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1.
Obesity and hyperlipidemia are major risk factors for developing vascular diseases. Bee bread (BB) has been reported to exhibit some biological actions, including anti-obesity and anti-hyperlipidemic. This study aims to investigate whether bee bread can ameliorate vascular inflammation and impaired vasorelaxation activity through eNOS/NO/cGMP pathway in obese rats. Forty male Sprague-Dawley rats were randomly divided into four groups (n = 10/group), namely: control (normal group), obese rats (OB group), obese rats treated with bee bread (0.5 g/kg/day, OB/BB group) and obese rats treated with orlistat (10 mg/kg/day, OB/OR group). The latter three groups were given a high-fat diet (HFD) for 6 weeks to induced obesity before being administered with their respective treatments for another 6 weeks. After 12 weeks of the total experimental period, rats in the OB group demonstrated significantly higher Lee obesity index, lipid profile (total cholesterol, triglyceride, low-density lipoprotein), aortic proinflammatory markers (tumor necrosis factor-α, nuclear factor-κβ), aortic structural damage and impairment in vasorelaxation response to acetylcholine (ACh). Bee bread significantly ameliorated the obesity-induced vascular damage manifested by improvements in the lipid profile, aortic inflammatory markers, and the impaired vasorelaxation activity by significantly enhancing nitric oxide release, promoting endothelial nitric oxide synthase (eNOS) and cyclic guanosine monophosphate (cGMP) immunoexpression. These findings suggest that the administration of bee bread ameliorates the impaired vasorelaxation response to ACh by improving eNOS/NO/cGMP-signaling pathway in obese rats, suggesting its vascular therapeutic role.  相似文献   
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PURPOSE: To determine trends in mammography in the United States. MATERIALS AND METHODS: A sample of mammographic facilities was selected for each year of the Nationwide Evaluation of X-ray Trends. The same protocol was followed for the 1985, 1988, and 1992 surveys. Data were collected with use of the same imaging phantom for all three surveys and also with a different phantom in the 1988 and 1992 surveys. RESULTS: Of the 356 facilities surveyed in 1992, 59% claimed to be in compliance with the Health Care Financing Administration (HCFA) mammography requirements, 42% were accredited by the American College of Radiology (ACR), and 23% did not hold credentials from either the HCFA or the ACR. Since 1985, there has been a 34% improvement in acceptable phantom image quality score and a 20% decrease in the mean glandular dose. CONCLUSION: Mammography as practiced today is essentially a screen-film technique. Mammographic phantom image quality has improved considerably. The overall mean glandular dose has decreased primarily because of the elimination of xeroradiography.  相似文献   
4.
A waste material called oil fly ash (OFA) was acid-functionalized, yielding f-OFA-COOH, which was then reacted with cerium oxide (CeO2) to make CeO2-functionalized OFA, or f-OFA-CeO2. Pristine OFA and f-OFA-CeO2 were used to make waterborne polyurethane (WBPU) dispersions, referred to as WBPU/OFA and WBPU/f-OFA-CeO2, respectively, with defined OFA and f-OFA-CeO2 content. All the dispersions were applied to mild steel as organic coatings to evaluate their protective properties, such as their hydrophobicity, adhesive strength and UV-shielding resistance. These protective properties varied based on the OFA and f-OFA-CeO2 content. The highest water contact angle, minimum water swelling and maximum adhesive strength were found using WBPU/f-OFA-CeO2-20 coating (using 2.00 wt% f-OFA-CeO2), which also showed the maximum ultraviolet (UV) absorption via UV–vis spectroscopy analysis. This UV shielding result also matched field test results, as that coating was found to exhibit the lowest UV degradation near a marine atmosphere, as shown by X-ray photoelectron spectroscopy (XPS) analysis. The least affected hydrophobicity was also recorded for the sample with the WBPU/f-OFA-CeO2-20 coating.  相似文献   
5.
In this study, blend membranes based on a combination of sulfonated poly (styrene-isobutylene-styrene) (SIBS) with isopentylamine (IPA) were synthetized as potential candidates for direct methanol fuel cell (DMFC) applications. The impact of sulfonation level (57–93 mol%) and percentage of IPA incorporation (1, 3, and 5 wt%) were analyzed via different properties of the resulting membrane. FTIR analysis showed that IPA was successfully incorporated into the sulfonated polymer matrix and also confirmed the interaction between the sulfonic and amine groups. This interaction generates significant morphological changes in the nanostructure of the membranes that are evident through results of small angle x-ray scattering and atomic force microscopy analysis. Proton conductivity and methanol permeability of the membranes were also analyzed. Proton conductivity was significantly enhanced with the incorporation of IPA at an optimum loading, creating additional paths for the conduction of protons through the membrane. It was also sensitive to the morphological changes produced after the IPA incorporation and the interconnection between the ionic domains. Methanol permeability increased slightly due to the additional water domains and the inability of the isopentyl groups of IPA to block the free-volume in the membrane. Despite this, the selectivity (proton conductivity over methanol permeability) of the membranes was comparable to the state-of-the-art Nafion®, especially at an optimum IPA incorporation of 3 wt%.  相似文献   
6.
Aortic aneurysm is a deceptively indolent disease that can cause severe complications such as aortic rupture and dissection. In the normal aorta, vascular smooth muscle cells within the medial layer produce and sustain the extracellular matrix (ECM) that provides structural support but also retains soluble growth factors and regulates their distribution. Although the ECM is an obvious target to identify molecular processes leading to structural failure within the vessel wall, an in-depth proteomics analysis of this important sub-proteome has not been performed. Most proteomics analyses of the vasculature to date used homogenized tissue devoid of spatial information. In such homogenates, quantitative proteomics comparisons are hampered by the heterogeneity of clinical samples (i.e. cellular composition) and the dynamic range limitations stemming from highly abundant cellular proteins. An unbiased proteomics discovery approach targeting the ECM instead of the cellular proteome may decipher the complex, multivalent signals that are presented to cells during aortic remodelling. A better understanding of the ECM in healthy and diseased vessels will provide important pathogenic insights and has potential to reveal novel biomarkers.  相似文献   
7.
Various damage detection methods have been proposed by several researchers in the past few decades. Amongst them, the efficiency of mode shapes in detecting damage has been demonstrated by many researchers when further processed. In most cases, the processing involves expansion or reduction of the mode shape data. However, vital information that are damage-prints are often lost during processing of the mode shape data. In addition, most of these processes involve long and complex computation, thus, leading to inaccurate damage identification. In this study, a simple and fast damage identification technique is proposed to identify damage in beam structures. Interval analysis is applied to the mode shapes of a beam structure in the damaged and undamaged states. The interval situations of each of the beam's segment via mode shape are derived to obtain the upper and lower bounds and the derived bounds are compared. To establish a relationship for identify the damaged point, a possibility of damage existence is defined for each segment of the beam structure. The mode shape increment is defined as the increase in the mode shape value. Furthermore, a damage measure index that provide enhance damage information is obtained as the product of the possibility of damage existence and mode shape increment. A numerical model of a simply supported steel beam is applied to demonstrate this method by imposing damage through thickness reduction of elements in segments. In addition, a parametric analysis is carried out to evaluate noise effect by considering varying damage severities and different noise levels. The results showed that this method is simple and provides considerable accurate results.  相似文献   
8.
Hybrid organic–inorganic materials made from sol–gel precursors can be used as anticorrosion barriers on metal substrates. The modification of epoxy resins with silicones is an interesting approach toward the synthesis of hybrid materials that combine the advantages offered by epoxy resins with those of silicones. In this study, novel hybrid epoxy‐silicon materials were synthesized using sol–gel chemistry and subsequently functionalized with 4,4′‐methylenebis(phenyl isocyanate), incorporating urethane functionality into the final polymer. The study screened five different epoxide precursors for use in the synthesis of the new hybrid materials and optimizing their anticorrosion properties. Spectral characterization confirms the proposed chemical structures of the newly synthesized polymers. The newly developed polymers were painted on mild steel panels, thermally cured, and their thermal, surface morphological, adhesion, and anticorrosion properties were fully characterized. The new coatings were found to have excellent thermal stability and adherence properties to steel surface. The results of corrosion testing on coated steel panels following long‐term immersion in a 3.5 wt % aqueous NaCl medium revealed that the polymer prepared using the epoxide precursor bisphenol A diglycidyl ether provided the best anticorrosion protection property among the synthesized polymers. This could be attributed to the excellent integrity and crosslink density properties in addition to the lack of microdefects in the surface of this coated sample as confirmed by scanning electron microscopy analyses. The newly prepared hybrid coatings reported in this study are very promising as an alternative to toxic chromate‐based coatings. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43947.  相似文献   
9.
This work discusses the effect of block composition on the properties of proton conducting polymer membranes. A homopolymer and two block copolymers were synthesized using atom transfer radical polymerization. The homopolymer poly(ethylene glycol phenyl ether methacrylate) (PEGPEM) was used as a bifunctional macroinitiator. Polystyrene (PS), was added to both sides of PEGPEM (A) with two different percentages of PS (B) (i.e., 18 and 31%). These copolymers, BAB 18, BAB 31 and the homopolymer A, were completely sulfonated (SA, SBAB 18 and SBAB 31). The resulting polymers produced different water absorption values and transport properties for direct methanol fuel cell (DMFC) applications. The nanostructure and morphology of the casted membranes were studied using small‐angle X‐ray scattering and atomic force microscopy. The results revealed that all six membranes exhibited a disordered phase‐segregated morphology, which changed on sulfonation into small‐interconnected ionic domains. Normalized DMFC selectivities (proton conductivity over methanol permeability divided by the respective values for Nafion®) were calculated and ranged from 1.16 (SBAB 31) to 15.30 (BAB 18), indicating that the performance of these materials can be comparable or better than Nafion®. Transport property results also suggest that chemistry (block nature and composition), morphology and water content play a critical role in the transport mechanism of protons and methanol. For example, the percentage of B in BAB 18 provides shorter interstitial ionic distances and sufficient water content to produce high proton conductivity, while maintaining low methanol permeability in a multi‐ionic proton exchange membrane. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44343.  相似文献   
10.
Amorphous anodic oxide films on InAlP have been grown at high efficiency in sodium tungstate electrolyte. The films are shown to comprise an outer layer containing indium species, an intermediate layer containing indium and aluminium species and an inner layer containing indium, aluminium and phosphorus species. The layering correlates with the influence on cation migration rates of the energies of In3+-O, Al3+-O and P5+-O bonds, which increase in this order. The film surface becomes increasingly rough with increase of the anodizing voltage as pores develop in the film, which appear to be associated with generation of oxygen gas.  相似文献   
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