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Modeling heterogeneous risk-taking behavior in route choice: A stochastic dominance approach 总被引:1,自引:0,他引:1
This paper proposes a unified approach to modeling heterogonous risk-taking behavior in route choice based on the theory of stochastic dominance (SD). Specifically, the first-, second-, and third-order stochastic dominance (FSD, SSD, TSD) are respectively linked to insatiability, risk-aversion and ruin-aversion within the framework of utility maximization. The paths that may be selected by travelers of different risk-taking preferences can be obtained from the corresponding SD-admissible paths, which can be generated using general dynamic programming. This paper also analyzes the relationship between the SD-based approach and other route choice models that consider risk-taking behavior. These route choice models employ a variety of reliability indexes, which often make the problem of finding optimal paths intractable. We show that the optimal paths with respect to these reliability indexes often belong to one of the three SD-admissible path sets. This finding offers not only an interpretation of risk-taking behavior consistent with the SD theory for these route choice models, but also a unified and computationally viable solution approach through SD-admissible path sets, which are usually small and can be generated without having to enumerate all paths. A generic label-correcting algorithm is proposed to generate FSD-, SSD-, and TSD-admissible paths, and numerical experiments are conducted to test the algorithm and to verify the analytical results. 相似文献
105.
橡胶沥青同步碎石应力吸收层的设计研究 总被引:1,自引:0,他引:1
针对橡胶沥青同步碎石应力吸收层的使用特性,在McLeod经验设计法的基础上,提出了以抗剪强度作为力学设计指标,并形成了橡胶沥青同步碎石应力吸收层的力学—经验设计法,同时给出设计示例;对采用两方法设计的应力吸收层进行了性能对比。研究结果表明:力学—经验法设计能设计出具有更高的抗剪强度、抗拉强度和动稳定度的同步碎石应力吸收层,值得推广应用。 相似文献
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基于滑坡体结构发展趋势的链式原理,建立起滑坡为结构体的模型并进行理论分析。滑坡属于地质力学的范畴,建立适当的力学结构模型,进行理论上的应力应变分析。通过灾害链式理论的指导,具体分析降雨对滑坡体发育的链式过程,发现滑坡体发展趋势,并通过有限元进行模拟,推测滑坡体稳定的极限状态,在降雨发生情况下,判断滑坡体是否处于稳定或即将出现滑坡提供理论参考。 相似文献
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目的研究半胱氨酸天冬氨酸特异性蛋白酶-1(cysteinyl aspartate specific protease-1,caspase-1)在大鼠急性脊髓损伤后的表达及意义。方法取健康成熟SD大鼠36只,随机分为对照组和损伤组,各18只,每组再分8 h、3 d7、d共3个时间点,每个时间点6只。对照组仅做单纯T8、T9椎板切除术,损伤组则按Nystrom法建立大鼠急性脊髓损伤动物模型。HE染色观察脊髓组织病理学变化,免疫组化测定各时间点caspase-1的表达变化。结果对照组大鼠脊髓组织中少量细胞caspase-1表达阳性。脊髓损伤后8 h时,损伤组caspase-1表达高于对照组,3 d时表达最高,7 d时略有降低,但仍高于对照组。脊髓损伤组各时间点caspase-1表达阳性细胞数较对照组明显升高(P<0.01)。结论大鼠脊髓损伤后caspase-1的表达迅速增强,可能是导致脊髓继发性损伤的因素之一。 相似文献
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通过快淬态Ag32Zn68条带在0.2M硫酸溶液中0.45V (SCE)去合金化制备出纳米多孔银.向硫酸溶液中加入表面活性剂十二烷基磺酸钠,能够很好地抑制纳米多孔银孔道和孔带的粗化.十二烷基磺酸钠的细化机理为,十二烷基磺酸根离子吸附在合金表面,降低银原子的表面扩散,从而细化多孔银的孔尺寸达到纳米级别. 相似文献
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It has been a focus of debate for a large time on construction methods for large-span loess tunnel. Reasonable construction
method has much effect on stability of tunnel and construction schedule. Deformation and failure of surrounding rock are quite
complex. Associating with the large-span loess tunnel of Zhengzhou—Xi’an high-speed passenger rail line in China, large scale
model test with geometric proportion 1:20 is applied to study on dynamic mechanical behavior of various construction methods.
They include full-face excavation with support and no support, and benching method with support. It is found that pre-deformation
and stress accumulation take place ahead of working face. The effects of three construction methods are further studied, particularly
in terms of tunnel displacement and stress changes. It is revealed that benching method transfers load to an unexcavated area,
limits horizontal deformation, reduces stress concentration effectively, lengthens the distance between location of peak for
stress concentration and working face, and consequently increases stability. The model test results not only supply theoretical
foundation for determination of reasonable construction method, but also can act as reference for similar tunnel and underground
engineering construction. 相似文献