全文获取类型
收费全文 | 795篇 |
免费 | 39篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 18篇 |
化学工业 | 191篇 |
金属工艺 | 8篇 |
机械仪表 | 18篇 |
建筑科学 | 26篇 |
矿业工程 | 5篇 |
能源动力 | 30篇 |
轻工业 | 99篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 69篇 |
一般工业技术 | 157篇 |
冶金工业 | 49篇 |
原子能技术 | 3篇 |
自动化技术 | 157篇 |
出版年
2024年 | 3篇 |
2023年 | 14篇 |
2022年 | 19篇 |
2021年 | 34篇 |
2020年 | 20篇 |
2019年 | 30篇 |
2018年 | 21篇 |
2017年 | 23篇 |
2016年 | 24篇 |
2015年 | 25篇 |
2014年 | 37篇 |
2013年 | 42篇 |
2012年 | 41篇 |
2011年 | 56篇 |
2010年 | 44篇 |
2009年 | 34篇 |
2008年 | 45篇 |
2007年 | 39篇 |
2006年 | 26篇 |
2005年 | 19篇 |
2004年 | 17篇 |
2003年 | 14篇 |
2002年 | 18篇 |
2001年 | 17篇 |
2000年 | 10篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 12篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1974年 | 5篇 |
1972年 | 2篇 |
1964年 | 2篇 |
排序方式: 共有836条查询结果,搜索用时 0 毫秒
11.
A case study validation of a knowledge-based approach for the selection of requirements engineering techniques 总被引:2,自引:1,他引:1
Requirements engineering (RE) is a critical phase in the software engineering process and plays a vital role in ensuring the
overall quality of a software product. Recent research has shown that industry increasingly recognizes the importance of good
RE practices and the use of appropriate RE techniques. However, due to the large number of RE techniques, requirements engineers
find it challenging to select suitable techniques for a particular project. Unfortunately, technique selection based on personal
experience has limitations with regards to the scope, effectiveness and suitability of the RE techniques for the project at
hand. In this paper, a Knowledge-based Approach for the Selection of Requirements Engineering Techniques (KASRET) is proposed
that helps during RE techniques selection. This approach has three major features. First, a library of requirements techniques
was developed which includes detailed knowledge about RE techniques. Second, KASRET integrates advantages of different knowledge
representation schemata and reasoning mechanisms. Thus, KASRET provides mechanisms for the management of knowledge about requirements
techniques and support for RE process development. Third, as a major decision support mechanism, an objective function evaluates
the overall ability and cost of RE techniques, which is helpful for the selection of RE techniques. This paper makes not only
a contribution to RE but also to research and application of knowledge management and decision support in process development.
A case study using an industrial project shows the support of KASRET for RE techniques selection.
相似文献
Behrouz H. FarEmail: |
12.
Yong Ryun Kim Oskar J. Sandberg Stefan Zeiske Gregory Burwell Drew B. Riley Paul Meredith Ardalan Armin 《Advanced functional materials》2023,33(16):2300147
Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) has been one of the most established hole transport layers (HTL) in organic solar cells (OSCs) for several decades. However, the presence of PSS− ions is known to deteriorate device performance via a number of mechanisms including diffusion to the HTL-active layer interface and unwanted local chemical reactions. In this study, it is shown that PSS− ions can also result in local p-doping in the high efficiency donor:non-fullerene acceptor blends – resulting in photocurrent loss. To address these issues, a facile and effective approach is reported to improve the OSC performance through a two-component hole transport layer (HTL) consisting of a self-assembled monolayer of 2PACz ([2-(9H-Carbazol-9-yl)ethyl]phosphonic acid) and PEDOT:PSS. The power conversion efficiency (PCE) of 17.1% using devices with PEDOT:PSS HTL improved to 17.7% when the PEDOT:PSS/2PACz two-component HTL is used. The improved performance is attributed to the overlaid 2PACz layer preventing the formation of an intermixed p-doped PSS− ion rich region (≈5–10 nm) at the bulk heterojunction-HTL contact interface, resulting in decreased recombination losses and improved stability. Moreover, the 2PACz monolayer is also found to reduce electrical shunts that ultimately yield improved performance in large area devices with PCE enhanced from 12.3% to 13.3% in 1 cm2 cells. 相似文献
13.
14.
Outsourcing der Informationsverarbeitung im Mittelstand: Test eines multitheoretischen Kausalmodells
In this paper determinants of information systems (IS) outsourcing are deduced from transaction cost economic theory, resource-based theory and power theory. They are summarized in a theoretical framework which is tested using a sample of small and medium sized enterprises (SMEs) in Germany. The results show that internal performance and know-how deficits vis-à-vis external service providers are key determinants that explain why different IS functions are outsourced to varying degrees in SMEs. Moreover, the determinants of IS functions were found to partially differ between IS functions. Revised reprint of an article from WIRTSCHAFTSINFORMATIK 43(4)2001:339–350. 相似文献
15.
Vasileios Belagiannis Xinchao Wang Horesh Beny Ben Shitrit Kiyoshi Hashimoto Ralf Stauder Yoshimitsu Aoki Michael Kranzfelder Armin Schneider Pascal Fua Slobodan Ilic Hubertus Feussner Nassir Navab 《Machine Vision and Applications》2016,27(7):1035-1046
Multiple human pose estimation is an important yet challenging problem. In an operating room (OR) environment, the 3D body poses of surgeons and medical staff can provide important clues for surgical workflow analysis. For that purpose, we propose an algorithm for localizing and recovering body poses of multiple human in an OR environment under a multi-camera setup. Our model builds on 3D Pictorial Structures and 2D body part localization across all camera views, using convolutional neural networks (ConvNets). To evaluate our algorithm, we introduce a dataset captured in a real OR environment. Our dataset is unique, challenging and publicly available with annotated ground truths. Our proposed algorithm yields to promising pose estimation results on this dataset. 相似文献
16.
Armin Pobitzer Ronald Peikert Raphael Fuchs Benjamin Schindler Alexander Kuhn Holger Theisel Krešimir Matković Helwig Hauser 《Computer Graphics Forum》2011,30(6):1789-1811
Vector fields are a common concept for the representation of many different kinds of flow phenomena in science and engineering. Methods based on vector field topology are known for their convenience for visualizing and analysing steady flows, but a counterpart for unsteady flows is still missing. However, a lot of good and relevant work aiming at such a solution is available. We give an overview of previous research leading towards topology‐based and topology‐inspired visualization of unsteady flow, pointing out the different approaches and methodologies involved as well as their relation to each other, taking classical (i.e. steady) vector field topology as our starting point. Particularly, we focus on Lagrangian methods, space–time domain approaches, local methods and stochastic and multifield approaches. Furthermore, we illustrate our review with practical examples for the different approaches. 相似文献
17.
Offshore outsourcing to vendors in foreign countries causes unique challenges which need to be understood and managed effectively.
This paper explores cultural differences in IS offshoring arrangements involving German client organizations that outsource
application development activities to Indian vendors. For this purpose, a research framework is developed based on both theoretical
considerations and specific empirical observations from multiple case studies. The goal is to (1) explore the nature of cultural
differences in offshore outsourcing arrangements in depth and to (2) analyze the relationship between those cultural differences
and offshore outsourcing success. Based on the case findings, implications and practices for the management of offshore development
projects are outlined. The results indicate that cultural differences in terms of power distance, IS designer values, and
an active versus passive working attitude critically affect several dimensions of relationship quality, thereby influencing
offshore outsourcing success. A clear definition of roles and mechanisms, strong leadership, and an active management of culture
by adapting to either the client’s or the vendor’s national culture appeared to be effective ways to manage cultural differences.
相似文献
Armin HeinzlEmail: |
18.
Bounded Model Checking Using Satisfiability Solving 总被引:10,自引:1,他引:9
Edmund Clarke Armin Biere Richard Raimi Yunshan Zhu 《Formal Methods in System Design》2001,19(1):7-34
The phrase model checking refers to algorithms for exploring the state space of a transition system to determine if it obeys a specification of its intended behavior. These algorithms can perform exhaustive verification in a highly automatic manner, and, thus, have attracted much interest in industry. Model checking programs are now being commercially marketed. However, model checking has been held back by the state explosion problem, which is the problem that the number of states in a system grows exponentially in the number of system components. Much research has been devoted to ameliorating this problem.In this tutorial, we first give a brief overview of the history of model checking to date, and then focus on recent techniques that combine model checking with satisfiability solving. These techniques, known as bounded model checking, do a very fast exploration of the state space, and for some types of problems seem to offer large performance improvements over previous approaches. We review experiments with bounded model checking on both public domain and industrial designs, and propose a methodology for applying the technique in industry for invariance checking. We then summarize the pros and cons of this new technology and discuss future research efforts to extend its capabilities. 相似文献
19.
Sobhani AM Amini SR Tyndall JD Azizi E Daneshtalab M Khalaj A 《Journal of molecular graphics & modelling》2006,25(4):459-469
Azolylalkylquinolines (AAQs) are a family of quinolines with varying degrees of cytotoxic activity (comparable or moderately superior to adriamycin in some cases) developed in the past decade in our group where their exact mode of action is still unclear. In this study the most probable DNA binding mode of AAQs was investigated employing a novel flexible ligand docking approach by using AutoDock 3.0. Forty-nine AAQs with known experimental inhibitory activity were docked onto d(CGCAAATTTGCG)(2), d(CGATCG)(2) and d(CGCG)(2) oligonucleotides retrieved from the Protein Data Bank (PDB IDs: 102D, 1D12 and 1D32, respectively) as the representatives of the three plausible models of interactions between chemotherapeutic agents and DNA (groove binding, groove binding plus intercalation and bisintercalation, respectively). Good correlation (r(2)=0.64) between calculated binding energies and experimental inhibitory activities was obtained using groove binding plus intercalation model for phenyl-azolylalkylquinoline (PAAQ) series. Our findings show that the most probable mode of action of PAAQs as DNA binding agents is via intercalation of quinolinic moiety between CG base pairs with linker chain and azole moiety binding to the minor groove. 相似文献
20.
Illustrative context-preserving exploration of volume data 总被引:2,自引:0,他引:2
Bruckner S Grimm S Kanitsar A Gröller ME 《IEEE transactions on visualization and computer graphics》2006,12(6):1559-1569
In volume rendering, it is very difficult to simultaneously visualize interior and exterior structures while preserving clear shape cues. Highly transparent transfer functions produce cluttered images with many overlapping structures, while clipping techniques completely remove possibly important context information. In this paper, we present a new model for volume rendering, inspired by techniques from illustration. It provides a means of interactively inspecting the interior of a volumetric data set in a feature-driven way which retains context information. The context-preserving volume rendering model uses a function of shading intensity, gradient magnitude, distance to the eye point, and previously accumulated opacity to selectively reduce the opacity in less important data regions. It is controlled by two user-specified parameters. This new method represents an alternative to conventional clipping techniques, sharing their easy and intuitive user control, but does not suffer from the drawback of missing context information 相似文献