全文获取类型
收费全文 | 769篇 |
免费 | 49篇 |
专业分类
电工技术 | 11篇 |
化学工业 | 158篇 |
金属工艺 | 2篇 |
机械仪表 | 7篇 |
建筑科学 | 28篇 |
矿业工程 | 1篇 |
能源动力 | 3篇 |
轻工业 | 108篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 67篇 |
一般工业技术 | 137篇 |
冶金工业 | 46篇 |
原子能技术 | 1篇 |
自动化技术 | 247篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 25篇 |
2021年 | 24篇 |
2020年 | 10篇 |
2019年 | 24篇 |
2018年 | 20篇 |
2017年 | 26篇 |
2016年 | 31篇 |
2015年 | 26篇 |
2014年 | 41篇 |
2013年 | 63篇 |
2012年 | 57篇 |
2011年 | 66篇 |
2010年 | 51篇 |
2009年 | 62篇 |
2008年 | 47篇 |
2007年 | 42篇 |
2006年 | 33篇 |
2005年 | 23篇 |
2004年 | 31篇 |
2003年 | 26篇 |
2002年 | 18篇 |
2001年 | 11篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有818条查询结果,搜索用时 13 毫秒
11.
Marleen Morbee Antoni Roca Josep Prades-Nebot Aleksandra Pižurica Wilfried Philips 《Signal, Image and Video Processing》2008,2(2):129-140
In some video coding applications, it is desirable to reduce the complexity of the video encoder at the expense of a more
complex decoder. Wyner–Ziv (WZ) video coding is a new paradigm that aims to achieve this. To allocate a proper number of bits
to each frame, most WZ video coding algorithms use a feedback channel, which allows the decoder to request additional bits
when needed. However, due to these multiple bit requests, the complexity and the latency of WZ video decoders increase massively.
To overcome these problems, in this paper we propose a rate allocation (RA) algorithm for pixel-domain WZ video coders. This
algorithm estimates at the encoder the number of bits needed for the decoding of every frame while still keeping the encoder
complexity low. Experimental results show that, by using our RA algorithm, the number of bit requests over the feedback channel—and
hence, the decoder complexity and the latency—are significantly reduced. Meanwhile, a very near-to-optimal rate-distortion
performance is maintained.
This work has been partially supported by the Spanish Ministry of Education and Science and the European Commission (FEDER)
under grant TEC2005-07751-C02-01.
A. Pižurica is a postdoctoral research fellow of FWO, Flanders. 相似文献
12.
A new scheme to alleviate contention in optical burst switching networks is proposed. It consists of preventively reserving resources in a node, to be used if resources are busy on the next hop node. The burst is sent back to the preceding node and then resent forward. Simulations are carried out to assess the feasibility of the proposed scheme. Its performance is compared with that of contention resolution based on deflection routing. 相似文献
13.
A new design of a BIC sensor for current testing static CMOS circuits is proposed. It is based on a lateral BJT device which is easy to incorporate in any standard CMOS process. The design diverts a fraction of the I
DDQ
current from the cell under test and a resistive component generates a voltage proportional to I
DDQ
. Additional features are the possibility of continuous measure of i
dd
and increased speed of this sensor compared with sensors based on the current integration principle. The design does not have substrate currents due to the parasitic vertical BJTs. Experimental work on the sensor is reported. 相似文献
14.
Consumption of polyunsaturated fat improves the saturated fatty acid‐mediated impairment of HDL antioxidant potential 下载免费PDF全文
15.
The present study investigates the antioxidant mechanism of grape procyanidins and, in particular, their aptitude to establish redox interactions with two important components of the endogenous antioxidant system of muscle tissues, α-tocopherol (α-TOH) and ascorbic acid (AA). To this end, the progress of lipid oxidation was monitored in fish muscle supplemented with grape procyanidins at the concentrations usually employed in antioxidant food applications, and then related to the redox stability of the endogenous α-TOH and AA. In addition to the lipid oxidation protective effect, the incorporation of procyanidins also provided an improvement of the redox stability of the endogenous components in a straight procyanidinic concentration-dependent manner. Results showed the capacity of procyanidins to repair oxidised α-TOH at medium-long term, and to delay the AA depletion. Therefore, such cooperative redox interaction of exogenous procyanidins adequately complements the natural α-TOH regenerative system supplied by AA that is efficient at the early post mortem stages. 相似文献
16.
Ana‐Paola Echavarría Albert Ibarz Josep Conde Carles Torras Jordi Pagán 《International Journal of Food Science & Technology》2012,47(1):47-52
The aim of this paper, in which clogging occurs on the filter at a constant vacuum pressure and constant pectin weight, is to find the optimal values of the variables, temperature and time, to know the best conditions to reduce this clogging by enzymatic hydrolysis. Moreover, different properties of the compression of the cake in the filter were determined such as the filtering medium total resistance (RfT), bed porosity (ε) and the cake‐specific resistance (α) at different times and temperatures. The filter area was 0.142 m2, and the value of the mass fraction of solids in the filtered suspension (S) was 0.12. Scanning electron microsopy (SEM) analyses were performed. The results showed that the compressive stress corresponding to the cake improves the flow rate in the filtration flux at the optimal temperature and time for the process, where the enzyme reaches its highest activity. The test results of this study can be applied in different system of filters during cross‐flow filtration. 相似文献
17.
Esteve Fernández Anna Schiaffino Carme Borrell Joan Benach Carles Ariza Josep Maria Ramon Jorge Twose Manel Nebot Anton Kunst 《Nicotine & tobacco research》2006,8(1):29-36
Our objective was to examine social class and educational differences in long-term smoking cessation success among a cohort of smokers attending a specialized smoking clinic. We studied sustained abstinence after cessation among 1,516 smokers (895 men and 621 women) treated for smoking cessation between 1995 and 2001 at a university teaching hospital in the metropolitan area of Barcelona, Spain. We calculated 1-year and long-term (up to 8-year) abstinence probabilities by means of Kaplan-Meier curves and the hazard ratio of relapse by means of Cox regression, after adjusting for other predictors of relapse. Overall abstinence probability was .277 (95% CI = .254-.301). Men and women in social classes IV-V had significant hazard ratios of relapse after long-term follow-up (men: 1.36, 95% CI = 1.07-1.72; women: 1.60, 95% CI = 1.24-2.06), as compared with patients in social classes I-II. The same independent effect was observed for education: Men and women with primary or less than primary studies had higher hazard ratios of relapse (men: 1.75, 95% CI = 1.35-2.25; women: 1.92, 95% CI = 1.51-2.46), as compared with patients with a university degree. Similar estimates were obtained after adjustment for stage of change, Fagerstr?m score for nicotine dependence, and type of treatment. Patients of lower socioeconomic status are at higher risk of relapse, and this association is independent of other well-known predictors of relapse. Social differences have to be taken into account in the clinical setting when tailoring specific actions to treat smoking dependence. 相似文献
18.
NaCl is an important multifunctional ingredient applied in dry-cured ham elaboration. However, its excessive intake has been linked to serious cardiovascular diseases causing a recent increase in the development of reduced salt products. In the present study Listeria monocytogenes and Salmonella, food-borne pathogens which can cross-contaminate post processed products, were spiked with < 100 CFU/g on slices of both standard (S) and NaCl-free processed (F) (elaborated with KCl + potassium lactate instead of NaCl) smoked dry-cured ham. Although L. monocytogenes and Salmonella counts decreased faster in S ham, pathogens were present in both types of non-pressure treated ham during the entire refrigerated storage period (112 days). Pressurisation at 600 MPa for 5 min caused the elimination of both pathogens in S ham after 14 days. In contrast, Salmonella and L. monocytogenes were present in F ham until days 28 and 56, respectively, indicating that the NaCl-free processed dry-cured ham had lower stability than standard smoked dry-cured ham. 相似文献
19.
Josep Rubert Kamila Hurkova Milena Stranska Jana Hajslova 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2018,35(4):605-613
Tiger nuts and tiger nut milk are well-known Valencian products, and step-by-step these tubers and the tuber-based beverage are becoming more and more relevant products in international markets. However, the increasing demand and success of Valencian tiger nuts did not allow protected designation of origin (PDO) tuber to supply the domestic and international markets. Therefore, the verification of the geographical origin is highly required. In this research, the main objective was to combine an advance analytical method and chemometrics tools in order to decipher the geographical origin of 45 tiger nut samples from (i) ‘Xufa de València’ PDO and (ii) African samples. The analytical method, based on solid-liquid extraction followed by ultra-high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC-HRMS) metabolomics approach, highlighted sensitivity and wide linear dynamic range in order to simultaneously analyse polar and non-polar metabolites. After data processing, a pronounced sample clustering according to the geographical origin was clearly observed using unsupervised models, and supervised models revealed that tiger nuts lipidome was associated with the geographical origin. As a result, African samples highlighted an overexpression of phospholipids, such as phosphatidylethanolamine 34:1, and triacylgricerols crosslinked to environmental stress and alteration of membrane lipid compositions. 相似文献
20.
Sara Castro-Barquero Rosa Casas Eric B. Rimm Anna Tresserra-Rimbau Dora Romaguera J. Alfredo Martínez Jordi Salas-Salvadó Miguel A. Martínez-González Josep Vidal Miguel Ruiz-Canela Jadwiga Konieczna Emilio Sacanella Jesús Francisco García-Gavilán Montse Fitó Ana García-Arellano Ramon Estruch 《Molecular nutrition & food research》2023,67(4):2200264