In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and a...In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and antenna length are established according to the law of energy conservation and microwave antenna radiation theory. Modeling and simulation are carried out using IE3D software. The simulation results demonstrate that, with a fixed horn surface size, the shortened electric antenna length is the main factor leading to the improved heating uniformity. On the other hand, with a fixed antenna length and diminished surface size, the standing wave ratio decreases with the improved radiation efficiency. Furthermore, the efficiency of radiation drops with increased distance between the horn surface and the asphalt pavement. Microwave heating experiments are carried out using this type of heater. The temperature distribution of asphalt samples is obtained by the grid temperature measurement method, and Matlab simulation is performed. The experimental results are in good agreement with the simulation.展开更多
Objective The present study was designed to investigate the effects of subchronic low level microwave radiation (MWR) on cognitive function, heat shock protein 70 (HSP70) level and DNA damage in brain of Fischer r...Objective The present study was designed to investigate the effects of subchronic low level microwave radiation (MWR) on cognitive function, heat shock protein 70 (HSP70) level and DNA damage in brain of Fischer rats. Methods Experiments were performed on male Fischer rats exposed to microwave radiation for 90 days at three different frequencies: 900, 2800, and 2450 MHz. Animals were divided into 4 groups: Group I: Sham exposed, Group I1: animals exposed to microwave radiation at 900 MHz and specific absorption rate (SAR) 5.953 x 10-4 W/kg, Group II1: animals exposed to 1800 MHz at SAR 5.835 x 20-4 W/kg and Group IV: animals exposed to 2450 MHz at SAR 6.672 x 10-4 W/kg. All the animals were tested for cognitive function using elevated plus maze and Morris water maze at the end of the exposure period and subsequently sacrificed to collect brain tissues. HSP70 levels were estimated by ELISA and DNA damage was assessed using alkaline comet assay. Results Microwave exposure at 900-2450 MHz with SAR values as mentioned above lead to decline in cognitive function, increase in HSP70 level and DNA damage in brain. Conclusion The results of the present study suggest that low level microwave exposure at frequencies 900, 2800, and 2450 MHz may lead to hazardous effects on brain.展开更多
In applying the microwave radiation to extractive me- tallurgy,it is essential first of all to find the extent of microwave energy absorbed by various minerals experi- mentally.In this paper,more than 25 kinds of comm...In applying the microwave radiation to extractive me- tallurgy,it is essential first of all to find the extent of microwave energy absorbed by various minerals experi- mentally.In this paper,more than 25 kinds of common useful minerals have been individually irradiated by a 500 W,2450 MHz microwave source in an enclosed quartz crucible to ascertain their heating temperature in a definite time.In addition,the reduction and cbloridization tests were also carried out on the titanomagnetite concentrate and pentlandite with microwave heating,respectively. These experiments indicate potential applications of util- izing microwave energy in extractive metallurgy.展开更多
The satellite remote sensing has become a promising technique for detecting earthquake and fault activities. But it is still very difficult to exactly extract the earthquake anomaly from the complicated remote sensing...The satellite remote sensing has become a promising technique for detecting earthquake and fault activities. But it is still very difficult to exactly extract the earthquake anomaly from the complicated remote sensing information. This paper presented a two-step method to extract the seismic microwave radiation anomaly related with earthquake, which could eliminate the stable influence of geography, terrain, coversphere and seasons, as well as the random influence of weather. Furthermore the two-step method was applied to analyze the anomaly of Wenchuan earthquake based on the data of AMSR-E. Microwave radiation anomalies were effectively detected related to the main shock and aftershocks. The extracted microwave radiation variation showed general features of three-stage: the positive radiation anomaly appeared around the epicenter in the first stage, quiet variation in the second stage, and abnormal area gradually moved to the epicenter in the third stage. After the main shock the microwave radiation anomalies distributed along the Longmenshan faults, and the epicenters of aftershocks were coincident with the anomaly area in space.展开更多
With the rapid development of electronic technologies, anxiety regarding the potential health hazards induced by microwave radiation(MW) has been growing in recent years. The brain is one of the most sensitive target ...With the rapid development of electronic technologies, anxiety regarding the potential health hazards induced by microwave radiation(MW) has been growing in recent years. The brain is one of the most sensitive target organs for microwave radiation, where mitochondrial injury occurs earlier and more severely than in other organs. Energy metabolism disorders do play an important role during the process of microwave radiation-induced brain damage. In this paper, we will review the biological effects of microwave radiation, the features of brain energy supply and consumption and the effects of microwave radiation on mitochondrial energy metabolism and potential related mechanisms.展开更多
Ground-based microwave radiometers profilers(MWRPs)have been used in numerical weather prediction(NWP)systems and show different impacts on forecasts.Currently,there are around hundreds of ground-based MWPRs used in w...Ground-based microwave radiometers profilers(MWRPs)have been used in numerical weather prediction(NWP)systems and show different impacts on forecasts.Currently,there are around hundreds of ground-based MWPRs used in weather stations over China;however,the application of MWPRs in NWP systems is rather limited.In this work,two MWRP retrieved profiles were assimilated into the Weather Research and Forecasting(WRF)model for a rainstorm event that occurred in Beijing,China.The quality of temperature and humidity profiles retrieved from the MWRP was evaluated against radiosonde observations and showed the reliability of the two MWRP products.Then,comparisons between the measurements of ground-based rain gauges and the corresponding forecasted precipitation in different periods of the rainstorm were investigated.The results showed that assimilating the two MWRPs affected the distribution and intensity of rainfall,especially in the early stage of the rainstorm.With the development of the rainstorm,adding MWRP data showed only a slight influence on the precipitation during the stable and mature period of the rainstorm,since the two MWRP observations were too limited to affect the large area of heavy rainfall.展开更多
We propose a method to determine the optimal power of the microwave resonance transition that simultaneously improves the signal-to-noise ratio and reduces line width based on saturation broadening theory and experime...We propose a method to determine the optimal power of the microwave resonance transition that simultaneously improves the signal-to-noise ratio and reduces line width based on saturation broadening theory and experiment. Saturation broadening spectra of the ground state hyperfine transition of trapped 199Hg+ ions are measured and analyzed. The value of the optimal microwave power is obtained by using the proposed method and is verified. Rabi oscillations decay spectra of trapped 199Hg+ ions are observed and the optimal microwave irradiation time for the maximum transition signal intensity is determined. This work will help to improve the short-term frequency stability of the mercury ion microwave frequency standard.展开更多
Microwave radiation has been widely used in various fields,such as communication,industry,medical treatment,and military applications.Microwave radiation may cause injuries to both the structures and functions of vari...Microwave radiation has been widely used in various fields,such as communication,industry,medical treatment,and military applications.Microwave radiation may cause injuries to both the structures and functions of various organs,such as the brain,heart,reproductive organs,and endocrine organs,which endanger human health.Therefore,it is both theoretically and clinically important to conduct studies on the biological effects induced by microwave radiation.The successful establishment of injury models is of great importance to the reliability and reproducibility of these studies.In this article,we review the microwave exposure conditions,subjects used to establish injury models,the methods used for the assessment of the injuries,and the indicators implemented to evaluate the success of injury model establishment in studies on biological effects induced by microwave radiation.展开更多
Deviation exists between measured and simulated microwave radiometer sounding data. The bias results in low-accuracy atmospheric temperature and humidity profiles simulated by Back Propagation artificial neural networ...Deviation exists between measured and simulated microwave radiometer sounding data. The bias results in low-accuracy atmospheric temperature and humidity profiles simulated by Back Propagation artificial neural network models. This paper evaluated a retrieving atmospheric temperature and humidity profiles method by adopting an input data adjustment-based Back Propagation artificial neural networks model. First, the sounding data acquired at a Nanjing meteorological site in June 2014 were inputted into the Mono RTM Radiative transfer model to simulate atmospheric downwelling radiance at the 22 spectral channels from 22.234 GHz to 58.8 GHz, and we performed a comparison and analysis of the real observed data; an adjustment model for the measured microwave radiometer sounding data was built. Second, we simulated the sounding data of the 22 channels using the sounding data acquired at the site from 2011 to 2013. Based on the simulated rightness temperature data and the sounding data, BP neural network-based models were trained for the retrieval of atmospheric temperature, water vapor density and relative humidity profiles. Finally, we applied the adjustment model to the microwave radiometer sounding data collected in July 2014, generating the corrected data. After that, we inputted the corrected data into the BP neural network regression model to predict the atmospheric temperature, vapor density and relative humidity profile at 58 high levels from 0 to 10 km. We evaluated our model's effect by comparing its output with the real measured data and the microwave radiometer's own second-level product. The experiments showed that the inversion model improves atmospheric temperature and humidity profile retrieval accuracy; the atmospheric temperature RMS error is between 1 K and 2.0 K; the water vapor density's RMS error is between 0.2 g/m^3 and 1.93 g/m3; and the relative humidity's RMS error is between 2.5% and 18.6%.展开更多
In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimenta...In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimental animal models[1,2].展开更多
The dynamic mechanical properties of basalt affected by microwave were investigated by performing dynamic compressive tests using the SHPB system.Meanwhile,the thermal damage of the treated basalt was characterized by...The dynamic mechanical properties of basalt affected by microwave were investigated by performing dynamic compressive tests using the SHPB system.Meanwhile,the thermal damage of the treated basalt was characterized by ultrasonic non-destructive testing and nuclear magnetic resonance technology.The results show that with the increase of microwave power and exposure time,the P-wave velocity,dynamic compressive strength and elastic modulus decrease continuously,and the dynamic failure mode tends to be a more complex fracturing.The increase in microwave power and exposure time can enhance the temperature difference and transfer coefficient among minerals,hence intensifying the rock damage induced by thermal shock.展开更多
The activated carbon(AC)was prepared from Solidago Canadensis(SC),an alien invasive plant.The plant was firstly carbonized under nitrogen at 400 ℃ for 90 min in an electrical furnace,and then the carbonized product w...The activated carbon(AC)was prepared from Solidago Canadensis(SC),an alien invasive plant.The plant was firstly carbonized under nitrogen at 400 ℃ for 90 min in an electrical furnace,and then the carbonized product was activated with KOH through microwave radiation.Effects of KOH/C ratio,microwave power,microwave radiation time on the adsorption capacities and yield of AC were evaluated.It indicated that the optimum conditions were KOH/C ratio 2 g/g,microwave power 700 W,and microwave radiation time 6 min.The carbonation process of SC was analyzed by thermogravimetry(TG).The pore structural parameters and surface functional groups of the AC were characterized by nitrogen adsorption-desorption and Fourier Transformed Infrared Spectroscopy(FTIR),respectively.The activation yield,the surface area,the average pore size,and the average micropore size of AC prepared from optimum conditions were 53.75%,1 888 m2/g,0.567 nm,and 0.488 nm,respectively.The adsorption amounts of AC were 302.4 mg/g for methylene blue and 1 470.27 mg/g for iodine.展开更多
The rate processes of oxidative dearsenication of niccolite ore in microwave oven and in conventional furnace were measured with thermogravimetric technique.The results show that the dearsenication rate of niccolite o...The rate processes of oxidative dearsenication of niccolite ore in microwave oven and in conventional furnace were measured with thermogravimetric technique.The results show that the dearsenication rate of niccolite ore with microwave heating becomes faster than that with conventional heating. Under the conditions of an approximate linear heating and a definite air flow,the oxidative dearsenication process of niccolite ore is mainly controlled by interfacial chemical reaction.The ex- perimental data are in agreement with the kinetic model of linear heating as follows: In{[1-(1-α)^(1/3)]/T}= In (PAM)/(r_oρφE)(1-(RT)/E)-E/(RT) Thus the apparent activation energies of oxidative dearsenication of the niccolite ore containing differ- ent additions have been obtained from the model.展开更多
Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble co...Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble constant, H<sub>0</sub>, are important cosmologic constants. The goal is to accurately derive and demonstrate the inter-relationships of the CMB peak spectral radiance frequency, t<sub>P</sub>, and H<sub>0</sub> from neutron and hydrogen quantum data only. Methods: The harmonic neutron hypothesis, HNH, evaluates physical phenomena within a finite consecutive integer and exponential power law harmonic fraction series that are scaled by a fundamental frequency of the neutron as the exponent base. The CMB and the H<sub>0</sub> are derived from a previously published method used to derive t<sub>P</sub>. Their associated integer exponents are respectively +1/2, −3/4, and −128/35. Results: Precise mathematical relationships of these three constants are demonstrated. All of the derived values are within their known observational values. The derived and known values are: ν<sub>CMB</sub>, 160.041737 (06) × 10<sup>9</sup> Hz, ~160 × 10<sup>9</sup> Hz;2.72519 K, 2.72548 ± 0.00057 K, H<sub>0</sub> 2.29726666 (11) × 10<sup>−18</sup> s<sup>−1</sup>, ~2.3 × 10<sup>−18</sup> s<sup>−1</sup>;and t<sub>P</sub> 5.3911418 (3) × 10<sup>−44</sup> s, 5.39106 (32) × 10<sup>−44</sup> s. Conclusion: The cosmic fundamental constants t<sub>P</sub>, H<sub>0</sub>, and CMB are mathematically inter-related constants all defined by gravity. They are also directly derivable from the quantum properties of the neutron and hydrogen within a harmonic power law.展开更多
In this paper, it is shown that the laser radiation intensity required for complete ionization of vapors produced on an irradiated metal surface can be reduced by more than an order of magnitude through using pulsed l...In this paper, it is shown that the laser radiation intensity required for complete ionization of vapors produced on an irradiated metal surface can be reduced by more than an order of magnitude through using pulsed laser radiation in combination with microwave radiation.展开更多
Thirty cases of central type lung cancer complicated with airway obstruction were treated with intrabronchial microwave tissue coagulation (IMTC ) in combination with Ir 192 radiation (Ir192--IR ). The needle--shaped ...Thirty cases of central type lung cancer complicated with airway obstruction were treated with intrabronchial microwave tissue coagulation (IMTC ) in combination with Ir 192 radiation (Ir192--IR ). The needle--shaped microwave irradiator was modified by the authors. After the treatment, airway obstruction was completely released in 19 cases and partially released in 10. Only 1 case had no response. In 4 to 6 months after the treatment, 20 out of the 30 cases that were followed up presented with no bronchial bleeding, fistula formation or other complications. of the 20 cases, 10 showed complete remission and the other 10 showed partial remission.展开更多
Objective Lately, microwave radiation (MR) has been successfully used to cure a variety ofdiseases including oral mucosal diseases and oral tumors in stomatology. Preventive MR of precancerous lesionsfrom canceration ...Objective Lately, microwave radiation (MR) has been successfully used to cure a variety ofdiseases including oral mucosal diseases and oral tumors in stomatology. Preventive MR of precancerous lesionsfrom canceration is the goal of this study which had been rarely reported. Methods Between leukoplakia modelanimals and MR treated model animals, the cancer incidences were compared and the macroscopic and microscopicpathology were detailed. The functional parameters of the microwave apparatus were analysed to yield the optimumdata for future clinical use. Results The cancer blocking effect of MR was proved by the incidence of canceration3.5 times less frequent in MR treated animals. Conclusion Analysis of the macroscopic and microscopicpathology may disclose the mechanism of the therapeutic MR.展开更多
Recently,many researchers have focused on the usage of electromagnetic waves in oil production and well stimulation,but so far the effect of these waves on the fluid and rock interaction and its simultaneous effect wi...Recently,many researchers have focused on the usage of electromagnetic waves in oil production and well stimulation,but so far the effect of these waves on the fluid and rock interaction and its simultaneous effect with nanoparticles have not been investigated.Fluid-rock interaction is one of the most important factors affecting fluid distribution in the reservoirs.In this study,the oil reservoir rock wettability alteration under electromagnetic heating and the presence of nanoparticles has been investigated.Three nanoparticles of TiO_2,Fe_(3)O_(4),and TiO_2/Fe_(3)O_(4)have been utilized.TiO_2 nanoparticles are commercially available,and the other mentioned nanoparticles are synthesized via a co-precipitation method.Citric acid has been used to modify surfaces of nanoparticles and stabilize them in water as the base fluid.Also,the adsorption of the nanoparticles on the rock surface has been determined.In the next step,the amount of oil outflow from the rock has been measured and reported as the external fluid imbibition.In this process,the nanoparticle performance in wettability alteration was investigated using pH and inductively coupled plasma(ICP)analyses.To better understand the governing mechanisms,oil viscosity was measured by mixing the oil with nanoparticles and put under irradiation.The results reveal that the microwave has a great ability to reduce oil contact angle with carbonate rock.In the presence of0.2 wt%Fe_(3)O_(4)nanoparticles,the contact angle was reduced from 155°to 19°after 28 min of irradiation,indicating strong rock hydrophilicity.Furthermore,microwave irradiation on Fe_(3)O_(4)nanofluid extracts75%of the oil from the rock.With microwave radiation,the pH of the nanofluid increases and hence,more nanoparticles are adsorbed on the rock which subsequently causes more rock dissolution.The viscosity change results prove that there is an optimal irradiation time of 5 min in which oil viscosity reduces from 481 cP to 410 cP and then increases to 827 cP.Moreover,the application of further nanoparticles diminishes the oil viscosity at optimum irradiation time in which Fe_(3)O_(4)has the most oil viscosity reduction,representing 481 cP to 200 cP at 50%microwave power level.展开更多
The article presents the results of the experimental study that was devoted to determining the blocking influence of the solar microwave radiation on the process of biofilm formation in Gram-positive and Gram-negative...The article presents the results of the experimental study that was devoted to determining the blocking influence of the solar microwave radiation on the process of biofilm formation in Gram-positive and Gram-negative microorganisms. The microwave generator that allows simulating microwave “splashes” of the Sun in the frequency range (4.0 - 4.3 GHz) with the controlled intensity of radiation (from 50 μW/sm2 to 500 μW/sm2) was used for conducting this research. It is found out that the simulated solar radiation of the microwave range blocks the formation of the extracellular matrix by the opportunistic microorganisms. The results of this study confirm the hypothesis of the evolutionary nature of the leading role of the microwave radiation of the Sun in the life processes of organisms. The technology of the exposure on the microorganisms that was used in the experiment opens up the real prospects for reducing the persistent potential of microorganisms and improving the efficiency of the bacterial infections treatment.展开更多
We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba2Mg2Alx/2Crx/2Fe12-xO22 (x = 0, 0.5 and 1.0). The study is performed by means of a vector network ana...We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba2Mg2Alx/2Crx/2Fe12-xO22 (x = 0, 0.5 and 1.0). The study is performed by means of a vector network analyzer, Fourier transform infrared spectroscopy, a vibrating sample magnetometer and x-ray powder diffraction. Ba2Mg2Fe12O22 hexaferrite shows radiation loss of -37.25dB (99.999% loss) at frequency 9.81 GHz, which can be attributed to its high value of saturation magnetization, i.e., 22.08emu/g. Moreover, we obtain that magnetic properties have strong influence on the radiation losses.展开更多
基金The Key Project of Science and Technology of Ministry of Education(No.03081,105085)the SciTech Achievements Transformation Program of Jiangsu Province(No.BA2006068)
文摘In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and antenna length are established according to the law of energy conservation and microwave antenna radiation theory. Modeling and simulation are carried out using IE3D software. The simulation results demonstrate that, with a fixed horn surface size, the shortened electric antenna length is the main factor leading to the improved heating uniformity. On the other hand, with a fixed antenna length and diminished surface size, the standing wave ratio decreases with the improved radiation efficiency. Furthermore, the efficiency of radiation drops with increased distance between the horn surface and the asphalt pavement. Microwave heating experiments are carried out using this type of heater. The temperature distribution of asphalt samples is obtained by the grid temperature measurement method, and Matlab simulation is performed. The experimental results are in good agreement with the simulation.
基金Indian Council of Medical Research (ICMR),New Delhi for grant in the form of the extramural research project vide sanction letter No.5/8/4-4(env) 07-NCD-I dated 3-08-09One of the authors Pravin Suryakantrao Deshmukh is grateful to ICMR for Senior Research Fellowship (SRF) support
文摘Objective The present study was designed to investigate the effects of subchronic low level microwave radiation (MWR) on cognitive function, heat shock protein 70 (HSP70) level and DNA damage in brain of Fischer rats. Methods Experiments were performed on male Fischer rats exposed to microwave radiation for 90 days at three different frequencies: 900, 2800, and 2450 MHz. Animals were divided into 4 groups: Group I: Sham exposed, Group I1: animals exposed to microwave radiation at 900 MHz and specific absorption rate (SAR) 5.953 x 10-4 W/kg, Group II1: animals exposed to 1800 MHz at SAR 5.835 x 20-4 W/kg and Group IV: animals exposed to 2450 MHz at SAR 6.672 x 10-4 W/kg. All the animals were tested for cognitive function using elevated plus maze and Morris water maze at the end of the exposure period and subsequently sacrificed to collect brain tissues. HSP70 levels were estimated by ELISA and DNA damage was assessed using alkaline comet assay. Results Microwave exposure at 900-2450 MHz with SAR values as mentioned above lead to decline in cognitive function, increase in HSP70 level and DNA damage in brain. Conclusion The results of the present study suggest that low level microwave exposure at frequencies 900, 2800, and 2450 MHz may lead to hazardous effects on brain.
文摘In applying the microwave radiation to extractive me- tallurgy,it is essential first of all to find the extent of microwave energy absorbed by various minerals experi- mentally.In this paper,more than 25 kinds of common useful minerals have been individually irradiated by a 500 W,2450 MHz microwave source in an enclosed quartz crucible to ascertain their heating temperature in a definite time.In addition,the reduction and cbloridization tests were also carried out on the titanomagnetite concentrate and pentlandite with microwave heating,respectively. These experiments indicate potential applications of util- izing microwave energy in extractive metallurgy.
基金supported by the National Important Basic Research Project(No.2011CB707102)by the National Natural Science Foundation of China(No.41074127)
文摘The satellite remote sensing has become a promising technique for detecting earthquake and fault activities. But it is still very difficult to exactly extract the earthquake anomaly from the complicated remote sensing information. This paper presented a two-step method to extract the seismic microwave radiation anomaly related with earthquake, which could eliminate the stable influence of geography, terrain, coversphere and seasons, as well as the random influence of weather. Furthermore the two-step method was applied to analyze the anomaly of Wenchuan earthquake based on the data of AMSR-E. Microwave radiation anomalies were effectively detected related to the main shock and aftershocks. The extracted microwave radiation variation showed general features of three-stage: the positive radiation anomaly appeared around the epicenter in the first stage, quiet variation in the second stage, and abnormal area gradually moved to the epicenter in the third stage. After the main shock the microwave radiation anomalies distributed along the Longmenshan faults, and the epicenters of aftershocks were coincident with the anomaly area in space.
文摘With the rapid development of electronic technologies, anxiety regarding the potential health hazards induced by microwave radiation(MW) has been growing in recent years. The brain is one of the most sensitive target organs for microwave radiation, where mitochondrial injury occurs earlier and more severely than in other organs. Energy metabolism disorders do play an important role during the process of microwave radiation-induced brain damage. In this paper, we will review the biological effects of microwave radiation, the features of brain energy supply and consumption and the effects of microwave radiation on mitochondrial energy metabolism and potential related mechanisms.
基金This work was supported by the National Key R&D Program of China[grant number 2017YFC1501700]the National Natural Science Foundation of China[grant number 41575033].
文摘Ground-based microwave radiometers profilers(MWRPs)have been used in numerical weather prediction(NWP)systems and show different impacts on forecasts.Currently,there are around hundreds of ground-based MWPRs used in weather stations over China;however,the application of MWPRs in NWP systems is rather limited.In this work,two MWRP retrieved profiles were assimilated into the Weather Research and Forecasting(WRF)model for a rainstorm event that occurred in Beijing,China.The quality of temperature and humidity profiles retrieved from the MWRP was evaluated against radiosonde observations and showed the reliability of the two MWRP products.Then,comparisons between the measurements of ground-based rain gauges and the corresponding forecasted precipitation in different periods of the rainstorm were investigated.The results showed that assimilating the two MWRPs affected the distribution and intensity of rainfall,especially in the early stage of the rainstorm.With the development of the rainstorm,adding MWRP data showed only a slight influence on the precipitation during the stable and mature period of the rainstorm,since the two MWRP observations were too limited to affect the large area of heavy rainfall.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11074282 and 11474320
文摘We propose a method to determine the optimal power of the microwave resonance transition that simultaneously improves the signal-to-noise ratio and reduces line width based on saturation broadening theory and experiment. Saturation broadening spectra of the ground state hyperfine transition of trapped 199Hg+ ions are measured and analyzed. The value of the optimal microwave power is obtained by using the proposed method and is verified. Rabi oscillations decay spectra of trapped 199Hg+ ions are observed and the optimal microwave irradiation time for the maximum transition signal intensity is determined. This work will help to improve the short-term frequency stability of the mercury ion microwave frequency standard.
基金supported by the National Natural Science Foundation of China(61801506)。
文摘Microwave radiation has been widely used in various fields,such as communication,industry,medical treatment,and military applications.Microwave radiation may cause injuries to both the structures and functions of various organs,such as the brain,heart,reproductive organs,and endocrine organs,which endanger human health.Therefore,it is both theoretically and clinically important to conduct studies on the biological effects induced by microwave radiation.The successful establishment of injury models is of great importance to the reliability and reproducibility of these studies.In this article,we review the microwave exposure conditions,subjects used to establish injury models,the methods used for the assessment of the injuries,and the indicators implemented to evaluate the success of injury model establishment in studies on biological effects induced by microwave radiation.
基金National Key Research and Development Program of China(2017YFC1501704,2016YFA0600703)Projects of International Cooperation and Exchanges NSFC(NSFC-RCUK_STFC)(61661136005)+2 种基金Major State Basic Research Development Program of China(973 Program)(2013CB430101)Six Talent Peaks Project in Jiangsu Province(2015-JY-013)Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites,National Satellite Meteorological Center,China Meteorological Administration
文摘Deviation exists between measured and simulated microwave radiometer sounding data. The bias results in low-accuracy atmospheric temperature and humidity profiles simulated by Back Propagation artificial neural network models. This paper evaluated a retrieving atmospheric temperature and humidity profiles method by adopting an input data adjustment-based Back Propagation artificial neural networks model. First, the sounding data acquired at a Nanjing meteorological site in June 2014 were inputted into the Mono RTM Radiative transfer model to simulate atmospheric downwelling radiance at the 22 spectral channels from 22.234 GHz to 58.8 GHz, and we performed a comparison and analysis of the real observed data; an adjustment model for the measured microwave radiometer sounding data was built. Second, we simulated the sounding data of the 22 channels using the sounding data acquired at the site from 2011 to 2013. Based on the simulated rightness temperature data and the sounding data, BP neural network-based models were trained for the retrieval of atmospheric temperature, water vapor density and relative humidity profiles. Finally, we applied the adjustment model to the microwave radiometer sounding data collected in July 2014, generating the corrected data. After that, we inputted the corrected data into the BP neural network regression model to predict the atmospheric temperature, vapor density and relative humidity profile at 58 high levels from 0 to 10 km. We evaluated our model's effect by comparing its output with the real measured data and the microwave radiometer's own second-level product. The experiments showed that the inversion model improves atmospheric temperature and humidity profile retrieval accuracy; the atmospheric temperature RMS error is between 1 K and 2.0 K; the water vapor density's RMS error is between 0.2 g/m^3 and 1.93 g/m3; and the relative humidity's RMS error is between 2.5% and 18.6%.
基金supported by National Science Foundation of China[No.81172620]。
文摘In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimental animal models[1,2].
基金supported by the National Natural Science Foundation of China(Nos.51774325,41972283,11972378).
文摘The dynamic mechanical properties of basalt affected by microwave were investigated by performing dynamic compressive tests using the SHPB system.Meanwhile,the thermal damage of the treated basalt was characterized by ultrasonic non-destructive testing and nuclear magnetic resonance technology.The results show that with the increase of microwave power and exposure time,the P-wave velocity,dynamic compressive strength and elastic modulus decrease continuously,and the dynamic failure mode tends to be a more complex fracturing.The increase in microwave power and exposure time can enhance the temperature difference and transfer coefficient among minerals,hence intensifying the rock damage induced by thermal shock.
基金Shanghai Leading Academic Discipline Project,China(No.B604)
文摘The activated carbon(AC)was prepared from Solidago Canadensis(SC),an alien invasive plant.The plant was firstly carbonized under nitrogen at 400 ℃ for 90 min in an electrical furnace,and then the carbonized product was activated with KOH through microwave radiation.Effects of KOH/C ratio,microwave power,microwave radiation time on the adsorption capacities and yield of AC were evaluated.It indicated that the optimum conditions were KOH/C ratio 2 g/g,microwave power 700 W,and microwave radiation time 6 min.The carbonation process of SC was analyzed by thermogravimetry(TG).The pore structural parameters and surface functional groups of the AC were characterized by nitrogen adsorption-desorption and Fourier Transformed Infrared Spectroscopy(FTIR),respectively.The activation yield,the surface area,the average pore size,and the average micropore size of AC prepared from optimum conditions were 53.75%,1 888 m2/g,0.567 nm,and 0.488 nm,respectively.The adsorption amounts of AC were 302.4 mg/g for methylene blue and 1 470.27 mg/g for iodine.
文摘The rate processes of oxidative dearsenication of niccolite ore in microwave oven and in conventional furnace were measured with thermogravimetric technique.The results show that the dearsenication rate of niccolite ore with microwave heating becomes faster than that with conventional heating. Under the conditions of an approximate linear heating and a definite air flow,the oxidative dearsenication process of niccolite ore is mainly controlled by interfacial chemical reaction.The ex- perimental data are in agreement with the kinetic model of linear heating as follows: In{[1-(1-α)^(1/3)]/T}= In (PAM)/(r_oρφE)(1-(RT)/E)-E/(RT) Thus the apparent activation energies of oxidative dearsenication of the niccolite ore containing differ- ent additions have been obtained from the model.
文摘Purpose: The cosmic microwave background radiation, CMB, is fundamental to observational cosmology, and is believed to be a remnant from the Big Bang. The CMB, Planck time, t<sub>P</sub>, and the Hubble constant, H<sub>0</sub>, are important cosmologic constants. The goal is to accurately derive and demonstrate the inter-relationships of the CMB peak spectral radiance frequency, t<sub>P</sub>, and H<sub>0</sub> from neutron and hydrogen quantum data only. Methods: The harmonic neutron hypothesis, HNH, evaluates physical phenomena within a finite consecutive integer and exponential power law harmonic fraction series that are scaled by a fundamental frequency of the neutron as the exponent base. The CMB and the H<sub>0</sub> are derived from a previously published method used to derive t<sub>P</sub>. Their associated integer exponents are respectively +1/2, −3/4, and −128/35. Results: Precise mathematical relationships of these three constants are demonstrated. All of the derived values are within their known observational values. The derived and known values are: ν<sub>CMB</sub>, 160.041737 (06) × 10<sup>9</sup> Hz, ~160 × 10<sup>9</sup> Hz;2.72519 K, 2.72548 ± 0.00057 K, H<sub>0</sub> 2.29726666 (11) × 10<sup>−18</sup> s<sup>−1</sup>, ~2.3 × 10<sup>−18</sup> s<sup>−1</sup>;and t<sub>P</sub> 5.3911418 (3) × 10<sup>−44</sup> s, 5.39106 (32) × 10<sup>−44</sup> s. Conclusion: The cosmic fundamental constants t<sub>P</sub>, H<sub>0</sub>, and CMB are mathematically inter-related constants all defined by gravity. They are also directly derivable from the quantum properties of the neutron and hydrogen within a harmonic power law.
文摘In this paper, it is shown that the laser radiation intensity required for complete ionization of vapors produced on an irradiated metal surface can be reduced by more than an order of magnitude through using pulsed laser radiation in combination with microwave radiation.
文摘Thirty cases of central type lung cancer complicated with airway obstruction were treated with intrabronchial microwave tissue coagulation (IMTC ) in combination with Ir 192 radiation (Ir192--IR ). The needle--shaped microwave irradiator was modified by the authors. After the treatment, airway obstruction was completely released in 19 cases and partially released in 10. Only 1 case had no response. In 4 to 6 months after the treatment, 20 out of the 30 cases that were followed up presented with no bronchial bleeding, fistula formation or other complications. of the 20 cases, 10 showed complete remission and the other 10 showed partial remission.
文摘Objective Lately, microwave radiation (MR) has been successfully used to cure a variety ofdiseases including oral mucosal diseases and oral tumors in stomatology. Preventive MR of precancerous lesionsfrom canceration is the goal of this study which had been rarely reported. Methods Between leukoplakia modelanimals and MR treated model animals, the cancer incidences were compared and the macroscopic and microscopicpathology were detailed. The functional parameters of the microwave apparatus were analysed to yield the optimumdata for future clinical use. Results The cancer blocking effect of MR was proved by the incidence of canceration3.5 times less frequent in MR treated animals. Conclusion Analysis of the macroscopic and microscopicpathology may disclose the mechanism of the therapeutic MR.
基金the National Iranian South Oil Company(NISOC)for their financial support。
文摘Recently,many researchers have focused on the usage of electromagnetic waves in oil production and well stimulation,but so far the effect of these waves on the fluid and rock interaction and its simultaneous effect with nanoparticles have not been investigated.Fluid-rock interaction is one of the most important factors affecting fluid distribution in the reservoirs.In this study,the oil reservoir rock wettability alteration under electromagnetic heating and the presence of nanoparticles has been investigated.Three nanoparticles of TiO_2,Fe_(3)O_(4),and TiO_2/Fe_(3)O_(4)have been utilized.TiO_2 nanoparticles are commercially available,and the other mentioned nanoparticles are synthesized via a co-precipitation method.Citric acid has been used to modify surfaces of nanoparticles and stabilize them in water as the base fluid.Also,the adsorption of the nanoparticles on the rock surface has been determined.In the next step,the amount of oil outflow from the rock has been measured and reported as the external fluid imbibition.In this process,the nanoparticle performance in wettability alteration was investigated using pH and inductively coupled plasma(ICP)analyses.To better understand the governing mechanisms,oil viscosity was measured by mixing the oil with nanoparticles and put under irradiation.The results reveal that the microwave has a great ability to reduce oil contact angle with carbonate rock.In the presence of0.2 wt%Fe_(3)O_(4)nanoparticles,the contact angle was reduced from 155°to 19°after 28 min of irradiation,indicating strong rock hydrophilicity.Furthermore,microwave irradiation on Fe_(3)O_(4)nanofluid extracts75%of the oil from the rock.With microwave radiation,the pH of the nanofluid increases and hence,more nanoparticles are adsorbed on the rock which subsequently causes more rock dissolution.The viscosity change results prove that there is an optimal irradiation time of 5 min in which oil viscosity reduces from 481 cP to 410 cP and then increases to 827 cP.Moreover,the application of further nanoparticles diminishes the oil viscosity at optimum irradiation time in which Fe_(3)O_(4)has the most oil viscosity reduction,representing 481 cP to 200 cP at 50%microwave power level.
文摘The article presents the results of the experimental study that was devoted to determining the blocking influence of the solar microwave radiation on the process of biofilm formation in Gram-positive and Gram-negative microorganisms. The microwave generator that allows simulating microwave “splashes” of the Sun in the frequency range (4.0 - 4.3 GHz) with the controlled intensity of radiation (from 50 μW/sm2 to 500 μW/sm2) was used for conducting this research. It is found out that the simulated solar radiation of the microwave range blocks the formation of the extracellular matrix by the opportunistic microorganisms. The results of this study confirm the hypothesis of the evolutionary nature of the leading role of the microwave radiation of the Sun in the life processes of organisms. The technology of the exposure on the microorganisms that was used in the experiment opens up the real prospects for reducing the persistent potential of microorganisms and improving the efficiency of the bacterial infections treatment.
文摘We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba2Mg2Alx/2Crx/2Fe12-xO22 (x = 0, 0.5 and 1.0). The study is performed by means of a vector network analyzer, Fourier transform infrared spectroscopy, a vibrating sample magnetometer and x-ray powder diffraction. Ba2Mg2Fe12O22 hexaferrite shows radiation loss of -37.25dB (99.999% loss) at frequency 9.81 GHz, which can be attributed to its high value of saturation magnetization, i.e., 22.08emu/g. Moreover, we obtain that magnetic properties have strong influence on the radiation losses.