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852.
The influences of dissolved oxygen (DO) on the removal process of nitrogen and phosphorous in a sludge reduction system had been studied by controlling aeration amounts. It was found that under the conditions of low doses of 2,4,5trichlorophenol (TCP), endogenous sour values of activated sludge increased with the extension of low DO state duration in SBR system and the decrease of cyclic average DO, which led to a low DO environment favored the formation of simultaneous nitrification and denitrification(SND).TCP concentration was recommended as 2mg / L and cyclic average DO value in SBR system was kept at 2mg / L based on the impacts of TCP concentration on sludge reduction, removal of nitrogen and phosphorous and sludge performance. Compared with the control system, aeration amounts increased by 23% and the discharge of excess sludge decreased by 34.6%. The water quality in effluents was equivalent in the aeration sludge reduction system with 2mg/LTCP, which met the discharge standards. Therefore, it was indicated that the removal of nitrogen and phosphorous and sludge reduction can obtain excellent performance in TCP system under low DO state with removing Phosphrous rich sewage. 相似文献
853.
In recent years wood trusses are widely used in buildings due to their excellent performance and ease of construction. As with solid lumber joists, however, the vibration of wood truss joist floors can cause occupants to feel discomfort. To understand the relationship between the vibration performance of wood truss joist floors and the perceptions of occupants, experimental and subjective evaluations were conducted on six truss joist floors. The results show there is close relationship between perceptions of occupants and the fundamental natural frequency, static deflection and vibration acceleration of truss joist floors. The installation of bracings and straps greatly improved the vibration performance of light truss joist floors. We suggest that two or more factors should be included in the design criteria for controlling wood floor vibration, such as static deflection and fundamental natural frequency. Peak acceleration can be adopted as a factor in the evaluation system of vibration performance of wood truss joist floors. 相似文献
854.
In this paper, based on the uniaxial compression tests, consolidated undrained shear tests,consolidation drainage shear tests of Malan loess with different water contents, and based on understanding deeply of peculiar physico mechanical property of Malan 相似文献
855.
Based on the braking theory of conventional vehicles and high efficient energy recovery and security braking, a control strategy for braking energy distribution and regenerative braking of a 4WD hybrid electric vehicle was proposed. Considering limiting factors, such as motor and battery efficiency, a simulation model of a regenerative braking system was built and a simulation of typical braking conditions was conducted. The simulation result shows that the highest energy recycle ratio can reach 87.5%, 47.8%, and 28.6% when z is 0.1, 0.3, and 0.5, respectively, at 30 km/h. The control strategy for braking energy distribution and regenerative braking can satisfy demand for vehicle braking and obtain high regenerative energy. 相似文献
856.
In order to meet the performance demands of train lorry, a die forging drawing method based on structure features analysis was proposed to form the L A break beam frame. The finite element method was used to simulate a series of die forging processes and the drawing processes with different parameters. The optimum cross section shape of the performing die was obtained from these simulation results. It is found that local back flow of the metal is the primary cause of necking defects in drawing. Furthermore, the best drawing speed is determined to be from 87 mm/s to 96 mm/s. The results of trial manufacturing and product detection indicate that employing a die forging drawing process to form the monobloc break beam frame is feasible. 相似文献
857.
WANG Hong jian XIAO Sha li SHI Jun TANG Chang huan LIU Shen ye QIAN Jia yu 《保鲜与加工》2008,(8):864-868
A new crystal spectrometer with high spatial and spectral resolution was designed to measure very low emissive X ray spectra of laser produced plasma in the 0.5 nm to 0.8 nm range. Twin channels collocated perpendicularly with two different crystal materials and forms were utilized for simultaneous measurement of spectral and spatial resolution. The imaging plate was employed to obtain high spatial resolution with effective area of 30 mm×80 mm. The basic parameters of crystals were analyzed and the design parameters of the spectrometer are presented herein. The first experiment was carried out at the 20 J energy laser facility of Research Center of Laser Fusion, CAEP. X ray spectra were obtained from Al laser produced plasmas with a spectral resolution of 1 000 to 1 500 for the spherically bent mica crystal spectrometer and spatial resolutions of 1.73 mm to 6.88 mm for the flat PET crystal in the same condition. It is suggested that the device be used in high density plasma diagnostics of a single laser shot. 相似文献
858.
The essentiality of human information system interaction efficiency was analyzed under the computerization environment of enterprises. Information processing ability was measured from three dimensions: working memory, cognitive skill, and computer self efficacy. The experimental method was used to study the influence of information processing ability on human information system interaction efficiency. Multiple regression results show that cognitive skill is the main factor influencing interaction efficiency for skill based tasks, working memory is the main factor for rule based tasks, and working memory has no significant influence on interaction efficiency for knowledge based tasks. Working memory and computer self efficacy are the main factors influencing interaction efficiency for total tasks. 相似文献
859.
A supercritical CO2 fluid extraction (SFE) method was developed to extract isoflavone. A uniform design was used to investigate the effect of the extraction pressure, extraction time, extraction temperature, and medicinal materials granularity on isoflavone extraction efficiency. The optimum conditions of extraction were as follows: 45 MPa extraction pressure, 50 ℃ extraction temperature, 4 h extraction time, 40 eyes medicinal materials granularity, and the extraction efficiency was (0.361±0.012)%. 相似文献
860.
The conductivity of a TiO2 cathode in the FFC process was studied by sintering and electrolyzing experiments. Sintered TiO2 cathode and electrochemical reduction of TiO2 were measured using X ray diffraction. Results show that changing the energy band structure of TiO2 via high temperature sintering can cause electric conduction vacancy. An electric double layer can be formed in molten salt. Ionization of oxygen atoms leads to formation of TiO2 x ionic structures. The ions infiltrate to the electrode in molten salt, increasing the number of conduction ions. The electrolyzing process proceeds smoothly, based on the integrated mechanism of activating the TiO2 cathode. The activated TiO2 cathode can be obtained by forming electric conduction vacancy at high temperature sintering, the TiO2 x ionic structure by electric double layer, and ions infiltrating to the interior of the electrode. 相似文献