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561.
合成了乙烯基咪唑碘盐(VImI)和聚乙二醇单甲醚甲基丙烯酸酯(PEGMA)的梳状共聚物.利用VImI/PEGMA共聚物制备了准固态聚合物电解质.通过光电流密度-电压(J-V)曲线和电导率测定以及电化学阻抗分析,探讨了基于此电解质的染料敏化太阳能电池的电荷传输与界面电子转移机制.结果表明,VImI/PEGMA共聚物可以有效抑制TiO2/电解质界面电子复合并提高TiO2导带能级,敏化电池的光伏性能并不完全取决于电解质的电导率.通过考察共聚物中VImI与PEGMA单元的摩尔比与开路电压的关系,发现共聚物对电子复合的抑制作用主要源于VImI链段.此外,开路电压衰减(OCVD)和瞬态光电流测试结果说明,共聚物能够提高TiO2薄膜的电子寿命,而且对陷阱电子能级的分布具有调节作用.当共聚物在电解质中的质量分数为50%,VImI与PEGMA的摩尔比为5.0时,准固态染料敏化太阳能电池于100mW·cm-2光强下获得了4.10%的光电转换效率.  相似文献   
562.
The decomposition products of the d6‐ethane cation following charge‐transfer ionization with Ar+, under conditions of varying ionization electron current, have been isolated in solid argon matrices at 18 K and examined using Fourier transform infrared spectroscopy. Gas samples containing 1 : 1600 d6‐ethane : Ar were subjected to electron bombardment by using either a high (pin) or a low (plate) ionization density anode configuration with ionization currents between 20 and 150 μA. Under high ionization density conditions, the observed major products were d4‐ethene (C2D4) and d2‐acetylene (C2D2), with smaller yields of C2D5, C2D3, and C2D. The yield of each dehydrogenation product was enhanced with increased current. Analogous experiments employing the low ionization density plate anode resulted in reduced C2D6 destruction and the formation of only C2D4 and C2D2. The results suggest the onset of dissociative recombination processes under high ion density conditions. In this context, the results can be interpreted as a dissociative recombination of primary ion products, which gives rise to further dehydrogenation, and appearance of additional neutral radical products. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
563.
InGaN/GaN epilayers,which are grown on sapphire substrates by the metal-organic chemical-vapour deposition(MOCVD) method,are formed into nanorod arrays using inductively coupled plasma etching via self-assembled Ni nanomasks.The formation of nanorod arrays eliminates the tilt of the InGaN(0002) crystallographic plane with respect to its GaN bulk layer.Photoluminescence results show an apparent S-shaped dependence on temperature.The light extraction efficiency and intensity of photoluminescence emission at low temperature of less than 30 K for the nanorod arrays are enhanced by the large surface area,which increases the quenching effect because of the high density of surface states for the temperature above 30 K.Additionally,a red-shift for the InGaN/GaN nanorod arrays is observed due to the strain relaxation,which is confirmed by reciprocal space mapping measurements.  相似文献   
564.
InGaN/GaN epilayers,which are grown on sapphire substrates by the metal-organic chemical-vapour deposition(MOCVD) method,are formed into nanorod arrays using inductively coupled plasma etching via self-assembled Ni nanomasks.The formation of nanorod arrays eliminates the tilt of the InGaN(0002) crystallographic plane with respect to its GaN bulk layer.Photoluminescence results show an apparent S-shaped dependence on temperature.The light extraction efficiency and intensity of photoluminescence emission at low temperature of less than 30 K for the nanorod arrays are enhanced by the large surface area,which increases the quenching effect because of the high density of surface states for the temperature above 30 K.Additionally,a red-shift for the InGaN/GaN nanorod arrays is observed due to the strain relaxation,which is confirmed by reciprocal space mapping measurements.  相似文献   
565.
孟腾飞  何志群  刘姝  刘淑洁  梁春军  张娇 《发光学报》2012,33(10):1095-1100
制备并研究了基于3种小分子荧光材料的白光有机电致发光器件。发光层采用红色发光材料DCJTB掺杂绿光材料Alq3构成混合发光层,与OXD-7构成的蓝色发光层形成异质结的结构,并以NPB为空穴注入层。通过改变结构参数详细研究了发射光谱及其色坐标的电场依赖性。通过分析载流子注入/传输特性,控制激子的复合区域等措施得到了色坐标稳定性好、光谱丰富的高性能白光电致发光器件。经过优化的器件结构可以覆盖更大的可见光区域,当电压从9 V增加到13 V时,色坐标仅从CIE(x,y)=(0.364,0.314)偏移到CIE(x,y)=(0.332,0.291),具有较好的色稳定性。  相似文献   
566.
针对超高声速流动中的高温真实气体效应,采用数值模拟求解考虑化学非平衡的三维Navier-Stokes(N-S)方程,研究了壁面催化对典型再入飞行器等离子体鞘套及电磁参数的影响规律.研究发现:(1)完全催化壁条件下等离子体密度计算结果与飞行试验符合较好;(2)完全催化壁条件下,离解原子在壁面的复合导致波后气体可压缩性增强...  相似文献   
567.
568.
Interferon-α2a (IFN-α2a) has been used for the treatment of various viral infections and cancers for many years. However some untolerable side effects have limited its application in some aspects. To evaluate whether or not an oligopeptide containing GFE motif can home human IFN-α2a to specific tissues, a fusion gene was constructed by fusing the coding sequence of GFE peptide (CGFECVRQCPERC), which was screened from phage display peptide library, to the 3′ end of human IFN-α2a gene by recombinant DNA technique. Fusion protein rhIFN-α2a-GFE was expressed in Escherichia coli as inclusion bodies using a T7 RNA polymerase expression system, pET-22b, refolded through dialysis and purified to homogeneity to >95% of purity by affinity chromatography. Characterization by sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting demonstrated the authenticity of the fusion protein. Purified rhIFN-α2a-GFE was found to be functionally active in terms of its antiviral activity for about 2.5×108 IU/mg in vitro. Yields of the purified fusion protein were about 200 mg/L of culture medium. Tissue distribution assay in mouse showed that at 30 min IFN-α2a could be enriched sevenfold higher in lung in the targeted IFN group of mice than in the standard IFN group of mice, and last for a long time. At 1 h, IFN-α2a in the targeted IFN group was still 4.02-fold higher than that in the standard group. This confirmed that GFE peptide has the ability to selectively deliver its fusion partner IFN-α2a to lungs. The results also showed that the IFN-α2a-GFE could be specifically enriched in kidney and liver. Its distribution in kidney was concordant with the finding of GFE receptor, MDP, in kidney. However, the IFN-α2a-GFE in liver may imply some significance in pharmacology and toxicology.  相似文献   
569.
Nanostructured semiconductor architectures have attractive optical properties mainly including bright photoluminescence (PL) resulting from the radiative recombination of charge carriers on surface states. Various approaches have been employed for the modification of surface states of these nanostructures to design new nanomaterials with enhanced PL primarily in aqueous medium to enable their applications in biological samples. Here, we report the varying efficiencies of three commercial surfactants viz. cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium chloride (CTAC) and cetylpyridinium chloride (CPyC) on the dynamics of PL emission enhancement during initial growth and Ostwald ripening of ZnS nanoparticles (NPs). The counterion has been estimated to behave differently to govern the PL enhancement. The exceptionally high tendency of CPyC in PL enhancement has been assigned to participation of π-electrons of pyridinium ring. The impact of UV-light in photoactivation of surfactant stabilized ZnS NPs has been utilized in exploring significance of surfactants in improving the surface emitting states in water soluble semiconductor NPs.  相似文献   
570.
In this paper, a novel interpretation of the effect of Auger recombination coefficient (C) on the turn-on time delay (ton) of semiconductor laser diodes (SLDs) is presented. To the date, the well-known conclusion is that the main effect of C is to decrease ton. This is because the earlier studies were based on less physical assumptions. Contrarily, we show that the general effect of C is to increase ton. This conclusion is supported by including the effect of temperature of operation (T) on ton of uncooled SLDs. Advanced analytical model is presented to determine ton analytically and in term of nonradiative (A), radiative (B) and C recombination coefficients. The derived model can be applied to bulk and multiple quantum-well (MQW) long-wavelength SLDs at any value of temperature of operation degree (T) within the range 25-85 °C. The temperature dependence of ton is calculated according to the temperature dependences of C and threshold carrier density (Nth). The temperature dependence of the latter is calculated according to the temperature dependence of laser cavity parameters and not by the well-known Parkovian relationship. Numerical and analytical results show that ton increases as T increases due to increasing of Nth and C which its effect dominates at high temperature degrees. In addition, we show that the effect of temperature dependence of ton in MQW SLD is smaller than the bulk one. Moreover, MQW SLD needs a lower injection current than the bulk one to achieve the same value of ton.  相似文献   
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