Perciformes,the largest order of vertebrates with 20 suborders,is the most diverse fish order that dominates vertebrate ocean life.The complete mitochondrial control region(CR) of Trichiurus japonicus(Trichiuridae,Sco...Perciformes,the largest order of vertebrates with 20 suborders,is the most diverse fish order that dominates vertebrate ocean life.The complete mitochondrial control region(CR) of Trichiurus japonicus(Trichiuridae,Scombroidei) and Pampus sp.(Stromateidae,Stromateoidei) were amplified and sequenced.Together with data from GenBank,the tandem repeats in the mitochondrial CR from 48 species,which covered nine suborders of Perciformes,are reported in this study.The tandem repeats tend to be long in the suborder Percoidei and Stromateoidei.The identical repeats in 21 species of Cichlidae suggest a common origin and have existed before species divergence.Larimichthys crocea shows tandem repeats instead of the typical structure of the central conserved sequence blocks,which was first reported in Perciformes and vertebrates.This might have resulted from interruption of the polymerase activity during the H-strand synthesis.The four broader patterns presented here for the tandem repeats,including those in both the 5' and 3' ends,only in the either 5' or 3' end,and in the central conserved domain of the control region,will be useful for understanding the evolution of species.展开更多
Headspace solid phase microextraction chromatography （HS-SPME/GC） was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary ma...Headspace solid phase microextraction chromatography （HS-SPME/GC） was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary major volatile breakdown product of linoleic acid. Samples of the headspace taken from sealed 20 mL vials, incubated 30 min at 50 ~C followed by 5 min adsorption, were injected into a gas chromatograph with 2 min thermal desorption. In applying SPME, different analytical conditions were evaluated. The linearity of response of the volatiles for the HS-SPME/GC procedure using a carboxen-polydimethylsiloxane fiber was determined from 3 g of mineral oil spiked with a hexanal standard solution at different levels. Using the optimized extraction conditions, an R value close to unity （R = 0.999） was found, and the repeatability （n = 1 l） was 6.31%. The results indicated that hexanal is linearly related to peroxide value （PV） only intermediate PV ranges （10-18 meq/kg）. The study also showed that HS-SPME/GC procedure was a simple and reproducible method for the analysis of hexanal in the HS of commercial soybean oil samples, and is useful as a quality control and research tool for the evaluation of flavor quality and shelf life of vegetable oils.展开更多
The problem of transmission power control in a rate-aware way is investigated to improve the throughput of wireless ad hoc network. The behavior of basic IEEE 802.11 DCF is approximated by the p-persistent CSMA throug...The problem of transmission power control in a rate-aware way is investigated to improve the throughput of wireless ad hoc network. The behavior of basic IEEE 802.11 DCF is approximated by the p-persistent CSMA through a Markov chain model. The throughput model takes hidden terminals, muhi-hop flow and concurrent interference into account. Numerical results show that the optimal transmission power derived from this model could balance the tradeoff between spatial reuse and data rate and hence yield maximum throughput.展开更多
This study aims to gradually reflect information concerning tourists and to propose tourist route model formulation techniques that take spatial reproducibility into account using GIS （geographic information systems...This study aims to gradually reflect information concerning tourists and to propose tourist route model formulation techniques that take spatial reproducibility into account using GIS （geographic information systems）. The conclusions can be summarized into the following three points： （1） Kawagoe city in Saitama Prefecture was selected as the area targeted by this study. All types of data about Kawagoe city and tourists was collected and processed, and a tourist route model formulation method that considered spatial reproducibility using GIS was proposed, （2） 3-stage scenarios were created with the presence or absence of Kawagoe city tourist policies set as standards and this was used to develop tourist route models. It is POSsible to expect synergy in the encouragement of the use of sightseeing buses and the same traffic regulations as the traffic pilot program, and （3） It is considered that it is possible to apply the tourist route model formulation method proposed by this study to other tourist destinations without being limited by spatiotemporal differences or the particular issues of each tourist destinations as spatial reproducibility was confirmed.展开更多
For impulse radio ultra-wideband (IR-UWB) ranging systems,effects of the settings of transmitter-related parameters, which include the pulse shape, the bandwidth and the pulse repetition interval (PRI), on ranging acc...For impulse radio ultra-wideband (IR-UWB) ranging systems,effects of the settings of transmitter-related parameters, which include the pulse shape, the bandwidth and the pulse repetition interval (PRI), on ranging accuracy were studied through theoretical analysis and simulations. Both the match-filtering based coherent TOA estimation algorithm and the energy-detection based non-coherent algorithm were used during simulations. Results show that the pulse shape has the least effect on the ranging accuracy. Increasing the pulse bandwidth can improve the ranging performance, but the performance is hardly improved any more when the bandwidth is increased beyond a certain level. PRI should be set long enough to guarantee the accurate ranging, because when PRI is shorter than the maximum excess delay of the channel, the ranging accuracy will be deteriorated by inter-pulse interference.展开更多
Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, t...Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, the investigation of bird migration at individual level （i.e. repeatability in migratory routes and timing） still remains seldom explored. Here, we investigated repeated migratory trips of a trans-Saharan endangered migratory raptor, the Egyptian Vulture Neophron percnopterus, tracked by GPS satellite telemetry. We compared between- and within-individual variation in migratory routes and timing in order to assess the degree of repeatability （or conversely, the flexibility） in migration. To this end, we analysed a dataset of 48 trips （23 springs and 25 autumns） recorded for six adult birds during 2007-2013. Our results showed consistent migration timing at the individual level, both in spring and autumn. Interestingly, there was a high degree of flexibility in the routes followed by the same individual in different years, probably due to variations in meteorological conditions. Contrary to expectations of a faster migration in spring than in autumn owing to a time-minimization strategy for breeding, birds spent less time in autumn migration （13 ± 2 days, range = 9-18 d） than in spring migration （19 ± 3 days, range = 13-26 d）, which can be explained by differences in environmental con- ditions en route. Egyptian vultures showed a consistent clockwise loop migration through western Africa, following more easterly routes in autumn than in spring. Finally, our results provide supporting evidence of low phenotypic plasticity in timing of migration （i.e. strong endogenous control of migration） and high flexibility in routes [Current Zoology 60 （5）： 642-652, 2014].展开更多
Linear recurring sequences over finite fields play an important role in coding theory and cryptography. It is known that subfield subcodes of linear codes yield some good codes. In this paper, we study linear recurrin...Linear recurring sequences over finite fields play an important role in coding theory and cryptography. It is known that subfield subcodes of linear codes yield some good codes. In this paper, we study linear recurring sequences and subfield subcodes. Let Mqm(f(x)) denote the set of all linear recurring sequences over Fqm with characteristic polynomial f(x) over Fqm . Denote the restriction of Mqm(f(x)) to sequences over Fq and the set after applying trace function to each sequence in Mqm(f(x)) by Mqm(f(x)) | Fq and Tr( Mqm(f(x))), respectively. It is shown that these two sets are both complete sets of linear recurring sequences over Fq with some characteristic polynomials over Fq. In this paper, we firstly determine the characteristic polynomials for these two sets. Then, using these results, we determine the generator polynomials of subfield subcodes and trace codes of cyclic codes over Fqm .展开更多
We propose a novel scheme for synchronous optical sampling based on multicast parametric process. The linearly chirped and time-broadened pulses are utilized to replace the traditional mode-locked sampling pulses. An ...We propose a novel scheme for synchronous optical sampling based on multicast parametric process. The linearly chirped and time-broadened pulses are utilized to replace the traditional mode-locked sampling pulses. An optical sampling rate of 80 Gbit/s is realized by using only one sampling source with repetition rate of 10 GHz.展开更多
基金Supported by the National Natural Science Foundation of China(No.40676085)
文摘Perciformes,the largest order of vertebrates with 20 suborders,is the most diverse fish order that dominates vertebrate ocean life.The complete mitochondrial control region(CR) of Trichiurus japonicus(Trichiuridae,Scombroidei) and Pampus sp.(Stromateidae,Stromateoidei) were amplified and sequenced.Together with data from GenBank,the tandem repeats in the mitochondrial CR from 48 species,which covered nine suborders of Perciformes,are reported in this study.The tandem repeats tend to be long in the suborder Percoidei and Stromateoidei.The identical repeats in 21 species of Cichlidae suggest a common origin and have existed before species divergence.Larimichthys crocea shows tandem repeats instead of the typical structure of the central conserved sequence blocks,which was first reported in Perciformes and vertebrates.This might have resulted from interruption of the polymerase activity during the H-strand synthesis.The four broader patterns presented here for the tandem repeats,including those in both the 5' and 3' ends,only in the either 5' or 3' end,and in the central conserved domain of the control region,will be useful for understanding the evolution of species.
文摘Headspace solid phase microextraction chromatography （HS-SPME/GC） was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary major volatile breakdown product of linoleic acid. Samples of the headspace taken from sealed 20 mL vials, incubated 30 min at 50 ~C followed by 5 min adsorption, were injected into a gas chromatograph with 2 min thermal desorption. In applying SPME, different analytical conditions were evaluated. The linearity of response of the volatiles for the HS-SPME/GC procedure using a carboxen-polydimethylsiloxane fiber was determined from 3 g of mineral oil spiked with a hexanal standard solution at different levels. Using the optimized extraction conditions, an R value close to unity （R = 0.999） was found, and the repeatability （n = 1 l） was 6.31%. The results indicated that hexanal is linearly related to peroxide value （PV） only intermediate PV ranges （10-18 meq/kg）. The study also showed that HS-SPME/GC procedure was a simple and reproducible method for the analysis of hexanal in the HS of commercial soybean oil samples, and is useful as a quality control and research tool for the evaluation of flavor quality and shelf life of vegetable oils.
基金the National High Technology Research and Development Programme of China(No.2004AA104280.2006AA01Z172)
文摘The problem of transmission power control in a rate-aware way is investigated to improve the throughput of wireless ad hoc network. The behavior of basic IEEE 802.11 DCF is approximated by the p-persistent CSMA through a Markov chain model. The throughput model takes hidden terminals, muhi-hop flow and concurrent interference into account. Numerical results show that the optimal transmission power derived from this model could balance the tradeoff between spatial reuse and data rate and hence yield maximum throughput.
文摘This study aims to gradually reflect information concerning tourists and to propose tourist route model formulation techniques that take spatial reproducibility into account using GIS （geographic information systems）. The conclusions can be summarized into the following three points： （1） Kawagoe city in Saitama Prefecture was selected as the area targeted by this study. All types of data about Kawagoe city and tourists was collected and processed, and a tourist route model formulation method that considered spatial reproducibility using GIS was proposed, （2） 3-stage scenarios were created with the presence or absence of Kawagoe city tourist policies set as standards and this was used to develop tourist route models. It is POSsible to expect synergy in the encouragement of the use of sightseeing buses and the same traffic regulations as the traffic pilot program, and （3） It is considered that it is possible to apply the tourist route model formulation method proposed by this study to other tourist destinations without being limited by spatiotemporal differences or the particular issues of each tourist destinations as spatial reproducibility was confirmed.
基金Sponsored by the National Natural Science Foundation of China (Grant No.60432040)the Natural Science Foundation of Guangdong Privince(Grant No.9451805707003235)
文摘For impulse radio ultra-wideband (IR-UWB) ranging systems,effects of the settings of transmitter-related parameters, which include the pulse shape, the bandwidth and the pulse repetition interval (PRI), on ranging accuracy were studied through theoretical analysis and simulations. Both the match-filtering based coherent TOA estimation algorithm and the energy-detection based non-coherent algorithm were used during simulations. Results show that the pulse shape has the least effect on the ranging accuracy. Increasing the pulse bandwidth can improve the ranging performance, but the performance is hardly improved any more when the bandwidth is increased beyond a certain level. PRI should be set long enough to guarantee the accurate ranging, because when PRI is shorter than the maximum excess delay of the channel, the ranging accuracy will be deteriorated by inter-pulse interference.
文摘Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, the investigation of bird migration at individual level （i.e. repeatability in migratory routes and timing） still remains seldom explored. Here, we investigated repeated migratory trips of a trans-Saharan endangered migratory raptor, the Egyptian Vulture Neophron percnopterus, tracked by GPS satellite telemetry. We compared between- and within-individual variation in migratory routes and timing in order to assess the degree of repeatability （or conversely, the flexibility） in migration. To this end, we analysed a dataset of 48 trips （23 springs and 25 autumns） recorded for six adult birds during 2007-2013. Our results showed consistent migration timing at the individual level, both in spring and autumn. Interestingly, there was a high degree of flexibility in the routes followed by the same individual in different years, probably due to variations in meteorological conditions. Contrary to expectations of a faster migration in spring than in autumn owing to a time-minimization strategy for breeding, birds spent less time in autumn migration （13 ± 2 days, range = 9-18 d） than in spring migration （19 ± 3 days, range = 13-26 d）, which can be explained by differences in environmental con- ditions en route. Egyptian vultures showed a consistent clockwise loop migration through western Africa, following more easterly routes in autumn than in spring. Finally, our results provide supporting evidence of low phenotypic plasticity in timing of migration （i.e. strong endogenous control of migration） and high flexibility in routes [Current Zoology 60 （5）： 642-652, 2014].
基金supported by National Key Basic Research Program of China(973 Program)(Grant No.2013CB834204)National Natural Science Foundation of China(Grant Nos.61171082 and 10990011)
文摘Linear recurring sequences over finite fields play an important role in coding theory and cryptography. It is known that subfield subcodes of linear codes yield some good codes. In this paper, we study linear recurring sequences and subfield subcodes. Let Mqm(f(x)) denote the set of all linear recurring sequences over Fqm with characteristic polynomial f(x) over Fqm . Denote the restriction of Mqm(f(x)) to sequences over Fq and the set after applying trace function to each sequence in Mqm(f(x)) by Mqm(f(x)) | Fq and Tr( Mqm(f(x))), respectively. It is shown that these two sets are both complete sets of linear recurring sequences over Fq with some characteristic polynomials over Fq. In this paper, we firstly determine the characteristic polynomials for these two sets. Then, using these results, we determine the generator polynomials of subfield subcodes and trace codes of cyclic codes over Fqm .
基金supported by the National Natural Science Foundation of China(Nos.61475023,61307109 and 61475131)the National High Technology Research and Development Program of China(No.2013AA031501)+4 种基金the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120005120021)the Fundamental Research Funds for the Central Universities(No.2013RC1202)the Program for New Century Excellent Talents in University(No.NECT-11-0596)the Beijing Nova Program(No.2011066)the Fund of State Key Laboratory of Information Photonics and Optical Communications
文摘We propose a novel scheme for synchronous optical sampling based on multicast parametric process. The linearly chirped and time-broadened pulses are utilized to replace the traditional mode-locked sampling pulses. An optical sampling rate of 80 Gbit/s is realized by using only one sampling source with repetition rate of 10 GHz.
