摘要 :
A weighing lysimeter measuring ETs of pot planted crops was developed with 150kg of weighing capacity and 150g of measurement precision. The hardware parts of the lysimeter includes a micro-controller, data collection and display ...
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A weighing lysimeter measuring ETs of pot planted crops was developed with 150kg of weighing capacity and 150g of measurement precision. The hardware parts of the lysimeter includes a micro-controller, data collection and display module, real time clock, storage module, communication and power modules. The circuits for these parts were designed. The data collection software for the host computer and the microcontroller of the lysimeter were written in C# and C respectively. The performance of this lysimeter was tested and the results showed that without human supervision, the micro-controller was able to automatically collect, display, store and communicate data through serial inten'ace to the host computer. The lysimeter was characterized by high stability and repeatability and its absolute and maximum relative error were 150g and 0.75%, respectively; and the ET results of pot planted crops obtained with the instrument were proved well matched with their actual ET of pot planted crops with time.
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摘要 :
Effects of Al and its content on high temperature tensile
behaviors and deformation mechanisms of Mg-xAl (x=2, 3, 4, 6
wt. %) alloys were investigated. Elongation-to-failure tests were
conducted at constant temperatures of 300,...
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Effects of Al and its content on high temperature tensile
behaviors and deformation mechanisms of Mg-xAl (x=2, 3, 4, 6
wt. %) alloys were investigated. Elongation-to-failure tests were
conducted at constant temperatures of 300, 350, 400, and 450℃,
and constant strain rates of 10~(-2) and 10~(-3) s~(-1). Strain-rate-change
tests were conducted at the same temperatures and varying strain
rate from 5×10~(-5) to 2×10~(-2) s~(-1). Experimental results show that
elongations of over 100% are achieved for each Mg-xAl alloy
when deformed at 450℃and 10~(-3) s~(-1), which are ascribed to an
evident drop of stress exponent due to Al addition. Particularly,
the stress exponent decreases with an increase of Al content,
indicating a potential variation of deformation mechanism. The
mechanisms were analyzed and discussed in terms of activation
energy, grain boundary sliding, and dislocation creep.
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摘要 :
A mathematical model of time-gated FLIM SPAD image sensors was established in behavioral level by MATLAB. The process of time-gated detection was simulated which includes photons emission, avalanche triggering and the restoration ...
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A mathematical model of time-gated FLIM SPAD image sensors was established in behavioral level by MATLAB. The process of time-gated detection was simulated which includes photons emission, avalanche triggering and the restoration of fluorescence lifetimes. A fluorescence lifetime map was used to model the virtual scene being photographed. In order to guide the design of FLIM SPAD image sensors, the impacts of some parameters of FLIM SPAD image sensors, such as DCR and timing jitter, were analyzed by the proposed model. The impacts of the above parameters on sensors quantified by the simulation results indicated that the FLIM SPAD image sensor can get a better performance with smaller DCR and shorter timing jitter.
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摘要 :
A mathematical model of time-gated FLIM SPAD image sensors was established in behavioral level by MATLAB. The process of time-gated detection was simulated which includes photons emission, avalanche triggering and the restoration ...
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A mathematical model of time-gated FLIM SPAD image sensors was established in behavioral level by MATLAB. The process of time-gated detection was simulated which includes photons emission, avalanche triggering and the restoration of fluorescence lifetimes. A fluorescence lifetime map was used to model the virtual scene being photographed. In order to guide the design of FLIM SPAD image sensors, the impacts of some parameters of FLIM SPAD image sensors, such as DCR and timing jitter, were analyzed by the proposed model. The impacts of the above parameters on sensors quantified by the simulation results indicated that the FLIM SPAD image sensor can get a better performance with smaller DCR and shorter timing jitter.
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摘要 :
Preparing process was presented and the influences of concentration of acetic acid, reaction temperature, the ratio of cerium carbonate and acetic acid, heat preservation time to the yield of cerium acetate were discussed. The cry...
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Preparing process was presented and the influences of concentration of acetic acid, reaction temperature, the ratio of cerium carbonate and acetic acid, heat preservation time to the yield of cerium acetate were discussed. The crystalline cerium acetate and rare earth acetate such as (La, Ce, Pr, Nd) (Ac)_3, (Ce, Pr, Nd) (Ac)_3, (Pr, Nd, Er, Y) (Ac)_3 and yttrium acetate were prepared under this condition. The shape, structure and composition of the crystals were determined by the methods of SEM, TG-DTA, X-ray diffraction and chemical analysis. The optimum prepared conditions of cerium acetate were described. This prepared process has characteristics such as simple process route, low cost, high yield, good quality, no pollution to environment, etc.
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摘要 :
Preparing process was presented and the influences of concentration of acetic acid, reaction temperature, the ratio of cerium carbonate and acetic acid, heat preservation time to the yield of cerium acetate were discussed. The cry...
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Preparing process was presented and the influences of concentration of acetic acid, reaction temperature, the ratio of cerium carbonate and acetic acid, heat preservation time to the yield of cerium acetate were discussed. The crystalline cerium acetate and rare earth acetate such as (La, Ce, Pr, Nd) (Ac)_3, (Ce, Pr, Nd) (Ac)_3, (Pr, Nd, Er, Y) (Ac)_3 and yttrium acetate were prepared under this condition. The shape, structure and composition of the crystals were determined by the methods of SEM, TG-DTA, X-ray diffraction and chemical analysis. The optimum prepared conditions of cerium acetate were described. This prepared process has characteristics such as simple process route, low cost, high yield, good quality, no pollution to environment, etc.
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摘要 :
Synthetic process is presented and influences of concentration and acidity of starting solution, addition quantity of ammonium nitrate, reaction temperature, reaction time on the yield of ammonium nitrate cerium(Ⅳ) are discussed....
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Synthetic process is presented and influences of concentration and acidity of starting solution, addition quantity of ammonium nitrate, reaction temperature, reaction time on the yield of ammonium nitrate cerium(Ⅳ) are discussed. The shape, structure and composition of crystal are determined by scanning electron microscope, thermogravimetry-differential thermal, X-ray diffraction and chemical analysis.
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摘要 :
Synthetic process is presented and influences of concentration and acidity of starting solution, addition quantity of ammonium nitrate, reaction temperature, reaction time on the yield of ammonium nitrate cerium(Ⅳ) are discussed....
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Synthetic process is presented and influences of concentration and acidity of starting solution, addition quantity of ammonium nitrate, reaction temperature, reaction time on the yield of ammonium nitrate cerium(Ⅳ) are discussed. The shape, structure and composition of crystal are determined by scanning electron microscope, thermogravimetry-differential thermal, X-ray diffraction and chemical analysis.
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摘要 :
Perovskite-type oxide SrFe_(0.5)Co_(0.5)O_(3-δ) was synthesized by citric acid method successfully. The structures of the catalyst were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM). Using Sr...
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Perovskite-type oxide SrFe_(0.5)Co_(0.5)O_(3-δ) was synthesized by citric acid method successfully. The structures of the catalyst were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM). Using SrCo_(0.5)Fe_(0.5)O_(3-δ) as photocatalyst, the photocatalytic properties of degrading gentian violet (GV) were evaluated under high pressure mercury lamp. SrFe_(0.5)Co_(0.5)O_(3-δ) exhibited higher photocatalytic activity than TiO_2, the degradation efficiency of gentian violet reached 98.09%. Several operational parameters were studied systematically, including irradiation time, photocatalyst dose, and initial gentian violet concentration. The kinetics of photocatalytic degradation of gentian violet fitted well pseudo first-order reaction with high regression coefficients R~2.
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