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981.
Jin Ni Qiuye Wu Yuguo Li Zhixin Guo Gusheng Tang Ding Sun Fu Gao Jianming Cai 《Journal of nanoparticle research》2008,10(4):643-651
There is growing evidence in recent years that the pristine fullerene may be endowed with strong pro-oxidant capacity to biological
samples. In this investigation we tested the hypothesis that water-soluble fullerene-C60 (nano-C60) may interact with ionizing radiation enhancing its antiproliferative effects. The two tumor cell lines with different radiosensitivity
B16 and SMMU-7721 were treated by a combination of pristine fullerene and 60Co γ irradiation. We measured cell survival rates, apoptotic characteristics, reactive oxygen species (ROS) production and
alteration of cell diameter with or without γ-irradiation. There was reduced survival with B16 and SMMU-7721 cells exposed
to nano-C60, with the inhibitory concentrations reducing the viability by 50% to 65 part per billion (ppb) and 150 ppb respectively.
For cells exposed to nano-C60 prior to γ-irradiation, damage to cell membranes and increased numbers of apoptotic cells were detected by morphologic Hoechst-staining
analysis and Annexin V/propidium iodide double-staining. In cells exposed to nano-C60, there were increased levels of ROS, as measured by fluorescence detection under laser confocal microscopy. Preincubation
with non-toxic pristine C60 before γ-ray caused enlargement of cells with increased diameter. The results show that nano-C60 inhibits the growth of tumor cells at certain concentrations and increases the effects of 60Co γ-irradiation, possibly through the elevated production of cellular ROS and the membrane disruption. Data in this study
indicates a possible consideration of using C60 as a candidate of sensitization modifier in tumor radiation biology. 相似文献
982.
We have evaporated Co on the pentagonal surface of an icosahedral Al-Pd-Mn quasicrystal kept at room temperature. For submonolayer Co deposits, five AlCo domains are formed exposing their (1 1 0) faces parallel to the surface and rotated by 72° with respect to each other. The orientational relationship between these domains and the substrate is determined by the optimum matching of the average quasicrystal structure and the CsCl structure with a lattice constant of about 2.88 Å. For further deposition, body-centred cubic Co domains grow epitaxially on the AlCo domains. 相似文献
983.
984.
Xiao-Yong Zhang Xue-Lin Ma Jun-Fang Gao Mei-Rong Wang Yu-Heng Zhang Sheng-Li Yong 《印度化学会志》2022,99(4):100394
A novel complex [Co(NO3)2(APTY)2H2O] (1) is synthesized based on 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one) antipyrine (APTY) and the structure of complex (1) is characterized via PXRD, SEM, FTIR and X-ray single crystal diffraction technique. It is found that the complex (1) has a good response to Fe3+ ion with colorimetric yellow change. In addition, we demonstrate that the sensing mechanism of complex (1) could is due to the disruption of complex (1) framework and the formation of complex Fe-APTY. The stability, rapid response and low detection limit enable this complex (1) to be a good Fe3+ ion chemical sensor for biological and environmental sensing applications. 相似文献
985.
《Acta Crystallographica. Section C, Structural Chemistry》2017,73(4):331-336
To investigate the influence of P/As substitution on structures and electrical properties, e.g. the effect on material densities, two new solid P/As‐doped solutions, Na2CoP1.60As0.40O7 (disodium cobalt diphosphorus arsenic heptaoxide) and Na2CoP1.07As0.93O7 (disodium cobalt phosphorus arsenic heptaoxide), with melilite‐like structures have been synthesized by solid‐state reactions. Their unit‐cell parameters are in agreement with Vegard's law. The obtained structural models were investigated by the bond valence sum (BVS) and charge distribution (CHARDI) validation tools and, for the latter, the structures are described as being built on anion‐centred polyhedra. The frameworks can be described as layered and formed by {[Co(P,As)2O7]2−}∞ slabs, with alkali cations sandwiched between the layers and with the interlayer spaces increased due to P/As substitution. The BVS model was extended to a preliminary simulation of the sodium conduction properties in the studied structural type and suggests that the most probable sodium conduction pathways are bidimensional, at the (002) planes. 相似文献
986.
Development of Pt-based oxygen reduction reaction catalysts with high efficiency and high durability is central to the application of proton-exchange membrane fuel cell systems. Pt–Co bimetallic catalysts have drawn extensive attention owing to their capability of delivering high performance and long lifetime for fuel cell applications including light-duty and heavy-duty vehicles. However, further improvements in durability and performance are needed to meet market requirements. To fully exploit the potential of Pt–Co catalysts, new insights into the relationship between catalyst properties and fuel cell performance and durability are needed, and more effective methods to tailor the features of Pt–Co catalysts need to be developed. This review provides a summary and perspective on recent efforts, including work on customizing the Pt shell and Pt:Co ratio, tailoring the crystal structure, and improving carbon support properties, with a particular emphasis on mechanisms leading to enhancement of mass activity, power density, and durability in membrane electrode assembly testing. 相似文献
987.
988.
W. Aslam Farooq Muhammad Sajjad Ul Hasan Muhammad Iftikhar Khan Ahmad Raza Ashraf Muhammad Abdul Qayyum Nafeesah Yaqub Mona A. Almutairi Muhammad Atif Atif Hanif 《Molecules (Basel, Switzerland)》2021,26(5)
A series of cobalt-inserted copper zinc ferrites, Cu0.6CoxZn0.4−xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) having cubic spinel structure were prepared by the coprecipitation method. Various characterization techniques, including XRD, FTIR, UV-vis and I–V were used to investigate structural optical and electrical properties, respectively. The lattice constant was observed to be decreased as smaller ionic radii Co2+ (0.74 Å) replaced the higher ionic radii Zn2+ (0.82 Å). The presence of tetrahedral and octahedral bands was confirmed by FTIR spectra. Optical bandgap energy was determined in the range of 4.44–2.05 eV for x = 0.0 to 0.4 nanoferrites, respectively. DC electrical resistivity was measured and showed an increasing trend (5.42 × 108 to 6.48 × 108 Ω·cm) with the addition of cobalt contents as cobalt is more conductive than zinc. The range of DC electrical resistivity (108 ohm-cm) makes these nanomaterials potential candidates for telecommunication devices. 相似文献
989.
Brajagopal Samanta Joy Chakraborty R.K. Bhubon Singh Manas K. Saha Stuart R. Batten Paul Jensen M. Salah El. Fallah Samiran Mitra 《Polyhedron》2007
Two new cyano bridged Cu–Co and Cu–Fe trinuclear bimetallic assemblies, [(CuL)[Co(CN)6](CuL)]ClO4 · 3.5H2O (1) and [(CuL)[Fe(CN)6](CuL)] · 13H2O (2) where [L = (3E,5E)-N1,N4-bis((pyridin-2-yl)methylene)butane-1,4-diamine] have been prepared using cyanometallates as anion precursors and characterised by elemental analyses, spectroscopic studies, single crystal X-ray diffraction and cryomagnetic susceptibility measurements. Magneto-structural correlations have been drawn from cryomagnetic susceptibility measurements over a wide temperature range (2–300 K) under 0.5 T magnetic fields. Weak antiferromagnetic interactions with J = −0.81 and −0.73 cm−1 are found for 1 and 2, respectively, showing a very weak coupling, as expected from the diamagnetic long chain –NC–Co–CN–CN– and –NC–Fe–CN–CN– bridges revealed from the single crystal X-ray diffraction studies. 相似文献
990.