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991.
Shweta J. Malode Prabhu K. Keerthi Nagaraj P. Shetti Raviraj M. Kulkarni 《Electroanalysis》2020,32(7):1590-1599
The present research involves the report on electrochemical deportment of Carbendazim (MBC) at multiwalled carbon nanotubes and calcium‐doped zinc oxide nanoparticles altered nanocomposite based carbon paste electrode (MWCNTs/Ca‐ZnO‐CPE). The modified carbon paste evidenced manifest electrocatalytic behavior for MBC in 0.2 M phosphate buffer (PB) solutions. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), and square wave voltammetry (SWV) techniques were used for the analysis. The working electrode assembly exhibits faster electron transfer of MBC with increase in the peak current. At bare CPE, MBC showed maximum peak current of 1.098 μA at potential 0.7568 V whereas at MWCNT/Ca‐ZnO/CPE peak current of 5.203 μA was observed at potential 0.7541 V in 0.2 M PBS of pH 7.0 at the sweep rate of 50 mV s?1. The synthesized 5 % Ca‐ZnO nanoparticles (NPs) were characterized by X‐ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X‐ray analysis (EDX), and Transmission electron microscopy (TEM) analysis. Various factors influencing the voltammetry of MBC such as pre‐concentration time, pH, sweep rate, and amount of MBC were studied and from the studies we observed that the response was found to be diffusion‐controlled. The concentration variation studies for MBC was watched in the linear working range of 0.01 μM to 0.45 μM and the detection limit was found by SWV technique. 相似文献
992.
A robust microwave-assisted acid digestion procedure followed by inductively coupled plasma-mass spectrometry (ICP-MS) was developed to quantify rare earth elements (REEs) in fluidized-bed catalytic cracking (FCC) catalysts and atmospheric fine particulate matter (PM2.5). High temperature (200 °C), high pressure (200 psig), acid digestion (HNO3, HF and H3BO3) with 20 min dwell time effectively solubilized REEs from six fresh catalysts, a spent catalyst and PM2.5. This method was also employed to measure 27 non-REEs including Na, Mg, Al, Si, K, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Zr, Mo, Cd, Cs, Ba, Pb and U. Complete extraction of several REEs (Y, La, Ce, Pr, Nd, Tb, Dy and Er) required HF indicating that they were closely associated with the aluminosilicate structure of the zeolite FCC catalysts. Internal standardization using 115In quantitatively corrected non-spectral interferences in the catalyst digestate matrix. Inter-laboratory comparison using ICP-optical emission spectroscopy (ICP-OES) and instrumental neutron activation analysis (INAA) demonstrated the applicability of the newly developed analytical method for accurate analysis of REEs in FCC catalysts. The method developed for FCC catalysts was also successfully implemented to measure trace to ultra-trace concentrations of La, Ce, Pr, Nd, Sm, Gd, Eu and Dy in ambient PM2.5 in an industrial area of Houston, TX. 相似文献
993.
Sol-gel immobilized short-chain poly(ethylene glycol) coating for capillary microextraction of underivatized polar analytes 总被引:1,自引:0,他引:1
Sol-gel coating with covalently bonded low-molecular-weight (MW<300 Da) poly(ethylene glycol) (PEG) chains was developed for capillary microextraction (CME). The sol-gel chemistry proved effective in the immobilization of low-molecular-weight PEGs thanks to the formation of chemical bonds between the organic-inorganic hybrid sol-gel PEG coating and the fused silica capillary inner surface. This chemical anchorage provided excellent thermal and solvent stability to the created sol-gel PEG coating as is evidenced by its high upper limit of allowable conditioning temperature (340 degrees C) and its practically identical performance before and after rinsing with various solvents. The prepared sol-gel PEG coating provided simultaneous extraction of moderately polar and highly polar analytes from aqueous samples without requiring derivatization, pH adjustment or salting-out procedures. Detection limits on the order of nanogram per liter (ng/L) were achieved in CME-GC-flame ionization detection experiments designed for the preconcentration and trace analysis of both highly polar and moderately polar compounds extracted directly from aqueous media using sol-gel short-chain PEG coated microextraction capillaries. 相似文献
994.
Heat transfer rates from a surface can be determined from the slope of the temperature profile measured with a thermocouple
wire traversing within a boundary layer. However, accuracy of such measurement can suffer due to flow distortion and conduction
through the thermocouple wire. The present numerical study consists of two parts—a 2D simulation of flow distortion due to
a cylinder in cross flow near a solid wall and a 3D simulation defined as a fin problem to calculate the thermal profile measurement
error due to conduction through the thermocouple wires. Results show that the measured temperature is lower than the true
temperature resulting in a 5% under-prediction of local heat transfer coefficient. A parametric study shows that low thermal
conductivity thermocouple (E type) with a small wire diameter (76 micron) is desirable to reduce the measurement error in
local Nusselt number. 相似文献
995.
Kamath A Kulkarni NV Netalkar PP Revankar VK 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1418-1424
Phenoxide bridged later first row transition metal(II) complexes have been prepared by the interaction of later 3d transition metal(II) chlorides with tetranucleating compartmental Schiff base ligand system derived from 2,6-diformyl-4-methylphenol, p-phenylenediamine and 2-hydrazinobenzothiazole. Ligand and complexes were characterized by analytical, spectral (IR, UV-visible, ESR, FAB-mass and fluorescence), magnetic and thermal studies. All complexes are found to have octahedral geometry. The mutual influence of metal centres in terms of cooperative effect on the electronic, magnetic, electrochemical and structural properties was investigated. The Schiff base and its complexes have been screened for their antibacterial (against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa) and antifungal activities (against Aspergillus niger, and Candida albicans). 相似文献
996.
Sabine Kraml Suchita Kulkarni Ursula Laa Andre Lessa Wolfgang Magerl Doris Proschofsky-Spindler Wolfgang Waltenberger 《The European Physical Journal C - Particles and Fields》2014,74(5):1-23
We present a general procedure to decompose Beyond the Standard Model (BSM) collider signatures presenting a $\mathbb {Z}_2$ symmetry into Simplified Model Spectrum (SMS) topologies. Our method provides a way to cast BSM predictions for the LHC in a model independent framework, which can be directly confronted with the relevant experimental constraints. Our concrete implementation currently focusses on supersymmetry searches with missing energy, for which a large variety of SMS results from ATLAS and CMS are available. As show-case examples we apply our procedure to two scans of the minimal supersymmetric standard model. We discuss how the SMS limits constrain various particle masses and which regions of parameter space remain unchallenged by the current SMS interpretations of the LHC results. 相似文献
997.
Felix Brümmer Sabine Kraml Suchita Kulkarni Christopher Smith 《The European Physical Journal C - Particles and Fields》2014,74(9):1-12
We study the screening effect for the multiparton interactions (MPI) for proton–deuteron collisions in the kinematics where one parton belonging to the deuteron has small \(x_1\) , so the leading twist shadowing is present, while the second parton ( \(x_2\) ) is involved in the interaction in the kinematics where shadowing effects are small. We find that the ratio of the shadowing and the impulse approximation terms is approximately a factor of 2 larger for MPI than for the single parton distributions. We also calculate the double parton antishadowing (DPA) contribution to the cross section due to the independent interactions of the partons of the projectile proton with two nucleons of the deuteron and find that shadowing leads to a strong reduction of the DPA effect. For example, for the resolution scale \(Q_1^2 \sim 4\) \(\text{ GeV }^2\) of the interaction with parton \(x_1\) we find that shadowing reduces the DPA effect by \(\sim \) 30 %. It is argued that in the discussed kinematics the contribution of the interference diagrams, which correspond to the interchange of partons between the proton and neutron, constitutes only a small correction to the shadowing contributions. 相似文献
998.
999.
1R-cis-2,2-Dimethyl-3-(2,2-dibromovinyl)cyclopropane carboxylic acid1 (1), the acid moiety of the highly potent photostable pyrethroid deltamethrin (2) has been obtained either by a Wittig reaction on 1R-cis-caronaldehyde ester (3) employing 1, 1-dibromomethylenetriphenylphosphorane or from the bicyclic tribromo-lactone2,3 (4) by reaction with zinc and acetic acid. Lactone (4) is thus an important intermediate in the deltamethrin synthesis. 相似文献
1000.
The liquid phase acylation of primary and secondary alcohols were carried out with acetic acid in the presence of zeolites. LaY zeolite is found to be the best catalyst. 相似文献