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181.
Novel Cu 2+ and Fe 3+ chelates derived from L 1 were synthesized and characterized by single crystal X‐ray diffraction. The results indicate that the Fe (III) crystal, [Fe(L1‐H)Cl2], has an orthorhombic structure of the type pc2b while the dimeric Cu (II) crystal, [Cu(L1‐H)Cl … ClCu(L1‐H)], has a monoclinic with space group Cc. X‐ray diffraction and spectroscopic studies revealed that L 1 acts as monobasic tetradentate with octahedral geometry in Fe (III) crystal while it behaves as dibasic tetradentate with distorted‐octahedral in the Cu (II) crystal. Also, the two chelates were characterized by spectral, magnetic and thermal analyses. DFT parameters were used to prove the liberation of a proton from COOH rather than NH groups. The kinetic and thermodynamic parameters of Fe (III) chelate were determined by Coats‐Redfern and Horowitz‐Metzger methods. Cyclic voltammogram provides information about the oxidation states of Cu (II) and Fe (III) chelates. Antitumor activity against Epitheliod carcinoma (Hela), breast cancer (MCF‐7) and antibacterial activities of chelates were investigated. 相似文献
182.
Lukas Kahlert Eman F. Bassiony Russell J. Cox Elizabeth J. Skellam 《Angewandte Chemie (International ed. in English)》2020,59(14):5816-5822
The sorbicillinoids are a class of biologically active and structurally diverse fungal polyketides arising from sorbicillin. Through co‐expression of sorA, sorB, sorC, and sorD from Trichoderma reesei QM6a, the biosynthetic pathway to epoxysorbicillinol and dimeric sorbicillinoids, which resemble Diels–Alder‐like and Michael‐addition‐like products, was reconstituted in Aspergillus oryzae NSAR1. Expression and feeding experiments demonstrated the crucial requirement of the flavin‐dependent monooxygenase SorD for the formation of dimeric sorbicillinoids, hybrid sorbicillinoids, and epoxysorbicillinol in vivo. In contrast to prior reports, SorD catalyses neither the oxidation of 2′,3′‐dihydrosorbicillin to sorbicillin nor the oxidation of sorbicillinol to oxosorbicillinol. This is the first report that both the intermolecular Diels–Alder and Michael dimerization reactions, as well as the epoxidation of sorbicillinol are catalysed in vivo by SorD. 相似文献
183.
Abdel Karim Mohamed Gafaar Ibrahim Abd El-Halim Eman Hanfi Mohamed Walley El-Dine Nadia 《Journal of Radioanalytical and Nuclear Chemistry》2021,330(3):707-720
Journal of Radioanalytical and Nuclear Chemistry - In the present study, the 238U and 232Th radioactivity afford a perfect indication of the attendance of heavy minerals. Herein, integrated ground... 相似文献
184.
Waseem El-Huneidi Shabana Anjum Khuloud Bajbouj Eman Abu-Gharbieh Jalal Taneera 《Molecules (Basel, Switzerland)》2021,26(17)
Kahweol is a diterpene molecule found in coffee that exhibits a wide range of biological activity, including anti-inflammatory and anticancer properties. However, the impact of kahweol on pancreatic β-cells is not known. Herein, by using clonal rat INS-1 (832/13) cells, we performed several functional experiments including; cell viability, apoptosis analysis, insulin secretion and glucose uptake measurements, reactive oxygen species (ROS) production, as well as western blotting analysis to investigate the potential role of kahweol pre-treatment on damage induced by streptozotocin (STZ) treatment. INS-1 cells pre-incubated with different concentrations of kahweol (2.5 and 5 µM) for 24 h, then exposed to STZ (3 mmol/L) for 3 h reversed the STZ-induced effect on cell viability, apoptosis, insulin content, and secretion in addition to glucose uptake and ROS production. Furthermore, Western blot analysis showed that kahweol downregulated STZ-induced nuclear factor kappa B (NF-κB), and the antioxidant proteins, Heme Oxygenase-1 (HMOX-1), and Inhibitor of DNA binding and cell differentiation (Id) proteins (ID1, ID3) while upregulated protein expression of insulin (INS), p-AKT and B-cell lymphoma 2 (BCL-2). In conclusion, our study suggested that kahweol has anti-diabetic properties on pancreatic β-cells by suppressing STZ induced apoptosis, increasing insulin secretion and glucose uptake. Targeting NF-κB, p-AKT, and BCL-2 in addition to antioxidant proteins ID1, ID3, and HMOX-1 are possible implicated mechanisms. 相似文献
185.
Abstract
Condensation of 2-acetylpyrrole with 5-methylfuran-2-carboxyaldehyde and 4-chlorobenzaldehyde in 20% NaOH give the corresponding 2-chalconylpyrroles. Some new 2-alkoxy-3-cyano-4,6-diarylpyridines were synthesized by condensation of chalcones with malononitrile, followed by cyclization in sodium alkoxide. The reactivity of chalcones towards nitrogen nucleophiles such as thiourea and hydroxylamine hydrochloride to provide thiopyrimidines and isoxazolines was investigated. 相似文献186.
A simple, sensitive and accurate spectrophotometric method for the determination of sulphonamides (sulphamethoxazole (SMZ),
sulphaguanidine (SGD), sulphaquinoxaline sodium (SQX), sulphametrole (SMR), and sulphadimidine sodium (SDD)) has been developed.
The charge-transfer reactions between sulphonamides as n-electron donors and 7,7,8,8-tetracyanoquinodimethane (TCNQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone
(chloranilic acid, p-CLA) as π-acceptors resulting in highly coloured complexes were studied. Experimental conditions for these CT reactions were carefully
optimised. Beer’s law is valid over the concentration ranges from 4–280 μg mL−1, 4–260 μg mL−1, 4–200 μg mL−1, and 4–200 μg mL−1 of SMZ, SGD, SQX, and SDD using DDQ reagent, respectively. While the calibration curves are linear in the concentration ranges
from 4–180 μg mL−1, 4–80 μg mL−1, 4–60 μg mL−1, 4–180 μg mL−1, and 4–60 μg mL−1 of SMZ, SGD, SQX, SMR, and SDD, respectively, using TCNQ reagent and from 4–380 μg mL−1 and 4–300 μg mL−1 of SQX and SDD, respectively, using p-CLA reagent, respectively. Different analytical parameters, namely molar absorptivity
(ε), standard deviation, relative standard deviation, correlation coefficient, limit of detection, and limit of quantification,
were calculated. The results obtained by the proposed methods are in good agreement with those obtained by the official method
as indicated by the percent recovery values. 相似文献
187.
Fayyaz Ahmad Eman Salem Al-Aidarous Dina Abdullah Alrehaili Sven-Erik Ekström Isabella Furci Stefano Serra-Capizzano 《Numerical Algorithms》2018,77(3):867-884
The problem of computing oscillatory integrals with general oscillators is considered. We employ a Filon-type method, where the interpolation basis functions are chosen in such a way that the moments are in terms of elementary functions and the oscillator only. This allows us to evaluate the moments rapidly and easily without needing to engage hypergeometric functions. The proposed basis functions form a Chebyshev set for any oscillator function even if it has some stationary points in the integration interval. This property enables us to employ the Filon-type method without needing any information about the stationary points if any. Interpolation by the proposed basis functions at the Fekete points (which are known as nearly optimal interpolation points), when combined with the idea of splines, leads to a reliable convergent method for computing the oscillatory integrals. Our numerical experiments show that the proposed method is more efficient than the earlier ones with the same advantages. 相似文献
188.
We consider the discrete time dynamics of an ensemble of fermionic quantum walkers moving on a finite discrete sample, interacting with a reservoir of infinitely many quantum particles on the one dimensional lattice. The reservoir is given by a fermionic quasifree state, with free discrete dynamics given by the shift, whereas the free dynamics of the non-interacting quantum walkers in the sample is defined by means of a unitary matrix. The reservoir and the sample exchange particles at specific sites by a unitary coupling and we study the discrete dynamics of the coupled system defined by the iteration of the free discrete dynamics acting on the unitary coupling, in a variety of situations. In particular, in absence of correlation within the particles of the reservoir and under natural assumptions on the sample’s dynamics, we prove that the one- and two-body reduced density matrices of the sample admit large times limits characterized by the state of the reservoir which are independent of the free dynamics of the quantum walkers and of the coupling strength. Moreover, the corresponding asymptotic density profile in the sample is flat and the correlations of number operators have no structure, a manifestation of thermalization. 相似文献
189.
Ahmed Khodairy Eman A. Ahmed Mohamed Ismael Khaled M. Mohamed Shymaa A. Thabet 《Journal of heterocyclic chemistry》2019,56(3):1055-1062
Some new triazole, thiadiazole, oxadiazole, thiazole, oxazole, and imidazole derivatives have been synthesized via the reaction of tramadol bearing a hydrazide, hydrazine carbodithioate, and/or acetic acid group with certain reagents. Molecular docking study had been carried out to demonstrate the reactivity of these synthetic compounds for interaction with Cytochrome P450 2D6 ( CYP2D6 ). 相似文献
190.
Tetrahydropyrimidine derivative 1 was employed as intermediate compound, which in turn was allowed to react with different electrophilic and nucleophilic reagents to synthesize new polyfunctionalized series of substituted pyrimidine‐2‐thione derivatives. Structures of the newly synthesized compounds have been elucidated by spectroscopic data and elemental analyses. The pharmacological and antimicrobial activities of synthesized products have been evaluated as drug candidates. 相似文献