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11.
Wireless Personal Communications - Private professional environments such as manufacturing industry, warehouses, hospitals, airports, among others, increasingly rely on end-to-end connected...  相似文献   
12.
The present study assessed the influence of essential oil and aqueous infusion from wild-grown caper (Capparis spinosa L.) on cell growth, NF-κB activation, apoptosis and cell cycle in the human colon carcinoma cell line, HT-29. Methyl isothiocyanate (92.06%), a degradation product of glucosinolate glucocapparin, was detected as major component of essential oil from caper leaves and flower buds. Aqueous infusion of caper showed an interesting and variegate compositional pattern containing several phenolic compounds, among which a flavonol glycoside, rutin (quercetin 3-O-rutinoside, 50.7%) and 5-caffeoyl-quinic acid (chlorogenic acid, 17.5%) were detected as dominant. Caper essential oil and aqueous infusion showed time- and dose-dependent high inhibitory effect on HT-29 cell proliferation. In addition, they induced the inhibition on nuclear factor κB (NF-κB) activity in a dose-dependent manner, while they did not show any effect on apoptosis in HT-29 cells. Flow cytometric analysis indicated that treatment with caper essential oil and aqueous infusion resulted in G2/M cell cycle arrest in a dose-dependent manner. Presented results suggest that caper contains volatile and non-volatile compounds which potentially can play an important role in colon cancer prevention.  相似文献   
13.
The influence of high-intensity pulsed electric field (HIPEF) parameters, pulse frequency, pulse width and pulse polarity in strawberry juice lipoxygenase (LOX) and β-glucosidase (β-GLUC) was studied using a response surface methodology. The studied parameters affected on both residual enzymatic activities at unchanging electric field strength of 35 kV/cm and treatment time for 1000 μs. The contour plots showed a minimum defined space where residual activity of LOX remained at 65% and 70% in monopolar and bipolar mode, respectively. Low pulse frequencies (up to 61.6 Hz) in monopolar treatments as well as pulse frequencies and widths higher than 218 Hz and 5.4 μs in bipolar treatments did not have any effect on LOX inactivation. On the other hand, the higher the pulse frequency and pulse width, the higher the β-GLUC inactivation obtained. Moreover, when the HIPEF treatment was applied in monopolar mode, an enhancement in β-GLUC activity was observed in most of the experimental range. HIPEF treatments have demonstrated adequately that can reduce activity of enzymes that are involved in the formation of desirable flavor compounds, helping processors to obtain juices that keep their fresh flavor.

Industrial relevance

High-intensity pulsed electric fields (HIPEF) have proved to be effective in the interaction of microorganisms and enzymes in juices, maintaining their quality and freshness.HIPEF juice processing has demonstrated to have some advantages with regard to conventional thermal treatment. HIPEF treatments can reduce adequately enzymes that are involved in the formation of desirable flavor or color compounds. Thus, HIPEF technology can help processors to obtain juices that keep their fresh flavor by achieving optimal inactivation of related enzymes. This would prevent the product from undesirable off-flavor formation, which in turn would result in greater acceptability by consumers.  相似文献   
14.
15.
Crystallization with additives is developed on milk samples from different processing treatments. Performance tests are carried out based on structure analysis of the crystallization patterns. Crystallization with milk as additive is applied following changes in milk after different processing treatments. When an aqueous cupric chloride dihydrate solution crystallizes in the presence of milk as additive, specific patterns emerge, which can be evaluated by image analysis. Milk samples were heated and homogenized in a pilot plant and characterized by various parameters. Furthermore, milk samples from the market were tested. Patterns from milk after heat treatment and homogenization are significantly different from those derived from untreated milk. The experiments could be reproduced for other milk samples, on different days and in another laboratory.  相似文献   
16.
Whole body saline-perfused rainbow trout (Oncorhynchus mykiss) was ice-stored for 4 weeks and compared with unwashed/washed minces from unbled and bled trout in terms of rancid odour, peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and redness loss. Muscle from saline-perfused fish, which had 72% less total haem, was deficient in rancid odour during the whole storage, while bled (54% less haem) and unbled samples developed rancid odour already after ~4 and 2 days; higher intensity without bleeding. PV/TBARS also developed in the order unbled > bled > perfused samples; however, PV/TBARS were not as completely prevented as rancid odour after perfusion. Saline washing (3 × 3 volumes) of unbled mince removed 84% haem and yielded the second most stable sample while saline washing (1 × 1 volumes) destabilised unbled mince, despite 64% haem removal. Concurrent antioxidant removal during washing of minces obviously counteracted the effect of blood removal and washing fish mince with small volumes of solution should be used with great care.  相似文献   
17.
Lactose solutions of up to 50% (w/v) were incubated with lactases and glucose isomerases for subsequent implementation in dairy product samples to enhance sweetness. A degree of hydrolysis of >90% and of isomerisation of 50% were attainable. The sensory sweetening power of lactose in solutions of up to 50% (w/v) can be enhanced 2–3 times. Based on sensory experiments, application of this bi‐enzymatic system in yoghurt and pudding samples allowed for a 10–20% (w/w) reduction in the total sugar content, whilst retaining equal sweetness. The growth of yoghurt starter cultures was not affected, yet furosine formation more than doubled in high heated, enzyme‐modified milk.  相似文献   
18.
Enterococcus faecium strain FAIR-E 345 isolated from food was shown to possess bile salt hydrolase (Bsh) activity in a plate screening assay and by high-performance liquid chromatography analysis. The bsh gene was cloned and sequenced. DNA sequence analysis revealed that it encoded a protein of 324 amino acids, with pI 4.877. A bsh gene probe was prepared from the cloned bsh gene and was used for probing plasmid and total genomic DNA of Bsh-positive enterococci isolated from food to determine the genomic location of their bsh genes. This probe was able to detect the bsh gene among total genomic DNA preparations but not from plasmid preparations of 10 plasmid-bearing Enterococcus strains. However, the probe could detect the bsh gene from total genomic DNA preparations of 12 Enterococcus strains that did not contain detectable plasmid DNA. In no cases did the probe hybridize with plasmid DNA preparations, suggesting that the bsh gene among enterococci is probably generally chromosomally encoded. This presumptive chromosomal location of bsh genes among food enterococci suggests that transfer of this trait by conjugative plasmids is unlikely.  相似文献   
19.
The enzyme-resistant starch (ERS) content in processed high amylose and regular maize starches has been studied, with and without acid dextrinisation. The physicochemical and structural characteristics of the starches were analysed using a variety of techniques. The increase in ERS in high amylose maize starch with dextrinisation was related to the formation of a critical molecular weight fraction (MW ∼ 20,000) that could rearrange structurally. Further dextrinisation reduced the processed starch MW to below where it could still form ERS. Regular maize starch containing less than 30% amylose did not increase its resistance to amylase digestibility with acid dextrinisation, probably due to impairment of amylose rearrangement by the numerous branched amylopectin chains. The ERS, which is likely to form during the enzyme-digestion process, is a linear molecule with a maximum degree of polymerisation (DP) of 30, irrespective of the starch source, processing conditions applied or type and amount of acid used.  相似文献   
20.
The effects of various thermal processing treatments (blanching, boiling and steaming) of red cabbage, Brassica oleracea L. ssp. capitata f. rubra cv. ‘Autoro’, were assessed for the levels of glucosinolates (GLS), total phenols (TP), total monomeric anthocyanins (TMA), l-ascorbic acid (L-AA) and soluble sugars, as well as for the antioxidant potential by the ferric reducing ability power (FRAP) and oxygen radical absorbance capacity (ORAC) assays. Individual native GLS were determined by ion-pair HPLC-MS/DAD. There were significant (p < 0.05) losses in blanched red cabbage: TP, 43%, TMA 59%, FRAP 42%, ORAC 51%, L-AA 48% and soluble sugars 45%. Boiling gave less extensive reductions: TP 16%, TMA 41%, FRAP 17%, ORAC 19%, L-AA 24% and soluble sugars 19%. Steaming caused no losses for TP, ORAC, FRAP or soluble sugars. However, significant reductions were found for TMA and L-AA, with 29% and 11%, respectively. In general losses were accounted for in the processing waters; however, TMA was not fully recovered, indicating degradation. Total GLS were severely affected by processing, with reductions of 64%, 38% and 19% in blanched, boiled and steamed red cabbage, respectively. Total aliphatic and indole GLS were similarly affected. Lost GLS were partially recovered in the processing water.  相似文献   
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