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The lipophilic and hydrophilic antioxidants were evaluated in eight plants: safflower (Carthamus tinctorius), viper’s bugloss (Echium vulgare), quince (Cydonia vulgaris), evening primrose (Oenothera biennis), rose mosqueta (Rosa affinis rubiginosa), black seed (Nigella sativa), sea buckthorn (Hippophae rhamnoides) and borage (Borago officinales). The highest amounts of tocopherols were contained in seeds of borage and sea buckthorn (66.9 mg/100 g and 45.9 mg/100 g, respectively). The sea buckthorn seed lipids had the highest amount of total sterols (10.4 mg/g of lipids). The predominant form was campesterol. Sitosterol was the major sterol in the lipids of other tested seeds. The content of phenolic compounds ranged from 736.5 mg/100 g dry matter (d.m.) (evening primrose) to 74.8 mg/100 g d.m. (safflower). The highest antioxidant activity, expressed in % scavenged DPPH· free radicals, was observed for evening primrose (91.2%), while the lowest for safflower (36.2%). The correlation coefficient between the level of phenolic compounds and antioxidant activity was 0.53.  相似文献   
23.
We analyze the fracture of single crystal silicon simulated by atomistic modeling with ReaxFF first principles based reactive force field. The simulations are performed at three temperatures: 500 K, 800 K and 1200 K, capturing both brittle and ductile behavior for the selected crystallographic orientation with (1 0 0) as the fracture plane. Three failure mechanisms are observed: bond breaking, amorphization and emission of dislocations. We demonstrate that the Crack Tip Opening Displacement (CTOD) gives a realistic estimate of the fracture toughness of brittle fracture, linking continuum mechanics fracture theory with the direct crack tip atomistic approach. We discuss the physics based mechanisms of failure in silicon in view of the CTOD measurements.  相似文献   
24.
Plaque visualisation : We identified three different D ‐enantiomeric peptides that bind to Alzheimer's amyloid β (Aβ1‐42). As there is currently no definitive pre‐mortem diagnosis for Alzheimer's disease, we investigated the peptides' suitability as molecular probes for in vivo imaging in transgenic mouse models.

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25.
Within the framework of the MABMEM research project, new high‐performance membranes are being developed for sustainable water management. The performance of the membranes will be evaluated in comparative and standardized fouling tests as well as in terms of the removal of trace impurities on a laboratory scale. Seven candidates are currently being tested in demonstrator trials with real‐water matrix in a waterworks for the direct treatment of dam water without prior coagulation over a period of 6 months. Subsequently, the new membrane materials will be operated with the effluent of a wastewater treatment plant.  相似文献   
26.
Mg-substituted hydroxyapatite (HAp) bioceramic microspheres were prepared by spray drying and subsequent processing at 1173, 1273 and 1373 K. Influence of various Mg substitution levels (up to 0.84 ± 0.10 wt%) on physicochemical properties of the HAp bioceramic microspheres was evaluated. Obtained results were used for the elucidation of the compositional and structural characteristics of the microspheres in conjunction with adsorption of protein, namely, bovine serum albumin (BSA). The primary difference among the microspheres processed at various temperature was the presence or absence of the micropores (<2 nm in diameter) and mesopores (between 2 and 50 nm). Presence of the micro- and mesopores resulted in higher specific surface area (SSA), enhanced solubility, i.e., ion release, and, accordingly, increase in the amount of BSA adsorbed on the microspheres. Furthermore, the BSA adsorption capacity of the microspheres decreased with increasing Mg content despite of higher SSA.  相似文献   
27.
We report a quantitative analysis of the forces acting on optically trapped single gold nanorods. Individual nanorods with diameters between 8 and 44 nm and aspect ratios between 1.7 and 5.6 were stably trapped in three dimensions using a laser wavelength exceeding their plasmon resonance wavelengths. The interaction between the electromagnetic field of an optical trap and a single gold nanorod correlated with particle polarizability, which is a function of both particle volume and aspect ratio.  相似文献   
28.
Annular folded imagers can be up to 10x thinner than corresponding full-aperture imagers, but have tight fabrication tolerances and relatively shallow depth of focus. Wavefront coding, the use of specialized optics with postdetection signal processing, has been used to improve the depth of focus in full-aperture imaging systems. Here we explore the application of wavefront coding to annular folded optics. We compare the design and experimental results for an imaging system with a 38 mm focal length and just 5 mm total track.  相似文献   
29.
Conditions of gauging of true microhardness of thin ribbons metallic glasses (MG) with the count of their depth are established. For the first time the method of a indentation was approved for an assessment of crack resistance of MG. The behavior of parameterKIc is found in a interval of temperature of viscous-brittle transition down to the beginning of volumetric crystallization of MG. The estimation method of temperature of viscous - brittle transition is offered at the microindentation of annealing ribbon on an elastic substrate.  相似文献   
30.
Secondary metabolism involves a broad diversity of biochemical reactions that result in a wide variety of biologically active compounds. Terminal amide formation during the biosynthesis of the myxobacterial electron-transport inhibitor, myxothiazol, was analyzed by heterologous expression of the unique nonribosomal-peptide synthetase, MtaG, and incubation with a synthesized substrate mimic. These experiments provide evidence that the terminal amide is formed from a carrier protein-bound myxothiazol acid that is thioesterified to MtaF. This intermediate is transformed to an amide by extension with glycine and subsequent oxidative cleavage by MtaG. The final steps of melithiazol assembly involve a highly similar protein-bound intermediate (attached to MelF, a homologue of MtaF), which is transformed to an amide by MelG (homologue of MtaG). In this study, we also show that the amide moiety of myxothiazol A can be hydrolyzed in vivo to the formerly unknown free myxothiazol acid by heterologous expression of melJ in the myxothiazol producer Stigmatella aurantiaca DW4/3-1. The methyltransferase MelK can finally methylate the acid to give rise to the methyl ester, which is produced as the final product in the melithiazol A biosynthetic pathway. These experiments clarify the role of MelJ and MelK during melithiazol assembly.  相似文献   
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