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11.
Several phenoxy-imine ligands bearing o-trityl group in phenoxy moiety RN=CHArOH (Ar = C6H2(CPh3)tBu, R = 2,6-Me2C6H3 ( L 1 H ); 2,6-iPr2C6H3 ( L 2 H ); 3,5-(CF3)2C6H3 ( L 3 H ); 3,5-(OMe)2C6H3 ( L 4 H ); CHPh2 ( L 5 H ); CPh3 ( L 6 H )) were synthesized and characterized by1H NMR and 13C NMR spectroscopy. The vanadium complexes based on these ligands LVCl2(THF)2 ( 1–6 ) were synthesized via conventional transmetalation reaction in moderate to high yields. Complexes 1–6 were fully characterized by FT-IR, elemental analyses and the molecular structures of 1 , 2 ·H2O, (2 ·H2O ) 2 (μ-Cl) 2 , 4 , and 5 were confirmed by X-ray crystallographic analysis in which the six-coordinated vanadium centers are in a typical octahedral geometry. Upon activation with Et2AlCl in toluene, complexes 1–6 showed high activities in ethylene polymerization affording polymers with moderate molecular weight (5.9–11.8 × 104 Da). Moreover, in hexane or CH2Cl2, 1–6 /Et2AlCl exhibited enhanced activities. When activated with MAO or MMAO in toluene, these complexes showed relatively low activities but afforded polymers with ultra-high molecular weight (up to 3.30 × 106 Da). 1–6 /Et2AlCl also showed high activities in ethylene/1-hexene copolymerization at room temperature giving moderate molecular-weight polymers (6.5–11.4 × 104 Da) with co-monomer incorporation being of 6.0 ~ 7.8%. 相似文献
12.
Tanja V. Soldatović Enisa Selimović Nevena Milivojević Milena Jovanović Biljana Šmit 《应用有机金属化学》2020,34(10):e5864
The novel heteronuclear complexes [{cis-PtCl (NH3)(μ-pyrazine)ZnCl (terpy)}](ClO4)2 (Pt-L1-Zn) and [{cis-PtCl (NH3)(μ-4,4′-bipyridyl)ZnCl (terpy)}](ClO4)2 (Pt-L2-Zn) (where terpy = 2,2′:6′,2′′-terpyridine, L1 = pyrazine, L2 = 4,4′-bipyridyl) were synthesized and characterized. The pKa values were determined, and based on them it was established that the π-acceptor ability of the pyrazine bridging ligand is more affective on lower pKa values. The kinetic measurements of the substitution reactions with biologically relevant ligands, such as guanosine-5′-monophosphate (5′-GMP), inosine-5′-monophosphate (5′-IMP) and glutathione (GSH), were studied at pH 7.4. The reactions were followed under pseudo-first-order conditions by UV–Vis spectrophotometry. The order of reactivity of the investigated biomolecules for the first reaction is 5′-GMP > 5′-IMP > GSH, while for the second is 5′-IMP > GSH. Pt-L1-Zn complex is more reactive than Pt-L2-Zn. The cytotoxic activity of heteronuclear Pt-L1-Zn and Pt-L2-Zn complexes was determined on human colorectal cancer cell line (HCT-116) and human breast cancer cell line (MDA-MB-231). Both complexes significantly reduced cell viability on tested cell lines and exerted significant cytotoxic effects, with better effect on HCT-116 cells than cisplatin, especially after 72 hr (IC50 < 0.52 μM). The Pt-L2-Zn complex showed higher activity against human breast cancer cells (MDA-MB-231) than cisplatin after 72 hr. The higher reactivity toward DNA constituent and significant cytotoxic activity may be attributed to the different geometry, Lewis acidity of different metal centers, as well as, to choice of bridging ligands. 相似文献
13.
A string of four new hetero binuclear Ru(III) complexes of ferrocenecarboxaldehyde-4(N)-substituted thiosemicarbazones were synthesized and characterized by various spectral (infrared, ultraviolet–visible, Electron Paramagnetic Resonance (EPR) and High Resolution Mass Spectrometry (HR-MS) techniques. The binding abilities of the ligands/complexes with nucleic acid (calf thymus DNA, CT-DNA) and bovine serum albumin (BSA) were analyzed by absorption and emission titration methods. The complexes exhibited better DNA binding affinity than their parent ligands. The interaction with CT-DNA was found to be intercalative and with BSA static quenching mechanism was observed. All the synthesized Ru(III) complexes were subjected to study their in vitro cytotoxicity against MCF-7 (human breast cancer) and HT-29 (human colon cancer) cell lines. Among the four complexes, complex 3 [RuCp (FF-etsc)PPh3]Cl exhibited the highest cytotoxicity in MCF-7 cells and complex 4 [RuCp (FF-ptsc)PPh3]Cl was the most active on HT-29 cells. 相似文献
14.
Ali El-Dissouky Eslam S. Abu-Elsoud Afaf Abdel Razik Mohamed K. Awad Hammed H.A.M. Hassan Amel F. Elhusseiny 《应用有机金属化学》2020,34(11):e5953
A series of nanometer-sized spherical sulfonamide imine ligands HL 1 -HL 5 and their copper and zinc complexes were synthesized and fully characterized based on elemental analyses, spectroscopic (UV/vis, FT-IR, NMR, EPR, SEM) studies, molar conductance and thermal analyses. Furthermore, computational studies of HL 1 -HL 5 were carried out by the DFT/B3LYP method. TD-DFT, HOMO and LUMO energy values, chemical hardness, electronegativity, electrophilic index, softness, and other parameters were calculated. Screening against several pathogenic microorganisms indicated that HL 1 exhibited high activity against the tested Gram-negative bacteria relative to other analogues and the inhibition activity is greater than the standard Gentamicin. Analogously, HL 2 exhibited high potent activity against the tested Gram-positive bacteria. Copper complexes exhibited a higher potent activity than zinc analogues. Noteworthy, inhibition activity of [Cu ( L 3 )(OAc)] complex is higher than that of the standard Ampicillin. [Cu ( L 2 )(OAc)] complex displayed a similar activity of the standard bactericides and fungicides in use. The complexes showed appreciated values of MIC against bacterial strains: B. subtilis (MIC = 0.4 μg / mL), E. coli and S. pneumonia (MIC = 1.95 μg / mL) and P. aeruginosa (MIC = 7.81 μg / mL). in vitro cytotoxic activities study proved that [Cu ( L 3 )(OAc)] complex exhibited appreciable activity versus (HEPG-2); IC50 = 4.8 μg/ml, while [Cu( L 2 )(OAc)] complex showed a high activity against (MCF-7); IC50 = 6.2 μg/ml. These results could be considered as new findings of promising antitumor candidates for experimental chemotherapy. 相似文献
15.
Florian Molton 《Magnetic resonance in chemistry : MRC》2020,58(8):718-726
Solid-state continuous wave (cw) electronic paramagnetic resonance (EPR) spectroscopy is particularly suitable for metal complex analysis. Extracting magnetic parameters by simulation is often necessary to describe the electronic structure of the studied molecular compounds that can have various electronic spin states and characterized by different parameters like g-values, hyperfine coupling or zero field splitting values. Easyspin toolbox on MATLAB is a powerful tool, but for the user, it requires spending time with coding and could discourage nonexperts. Facing this context, we have developed a graphical user interface called Simultispin, dedicated to solid-state cw-EPR spectra simulation. Some examples of experimental spectra of metal complexes (mixture of low spin and high spin FeIII complexes, dynamic disorder of a CuII complex, photogeneration of a MnIII complex), highlighting specific solid-state functions, are described and analyzed based on simulations performed with Simultispin. We hope that its ergonomy and the ease to set up a complete set of parameters to get reliable simulations could help a large EPR community to improve the efficiency of their interpretations. 相似文献
16.
Dr. Aleksandra Markovic Luca Gerhards Dr. Pia Sander Dr. Carsten Dosche Prof. Dr. Thorsten Klüner Prof. Dr. Rüdiger Beckhaus Prof. Gunther Wittstock 《Chemphyschem》2020,21(22):2506-2514
Multinuclear transition metal complexes bridged by ligands with extended π-electronic systems show a variety of complex electronic transitions and electron transfer reactions. While a systematic understanding of the photochemistry and electrochemistry has been attained for binuclear complexes, much less is known about trinuclear complexes such as hexaphenyl-5,6,11,12,17,18-hexaazatrinaphthylene-tristitanocene [(Cp2Ti)3HATN(Ph)6]. The voltammogram of [(Cp2Ti)3HATN(Ph)6] shows six oxidation and three reduction waves. Solution spectra of [(Cp2Ti)3HATN(Ph)6] and of the electrochemically formed oxidation products show electronic transitions in the UV, visible and the NIR ranges. Density functional theory (DFT) and linear response time-dependent DFT show that the three formally titanium(II) centers transfer an electron to the HATN ligand in the ground state. The optically excited transitions occur exclusively between ligand-centered orbitals. The charged titanium centers only provide an electrostatic frame to the extended π-electronic system. Complete active self-consistent field (CASSCF) calculation on a structurally simplified model compound, which considers the multi-reference character imposed by the three titanium centers, can provide an interpretation of the experimentally observed temperature-dependent magnetic behavior of the different redox states of the title compound in full consistency with the interpretation of the electronic spectra. 相似文献
17.
Steffen Pospiech Dr. Michael Bolte Dr. Hans‐Wolfram Lerner Prof. Dr. Matthias Wagner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8229-8236
9,10‐(Bpin)2‐anthracene ( 3 , HBpin=pinacolborane) was synthesized from 9,10‐dibromoanthracene in a stepwise lithiation/borylation sequence. The reaction of 3 with highly activated magnesium furnished the diborylated magnesium anthracene 4 , which was quenched in situ with ethereal HCl to yield cis‐9,10‐(Bpin)2‐DHA (cis‐ 5 , DHA=9,10‐dihydroanthracene). Compound cis‐ 5 , in turn, can be reduced with Li[AlH4] in THF to give its diborate Li2[cis‐9,10‐(BH3)2‐DHA] (Li2[cis‐ 6 ]). In the crystal lattice, the THF solvate Li2[cis‐ 6 ] ? 3 THF establishes a dimeric structure with Li‐(μ‐H)‐B coordination modes. Hydride abstraction from Li2[cis‐ 6 ] with Me3SiCl yields the B?H?B‐bridged DHA Li[ 7 ]. This product can also be viewed as a unique cyclic B2H7? derivative with a hydrocarbon backbone. Treatment of Li2[cis‐ 6 ] with the stronger hydride abstracting agent Me3SiOTf (HOTf=trifluoromethanesulfonic acid) in THF affords the THF diadduct of cis‐9,10‐(BH(OTf))2‐DHA. 相似文献
18.
A series of chalcone ligands and their corresponding vanadyl complexes of composition [VO (LI–IV)2(H2O)2]SO4 (where LI = 1,3‐Diphenylprop‐2‐en‐1‐one, LII = 3‐(2‐Hydroxy‐phenyl)‐1‐phenyl‐propenone, LIII = 3‐(3‐Nitro‐phenyl)‐1‐phenyl‐propenone, LIV = 3‐(4‐Methoxy‐phenyl)‐1‐phenyl‐propenone) have been synthesized and characterized using various spectroscopic (Fourier‐transform infrared, electrospray ionization mass, nuclear magnetic resonance, electron paramagnetic resonance, thermogravimetric analysis, vibrating sample magnetometer) and physico‐analytic techniques. Antidiabetic activities of synthesized complexes along with chalcones were evaluated by performing in vitro and in silico α‐amylase and α‐glucosidase inhibition studies. The obtained results displayed moderate to significant inhibition activity against both the enzymes by vanadyl chalcone complexes. The most potent complexes were further investigated for the enzyme kinetic studies and displayed the mixed inhibition for both the enzymes. Further, antioxidant activity of vanadyl chalcone complexes was evaluated for their efficiency to release oxidative stress using 2,2‐diphenyl‐1‐picryl‐hydrazyl‐hydrate assay, and two complexes (Complexes 2 and 4 ) have demonstrated remarkable antioxidant activity. All the complexes were found to possess promising antidiabetic and antioxidant potential. 相似文献
19.
Viktoria V. Sursyakova Vladimir A. Levdansky Anatoly I. Rubaylo 《Electrophoresis》2019,40(12-13):1656-1661
The complexation of betulinic and betulonic acids (BIA and BOA) (pentacyclic lupane triterpenoids) with (2‐hydroxypropyl)‐γ‐cyclodextrin (HP‐γ‐CD) was studied at different temperatures using the method combining phase‐solubility technique and CZE. In contrast to mobility shift ACE utilizing the electrophoretic mobility, in this approach, the peak areas are used. The apparent binding (stability, formation) constants are obtained by the Higuchi and Connors method from the linear segment of compound solubility diagrams in CD solutions. It was found that the apparent binding constants of the HP‐γ‐CD complexes of BIA and BOA decrease with increasing temperature. The binding constants of BOA complexes are slightly higher than those of BIA complexes; this can be explained by difference in the hydration degrees of carbonyl and hydroxyl groups. On the basis of the binding constants obtained and their temperature dependences (van't Hoff plot), the enthalpy as well as entropy changes and Gibbs free energies were calculated. It was found that the complexation was characterized by negative changes of enthalpy and entropy, that is, it was controlled by enthalpy changes. The results obtained can be used for the optimization of microcapsulation processes of BOA and BIA with the HP‐γ‐CD application in order to increase solubility and bioavailability of these compounds. 相似文献
20.
New thiazole derivatives were synthesized and fully characterized, then coordinated with PtCl4 salt. Also, the newly synthesized Pt(IV) complexes were investigated analytically (elemental and thermogravimetric analyses), spectrally (infrared, UV–visible, mass, 1H NMR, 13C NMR, X‐ray diffraction) as well as theoretically (kinetics, modeling and docking). The data extracted led to the establishment of the best chemical and structural forms. Octahedral geometry was the only formula proposed for all complexes, which is favorable for d6 systems. The molecular ion peaks from mass spectral analysis coincide with all analytical data, confirming the molecular formula proposed. X‐ray diffraction (XRD) and scanning electron microscopy (SEM) allowed discrimination of features between crystalline particles and other amorphous morphology. By applying Gaussian09 as well as HyperChem 8.2 programs, the best structural forms were obtained, as well as computed significant parameters. Computed parameters such as softness, hardness, surface area and reactivity led us towards application in two opposing pathways: tumor inhibition and oxidation activation. The catalytic oxidation for CO was conducted over PtO2, which was yielded from calcination of the most reactive complex. The success of catalytic role for synthesized PtO2 was due to its particulate size and surface morphology, which were estimated from XRD patterns and SEM images, respectively. The antitumor activity was tested versus HCT‐116 and HepG‐2 cell lines. Mild toxicity was recorded for two of the derivatives and their corresponding complexes. This degree of toxicity is more favorable in most cases, due to exclusion of serious side effects, which is coherently attached with known antitumor drugs. 相似文献