全文获取类型
收费全文 | 11476篇 |
免费 | 0篇 |
专业分类
教育 | 8874篇 |
科学研究 | 1214篇 |
各国文化 | 1篇 |
体育 | 334篇 |
文化理论 | 382篇 |
信息传播 | 671篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 2172篇 |
2017年 | 2075篇 |
2016年 | 1563篇 |
2015年 | 107篇 |
2014年 | 113篇 |
2013年 | 69篇 |
2012年 | 214篇 |
2011年 | 687篇 |
2010年 | 832篇 |
2009年 | 427篇 |
2008年 | 637篇 |
2007年 | 1145篇 |
2006年 | 66篇 |
2005年 | 391篇 |
2004年 | 443篇 |
2003年 | 355篇 |
2002年 | 127篇 |
2001年 | 4篇 |
2000年 | 19篇 |
1998年 | 1篇 |
1997年 | 14篇 |
1991年 | 6篇 |
1976年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Based on five scheduling types and their QoS requirements defined in IEEE 802.16e specification, this paper proposes a new scheduring algorithm for non-real-time or real-time multimedia services. Taking the performances of efficiency, fairness and complexity into consideration, the proposed algorithm enhances the efficiency of air interface resource at the expense of the short-time unfairness, but ensures the long-time fairness. Moreover, the proposed algorithm introduces an efficient QoS assurance mechanism, which implements the functions of congestion control, queuing management and traffic management. The simulation results based on a simplified traffic model show that the proposed algorithm guarantees better performances of efficiency and fairness than conventional algorithms, without increasing the algorithm complexity. Especially on the occasion of heavy-traffic requirement, the performance of efficiency and fairness can be improved by 50% at most. 相似文献
992.
Reinforced concrete (RC) columns lacking adequately detailed transverse reinforcement do not possess the necessary ductility to dissipate seismic energy during a major earthquake without severe strength degradation. In this paper, a new retrofit method, which utilized fiber-reinforced plastics (FRP) confinement mechanism and anchorage of embedded bars, was developed aiming to retrofit non-ductile large RC rectangular columns to prevent the damage of the plastic hinges. Carbon FRP (CFRP) sheets and glass FRP (GFRP) bars were used in this test, and five scaled RC columns were tested to examine the function of this new method for improving the ductility of columns. Responses of columns were examined before and after being retrofitted. Test results indicate that this new composite method can be very effective to improve the anti-seismic behavior of non-ductile RC columns compared with normal CFRP sheets retrofitted column. 相似文献
993.
马晨明 《上海大学学报(英文版)》2008,12(5):377-382
Hamiltonian system for the problem on clamped Mindlin plate bending was established by introducing the dual variables for the generalized displacements in this letter. By separation of variables, the transverse eigen-problem was derived based on the sympletic geometry method. With the solved sympletic eigen-values, the generalized sympletic eigen-solution was derived through eigenfunction expansion. An example of plate with all edges clamped was given. The sympletic solution system was worked out directly from the Hamiltonian system. It breaks the limitation of traditional analytic methods which need to select basis functions in advance. The results indicate that the sympletic solution method could find its more extensive applications. 相似文献
994.
Cynthia Jane A. V. Nerurkar F. R. Karjodkar 《Indian journal of clinical biochemistry : IJCB》2007,22(2):114-117
Oral Cancer is one of the five leading sites of cancer in Indian population. The circulating immune complexes were investigated
in 100 serum samples of 60 oral cancer patients having different grades of the disease and 40 patients with precancerous lesions
obtained from Nair Hospital Dental collage, Mumbai. The results obtained were compared with those of group of 40 healthy blood
donors. Elevated levels of Circulating Immune Complexes were observed in oral cancer patients and patients with oral precancerous
lesions. 92% positive samples were observed in well differentiated squamous cell carcinoma whereas 100% positive samples were
observed in both moderately and poorly differentiated squamous cell carcinoma. Oral leukoplakia and oral submucous fibrosis
showed 15% and 90% positivity respectively. Increased level of Circulating Immune complexes in high grade tumor suggest that
Circulating Immune complexes is likely to contribute in evaluating the degree of malignancy, but follow up study is needed
to draw any conclusion regarding it's prognostic role 相似文献
995.
996.
997.
Oliver K. Burmeister 《Ethics and Information Technology》2016,18(3):185-198
Developing technology that accounts for values has been achieved in many areas, including security, gaming, finance, engineering, and many more. The main methodological approach has been that of value sensitive design. But most of the work to date has been on the first of its three stages. The focus of this article is on advances related to its second stage, empirical investigation, and in particular the impact of contextual understanding in that stage. Although lessons can be learnt from other domains, the specific context of dementia means that there are nuances to understanding values, including justice and autonomy, that differ from other areas. The integration of value considerations in the development of assistive technology in dementia is explored in two broad categories: the traditional and ongoing need for fixed decision support, and adaptable decision support technologies. For fixed decision support the A&D Benchmark is particularly useful in design. But for adaptable technologies, that benchmark requires further development, including consideration of the values of additional stakeholders, such as the general public. 相似文献
998.
999.
Kapil Mehta 《Indian journal of clinical biochemistry : IJCB》1997,12(1):23-25
A rational approach for developing effective filaricides awaits greater knowledge on the biochemical pathways operating in filarial parasites. For example, metabolic pathways or key enzymes that are so pivotal to the parasite that their interruption or inhibition causes spontaneous death, could be exploited to develop effective chemotherapeutic agents. Similarly, developing a safe and nontoxic filaricidal will require precise understanding of whether or not the potential molecular target in the parasite is unique or at least different enough from the host system. Recently, we identified a novel transglutaminase enzyme (EC2.3.2.13; TGase) in filarial parasites that plays an important role during their normal growth and development. Based on these principles, TGase may serve as a new target for the development of effective chemotherapeutic agent and vaccine for controlling and preventing the infections caused by these parasites. 相似文献
1000.