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991.
In this paper, we introduce and study a class of generalized vector quasivariational-like inequality problems, which includes generalized nonlinear vector variational inequality problems, generalized vector variational inequality problems and generalized vector variational-like inequality problems as special cases. We use the maximal element theorem with an escaping sequence to prove the existence results of a solution for generalized vector quasi-variational-like inequalities without any monotonicity conditions in the setting of locally convex topological vector space.  相似文献   
992.
We study the behavior of spiral wave under the driving of a rotating electric field. The rotating electric field can drive a spiral wave to be synchronous, depending on four factors: its frequency and amplitude, chirality, and polarized modes. Rotation-synchronization characterized by the rotating direction is focused on. We discuss the behavior of synchronization, such as the dependence of angle-differences between the spiral tip and the electric field on ratio of frequency, the influences of different polarized modes of the electric field, the radius of synchronous spiral wave, and so on. A circularly polarized electric fields (CPEF) can suppress meandering spiral to rigid one and prevent breakup of spiral in medium with low excitability. The phase diagram describing the controllable region in excitability-period plane is presented. The influences of polarized modes of electric field on minimum excitability of medium are also studied.  相似文献   
993.
Polyaniline(PANI)/LiNi0.5La0.08Fe1.92O4 nanocomposite was synthesized by an in situ polymerization of aniline in the presence of LiNi0.5La0.08Fe1.92O4 nanoparticles. The dielectric properties of a PANI/LiNi0.5La0.08Fe1.92O4 (10 wt% weight ratio of LiNi0.5La0.08Fe1.92O4 to aniline monomer) nanocomposite were investigated in the frequency range of 106–109 Hz. The dielectric constant (?′) and dielectric loss (?″) were frequency dependent, having relatively high values at low frequency and decreasing with increasing frequency. The values of ?′ and ?″ of PANI/LiNi0.5La0.08Fe1.92O4 nanocomposite were found to be lower than those of the pristine PANI. Electric modulus analysis was carried out to understand the electrical relaxation process.  相似文献   
994.
The electron paramagnetic resonance (EPR) parameters (g factors g //, g and hyperfine structure constants A //, A ) for 15MgO-15Na2O-69B2O3 (MNB):Cu2+ ternary glasses were calculated based on the high-order perturbation formulae of 3d9 ion in a tetragonal symmetry. From the calculations, the defect structures of MNB:Cu2+ ternary glasses were obtained and a negative sign for A // and A for the Cu2+ center is suggested in the discussion.  相似文献   
995.
High-temperature emission spectra of LiF:Mg,Cu,P (MCP-N) TL detectors, irradiated above the nominal saturation level, up to the hundreds of kGy, have been measured. Emission spectra integrated over the whole temperature range, as well as the spectra recorded at the temperatures corresponding to the TL peaks maxima, were analyzed. With increasing dose of γ-radiation no significant changes were observed in the short wavelength emission range (220–450 nm) of the measured spectra. For doses of 4 kGy and higher the long wavelength emission (450–800 nm) started to be visible. All recorded spectra have been expressed in a form of the sum of several Gaussian-shape bands in the energy domain, which parameters remain in a general agreement with the measurements of Mandowska et al. (2010). Spectra of the low-temperature, main, high-temperature and “B” TL peaks were investigated. In the ranges of the low-temperature and the main dosimetric peaks, that is 100–125 and 210–230 °C, respectively, the short wavelength emission disappeared with increasing dose and for the highest doses the long wavelength emission became dominant. Both the high-temperature (290–320 °C) and the “B” (370–425 °C) peaks emission spectra exhibited somewhat different behavior with increasing dose. Initially, an even growth of the whole spectrum was observed and for doses higher than 16 kGy the intensity of the spectrum decreased, but the short wavelength emission band fell significantly faster, in case of the high-temperature TL peaks. In case of the “B” peak emission spectra the long wavelength emission did not play any role in the analyzed dose range. The spectra measured at the TL peaks maxima were also fitted with several Gaussian-shape bands. Dose-intensity dependences for all Gaussian-shape bands fitted to the measured spectra are also included in this paper.  相似文献   
996.
When an electron is scattered by a tightly focused laser beam in vacuum, the intensity gradient is a critical factor to influence the electron dynamics. In this paper, we have further investigated its influence upon the electron high-harmonic generation (HHG) by treating the spacial gradient of the laser intensity as a ponderomotive potential. Based upon perturbative quantum electrodynamics calculations, it has been found that the main effect of the intensity gradient is the broadening of the originally line HHG spectra. A one-to-one relationship can be built between the beam width and the corresponding line width. Hence, this finding may provide us a promising way to measure the beam width of intense lasers in experiments. In addition, for a laser pulse, we have also studied the different influences from transverse and longitudinal intensity gradients upon HHG.  相似文献   
997.
采用提拉法在硅基底上制备了多孔溶胶凝胶SiO2膜,用椭偏法测量薄膜的厚度与折射率,考察了提拉速度和胶体浓度对膜层厚度与折射率的影响。对厚度与提拉速度的关系进行线性与幂函数拟合,并比较分析两种拟合的关系及其对工艺流程的作用。比较了不同浓度胶体所得到的同一厚度薄膜的折射率变化规律。结果表明:对于同一胶体浓度下薄膜厚度与提拉速度的正相关关系,线性拟合相比幂函数拟合可以更好地解释实验结果的规律性。同时,折射率在一定范围内也会随着提拉速度的增加而减小。镀同一厚度膜时,浓度大的胶体膜层折射率大。通过对提拉速度和胶体浓度的控制可以得到理想的薄膜厚度与折射率。  相似文献   
998.
利用环糊精类物质能够形成超分子包合物的性质,研究了电中性的β-环糊精(β-CD)和负电性的羧甲基-β-环糊精(CM-β-CD)与电化学发光(ECL)活性物质三联吡啶钌(Ru(bpy)32+)形成超分子包合物的能力及其对ECL的增强作用。结果表明:形成的超分子包合物能够增强Ru(bpy)32+的ECL,其中CM-β-CD具有更强的增强作用。相对于Ru(bpy)32+,CM-β-CD增强了1.42倍,而β-CD仅为1.28倍。以制备的表面电荷为负的SiO2纳米粒为载体,考察了其对Ru(bpy)32+超分子包合物的吸附能力。结果表明,与Ru(bpy)32+的CM-β-CD超分子包合物相比,SiO2纳米粒载体对Ru(bpy)32+的β-CD 超分子包合物表现出了更强的吸附能力。制备了ECL信号放大能力最强的β-CD-Ru(bpy)32+超分子包合物的SiO2复合纳米粒。  相似文献   
999.
The reduced graphene oxide (rGO) incorporated ZnO thin films were fabricated by dip-coating method. The Raman and FT-IR spectra of 0.075 wt% incorporated composite film showed reduction of GO in composite film. The transmittanceProd. Type: FTP spectra have shown that rGO incorporation increase the visible light absorption of ZnO thin film while the calculated band gaps of samples were decreased from 3.28 to 3.25 eV by increasing the rGO content. The linear trend of IV curve suggests an ohmic contact between ZnO and rGO. Besides, it was found that by increasing the rGO content, the electrical resistivity was decreased from 4.32×102 Ω cm for pure ZnO film to 2.4×101 Ω cm for 0.225 wt% rGO incorporated composite film. The composite photodetectors not only possessed a desirable UV photosensitivity, but also the response time of optimum sample containing 0.075 wt% rGO was reduced to about one-half of pure ZnO thin film. Also, the calculated signal to noise (SNR) showed that highly conductive rGO in composite thin films facilitate the carrier transportation by removing the trapping centers. The mechanism of photoresponsivity improvement of composite thin films was proposed by carrier transportation process.  相似文献   
1000.
何代平  丁云杰 《催化学报》2005,26(11):961-964
 采用H2和CO吸附、FT-IR和TPR等表征手段对不同Pd含量的Pd-K/MnOx-ZrO2催化剂进行了研究,并考察了其对CO加氢制甲醇和异丁醇反应的催化性能. 结果表明, Pd的加入促进了锰的还原和氧空位的生成,有利于异丁醇的生成; Pd的加入改变了催化剂表面的吸附行为. Pd-K/MnOx-ZrO2催化剂表面有较高的H2和CO吸附量,有利于甲醇与异丁醇合成速率的提高. 当Pd的添加量超过1.5%时, Pd的分散度降低,粒径变大,致使甲醇与异丁醇的合成速率降低.  相似文献   
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