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排序方式: 共有137条查询结果,搜索用时 15 毫秒
101.
考虑碳排放税,建立双寡头制造商分别实施废品回收和绿色低碳广告投入策略的动态博弈模型。通过系统稳定域,分岔图,功率谱等分析了博弈模型纳什均衡解处的稳定性及参数对系统稳定域的影响,同时对系统的复杂性特征进行了研究。结果表明,消费者回收价格敏感性增加会使整个系统稳定域缩小,而绿色低碳广告投入水平增加只会使实施该策略的企业自身稳定域扩大;当制造商价格调整速度过快时,系统会进入混沌状态;混沌状态下,对比实施广告策略的制造商,实施废品回收策略的制造商价格调整行为对市场造成的震荡更大。最后使用反馈控制策略对系统混沌状态进行了有效的控制,研究结果对制造商低碳策略选择及价格决策有着较好的借鉴意义。 相似文献
102.
The surface structures of cubo-octahedral Pt-Mo nanoparticles have been investigated using the Monte Carlo method and modified embedded atom method potentials that we developed for Pt-Mo alloys. The cubo-octahedral Pt-Mo nanoparticles are constructed with disordered fcc configurations, with sizes from 2.5 to 5.0 nm, and with Pt concentrations from 60 to 90 atom %. The equilibrium Pt-Mo nanoparticle configurations were generated through Monte Carlo simulations allowing both atomic displacements and element exchanges at 600 K. We predict that the Pt atoms weakly segregate to the surfaces of such nanoparticles. The Pt concentrations in the surface are calculated to be 5-14 atom % higher than the Pt concentrations of the nanoparticles. Moreover, the Pt atoms preferentially segregate to the facet sites of the surface, while the Pt and Mo atoms tend to alternate along the edges and vertexes of these nanoparticles. We found that decreasing the size or increasing the Pt concentration leads to higher Pt concentrations but fewer Pt-Mo pairs in the Pt-Mo nanoparticle surfaces. 相似文献
103.
Fin materials can be observed in a variety of engineering applications. They are used to ease the dissipation of heat from a heated wall to the surrounding environment. In this work, we consider a nonlinear fin problem with temperature-dependent thermal conductivity and heat transfer coefficient. The equation(s) under study are highly nonlinear. Both the thermal conductivity and the heat transfer coefficient are given as arbitrary functions of temperature. Firstly, we consider the Lie group analysis for different cases of thermal conductivity and the heat transfer coefficients. These classifications are obtained from the Lie group analysis. Then, the first integrals of the nonlinear straight fin problem are constructed by three methods, namely, Noether’s classical method, partial Noether approach and Ibragimov’s nonlocal conservation method. Some exact analytical solutions are also constructed. The obtained result is also compared with the result obtained by other methods. 相似文献
104.
Adsorbed atoms and molecules frequently cause restructuring of single-crystal surfaces, ranging from small atomic relaxations and reconstructions to macroscopic shape modifications. The occurrence of such adsorbate-induced restructuring is reviewed, and the mechanisms and dynamic time scales are discussed. The importance of adsorbate-induced restructuring in a variety of surface processes is stressed. It is proposed that such restructuring can explain the observed “structure insensitivity” of a class of catalytic reactions, and that it could play a major role in most forms of reactivity. 相似文献
105.
Jakobsen HJ Hove AR Bildsøe H Skibsted J 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2006,180(2):170-177
Experiences obtained from recent improvements in the performance of solid-state (14)N MAS NMR spectroscopy have been used in a natural abundance (33)S MAS NMR investigation of the satellite transitions for this interesting spin I=3/2 isotope. This study reports the first observation of manifolds of spinning sidebands for these transitions in (33)S MAS NMR as observed for the two alums XAl(SO(4))(2) x 12H(2)O with X=NH(4) and K. For the NH(4)-alum a variable temperature (33)S MAS NMR study, employing the satellite transitions, shows that the (33)S quadrupole coupling constant (C(Q)) exhibits a linear temperature dependence (in the range -35 degrees C to 70 degrees C) with a temperature gradient of 3.1 kHz/ degrees C and undergoes a sign change with zero-crossing for C(Q) at 4 degrees C (277 K). For the isostructural K-alum a quite similar increase in the magnitude of C(Q) with increasing temperature is observed, and with a temperature gradient of 2.3 kHz/ degrees C. Finally, for optimization purposes, a study on the effect of the applied pulse widths at constant rf field strength on the intensity and variation in second-order quadrupolar lineshape for the central (1/2<-->-1/2) transition of the K-alum has been performed. 相似文献
106.
The semileptonic decay width of heavy baryons such as (Λ
b
→ Λcev) has been estimated in the framework of a nonrelativistic field theoretic quark model where four component quark field
operators along with a harmonic oscillator wave function are used to describe translationally invariant hadronic states. The
present estimation does not make an explicit use of heavy quark symmetry and has a reasonable agreement with the experimentally
measured decay width, polarisation ratio and form factors with the harmonic oscillator radii and quark momentum distribution
inside the hadron as free parameters. 相似文献
107.
The optical reflection of V6O13 single crystals has been studied between 0.06 and 3 eV at temperatures both below and above the semiconductor-to-metal transition temperature (Tt?150K). In addition to the metallic reflection, present only at T>Tt, discrete resonances are observed in both phases: four with polarization E//b and three with E⊥b.The results of a dispersion analysis using classical-oscillator and Drude terms are presented. The resonances above 2 eV are attributed to oxygen 2p - vanadium 3d interband transitions. The maxima at the lower energies are interpreted as transitions between vanadium 3d subbands. 相似文献
108.
109.
The results of a quantitative LEED study of the clean, reconstructed Pt(110)-(1 × 2) surface are described, in which experimental intensity-energy spectra for ten diffracted beams have been compared, by an γ-factor analysis, to intensity spectra calculated using a dynamic theory for various structural models. Despite considerable effort in ensuring the reliability of the experimental and calculated intensities, a satisfactory level of agreement has not been achieved for any of the model structures considered although a “missing-row” model leads to the closest agreement between experimental and calculated intensities. 相似文献
110.
The influence of alcohol modifiers with different chain length on the migration time window in micellar electrokinetic chromatography (MEKC) has been studied. Highly polar alcohols like methanol and 1-propanol are typical aqueous phase modifiers. Higher alcohols like 1-butanol, 1-pentanol and 1-hexanol influence the micellar structure and are considered as micellar phase modifiers. The effect of long chain alcohols is small because of their low applicable concentrations. 相似文献