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61.
Based on some known facts of integrable models, this paper proposes a new (2+1)-dimensional bilinear model equation. By virtue of the formal series symmetry approach, the new model is proved to be integrable because of the existence of the higher order symmetries. The Lie point symmetries of the model constitute an infinite dimensional Kac- Moody Virasoro symmetry algebra. Making use of the infinite Lie point symmetries, the possible symmetry reductions of the model are also studied  相似文献   
62.
Motivated by the hyperentangled Bell states analysis, an arbitrated quantum proxy blind signature (QPBS) scheme is developed. Four participants accomplish the task of signing and verifying via exchanging the entanglement of polarization and spatial-mode degrees of freedom. Alice blinds message and sends it to a proxy signatory David who is delegated by the original signatory Charlie. David generates a signature using the delegating code while Bob verifies the signing with the help of an arbitrator Trent. Unlike previous schemes, the verifying phase is no longer executed only by a recipient. Analysis shows that when the even numbers of blinding string always equal 1, the scheme protects the proxy blind signature against forgery and disavow while maintaining the properties of verifiability and identifiability.  相似文献   
63.
Based on the output saturation of classcial bistable stochastic resonance (CBSR), a new type of piecewise nonlinear bistable stochastic resonance (PNBSR) system is constructed. The mean signal-to-noise ratio gain is regarded as an index to measure the stochastic resonance phenomenon. The laws for the resonant output of piecewise nonlinear bistable system governed by l, c, a, b and D of Levy noise are explored under different characteristic index α and symmetry parameter β of Levy noise. The results show that the output of PNBSR system has increased 4?dB by comparing with the output signal-to-noise ratio of CBSR system. And the stochastic resonance phenomenon can be induced by adjusting the piecewise nonlinear system's parameters under any α or β of Levy noise. The interval of the parameters of system which induces good stochastic resonance is roughly the same. And the output signal waveform of resonance is very similar to the input signal waveform, which has some reference value for the signal recovery. Moreover, we can find the good stochastic resonance interval of the system parameters do not change with D of Levy noise under the different noise intensity D of Levy noise. On the basis of this, adjusting the intensity amplification factor D of Levy noise, which induces good stochastic resonance, and the interval does not change with α or β. At last, the piecewise nonlinear bistable system is applied to detect bearing fault signals, which achieves better performance compared with the classical bistable system.  相似文献   
64.
An experiment for p(~(14)C,~(14)C~*→~(10)Be+α)p inelastic excitation and decay was performed in inverse kinematics at a beam energy of 25.3 Me V/u.A series of~(14)C excited states,including a new one at 18.3(1)Me V,were observed which decay to various states of the final nucleus of~(10)Be.A specially designed telescope system,installed around zero degrees,played an essential role in detecting the resonant states near theα-separation threshold.A state at 14.1(1)Me V is clearly identified,being consistent with the predicted band-head of the molecular rotational band characterized by theπ-bond linear chain configuration.Further clarification of the properties of this exotic state is suggested by using appropriate reaction tools.  相似文献   
65.
The residual symmetry of the generalized Kaup-Kupershmidt(gKK) equation is obtained from the truncated Painlevé expansion and localized to a Lie point symmetry in a prolonged system. New symmetry reduction solutions of the prolonged system are given by using the standard Lie symmetry method. Furthermore, the g KK equation is proved to integrable in the sense of owning consistent Riccati expansion and some new B¨acklund transformations are given based on this property, from which interaction solutions between soliton and periodic waves are given.  相似文献   
66.
王春江  苑轶  王强  刘铁  娄长胜  赫冀成 《物理学报》2010,59(5):3116-3122
理论分析表明,第二相的迁移行为可以通过迁移速度进行表征.影响迁移速度的因素包括第二相和熔体的物理性质、磁场强度和梯度大小、第二相的形状和体积等因素.强磁场下洛伦兹力的效果为促进第二相在基体中的均匀分布,其效率在磁场强度大于某一定值时逐渐降低.在梯度强磁场条件下,第二相迁移行为和分布状态的主要控制参数是梯度磁场下的磁化力.在磁场梯度较小时,因洛伦兹力的制约磁化力控制第二相迁移的效果不明显,随着磁场梯度的增加,磁化力的作用效果逐渐增强.通过研究强磁场下Al-Si合金、Al-Ni合金中原位自生第二相的迁移行为实 关键词: 强磁场 迁移 第二相 凝固  相似文献   
67.
分析了光子晶体光纤拉制中各工艺参数之间的相互影响,建立了工艺参数与最终光纤结构之间的对应关系.在温度和送料速度的协调控制下,通过调节气压参数可有效控制气孔结构.实验拉制出孔径孔距比分别为0.45和0.8的单模以及高占空比光子晶体光纤.在制备非均匀孔径光子晶体光纤时,仅靠调控工艺参数往往难以拉制出理想结构,本文以一种单偏振单模PCF结构为例,对预制棒结构进行了优化设计.计算表明可由此拉制出满足要求的光子晶体光纤. 关键词: 光子晶体光纤 工艺参数 气压控制 气孔结构  相似文献   
68.
用266nm激光解离亚硝基苯(C6H5NO)产生光解碎片NO,并利用单光子激光诱导荧光(LIF)技术(X^2Ⅱv″=0→A^2∑^+v′=0)测得初生态光解产物NO的振转光谱。根据计算所得的模拟光谱对光解碎片NO(X,v^″=0)的转动量子数J″进行了归属,得到了量子数最大到J″=50.5的转动能级的相对布居,这表面光解碎片NO具有较高的转动激发。提出了C6H5NO在266nm下可能的光解机理。  相似文献   
69.
The transmissions of oxygen ions through Al2O3 nanocapillaries each 50 nm in diameter and 10 μm in length at a series of different tilt angles are measured,where the ions with energies ranging from 10 to 60 keV and charge states from 1 up to 6 are involved.The angular distribution and the transmission yields of transported ions are investigated.Our results indicate both the existence of a guiding effect when ions pass through the capillary and a significant dependence of the ion transmission on the energy and the charge state of the ions.The guiding effects are observed to be enhanced at lower projectile energies and higher charge states.Meanwhile,the results also exhibit that the transmission yields increase as the tilt angle decreases at a given energy and charge state.  相似文献   
70.
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