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991.
992.
起泡剂C12E8的表面动力学性质 总被引:4,自引:1,他引:3
利用表面波技术测定起泡剂C12E8的表面流变学性质以及通过对三种吸附模型(扩散是速率控制步骤,吸附-脱附是控制步骤和混合模型)的研究,揭示了C12E8溶液表面的吸附机理.认为在浓度小于cmc的范围内,C12E8分子的吸附和脱附是一个迅速的过程,而表面吸附速率是由分子从本体溶液到次表面层的迁移所控制.利用扩散是吸附速率控制步骤模型和Frulnkin状态方程研究了扩散系数、松弛特征频率、极限膨胀模量随C12E8浓度变化的规律,以及它们与表面张力梯度修复机理的关系. 相似文献
993.
Drawbacks of the standard method for solving the problem of internal rotation (IR) in molecules with symmetrical tops were
examined. The drawbacks can be eliminated by taking into account the higher harmonics of the IR potentials. A new calculation
procedure based on the approximation of the lower portion of the potential curve by the equationV(φ)=1/2V
n
*
(1-cosn φ), which describes adequately the arrangement of the torsion levels, was proposed. The successfull implementation of the
proposed procedure showed that the procedures used currently are incorrect as well as the Herschbach procedure, which includes
a systematic error at each iteration step.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 239–244, February, 1999. 相似文献
994.
G. K. Semin E. N. Tsvetkov T. L. Khotsyanova E. V. Bryukhova 《Russian Chemical Bulletin》1999,48(5):906-913
Regularities of transmission of the effect of equatorial and axial substituents were established for a number of chlorine-containing
organic compounds of pentatalent phosphorus using35Cl NQR spectra. The field constants of35Cl NQR frequencies of the chlorine atoms participating in the P−Cl bond were estimated for a series of tetrahedral phosphorus
ions. The35Cl NQR frequencies of chlorine atoms in tetracoordinated ions of pentavalent phosphorus and in analogous isoelectronic silicon
compounds are related by a linear dependence.
Deceased
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 915–922, May, 1999. 相似文献
995.
Whenwestudytorsionalvibration,thegearsaregenerallytreatedasrigiddisks,shaftsegmentastorsionalspringwithoutmass.Eveniftherotationalinertiaofshaftssegmentcannotbeneglected,theyareoftenallocatedtotheneighbordisksorreplacedwithsomerigiddisksconcatenatedb… 相似文献
996.
In this paper, a new technique of state vector approach to solving damping ratios of adaptive structures is proposed, by which
the state matrix can be analytically conducted the Cholesky decomposition, providing that the mass matrix is derived by lumped
method. In this case, not only the computional accuracy is raised, but also the numerical operations are reduced. Finally,
some numerical results are presented to show that the solution method is simple and efficient.
Foundation item: the National 863 Program Foundation of China(863-2-4-4-4) 相似文献
997.
Si2Br6的分子振动光谱的理论研究 总被引:1,自引:1,他引:0
用量化从头算方法(HF/6-31G*)和密度泛函方法(B3LYP/6-31G*)以6-31G标准基组加一个极化函数,对Si2Br6分子的平衡几何构型和振动频率分别进行优化和计算,优化的结果与实验结果吻合得较好.按照Pulay的建议对HF/6-31G*水平上所计算的谐性力场进行标度(标度因子取0.9).用HF/6-31G*SQM力场所计算的基频预测值和实验值的平均误差为9.4cm-1,最大误差为23.6cm-1;用B3LYP/6-31G*未标度力场所计算的基频预测值和实验值的平均误差为8.6cm-1,最大误差为16.6cm-1;用该密度泛函方法所计算的基频预测值比用HF/6-31G*的标度后的SQM力场所计算的基频预测值和实验值(除Si-Si键扭转振动基频之外的11条振动基频)吻合得更好.HF/6-31G*和B3LYP/6-31G*计算给出Si-Si键扭转振动基频的预测值分别为14cm-1和9cm-1. 相似文献
998.
V. A. Saechnikov É. A. Chernyavskaya T. P. Yanukovich 《Journal of Applied Spectroscopy》1999,66(5):830-834
We consider a method for measuring the temperature and deformation from a distributed source by means of optic-fiber sensors
with the use of Brillouin scattering in combination with analysis of the frequency domain. The method is investigated theoretically.
It is based on measurements of the complex transfer function. We carry out a numerical simulation of the response function
for a single-mode optic fiber with elevated-temperature regions and deformed regions.
To whom correspondence should be addressed.
Reported at the Second International Scientific and Technical Conference on Quantum Electronics, Minsk, November 23–25, 1998.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 66, No. 5, pp. 718–721, September–October, 1999. 相似文献
999.
The expansion coefficients in powers of time (or frequency moments) of the spin autocorrelation function are represented at the simple self-consistent approximation as a sum of weighted trees on a Bethe lattice. Using the computer numeration and the Monte Carlo method for self-avoidingly embedding these trees on the square lattice, we estimate the moments and the convergence radius of the expansion. We show that the moments decrease and the radius increases in consequence of the volume exclusion. 相似文献
1000.