The measurement and observation for this study were carried out by using a three-dimensional (u, v, w) Sonic anemometer (IAP-SA 485), at Forest Ecosystem Opened Research Station of Changbai Mountains (12828扙 and 4224...The measurement and observation for this study were carried out by using a three-dimensional (u, v, w) Sonic anemometer (IAP-SA 485), at Forest Ecosystem Opened Research Station of Changbai Mountains (12828扙 and 4224?N, Jilin Province, P. R. China) in August 2001. The basic characteristics of turbulence, such as turbulence intensity, atmospheric stability, time scales, and convection state, near the forest floor were analyzed. It is concluded that the airflow near forest floor is characterized by high intermittence and asymmetry, and the active and upward movement takes the leading position. Near forest floor, the vertical turbulence is retained and its time scale and length scale are much less than that of u, v components. The eddy near forest floor shows a flat structure and look like a ’Disk’. Buoyancy plays a leading role in the generation and maintenance of local turbulence展开更多
[Objective] The aim was to analyze the exterior quality and physical prop- erties of Hongda Tobacco in Yunnan Province, thus providing references for planting planning, technology and selection of raw materials. [Meth...[Objective] The aim was to analyze the exterior quality and physical prop- erties of Hongda Tobacco in Yunnan Province, thus providing references for planting planning, technology and selection of raw materials. [Method] Hongda C3F progenies were chosen from 24 villages and towns in Qujing, Kunming, Baoshan and Dali, and the concerning exterior quality and physical properties were analyzed through cluster analysis. [Result] The openness and width of C3F differed significantly among Qujing, Kunming, Baoshan and Dali. The thickness, stem content, equilibrium moisture con- tent extremely differed, and density and filling power varied significantly. Most physi- cal properties, such as equilibrium moisture content and density, of Dali Hongda were quite different from those in Qujing, Kunming and Baoshan, indicating that Dali Hongda enjoys special characteristics in physical properties. In addition, stem content in east, center and west areas of Yunnan Province differed significantly and Hongda in Yunnan could be classified into four species according to physical property. [Conclusion] The research has laid basis for planting planning, technology and raw mate- rials selection of Hongda tobacco.展开更多
The anthropogenic CO column content in the atmosphere is derived from measurements with infrared grating spectrometers in Beijing,China,and Moscow,Russia,during 1992–2012.Some specific variation characteristics and l...The anthropogenic CO column content in the atmosphere is derived from measurements with infrared grating spectrometers in Beijing,China,and Moscow,Russia,during 1992–2012.Some specific variation characteristics and long-term variation trends of the CO column content in the atmosphere in these regions are discussed.An evident variation trend of anthropogenic CO in the atmosphere for the Beijing region is not observed during 1992–2012,while for the Moscow region,it decreases yearly by about 1.4% for the same period.High CO concentrations appear quite frequently in Beijing,but much less frequently in Moscow,except during the natural fire events in summer 2010.From back trajectory analysis,the high CO concentration observed in Beijing can be attributed to the intensive CO emission sources in its surrounding areas.展开更多
This paper presents an experimental study of the physical characteristic effects of large particles on hydraulic transport in a horizontal pipe.The particles are spherical and are large with respect to the diameter of...This paper presents an experimental study of the physical characteristic effects of large particles on hydraulic transport in a horizontal pipe.The particles are spherical and are large with respect to the diameter of the pipe(8%,10%,16% and 25%).Experiments were done to test the important parameters in solid transport(pressure,velocity,etc.).As a result,the relationship between the pressure gradient forces and the mixture velocity was substantially different from the pure liquid flow.However,in a single-phase flow a monotonous behavior of the pressure drop curve is observed,and the curve of the solid particle flow attains its minimum at the critical velocity.The regimes are characterized with differential pressure measurements and visualizations.展开更多
Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908e2008...Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908e2008 from 3 meteorological stations in the south(Kaisaniemi),centre(Kajaani) and north(Sodankyl€a). Although precipitation days in northern part were more frequent than in central and southern parts, daily precipitation intensity in the south was generally higher than those in the centre and north of the country. Annual sum of very light precipitation(0 mm < daily precipitation long-term 50 th percentile of daily precipitation more than 0 mm) significantly( p < 0.05) decreased over time,with the highest rate in northern Finland. These decreasing trends might be the result of significant increases in frequency of days with very light precipitation at all the stations, with the highest and lowest rates in northern and southern Finland, respectively. Ratio of annual total precipitation to number of precipitation days also declined in Finland over 1908e2008, with a decreasing north to south gradient. However, annual duration indices of daily precipitation revealed no statistically significant trends at any station. Daily precipitation characteristics showed significant relationships with various well-known atmospheric circulation patterns(ACPs). In particular, the East Atlantic/West Russia(EA/WR)pattern in summer was the most influential ACP negatively associated with different daily precipitation intensity, frequency and duration indices at all three stations studied.展开更多
The theory model of fiber optical parametric amplifier (FOPA) was introduced, which is based on optical nonlinear effect. And then numerical simulation was done to analyze and discuss the gain spectral characteristics...The theory model of fiber optical parametric amplifier (FOPA) was introduced, which is based on optical nonlinear effect. And then numerical simulation was done to analyze and discuss the gain spectral characteristics of one-pump and two-pump FOPA. The results show that for one-pump FOPA, when pump wavelength is near to fiber zero-dispersion wavelength(ZDW), the gain flatness is better, and with the increase of the pump power, fiber length and its nonlinear coefficient, the gain value will increase while the gain bandwidth will become narrow. For two-pump FOPA, when the pump central wavelength is near to fiber ZDW, the gain flatness is better. Moreover, by decreasing the space of two pumps wavelength, the gain flatness can be improved. Finally, some problems existing in FOPA were addressed.展开更多
Starting from a special variable transformation and with the help of an extended mapping approach, the high-order Schrodinger equation (n = 3, 4) is solved. A new family of variable separation solutions with arbitra...Starting from a special variable transformation and with the help of an extended mapping approach, the high-order Schrodinger equation (n = 3, 4) is solved. A new family of variable separation solutions with arbitrary functions is derived.展开更多
The reasonability of the adopted capacity load ratio numerical value in urban power grid planning determines the economy of planning level yearly power grid.Too large capacity load ratio will result in the increasing ...The reasonability of the adopted capacity load ratio numerical value in urban power grid planning determines the economy of planning level yearly power grid.Too large capacity load ratio will result in the increasing investment in the early period of power grid construction, however, too small capacity load ratio will make the power grid have poor adaptability, affecting the power supply. Reasonably determining the adopted regional power grid capacity load ratio quantitative numerical value in planning has a strong guiding significance for constructing reliable and economic power grid and preventing power grid from excessive advance or lagging behind the load development. This paper, through the statistics and analysis of a certain regional power grid 2010-2012 three years' power grid daily load characteristics and the investment benefit evaluation of three years' 220KV power grid individual project, makes a preliminary analysis and puts forwards the specific advice on the reasonable values of power ~rid 35-220KV power transformation capacity load ratio.展开更多
Topic effect on L2 writing has long been an issue of controversy. This study was carried out to investigate the influence of topic type on the quality of topic sentence. The participants, 150 college students at three...Topic effect on L2 writing has long been an issue of controversy. This study was carried out to investigate the influence of topic type on the quality of topic sentence. The participants, 150 college students at three different proficiency levels, were asked to write both on a private topic and a public topic. The results show that the participants on the whole wrote better on the public topic, and their proficiencies can be differentiated by the quality of their topic sentences. The public topic was conducive to the production of complete English discourse structures, as well as the generation of informative and predictive topic sentences. Moreover, the results also reveal the dynamic nature of contrastive rhetoric展开更多
In recent years, the complaints against the vibration as environmental pollution tends to increase gradually in Japan. The measurement investigation to demonstrate the actual situation of the environmental vibration w...In recent years, the complaints against the vibration as environmental pollution tends to increase gradually in Japan. The measurement investigation to demonstrate the actual situation of the environmental vibration was carried out for several years. The measurement manual for each vibration source such as operations of factory machine, construction works, road traffics and railways to unify measurement methods was made at the start. From the measurement investigation, the vibration amplification characteristics of the detached house by one-third octave frequency in Japan was analyzed as a purpose to improve estimated precision of the vibration in a detached house. In this paper, the vibration amplification characteristic expressed at onethird octave band frequency was shown, and the characteristics was arranged about a result measured with 27 detached houses in Japan.展开更多
Teleportation of a qubit with two partially entangled qubit states linking three nodes as quantum channels is extensively studied via the usual ancilla method. With the method two realization approaches, i.e., the nod...Teleportation of a qubit with two partially entangled qubit states linking three nodes as quantum channels is extensively studied via the usual ancilla method. With the method two realization approaches, i.e., the node progression approach and the global accumulation approach, are presented. Their resource consumptions, operation complexities, and el^ciencies axe evaluated and compared. It is found that the latter approach is better than the former one besides the error is partially self-corrected. The latter approach is further improved so that two merits are resultant. The improved version is compared with a similar protocol [M.Y. Wang and F.L. Yah, Eur. Phys. J. D 54 (2009) 111]. Their merits and additional costs are exposed.展开更多
Today, just by activating a button on the display panel of a total station, one can measure horizontal and vertical angles or calculate distances and coordinates of points. For this reason, it has become necessary to ...Today, just by activating a button on the display panel of a total station, one can measure horizontal and vertical angles or calculate distances and coordinates of points. For this reason, it has become necessary to improve the check of a total station in order to respond to its contemporary way of use. The aim of this research is to create a new method for checking total stations using only one check--field, in a different way of the today's standards. The basic principle, of the comparison of an instrument's measurements to those of another instrument with higher accuracy, is implemented into a mathematical model such as the adjustment of an indoor geodetic network. Thus, the check of the proper function of a total station is applied. An a-priori calculation Of^o of the network's adjustment can be calculated by modeling the uncertainties using statistical methods as the random number generators by means of the Monte Carlo method. The prospective ao can then be compared to the a-posteriori ao provided by the adjustment of the measurements which are carried out by using the total station under check.展开更多
In the past 10 years (2004-2013), annual open cruise during late summer provided new opportunities for comprehensive studies in the Northern South China Sea (NSCS). The 10-year field investigation program was carr...In the past 10 years (2004-2013), annual open cruise during late summer provided new opportunities for comprehensive studies in the Northern South China Sea (NSCS). The 10-year field investigation program was carried out by the South China Sea Institute of Oceanology, Chinese Academy of Sciences (SCSIO, CAS). Measurements inclu- ded water mass property, ocean circulation, atmospheric structure, and chemical and biological elements. The observation data collected during these open cruises have been intensively used in the studies of marine oceanographic, meteorological, chemical, and biological processes in the NSCS. In this study, comprehensive assessment of data application in oceanographic and meteorological studies is provided: (1) the property and variability of water masses in different layers; (2) the distribution of main currents and three-dimensional structure of mesoscale eddies; and (3) atmospheric structure and its feedback to the ocean. With the continuance of open cruises, it is feasible to construct high- quality, gridded climatological marine meteorological datasets in the NSCS in the near future.展开更多
Nonadiabatic holonomic quantum computation has received increasing attention due to its robustness against control errors. However, all the previous schemes have to use at least two sequentially implemented gates to r...Nonadiabatic holonomic quantum computation has received increasing attention due to its robustness against control errors. However, all the previous schemes have to use at least two sequentially implemented gates to realize a general one-qubit gate. Based on two recent reports, we construct two Hamiltonians and experimentally realized nonadiabatic holonomic gates by a single-shot implementation in a two-qubit nuclear magnetic resonance (NMR) system. Two noncommuting one-qubit holonomic gates, rotating along .~ and ~ axes respectively, are implemented by evolving a work qubit and an ancillary qubit nonadiabatically following a quantum circuit designed. Using a sequence compiler developed for NMR quantum information processor, we optimize the whole pulse sequence, minimizing the total error of the implementation. Finally, all the nonadiabatic holonomic gates reach high unattenuated experimental fidelities over 98%.展开更多
We present an efficient faithful multipartite polarization entanglement distribution protocol over an ar- bitrary noisy channel. The spatial degree of freedom is used to carry the entanglement during the transmission....We present an efficient faithful multipartite polarization entanglement distribution protocol over an ar- bitrary noisy channel. The spatial degree of freedom is used to carry the entanglement during the transmission. We describe the principle by distributing n-qubit Greenberge-Horne--Zeilinger state and n-qubit W state. Our scheme can be used to distribute arbitrary n-qUbit entangled states to n distant locations. The remote parties can obtain maximally entangled states deterministically on the polarization of photons. Only passive linear optics are employed in our setup, which makes our scheme more feasible and efficient for practical application in long distance quantum communication.展开更多
We investigate the pump-depleted model of a dual-pump fiber optical parametric amplifier(FOPA) with Raman effect.As bandwidth increases,the gain profile of the distorted FOPA would be impacted seriously.Under the wide...We investigate the pump-depleted model of a dual-pump fiber optical parametric amplifier(FOPA) with Raman effect.As bandwidth increases,the gain profile of the distorted FOPA would be impacted seriously.Under the widebands,especially when the pump separation is large,zero dispersion wavelength(ZDW) fluctuation is another factor which can not be neglected.Numerical simulations with these comprehensive factors are mainly analyzed to obtain their influence on gain characteristics.Saturated gain spectrum is also discussed in detail.展开更多
We present two robust quantum secure direct communication (QSDC) schemes with a quantum one-time pad over a collective-noise channel. Each logical qubit is made up of two physical qubits and it is invariant over a col...We present two robust quantum secure direct communication (QSDC) schemes with a quantum one-time pad over a collective-noise channel. Each logical qubit is made up of two physical qubits and it is invariant over a collective-noise channel. The two photons in each logical qubit can be produced with a practically entangled source, i.e., a parametric down-conversion source with a beta barium borate crystal and a pump pulse of ultraviolet light. The information is encoded on each logical qubit with two logical unitary operations, which will not destroy the antinoise feather of the quantum systems. The receiver Bob can read out the sender's message directly with two single-photon measurements on each logical qubit, instead of Bell-state measurements, which will make these protocols more convenient in a practical application. With current technology, our two robust QSDC schemes are feasible and may be optimal ones.展开更多
基金This study was supported by the grand of the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX1-SW-01) and National Natural Science Foundation (30070158).
文摘The measurement and observation for this study were carried out by using a three-dimensional (u, v, w) Sonic anemometer (IAP-SA 485), at Forest Ecosystem Opened Research Station of Changbai Mountains (12828扙 and 4224?N, Jilin Province, P. R. China) in August 2001. The basic characteristics of turbulence, such as turbulence intensity, atmospheric stability, time scales, and convection state, near the forest floor were analyzed. It is concluded that the airflow near forest floor is characterized by high intermittence and asymmetry, and the active and upward movement takes the leading position. Near forest floor, the vertical turbulence is retained and its time scale and length scale are much less than that of u, v components. The eddy near forest floor shows a flat structure and look like a ’Disk’. Buoyancy plays a leading role in the generation and maintenance of local turbulence
基金Supported by Project of China Tobacco Yunnan Industrial Co.,Ltd.(2008YL07)Project of Hongyun Honghe Group(HYHH2010YL02)~~
文摘[Objective] The aim was to analyze the exterior quality and physical prop- erties of Hongda Tobacco in Yunnan Province, thus providing references for planting planning, technology and selection of raw materials. [Method] Hongda C3F progenies were chosen from 24 villages and towns in Qujing, Kunming, Baoshan and Dali, and the concerning exterior quality and physical properties were analyzed through cluster analysis. [Result] The openness and width of C3F differed significantly among Qujing, Kunming, Baoshan and Dali. The thickness, stem content, equilibrium moisture con- tent extremely differed, and density and filling power varied significantly. Most physi- cal properties, such as equilibrium moisture content and density, of Dali Hongda were quite different from those in Qujing, Kunming and Baoshan, indicating that Dali Hongda enjoys special characteristics in physical properties. In addition, stem content in east, center and west areas of Yunnan Province differed significantly and Hongda in Yunnan could be classified into four species according to physical property. [Conclusion] The research has laid basis for planting planning, technology and raw mate- rials selection of Hongda tobacco.
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDA05100300)the National Basic Research Program of China (Grant No.2013CB955801)+1 种基金the National Natural Science Foundation of China (Grant No.41175030)the Russian Foundation for Basic Research (Grant No.13-05-00956)
文摘The anthropogenic CO column content in the atmosphere is derived from measurements with infrared grating spectrometers in Beijing,China,and Moscow,Russia,during 1992–2012.Some specific variation characteristics and long-term variation trends of the CO column content in the atmosphere in these regions are discussed.An evident variation trend of anthropogenic CO in the atmosphere for the Beijing region is not observed during 1992–2012,while for the Moscow region,it decreases yearly by about 1.4% for the same period.High CO concentrations appear quite frequently in Beijing,but much less frequently in Moscow,except during the natural fire events in summer 2010.From back trajectory analysis,the high CO concentration observed in Beijing can be attributed to the intensive CO emission sources in its surrounding areas.
基金the Dyn Fluid Laboratory at Arts et Métiers Paris Tech
文摘This paper presents an experimental study of the physical characteristic effects of large particles on hydraulic transport in a horizontal pipe.The particles are spherical and are large with respect to the diameter of the pipe(8%,10%,16% and 25%).Experiments were done to test the important parameters in solid transport(pressure,velocity,etc.).As a result,the relationship between the pressure gradient forces and the mixture velocity was substantially different from the pure liquid flow.However,in a single-phase flow a monotonous behavior of the pressure drop curve is observed,and the curve of the solid particle flow attains its minimum at the critical velocity.The regimes are characterized with differential pressure measurements and visualizations.
基金the Finnish Cultural Foundation and Maa-ja vesitekniikan tuki r.y. (MVTT, 29188) for funding this researchsupported by Swedish VR, BECC and MERGE programs
文摘Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908e2008 from 3 meteorological stations in the south(Kaisaniemi),centre(Kajaani) and north(Sodankyl€a). Although precipitation days in northern part were more frequent than in central and southern parts, daily precipitation intensity in the south was generally higher than those in the centre and north of the country. Annual sum of very light precipitation(0 mm < daily precipitation long-term 50 th percentile of daily precipitation more than 0 mm) significantly( p < 0.05) decreased over time,with the highest rate in northern Finland. These decreasing trends might be the result of significant increases in frequency of days with very light precipitation at all the stations, with the highest and lowest rates in northern and southern Finland, respectively. Ratio of annual total precipitation to number of precipitation days also declined in Finland over 1908e2008, with a decreasing north to south gradient. However, annual duration indices of daily precipitation revealed no statistically significant trends at any station. Daily precipitation characteristics showed significant relationships with various well-known atmospheric circulation patterns(ACPs). In particular, the East Atlantic/West Russia(EA/WR)pattern in summer was the most influential ACP negatively associated with different daily precipitation intensity, frequency and duration indices at all three stations studied.
文摘The theory model of fiber optical parametric amplifier (FOPA) was introduced, which is based on optical nonlinear effect. And then numerical simulation was done to analyze and discuss the gain spectral characteristics of one-pump and two-pump FOPA. The results show that for one-pump FOPA, when pump wavelength is near to fiber zero-dispersion wavelength(ZDW), the gain flatness is better, and with the increase of the pump power, fiber length and its nonlinear coefficient, the gain value will increase while the gain bandwidth will become narrow. For two-pump FOPA, when the pump central wavelength is near to fiber ZDW, the gain flatness is better. Moreover, by decreasing the space of two pumps wavelength, the gain flatness can be improved. Finally, some problems existing in FOPA were addressed.
基金The project supported by the Natural Science Foundation of Zhejiang Province of China under Grant No. Y604106, the Foundation of New Century "151 Talent Engineering" of Zhejiang Province, the Scientific Research Foundation of Key Discipline of Zhejiang Province, and the Natural Science Foundation of Zhejiang Lishui University under Grant No. KZ04008
文摘Starting from a special variable transformation and with the help of an extended mapping approach, the high-order Schrodinger equation (n = 3, 4) is solved. A new family of variable separation solutions with arbitrary functions is derived.
文摘The reasonability of the adopted capacity load ratio numerical value in urban power grid planning determines the economy of planning level yearly power grid.Too large capacity load ratio will result in the increasing investment in the early period of power grid construction, however, too small capacity load ratio will make the power grid have poor adaptability, affecting the power supply. Reasonably determining the adopted regional power grid capacity load ratio quantitative numerical value in planning has a strong guiding significance for constructing reliable and economic power grid and preventing power grid from excessive advance or lagging behind the load development. This paper, through the statistics and analysis of a certain regional power grid 2010-2012 three years' power grid daily load characteristics and the investment benefit evaluation of three years' 220KV power grid individual project, makes a preliminary analysis and puts forwards the specific advice on the reasonable values of power ~rid 35-220KV power transformation capacity load ratio.
文摘Topic effect on L2 writing has long been an issue of controversy. This study was carried out to investigate the influence of topic type on the quality of topic sentence. The participants, 150 college students at three different proficiency levels, were asked to write both on a private topic and a public topic. The results show that the participants on the whole wrote better on the public topic, and their proficiencies can be differentiated by the quality of their topic sentences. The public topic was conducive to the production of complete English discourse structures, as well as the generation of informative and predictive topic sentences. Moreover, the results also reveal the dynamic nature of contrastive rhetoric
文摘In recent years, the complaints against the vibration as environmental pollution tends to increase gradually in Japan. The measurement investigation to demonstrate the actual situation of the environmental vibration was carried out for several years. The measurement manual for each vibration source such as operations of factory machine, construction works, road traffics and railways to unify measurement methods was made at the start. From the measurement investigation, the vibration amplification characteristics of the detached house by one-third octave frequency in Japan was analyzed as a purpose to improve estimated precision of the vibration in a detached house. In this paper, the vibration amplification characteristic expressed at onethird octave band frequency was shown, and the characteristics was arranged about a result measured with 27 detached houses in Japan.
基金Supported by the program for New Century Excellent Talents at the University of China under Grant No.NCET-06-0554the National Natural Science Foundation of China under Grant Nos.10975001,60677001,10747146,and 10874122+3 种基金the science-technology fund of Anhui province for outstanding youth under Grant No.06042087 the general fund of the educational committee of Anhui province under Grant No.2006KJ260Bthe Talent Foundation of High Education of Anhui Province for Outstanding Youth under Grant No.2009SQRZ018the Natural Science Foundation of Guangdong Province under Grant Nos.06300345 and 7007806
文摘Teleportation of a qubit with two partially entangled qubit states linking three nodes as quantum channels is extensively studied via the usual ancilla method. With the method two realization approaches, i.e., the node progression approach and the global accumulation approach, are presented. Their resource consumptions, operation complexities, and el^ciencies axe evaluated and compared. It is found that the latter approach is better than the former one besides the error is partially self-corrected. The latter approach is further improved so that two merits are resultant. The improved version is compared with a similar protocol [M.Y. Wang and F.L. Yah, Eur. Phys. J. D 54 (2009) 111]. Their merits and additional costs are exposed.
文摘Today, just by activating a button on the display panel of a total station, one can measure horizontal and vertical angles or calculate distances and coordinates of points. For this reason, it has become necessary to improve the check of a total station in order to respond to its contemporary way of use. The aim of this research is to create a new method for checking total stations using only one check--field, in a different way of the today's standards. The basic principle, of the comparison of an instrument's measurements to those of another instrument with higher accuracy, is implemented into a mathematical model such as the adjustment of an indoor geodetic network. Thus, the check of the proper function of a total station is applied. An a-priori calculation Of^o of the network's adjustment can be calculated by modeling the uncertainties using statistical methods as the random number generators by means of the Monte Carlo method. The prospective ao can then be compared to the a-posteriori ao provided by the adjustment of the measurements which are carried out by using the total station under check.
基金Constructive comments by three reviewers are gratefully acknowledged. Special gratitude goes to our colleagues Drs. Rui Shi, Jian Li, and Ke Huang for their help in data collection. This work was supported by the National Basic Research Program of China (2011CB403501), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDAll010403 and XDA11010 302), Sanya and Chinese Academy of Sciences Cooperation Project (2013YD77), the National Natural Science Foundation of China (41276024, 41206011, 41106028, 41406038, 41306012, 41306014, 41476014, 41476012 and 41406131), the Infrastructure Facilities Project of Xisha station and Nansha station (KZCX2-EW-Y040), and the Major National Scientific Instrument and Equipment Develop- ment Project (2012YQ12003910).
文摘In the past 10 years (2004-2013), annual open cruise during late summer provided new opportunities for comprehensive studies in the Northern South China Sea (NSCS). The 10-year field investigation program was carried out by the South China Sea Institute of Oceanology, Chinese Academy of Sciences (SCSIO, CAS). Measurements inclu- ded water mass property, ocean circulation, atmospheric structure, and chemical and biological elements. The observation data collected during these open cruises have been intensively used in the studies of marine oceanographic, meteorological, chemical, and biological processes in the NSCS. In this study, comprehensive assessment of data application in oceanographic and meteorological studies is provided: (1) the property and variability of water masses in different layers; (2) the distribution of main currents and three-dimensional structure of mesoscale eddies; and (3) atmospheric structure and its feedback to the ocean. With the continuance of open cruises, it is feasible to construct high- quality, gridded climatological marine meteorological datasets in the NSCS in the near future.
基金supported by the National Natural Science Foundation of China(Grant Nos.91221205,and 11474181)the National Basic Research Program of China(Grants No.2015CB921002)
文摘Nonadiabatic holonomic quantum computation has received increasing attention due to its robustness against control errors. However, all the previous schemes have to use at least two sequentially implemented gates to realize a general one-qubit gate. Based on two recent reports, we construct two Hamiltonians and experimentally realized nonadiabatic holonomic gates by a single-shot implementation in a two-qubit nuclear magnetic resonance (NMR) system. Two noncommuting one-qubit holonomic gates, rotating along .~ and ~ axes respectively, are implemented by evolving a work qubit and an ancillary qubit nonadiabatically following a quantum circuit designed. Using a sequence compiler developed for NMR quantum information processor, we optimize the whole pulse sequence, minimizing the total error of the implementation. Finally, all the nonadiabatic holonomic gates reach high unattenuated experimental fidelities over 98%.
基金Supported by the National Natural Science Foundation of China under Grant No.11004258Fundamental Research Funds for the Central Universities under Grant No.CQDXWL-2012-014
文摘We present an efficient faithful multipartite polarization entanglement distribution protocol over an ar- bitrary noisy channel. The spatial degree of freedom is used to carry the entanglement during the transmission. We describe the principle by distributing n-qubit Greenberge-Horne--Zeilinger state and n-qubit W state. Our scheme can be used to distribute arbitrary n-qUbit entangled states to n distant locations. The remote parties can obtain maximally entangled states deterministically on the polarization of photons. Only passive linear optics are employed in our setup, which makes our scheme more feasible and efficient for practical application in long distance quantum communication.
基金supported by the National Key Basic Research Special Foundation of China (No.2010CB328304)the National Natural Science Foundation of China (No.60807022)+1 种基金the Key Grant of Chinese Ministry of Education (No.109015)the Discipline Co-construction Project of Beijing Municipal Commission of Education (No.YB20081001301)
文摘We investigate the pump-depleted model of a dual-pump fiber optical parametric amplifier(FOPA) with Raman effect.As bandwidth increases,the gain profile of the distorted FOPA would be impacted seriously.Under the widebands,especially when the pump separation is large,zero dispersion wavelength(ZDW) fluctuation is another factor which can not be neglected.Numerical simulations with these comprehensive factors are mainly analyzed to obtain their influence on gain characteristics.Saturated gain spectrum is also discussed in detail.
基金supported by the Natural Science Foundation of Jiangsu Provincial Universities (Grant No. 10KJB180004)the National Natural Science Foundation of China (Grant No. 10847147)
文摘We present two robust quantum secure direct communication (QSDC) schemes with a quantum one-time pad over a collective-noise channel. Each logical qubit is made up of two physical qubits and it is invariant over a collective-noise channel. The two photons in each logical qubit can be produced with a practically entangled source, i.e., a parametric down-conversion source with a beta barium borate crystal and a pump pulse of ultraviolet light. The information is encoded on each logical qubit with two logical unitary operations, which will not destroy the antinoise feather of the quantum systems. The receiver Bob can read out the sender's message directly with two single-photon measurements on each logical qubit, instead of Bell-state measurements, which will make these protocols more convenient in a practical application. With current technology, our two robust QSDC schemes are feasible and may be optimal ones.