全文获取类型
收费全文 | 18088篇 |
免费 | 467篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 238篇 |
综合类 | 9篇 |
化学工业 | 3578篇 |
金属工艺 | 280篇 |
机械仪表 | 310篇 |
建筑科学 | 1100篇 |
矿业工程 | 109篇 |
能源动力 | 505篇 |
轻工业 | 1382篇 |
水利工程 | 158篇 |
石油天然气 | 194篇 |
武器工业 | 1篇 |
无线电 | 1064篇 |
一般工业技术 | 2877篇 |
冶金工业 | 4167篇 |
原子能技术 | 162篇 |
自动化技术 | 2439篇 |
出版年
2022年 | 138篇 |
2021年 | 214篇 |
2020年 | 170篇 |
2019年 | 223篇 |
2018年 | 266篇 |
2017年 | 260篇 |
2016年 | 319篇 |
2015年 | 238篇 |
2014年 | 380篇 |
2013年 | 1101篇 |
2012年 | 663篇 |
2011年 | 870篇 |
2010年 | 674篇 |
2009年 | 662篇 |
2008年 | 858篇 |
2007年 | 870篇 |
2006年 | 685篇 |
2005年 | 719篇 |
2004年 | 559篇 |
2003年 | 569篇 |
2002年 | 509篇 |
2001年 | 329篇 |
2000年 | 300篇 |
1999年 | 303篇 |
1998年 | 312篇 |
1997年 | 300篇 |
1996年 | 299篇 |
1995年 | 333篇 |
1994年 | 267篇 |
1993年 | 303篇 |
1992年 | 272篇 |
1991年 | 164篇 |
1990年 | 237篇 |
1989年 | 283篇 |
1988年 | 204篇 |
1987年 | 215篇 |
1986年 | 211篇 |
1985年 | 265篇 |
1984年 | 258篇 |
1983年 | 227篇 |
1982年 | 217篇 |
1981年 | 213篇 |
1980年 | 172篇 |
1979年 | 187篇 |
1978年 | 176篇 |
1977年 | 177篇 |
1976年 | 147篇 |
1975年 | 178篇 |
1974年 | 165篇 |
1973年 | 133篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Charlie Wilson Tom Hargreaves Richard Hauxwell-Baldwin 《Personal and Ubiquitous Computing》2015,19(2):463-476
Published research on smart homes and their users is growing exponentially, yet a clear understanding of who these users are and how they might use smart home technologies is missing from a field being overwhelmingly pushed by technology developers. Through a systematic analysis of peer-reviewed literature on smart homes and their users, this paper takes stock of the dominant research themes and the linkages and disconnects between them. Key findings within each of nine themes are analysed, grouped into three: (1) views of the smart home—functional, instrumental, socio-technical; (2) users and the use of the smart home—prospective users, interactions and decisions, using technologies in the home; and (3) challenges for realising the smart home—hardware and software, design, domestication. These themes are integrated into an organising framework for future research that identifies the presence or absence of cross-cutting relationships between different understandings of smart homes and their users. The usefulness of the organising framework is illustrated in relation to two major concerns—privacy and control—that have been narrowly interpreted to date, precluding deeper insights and potential solutions. Future research on smart homes and their users can benefit by exploring and developing cross-cutting relationships between the research themes identified. 相似文献
992.
To evade signature-based detection, metamorphic viruses transform their code before each new infection. Software similarity measures are a potentially useful means of detecting such malware. We can compare a given file to a known sample of metamorphic malware and compute their similarity—if they are sufficiently similar, we classify the file as malware of the same family. In this paper, we analyze an opcode-based software similarity measure inspired by simple substitution cipher cryptanalysis. We show that the technique provides a useful means of classifying metamorphic malware. 相似文献
993.
994.
Aweaving W is a simple arrangement of lines (or line segments) in the plane together with a binary relation specifying which line is above the other. A system of lines (or line segments) in 3-space is called arealization ofW, if its projection into the plane isW and the above-below relations between the lines respect the specifications. Two weavings are equivalent if the underlying arrangements of lines are combinatorially equivalent and the above-below relations are the same. An equivalence class of weavings is said to be aweaving pattern. A weaving pattern isrealizable if at least one element of the equivalence class has a three-dimensional realization. A weaving (pattern)W is calledperfect if, along each line (line segment) ofW, the lines intersecting it are alternately above and below. We prove that (i) a perfect weaving pattern ofn lines is realizable if and only ifn 3, (ii) a perfect m byn weaving pattern of line segments (in a grid-like fashion) is realizable if and only if min(m, n) 3, (iii) ifn is sufficiently large, then almost all weaving patterns ofn lines are nonrealizable.Jànos Pach has been supported in part by Hungarian NFSR Grant 1812, NSF Grant CCR-8901484, and the Center for Discrete Mathematics and Theoretical Computer Science (DIMACS), a National Science Foundation Science and Technology Center, under NSF Grant STC88-09648. Richard Pollack has been supported in part by NSA Grant MDA904-89-H-2030, NSF Grants DMS-85-01947 and CCR-8901484, and DIMACS. Emo Welzl has been supported in part by the ESPRIT II Basic Research Actions Program of the EC under Contract No. 3075 (project ALCOM) and DIMACS. 相似文献
995.
996.
The unceasing growth and divergence of the mobile landscape have led to the use of smartphone and tablet devices in consuming Web services (WS) in enterprises. However, in heterogeneous WS, the shift from the mobile client consumer approach to the mobile service hosting approach is insufficiently studied. With the advancement of storage and processing capabilities of these devices, coupled with the high availability of the Web, this research focuses on the use of the mobile devices as hosts of WS in a mHealth domain. In this paper, a cloud-centric middleware technique is employed to enable access to the mobile hosts. The paper presents mobile hosting of medical data which are modeled as light-weight WS which is deployed in a real-world system. Further, a workflow authorization model is proposed to ensure privacy and the prevention of unauthorized modification of data on the mobile hosts. A data encryption technique is also put forward to enforce security and privacy of the mobile hosted data. Our current implemented project, called SOPHRA, supports mobile communication over HTTP in a Wi-Fi environment. 相似文献
997.
This paper characterizes a specification for the utility of leisure that is based on the general equation for an ellipse. We show that this functional form has multiple benefits. The elliptical utility function provides Inada conditions at both the upper-bound and lower-bound constraints on labor supply, which is not the case for the two most common alternative functions. The presence of these two Inada conditions in the elliptical utility of leisure specification speeds up the computation by a factor between three and six times. We further show that the elliptical utility of leisure function is a close approximation to the constant relative risk aversion and constant Frisch elasticity functions in terms of marginal utilities, microeconomic outcomes in a life cycle model, and macroeconomic outcomes in a simple real business cycle model. 相似文献
998.
999.
Shan Nan Xu-dong Lu Pieter Van Gorp Hendrikus H. M. Korsten Richard Vdovjak Uzay Kaymak Hui-long Duan 《浙江大学学报:C卷英文版》2018,19(7):937-946
In recent years, it has been demonstrated that checklists can improve patient safety significantly. To facilitate the effective use of checklists in daily practice, both the medical community and the informatics community propose to implement checklists in dynamic checklist applications that can be integrated into the clinical workflow and that is specific to the patient context. However, it is difficult to develop such applications because they are tightly intertwined with the content of specific checklists. We propose a platform that enables access to dynamic checklist applications by configuring the infrastructures provided in the platform. Then, the applications can be developed without time-consuming programming work. We define a number of design criteria regarding point of care and clinical processes by analyzing the existing checklist applications and the lessons learned from implementations. Then, by applying rule-based clinical decision support and workflow management technologies, we design technical mechanisms to satisfy the design criteria. A dynamic checklist application platform is designed based on these mechanisms. Finally, we build a platform in various design cycle iterations, driven by multiple clinical cases. By applying the platform, we develop nine comprehensive dynamic checklist applications with 242 dynamic checklists. The results demonstrate both the feasibility and the overall generic nature of the proposed approach. We propose a novel platform for configuring dynamic checklist applications. This platform satisfies the general requirements and can be easily configured to satisfy different scenarios in which safety checklists are used. 相似文献
1000.