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31.
Wind energy is now recognized as an important energy resource throughout the world. Within the United States, the state of Texas currently has the largest wind energy capacity with 8797 total megawatts and an additional 660 MW under construction. With this rapid growth, it is important to achieve a better understanding of how wind energy is being perceived by the public.  相似文献   
32.
Hydrogen interaction of porphyrin hetero-pairs has been studied by differential scanning calorimetry (DSC). Aggregates were prepared by spontaneous aggregation of water soluble anionic porphyrins meso-tetra(4-carboxyphenyl)porphine (TCPP) and meso-tetra(4-sulfonatophenyl)porphine (TPPS) with cationic meso-tetra-p-trimethylaminophenyl porphine tetrachloride (TAP). Aggregate formation in solution was investigated via UV-visible spectroscopy at different pH ranges. At neutral to basic conditions, porphyrin pairs formed partially soluble hetero H-aggregates and at low pH, soluble homo J-aggregates was formed. H-aggregates were isolated by centrifuging and freeze-drying. The obtained solids were studied by X-ray powder diffraction. Thermal stability of dry aggregates was determined by thermogravimetric analysis. The TCPP-TAP hetero aggregates exhibited hydrogen uptake between 80 °C and 250 °C. The amount of hydrogen absorbed by the sample corresponds to 0.29% by weight, indicating a potential use of such materials as a solid state hydrogen storage medium.  相似文献   
33.
Wind energy is one of the fastest growing sources of power generation in the world. While general public and political support for wind energy is often high, siting wind farms frequently raises concerns in local communities, and individual projects often fail because of effective public opposition. This paper presents the results of a postal and online survey questionnaire that explores public perceptions of wind energy in two of the most important states for wind development, Texas and Iowa. The goal is a better understanding of public reactions to large-scale wind developments as a prerequisite of more widespread use of renewable energy resources. We found a high level of public support for wind energy, with more than two-thirds of respondents being in favor of building more wind farms either in their community or within the U.S. as a whole. Given that the majority of respondents had a very high level of concern for the general environment, we also found that almost two-thirds of respondents counter-intuitively indicated that producing electricity using fossil fuels is not detrimental to the environment, and that they had little concern for global climate change. Our results suggest that arguing for more renewable sources of energy based on reducing our carbon footprint is less persuasive in these communities than simply approaching it from the perspective of wind being a clean and safe source of energy. More than two-thirds of respondents felt their county had benefited economically from the wind farms and that they were a source of job creation in the county. Support for wind power in these communities is associated far more with socioeconomic factors than foundational aesthetic or moral values, with wind farms perceived as the vehicle that will reverse economic decline.  相似文献   
34.
This paper uses the Jobs and Economic Development Impacts (JEDI) model to estimate economic impacts from 1398 MW of wind power development in four counties in west Texas. Project-specific impacts are estimated at the local level (i.e., within a 100-mile radius around the wind farms) and at the state level. The primary economic policy question addressed is how investment in wind energy affects the state and local communities where the wind farms are built. During the four-year construction phase approximately 4100 FTE (full time equivalents) jobs were supported with turbine and supply chain impacts accounting for 58% of all jobs generated. Total lifetime economic activity to the state from the projects equated to more than $1.8 billion, or $1.3 million per MW of installed capacity. The total economic activity to the local communities was also substantial, equating to nearly $730 million over the assumed 20-year life cycle of the farms, or $0.52 million per MW of installed capacity. Given the current level of impacts observed, and the potential for increased impacts via greater utilization of instate manufacturing capacity and the development of trained wind industry specific laborers, Texas appears to be well positioned to see increasing impacts from continued wind development.  相似文献   
35.
    
The relationship between the nanoscale structure of vanadium pentoxide nanotubes and their ability to accommodate Li+ during intercalation/deintercalation is explored. The nanotubes are synthesized using two different precursors through a surfactant‐assisted templating method, resulting in standalone VO x (vanadium oxide) nanotubes and also “nano‐urchin”. Under highly reducing conditions, where the interlaminar uptake of primary alkylamines is maximized, standalone nanotubes exhibit near‐perfect scrolled layers and long‐range structural order even at the molecular level. Under less reducing conditions, the degree of amine uptake is reduced due to a lower density of V4+ sites and less V2O5 is functionalized with adsorbed alkylammonium cations. This is typical of the nano‐urchin structure. High‐resolution TEM studies revealed the unique observation of nanometer‐scale nanocrystals of pristine unreacted V2O5 throughout the length of the nanotubes in the nano‐urchin. Electrochemical intercalation studies revealed that the very well ordered xerogel‐based nanotubes exhibit similar specific capacities (235 mA h g?1) to Na+‐exchange nanorolls of VOx (200 mA h g?1). By comparison, the theoretical maximum value is reported to be 240 mA h g?1. The VOTPP‐based nanotubes of the nano‐urchin 3D assemblies, however, exhibit useful charge capacities exceeding 437 mA h g?1, which is a considerable advance for VOx based nanomaterials and one of the highest known capacities for Li+ intercalated laminar vanadates.  相似文献   
36.
The local volume averages of the equations of motion as well as the appropriate boundary conditions for neutrally buoyant suspensions of spheres in second-order fluids (Li and Slattery, 1989a) are employed to analyze both the cone-plate viscometer and the parallel-plate viscometer. The predicted results are compared with measurements of apparent viscosity and of the primary normal stress difference. Predictions of measured apparent viscosities are in excellent agreement with the experimental data up to 20% solids by volume; the average error is no more than 5%. Predictions of apparent viscosities for the limiting case of a very dilute suspension are restricted to less than 10% solids by volume. The primary normal stress difference is predicted to be independent of the volume fraction of solids, in approximate agreement with previously reported data.

Both theory and experiment have demonstrated that a neutrally buoyant suspension of uniform spheres in an incompressible second-order fluid behaves like a single-phase second-order fluid in these two viscometers.  相似文献   
37.
Interfacial transport phenomena include all effects associated with momentum, energy, and mass transfer at phase interfaces.

I shall begin by examining the nature of the phase interface and associated common lines. I then will develop the general balance equations at each point within a phase, at each point on a dividing surface, and at each point on a common line. Mass conservation, momentum transfer, energy transfer, and mass transfer are treated as special cases.  相似文献   
38.
We have examined the catalytic activity of glutathione S-transferases (GST) in the conjugation of busulfan with glutathione (GSH) in human liver cytosol, purified human liver GST, and cDNA-expressed GST-alpha 1-1. Human liver microsomes and cytosol were incubated with 40 microM busulfan and 1 mM GSH. Cytosol catalyzed the formation of the GSH-busulfan tetrahydrothiophenium ion (THT+) in a concentration-dependent manner, whereas microsomes lacked activity. The total and spontaneous rates of THT+ formation increased with pH (pH range, 6.50-7.75), with the maximum difference at pH 7.4. Due to the limited aqueous solubility of busulfan, a K(m) for busulfan was not determined. The intrinsic clearance (Vmax/K(m)) of busulfan conjugation was 0.167 microliter/min/mg with 50-1200 microM busulfan and 1 mM GSH. GSH Vmax and K(m) for busulfan conjugation were 30.6 pmol/min/mg and 312 microM, respectively. Ethacrynic acid (0.03-15 microM) inhibited cytosolic busulfan-conjugating activity with 40 microM busulfan and 1 mM GSH. Enzyme-mediated THT+ formation was decreased 97% by 15 microM ethacrynic acid with no effect on the spontaneous reaction. In incubations with affinity-purified liver GST and GST-alpha 1-1, the intrinsic clearance for busulfan conjugation was 0.87 and 2.92 microliters/min/mg, respectively. Busulfan is a GST substrate with a high K(m) relative to concentrations achieved clinically (1-8 microM).  相似文献   
39.
Chemical diversity represents a measure of selective pressures acting on genotypic variability. In order to understand patterns of chemical ecology and biodiversity in the environment, it is necessary to enhance our knowledge of chemical diversity within and among species. Many sponges produce variable levels of secondary metabolites in response to diverse biotic and abiotic environmental factors. This study evaluated intra-specific variability in secondary metabolites in the common Indo-Pacific sponge Stylissa massa over various geographic scales, from local to ocean basin. Several major metabolites were quantified in extracts from sponges collected in American Samoa, Pohnpei, Saipan, and at several sites and depths in Guam. Concentrations of several of these metabolites varied geographically across the Pacific basin, with American Samoa and Pohnpei exhibiting the greatest differences, and Guam and Saipan more similar to each other. There were also significant differences in concentrations among different sites and depths within Guam. The crude extract of S. massa exhibited feeding deterrence against the omnivorous pufferfish Canthigaster solandri at natural concentrations, however, none of the isolated compounds was deterrent at the maximum natural concentrations observed, nor were mixtures of these compounds, thus emphasizing the need for bioassay-guided isolation to characterize specific chemical defenses. Antibacterial activity against a panel of ecologically relevant pathogens was minimal. Depth transplants, predator exclusion, and UV protection experiments were performed, but although temporal variability in compound concentrations was observed, there was no evidence that secondary metabolite concentration in S. massa was induced by any of these factors. Although the reasons behind the variability observed in the chemical constituents of S. massa are still in question, all sponges are not created equal from a chemical standpoint, and these studies provide further insights into patterns of chemical diversity within S. massa.  相似文献   
40.
We report the development of an aqueous buffer system tailored to the fluidic and hemodynamic requirements of our recently reported microfluidic platelet dynamic assay device, which uses hydrodynamic focusing to "shape" a blood sample into a thin flowing layer adjacent to its protein-functionalized surface. By matching the dynamic viscosity of whole blood (3.13 ± 0.08 mPa·s, from healthy donors), the selected buffer minimizes interfacial fluid mixing and better controls shear rate within the device, permitting platelet/protein-surface interaction assays with as little as 50 μL of whole blood. Buffers containing the viscosity-enhancing components bovine serum albumin (BSA), gelofusine/glycine, or histopaque (Ficoll gradient solution) were found not to activate platelets when incubated with blood at concentrations up to 50%, as assessed by flow cytometry quantitation of P-selectin expression and αIIbβ (3) activation. In contrast, glycerol-based buffer activated platelets (two-fold increase in P-selectin levels) at concentrations as low as 10% by volume. BSA- and gelofusine/glycine-based buffers were problematic in preparation and use, and therefore, were not used beyond initial characterization. The histopaque solution selected as the best choice for flow studies stabilizes sample contact with the device's thrombogenic surface, does not activate platelets, and does not interfere with the action of agonists added to deliberately activate platelets.  相似文献   
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