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101.
Differential scanning calorimetry (DSC) was performed to investigate thermodynamic properties of three carp fast skeletal light meromyosin (LMM) isoforms expressed in Escherichia coli by recombinant DNAs. Three isoforms were the 10 degreesC-, intermediate-, and 30 degreesC-type LMM predominantly expressed in carp acclimated to 10, 20, and 30 degreesC. The isoforms expressed in E. coli by recombinant DNAs exhibited a typical pattern of alpha-helix in CD spectroscopy with two minima at 222 and 208 nm. Moreover, the three isoforms formed paracrystals typical of LMM, suggesting that expressed proteins retained intact structural properties. When the LMM isoforms were subjected to DSC analysis, the 10 degreesC and 30 degreesC types showed endotherms having transition temperatures (Tm) at 35.1 and 39.5 degreesC, respectively, which are responsible for thermal unfolding of alpha-helix. The intermediate type exhibited two comparable endotherms with Tm values at 34.9 and 40.6 degreesC, implying that it has intermediate thermodynamic properties between those of 10 degreesC and 30 degreesC types. However, a chimeric LMM having the 10 degreesC and 30 degreesC type as N- and C-terminal halves, respectively, showed the DSC pattern typical of the whole 30 degreesC-type molecule. On the other hand, another chimeric LMM composed of the N-terminal 30 degreesC type and C-terminal 10 degreesC type gave the pattern of the full 10 degreesC type. These results suggest that thermodynamic properties of the C-terminal half largely account for thermal unfolding of the whole molecule.  相似文献   
102.
A study was carried out into the use of hardwood charcoal as a supplementary fuel in the iron-ore sintering process. The primary fuel was coke breeze with 0%, 20%, 50% and 100% replacement of the energy input with charcoal to produce raw blends with the same heat output as 4.0 wt.% coke breeze. Experimental results indicate that fuel blends where 20% of the heat input was provided by charcoal may improve both the sinter yield and sintering productivity by up to 8%, under normal sintering conditions. In addition, the 20% replacement of coke energy with charcoal would mean that part of the carbon dioxide emitted from the process would be from a renewable source and could be used to offset carbon dioxide emissions from non-renewable fossil fuels. At higher rates of coke breeze energy substitution with charcoal, the lower sintering performance observed was mainly attributed to the lower fixed carbon content and higher volatile matter content of the fuel mix.At the optimum rate of 20% substitution of coke breeze energy input with charcoal, the emission of dioxins were similar to those observed with coke breeze alone as the fuel. However, sintering with 20% energy input from charcoal resulted in a slight increase in middle molecular weight and lower molecular weight PAHs, contributing to a minor increase in B[a]P-eq from 0.15 μg/m3 to 0.17 μg/m3. Overall the results from the laboratory scale tests suggest that it is feasible to substitute 20% of the coke breeze energy input with an equivalent amount of energy from charcoal in the iron-ore sintering process.  相似文献   
103.
Platinum (Pt) nanocrystals of cubic and octopod structures were synthesized via seed-mediated solvothermal growth with monoethanolamine as the solvent. The combination of nanocube and octopod structures was formed using 0.025 ml seeds loading, while increasing the seeds volume to 0.050 ml and 0.100 ml produced nanocube as the primary product. The octopod structure evolves from the overgrown nanocube via kinetic growth mechanism. Pt nanocube formed with 0.050 ml seeded solution has the potential to serve as a catalyst in formic acid oxidation by virtue of its high electrochemical surface area of 10.93 m2/g, over that of Pt black at 8.62 m2/g and resistance to poisonous CO. Nonetheless, it is less catalytically active in ethanol oxidation as depicted by the small electrochemical surface area of 8.64 m2/g and low current density in longer period.  相似文献   
104.
This paper shows that by transforming both sides of the matrix converter to the d-q-o frames of their respective frequencies, there is significant simplification in the transformation matrix which enables the network of one side to be integrated to the other. Thus, it is possible to design for operation with field vector control on the motor side and unity displacement factor on the supply side. Laboratory experimental and digital simulation results are presented to substantiate the theory. The matrix converter used in the test is based on three modules of voltage-source SPWM converters to implement the nine switches and it has the innovative feature that the SVC voltages (for displacement factor improvement) can be derived from the zero-sequence voltages  相似文献   
105.
The indirect current control scheme has evolved from the success of the hysteresis current controlled voltage regulated rectifier, which has been shown to be capable of: unity and even leading power factor operation; near sinusoidal current waveforms; and bilateral power transfer without the need of bi-directional solid state power switches. The advance consists of replacing the inner hysteresis current feedback loop by the standard sinusoidal PWM control and in the process saving the cost of the current measuring transducers. The scheme is evaluated through tests on 1 KW size laboratory models and through digital simulations. A theory of the system dynamics is developed and stability boundaries are presented  相似文献   
106.
A real-time degradable four-way set-associative cache memory control (CMC) LSI is described. Three kinds of errors, address parity error, comparator error, and multihit error, can cause functional degradation by killing the associative unit corresponding to the fault detection. The parity generator and the double comparator have no effect on the timing-sensitive path delay because of the parallel configuration of the circuits. The multihit detector occupies about 16% of the propagation delay of the critical path, from the external address input to the hit/miss output  相似文献   
107.
The design and implementation of the Hewlett-Packard active node gigabit-per-second metropolitan area network (HANGMAN) prototype network are discussed. The three main areas addressed are the physical-layer transmission system, the MAC sublayer protocols, and the architecture of the network interface unit. It is shown that low-cost gigabit-per-second transmission systems are practical, particularly in the local area environment where network links are typically limited to a few hundred meters. A MAC protocol that provides a synchronous service as well as the conventional asynchronous data service is described. The node architecture is presented and the way in which a single node can support multiple concurrent physical connections and how this architecture might be used in the future to develop high-performance protocol implementations are also discussed  相似文献   
108.
3 groups of female children, comprising a total of 169 patients, were followed through successive episodes of urinary tract infection with respect to recurrence of infection. Group A consisted of 66 patients with no evidence of vesico-ureteral reflux. Group B comprised 42 patients with demonstrated vesico-ureteral reflux. The infections in these patients were treated with medical therapy alone and the reflux was not corrected. Group C consisted of 61 children who had surgical correction of vesico-ureteral reflux. While Groups B and C were not strictly comparable, the data indicate that there was no demonstrable difference in the rate of urinary tract infection among the 3 groups. Following short-term specific antibacterial therapy of a new infection, about 20% of children in each group were "cured", i.e., had no further infections during the 12 months or more that they were subsequently followed by the authors. Patients with less severe grades of reflux treated by medication alone (Group B) experienced no greater rate of reinfection than those children presenting with infections in the absence of vesico-ureteral reflux. In those children whose infections could not be adequately controlled by antimicrobial therapy, and those patients with severe (Grade III) reflux, surgery was performed to eliminate the vesico-ureteral reflux. The data also reinforced the concept that correction of reflux does not eliminate the need for constant vigilance and proper treatment of recurrent infections even after successful surgery has been carried out.  相似文献   
109.
Well-dispersed fish gelatin-based nanocomposites were prepared by adding ZnO nanorods (NRs) as fillers to aqueous gelatin. The effects of ZnO NR fillers on the mechanical, optical, and electrical properties of fish gelatin bio-nanocomposite films were investigated. Results showed an increase in Young''s modulus and tensile strength of 42% and 25% for nanocomposites incorporated with 5% ZnO NRs, respectively, compared with unfilled gelatin-based films. UV transmission decreased to zero with the addition of a small amount of ZnO NRs in the biopolymer matrix. X-ray diffraction showed an increase in the intensity of the crystal facets of (10ī1) and (0002) with the addition of ZnO NRs in the biocomposite matrix. The surface topography of the fish gelatin films indicated an increase in surface roughness with increasing ZnO NR concentrations. The conductivity of the films also significantly increased with the addition of ZnO NRs. These results indicated that bio-nanocomposites based on ZnO NRs had great potentials for applications in packaging technology, food preservation, and UV-shielding systems.  相似文献   
110.
A series of biodegradable polymer films based on poly(vinyl alcohol) (PVOH) and jackfruit waste flour (JWF) was prepared in the presence of water and glycerol and cast by a solution casting method. The JWF was introduced as a promoter of biodegradability. The blended films were evaluated for their tensile properties, water absorption, water vapor transmission rate (WVTR), and degradation behavior under different environmental conditions such as natural weathering and natural soil. The tensile strength (1.7–6.4 MPa) and elongation at break (13–108%) of the PVOH/JWF films were lower than those of unfilled PVOH film (26MPa and 238%). However, the Young's modulus values (157–196 MPa) of the PVOH/JWF films were higher than that of unfilled PVOH film (137 MPa). The PVOH/JWF blended films showed higher water absorption and WVTR, which increased with increasing JWF content. Biodegradability tests revealed that the presence of JWF stimulated the degradation rate and caused the weight loss and reduction in tensile properties of the PVOH/JWF blended films. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers  相似文献   
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