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411.
Two atmospheric-pressure plasma sources were studied. One was a helium plasma generated by a RF discharge, and the other was
an air plasma generated by a dielectric barrier discharge (DBD). The two plasma sources were characterized on electron density,
emission spectrum, and ozone density. The modification of polyethyleneterephthalate (PET) surfaces by the two plasmas was
investigated. PET strips were exposed to the plasma at the exit of the plasma source. Water contact angles were measured for
surfaces modified with different processing parameters. The change in contact angles was monitored as a function of time.
Modification mechanisms were also investigated. 相似文献
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本文评述毛细管区带电泳中蛋白质的吸附及解决办法,内容包括吸附的原因,通过缓冲溶液组成的变化、通过毛细管内壁改性、通过附加电场等方法降低吸附。对毛细管内壁电荷密度等方法降低吸附。尤其对毛细管内壁改性方法,改性对电渗流及分离效率的影响,改性的稳定性和重复性等进行了较为详细的阐述。 相似文献
417.
YU Jin-gang HUANG Ke-long HONG Yong HUANG Du-shu 《高等学校化学研究》2007,23(5):505-507
Multiple-walled carbon nanotubes were functionalized by cycloaddition of dichlorocarbene.The chemical modification was performed by using chloroform and sodium hydroxide.Various phase transfer catalysts were used to increase the efficiency of the reaction.Benzyltriethylammonium chloride used as phase transfer catalyst could highly enhance the effect of functionalization.Elemental analysis was used to evaluate the degree of functionalization.Characterization was performed using scanning electron microscopy(SEM)and transmission electron microscopy(TEM).Fourier transform infrared spectroscopy(FTIR)and energy-dispersive X-ray spectroscopy(EDS)were used to confirm the resulting material. 相似文献
418.
Fe3O4 was obtained by reacting FeCl2 and FeCl3 with polyethylene glycol, and labeled onto a amphiphilic Janus nanosheet. It was confirmed by infrared spectroscopy, SEM, AFM and EDS that the Fe3O4 nanoparticles changed from hydrophilic to amphiphilic. The oxidative desulfurization performance of amphiphilic iron oxide was studied. Results showed that the Janus nanosheets labeled with Fe3O4 could significantly improve the removal rate of thiophene sulfide in simulated oil synergistically with ultrasonic waves, and the desulfurization rate could reach 100%. Further, the effect of ultrasound on the sensing ability of the oil–water interface was studied and the ultrasonic attenuation coefficient was calculated. In addition to the desulfurization mechanism of Fe3O4, it was found that although the ultrasonic attenuation coefficient of the amphiphilic nanosheets was high, the number of hydroxyl radicals determined the desulfurization efficiency. The amphiphilic Fe ions were more favorable for the formation of hydroxyl radicals than the single hydrophilic ones. 相似文献
419.
A one-pot two-step method based on direct melt polymerization (DMP) for the synthesis of polylactic acid (PLA) macromonomer and its further functionalized application has been developed. The first stage of the reaction is a copolycondensation of lactic acid (LA) and maleic anhydride (MAH) to obtain the macromolecule poly(lactic acid-co-maleic anhydride) (PLAM) with reactive double bonds, and the second stage is a radical copolymerization of different acrylates with PLAM to afford the modified PLA functional materials. The influences of the acrylates have been investigated. The results show that the species with substituted methyl groups in acrylate can polymerize relatively stable. On the other hand, the more carbon atoms in the ester segment of acrylate, the higher intrinsic viscosity [η] and terminal decomposition temperature for the acrylate-modified PLAMs. Among six kinds of acrylates used as the third monomer, such as acrylic acid (AA), methyl acrylate (MA), butyl acrylate (BA), methacrylic acid (MAA), methyl methacrylate (MMA), and butyl methacrylate (BMA), the BMA-modified PLAM has the biggest [η] (0.7566 dL/g) and the terminal decomposition temperature (418 °C) for there are more carbon atoms in BMA. Due to excellent reactivity of the intermediate PLAM, the final modified product can have the anticipated properties for the PLA material by the controllable regulating as different purposes. Thus, this strategy as a green and simple method provides well application prospect for PLA materials in industrial plastics, biomedicine etc. 相似文献
420.
《Discrete Mathematics》2022,345(2):112688
A regular Kähler graph is a compound of two regular graphs. When adjacency operators of component graphs are commutative, we introduce equivalence relations on sets of primitive bicolored paths, which are considered as sets of trajectory-segments of magnetic fields on this Kähler graph, we study their zeta functions of Ihara type, and show a correspondence to those for ordinary regular graphs. 相似文献