全文获取类型
收费全文 | 2478篇 |
免费 | 136篇 |
国内免费 | 37篇 |
专业分类
电工技术 | 142篇 |
综合类 | 90篇 |
化学工业 | 67篇 |
金属工艺 | 15篇 |
机械仪表 | 30篇 |
建筑科学 | 424篇 |
矿业工程 | 26篇 |
能源动力 | 146篇 |
轻工业 | 603篇 |
水利工程 | 69篇 |
石油天然气 | 49篇 |
武器工业 | 12篇 |
无线电 | 131篇 |
一般工业技术 | 158篇 |
冶金工业 | 163篇 |
原子能技术 | 19篇 |
自动化技术 | 507篇 |
出版年
2024年 | 7篇 |
2023年 | 30篇 |
2022年 | 28篇 |
2021年 | 117篇 |
2020年 | 102篇 |
2019年 | 72篇 |
2018年 | 57篇 |
2017年 | 76篇 |
2016年 | 117篇 |
2015年 | 142篇 |
2014年 | 195篇 |
2013年 | 153篇 |
2012年 | 186篇 |
2011年 | 193篇 |
2010年 | 145篇 |
2009年 | 144篇 |
2008年 | 135篇 |
2007年 | 146篇 |
2006年 | 81篇 |
2005年 | 92篇 |
2004年 | 76篇 |
2003年 | 66篇 |
2002年 | 83篇 |
2001年 | 42篇 |
2000年 | 25篇 |
1999年 | 20篇 |
1998年 | 21篇 |
1997年 | 12篇 |
1996年 | 15篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1987年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1977年 | 2篇 |
1964年 | 3篇 |
1963年 | 1篇 |
1961年 | 4篇 |
1960年 | 2篇 |
1959年 | 1篇 |
1958年 | 4篇 |
1957年 | 1篇 |
1955年 | 5篇 |
1954年 | 2篇 |
排序方式: 共有2651条查询结果,搜索用时 15 毫秒
51.
郭建章 《青岛科技大学学报(自然科学版)》1998,(2)
对我国现行的常规压力容器无损检测验收标准做了分析,指出了其中存在的问题并提出了改进设想。 相似文献
52.
Well-founded criticisms of the Consumer Reports (CR; 1995) study of psychotherapy include possible bias of the CR sample; limitations of self-report; and the limitations of cross-sectional, retrospective data. Poorly founded criticisms concern "consumer satisfaction" and the claim that the remarkably good effects of long-term therapy resulted from spontaneous remission, that psychotherapy effects were small, and that nondoctoral providers did as well as doctoral-level providers. Both the experimental method (efficacy) and the observational method with causal modeling (effectiveness) answer complementary questions, and they both do so by eliminating alternative possible causes. Efficacy studies, however, cannot test long-term psychotherapy because long-term manuals cannot be written and patients cannot be randomized into two-year-long placebo controls, so the "empirical validation" of long-term therapy will likely come from effectiveness studies. Such studies of long-term therapy, of qualifications of providers, and of clinical judgment versus case management are urgently needed as practice confronts managed care. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
53.
Provides an overview of the 1995 Consumer Reports survey of the effectiveness of psychotherapy. Specific issues addressed include the study's goals; the findings for mental health professionals, family doctors, and self-help groups; and methodological strengths and weaknesses related to external validity, sampling, controls, self-reports, and time frame. The data show that, free of the artificial constraints of controlled studies in the real world, a population of consumers can often benefit from psychological intervention services. Real relief can be found at the hands of professional mental health providers. M. Kotkin et al reaffirm their independence from M. E. P. Seligman (see record 1996-13324-001) regarding the interpretation of the data. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
54.
Contends that there are 3 methodological errors and an inconsistency in M. E. P. Seligman's (see record 1996-13324-001) reanalysis of the 1995 Consumer Reports survey of the effectiveness of psychotherapy. These errors are directly relevant to the cost-effectiveness of psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
55.
Viswanath Venkatesh James Y. L. Thong Frank K. Y. Chan Paul Jen‐Hwa Hu Susan A. Brown 《Information Systems Journal》2011,21(6):527-555
This study presents two extensions to the two‐stage expectation‐confirmation theory of information systems (IS) continuance. First, we expand the belief set from perceived usefulness in the original IS continuance model to include three additional predictors identified in the unified theory of acceptance and use of technology, namely effort expectancy, social influence and facilitating conditions. Second, we ground the IS continuance model in the context of transactional systems that involve transmission of personal and sensitive information and include trust as a key contextual belief in the model. To test the expanded IS continuance model, we conducted a longitudinal field study of 3159 Hong Kong citizens across two electronic government (e‐government) technologies that enable citizens' access to government services. In general, the results support the expanded model that provides a rich understanding of the changes in the pre‐usage beliefs and attitudes through the emergent constructs of disconfirmation and satisfaction, ultimately influencing IS continuance intention. Finally, we discuss the theoretical and practical implications of the expanded model. 相似文献
56.
This paper studies a generalization of the order acceptance and scheduling problem in a single-machine environment where a pool consisting of firm planned orders as well as potential orders is available from which an over-demanded company can select. The capacity available for processing the accepted orders is limited and each order is characterized by a known processing time, delivery date, revenue and a weight representing a penalty per unit-time delay beyond the delivery date. We prove that the existence of a constant-factor approximation algorithm for this problem is unlikely. We propose two linear formulations that are solved using an IP solver and we devise two exact branch-and-bound procedures able to solve instances with up to 50 jobs within reasonable CPU times. We compare the efficiency and quality of the results obtained using the different solution approaches. 相似文献
57.
Keng-Boon Ooi 《Computers in human behavior》2011,27(3):1168-1178
The purpose of this paper is to examine various normative, attitudinal and control factors influencing consumers’ intention to adopt broadband internet in a developing country such as Malaysia. This study is based on empirical data collected using a self-administered questionnaire relating to the normative, attitudinal and control variables. Structural equation modeling analysis is conducted to test the role of numerous variables on consumers’ behavioral intentions to adopt broadband internet in Malaysia. Results revealed that Primary Influences (PI), Relative Advantage (RA), Hedonic Outcomes (HO), Facilitating Conditions Resources (FCR), and Self-Efficacy (SE) are positively associated with consumers’ Behavioral Intention (BI) to adopt broadband in Malaysia. The significance of this research study is twofold. Practically, this research study provide some useful guidelines to industry players, be it the internet service providers (ISPs) or the policy makers, to understand which are the factors (primary influences, self-efficacy, relative advantage, hedonic outcomes and facilitating conditions resources) that can have an influence on consumers’ intention to adopt broadband technology. It was found that primary influences, self-efficacy and relative advantage are the key determinants that influences consumers’ broadband adoption. From here, practitioners could take into consideration our findings when revising and restructuring their marketing strategy. Theoretically, the research framework used in this study is an extension from the past research models used (i.e. TPB, DOI and MATH). With the newly integrated framework, a greater level of comprehension can be attained with regards to the broadband acceptance among the Malaysian consumers. 相似文献
58.
This study seeks to validate a comprehensive model of consumer acceptance in the context of mobile payment. It uses the unified theory of acceptance and use of technology (UTAUT) model with constructs of security, trust, social influence, and self-efficacy. Structural equation modeling is used to construct a predictive model of attitudes toward the mobile wallet. Individuals’ responses to questions about attitude and intention to adopt/use a mobile wallet were collected and analyzed with various factors modified from UTAUT. While the model confirms the classical role of technology acceptance factors (i.e., perceived usefulness and ease of use are key antecedents to users’ attitude), the results also show that users’ attitudes and intentions are influenced by perceived security and trust. In the extended model, the moderating effects of demographics on the relations among the variables were found to be significant. The proposed model brings together extant research on mobile payment and provides an important cluster of antecedents to eventual technology acceptance via constructs of behavioral intention to use and actual system usage. 相似文献
59.
E-commerce present opportunities and challenges for businesses, especially for micro-enterprises. This paper proposed a theoretical framework that in line with the unique characteristics of E-commerce acceptance in micro-enterprises in Chengdu, which is based on the unified theory of acceptance and use of technology (UTAUT) model. The extending UTAUT model includes key constructs of performance expectation, perceived behavioral control and the characteristics of owner-managers. 相似文献
60.
Mining significant factors affecting the adoption of SaaS using the rough set approach 总被引:1,自引:0,他引:1
Wei-Wen WuAuthor Vitae 《Journal of Systems and Software》2011,84(3):435-441
Despite that Software as a Service (SaaS) seems to be the most tempting solution among different types of cloud services, yet it has not been adopted to-date with as much alacrity as was originally expected. A variety of factors may influence the adoption of SaaS solutions. The objective of this study is thus to explore the significant factors affecting the adoption of SaaS for vendors and enterprise users. An analytical framework is proposed containing two approaches—Technology Acceptance Model (TAM) and Rough Set Theory (RST). An empirical study on the IT/MIS enterprises in Taiwan is carried out. The results have revealed a considerable amount of meaningful information, which not only facilitates the SaaS vendors to grasp users’ needs and concerns about SaaS adoption, but also helps the managers to introduce effective marketing strategies and actions to promote the growth of SaaS market. Based on the findings, some managerial implications are discussed. 相似文献