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101.
Photosensitizers: therapy and detection of malignant tumors 总被引:21,自引:0,他引:21
T J Dougherty 《Photochemistry and photobiology》1987,45(6):879-889
102.
Adams MR Aïd S Anthony PL Baker MD Bartlett J Bhatti AA Braun HM Busza W Carroll T Conrad JM Coutrakon G Davisson R Derado I Dhawan SK Dougherty W Dreyer T Dziunikowska K Eckardt V Ecker U Erdmann M Eskreys A Figiel J Gebauer HJ Geesaman DF Gilman R Green MC Haas J Halliwell C Hanlon J Hantke D Hughes VW Jackson HE Jaffe DE Jancso G Jansen DM Kaufman S Kennedy RD Kirk T Kobrak HG Krzywdzinski S Kunori S Lord JJ Lubatti HJ McLeod D Magill S Malecki P Manz A Melanson H Michael DG Mohr W 《Physical review D: Particles and fields》1994,50(3):1836-1873
103.
104.
Synthetic routes to a diverse set of cyclic sulfamoyl carbamates and ureas are reported. These routes utilize 3-component coupling, Mitsunobu alkylation, and ring-closing metathesis using the second-generation Grubbs catalyst to achieve the synthesis of the target S-heterocyclic compounds. Cyclic S-heterocycles ranging from 9- to 11-membered rings have been obtained. 相似文献
105.
A first example of spirochlorin-chlorin dimer with fixed distances and orientations as potential model for the "special pair" of the photosynthetic reaction center is discussed. For the preparation of such a novel structure, the Wittig reagent of the desired "spacer" 5 was reacted with photoprotoporphyrin IX dimethyl ester 3 to produce the intermediate dimer 6, which on intramolecular [4 + 2] Diels-Alder cycloaddition gave an unexpected spirochlorin-chlorin dimer 9. Dehydration of dimer 6 under acid-catalyzed conditions generated the corresponding spirochlorin-porphyrin dimer 16 in quantitative yield. The asymmetry in dimer 6 caused by the biphenyl-type anisotropic effect was confirmed by NMR and model studies. The formation of dihydrobenzoporphyrin 14 by reacting chlorin 3 with the phosphonium salt of p-methylbenzylbromide 10 and isolation of 8-phenanthrenevinylporphyrin 19 from chlorin 7 further confirmed our proposed mechanism for the formation of a spirochlorin-chlorin dimer 9. Following a similar approach, chlorin 3 on reacting with bis-phosphonium salt of 4, 4'-bischloromethylbiphenyl produced conjugated chlorin dimer 25. The spectroscopic data obtained from these dimers suggest that, in these compounds, the individual chromophores are not behaving as an individual molecule, but as a single macrocycle. To examine whether the pi-pi interaction exhibited by dimer 9 resembles the structural arrangement of bacteriochlorophylls in reaction center (RC), we investigated the geometrical parameters used to characterize the pi-pi interactions in tetrapyrrolic macrocycles. Starting from the crystallographic coordinates of 9, the molecular mechanics energy minimization was performed to obtain the model dimer structure. The geometrical parameters that measure the single pyrrole ring overlap were used to compare the model structure with the crystallographic coordinates of the special pair in photosynthetic reaction center. The results indicated that the ring A of spirochlorin and the ring C of chlorin in our model dimer 9 mimic the ring A-ring A interaction found in the crystallographic special pairs, which are strategically placed by the surrounding photosynthetic reaction center protein matrix. 相似文献
106.
Li G Graham A Potter W Grossman ZD Oseroff A Dougherty TJ Pandey RK 《The Journal of organic chemistry》2001,66(4):1316-1325
Starting from commercially available Ni(II)octaethylporphyrin (OEP), an efficient approach for the preparation of a series of fluorinated and nonfluorinated benzochlorins with variable lipophicity has been developed. Their spectroscopic properties, preliminary in vitro photosensitizing efficacy, and tumor selectivity were determined. Our methodology provides a facile approach for the preparation of the free-base and the related Zn(II) benzochlorins containing alkyl and alkyl ether side chains with variable carbon units. For the preparation of benzochlorins containing alkyl groups attached to the exocyclic phenyl ring, the Ni(II) meso-(2-formylvinyl)octaethyl porphyrin 2 was reacted with various reagents such as (trifluoromethyl)trimethylsilane (TMS-CF3) or the Grignard reagents of various fluorinated or nonfluorinated alkyl halides. The corresponding intermediates 3, 6a-6e, and 8 obtained via intramolecular cyclization under acidic conditions afforded the related benzochlorins 5, 7a-d, and 9 in good yields except for 7e which was obtained in poor yield (11.4%). The alcohol 10 obtained by reacting porphyrin 2 with ethynylmagnesium chloride did not produce the expected acetylenic benzochlorin; instead the corresponding acetyl derivative 11 was obtained as a major product, which under appropriate reaction conditions was converted into a series of alkyl ether derivatives 13a-13d. To obtain a benzochlorin bearing an ester functionality (15), porphyrin 2 was first reacted with ethyl acetate/LDA and the intermediate alcohol 14 was then cyclized with sulfuric acid. Unlike most of the natural and synthetic chlorins, the Zn(II) complexes of the benzochlorin analogues exhibited a significant bathochromic shift ( approximately 10 nm) in the electronic absorption spectra, and the long wavelength absorptions were observed in the range 671-677 nm (epsilon: 43270-50360). For investigating the in vitro efficacy of these analogues, Molt-4 cells were used. At a concentration of 2.5 microM, and a light dose of 4 J/cm2, all benzochlorins produced significant photosensitizing efficacy. The tumor (RIF) and muscle uptake in C3H mice of these photosensitizers was determined by in vivo reflectance spectroscopy. These results indicate that in this series increasing the length of the alkyl or alkyl ether carbon chains at the fused phenyl ring system produced a significant increase in tumor uptake. 相似文献
107.
Yau-Kwan Ho Ravindra K. Pandey Joseph R. Missert Thomas J. Dougherty 《Photochemistry and photobiology》1990,52(6):1085-1088
In continuation of the effort to delineate the structure of Photofrin, a chromatographically well separated component of the tumor-localizing fraction was isolated and purified using a combination of gel filtration chromatography and semi-preparative high-performance liquid chromatography. This component, the least hydrophobic of the tumor-localizing fraction, was deemed to be dihematoporphyrin ether, based on mass spectrometric analysis and its behavior toward base hydrolysis and lithium aluminum hydride reduction. Although less potent than Photofrin, the purified component was an active photosensitizer. 相似文献
108.
Ralph C. Dougherty John Dalton Francis J. Biros 《Journal of mass spectrometry : JMS》1972,6(11):1171-1181
Negative ion mass spectra obtained under chemical ionization conditions (NCI) employing methane, isobutane or methylene chloride as the enhancement gas are presented for a series of chlorinated polycyclic insecticides. All of the compounds examined except 1-hydroxychlordene yielded molecular anions of substantial relative abundance (6 to 39%). The most significant features of the spectra are the prominent peaks at masses greater than that of the molecule ion formed via ionmolecule association reactions. Peaks representing association of the parent molecule with ionic species such as H?, O?, OH?, Cl?, H2OCl?, HCl2?, ClO? and Cl3? were observed in some cases. The base peak in all spectra was associated with the isotopic group of the [M + Cl]? on if contributions from other negative, even electron ions of low mass values present in high concentrations (Cl?, H2OCl? Cl2? and HCl2?) are neglected. Fragmentation processes were limited to elimination reactions involving loss of combinations of the even electron neutral species H, Cl and HCl. In addition, fragmentation resulting from a nucleophilic radical displacement of Cl by O? from the parent molecule was observed in all cases except 1-hydroxychlordene when the source was modestly wet (methane as reactant gas). NCI mass spectra of polycyclic chlorinated pesticides are reproducible, intense, interpretable in terms of classical carbanion chemistry and thus may have important analytical utility, particularly when used in conjunction with positive electron-impact and chemical ionization mass spectral methods and selective use of different enhancement gases. 相似文献
109.
NMR evidence establishes that both diastereomers of 1,2-diphenyl-1,2-bis(4-pyridyl)ethane (2), identified by optical resolution of the racemic form, exist predominantly in the anti conformation. Furthermore, empirical force field calculations show that the gauche conformer of 1,1,2,2-tetrakis(2,6-dimethylphenyl)ethane (3) is less stable by ca. 10 than the anti structure. It thus appears that neither polar effects nor steric congestion are effective in reversing the marked preference of 1,1,2,2-tetraphenylethane (1) and other unclamped tetraarylethanes for an anti ground state. In contrast, as predicted by empirical force field calculations and confirmed by X-ray and NMR evidence, the ground state structure of 9,9'-bifluorenyl (4) is gauche. The conformational behavior of 1–4 is discussed in terms of the intramolecular aryl ring stacking in clamped and unclamped tetraarylethanes. 相似文献
110.
V. W. Goodlett J. T. Dougherty H. W. Patton 《Journal of polymer science. Part A, Polymer chemistry》1971,9(1):155-161
An NMR method for determining the distribution of acetyl groups in cellulose acetates was developed. Treatment of cellulose acetates with acetyl-d3 chloride gave products having simple spectra which could be analyzed quantitatively to give the distribution of acetyl groups in the original sample. The method was applied to studying (1) the hydrolysis of cellulose triacetate with ammonia, (2) the acetylation of cellulose acetate with acetyl chloride, and (3) the acetylation of cellulose acetate with acetic anhydride. 相似文献