全文获取类型
收费全文 | 503篇 |
免费 | 47篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 208篇 |
金属工艺 | 12篇 |
机械仪表 | 6篇 |
建筑科学 | 12篇 |
矿业工程 | 1篇 |
能源动力 | 12篇 |
轻工业 | 152篇 |
水利工程 | 2篇 |
石油天然气 | 3篇 |
无线电 | 11篇 |
一般工业技术 | 74篇 |
冶金工业 | 12篇 |
自动化技术 | 44篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 39篇 |
2021年 | 52篇 |
2020年 | 25篇 |
2019年 | 22篇 |
2018年 | 23篇 |
2017年 | 21篇 |
2016年 | 26篇 |
2015年 | 16篇 |
2014年 | 22篇 |
2013年 | 43篇 |
2012年 | 48篇 |
2011年 | 44篇 |
2010年 | 30篇 |
2009年 | 28篇 |
2008年 | 20篇 |
2007年 | 13篇 |
2006年 | 17篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 13篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1971年 | 1篇 |
排序方式: 共有550条查询结果,搜索用时 0 毫秒
541.
Ivana?PoustkováEmail author Jaroslav?Dobiá? Ingrid?Steiner Jan?Poustka Michal?Vold?ich 《European Food Research and Technology》2004,219(5):534-539
Varnishes used for the inner coatings of food cans are often based on epoxy resins or vinylic organosols. The epoxy resins can be produced from bisphenol A (BPA) and bisphenol F (BPF), and these also contain bisphenol A diglycidyl ether (BADGE) or bisphenol F diglycidyl ether (BFDGE) as stabilising components. These compounds may break down during storage and also by the influence of food simulants. The stability of BADGE and BFDGE were studied using reverse-phase gradient high-performance liquid chromatography (RP-HPLC) with ultraviolet detection (UV). Three experimental conditions for spiked simulants were compared: (1) the storage at 25 °C (C1), (2) the storage at 40 °C (C2) and (3) the storage at 25 °C after 15 min heating at 120 °C (C3). Distilled water, 3% acetic acid and 10% ethanol were used as food simulants. It was observed that BADGE is more stabile than BFDGE. The loss of BADGE and BFDGE were minimal in 10% ethanol (39 and 46% at 25 °C, 60 and 69% at 40 °C, respectively) and highest in 3% acetic acid (60 and 63% at 25 °C, 76 and 82% at 40 °C, respectively). At experiment (C3), the hardest conditions, significant degradation was not shown in comparison with conditions (C1) and (C2), contrariwise BADGE and BFDGE in 10% ethanol were minimal degradated at conditions (C3) from all these experiments (loss of 5 and 8%, respectively). 相似文献
542.
543.
Jéssica Rosso Motta Ivo Emilio da Cruz Jung Verônica Farina Azzolin Cibele Ferreira Teixeira Luiza Elizabete Braun Daniel Augusto De Oliveira Nerys Marco Aurélio Echart Motano Marta Maria Medeiros Frescura Duarte Ednea Aguiar Maia-Ribeiro Ivana Beatrice Mânica da Cruz Fernanda Barbisan 《Journal of Food Biochemistry》2021,45(2):e13596
544.
Jon O Ebbert Lowell C Dale Herbert Severson Ivana T Croghan Donna F Rasmussen Darrell R Schroeder Mark W Vander Weg Richard D Hurt 《Nicotine & tobacco research》2007,9(2):233-240
Nicotine lozenges have been shown to increase tobacco abstinence rates in cigarette smokers, but they have not been evaluated in smokeless tobacco (ST) users. We conducted an open-label, one-arm, phase II clinical trial to evaluate the efficacy of the 4-mg nicotine lozenge for the treatment of withdrawal and craving associated with tobacco abstinence among ST users. Eligible subjects received 4-mg nicotine lozenges for 6 weeks followed by a 6-week taper. Subjects completed daily tobacco withdrawal diaries, and data on lozenge use, adverse events, and lozenge acceptability were collected. Urine anabasine was collected at 3 and 6 months for biochemical confirmation of self-reported tobacco abstinence. Participants were 30 ST users with a mean age of 35.4 years (SD=6.5) using an average of 4.2 cans or pouches (SD=3.2) of ST per week for a mean of 15.1 years (SD=6.5). Among subjects continuously tobacco abstinent for the first 2 weeks, no significant increases in composite withdrawal symptoms were observed, compared with baseline symptoms, whereas craving decreased significantly. Biochemically confirmed 7-day point-prevalence tobacco abstinence was 53% (95% CI=34%-72%) at 12 weeks (end of treatment) and 47% (95% CI=28%-66%) at 6 months. Few adverse events attributable to the nicotine lozenge occurred, and the lozenge was perceived as helpful in assisting subjects quit ST. The use of the 4-mg nicotine lozenge appears promising for the clinical treatment of withdrawal symptoms and craving associated with tobacco abstinence in ST users. Future phase III clinical trials investigating the efficacy of nicotine lozenges are warranted. 相似文献
545.
Ivana Cesarino Vivian Cesarino Fernando C. Moraes Tanare C.R. Ferreira Marcos R.V. Lanza Lucia H. Mascaro Sergio A.S. Machado 《Materials Chemistry and Physics》2013
In this study, a novel methodology for the electrochemical degradation of benzene in natural water using silver nanoparticle-decorated carbon nanotubes has been investigated. The morphology, the structure, and the electrochemical performance of the multi-walled carbon nanotubes-silver (MWCNT-Ag) nanocomposite film were characterised by transmission electron microscopy (TEM), X-ray diffraction (XRD), and cyclic voltammetry (CV), respectively. Electrocatalytic oxidation of benzene in an aqueous solution was studied to evaluate potential applications of the MWCNT-Ag modified glassy carbon (GC) electrode in environmental science. The benzene removal efficiency in natural water containing 10 mg L−1 benzene yielded 77.9% at an applied potential of +2.0 V for 2 h using the MWCNT-Ag-GC electrode. In comparison, the removal efficiency reached only 8.0% with the bare GC electrode, showing the suitability of the MWCNT-Ag nanocomposite modified GC electrode for electro-oxidation of benzene in natural water. 相似文献
546.
Marco Piccoli Simona Coviello Maria Elena Canali Paola Rota Paolo La Rocca Federica Cirillo Ivana Lavota Adriana Tarantino Giuseppe Ciconte Carlo Pappone Andrea Ghiroldi Luigi Anastasia 《International journal of molecular sciences》2022,23(11)
Coronary reperfusion strategies are life-saving approaches to restore blood flow to cardiac tissue after acute myocardial infarction (AMI). However, the sudden restoration of normal blood flow leads to ischemia and reperfusion injury (IRI), which results in cardiomyoblast death, irreversible tissue degeneration, and heart failure. The molecular mechanism of IRI is not fully understood, and there are no effective cardioprotective strategies to prevent it. In this study, we show that activation of sialidase-3, a glycohydrolytic enzyme that cleaves sialic acid residues from glycoconjugates, is cardioprotective by triggering RISK pro-survival signaling pathways. We found that overexpression of Neu3 significantly increased cardiomyoblast resistance to IRI through activation of HIF-1α and Akt/Erk signaling pathways. This raises the possibility of using Sialidase-3 activation as a cardioprotective reperfusion strategy after myocardial infarction. 相似文献
547.
In this paper, we present a query-driven indexing/retrieval strategy for efficient full text retrieval from large document collections distributed within a structured P2P network. Our indexing strategy is based on two important properties: (1) the generated distributed index stores posting lists for carefully chosen indexing term combinations that are frequently present in user queries, and (2) the posting lists containing too many document references are truncated to a bounded number of their top-ranked elements. These two properties guarantee acceptable latency and bandwidth requirements, essentially because the number of indexing term combinations remains scalable and the posting lists transmitted during retrieval never exceed a constant size. A novel index update mechanism efficiently handles adding of new documents to the document collection. Thus, the generated distributed index corresponds to a constantly evolving query-driven indexing structure that efficiently follows current information needs of the users and changes in the document collection.We show that the size of the index and the generated indexing/retrieval traffic remains manageable even for Web-size document collections at the price of a marginal loss in precision for rare queries. Our theoretical analysis and experimental results provide convincing evidence about the feasibility of the query-driven indexing strategy for large scale P2P text retrieval. 相似文献
548.
Stefanie Hanreich Dr. Elisa Bonandi Dr. Ivana Drienovská 《Chembiochem : a European journal of chemical biology》2023,24(6):e202200566
The design of artificial enzymes has emerged as a promising tool for the generation of potent biocatalysts able to promote new-to-nature reactions with improved catalytic performances, providing a powerful platform for wide-ranging applications and a better understanding of protein functions and structures. The selection of an appropriate protein scaffold plays a key role in the design process. This review aims to give a general overview of the most common protein scaffolds that can be exploited for the generation of artificial enzymes. Several examples are discussed and categorized according to the strategy used for the design of the artificial biocatalyst, namely the functionalization of natural enzymes, the creation of a new catalytic site in a protein scaffold bearing a wide hydrophobic pocket and de novo protein design. The review is concluded by a comparison of these different methods and by our perspective on the topic. 相似文献
549.
Ass. Prof. Tien Dinh Vu Associate Prof. Rangabhashiyam Selvasembian Dr.-Ing. Ivana Mutavdžin Dr.-Ing. Elena Horosanskaia Prof. Heike Lorenz Prof. Andreas Seidel-Morgenstern 《化学,工程师,技术》2023,95(11):1851-1857
The flavonoid rutin is present in significant amounts in the flower buds of Sophora japonica L. It offers numerous desired pharmacological effects. Under certain extraction conditions quercetin is found as a hydrolysis product which needs to be separated from rutin. This paper describes the application of liquid chromatography to solve this task. Based on the determination of adsorption equilibrium constants and column efficiencies, the productivity of the separation process is estimated, and scale-up considerations are presented. A comparison with alternatively directly crystallizing rutin from raw extracts is also reported. 相似文献
550.
Biljana Pajin Ljubica Dokić Danica Zarić Dragana Šoronja-Simović Ivana Lončarević Ivana Nikolić 《Journal of food engineering》2013
The aim of this paper is to define the optimal conditions for the pre-crystallization of chocolate produced in a ball mill, that contains 20% soya milk. Chocolate mass and soya milk are refined in a ball mill employing three refining times (30, 60 and 90 min) and pre-crystallization temperatures (26, 28 and 30 °C). 相似文献