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991.
Sami Ullah Humbul Suleman Muhammad Suleman Tahir Muhammad Sagir Shabbir Muhammad Abdullah G. Al-Sehemi Masood-ur-Rauf Zafar Firas A. Abdul Kareem Abdulhalim Shah Maulud Mohamad Azmi Bustam 《国际化学动力学杂志》2019,51(4):291-298
In this study, a new pressure drop method has been used to investigate the kinetics of carbon dioxide reaction with aqueous blend of 2-amino-2-ethyl-1,3-propanediol (AEPD) with piperazine (PZ). The blending of a small amount of PZ with AEPD has a significant effect on the observed rate constant, kobs. It was observed that kobs values of the blend increased more than twice than the summation of kobs values of individual alkanolamines. The reaction kinetics in this study were modeled by assuming a termolecular mechanism. The addition of 0.1 mol/L of PZ to 1 mol/L AEPD exhibited an observed rate constant, kobs of 8824.1 s−1, which is comparable to other alkanolamine mixtures. Hence, PZ/AEPD mixtures can be potentially used for rapid carbon dioxide capture. 相似文献
992.
Yong Wang Katerina Szokolova Dr. Muhammad Zafir Mohamad Nasir Prof. Zdenek Sofer Prof. Martin Pumera 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(30):7330-7338
Group 6 transition metal dichalcogenides (TMDs), such as MoS2 and WS2 have been extensively studied for various applications while few studies have delved into other TMDs such as platinum dichalcogenides. In this work, layered crystalline and amorphous platinum disulfide (PtS2) were synthesized, characterised and their fundamental electrochemical properties were investigated. Both materials exhibited inherent oxidation and reduction reactions which would limit their operating potential window for sensing applications. Amorphous phase materials are considered to be promising electrocatalysts due to the porous, and nanostructured morphology with high concentration of unsaturated active sites. The electrocatalytic performances towards oxygen reduction (ORR) and hydrogen evolution reactions (HER) of crystalline and amorphous PtS2 were analysed. Amorphous PtS2 was found to exhibit superior electrocatalytic performances towards ORR and HER as compared to crystalline PtS2. For HER, amorphous and crystalline PtS2 have overpotential values of 0.30 V and 0.70 V (vs. RHE) at current density of 10 mA cm−2, respectively. The influence of electrochemical reduction pre-treatment on their catalytic behaviours was also investigated. Electrochemical reduction pre-treatment on both crystalline and amorphous PtS2 removed the oxidized sulfate groups and increased the proportion of Pt0 oxidation state which exposed more catalytic sites. As such, these materials were activated and displayed improved ORR and HER performances. Electrochemically reduced amorphous PtS2 outperformed the untreated counterparts and exhibited the best HER performance with overpotential of 0.17 V (vs. RHE) at current density of −10 mA cm−2. These findings provide insights into the electrochemical properties of noble metal PtS2 in both crystalline and amorphous states which can be activated by electrochemical reduction pre-treatment. 相似文献
993.
Chaudhary Muhammad Zaman Ahmad Nasir Mashiatullah Azhar Yaqoob Nadeem Um-e-Robab 《Journal of Radioanalytical and Nuclear Chemistry》2021,328(2):605-615
Journal of Radioanalytical and Nuclear Chemistry - This paper describes the pollution level in sediment core collected from Sunairi Point of Karachi coastal area Pakistan. The sediment was... 相似文献
994.
Hüseyin Budak Samet Erden Muhammad Aamir Ali 《Mathematical Methods in the Applied Sciences》2021,44(1):378-390
We first establish two new identities, based on the kernel functions with either two section or three sections, involving quantum integrals by using new definition of quantum derivative. Then, some new inequalities related to Simpson's 1/3 formula for convex mappings are provided. In addition, Newton type inequalities, for functions whose quantum derivatives in modulus or their powers are convex, are deduced. We also mention that the results in this work generalize inequalities given in earlier study. 相似文献
995.
Mohamad Riduwan Ramli Muhammad Bisyrul Hafi Othman Azlan ArifinZulkifli Ahmad 《Polymer Degradation and Stability》2011,96(12):2064-2070
A series of highly cross-linked polysiloxane was synthesised via hydrosilylation and condensation reaction. Structural identification using Fourier Transform Infrared (FTIR) and 1H-NMR confirmed their chemical structures. Their thermal and, mechanical properties, and crystallinity, were analysed and related to the level of cross-link density. These systems displayed elevated thermal and hardness properties at an increased cross-link density. Furthermore, the level of crystallinity was reduced as displayed by XRD analysis. Along with this observation, the calculated fractional free volume (FFV) showed a decreasing trend leading to the ‘densification’ effect. It was envisaged that the linear polysiloxane chain segments aligned parallel to each other in a triclinic crystal system to generate a crystalline domain. The spacing between these stacking chains was found to be about 7.2 Å as measured from simulated XRD pattern. 相似文献
996.
Russian Journal of Electrochemistry - Iron oxide nanoparticles (IONPs) were green synthesized using an aqueous leaves extract of Christ’s thorn jujube and were characterized by TGA, FTIR,... 相似文献
997.
Robert Malmberg Dr. Tobias von Arx Monirul Hasan Dr. Olivier Blacque Atul Shukla Dr. Sarah K. M. McGregor Prof. Shih-Chun Lo Prof. Ebinazar B. Namdas Prof. Koushik Venkatesan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(25):7265-7274
N-Heterocyclic carbene (NHC) cyclometalated gold(III) complexes remain very scarce and therefore their photophysical properties remain currently underexplored. Moreover, gold(III) complexes emitting in the blue region of the electromagnetic spectrum are rare. In this work, a series of four phosphorescent gold(III) complexes was investigated bearing four different NHC monocyclometalated (C^C*)-type ligands and a dianionic (N^N)-type ancillary ligand ((N^N)=5,5’-(propane-2,2-diyl)bis(3-(trifluoromethyl)-1 H-pyrazole) (mepzH2)). The complexes exhibit strong phosphorescence when doped in poly(methyl methacrylate) (PMMA) at room temperature, which were systematically tuned from sky-blue [λPL=456 nm, CIE coordinates: (0.20, 034)] to green [λPL=516 nm, CIE coordinates: (0.31, 0.54)] by varying the monocyclometalated (C^C*) ligand framework. The complexes revealed high quantum efficiencies (ϕPL) of up to 43 % and excited-state lifetimes (τ0) between 15–266 μs. The radiative rate constant values found for these complexes (kr=103–104 s−1) are the highest found in comparison to previously known best-performing monocyclometalated gold(III) complexes. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations of these complexes further lend support to the excited-state nature of these complexes. The calculations showed a significant contribution of the gold(III) metal center in the lowest unoccupied molecular orbitals (LUMOs) of up to 18 %, which was found to be unique for this class of cyclometalated gold(III) complexes. Additionally, organic light-emitting diodes (OLEDs) were fabricated by using a solution process to provide the first insight into the electroluminescent (EL) properties of this new class of gold(III) complexes. 相似文献
998.
Mahrous Sara S. Galil E. A. Abdel Mansy Muhammad S. 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):985-997
Journal of Radioanalytical and Nuclear Chemistry - Eco-friendly and cost-effective adsorbent material was successfully synthesized from orange peel (OP). Using H2O2, the modification of the... 相似文献
999.
Excess molar enthalpies, measured at the temperature 298.15 K and atmospheric pressure conditions by means of a flow microcalorimeter, are reported for the ternary mixtures {x1(dibutyl ether or dipropyl ether) + x2 2,2-dimethylbutane + (1 ? x1 ? x2) 2,3-dimethylbutane}. A smooth representation of the results is described and the constant-enthalpy contours for each ternary system are displayed on the respective Roozeboom diagrams. The results serve to show that good estimates of the excess molar enthalpies of the ternary systems can be obtained from the Liebermann–Fried model by using the physical properties of the constituent pure components and the parameters determined from the binary mixtures of these components. 相似文献
1000.