全文获取类型
收费全文 | 3930篇 |
免费 | 332篇 |
国内免费 | 1篇 |
出版年
2023年 | 19篇 |
2022年 | 29篇 |
2021年 | 58篇 |
2020年 | 34篇 |
2019年 | 40篇 |
2018年 | 83篇 |
2017年 | 54篇 |
2016年 | 92篇 |
2015年 | 162篇 |
2014年 | 206篇 |
2013年 | 201篇 |
2012年 | 294篇 |
2011年 | 261篇 |
2010年 | 175篇 |
2009年 | 157篇 |
2008年 | 220篇 |
2007年 | 240篇 |
2006年 | 209篇 |
2005年 | 221篇 |
2004年 | 172篇 |
2003年 | 206篇 |
2002年 | 178篇 |
2001年 | 42篇 |
2000年 | 29篇 |
1999年 | 31篇 |
1998年 | 46篇 |
1997年 | 37篇 |
1996年 | 31篇 |
1995年 | 30篇 |
1994年 | 22篇 |
1993年 | 27篇 |
1992年 | 16篇 |
1991年 | 30篇 |
1990年 | 39篇 |
1989年 | 23篇 |
1988年 | 30篇 |
1987年 | 26篇 |
1986年 | 16篇 |
1985年 | 17篇 |
1984年 | 22篇 |
1983年 | 19篇 |
1982年 | 22篇 |
1981年 | 24篇 |
1980年 | 19篇 |
1978年 | 15篇 |
1977年 | 17篇 |
1974年 | 14篇 |
1969年 | 13篇 |
1968年 | 13篇 |
1967年 | 15篇 |
排序方式: 共有4263条查询结果,搜索用时 15 毫秒
1.
Georg Söderbom 《Ethnos》2013,78(1-2):95-100
Current debates over the concept of culture are examined, especially with regard to the relationship of culture to bounded collectivities, human nature, and individuality; present‐day views are seen against the background of back‐and‐forth swings in the history of anthropological thought. Recent theorizing about cultural acquisition is also considered. 相似文献
2.
Georg Mosebach 《Planta》1945,34(2):249-292
Ohne ZusammenfassungMit 16 Textabbildungen.Vor seinem letzten Abschied legte mir mein Mann die Manuskripte zweier Arbeiten in die Hand mit der Bitte, wenn nötig, statt seiner für ihre Veröffentlichung zu sorgen. Die erste Arbeit (Über die Polarisierung derEquiselum-Spore durch das Licht, Planta 33, 1943) war so gut wie druckfertig und wurde von den Herren ProfessorenJ. Buder, Breslau, undL. Jost, Heidelberg, durchgesehen. Herr ProfessorBuder hatte auch die Freundlichkeit, die Korrekturen zu lesen. Die zweite, hier vorliegende Arbeit war vonGeorg Mosebach in dieser Fassung noch nicht für die Veröffentlichung bestimmt; trotzdem ist sie nun doch in der ursprünglichen Form erschienen — abgesehen von wenigen oder unbedeutenden Änderungen, die Herr ProfessorBuder und Herr ProfessorRuhland, Leipzig, die Güte hatten vorzunehmen. Herrn Professor Dr.J. Buder, Herrn Professor Dr.L. Jost und Herrn Professor Dr.W. Ruhland spreche ich auch an dieser Stelle meinen Dank aus für alle selbstlose Hilfe, die mir bei meiner Aufgabe zuteil wurde; für viele gute. Ratschläge und alle Mühe, die mit der Durchsicht einer Arbeit verbunden ist.Erna Mosebach, Dr. phil. nat. 相似文献
3.
Se-Chan Kim Alexander Ghanem Heidi Stapel Klaus Tiemann Pascal Knuefermann Andreas Hoeft Rainer Meyer Christian Grohé Anne A Knowlton Georg Baumgarten 《BMC physiology》2007,7(1):5
Backgound
It has been reported that Toll-like receptor 4 (TLR4) deficiency reduces infarct size after myocardial ischemia/reperfusion (MI/R). However, measurement of MI/R injury was limited and did not include cardiac function. In a chronic closed-chest model we assessed whether cardiac function is preserved in TLR4-deficient mice (C3H/HeJ) following MI/R, and whether myocardial and systemic cytokine expression differed compared to wild type (WT). 相似文献4.
Georg Steinhauser Johannes H. Sterba Karin Poljanc Max Bichler Karl Buchtela 《Journal of trace elements in medicine and biology》2006,20(3):119-153
In this study, 18 partly commercially available samples of rock salt from Austria, Germany, Pakistan, Poland, Switzerland, and Ukraine were investigated with respect to their content of trace elements using instrumental neutron activation analysis. Elements detected were Al, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, La, Mn, Na, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Th, and Zn, some of them only in individual cases. An estimation of the bioavailability of these trace elements was performed by dissolving an equivalent of the sodium chloride samples in diluted hydrochloric acid (simulating stomach acid), filtering off the insoluble components, and analyzing the evaporated filtrate. It could be shown that in most cases bioactive trace elements like Fe can be found in rock salt in the form of almost insoluble compounds and are therefore not significantly bioavailable, whereas thorium, for example, was partly bioavailable in two cases. A significant contribution to the recommended daily intake of metal trace elements by using rock salt for nutrition can be excluded. 相似文献
5.
Markus Hoffmann Nadine Krüger Pawel Zmora Florian Wrensch Georg Herrler Stefan P?hlmann 《PloS one》2016,11(3)
New World bats have recently been discovered to harbor influenza A virus (FLUAV)-related viruses, termed bat-associated influenza A-like viruses (batFLUAV). The internal proteins of batFLUAV are functional in mammalian cells. In contrast, no biological functionality could be demonstrated for the surface proteins, hemagglutinin (HA)-like (HAL) and neuraminidase (NA)-like (NAL), and these proteins need to be replaced by their human counterparts to allow spread of batFLUAV in human cells. Here, we employed rhabdoviral vectors to study the role of HAL and NAL in viral entry. Vectors pseudotyped with batFLUAV-HAL and -NAL were able to enter bat cells but not cells from other mammalian species. Host cell entry was mediated by HAL and was dependent on prior proteolytic activation of HAL and endosomal low pH. In contrast, sialic acids were dispensable for HAL-driven entry. Finally, the type II transmembrane serine protease TMPRSS2 was able to activate HAL for cell entry indicating that batFLUAV can utilize human proteases for HAL activation. Collectively, these results identify viral and cellular factors governing host cell entry driven by batFLUAV surface proteins. They suggest that the absence of a functional receptor precludes entry of batFLUAV into human cells while other prerequisites for entry, HAL activation and protonation, are met in target cells of human origin. 相似文献
6.
Tobias Consmüller Antonius Rohlmann Daniel Weinland Claudia Druschel Georg N. Duda William R. Taylor 《PloS one》2012,7(11)
The importance of functional parameters for evaluating the severity of low back pain is gaining clinical recognition, with evidence suggesting that the angular velocity of lordosis is critical for identification of musculoskeletal deficits. However, there is a lack of data regarding the range of functional kinematics (RoKs), particularly which include the changing shape and curvature of the spine. We address this deficit by characterising the angular velocity of lordosis throughout the thoracolumbar spine according to age and gender. The velocity of lumbar back shape changes was measured using Epionics SPINE during maximum flexion and extension activities in 429 asymptomatic volunteers. The difference between maximum positive and negative velocities represented the RoKs. The mean RoKs for flexion decreased with age; 114°/s (20–35 years), 100°/s (36–50 years) and 83°/s (51–75 years). For extension, the corresponding mean RoKs were 73°/s, 57°/s and 47°/s. ANCOVA analyses revealed that age and gender had the largest influence on the RoKs (p<0.05). The Epionics SPINE system allows the rapid assessment of functional kinematics in the lumbar spine. The results of this study now serve as normative data for comparison to patients with spinal pathology or after surgical treatment. 相似文献
7.
8.
9.
Lower Miocene siliciclastic sediments of the Vöckla Schichten and Atzbacher Sande, Austria, contain a shallow-water trace-fossil assemblage of the Cruziana ichnofacies includingSkolithos isp.,Planolites ? beverleyensis, Ophiomorpha annulata, O.nodosa, Rosselia socialis, Cylindrichnus concentricus, Scolicia isp., andBichordites monastiriensis. The ichnogenusRosselia and the ichnospeciesRosselia socialis are revised. Analysis ofScolicia isp. andB. monastiriensis provides new information about their morphology and ichnotaxonomy. 相似文献
10.
Antonius Rohlmann Thomas Zander Friedmar Graichen Hendrik Schmidt Georg Bergmann 《PloS one》2014,9(4)
Cycling on an ergometer is an effective exercise for improving fitness. However, people with back problems or previous spinal surgery are often not aware of whether cycling could be harmful for them. To date, little information exists about spinal loads during cycling. A telemeterized vertebral body replacement allows in vivo measurement of implant loads during the activities of daily living. Five patients with a severe compression fracture of a lumbar vertebral body received these implants. During one measurement session, four of the participants exercised on a bicycle ergometer at various power levels. As the power level increased, the maximum resultant force and the difference between the maximum and minimum force (force range) during each pedal revolution increased. The average maximum-force increases between the two power levels 25 and 85 W were 73, 84, 225 and 75 N for the four patients. The corresponding increases in the force range during a pedal revolution were 84, 98, 166 and 101 N. There were large variations in the measured forces between the patients and also within the same patient, especially for high power levels. In two patients, the maximum forces during high-power cycling were higher than the forces during walking measured on the same day. Therefore, the authors conclude that patients with back problems should not cycle at high power levels shortly after surgery as a precaution. 相似文献