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31.
The first water‐soluble copper(I) complexes bearing sulfonated imidazole‐ and benzimidazole‐derived N‐heterocyclic carbenes: Synthesis and anticancer studies
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Maura Pellei Valentina Gandin Cristina Marzano Marika Marinelli Fabio Del Bello Carlo Santini 《应用有机金属化学》2018,32(3)
The first water‐soluble bis(NHCSO3)CuCl complexes (NHCSO3 = NaImBn,PrSO3, Na2(4‐Me)ImPrSO3 and Na2BzImPrSO3) derived from the sulfonated N‐heterocyclic carbene precursors HImBn,PrSO3 (3‐(1‐benzyl‐1H‐imidazol‐3‐ium‐3‐yl)propane‐1‐sulfonate), Na(4‐Me)HImPrSO3 (sodium 3,3′‐(4‐methyl‐1H‐imidazole‐3‐ium‐1,3‐diyl)dipropane‐1‐sulfonate) and NaHBzImPrSO3 (sodium 3,3′‐(1H‐benzoimidazole‐3‐ium‐1,3‐diyl)dipropane‐1‐sulfonate) have been synthesized. These compounds have been characterized using infrared and NMR spectroscopy and electrospray ionization mass spectrometry. The in vitro anti‐tumour effects of the bis(NHCSO3)CuCl complexes and the corresponding free ligands were evaluated for a panel of various human tumour cell lines, including examples of lung, colon, ovarian and cervical carcinoma as well as of melanoma. Their cytotoxic properties were also evaluated against non‐transformed human cells and on a cellular model of cisplatin resistance. NHC–copper complexes induced cell killing effects preferentially against tumour cells, with IC50 values in the micromolar range. Additionally, they were found able to overcome acquired cisplatin resistance. 相似文献
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33.
Angela Chambery Antimo Di Maro Carmen Sanges Valeria Severino Maura Tarantino Annalisa Lamberti Augusto Parente Paolo Arcari 《Analytical and bioanalytical chemistry》2009,395(7):2281-2291
Diagnostic techniques applied to the field of cultural heritage represent a very important aspect of scientific investigation.
Recently, proteomic approaches based on mass spectrometry coupled with traditional spectroscopic methods have been used for
painting analysis, generating promising results for binder’s protein identification. In the present work, an improved procedure
based on LC-ESI/Q-q-TOF tandem mass spectrometry for the identification of protein binders has been developed for the molecular
characterization of samples from an early-twentieth-century mural painting from the St. Dimitar Cathedral in Vidin, Bulgaria.
The proteomic investigation has led to the identification of both egg white and egg yolk proteins, according to traditional
old recipes for tempera paintings. In addition, beyond the egg components, the presence of caseins was also revealed, thus
suggesting the use of milk as binding medium, fixative or stabilising agent. Furthermore, for the first time, the capability
to discriminate the milk origin on the basis of alpha casein proteotypic peptides is reported, that are diagnostic for a given
species, thus opening interesting perspectives in art and archaeological fields. 相似文献
34.
Ma L Iezzi M Kaucher MS Lam YF Davis JT 《Journal of the American Chemical Society》2006,128(47):15269-15277
Lipophilic guanosine derivatives that form G-quadruplexes are promising building blocks for ionophores and ion channels. Herein, cation exchange between solvated cations (K+ and NH4+) and bound cations in the G-quadruplex [G1]16.4Na+.4DNP- was studied by electrospray ionization mass spectrometry and solution 1H, 15N NMR spectroscopy. The ESI-MS and 1H NMR data provided evidence for the formation of mixed-cationic Na+, K+ G-quadruplexes. The use of 15NH4+ cations in NMR titrations, along with 15N-filtered 1H NMR and selective NOE experiments, identified two mixed-cationic intermediates in the cation exchange pathway from [G1]16.4Na+.4DNP- to [G1]16.4NH4+.4DNP-. The central Na+, bound between the two symmetry-related G8-Na+ octamers, exchanges with either K+ or NH4+ before the two outer Na+ ions situated within the C4 symmetric G8 octamers. A structural rationale, based on differences in the cations' octahedral coordination geometries, is proposed to explain the differences in site exchange for these lipophilic G-quadruplexes. Large cations such as Cs+ can be exchanged into the central cation binding site that holds the two symmetry-related C4 symmetric G8 octamer units together. The potential relevance of these findings to both supramolecular chemistry and DNA G-quadruplex structure are discussed. 相似文献
35.
Salis A Pinna MC Bilanicová D Monduzzi M Lo Nostro P Ninham BW 《The journal of physical chemistry. B》2006,110(6):2949-2956
The effect of electrolytes on pH measurements via glass electrodes is explored with solutions buffered at pH 7 (phosphate and cacodylate). Salt and buffer concentrations are varied. Direct and reverse Hofmeister effects are observed. The phenomena are significant for salt concentrations above 0.1 M and for buffer concentrations below 20 mM. Changes in measured pH show up most strongly with anions. They can be related to the usual physicochemical parameters (anion molar volumes, molar refractivity, and surface tensions) that are characteristic of Hofmeister series. They correlate strongly with anionic excess polarizabilities; this suggests the involvement of non-electrostatic, or dispersion, forces acting on ions. These forces contribute to ionic adsorption at the glass electrode surface, and to the liquid junction potential. 相似文献
36.
Cingolani A Effendy E Hanna JV Pellei M Pettinari C Santini C Skelton BW White AH 《Inorganic chemistry》2003,42(16):4938-4948
Adducts of triphenyl phosphine, triphenyl arsine, and triphenyl stibine with silver(I) bromate have been synthesized and characterized both in solution ((1)H and ESI MS spectroscopy) and in the solid state (IR, single-crystal X-ray structure analysis). The triphenyl phosphine complexes have been also investigated by (31)P[(1)H] solution and (31)P cross-polarization magic-angle-spinning (CPMAS) NMR spectroscopy. The topology of the structures in the solid state was found to depend on the nature of EPh(3) and on the stoichiometric ratio AgBrO(3)/EPh(3). In AgBrO(3)/PPh(3) (1:1)(4) (1) and AgBrO(3)/PPh(3) (1:2) (2), the bromate is in the unfamiliar and hitherto structurally uncharacterized role of coordinating ligand, the complex having a mononuclear form in 2 and a less familiar tetrameric form in 1. In AgBrO(3)/AsPh(3) (1:4).CH(3)OH (7) and AgBrO(3)/SbPh(3) (1:4).C(2)H(5)OH (11), the cations are the familiar homoleptic [Ag(EPh(3))(4)](+) array with the bromate role simply that of counterion. The AgBrO(3)/AsPh(3) (1:2)(2).0.7"H(2)O" derivative (6) is binuclear L(2)Ag(mu-BrO(3))(2)AgL(2) with a four-membered ring core (L = AsPh(3)). 相似文献
37.
A degenerate parabolic equation modelling the spread of an epidemic 总被引:10,自引:0,他引:10
Maura Ughi 《Annali di Matematica Pura ed Applicata》1986,143(1):385-400
Summary
We consider the Cauchy problem for a degenerate parabolic equation, not in divergence form, representing the diffusive approximation of a model for the spread of an epidemic in a closed population without remotion. We prove existence and uniqueness of the weak solution, defined in a suitable way, and some qualitative properties. 相似文献
38.
Pellicciari R Marinozzi M Camaioni E del Carmen Nùnez M Costantino G Gasparini F Giorgi G Macchiarulo A Subramanian N 《The Journal of organic chemistry》2002,67(16):5497-5507
In search for novel conformationally constrained analogues of L-glutamic acid, a diastereodivergent synthesis of the four 1-aminospiro[2.2]pentyl-1,4-dicarboxylic acid racemic pairs is reported along with their stereochemical assignment, conformational analysis, and preliminary biological evaluation as potential glutamate (ionotropic and metabotropic) ligands. 相似文献
39.
Sergio Murgia Maura Monduzzi Francesco Lopez Gerardo Palazzo 《Journal of solution chemistry》2013,42(6):1111-1122
This work is devoted to highlighting some peculiar aspects of ionic liquid self-aggregation in water, which is still a matter of wide debate. Here, the whole water /1-butyl-3-methyl imidazolium (bmim+) tetrafluoborate ( $ {\text{BF}}_{4}^{ - } $ ) phase diagram was thoroughly re-investigated, at a molecular level, by means of 1H and 19F PGSTE and 11B relaxation NMR experiments performed at room temperature. The analysis of H2O, bmim+ and $ {\text{BF}}_{4}^{ - } $ ions self-diffusion coefficients and the 11B relaxation times revealed that ion-pair dissociation is a progressive process starting at a H2O molar fraction equal to 0.2 and ending at high water content. More importantly, the collected results indicate that H2O and ions diffuse within different domains, strongly suggesting that the system under investigation is actually nanostructured. This fact agrees with some other recent works focusing on the possible mesoscopic order that ionic liquids possess when dissolved in water because of their hydrophobic tail segregation. 相似文献
40.
M. Manickam Alun Smith Maura Belloni Elwyn J. Shelley Peter R. Ashton Neil Spencer 《Liquid crystals》2013,40(4):497-504
The synthesis and characterization of four C 60 Bingel cyclopropanation adducts incorporating bis-biphenylene (three adducts) and bis-triphenylene (one adduct) moieties are described. The thermal analysis (POM and DSC) of these materials reveals that they are not liquid crystalline. However, two of the precursor bis-biphenylene malonate esters possess monotropic mesophases. Furthermore, each of the corresponding C60adducts is miscible in the melts of the precursor malonate ester, and at low dopings, retains the liquid crystalline monotropic mesophases of the precursor. 相似文献