全文获取类型
收费全文 | 3507篇 |
免费 | 201篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 19篇 |
综合类 | 6篇 |
化学工业 | 949篇 |
金属工艺 | 39篇 |
机械仪表 | 49篇 |
建筑科学 | 206篇 |
矿业工程 | 3篇 |
能源动力 | 57篇 |
轻工业 | 589篇 |
水利工程 | 36篇 |
石油天然气 | 18篇 |
无线电 | 139篇 |
一般工业技术 | 517篇 |
冶金工业 | 622篇 |
原子能技术 | 9篇 |
自动化技术 | 453篇 |
出版年
2023年 | 26篇 |
2022年 | 85篇 |
2021年 | 132篇 |
2020年 | 56篇 |
2019年 | 87篇 |
2018年 | 95篇 |
2017年 | 84篇 |
2016年 | 114篇 |
2015年 | 85篇 |
2014年 | 153篇 |
2013年 | 221篇 |
2012年 | 184篇 |
2011年 | 266篇 |
2010年 | 179篇 |
2009年 | 154篇 |
2008年 | 183篇 |
2007年 | 154篇 |
2006年 | 168篇 |
2005年 | 104篇 |
2004年 | 119篇 |
2003年 | 100篇 |
2002年 | 84篇 |
2001年 | 57篇 |
2000年 | 57篇 |
1999年 | 49篇 |
1998年 | 44篇 |
1997年 | 44篇 |
1996年 | 51篇 |
1995年 | 43篇 |
1994年 | 37篇 |
1993年 | 33篇 |
1992年 | 40篇 |
1991年 | 36篇 |
1990年 | 47篇 |
1989年 | 32篇 |
1988年 | 35篇 |
1987年 | 29篇 |
1986年 | 22篇 |
1985年 | 22篇 |
1984年 | 31篇 |
1983年 | 12篇 |
1982年 | 24篇 |
1980年 | 15篇 |
1979年 | 23篇 |
1978年 | 13篇 |
1977年 | 8篇 |
1975年 | 13篇 |
1974年 | 6篇 |
1971年 | 6篇 |
1969年 | 6篇 |
排序方式: 共有3711条查询结果,搜索用时 15 毫秒
91.
Paul R. Ehrlich Anne H. Ehrlich 《The International journal of environmental studies》2013,70(4):481-492
The development of an enormous culture gap, in which no individuals of advanced societies possess even a billionth of the non‐genetic information possessed by their entire society, has threatened a global collapse of civilisation. Critical parts of that gap must be rapidly bridged so that problems such as climate disruption, toxification of the Earth, loss of biodiversity and ecosystem services, and the decay of the epidemiological environment can be satisfactorily attacked. The essential need is to alter human behaviour to put society on a route to sustainability; one cheering development is a growing interest in the Millennium Assessment of Human Behaviour (MAHB), whose goal is to do just that. 相似文献
92.
Roxana E. Teppa Daniel Petit Olga Plechakova Virginie Cogez Anne Harduin-Lepers 《International journal of molecular sciences》2016,17(8)
Cell surface of eukaryotic cells is covered with a wide variety of sialylated molecules involved in diverse biological processes and taking part in cell–cell interactions. Although the physiological relevance of these sialylated glycoconjugates in vertebrates begins to be deciphered, the origin and evolution of the genetic machinery implicated in their biosynthetic pathway are poorly understood. Among the variety of actors involved in the sialylation machinery, sialyltransferases are key enzymes for the biosynthesis of sialylated molecules. This review focus on β-galactoside α2,3/6-sialyltransferases belonging to the ST3Gal and ST6Gal families. We propose here an outline of the evolutionary history of these two major ST families. Comparative genomics, molecular phylogeny and structural bioinformatics provided insights into the functional innovations in sialic acid metabolism and enabled to explore how ST-gene function evolved in vertebrates. 相似文献
93.
Marie-Alix Pizzoccaro Martin Drobek Eddy Petit Gilles Guerrero Peter Hesemann Anne Julbe 《International journal of molecular sciences》2016,17(8)
Imidazolium bromide-based ionic liquids bearing phosphonyl groups on the cationic part were synthesized and grafted on γ-alumina (γ-Al2O3) powders. These powders were prepared as companion samples of conventional mesoporous γ-alumina membranes, in order to favor a possible transfer of the results to supported membrane materials, which could be used for CO2 separation applications. Effective grafting was demonstrated using energy dispersive X-ray spectrometry (EDX), N2 adsorption measurements, fourier transform infrared spectroscopy (FTIR), and special attention was paid to 31P and 13C solid state nuclear magnetic resonance spectroscopy (NMR). 相似文献
94.
Pit Losch Anne‐Sophie Felten Patrick Pale 《Advanced Synthesis \u0026amp; Catalysis》2015,357(13):2931-2938
Zeolites with the right shape and acid site density and strength, such as certain ZSM‐5 forms, were able to cleanly decompose formic acid to carbon monoxide (CO), and the latter could be directly used in palladium‐catalyzed carbonylation reactions. A simple two‐reactor system was designed to produce CO conveniently and then further react this gas in a safe way. The two‐reactor system is particularly cheap, easy to set up and use. In addition, the carbonylation conditions without pressure allowed for very efficient CO incorporation, with only 1% of palladium(II) chloride (PdCl2) and Xantphos.
95.
96.
Jean-Denis Troadec Stphanie Gaig Manon Barbot Bruno Lebrun Rym Barbouche Anne Abysique 《International journal of molecular sciences》2022,23(2)
The avoidance of being overweight or obese is a daily challenge for a growing number of people. The growing proportion of people suffering from a nutritional imbalance in many parts of the world exemplifies this challenge and emphasizes the need for a better understanding of the mechanisms that regulate nutritional balance. Until recently, research on the central regulation of food intake primarily focused on neuronal signaling, with little attention paid to the role of glial cells. Over the last few decades, our understanding of glial cells has changed dramatically. These cells are increasingly regarded as important neuronal partners, contributing not just to cerebral homeostasis, but also to cerebral signaling. Our understanding of the central regulation of energy balance is part of this (r)evolution. Evidence is accumulating that glial cells play a dynamic role in the modulation of energy balance. In the present review, we summarize recent data indicating that the multifaceted glial compartment of the brainstem dorsal vagal complex (DVC) should be considered in research aimed at identifying feeding-related processes operating at this level. 相似文献
97.
Jerome Kluza Victoriane Peugnet Blanche Daunou William Laine Gwenola Kervoaze Gaëlle Rmy Anne Loyens Patrice Maboudou Quentin Fovez Corinne Grangette Isabelle Wolowczuk Philippe Gosset Guillaume Garon Philippe Marchetti Florence Pinet Muriel Pichavant Emilie Dubois-Deruy 《International journal of molecular sciences》2022,23(1)
Mitochondrial dysfunctions are implicated in several pathologies, such as metabolic, cardiovascular, respiratory, and neurological diseases, as well as in cancer and aging. These metabolic alterations are usually assessed in human or murine samples by mitochondrial respiratory chain enzymatic assays, by measuring the oxygen consumption of intact mitochondria isolated from tissues, or from cells obtained after physical or enzymatic disruption of the tissues. However, these methodologies do not maintain tissue multicellular organization and cell-cell interactions, known to influence mitochondrial metabolism. Here, we develop an optimal model to measure mitochondrial oxygen consumption in heart and lung tissue samples using the XF24 Extracellular Flux Analyzer (Seahorse) and discuss the advantages and limitations of this technological approach. Our results demonstrate that tissue organization, as well as mitochondrial ultrastructure and respiratory function, are preserved in heart and lung tissues freshly processed or after overnight conservation at 4 °C. Using this method, we confirmed the repeatedly reported obesity-associated mitochondrial dysfunction in the heart and extended it to the lungs. We set up and validated a new strategy to optimally assess mitochondrial function in murine tissues. As such, this method is of great potential interest for monitoring mitochondrial function in cohort samples. 相似文献
98.
Mario Fleischer Lukas Schumann Anne Hartmann Reuben Scott Walker Liliana Ifrim Dorothea von Zadow Jonas Lüske Joachim Seybold Martin Kriegel Dirk Mürbe 《Journal of the Royal Society Interface》2022,19(187)
Speaking and singing are activities linked to increased aerosol particle emissions from the respiratory system, dependent on the utilized vocal intensity. As a result, these activities have experienced considerable restrictions in enclosed spaces since the onset of the COVID-19 pandemic due to the risk of infection from the SARS-CoV-2 virus, transmitted by virus-carrying aerosols. These constraints have affected public education and extracurricular activities for children as well, from in-person music instruction to children’s choirs. However, existing risk assessments for children have been based on emission measurements of adults. To address this, we measured the particle emission rates of 15 pre-adolescent children, all eight to ten years old, with a laser particle counter for the test conditions: breathing at rest, speaking, singing and shouting. Compared with values taken from 15 adults, emission rates for breathing, speaking and singing were significantly lower for children. Particle emission rates were reduced by a factor of 4.3 across all conditions, whereas emitted particle volume rates were reduced by a factor of 4.8. These data can supplement SARS-CoV-2 risk management scenarios for various school and extracurricular settings. 相似文献
99.
100.