The new improved approach for noise Figure are introduced in terms of the signal analysis and two terminal theory. Compared with the traditional method, it is convenient to improve the mismatch problem and reflection ...
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External pacemakers, also known as temporary pacemakers, have been widely used in clinical settings, significantly reducing patient mortality rates. Pacemaker analyzers are utilized to measure the parameters of pacema...
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ISBN:
(数字)9798331542856
ISBN:
(纸本)9798331542863
External pacemakers, also known as temporary pacemakers, have been widely used in clinical settings, significantly reducing patient mortality rates. Pacemaker analyzers are utilized to measure the parameters of pacemakers, ensuring their accuracy, as these parameters are critical to patient safety. Regular calibration is essential since pacemaker analyzers have been widely used. However, measurement institutions and published measurement standards rarely focus on the calibration of pacemaker analyzers. This paper designs a calibration method that uses a digital multimeter and a waveform generator to calibrate parameters such as internal resistance, current amplitude, pulse width, rate, and energy of the pacemaker analyzer. A program by C# in Visual Studio is developed to control the calibration instruments, therefore improving measurement efficiency. At the end of the paper, uncertainty evaluation of the calibration results is conducted.
A traceable accuracy test method of multi-instrument cooperative measurement system is studied. Here a precise angle dividing table and a linear guide with a laser interferometer are used as standards to test the coop...
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In this paper, a new corrugated horn antenna ranges from 40 GHz to 60GHz is simulated based on the static zone performance of the compact field, which satisfies measurement demands of feed antenna. After simulation an...
In this paper, a new corrugated horn antenna ranges from 40 GHz to 60GHz is simulated based on the static zone performance of the compact field, which satisfies measurement demands of feed antenna. After simulation and optimization, main parameters of the antenna, such as standing-wave coefficient, radiation pattern and radiation gain are highly improved, comparing with the traditional antenna.
Sulfation treatment has been widely used to promote the catalytic performance of ceria(CeO_(2))based catalysts for the selective catalytic reduction of NO by NH_(3)(NH_(3)-SCR of NO).Praseodymium oxide(PrO_(x)),anothe...
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Sulfation treatment has been widely used to promote the catalytic performance of ceria(CeO_(2))based catalysts for the selective catalytic reduction of NO by NH_(3)(NH_(3)-SCR of NO).Praseodymium oxide(PrO_(x)),another commonly used rare earth material with similar structural properties as CeO_(2),also shows satistactory redox properties due to the facile redox cycle of Pr^(3+)■Pr^(4+).In this work,gas phase sulfation treatment with varied duration was performed on PrO_(x) at 200℃,and the NH_(3)-SCR activity of sulfated PrO_(x) was *** on the results of systematic characterizations(e.g.,N_(2)-physisorption,NH_(3) oxidation,NO oxidation,in situ diffuse Fourier transform infrared spectroscopy),it is revealed that the catalytic performance of sulfated PrO_(x)is highly dependent on the sulfation time(or the amount of sulfate species deposited on PrO_(x)),which has a significant impact on the competitive reaction between NH_(3) oxidation and NH_(3)-SCR of NO,thus determining the NH_(3)-SCR activity of PrO_(x).This work provides new insight into tuning the interaction between PrO_(x) surface and reactants(NO,NH_(3))via sulfation treatment,which cam guide the design and application of PrO_(x)based catalysts for NH_(3)-SCR of NO in the future.
Antibiotics,as widely used antibacterial drug,exist in various environmental *** residues can affect biological metabolism and lead to bacterial resistance and the formation of antibiotic-resistance genes,posing a thr...
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Antibiotics,as widely used antibacterial drug,exist in various environmental *** residues can affect biological metabolism and lead to bacterial resistance and the formation of antibiotic-resistance genes,posing a threat to human health and ecological *** efficient detection methods for antibiotics and antibiotic-resistance genes has great environmental *** detection methods,due to their fast response,high sensitivity and specificity,and low-cost,are widely used in chemical and biological *** review first summarizes the pre-treatment methods for different types of environmental samples,and then focuses on the recent advances of fluorescence methods for the detection of antibiotics and antibiotic-resistance ***,main challenges and future research directions of fluorescence methods for antibiotic and antibiotic-resistance genes detection are *** review highlights the promising prospect of fluorescence methods in-situ detection and monitoring of antibiotics and antibiotic-resistance genes,and provides guidance for the construction of overall risk assessment system of environmental media.
Halogenated benzoquinones(HBQs)could cause bladder cancer,but there were few related studies on the generation and *** this study,the impact of different precursors,pH,bromide concentration,and algae-derived organic m...
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Halogenated benzoquinones(HBQs)could cause bladder cancer,but there were few related studies on the generation and *** this study,the impact of different precursors,pH,bromide concentration,and algae-derived organic matters on the formation of HBQs and the removal efficiency by activated carbon were *** was found that the chlorination of bisphenol A produced the most 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ),reaching 14.86μg/L at 1 hr,followed by tyrosine,2-chlorophenol,P-hydroxybenzoic acid,trichlorophenol,and *** production of 2,6-DCBQ increased first and then decreased from 0 to 36 hr(chlorination doses 0-20 mg/L),indicating that HBQs were unstable in ***(THMs)were detected during chlorination,and the concentration increased with prolongation of reaction time.2,6-DCBQ production decreased and 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ)production increased with increment bromide concentration and the bromide promoted the formation of *** production of 2,6-DCBQ decreased with increase of pH,and the maximum production was 141.38μg/L at pH of *** aeruginosa,Chlorella algae cells,and intracellular organic matters(IOM)could be chlorinated as potential precursors for *** most amount of 2,6-DCBQ was generated from algae cells of Microcystis aeruginosa,followed by Chlorella algae cells,Microcystis aeruginosa IOM,and Chlorella *** study compared the removal efficiency of HBQs by granular activated carbon(GAC)and columnar activated carbon(CAC)under different carbon doses and initial concentrations of *** was found that the removal efficiency by GAC(80.1%)was higher than that by CAC(51.8%),indicating that GAC has better control for HBQs.
Electromagnetic flowmeter is a reliable and high linearity speed type liquid flow meter. The accuracy of electromagnetic flowmeter is affected by the distribution of the measured fluid. The cross section of the usual ...
Electromagnetic flowmeter is a reliable and high linearity speed type liquid flow meter. The accuracy of electromagnetic flowmeter is affected by the distribution of the measured fluid. The cross section of the usual electromagnetic flow sensor is circular, which is to ensure that the flow field distribution in the sensor is symmetrical, but in many actual working conditions, it is necessary to use the electromagnetic flowmeter of the different diameter sensor to control the flow process. In this paper, the weight function of the electromagnetic flowmeter of the elliptical section sensor is analyzed, and the intentional conclusion is given. The weight function of the special-shaped sensor and the uneven distribution characteristics of the weight function are revealed, which provides a reference for optimizing the structure of the electromagnetic flowmeter and improving the measurement accuracy.
Persistent low temperatures in autumn and winter have a huge impact on crops,and greenhouses rely on solar radiation and heating equipment to meet the required indoor *** the energy cost of frequent operation of the a...
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Persistent low temperatures in autumn and winter have a huge impact on crops,and greenhouses rely on solar radiation and heating equipment to meet the required indoor *** the energy cost of frequent operation of the actuators is exceptionally *** relationship between greenhouse environmental control accuracy and energy consumption is one of the key issues faced in greenhouse *** this study,a non-linear model predictive control method with an improved objective function was *** improved objective function used tolerance intervals and boundary constraints to optimize the objective *** nonlinear model predictive control(NMPC)controller design was based on the wavelet neural network(WNN)data-driven model and applied the interior point method to solve the optimal solution of the objective function control,thus balancing the contradiction between energy consumption and control *** simulation results showed that the improved NMPC method reduced energy consumption by 21.02%and 9.54%compared with the model predictive control and regular NMPC,which proved the method achieved good results in a low-temperature *** research can provide an important reference for the field as it offers a more efficient approach to managing greenhouse climates,potentially leading to substantial energy savings and enhanced sustainability in agricultural practices.
Electromagnetic flowmeter (EMFM) plays an important role in many production processes such as industry, medicine and agriculture. According to the measurement principle, the traditional electromagnetic flowmeter must ...
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