全文获取类型
收费全文 | 804篇 |
免费 | 116篇 |
国内免费 | 93篇 |
专业分类
电工技术 | 14篇 |
综合类 | 94篇 |
化学工业 | 16篇 |
金属工艺 | 10篇 |
机械仪表 | 25篇 |
建筑科学 | 9篇 |
矿业工程 | 17篇 |
能源动力 | 16篇 |
轻工业 | 4篇 |
水利工程 | 61篇 |
石油天然气 | 15篇 |
武器工业 | 19篇 |
无线电 | 46篇 |
一般工业技术 | 194篇 |
冶金工业 | 6篇 |
原子能技术 | 3篇 |
自动化技术 | 464篇 |
出版年
2024年 | 4篇 |
2023年 | 6篇 |
2022年 | 15篇 |
2021年 | 16篇 |
2020年 | 29篇 |
2019年 | 24篇 |
2018年 | 22篇 |
2017年 | 25篇 |
2016年 | 34篇 |
2015年 | 27篇 |
2014年 | 33篇 |
2013年 | 50篇 |
2012年 | 52篇 |
2011年 | 59篇 |
2010年 | 62篇 |
2009年 | 77篇 |
2008年 | 76篇 |
2007年 | 62篇 |
2006年 | 56篇 |
2005年 | 52篇 |
2004年 | 53篇 |
2003年 | 35篇 |
2002年 | 29篇 |
2001年 | 16篇 |
2000年 | 22篇 |
1999年 | 15篇 |
1998年 | 11篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有1013条查询结果,搜索用时 15 毫秒
101.
Amir Vaxman 《Computer Graphics Forum》2014,33(8):121-131
We present a novel framework for polyhedral mesh editing with face‐based projective maps that preserves planarity by definition. Such meshes are essential in the field of architectural design and rationalization. By using homogeneous coordinates to describe vertices, we can parametrize the entire shape space of planar‐preserving deformations with bilinear equations. The generality of this space allows for polyhedral geometric processing methods to be conducted with ease. We demonstrate its usefulness in planar‐quadrilateral mesh subdivision, a resulting multi‐resolution editing algorithm, and novel shape‐space exploration with prescribed transformations. Furthermore, we show that our shape space is a discretization of a continuous space of conjugate‐preserving projective transformation fields on surfaces. Our shape space directly addresses planar‐quad meshes, on which we put a focus, and we further show that our framework naturally extends to meshes with faces of more than four vertices as well. 相似文献
102.
针对各种基于流言机制的通信协议在构造非结构化P2P覆盖网络中,其适用范围缺乏广泛的实证问题,提出了一个通用的协议框架——基于流言机制的节点采样服务,以执行高效和可靠的节点采样服务。在这种协议框架下通过实验分析了8种通信协议的差异。实验表明,采用不同的通信协议,所构造的非结构化P2P覆盖网络就表现出多种不同的行为特性,为构造非结构化P2P覆盖网络中选取通信协议提供了重要的参考依据。 相似文献
103.
非结构网格上求解中子输运方程的并行流水线Sn扫描算法 总被引:7,自引:4,他引:7
间断有限元离散纵标方法(Sn)是广泛应用于求解高维非定常中子输运方程的数值方法,它涉及几何网格空间、速度相空间和中子能群的离散,计算量很大.该文基于非结构网格,提出了基于区域分解的并行流水线Sn扫描算法,通过设计具有不同内在并行度和通信面体比的区域分解方法和队列插入算法,对两个不同物理模型,分别使用两台并行机的92个和256个CPU,获得72倍和78倍以上的加速.可扩展性能分析表明,算法的性能非常依赖于并行机的点对点通信延迟. 相似文献
104.
105.
Wei Wen-li 《水动力学研究与进展(B辑)》1995,(3)
NUMERICALSOLUTIONFORUNSTEADY2-DFLOWUSINGTHETRANSFORMEDSHALLOWWATEREQUATIONS¥WeiWen-li(Xi'anUniversityofTechnology,Xi'an710048... 相似文献
106.
Subhajit Sanfui Deepak Sharma 《International journal for numerical methods in engineering》2020,121(17):3824-3848
With the development of parallel computing architectures, larger and more complex finite element analyses (FEA) are being performed with higher accuracy and smaller execution times. Graphics processing units (GPUs) are one of the major contributors of this computational breakthrough. This work presents a three-stage GPU-based FEA matrix generation strategy with the key idea of decoupling the computation of global matrix indices and values by use of a novel data structure referred to as the neighbor matrix. The first stage computes the neighbor matrix on the GPU based on the unstructured mesh. Using this neighbor matrix, the indices and values of the global matrix are computed separately in the second and third stages. The neighbor matrix is computed for three different element types. Two versions for performing numerical integration and assembly in the same or separate kernels are implemented and simulations are run for different mesh sizes having up to three million degrees of freedom on a single GPU. Comparison with GPU-based parallel implementation from the literature reveals speedup ranging from 4× to 6× for the proposed workload division strategy. Furthermore, the same kernel implementation is found to outperform the separate kernel implementation by 70% to 150% for different element types. 相似文献
107.
Chang Lu Zhi Yang Jinwei Bai Yong Cao Xiaoming He 《International journal for numerical methods in engineering》2020,121(10):2107-2127
Anisotropic diffusion is important to many different types of common materials and media. Based on structured Cartesian meshes, we develop a three-dimensional (3D) nonhomogeneous immersed finite-element (IFE) method for the interface problem of anisotropic diffusion, which is characterized by an anisotropic elliptic equation with discontinuous tensor coefficient and nonhomogeneous flux jump. We first construct the 3D linear IFE space for the anisotropic nonhomogeneous jump conditions. Then we present the IFE Galerkin method for the anisotropic elliptic equation. Since this method can efficiently solve interface problems on structured Cartesian meshes, it provides a promising tool to solve the physical models with complex geometries of different materials, hence can serve as an efficient field solver in a simulation on Cartesian meshes for related problems, such as the particle-in-cell simulation. Numerical examples are provided to demonstrate the features of the proposed method. 相似文献
108.
Chao Ma Anke Malessa Arnold J. Boersma Kai Liu Andreas Herrmann 《Advanced materials (Deerfield Beach, Fla.)》2020,32(20):1905309
Electrostatic interactions play a vital role in nature. Biomacromolecules such as proteins are orchestrated by electrostatics, among other intermolecular forces, to assemble and organize biochemistry. Natural proteins with a high net charge exist in a folded state or are unstructured and can be an inspiration for scientists to artificially supercharge other protein entities. Recent findings show that supercharging proteins allows for control of their properties such as temperature resistance and catalytic activity. One elegant method to transfer the favorable properties of supercharged proteins to other proteins is the fabrication of fusions. Genetically engineered, supercharged unstructured polypeptides (SUPs) are just one promising fusion tool. SUPs can also be complexed with artificial entities to yield thermotropic and lyotropic liquid crystals and liquids. These architectures represent novel bulk materials that are sensitive to external stimuli. Interestingly, SUPs undergo fluid–fluid phase separation to form coacervates. These coacervates can even be directly generated in living cells or can be combined with dissipative fiber assemblies that induce life-like features. Supercharged proteins and SUPs are developed into exciting classes of materials. Their synthesis, structures, and properties are summarized. Moreover, potential applications are highlighted and challenges are discussed. 相似文献
109.
Michael Cortis William Coombs Charles Augarde Michael Brown Andrew Brennan Scott Robinson 《International journal for numerical methods in engineering》2018,113(1):130-152
There is increasing interest in the material point method (MPM) as a means of modelling solid mechanics problems in which very large deformations occur, e.g. in the study of landslides and metal forming; however, some aspects vital to wider use of the method have to date been ignored, in particular methods for imposing essential boundary conditions in the case where the problem domain boundary does not coincide with the background grid element edges. In this paper, we develop a simple procedure originally devised for standard finite elements for the imposition of essential boundary conditions, for the MPM, expanding its capabilities to model boundaries of any inclination. To the authors' knowledge, this is the first time that a method has been proposed that allows arbitrary Dirichlet boundary conditions (zero and nonzero values at any inclination) to be imposed in the MPM. The method presented in this paper is different from other MPM boundary approximation approaches, in that (1) the boundaries are independent of the background mesh, (2) artificially stiff regions of material points are avoided, and (3) the method does not rely on mirroring of the problem domain to impose symmetry. The main contribution of this work is equally applicable to standard finite elements and the MPM. 相似文献
110.
Baili Zhang Yong Zhao 《International journal for numerical methods in engineering》2001,50(11):2443-2457
An upwind characteristic‐based finite volume method on unstructured grids is employed for numerical simulation of incompressible laminar flow and forced convection heat transfer in 2D channels containing simultaneously fluid layers and fluid‐saturated porous layers. Hydrodynamic and heat transfer results are reported for two configurations: the first one is a backward‐facing step channel with a porous block inserted behind the step, and the second one is a partially porous channel with discrete heat sources on the bottom wall. The effects of Darcy numbers on heat transfer augmentation and pressure loss were investigated for low Reynolds laminar flows. The results demonstrate the accuracy and robustness of the numerical scheme proposed, and suggest that partially porous insertion in a channel can significantly improve heat transfer performance with affordable pressure loss. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献