全文获取类型
收费全文 | 1712篇 |
免费 | 46篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 302篇 |
金属工艺 | 16篇 |
机械仪表 | 12篇 |
建筑科学 | 87篇 |
矿业工程 | 3篇 |
能源动力 | 24篇 |
轻工业 | 172篇 |
水利工程 | 10篇 |
石油天然气 | 2篇 |
无线电 | 83篇 |
一般工业技术 | 195篇 |
冶金工业 | 662篇 |
原子能技术 | 5篇 |
自动化技术 | 179篇 |
出版年
2022年 | 28篇 |
2021年 | 54篇 |
2020年 | 25篇 |
2019年 | 28篇 |
2018年 | 25篇 |
2017年 | 20篇 |
2016年 | 24篇 |
2015年 | 24篇 |
2014年 | 44篇 |
2013年 | 100篇 |
2012年 | 71篇 |
2011年 | 63篇 |
2010年 | 60篇 |
2009年 | 54篇 |
2008年 | 73篇 |
2007年 | 57篇 |
2006年 | 55篇 |
2005年 | 49篇 |
2004年 | 48篇 |
2003年 | 20篇 |
2002年 | 52篇 |
2001年 | 40篇 |
2000年 | 35篇 |
1999年 | 36篇 |
1998年 | 22篇 |
1997年 | 22篇 |
1996年 | 31篇 |
1995年 | 27篇 |
1994年 | 36篇 |
1993年 | 42篇 |
1992年 | 40篇 |
1991年 | 11篇 |
1990年 | 37篇 |
1989年 | 34篇 |
1988年 | 33篇 |
1987年 | 31篇 |
1986年 | 23篇 |
1985年 | 31篇 |
1984年 | 32篇 |
1983年 | 21篇 |
1982年 | 15篇 |
1981年 | 16篇 |
1980年 | 15篇 |
1979年 | 26篇 |
1978年 | 16篇 |
1977年 | 11篇 |
1976年 | 14篇 |
1975年 | 19篇 |
1973年 | 9篇 |
1972年 | 12篇 |
排序方式: 共有1760条查询结果,搜索用时 15 毫秒
21.
Judith Segal 《Computer Supported Cooperative Work (CSCW)》2009,18(5-6):581-606
In earlier work, I identified a particular class of end-user developers, who include scientists and whom I term ‘professional end-user developers’, as being of especial interest. Here, I extend this work by articulating a culture of professional end-user development, and illustrating by means of a field-study how the influence of this culture causes cooperation problems in an inter-disciplinary team developing a software system for a scientific community. My analysis of the field study data is informed by some recent literature on multi-national work cultures. Whilst acknowledging that viewing a scientific development through a lens of software development culture does not give a full picture, I argue that it nonetheless provides deep insights. 相似文献
22.
A Lack of Insight: An Experimental Analysis of R&D Managers’ Decision Making in Innovation Portfolio Management 下载免费PDF全文
Judith Behrens 《Creativity & Innovation Management》2016,25(2):239-250
This study analyses the decision to exploit an innovation project and investigates differences in individuals’ evaluations of project attributes in the context of innovation project portfolio management. A conjoint field experiment was used to collect data on exploitation decisions made by 126 research and development (R&D) managers to test how managers evaluate specific project attributes in the context of innovation project portfolio management. I analyse the relative power and popularity of profitability, strategy, uncertainty and social dimensions of the portfolio while R&D managers exploit an innovation project. Moreover, using social judgement theory, I analyse actual exploitation processes (i.e., the innovation attributes an R&D manager considers while he or she is making an exploitation decision) and self‐reported decision‐making attributes (i.e., managers’ self‐reported data). The data underline that R&D managers value specific project attributes more and others less, and therefore find disparities in innovation project portfolio decision making. Based on this study's results, decision makers are better able to reflect and understand the influence of specific project attributes. Therefore, they should investigate established decision‐making processes which can help them to improve portfolio performance. 相似文献
23.
Minds and Machines - 相似文献
24.
25.
Dayhoff JE 《Neural computation》2007,19(9):2433-2467
We demonstrate a model in which synchronously firing ensembles of neurons are networked to produce computational results. Each ensemble is a group of biological integrate-and-fire spiking neurons, with probabilistic interconnections between groups. An analogy is drawn in which each individual processing unit of an artificial neural network corresponds to a neuronal group in a biological model. The activation value of a unit in the artificial neural network corresponds to the fraction of active neurons, synchronously firing, in a biological neuronal group. Weights of the artificial neural network correspond to the product of the interconnection density between groups, the group size of the presynaptic group, and the postsynaptic potential heights in the synchronous group model. All three of these parameters can modulate connection strengths between neuronal groups in the synchronous group models. We give an example of nonlinear classification (XOR) and a function approximation example in which the capability of the artificial neural network can be captured by a neural network model with biological integrate-and-fire neurons configured as a network of synchronously firing ensembles of such neurons. We point out that the general function approximation capability proven for feedforward artificial neural networks appears to be approximated by networks of neuronal groups that fire in synchrony, where the groups comprise integrate-and-fire neurons. We discuss the advantages of this type of model for biological systems, its possible learning mechanisms, and the associated timing relationships. 相似文献
26.
Jobs in many modern settings, including manufacturing, service, agriculture and construction, are variable in their content and timing. This prompts the need for exposure assessment methods that do not assume regular work cycles. A scheme is presented for classifying levels of routinization to inform development of an appropriate exposure assessment strategy for a given occupational setting. Five levels of routinization have been defined based on the tasks of which the job is composed: 1) a single scheduled task with a regular work cycle; 2) multiple cyclical tasks; 3) a mix of cyclical and non-cyclical tasks; 4) one non-cyclical task; 5) multiple non-cyclical tasks. This classification, based primarily on job observation, is illustrated through data from a study of automobile manufacturing workers (n = 1200), from which self-assessed exposures to physical and psychosocial stressors were also obtained. In this cohort, decision latitude was greater with higher routinization level (p < 0.0001), and the least routinized jobs showed the lowest self-reported exposure to physical ergonomic stressors. The job analysis checklist developed for non-routinized jobs is presented, and limitations of the task analysis method utilized in the study are discussed. A work sampling approach to job analysis is recommended as the most efficient way to obtain a comparable unbiased exposure estimate across all routinization levels. 相似文献
27.
Companies have introduced innovative organizational structures to deal with rapidity of change, the globalization of markets, and expectations for increased quality and customer service. During this process, many have discovered that the interaction between IT and business units is key to success. This article presents the results of a pilot study that examined the structure of this interaction in eight Fortune 500 manufacturing companies. It answers the questions: What prototypes describe the interaction between IT corporate business units? What outcomes are associated with the various prototypes? What are the implications of these models of structure for the effective delivery of IT services? 相似文献
28.
29.
Richard Ashley David Blackwood Nicki Souter Sarah Hendry Jim Moir Judith Dunkerley John Davies David Butler Andrew Cook Jim Conlin Martin Squibbs Andrew Britton Peter Goldie 《Canadian Metallurgical Quarterly》2005,131(2):206-215
The study presented is an example of the assessment of the relative sustainability of either option for disposal of domestic sanitary waste, either via the toilet or via the solid waste route. This required an evaluation of the total (social, economic, environmental, and technical) benefit/cost of implementing and adopting the alternative routes and an assessment of public responsiveness to encouragement to change sanitary waste disposal practices. It illustrates how, even for an apparently straightforward either/or question, the assessment of relative sustainability is complex and the amount of data needed to quantify sustainability indicators is prodigious. The study also provides an appraisal of the effectiveness of public campaigns to reduce waterborne disposal. Important information regarding public attitude and behavior in relation to wastewater systems has been acquired and lessons for ways of encouraging behavioral change to more sustainable ways of living have been gleaned. 相似文献
30.
R. M. Gordon (2005; see record 2005-08806-011) insists in his commentary on J. S. Wallerstein and J. M. Lewis's (2004; see record 2004-17367-002) work that the impact of divorce on children is fleeting, and he proposes, without supporting evidence, that the long-lasting psychological problems displayed by children of divorce in adolescence and adulthood reflect more the preexisting psychopathology of the parents and their traumatic parenting than any consequence of the disrupted marriage and the unhappy sequelae that so regularly constitute the postdivorce family. The authors' data, based on intensive periodic clinical study of these youngsters and their parents over several decades, indicate the contrary. No research has established that divorcing parents exhibit as a class more mental illness than parents in intact families. The authors' findings speak to the unmet needs of children of divorce for psychological help with their intimate relationships when they enter adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献