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11.
ABSTRACT: BACKGROUND: Previous studies reported divergent results on nutraceutical actions and free radical scavenging capability of ginseng extracts. Variations in ginsenoside profile of ginseng due to different soil and cultivating season may contribute to the inconsistency. To circumvent this drawback, we assessed the effect of major ginsenoside-Rg1 (Rg1) on skeletal muscle antioxidant defense system against exhaustive exercise-induced oxidative stress. METHODS: Forty weight-matched rats were evenly divided into control (N = 20) and Rg1 (N = 20) groups. Rg1 was orally administered at the dose of 0.1 mg/kg bodyweight per day for 10- week. After this long-term Rg1 administration, ten rats from each group performed an exhaustive swimming, and remaining rats considered as non-exercise control. Tibialis anterior (TA) muscles were surgically collected immediately after exercise along with nonexercise rats. RESULTS: Exhaustive exercise significantly (p <0.05) increased the lipid peroxidation of control group, evidenced by elevated malondialdehyde (MDA) levels. The increased oxidative stress after exercise was also confirmed by decreased reduced glutathione to oxidized glutathione ratio (GSH/GSSG ratio) in control rats. However, these changes were completely eliminated in Rg1 group. Catalase (CAT) and glutathione peroxidase (GPx) activities were significantly (p <0.05) increased by Rg1 in non-exercise rats, while no significant change after exercise. Nevertheless, glutathione reductase (GR) and glutathione S-transferase (GST) activities were significantly increased after exercise in Rg1 group. CONCLUSIONS: This study provide compelling evidences that Rg1 supplementation can strengthen antioxidant defense system in skeletal muscle and completely attenuate the membrane lipid peroxidation induced by exhaustive exercise. Our findings suggest that Rg1 can use as a nutraceutical supplement to buffer the exhaustive exercise-induced oxidative stress.  相似文献   
12.
The aim of our study was to investigate the mechanisms by which rhubarb regulates β-catenin as well as metastasis of hepatocellular carcinomas. Our results revealed that rhubarb extract inhibited HA22T cell migration ability in wound healing, migration and invasion assays in a dose-dependent manner. Rhubarb also reduced β-catenin protein level, downregulated its downstream proteins, cyclin D, Tbx3 and c-Myc, and attenuated the expression of MMP9 and contactin-1 metastatic factors. Additionally, rhubarb inhibited β-catenin nuclear accumulation and induced its degradation via proteasome-mediated pathway. Furthermore, we found that rhubarb suppressed the p-ser9 GSK-3-β protein level to inactivate Wnt signalling and reduce β-catenin protein level. Taken together; we found that rhubarb blocked the metastatic process of HA22T hepatocellular carcinoma cells mediated through GSK-3-β activation, and enhancement of protein degradation as well as reduction of the nuclear accumulation of β-catenin.  相似文献   
13.

A rain streak in an image can degrade visual quality of that image to the human eye. Unfortunately, removing the rain streak from a single image represents a very challenging task. In this paper, a single image rain removal process based on non-negative matrix factorization is proposed. First, the rain image is broken down into a low-frequency and high-frequency part by a Gaussian filter. Therefore, the rain component, which lies mostly in the middle frequency range, can be discarded in high and low frequency domains. Next, non-negative matrix factorization (NMF) method is applied to deal with the rain streak in the low frequency domain. Finally, Canny edge detection and block copy strategy are performed separately to remove the rain component in the high frequency domain to improve image quality. In comparison with state-of-the-art approaches, the proposed method achieves competitive results without the need for an extra image database to train the dictionary.

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14.
Multimedia Tools and Applications - A static image always becomes more eye-catching with an animation. In this paper, we present a system for adding a waterfall animation to a single image by...  相似文献   
15.
The quaternary ammonium resin is synthesized by the ring-opening reaction of an epoxy resin with a tertiary amine in the presence of a proton donor in the solution. This kind of resin can be dispersed in the water phase to form a conductible milky dispersion. In this study, different kinds of tertiary amines including the full-alkyl group and the ester group-containing or urethane group containing tertiary amine are reacted with DGEBA-type epoxy resin to synthesize the quaternary ammonium resins. The resin characteristics and the electrochemical properties of its emulsion are investigated. In addition, properties of the emulsion prepared from tertiary amine salt resin are also measured for comparison. It is found that if the substituted groups of the ammonium structure of the quaternary ammonium resin are all alkyl groups, rupture voltage of the emulsion is very low. But when one of the substituted group contains an ester group or an urethane group, rupture voltage increases remarkably and the resin can be used for electrodeposition. Meanwhile, the electrodeposition theory of quaternary ammonium resin and its thermal cross-linking reaction and the electrochemical properties of coemulsion prepared by mixing the quaternary ammonium resin and the tertiary amine salt resin are also discussed. © 1993 John Wiley & Sons, Inc.  相似文献   
16.
Two-component electrodepositable coemulsion-contained quaternary ammonium resin Q , as a pigment grinding vehicle, and DGEBA–N-methylethanolamine (MEA) tertiary amine salt resin T , as the principal resin, were obtained and then deposited to form a resinous film on the cathode during electrodeposition. The resin composition of this deposited film was determined by the quantitative analysis of FTIR and it was found different from the resin composition of the original coemulsion. The electrodeposition behaviors of the coemulsion were deeply affected by the quaternary ammonium resin. In addition, the electrodeposition properties of emulsions dispersed by quaternary ammonium resin and tertiary amine salt resin were also studied for comparison. © 1994 John Wiley & Sons, Inc.  相似文献   
17.
Optimization of the production of antifungal lipopeptide, iturin A, by B. subtilis was carried out in submerged cultural fermentation. In a shake-flask experiment, response surface methodology (RSM) was employed to optimize the cultivation conditions of Bacillus subtilis S3 for the enhancement of iturin A production. The optimal conditions for iturin A production obtained from RSM were pH 6.0, 0.93% maltodextrin, 1.11% glucose, 0.72% corn steep powder (C.S.P), 1.5 mM MgSO4, 0.75 mM KH2PO4, rotation speed 180 rpm and area of aeration 4.35 cm2. 57% increase of iturin A productivity (from 47.19 mg/L to 74.22 mg/L) was observed using the one-factor-at -a-time technique; however, 180% increase of iturin A productivity (from 47.19 mg/L to 132.23 mg/L) was observed with RSM. The iturin A production was further studied in a 5-L fermentor with a variation of agitation speed, aeration and baffles. In the 5-L fermentor, it was found that increased agitation speed improved the growth of B. subtilis and the production of iturin A. Aeration at 2 vvm gave excellent production of iturin A (175.52 mg/L) at 6 d of fermentation. The addition of baffles in the fermentor has significantly influenced the oxygen mass transfer coefficient (KLa) and iturin A production.  相似文献   
18.
This paper designs an adaptive sliding-mode dynamic controller for wheeled mobile robots to implement the trajectory-tracking mission. First, a kinematic controller is introduced for the wheeled mobile robot. Secondly, the adaptive sliding-mode dynamic controller is proposed to make the real velocity of the wheeled mobile robot reach the desired velocity command, although the wheeled mobile robot is even with system uncertainties and disturbances. The convergence of the complete equations of motion of the wheeled mobile robot is proved by the Lyapunov stability theory. Computer simulation results illustrate the effectiveness of the proposed control schemes. Finally, the real-time experiments of the adaptive sliding-mode dynamic controller on the test ground demonstrate the feasibility of practical wheeled mobile robot maneuvers.  相似文献   
19.
In this work, we derive the integral equations of radiative transfer in terms of intensity moments for radiative transfer in an anisotropically scattering slab with a spatially varying refractive index (VRI). The integral equations are solved by the Nyström method. We apply this method to study radiative heat transfer in a cold slab with higher-degree anisotropic scattering and linearly VRI. The slab lays on an opaque substratum. The refractive index may have a jump at the interface between the surroundings and the slab, while the interface between the slab and the substratum is assumed to be non-reflecting. To exemplify the application of the integral formulation, we consider the case with irradiation from external source in the surroundings and the case with an emitting substratum. We also solve the problems by the Monte Carlo method (MCM). The hemispherical reflectance and transmittance of the slabs obtained by solving integral equations are in excellent agreement with those obtained by the MCM. A positive gradient of refractive index (n′) enhances forward radiative transfer, and so the dimensionless radiative heat flux increases with the increase of n′ for the cases with irradiation from the surroundings. Effects of the optical thickness, the scattering albedo and the scattering phase function are also investigated.  相似文献   
20.
Chitosan tablets containing theophylline were prepared by directly compressing the wet or dry blended polymer—drug powders. The effects of the viscosity and swelling ability on the release rates of drugs were examined. The theophylline releasing rates of tablets prepared by polymer—drug wet blending increase with a decrease in the viscosity of the blending chitosan solution. On the other hand, the swelling ability of the polymer greatly influences the release kinetics of the tablets prepared by polymer—drug dry blending. Tablets prepared by both polymer—drug wet and dry blending were acid-nonresisted. Tablets in simulated gastric fluid disintegrated quickly, and the drugs were released within four hours. To retard the disintegrated rate of chitosan tablets in acid medium, interpolymer complex of chitosan with anionic polyelectrolyte (alginate) is needed. By this treatment, the swelling and erosion rate of the chitosan tablets could be reduced, then controlling the release rate of the theophylline can be achieved. Drug release mechanism of the various tablets were investigated by the model of Peppas; in addition, a nuclear magnetic resonance imagine microscopy is also introduced to examine the swelling or diffusion mechanism of various tablets. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2495–2505, 1997  相似文献   
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