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141.
碎裂结构边坡稳定性受多组相交结构面控制,且受降雨、地震等多因素影响强烈,具有一定的特殊性。本文以某花岗岩碎裂结构边坡为例,在边坡的地质条件和岩体结构研究的基础上,结合施工及监测反馈信息,深入分析了边坡变形破坏模式,并根据稳定性计算结果,提出锚索、钢筋桩与排水相结合的支护方案。研究结果表明:坡体内部陡倾卸荷裂缝发育形成后缘切割面,中下部滑面追踪陡缓两组结构面发展;支护措施实施后,边坡经历“5•12”地震及雨季,多点位移计监测结果表明,地震和降雨对边坡稳定性影响较大,支护措施较好地控制了边坡变形。 相似文献
142.
爆炸冲击载荷作用下岩石的损伤实验 总被引:6,自引:0,他引:6
基于声波测试原理,利用RSM-SY5智能型声波仪,对某露天矿围岩在爆破冲击荷载作用下产生的损伤进行了现场实验研究。研究结果表明:爆破冲击荷载对距离爆源7 m范围内的岩石会造成损伤破坏,其损伤程度随着岩石与爆源距离的增大而减小;岩体声波速度随着爆破次数的不断增加而逐渐降低,多次爆破对岩石具有损伤累积效应;多次爆破的累积损伤不是单次爆破损伤的简单叠加,具有非线性特性,且距离爆源越近爆破累积损伤效应越明显。 相似文献
143.
运用离散小波阈值去噪原理对SHPB测试信号进行了处理,针对SHPB测试信号持时短、突变快等特性,并根据各小波基对信号的重构均方根误差,选择Symlets小波系中的小波基Sym5为适合SHPB测试信号小波分析的最佳小波基,并运用无偏估计程序SURE确定了各分解层的阈值。比较了小波阈值去噪与动态应变仪中常规低通滤波器去噪的信噪比和均方根误差,研究结果表明,相对于常规低通滤波器的去噪处理,离散小波变换不仅有良好的去噪效果,而且能得到更精确的重构信号,可以取代动态应变仪中的低通滤波器对SHPB测试信号进行去噪处理。 相似文献
144.
A. N. Guz 《International Applied Mechanics》2009,45(1):1-31
Nonclassical problems of fracture and failure mechanics that have been analyzed by the author and his collaborators at the
S. P. Timoshenko Institute of Mechanics (Kiev, National Academy of Sciences of Ukraine) during the past forty years are considered
in brief. The results of the analysis are presented in a form that would be quite informative for the majority of experts
interested in various fundamental and applied aspects of fracture and failure problems including the identification of related
mechanisms. This paper was prepared on invitation of the Editorial Board of the journal “Annals. The European Academy of Sciences”
and may be considered as an Extended Pascal Medal Lecture (The 2007 Blaise Pascal Medal in Materials Sciences of the EAS)
This is an updated edition of the author’s lecture prepared at the invitation of the Annals—The European Academy of Sciences Magazine on the occasion of awarding him the 2007 Blaise Pascal Medal in Materials Sciences by the EAS. The author’s speech
at the award ceremony at the General Assembly of the Academy has already been published in International Applied Mechanics [75]. The electronic version of the paper in Annals has been prepared; this issue of Annals is to be published as a book. The paper includes an additional section and extended list of references [41–99].
Published in Prikladnaya Mekhanika, Vol. 45, No. 1, pp. 3–40, January 2009. 相似文献
145.
Capillary pressure curves of six low porosity and low permeability core samples from The Geysers geothermal field were measured
using the mercury-intrusion approach to characterize the heterogeneity of rock. One high permeability Berea sandstone core
sample was analyzed similarly, for comparison. The maximum pressure of mercury intruded into the rock was about 200 MPa to
reach the extremely small pores. Experimental data showed that the capillary pressure curves of The Geysers rock are very
different from that of the Berea sandstone. It was found that the frequently used capillary pressure models could not be used
to represent the data from The Geysers rock samples. This might be because of the fractures in the rock. To this end, a fractal
technique was proposed to model the features of the capillary pressure curves and to characterize the difference in heterogeneity
between The Geysers rock and Berea sandstone. The results demonstrated that the rock from The Geysers geothermal field was
fractal over a scaling range of about five orders of magnitude. The values of the fractal dimension of all the core samples
(six from The Geysers and one Berea sandstone) calculated using the proposed approach were in the range from 2 to 3. The results
showed that The Geysers rock with a high density of fractures had a greater fractal dimension than Berea sandstone which is
almost without fractures. This shows that The Geysers rock has greater heterogeneity, as expected. 相似文献
146.
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150.
岩石破裂电磁辐射幅值与岩石属性参数的关系 总被引:1,自引:0,他引:1
基于岩石破裂电磁辐射是由岩石破裂时传播裂纹引起原子扰动产生的假说,
通过断裂力学理论计算了岩石破裂时的裂纹扩展长度及裂纹面积. 由电磁辐射幅值与裂纹长度
及裂纹面积之间的关系,给出了电磁辐射幅值与岩石属性参数之间的关系表达式. 讨论了主
要的不同属性参数对电磁辐射幅值的影响. 发现电磁辐射幅值随岩石弹性模量增大而增大;岩石破
裂的电磁辐射与岩石的尺寸有关,且岩石尺寸因素影响大于岩性因素影响. 本文的研究结果与现有的
实验结果是吻合的. 相似文献