We propose a method that uses linear chirp modulated Gaussian functions as the elementary functions, by adaptively adjusting variances, time frequency centers and sweep rates, to decompose signals. By taking WVD, an ...We propose a method that uses linear chirp modulated Gaussian functions as the elementary functions, by adaptively adjusting variances, time frequency centers and sweep rates, to decompose signals. By taking WVD, an improved adaptive time frequency distribution is developed, which is non negative, free of cross term interference, and of better time frequency resolution. The paper presents an effective numerical algorithm to estimate the optimal parameters of the basis. Simulations indicate that the proposed approach is effective in analyzing signal's time frequency behavior.展开更多
The estimation of model parameters is an important subject in engineering.In this area of work,the prevailing approach is to estimate or calculate these as deterministic parameters.In this study,we consider the model ...The estimation of model parameters is an important subject in engineering.In this area of work,the prevailing approach is to estimate or calculate these as deterministic parameters.In this study,we consider the model parameters from the perspective of random variables and describe the general form of the parameter distribution inference problem.Under this framework,we propose an ensemble Bayesian method by introducing Bayesian inference and the Markov chain Monte Carlo(MCMC)method.Experiments on a finite cylindrical reactor and a 2D IAEA benchmark problem show that the proposed method converges quickly and can estimate parameters effectively,even for several correlated parameters simultaneously.Our experiments include cases of engineering software calls,demonstrating that the method can be applied to engineering,such as nuclear reactor engineering.展开更多
We investigate the distribution of the switching current of a current-biased Josephson junction (CBJJ) and its dependence on the microwave frequency using two theoretical methods, one of which is the quantum traject...We investigate the distribution of the switching current of a current-biased Josephson junction (CBJJ) and its dependence on the microwave frequency using two theoretical methods, one of which is the quantum trajectory method and the other is the master equation method. Both the methods show that the distribution of the switching current of CBJJ will exhibit double peaks in a certain range of microwave frequency if proper microwave power is given, and the gap between the two peaks will increase with the microwave frequency. The obtained results can be used to identify the energy difference of the ground and first excited states in a Josephson junction for any bias current.展开更多
Stress-associated protein (SAP) has functions in maintaining plant cell elongation, embryo development and response to abiotic stresses. TaSAP1-A1, one of the Triticum aestivum SAP1 (TaSAP1) members located on whe...Stress-associated protein (SAP) has functions in maintaining plant cell elongation, embryo development and response to abiotic stresses. TaSAP1-A1, one of the Triticum aestivum SAP1 (TaSAP1) members located on wheat chromosome 7A was isolated for polymorphism analysis. HaplII of TaSAP1-A1 was found significantly associated with thousand-grain weight (TGW) in multiple environments. In this study, HaplII also made a positive contribution to TGW in Population 2. The distribution of TaSAP1-A1 HapIII was tracked among varieties released in different years and geographical environments of China. The frequency of HapIII showed an increasing trend during the breeding process in two different populations. The ItapIII was gradually selected and applied from 6.36% in landraces to 13.50% in modem varieties. These results exhibited that TaSAP1-A1 HapIII was positively selected during wheat breeding, which is beneficial for grain-yield improvement. The preferred HapIIl was initially selected and applied in the higher latitude areas of China in accord with the long day season and longer grain filling stage in these areas. Moreover, the frequency of HaplII in recent modem varieties was still quite low (19.29-26.67%). It indicated a high application potential of TaSAP1-A 1 HapIII for improving grain yield in wheat breeding.展开更多
Staff attendance information has always been an important part of corporate management.However,some opportunistic employees may consign others to punch their time cards,which hampers the authenticity of attendance and...Staff attendance information has always been an important part of corporate management.However,some opportunistic employees may consign others to punch their time cards,which hampers the authenticity of attendance and effectiveness of record keeping.Hence,it is necessary to develop an innovative anti-cheating system for office attendance.Radio-Frequency IDentification(RFID)offers new solutions to solve such problems because of its strong anti-interference capability and non-intrusiveness.In this paper,we present a smart attendance system that extracts distinguishable phase characteristics of individuals to enable recognition of various targets.A frequency distribution histogram is extracted as a fingerprint for recognition and the K-means clustering method is utilized for more fine-grained recognition of targets with similar features.Compared with traditional attendance mechanisms,RFID-based attendance systems are based on living biological characteristics,which greatly reduces the possibility of false records.To evaluate the performance of our system,we conducted extensive experiments.The results of which demonstrate the efficiency and accuracy of our system with an average accuracy of 92%.Moreover,the system evaluation shows that our design is robust against differences in the clothing worn and time of day,which further verifies the successful performance of our system.展开更多
An inconsecutive high frequency distribution with a"sandwich structure"pattern for high temperature warm water warmer than 29℃ in the western Pacific warm pool(WPWP) was found using Tropical Rainfall Measur...An inconsecutive high frequency distribution with a"sandwich structure"pattern for high temperature warm water warmer than 29℃ in the western Pacific warm pool(WPWP) was found using Tropical Rainfall Measuring Mission(TRMM) sea surface temperature(SST) data,a relatively high resolution data for space.This phenomenon only shows up in boreal summer(June to September),and becomes obvious when WPWP SST is higher than 29℃.As observed,East Asian summer monsoon(EASM) impinges on Philippine Islands in July,which has an important impact on the formation and maintenance of the "sandwich structure".Winds affect the distribution of SST in two ways:one by increasing the local latent heat flux and the other by transporting cold water towards the southeast of Philippine Islands.展开更多
Ecological protection and high-quality development of the Yellow River basin are becoming part of the national strategy in recent years.The Yellow River Estuary has been seriously affected by human activities.Especial...Ecological protection and high-quality development of the Yellow River basin are becoming part of the national strategy in recent years.The Yellow River Estuary has been seriously affected by human activities.Especially,it has been severely polluted by the nitrogen and phosphorus from land sources,which have caused serious eutrophication and harmful algal blooms.Nutrient criteria,however,was not developed for the Yellow River Estuary,which hindered nutrient management measures and eutrophication risk assessment in this key ecological function zone of China.Based on field data during 2004-2019,we adopted the frequency distribution method,correlation analysis,Linear Regression Model(LRM),Classification and Regression Tree(CART)and Nonparametric Changepoint Analysis(nCPA)methods to establish the nutrient criteria for the adjacent waters of Yellow River Estuary.The water quality criteria of dissolved inorganic nitrogen(DIN)and soluble reactive phosphorus(SRP)are recommended as 244.0μg L^(−1) and 22.4μg L^(−1),respectively.It is hoped that the results will provide scientific basis for the formulation of nutrient standards in this important estuary of China.展开更多
<strong>Objective:</strong> To investigate the correlation between 5-HTTLPR (5-and serotonin transporter linked polymer region) gene polymorphism and BDNF (brain derived neural factor) gene polymorphism an...<strong>Objective:</strong> To investigate the correlation between 5-HTTLPR (5-and serotonin transporter linked polymer region) gene polymorphism and BDNF (brain derived neural factor) gene polymorphism and PTSD (post traumatic stress disorders) in Li and Han nationalities in Hainan Province. <strong>Methods:</strong> 167 Hainan Li PTSD patients, 141 Hainan Han PTSD patients and 158 healthy volunteers (control group) were investigated by ETI, caps, Toh, WCST, TMT and WAIS-RC. The polymorphisms of rs6265 locus of 5-HTTLPR and BDNF genes were detected by PCR (polymerase chain reaction) and page (polycylamide gel electrophoresis), and the correlation with PTSD was analyzed. Logistic regression analysis was used to analyze the influencing factors of PTSD. <strong>Results:</strong> The ETI score, total PTSD score and TMT time of Li PTSD patients were significantly higher than those of Han PTSD patients (P < 0.01). The comprehension, picture filling, picture arrangement, operation IQ and total IQ of WAIS-RC were significantly lower than those of Han PTSD patients (P < 0.01);The numbers of errors, TMT and Toh in WCST were significantly lower than those in Han PTSD patients (P < 0.01). There was no significant difference in the distribution of 5-HTTLPR genotype and allele between Li PTSD patients and control group (P > 0.05). SS genotype of 5-HTTLPR and (GA + AA) genotype of rs6265 locus may increase the risk of PTSD in Hainan Han population. AA and GA + AA genotypes at rs6265 locus may increase the risk of PTSD in Li population (P < 0.05). Among Li PTSD patients, the ETI score, PTSD total score, TMT time, Toh planning time and execution time of AA genotype at rs6265 locus were significantly higher than those of GG genotype;the total scores of comprehension and operation IQ, and Toh in WAIS-RC were significantly lower than those in GG genotype (P < 0.05). Among Han PTSD patients, the ETI score, PTSD total score and TMT time of SS genotype of 5-HTTLPR were significantly higher than those of LL genotype, and the comprehension, arithmetic and block diagram in WAIS-RC were significantly lower than those of LL genotype;The ETI score, PTSD total score and TMT time of patients with (GA + AA) genotype at rs6265 locus were also significantly higher than those of patients with GG genotype. The comprehension and block diagram in WAIS-RC were significantly lower than those of patients with GG genotype. The number of WCST errors in patients with AA genotype was significantly higher than those of patients with GG genotype, and the operational IQ in WAIS-RC was significantly lower than those of patients with GG genotype (P < 0.05). <strong>Conclusion:</strong> The LL genotype of 5-HTTLPR and the GG genotype of rs6265 locus are related to PTSD of Li and Han nationalities in Hainan, which are important protective factors for PTSD of Li and Han nationalities in Hainan.展开更多
A rubidium-beam microwave clock, optically pumped by a distributed feedback diode laser, is experimentally investigated. The clock is composed of a physical package, optical systems, and electric servo loops. The phys...A rubidium-beam microwave clock, optically pumped by a distributed feedback diode laser, is experimentally investigated. The clock is composed of a physical package, optical systems, and electric servo loops. The physical package realizes the microwave interrogation of a rubidium-atomic beam. The optical systems, equipped with two 780-nm distributed feedback laser diodes, yield light for pumping and detecting. The servo loops control the frequency of a local oscillator with respect to the microwave spectrum. With the experimental systems, the microwave spectrum, which has an amplitude of 4 n A and a line width of 700 Hz, is obtained. Preliminary tests show that the clock short-term frequency stability is 7 × 10^-11 at 1 s, and 3 × 10^-12 at 1000 s. These experimental results demonstrate the feasibility of the scheme for a manufactured clock.展开更多
The CloudSat satellite data from June 2006 to April 2011 are used to investigate the characteristics of cloud vertical profiles over East Asia (20°-50°N, 80°- 120°E), with particular emphasis on ...The CloudSat satellite data from June 2006 to April 2011 are used to investigate the characteristics of cloud vertical profiles over East Asia (20°-50°N, 80°- 120°E), with particular emphasis on the profiles of precipitative clouds in comparison with those of nonprecipitative clouds, as well as the seasonal variations of these profiles. There are some obvious differences between the precipitative and nonprecipitative cloud profiles. Generally, precipitative clouds mainly locate below 8 km with radar refiectivity in the range of-20 to 15 dBZ and maximum values appearing within 2-4-km height, and the clouds usually reach the ground; while nonprecipitative clouds locate in the layers of 4 12 km with radar refiectivity between -28 and 0 dBZ and maximum values within 8-10-km height. There are also some differences among the liquid precipitative, solid precipitative, and possible drizzle precipitative cloud profiles. In precipitative clouds, radar reflectivity increases rapidly from 11 to 7 km in vertical, implying that condensation and collision-coalescence processes play a crucial role in the formation of large-size drops. The frequency distribution of temperature at -15℃ is consistent with the highest frequency of radar reflectivity in solid precipitative clouds, which suggests that the temperatures near -15℃ are conductive to deposition and accretion processes. The vertical profiles of liquid precipitative clouds show almost the same distributions in spring, summer, and autumn but with differences in winter at mainly lower levels. In contrast, the vertical profiles of solid precipitative clouds change from spring to winter with an alternate double and single high-frequency core, which is consistent with variations of the frequency distribution of temperature at 15℃. The vertical profiles of nonprecipitative clouds show a little change with season. The observations also show that the precipitation events over East Asia are mostly related to deep convective clouds and nimbostratus clouds. These results are expected to be useful for evaluation of weather and climate .models and for improvement of microphysical parameterizations in numerical models.展开更多
This paper addresses distributed computation Sylvester equations of the form AX+XB=C with fractional order dynamics.By partitioning parameter matrices A,B and C,we transfer the problem of distributed solving Sylvester...This paper addresses distributed computation Sylvester equations of the form AX+XB=C with fractional order dynamics.By partitioning parameter matrices A,B and C,we transfer the problem of distributed solving Sylvester equations as two distributed optimization models and design two fractional order continuous-time algorithms,which have more design freedom and have potential to obtain better convergence performance than that of existing first order algorithms.Then,rewriting distributed algorithms as corresponding frequency distributed models,we design Lyapunov functions and prove that proposed algorithms asymptotically converge to an exact or least squares solution.Finally,we validate the effectiveness of proposed algorithms by providing a numerical example.展开更多
This paper presents an in-depth analysis of the interference strength and required guardband width between coexistent users for distributed orthogonal frequency division multiple access (OFDMA). In dynamic spectrum ...This paper presents an in-depth analysis of the interference strength and required guardband width between coexistent users for distributed orthogonal frequency division multiple access (OFDMA). In dynamic spectrum access networks, the cross-band interference between spectrally adjacent users is considered harmful with frequency guardbands inserted between spectrum blocks to eliminate the interference. However, the strength of the cross-band interference depends heavily on the user heterogeneity in different OFDM configurations. The cross-band interference due to the three user heterogeneity artifacts of power heterogeneity, sampling rate heterogeneity, and symbol length heterogeneity is investigated to determine the required guardband width. Analytical and simulation results show that the greater user heterogeneity requires larger guardbands with the sampling rate heterogeneity having the greatest effect. These results can be used to assist the design of spectrum allocation strategies.展开更多
A method is presented for the detection and parameter estimation of a single Linear Frequency Modulation (LFM) signal in spread spectrum systems based on Wigner Hough Transform (WHT) , followed by the theoreti...A method is presented for the detection and parameter estimation of a single Linear Frequency Modulation (LFM) signal in spread spectrum systems based on Wigner Hough Transform (WHT) , followed by the theoretical analysis. A simulation result is given to show the effectiveness of this method.展开更多
Objective:To determine growth and reproduction biology of Philocheras trispinosus(P.trispinosus)with abundance of other caridean shrimps caught by beam trawl in the Southern Black Sea.Methods:Samplings were carried ou...Objective:To determine growth and reproduction biology of Philocheras trispinosus(P.trispinosus)with abundance of other caridean shrimps caught by beam trawl in the Southern Black Sea.Methods:Samplings were carried out monthly with a beam trawl of 2 m length and 15 mm cod-end mesh size between December 2012 and November 2013.All individuals were sampled between 1 and 40+m water depth from 146 hauls.Results:A total of 550 P.trispinosus,618 Palaemon adspersus,12 Palaemon serratus,11 Philocheras fasciatus and 10 Crangon crangon were sampled during the study period.The crangonid shrimps started appearing during the winter and spring and the number of individuals increased to reach their highest value in mid-winter and mid-spring.The seasonal von Bertalanffy growth parameters for P.trispinosus were estimated as L_(∞)=29.3 mm total length,K=0.860/year,t_(0)=–0.900 year,C=0.180,and t_(s)=0.010.The start of the slow growth period was at the beginning of July(WP=0.510).Ovigerous females appeared in the sampling area between January and April.Size at sexual maturity was estimated as 25.69 mm total length.Conclusions:The results supported the distribution and abundance of caridean shrimp species from the study area and the population dynamics of the most abundant shrimp species,P.trispinosus.The current study can be answered as baseline data prior to management strategies to ensure sustainable conservation of the shrimp species.展开更多
This article investigates the problem of on line parameter estimation for fractionalorder linear systems.Based on the theory of fractional-order calculus,the conventional gradient estimator is extended to the fraction...This article investigates the problem of on line parameter estimation for fractionalorder linear systems.Based on the theory of fractional-order calculus,the conventional gradient estimator is extended to the fractional-order areas.The stability of the estimator and the convergence are analysed using the continuous frequency distributed model and indirect Lyapunov method.Finally,numerical simulation examples are given to demonstrate the effectiveness of the proposed schemes.展开更多
文摘We propose a method that uses linear chirp modulated Gaussian functions as the elementary functions, by adaptively adjusting variances, time frequency centers and sweep rates, to decompose signals. By taking WVD, an improved adaptive time frequency distribution is developed, which is non negative, free of cross term interference, and of better time frequency resolution. The paper presents an effective numerical algorithm to estimate the optimal parameters of the basis. Simulations indicate that the proposed approach is effective in analyzing signal's time frequency behavior.
基金partially sponsored by the Natural Science Foundation of Shanghai(No.23ZR1429300)the Innovation Fund of CNNC(Lingchuang Fund)。
文摘The estimation of model parameters is an important subject in engineering.In this area of work,the prevailing approach is to estimate or calculate these as deterministic parameters.In this study,we consider the model parameters from the perspective of random variables and describe the general form of the parameter distribution inference problem.Under this framework,we propose an ensemble Bayesian method by introducing Bayesian inference and the Markov chain Monte Carlo(MCMC)method.Experiments on a finite cylindrical reactor and a 2D IAEA benchmark problem show that the proposed method converges quickly and can estimate parameters effectively,even for several correlated parameters simultaneously.Our experiments include cases of engineering software calls,demonstrating that the method can be applied to engineering,such as nuclear reactor engineering.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00107,2011CB922104 and2011CBA00202the National Natural Science Foundation of China under Grant Nos 61371036,11234006,11227904 and 11474154+3 种基金the Natural Science Foundation of Jiangsu Province under Grant No BK2012013the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 20120091110030the Dengfeng Project B of Nanjing University,Jiangsu Key Laboratory of Advanced Manipulating Techniques of Electromagnetic Wavesthe Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘We investigate the distribution of the switching current of a current-biased Josephson junction (CBJJ) and its dependence on the microwave frequency using two theoretical methods, one of which is the quantum trajectory method and the other is the master equation method. Both the methods show that the distribution of the switching current of CBJJ will exhibit double peaks in a certain range of microwave frequency if proper microwave power is given, and the gap between the two peaks will increase with the microwave frequency. The obtained results can be used to identify the energy difference of the ground and first excited states in a Josephson junction for any bias current.
基金supported by the National Basic Research Program of China(2010CB951501)the National High-Tech R&D Program of China(2011AA100501)
文摘Stress-associated protein (SAP) has functions in maintaining plant cell elongation, embryo development and response to abiotic stresses. TaSAP1-A1, one of the Triticum aestivum SAP1 (TaSAP1) members located on wheat chromosome 7A was isolated for polymorphism analysis. HaplII of TaSAP1-A1 was found significantly associated with thousand-grain weight (TGW) in multiple environments. In this study, HaplII also made a positive contribution to TGW in Population 2. The distribution of TaSAP1-A1 HapIII was tracked among varieties released in different years and geographical environments of China. The frequency of HapIII showed an increasing trend during the breeding process in two different populations. The ItapIII was gradually selected and applied from 6.36% in landraces to 13.50% in modem varieties. These results exhibited that TaSAP1-A1 HapIII was positively selected during wheat breeding, which is beneficial for grain-yield improvement. The preferred HapIIl was initially selected and applied in the higher latitude areas of China in accord with the long day season and longer grain filling stage in these areas. Moreover, the frequency of HaplII in recent modem varieties was still quite low (19.29-26.67%). It indicated a high application potential of TaSAP1-A 1 HapIII for improving grain yield in wheat breeding.
基金supported in part by the National Key Basic Research and Development (973) Program of China (No.2018YFB0803400)the Nature Science Foundation of Jiangsu for Distinguished Young Scientist (No.BK20170039)the National Natural Science Foundation of China (Nos.61702283,61873131,and 61872196)
文摘Staff attendance information has always been an important part of corporate management.However,some opportunistic employees may consign others to punch their time cards,which hampers the authenticity of attendance and effectiveness of record keeping.Hence,it is necessary to develop an innovative anti-cheating system for office attendance.Radio-Frequency IDentification(RFID)offers new solutions to solve such problems because of its strong anti-interference capability and non-intrusiveness.In this paper,we present a smart attendance system that extracts distinguishable phase characteristics of individuals to enable recognition of various targets.A frequency distribution histogram is extracted as a fingerprint for recognition and the K-means clustering method is utilized for more fine-grained recognition of targets with similar features.Compared with traditional attendance mechanisms,RFID-based attendance systems are based on living biological characteristics,which greatly reduces the possibility of false records.To evaluate the performance of our system,we conducted extensive experiments.The results of which demonstrate the efficiency and accuracy of our system with an average accuracy of 92%.Moreover,the system evaluation shows that our design is robust against differences in the clothing worn and time of day,which further verifies the successful performance of our system.
基金National Natural Science Foundation of China (40975038, 40830106)National Basic Research Program of China (973 Program:2012CB955604)+1 种基金Program from China Meteorological Administration (GYHY200906008)Project 111 (B07036)
文摘An inconsecutive high frequency distribution with a"sandwich structure"pattern for high temperature warm water warmer than 29℃ in the western Pacific warm pool(WPWP) was found using Tropical Rainfall Measuring Mission(TRMM) sea surface temperature(SST) data,a relatively high resolution data for space.This phenomenon only shows up in boreal summer(June to September),and becomes obvious when WPWP SST is higher than 29℃.As observed,East Asian summer monsoon(EASM) impinges on Philippine Islands in July,which has an important impact on the formation and maintenance of the "sandwich structure".Winds affect the distribution of SST in two ways:one by increasing the local latent heat flux and the other by transporting cold water towards the southeast of Philippine Islands.
基金supported by the National Key Research and Development Program of China(No.2018YFC1407601).
文摘Ecological protection and high-quality development of the Yellow River basin are becoming part of the national strategy in recent years.The Yellow River Estuary has been seriously affected by human activities.Especially,it has been severely polluted by the nitrogen and phosphorus from land sources,which have caused serious eutrophication and harmful algal blooms.Nutrient criteria,however,was not developed for the Yellow River Estuary,which hindered nutrient management measures and eutrophication risk assessment in this key ecological function zone of China.Based on field data during 2004-2019,we adopted the frequency distribution method,correlation analysis,Linear Regression Model(LRM),Classification and Regression Tree(CART)and Nonparametric Changepoint Analysis(nCPA)methods to establish the nutrient criteria for the adjacent waters of Yellow River Estuary.The water quality criteria of dissolved inorganic nitrogen(DIN)and soluble reactive phosphorus(SRP)are recommended as 244.0μg L^(−1) and 22.4μg L^(−1),respectively.It is hoped that the results will provide scientific basis for the formulation of nutrient standards in this important estuary of China.
文摘<strong>Objective:</strong> To investigate the correlation between 5-HTTLPR (5-and serotonin transporter linked polymer region) gene polymorphism and BDNF (brain derived neural factor) gene polymorphism and PTSD (post traumatic stress disorders) in Li and Han nationalities in Hainan Province. <strong>Methods:</strong> 167 Hainan Li PTSD patients, 141 Hainan Han PTSD patients and 158 healthy volunteers (control group) were investigated by ETI, caps, Toh, WCST, TMT and WAIS-RC. The polymorphisms of rs6265 locus of 5-HTTLPR and BDNF genes were detected by PCR (polymerase chain reaction) and page (polycylamide gel electrophoresis), and the correlation with PTSD was analyzed. Logistic regression analysis was used to analyze the influencing factors of PTSD. <strong>Results:</strong> The ETI score, total PTSD score and TMT time of Li PTSD patients were significantly higher than those of Han PTSD patients (P < 0.01). The comprehension, picture filling, picture arrangement, operation IQ and total IQ of WAIS-RC were significantly lower than those of Han PTSD patients (P < 0.01);The numbers of errors, TMT and Toh in WCST were significantly lower than those in Han PTSD patients (P < 0.01). There was no significant difference in the distribution of 5-HTTLPR genotype and allele between Li PTSD patients and control group (P > 0.05). SS genotype of 5-HTTLPR and (GA + AA) genotype of rs6265 locus may increase the risk of PTSD in Hainan Han population. AA and GA + AA genotypes at rs6265 locus may increase the risk of PTSD in Li population (P < 0.05). Among Li PTSD patients, the ETI score, PTSD total score, TMT time, Toh planning time and execution time of AA genotype at rs6265 locus were significantly higher than those of GG genotype;the total scores of comprehension and operation IQ, and Toh in WAIS-RC were significantly lower than those in GG genotype (P < 0.05). Among Han PTSD patients, the ETI score, PTSD total score and TMT time of SS genotype of 5-HTTLPR were significantly higher than those of LL genotype, and the comprehension, arithmetic and block diagram in WAIS-RC were significantly lower than those of LL genotype;The ETI score, PTSD total score and TMT time of patients with (GA + AA) genotype at rs6265 locus were also significantly higher than those of patients with GG genotype. The comprehension and block diagram in WAIS-RC were significantly lower than those of patients with GG genotype. The number of WCST errors in patients with AA genotype was significantly higher than those of patients with GG genotype, and the operational IQ in WAIS-RC was significantly lower than those of patients with GG genotype (P < 0.05). <strong>Conclusion:</strong> The LL genotype of 5-HTTLPR and the GG genotype of rs6265 locus are related to PTSD of Li and Han nationalities in Hainan, which are important protective factors for PTSD of Li and Han nationalities in Hainan.
基金Project supported by the National Natural Science Foundation of China(Grant No.11174015)
文摘A rubidium-beam microwave clock, optically pumped by a distributed feedback diode laser, is experimentally investigated. The clock is composed of a physical package, optical systems, and electric servo loops. The physical package realizes the microwave interrogation of a rubidium-atomic beam. The optical systems, equipped with two 780-nm distributed feedback laser diodes, yield light for pumping and detecting. The servo loops control the frequency of a local oscillator with respect to the microwave spectrum. With the experimental systems, the microwave spectrum, which has an amplitude of 4 n A and a line width of 700 Hz, is obtained. Preliminary tests show that the clock short-term frequency stability is 7 × 10^-11 at 1 s, and 3 × 10^-12 at 1000 s. These experimental results demonstrate the feasibility of the scheme for a manufactured clock.
基金Supported by the China Meteorological Administration Special Public Welfare Research Fund(GYHY200806007 and GYHY201006014)National Natural Science Foundation of China(40875022,40633016,and 40975021)+1 种基金National Basic Research and Development(973)Program of China(2012CB417204)Basic Research Project of the State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences(2008LASWZI01)
文摘The CloudSat satellite data from June 2006 to April 2011 are used to investigate the characteristics of cloud vertical profiles over East Asia (20°-50°N, 80°- 120°E), with particular emphasis on the profiles of precipitative clouds in comparison with those of nonprecipitative clouds, as well as the seasonal variations of these profiles. There are some obvious differences between the precipitative and nonprecipitative cloud profiles. Generally, precipitative clouds mainly locate below 8 km with radar refiectivity in the range of-20 to 15 dBZ and maximum values appearing within 2-4-km height, and the clouds usually reach the ground; while nonprecipitative clouds locate in the layers of 4 12 km with radar refiectivity between -28 and 0 dBZ and maximum values within 8-10-km height. There are also some differences among the liquid precipitative, solid precipitative, and possible drizzle precipitative cloud profiles. In precipitative clouds, radar reflectivity increases rapidly from 11 to 7 km in vertical, implying that condensation and collision-coalescence processes play a crucial role in the formation of large-size drops. The frequency distribution of temperature at -15℃ is consistent with the highest frequency of radar reflectivity in solid precipitative clouds, which suggests that the temperatures near -15℃ are conductive to deposition and accretion processes. The vertical profiles of liquid precipitative clouds show almost the same distributions in spring, summer, and autumn but with differences in winter at mainly lower levels. In contrast, the vertical profiles of solid precipitative clouds change from spring to winter with an alternate double and single high-frequency core, which is consistent with variations of the frequency distribution of temperature at 15℃. The vertical profiles of nonprecipitative clouds show a little change with season. The observations also show that the precipitation events over East Asia are mostly related to deep convective clouds and nimbostratus clouds. These results are expected to be useful for evaluation of weather and climate .models and for improvement of microphysical parameterizations in numerical models.
基金supported in part by the National Natural Science Foundation of China(Nos.61903027,61973002)in part by the National Postdoctoral Program for Innovative Talents(BX20180346)+1 种基金in part by the General Financial Grant from the China Postdoctoral Science Foundation(2019M660834)in part by the Anhui Provincial Natural Science Foundation(No.2008085J32).
文摘This paper addresses distributed computation Sylvester equations of the form AX+XB=C with fractional order dynamics.By partitioning parameter matrices A,B and C,we transfer the problem of distributed solving Sylvester equations as two distributed optimization models and design two fractional order continuous-time algorithms,which have more design freedom and have potential to obtain better convergence performance than that of existing first order algorithms.Then,rewriting distributed algorithms as corresponding frequency distributed models,we design Lyapunov functions and prove that proposed algorithms asymptotically converge to an exact or least squares solution.Finally,we validate the effectiveness of proposed algorithms by providing a numerical example.
基金Supported in part by the National High-Tech Research and Development (863) Program of China(Nos. 2006AA10Z261,2006AA10A301,and 2007AA100408)
文摘This paper presents an in-depth analysis of the interference strength and required guardband width between coexistent users for distributed orthogonal frequency division multiple access (OFDMA). In dynamic spectrum access networks, the cross-band interference between spectrally adjacent users is considered harmful with frequency guardbands inserted between spectrum blocks to eliminate the interference. However, the strength of the cross-band interference depends heavily on the user heterogeneity in different OFDM configurations. The cross-band interference due to the three user heterogeneity artifacts of power heterogeneity, sampling rate heterogeneity, and symbol length heterogeneity is investigated to determine the required guardband width. Analytical and simulation results show that the greater user heterogeneity requires larger guardbands with the sampling rate heterogeneity having the greatest effect. These results can be used to assist the design of spectrum allocation strategies.
文摘A method is presented for the detection and parameter estimation of a single Linear Frequency Modulation (LFM) signal in spread spectrum systems based on Wigner Hough Transform (WHT) , followed by the theoretical analysis. A simulation result is given to show the effectiveness of this method.
基金Supported by Recep Tayyip Erdoğan University with project number 2013.103.03.01.
文摘Objective:To determine growth and reproduction biology of Philocheras trispinosus(P.trispinosus)with abundance of other caridean shrimps caught by beam trawl in the Southern Black Sea.Methods:Samplings were carried out monthly with a beam trawl of 2 m length and 15 mm cod-end mesh size between December 2012 and November 2013.All individuals were sampled between 1 and 40+m water depth from 146 hauls.Results:A total of 550 P.trispinosus,618 Palaemon adspersus,12 Palaemon serratus,11 Philocheras fasciatus and 10 Crangon crangon were sampled during the study period.The crangonid shrimps started appearing during the winter and spring and the number of individuals increased to reach their highest value in mid-winter and mid-spring.The seasonal von Bertalanffy growth parameters for P.trispinosus were estimated as L_(∞)=29.3 mm total length,K=0.860/year,t_(0)=–0.900 year,C=0.180,and t_(s)=0.010.The start of the slow growth period was at the beginning of July(WP=0.510).Ovigerous females appeared in the sampling area between January and April.Size at sexual maturity was estimated as 25.69 mm total length.Conclusions:The results supported the distribution and abundance of caridean shrimp species from the study area and the population dynamics of the most abundant shrimp species,P.trispinosus.The current study can be answered as baseline data prior to management strategies to ensure sustainable conservation of the shrimp species.
文摘This article investigates the problem of on line parameter estimation for fractionalorder linear systems.Based on the theory of fractional-order calculus,the conventional gradient estimator is extended to the fractional-order areas.The stability of the estimator and the convergence are analysed using the continuous frequency distributed model and indirect Lyapunov method.Finally,numerical simulation examples are given to demonstrate the effectiveness of the proposed schemes.