全文获取类型
收费全文 | 16899篇 |
免费 | 8篇 |
专业分类
财政金融 | 2680篇 |
工业经济 | 758篇 |
计划管理 | 2584篇 |
经济学 | 3923篇 |
综合类 | 482篇 |
运输经济 | 1篇 |
旅游经济 | 3篇 |
贸易经济 | 4497篇 |
农业经济 | 8篇 |
经济概况 | 1355篇 |
信息产业经济 | 44篇 |
邮电经济 | 572篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 1篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 2305篇 |
2017年 | 2060篇 |
2016年 | 1209篇 |
2015年 | 95篇 |
2014年 | 98篇 |
2013年 | 85篇 |
2012年 | 449篇 |
2011年 | 1955篇 |
2010年 | 1832篇 |
2009年 | 1526篇 |
2008年 | 1514篇 |
2007年 | 1872篇 |
2006年 | 66篇 |
2005年 | 389篇 |
2004年 | 463篇 |
2003年 | 551篇 |
2002年 | 251篇 |
2001年 | 62篇 |
2000年 | 51篇 |
1998年 | 16篇 |
1996年 | 14篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1986年 | 13篇 |
1983年 | 2篇 |
1980年 | 2篇 |
1973年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Onshore wind energy utilisation in Germany has developed very dynamically in the last decade. This has mainly been driven
by the renewable energy laws that systematically support the expansion of renewable energy in the electricity sector. In 2009
a revised law with increased feed-in tariffs for wind energy has come into force. Existing studies already predict a wide
range of development patterns under the Renewable Energy Sources Acts 2000 and 2004. This paper investigates the long term
impact of different feed-in tariffs implemented by the legislative authorities and it provides corresponding future development
patterns of onshore wind energy utilisation in Germany. The underlying System Dynamics model considers technical as well as
economic conditions and constraints. The approach and the model’s results are contrasted with other published predictions
qualitatively and quantitatively. This comparison shows that the model’s outcome lies in the range of predictions by existing
studies, but also shows some interesting differences.
Zusammenfassung Die Entwicklung der Windenergienutzung in Deutschland wahrend der letzten Dekade verlief sehr dynamisch. MagBgeblich dafur war die systematische Forde-rung mittels der Erneuerbare Energien Gesetze (EEG) bzw. deren Vorlaufer. Vom Jahr 2009 an gilt ein uberarbeitetes Gesetz, welches u.a. erhohte Einspeisever-gutungen furWindenergie beinhaltet.Vorliegende Studien, die sich mit derzu-kunftigen Entwicklung auseinandersetzten, zeigen bereits deutlich unterschied-liche Szenarien fur die Entwicklung unter dem EEG 2000 und 2004. Diese Arbeit setzt sich mit den langfristigen Auswirkungen der verschiedenen vom Gesetz-geber festgelegten Einspeisetarife auseinander und stellt entsprechend unter-schiedliche Ausbauszenarien fur die deutsche Onshore Windenergienutzung dar. Das zugrunde liegende System Dynamics Modell berucksichtigt dabei sowohl technische als auch okonomische Parameter. Der Ansatz sowie die Ergebnisse werden anderen veroffentlichten Prognosen gegenubergestellt. Die Ergebnisse liegen innerhalb der Spannbreite der anderen berucksichtigten Studien, zei-gen jedoch auch interessante Unterschiede.相似文献
92.
This contribution analyses the development of power generation from geothermal energy in Germany. It considers research funding schemes, the support through the german Renewable Energy Sources Act (EEG) and the role of decisive actors as well as technical, economic and societal framework conditions. Compared to other renewable energy sources research funding for geothermal energy had played an inferior role in the past. After the potentials for geothermal power generation had been underlined by a study in 2003, geothermal power gained more political and institutional advocates. Subsequently it was equipped with a higher tariff in the EEG 2004 and led to realization of demonstration projects. Yet, the appliance of technologies for electrical power transformation, ORC and Kalina, are at the very beginning. Presently, the geothermal energy industry consists of a small amount of medium-sized businesses. Regional and nationwide energy providers, acting as operators and investors, do not exert much pressure in view of limited returns. Despite the compatibility with existing power supply systems, constraints to the expansion of geothermal energy use — above all exploration risks and high drilling costs- are likely to lead to a step-by step enhancement rather than a rush. 相似文献
93.
Abusive supervision has received increasing attention in the field. However, few studies have qualitatively reviewed its latest developments. The current paper reviews 48 studies on abusive supervision using content analysis. We identify six emerging trends of abusive supervision, including inconsistency of abusive behaviors, comparison between perceived and objective behaviors, reciprocity, team-level climate, coworker effects, and comparisons between theoretical perspectives. Based on a review of those six trends and some emerging findings, we identify and validate the possible positive effects of abusive supervision from an integrated analysis. We also determine the moderating role that Asian culture plays in differentiating the negative and positive effects of abusive supervision. Specifically, we identify the differences between Asian and Western cultures, and then explore the moral mechanisms (i.e., violation of moral standards, conflict of moral principles) through which abusive supervision may exert positive effects in the Asian cultural context. Finally, we clarify our theoretical implications and provide suggestions for future research. 相似文献
94.
Patricia Potter Bev France 《International Journal of Technology and Design Education》2018,28(1):101-120
Design and problem solving are central to technology and have distinguished learning in technology from other curriculum areas. This research investigated how expert technologists learn design and problem solving through experience. Data was collected from four expert technologists and this information was analysed using learning theories that focus on learning through experience—that is experiential learning theory, situated cognition, distributed cognition and activity theory. This framework of analysis provided evidence that learning through experience is central to these experts’ development and justify a broader construct of experience than normally associated with hard materials. This information supports curriculum development in hard materials technology that employs a wide range of experiences and provides justification for curriculum developers and teachers to justify, inform and develop effective design and problem solving learning programmes focussed on a broadened construct of experience. 相似文献
95.
Patrick Schooner Claes Klasander Jonas Hallström 《International Journal of Technology and Design Education》2018,28(1):169-188
Technology education is a new school subject in comparison with other subjects within the Swedish compulsory school system. Research in technology education shows that technology teachers lack experience of and support for assessment in comparison with the long-term experiences that other teachers use in their subjects. This becomes especially apparent when technology teachers assess students’ knowledge in and about technological systems. This study thematically analysed the assessment views of eleven technology teachers in a Swedish context. Through the use of in-depth semi-structured qualitative interviews, their elaborated thoughts on assessing knowledge about technological systems within the technology subject (for ages 13–16) were analysed. The aim was to describe the teachers’ assessment views in terms of types of knowledge, and essential knowledge in relation to a progression from basic to advanced understanding of technological systems. The results showed three main themes that the interviewed teachers said they consider when performing their assessment of technological systems; understanding (a) a system’s structure, (b) its relations outside the system boundary and (c) its historical context and technological change. Each theme included several underlying items that the teachers said they use in a progressive manner when they assess their students’ basic, intermediate and advanced level of understanding technological systems. In conclusion, the results suggest that the analysed themes can provide a basis for further discussion about defining a progression for assessing students’ understanding about technological systems. However, the findings also need to be examined critically as the interviewed teachers’ views on required assessment levels showed an imbalance; few students were said to reach beyond the basic level, but at the same time most assessment items lay on the intermediate and advanced levels. 相似文献
96.
Hao Jiang MingXi Tang Xiang Peng Xiaoli Liu 《International Journal of Technology and Design Education》2018,28(1):189-206
The subject of design and technology was introduced to the curriculum for high schools in China 10 years ago. However, the teaching and learning of this subject have become difficult for both teachers and students because there is a lack of qualified teachers with design background to deliver this subject in a way to stimulate the learning interests of the students. This paper presents a research that is aimed at improving this situation by integrating the teaching and learning of design and technology within a computational environment as part of social networks sites. The purpose is to enable the collaboration among the students and interaction between teachers and students. In this research, a series of investigations were conducted, by following through several taught subjects in design and technology in prominent high schools in China. Based on these investigations, a theoretical framework for web-based design learning and teaching system in the style of social networking is developed, implemented and tested, emphasizing three features of design: innovation, collaboration, and interaction. This framework has been tested among high school students and teachers in a high school in Nanjing. It identified and validated necessary techniques and design features required to make an education-related social networking site effective and affective for the students and teachers. The results of this research indicated that social networking sites have significantly positive values in design education, especially for the collaboration and interaction on the subject of design and technology. 相似文献
97.
Dalia H. Eldardiry Zeinab A. Elmoghazy 《International Journal of Technology and Design Education》2018,28(1):287-302
The paper explores the impact of the internet on students and their enhancement of their Identity and culture in the world of globalization. It is based on two stages; a theoretical background in the literature that provides criteria for examining the issue of the study. Then, the analytical study is done to the collected data. The paper incorporates two methods of data collection; a questionnaire survey to measure the instructors’ perception of how students should reflect the identity and local culture in their projects in the internet era, and statistical analysis of students’ implementation of cultural knowledge and identity features in their graduation projects in the new millennium before the usage of internet in the design education in the interval of 2001–2007 and after the usage of internet the interval between 2008 and 2015. Consequently, the paper is designed to generate both statistical quantitative and qualitative data. Despite the apparent impact of Globalization and internet based education on abandoning individual identity, yet it might lead to opening new horizons in front of dealing with cultural identity and heritage with a contemporary vision that integrates with nowadays architecture and at the same time refer to the unique identity. 相似文献
98.
Emine Şendurur Esen Ersoy İsmail Çetin 《International Journal of Technology and Design Education》2018,28(2):507-522
The design and development processes of instructional materials might be considered simple and clear because the pre-established instructional goals can lead the way. However, in practice, there are lots of issues to be considered during these processes. The quality of the material, appropriate visual design, usability, and acceptable amount of cognitive load are some of these issues. On the other hand, an instructional material needs to be as original as possible. In this study, we focused on the creativity of the instructional materials designed and developed by second year students from the Computer Education and Instructional Technologies (CEIT) department. We divided students into two groups: (1) CEIT students designing and developing materials about Information Technology (IT); (2) CEIT students designing and developing materials about Math. The main aim of this study is to understand how CEIT students’ instructional materials differ when they design and develop materials, which are out of their field of experience. In other words, we tried to compare how the creativity of materials change when students create materials with familiar domain (IT) in comparison to unfamiliar domain (Math). Students worked on ten instructional materials such as digital story, animation, and worksheet for 14 weeks. The materials of students were evaluated in terms of creativity, and then they were interviewed. The students worked in groups of 4–5, and during the material development period, we as researchers observed and took notes about the whole process. The findings indicated that materials developed in familiar domain were higher in creativity than those of the unfamiliar. Students’ explanations of creativity and their evaluations about the process helped us to understand the reasons of the produced materials’ creativeness. Technical skills, authentic contributions, material type, and the boundaries of the content or familiarity were found as the primary factors affecting the design and development of creative instructional materials. 相似文献
99.
100.
If teachers are not equipped to teach Technology Education subject nationally and internationally, the continent of Africa will continue to bear the brunt of unsavoury results unless radical interventions are implemented to transform the situation. It is against this background that action research methods became a useful site-based support to empower Technology teachers at three sampled schools from Tshwane South Circuit in Gauteng Province of South Africa. The purpose of this study was to share fresh perspectives on how a sample of Technology teachers responded to content-related classroom practices during reflective action research activities that took place during community engagement contact sessions. These teachers, who are under qualified and unqualified to teach this subject, were engaged in circular and spiral action research cycles. The teachers’ engagement brought forth the development of Technology Education Cascading Theory. It was evident that community engagement activities served as a podium to transform teachers’ teaching of Technology Education and enhance learners’ achievement. The study was underpinned by cooperative enquiry theory and engaged participants in reflective practices of developmental action paradigm. Interaction with Technology Education teachers further revealed that most of them need their schools to budget for this Technology subject they are teaching. 相似文献