In order to optionally regulate embedding capacity and embedding transparency according to user's requirements in voice-over-IP(VoIP) steganography,a dynamic matrix encoding strategy(DMES) was presented.Differing ...In order to optionally regulate embedding capacity and embedding transparency according to user's requirements in voice-over-IP(VoIP) steganography,a dynamic matrix encoding strategy(DMES) was presented.Differing from the traditional matrix encoding strategy,DMES dynamically chose the size of each message group in a given set of adoptable message sizes.The appearance possibilities of all adoptable sizes were set in accordance with the desired embedding performance(embedding rate or bit-change rate).Accordingly,a searching algorithm that could provide an optimal combination of appearance possibilities was proposed.Furthermore,the roulette wheel algorithm was employed to determine the size of each message group according to the optimal combination of appearance possibilities.The effectiveness of DMES was evaluated in StegVoIP,which is a typical covert communication system based on VoIP.The experimental results demonstrate that DMES can adjust embedding capacity and embedding transparency effectively and flexibly,and achieve the desired embedding performance in any case.For the desired embedding rate,the average errors are not more than 0.000 8,and the standard deviations are not more than 0.002 0;for the desired bit-change rate,the average errors are not more than 0.001 4,and the standard deviations are not more than 0.002 6.展开更多
The luminance in the road tunnel threshold zone attracts broad attention due to its enormous energy consumption and direct influence on tunnel transportation security.Current lighting design methods in threshold zones...The luminance in the road tunnel threshold zone attracts broad attention due to its enormous energy consumption and direct influence on tunnel transportation security.Current lighting design methods in threshold zones mostly adopt the reduction coefficient method.However,the determination of reduction coefficient k simply considers tunnel design speed and flow rate,while excluding outside tunnel luminance and threshold zone color temperature and luminance,which have a major impact on driver visual adaptation.Existing problems in the determination of k value are analyzed;a visual performance experiment is utilized;and the reaction time of drivers in changeable outside tunnel luminance and threshold zone color temperature and luminance conditions is obtained;thus,the equations concerning reduction coefficient variation law are derived.In the end,a comparative analysis is made of the k values of the reduction coefficient stipulated by various norms under different color temperature conditions.展开更多
We consider the problem about the space embedded by the space and the embedding inequality. With the HSlder inequality and interpolation inequality, we give the proof of the space embedding theorem and the space holde...We consider the problem about the space embedded by the space and the embedding inequality. With the HSlder inequality and interpolation inequality, we give the proof of the space embedding theorem and the space holder embedding theorem.展开更多
The purpose of this article is to characterize symplectic and Hamiltonian circle actions on symplectic manifolds in terms of symplectic embeddings of Riemann surfaces.More precisely, it is shown that(1) if(M, ω) admi...The purpose of this article is to characterize symplectic and Hamiltonian circle actions on symplectic manifolds in terms of symplectic embeddings of Riemann surfaces.More precisely, it is shown that(1) if(M, ω) admits a Hamiltonian S^1-action, then there exists a two-sphere S in M with positive symplectic area satisfying c1(M, ω), [S] > 0,and(2) if the action is non-Hamiltonian, then there exists an S^1-invariant symplectic2-torus T in(M, ω) such that c1(M, ω), [T] = 0. As applications, the authors give a very simple proof of the following well-known theorem which was proved by Atiyah-Bott,Lupton-Oprea, and Ono: Suppose that(M, ω) is a smooth closed symplectic manifold satisfying c1(M, ω) = λ· [ω] for some λ∈ R and G is a compact connected Lie group acting effectively on M preserving ω. Then(1) if λ < 0, then G must be trivial,(2) if λ = 0, then the G-action is non-Hamiltonian, and(3) if λ > 0, then the G-action is Hamiltonian.展开更多
A theorem of Lambrechts and Stanley is used to find the rational cohomology of the complement of an embedding S^(4n-1)→ S^(2n)× S^m as a module and demonstrate that it is not necessarily determined by the map in...A theorem of Lambrechts and Stanley is used to find the rational cohomology of the complement of an embedding S^(4n-1)→ S^(2n)× S^m as a module and demonstrate that it is not necessarily determined by the map induced on cohomology by the embedding, nor is it a trivial extension. This demonstrates that the theorem is an improvement on the classical Lefschetz duality.展开更多
Perovskite quantum-dot-based light-emitting diodes(QLEDs)are highly promising for future solid-state lightings and high-definition displays due to their excellent color purity.However,their device performance is easil...Perovskite quantum-dot-based light-emitting diodes(QLEDs)are highly promising for future solid-state lightings and high-definition displays due to their excellent color purity.However,their device performance is easily affected by charge accumulation induced luminescence quenching due to imbalanced charge injection in the devices.Here we report green perovskite QLEDs with simultaneously improved efficiency and operational lifetime through balancing the charge injection with the employment of a bilayered electron transport structure.The charge-balanced QLEDs exhibit a color-saturated green emission with a full-width at half-maximum(FWHM)of 18 nm and a peak at 520 nm,a low turn-on voltage of2.0 V and a champion external quantum efficiency(EQE)of 21.63%,representing one of the most efficient perovskite QLEDs so far.In addition,the devices with modulated charge balance demonstrate a nearly 20-fold improvement in the operational lifetime compared to the control device.Our results demonstrate the great potential of further improving the device performance of perovskite QLEDs toward practical applications in lightings and displays via rational device engineering.展开更多
Remarkable progress has been made in developing intramuscular vaccines against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);however,they are limited with respect to eliciting local immunity in the respi...Remarkable progress has been made in developing intramuscular vaccines against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);however,they are limited with respect to eliciting local immunity in the respiratory tract,which is the primary infection site for SARS-CoV-2.To overcome the limitations of intramuscular vaccines,we constructed a nasal vaccine candidate based on an influenza vector by inserting a gene encoding the receptor-binding domain(RBD)of the spike protein of SARSCoV-2,named CA4-d NS1-n CoV-RBD(d NS1-RBD).A preclinical study showed that in hamsters challenged 1d after single-dose vaccination or 9 months after booster vaccination,d NS1-RBD largely mitigated lung pathology,with no loss of body weight.Moreover,such cellular immunity is relatively unimpaired for the most concerning SARS-Co V-2 variants,especially for the latest Omicron variant.In addition,this vaccine also provides cross-protection against H1N1 and H5N1 influenza viruses.The protective immune mechanism of d NS1-RBD could be attributed to the innate immune response in the nasal epithelium,local RBD-specific T cell response in the lung,and RBD-specific Ig A and Ig G response.Thus,this study demonstrates that the intranasally delivered d NS1-RBD vaccine candidate may offer an important addition to the fight against the ongoing coronavirus disease 2019 pandemic and influenza infection,compensating limitations of current intramuscular vaccines.展开更多
In this paper, the author studies the coarse embedding into uniformly convex Banach spaces. The author proves that the property of coarse embedding into Banach spaces can be preserved under taking the union of the met...In this paper, the author studies the coarse embedding into uniformly convex Banach spaces. The author proves that the property of coarse embedding into Banach spaces can be preserved under taking the union of the metric spaces under certain condi- tions. As an application, for a group G strongly relatively hyperbolic to a subgroup H, the author proves that B（n） = {g ∈ G／ │g│suЭe≤ n} admits a coarse embedding into a uniformly convex Banach space if H does.展开更多
基金Project(2009AA01A402) supported by the National High-Tech Research and Development Program of ChinaProject(NCET-06-0650) supported by Program for New Century Excellent Talents in University Project(IRT-0725) supported by Program for Changjiang Scholars and Innovative Research Team in Chinese University
文摘In order to optionally regulate embedding capacity and embedding transparency according to user's requirements in voice-over-IP(VoIP) steganography,a dynamic matrix encoding strategy(DMES) was presented.Differing from the traditional matrix encoding strategy,DMES dynamically chose the size of each message group in a given set of adoptable message sizes.The appearance possibilities of all adoptable sizes were set in accordance with the desired embedding performance(embedding rate or bit-change rate).Accordingly,a searching algorithm that could provide an optimal combination of appearance possibilities was proposed.Furthermore,the roulette wheel algorithm was employed to determine the size of each message group according to the optimal combination of appearance possibilities.The effectiveness of DMES was evaluated in StegVoIP,which is a typical covert communication system based on VoIP.The experimental results demonstrate that DMES can adjust embedding capacity and embedding transparency effectively and flexibly,and achieve the desired embedding performance in any case.For the desired embedding rate,the average errors are not more than 0.000 8,and the standard deviations are not more than 0.002 0;for the desired bit-change rate,the average errors are not more than 0.001 4,and the standard deviations are not more than 0.002 6.
基金Project(51278507)supported by the National Natural Science Foundation of ChinaProject(cstc2017jcyjAX0346)supported by Chongqing Association for Science and Technology,China
文摘The luminance in the road tunnel threshold zone attracts broad attention due to its enormous energy consumption and direct influence on tunnel transportation security.Current lighting design methods in threshold zones mostly adopt the reduction coefficient method.However,the determination of reduction coefficient k simply considers tunnel design speed and flow rate,while excluding outside tunnel luminance and threshold zone color temperature and luminance,which have a major impact on driver visual adaptation.Existing problems in the determination of k value are analyzed;a visual performance experiment is utilized;and the reaction time of drivers in changeable outside tunnel luminance and threshold zone color temperature and luminance conditions is obtained;thus,the equations concerning reduction coefficient variation law are derived.In the end,a comparative analysis is made of the k values of the reduction coefficient stipulated by various norms under different color temperature conditions.
基金Supported by Soft Science Project of Henan Province(072102210020)
文摘We consider the problem about the space embedded by the space and the embedding inequality. With the HSlder inequality and interpolation inequality, we give the proof of the space embedding theorem and the space holder embedding theorem.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIPMinistry of Science,ICT&Future Planning)(No.NRF-2017R1C1B5018168)+2 种基金supported by Gyeongin National University of Education Research Fundsupported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)Funded by the Ministry of Science,ICT&Future Planning(No.2016R1A2B4010823)
文摘The purpose of this article is to characterize symplectic and Hamiltonian circle actions on symplectic manifolds in terms of symplectic embeddings of Riemann surfaces.More precisely, it is shown that(1) if(M, ω) admits a Hamiltonian S^1-action, then there exists a two-sphere S in M with positive symplectic area satisfying c1(M, ω), [S] > 0,and(2) if the action is non-Hamiltonian, then there exists an S^1-invariant symplectic2-torus T in(M, ω) such that c1(M, ω), [T] = 0. As applications, the authors give a very simple proof of the following well-known theorem which was proved by Atiyah-Bott,Lupton-Oprea, and Ono: Suppose that(M, ω) is a smooth closed symplectic manifold satisfying c1(M, ω) = λ· [ω] for some λ∈ R and G is a compact connected Lie group acting effectively on M preserving ω. Then(1) if λ < 0, then G must be trivial,(2) if λ = 0, then the G-action is non-Hamiltonian, and(3) if λ > 0, then the G-action is Hamiltonian.
基金supported by the National Science and Engineering Research Council of Canada
文摘A theorem of Lambrechts and Stanley is used to find the rational cohomology of the complement of an embedding S^(4n-1)→ S^(2n)× S^m as a module and demonstrate that it is not necessarily determined by the map induced on cohomology by the embedding, nor is it a trivial extension. This demonstrates that the theorem is an improvement on the classical Lefschetz duality.
基金supported by the National Natural Science Foundation of China (51922049, 61604074)the National Key Research and Development Program of China (2016YFB0401701)+2 种基金the Natural Science Foundation of Jiangsu Province (BK20180020)the Fundamental Research Funds for the Central Universities (30920032102)PAPD of Jiangsu Higher Education Institutions
文摘Perovskite quantum-dot-based light-emitting diodes(QLEDs)are highly promising for future solid-state lightings and high-definition displays due to their excellent color purity.However,their device performance is easily affected by charge accumulation induced luminescence quenching due to imbalanced charge injection in the devices.Here we report green perovskite QLEDs with simultaneously improved efficiency and operational lifetime through balancing the charge injection with the employment of a bilayered electron transport structure.The charge-balanced QLEDs exhibit a color-saturated green emission with a full-width at half-maximum(FWHM)of 18 nm and a peak at 520 nm,a low turn-on voltage of2.0 V and a champion external quantum efficiency(EQE)of 21.63%,representing one of the most efficient perovskite QLEDs so far.In addition,the devices with modulated charge balance demonstrate a nearly 20-fold improvement in the operational lifetime compared to the control device.Our results demonstrate the great potential of further improving the device performance of perovskite QLEDs toward practical applications in lightings and displays via rational device engineering.
基金supported by the National Program on Key Research Project of China(2020YFC0842600)the National Natural Science Foundation of China(82041038,81871651,and 81991491)+1 种基金the Major Science and Technology Program of Fujian Province(2020YZ014001)the Natural Science Foundation of Fujian Province(2021J02006)。
文摘Remarkable progress has been made in developing intramuscular vaccines against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);however,they are limited with respect to eliciting local immunity in the respiratory tract,which is the primary infection site for SARS-CoV-2.To overcome the limitations of intramuscular vaccines,we constructed a nasal vaccine candidate based on an influenza vector by inserting a gene encoding the receptor-binding domain(RBD)of the spike protein of SARSCoV-2,named CA4-d NS1-n CoV-RBD(d NS1-RBD).A preclinical study showed that in hamsters challenged 1d after single-dose vaccination or 9 months after booster vaccination,d NS1-RBD largely mitigated lung pathology,with no loss of body weight.Moreover,such cellular immunity is relatively unimpaired for the most concerning SARS-Co V-2 variants,especially for the latest Omicron variant.In addition,this vaccine also provides cross-protection against H1N1 and H5N1 influenza viruses.The protective immune mechanism of d NS1-RBD could be attributed to the innate immune response in the nasal epithelium,local RBD-specific T cell response in the lung,and RBD-specific Ig A and Ig G response.Thus,this study demonstrates that the intranasally delivered d NS1-RBD vaccine candidate may offer an important addition to the fight against the ongoing coronavirus disease 2019 pandemic and influenza infection,compensating limitations of current intramuscular vaccines.
基金supported by the National Natural Science Foundation of China(No.11301566)the Postdoc Scholarship(No.2012M511900)
文摘In this paper, the author studies the coarse embedding into uniformly convex Banach spaces. The author proves that the property of coarse embedding into Banach spaces can be preserved under taking the union of the metric spaces under certain condi- tions. As an application, for a group G strongly relatively hyperbolic to a subgroup H, the author proves that B（n） = {g ∈ G／ │g│suЭe≤ n} admits a coarse embedding into a uniformly convex Banach space if H does.
