With the help of technique of integration within an ordered product of operators we can fully display the partial trace method to deduce some new density operators of light field. The general form of single-mode densi...With the help of technique of integration within an ordered product of operators we can fully display the partial trace method to deduce some new density operators of light field. The general form of single-mode density operator is derived in this way from a normalized two-mode generalized squeezed pure state density operator.展开更多
Linear minimum mean square error(MMSE)detection has been shown to achieve near-optimal performance for massive multiple-input multiple-output(MIMO)systems but inevitably involves complicated matrix inversion,which ent...Linear minimum mean square error(MMSE)detection has been shown to achieve near-optimal performance for massive multiple-input multiple-output(MIMO)systems but inevitably involves complicated matrix inversion,which entails high complexity.To avoid the exact matrix inversion,a considerable number of implicit and explicit approximate matrix inversion based detection methods is proposed.By combining the advantages of both the explicit and the implicit matrix inversion,this paper introduces a new low-complexity signal detection algorithm.Firstly,the relationship between implicit and explicit techniques is analyzed.Then,an enhanced Newton iteration method is introduced to realize an approximate MMSE detection for massive MIMO uplink systems.The proposed improved Newton iteration significantly reduces the complexity of conventional Newton iteration.However,its complexity is still high for higher iterations.Thus,it is applied only for first two iterations.For subsequent iterations,we propose a novel trace iterative method(TIM)based low-complexity algorithm,which has significantly lower complexity than higher Newton iterations.Convergence guarantees of the proposed detector are also provided.Numerical simulations verify that the proposed detector exhibits significant performance enhancement over recently reported iterative detectors and achieves close-to-MMSE performance while retaining the low-complexity advantage for systems with hundreds of antennas.展开更多
A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process...A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process is omitted.The detection limit is about 10^(10) mol/L antigen.The relative standard deviation of immunoassay is less than 10%.The recoveries of human serum albumin and estradiol protein conjugate are 96-105% and 111% respectively.展开更多
A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process ...A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process is unnecessary.The recovery of HSA and albumin in urine is 107% and 95% respectively.The standard deviation is tess than 10%.展开更多
Although previous investigations of the trace elements in snow and ice from the Qinghai-Tibetan Plateau obtained interesting information about pollution from human activities on the plateau, most were based on traditi...Although previous investigations of the trace elements in snow and ice from the Qinghai-Tibetan Plateau obtained interesting information about pollution from human activities on the plateau, most were based on traditional acidification methods.To emphasize the influence of the different sample-preparation methods on the records of trace elements and rare earth elements, snow samples were collected from glaciers on the Qinghai-Tibetan Plateau in China and prepared using two methods: traditional acidification and total digestion. Concentrations of 18 trace elements(Al, Ti, Fe, Rb, Sr, Ba, V, Cr, Mn, Li,Cu, Co, Mo, Cs, Sb, Pb, Tl, and U), along with 14 rare earth elements(REEs: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er,Tm, Yb, and Lu), Y, and Th in the snow samples, were measured using inductively coupled plasma-sector field mass spectrometry(ICP-SFMS). The results showed that the mass fraction of the trace elements(defined as ratio of concentration in the acid-leachable fraction to that in the digested sample) such as Mo, Ti, Al, Rb, and V, varied from 0.06 to 0.5. The mass fraction of other trace elements varied from about 0.6 to more than 0.9; those of the REEs, Y, and Th varied from 0.34 to0.75. Lower mass fractions will lead to an overestimated contribution of other sources, especially human activities, and the underestimated fluxes of these trace elements(especially REEs, Y, and Th, as well as dust) if the REEs are used as the proxy for the crust dust. The two sample-preparation methods exhibited different REE normalized distribution patterns,REE ratios, and provenance-tracing results. The REE normalized distribution patterns and proxies in the digested samples are more reliable and integrated than those found in traditional acidification method for dust-provenance tracing.展开更多
The spinors applied to describe position and attitude of robot are studied. In dual spaces, the terminal trace of robot is planned through the mapping point, of attitude spinors. As a handy method directly perceived t...The spinors applied to describe position and attitude of robot are studied. In dual spaces, the terminal trace of robot is planned through the mapping point, of attitude spinors. As a handy method directly perceived through the sense, the spinor method directly converges tracking error in the planning. It promotes the dynamic accuracy of trace operation. It is also suitable to the exerciser with redundant freedom.展开更多
In order to extend the eN method to general three-dimensional boundary layers, the conservation law of the imaginary parts for the wave parameters with a fixed wave vector is deduced. The compatibility relationship ...In order to extend the eN method to general three-dimensional boundary layers, the conservation law of the imaginary parts for the wave parameters with a fixed wave vector is deduced. The compatibility relationship （CR） and the general theory of ray tracing （RT）, which have been extensively used in conservative systems, are applied to a general three-dimensional boundary layer belonging to non-conservative systems. Two kinds of eN methods, i.e., the eN-CR method and the eN-RT method, are established. Both the two kinds of methods can wavenumber and the amplitude of the be used to predict the evolutions of the spanwise disturbances in general three-dimensional boundary layers. The reliability of the proposed methods is verified and validated by performing a direct numerical simulation （DNS） in a hypersonic general three-dimensional boundary layer over an aircraft model. The results are also compared with those obtained by other eN methods, indicating that the proposed methods have great potential applications in improving the transition prediction accuracy in general three-dimensional boundary layers.展开更多
Submarine groundwater discharge(SGD)is an important part in the land-sea interactions,which mainly contains three components:submarine fresh groundwater discharge(SFGD),tidal flat recirculated saline groundwater disch...Submarine groundwater discharge(SGD)is an important part in the land-sea interactions,which mainly contains three components:submarine fresh groundwater discharge(SFGD),tidal flat recirculated saline groundwater discharge(tidal flat RSGD)and subtidal recirculated saline groundwater discharge(subtidal RSGD).In order to make a more accurate assessment of the impact of SGD on coastal ecological environment,it is necessary to distinguish the main components of SGD.In this study,the Maowei Sea,located in the northern part of the Beibu Gulf,was selected as the study area.Based on the radium(Ra)tracing method,we present a new analytical method for distinguishing the three main components of SGD in this area combined with field data.The average daily flow along the coastline of the Maowei Sea of tidal flat RSGD was slightly higher than that of SFGD,and both two were on the magnitude of 1×10^(5)m^(3)/d.The average daily flow for the subtidal RSGD of the entire subtidal zone of the Maowei Sea reached to the magnitude of 1×10^(6)-1×10^(7)m^(3)/d.The long-term variation trend of terrestrial SGD is a valuable information for the study of the influence of terrigenous material on the coastal ecological environment.Based on the results of four sampling periods,it is found that the fluxes of SFGD and tidal flat RSGD in the Maowei Sea had good linear correlation with the net precipitation.As an example,January 2015 to August 2022 were selected as the study periods,and the variation trends of SFGD and tidal flat RSGD were calculated by linear function with net precipitation as the independent variable.The results showed that the flux of tidal flat RSGD was slightly higher than that of SFGD,and the difference between the two is larger in flood season while smaller in dry season.In general,in the coastal range of China,the total SGD flux in the Maowei Sea area is at a high level,and the SFGD flux is at a medium level.展开更多
The classical Lagrangian particle tracing method is widely used in the evaluation of the ocean annual subduction rate.However,our analysis indicates that in addition to neglecting the effect of mixing,there are two po...The classical Lagrangian particle tracing method is widely used in the evaluation of the ocean annual subduction rate.However,our analysis indicates that in addition to neglecting the effect of mixing,there are two possible deviations in the method:one is an overestimation due to not considering that the amount of subducted water at the source location may be inadequate during the late winter of the first year when the mixed layer becomes shallow;the other one is an underestimation due to the neglect of the effective subduction caused by strong vertical pumping.Quantitative analysis shows that these two deviations mainly exist in the low-latitude subduction areas of the South Pacific and South Atlantic.The two deviations have very similar distribution areas and can partially off set each other.However,the overall deviation is still large,and the maximum relative deviation ratio can reach 50%;therefore,it cannot be ignored.展开更多
With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical ...With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam positioning.However,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge beam.By analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial function.Therefore,an error correction algorithm based on polynomial fitting is obtained.The simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.展开更多
A new method of NAA for sediment movement study is presented in this paper. Through analyzing the natural sediment, the information about natural tracing agents has been obtained, which can show the direction of sedim...A new method of NAA for sediment movement study is presented in this paper. Through analyzing the natural sediment, the information about natural tracing agents has been obtained, which can show the direction of sediment movement and relative discharge of sediment transportation. Test results in some areas, such as Shantou Harbour and Hangzhou Bay, are in good agreement with those from normal hydrologic measurements and some results are not obtainable with the latter. The NAA is economical, practical and reliable, and should be widely used in engineering practice.展开更多
A An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of 24 elements （Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, ...A An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of 24 elements （Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb） in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.展开更多
基金Supported by the President Foundation of Chinese Academy of Science and National Natural Science Foundation of China under Grant Nos.10775097 and 10874174
文摘With the help of technique of integration within an ordered product of operators we can fully display the partial trace method to deduce some new density operators of light field. The general form of single-mode density operator is derived in this way from a normalized two-mode generalized squeezed pure state density operator.
基金supported by National Natural Science Foundation of China(62371225,62371227)。
文摘Linear minimum mean square error(MMSE)detection has been shown to achieve near-optimal performance for massive multiple-input multiple-output(MIMO)systems but inevitably involves complicated matrix inversion,which entails high complexity.To avoid the exact matrix inversion,a considerable number of implicit and explicit approximate matrix inversion based detection methods is proposed.By combining the advantages of both the explicit and the implicit matrix inversion,this paper introduces a new low-complexity signal detection algorithm.Firstly,the relationship between implicit and explicit techniques is analyzed.Then,an enhanced Newton iteration method is introduced to realize an approximate MMSE detection for massive MIMO uplink systems.The proposed improved Newton iteration significantly reduces the complexity of conventional Newton iteration.However,its complexity is still high for higher iterations.Thus,it is applied only for first two iterations.For subsequent iterations,we propose a novel trace iterative method(TIM)based low-complexity algorithm,which has significantly lower complexity than higher Newton iterations.Convergence guarantees of the proposed detector are also provided.Numerical simulations verify that the proposed detector exhibits significant performance enhancement over recently reported iterative detectors and achieves close-to-MMSE performance while retaining the low-complexity advantage for systems with hundreds of antennas.
基金This work was supported by National Natural Science Foundation of China.
文摘A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process is omitted.The detection limit is about 10^(10) mol/L antigen.The relative standard deviation of immunoassay is less than 10%.The recoveries of human serum albumin and estradiol protein conjugate are 96-105% and 111% respectively.
基金supported by National Commission of Natural Science Foundation of China.
文摘A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process is unnecessary.The recovery of HSA and albumin in urine is 107% and 95% respectively.The standard deviation is tess than 10%.
基金supported by grants provided by the National Natural Science Foundation of China(Grant Nos.41276194,40771046,and 40601021)
文摘Although previous investigations of the trace elements in snow and ice from the Qinghai-Tibetan Plateau obtained interesting information about pollution from human activities on the plateau, most were based on traditional acidification methods.To emphasize the influence of the different sample-preparation methods on the records of trace elements and rare earth elements, snow samples were collected from glaciers on the Qinghai-Tibetan Plateau in China and prepared using two methods: traditional acidification and total digestion. Concentrations of 18 trace elements(Al, Ti, Fe, Rb, Sr, Ba, V, Cr, Mn, Li,Cu, Co, Mo, Cs, Sb, Pb, Tl, and U), along with 14 rare earth elements(REEs: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er,Tm, Yb, and Lu), Y, and Th in the snow samples, were measured using inductively coupled plasma-sector field mass spectrometry(ICP-SFMS). The results showed that the mass fraction of the trace elements(defined as ratio of concentration in the acid-leachable fraction to that in the digested sample) such as Mo, Ti, Al, Rb, and V, varied from 0.06 to 0.5. The mass fraction of other trace elements varied from about 0.6 to more than 0.9; those of the REEs, Y, and Th varied from 0.34 to0.75. Lower mass fractions will lead to an overestimated contribution of other sources, especially human activities, and the underestimated fluxes of these trace elements(especially REEs, Y, and Th, as well as dust) if the REEs are used as the proxy for the crust dust. The two sample-preparation methods exhibited different REE normalized distribution patterns,REE ratios, and provenance-tracing results. The REE normalized distribution patterns and proxies in the digested samples are more reliable and integrated than those found in traditional acidification method for dust-provenance tracing.
文摘The spinors applied to describe position and attitude of robot are studied. In dual spaces, the terminal trace of robot is planned through the mapping point, of attitude spinors. As a handy method directly perceived through the sense, the spinor method directly converges tracking error in the planning. It promotes the dynamic accuracy of trace operation. It is also suitable to the exerciser with redundant freedom.
基金supported by the National Natural Science Foundation of China(No.11332007)the Natural Science Foundation of Tianjin(No.15JCYBJC19500)
文摘In order to extend the eN method to general three-dimensional boundary layers, the conservation law of the imaginary parts for the wave parameters with a fixed wave vector is deduced. The compatibility relationship （CR） and the general theory of ray tracing （RT）, which have been extensively used in conservative systems, are applied to a general three-dimensional boundary layer belonging to non-conservative systems. Two kinds of eN methods, i.e., the eN-CR method and the eN-RT method, are established. Both the two kinds of methods can wavenumber and the amplitude of the be used to predict the evolutions of the spanwise disturbances in general three-dimensional boundary layers. The reliability of the proposed methods is verified and validated by performing a direct numerical simulation （DNS） in a hypersonic general three-dimensional boundary layer over an aircraft model. The results are also compared with those obtained by other eN methods, indicating that the proposed methods have great potential applications in improving the transition prediction accuracy in general three-dimensional boundary layers.
基金The National Natural Science Foundation of China under contract Nos 41576083 and 41906150the National Key R&D Program of China under contract No.2022YFE0209300.
文摘Submarine groundwater discharge(SGD)is an important part in the land-sea interactions,which mainly contains three components:submarine fresh groundwater discharge(SFGD),tidal flat recirculated saline groundwater discharge(tidal flat RSGD)and subtidal recirculated saline groundwater discharge(subtidal RSGD).In order to make a more accurate assessment of the impact of SGD on coastal ecological environment,it is necessary to distinguish the main components of SGD.In this study,the Maowei Sea,located in the northern part of the Beibu Gulf,was selected as the study area.Based on the radium(Ra)tracing method,we present a new analytical method for distinguishing the three main components of SGD in this area combined with field data.The average daily flow along the coastline of the Maowei Sea of tidal flat RSGD was slightly higher than that of SFGD,and both two were on the magnitude of 1×10^(5)m^(3)/d.The average daily flow for the subtidal RSGD of the entire subtidal zone of the Maowei Sea reached to the magnitude of 1×10^(6)-1×10^(7)m^(3)/d.The long-term variation trend of terrestrial SGD is a valuable information for the study of the influence of terrigenous material on the coastal ecological environment.Based on the results of four sampling periods,it is found that the fluxes of SFGD and tidal flat RSGD in the Maowei Sea had good linear correlation with the net precipitation.As an example,January 2015 to August 2022 were selected as the study periods,and the variation trends of SFGD and tidal flat RSGD were calculated by linear function with net precipitation as the independent variable.The results showed that the flux of tidal flat RSGD was slightly higher than that of SFGD,and the difference between the two is larger in flood season while smaller in dry season.In general,in the coastal range of China,the total SGD flux in the Maowei Sea area is at a high level,and the SFGD flux is at a medium level.
基金Supported by the National Natural Science Foundation of China(No.41676009)the National Key R&D Program of China(No.2016YFC0301203)the State Key Program of National Natural Science of China(No.41730534)。
文摘The classical Lagrangian particle tracing method is widely used in the evaluation of the ocean annual subduction rate.However,our analysis indicates that in addition to neglecting the effect of mixing,there are two possible deviations in the method:one is an overestimation due to not considering that the amount of subducted water at the source location may be inadequate during the late winter of the first year when the mixed layer becomes shallow;the other one is an underestimation due to the neglect of the effective subduction caused by strong vertical pumping.Quantitative analysis shows that these two deviations mainly exist in the low-latitude subduction areas of the South Pacific and South Atlantic.The two deviations have very similar distribution areas and can partially off set each other.However,the overall deviation is still large,and the maximum relative deviation ratio can reach 50%;therefore,it cannot be ignored.
基金The Natural Science Foundation of Shandong Province of China under contract Nos ZR2022MA051 and ZR2020MA090the National Natural Science Foundation of China under contract No.U22A2012+2 种基金China Postdoctoral Science Foundation under contract No.2020M670891the SDUST Research Fund under contract No.2019TDJH103the Talent Introduction Plan for Youth Innovation Team in universities of Shandong Province(innovation team of satellite positioning and navigation)。
文摘With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam positioning.However,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge beam.By analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial function.Therefore,an error correction algorithm based on polynomial fitting is obtained.The simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.
文摘A new method of NAA for sediment movement study is presented in this paper. Through analyzing the natural sediment, the information about natural tracing agents has been obtained, which can show the direction of sediment movement and relative discharge of sediment transportation. Test results in some areas, such as Shantou Harbour and Hangzhou Bay, are in good agreement with those from normal hydrologic measurements and some results are not obtainable with the latter. The NAA is economical, practical and reliable, and should be widely used in engineering practice.
基金the Natural Science Foundation of Hunan Province, China (No. 05JJ40017).
文摘A An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of 24 elements （Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb） in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.
