A new approach for studying the time-evolution law of a chaotic light field in a damping-gaining coexisting process is presented. The new differential equation for determining the parameter of the density operator p（...A new approach for studying the time-evolution law of a chaotic light field in a damping-gaining coexisting process is presented. The new differential equation for determining the parameter of the density operator p（t） is derived and the solution of f for the damping and gaining processes are studied separately. Our approach is direct and the result is concise since it is not necessary for us to know the Kraus operators in advance.展开更多
According to Bloomberg on March 18,corn imports by China,the world’s second-largest consumer,may surge sevenfold to a record 28 million metric tons by 2015-2016 as local production fails to keep pace with increased
Alongside China’s rapid economic growth after the adoption of the reform and opening-up policy,urbanization has progressed fairly quickly. Since 1998 in particular the urbanization drive has been accelerating.What is...Alongside China’s rapid economic growth after the adoption of the reform and opening-up policy,urbanization has progressed fairly quickly. Since 1998 in particular the urbanization drive has been accelerating.What is the current status of China’s urbanization drive?In this article Cui Ruchun consults an enormous range of statistics to analyze China’s current urbanization level,urban economic development,infrastructure construction,environment construction, developments in science,technology and education,as well as the living standard of urban residents.展开更多
Russian is proactively tapping into the Chinese food market and China is importing more Russian food.According to statistics from customs,the Sino-Russian trade volume hit$64.2billion in the year of 2015,down 27.8%,an...Russian is proactively tapping into the Chinese food market and China is importing more Russian food.According to statistics from customs,the Sino-Russian trade volume hit$64.2billion in the year of 2015,down 27.8%,and Russia’s exports to China stood at$31.4 billion,down by 19.1%.'It is difficult for Russian companies to nudge into the展开更多
Status quo and future trends of 2015children’s publications released by the Shanghai Press and Publication shows that in the past decade,the domestic children’s book market is developing rapidly with an average annu...Status quo and future trends of 2015children’s publications released by the Shanghai Press and Publication shows that in the past decade,the domestic children’s book market is developing rapidly with an average annual growth of 10%.Children’s books are seeing an increasing ratio with a market share of over 40%.展开更多
Domestic toothpastes forced to retreat The stories of domestic toothpastes are not as good as soda water. Due to the strength of domestic drinks in recent years, soda water are regaining power. Two Cola brands made ot...Domestic toothpastes forced to retreat The stories of domestic toothpastes are not as good as soda water. Due to the strength of domestic drinks in recent years, soda water are regaining power. Two Cola brands made other drinks lose grounds in the market. Nowadays, the latest domestic drinks keep emerging and the competition in the market is getting fierce.展开更多
AFRICA is much closer to China than people think. There is a little bit of Africa in Songzhuang, a town in suburban Beijing＇s Tongzhou District, where the African Art Village came up last year. The sprawling 1.3-hect...AFRICA is much closer to China than people think. There is a little bit of Africa in Songzhuang, a town in suburban Beijing＇s Tongzhou District, where the African Art Village came up last year. The sprawling 1.3-hectare project showcases an eclectic collection of African art - Makonde sculptures from Tanzania, copper plate etchings from Zambia, masks from Malawi, and much more.展开更多
THE upcoming G20 Summit is not just an occasion for world leaders and top entrepreneurs to come together and discuss the trends and solutions for global economic development. The residents of Mantoushan Community of S...THE upcoming G20 Summit is not just an occasion for world leaders and top entrepreneurs to come together and discuss the trends and solutions for global economic development. The residents of Mantoushan Community of Shangcheng District in Hangzhou. host city of the summit to be held on Sep- tember 4-5, have also been reaping the benefits from the summit＇s preparations.展开更多
AFTER the revised regulation on domestic waste classification came into force in Beijing on May 1 this year,waste sorting has gained renewed public attention.In previous months,similar regulations were introduced in m...AFTER the revised regulation on domestic waste classification came into force in Beijing on May 1 this year,waste sorting has gained renewed public attention.In previous months,similar regulations were introduced in many cities across China,making the practice widespread.To help citizens adapt to and accept the new rules,local authorities have come up with creative methods to help citizens classify waste properly and understand the benefits of doing so.展开更多
Since the launch of island-wide special customs operations at Hainan Free Trade Port(Hainan FTP),the proportion of “zero-tariff”imported goods has increased significantly from 21 to 74 percent, and high-quality good...Since the launch of island-wide special customs operations at Hainan Free Trade Port(Hainan FTP),the proportion of “zero-tariff”imported goods has increased significantly from 21 to 74 percent, and high-quality goods from Southeast Asia can enter Hainan at a more competitive price. If goods contain imported materials and achieve at least 30 percent added value through local processing,they can enter the Chinese mainland market with an exemption from import tariffs, effectively gaining market access across China.展开更多
In the analysis of correlated data, it is ideal to capture the true dependence structure to increase effciency of the estimation. However, for multivariate survival data, this is extremely
Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,...Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,we introduce ethyl acetate(EA)as a green antisolvent to fabricate high-quality quasi-2D PEA_(0.4)MAPbBr_(3)films.The EA-treated films exhibit superior morphology,enhanced crystallinity,and notably inhibited low n-phases.These improvements yield a prolonged photoluminescence lifetime of 26.3 ns and a substantially extended gain lifetime of 129 ps.Consequently,the optimized film exhibits a markedly reduced amplified spontaneous emission(ASE)threshold of 5.6μJ·cm^(-2)and a high net modal gain of 935 cm^(-1).Leveraging these enhanced gain properties,we successfully demonstrate a vertical-cavity surface-emitting laser(VCSEL)based on a dielectric Bragg reflector microcavity,which delivers single-mode lasing at 528.3 nm and a high quality factor of~5886.This work presents a green-solvent-engineering strategy for high-performance perovskite lasers,advancing their prospects for scalable photonic integration.展开更多
The survival analysis literature has always lagged behind the categorical data literature in developing methods to analyze clustered or multivariate data. While estimators based on
In this study,with the aim of achieving a high signal-to-noise ratio(SNR)in an electron-bombarded complementary metal-oxide-semiconductor(EBCMOS)imaging chip,we analyzed the sources of noise using principles from low-...In this study,with the aim of achieving a high signal-to-noise ratio(SNR)in an electron-bombarded complementary metal-oxide-semiconductor(EBCMOS)imaging chip,we analyzed the sources of noise using principles from low-light-level imaging and semiconductor theory,and established a physical computational model that relates the electron-multiplication layer to the noise characteristics of an EBCMOS chip in a uniformly doped structure with a P-type substrate.We conducted theoretical calculations to analyze the effects on noise characteristics of the passivation layer material and thickness,P-substrate doping concentration,P-substrate thickness,incident electron energy,and substrate temperature.By comparing the characteristics of pixel noise,dark current,multiplication electron numbers,and SNR under various structures,we simulated optimized structural parameters of the device.Our simulation results showed that the noise characteristics of the device could be optimized using an Al_(2)O_(3)passivation thickness of 15 nm and substrate temperature of 260 K,and by decreasing the doping concentration and thickness of the P-type substrate and increasing the incident electron energy.The optimized SNR were 252 e/e.And the substantial impact of dark current noise,primarily governed by interfacial defects,on the overall noise characteristics of the device.This research offers theoretical support to develop EBCMOS imaging chips with high gain and SNR.展开更多
We thank all the discussants for their interesting and stimulating contributions. They have touched various aspects that have not been considered by the original articles.
Root nodule symbiosis(RNS)is a mutualistic association formed between nitrogen-fixing rhizobia or Frankia and host plants limited to four orders within Rosid I―Fabales,Fagales,Cucurbitales,and Rosales―which comprise...Root nodule symbiosis(RNS)is a mutualistic association formed between nitrogen-fixing rhizobia or Frankia and host plants limited to four orders within Rosid I―Fabales,Fagales,Cucurbitales,and Rosales―which comprise the so-called‘Nitrogen Fixing Nodulation Clade’(NFNC).The majority of nodulation studies have focused on Leguminosae,given their agricultural and environmental importance,as well as the widespread occurrence of nodulation among members of this family.Endowing cereal crops with nitrogen fixation,like Leguminosae,presents a strategy to reduce the detrimental effects of synthetic fertilizer overuse.Different hypotheses on the origin of RNS have been proposed;however,key genetic innovations underlying the evolution of RNS,even in Leguminosae,have been rarely reported.In this review,we begin by examining current knowledge of genetic innovations―including gene gain,gene loss,and the acquisition or loss of conserved noncoding sequences(CNS)in preexisting genes.We explore the available evidence supporting these genetic innovations underlying the evolution of RNS in Leguminosae and offer the phylogenomics approach that could be applied to uncover these genetic innovations.Finally,we conclude by proposing a model of genetic innovations underlying the evolution of RNS in Leguminosae and consider the potential implications for the development of nitrogen-fixing crops.展开更多
Integrated sensing and communication(ISAC)is an appealing approach to address spectrum congestion and beamforming is an effective method to realize ISAC.In this paper,we investigate the beamforming design problem for ...Integrated sensing and communication(ISAC)is an appealing approach to address spectrum congestion and beamforming is an effective method to realize ISAC.In this paper,we investigate the beamforming design problem for multiple-input multipleoutput(MIMO)ISAC systems and propose to maximize the radar beampattern gain of the target direction while ensuring the signal-to-interference-plus-noise ratio(SINR)constraints of communication users.Particularly,we discuss two cases of ISAC transmit beamforming,i.e.,Case-Ⅰand Case-Ⅱ,which do not have and do have the dedicated probing signal,respectively.For these two cases of transmit beamforming design problems,we start from the single-user scenario and provide the closed-form solutions for MIMO ISAC beamforming vectors.Then,we consider the multiuser scenario and utilize the semidefinite relaxation technique to convert the beamforming design problems into convex semidefinite programming problems.Furthermore,we investigate the impact of the channel correlation between radar and communication on the performance gain of MIMO ISAC systems and characterize the performance tradeoff.Numerical results validate that the dedicated probing signal is unnecessary in the single-user scenario,whereas it has a slight improvement in target detection performance at low SINR thresholds in the multi-user scenario.It is also shown that the stronger the correlation between radar and communication channels,the greater the performance gain of the system.展开更多
Integrated sensing and communication(ISAC) systems can enhance security and reliability in full-duplex( FD) networks.This paper studies the resource allocation problem in FD networks based on ISAC.We formulate an opti...Integrated sensing and communication(ISAC) systems can enhance security and reliability in full-duplex( FD) networks.This paper studies the resource allocation problem in FD networks based on ISAC.We formulate an optimization problem that jointly considers beamforming,radar waveform,and reflection coefficient of a hybrid reconfigurable intelligent surface,aiming to maximize the beampattern gain of the concealed target while maintaining the quality of service of communication users.A two-stage algorithm is designed to solve this problem: the first stage optimizes the radar waveform and beamforming,and the second focuses on the reflection coefficient design.We acquire the feasible solution using semidefinite programming relaxation.The optimality of the feasible solution for radar waveform and beamforming subproblem is ensured through Cauchy-Schwartz inequality.For the reflection coefficient design,an approximate optimal solution is acquired through successive convex approximation.Numerical results demonstrate that the proposed algorithm can achieve a superior performance trade-off between communication and radar sensing compared to the benchmarks.展开更多
Investigated theoretically is a photonic-crystal surface-emitting GaN laser based on surface-etched holes with a porous-GaN cladding layer.The porous GaN has a low refractive index,supporting effective confinement to ...Investigated theoretically is a photonic-crystal surface-emitting GaN laser based on surface-etched holes with a porous-GaN cladding layer.The porous GaN has a low refractive index,supporting effective confinement to the resonant mode,and the porous GaN is derived from as-grown GaN,eliminating the lattice mismatch issues typically associated with GaN platforms.Studied systematically is how the photoniccrystal lattice constant,air hole radius,etching depth,and porous-GaN refractive index affect the performance of the laser.The results show that the laser exhibits optimal overall performance when the lattice constant is 216 nm and the hole radius is 60 nm.The etching depth can be chosen between 30 and 100 nm,and the porous-GaN refractive index is preferably in the range of 1.7–1.9.The research achieves a quality factor as high as 1.9×10^(4),with a photonic-crystal-layer confinement factor of 4.24%and an active-layer confinement factor of 21.8%,along with a low threshold gain of 77 cm^(−1).展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61141007,11047133,and 11175113)the Natural Science Foundation of Jiangxi Province of China (Grant Nos. 2010GQS0080 and 2010GQW0027)+1 种基金the Research Foundation of the Education Department of Jiangxi Province of China (Grant No. GJJ11339)the Sponsored Program for Cultivating Youths of Outstanding Ability in Jiangxi Normal University
文摘A new approach for studying the time-evolution law of a chaotic light field in a damping-gaining coexisting process is presented. The new differential equation for determining the parameter of the density operator p（t） is derived and the solution of f for the damping and gaining processes are studied separately. Our approach is direct and the result is concise since it is not necessary for us to know the Kraus operators in advance.
文摘According to Bloomberg on March 18,corn imports by China,the world’s second-largest consumer,may surge sevenfold to a record 28 million metric tons by 2015-2016 as local production fails to keep pace with increased
文摘Alongside China’s rapid economic growth after the adoption of the reform and opening-up policy,urbanization has progressed fairly quickly. Since 1998 in particular the urbanization drive has been accelerating.What is the current status of China’s urbanization drive?In this article Cui Ruchun consults an enormous range of statistics to analyze China’s current urbanization level,urban economic development,infrastructure construction,environment construction, developments in science,technology and education,as well as the living standard of urban residents.
文摘Russian is proactively tapping into the Chinese food market and China is importing more Russian food.According to statistics from customs,the Sino-Russian trade volume hit$64.2billion in the year of 2015,down 27.8%,and Russia’s exports to China stood at$31.4 billion,down by 19.1%.'It is difficult for Russian companies to nudge into the
文摘Status quo and future trends of 2015children’s publications released by the Shanghai Press and Publication shows that in the past decade,the domestic children’s book market is developing rapidly with an average annual growth of 10%.Children’s books are seeing an increasing ratio with a market share of over 40%.
文摘Domestic toothpastes forced to retreat The stories of domestic toothpastes are not as good as soda water. Due to the strength of domestic drinks in recent years, soda water are regaining power. Two Cola brands made other drinks lose grounds in the market. Nowadays, the latest domestic drinks keep emerging and the competition in the market is getting fierce.
文摘AFRICA is much closer to China than people think. There is a little bit of Africa in Songzhuang, a town in suburban Beijing＇s Tongzhou District, where the African Art Village came up last year. The sprawling 1.3-hectare project showcases an eclectic collection of African art - Makonde sculptures from Tanzania, copper plate etchings from Zambia, masks from Malawi, and much more.
文摘THE upcoming G20 Summit is not just an occasion for world leaders and top entrepreneurs to come together and discuss the trends and solutions for global economic development. The residents of Mantoushan Community of Shangcheng District in Hangzhou. host city of the summit to be held on Sep- tember 4-5, have also been reaping the benefits from the summit＇s preparations.
文摘AFTER the revised regulation on domestic waste classification came into force in Beijing on May 1 this year,waste sorting has gained renewed public attention.In previous months,similar regulations were introduced in many cities across China,making the practice widespread.To help citizens adapt to and accept the new rules,local authorities have come up with creative methods to help citizens classify waste properly and understand the benefits of doing so.
文摘Since the launch of island-wide special customs operations at Hainan Free Trade Port(Hainan FTP),the proportion of “zero-tariff”imported goods has increased significantly from 21 to 74 percent, and high-quality goods from Southeast Asia can enter Hainan at a more competitive price. If goods contain imported materials and achieve at least 30 percent added value through local processing,they can enter the Chinese mainland market with an exemption from import tariffs, effectively gaining market access across China.
文摘In the analysis of correlated data, it is ideal to capture the true dependence structure to increase effciency of the estimation. However, for multivariate survival data, this is extremely
文摘Quasi-two-dimensional(quasi-2d)perovskites are promising gain media for micro-nano lasers,yet their uncontrolled crystallization and abundant low-n phases often hinder optical gain and device performance.In this work,we introduce ethyl acetate(EA)as a green antisolvent to fabricate high-quality quasi-2D PEA_(0.4)MAPbBr_(3)films.The EA-treated films exhibit superior morphology,enhanced crystallinity,and notably inhibited low n-phases.These improvements yield a prolonged photoluminescence lifetime of 26.3 ns and a substantially extended gain lifetime of 129 ps.Consequently,the optimized film exhibits a markedly reduced amplified spontaneous emission(ASE)threshold of 5.6μJ·cm^(-2)and a high net modal gain of 935 cm^(-1).Leveraging these enhanced gain properties,we successfully demonstrate a vertical-cavity surface-emitting laser(VCSEL)based on a dielectric Bragg reflector microcavity,which delivers single-mode lasing at 528.3 nm and a high quality factor of~5886.This work presents a green-solvent-engineering strategy for high-performance perovskite lasers,advancing their prospects for scalable photonic integration.
文摘The survival analysis literature has always lagged behind the categorical data literature in developing methods to analyze clustered or multivariate data. While estimators based on
文摘In this study,with the aim of achieving a high signal-to-noise ratio(SNR)in an electron-bombarded complementary metal-oxide-semiconductor(EBCMOS)imaging chip,we analyzed the sources of noise using principles from low-light-level imaging and semiconductor theory,and established a physical computational model that relates the electron-multiplication layer to the noise characteristics of an EBCMOS chip in a uniformly doped structure with a P-type substrate.We conducted theoretical calculations to analyze the effects on noise characteristics of the passivation layer material and thickness,P-substrate doping concentration,P-substrate thickness,incident electron energy,and substrate temperature.By comparing the characteristics of pixel noise,dark current,multiplication electron numbers,and SNR under various structures,we simulated optimized structural parameters of the device.Our simulation results showed that the noise characteristics of the device could be optimized using an Al_(2)O_(3)passivation thickness of 15 nm and substrate temperature of 260 K,and by decreasing the doping concentration and thickness of the P-type substrate and increasing the incident electron energy.The optimized SNR were 252 e/e.And the substantial impact of dark current noise,primarily governed by interfacial defects,on the overall noise characteristics of the device.This research offers theoretical support to develop EBCMOS imaging chips with high gain and SNR.
文摘We thank all the discussants for their interesting and stimulating contributions. They have touched various aspects that have not been considered by the original articles.
基金supported by the National Natural Science Foundation of China(32300512)and the Xplorer Prize.
文摘Root nodule symbiosis(RNS)is a mutualistic association formed between nitrogen-fixing rhizobia or Frankia and host plants limited to four orders within Rosid I―Fabales,Fagales,Cucurbitales,and Rosales―which comprise the so-called‘Nitrogen Fixing Nodulation Clade’(NFNC).The majority of nodulation studies have focused on Leguminosae,given their agricultural and environmental importance,as well as the widespread occurrence of nodulation among members of this family.Endowing cereal crops with nitrogen fixation,like Leguminosae,presents a strategy to reduce the detrimental effects of synthetic fertilizer overuse.Different hypotheses on the origin of RNS have been proposed;however,key genetic innovations underlying the evolution of RNS,even in Leguminosae,have been rarely reported.In this review,we begin by examining current knowledge of genetic innovations―including gene gain,gene loss,and the acquisition or loss of conserved noncoding sequences(CNS)in preexisting genes.We explore the available evidence supporting these genetic innovations underlying the evolution of RNS in Leguminosae and offer the phylogenomics approach that could be applied to uncover these genetic innovations.Finally,we conclude by proposing a model of genetic innovations underlying the evolution of RNS in Leguminosae and consider the potential implications for the development of nitrogen-fixing crops.
基金National Natural Science Foundation of China under Grant 62571248 and Grant 62201266Key Laboratory of Intelligent Space TTC&O(Space Engineering University),Ministry of Education under Grant CYK2025-01-12。
文摘Integrated sensing and communication(ISAC)is an appealing approach to address spectrum congestion and beamforming is an effective method to realize ISAC.In this paper,we investigate the beamforming design problem for multiple-input multipleoutput(MIMO)ISAC systems and propose to maximize the radar beampattern gain of the target direction while ensuring the signal-to-interference-plus-noise ratio(SINR)constraints of communication users.Particularly,we discuss two cases of ISAC transmit beamforming,i.e.,Case-Ⅰand Case-Ⅱ,which do not have and do have the dedicated probing signal,respectively.For these two cases of transmit beamforming design problems,we start from the single-user scenario and provide the closed-form solutions for MIMO ISAC beamforming vectors.Then,we consider the multiuser scenario and utilize the semidefinite relaxation technique to convert the beamforming design problems into convex semidefinite programming problems.Furthermore,we investigate the impact of the channel correlation between radar and communication on the performance gain of MIMO ISAC systems and characterize the performance tradeoff.Numerical results validate that the dedicated probing signal is unnecessary in the single-user scenario,whereas it has a slight improvement in target detection performance at low SINR thresholds in the multi-user scenario.It is also shown that the stronger the correlation between radar and communication channels,the greater the performance gain of the system.
基金Supported by the National Science and Technology Major Project of China (No.C6-3416-M01)。
文摘Integrated sensing and communication(ISAC) systems can enhance security and reliability in full-duplex( FD) networks.This paper studies the resource allocation problem in FD networks based on ISAC.We formulate an optimization problem that jointly considers beamforming,radar waveform,and reflection coefficient of a hybrid reconfigurable intelligent surface,aiming to maximize the beampattern gain of the concealed target while maintaining the quality of service of communication users.A two-stage algorithm is designed to solve this problem: the first stage optimizes the radar waveform and beamforming,and the second focuses on the reflection coefficient design.We acquire the feasible solution using semidefinite programming relaxation.The optimality of the feasible solution for radar waveform and beamforming subproblem is ensured through Cauchy-Schwartz inequality.For the reflection coefficient design,an approximate optimal solution is acquired through successive convex approximation.Numerical results demonstrate that the proposed algorithm can achieve a superior performance trade-off between communication and radar sensing compared to the benchmarks.
基金funded by the Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY224125)the Open Fund of the State Key Laboratory of Advanced Optical Communication Systems and Networks(SJTU)(Grant No.2023GZKF018)the Postgraduate Research and Practice Innovation Program of Jiangsu Province(Grant Nos.KYCX24_1199 and SJCX24_0286).
文摘Investigated theoretically is a photonic-crystal surface-emitting GaN laser based on surface-etched holes with a porous-GaN cladding layer.The porous GaN has a low refractive index,supporting effective confinement to the resonant mode,and the porous GaN is derived from as-grown GaN,eliminating the lattice mismatch issues typically associated with GaN platforms.Studied systematically is how the photoniccrystal lattice constant,air hole radius,etching depth,and porous-GaN refractive index affect the performance of the laser.The results show that the laser exhibits optimal overall performance when the lattice constant is 216 nm and the hole radius is 60 nm.The etching depth can be chosen between 30 and 100 nm,and the porous-GaN refractive index is preferably in the range of 1.7–1.9.The research achieves a quality factor as high as 1.9×10^(4),with a photonic-crystal-layer confinement factor of 4.24%and an active-layer confinement factor of 21.8%,along with a low threshold gain of 77 cm^(−1).
