To fulfill the requirements of data security in environments with nonequivalent resources,a high capacity data hiding scheme in encrypted image based on compressive sensing(CS)is proposed by fully utilizing the adapta...To fulfill the requirements of data security in environments with nonequivalent resources,a high capacity data hiding scheme in encrypted image based on compressive sensing(CS)is proposed by fully utilizing the adaptability of CS to nonequivalent resources.The original image is divided into two parts:one part is encrypted with traditional stream cipher;the other part is turned to the prediction error and then encrypted based on CS to vacate room simultaneously.The collected non-image data is firstly encrypted with simple stream cipher.For data security management,the encrypted non-image data is then embedded into the encrypted image,and the scrambling operation is used to further improve security.Finally,the original image and non-image data can be separably recovered and extracted according to the request from the valid users with different access rights.Experimental results demonstrate that the proposed scheme outperforms other data hiding methods based on CS,and is more suitable for nonequivalent resources.展开更多
Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely orien...Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely oriented.Using NbOCl_(2) monolayer with competing ferroelectric(FE)and antiferroelectric(AFE)phases as a 2D material platform,we demonstrate the emergence of intrinsic antiferroelectricity in NbOCl_(2) monolayer under experimentally accessible shear strain,along with new functionality associated with electric field-induced AFE-to-FE phase transition.Specifically,the complex configuration space accommodating FE and AFE phases,polarization switching kinetics,and finite temperature thermodynamic properties of 2D NbOCl_(2) are all accurately predicted by large-scale molecular dynamics simulations based on deep learning interatomic potential model.Moreover,room temperature stable antiferroelectricity with low polarization switching barrier and one-dimensional collinear polarization arrangement is predicted in shear-deformed NbOCl_(2) monolayer.The transition from AFE to FE phase in 2D NbOCl_(2) can be triggered by a low critical electric field,leading to a double polarization–electric(P–E)loop with small hysteresis.A new type of optoelectronic device composed of AFE-NbOCl_(2) is proposed,enabling electric“writing”and nonlinear optical“reading”logical operation with fast operation speed and low power consumption.展开更多
The transformation groups and symmetries of the baroclinic mode for rotating stratified flow can be obtained via the standard approach. Applying the symmetry group on some special solutions, the newly obtained results...The transformation groups and symmetries of the baroclinic mode for rotating stratified flow can be obtained via the standard approach. Applying the symmetry group on some special solutions, the newly obtained results disprove a known conjecture.展开更多
The crystal and molecular structure of diethyl l-(p-toluenesulfon-amido ) - p chlofoPhenylmet hylphosphonate has been determined by X- ray d iffractionmethod- The crystal (C18,H23,ClNO5PS) is monoclinic with space gro...The crystal and molecular structure of diethyl l-(p-toluenesulfon-amido ) - p chlofoPhenylmet hylphosphonate has been determined by X- ray d iffractionmethod- The crystal (C18,H23,ClNO5PS) is monoclinic with space group P21/c, a =8. 162(6), b= l8. O64(7), c= l4. 362(4) A, β=96. 29(3)°, V=2lO4. 7 A3, M.=431, 88, Z=4, Dx= l. 364 g/cm3, μ, = 3. 765 cm-1, F(000) = 904, R=0. 047 andRw=0. 0049 for 998 reflections with I>3σ(I). The 1H NMR spetrum of the title com-pound shows that the two ethoxy groups are magnetic nonequivalent, which is in agree-ment with its X-ray analysis result-展开更多
The 1H NMR spectrum of the title compound shows that the two hydrogen atoms at a-C are magnetic nonequivalence. To explain the nonequivalence phenomenon, the crystal and molecular structure of the title compound has b...The 1H NMR spectrum of the title compound shows that the two hydrogen atoms at a-C are magnetic nonequivalence. To explain the nonequivalence phenomenon, the crystal and molecular structure of the title compound has been determined by X-ray diffraction methed. The crystal (C27H26NO5PS) is monoclinic withspace group P21/c, a = 11. 310(4), b =20. 692(5), c =11. 826(4) A, β =112. 46(3)°， V = 2256(1) A3, Mr- 507. 55, Z = 4, Dx= 1. 319g/cm3, μ= 2. 179cm-1,F(000) =1064, R = 0. 054 and Rw= 0. 064 for 2405 renections with I≥>3δ(I). TheX-ray diffraction analysis reveals that the two hydrogen atoms at a-C are located at differeat magnetic environments, which can explain the nonequivalence phenomnon in 1HNMR spetrum.展开更多
<正> A series of O,O-diethyl-α-（p-toluenesulphonamido）phosphonates have been synthesized by theMannich-type reaction of p-toluenesulphonamide,substituted benzaldehydes and diethyl phosphite with acetylchlorid...<正> A series of O,O-diethyl-α-（p-toluenesulphonamido）phosphonates have been synthesized by theMannich-type reaction of p-toluenesulphonamide,substituted benzaldehydes and diethyl phosphite with acetylchloride as the solvent.The mechanism of the reaction is suggested,and the structures of new products areconfirmed by1H NMR,31p NMR,elemental analysis and X-ray diffraction.The results of preliminarybioassay showed that some of them possess herbicidal activities.展开更多
基金The work was funded by the National Natural Science Foundation of China(Grant Nos.61572089,61502399,61633005)the Chongqing Research Program of Basic Research and Frontier Technology(Grant No.cstc2017jcyjBX0008)+3 种基金the Project Supported by Graduate Student Research and Innovation Foundation of Chongqing(Grant No.CYB17026)the Chongqing Postgraduate Education Reform Project(Grant No.yjg183018)the Chongqing University Postgraduate Education Reform Project(Grant No.cquyjg18219)the Fundamental Research Funds for the Central Universities(Grant Nos.106112017CDJQJ188830,106112017CDJXY180005).
文摘To fulfill the requirements of data security in environments with nonequivalent resources,a high capacity data hiding scheme in encrypted image based on compressive sensing(CS)is proposed by fully utilizing the adaptability of CS to nonequivalent resources.The original image is divided into two parts:one part is encrypted with traditional stream cipher;the other part is turned to the prediction error and then encrypted based on CS to vacate room simultaneously.The collected non-image data is firstly encrypted with simple stream cipher.For data security management,the encrypted non-image data is then embedded into the encrypted image,and the scrambling operation is used to further improve security.Finally,the original image and non-image data can be separably recovered and extracted according to the request from the valid users with different access rights.Experimental results demonstrate that the proposed scheme outperforms other data hiding methods based on CS,and is more suitable for nonequivalent resources.
基金supported by the National Natural Science Foundation of China (Grant No.11574244 for G.Y.G.)the XJTU Research Fund for AI Science (Grant No.2025YXYC011 for G.Y.G.)the Hong Kong Global STEM Professorship Scheme (for X.C.Z.)。
文摘Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely oriented.Using NbOCl_(2) monolayer with competing ferroelectric(FE)and antiferroelectric(AFE)phases as a 2D material platform,we demonstrate the emergence of intrinsic antiferroelectricity in NbOCl_(2) monolayer under experimentally accessible shear strain,along with new functionality associated with electric field-induced AFE-to-FE phase transition.Specifically,the complex configuration space accommodating FE and AFE phases,polarization switching kinetics,and finite temperature thermodynamic properties of 2D NbOCl_(2) are all accurately predicted by large-scale molecular dynamics simulations based on deep learning interatomic potential model.Moreover,room temperature stable antiferroelectricity with low polarization switching barrier and one-dimensional collinear polarization arrangement is predicted in shear-deformed NbOCl_(2) monolayer.The transition from AFE to FE phase in 2D NbOCl_(2) can be triggered by a low critical electric field,leading to a double polarization–electric(P–E)loop with small hysteresis.A new type of optoelectronic device composed of AFE-NbOCl_(2) is proposed,enabling electric“writing”and nonlinear optical“reading”logical operation with fast operation speed and low power consumption.
基金Supported by National Natural Science Foundation of China under Grant Nos.10735030,10675065,and 90503006PCSIRT (IRT0734)+1 种基金the National Basic Research Programme of China under Grant Nos.2007CB814800K.C.Wong Magna Fund in Ningbo University
文摘The transformation groups and symmetries of the baroclinic mode for rotating stratified flow can be obtained via the standard approach. Applying the symmetry group on some special solutions, the newly obtained results disprove a known conjecture.
文摘The crystal and molecular structure of diethyl l-(p-toluenesulfon-amido ) - p chlofoPhenylmet hylphosphonate has been determined by X- ray d iffractionmethod- The crystal (C18,H23,ClNO5PS) is monoclinic with space group P21/c, a =8. 162(6), b= l8. O64(7), c= l4. 362(4) A, β=96. 29(3)°, V=2lO4. 7 A3, M.=431, 88, Z=4, Dx= l. 364 g/cm3, μ, = 3. 765 cm-1, F(000) = 904, R=0. 047 andRw=0. 0049 for 998 reflections with I>3σ(I). The 1H NMR spetrum of the title com-pound shows that the two ethoxy groups are magnetic nonequivalent, which is in agree-ment with its X-ray analysis result-
文摘The 1H NMR spectrum of the title compound shows that the two hydrogen atoms at a-C are magnetic nonequivalence. To explain the nonequivalence phenomenon, the crystal and molecular structure of the title compound has been determined by X-ray diffraction methed. The crystal (C27H26NO5PS) is monoclinic withspace group P21/c, a = 11. 310(4), b =20. 692(5), c =11. 826(4) A, β =112. 46(3)°， V = 2256(1) A3, Mr- 507. 55, Z = 4, Dx= 1. 319g/cm3, μ= 2. 179cm-1,F(000) =1064, R = 0. 054 and Rw= 0. 064 for 2405 renections with I≥>3δ(I). TheX-ray diffraction analysis reveals that the two hydrogen atoms at a-C are located at differeat magnetic environments, which can explain the nonequivalence phenomnon in 1HNMR spetrum.
基金the National Natural Science Foundation of China
文摘<正> A series of O,O-diethyl-α-（p-toluenesulphonamido）phosphonates have been synthesized by theMannich-type reaction of p-toluenesulphonamide,substituted benzaldehydes and diethyl phosphite with acetylchloride as the solvent.The mechanism of the reaction is suggested,and the structures of new products areconfirmed by1H NMR,31p NMR,elemental analysis and X-ray diffraction.The results of preliminarybioassay showed that some of them possess herbicidal activities.
