全文获取类型
收费全文 | 4123篇 |
免费 | 26篇 |
专业分类
教育 | 2862篇 |
科学研究 | 608篇 |
各国文化 | 19篇 |
体育 | 191篇 |
综合类 | 7篇 |
文化理论 | 70篇 |
信息传播 | 392篇 |
出版年
2023年 | 8篇 |
2022年 | 10篇 |
2021年 | 26篇 |
2020年 | 23篇 |
2019年 | 50篇 |
2018年 | 112篇 |
2017年 | 156篇 |
2016年 | 217篇 |
2015年 | 145篇 |
2014年 | 103篇 |
2013年 | 357篇 |
2012年 | 199篇 |
2011年 | 205篇 |
2010年 | 104篇 |
2009年 | 56篇 |
2008年 | 107篇 |
2007年 | 89篇 |
2006年 | 69篇 |
2005年 | 716篇 |
2004年 | 483篇 |
2003年 | 323篇 |
2002年 | 158篇 |
2001年 | 83篇 |
2000年 | 50篇 |
1999年 | 39篇 |
1998年 | 18篇 |
1997年 | 20篇 |
1996年 | 14篇 |
1995年 | 14篇 |
1994年 | 8篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 19篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 5篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1971年 | 6篇 |
1967年 | 3篇 |
排序方式: 共有4149条查询结果,搜索用时 15 毫秒
101.
This study describes one teacher's use of multimedia, specifically CD-ROM talking books, in the classroom. The goal of the investigation was to reveal and analyse how a primary (Grade 3) teacher integrated CD-ROM books into her curriculum. Issues emerging from the study included how features of the software interact with features of classrooms, how patterns of instruction are affected by the infusion of technology, and how students interact with the software, and each other, while reading the CD- ROM books 相似文献
102.
Johnny Hartz S?raker 《Ethics and Information Technology》2012,14(3):209-219
It has become commonplace to hold the view that virtual surrogates for the things that are good in life are inferior to their actual, authentic counterparts, including virtual education, virtual skill-demanding activities and virtual acts of creativity. Virtual friendship has also been argued to be inferior to traditional, embodied forms of friendship. Coupled with the view that virtual friendships threaten to replace actual ones, the conclusion is often made that we ought to concentrate our efforts on actual friendships rather than settle for virtual replacements. The purpose of this paper is to offer a balanced and empirically grounded analysis of the relative prudential value of actual and virtual friendship. That is, do actual and virtual friendships differ when it comes to enhancing our subjective well-being? In doing so, I will discuss a number of presuppositions that lie behind common criticisms of virtual friendship. This will include, among other considerations, their potential for replacing actual friendship, as well as the possibility for self-disclosure, trust, sharing and dynamic spread of happiness in virtual worlds. The purpose is not to arrive at a firm, normative conclusion, but rather to introduce a number of considerations that we should take into account in our individual deliberations over which role virtual friendships ought to have in our unique life situations. 相似文献
103.
Lee K Kim C Young Yang J Lee H Ahn B Xu L Yoon Kang J Oh KW 《Biomicrofluidics》2012,6(1):14114-141147
We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours. 相似文献
104.
105.
Recently, there has been a heavy debate in the US about the government’s use of data mining in its fight against terrorism.
Privacy concerns in fact led the Congress to terminate the funding of TIA, a program for advanced information technology to
be used in the combat of terrorism. The arguments put forward in this debate, more specifically those found in the main report
and minority report by the TAPAC established by the Secretary of Defense to examine the TIA issue, will be analysed to trace
the deeper roots of this controversy. This analysis will in turn be used as a test case to examine the adequacy of the usual
theoretical frameworks for these kinds of issues, in particular the notion of privacy. Whereas the dominant theoretical framing
of the notion of privacy turns around access to information, most of the core arguments in the debate do not fit in this kind of framework. The basic disagreements in
the controversy are not about mere access, they involve both access and use. Furthermore, whereas the issue of access by itself refers to a more or less static situation, the real disagreements much
more concern the organisational dynamics of the use of information, the mechanisms in the organisation that control these
dynamics, and the awareness present within the organisation of the ‘social risks’ these dynamics represent. The bottom line
question is whether the assessment of these gives sufficient reason for trust. 相似文献
106.
This paper deals with intercultural aspects of privacy, particularly with regard to important differences between Japanese
and the Western views. This paper is based on our discussions with Rafael Capurro – a dialogue now represented by two separate
but closely interrelated articles. The companion paper is broadly focused on the cultural and historical backgrounds of the
concepts of privacy and individualism in “Western” worlds; our main theme focuses on different concepts of privacy in Japan
and their sources in related aspects of Japanese culture. The interrelationship between our two papers is apparent in our
taking up identical or similar topics in each paper. Reading our two papers in conjunction with each other will bring about
deeper and broader insights into the diverse values and worldviews of Japan and Western cultures that underlie concepts of
privacy that at a surface level appear to be similar 相似文献
107.
Today all parties within the health-care system demand more information and evidence to take more efficient and pinpointed management decisions. Their goal is a better patient and patient-care management. This paper presents an information visualisation approach to discover knowledge for the management of tele-home care for the elderly using the video-telephone: what type of elderly need what type of video-telephone interventions? This document focuses on the synthesis aspects of data mining with a view to knowledge discovery: the global, holistic, synthesis approach. More specifically, it summarises visually the relationships among the types of video-telephony care, among the segments of elderly, and between the types of interventions and the segments of elderly simultaneously. The graphical display allows delineating areas that group elderly with a similar/dissimilar video-telephony care profile. Information visualisation is a promising approach to provide insight into large multidimensional data sets. It fosters knowledge discovery. 相似文献
108.
109.
Inger Andersen Naoko Ishii Thomas Brooks Cynthia Cummis Gustavo Fonseca Astrid Hillers Nicholas Macfarlane Nebojsa Nakicenovic Kevin Moss Johan Rockstr?m Andrew Steer Dominic Waughray Caroline Zimm 《国家科学评论(英文版)》2021,(7):12-15
The 2015 Paris Agreement to keep global warming well below 2℃above pre-industrial levels and aim towards limiting warming to 1.5℃marked a wa-tershed in planetar... 相似文献
110.
Size-dependent trajectories of DNA macromolecules due to insulative dielectrophoresis in submicrometer-deep fluidic channels 总被引:1,自引:0,他引:1
Gea O. F. Parikesit Anton P. Markesteijn Oana M. Piciu Andre Bossche Jerry Westerweel Ian T. Young Yuval Garini 《Biomicrofluidics》2008,2(2)
In this paper, we demonstrate for the first time that insulative dielectrophoresis can induce size-dependent trajectories of DNA macromolecules. We experimentally use λ (48.5 kbp) and T4GT7 (165.6 kbp) DNA molecules flowing continuously around a sharp corner inside fluidic channels with a depth of 0.4 μm. Numerical simulation of the electrokinetic force distribution inside the channels is in qualitative agreement with our experimentally observed trajectories. We discuss a possible physical mechanism for the DNA polarization and dielectrophoresis inside confining channels, based on the observed dielectrophoresis responses due to different DNA sizes and various electric fields applied between the inlet and the outlet. The proposed physical mechanism indicates that further extensive investigations, both theoretically and experimentally, would be very useful to better elucidate the forces involved at DNA dielectrophoresis. When applied for size-based sorting of DNA molecules, our sorting method offers two major advantages compared to earlier attempts with insulative dielectrophoresis: Its continuous operation allows for high-throughput analysis, and it only requires electric field strengths as low as ∼10 V∕cm. 相似文献