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51.
Olive leaves extracts are a natural source of polyphenols, mainly oleuropein, widely considered to be potentially beneficial for health. This study focused on evaluation of the anti-tumoural activities of some oleuropein peracetylated derivatives, obtained with “green chemical” methodologies, against two human breast cancer cell lines. MCF-7 and T-47D cells were treated with oleuropein, peracetylated oleuropein, peracetylated aglycone and peracetylated hydroxytyrosol and the effects on growth and viability were investigated. Antioxidant effects were analysed after treatment with hydrogen peroxide. The peracetylated compounds exerted higher antiproliferative effects than oleuropein, by an arrest of cell cycle progression, associated with a strong antioxidant activity. Our results demonstrate that olive leaves, a by-product of olive manufacture, may provide a precious source of chemical derivatives, obtainable by peracetylation of oleuropein derivatives, which provide beneficial properties for human health.  相似文献   
52.
Resveratrol, a dietary polyphenol, is under consideration as chemopreventive and chemotherapeutic agent for several diseases, including cancer. However, its mechanisms of action and its effects on non-tumor cells, fundamental to understand its real efficacy as chemopreventive agent, remain largely unknown. Proline-rich tyrosine kinase 2 (PYK2), a non-receptor tyrosine kinase acting as signaling mediator of different stimuli, behaves as tumor-suppressor in prostate. Since, PYK2 and RSV share several fields of interaction, including oxidative stress, we have investigated their functional relationship in human non-transformed prostate EPN cells and in their tumor-prone counterpart EPN-PKM, expressing a PYK2 dead-kinase mutant. We show that RSV has a strong biological activity in both cell lines, decreasing ROS production, inducing morphological changes and reversible growth arrest, and activating autophagy but not apoptosis. Interestingly, the PYK2 mutant increases basal ROS and autophagy levels, and modulates the intensity of RSV effects. In particular, the anti-oxidant effect of RSV is more potent in EPN than in EPN-PKM, whereas its anti-proliferative and pro-autophagic effects are more significant in EPN-PKM. Consistently, PYK2 depletion by RNAi replicates the effects of the PKM mutant. Taken together, our results reveal that PYK2 and RSV act on common cellular pathways and suggest that RSV effects on prostate cells may depend on mutational-state or expression levels of PYK2 that emerges as a possible mediator of RSV mechanisms of action. Moreover, the observation that resveratrol effects are reversible and not associated to apoptosis in tumor-prone EPN-PKM cells suggests caution for its use in humans.  相似文献   
53.
Additional new lupane lactones were isolated from the stem bark of Kokoona ochracea (Celastraceae). Their structures have been elucidated, through the application of 1D and 2D nmr spectroscopic methods, as 20,29-dihydroxy-3-oxolupan-30,21 alpha-olide (ochraceolide D) [1] and 28-hydroxy-3-oxolup-20(29)-en-30,21 alpha-olide (ochraceolide E) [2]. These compounds and the mono- and di-acetates of ochraceolide D (4 and 5, respectively) were evaluated for in vitro cytotoxic activity against P-388 murine lymphocytic leukemia cells and a panel of human cancer cell systems. Ochraceolide D [1] was significantly cytotoxic (ED50, 3.9 micrograms/ml) against human glioblastoma (U373) cells. Other compounds (4, 5, and 2) exhibited only a weak cytotoxic response in certain cancer cell lines.  相似文献   
54.
Generalized cross-validation (GCV) is a popular tool for specifying the tuning parameter in linear regression model or equivalently the regularization parameter in Tikhonov regularization. In this work, we are concerned with the estimation and minimization of the GCV function by using a combination of an extrapolation procedure and a statistical approach. In particular, we derive families of estimates for the GCV function. By minimizing the estimated GCV function over a grid of values, a GCV estimate of the regularization parameter is achieved. We present several numerical examples to illustrate the effectiveness of the derived families of estimates for approximating the regularization parameter for several linear discrete ill-posed problems.  相似文献   
55.
Systems evolve in order to adjust and survive. The paper’s contribution is that this evolvement is inadequate without an evolutionary telos. It is argued that without the presence of self-destruction in multiple levels of our existence and surroundings, our survival would have been impossible. This paper recognises an appreciation of auto-catastrophe at the cell level, in human attitudes (both as an individual and in societies), and extended to Earth and out to galaxies. Auto-Catastrophic Theory combines evolution with auto-catastrophic behaviours and innovative machinery by offering new themes of understanding their merging such as (a) protogenic and deuterogenic auto-catastrophic processes, (b) protogenic and deuterogenic survival processes, and (c) ‘alive’, partially ‘alive’, and non-‘alive’ systems. The value of self-destruction relies on a numerical stability within a system and correlational relationships between systems. Auto-Catastrophic Theory provides novel justifications why artificial intelligence: (a) is crucial to overcome the extinction of humanity (via H+), (b) is crucial to offer indirect survival of humanity (by saving its history), and (c) is at the same time a threat for humanity. These novel justifications and themes, developed by combining evolution with catastrophe as well as innovative machinery, expand our knowledge of how best to handle fresh challenges ahead.  相似文献   
56.
The aim of this paper was to provide a background review to assist experimental, survey and field studies that will start emerging on the effects of robot crime interviewers on children and on forensic investigations. The paper captures topics such as describing how, historically, technology has determined our legal systems, criminal investigations and, of course, children’s forensic testimonies. It discusses studies that have already explored the idea of robot crime interviewers in the context of relevant ethical concerns as well as experimental studies on the different ways in which children react in an interview elicited by a human compared with a robot interviewer. The article continues by suggesting research methodological designs that could benefit studies exploring robot interviews with children such as a robot exposure phase prior to the main data collection, the robot’s “personality” and the instructions given to children for semi-autonomous interviewers. This is based on the available literature on human–robot interactions. There is an attempt here to provide a literature review and methodological suggestions to form future studies on robot crime interviewers.  相似文献   
57.
    
Resistive oxygen sensors based on gallium oxide were fabricated in order to analyze their sensing performances (as sensitivity, response, and recovery time) in an oxygen atmosphere at 1000°C. We prepared three types of sensors using a β-Ga2O3 single crystal in a sandwich structure with Pt pad electrodes and β-Ga2O3 polycrystalline thin films deposited by using both the sputtering technique and the chemical solution deposition method. For thin-film sensors, Pt interdigital electrodes were deposited on the surface of the films using the lift-off method. X-ray diffraction and atomic force microscopy investigations were performed to compare the structure and surface morphology of the samples. We achieved a response time of 10 s at 1000°C, while the sensitivity was 1.03 for the single crystal and 1.35–1.45 for thin films. The sensing properties depend on the preparation condition of Ga2O3 devices.  相似文献   
58.
From January 1, 2011, in all UE countries the combined production of electric (or mechanical) and thermal energy (also called Combined Heat and Power, CHP, or cogeneration) is recognized as a high efficiency technology only when it is able to ensure a minimum value of energy saving with respect to the separate production of the same energy flows. The Directive 8/2004/EC, and a few successive Decisions of the European Commission, introduced a methodology to establish whether any cogeneration plant, existing or new, can be acknowledged as a high-efficiency CHP plant, and can therefore be supported from the UE member states. In the paper, such methodology, based on the evaluation of a standard Primary Energy Saving (PES) index, is briefly described, and then a metrological analysis is presented, in order to evaluate the uncertainties affecting the field evaluation of such index. Three numerical examples are also presented and discussed, referred to natural gas plants, showing that the evaluation of the PES index can be quite critical, especially for values close to the minimum limit fixed by the Directive, and in particular for small and medium scale CHP units, mainly due to the low accuracy that usually affect, in such cases, the measures of the fuel input.  相似文献   
59.
Fifteen eukaryotic microorganisms were tested for their ability to assimilate biodiesel derived waste glycerol and convert it into value-added metabolic products. For this purpose yeast and Zygomycetes strains were cultivated in nitrogen-limited raw glycerol-based media (initial glycerol concentration 30 g/L). Yeasts tested accumulated restricted lipid quantities (up to ∼22%, wt/wt, in the case of Rhodotorula sp), while differentiations in their fatty acid composition were recorded in relation to the yeast strains employed and the fermentation time. On the contrary, fungi accumulated higher quantities of lipid inside their mycelia (ranging between 18.1 and 42.6%, wt/wt, of dry biomass) that contained in variable amounts the medically important GLA (γ-linolenic acid). Moreover, Yarrowia lipolytica, Pichia membranifaciens and Thamnidium elegans were further studied in media having increased initial glycerol concentrations. In these conditions Y. lipolytica secreted significant amounts of acetic acid (29.2 g/L), as well as mannitol (19.4 g/L) while P. membranifaciens reached 28.4 g/L of biomass at glycerol concentration 90 g/L. T. elegans produced 11.6 g/L of oil, with 71.1%, wt/wt, of fat in biomass, while the maximum concentration of GLA was 371 mg/L. Detailed analysis of T. elegans lipids indicated that the phospholipids fraction was particularly rich in polyunsaturated fatty acids.  相似文献   
60.
Craft beer is often produced as a non‐filtered, unpasteurized and bottle re‐fermented beer, whose production is aimed at maintaining original sensory characteristics. The intention of most micro‐breweries is to meet these requirements in producing a high‐quality beer. In Italy, as well as in Sardinia, the number of micro‐breweries is increasing. In an attempt to make this product more original, new strains of Saccharomyces cerevisiae were selected. Sourdough yeasts were used as an alternative source of starters for beer production. In this particular work, two wheat beers were compared, one brewed with an autochthonous yeast isolated from sourdough and the other brewed with a commercial yeast normally used in Italian micro‐breweries. The wheat beer fermented with the autochthonous yeast had the highest ethanol content, the lowest pH and the highest content of esters and alcohols. From a sensory point of view the two beers showed significant differences in the triangle test, but were not significantly different in the paired test with preference. Copyright © 2015 The Institute of Brewing & Distilling  相似文献   
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