摘要：
Sensors play an important role in shaping and monitoring human health.Exploration of methods to use Fiber Bragg Grating(FBG)with enhanced sensitivity has attracted great interest in the field of medical research.In this paper,a novel apodization function is proposed and performance evaluation and optimization of the same have been made.A comparison was conducted between various existing apodization functions and the proposed one based on optical characteristics and sensor parameters.The results evince the implementation of the proposed apodization function for vital sign measurement.The optical characteristics considered for evaluation are Peak Resonance Reflectivity level,Side Lobes Reflectivity level and FullWidth HalfMaximum(FWHM).The proposed novel apodization novel function has better FWHM,which is narrower than the FWHM of uniform FBG.Sensor characteristics like a quality parameter,detection accuracy and sensitivity also show improvement.The proposed novel apodization function is demonstrated to have a better shift in wavelength in terms of temperature and pulse measurement than the existing functions.The sensitivity of the proposed apodized function is enhanced with a Poly-dimethylsiloxane coating of varying thickness,which is 6 times and 5.14 times greater than uniform Fiber Bragg grating and FBG with the proposed novel apodization function,respectively,enhancing its utilization in the field of medicine.
摘要：
We present interesting application of artificial intelligence for investigating effect of the COVID-19 lockdown on 3-dimensional temperature variation across Nigeria(2°-15°E,4°-14°N),in equatorial Africa.Artificial neural networks were trained to learn time-series temperature variation patterns using radio occultation measurements of atmospheric temperature from the Constellation Observing System for Meteorology,Ionosphere,and Climate(COSMIC).Data used for training,validation and testing of the neural networks covered period prior to the lockdown.There was also an investigation into the viability of solar activity indicator(represented by the sunspot number)as an input for the process.The results indicated that including the sunspot number as an input for the training did not improve the network prediction accuracy.The trained network was then used to predict values for the lockdown period.Since the network was trained using pre-lockdown dataset,predictions from the network are regarded as expected temperatures,should there have been no lockdown.By comparing with the actual COSMIC measurements during the lockdown period,effects of the lockdown on atmospheric temperatures were deduced.In overall,the mean altitudinal temperatures rose by about 1.1°C above expected values during the lockdown.An altitudinal breakdown,at 1 km resolution,reveals that the values were typically below0.5°C at most of the altitudes,but exceeded 1°C at 28 and 29 km altitudes.The temperatures were also observed to drop below expected values at altitudes of 0-2 km,and 17-20 km.
摘要：
Two hypotheses of modern warming are considered:natural and anthro-pogenic.The probabilities of each of them are compared.It is proved that the hypothesis of natural warming is much more likely than the hypothesis of anthropogenic warming.It is shown that the displacement of the Sun from the center of mass of the solar system directly affects the temperature of the surface atmosphere in the synoptic regions of Eurasia.This result corresponds to the model of E.P.Borysenkov with variations of the solar constant or,equivalently,with variations of the Bond albedo.
摘要：
Based on the observation data of temperature in Wengyuan County from 1981 to 2021,the changing trends of annual average temperature,annual average maximum and minimum temperature,annual extreme maximum and minimum temperature,seasonal and monthly average temperature in Wengyuan County in the past 41 years were analyzed.The results show that the annual average temperature,annual average maximum and minimum temperature,and annual extreme maximum and minimum temperature in Wengyuan County in the past 41 years showed a fluctuating upward trend,which is consistent with the changing trend of global climate;the temperature rose obviously in winter and spring and slightly in summer;January was the coldest,while July was the hottest,and the average temperature from April to October was above 20.0°C.In general,the annual average temperature in Wengyuan County changed significantly in 1997.It was relatively cold before 1997 and became relatively warm after 1997.
摘要：
In work features of a hydrological regime of catchments of the river of the Pripyat in climate change are considered.Researches of meteorological characteristics of the given territory show the tendency to growth,both tem-peratures of air,and precipitation,evaporation from a surface of water and ground also show the tendency to increase.That is not unequivocally re-flected in change of a course of hydrological characteristics waters objects of territory.On a part of pools of the rivers the mid-annual runoff of water in the rivers in time tends to growth,and Change of levels of subsoil waters decreases for parts-on a turn-here,as a rule,tends a course in time oppo-site to a mid-annual runoff of water in the rivers.Change of the maximal temperature of water in the rivers in time repeats the tendency of a course of a runoff of water in them,i.e.at increase in a runoff of water in the riv-ers-the maximal temperature increases,and at reduction-decreases.The increase in temperature of a superficial component of a runoff of the rivers occurs because of the general increase in temperature of air in considered territory.Silt charge waters in all territory decreases,despite of increase in quantity of atmospheric precipitation and increases or reduction of a runoff of water in the rivers.The relationship between the water runoff layer and precipitation and soil moisture has a certain time delay.The average annual water temperature over time shows a tendency to increase at almost all stations,while the change in the maximum water temperature in rivers over time has a multidirectional tendency and to a greater extent depends on the change in water depth in the river,a decrease in high water maximums and frequent thaws,etc.The studies carried out show that the preservation of moisture in thick layers of soil(0 cm-100 cm)contributes to an increase in water flow in rivers and in the modern conditions of Polesie of Ukraine this will solve a number of problems with the provision of high-quality water resources for various industries and the population.
摘要：
The responses of Hongyang,Donghong and Jinhong varieties to temperature and precipitation were analyzed by observing the growth stages of different kiwifruit varieties in Longhe red cartridge kiwifruit base of Liuzhi Special Zone of Guizhou Province in 2021 and combining with the meteorological data of temperature and precipitation in the base in the same period.The results showed that Hongyang,Donghong and Jinhong all sprouted on February 1,and had the same response to temperature and precipitation.From germination to leaf spreading stage,Hongyang and Donghong had the same response to precipitation,while Donghong and Jinhong had the same response to temperature,but Jinhong needed 32.5 mm precipitation to meet its growth and development.From leaf spreading stage to budding stage,Hongyang and Donghong had similar responses to temperature and precipitation,while Jinhong needed average daily temperature of 16.5°Cand precipitation of 2.1 mm.The responses of the three varieties from budding to flowering to temperature and precipitation were consistent.From flowering to fruiting,Hongyang needed 19.9°Ctemperature and the least precipitation,while Jinhong needed the lowest temperature and the maximum precipitation.Donghong's response to temperature and precipitation was between Hongyang and Jinhong.During the period from fruit setting to fruit ripening and picking,Hongyang needed the least temperature and precipitation,while Donghong and Jinhong had the same response to temperature and precipitation.In the key period of fruit expansion of the three kiwifruit varieties in 2021,temperature and precipitation were the most suitable for fruit expansion.In short,red cartridge kiwifruit has a good response to temperature and precipitation in different growth stages,and it requires 201 d for Hongyang variety from germination to maturity and picking,211 d for Donghong variety and 218 d for Jinhong variety.
摘要：
The accelerated depletion of oil reserves and the often exorbitant cost of fossil fuels contribute to the development of fuels from renewable sources. The objective of this work is to analyze the influence of the properties of renewable fuels on their evaporation in natural convection, their combustion and their use in internal combustion engines. A summary of the various numerical and experimental works from the literature has been presented in this work. This work focuses on the numerical modelling of the natural convection evaporation of an isolated drop of a liquid fuel in natural convection. The transfers in the liquid and vapour phases are described by the conservation equations of mass and species, momentum and energy. The main feature of this work is the consideration of advection, azimuthal angle and thickness of the vapour phase of the drop during evaporation of the drop.
摘要：
Because the sound speeds of seawater and seafloor sediment both increase with temperature,the influence of tempera-ture on the bottom reflection characteristics of seafloor sediments needs to be investigated.Based on the calculation of the temperature-controlled experimental measurement data of typical seafloor surface sediment samples,the temperature-dependent acoustic characteristics,including acoustic impedance,acoustic impedance ratio between surface sediment and seawater,and reflection coefficient,were analyzed.The effective density fluid model was used to analyze and explain the reflection coefficient variation of surface sediments with temperature and predict the dispersion characteristics.Results show that the acoustic impedance of the seabed sediment increases with temperature,whereas the acoustic impedance ratio and acoustic reflection coefficient slightly decrease.The acoustic impedance,acoustic impedance ratio,and acoustic reflection coefficient of sandy,silty,and clayey sediments vary similarly with tem-perature variation.Moreover,the influence of temperature on these acoustic characteristics is independent of detection frequencies.
摘要：
Increasing the thermal efficiency in newly designed power stations is a priority.Keeping the efficiency in existed plants close to the rated one is of paramount importance.This research contributes to investigating the adverse effects of changes in condenser seawater coolant characteristics,(temperature,fouling,and salinity),on the thermal performance of a Boiling Water Reactor Nuclear Power Plant(BWR)NPP.A mathematical model is developed to relate seawater cooling temperature,fouling,and salinity to output power and thermal efficiency.The model also explains the impact of the condenser performance on power and efficiency.The thermal efficiency of the considered BWR NPP is reduced by 2.26%for a combined extreme increases in the condenser cooling seawater temperature,fouling factor of seawater and treated boiler feed water,and salinity by 10°C,0.0002,0.00001 m2K/W,and 100 g/kg,respectively.A rise in the condenser efficiency from 40%-100%results in an increase in the output power by 7.049%,and the thermal efficiency increases by about 2.62%.Conclusions are useful for reactor’s design.
摘要：
In order to clarify the charging characteristics of suspension droplets in ion flow field under different temperatures and humidity,the effective charging factor used to characterize the charging characteristics of suspension droplets is introduced in this paper,and a calculation method of charging factor is proposed based on the upstream finite element method(FEM).Then,the charging factor under different temperatures and humidity is calculated,and the analytic expression of the charging factor considering the influence of temperature and humidity is obtained by fitting the calculation results.The influence of suspension droplets on the ion flow field is analyzed.The results show that the charging factor is small and increases little with the relative humidity when the relative humidity is less than 60%,and the charging factor is large and increases rapidly with the relative humidity when the relative humidity is more than 60%.At the same relative humidity,the charging factor increases linearly with the temperature.The influence of charged suspension droplets on the ion flow field can be ignored when the relative humidity is less than 60%and must be considered under high temperature and humidity.The calculation method and analytic expression of the charging factor proposed in this paper can be used to model of ion flow field considering the influence of temperature and humidity and provide technical support for the construction of HVDC transmission lines across high temperature and humidity.
摘要：
Abstrac The questiones during the commissioning of HG-220／9.8-L·yml5circu1ating fluilized bed boiler and answeres are introduced，the causes ofhigh bed temperature and much desuperheat water flow are analyzed especiallyinthis paper.
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