全文获取类型
收费全文 | 7928篇 |
免费 | 455篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 229篇 |
妇产科学 | 203篇 |
基础医学 | 1275篇 |
口腔科学 | 106篇 |
临床医学 | 584篇 |
内科学 | 1503篇 |
皮肤病学 | 268篇 |
神经病学 | 781篇 |
特种医学 | 363篇 |
外国民族医学 | 5篇 |
外科学 | 1177篇 |
综合类 | 50篇 |
预防医学 | 361篇 |
眼科学 | 213篇 |
药学 | 494篇 |
中国医学 | 4篇 |
肿瘤学 | 760篇 |
出版年
2023年 | 59篇 |
2022年 | 138篇 |
2021年 | 191篇 |
2020年 | 114篇 |
2019年 | 146篇 |
2018年 | 183篇 |
2017年 | 134篇 |
2016年 | 187篇 |
2015年 | 201篇 |
2014年 | 231篇 |
2013年 | 302篇 |
2012年 | 425篇 |
2011年 | 456篇 |
2010年 | 257篇 |
2009年 | 244篇 |
2008年 | 422篇 |
2007年 | 356篇 |
2006年 | 392篇 |
2005年 | 421篇 |
2004年 | 338篇 |
2003年 | 315篇 |
2002年 | 284篇 |
2001年 | 246篇 |
2000年 | 212篇 |
1999年 | 195篇 |
1998年 | 87篇 |
1997年 | 77篇 |
1996年 | 67篇 |
1995年 | 40篇 |
1994年 | 54篇 |
1993年 | 39篇 |
1992年 | 103篇 |
1991年 | 90篇 |
1990年 | 87篇 |
1989年 | 80篇 |
1988年 | 91篇 |
1987年 | 85篇 |
1986年 | 77篇 |
1985年 | 56篇 |
1984年 | 48篇 |
1983年 | 47篇 |
1982年 | 34篇 |
1981年 | 33篇 |
1979年 | 52篇 |
1975年 | 33篇 |
1974年 | 42篇 |
1973年 | 38篇 |
1972年 | 37篇 |
1971年 | 32篇 |
1966年 | 47篇 |
排序方式: 共有8417条查询结果,搜索用时 15 毫秒
101.
Removing power line noise and other frequency‐specific artifacts from electrophysiological data without affecting neural signals remains a challenging task. Recently, an approach was introduced that combines spectral and spatial filtering to effectively remove line noise: Zapline. This algorithm, however, requires manual selection of the noise frequency and the number of spatial components to remove during spatial filtering. Moreover, it assumes that noise frequency and spatial topography are stable over time, which is often not warranted. To overcome these issues, we introduce Zapline‐plus, which allows adaptive and automatic removal of frequency‐specific noise artifacts from M/electroencephalography (EEG) and LFP data. To achieve this, our extension first segments the data into periods (chunks) in which the noise is spatially stable. Then, for each chunk, it searches for peaks in the power spectrum, and finally applies Zapline. The exact noise frequency around the found target frequency is also determined separately for every chunk to allow fluctuations of the peak noise frequency over time. The number of to‐be‐removed components by Zapline is automatically determined using an outlier detection algorithm. Finally, the frequency spectrum after cleaning is analyzed for suboptimal cleaning, and parameters are adapted accordingly if necessary before re‐running the process. The software creates a detailed plot for monitoring the cleaning. We highlight the efficacy of the different features of our algorithm by applying it to four openly available data sets, two EEG sets containing both stationary and mobile task conditions, and two magnetoencephalography sets containing strong line noise. 相似文献
102.
103.
Christian Koelsche Marcus Renner Wolfgang Hartmann Regine Brandt Burkhard Lehner Nina Waldburger Ingo Alldinger Thomas Schmitt Gerlinde Egerer Roland Penzel Eva Wardelmann Peter Schirmacher Andreas von Deimling Gunhild Mechtersheimer 《Journal of experimental & clinical cancer research : CR》2014,33(1):33
104.
105.
Werner Faust Konrad Lang Lehnartz Druckrey A. Fröhlich Langendorff Demuth Hartmann Hinsberg Orzechowski Mühlbock A. Juhász-Schäffer Reiss 《Journal of cancer research and clinical oncology》1936,43(2-3):74-80
Ohne Zusammenfassung 相似文献
106.
107.
V. E. Mertens Pickhan F. Klopstock Collier Krah Hartmann Sponholz V. E. Mertens Demuth Cokkalis Carl Feldmann und Gerlach 《Journal of cancer research and clinical oncology》1931,33(1):32-37
Ohne Zusammenfassung 相似文献
108.
E. Frank E. Hartmann und M. Nothmann 《Journal of molecular medicine (Berlin, Germany)》1925,4(22):1067
Ohne Zusammenfassung 相似文献
109.
Sylvia J. Gasparini Karen Tessmer Miriam Reh Stephanie Wieneke Madalena Carido Manuela Vlkner Oliver Borsch Anka Swiersy Marta Zuzic Olivier Goureau Thomas Kurth Volker Busskamp Günther Zeck Mike O. Karl Marius Ader 《The Journal of clinical investigation》2022,132(12)
Once human photoreceptors die, they do not regenerate, thus, photoreceptor transplantation has emerged as a potential treatment approach for blinding diseases. Improvements in transplant organization, donor cell maturation, and synaptic connectivity to the host will be critical in advancing this technology for use in clinical practice. Unlike the unstructured grafts of prior cell-suspension transplantations into end-stage degeneration models, we describe the extensive incorporation of induced pluripotent stem cell (iPSC) retinal organoid–derived human photoreceptors into mice with cone dysfunction. This incorporative phenotype was validated in both cone-only as well as pan-photoreceptor transplantations. Rather than forming a glial barrier, Müller cells extended throughout the graft, even forming a series of adherens junctions between mouse and human cells, reminiscent of an outer limiting membrane. Donor-host interaction appeared to promote polarization as well as the development of morphological features critical for light detection, namely the formation of inner and well-stacked outer segments oriented toward the retinal pigment epithelium. Putative synapse formation and graft function were evident at both structural and electrophysiological levels. Overall, these results show that human photoreceptors interacted readily with a partially degenerated retina. Moreover, incorporation into the host retina appeared to be beneficial to graft maturation, polarization, and function. 相似文献
110.
Christoph Hartmann Lucas van den Bosch Johannes Spiegel Dominik Rumschttel Daniel Günther 《Materials》2022,15(11)
Binder jetting is a layer-based additive manufacturing process for three-dimensional parts in which a print head selectively deposits binder onto a thin layer of powder. After the deposition of the binder, a new layer of powder is applied. This process repeats to create three-dimensional parts. The binder jetting principle can be adapted to many different materials. Its advantages are the high productivity and the high degree of freedom of design without the need for support structures. In this work, the combination of binder jetting and casting is utilized to fabricate metal parts. However, the achieved properties of binder jetting parts limit the potential of this technology, specifically regarding surface quality. The most apparent surface phenomenon is the so-called stair-step effect. It is considered an inherent feature of the process and only treatable by post-processing. This paper presents a method to remove the stair-step effect entirely in a binder jetting process. The result is achieved by controlling the binder saturation of the individual voxel volumes by either over or underfilling them. The saturation is controlled by droplet size variation as well as dithering, creating a controlled migration of the binder between powder particles. This work applies the approach to silica sand particle material with an organic binder for casting molds and cores. The results prove the effectiveness of this approach and outline a field of research not identified previously. 相似文献