Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG r...Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG receiving terminals.In 2006,China's first LNG receiving terminal,namely Dapeng LNG Receiving Terminal in Shenzhen,Guangdong Province,was put into operation,marking the beginning of the use of overseas natural gas in China.展开更多
Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without informat...Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without information loss. However, conventional receiving scheme is hard to have large dynamic range and ultra-wideband receiving simultaneously because of the analog-to-digital converter(ADC) dynamic range and sample rate limitations. In this paper, based on the modulated sampling and unlimited sampling, a novel receiving scheme is proposed to achieve large dynamic range and ultra-wideband receiving. Focusing on the single carrier signals, the proposed scheme only uses a single self-rest ADC(SR-ADC) with low sample rate, and it achieves large dynamic range and ultra-wideband receiving simultaneously. Two receiving scenarios are considered, and they are cooperative strong signal receiving and non-cooperative strong/weak signals receiving. In the cooperative receiving scenario, an improved fast recovery method is proposed to obtain the modulated sampling output. In the non-cooperative receiving scenario, the strong and weak signals with different carrier frequencies are considered, and the signal processing method can recover and estimate each signal. Simulation results show that the proposed scheme can realize large dynamic range and ultra-wideband receiving simultaneously when the input signal-to-noise(SNR) ratio is high.展开更多
An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagne...An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagnetic and circuit analysis is conducted to establish the magnetic induction intensity and equivalent circuit models for the wireless power transmission system.Combining these models involves using the number of layers in each dimension as the optimization variable.Constraints are imposed based on the normalized standard deviation of the receiving-end load power and spatial dimensions.At the same time,the optimization objective aims to maximize the average power of the receiving-end load.This process leads to formulating an optimization model for the RC.Finally,three-dimensional RCs with three different sets of parameters are wound,and the receiving-end load power of these coils is experimentally tested under various drive currents.The experimental values of the receiving-end load power exhibit a consistent trend with theoretical values,with experimental values consistently lower than theoretical values.The optimized coil parameters are determined by conducting comparative exper-iments,with a theoretical value of 4.6%for the normalized standard deviation of the receiving-end load power and an average experimental value of 9.6%.The study addressed the power supply issue of near-infrared capsule robots,which is important for early diagnosing and treating gastrointestinal diseases.展开更多
Currently, the selection of receiving traces in geometry design is mostly based on the horizontal layered medium hypothesis, which is unable to meet survey requirements in a complex area. This paper estimates the opti...Currently, the selection of receiving traces in geometry design is mostly based on the horizontal layered medium hypothesis, which is unable to meet survey requirements in a complex area. This paper estimates the optimal number of receiving traces in field geometry using a numerical simulation based on a field test conducted in previous research （Zhu et al., 2011）. A mathematical model is established for total energy and average efficiency energy using fixed trace spacing and optimal receiving traces are estimated. Seismic data acquired in a complex work area are used to verify the correctness of the proposed method. Results of model data calculations and actual data processing show that results are in agreement. This indicates that the proposed method is reasonable, correct, sufficiently scientific, and can be regarded as a novel method for use in seismic geometry design in complex geological regions.展开更多
Radar target probing and measurement are challenging tasks for Radio Frequency Simulation（RFS） with pulse radar signal. Due to the long-time duration of pulse radar signal and the limited space of anechoic chamber, ...Radar target probing and measurement are challenging tasks for Radio Frequency Simulation（RFS） with pulse radar signal. Due to the long-time duration of pulse radar signal and the limited space of anechoic chamber, the reflected signal returns before pulse radar signal is fully transmitted in RFS. As a consequence, the transmitted and reflected signals are coupled at the receiver. To handle this problem, the Interrupted Transmitting and Receiving（ITR） experiment system is constructed in this paper by dividing the pulse radar signal into sub-pulses. The target echo can be obtained by transmitting and receiving the sub-pulses intermittently. Furthermore, the principles of ITR are discussed and the target probing experiments are performed with the ITR system. It is demonstrated that the ITR system can overcome the coupling between the reflected and transmitted signals. Based on the target probing results, the performance of pulse radar target probing and measurement can be verified in RFS with the ITR system.展开更多
Hyperthyroidism refers to a clinical state that results from inappropriately hight hyroid hormone levels in the tissues;.Ⅰ-131 therapy plays a critical role and provides a remarkable curative effect in targeting thyr...Hyperthyroidism refers to a clinical state that results from inappropriately hight hyroid hormone levels in the tissues;.Ⅰ-131 therapy plays a critical role and provides a remarkable curative effect in targeting thyroid diseases. Thyroid cells can take up isotope I-131, which emits not only beta rays but also展开更多
Drug dependence is a serious global health problem.To assist individuals with drug addiction,China alone has established 678 Compulsory Detoxification Detention Centers （CDDCs） that treat over300,000i ndividuals who...Drug dependence is a serious global health problem.To assist individuals with drug addiction,China alone has established 678 Compulsory Detoxification Detention Centers （CDDCs） that treat over300,000i ndividuals who are required by national law to receive compulsory treatment;because community-based outpatient treatment failed.展开更多
Anthropogenic activities usually contaminate water environments, and have led to the eutrophication of many estuaries and shifts in microbial communities. In this study, the temporal and spatial changes of the microbi...Anthropogenic activities usually contaminate water environments, and have led to the eutrophication of many estuaries and shifts in microbial communities. In this study, the temporal and spatial changes of the microbial community in an industrial effluent receiving area in Hangzhou Bay were investigated by 454 pyrosequencing. The bacterial community showed higher richness and biodiversity than the archaeal community in all sediments. Proteobacteria dominated in the bacterial communities of all the samples; MarineGroupⅠand Methanomicrobia were the two dominant archaeal classes in the effluent receiving area. PCoA and AMOVA revealed strong seasonal but minor spatial changes in both bacterial and archaeal communities in the sediments. The seasonal changes of the bacterial community were less significant than those of the archaeal community, which mainly consisted of fluctuations in abundance of a large proportion of longstanding species rather than the appearance and disappearance of major archaeal species. Temperature was found to positively correlate with the dominant bacteria, Betaproteobacteria, and negatively correlate with the dominant archaea,MarineGroupⅠ; and might be the primary driving force for the seasonal variation of the microbial community.展开更多
To address the problem that it is difficult to detect an intermediate frequency(IF)signal at the receiving end of a communication system under extremely low signal-to-noise ratio(SNR)conditions,we propose a stochastic...To address the problem that it is difficult to detect an intermediate frequency(IF)signal at the receiving end of a communication system under extremely low signal-to-noise ratio(SNR)conditions,we propose a stochastic resonance(SR)-enhanced sine-signal detection method based on the sign function.By analyzing the SR mechanism of the sine signal and combining it with the characteristics of a dual-sequence frequency-hopping(DSFH)receiver,a periodic stationary solution of the Fokker-Planck equation(FPE)with a time parameter is obtained.The extreme point of the sine signal is selected as the decision time,and the force law of the electromagnetic particles is analyzed.A receiving structure based on the sign function is proposed to maximize the output difference of the system,and the value condition of the sign function is determined.In order to further improve the detection performance,in combination with the central-limit theorem,the sampling points are averaged N times,and the signal-detection problem is transformed into a hypothesis-testing problem under a Gaussian distribution.The theoretical analysis and simulation experiment results confirm that when N is 100 and the SNR is greater than 20 dB,the bit-error ratio(BER)is less than 1.5×10^(-2) under conditions in which the signal conforms to the optimal SR parameters.展开更多
In recent years,the semi-airborne transient electromagnetic method(SATEM)has been rapidly developed in China.Based on the theoretical development of the long grounding wire source transient electromagnetic method,the ...In recent years,the semi-airborne transient electromagnetic method(SATEM)has been rapidly developed in China.Based on the theoretical development of the long grounding wire source transient electromagnetic method,the unmanned aerial vehicle is equipped with the receiving coil to collect the electromagnetic response data at high altitude,making the TEM no longer affected by the terrain and greatly improving the actual working efficiency.However,its flight altitude has not been concerned for a long time.It is generally believed that the change of flight altitude only affects the amplitude of the received response.However,under special circumstances,the electromagnetic response data received at different flight altitudes in the near and far regions may lose the characteristic information of the target geological body.This paper simulates the low resistance thin layer model and analyzes the electromagnetic responses of different receiving heights under different transceiver distances.The results show that in the near area,when the flight altitude is higher than 30 meters or more,the received electromagnetic response will lose the information of the shallow lowresistance thin layer,while in the far area,the change of flight altitude has no obvious influence on the characteristic electromagnetic response information of the received geological body.展开更多
A novel technique based on sub-wavelength plasma structure effects on enhancement of RF communication signals on a receiving antenna is carried out in this paper in laboratory experiments and analyzed by corresponding...A novel technique based on sub-wavelength plasma structure effects on enhancement of RF communication signals on a receiving antenna is carried out in this paper in laboratory experiments and analyzed by corresponding numerical simulations.Considerable intensification on receiving signal gain up to -10 d B in comparison with that without the plasma modulation is observed experimentally in -1 GHz RF band,with an effective enhancement bandwidth of -340 MHz and the fractional bandwidth of -34%.Then,the optimal modulation parameters of plasma are further studied by a numerical simulation.It is shown that the number density,the layer thickness,and the collision frequency of the plasma,as well as the relative distance between the plasma layer and antenna synergistically affect the modulation.Compared to the metallic antenna with the same overall dimension,the modulated antenna covered by the subwavelength plasma structure features higher receiving efficiency and lower radar cross section in the studied RF band.The mechanism of the reception enhancement is further revealed by analyzing characteristics of electromagnetic scattering and electric field distribution in the subwavelength plasma layer.The results then exhibit scientific significance and application potential of sub-wavelength plasma modulation on compact receiving antennas with higher performance and better feature of radar stealth.展开更多
The influence of the selection of receiving slits and the use of standard samples with random orientation on the result of quantitative texture analysis was tested and discussed. The result proves that it will improve...The influence of the selection of receiving slits and the use of standard samples with random orientation on the result of quantitative texture analysis was tested and discussed. The result proves that it will improve the precision of the analysis to use proper slits and a randomly oriented standard sample. A simple method was given to interpolate the correction curves of random intensities.展开更多
The influence of close-up feed strategies on growth performance and dietary NE in light-weight feedlot steers during a 56 d receiving period was evaluated. Dietary treatments were formulated to meet the average metabo...The influence of close-up feed strategies on growth performance and dietary NE in light-weight feedlot steers during a 56 d receiving period was evaluated. Dietary treatments were formulated to meet the average metabolizable amino acid requirements of calves during 1) the initial 7 d;2) the initial 14 d;and 3) the initial 21 d following arrival into the feedlot, assuming average interval DMI of 2.8, 3.0, and 3.6 kg/d, respectively. Thereafter, all steers received dietary treatment 3. Fish meal was the source of supplemental protein. One hundred eight medium-framed crossbred steers (168.4 ± 5.0 kg) were blocked by weight and assigned to 18 pen groups (6 steers per pen). P-value (≤0.10) was considered as statistically significant. Daily weight gain (linear effect, P = 0.09) and gain efficiency (linear effect, P = 0.08) decreased as the close-up interval increased. DMI was not influenced by feeding program (P = 0.46). The ratio of observed to expected dietary NEm (linear effect P = 0.06) and NEg (linear effect, P = 0.05) decreased as length of close-up interval increased. Morbidity was low (18%) and not affected (P > 0.40) by dietary treatments. It is concluded that the addition of a close-up diet formulated to meet the metabolizable amino acid requirements of shipping stressed calves during the initial 7 d in the feedlot, when feed intakes are comparatively low, will have long-term beneficial effect on cattle growth performance and dietary NE.展开更多
Taking 13 water-receiving areas on the East Route of the South-to-North Water Diversion Project(ERSNWDP)in Shandong Province as the study area,and comparing it with Jiangsu Province on the ERSNWDP and the Middle Route...Taking 13 water-receiving areas on the East Route of the South-to-North Water Diversion Project(ERSNWDP)in Shandong Province as the study area,and comparing it with Jiangsu Province on the ERSNWDP and the Middle Route of the South-to-North(MRSNWDP),the current water-saving potential of the water-receiving areas within the municipalities of Shandong was analyzed.Different water-saving scenarios were constructed and analyzed with key water-saving indexes in various industries.These indexes include the effective utilization coefficient of farmland irrigation water,total water consumption of industrial sectors with an added value of over 10000 RMB,average leakage rate of the urban public water supply pipe network and the penetration rate of water-saving appliances.Based on the scenarios,comprehensive water-saving potential of the 13 water-receiving area cities was calculated.The results show that the water-saving potential of the study area is at a relative high level.However,some cities still have a certain amount of water-saving potential for agriculture and industry to be elevated.Under the recommended water-saving scenario,the water-saving potential is 1.134 billion m3,accounting for 5.33%of the current total water consumption,of which 460 million m3 is in agriculture,600 million m3 in industry,is and 74.20 million m3 in urban domestic sector.Comprehensive water-saving measures for the study area were proposed from the aspects of agricultural,industrial and domestic water uses.Agricultural and industrial water saving are more significant.The major cities for agricultural water saving include Jining City,Heze City,Weifang City and Jinan City;the focus cities of industrial water saving mainly include Weihai City,Jining City and Qingdao City and etc.;the key water-saving areas for urban use mainly include Zaozhuang City,Jining City and Heze City.展开更多
Designing an Ethernet switch that can assure normal interaction of protocol packets between switches in a network environment of massive traffic is an important matter. Taking the L3 Ethernet switch based on Applicati...Designing an Ethernet switch that can assure normal interaction of protocol packets between switches in a network environment of massive traffic is an important matter. Taking the L3 Ethernet switch based on Application Specific Integrated Circuit (ASIC) as an example,this article analyzes several typical issues about packet receiving and sending by the CPU in a multi-progress environment,including CPU load,software and hardware queue settings,and communication mechanism between CPU and the switch chip. This article gives solutions to these issues mentioned above. The solutions are applicable to Network Processor (NP) issues as well.展开更多
The era of mobile Internet is coming, broadband digital communication technology is in the stage of continuous development and progress, with us moving towards the era of mobile Internet. This paper first analyzes the...The era of mobile Internet is coming, broadband digital communication technology is in the stage of continuous development and progress, with us moving towards the era of mobile Internet. This paper first analyzes the connotation and characteristics of broadband digital communication technology, then analyzes the concept of signaling and multi-channel communication technology, establishes a wide range of digital communication receiving channel model that can perform high performance, and discusses simulation. Finally, in view of this communication technology, the development of the possible realization of their own prospects in the future, for the development of broadband digital communication technology and practical application to provide relevant data support.展开更多
I feel that this award was not made to me as a man,but to mywork—a life s work in the agony and sweat of the human spirit,not for glory and least of all for profit,but to create out of thematerials of the human spiri...I feel that this award was not made to me as a man,but to mywork—a life s work in the agony and sweat of the human spirit,not for glory and least of all for profit,but to create out of thematerials of the human spirit something which did not exist before,sothis award is only mine in trust.It will not be difficult to fred a dedi-cation for the money part of it commensurate with the purpose andsignificance of its origin.But I would like to do the same with the ac-claim too,by using this moment as a ...展开更多
The receiving response of towed line array to the noise radiated from the tow ship is investigated through normal mode modeling and computer simulation. The phenomenon that the maximum output of the towed line array i...The receiving response of towed line array to the noise radiated from the tow ship is investigated through normal mode modeling and computer simulation. The phenomenon that the maximum output of the towed line array is away from the endfire direction towards the tow ship is explained. The result is important for the understanding of the phenomenon and also for the application research concerning the suppression of the noise from the tow ship as well as adequate application of towed array techniques in shallow water.展开更多
The contact face and shock wave motion in an open ends receiving tube of gas wave refrigerator are investigated numerically and experimentally. The results show that, velocity of the contact face rises rapidly as gas ...The contact face and shock wave motion in an open ends receiving tube of gas wave refrigerator are investigated numerically and experimentally. The results show that, velocity of the contact face rises rapidly as gas is injected into the receiving tube, and drops sharply after a steady propagation. However, velocity of the shock wave in the tube is almost linear. With increasing of inlet pressure, velocity of the shock wave and steady velocity of contact face also increase. In addition, time and distance of contact face propagation in the receiving tube become longer.展开更多
文摘Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG receiving terminals.In 2006,China's first LNG receiving terminal,namely Dapeng LNG Receiving Terminal in Shenzhen,Guangdong Province,was put into operation,marking the beginning of the use of overseas natural gas in China.
文摘Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without information loss. However, conventional receiving scheme is hard to have large dynamic range and ultra-wideband receiving simultaneously because of the analog-to-digital converter(ADC) dynamic range and sample rate limitations. In this paper, based on the modulated sampling and unlimited sampling, a novel receiving scheme is proposed to achieve large dynamic range and ultra-wideband receiving. Focusing on the single carrier signals, the proposed scheme only uses a single self-rest ADC(SR-ADC) with low sample rate, and it achieves large dynamic range and ultra-wideband receiving simultaneously. Two receiving scenarios are considered, and they are cooperative strong signal receiving and non-cooperative strong/weak signals receiving. In the cooperative receiving scenario, an improved fast recovery method is proposed to obtain the modulated sampling output. In the non-cooperative receiving scenario, the strong and weak signals with different carrier frequencies are considered, and the signal processing method can recover and estimate each signal. Simulation results show that the proposed scheme can realize large dynamic range and ultra-wideband receiving simultaneously when the input signal-to-noise(SNR) ratio is high.
基金the Project of the Science and Technology Commission of Shanghai Municipality(No.20142201300)the National Facility for Translational Medicine(Shanghai)Open Project Foundation(No.TMSK-2021-302)the China Postdoctoral Science Foundation(No.2023M732267)。
文摘An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagnetic and circuit analysis is conducted to establish the magnetic induction intensity and equivalent circuit models for the wireless power transmission system.Combining these models involves using the number of layers in each dimension as the optimization variable.Constraints are imposed based on the normalized standard deviation of the receiving-end load power and spatial dimensions.At the same time,the optimization objective aims to maximize the average power of the receiving-end load.This process leads to formulating an optimization model for the RC.Finally,three-dimensional RCs with three different sets of parameters are wound,and the receiving-end load power of these coils is experimentally tested under various drive currents.The experimental values of the receiving-end load power exhibit a consistent trend with theoretical values,with experimental values consistently lower than theoretical values.The optimized coil parameters are determined by conducting comparative exper-iments,with a theoretical value of 4.6%for the normalized standard deviation of the receiving-end load power and an average experimental value of 9.6%.The study addressed the power supply issue of near-infrared capsule robots,which is important for early diagnosing and treating gastrointestinal diseases.
基金supported by the National Natural Science Foundation of China(No.41304115)National Key S&T Special Projects(No.2016ZX050 24001-003)+2 种基金Open Fund for Sichuan Province Key Laboratory of Natural Gas Geology(No.2015trqdz02)the Research Project,CNPC(No.2016A-33)"Young and Middle-aged Key Teachers"Training Program in Southwest Petroleum University
文摘Currently, the selection of receiving traces in geometry design is mostly based on the horizontal layered medium hypothesis, which is unable to meet survey requirements in a complex area. This paper estimates the optimal number of receiving traces in field geometry using a numerical simulation based on a field test conducted in previous research （Zhu et al., 2011）. A mathematical model is established for total energy and average efficiency energy using fixed trace spacing and optimal receiving traces are estimated. Seismic data acquired in a complex work area are used to verify the correctness of the proposed method. Results of model data calculations and actual data processing show that results are in agreement. This indicates that the proposed method is reasonable, correct, sufficiently scientific, and can be regarded as a novel method for use in seismic geometry design in complex geological regions.
基金supported in part by the National Natural Science Foundation of China(Nos.61101180,61401491 and 61490692)
文摘Radar target probing and measurement are challenging tasks for Radio Frequency Simulation（RFS） with pulse radar signal. Due to the long-time duration of pulse radar signal and the limited space of anechoic chamber, the reflected signal returns before pulse radar signal is fully transmitted in RFS. As a consequence, the transmitted and reflected signals are coupled at the receiver. To handle this problem, the Interrupted Transmitting and Receiving（ITR） experiment system is constructed in this paper by dividing the pulse radar signal into sub-pulses. The target echo can be obtained by transmitting and receiving the sub-pulses intermittently. Furthermore, the principles of ITR are discussed and the target probing experiments are performed with the ITR system. It is demonstrated that the ITR system can overcome the coupling between the reflected and transmitted signals. Based on the target probing results, the performance of pulse radar target probing and measurement can be verified in RFS with the ITR system.
基金supported by a fund from the Key Project of Natural Science Foundation of Tianjin [16JCZDJC36100]Medical and Health Technology Innovation Project of the Chinese Academy of Medical Sciences [2017-I2M-1-016]+2 种基金Fundamental Research Funds for the Central Universities [3332018116]PUMC Youth Fund [3332015101]Fundamental Research Funds for CAMS&PUMC [2016ZX310074]
文摘Hyperthyroidism refers to a clinical state that results from inappropriately hight hyroid hormone levels in the tissues;.Ⅰ-131 therapy plays a critical role and provides a remarkable curative effect in targeting thyroid diseases. Thyroid cells can take up isotope I-131, which emits not only beta rays but also
基金supported by the National Natural Science Foundation of China [No.71774175]
文摘Drug dependence is a serious global health problem.To assist individuals with drug addiction,China alone has established 678 Compulsory Detoxification Detention Centers （CDDCs） that treat over300,000i ndividuals who are required by national law to receive compulsory treatment;because community-based outpatient treatment failed.
基金supported by a General Project granted by the National Natural Science Foundation of China (No. 51178002)
文摘Anthropogenic activities usually contaminate water environments, and have led to the eutrophication of many estuaries and shifts in microbial communities. In this study, the temporal and spatial changes of the microbial community in an industrial effluent receiving area in Hangzhou Bay were investigated by 454 pyrosequencing. The bacterial community showed higher richness and biodiversity than the archaeal community in all sediments. Proteobacteria dominated in the bacterial communities of all the samples; MarineGroupⅠand Methanomicrobia were the two dominant archaeal classes in the effluent receiving area. PCoA and AMOVA revealed strong seasonal but minor spatial changes in both bacterial and archaeal communities in the sediments. The seasonal changes of the bacterial community were less significant than those of the archaeal community, which mainly consisted of fluctuations in abundance of a large proportion of longstanding species rather than the appearance and disappearance of major archaeal species. Temperature was found to positively correlate with the dominant bacteria, Betaproteobacteria, and negatively correlate with the dominant archaea,MarineGroupⅠ; and might be the primary driving force for the seasonal variation of the microbial community.
基金Project supported by the Natural Science Foundation of Hebei Province of China(Grant Nos.F2019506031,F2019506037,and F2020506036)the Frontier Innovation Program of Army Engineering University(Grant No.KYSZJQZL2005)the Basic Frontier Science and Technology Innovation Program of Army Engineering University(Grant No.KYSZJQZL2020).
文摘To address the problem that it is difficult to detect an intermediate frequency(IF)signal at the receiving end of a communication system under extremely low signal-to-noise ratio(SNR)conditions,we propose a stochastic resonance(SR)-enhanced sine-signal detection method based on the sign function.By analyzing the SR mechanism of the sine signal and combining it with the characteristics of a dual-sequence frequency-hopping(DSFH)receiver,a periodic stationary solution of the Fokker-Planck equation(FPE)with a time parameter is obtained.The extreme point of the sine signal is selected as the decision time,and the force law of the electromagnetic particles is analyzed.A receiving structure based on the sign function is proposed to maximize the output difference of the system,and the value condition of the sign function is determined.In order to further improve the detection performance,in combination with the central-limit theorem,the sampling points are averaged N times,and the signal-detection problem is transformed into a hypothesis-testing problem under a Gaussian distribution.The theoretical analysis and simulation experiment results confirm that when N is 100 and the SNR is greater than 20 dB,the bit-error ratio(BER)is less than 1.5×10^(-2) under conditions in which the signal conforms to the optimal SR parameters.
基金sponsored by National Natural Resources Foundation program(SKLGP2020K023).
文摘In recent years,the semi-airborne transient electromagnetic method(SATEM)has been rapidly developed in China.Based on the theoretical development of the long grounding wire source transient electromagnetic method,the unmanned aerial vehicle is equipped with the receiving coil to collect the electromagnetic response data at high altitude,making the TEM no longer affected by the terrain and greatly improving the actual working efficiency.However,its flight altitude has not been concerned for a long time.It is generally believed that the change of flight altitude only affects the amplitude of the received response.However,under special circumstances,the electromagnetic response data received at different flight altitudes in the near and far regions may lose the characteristic information of the target geological body.This paper simulates the low resistance thin layer model and analyzes the electromagnetic responses of different receiving heights under different transceiver distances.The results show that in the near area,when the flight altitude is higher than 30 meters or more,the received electromagnetic response will lose the information of the shallow lowresistance thin layer,while in the far area,the change of flight altitude has no obvious influence on the characteristic electromagnetic response information of the received geological body.
基金supported by National Natural Science Foundation of China(Nos.51577044 and 11605035)
文摘A novel technique based on sub-wavelength plasma structure effects on enhancement of RF communication signals on a receiving antenna is carried out in this paper in laboratory experiments and analyzed by corresponding numerical simulations.Considerable intensification on receiving signal gain up to -10 d B in comparison with that without the plasma modulation is observed experimentally in -1 GHz RF band,with an effective enhancement bandwidth of -340 MHz and the fractional bandwidth of -34%.Then,the optimal modulation parameters of plasma are further studied by a numerical simulation.It is shown that the number density,the layer thickness,and the collision frequency of the plasma,as well as the relative distance between the plasma layer and antenna synergistically affect the modulation.Compared to the metallic antenna with the same overall dimension,the modulated antenna covered by the subwavelength plasma structure features higher receiving efficiency and lower radar cross section in the studied RF band.The mechanism of the reception enhancement is further revealed by analyzing characteristics of electromagnetic scattering and electric field distribution in the subwavelength plasma layer.The results then exhibit scientific significance and application potential of sub-wavelength plasma modulation on compact receiving antennas with higher performance and better feature of radar stealth.
文摘The influence of the selection of receiving slits and the use of standard samples with random orientation on the result of quantitative texture analysis was tested and discussed. The result proves that it will improve the precision of the analysis to use proper slits and a randomly oriented standard sample. A simple method was given to interpolate the correction curves of random intensities.
文摘The influence of close-up feed strategies on growth performance and dietary NE in light-weight feedlot steers during a 56 d receiving period was evaluated. Dietary treatments were formulated to meet the average metabolizable amino acid requirements of calves during 1) the initial 7 d;2) the initial 14 d;and 3) the initial 21 d following arrival into the feedlot, assuming average interval DMI of 2.8, 3.0, and 3.6 kg/d, respectively. Thereafter, all steers received dietary treatment 3. Fish meal was the source of supplemental protein. One hundred eight medium-framed crossbred steers (168.4 ± 5.0 kg) were blocked by weight and assigned to 18 pen groups (6 steers per pen). P-value (≤0.10) was considered as statistically significant. Daily weight gain (linear effect, P = 0.09) and gain efficiency (linear effect, P = 0.08) decreased as the close-up interval increased. DMI was not influenced by feeding program (P = 0.46). The ratio of observed to expected dietary NEm (linear effect P = 0.06) and NEg (linear effect, P = 0.05) decreased as length of close-up interval increased. Morbidity was low (18%) and not affected (P > 0.40) by dietary treatments. It is concluded that the addition of a close-up diet formulated to meet the metabolizable amino acid requirements of shipping stressed calves during the initial 7 d in the feedlot, when feed intakes are comparatively low, will have long-term beneficial effect on cattle growth performance and dietary NE.
基金We would like to give our thanks to Water Resources Department of Shandong Province and Water Resources Research Institute of Shandong Province for their help.
文摘Taking 13 water-receiving areas on the East Route of the South-to-North Water Diversion Project(ERSNWDP)in Shandong Province as the study area,and comparing it with Jiangsu Province on the ERSNWDP and the Middle Route of the South-to-North(MRSNWDP),the current water-saving potential of the water-receiving areas within the municipalities of Shandong was analyzed.Different water-saving scenarios were constructed and analyzed with key water-saving indexes in various industries.These indexes include the effective utilization coefficient of farmland irrigation water,total water consumption of industrial sectors with an added value of over 10000 RMB,average leakage rate of the urban public water supply pipe network and the penetration rate of water-saving appliances.Based on the scenarios,comprehensive water-saving potential of the 13 water-receiving area cities was calculated.The results show that the water-saving potential of the study area is at a relative high level.However,some cities still have a certain amount of water-saving potential for agriculture and industry to be elevated.Under the recommended water-saving scenario,the water-saving potential is 1.134 billion m3,accounting for 5.33%of the current total water consumption,of which 460 million m3 is in agriculture,600 million m3 in industry,is and 74.20 million m3 in urban domestic sector.Comprehensive water-saving measures for the study area were proposed from the aspects of agricultural,industrial and domestic water uses.Agricultural and industrial water saving are more significant.The major cities for agricultural water saving include Jining City,Heze City,Weifang City and Jinan City;the focus cities of industrial water saving mainly include Weihai City,Jining City and Qingdao City and etc.;the key water-saving areas for urban use mainly include Zaozhuang City,Jining City and Heze City.
文摘Designing an Ethernet switch that can assure normal interaction of protocol packets between switches in a network environment of massive traffic is an important matter. Taking the L3 Ethernet switch based on Application Specific Integrated Circuit (ASIC) as an example,this article analyzes several typical issues about packet receiving and sending by the CPU in a multi-progress environment,including CPU load,software and hardware queue settings,and communication mechanism between CPU and the switch chip. This article gives solutions to these issues mentioned above. The solutions are applicable to Network Processor (NP) issues as well.
文摘The era of mobile Internet is coming, broadband digital communication technology is in the stage of continuous development and progress, with us moving towards the era of mobile Internet. This paper first analyzes the connotation and characteristics of broadband digital communication technology, then analyzes the concept of signaling and multi-channel communication technology, establishes a wide range of digital communication receiving channel model that can perform high performance, and discusses simulation. Finally, in view of this communication technology, the development of the possible realization of their own prospects in the future, for the development of broadband digital communication technology and practical application to provide relevant data support.
文摘I feel that this award was not made to me as a man,but to mywork—a life s work in the agony and sweat of the human spirit,not for glory and least of all for profit,but to create out of thematerials of the human spirit something which did not exist before,sothis award is only mine in trust.It will not be difficult to fred a dedi-cation for the money part of it commensurate with the purpose andsignificance of its origin.But I would like to do the same with the ac-claim too,by using this moment as a ...
文摘The receiving response of towed line array to the noise radiated from the tow ship is investigated through normal mode modeling and computer simulation. The phenomenon that the maximum output of the towed line array is away from the endfire direction towards the tow ship is explained. The result is important for the understanding of the phenomenon and also for the application research concerning the suppression of the noise from the tow ship as well as adequate application of towed array techniques in shallow water.
文摘The contact face and shock wave motion in an open ends receiving tube of gas wave refrigerator are investigated numerically and experimentally. The results show that, velocity of the contact face rises rapidly as gas is injected into the receiving tube, and drops sharply after a steady propagation. However, velocity of the shock wave in the tube is almost linear. With increasing of inlet pressure, velocity of the shock wave and steady velocity of contact face also increase. In addition, time and distance of contact face propagation in the receiving tube become longer.
