全文获取类型
收费全文 | 2280篇 |
免费 | 8篇 |
专业分类
公路运输 | 325篇 |
综合类 | 764篇 |
水路运输 | 752篇 |
铁路运输 | 75篇 |
综合运输 | 372篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 14篇 |
2021年 | 16篇 |
2020年 | 18篇 |
2019年 | 6篇 |
2018年 | 336篇 |
2017年 | 296篇 |
2016年 | 254篇 |
2015年 | 18篇 |
2014年 | 11篇 |
2013年 | 19篇 |
2012年 | 87篇 |
2011年 | 232篇 |
2010年 | 244篇 |
2009年 | 73篇 |
2008年 | 200篇 |
2007年 | 162篇 |
2006年 | 25篇 |
2005年 | 79篇 |
2004年 | 50篇 |
2003年 | 75篇 |
2002年 | 23篇 |
2001年 | 10篇 |
2000年 | 12篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有2288条查询结果,搜索用时 515 毫秒
671.
LIU Yu-jun ZHU Xiu-li JI Zhuo-shang 《船舶与海洋工程学报》2005,4(3):13-17
The problem of ship hull plate processing surface fairing with constraints based on B-spline is solved in this paper. The algorithm for B-spline curve fairing with constraints is one of the most common methods in plane curve fairing. The algorithm can be applied to global and local curve fairing. It can constrain the perturbation range of the control points and the shape variation of the curve, and get a better fairing result in plane curves. In this paper, a new fairing algorithm with constraints for curves and surfaces in space is presented. Then this method is applied to the experiments of ship hull plate processing surface. Finally numerical results are obtained to show the efficiency of this method. 相似文献
672.
本文结合实际工程,并根据工程现场试验实测资料,用不同方法推算软土地基的最终沉降量和固结度。通过比较分析,采用三点法推算软土地基最终沉降量是可行的。通过对采用塑料板排水堆载预压后的固结沉降计算和沉降规律的分析,达到验证设计、指导施工的目的。 相似文献
673.
印尼布敦岩沥青改性沥青性能研究 总被引:2,自引:0,他引:2
以埃索70#沥青作为基质沥青,对不同掺量的印尼布敦岩沥青改性沥青的性能进行了研究,试验结果表明,随着岩沥青掺量的增加,改性沥青的抗变形能力、感温性能、高温性能和低温性能得到提高.同时,岩沥青为天然沥青且不含蜡,可有效提高改性沥青的抗老化能力.据此推荐了改性沥青综合性能优良的岩沥青,其适宜掺量为10%~20%,从而为岩沥青的应用提供了参考. 相似文献
674.
This paper introduces a new means to predict consolidation deformation of soil from its microstructure. Based on a kind of
pore-size distribution density function, a fractal model for soil consolidation is established. Through this model, the relation
between macroscopic deformation and microcosmic pore property of soil is founded. In order to justify this proposed model
for soil consolidation, consolidation experiments of soft clay are performed. Afterward, the microstructure of soft clay unconsolidated
and consolidated under every pressure is studied by a scanning electron microscope (SEM). The results show that the proposed
model for soil consolidation is valid in predicting consolidation deformation. 相似文献
675.
The non-destructive testing (NDT) of debonding in stainless steel composites plate (SSCP) is performed by infrared thermography,
finite element analysis (FEA) software ANSYS is taken as the simulative tool, and 2D simulative model has been set up to investigate
effect of the thickness of coating and/or substrate on the detectibility of debonging in SSCPs. Two parameters, namely the
maximum defect temperature difference and defect appearing index, are defined to evaluate the detectivity of defects, and
their computational methods and formulas are given respectively. The preliminary changing tendency of the maximum defect temperature
difference and defect appearing index with the thickness of coating and/or substrate is found by numerical simulation. 相似文献
676.
Philip J. Zwart Philippe G. Godin Justin Penrose Shin Hyung Rhee 《Journal of Marine Science and Technology》2008,13(4):346-355
An accurate, efficient algorithm for solving free surface flows around ship hulls is described. Accuracy is achieved using
a compressive advection discretization which maintains a sharp free surface interface representation without relying on a
small time step. Efficiency is obtained using a solution algorithm which implicitly couples velocity, pressure, and volume
fractions. The algorithm has been implemented in a computational fluid dynamics code called CFX and is validated by means
of a comparisonwith experimental data of benchmark cases in both steady and transient conditions. 相似文献
677.
文章从零库存管理的起源、特点、作用和如何成功实施零库存管理等方面进行分析,同时结合许多成功企业的典型事例,来阐述零库存管理在整个物流系统中的应用. 相似文献
678.
679.
Marlene Calderon Veiga 《WMU Journal of Maritime Affairs》2004,3(2):171-192
Background
The question of what should be the right level of preparedness to react to a major oil spill (i.e. the EXXON VALDEZ spill, the ERIKA spill, and the PRESTIGE spill) is highly debated, especially in the aftermath of such spills. Little research, however, has been conducted with the aim to identify and compare governments’ best practices not only to fund preparedness measures but also to assess the countries’ ability to respond effectively to catastrophic oil spills. It is the author’s belief that important lessons can be learnt from a comparative analysis of countries’ best practices. 相似文献680.
A 3D displacement discontinuity method is applied to solve the fracture mechanics problems of the mixed mode crack under compression.
Friction between the surface of the closed crack is considered by establishing a simple and efficient iterative algorithm
based on method of contact resistance mitigation. On the surfaces of the closed crack, the Mohr-coulomb rule is satisfied
by iteration when the crack is in condition of sliding. The stress intensity factors are obtained using displacement fitting
method. It is shown that the numerical results agree with the experimental results well and that friction plays an important
role in resisting crack propagation. 相似文献