全文获取类型
收费全文 | 941篇 |
免费 | 27篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 108篇 |
金属工艺 | 6篇 |
机械仪表 | 8篇 |
建筑科学 | 29篇 |
矿业工程 | 2篇 |
能源动力 | 12篇 |
轻工业 | 84篇 |
水利工程 | 5篇 |
石油天然气 | 2篇 |
无线电 | 69篇 |
一般工业技术 | 133篇 |
冶金工业 | 400篇 |
原子能技术 | 8篇 |
自动化技术 | 93篇 |
出版年
2022年 | 6篇 |
2021年 | 16篇 |
2020年 | 12篇 |
2019年 | 17篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 10篇 |
2015年 | 18篇 |
2014年 | 14篇 |
2013年 | 39篇 |
2012年 | 23篇 |
2011年 | 20篇 |
2010年 | 24篇 |
2009年 | 14篇 |
2008年 | 27篇 |
2007年 | 24篇 |
2006年 | 18篇 |
2005年 | 22篇 |
2004年 | 14篇 |
2003年 | 19篇 |
2002年 | 23篇 |
2001年 | 16篇 |
2000年 | 14篇 |
1999年 | 34篇 |
1998年 | 83篇 |
1997年 | 75篇 |
1996年 | 47篇 |
1995年 | 28篇 |
1994年 | 29篇 |
1993年 | 32篇 |
1992年 | 21篇 |
1991年 | 8篇 |
1990年 | 15篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 15篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 13篇 |
1976年 | 14篇 |
1973年 | 8篇 |
1970年 | 8篇 |
1968年 | 6篇 |
排序方式: 共有969条查询结果,搜索用时 15 毫秒
91.
Lane Hauck 《电子设计技术》2007,14(5):88-94
引言 我工作时喜欢有点背景音乐,会打开Windows Media Player,按下PLAY键来播放音乐.但有电话打进来时,我希望能不用鼠标在桌面上到处找Media Player图标来调低音量或按暂停键. 相似文献
92.
The pseudouridine residues of ribosomal RNA 总被引:3,自引:0,他引:3
J Ofengand A Bakin J Wrzesinski K Nurse BG Lane 《Canadian Metallurgical Quarterly》1995,73(11-12):915-924
93.
The effects of loss of resources and illness symptoms on experienced anger, anger expression, and supporter's anger was studied among patients with severe chronic breathing disorder. Both illness symptoms and resource loss were related to greater anger. Angry feelings, in turn, led to more angry behavior. This angry behavior, in turn, resulted in increased anger of supporters. This process illustrates how chronic stress depletes both personal resources and social resources, making the individual increasingly vulnerable to further stressful experiences, inevitably to be confronted in chronic stress sequences. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
95.
Long-term trends and opportunities for managing regional water supply and wastewater greenhouse gas emissions 总被引:2,自引:0,他引:2
Greenhouse gas emissions are likely to rise faster than growth in population and more than double for water supply and wastewater services over the next 50 years in South East Queensland (SEQ), Australia. New sources of water supply such as rainwater tanks, recycled water, and desalination currently have greater energy intensity than traditional sources. In addition, direct greenhouse gas emissions from reservoirs and wastewater treatment and handling have potentially the same magnitude as emissions from the use of energy. Centralized and decentralized water supply and wastewater systems are considered for a scenario based upon a government water supply strategy for the next 50 years. Many sources of data have large uncertainties which are estimated following the IPCC Good Practice Guidelines. Important sources of emissions with large uncertainties such as rainwater tanks and direct emissions were identified for further research and potential mitigation of greenhouse gas emissions. 相似文献
96.
Carbon electrodes coupled with electrochemical detection have been used extensively for the investigation of biogenic amines. Herein we report the fabrication and characterization of carbonaceous electrodes prepared from pyrolyzed parylene C (PPC) films. High-aspect ratio carbonaceous microelectrodes have been prepared by masking PPC coated pipets with an insulating parylene C film. PPC thin film electrodes were characterized electrochemically, spectroscopically, and with electron microscopy. The procedures described here offer a route to fabrication of thin film carbon electrodes that can be patterned and produced in parallel. These electrodes are similar to carbon electrodes derived from pyrolyzed photoresist films but do not require spin-coating or lithography and can readily coat three-dimensional surfaces. 相似文献
97.
Isotope dilution liquid chromatography - mass spectrometry methods for fat- and water-soluble vitamins in nutritional formulations 总被引:1,自引:0,他引:1
Phinney KW Rimmer CA Thomas JB Sander LC Sharpless KE Wise SA 《Analytical chemistry》2011,83(1):92-98
Vitamins are essential to human health, and dietary supplements containing vitamins are widely used by individuals hoping to ensure they have adequate intake of these important nutrients. Measurement of vitamins in nutritional formulations is necessary to monitor regulatory compliance and in studies examining the nutrient intake of specific populations. Liquid chromatographic methods, primarily with UV absorbance detection, are well established for both fat- and water-soluble measurements, but they do have limitations for certain analytes and may suffer from a lack of specificity in complex matrices. Liquid chromatography-mass spectrometry (LC-MS) provides both sensitivity and specificity for the determination of vitamins in these matrices, and simultaneous analysis of multiple vitamins in a single analysis is often possible. In this work, LC-MS methods were developed for both fat- and water-soluble vitamins and applied to the measurement of these analytes in two NIST Standard Reference Materials. When possible, stable isotope labeled internal standards were employed for quantification. 相似文献
98.
Balmer BC Schwacke LH Wells RS George RC Hoguet J Kucklick JR Lane SM Martinez A McLellan WA Rosel PE Rowles TK Sparks K Speakman T Zolman ES Pabst DA 《The Science of the total environment》2011,409(11):2094-2101
Bottlenose dolphins (Tursiops truncatus) are apex predators in coastal southeastern U.S. waters; as such they are indicators of persistent organic pollutants (POPs) in coastal ecosystems. POP concentrations measured in a dolphin's blubber are influenced by a number of factors, including the animal's sex and ranging pattern in relation to POP point sources. This study examined POP concentrations measured in bottlenose dolphin blubber samples (n = 102) from the Georgia, USA coast in relation to individual ranging patterns and specifically, distance of sightings from a polychlorinated biphenyl (PCB) point source near Brunswick, Georgia. Dolphin ranging patterns were determined based upon 5 years of photo-identification data from two field sites approximately 40 km apart: (1) the Brunswick field site, which included the Turtle/Brunswick River Estuary (TBRE), and (2) the Sapelo field site, which included the Sapelo Island National Estuarine Research Reserve (SINERR). Dolphins were categorized into one of three ranging patterns from photo-identification data. Individuals with sighting histories exclusively within one of the defined field sites were considered to have either Brunswick or Sapelo ranging patterns. Individuals sighted in both field sites were classified as having a Mixed ranging pattern. Brunswick males had the highest concentrations of PCBs reported for any marine mammal. The pattern of PCB congeners was consistent with Aroclor 1268, a highly chlorinated PCB mixture associated with a Superfund site in Brunswick. PCB levels in Sapelo males were lower than in Brunswick males, but comparable to the highest levels measured in other dolphin populations along the southeastern U.S. Female dolphins had higher Aroclor 1268 proportions than males, suggesting that the highly chlorinated congeners associated with Aroclor 1268 may not be offloaded through parturition and lactation, as easily as less halogenated POPs. Individuals sighted farther from the Superfund point source had lower Aroclor 1268 proportions. 相似文献
99.
Nicholas D. Lane Mu Lin Mashfiqui Mohammod Xiaochao Yang Hong Lu Giuseppe Cardone Shahid Ali Afsaneh Doryab Ethan Berke Andrew T. Campbell Tanzeem Choudhury 《Mobile Networks and Applications》2014,19(3):345-359
Smartphone sensing and persuasive feedback design is enabling a new generation of wellbeing apps capable of automatically monitoring multiple aspects of physical and mental health. In this article, we present BeWell+ the next generation of the BeWell smartphone wellbeing app, which monitors user behavior along three health dimensions, namely sleep, physical activity, and social interaction. BeWell promotes improved behavioral patterns via feedback rendered as an ambient display on the smartphone’s wallpaper. With BeWell+, we introduce new mechanisms to address key limitations of the original BeWell app; specifically, (1) community adaptive wellbeing feedback, which generalizes to diverse user communities (e.g., elderly, children) by promoting better behavior yet remains realistic to the user’s lifestyle; and, (2) wellbeing adaptive energy allocation, which prioritizes monitoring fidelity and feedback responsiveness on specific health dimensions (e.g., sleep) where the user needs additional help. We evaluate BeWell+ with a 27 person, 19 day field trial. Our findings show that not only can BeWell+ operate successfully on consumer smartphones; but also users understand feedback and respond by taking steps towards leading healthier lifestyles. 相似文献
100.
Three symbols of terror are examined as representations of preoedipal conflicts that intrude upon conscious awareness and. interfere with current functioning. To understand each of these symbols and their origins in a state of chronic terror, it is necessary to understand the complete life history of the patient. All three symbols--the witch/vampire, the spider, and the shark--relate to earliest experiences within the parent/infant dyad. We suggest that although all three symbols relate to the dimension of oral aggression, they can be placed conceptually along a continuum of distance from the quality of humanness. Clinical examples are given to illustrate the use of these symbols by patients in treatment and their theoretical implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献