全文获取类型
收费全文 | 1562篇 |
免费 | 159篇 |
国内免费 | 76篇 |
专业分类
电工技术 | 12篇 |
综合类 | 165篇 |
化学工业 | 154篇 |
金属工艺 | 31篇 |
机械仪表 | 24篇 |
建筑科学 | 142篇 |
矿业工程 | 47篇 |
能源动力 | 12篇 |
轻工业 | 494篇 |
水利工程 | 34篇 |
石油天然气 | 479篇 |
武器工业 | 5篇 |
无线电 | 18篇 |
一般工业技术 | 42篇 |
冶金工业 | 78篇 |
原子能技术 | 4篇 |
自动化技术 | 56篇 |
出版年
2024年 | 7篇 |
2023年 | 30篇 |
2022年 | 50篇 |
2021年 | 57篇 |
2020年 | 71篇 |
2019年 | 59篇 |
2018年 | 42篇 |
2017年 | 64篇 |
2016年 | 45篇 |
2015年 | 56篇 |
2014年 | 80篇 |
2013年 | 71篇 |
2012年 | 81篇 |
2011年 | 122篇 |
2010年 | 95篇 |
2009年 | 99篇 |
2008年 | 77篇 |
2007年 | 116篇 |
2006年 | 85篇 |
2005年 | 85篇 |
2004年 | 67篇 |
2003年 | 57篇 |
2002年 | 43篇 |
2001年 | 31篇 |
2000年 | 34篇 |
1999年 | 26篇 |
1998年 | 23篇 |
1997年 | 19篇 |
1996年 | 20篇 |
1995年 | 20篇 |
1994年 | 18篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1965年 | 1篇 |
1961年 | 1篇 |
排序方式: 共有1797条查询结果,搜索用时 31 毫秒
61.
《Oil and Energy Trends》2019,44(5):49-53
Values of net oil imports(-)/exports for Austria, Belgium, Denmark, Finland, France, Germany, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, the United Kingdom, Japan, Canada, the United States and Australia. Updated on a monthly basis. Number of imports for Belgium, France, Germany, Greece, Republic of Ireland, Italy, Netherlands, Portugal, Spain, Sweden, the United Kingdom, and Other EU-15 (EU-15), Norway, Poland, Switzerland, Turkey, and Other Europe (OECD Europe), Canada, Chile, Mexico, and the United States (OECD Western Hemisphere), and Australia, Japan, Republic of Korea, New Zealand, (OECD Asia-Pacific), and Total OECED. Current data for Austria, Belgium, Finland, France, Germany, Greece, Italy, Netherlands, Portugal, Spain, Sweden, the United Kingdom, Other EU-15 (EU-15), Czech Republic, Hungary, Poland, Slovakia, Turkey, and Other Europe (OECD Europe), Canada, Mexico, and the United States (OECD Western Hemisphere), Australia, Japan, Republic of Korea, and New Zealand (OECD Asia-Pacific). Updated on a monthly basis. Current data for principal importers of natural gas and the amount in which they import from United States, Republic of Korea, United Kingdom, France, Japan, Italy, Germany and Spain (Table 19.1). Current data for principal exporters of natural gas and the amount they export to Canada, Trinidad and Tobago, the United States, Netherlands, Norway, Russia, Turkmenistan, Qatar, Algeria, Nigeria, Indonesia, Malaysia and Australia (Table 19.2). Updated on a monthly basis. 相似文献
62.
黄骅坳陷埕海地区奥陶系天然气地球化学特征较为特殊,具有非烃含量高、稳定同位素重的特征。通过同位素特征,进一步结合地质、地化资料综合分析,对埕海地区奥陶系天然气的成因类型和气源进行探讨。认为埕海地区奥陶系天然气为煤成气,主力气源岩为石炭-二叠系烃源岩。 相似文献
63.
《Oil and Energy Trends》2020,45(2):47-51
Values of net oil imports(-)/exports for Austria, Belgium, Denmark, Finland, France, Germany, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, the United Kingdom, Japan, Canada, the United States and Australia. Updated on a monthly basis. Number of imports for Belgium, France, Germany, Greece, Republic of Ireland, Italy, Netherlands, Portugal, Spain, Sweden, the United Kingdom, and Other EU-15 (EU-15), Norway, Poland, Switzerland, Turkey, and Other Europe (OECD Europe), Canada, Chile, Mexico, and the United States (OECD Western Hemisphere), and Australia, Japan, Republic of Korea, New Zealand, (OECD Asia-Pacific), and Total OECED. Current data for Austria, Belgium, Finland, France, Germany, Greece, Italy, Netherlands, Portugal, Spain, Sweden, the United Kingdom, Other EU-15 (EU-15), Czech Republic, Hungary, Poland, Slovakia, Turkey, and Other Europe (OECD Europe), Canada, Mexico, and the United States (OECD Western Hemisphere), Australia, Japan, Republic of Korea, and New Zealand (OECD Asia-Pacific). Updated on a monthly basis. Current data for principal importers of natural gas and the amount in which they import from United States, Republic of Korea, United Kingdom, France, Japan, Italy, Germany and Spain (Table 19.1). Current data for principal exporters of natural gas and the amount they export to Canada, Trinidad and Tobago, the United States, Netherlands, Norway, Russia, Turkmenistan, Qatar, Algeria, Nigeria, Indonesia, Malaysia and Australia (Table 19.2). Updated on a monthly basis. 相似文献
64.
Microbial profile and bacterial characterisation of naturally debittered Hurma olives compared to non‐debittered Erkence variety during ripening period
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gozde Seval Sozbilen Ayse Handan Baysal 《International Journal of Food Science & Technology》2016,51(9):2099-2105
Naturally debittered Hurma olive is grown in a specific area in Karaburun peninsula in Turkey. It is characterised by its sweet taste and it differs from other varieties by losing its bitterness caused by phenolic compounds during its maturation period on the tree. Therefore, Hurma olive does not require any further debittering process to be served as table olive. This study was particularly interested in the comparison of the microbial profile of Hurma olive during its 8 weeks of maturation period in two subsequent harvest years and Erkence (not naturally debittered) olive. In addition, main bacterial profile of both Hurma and Erkence olives were isolated and identified. Aerobic mesophilic microorganism (AMM), lactic acid bacteria (LAB), Enterobacteriaceae, Pseudomonadaceae, Staphylococci, Micrococcaceae, yeasts and moulds (Y&Ms) were detected (counted and isolated) in the olive drupes during the maturation period. Isolated bacteria were identified as different spp. of Bacillaceae, Enterobacteriaceae, Micrococcoceae and Pseudomonadaceae. 相似文献
65.
《Oil and Energy Trends》2019,44(6):41-45
Values of net oil imports(-)/exports for Austria, Belgium, Denmark, Finland, France, Germany, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, the United Kingdom, Japan, Canada, the United States and Australia. Updated on a monthly basis. Number of imports for Belgium, France, Germany, Greece, Republic of Ireland, Italy, Netherlands, Portugal, Spain, Sweden, the United Kingdom, and Other EU-15 (EU-15), Norway, Poland, Switzerland, Turkey, and Other Europe (OECD Europe), Canada, Chile, Mexico, and the United States (OECD Western Hemisphere), and Australia, Japan, Republic of Korea, New Zealand, (OECD Asia-Pacific), and Total OECED. Current data for Austria, Belgium, Finland, France, Germany, Greece, Italy, Netherlands, Portugal, Spain, Sweden, the United Kingdom, Other EU-15 (EU-15), Czech Republic, Hungary, Poland, Slovakia, Turkey, and Other Europe (OECD Europe), Canada, Mexico, and the United States (OECD Western Hemisphere), Australia, Japan, Republic of Korea, and New Zealand (OECD Asia-Pacific). Updated on a monthly basis. Current data for principal importers of natural gas and the amount in which they import from United States, Republic of Korea, United Kingdom, France, Japan, Italy, Germany and Spain (Table 19.1). Current data for principal exporters of natural gas and the amount they export to Canada, Trinidad and Tobago, the United States, Netherlands, Norway, Russia, Turkmenistan, Qatar, Algeria, Nigeria, Indonesia, Malaysia and Australia (Table 19.2). Updated on a monthly basis. 相似文献
66.
One of the most prominent energy storage technologies which are under continuous development, especially for mobile applications, is the Li‐ion batteries due to their superior gravimetric and volumetric energy density. However, limited cycle life of Li‐ion batteries inhibits their extended use in stationary energy storage applications. To enable wider market penetration of Li‐ion batteries, detailed understanding of the degradation mechanisms is required. A typical Li‐ion battery comprised of an active material, binder, separator, current collector, and electrolyte, and the interaction between these components plays a critical role in successful operation of such batteries. Degradation of Li‐ion batteries can have both chemical and mechanical origins and manifests itself by capacity loss, power fading or both. Mechanical degradation mechanisms are associated with the volume changes and stress generated during repetitive intercalation of Li ions into the active material, whereas chemical degradation mechanisms are associated with the parasitic side reactions such as solid electrolyte interphase formation, electrolyte decomposition/reduction and active material dissolution. In this study, the main degradation mechanisms in Li‐ion batteries are reviewed. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
67.
《Food Control》2017
Coffee quality is highly dependent on geographical factors. Based on the chemical characterization of 25 coffee samples from worldwide provenances and same roasting degree, Discriminant Analysis (DA) was employed to develop models that are able to identify the continental or country (Brazil) provenance of blind coffee samples. These models are based on coffee composition, particularly on several key compounds either with or without significant impact on aroma, such as 2,3-butanedione, 2,3-pentanedione, 2-methylbutanal and 2-ethyl-6-methylpyrazine. All models were validated with new and independent data from literature, and also through cross validation and permutation tests. Furthermore, the robustness of the proposed models in case of incomplete characterization data was also tested, being concluded that missing data is supportable by the models. In the whole, this article provides compelling arguments for the development of DA-based tools with the purpose of controlling the quality of coffee in terms of their continental and/or national origins. 相似文献
68.
以试气井段为单位对徐家围子断陷深层天然气进行分析,探索各气藏天然气组成及碳同位素的分布规律。研究表明:乙烷碳同位素在平面上存在明显差异,断陷边部乙烷碳同位素较重,具有煤型气特征,断陷中部乙烷碳同位素较轻,达到油型气标准;天然气C_5以上的重烃碳同位素异常轻,可能来源于原油裂解;碳同位素反序的天然气不一定是无机成因,复杂的碳同位素序列可能是油型气和煤型气混合造成;无机成因烃气数量甚微,不可能单独成藏。 相似文献
69.
《Food Control》2015
The use of oak wood is a common practice for the maturation of higher quality wines, but this practice also has been occasionally related with the spoilage of wines with ethylphenols produced by Brettanomyces/Dekkera yeasts. This work studied the presence of these yeasts and ethylphenol production in the same wine aged in different conditions: aerobic/anaerobic, sulfur dioxide additions, and oak origin of the casks used (American, French, Russian and Chinese), with the aim of characterizing factors affecting the development and production of volatile phenols by Brettanomyces. Results obtained indicated the spoilage risk exists when Brettanomyces cells are present, even at a low level, in wines subjected to ageing, both in the cask and the bottle. Brettanomyces presence (cfu/ml and strains) and ethylphenol production during ageing, is affected more by the ageing conditions (aerobic/anaerobic and sulfiting) than by the origin of the oak. 相似文献
70.
Vadim A. Davankov 《Israel journal of chemistry》2016,56(11-12):1036-1041
Of the many hypotheses on the origin of biological homochirality on the Earth, the combination of the notion of subatomic particles composing a homochiral pool of primary matter, on the one hand, with the suggestion of the synthesis of chiral organic molecules in the plasma torch generated by super-high-velocity impacts (SHVI) of meteorites, on the other hand, was chosen as the working assumption. 相似文献