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151.
Editorial     
International Journal on Software Tools for Technology Transfer -  相似文献   
152.
153.
Some biomolecules are able to generate directional forces by rectifying random thermal motions. This allows these molecular machines to perform mechanical tasks such as intracellular cargo transport or muscle contraction in plants and animals. Although some artificial molecular machines have been synthesized and used collectively to perform mechanical tasks, so far there have been no direct measurements of mechanical processes at the single-molecule level. Here we report measurements of the mechanical work performed by a synthetic molecule less than 5?nm long. We show that biased Brownian motion of the sub-molecular components in a hydrogen-bonded [2]rotaxane-a molecular ring threaded onto a molecular axle-can be harnessed to generate significant directional forces. We used the cantilever of an atomic force microscope to apply a mechanical load to the ring during single-molecule pulling-relaxing cycles. The ring was pulled along the axle, away from the thermodynamically favoured binding site, and was then found to travel back to this site against an external load of 30?pN. Using fluctuation theorems, we were able to relate measurements of the work done at the level of individual rotaxane molecules to the free-energy change as previously determined from ensemble measurements. The results show that individual rotaxanes can generate directional forces of similar magnitude to those generated by natural molecular machines.  相似文献   
154.
Saffron production from Crocus sativus flowers produces large amounts of by-products that may represent an excellent source of polyphenols. The aim of this work was to evaluate infusions originating from different brewing processes and from different saffron flower portions, in terms of both functional and sensory traits. For this aim, total polyphenols and total flavonoids, in vitro antioxidant assays and an untargeted phenolic profiling were applied. In general, tepals showed higher polyphenol and flavonoid content than stamen infusions, and their bioactive content depended more on brewing temperature than brewing time. These findings were consistent with both antioxidant capacity and phenolic profiling. Multivariate statistics highlighted polyphenols discriminating ‘boiled’ vs. ‘cold’ infusions, being mainly flavonoids, phenolic acids and the alkylphenol 5-pentadecylresorcinol (showing a strong down-accumulation at the higher brewing temperatures). Positive correlations could be highlighted between anthocyanins, flavones, flavonols and lignans, and the in vitro antioxidant assays. In general, cold brewing was successful in extracting phenolic compounds and provided better sensory properties, thus indicating that this may represent a valuable strategy to develop saffron-based functional beverages with better consumers' acceptability.  相似文献   
155.
Barrels play an important role in winemaking, giving wines a specific flavour and assisting the ageing process. However, the porosity and inertness of wood encourage the proliferation of spoilage yeasts which can severely affect wine quality. The yeast microbiota resident inside barriques located in a traditional Tuscan winery were identified by partial sequencing of the 26S rDNA gene. Most of them belonged to the Saccharomyces, Candida and Pichia genera, while Brettanomyces/Dekkera represented a limited part of the population. The ability of the isolated yeasts to spoil wine through the production of volatile phenols was evaluated. Brettanomyces showed significant production of ethylphenols, with a conversion rate of over 70%; many other species of yeast showed extensive production of vinylphenols, which can have a negative impact on wine quality. To improve the microbiological control of barrels, 4 treatments were tested for their efficacy in eradicating the yeast inside the barrels: aqueous steam (100 °C, 5–30-min treatment), UV irradiation (36-W lamp, 5–30-min treatment), gaseous O3 (40 mg/m3, 30-min treatment) and aqueous O3 (2 mg/L, 30-min treatment). Steam and O3 were the most effective treatments, eliminating about 70% of yeasts. UV appeared to be less effective, probably due to the porous nature of wood, which protects cells from direct irradiation.  相似文献   
156.
Supercritical fluid chromatography (SFC) was employed to fractionate thyme (Thymus vulgaris L.) extracts, which were obtained by supercritical carbon dioxide extraction of thyme leaves. First, different supercritical extracts were produced at 313 K and at different pressures (15, 30 and 40 MPa). Thymol, a monocyclic terpenoid with recognized antiseptic, analgesic and anti-inflammatory properties, was identified and quantified in the different samples by GC-MS. Then, the supercritical extracts were fractionated by semi-preparative SFC, and different conditions such as pressure, temperature and amount of cosolvent (ethanol) employed were studied. Around a two fold increase of thymol was achieved at 15 MPa, 50 °C and 3% ethanol cosolvent, recovering 97% of the monocyclic terpenoid extracted.  相似文献   
157.
Chrastil (1982) established that the solubility of a substance in a supercritical fluid can be correlated with the density of the pure supercritical gas. Recently, the solubility of supercritical fluids in different organic liquids was successfully correlated as a function solely of the supercritical fluid density, since we demonstrated that the supercritical fluid density also defines the solubility of the gas in the liquid phase. In this work, the solubility of supercritical carbon dioxide in high‐molecular weight substances, such as high‐molecular weight paraffins, alcohols, fatty acids, fatty acid methyl and ethyl esters, has been correlated and constants provided. More than 20 binary systems comprising around 1000 solubility data points were correlated, obtaining regression coefficients greater than 0.96 and confirming the goodness of the density‐dependent equation previously reported. © 2010 American Institute of Chemical Engineers AIChE J, 2011  相似文献   
158.
Endometriosis is a common gynecological disease. Here, we aimed to investigate the anti-fibrotic, anti-inflammatory, and anti-oxidative role of the methyl ester of 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO-Me) on endometriosis. An endometriosis rat model was constructed by intraperitoneally injecting recipient rats with an equivalent of tissue from the uterus of a donor animal. Endometriosis was allowed to develop for seven days. CDDO-Me was administered on the 7th day and for the next 7 days. On day 14, rats were sacrificed, and peritoneal fluid and endometriotic implants were collected. CDDO-Me displayed antioxidant activity by activating the Nfr2 pathway and the expression of antioxidant mediators such as NQO-1 and HO-1. Moreover, it reduced lipid peroxidation and increased glutathione (GSH) levels and superoxide dismutase (SOD) activity. CDDO-Me also showed anti-inflammatory activity by decreasing the expression of pro-inflammatory cytokines in peritoneal fluids and NFkB activation. It, in turn, reduced cyclooxygenase-2 (COX-2) expression in the endometriotic loci and prostaglandin E2 (PGE2) levels in the peritoneal fluids, leading to increased apoptosis and reduced angiogenesis. The reduced oxidative stress and pro-inflammatory microenvironment decreased implants diameter, area, and volume. In particular, CDDO-Me administration reduced the histopathological signs of endometriosis and inflammatory cells recruitment into the lesions, as shown by toluidine blue staining and myeloperoxidase (MPO) activity. CDDO-Me strongly suppressed α-SMA and fibronectin expression and collagen deposition, reducing endometriosis-associated fibrosis. In conclusion, CDDO-Me treatment resulted in a coordinated and effective suppression of endometriosis by modulating the Nrf2 and NFkB pathways.  相似文献   
159.
Bi-dimensional culture systems have represented the most used method to study cell biology outside the body for over a century. Although they convey useful information, such systems may lose tissue-specific architecture, biomechanical effectors, and biochemical cues deriving from the native extracellular matrix, with significant alterations in several cellular functions and processes. Notably, the introduction of three-dimensional (3D) platforms that are able to re-create in vitro the structures of the native tissue, have overcome some of these issues, since they better mimic the in vivo milieu and reduce the gap between the cell culture ambient and the tissue environment. 3D culture systems are currently used in a broad range of studies, from cancer and stem cell biology, to drug testing and discovery. Here, we describe the mechanisms used by cells to perceive and respond to biomechanical cues and the main signaling pathways involved. We provide an overall perspective of the most recent 3D technologies. Given the breadth of the subject, we concentrate on the use of hydrogels, bioreactors, 3D printing and bioprinting, nanofiber-based scaffolds, and preparation of a decellularized bio-matrix. In addition, we report the possibility to combine the use of 3D cultures with functionalized nanoparticles to obtain highly predictive in vitro models for use in the nanomedicine field.  相似文献   
160.
The gut microbiota could influence the pathophysiology of age-related sarcopenia through multiple mechanisms implying modulation of chronic inflammation and anabolic resistance. The aim of this study was to compare the fecal microbiota composition and functionality, assessed by shotgun metagenomics sequencing, between two groups of elderly outpatients, differing only for the presence of primary sarcopenia. Five sarcopenic elderly subjects and twelve non-sarcopenic controls, classified according to lower limb function and bioimpedance-derived skeletal muscle index, provided a stool sample, which was analyzed with shotgun metagenomics approaches, to determine the overall microbiota composition, the representation of bacteria at the species level, and the prediction of bacterial genes involved in functional metabolic pathways. Sarcopenic subjects displayed different fecal microbiota compositions at the species level, with significant depletion of two species known for their metabolic capacity of producing short-chain fatty acids (SCFAs), Faecalibacterium prausnitzii and Roseburia inulinivorans, and of Alistipes shahii. Additionally, their fecal metagenome had different representation of genes belonging to 108 metabolic pathways, namely, depletion of genes involved in SCFA synthesis, carotenoid and isoflavone biotransformation, and amino acid interconversion. These results support the hypothesis of an association between microbiota and sarcopenia, indicating novel possible mediators, whose clinical relevance should be investigated in future studies.  相似文献   
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