We demonstrate an experimental method for the in situ temperature measurement of atomic vapor using the saturated absorption spectrum. By separately manipulating the frequency of the pump and probe beams, the position...We demonstrate an experimental method for the in situ temperature measurement of atomic vapor using the saturated absorption spectrum. By separately manipulating the frequency of the pump and probe beams, the position of the crossover peaks can move along the spectrum. Different velocity classes of atoms contribute to the crossover during the movement. We study the relationship between the intensity change of peaks and vapor temperature. Our experimental result around room temperature shows a deviation of less than 0.3 K. Compared with traditional thermometry using absorption spectroscopy, higher accuracy can theoretically be achieved with real-time thermometry.展开更多
The function,features,and architecture of a robot that performs automatic temperature measurement and sampling applied on a 150-t AC electric arc furnace(EAF)production line of Baosteel were presented,and the key poin...The function,features,and architecture of a robot that performs automatic temperature measurement and sampling applied on a 150-t AC electric arc furnace(EAF)production line of Baosteel were presented,and the key points of design and revamping experience on the site layout,device protection,lance tool,probe container,measuring position control,and system safety were summarized.Furthermore,a valuable reference for the application of automatic temperature measuring and sampling robots in EAF steelmaking plants will be provided.展开更多
The plastic work-heat conversion coefficient is one key parameter for studying the work-heat conversion under dynamic deformation of materials. To explore this coefficient of 7075-T651 aluminum alloy under dynamic com...The plastic work-heat conversion coefficient is one key parameter for studying the work-heat conversion under dynamic deformation of materials. To explore this coefficient of 7075-T651 aluminum alloy under dynamic compression, dynamic compression experiments using the Hopkinson bar under four groups of strain rates were conducted, and the temperature signals were measured by constructing a transient infrared temperature measurement system. According to stress versus strain data as well as the corresponding temperature data obtained through the experiments, the influences of the strain and the strain rate on the coefficient of plastic work converted to heat were analyzed.The experimental results show that the coefficient of plastic work converted to heat of 7075-T651 aluminum alloy is not a constant at the range of 0.85–1 and is closely related to the strain and the strain rate. The change of internal structure of material under high strain rate reduces its energy storage capacity, and makes almost all plastic work convert into heat.展开更多
A new method for reconstructing the geological history of hydrocarbon accumulation is developed, which are constrained by U-Pb isotope age and clumped isotope((35)47) temperature of host minerals of hydrocarbon-bearin...A new method for reconstructing the geological history of hydrocarbon accumulation is developed, which are constrained by U-Pb isotope age and clumped isotope((35)47) temperature of host minerals of hydrocarbon-bearing inclusions. For constraining the time and depth of hydrocarbon accumulation by the laser in-situ U-Pb isotope age and clumped isotope temperature, there are two key steps:(1) Investigating feature, abundance and distribution patterns of liquid and gaseous hydrocarbon inclusions with optical microscopes.(2) Dating laser in-situ U-Pb isotope age and measuring clumped isotope temperature of the host minerals of hydrocarbon inclusions. These technologies have been applied for studying the stages of hydrocarbon accumulation in the Sinian Dengying gas reservoir in the paleo-uplift of the central Sichuan Basin. By dating the U-Pb isotope age and measuring the temperature of clumped isotope((35)47) of the host minerals of hydrocarbon inclusions in dolomite, three stages of hydrocarbon accumulation were identified:(1) Late Silurian: the first stage of oil accumulation at(416±23) Ma.(2) Late Permian to Early Triassic: the second stage of oil accumulation between(248±27) Ma and(246.3±1.5) Ma.(3) Yanshan to Himalayan period: gas accumulation between(115±69) Ma and(41±10) Ma. The reconstructed hydrocarbon accumulation history of the Dengying gas reservoir in the paleo-uplift of the central Sichuan Basin is highly consistent with the tectonic-burial history, basin thermal history and hydrocarbon generation history, indicating that the new method is a reliable way for reconstructing the hydrocarbon accumulation history.展开更多
A novel method based on wavelength-multiplexed line-of-sight absorption and profile fitting for nonuniform flow field measurement is reported. A wavelength scanning combing laser temperature and current modulation WMS...A novel method based on wavelength-multiplexed line-of-sight absorption and profile fitting for nonuniform flow field measurement is reported. A wavelength scanning combing laser temperature and current modulation WMS scheme is used to implement the wavelength-multi- plexed-profile fitting method. Second harmonic (2f) signal of eight H20 transitions features near 7,170 cm^-1 are measured in one period using a single tunable diode laser. Spatial resolved temperature distribution upon a CH4/air premixed flat flame burner is obtained. The result validates the feasibility of strategy for non-uniform flow field diagnostics by means of WMS-2f TDLAS.展开更多
This report describes a new method for measuring the temperature of the gas behind the reflected shock wave in shock tube, corresponding to the reservoir temperature of a shock tunnel, based on the chemical reaction o...This report describes a new method for measuring the temperature of the gas behind the reflected shock wave in shock tube, corresponding to the reservoir temperature of a shock tunnel, based on the chemical reaction of small amount of CF4 premixed in the test gas. The final product C2F4 is used as the temperature indicator, which is sampled and detected by a gas chromatography in the experiment. The detected concentration of C2F4 is correlated to the temperature of the reflected shock wave with the initial pressure P-1 and test time tau as parameters in the temperature range 3 300 K < T < 5 600 K, pressure range 5 kPa < P1 <12 kPa and tau similar or equal to 0.4 ms.展开更多
Under coronal conditions, the steady state rate-equations are used to calculate the inter-stage line ratios between Li-like ls22p(2P3/2)→ls22s(2S1/2) and He-like ls2p(1P1)→1s2(1S0) transitions for Ti in the electron...Under coronal conditions, the steady state rate-equations are used to calculate the inter-stage line ratios between Li-like ls22p(2P3/2)→ls22s(2S1/2) and He-like ls2p(1P1)→1s2(1S0) transitions for Ti in the electronic temperature ranges from 0.1keV to 20 keV. The results show that the temperature sensitivities are higher at the electronic temperature less than 5000 eV and the temperature sensitivities will decrease with the increase of electronic temperature.展开更多
Noninvasive technology for measuring instantaneously two-dimensional (2D) temperature distributions of flame using two-color planar laser induced fluorescence (PLIF) of OH is investigated. A calibration method is ...Noninvasive technology for measuring instantaneously two-dimensional (2D) temperature distributions of flame using two-color planar laser induced fluorescence (PLIF) of OH is investigated. A calibration method is researched and developed. This method is based on the calibration experiments with a laminar premixed flame and thermocouple, and avoids complex calculation and uncertainty of the spectrum parameters. Measurements for a flat burner at ambient temperature under atmospheric pressure are also presented; calibration results are used to diagnose a supersonic combustion in scramjet combustor. The conclusion indicates that this method is useful, and a better precision of calibration can be acquired by correcting the line shapes of the spectral lines and lasers.展开更多
Hot air and hot water treatments are practical,environmentally-friendly and non-chemical heating methods,which are widely used for postharvest insect control and quality preservation in agricultural products.Taking ap...Hot air and hot water treatments are practical,environmentally-friendly and non-chemical heating methods,which are widely used for postharvest insect control and quality preservation in agricultural products.Taking apple and pear as representative fruits,this study mainly analyzed influences of their thermal properties,diameter,and medium speed on the heating rates of fruits through their real-time measured temperatures at surface and center.Based on the reported thermal death kinetic models of the target codling moth,the minimum heating time was estimated to achieve 100%insect mortality.The results showed that the heating rates in fruits decreased gradually with the increasing depth from the surface to the center.With increasing heating time,the heating rate became small.The apple was heated faster than the pear.Hot water was more effective than hot air in treating fruits.Increasing hot air speed increased the heating rate but increasing water circulating speed had no clear effects on the heating rate.Based on the measured temperature-time history of the fruit center,the minimum heating time could be effectively determined for codling moth control through the estimated total equivalent thermal lethal time.The results could provide reliable validation data for the computer simulation and a scientific basis to improve the hot air and hot water treatments.展开更多
Resistance-to-time converter is always used for digital temperature measurement. An reset-set (RS) trigger based, relaxation oscillator based temperature measurement circuit, which is used to convert the change of t...Resistance-to-time converter is always used for digital temperature measurement. An reset-set (RS) trigger based, relaxation oscillator based temperature measurement circuit, which is used to convert the change of thermistor sensor into a frequency signal for later processing, has been presented in this article. The RS trigger, which is composed of two inverters designed with distinct logical transition threshold voltages by changing the metal-oxide-semiconductor (MOS) transistor gains, has the same function as the Schmitt trigger in the relaxation oscillator. The advantage of the RS trigger based Schmitt trigger is that it reduces the dependence to supply voltage, chip temperature, and process variation. This temperature measurement circuit has been applied in a clinical thermometer chip that can measure temperature to an accuracy of better than 0.05 ℃ down to 1.1 V battery voltage. It is fabricated in 0.5 μm double metal single poly complementary MOS (CMOS) process.展开更多
Temperature is one of the physical quantifies through which quantitative evaluation of the safety and reliability of industrial products can be achieved, and this has been used widely in practice. Under any environmen...Temperature is one of the physical quantifies through which quantitative evaluation of the safety and reliability of industrial products can be achieved, and this has been used widely in practice. Under any environmental condifion, regardless of the size of the object to be inspected, accurate and reliable measurement of temperature is of great practical importance. This review article presents a simple and direct method of temperature measurement, that can be applied to the local areas with difficulty in measuring the temperature by using normal thermometers. In the present article, two different application examples are demonstrated. One addresses the study of the electromigration of solders which are used as bonding metals in electronic devices (micro-structures). The application of the method to the shaft of a motor used in heavy industrial fields is explained as the second.展开更多
Chaotic Brillouin optical correlation domain analysis(BOCDA)has been proposed and experimentally demonstrated with the advantage of high spatial resolution.However,it faces the same issue of the temperature and strain...Chaotic Brillouin optical correlation domain analysis(BOCDA)has been proposed and experimentally demonstrated with the advantage of high spatial resolution.However,it faces the same issue of the temperature and strain cross-sensitivity.In this paper,the simultaneous measurement of temperature and strain can be preliminarily achieved by analyzing the two Brillouin frequencies of the chaotic laser in a large-effective-area fiber(LEAF).A temperature resolution of 1℃ and a strain resolution of 20μξ can be obtained with a spatial resolution of 3.9cm.The actual temperature and strain measurement errors are 0.37℃ and 10μξ,respectively,which are within the maximum measurement errors.展开更多
A Fourier analysis applied to the Mach-Zehnder interferometer (MZI) transmission spectrum for simultaneous refractive index (RI) and temperature measurements is proposed and experimentally demonstrated in this Let...A Fourier analysis applied to the Mach-Zehnder interferometer (MZI) transmission spectrum for simultaneous refractive index (RI) and temperature measurements is proposed and experimentally demonstrated in this Letter. In the fast Fourier transform (FFT) spectrum of the MZI transmission spectrum, several frequency components are generally observed, which means that the transmission spectrum of the MZI is formed by the superposition of some dual-mode interference (DMI) spectra, and each frequency component represents different core-cladding interferences. We can select some dominant frequency components in the FFT spectrum of the MZI transmission spectrum to take the inverse FFT (IFFT). Then, the corresponding DMI patterns can be obtained. Due to the shift of the wavelength of these DMI spectra with changes in the environmental parameters, we can use the coefficient matrix of these DMI spectra for multi-parameter sensing. In this Letter, two DMI patterns are separated from the resultant transmission spectrum of the MZI. As the RI and temperature change, the shifts of the two DMI patterns with respect to the RI and temperature will be observed. The sensitivities of the RI and temperature are -137.1806 nm/RIU (RI unit) and 0.0860 nm/℃, and -22.9955 nm/RIU and 0.0610 nm/℃ for the two DMIs. Accordingly, it can be used to simultaneously measure RI and temperature changes. The approach can eliminate the influence of multiple interferences and improve the accuracy of the sensor.展开更多
Biochemical reaction in microfluidic chip is sensitive to temperature.Temperature precise control in a small size device requires the temperature measurement with high measurement precision.Traditional temperature mea...Biochemical reaction in microfluidic chip is sensitive to temperature.Temperature precise control in a small size device requires the temperature measurement with high measurement precision.Traditional temperature measurement method usually measures the voltage drop of the thermistor,which is excited by a constant current source.This method requires the constant current source with high precision and stability.The output of the constant current source is influenced by environmental factors,resulting in a larger measurement error.To solve this problem,a proportion method,a two-layer filtering algorithm,and a power management technique were applied to improve the temperature measurement precision.The proportion method can reduce the low frequency fluctuation error.The two-layer filtering algorithm can reduce the high frequency fluctuation error furtherly.The power management technique used can improve the system stability.Through testing the temperature measurement system built,the experimental results show that the fluctuation error can be significantly decreased from 0.5◦C to 0.2◦C.展开更多
The embedded temperature sensing fabric was designed and woven according to the heat transmission model of the fabric.The temperature sensors were embedded into the multi-layered fabric that weft yarns were high-shrin...The embedded temperature sensing fabric was designed and woven according to the heat transmission model of the fabric.The temperature sensors were embedded into the multi-layered fabric that weft yarns were high-shrinkage polyester filaments.And the fabric was treated by a self-designed partial heat device,which can make the sensor be fixed in the fabric.The effects of yarn type,yarn linear density,fabric warp density,fabric structure,fabric layer numbers where the sensor is located,and the ambient temperature on the temperature measured value were investigated.The results demonstrated that when the higher thermal conductivity of yarns and lower density yarns were applied in the fabric as rawmaterials,they were favored to improve the measurement precision.Meanwhile,there were many factors that could make the measured values closer to the real value of the body,such as the plain fabric,the increased warp density of the fabric,the multiple-layer fabric where the sensor was located,the raised ambient testing temperature and the prolonged test time in the certain range.展开更多
BACKGROUND Fever is a common cause of medical consultation and hospital admission,particularly among children.Recently,the United Kingdom’s National Institute for Health and Care Excellence(NICE)updated its guideline...BACKGROUND Fever is a common cause of medical consultation and hospital admission,particularly among children.Recently,the United Kingdom’s National Institute for Health and Care Excellence(NICE)updated its guidelines for assessing fever in children under five years of age.The efficient assessment and management of children with fever are crucial for improving patient outcomes.AIM To evaluate fever assessment in hospitalized children and to assess its adherence with the NICE Fever in under 5s guideline.METHODS We conducted a retrospective cohort review of the electronic medical records of children under five years of age at the Department of Pediatrics,Salmaniya Medical Complex,Bahrain,between June and July 2023.Demographic data,vital signs during the first 48 h of admission,route of temperature measurement,and indications for admission were gathered.Fever was defined according to the NICE guideline.The children were divided into five groups according to their age(0-3 months,>3-6 months,>6-12 months,>12-36 months,and>36-60 months).Patients with and without fever were compared in terms of demography,indication for admission,route of temperature measurement,and other vital signs.Compliance with the NICE Fever in the under 5s guideline was assessed.Full compliance was defined as>95%,partial compliance as 70%-95%,and minimal compliance as≤69%.Pearson’sχ^(2),Student’s t test,the Mann-Whitney U test,and Spearman’s correlation coefficient(rs)were used for comparison.RESULTS Of the 136 patients reviewed,80(58.8%)were boys.The median age at admission was 14.2[interquartile range(IQR):1.7-44.4]months,with the most common age group being 36-60 months.Thirty-six(26.4%)patients had fever,and 100(73.6%)were afebrile.The commonest age group for febrile patients(>12-36 months)was older than the commonest age group for afebrile patients(0-3 months)(P=0.027).The median weight was 8.3(IQR:4.0-13.3)kg.Patients with fever had higher weight than those without fever[10.2(IQR:7.3-13.0)vs 7.1(IQR:3.8-13.3)kg,respectively](P=0.034).Gastrointestinal disease was the leading indication for hospital admission(n=47,34.6%).Patients with central nervous system diseases and fever of unknown etiology were more likely to be febrile(P=0.030 and P=0.011,respectively).The mean heart rate was higher in the febrile group than the afebrile group(140±24 vs 126±20 beats per minute,respectively)[P=0.001(confidence interval:5.8-21.9)]with a positive correlation between body temperature and heart rate,r=0.242,n=136,P=0.004.A higher proportion of febrile patients received paracetamol(n=35,81.3%)compared to the afebrile patients(n=8,18.6%)(P<0.001).The axillary route was the most commonly used for temperature measurements(n=40/42,95.2%),followed by the rectal route(n=2/42,4.8%).The department demonstrated full compliance with the NICE guideline for five criteria:the type of thermometer used,route and frequency of temperature measurement,frequency of heart rate measurement,and use of antipyretics as needed.Partial compliance was noted for two criteria,the threshold of fever at 38°C or more,and the respiratory rate assessment in febrile patients.Minimal compliance or no record was observed for the remaining three criteria;routine assessment of capillary refill,temperature reassessment 1-2 h after each antipyretic intake,and refraining from the use of tepid sponging.CONCLUSION This study showed that fever assessment in hospitalized children under five years of age was appropriate,but certain areas of adherence to the NICE guideline still need to be improved.展开更多
The temperature is one of the principal controlling parameters of oncological hyperthermia. However, local heating forms a complicated thermal distribution in space and has developed over time, too. The decisional fac...The temperature is one of the principal controlling parameters of oncological hyperthermia. However, local heating forms a complicated thermal distribution in space and has developed over time, too. The decisional factors are the heterogeneity of the targeted volume, the electrolyte perfusions controlled by thermal homeostasis, and the spreading of the heat energy with time. A further complication is that the energy absorption sharply changes by depth, so the spatiotemporal development of the temperature distribution requires specialized methods to control. Most of the temperature imaging facilities (thermography, radiometry, electric impedance tomography, etc.) are less precise than the medical practice needs. In contrast, precise point sensing (like thermocouples, thermistors, and fluoroptical methods) is invasive and measures only a discrete point in the robustly changing thermal map. The two most precise thermal imaging methods, computer tomography, and magnetic resonance are expensive and have numerous technical complications. Our objective is to show the complexity of the temperature distribution inside the human body, and offer a relatively simple and cheap method to visualize its spatiotemporal development. A novel emerging technology, the application of ultrasound microbubble contrast agents is a promising method for solving complicated tasks of thermal distribution deep inside the living body. Noteworthy, the temperature distribution does not determine the full hyperthermia process, nonthermal effects make considerable impact, too. Additionally to the difficulties to measure the thermal heterogeneity during hyperthermia in oncology, numerous nonthermal processes, molecular and structural changes are triggered by the incoming electromagnetic energy, which presently has no spatiotemporal visualization technique. Microbubble imaging has a suitable spatiotemporal thermal resolution, and also it is sensitive to nonthermal effects. Its application for characterization of the modulated electrohyperthermia (mEHT) may open a new theranostic facility, using the synergy of the thermal and nonthermal effects of the radiofrequency delivered energy. This complex approach gives facility to follow the mEHT processes, and the proposed microbubble ultrasound imaging has a particularly promising advantage sensing and acting also nonthermally, having potential to characterize the thermally conditioned nonthermal electromagnetic effects in oncologic hyperthermia. The mEHT combined with microbubble ultrasound images could be a robust theranostic method against cancer.展开更多
In a context of cryosphere degradation caused by climate warming,rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes.In order to improve the knowledge of this ...In a context of cryosphere degradation caused by climate warming,rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes.In order to improve the knowledge of this critical relationship,it is necessary to increase measurement capability of rock temperature and its variability in different lithological and slope/aspect conditions,and also to increase local scale studies,increasing the quality and the comparability of the data.This paper shows an example of metrological characterization of sensors used for rock temperature measurement in mountain regions,by means of the measurement uncertainty.Under such approach,data and results from temperature measurements carried out in the Bessanese high-elevation experimental site(Western European Alps)are illustrated.The procedures for the calibration and field characterization of sensors allow to measure temperature in different locations,depths and lithotypes,within 0.10°C of overall uncertainty.This work has highlighted that metrological traceability is fundamental to asses data quality and establish comparability among different measurements;that there are strong differences between air temperature and near-surface rock temperature;and that there are significant differences of rock temperature acquired in different aspect conditions.Finally,solar radiation,slope/aspect conditions and lithotype,seem to be the main driving factors of rock temperature.展开更多
An infrared colorimetric radiation thermometrical system was established based on the theory of optical radiation. The dynamic temperature history of fuel air explosive (FAE) was measured to obtain the temperature res...An infrared colorimetric radiation thermometrical system was established based on the theory of optical radiation. The dynamic temperature history of fuel air explosive (FAE) was measured to obtain the temperature responses of primary initiation FAE and secondary initiation FAE in real time. And the characteristics of their temperature history curves were compared and analyzed. The results show that the primary initiation FAE has higher explosion temperature and longer duration compared to the secondary initiation FAE.展开更多
The magnetic field is one of the most important parameters in solar physics,and a polarimeter is the key device to measure the solar magnetic field.Liquid crystals based Stokes polarimeter is a novel technology,and wi...The magnetic field is one of the most important parameters in solar physics,and a polarimeter is the key device to measure the solar magnetic field.Liquid crystals based Stokes polarimeter is a novel technology,and will be applied for magnetic field measurement in the first space-based solar observatory satellite developed by China,Advanced Space-based Solar Observatory.However,the liquid crystals based Stokes polarimeter in space is not a mature technology.Therefore,it is of great scientific significance to study the control method and characteristics of the device.The retardation produced by a liquid crystal variable retarder is sensitive to the temperature,and the retardation changes 0.09°per 0.10℃.The error in polarization measurement caused by this change is 0.016,which affects the accuracy of magnetic field measurement.In order to ensure the stability of its performance,this paper proposes a high-precision temperature control system for liquid crystals based Stokes polarimeter in space.In order to optimize the structure design and temperature control system,the temperature field of liquid crystals based Stokes polarimeter is analyzed by the finite element method,and the influence of light on the temperature field of the liquid crystal variable retarder is analyzed theoretically.By analyzing the principle of highprecision temperature measurement in space,a high-precision temperature measurement circuit based on integrated operational amplifier,programmable amplifier and 12 bit A/D is designed,and a high-precision space temperature control system is developed by applying the integral separation PI temperature control algorithm and PWM driving heating films.The experimental results show that the effect of temperature control is accurate and stable,whenever the liquid crystals based Stokes polarimeter is either in the air or vacuum.The temperature stability is within±0.0150℃,which demonstrates greatly improved stability for the liquid crystals based Stokes polarimeter.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 61703025)。
文摘We demonstrate an experimental method for the in situ temperature measurement of atomic vapor using the saturated absorption spectrum. By separately manipulating the frequency of the pump and probe beams, the position of the crossover peaks can move along the spectrum. Different velocity classes of atoms contribute to the crossover during the movement. We study the relationship between the intensity change of peaks and vapor temperature. Our experimental result around room temperature shows a deviation of less than 0.3 K. Compared with traditional thermometry using absorption spectroscopy, higher accuracy can theoretically be achieved with real-time thermometry.
文摘The function,features,and architecture of a robot that performs automatic temperature measurement and sampling applied on a 150-t AC electric arc furnace(EAF)production line of Baosteel were presented,and the key points of design and revamping experience on the site layout,device protection,lance tool,probe container,measuring position control,and system safety were summarized.Furthermore,a valuable reference for the application of automatic temperature measuring and sampling robots in EAF steelmaking plants will be provided.
基金supported by the National Nature Science Foundation of China (Grants 11132011 and 11472288)
文摘The plastic work-heat conversion coefficient is one key parameter for studying the work-heat conversion under dynamic deformation of materials. To explore this coefficient of 7075-T651 aluminum alloy under dynamic compression, dynamic compression experiments using the Hopkinson bar under four groups of strain rates were conducted, and the temperature signals were measured by constructing a transient infrared temperature measurement system. According to stress versus strain data as well as the corresponding temperature data obtained through the experiments, the influences of the strain and the strain rate on the coefficient of plastic work converted to heat were analyzed.The experimental results show that the coefficient of plastic work converted to heat of 7075-T651 aluminum alloy is not a constant at the range of 0.85–1 and is closely related to the strain and the strain rate. The change of internal structure of material under high strain rate reduces its energy storage capacity, and makes almost all plastic work convert into heat.
基金Supported by the China National Science and Technology Major Project(2016ZX05004-002)Basic Research and Strategic Reserve Technology Research Fund of Institutes Directly Under CNPC(2018D-5008-03)PetroChina Science and Technology Project(2019D-5009-16)。
文摘A new method for reconstructing the geological history of hydrocarbon accumulation is developed, which are constrained by U-Pb isotope age and clumped isotope((35)47) temperature of host minerals of hydrocarbon-bearing inclusions. For constraining the time and depth of hydrocarbon accumulation by the laser in-situ U-Pb isotope age and clumped isotope temperature, there are two key steps:(1) Investigating feature, abundance and distribution patterns of liquid and gaseous hydrocarbon inclusions with optical microscopes.(2) Dating laser in-situ U-Pb isotope age and measuring clumped isotope temperature of the host minerals of hydrocarbon inclusions. These technologies have been applied for studying the stages of hydrocarbon accumulation in the Sinian Dengying gas reservoir in the paleo-uplift of the central Sichuan Basin. By dating the U-Pb isotope age and measuring the temperature of clumped isotope((35)47) of the host minerals of hydrocarbon inclusions in dolomite, three stages of hydrocarbon accumulation were identified:(1) Late Silurian: the first stage of oil accumulation at(416±23) Ma.(2) Late Permian to Early Triassic: the second stage of oil accumulation between(248±27) Ma and(246.3±1.5) Ma.(3) Yanshan to Himalayan period: gas accumulation between(115±69) Ma and(41±10) Ma. The reconstructed hydrocarbon accumulation history of the Dengying gas reservoir in the paleo-uplift of the central Sichuan Basin is highly consistent with the tectonic-burial history, basin thermal history and hydrocarbon generation history, indicating that the new method is a reliable way for reconstructing the hydrocarbon accumulation history.
基金supported by the National Natural Science Foundation of China(10772188)
文摘A novel method based on wavelength-multiplexed line-of-sight absorption and profile fitting for nonuniform flow field measurement is reported. A wavelength scanning combing laser temperature and current modulation WMS scheme is used to implement the wavelength-multi- plexed-profile fitting method. Second harmonic (2f) signal of eight H20 transitions features near 7,170 cm^-1 are measured in one period using a single tunable diode laser. Spatial resolved temperature distribution upon a CH4/air premixed flat flame burner is obtained. The result validates the feasibility of strategy for non-uniform flow field diagnostics by means of WMS-2f TDLAS.
基金The project supported by the China Aerodynamics Project for Basic Researches(J13.5.2 ZK04)
文摘This report describes a new method for measuring the temperature of the gas behind the reflected shock wave in shock tube, corresponding to the reservoir temperature of a shock tunnel, based on the chemical reaction of small amount of CF4 premixed in the test gas. The final product C2F4 is used as the temperature indicator, which is sampled and detected by a gas chromatography in the experiment. The detected concentration of C2F4 is correlated to the temperature of the reflected shock wave with the initial pressure P-1 and test time tau as parameters in the temperature range 3 300 K < T < 5 600 K, pressure range 5 kPa < P1 <12 kPa and tau similar or equal to 0.4 ms.
文摘Under coronal conditions, the steady state rate-equations are used to calculate the inter-stage line ratios between Li-like ls22p(2P3/2)→ls22s(2S1/2) and He-like ls2p(1P1)→1s2(1S0) transitions for Ti in the electronic temperature ranges from 0.1keV to 20 keV. The results show that the temperature sensitivities are higher at the electronic temperature less than 5000 eV and the temperature sensitivities will decrease with the increase of electronic temperature.
基金supported by the National Natural Science Foundation of China under Grant No.11272338
文摘Noninvasive technology for measuring instantaneously two-dimensional (2D) temperature distributions of flame using two-color planar laser induced fluorescence (PLIF) of OH is investigated. A calibration method is researched and developed. This method is based on the calibration experiments with a laminar premixed flame and thermocouple, and avoids complex calculation and uncertainty of the spectrum parameters. Measurements for a flat burner at ambient temperature under atmospheric pressure are also presented; calibration results are used to diagnose a supersonic combustion in scramjet combustor. The conclusion indicates that this method is useful, and a better precision of calibration can be acquired by correcting the line shapes of the spectral lines and lasers.
基金grants from PhD Programs Foundation of Ministry of Education of China(20120204110022)Special Talent Fund of Northwest A&F University(No.Z111021101).
文摘Hot air and hot water treatments are practical,environmentally-friendly and non-chemical heating methods,which are widely used for postharvest insect control and quality preservation in agricultural products.Taking apple and pear as representative fruits,this study mainly analyzed influences of their thermal properties,diameter,and medium speed on the heating rates of fruits through their real-time measured temperatures at surface and center.Based on the reported thermal death kinetic models of the target codling moth,the minimum heating time was estimated to achieve 100%insect mortality.The results showed that the heating rates in fruits decreased gradually with the increasing depth from the surface to the center.With increasing heating time,the heating rate became small.The apple was heated faster than the pear.Hot water was more effective than hot air in treating fruits.Increasing hot air speed increased the heating rate but increasing water circulating speed had no clear effects on the heating rate.Based on the measured temperature-time history of the fruit center,the minimum heating time could be effectively determined for codling moth control through the estimated total equivalent thermal lethal time.The results could provide reliable validation data for the computer simulation and a scientific basis to improve the hot air and hot water treatments.
基金Natural Science Foundation of Hubei Province of China (226ABA080)
文摘Resistance-to-time converter is always used for digital temperature measurement. An reset-set (RS) trigger based, relaxation oscillator based temperature measurement circuit, which is used to convert the change of thermistor sensor into a frequency signal for later processing, has been presented in this article. The RS trigger, which is composed of two inverters designed with distinct logical transition threshold voltages by changing the metal-oxide-semiconductor (MOS) transistor gains, has the same function as the Schmitt trigger in the relaxation oscillator. The advantage of the RS trigger based Schmitt trigger is that it reduces the dependence to supply voltage, chip temperature, and process variation. This temperature measurement circuit has been applied in a clinical thermometer chip that can measure temperature to an accuracy of better than 0.05 ℃ down to 1.1 V battery voltage. It is fabricated in 0.5 μm double metal single poly complementary MOS (CMOS) process.
文摘Temperature is one of the physical quantifies through which quantitative evaluation of the safety and reliability of industrial products can be achieved, and this has been used widely in practice. Under any environmental condifion, regardless of the size of the object to be inspected, accurate and reliable measurement of temperature is of great practical importance. This review article presents a simple and direct method of temperature measurement, that can be applied to the local areas with difficulty in measuring the temperature by using normal thermometers. In the present article, two different application examples are demonstrated. One addresses the study of the electromigration of solders which are used as bonding metals in electronic devices (micro-structures). The application of the method to the shaft of a motor used in heavy industrial fields is explained as the second.
基金This work was supported in part by the National Natural Science Foundation of China(NSFC)(Grant Nos.61527819 and 61875146)in part by the Research Project Supported by Shanxi Province Youth Science and Technology Foundation(Grant No.201601D021069)+1 种基金in part by the Key Research and Development Program(High-Tech Field)of Shanxi Province(Grant Nos.201803D121064 and 201803D31044)in part by the Program for Sanjin Scholar,in part by the Transformation of Scientific and Technological Achievements Programs(TSTAP)of Higher Education Institutions in Shanxi,and in part by the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi.
文摘Chaotic Brillouin optical correlation domain analysis(BOCDA)has been proposed and experimentally demonstrated with the advantage of high spatial resolution.However,it faces the same issue of the temperature and strain cross-sensitivity.In this paper,the simultaneous measurement of temperature and strain can be preliminarily achieved by analyzing the two Brillouin frequencies of the chaotic laser in a large-effective-area fiber(LEAF).A temperature resolution of 1℃ and a strain resolution of 20μξ can be obtained with a spatial resolution of 3.9cm.The actual temperature and strain measurement errors are 0.37℃ and 10μξ,respectively,which are within the maximum measurement errors.
基金supported by the National Natural Science Foundation of China(Nos.61327012 and 61275088)the Research Foundation of Education Bureau of Shaanxi Province,China(No.14JS073)+2 种基金the Youth Science and Technology Innovation Fund of Xi’an Shiyou University(No.2014QN005)the Excellent MA Theses Fund of Xi’an Shiyou University(No.2014yp130816)the Graduate Student Innovation Fund(No.2014cx130842)
文摘A Fourier analysis applied to the Mach-Zehnder interferometer (MZI) transmission spectrum for simultaneous refractive index (RI) and temperature measurements is proposed and experimentally demonstrated in this Letter. In the fast Fourier transform (FFT) spectrum of the MZI transmission spectrum, several frequency components are generally observed, which means that the transmission spectrum of the MZI is formed by the superposition of some dual-mode interference (DMI) spectra, and each frequency component represents different core-cladding interferences. We can select some dominant frequency components in the FFT spectrum of the MZI transmission spectrum to take the inverse FFT (IFFT). Then, the corresponding DMI patterns can be obtained. Due to the shift of the wavelength of these DMI spectra with changes in the environmental parameters, we can use the coefficient matrix of these DMI spectra for multi-parameter sensing. In this Letter, two DMI patterns are separated from the resultant transmission spectrum of the MZI. As the RI and temperature change, the shifts of the two DMI patterns with respect to the RI and temperature will be observed. The sensitivities of the RI and temperature are -137.1806 nm/RIU (RI unit) and 0.0860 nm/℃, and -22.9955 nm/RIU and 0.0610 nm/℃ for the two DMIs. Accordingly, it can be used to simultaneously measure RI and temperature changes. The approach can eliminate the influence of multiple interferences and improve the accuracy of the sensor.
基金the Professional Technical Service Platform of Science and Technology Commission of Shanghai Municipality(No.19DZ2291103)。
文摘Biochemical reaction in microfluidic chip is sensitive to temperature.Temperature precise control in a small size device requires the temperature measurement with high measurement precision.Traditional temperature measurement method usually measures the voltage drop of the thermistor,which is excited by a constant current source.This method requires the constant current source with high precision and stability.The output of the constant current source is influenced by environmental factors,resulting in a larger measurement error.To solve this problem,a proportion method,a two-layer filtering algorithm,and a power management technique were applied to improve the temperature measurement precision.The proportion method can reduce the low frequency fluctuation error.The two-layer filtering algorithm can reduce the high frequency fluctuation error furtherly.The power management technique used can improve the system stability.Through testing the temperature measurement system built,the experimental results show that the fluctuation error can be significantly decreased from 0.5◦C to 0.2◦C.
基金Hubei Province Natural Science Fund Project,China(No.2013CFA090)
文摘The embedded temperature sensing fabric was designed and woven according to the heat transmission model of the fabric.The temperature sensors were embedded into the multi-layered fabric that weft yarns were high-shrinkage polyester filaments.And the fabric was treated by a self-designed partial heat device,which can make the sensor be fixed in the fabric.The effects of yarn type,yarn linear density,fabric warp density,fabric structure,fabric layer numbers where the sensor is located,and the ambient temperature on the temperature measured value were investigated.The results demonstrated that when the higher thermal conductivity of yarns and lower density yarns were applied in the fabric as rawmaterials,they were favored to improve the measurement precision.Meanwhile,there were many factors that could make the measured values closer to the real value of the body,such as the plain fabric,the increased warp density of the fabric,the multiple-layer fabric where the sensor was located,the raised ambient testing temperature and the prolonged test time in the certain range.
文摘BACKGROUND Fever is a common cause of medical consultation and hospital admission,particularly among children.Recently,the United Kingdom’s National Institute for Health and Care Excellence(NICE)updated its guidelines for assessing fever in children under five years of age.The efficient assessment and management of children with fever are crucial for improving patient outcomes.AIM To evaluate fever assessment in hospitalized children and to assess its adherence with the NICE Fever in under 5s guideline.METHODS We conducted a retrospective cohort review of the electronic medical records of children under five years of age at the Department of Pediatrics,Salmaniya Medical Complex,Bahrain,between June and July 2023.Demographic data,vital signs during the first 48 h of admission,route of temperature measurement,and indications for admission were gathered.Fever was defined according to the NICE guideline.The children were divided into five groups according to their age(0-3 months,>3-6 months,>6-12 months,>12-36 months,and>36-60 months).Patients with and without fever were compared in terms of demography,indication for admission,route of temperature measurement,and other vital signs.Compliance with the NICE Fever in the under 5s guideline was assessed.Full compliance was defined as>95%,partial compliance as 70%-95%,and minimal compliance as≤69%.Pearson’sχ^(2),Student’s t test,the Mann-Whitney U test,and Spearman’s correlation coefficient(rs)were used for comparison.RESULTS Of the 136 patients reviewed,80(58.8%)were boys.The median age at admission was 14.2[interquartile range(IQR):1.7-44.4]months,with the most common age group being 36-60 months.Thirty-six(26.4%)patients had fever,and 100(73.6%)were afebrile.The commonest age group for febrile patients(>12-36 months)was older than the commonest age group for afebrile patients(0-3 months)(P=0.027).The median weight was 8.3(IQR:4.0-13.3)kg.Patients with fever had higher weight than those without fever[10.2(IQR:7.3-13.0)vs 7.1(IQR:3.8-13.3)kg,respectively](P=0.034).Gastrointestinal disease was the leading indication for hospital admission(n=47,34.6%).Patients with central nervous system diseases and fever of unknown etiology were more likely to be febrile(P=0.030 and P=0.011,respectively).The mean heart rate was higher in the febrile group than the afebrile group(140±24 vs 126±20 beats per minute,respectively)[P=0.001(confidence interval:5.8-21.9)]with a positive correlation between body temperature and heart rate,r=0.242,n=136,P=0.004.A higher proportion of febrile patients received paracetamol(n=35,81.3%)compared to the afebrile patients(n=8,18.6%)(P<0.001).The axillary route was the most commonly used for temperature measurements(n=40/42,95.2%),followed by the rectal route(n=2/42,4.8%).The department demonstrated full compliance with the NICE guideline for five criteria:the type of thermometer used,route and frequency of temperature measurement,frequency of heart rate measurement,and use of antipyretics as needed.Partial compliance was noted for two criteria,the threshold of fever at 38°C or more,and the respiratory rate assessment in febrile patients.Minimal compliance or no record was observed for the remaining three criteria;routine assessment of capillary refill,temperature reassessment 1-2 h after each antipyretic intake,and refraining from the use of tepid sponging.CONCLUSION This study showed that fever assessment in hospitalized children under five years of age was appropriate,but certain areas of adherence to the NICE guideline still need to be improved.
文摘The temperature is one of the principal controlling parameters of oncological hyperthermia. However, local heating forms a complicated thermal distribution in space and has developed over time, too. The decisional factors are the heterogeneity of the targeted volume, the electrolyte perfusions controlled by thermal homeostasis, and the spreading of the heat energy with time. A further complication is that the energy absorption sharply changes by depth, so the spatiotemporal development of the temperature distribution requires specialized methods to control. Most of the temperature imaging facilities (thermography, radiometry, electric impedance tomography, etc.) are less precise than the medical practice needs. In contrast, precise point sensing (like thermocouples, thermistors, and fluoroptical methods) is invasive and measures only a discrete point in the robustly changing thermal map. The two most precise thermal imaging methods, computer tomography, and magnetic resonance are expensive and have numerous technical complications. Our objective is to show the complexity of the temperature distribution inside the human body, and offer a relatively simple and cheap method to visualize its spatiotemporal development. A novel emerging technology, the application of ultrasound microbubble contrast agents is a promising method for solving complicated tasks of thermal distribution deep inside the living body. Noteworthy, the temperature distribution does not determine the full hyperthermia process, nonthermal effects make considerable impact, too. Additionally to the difficulties to measure the thermal heterogeneity during hyperthermia in oncology, numerous nonthermal processes, molecular and structural changes are triggered by the incoming electromagnetic energy, which presently has no spatiotemporal visualization technique. Microbubble imaging has a suitable spatiotemporal thermal resolution, and also it is sensitive to nonthermal effects. Its application for characterization of the modulated electrohyperthermia (mEHT) may open a new theranostic facility, using the synergy of the thermal and nonthermal effects of the radiofrequency delivered energy. This complex approach gives facility to follow the mEHT processes, and the proposed microbubble ultrasound imaging has a particularly promising advantage sensing and acting also nonthermally, having potential to characterize the thermally conditioned nonthermal electromagnetic effects in oncologic hyperthermia. The mEHT combined with microbubble ultrasound images could be a robust theranostic method against cancer.
基金carried out in the framework of the Ri ST2 Project,cofinanced by Fondazione Cassa di Risparmio di Torino。
文摘In a context of cryosphere degradation caused by climate warming,rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes.In order to improve the knowledge of this critical relationship,it is necessary to increase measurement capability of rock temperature and its variability in different lithological and slope/aspect conditions,and also to increase local scale studies,increasing the quality and the comparability of the data.This paper shows an example of metrological characterization of sensors used for rock temperature measurement in mountain regions,by means of the measurement uncertainty.Under such approach,data and results from temperature measurements carried out in the Bessanese high-elevation experimental site(Western European Alps)are illustrated.The procedures for the calibration and field characterization of sensors allow to measure temperature in different locations,depths and lithotypes,within 0.10°C of overall uncertainty.This work has highlighted that metrological traceability is fundamental to asses data quality and establish comparability among different measurements;that there are strong differences between air temperature and near-surface rock temperature;and that there are significant differences of rock temperature acquired in different aspect conditions.Finally,solar radiation,slope/aspect conditions and lithotype,seem to be the main driving factors of rock temperature.
基金Sponsored by the National Natural Science Foundation of China (10772032)
文摘An infrared colorimetric radiation thermometrical system was established based on the theory of optical radiation. The dynamic temperature history of fuel air explosive (FAE) was measured to obtain the temperature responses of primary initiation FAE and secondary initiation FAE in real time. And the characteristics of their temperature history curves were compared and analyzed. The results show that the primary initiation FAE has higher explosion temperature and longer duration compared to the secondary initiation FAE.
基金the National Natural Science Foundation of China(Grant Nos.11427803,11427901 and 11773040)the Strategic Pioneer Program on Space Science,Chinese Academy of Sciences(CAS)(XDA04061002 and XDA15010800)the Public Technology Service Center,National Astronomical Observatories of CAS(829011V01)。
文摘The magnetic field is one of the most important parameters in solar physics,and a polarimeter is the key device to measure the solar magnetic field.Liquid crystals based Stokes polarimeter is a novel technology,and will be applied for magnetic field measurement in the first space-based solar observatory satellite developed by China,Advanced Space-based Solar Observatory.However,the liquid crystals based Stokes polarimeter in space is not a mature technology.Therefore,it is of great scientific significance to study the control method and characteristics of the device.The retardation produced by a liquid crystal variable retarder is sensitive to the temperature,and the retardation changes 0.09°per 0.10℃.The error in polarization measurement caused by this change is 0.016,which affects the accuracy of magnetic field measurement.In order to ensure the stability of its performance,this paper proposes a high-precision temperature control system for liquid crystals based Stokes polarimeter in space.In order to optimize the structure design and temperature control system,the temperature field of liquid crystals based Stokes polarimeter is analyzed by the finite element method,and the influence of light on the temperature field of the liquid crystal variable retarder is analyzed theoretically.By analyzing the principle of highprecision temperature measurement in space,a high-precision temperature measurement circuit based on integrated operational amplifier,programmable amplifier and 12 bit A/D is designed,and a high-precision space temperature control system is developed by applying the integral separation PI temperature control algorithm and PWM driving heating films.The experimental results show that the effect of temperature control is accurate and stable,whenever the liquid crystals based Stokes polarimeter is either in the air or vacuum.The temperature stability is within±0.0150℃,which demonstrates greatly improved stability for the liquid crystals based Stokes polarimeter.