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101.
The present investigation describes the hydrogen storage properties of MgH2 ball milled with different additives i.e. graphene templated rare earth metal (La and Ce) fluorides, CeF4 and LaF3. MgH2 ball milled with graphene templated CeF4 (MgH2:CeF4@Gr) has onset desorption temperature of 245 °C, which is 50 °C, 52 °C and 75 °C lower than MgH2 ball milled with LaF3 templated graphene, CeF4 and LaF3 respectively. CeF4@Gr also shows the superior effect amongst all additives during rehydrogenation where MgH2:CeF4@Gr absorbs 5.50 wt% within 2.50 min at 300 °C under 15 atm H2 pressure. Dual tuning effect, i.e. lowering of thermodynamic (62.77 kJ/mol H2: lower from 74 kJ/mol for pristine MgH2) and kinetics barrier (93.01 kJ/mol) has been observed for MgH2:CeF4@Gr. Additionally, MgH2 ball milled with CeF4@Gr shows good reversibility up to 24 cycles of de/rehydrogenation. The feasible working mechanism of CeF4@Gr as additive for MgH2 has been studied in detail with the help of Transmission Electron Microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction characterizations (XRD).  相似文献   
102.

Biometric systems proven to be one of the most reliable and robust method for human identification. Integration of biometrics among the standard of living provokes the necessity to vogue secure authentication systems. The use of palm-prints for user access and authentication has increased in the last decade. To give the essential security and protection benefits, conventional neural networks (CNNs) has been bestowed during this work. The combined CNN and feature transform structure is employed for mapping palm-prints to random base-n codes. Further, secure hash algorithm (SHA-3) is used to generate secure palm-print templates. The proficiency of the proposed approach has been tested on PolyU, CASIA and IIT-Delhi palm-print datasets. The best recognition performance in terms of Equal Error Rate (EER) of 0.62% and Genuine Acceptance Rate (GAR) of 99.05% was achieved on PolyU database.

  相似文献   
103.
A nematogenic Schiff's base, N,N′-di-4-(4′-pentyloxybenzoate)salicylidene-l″, 3″-diamino-2″-propanol, (abbreviated as H2L6), was synthesized and its structure studied by elemental analyses, mass, NMR and IR spectra. The Schiff's base behaves as a dinegative hexa/tetradentate species in its metal complexes of the general formula, [ML6]n where MII═Mn, Co, Ni, Cu and Zn. Their structural characterizations were made by various spectroscopic techniques.  相似文献   
104.
The DC magnetic hysteresis loop measurements were carried out for temperatures varying from 5 to 300 K over a field range of ±10 T on nanocrystalline (~35 nm) cobalt ferrite samples (crystallized to \(Fd\bar {3} m\) space group with cubic symmetry) to validate the law of approach at low temperature for the nanocrystalline cobalt ferrite. A magnetocrystalline anisotropy constant and saturation magnetization have been obtained by analyzing the magnetization curve in saturation using the “law of approach (LA) to saturation.” The magnetocrystalline anisotropy constant is found to be almost constant in the temperature range of 5 to 150 K due to the freezing of spin at low temperature. Also, spin freezing leads to a decrease of coercivity with the increase in the temperature.  相似文献   
105.
The Khimti headrace tunnel experienced instability related to tunnel deformations in several tunnel stretches through mica schist and schistose mica gneiss rock mass. The monitored convergence pattern indicated that the tunnel deformation continued for a long period of time after excavation. This paper aims to analyze plastic deformation behavior of the selected four headrace tunnel sections with considerable deformation where extensive deformation monitoring was conducted. The Convergence Law proposed by Sulem et al. (Int J Rock Mech Min Sci Geomech 24(3):145–154, 1987a) for estimating long-term time-dependent deformation, and the convergence confinement method proposed by Carranza-Torres and Fairhurst (Tunn Undergr Space Technol 15(2):187–213, 2000) for estimating tunnel convergences have been used as analytical tools for the assessment. The achieved results are compared, and similarities and differences are discussed. In addition, the results are also verified by three-dimensional (3D) numerical modeling. The achieved results indicated a fairly good match between measured, back-calculated and numerically modeled results. However, one should note that such calculations are highly sensitive to the accuracy and reliability of the estimated input parameters.  相似文献   
106.
Characterizing water and fat distributions in fried foods is of major importance in terms of taste and nutrition. The objective of this study was to introduce a new technique to quantify water and fat distributions of chicken nuggets coated with methylcellulose (MC) through the use of magnetic resonance imaging (MRI) and NMR relaxometry. Multi-slice-multi-echo (MSME-Spin Echo based) images were performed on a 1.03 T spectrometer for the whole chicken nuggets to obtain relaxation time distribution of different regions (core and crust) of the nugget. MSME images provided the relaxation spectra of the core and crust separately and showed that relaxation times and relative areas of the proton pools in crust and core regions are correlated (mostly, R2 > 0.85) with moisture and fat content. Results demonstrated that MSME images in combination with T2 relaxometry are appropriate tools to quantify spatial water and fat distribution in various food products.  相似文献   
107.
Potatoes are an important food in many regions of the world and are commonly used in a variety of food products. Thermal transition and thermo-physical properties of potatoes are important in order to design efficient food processes and select appropriate storage conditions. In this study, we determined the thermal transitions and thermophysical properties of raw and blanched/par-fried potato for a temperature range of ??32 to 21.1 °C. Using differential scanning calorimetry, we found an initial freezing point (Tf) at ??1.8?±?0.1 °C, an onset of melting (Tm) at ??9.9?±?0.2 °C and an unfreezable water content (Xw) for maximally freeze-concentrated raw potato at 0.21 kg water/kg potato. Corresponding values for blanched/par-fried potatoes were ??0.9?±?0.1 °C, ??11.0?±?0.2 °C and 0.18 kg water/kg potato. Results show that an increase in solids content decreased Tf of both raw and blanched potatoes. We modelled the relationship between them using the Chen model. The apparent specific heat (Capp) increased around Tf to 31.7?±?1.13 kJ/kg K for raw potato and 26.7?±?0.62 kJ/kg K for blanched/par-fried potato. For frozen raw potato at ??32 °C, thermal diffusivity (α) was 0.89?±?0.01?×?10??6 m2/s and thermal conductivity (k), 1.82?±?0.14 W/m K, respectively. These values were higher for frozen raw potato than for the unfrozen raw potato (0.15?±?0.01?×?10??6 m2/s and 0.56?±?0.08 W/m K, respectively at 21.1 °C). The apparent density (ρ) of frozen raw potato (992?±?4.00 kg/m3 at ??32 °C) was less than that for unfrozen raw potato (1053?±?4.00 kg/m3 at 21.1 °C), and a similar trend was obtained for blanched/par-fried potato (993?±?2.00 kg/m3 at ??32 °C and 1188?±?7.00 kg/m3 at 21.1 °C, respectively). This study established a correlation between thermo-physical properties and temperature. Findings may be used to inform the design and optimization of freezing processes and frozen storage for potato products.  相似文献   
108.
Microstructure and mechanical properties of Fe3Al alloys with chromium   总被引:1,自引:0,他引:1  
Alloys based on Fe3Al have an equilibrium DO3 structure at low temperatures and transform to a B2 structure above about 550°C. The influence of different rates of quenching from the B2 region to room temperature and of subsequent heat treatments on the microstructure and mechanical properties of powder metallurgy (P/M) alloys with two different chromium contents have been examined. Optimizing the processing to maximize the amount of B2 order, without eliminating dislocations that enhance both strength and ductility, yields room-temperature ductility approaching 20%, although the fracture mode is primarily brittle cleavage. The B2 structure generally has lower flow stress than the DO3 structure because of its lower strain-hardening rate, although B2 order actually has higher yield strength when the structure is free of dislocations. Increasing the chromium content from 2% to 5% has little effect on ductility, although the 2% Cr alloys generally have higher yield strengths and larger order parameters.  相似文献   
109.
Deficiency of the vitamin folic acid has recently been linked with increased incidence of neural tube defects and of cardiovascular disease, through elevated plasma homocysteine levels. The kidney has an important role in conserving folate to counteract development of deficiency. Urinary folate excretion is regulated by the degree of reabsorption of folate by the proximal tubule cell. To evaluate an in vitro model for studies of the regulation of urinary folate excretion, the present studies examined the transport of 5-methyltetrahydrofolate (5-CH3-H4PteGlu), the primary form of folate in the glomerular filtrate, by normal rat proximal tubule (RPT) cells in confluent monolayer cultures. Specific binding of 5-CH3-H4PteGlu to the apical membrane was saturable (K(D) = 27 nM), but intracellular transport was not saturated up to 100 nM concentrations. 5-CH3-H4PteGlu transport was decreased 50% by concentrations of folic acid that completely blocked 5-CH3-H4PteGlu binding by the apical folate receptor. Probenecid (10 mM), an anion exchange (reduced folate carrier) inhibitor, reduced 5CH3-H4PteGlu transport by 50% without significantly affecting binding. Aspirin (3 mM) did not alter 5-CH3-H4PteGlu transport, but significantly enhanced the inhibition due to probenecid. Similarly, indomethacin (5 microM) potentiated the inhibition of 5-CH3-H4PteGlu transport by probenecid. These data suggest that RPT cells take up 5-CH3-H4PteGlu by both the folate receptor and the reduced folate carrier, implying a role for both pathways in regulating urinary folate excretion.  相似文献   
110.
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