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41.
Nano scale devices with improved performance than the conventional CMOS devices is of great need in recent days. The paper investigates the performance of  相似文献   
42.
Methoxy ethyl oleate, a nonionic surfactant, has been investigated at the air/water interface for various surface properties by employing the Langmuir film balance technique. The ester forms an expanded isotherm at the air/water interface. The minimum area of packing (A 0), initial area of increase of surface pressure (A i ), collapse pressure (π c ), and area/molecule at collapse pressure (A c ) have been estimated from the isotherm curve.The higher compressibility coefficient (K) suggests that the ester forms a more expanded liquid film than the parent oleic acid. Besides, the ester film is fairly stable as suggested by only about 30% loss in area over a period of 20 min. The relaxation rates of the ester film at different surface pressures of 10, 15, and 20 mN·m?1 have been estimated from changes in the surface area/molecule with time. Interestingly, the surface area (54.2 Å2/molecule) that corresponds to a minimized structure projected for the ester, calculated theoretically, agrees reasonably well with the experimental value (57.2 Å2/molecule).  相似文献   
43.
44.
N-Acylethanolamines (NAE) are fatty acid derivatives, some of which function as endocannabinoids in mammals. NAE metabolism involves common (phosphatidylethanolamines, PEs) and uncommon (N-acylphosphatidylethanolamines, NAPEs) membrane phospholipids. Here we have identified and quantified more than a hundred metabolites in the NAE/endocannabinoid pathway in mouse brain and heart tissues, including many previously unreported molecular species of NAPE. We found that brain tissue of mice lacking fatty acid amide hydrolase (FAAH −/−) had elevated PE and NAPE molecular species in addition to elevated NAEs, suggesting that FAAH activity participates in the overall regulation of this pathway. This perturbation of the NAE pathway in brain was not observed in heart tissue of FAAH −/− mice, indicating that metabolic regulation of the NAE pathway differs in these two organs and the metabolic enzymes that catabolize NAEs are most likely differentially distributed and/or regulated. Targeted lipidomics analysis, like that presented here, will continue to provide important insights into cellular lipid signaling networks.  相似文献   
45.
The strength and elongation to fracture of spray deposited Al-Si-Pb alloys were studied as a function of lead content, silicon content, and distance from the centre to periphery of the deposit. It is found that the ultimate tensile strength, proof stress and elongation to fracture decrease, linearly and exponentially, with the increase in lead content and porosity of the deposit, respectively. Both the strengths and elongation to fracture linearly increase with increasing distance from the centre to periphery of the deposit. The ultimate tensile strength and proof stress are higher at a higher silicon content and they have a linear relationship with the hardness of the deposit.  相似文献   
46.
Multiwalled carbon nanotube (MWCNT) filled poly(ether sulfone) (PES) and poly(ether imide) (PEI) composites were prepared with different MWCNT weight fractions (0.5–5wt%) by a solution mixing technique. Their electrical conductivities, electromagnetic interference (EMI), shielding effectiveness (SE), return loss (RL), and absorption loss (AL) were investigated. Morphologies of the fracture surfaces of nanocomposites studied by scanning electron and transmission electron microscopy showed relatively good MWCNT dispersion and distribution. The electrical conductivity of compression molded samples measured at room temperature indicated that the electrical percolation network was achieved already at 0.5% loading. The measurements of shielding effectiveness (SE) carried out in the frequency range of 8 to 12 GHz (X‐band range) showed that SE increases with measurement frequency and with filler loading, whereby no significant differences could be observed between PES and PEI as matrices. The nanocomposites based on both matrices with 5 wt% loading of MWCNT exhibited shielding levels at 8 GHz between 42 and 45 dB in comparison with the pure polymers which showed value in the range of 1 to 2 dB. RL and AL showed significantly lower values for the composites as compared to unfilled polymers, but no systematic trends were observed on frequency. POLYM. ENG. SCI., 54:2560–2570, 2014. © 2013 Society of Plastics Engineers  相似文献   
47.
The hot compression behaviour of AA2014 alloy having 10 wt% SiC particles was studied over a wide range of temperatures (ambient to 400 °C) and strain rates (0.01–10/s). The results were compared with those obtained from identical tests performed on the base alloy to understand the effect of the SiC particle reinforcement. Processing maps were generated using dynamic materials model from the flow stress of the samples. Microstructures of the deformed samples suggest the occurrence of dynamic recrystallization at high temperatures and low strain rate. Flow localization and adiabatic shear bands were observed at higher strain rates and temperatures. The lack of cohesion between SiC particles and the matrix was found to be responsible for the deteriorating deformation behavior of the composite over most of the processing domains. The activation energy for high temperature deformation in the presence of the SiC particles in the alloy was found to be significantly higher than that of the matrix. This makes deformation processing of the composite more difficult than that of the matrix.  相似文献   
48.
The frequency of micronuclei was evaluated in the bone marrow of mice of either sex administered with 0, 0.625, 1.25, 2.5, 5, 10, 20, 40 and 80 mg/kg b.wt of lead nitrate at 12, 24 and 36 h post-treatment. The frequency of micronucleated polychromatic erythrocytes (MPCE) and micronucleated normochromatic erythrocytes (MNCE) increased significantly at 12, 24 and 36 h after treatment with lead nitrate compared to non-drug treated controls. The frequency of micronuclei did not show a dose related increase and the elevation in the frequency of micronuclei was fluctuating type. One important observation which emerged from this study was that the male mice were more sensitive to the induction of micronuclei compared to female mice. This was evidenced by higher frequencies of MPCE in males than females at all the doses for all the post-treatment time periods. The lead nitrate treatment resulted in a spurt in the erythropoiesis as is evidenced by a significant increase in the ratios of polychromatic to normochromatic erythrocytes (P/N ratio) compared to non-drug treated controls at 12, 24 and 36 h post-treatment. The P/N ratio was significantly higher in females than males at 12 and 24 h post-treatment.  相似文献   
49.
Khargonekar and Tannenbaum have shown how to modify the Nevanlinna‐Pick (N–P) interpolation theory to design an internally stable and robust controller. In this paper, we present a new modification of the N‐P theory so that closed‐loop poles can be placed inside a circular region in the left half of the complex plane, in addition to the control system design being robust and internally stable. This ensures a minimum damping of the closed‐loop system. Numerical examples illustrate the theory.  相似文献   
50.
Cardiovascular disease claims millions of lives every year throughout the world. Biomaterials are used widely for the treatment of this fatal disease. With the advent of nanotechnology, the use of nanocomposites has become almost inevitable in the field of biomaterials. The versatile properties of nanocomposites, such as improved durability and biocompatibility, make them an ideal choice for various biomedical applications. Among the various nanocomposites, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane, bacterial cellulose with polyvinyl alcohol, carbon nanotubes, graphene oxide and nano-hydroxyapatite nanocomposites have gained popularity as putative choices for biomaterials in cardiovascular applications owing to their superior properties. In this review, various studies performed utilizing these nanocomposites for improving the mechanical strength, anti-calcification potential and hemocompatibility of heart valves are reviewed and summarized. The primary motive of this work is to shed light on the emerging nanocomposites for heart valve applications. Furthermore, we aim to promote the prospects of these nanocomposites in the campaign against cardiovascular diseases.  相似文献   
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