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71.
Teerapon Pirom Thidarat Wongsawa Thanaporn Wannachod Niti Sunsandee Ura Pancharoen Soorathep Kheawhom 《Chemical Papers》2017,71(7):1291-1302
Amoxicillin was removed from aqueous solutions using hollow fibre supported liquid membrane system (HFSLM). After evaluation of the influencing variables, the highest permeation coefficient of amoxicillin reached 2.778 × 10?4 ms?1 when the length of hollow fibres was 15 cm and the operating time was 60 min. Then, the reaction flux models of extraction and stripping were calculated. Thereafter, the modelling results were compared with the experimental data at standard deviations of 2.07 and 3.19%. In the comparison of carrier and diluent, the best conditions were achieved when Aliquat 336 and 1-Decanol were used. Results showed that amoxicillin extraction and stripping were of first and zero reaction orders; their reaction rate constants were 0.0344 min?1 and 0.0445 mg/L·min, respectively. 相似文献
72.
Augustine A. Ahmadu Claire Delehouz Anas Haruna Lukman Mustapha Bilqis A. Lawal Aniefiok Udobre Blandine Baratte Camilla Triscornia Axelle Autret Thomas Robert Jeannette Chloë Bulinski Morgane Rousselot Mlanie Simoes Eugnio Marie-Thrse Dimanche-Boitrel Jacobus P. Petzer Lesetja J. Legoabe Stphane Bach 《Molecules (Basel, Switzerland)》2021,26(15)
The purpose of this work is to investigate the protein kinase inhibitory activity of constituents from Acacia auriculiformis stem bark. Column chromatography and NMR spectroscopy were used to purify and characterize betulin from an ethyl acetate soluble fraction of acacia bark. Betulin, a known inducer of apoptosis, was screened against a panel of 16 disease-related protein kinases. Betulin was shown to inhibit Abelson murine leukemia viral oncogene homolog 1 (ABL1) kinase, casein kinase 1ε (CK1ε), glycogen synthase kinase 3α/β (GSK-3 α/β), Janus kinase 3 (JAK3), NIMA Related Kinase 6 (NEK6), and vascular endothelial growth factor receptor 2 kinase (VEGFR2) with activities in the micromolar range for each. The effect of betulin on the cell viability of doxorubicin-resistant K562R chronic myelogenous leukemia cells was then verified to investigate its putative use as an anti-cancer compound. Betulin was shown to modulate the mitogen-activated protein (MAP) kinase pathway, with activity similar to that of imatinib mesylate, a known ABL1 kinase inhibitor. The interaction of betulin and ABL1 was studied by molecular docking, revealing an interaction of the inhibitor with the ABL1 ATP binding pocket. Together, these data demonstrate that betulin is a multi-target inhibitor of protein kinases, an activity that can contribute to the anticancer properties of the natural compound and to potential treatments for leukemia. 相似文献
73.
Makoto Shimizu Haruna Katsurayama Isao Mizota Yusong Zhu 《Journal of heterocyclic chemistry》2019,56(9):2479-2486
Synthesis of 2‐methyl‐3‐oxoindoline‐2‐carboxylates is developed using a bis(trimethylsilyl)aluminum chloride‐induced aza‐Brook rearrangement as a crucial step. Regarding the organoaluminum species, use of readily available tris(trimethylsilyl)aluminum·ether complex was not suitable for the present cyclization. After a series of examination of the reaction conditions, the aza‐Brook rearrangement and the subsequent cyclization with 2 equivalens of bis(trimethylsilyl)aluminum chloride were found to be the most effective. An application to the synthesis of a potential intermediate of duocarmycin A is also described, in which ozonolysis of the styrenyl moiety and the Barton–McCombie deoxygenation of the hydroxymethyl group were successfully carried out. 相似文献
74.
Water-soluble pyrenophanes possessing polycationic or amphiphilic side chains have been developed as synthetic host molecules to investigate hydrophobic and/or pi-stacking interactions. By utilizing omega-acetalic alkyl side chains to retain solubility and versatility, water-soluble macrocyclic pyrenophanes could be easily obtained by Stille coupling, followed by conversion of the acetal groups to hydrophilic substituents. Among the pyrenophanes synthesized, hexaammonium-, bis(diazoniacrown)-, and tetrakis[octa(oxyethylene)]-derived ones showed enough solubility in pure water. The former two cationic pyrenophanes strongly recognized anionic arenes including nucleotides, while the latter neutral one associated with monopyrenyl guests regardless of their electric natures. The strength of recognition for nucleotides by bis(diazoniacrown)pyrenophane depended on the number of phosphate moieties, decreasing in the following order: triphosphate > diphosphate approximately monophosphate. 相似文献
75.
We develop the minimal requirements for the complete entanglement quantification of an arbitrary two-mode bipartite Gaussian state via local measurements and a classical communication channel. The minimal set of measurements is presented as a reconstruction protocol of local covariance matrices and no previous knowledge of the state is required but its Gaussian character. The protocol becomes very simple mostly when dealing with Gaussian states transformed to its standard form, since photocounting or intensity measurements define the whole set of entangled states. In addition, conditional on some prior information, the protocol is also useful for a complete global state reconstruction. 相似文献
76.
Kwon HJ Kakugo A Ura T Okajima T Tanaka Y Furukawa H Osada Y Gong JP 《Langmuir : the ACS journal of surfaces and colloids》2007,23(11):6257-6262
We show that F-actins form three-dimensional giant network under uni-directional diffusion of polycations, at a dilute actin concentration (0.01 mg/mL) that only bundles are formed by homogeneous mixing with polycations. The mesh size of the actin network depends on polycation concentration and ionic strength, while bundle thickness of network depends only on ionic strength, which indicates that actin network is formed through nucleation-growth mechanism. The mesh size and the bundle thickness are determined by nucleus concentration and nucleus size, respectively. The atomic force microscopy measurement correlates the elasticity of the actin network, E, with the mesh size, xi, as E approximately xi-1, while the bundle thickness, D dependence of E cannot be described by a simple scaling relation. E approximately D6.5 when D is small and E approximately D0.1 when D is large. Our study on the self-assembly of actin network under asymmetric polycation condition would provide the crucial insight into the organization of biopolymers in polarized condition of cell. 相似文献
77.
Low coherence interferometry can provide simultaneous measurement of refractive index n and thickness t of a transparent plate, as reported recently by some research groups. Precise measurement of n and t is impossible unless chromatic dispersion of index is taken into account. We then proposed and demonstrated a unique technique for simultaneous measurement of phase index np, group index ng and thickness t using a special sample holder. This paper describes a novel technique for simultaneous measurement of np, ng and t using an approximate expression of the chromatic dispersion in terms of np. The approximate expression of chromatic dispersion does not require use of the special sample holder, and np, ng and t are determined from two measurable quantities with an accuracy of 0.3% or less, for the sample thickness was around 1 mm. In addition, it is possible to shorten the measurement time compared with the above method. 相似文献
78.
Bunpei Hatano Katsunori Miyoshi Haruna Sato Tomohiro Ito Tateaki Ogata Tatsuro Kijima 《Tetrahedron letters》2010,51(41):5399-1991
We have achieved an efficient synthesis of 1,1-dimethyl-3-(trifluoromethyl)-1H-isoindole N-oxide (2) in 39% yield by seven steps from 2-bromobenzoic acid (3). This compound serves as a spin trap reagent, giving a strong and stable ESR signal of the radical adduct of 2 in the presence of i-amyloxy radical generated by UV photolysis of i-amyl nitrite. 相似文献
79.
Bréfuel N Imatomi S Torigoe H Hagiwara H Shova S Meunier JF Bonhommeau S Tuchagues JP Matsumoto N 《Inorganic chemistry》2006,45(20):8126-8135
The synthesis and detailed study of the new mononuclear spin crossover complex [Fe(II)H2L(2-Me)](ClO4)2 (where H2L(2-Me) = bis[((2-methylimidazol-4-yl)methylidene)-3-aminopropyl]ethylenediamine) are reported. Variable-temperature magnetic susceptibility measurements show the occurrence of a steep spin crossover centered at 171.5 K with a hysteresis loop of ca. 5 K width (T(/2)(increasing) = 174 K and T(1/2)(decreasing) = 169 K, for increasing and decreasing temperatures, respectively). The crystal structure has been resolved for the high-spin (HS) and low-spin (LS) states at 200 and 123 K, respectively, revealing a crystallographic phase transition that occurs concomitantly to the spin crossover: at 200 K, the complex crystallizes in the monoclinic system, space group P2(1)/n, while the space group is P2(1) at 123 K. The mean Fe-N distances are shortened by 0.2 A, but the thermal spin crossover is accompanied by significant structural changes: the rearrangement of the central atom C12 of a six-membered chelate ring of [Fe(II)H2L(2-Me)]2+ to two positions (C12A and C12B) and, consequently, the lack of an inversion center at 123 K (P2(1) space group). Both HS and LS supramolecular structures involve all possible hydrogen bonds between imidazole and amine NH functions, and perchlorate anions; however, the HS supramolecular structure is a one-dimensional (1D) network, and the LS phase may better be described as a two-dimensional (2D) extended structure of A and B molecules. The structural phase transition of [FeH2L(2-Me)](ClO4)2 seems to trigger the steep and hysteretic spin crossover. Discontinuities in the temperature dependence of the M?ssbauer parameters (isomer shift and quadrupole splitting) at the spin crossover temperature confirmed the occurrence of a structural phase transition. The experimental enthalpy and entropy variations were determined by differential scanning calorimetry (DSC) as 7.5 +/- 0.4 kJ/mol and 45 +/- 3 J K(-1) mol(-1), respectively. The regular solution theory was applied to the experimental data, yielding an interaction parameter of Gamma = 3.36 kJ/mol, which is larger than 2RT(1/2), which fulfills the condition for observing hysteresis. 相似文献
80.
The chemistry of a novel zerovalent Ru complex, Ru(eta6-cot)(eta2-dmfm)2 (1) (cot=1,3,5-cyclooctatriene; dmfm=dimethyl fumarate), is reviewed with a focus on its reactivity toward phosphines, amines, and H2O, as well as arenes and p-quinones. A variety of novel zerovalent Ru complexes were synthesized from Ru(eta6-cot)(eta2-dmfm)2 (1), and it was shown that the complexes preferably bear both electron-donating and -accepting ligands simultaneously to exhibit thermodynamic stability. The first isolable zerovalent Ru aqua complexes were successfully prepared, and in these complexes, the generation of a chiral center on the O atom of the coordinated H2O was disclosed. In addition, the characteristic catalytic activity of 1 in organic synthesis was considered by reviewing recently developed novel reactions: (i) dimerization of 2,5-norbornadiene to pentacyclo[6.6.0.0(2,6).0(3,13).0(10,14)]tetradeca-4,11-diene (PCTD), (ii) intramolecular hydroamination of aminoalkynes to cyclic imines, (iii) formal [4+2] cycloaddition of alkynes with dmfm to trans-4-cyclohexene-1,2-dicarboxylates, and (iv) co-dimerization of dihydrofurans with alpha,beta-unsaturated esters to 2-alkylidenetetrahydrofurans. The products obtained here are expected to be used as novel functional organic monomers. 相似文献