl--ferrocenyl-buttersäure (deren Absolutkonfiguration primär bestimmt wurde) mit der Konfiguration des planar asymmetrischen Anteils in den optisch aktiven Ketonen.Die erhaltenen Ergebnisse waren auch mit der früher für (+)-1,2-(-Ketotetramethylen)-ferrocen (I) auf unabhängigem Weg ermittelten Konfiguration in Einklang, wie durch Messung des optischen Circulardichroismus erwiesen werden konnte: die rechtsdrehenden Enantiomeren besitzen die (R), die linksdrehenden (S)-Konfiguration.
Mit 1 Abbildung
Über die Verwendung des Ausdruckes Ferrocen-Chiralität (bzw. Chiralitäts-Zentrum und Planar-Chiralität) vgl., Fußnote S. 266.
Vgl. hierzu die Fußnote auf S. 1066
3. Mitt. über Ferrocenasymmetrie, zugleich 24. Mitt. über Ferrocenderivate:H. Falk undK. Schlögl, Mh. Chem.96, 266 (1965). 相似文献
Ring closure of - and -phenyl--ferrocenylbutyric acid yielded the corresponding homoannularily bridged ketones, (- and -phenyl--ketotetramethylene)-ferrocene (VI, VII, XIV), respectively. The absolute configuration of these ketones could be established by correlation of the asymmetric center of the optically active -phenyl--ferrocenylbutyric acid (whose absolute configuration was determined previously) with the configuration of the planar asymmetric part in the optically active ketones.The results obtained support the configuration reported earlier for (+)-1,2-(-ketotetramethylene)-ferrocene (I) and established by an independent route. The configurations could also be supported by use of optical circular dichroism, i. e., the dextrorotatory enantiomers have the (R)-configuration, the laevorotatory the (S)-configuration.
Mit 1 Abbildung
Über die Verwendung des Ausdruckes Ferrocen-Chiralität (bzw. Chiralitäts-Zentrum und Planar-Chiralität) vgl., Fußnote S. 266.
Vgl. hierzu die Fußnote auf S. 1066
3. Mitt. über Ferrocenasymmetrie, zugleich 24. Mitt. über Ferrocenderivate:H. Falk undK. Schlögl, Mh. Chem.96, 266 (1965). 相似文献