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121.
Traditional Earned Value Management (EVM) index-based methods for Cost Estimate at Completion (CEAC) of an ongoing project have been known for their limitations inherent with both the assumption that past EVM data is the best available information and early-stage unreliability.  相似文献   
122.
The manufacturing process of forged parts is usually conducted by different subsequent process steps. According to various technological as well as economical and ecological requirements, different and often opposing objectives have to be fulfilled. A representative example for this conflicting situation is the requirement of high product qualities on the one hand and low processing costs on the other hand. A third important factor influencing the process in addition to quality and cost-efficiency is the ecological aspect that is focused more and more in recent years. Material shortage, high energy costs and increasing intensification of statutory regulations lead to the necessity of ecologically optimized processes. Nevertheless, an economic-based evaluation of forging processes is not easy to carry out due to a versatile process chain from raw material to final product. Within the framework of the joint research project “Holistic process chain optimization for forging production of automotive parts in terms of manufacturing efficiency and saving operation energy” an entire evaluation and optimization with special regard to ecologic aspects will be conducted on the example of a crank shaft forging process (Denkena et al. in ZWF 4:224–228, 2013; Int J Precis Eng Manuf 14(7), 2013).  相似文献   
123.
The projects of ITER and DEMO reactors showed that there are serious difficulties with solving the issues of plasma facing elements (PFE) based on the solid materials. Problems of PFE can be overcome by the use of liquid lithium. Application of lithium will allow to create a self-renewal and MHD stable liquid metal surface of the in-vessel devices possessing practically unlimited service life. Realization of these advantages is based on use of so-called lithium capillary-porous system (CPS) – new material, in which liquid lithium fills a solid matrix from porous material. The progress in development of lithium technology and also lithium experiments in the tokamaks TFTR, T-11M, T-10, FTU, NSTX, LTX, HT-7 and stellarator TJ II is a good basis for development of the project of steady-state operating lithium divertor module for Kazakhstan tokamak. At present the lithium divertor module for KTM tokamak is development and manufacturing. The paper describes main design features of the module of lithium divertor (MLD). The first step of the hydraulic tests of MLD with fully assembled external thermo-stabilization system, which was connected to in-vessel lithium unit, were performed using ethanol as a model heat transfer media. Test results of MLD have shown that operating parameters of designed and manufactured system for thermo-stabilization are sufficient for proper operation; basic hydraulic characteristics of the system are close to expected values.  相似文献   
124.
We describe the peculiar conditions under which optically driven gold nanoparticles (NPs) can significantly increase temperature or even melt a surrounding matrix. The heating and melting processes occur under light illumination and involve the plasmon resonance. For the matrix, we consider water, ice, and polymer. Melting and heating the matrix becomes possible if a nanoparticle size is large enough. Significant enhancement of the heating effect can appear in ensembles of NPs due to an increase of a volume of metal and electric-field amplification.  相似文献   
125.
Diffuse–reflectance FTIR results obtained with tert-amyl-methyl-ether (TAME), ethanol, methanol, i-amylenes and mixtures of i-amylenes with alcohols supported a Langmuir–Hinshelwood type reaction mechanism involving adsorbed i-amylene molecules, which form a bridged structure between the adsorbed alcohols and the SO3H sites of Amberlyst-15. Number of available sites involved in the adsorption of i-olefins is drastically decreased with an increase in alcohol concentration. The reaction rate model, which was proposed basing on the DRIFTS results, was shown to give good agreement with the published initial rate data for TAEE synthesis. The rate of tert-amyl-ethyl-ether (TAEE) formation was found to give a rather sharp maximum at an ethanol activity smaller than 0.1.  相似文献   
126.
Experiments with a sample of a lithium capillary-porous system (CPS) were performed at the reactor IVG-1.M of the Institute of Atomic Energy NNC RK to study the effects of neutron irradiation on the parameters of hydrogen isotope interactions with a lithium CPS. The absorption technique was used during the experiments, and this technique allowed the temperature dependences of the hydrogen isotope interaction rate constants with the lithium CPS to be obtained under various reactor powers. The obtained dependencies were used to determine the main interaction parameters: the activation energies and the pre-exponents of the Arrhenius dependence of the hydrogen interaction rate constants with lithium and the lithium CPS. An increase of the hydrogen isotope interaction rate with the lithium CPS was observed under reactor irradiation.  相似文献   
127.
A series of well-defined amphiphilic graft copolymers with hydrophobic polysulfone (PSU) as backbones and hydrophilic poly(ethylene glycol) (PEG) as side chains were synthesized and characterized. For this purpose, PSUs were converted to azido-functionalized polymers by successive chloromethylation and azidation processes to give clickable PSUs. Then, the ω-hydroxyl function of the commercially available PEG-OH was converted into propargyl functionality by simple esterification process. Ultimately, the alkyne functionalized PEO was successfully grafted onto the PSUs by click chemistry. The final polymers and intermediates at various stages were characterized by 1H NMR, FT-IR, and GPC techniques. The bioinert character of PEG grafted PSU was confirmed by static protein adsorption and prokaryotic and eukaryotic cell adhesion studies, and compared to that of unmodified PSU.  相似文献   
128.
A novel pyranose oxidase (PyOx) biosensor based on gold nanoparticles (AuNPs)–polyaniline(PANI)/AgCl/gelatin nanocomposite has been developed for the glucose detection. PyOx was immobilized on the surface of glassy carbon electrode (GCE) via the nanocomposite matrix. The electrode surface was imaged by scanning electron microscopy (SEM). Amperometric detection of the consumed oxygen during the enzymatic reaction was monitored at −0.7 V. After optimization studies, analytical characterization of the biosensor was carried out. The linear response of the AuNPs–AgCl/PANI/gelatin modified PyOx biosensor is found to be from 0.05 to 0.75 mM glucose with the equation of y = 2.043x + 0.253; R2 = 0.993. Finally, proposed biosensor was used to analyze glucose content in real samples. Obtained data from the biosensing system was compared with a commercial enzyme assay kit based on spectrophotometric Trinder reaction as a reference method.  相似文献   
129.
Mesoporous aluminosilicate catalysts having different Al/Si ratios were synthesized following a hydrothermal synthesis route and using different aluminum sources, such as aluminum nitrate and aluminum isopropoxide. These mesoporous materials have high surface areas, in the range of 520–1001 m2/g, and exhibit Type IV nitrogen adsorption isotherms. EDS and 27Al MAS NMR results showed that aluminum was incorporated more effectively into the structure of the catalyst forming a tetrahedral framework when aluminum nitrate was used as the aluminum source. The activities of these catalysts in the polypropylene pyrolysis reaction were tested in a TGA apparatus. Results showed a marked reduction in the degradation temperature in the presence of aluminosilicate catalysts. The activation energy of degradation was 172 kJ/mole without any catalyst. However, using the mesoporous aluminosilicate catalysts synthesized by using aluminum nitrate as the aluminum source, activation energy of the degradation reaction decreased to values of about 24–28 kJ/mole.  相似文献   
130.
Sigma (σ) receptors are unique non‐opioid binding sites that are associated with a broad range of disease states. Sigma‐2 receptors provide a promising target for diagnostic imaging and pharmacological interventions to curb tumor progression. Most recently, the progesterone receptor (PGRMC1, 25 kDa) has been shown to have σ2 receptor‐like binding properties, thus highlighting the need to understand the biological function of an 18 kDa protein that exhibits σ2‐like photoaffinity labeling (denoted here as σ2‐18k) but the amino acid sequence of which is not known. In order to provide new tools for the study of the σ2‐18k protein, we have developed bifunctional σ receptor ligands each bearing a benzophenone photo‐crosslinking moiety and an alkyne group to which an azide‐containing biotin affinity tag can be covalently attached through click chemistry after photo‐crosslinking. Although several compounds showed favorable σ2 binding properties, the highest affinity (2 nM ) and the greatest potency in blocking photolabeling of σ2‐18k by a radioactive photoaffinity ligand was shown by compound 22 . These benzophenone‐alkyne σ receptor ligands might therefore be amenable for studying the σ2‐18k protein through chemical biology approaches. To the best of our knowledge, these compounds represent the first reported benzophenone‐containing clickable σ receptor ligands, which might potentially have broad applications based on the “plugging in” of various tags.  相似文献   
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