排序方式: 共有46条查询结果,搜索用时 0 毫秒
41.
Kalyuzhnyi S Sklyar V Epov A Arkhipchenko I Barboulina I Orlova O Kovalev A Nozhevnikova A Klapwijk A 《Applied biochemistry and biotechnology》2003,109(1-3):77-94
This article summarizes the results obtained during the laboratory and pilot development of integrated biologic and physicochemical
treatment and reuse of diluted pig manure streams. The application of a straw filter was an effective means to separate the
solid and liquid fractions of raw wastewater and resulted in the removal of a significant part of the dry matter, total nitrogen,
and phosphorus (65, 27, and 32%, respectively). From the filtrate generated, 60–80% of the total chemical oxygen demand (COD)
was removed in an upflow anaerobic sludge bed reactor operating at 15–30°C. Ammonia was efficiently eliminated (>99%) from
the anaerobic effluents using Ural laumantite as an ion exchanger. However, the nitrogen-content of the zeolite was too low
to consider this method of ammonia removal economically feasible. The phosphate precipitation block, consisting of stripper
of CO2 and fluidized-bed crystallizator, was able to decrease the concentration of soluble phosphate in the anaerobic effluents
up to 7–15 mg of phosphate/L. The application of aerobic/anoxic biofilter as a sole polishing step was acceptable from an
aesthetic point of view (the effluents were transparent and almost colorless and odorless) and elimination of biochemical
oxygen demand (the resting COD was hardly biodegradable). However, the effluent nutrient concentrations (especially nitrogen)
were far from the current standards for direct discharge of treated wastewater. We discuss the approaches for further improvement
of effluent quality. Finally, we provide an outline of a full-scale system that partially implements the laboratory- and pilot-scale
results obtained. 相似文献
42.
S. Withington K. G. Isaak S. A. Kovtonyuk R. A. Panhuyzen T. M. Klapwijk 《Infrared Physics & Technology》1995,36(7):1059-1075
Superconducting tunnel-junction direct detectors are considered in some detail. For frequencies below twice that of the gap there is some bias voltage for which the input impedance is real, the responsivity quantum limited, and the dynamic range high. A susperconducting detector saturates for two reasons: intrinsic saturation due to the relative increase in two-photon tunnelling processes, and extrinsic saturation due to the input match changing with bias voltage. The responsivity of a detector with a resistive RF source is least sensitive to bias-voltage changes and has the greatest dynamic range when operating with a sloping load line. In the case of an inductive source, the dynamic range can be higher than the intrinsic saturation rate would suggest. Ideally, superconducting tunnel-junction detectors should be biased in a constant-voltage mode. If the responsivity is to be depressed by no more than a few percent, the photon step should have a height which is no more than one quarter of the total current turn-on at the gap. Superconducting direct detectors can be used to make precise and well-calibrated optical measurements at submillimetre wavelengths. 相似文献
43.
44.
45.
46.