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Angelika Zimmermann Ilan Oshri Eleni Lioliou Alexandra Gerbasi 《The Journal of Strategic Information Systems》2018,27(1):82-100
The sharing of knowledge between a firm and its internal or external service suppliers has become an important element of contemporary sourcing arrangements. Moreover, the knowledge based view (KBV) has long suggested that due to stronger cognitive links within firms, internal compared to external service provision creates better conditions for knowledge sharing. Empirical evidence for this claim is however scarce, and the KBV does not explain the mechanisms for more knowledge sharing in internal sourcing in detail. Moreover, there is now some evidence to suggest that firms’ relationships with external sourcing partners are becoming more similar to those with captive centres, which represent a less traditional form of insourcing setting. To scrutinize the possible knowledge sharing advantages of internal sourcing in more depth, we turn to social capital (SC) research. There are some theoretical claims that SC and knowledge sharing are stronger within than between firms, and there is ample evidence that SC facilitates knowledge sharing. Our survey results suggest that the extent of knowledge sharing and SC are indeed stronger in a captive than in an external sourcing mode, and that structural (tie strength), cognitive (shared understanding), and relational (trust) aspects of SC mediate the effect of sourcing mode on the extent of knowledge sharing. By contrast, network stability (a structural aspect) mediated knowledge sharing only indirectly, by reinforcing the other SC aspects. We highlight important contributions to research and practice of IS outsourcing and social capital. 相似文献
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Matthias Rass Martin Dumbach Frank Danzinger Angelika C. Bullinger Kathrin M. Moeslein 《Creativity & Innovation Management》2013,22(2):177-194
This article examines the role of social relations and networks in open innovation settings. Building on extant open innovation literature as well as on social capital theory, we develop a model that conceptualizes social capital as a mediator between the implementation of open innovation instruments and firm performance. In doing so, this paper adds to the understanding of the role of structure and content of social relations in open innovation contexts as well as of sustainable side‐effects of open innovation. In particular, we argue that apart from a direct effect of open innovation instruments on firm performance, there is also a mediated relationship between these variables. More precisely, we propose that the implementation of open innovation instruments strengthens an organization's social capital, which is, in turn, positively related to firm performance. 相似文献
35.
Pesticides and polychlorinated biphenyls (PCBs) are found in various parts of the environment in quite small concentrations, but they accumulate and thus become a threat to human health and life. A review is focused on the application of some popular techniques for sample preparation in analysis of these compounds in food. Even with the emergence of advanced techniques of final analysis, complex matrices, such as food, require extensive sample extraction and purification. Traditional sample preparation techniques are time consuming and require large amount of solvents, which are expensive, generate considerable waste, contaminate the sample and can enrich it for analytes. There have been many sample preparation techniques proposed to meet the requirements connected with the multiplicity of food. Optimal sample preparation can reduce analysis time, sources of error, enhance sensitivity and enable unequivocal identification and quantification. Sample extraction and purification techniques are discussed and their most recent applications in food analysis are provided. This review pointed out that sample preparation is the critical step. 相似文献
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Burghardt Scheibe Walter Weiss Carl-Peter Bauer Angelika Görg 《European Food Research and Technology》2001,212(6):691-695
The present study was undertaken to develop a specific and sensitive method which allows the detection of trace amounts of the potentially allergenic bioindustrial enzymes Pectinex Ultra-SPL (pectinase) and Gamylo 200L (amylase) in apple juice. This was achieved by an immunoblotting procedure based on sodium dodecyl sulfate (SDS) electrophoretic separation, followed by an immunochemical detection step using polyclonal rabbit antisera directed against these enzymes and, secondly, alkaline phosphatase labelled antibodies in combination with a highly sensitive enhanced chemiluminescent (ECL) detection method. In a juice spiked with enzyme at various concentrations between 10,000 and 1 ppm (1.0-0.0001%), the detection limit was 10 ppm (=0.001%) for Pectinex Ultra-SPL and 1 ppm (=0.0001%) for Gamylo 200L, respectively. Since the enzyme preparations contain less than 5% of enzymes, the detection limit for the pure enzymes is markedly lower, at least below 1 ppm. Whereas in the samples withdrawn during the initial stages of the industrial production process of apple juice, Pectinex Ultra-SPL and Gamylo 200L components were detectable in concentrations between 50 and 100 ppm, after clearing, ultrafiltration and pasteurization, neither pectinase nor amylase was detectable in the final consumer's product. Under the conditions employed, the bioindustrial enzymes Pectinex Ultra-SPL and Gamylo 200L were virtually removed during the course of production. The risk of sensitizing consumers by intake of apple juice seems to be marginal. This view is supported by the results of an animal model (anaphylaxis test), in which neither gastro-enteral reactions in guinea pigs and mice, nor IgE or IgG production by orally feeding these animals with apple juice concentrate, could be induced. 相似文献
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Patrick P.J. Mulder Patricia López Massimo Castelari Dorina Bodi Stefan Ronczka Angelika Preiss-Weigert 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2018,35(1):118-133
Pyrrolizidine alkaloids (PAs) are secondary metabolites of plant families such as Asteraceae or Boraginaceae and are suspected to be genotoxic carcinogens. Recent investigations revealed their frequent occurrence in honey and particularly in tea. To obtain a comprehensive overview of the PA content in animal- and plant-derived food from the European market, and to provide a basis for future risk analysis, a total of 1105 samples were collected in 2014 and 2015. These comprised milk and milk products, eggs, meat and meat products, (herbal) teas, and (herbal) food supplements collected in supermarkets, retail shops, and via the internet. PAs were detected in a large proportion of plant-derived foods: 91% of the (herbal) teas and 60% of the food supplements contained at least one individual PA. All types of (herbal) teas investigated were found to contain PAs, with a mean concentration of 460 µg kg?1 dry tea (corresponding to 6.13 µg L?1 in [herbal] tea infusion). The highest mean concentrations were found in rooibos tea (599 µg kg?1 dry tea, 7.99 µg L?1 tea infusion) and the lowest in camomile tea (274 µg kg?1 dry tea, 3.65 µg L?1 tea infusion). Occurrence of PAs in food supplements was found to be highly variable, but in comparable ranges as for (herbal) tea. The highest concentrations were present in supplements containing plant material from known PA-producing plants. In contrast, only 2% of the animal-derived products, in particular 6% of milk samples and 1% of egg samples, contained PAs. Determined levels in milk were relatively low, ranged between 0.05 and 0.17 µg L?1 and only trace amounts of 0.10–0.12 µg kg?1 were found in eggs. No PAs were detected in the other animal-derived products. 相似文献
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BACKGROUND: The origin of the raw spirits influences the sensory quality of rectified spirits that are subsequently used for the production of vodka. The aim of this research was to evaluate the effectiveness of two methods based on the comparison of profiles of volatile compounds [solid phase microextraction–gas chromatography–mass spectrometry (SPME‐GC‐MS) and gas chromatography with flame ionisation detection (GC‐FID)] for the determination of origin of raw spirits obtained from rye, corn (maize) and potato. RESULTS: Profiles obtained for the volatile compounds by using these methods were different and were influenced by the sample introduction method. The main groups of volatiles obtained using SPME‐GC‐MS method were fatty acid ethyl esters, while in the case of GC‐FID fusel alcohols and ethyl acetate dominated. Data obtained from these methods were treated using principal component analysis and linear discriminant analysis to test the possibility of sample differentiation and classification. It was relatively easy to differentiate potato spirits from the remainder; however, it was not possible to fully distinguish the corn samples from rye samples. The classification ability of the SPME‐GC‐MS method was 95% but the prediction ability was 97.4%. For the GC‐FID method the classification ability was 90.1%, whereas the prediction ability was 94.27%. CONCLUSIONS: The methods presented can be used for reliable differentiation of potato spirits from corn and rye spirits. Copyright © 2012 Society of Chemical Industry 相似文献