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121.
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123.
Distribution and activity of ammonia oxidizing bacteria in a large full-scale trickling filter 总被引:12,自引:0,他引:12
The biofilm in a full-scale nitrifying trickling filter (NTF) treating municipal wastewater has been investigated with microbiological methods using fluorescence in situ hybridization (FISH) with 16S rRNA oligonucleotide probes in combination with confocal laser scanning microscopy (CLSM) and mathematical modeling using a dynamic multi-species biofilm reactor model. Ammonia oxidizing bacteria (AOB) were found to belong to the genus Nitrosomonas at different depths in the NTF at every sampling occasion, corresponding to different long-term operational conditions for the NTF. Both the measurements and the corresponding simulated predictions showed the same general trend of a decrease with filter depth of the amount of biofilm, the proportion of AOB to all bacteria and the total amount of AOB. The latter decreased by several times from top to bottom of the NTF. Measurements and simulations of potential ammonium oxidizing activity in the biofilm also showed a decreasing activity with depth in the NTF, which generally was operating at close to complete nitrification. However, no difference was observed when the activity was normalized to the amount of biofilm, despite decreasing proportions of AOB to all bacteria with depth in the NTF. This could be explained by diffusion limitations in the biofilm from the upper parts of the NTF according to the biofilm reactor model. The relatively good agreement between the simulations and the measurements shows that the kind of biofilm reactor model used can qualitatively describe an averaged behavior and averaged composition of the biofilm in the reactor. 相似文献
124.
Coupled Continuous Chromatography and Racemization Processes for the Production of Pure Enantiomers
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Combining an enantioseparation by continuous chromatography with the racemization of the undesired enantiomer in a recycle is a promising approach. Two different cases were considered: limited conversion of the reaction with moderate product purity requirements and high conversion with high product purity requirements. For the first case, a simple plantwide control strategy is presented, manipulating the solvent removal in front of the racemization reactor. It is shown that the various disturbances can be compensated with this strategy without performing the more complex readjustment of the chromatographic unit. Further, it is shown that this strategy is likely to fail in the second scenario and that readjustment of the chromatographic unit is required for a successful control strategy. 相似文献
125.
Changhun Yun Guohua Xie Caroline Murawski Jonghee Lee Fabian Ventsch Karl Leo Malte C. Gather 《Organic Electronics》2013,14(7):1695-1703
We report on the development and detailed investigation of highly efficient p–i–n phosphorescent organic light-emitting diodes (PhOLEDs) using 4,4′-bis(carbazol-9-yl)-biphenyl (CBP) as a single organic semiconductor matrix. Following optimization of doping concentration of both the phosphorescent emitter molecule and of the p- and n-type dopants, an external quantum efficiency (EQE) of 15% and a power efficiency (PE) of 28 lm/W are realized at a luminance of 1000 cd/m2. These values are comparable to the state-of-the-art for conventional complex multilayered PhOLEDs. By analyzing the device characteristics (i.e. electroluminescence spectra, the current density–voltage behavior of single carrier devices, the transient electroluminescent decay, and the impedance spectroscopy response), we find that the device performance is closely linked to the charge carrier balance in the device, which in turn is governed by the interplay of the conductivities of the doped layers and the transport of each charge carrier species within the emitting layer. 相似文献
126.
Data for adjustment of weather radar rainfall estimations are mostly obtained from rain gauge observations. However, the density of rain gauges is often very low. Yet in many urban catchments, runoff sensors are typically available which can measure the rainfall indirectly. By utilising these sensors, it may be possible to improve the ground rainfall estimate, and thereby improve the quantitative precipitation estimation from weather radars for urban drainage applications. To test the hypothesis, this paper presents a rainfall measurement method based on flow rate measurements from well-defined urban surfaces. This principle was used to design a runoff measurement system in a parking structure in Aalborg, Denmark, where it was evaluated against rain gauges. The measurements show that runoff measurements from well-defined urban surfaces perform just as well as rain gauges. This opens up the possibility of improving the ground rainfall estimate by the use of flow rate measurements. 相似文献
127.
Covalent polyester–biomolecule conjugates: advances in their synthesis and applications in biomedicine and nanotechnology
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Malte Winnacker 《Polymer International》2017,66(12):1747-1755
Among the variety of polymeric biomaterials, polyesters have a significant position, for example due to their biocompatibility and (tunable) biodegradability. In addition to their established and ‘pristine’ use as, for example, implants or sutures, the introduction of specific functional biomolecules to polyesters has been attracting increasing attention within the past few years to afford polyester‐based functional bioconjugates, which require certain synthesis strategies. Selected recent concepts for these covalent conjugations are summarized in this article in terms of the attachment of biological macromolecules as well as small bioactive drugs on polyesters. © 2017 Society of Chemical Industry 相似文献
128.
Malte Lochau Johannes Bürdek Stefan Hölzle Andy Schürr 《Software and Systems Modeling》2017,16(1):125-152
Dynamic software product lines (DSPLs) propose elaborated design and implementation principles for engineering highly configurable runtime-adaptive systems in a sustainable and feature-oriented way. For this, DSPLs add to classical software product lines (SPL) the notions of (1) staged (pre-)configurations with dedicated binding times for each individual feature, and (2) continuous runtime reconfigurations of dynamic features throughout the entire product life cycle. Especially in the context of safety- and mission-critical systems, the design of reliable DSPLs requires capabilities for accurately specifying and validating arbitrary complex constraints among configuration parameters and/or respective reconfiguration options. Compared to classical SPL domain analysis which is usually based on Boolean constraint solving, DSPL validation, therefore, further requires capabilities for checking temporal properties of reconfiguration processes. In this article, we present a comprehensive approach for modeling and automatically verifying essential validity properties of staged reconfiguration processes with complex binding time constraints during DSPL domain engineering. The novel modeling concepts introduced are motivated by (re-)configuration constraints apparent in a real-world industrial case study from the automation engineering domain, which are not properly expressible and analyzable using state-of-the-art SPL domain modeling approaches. We present a prototypical tool implementation based on the model checker SPIN and present evaluation results obtained from our industrial case study, demonstrating the applicability of the approach. 相似文献
129.
Theresa Sophie Braun Pia Widder Uwe Osswald Lina Groß Lara Williams Dr. Moritz Schmidt Irina Helmle Prof. Dr. Daniel Summerer Prof. Dr. Malte Drescher 《Chembiochem : a European journal of chemical biology》2020,21(7):958-962
Electron paramagnetic resonance (EPR) spectroscopy in combination with site-directed spin labeling (SDSL) is a powerful tool in protein structural research. Nitroxides are highly suitable spin labeling reagents, but suffer from limited stability, particularly in the cellular environment. Herein we present the synthesis of a maleimide- and an azide-modified tetraethyl-shielded isoindoline-based nitroxide (M- and Az-TEIO) for labeling of cysteines or the noncanonical amino acid para-ethynyl-l -phenylalanine (pENF). We demonstrate the high stability of TEIO site-specifically attached to the protein thioredoxin (TRX) against reduction in prokaryotic and eukaryotic environments, and conduct double electron–electron resonance (DEER) measurements. We further generate a rotamer library for the new residue pENF-Az-TEIO that affords a distance distribution that is in agreement with the measured distribution. 相似文献
130.
V. Prot B. Skallerud G. A. Holzapfel 《International journal for numerical methods in engineering》2007,71(8):987-1008
The present study addresses constitutive modelling and implementation of transversely isotropic hyper‐elastic material models for the analysis of the mitral valve. This valve separates the left atrium and left ventricle in the heart. Two convex strain energy potentials are employed in derivation of stress tensors and elasticity tensors. The plane stress and incompressibility conditions are accounted for directly. The relationships are implemented in an implicit code (ABAQUS) via the user‐defined interface. Numerical simulations of the valve motion during a part of the heart cycle are carried out and compared to ultrasound measurements of a healthy human valve. The significance of placement of chordae tendinae is illustrated. The implementation provides a tool for simulations of both healthy and pathological mitral valve conditions. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献