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491.
492.
Latif M. A. Tofaz Tania Chaki B. M. Tariqul Islam H. M. Hossain Md. Saddam Kudrat-E-Zahan Md. 《Russian Journal of General Chemistry》2019,89(6):1197-1201
Russian Journal of General Chemistry - A Schiff base containing the nitrogen-sulfur donor chain [(CH3)2N-C6H4-CH=N-NH-C(S)-SCH2C6H5] was prepared by the condensation of... 相似文献
493.
Photoinduced Charge Separation in a Donor–Spacer–Acceptor Dyad with N‐Annulated Perylene Donor and Methylviologen Acceptor 下载免费PDF全文
Dr. Marie‐Pierre Santoni Antonio Santoro Tania M. G. Salerno Prof. Fausto Puntoriero Dr. Francesco Nastasi Dr. M. Letizia Di Pietro Dr. Maurilio Galletta Prof. Sebastiano Campagna 《Chemphyschem》2015,16(15):3147-3150
The first donor–acceptor species in which a strongly emissive N‐annulated perylene dye is connected to a methylviologen electron acceptor unit via its macrocyclic nitrogen atom, is prepared by a stepwise, modular procedure. The absorption spectra, redox behavior, spectroelectrochemistry and photophysical properties of this dyad and of its model species are investigated, also by pump–probe fs transient absorption spectroscopy. Photoinduced oxidative electron transfer from the excited state of the dyad, centered on the N‐annulated perylene subunit, to the appended methyviologen electron acceptor takes place in a few ps. The charge‐separated species recombines in 19 ps. Our results indicate that N‐annulated perylene can be connected to functional units by taking advantage of the macrocyclic nitrogen, an option never used until now, without losing their properties, so opening the way to new designing approaches. 相似文献
494.
Luis Alvarez Chantal Houée Levin Fabienne Merola Tania Bizouarn Hélène Pasquier Laura Baciou Filippo Rusconi Marie Erard 《Photochemistry and photobiology》2010,86(1):55-61
The modifications induced by reactive oxygen species (ROS) on fluorescent proteins (FPs) may have important implications for live cell fluorescence imaging. Using quantitative γ-radiolysis, we have studied the ROS-induced biochemical and photophysical perturbations on recombinant cyan fluorescent protein (CFP). After oxidation by the ˙OH radical, the protein displays a modified RP-HPLC elution profile, while the CFP fluorescence undergoes pronounced decreases in intensity and lifetime, without changes in its excitation and emission spectra. Meanwhile, the Förster resonant energy transfer (FRET) between the single W57 and the chromophore remains unperturbed. These results rule out a direct oxidation of the CFP chromophore and of W57 as well as major changes in the protein 3D structure, but show that new fluorescent forms associated to a higher level of dynamic quenching have been generated. Thus, strict in situ controls are required when CFP is to be used for FRET studies in situations of oxidative activity, or under strong illumination. 相似文献
495.
Damir A. Safin Dr. Maria G. Babashkina Felix D. Sokolov Sergey V. Baranov F. Ekkehardt Hahn Tania Pape 《无机化学与普通化学杂志》2009,635(11):1613-1619
The reaction of the potassium salts of N‐phosphorylated thioureas [4′‐benzo‐15‐crown‐5]NHC(S)NHP(Y)(OiPr)2 (Y = S, HLI ; Y = O, HLII ) with ZnII and CoII cations in aqueous EtOH leads to complexes of formulae Zn(LI,II‐S,Y)2 (Y = S, 1 ; Y = O, 2 ) and Co(LI‐S,S′)2 ( 3 ), while interaction of the potassium salt of N‐phosphorylated thioamide [4′‐benzo‐15‐crown‐5]C(S)NHP(O)(OiPr)2 ( HLIII ) with ZnII in the same conditions leads to the complex Zn(HLIII)(LIII‐S,O)2 ( 4 ). The reaction of the potassium salt of crown ether‐containing N‐phosphorylated bis‐thiourea N,N′‐[C(S)NHP(O)(OiPr)2]2‐1,10‐diaza‐18‐crown‐6 ( H2L ) with CoII, ZnII and PdII cations in anhydrous CH3OH leads to complexes M2(L‐O,S)2 (M = Co, 5 ; Zn, 6 ; M = Pd, 7 ). Thioamide HLIII was investigated by single‐crystal X‐ray diffraction. 相似文献
496.
Several techniques of polymer characterization and different ageing methods have been used with the aim of developing a simple, fast and reliable method to qualify commercial pipe-grade polyethylene samples, and possibly to evidence the presence of recycled PE within PE pipes. The results of the different techniques used have been compared with respect to their capability to evidence differences in the degradation rate of different HDPE samples (including virgin HDPE, HDPE pipes obtained from virgin HDPE and HDPE pipes that probably contain recycled HDPE). FT-IR, TGA and DSC were found unsuitable for this purpose but, on the contrary, MFI measurements have been found sensitive enough to evidence different degradation rates when a suitable combination of high temperature, oxygen, mechanical stresses and mixing time had been used for ageing the sample. 相似文献
497.
Tania Petta Luiz A. B. Moraes Lúcia H. Faccioli 《Journal of mass spectrometry : JMS》2015,50(7):879-890
Liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) in the multiple reaction monitoring (MRM) scan mode has been the primary MS method applied for the target identification of specific and minor oxylipids in complex matrices, such as eicosanoids and docosanoids, which are potent lipid mediators derived from polyunsaturated fatty acid oxygenation. However, the high specificity of MRM can limit the detection of species with m/z MRM transitions not covered by the method. In addition to MRM, tandem‐quadrupole mass analyzers enable other experiments to be conducted, by fragmenting ions via collision‐induced dissociation process (CID). This paper presents the potential of tandem mass spectrometry for the focused analysis of oxylipids. We have successfully developed an LC‐MS/MS method for the identification of precursor ions of m/z 115, a diagnostic product ion of 5‐hydroxy‐ and 5‐epoxy‐fatty acids. As a proof of concept, the developed method was used to discover several oxylipids oxidized at C5 derived from arachidonic acid (C20 : 4) oxygenation in a hypothalamus rat extract that were not identified using the target MRM methodology. The proposed focused MS/MS‐based approach in a tandem mass analyzer has proven to be a powerful strategy to accelerate the identification of oxylipids with structural similarities and assist the field of lipidomic research. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
498.
Salla I Montanari T Salagre P Cesteros Y Busca G 《Physical chemistry chemical physics : PCCP》2005,7(12):2526-2533
The low temperature adsorption of CO and the room temperature adsorption of propionitrile and ortho-toluonitrile on LiMOR, NaMOR, KMOR and CsMOR zeolites have been investigated by FT-IR spectroscopy. Two different CO species, both most probably located in the main channels coordinated on Na ions at IV and VI sites, have been observed. They are associated to a shift of the CO stretching to higher frequencies, as usual. However, together, more strongly bonded species associated to a slight shift of the CO stretching to a lower frequency are also observed. Similar species, with the CN stretching shifted upwards (weaker adsorption) and with the CN stretching shifted downwards (stronger adsorption) are also observed in the case of the interaction of propionitrile (PrN), a molecule that should enter the main channels, and in the case of the interaction of ortho-toluonitrile (o-TN), whose access to the main channels should be highly hindered. The data show that the species characterized by a stronger adsorption but a lower stretching frequency may form both in the main channels and at the external surface. Their formation is easier with the larger cations. These species are identified as "multiply bonded", possibly to two cations. The evidence for this new interaction, stronger than the usual one site-one molecule species, may change considerably the view of the adsorption chemistry of cationic zeolites, from localized simple sites to cooperative complex interactions. 相似文献
499.
Pooja?SabhachandaniView authors OrcID profile Saheli?Sarkar Paola?C.?Zucchi Betsy?A.?Whitfield James?E.?Kirby Elizabeth?B.?Hirsch Tania?KonryEmail author 《Mikrochimica acta》2017,184(12):4619-4628
The paper describes a droplet-based microfluidic method for phenotypic-based antimicrobial susceptibility testing (AST). In particular, this micro-droplet-based phenotypic assay evaluates susceptibility of different bacterial strains towards antibiotics by tracking effects on individual bacterial cells, including changes in bacterial cell number and morphology. The platform was validated by applying the method to test the responses of E. coli ATCC 25922 and 6937 (a clinical isolate), in spiked urine samples at a concentration of 5 × 104 cfu mL?1, to the antibiotics ceftazidime and levofloxacin. Both E. coli strains showed dose-dependent inhibition of bacterial replication and morphological alteration. These correlated well with minimal inhibitory concentrations determined by the reference broth microdilution method. Discrete bacterial divisions and morphological changes were observed within 20 min of on-chip incubation, demonstrating performance of rapid AST directly on urine samples. As proof-of-concept, specific bead-based biosensors were tested for capture and detection of E. coli for on-bead proliferation. The method has the attractive feature of allowing the detection of at least one bacterium per bead in less than 30 min. It can potentially be used to isolate a specific bacterial strain directly from patient urine samples for AST monitoring. 相似文献
500.
Dubois L Xiang DF Tan XS Pécaut J Jones P Baudron S Le Pape L Latour JM Baffert C Chardon-Noblat S Collomb MN Deronzier A 《Inorganic chemistry》2003,42(3):750-760
Reactions of the unsymmetrical phenol ligand 2-(bis(2-pyridylmethyl)aminomethyl)-6-((2-pyridylmethyl)(benzyl)aminomethyl)-4-methylphenol with Mn(OAc)(2).4H(2)O or Mn(H(2)O)(6)(ClO(4))(2) in the presence of NaOBz affords the dimanganese(II) complexes 1(CH(3)OH), [Mn(2)(L)(OAc)(2)(CH(3)OH)](ClO(4)), and 2(H(2)O), [Mn(2)(L)(OBz)(2)(H(2)O)](ClO(4)), respectively. On the other hand, reaction of the ligand with hydrated manganese(III) acetate furnishes the mixed-valent derivative 3(H(2)O), [Mn(2)(L)(OAc)(2)(H(2)O)](ClO(4))( 2). The three complexes have been characterized by X-ray crystallography. 1(CH(3)OH) crystallizes in the monoclinic system, space group P2(1)/c, with a = 10.9215(6) A, b = 20.2318(12) A, c = 19.1354(12) A, alpha = 90 degrees, beta = 97.5310(10) degrees, gamma = 90 degrees, V = 4191.7 A(3), and Z = 4. 2(H(2)O) crystallizes in the monoclinic system, space group P2(1)/n, with a = 10.9215(6) A, b = 20.2318(12) A, c = 19.1354(12) A, alpha = 90 degrees, beta = 97.5310(10) degrees, gamma = 90 degrees, V = 4191.7 A(3), and Z = 4. 3(H(2)O) crystallizes in the monoclinic system, space group P2(1)/c, with a = 11.144(6) A, b = 18.737(10) A, c = 23.949(13) A, alpha = 90 degrees, beta = 95.910(10) degrees, gamma = 90 degrees, V = 4974(5) A(3), and Z = 4. Magnetic measurements revealed that the three compounds exhibit very similar magnetic exchange interactions -J = 4.3(3) cm(-)(1). They were used to establish tentative magneto-structural correlations which show that for the dimanganese(II) complexes -J decreases when the Mn-O(phenoxo) distance increases as expected from orbital overlap considerations. For the dimanganese(II,III) complexes, crystallographic results show that the Mn(II)-O(phenoxo) and Mn(III)-O(phenoxo) bond lengths are inversely correlated. An interesting magneto-structural correlation is found between -J and the difference between these bond lengths, delta(Mn)(-)(O) = d(Mn)()II(-)(O) - d(Mn)()III(-)(O): the smaller this difference, the larger -J. Electrochemical studies show that the mixed-valence state is favored in 1-3 by ca. 100 mV with respect to analogous complexes of symmetrical ligands, owing to the asymmetry of the electron density as found in the analogous diiron complexes. 相似文献