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41.
42.
Sea bream scales and bones were used as sources of gelatin. Scales gave a higher gelatin yield than bones pretreated with HCl or Alcalase. Demineralization with EDTA was effective especially in the case of scale gelatin that showed the lowest ash content. The pretreatment of bones with HCl led to an increase in the removal of minerals. The gel strength and viscoelastic properties of sea bream scale gelatins were higher than those of bone gelatins, and only slight differences were found between gelatin extracted from bones pretreated with HCl or Alcalase, although the amino acid profile was similar in the three gelatins. The gel strength of scale gelatins was higher than that of a commercial bovine gelatin used for comparative purpose (Bloom 200–220). When the scales gelatin was hydrolyzed with Esperase, a high ACE-inhibitory activity was found in the peptide fraction below 3 kDa, and the amount of this peptide fraction required to inhibit 50% of the ACE activity (IC50) was around 60 μg/mL.  相似文献   
43.
In the present study, thermal conductivity and mechanical properties of MgO-C refractory ceramic bricks were investigated. Pyrolytic liquid and pyrolytic carbon black obtained from pyrolysis of waste tires were used as a resin and carbon source, respectively. The pyrolysis of the tires was conducted in a fixed bed reactor at the temperature of 500?°C with a 15?°C/min heating rate under nitrogen flow (0.5?lt/min). Before using in MgO-C refractory ceramic blends, pyrolytic products were purified with the acidic extraction methods which resulted in 61and 66?wt%. decreases in sulfur and ash contents in pyrolytic carbon, respectively. After this treatment of pyrolytic liquid, the sulfur content was reduced by 24?wt%. Eight different blends of MgO-C refractory ceramics consisting of different pyrolytic product contents were prepared, pressed, and tempered at 250?°C, and then characterized in terms of porosity, thermal conductivity, and density. The mechanical behavior of the samples was tested using a three-point bending test. Archimedes test was employed to determine the porosity and density. Surface properties of the bricks were analyzed by scanning electron microscopy (SEM). The obtained results were compared with a reference consisting of graphite and resin. The results revealed that mechanical and thermal properties of the developed bricks were highly sensitive to the porosity and the carbon source as well as the type of binder.  相似文献   
44.
Oxygen plasma modification of polyurethane membranes   总被引:1,自引:0,他引:1  
Polyurethane membranes were prepared under nitrogen atmosphere by using various proportions of toluene diisocyanates (TDI) and polypropylene-ethylene glycol (P) with addition of no other ingredients such as catalysts, initiator or solvent in order to achieve medical purity. Effects of composition on mechanical properties were examined. In general, modulus and UTS values demonstrated an increase and PSBR demonstrated a decrease as the TDI/Polyol ratio of the polymer increased. Elastic modulus, ultimate tensile strength (UTS) and per cent strain before rupture (PSBR) values were found to be in the range of 1.4–5.4 MPa, 0.9–1.9 MPa, and 60.4–99.7%, respectively. Surfaces of the membranes were modified by oxygen plasma applying glow-discharge technique and the effect of applied plasma power (10 W or 100 W, 15 min) on surface hydrophilicity and on the attachment of Vero cells were studied. Water contact angle values of the plasma modified surfaces varied between 67° and 46°, demonstrating a decrease as the applied plasma power was increased. The unmodified material had 42–45 cells attached per cm2. It was observed that as the applied power increased the number of attached cells first increased (60–70 cells/cm2 at 10 W) and then decreased (27–40 cells/cm2 at 100 W). These demonstrated that surface properties of polyurethanes can be modified by plasma-glow discharge technique to achieve the optimum levels of cell attachment.  相似文献   
45.
Summary 4,4-azobis(4-cyanopyrenylmethyl pentanoate) (ACPMP) was synthesized by the reaction of pyrenylmethanol with 4,4-azobis(4-cyanopentanoyl chloride) (ACPC). ACPMP was further used in the synthesis of polystyrene with pyrene terminal groups by using conventional free radical polymerization (FRP) and stable free radical polymerization (SFRP) techniques. Incorporatioil of terminal groups were confirmed by spectral measurements.  相似文献   
46.
The enzymatic synthesis of glycerides from glycerol and oleic acid in organic solvent was studied, and the optimal conditions for glyceride synthesis by lipases were established. Of the commercially available lipases that were investigated, Candida rugosa lipase and porcine pancreas lipase resulted in the highest extent of esterification. Iso-octane and hexane were particularly useful organic solvents in glyceride synthesis. The water content in the reaction mixture was of primary importance. For C. rugosa lipase and porcine pancreas lipase, the optimal water contents were 5 and 1%, respectively. Candida rugosa lipase and porcine pancreas lipase manifested contrasting positional specificities in glyceride synthesis.  相似文献   
47.
We investigated plasma sphingomyelin (CerPCho) and ceramide (Cer) levels in pediatric patients with cystic fibrosis (CF) and primary ciliary dyskinesia (PCD). Plasma samples were obtained from CF (n = 19) and PCD (n = 7) patients at exacerbation, discharge, and stable periods. Healthy children (n = 17) of similar age served as control. Levels of 16–24 CerPCho and 16–24 Cer were measured by LC–MS/MS. Concentrations of all CerPCho and Cer species measured at exacerbation were significantly lower in patients with CF than PCD. 16, 18, 24 CerPCho, and 22, 24 Cer in exacerbation; 18, 24 CerPCho, and 18, 20, 22, 24 Cer at discharge; 18, 24 CerPCho and 24 Cer at stable period were significantly lower in CF patients than healthy children (p < 0.001 and p < 0.05). All CerPCho and Cer levels of PCD patients were significantly higher except 24 CerPCho and 24 Cer during exacerbation, 24 CerPCho at discharge, and 18, 22 CerPCho levels at stable period (p < 0.001 and p < 0.05) compared with healthy children. There was no significant difference among exacerbation, discharge, and stable periods in each group for Cer and CerPCho levels. This is the first study measuring plasma Cer and CerPCho levels in PCD and third study in CF patients. The dramatic difference in plasma levels of most CerPCho and Cer species found between two diseases suggest that cilia pathology in PCD and CFTR mutation in CF seem to alter sphingolipid metabolism possibly in opposite directions.  相似文献   
48.
Seafood and seafood products (SSPs) are highly perishable foods due to their chemical composition (high moisture content and nutrients). They are regarded as highly sensitive to different processing technologies. SSPs are subjected to various processing conditions with intent to extend their shelf life, quality and minimal nutritional degradation. Recently developed non-thermal technologies (NTTs) have proved their efficacy in inactivation of microorganisms and enzymatic activities, enhancing the shelf life while maintaining the nutritional quality. Considering the significant impacts of NTTs on shelf life extension and maintaining quality parameters, it has attracted considerable interest by scientific communities and commercial applications in some cases. Thus, this article focuses on recent developments in the application of NTTs namely, cold plasma, pulsed electric field and high hydrostatic pressure as well as advantages and limitations of NTTs. In addition, their impacts on microbiological, physicochemical, quality and safety of SSPs are elucidated.  相似文献   
49.
The significance of marine creatures as a source of unique bioactive compounds is expanding. Marine organisms constitue nearly half of the wordwide biodiversity; thus, oceans and sea present a vast resource for new substances and it is considered the largest remaining reservoir of beneficial natural molecules that maight be used as functional constituents in the food sector. This review is an update to the information about recent functional seafood compounds (proteins, peptides, amino acids, fatty acids, sterols, polysaccharides, oligosaccharides, phenolic compounds, photosynthetic pigments, vitamins, and minerals) focusing on their potential use and health benefits.  相似文献   
50.
This paper investigates the relations between festivals and their institutional settings, and how these relations shape festival management. We analyze institutional logics and work practices in a complex project, Lucca Comics & Games, which is the biggest festival dedicated to fantasy culture in Italy. Our results, based on archival research, media coverage and interview data, reveal the recursive interplay between institutional logics and work practices for institutional maintenance. We argue that the study of festivals is essential to understanding key aspects of project-based organizing more generally. In this regard, the maintaining of institutions must be distinguished from stability or the absence of change and consideration of historical and contextual analysis, and multiple tensions that occur due to competing institutional logics can open up new ways of thinking for prospective research. We also demonstrate that future research can use institutional work practices for understanding institutional maintenance in recurring temporary organizations.  相似文献   
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