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771.
Aqueous-based LiFePO(4) pastes to fabricate the cathode of lithium-ion battery were investigated with an emphasis on chemical control of suspension component interactions among LiFePO(4) particulates, carbon black, carboxymethyl cellulose (CMC), and poly(acrylic acid) (PAA). The dispersion properties of LiFePO(4) were characterized using electroacoustic, flow behavior and green microstructural observation. Correlation was made between the dispersion properties and electrochemical performance of the particles. It was found that the addition of PAA significantly decreases the viscosity of the LiFePO(4) paste. The decrease of viscosity leads to increasing the solid concentration, which affects the electrochemical properties. The electrochemical characteristics of formulated pastes were evaluated using coin-type half cells. Although there is no significant difference between coin cells fabricated with CMC only and CMC/PAA combination in electrochemical cycling test, the dispersion properties of pastes indicate that the electrode fabricated with CMC/PAA, potentially, has much improved discharge capacity compared to that with CMC alone because of the possibility to increase active mass portion in electrode paste. 相似文献
772.
773.
Mesophilic and thermophilic temperature co-phase anaerobic digestion compared with single-stage mesophilic- and thermophilic digestion of sewage sludge 总被引:17,自引:0,他引:17
The performance of thermophilic and mesophilic temperature co-phase anaerobic digestions for sewage sludge, using the exchange process of the digesting sludge between spatially separated mesophilic and thermophilic digesters, was examined, and compared to single-stage mesophilic and thermophilic anaerobic digestions. The reduction of volatile solids from the temperature co-phase anaerobic digestion system was dependent on the sludge exchange rate, but was 50.7-58.8%, which was much higher than 46.8% of single-stage thermophilic digestion, as well as 43.5% of the mesophilic digestion. The specific methane yield was 424-468 mL CH(4) per gram volatile solids removed, which was as good as that of single-stage mesophilic anaerobic digestion. The process stability and the effluent quality in terms of volatile fatty acids and soluble chemical oxygen demand of the temperature co-phase anaerobic digestion system were considerably better than those of the single-stage mesophilic anaerobic processes. The destruction of total coliform in the temperature co-phase system was 98.5-99.6%, which was similar to the single-stage thermophilic digestion. The higher performances on the volatile solid and pathogen reduction, and stable operation of the temperature co-phase anaerobic system might be attributable to the well-functioned thermophilic digester, sharing nutrients and intermediates for anaerobic microorganisms, and selection of higher substrate affinity anaerobic microorganisms in the co-phase system, as a result of the sludge exchange between the mesophilic and thermophilic digesters. 相似文献
774.
Novel method for enhancing permeate flux of submerged membrane system in two-phase anaerobic reactor 总被引:7,自引:0,他引:7
A two-phase anaerobic reactor system with a submerged membrane in the acidogenic reactor was designed for the enhancement of organic acid conversion and methane recovery. A submerged membrane system in a two-phase anaerobic reactor was tested to increase the sludge retention time (SRT) of acidogen and to enhance the solid separation. The pilot plant experiment was performed for piggery wastewater treatment for a year. The membrane material used was mixed esters of cellulose of 0.5 micron pore size. COD removal efficiency was 80% and the methane production showed 0.32 m3/kg COD removed for the submerged membrane system in the anaerobic digester. As the cake resistance of the membrane caused a serious problem, a stainless-steel prefilter and air backwashing methods were applied to minimize the cake resistance effectively. Among the tested prefilters, the 63 microns pore prefilter showed the best performance for reducing cake resistance and a successful long-term operation. By cleaning with alkali first and acidic solutions later, the permeate flux decreased by long-term operation was recovered to 89% of that with a new membrane. 相似文献
775.
Shieh YC Khudyakov YE Xia G Ganova-Raeva LM Khambaty FM Woods JW Veazey JE Motes ML Glatzer MB Bialek SR Fiore AE 《Journal of food protection》2007,70(1):145-150
Numerous hepatitis A outbreaks were linked to the consumption of raw molluscan shellfish in the United States between 1960 and 1989. However, there had been no major molluscan shellfish-associated hepatitis A outbreaks reported in the United States for more than a decade (1989 to 2004). Beginning in late August 2005, at least 10 clusters of hepatitis A illnesses, totaling 39 persons, occurred in four states among restaurant patrons who ate oysters. Epidemiologic data indicated that oysters were the source of the outbreak. Traceback information showed that the implicated oysters were harvested from specific Gulf Coast areas. A voluntary recall of oysters was initiated in September. Hepatitis A virus (HAV) was detected in multiple 25-g portions in one of two recalled samples, indicating that as many as 1 of every 15 oysters from this source was contaminated. Comparing 315 nucleotides within the HAV VPl-2B region, 100% homology was found among four amplicons recovered from a total of six independent experiments of the implicated oysters, and an identical HAV sequence was detected in sera from all 28 patient serum specimens tested. Ten percent heterogeneity over 315 nucleotides (31 variants) was observed between the outbreak strain (subgenotype 1A) and an HM-175 strain (subgenotype 1B) used in the laboratory where the oysters were processed. To our knowledge, this investigation is the first in the United States to identify an HAV-identical strain in persons with hepatitis A as well as in the food that was implicated as the source of their infections. 相似文献
776.
Novel nanobiocomposites multiwalled carbon nanotube-poly(vinyl alcohol)-glucose oxidase have been successfully prepared by a simple solution-evaporation method. The morphology and performance of the multiwalled carbon nanotube-poly(vinyl alcohol)-glucose oxidase film have been characterized by atomic force microscopy, cyclic voltammetry, and amperometry. The multiwalled carbon nanotube and glucose oxidase were observed to be homogeneously dispersed throughout the poly(vinyl alcohol) matrix. When compared with bare glassy carbon electrode, the sensitivity to hydrogen peroxide is greatly improved by about 115 times at multiwalled carbon nanotubepoly(vinyl alcohol) modified glassy carbon electrode. The glucose biosensor sensitivity was strongly influenced by the glucose oxidase concentration within the multiwalled carbon nanotube-poly(vinyl alcohol)-glucose oxidase composite. 相似文献
777.
Lim YS Moon DJ Park NC Shin JS Kim JH Kim YC 《Journal of nanoscience and nanotechnology》2007,7(11):4009-4012
Hydrotalcite-like catalysts were synthesized by co-precipitation and then these were promoted by the addition of noble metals, alkaline earth metals and ceria. Reaction tests were conducted using a feed of H2O/C/O2 = 3/1/0.37 at a temperature range from 300 degrees C to 700 degrees C. Catalysts were characterized by XRD, TEM, FESEM, TPR, and BET. Reaction test results confirmed an enhancement of the catalytic activity of the promotor-modified catalysts due to low carbon deposition. Among the alkaline earth metals tested, those with larger atomic number exhibited higher activity at a lower temperature range. 相似文献
778.
Jang S Kim J Koh Y Ko YC Woo HG Sohn H 《Journal of nanoscience and nanotechnology》2007,7(11):4049-4052
The nanostructured rugate porous silicons (PSi) containing multiple photonic band gaps have been generated by an electrochemical etching through applying a composite waveform summed three computer-generated pseudo-sinusoidal current waveforms. They exhibit three sharp photonic band gaps in the optical reflectivity spectrum, corresponding to the each of the sine components varied from 0.42, 0.36, and 0.30 Hz, with a spacing of 0.06 Hz between each sine component. The sensing experiments using multi-encoded rugate PSi for the detection of nerve agents such as triethyl phosphate (TEP), diethyl chlorophosphate (DCP), dimethyl methylphosphonate (DMMP), and diethyl ethylphosphonate (DEEP) have been achieved. Capillary condensation in the pores causes the reflectivity of rugate PSi to shift to longer wavelengths due to an increase in refractive indices of the porous medium. 相似文献
779.
780.
Huang YT Wu WJ Wang YC Lee CK 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2007,54(2):359-367
An innovative, multilayer piezoelectric transformer equipped with a full modal filtering input electrode is reported herein. This modal-shaped electrode, based on the orthogonal property of structural vibration modes, is characterized by full modal filtering to ensure that only the desired vibration mode is excited during operation. The newly developed piezoelectric transformer is comprised of three layers: a multilayered input layer, an insulation layer, and a single output layer. The electrode shape of the input layer is derived from its structural vibration modal shape, which takes advantage of the orthogonal property of the vibration modes to achieve a full modal filtering effect. The insulation layer possesses two functions: first, to couple the mechanical vibration energy between the input and output, and second, to provide electrical insulation between the two layers. To meet the two functions, a low temperature, co-fired ceramic (LTCC) was used to provide the high mechanical rigidity and high electrical insulation. It can be shown that this newly developed piezoelectric transformer has the advantage of possessing a more efficient energy transfer and a wider optimal working frequency range when compared to traditional piezoelectric transformers. A multilayer piezoelectric, transformer-based inverter applicable for use in LCD monitors or portable displays is presented as well. 相似文献