全文获取类型
收费全文 | 2266篇 |
免费 | 120篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 29篇 |
综合类 | 11篇 |
化学工业 | 423篇 |
金属工艺 | 50篇 |
机械仪表 | 33篇 |
建筑科学 | 204篇 |
矿业工程 | 7篇 |
能源动力 | 71篇 |
轻工业 | 203篇 |
水利工程 | 26篇 |
石油天然气 | 13篇 |
无线电 | 182篇 |
一般工业技术 | 389篇 |
冶金工业 | 215篇 |
原子能技术 | 5篇 |
自动化技术 | 529篇 |
出版年
2024年 | 8篇 |
2023年 | 31篇 |
2022年 | 45篇 |
2021年 | 68篇 |
2020年 | 51篇 |
2019年 | 69篇 |
2018年 | 76篇 |
2017年 | 63篇 |
2016年 | 93篇 |
2015年 | 74篇 |
2014年 | 107篇 |
2013年 | 171篇 |
2012年 | 127篇 |
2011年 | 176篇 |
2010年 | 148篇 |
2009年 | 101篇 |
2008年 | 131篇 |
2007年 | 113篇 |
2006年 | 120篇 |
2005年 | 101篇 |
2004年 | 74篇 |
2003年 | 79篇 |
2002年 | 55篇 |
2001年 | 43篇 |
2000年 | 33篇 |
1999年 | 28篇 |
1998年 | 27篇 |
1997年 | 15篇 |
1996年 | 30篇 |
1995年 | 18篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1980年 | 5篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有2390条查询结果,搜索用时 15 毫秒
31.
32.
Tim Menzies Ye Yang George Mathew Barry Boehm Jairus Hihn 《Empirical Software Engineering》2017,22(5):2658-2683
More than half the literature on software effort estimation (SEE) focuses on comparisons of new estimation methods. Surprisingly, there are no studies comparing state of the art latest methods with decades-old approaches. Accordingly, this paper takes five steps to check if new SEE methods generated better estimates than older methods. Firstly, collect effort estimation methods ranging from “classical” COCOMO (parametric estimation over a pre-determined set of attributes) to “modern” (reasoning via analogy using spectral-based clustering plus instance and feature selection, and a recent “baseline method” proposed in ACM Transactions on Software Engineering). Secondly, catalog the list of objections that lead to the development of post-COCOMO estimation methods. Thirdly, characterize each of those objections as a comparison between newer and older estimation methods. Fourthly, using four COCOMO-style data sets (from 1991, 2000, 2005, 2010) and run those comparisons experiments. Fifthly, compare the performance of the different estimators using a Scott-Knott procedure using (i) the A12 effect size to rule out “small” differences and (ii) a 99 % confident bootstrap procedure to check for statistically different groupings of treatments. The major negative result of this paper is that for the COCOMO data sets, nothing we studied did any better than Boehms original procedure. Hence, we conclude that when COCOMO-style attributes are available, we strongly recommend (i) using that data and (ii) use COCOMO to generate predictions. We say this since the experiments of this paper show that, at least for effort estimation, how data is collected is more important than what learner is applied to that data. 相似文献
33.
Tim Horberry 《International Journal of Industrial Ergonomics》2011,41(5):551-560
Designing and implementing safe, efficient and operator-centred traffic management systems for mobile equipment, other vehicles and pedestrians is of key importance in almost every industrial domain. Such systems rarely develop successfully on their own; whilst standards and guidelines do exist, they are often not stringently and comprehensively employed in all industrial settings, and additional guidance to managers responsible for traffic management would be beneficial.Building on models of the elements required for effective traffic management, the work described in this paper used a review of the literature, case studies from a variety of different industrial domains and operator-centred safe design processes to develop a set of 50 human element questions to help ensure mobile equipment safety. The process was iterative, and involved subject matter expert feedback, trialling the draft question set in an audit of several sites following a major incident and incorporating emerging findings about the possible use of new assistive technologies (such as collision detection systems).
Relevance to industry
In terms of industrial applications, the resultant question list can be used to identify potential problem areas, primarily safety but also partly inefficiency, regarding mobile equipment interactions with pedestrians, infrastructure or other equipment. Potential problem areas revealed could then undergo more detailed investigation and possible correction using risk assessment techniques or similar. 相似文献34.
Roman Beck Daniel Beimborn Tim Weitzel Wolfgang König 《Information Systems Frontiers》2008,10(4):415-429
Adoption research has largely ignored the dynamic impact of network effects on technology adoption and diffusion. For example, some technologies become more attractive the more social peers use them as well. But adoption at the same time increases the value for the peers and thereby their adoption decisions as well. Unfortunately, interdependencies like these make adoption and diffusion patterns very complex. Drawing on network effect theory, we develop an adoption and diffusion model that explicitly considers the role of direct and indirect network effects for individual technology adoption, using mobile commerce adoption as application example. By applying a simulation approach we can exemplify and analyze the fundamental adoption dynamics given rise to by network effects. We thereby propose a way of how to incorporate network effects into adoption research and disclose the role of the technology diffusion lifecycle for individual adoption. 相似文献
35.
Kim Wüllenweber Daniel Beimborn Tim Weitzel Wolfgang König 《Information Systems Frontiers》2008,10(2):211-224
What is the impact of business process standardization on business process outsourcing (BPO) success? This paper argues that there is a direct impact of process standardization on BPO success, due to production cost economies, and also an indirect effect via improved contractual and relational governance resulting from better monitoring opportunities and facilitated communication and coordination. This threefold impact of standardization on BPO success is empirically confirmed using data from 335 BPO ventures in 215 German banks. 相似文献
36.
The primary aims of this study were to establish a client injury baseline for the New Zealand adventure tourism and adventure sport sector, and to examine patterns and trends in claims for injury during participation in adventure activities. Content analysis of narrative text data for compensated injuries occurring in a place for recreation and sport over a 12-month period produced over 15,000 cases involving adventure tourism and adventure sport. As found in previous studies in New Zealand, highest claim counts were observed for activities that are often undertaken independently, rather than commercially. Horse riding, tramping, surfing and mountain biking were found to have highest claim counts, while hang gliding/paragliding/parasailing and jet boating injuries had highest claim costs, suggesting greatest injury severity. Highest claim incidence was observed for horse riding, with female claimants over-represented for this activity. Younger male claimants comprised the largest proportion of adventure injuries, and falls were the most common injury mechanism. 相似文献
37.
Programmable logic designs are presented that achieve exact integration of leaky integrate-and-fire soma and dynamical synapse neuronal models and incorporate spike-time dependent plasticity and axonal delays. Highly accurate numerical performance has been achieved by modifying simpler forward-Euler-based circuitry requiring minimal circuit allocation, which, as we show, behaves equivalently to exact integration. These designs have been implemented and simulated at the behavioral and physical device levels, demonstrating close agreement with both numerical and analytical results. By exploiting finely grained parallelism and single clock cycle numerical iteration, these designs achieve simulation speeds at least five orders of magnitude faster than the nervous system, termed here hyper-real-time operation, when deployed on commercially available field-programmable gate array (FPGA) devices. Taken together, our designs form a programmable logic construction kit of commonly used neuronal model elements that supports the building of large and complex architectures of spiking neuron networks for real-time neuromorphic implementation, neurophysiological interfacing, or efficient parameter space investigations. 相似文献
38.
Tim D. Sparks Bettina N. Bockelmann-Evans Roger A. Falconer 《Water Resources Management》2013,27(8):2989-3004
DIVAST is a two-dimensional hydrodynamic and water quality numerical model developed for estuarine and coastal modelling. The original model enables the simulation of problems such as pollution and flooding in surface waters. In this paper the existing model is extended to allow the modelling of 2-D groundwater as well as surface water in the same model, using an integrated approach rather than two disparate models. The changes to the original model are summarised and the method of implementation is outlined. The new extended model (DIVAST-SG) is then tested against an analytical solution to verify that the model solves the equations correctly. The model is shown to predict the analytical solution for two different scenarios to within approximately 1 % of the height of flood wave. 相似文献
39.
Frederick Ira Moxley Tim Byrnes Fumitaka Fujiwara Weizhong Dai 《Computer Physics Communications》2012,183(11):2434-2440
The Quantum Finite-Difference Time-Domain (FDTD-Q) method is a numerical method for solving the time evolution of the Schrödinger equation. It can be applied to systems of interacting particles, allowing for realistic simulations of quantum mechanics of various experimental systems. One of the drawbacks of the method is that divergences in the numerical evolution occur rather easily in the presence of interactions, which necessitates a large number of evolution steps or imaginary time evolution. We present a generalized (GFDTD-Q) method for solving the time-dependent Schrödinger equation including interactions between the particles. The new scheme provides a more relaxed condition for stability when the finite difference approximations for spatial derivatives are employed, as compared with the original FDTD-Q scheme. We demonstrate our scheme by simulating the time evolution of a two-particle interaction Hamiltonian. Our results show that the generalized method allows for stable time evolutions, in contrast to the original FDTD-Q scheme which produces a divergent solution. 相似文献
40.
Tim Weitzel Daniel Beimborn Wolfgang König 《Information Systems and E-Business Management》2003,1(2):189-211
Networks utilizing modern communication technologies can offer competitive advantages to those using them wisely. But due
to the existence of network effects, planning and operating cooperation networks is difficult. In this paper, the strategic
situation of individual agents deciding on network participation is analysed. A systematic equilibrium analysis using computer-based
simulations reveals principal solution scenarios for network agents and shows that network cooperation problems might frequently
be not as difficult to resolve as often feared. In particular, strategic situations are identified showing that a majority
of individuals might be better off getting the optimal solution from a central principal and that in many cases simple information
intermediation can solve the start-up problem notorious in network economics. 相似文献