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231.
地质体构造边界位置的确定是位场数据解释中的一项重要工作,现有很多基于位场梯度张量数据的边界检测滤波器,但存在识别边界位置模糊且无法均衡深浅地质体异常的缺点.本文定义了位场数据的三维构造张量,并提出基于位场构造张量的边界滤波器.为了同时显示不同振幅异常的边界位置,对新定义的滤波器进行归一化处理.在高阶均衡滤波器的计算中需要计算位场的垂向高阶导数,本文引入一种计算的稳定算法,基于拉普拉斯方程利用位场水平导数求解垂向导数,可减小垂向导数计算中产生的误差.将定义的滤波器应用到合成的重磁数据中证明了新方法相比传统的滤波器能更加清晰、准确地圈定边界位置,而且针对同时含有正负异常的地质情况,可避免产生额外的错误边界.最后将新的滤波器应用到实测的重磁数据的解释中,结果显示基于构造张量的滤波器可更准确清晰地划分出断裂的边界位置,发现更多的构造细节. 相似文献
232.
Values of the complete adiabatic elastic tensor for single-crystal chrome-diopside (a monoclinic pyroxene mineral) are presented from 298 to 1,300 K. The data were obtained using resonant ultrasound spectroscopy (RUS). They are the first published results for the temperature T dependences of the 13 individual elastic constants C
ij
of any clinopyroxene mineral. Each C
ij
is appropriately described by a linear function in T throughout the range of T. Values for each (∂C
ij
/∂T)
P
in GPa K−1 are as follows: C
11, −0.0291; C
22, −0.0248; C
33, −0.0179; C
44, −0.0103; C
55, −0.0077; C
66, −0.0152; C
12, −0.0119; C
13, −0.0064; C
23, 0.0000; C
15, 0.0025; C
25, 0.0022; C
35, −0.0046; and C
46, 0.0026. Values of (∂M/∂T)
P
in GPa K−1, where M represents an isotropic bulk property calculated from the C
ij
data, are as follows: adiabatic bulk modulus K
S
, −0.0123; isothermal bulk modulus K
T
, −0.0178; and shear modulus G, −0.00998. Some diopside derivatives, notably (∂K
S
/∂T)
P
, (∂K
T
/∂T)
P
, and (∂V
P
/∂T)
P
, where V
P
is the compressional wave velocity, have smaller magnitudes than all other minerals of importance in Earth’s mantle, thus, confirming predictions from systematics studies. We find several dimensionless quantities for this monoclinic mineral have normal values compared to other mantle minerals. Further, αK
T
(α is the volume coefficient of thermal expansion) for diopside is approximately independent of both T and volume V at elevated temperature, so its equation of state is accurately expressed in simplified form. 相似文献
233.
The purpose of this study is to investigate the phenomenon of free surface flow impacting on elastic structures, which is a research topic of great interest in ship and ocean engineering. A series of quasi two-dimensional experiments on dam-break with an elastic plate are conducted. The main features of free surface flow impacting on elastic structures including large impacting force, structural vibration, violent free surface flow, are investigated. The coupled FDM–FEM method developed by the authors is applied for numerical simulation of such dam-break problem. Extensive analysis and discussion based on the comparisons between experimental data and numerical results are made and presented in this paper. 相似文献
234.
235.
The first pressure derivatives of the second-order elastic constants
have been calculated for brucite, Mg(OH)2 from the second- and third-order elastic constants. The deformation theory and finite strain elasticity theory have been used to obtain the second- and third-order elastic constants of Mg(OH)2 from the strain energy of the lattice. The strain energy ϕ is calculated by taking into account the interactions up to third nearest neighbors in the Mg(OH)2 lattice. ϕ is then compared with the strain dependent lattice energy from continuum model approximation to obtain the expressions of elastic constants. The complete set of six second-order elastic constants C
IJ
of brucite exhibits large anisotropy. Since C
33 (= 21.6 GPa), which corresponds to the strength of the material along the c-axis direction, is less than the longitudinal mode C
11 (= 156.7 GPa), the interlayer binding forces are weaker than the binding forces along the basal plane of Mg(OH)2. The 14 nonvanishing components of the third-order elastic constants, C
IJK
, of brucite have been obtained. All the C
IJK
of brucite are negative except the values of C
114 (= 230.36 GPa), C
124 (= 75.45 GPa) and C
134 (= 36.98 GPa). The absolute values of the C
IJK
are, in general, one order of magnitude greater than the C
IJ
’s in the Mg(OH)2 system as usually expected for a crystalline material. To our knowledge, no previous data are available to compare the pressure derivatives of brucite. The pressure derivatives of the two components viz., C
14 and C
33 become negative
indicating an elastic instability in brucite while under pressure. This may be related to the phase transition of brucite largely involving rearrangements of H atoms revealed in the Raman spectroscopic, powder neutron diffraction and synchrotron X-ray diffraction studies. 相似文献
236.
237.
大地电磁阻抗张量正则分解的地质含义分析 总被引:2,自引:1,他引:2
由于常规的张量旋转分析方法的局限性,在处理三维阻抗问题时不能得到令人满意的结果.最新发展的三维阻抗张量的正则分解方法由于不需约束条件,可以自然的从三维阻抗张量中提取完整的参数体系,因而具有很好的应用前景.本文对正则分解的方法从理论上进行了分析和证明,对原有参数计算公式做适当的修改,将正则分解与坐标旋转结合起来,分析二者之间的联系与区别,并探讨参数的地质含义. 相似文献
238.
239.
240.