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91.
Matthias Eng Rasmus Jonsson Anders Rasmuson 《American Institute of Chemical Engineers》2016,62(1):338-348
Local and temporal variations of the particle cloud formed in a cylindrical mixing vessel were investigated experimentally. Different particle sizes (0.5, 1, and 2 mm) and volumetric concentration up to 20 vol % were evaluated at different impeller speeds. The time‐averaged cloud height was linear with impeller frequency and with volume concentration. Suspensions with larger particles had a lower average cloud height, while the standard deviation for the temporal cloud height variation was larger. Two strong periodic phenomena were identified to be dominating the particle cloud height variations. The frequencies were linear with impeller speed, resulting in dimensionless frequencies of S1=0.02–0.03 and S2=0.05–0.06. The frequencies were affected by neither the particle size nor the volumetric concentration. The amplitude showed no dependency on the particle size, but the S2 amplitude significantly decreases and S1 increases with increasing solid concentration. The results were compared to LES/discrete element method simulations and showed a fair agreement. © 2015 American Institute of Chemical Engineers AIChE J, 62: 338–348, 2016 相似文献
92.
Bioavailability Studies and in vitro Profiling of the Selective Excitatory Amino Acid Transporter Subtype 1 (EAAT1) Inhibitor UCPH‐102 下载免费PDF全文
Dr. Isabell Haym Dr. Tri H. V. Huynh Dr. Stinne W. Hansen Dr. Martin H. F. Pedersen Dr. Josep A. Ruiz Dr. Mette N. Erichsen Dr. Mikko Gynther Walden E. Bjørn‐Yoshimoto Dr. Bjarke Abrahamsen Dr. Jesper F. Bastlund Dr. Christoffer Bundgaard Anette L. Eriksen Prof. Anders A. Jensen Prof. Lennart Bunch 《ChemMedChem》2016,11(4):403-419
Although the selective excitatory amino acid transporter subtype 1 (EAAT1) inhibitor UCPH‐101 has become a standard pharmacological tool compound for in vitro and ex vivo studies in the EAAT research field, its inability to penetrate the blood–brain barrier makes it unsuitable for in vivo studies. In the present study, per os (p.o.) administration (40 mg kg?1) of the closely related analogue UCPH‐102 in rats yielded respective plasma and brain concentrations of 10.5 and 6.67 μm after 1 h. Three analogue series were designed and synthesized to improve the bioavailability profile of UCPH‐102, but none displayed substantially improved properties in this respect. In vitro profiling of UCPH‐102 (10 μm ) at 51 central nervous system targets in radioligand binding assays strongly suggests that the compound is completely selective for EAAT1. Finally, in a rodent locomotor model, p.o. administration of UCPH‐102 (20 mg kg?1) did not induce acute effects or any visible changes in behavior. 相似文献
93.
94.
After hydrothermal pretreatment and enzymatic hydrolysis of wheat straw, a slurry rich in lignin but with a high content of inorganic substances, especially silica, and residual carbohydrates is produced. This slurry was used to develop an ethanol organosolv separation method to produce silica-free lignin fractions. The addition of para toluene sulphonic acid (PTSA) and the use of two alternative long-chain alcohols, oleyl alcohol or nonylphenol, were tested. In every reaction, two lignin fractions were produced and their molecular size and elemental composition were characterized. The yield of each fraction and the change in MWD were studied as a function of temperature and solid to liquid ratio. At 100, 150, and 200°C and with the use of PTSA, high-purity lignin fractions were obtained. After lignin fractionation with nonylphenol, a liquid silica-free product with high lignin content was obtained in yields between 17 and 72%. 相似文献
95.
Scheidler Stefan Anders Birte Regli Christian Bolay Stephan Huggenberger Peter 《Grundwasser》2019,24(4):277-286
Grundwasser - Topographically induced Alpine regional groundwater flow systems below the unconsolidated valley fillings constitute a substantial unused geothermal resource. Within the... 相似文献
96.
Analyses of samples of bed ash from a stationary fluidized bed boiler show the presence of calcium sulphide. In some samples, half of the total sulphur was present as sulphide. The samples containing CaS were obtained under unstaged conditions and with a high excess air ratio, 1.3 to 1.4. The samples were taken after a stop in the limestone addition, i.e. at high SO2 emissions of about 1000 mL/m3 (ppm). No CaS was found during limestone addition when the SO2 emission was 300–400 mL/m3. This indicates that formation of large amounts of CaS may be initiated as the SO2 concentration exceeds some critical level. 相似文献
97.
Fish and shellfish products imported into Denmark are routinely analyzed for pathogenic Vibrio spp., particularly Vibrio cholerae, if products originate from subtropical or tropical areas. A V. cholerae strain that agglutinated commercial O139 antiserum but not the O1, Inaba, or Ogawa antisera was isolated from imported raw frozen shrimp. The toxigenicity of the strain was analyzed, and the results of a polymerase chain reaction showed that the V. cholerae strain did not contain the virulence genes ctx, tcpA, and zot, which are normally found in V. cholerae O1 and O139. The strain was resistant to colistin and spectinomycin. The high susceptibility of the strain to antimicrobial agents was confirmed by the lack of an SXT element, a self-transmissible, chromosomal genetic element that is normally present in 0139 strains and encodes resistance to sulfonamides, trimethoprim, and streptomycin. The strain contained two plasmids, in contrast to other O139 strains, which normally do not contain plasmids. The characteristics of the strain led to further agglutination testing with other antisera that are not commercially available, and the strain was found to agglutinate O155 antiserum in repeated testing. Manufacturers of 0139 antiserum should be aware of the closely related O antigens of the O139, O22, and O155 serogroups and should be aware that their commercial diagnostic O139 antiserum must be absorbed to remove cross-reacting agglutinins of O22 and O155 strains. 相似文献
98.
Anders Andersson Vassilis Gekas Irene Lind Fernanda Oliveira Rickard Öste Dr. Jose Miguel Aguilfra 《Critical reviews in food science and nutrition》1994,34(3):229-251
Preheating potatoes at 50 to 80°C has a firming effect on the cooked potato tissue. This effect is particularly pronounced at a preheating temperature of 60 to 70°C followed by cooling. Several theories have been presented in the literature to explain this firming effect: retrogradation of starch, leaching of amylose, stabilization of the middle lamellae and cell walls by the activation of the pectin methylesterase (PME) enzyme, and by the release of calcium from gelatinized starch and the formation of calcium bridges between pectin molecules. Most probably, none of these theories alone can explain the phenomenon and more than one mechanism seems to be involved. Some of these mechanisms seem to be interdependent. As an example, calcium could be considered as a link all the way through release after starch gelatinization to cross‐linking pectin substances in the cell wall and the middle lamellae, which has been demethylated by the PME enzyme. More research and “clear cut” experiments are needed in order to elucidate the role of each mechanism, especially which of them is the main contributor to the process of firming. Most probably, the calcium‐pectin‐PME mechanism plays a secondary role, that is, it only retards the collapse of the tissue structure that would otherwise occur during the final heating without preheating, and it is not the main factor of firmness. 相似文献
99.
Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) from coal tar pitch polluted sediments was predicted by (1) a generic approach based on organic carbon-water partitioning and Gibbs linear free energy relationship (between K(OW) and K(OC)), and (2) measurements of freely dissolved concentrations of PAHs in the sediment pore water, using passive samplers and solid phase extraction. Results from these predictions were compared with those from in vivo bioaccumulation experiments using Nereis diversicolor (Polychaeta), Hinia reticulata (Gastropoda), and Nuculoma tenuis (Bivalvia). Measured sediment/water partition coefficients were higher than predicted by the generic approach. Furthermore, predicted biota-to-sediment accumulation factors (BSAFs) derived from measured pore water concentrations were more in agreement with the bioaccumulation observed for two of the three species. Discrepancies associated with the third species (N. tenuis) were likely a result of particles remaining in the intestine (as shown by microscopic evaluation). These results indicate the importance of conducting site-specific evaluations of pore water concentrations and/or bioaccumulation studies by direct measurements to accurately provide a basis for risk assessment and remediation plans. The importance of knowledge regarding specific characteristics of model organisms is emphasized. 相似文献
100.
Liang Li Anders Rasmuson Andy Ingram Mats Johansson Johan Remmelgas Christian von Corswant Staffan Folestad 《American Institute of Chemical Engineers》2015,61(3):756-768
Particle cycle and residence time distributions are critical factors in determining the coating quality in the Wurster process. Positron emission particle tracking experiments are performed to determine the cycle and residence times of particles in different regions of a Wurster fluid bed. The results show that particles tend to recirculate in and sneak out below from the Wurster tube. The experiments also show that a larger batch size leads to a shorter cycle time and a narrower cycle time distribution (CTD). It is possible to avoid recirculations and obtain a shorter cycle time and a narrower CTD by selecting the operating conditions appropriately or via equipment design. Experiments using binary mixtures of particles with a diameter ratio of 1.5 show that large particles have a longer cycle time than small particles and that the cycle time is shorter for mixtures with approximately equal amounts of small and large particles. © 2014 American Institute of Chemical Engineers AIChE J, 61: 756–768, 2015 相似文献