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81.
In this study, quinazolinone derivatives have been synthesized via a suitable and efficient procedure by one-potmulti-component reactions of 3-amino-1,2,4-triazole or 2-aminobenzimidazole, dimedone and aromatic aldehydes in the presence of Fe3O4@TiO2-IL as nanocatalyst under solvent-free condition. The products were prepared in good to excellent yields using Fe3O4@TiO2-IL magnetic nanocatalyst. The Fe3O4@TiO2 magnetic nanoparticles (MNPs) were prepared using beet juice extract and functionalized with IL based on DABCO. Moreover, the core-shell structured magnetic Fe3O4@TiO2-IL has been characterized by different techniques such as 1H-NMR, FT-IR, VSM, XRD, SEM, TGA, TEM and EDX. To the best of our knowledge, the prepared ionic liquid displayed a good protective and activator agent for magnetic nanocatalyst. 相似文献
82.
Soodabeh Davaran Mohammad Sadeghinia Zahra Jamalpoor Vahideh Raeisdasteh Hokmabad Mehdi Doosti-Telgerd Ansar Karimian Zahra Sadeghinia Javad Khalilifard Akram keramt Farzad Moradikhah Ali Sadeghinia 《Electrophoresis》2020,41(12):1081-1094
Microfluidic system, or lab-on-a-chip, has grown explosively. This system has been used in research for the first time and then entered in the clinical section. Due to economic reasons, this technique has been used for screening of laboratory and clinical indices. The microfluidic system solves some difficulties accompanied by clinical and biological applications. In this review, the interpretation and analysis of some recent developments in microfluidic systems in biomedical applications with more emphasis on tissue engineering and cancer will be discussed. Moreover, we try to discuss the features and functions of microfluidic systems. 相似文献
83.
DFT calculations are employed to compare and contrast six-membered ring carbenes including 1,3-dimethyltetrahydropyrimidin-2-ylidene (1a), 1-methyl-3-cyclopropyltetrahydropyridine-2-ylidene (2a), and 1,3-dicyclopropylcyclohexane-2-ylidene (3a) as well as their unsaturated analogues 1b, 2b, 3b, and 2c. The amino groups exert singlet-triplet energy separation (?Es−t) of 60.9 kcal/mol to 1a while cyclopropyls induce a ?Es−t of 14.8 kcal/mol to 3a. The simultaneous presence of amino and cyclopropyl in 2a leads to a ?Es−t of 43.3 kcal/mol. Unsaturation slightly increases the ?Es−t of 1a and 3a but not that of 2a. Our thermodynamic, kinetic, and reactivity results are compared with those of synthetic five-membered ring N-heterocyclic carbenes. 相似文献
84.
An effective route to spiro[indoline-3,4′-pyridine]-3′-carboxylate derivatives is described. This involves reaction of isatin, 1-phenyl-2-(1,1,1-triphenyl-λ5-phosphanylidene)-1-ethanone, and benzylamine derivatives or aliphatic amines in the presence of alkyl acetoacetate (1,3-dicarbonyl compounds) in dry methanol under reflux conditions. The reactive 1:1 enaminone, which is obtained from the addition of the amine to 1,3-dicarbonyl compound, adds to the α,β-unsaturated ketone, which is formed from the reaction of isatin and 1-phenyl-2-(1,1,1-triphenyl-λ5-phosphanylidene)-1-ethanone, to produce the alkyl 1′-benzyl-2′-methyl-2-oxo-6′-phenyl-1′H-spiro[indoline-3,4′-pyridine]-3′-carboxylate derivatives in excellent yields. 相似文献
85.
Morteza Hosseini Mehdi Khoobi Roghayeh Tarasi Mohammad Reza Ganjali 《Research on Chemical Intermediates》2018,44(9):5031-5042
A rhodamine-conjugated coumarin (L) was used in designing a selective fluorescence chemosensor for the determination of trace amounts of Cr3+ ions in acetonitrile–water (MeCN/H2O (90:10, %v/v) solutions. The intensity of the fluoresce emission of the chemosensor is intensified upon addition of Cr3+ ions in MeCN/H2O (90:10, %v/v) solutions, due to the formation of a selective 1:1 complex between L and Cr3+ ions. The fluorescence enhancement versus Cr3+ concentration has been found to be linear from 1.0?×?10?7 to 1.8?×?10?5 M and a detection limit of 7.5?×?10?8 M. The proposed fluorescent probe proved to be highly selective towards Cr3+ ions as compared to other common metal ions and could be successfully applied to the determination of Cr3+ concentrations in some water and wastewater samples. 相似文献
86.
Javad Zolgharnein Fariborz Riahii Saeid Amani 《Journal of inclusion phenomena and macrocyclic chemistry》2003,45(1-2):13-17
The complexation of La(III), Ce(III), Pr(III) and Er(III) with 18-crown-6(18C6), dibenzo-18-crown-6 (DB18C6), dicyclohexano-18-crown-6 (DCY18C6) anddibenzopyridino-18-crown-6 (DBPY18C6) has been studied in dimethylsulfoxide(DMSO) by means of a competitive spectrophotometric method using murexide asa metal ion indicator. The formation constants of the 1 : 1 complexeswere found tovary in the order La(III) > Ce(III) > Pr(III) > Er(III). It was foundthat the structure influences the formation and stability of the resultingcomplexes. The effects ofvarious parameters on complexation are discussed. The order of the stabilityconstants of each lanthanide ion with these macrocycles are18C6 > DC18C6 > DB18C6 > DBPY18C6. 相似文献
87.
Javad Mostaghimi Pierre Proulx Maher I. Boulos 《Plasma Chemistry and Plasma Processing》1984,4(3):199-217
A theoretical investigation of the effect of different parameters on the flow and the temperature fields in a radiofrequency
inductively coupled plasma is carried out. The parameters studied are: central injection gas flow rate, total gas flow rate,
input power, and the type of plasma gas. The results obtained for argon and nitrogen plasmas at atmospheric pressure indicate
that the flow and the temperature fields in the coil region, as well as the heat flux to the wall of the plasma confinement
tube, are considerably altered by the changes in the torch operating conditions. 相似文献
88.
S. Zahra Sayyed-Alangi Mohammad T. Baei Javad Nejati Ali Varasteh Moradi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1595-1603
Abstract Minimum-energy and transition-state geometries of 4-oxobuta-1,3-diene-1-thione, buta-1,3-diene-1,4-dithione, 4-selenoxobuta-1,3-diene-1-thione, 4-selenoxobuta-1,3-diene-1-one, and buta-1,3-diene-1,4-diselenone were calculated using HF, B3LYP, and MP2 levels of theory and 6–31 + G* basis set by rotation around the related ?C?C? single bonds. In all of the above-mentioned molecules, the s-trans conformation was obtained as the most stable conformer with the 180° dihedral angle. In buta-1,3-diene-1,4-dithione, 4-selenoxobuta-1,3-diene-1-thione, and buta-1,3-diene-1,4-diselenone, the s-cis form of these compounds corresponded to the other energy-minimum geometry. Their skew geometries, with torsional angles approximately 100°, were a transition state for conformational interconversion between the two global minima forms. In 4-oxobuta-1,3-diene-1-thione and 4-selenoxobuta-1,3-diene-1-one, geometries with the C?C?C?C dihedral angles about 51 and 43° (respectively) were attributed to the second energy-minimum geometry. Transition-state structures from both molecules were found in the torsional angles at about 0 and 100°. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT 相似文献
89.
Davood Nori-Shargh Maryam Malek Hosseini Tina Ohaninan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2410-2420
An investigation employing the ab initio molecular orbital (MO) and density functional theory (DFT) methods to calculate structural optimization and conformational interconversion pathways for the two diastereoisomeric forms, (±) and meso configurations of 1,3,7,9-tetraphospha-cyclododeca-1,2,7,8-tetraene (1) was undertaken. Two axial symmetrical conformations are found for (±)-1 configuration. (±)-1-TB axial symmetrical form is found to be about 0.35 and 0.99 kcal mol?1 more stable than (±)-1-Crown axial symmetrical conformation, as calculated by HF/6-31G*//HF/6-31G* and B3LYP/6-31G*//HF/6-31G* levels of theory, respectively. The unsymmetrical meso-1-TBCC form is found to be the most stable geometry, among the various conformations of meso-1 configuration. HF/6-31G*//HF/6-31G* and B3LYP/6-31G*//HF/6-31G* results showed that between the two most stable conformations of (±) and meso configurations, (±)-1-TB is more stable than meso-1-TBCC by about 3.35 and 2.43 kcal mol?1, respectively. In addition, MP2/6-31G* and B3LYP/6-311+G** results showed that the (±)-1-TB form is about 1.10 and 2.36 kcal mol?1 more stable than the meso-1-TBCC form. Further, NBO results revealed that in the most stable form of meso configuration (meso-1-TBCC), the sum of the π* allenic antibonding orbital occupancies (Σ π *occupancy) is greater than dl configuration ((±)-1-TB). Also, NBO results indicated that in the (±)-1-TB conformer, the sum of σ and π allenic moieties bonding orbital deviations (Σ σ dev+Σ π dev) from their normal values, is lower than in the meso-1-TBCC form. 相似文献
90.
Ali Taherkhani Hassan Karimi-Maleh Ali A.Ensafi Hadi Beitollahi Ahmad Hosseini Mohammad A.Khalilzadeh Hassan Bagheri 《中国化学快报》2012,23(2):237-240
A carbon paste electrode(CPE) chemically modified with multiwall carbon nanotubes and ferrocene(FC) was used as a selective electrochemical sensor for the simultaneous determination of trace amounts of cysteamine(CA) and folic acid(FA).This modified electrode showed very efficient electrocatalytic activity for the anodic oxidation of CA.The peak current of differential pulse voltammograms of CA and FA increased linearly with their concentration in the ranges of 0.7-200μmol/L CA and 5.0- 700μmol/L FA.The detection limits for CA and FA were 0.3μmol/L and 2.0μmoI/L,respectively.The diffusion coefficient(D) and transfer coefficient(α) of CA were also determined.These conditions are sufficient to allow determination of CA and FA both individually and simultaneously. 相似文献