全文获取类型
收费全文 | 3480篇 |
免费 | 234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 | 948篇 |
金属工艺 | 41篇 |
机械仪表 | 49篇 |
建筑科学 | 206篇 |
矿业工程 | 3篇 |
能源动力 | 55篇 |
轻工业 | 590篇 |
水利工程 | 36篇 |
石油天然气 | 18篇 |
无线电 | 141篇 |
一般工业技术 | 517篇 |
冶金工业 | 625篇 |
原子能技术 | 9篇 |
自动化技术 | 454篇 |
出版年
2023年 | 24篇 |
2022年 | 84篇 |
2021年 | 131篇 |
2020年 | 56篇 |
2019年 | 87篇 |
2018年 | 96篇 |
2017年 | 84篇 |
2016年 | 115篇 |
2015年 | 85篇 |
2014年 | 153篇 |
2013年 | 222篇 |
2012年 | 184篇 |
2011年 | 266篇 |
2010年 | 179篇 |
2009年 | 153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 | 47篇 |
1997年 | 44篇 |
1996年 | 53篇 |
1995年 | 44篇 |
1994年 | 38篇 |
1993年 | 33篇 |
1992年 | 40篇 |
1991年 | 36篇 |
1990年 | 47篇 |
1989年 | 33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3717条查询结果,搜索用时 15 毫秒
151.
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
152.
当人类的法律和社会实践忽视自然进程,当规划、设计和建造城市的人士关注于邻里存在的问题,而不能认识其拥有的资源时,就会导致不公正现象.位于费城的磨坊河邻里的故事诠释了上述议题.在这里,高水位和地基失稳所造成的健康和安全危险,加剧了严峻的社会-经济状况和种族歧视.通过规划、设计和社区发展而达到的普及景观知识是认识到存在不公正现象、并加以纠正的一种手段,正如普及文化知识曾经是1950年代和1960年代美国民权运动的基石. 相似文献
153.
154.
155.
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
156.
Alexandre Joushomme Andr Garenne Mlody Dufosse Rmy Renom Hermanus Johannes Ruigrok Yann Loick Chappe Anne Canovi Lorenza Patrignoni Annabelle Hurtier Florence Poulletier de Gannes Isabelle Lagroye Philippe Lvêque Noëlle Lewis Muriel Priault Delia Arnaud-Cormos Yann Percherancier 《International journal of molecular sciences》2022,23(2)
It remains controversial whether exposure to environmental radiofrequency signals (RF) impacts cell status or response to cellular stress such as apoptosis or autophagy. We used two label-free techniques, cellular impedancemetry and Digital Holographic Microscopy (DHM), to assess the overall cellular response during RF exposure alone, or during co-exposure to RF and chemical treatments known to induce either apoptosis or autophagy. Two human cell lines (SH-SY5Y and HCT116) and two cultures of primary rat cortex cells (astrocytes and co-culture of neurons and glial cells) were exposed to RF using an 1800 MHz carrier wave modulated with various environmental signals (GSM: Global System for Mobile Communications, 2G signal), UMTS (Universal Mobile Telecommunications System, 3G signal), LTE (Long-Term Evolution, 4G signal, and Wi-Fi) or unmodulated RF (continuous wave, CW). The specific absorption rates (S.A.R.) used were 1.5 and 6 W/kg during DHM experiments and ranged from 5 to 24 W/kg during the recording of cellular impedance. Cells were continuously exposed for three to five consecutive days while the temporal phenotypic signature of cells behavior was recorded at constant temperature. Statistical analysis of the results does not indicate that RF-EMF exposure impacted the global behavior of healthy, apoptotic, or autophagic cells, even at S.A.R. levels higher than the guidelines, provided that the temperature was kept constant. 相似文献
157.
158.
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
159.
160.
Line Riis Christensen Ole Hassager Anne Ladegaard Skov 《American Institute of Chemical Engineers》2020,66(8):e16275
Multiple breakdown phenomena may take place when operating dielectric elastomers. Thermal breakdown, which occurs due to Joule heating, becomes of special importance when using multilayered stacks of dielectric elastomers, due to the large volume-to-surface-area-ratio. In this article, a 2D axisymmetric finite-element model of a multilayered stack of dielectric elastomers is set up in COMSOL Multiphysics®. Both the electro-thermal and electro-mechanical couplings are considered, allowing for determination of the onset of thermal breakdown. Simulation results show that an entrapped particle in the dielectric elastomer drastically reduces the possible number of layers in the stack. Furthermore, the possible number of layers is greatly affected by the ambient temperature and the applied voltage. The performance of three hyperelastic material models for modeling the elastomer deformation are compared, and it is established that the Gent model yields the most restrictive prediction of breakdown point, while the Ogden model yields the least restrictive estimation. 相似文献