A new flexible double betaine L (L = 1,4-bis(pyridinio-4-carboxylato-N-methyl)benzene, C20H16N2O4) and its cadmium(Ⅱ) complex [Cd(H2O)aL(NO3)]NO3.H2O 1 were synthesized. Complex 1 was obtained by self-assem...A new flexible double betaine L (L = 1,4-bis(pyridinio-4-carboxylato-N-methyl)benzene, C20H16N2O4) and its cadmium(Ⅱ) complex [Cd(H2O)aL(NO3)]NO3.H2O 1 were synthesized. Complex 1 was obtained by self-assembly reaction of [Cd(NO3)2]-4H2O and L in hot water,and its crystal structure was determined by single-crystal X-ray diffraction analysis. Crystallographic data for complex 1: C20H24CdN4O14.H2O, Mr = 674.85, monoclinic, space group P21/c, a =13.7854(3), b = 14.2820(3), c = 14.9188(4) ,A°, β = 116.418(1)°, V = 2630.5(1)A°^3, Z = 4, Dc= 1.704g/cm^3,/J(MoKα) = 0.911 mm^-1, F(000) = 1368, the final R = 0.0315 and wR = 0.0768 for 3637 observed reflections with I 〉 2σ(I). In complex 1, L acts as a monodentate ligand to link a Cd(Ⅱ) ion in a novel coordination mode of double betaines. The mononuclear [Cd(H2O)aL(NO3)] units are connected through intermolecular hydrogen bonds and π-π stacking reactions to generate a 3D network.展开更多
Various novel double metal cyanide (DMC) catalysts were successfully prepared by modifying the central metal (M) and one of cyanide ion (CN-) in Zna[M(CN)b]c complex. Such modifications have significant impact...Various novel double metal cyanide (DMC) catalysts were successfully prepared by modifying the central metal (M) and one of cyanide ion (CN-) in Zna[M(CN)b]c complex. Such modifications have significant impact on the catalytic efficiency as well as the polymer selectivity for the reaction of PO/CO2. Zn-Ni(Ⅱ) DMC is a potential catalyst for alternating copolymerization of PO/CO2,and DMC catalysts based on Zn3[Co(CN)5X]2 (X = Br^- and N3^-) exhibit moderate efficiency for the production of polycarbonates.This research presents the preliminary exploration of novel DMC complex via chemical modification of its central metal and ligand.展开更多
Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H...Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H-1-NMR analysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecular weight copolymers with various EO content were obtained and their values of molecular weight distribution (MWD) fell in the range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO+PO to initiator moles used, The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.展开更多
A flexible double betaine 1,4-bis(pyridinil-4-carboxylato)-1,4-dimethylbenzene L has been used to generate two Cu(Ⅱ)-containing metal complexes that exhibit different polymeric structures: [Cu(H2O)2 L].2NO3 1 ...A flexible double betaine 1,4-bis(pyridinil-4-carboxylato)-1,4-dimethylbenzene L has been used to generate two Cu(Ⅱ)-containing metal complexes that exhibit different polymeric structures: [Cu(H2O)2 L].2NO3 1 and [Cu(H2O)3 L].2Cl.H2O 2. The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1: triclinic, space group PT, a = 5.253(2), b = 7.406(3), c = 14.792(5) A, α = 84.195(5), β = 80.014(5), γ = 78.053(5)°, V= 553.2(3)A^3, Z = 1, F(000) = 293, Dc = 1.717 g/cm^3, the final R = 0.0385 and wR = 0.1079 for 1883 observed reflections (I 〉 2σ(I)); and those for 2: monoclinic, space group P21/c, a = 10.222(3), b = 25.287(7), c = 9.277(3)A, β = 93.572(5)°, V = 2393.2(12)A^3, Z = 4, F(000) = 1140, Dc = 1.540 g/cm^3, the final R = 0.0472 and wR = 0.0956 for 3204 observed reflections (I 〉2o(/)).展开更多
Highly active calcium chloride(CaCl2) doped Zn-Co^Ⅲdouble metal-cyanide(Ca-DMC) catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield(54 kg polymer/g catalyst) at relative low temperatur...Highly active calcium chloride(CaCl2) doped Zn-Co^Ⅲdouble metal-cyanide(Ca-DMC) catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield(54 kg polymer/g catalyst) at relative low temperature(80-115℃) toward ringopening polymerization(ROP) of propylene oxide(PO) than did DMC catalysts without modification.展开更多
We propose to study the accelerating expansion of the universe in the double complex symmetric gravitational theory (DCSGT). The universe we live in is taken as the real part of the whole spacetime MC^4(J), which ...We propose to study the accelerating expansion of the universe in the double complex symmetric gravitational theory (DCSGT). The universe we live in is taken as the real part of the whole spacetime MC^4(J), which is double complex. By introducing the spatially flat FRW metric, not only the double Friedmann equations but also the two constraint conditions py = 0 and J^2 = 1 are obtained. Farthermore, using parametric DL(z) ansatz, we reconstruct the ω/(z) and V(Ф) for dark energy from real observational data. We find that in the two cases of J = i, pJ = 0, and J = ε, pJ≠0, the corresponding equations of state ω'(z) remain close to -1 at present (z = 0) and change from below -1 to above -1. The results illustrate that the whole spacetime, i.e. the double complex spacetime MC^4(J), may be either ordinary complex (J = i, pJ = 0) or hyperbolic complex (J = ε, pJ≠ 0). And the fate of the universe would be Big Rip in the future.展开更多
The excited-state double-proton transfer (ESDPT) mechanism of 2-amino-3-methoxypyridine and acetic acid com- plex is studied by the density functional theory (DFT) and time-dependent DFT with CAM-B3LYP functional....The excited-state double-proton transfer (ESDPT) mechanism of 2-amino-3-methoxypyridine and acetic acid com- plex is studied by the density functional theory (DFT) and time-dependent DFT with CAM-B3LYP functional. The complex is connected through two different types of inter-molecular hydrogen bonds. After photo-excitation, both hydrogen bonds get strengthened, which can facilitate the ESDPT reaction. The scanned potential energy curve along the proton transfer coordinate indicates that the ESDPT reaction proceeds in a stepwise pattern.展开更多
Image denoising is an important step in eliminating any noise impact in any image transmission process. Recently we presented two approaches for Bivariate based image denoising. They were Double Density Discrete Wavel...Image denoising is an important step in eliminating any noise impact in any image transmission process. Recently we presented two approaches for Bivariate based image denoising. They were Double Density Discrete Wavelet Transform (DD DWT) and Double Density Dual Tree Complex Wavelet Transform (DD CWT). In both techniques we decomposed noisy images with either DD DWT or DD CWT decompositions and then applied the Bivariate based denoising technique for noise removal. In this paper we propose an adaptive hybrid technique for Bivariate based image denoising that is based on the synthesis of DD-DWT bands or DD-CWT bands but with different weights, to deliver enhanced image features with less denoising impact especially around image edges, which is the most effected by noisy transmission channels. This proposed technique has been also enhanced by edge sharpening and Eigen analysis, as two separate stages. Simulation result comparisons have been performed between the proposed hybrid band adaptive DD-DWT and DD-CWT technique and the two primary techniques DD-DWT, DD- CWT, as well as other superior literature techniques such the original bivariate denoising technique with both original Complex Wavelet Transform and Double Density decompositions. This work in specific compares between Double Density DWT and Double Density CWT decompositions, proposes new filter design that suits each of them and proposes a hybrid technique between as will be shown.展开更多
This paper presents a novel scheme of high efficiency spreading spectrum modulation using double orthogonal complex sequences (DoCS). In this scheme, input data bit-stream is split into many groups with length M. Ea...This paper presents a novel scheme of high efficiency spreading spectrum modulation using double orthogonal complex sequences (DoCS). In this scheme, input data bit-stream is split into many groups with length M. Each group is then mapped into a word of width M and then utihzed to select one sequence from 2u-2 DoCS sequences each with length L. After that, the selected sequence is modulated on carrier in quadrature phase shift keying (QPSK) mode. In addition, a new method named forward phase correction (FPC) is put forward for carrier recovery. Theoretical analysis and bit-error-ratio(BER) experiment results indicate that the proposed scheme has better performance than the conventional direct sequence spread spectrum(DSSS) scheme both in bandwidth efficiency and processing gain of the receiver.展开更多
The double-double (or tetrad) effect of low molecular lanthanide complexes has been reportedsince the effect was discovered by Fidelis and Siekierski.However,so far no description concerning thedouble-double effect of...The double-double (or tetrad) effect of low molecular lanthanide complexes has been reportedsince the effect was discovered by Fidelis and Siekierski.However,so far no description concerning thedouble-double effect of macromolecular lanthanide complexes has been published in literature.We have been successful in preparing lanthanide complexes with styrene-acrylic acid copolymer,someof which exhibite high activitiest in butadiene polymerization.It was found that the complexes showedthe double-double effect as they were characterized.In the present paper,the SAAC·Ln IR spectra whichcharacterize the double-double effect have been discussed in detail.展开更多
The double crush syndrome is described as an increased risk of distal nerve injury after a more proximal injury. This was a case series of two patients who developed Complex Regional Pain Syndrome under circumstances ...The double crush syndrome is described as an increased risk of distal nerve injury after a more proximal injury. This was a case series of two patients who developed Complex Regional Pain Syndrome under circumstances when a double crush phenomenon could have occurred. Both initially had spinal stenosis and subsequent spinal surgery. Both later had crush injuries to a unilateral lower extremity, which progressed to CRPS. There is no documented correlation between double crush syndrome and CRPS;however, these cases raise awareness about a heightened propensity for CRPS in such patients, which will lead to earlier, accurate diagnosis and treatment.展开更多
Two new polymeric erbium(Ⅲ) complexes of two flexible double betaine ligands have been synthesized and characterized by X-ray analysis. In {[Er(L1)(H2O)4)Cl3 H2O}n (1) (L1 = 4, 4’ -trimethylenedipyridinio-N, N’-dia...Two new polymeric erbium(Ⅲ) complexes of two flexible double betaine ligands have been synthesized and characterized by X-ray analysis. In {[Er(L1)(H2O)4)Cl3 H2O}n (1) (L1 = 4, 4’ -trimethylenedipyridinio-N, N’-diacetate ), the erbium(Ⅲ) ions form a two-dimensional metal carboxylate layer in which each pair of Er(Ⅲ) atoms is bridged by two syn-anti μ-carboxylato-o,o’ groups, Adjacent layers arecross-linked through hydrogen bonds among aqua ligands, lattice water molecules andchloride ions to form a three-dimensional network. Complex l, C17 H28 N2 O9 ErC13 (Mr =676.0) is monoclinic, space group C2, with a= 27. 408(4), b= 9. 645 (3), c= 9. 423(2) A, p=1loo. 85(1)’, V=2446. 2(9) A’, Z=4, D=l. 836 g/cm’, F(OOO) =1332, μ(MoKa) = 38.06 cm-1, R=0. 048 for 2451 reflections with I>2σ(I). { [Er(L2 ) (H2O)4]Cl3. 5H2O}. (2) (L2=1, 3-bis (pyridinio-4-carboxylato) propane) comprises lanthanide carboxylate chains built from centrosymmetric dimeric units crosslinked by a pair of L2 ligands, discrete anions and lattice water molecules. In the dimeric unit of complex 2, each pair of metal ions is bridged by four syn-syn μ-carboxylatoO, O’ groups that are oriented nearly perpendicular to each other about the metal-metalaxis. The metal carboxylate chains of complex 2 are further cross-linked by hydrogenbonds to form a three-dimensional network. Complex 2, C15 H32 N2O13 ErCl3 (Mr=722.0) belongs to the monoclinic space group C2/m with a=16. 564 (3), b=15. 839(3), c=11. 792(4) , β=122. 27(1)°, V=2616(1), Z=4, Dc=1.833 g/cm3,F(000) =1436, μ (MoKa) = 35. 75 cm-1, R =0.043 for 2436 observed reflectionswithI>2σ(I).展开更多
The title complex [Cd(IPA)L(H2O)]n(1,H2IPA = isophthalic acid,L = 1,4-bis(pyra-zole-1-ylmethyl)benzene) has been hydrothermally synthesized,and characterized by elemental analyses,IR spectroscopy,TGA and X-ray...The title complex [Cd(IPA)L(H2O)]n(1,H2IPA = isophthalic acid,L = 1,4-bis(pyra-zole-1-ylmethyl)benzene) has been hydrothermally synthesized,and characterized by elemental analyses,IR spectroscopy,TGA and X-ray single-crystal diffraction.It crystallizes in the triclinic system,space group P1 with a = 9.3060(6),b = 10.2374(7),c = 11.9706(8) ?,α = 73.804(6),β = 77.883(5),γ = 85.942(5)°,V = 1070.7(1) ?3,Z = 2,C22H20CdN4O5,Mr = 532.82,Dc = 1.653 g/cm3,μ = 1.062 mm-1,λ(MoKα) = 0.71073 ?,F(000) = 536,R = 0.0392 and wR = 0.0640 for 3751 observed reflections with I 2σ(I).Crystal structure analysis showed that complex 1 has a 1D double chain structure,which is assembled together through strong O-H...O hydrogen bonding interactions between coordinated water molecules and carboxylate groups of isophthalate to form a 2D supramolecular network.In addition,the solid-state fluorescent spectrum of 1 exhibits strong emission at 364 nm.展开更多
The Scandinavian Caledonides comprise nappe stacks of far-travelled allochthons that record closure of the Iapetus Ocean and subsequent continental collision of Baltica and Laurentia.The Seve Nappe Complex(SNC)of the ...The Scandinavian Caledonides comprise nappe stacks of far-travelled allochthons that record closure of the Iapetus Ocean and subsequent continental collision of Baltica and Laurentia.The Seve Nappe Complex(SNC)of the Scandinavian Caledonides includes relics of the outermost Baltoscandian passive margin that were subducted to mantle depths.The earliest of the deep subduction events has been dated to ca.500-480 Ma.Evidence of this event has been reported from the northern exposures of the SNC.Farther south in the central and southern segments of the SNC,(ultra)high-pressure rocks have yielded younger ages in the range of ca.470-440 Ma.This study provides the first record of the early Caledonian event in the southern SNC.The evidence has been obtained by depth profiling of zircon grains that were extracted from the Tv?r?klumparna microdiamond-bearing gneiss.These zircon grains preserve eclogite facies overgrowths that crystallized at 482.6±3.8 Ma.A second,chemically-distinct zircon overgrowth records granulite facies metamorphism at 439.3±3.6 Ma,which corroborates previous geochronological evidence for granulite facies metamorphism at this time.Based on these results,we propose that the entire outer margin of Baltica was subducted in the late Cambrian to early Ordovician,but the record of this event may be almost entirely eradicated in the vast majority of lithologies by pervasive late Ordovician to early Silurian metamorphism.展开更多
The major histocompatibility complex(MHC) is the exclusive chaperone that presents intracellular antigens,either self or foreign to T cells.Interestingly,aberrant expression of MHC molecules has been reported in vario...The major histocompatibility complex(MHC) is the exclusive chaperone that presents intracellular antigens,either self or foreign to T cells.Interestingly,aberrant expression of MHC molecules has been reported in various autoimmune target tissues such as thyroid follicular cells in Grave's disease.Herein,we review the discovery of an unexpected effect of cytosolic doublestranded DNA(ds DNA),despite its origins,to induce antigen processing and presenting genes,including MHC molecules,in non-immune cells.Moreover,we highlight several recent studies that suggest cell injury endows thyroid epithelial cells with a phenotype of mature antigen presenting cells by inducing multiple antigen processing and presenting genes via releasing genomic DNA fragments into the cytosol.We discuss the possibility that such cytosolic ds DNA,in naked form without binding to histone proteins,might be involved in the development of cell damage-triggered autoimmune responses.We also discuss the possible molecular mechanism by which cytosolic ds DNA can induce MHC molecules.It is reasonable to speculate that cytosolic ds DNA-induced MHC class Ⅰ is partially due to an autocrine/paracrine effect of type Ⅰ interferon(IFN).While the mechanism of cytosolic ds DNA-induced MHC class Ⅱ expression appears,at least partially,distinct from that mediated by IFN-γ.Further in-depth are required to clarify this picture.展开更多
Based on the analysis for the situation about heat pipe,this paper points out that high efficiency micro heat pipe,high temperaturelarge heat pipe,high efficiency heat pipe reaction equipment and high efficiency heat ...Based on the analysis for the situation about heat pipe,this paper points out that high efficiency micro heat pipe,high temperaturelarge heat pipe,high efficiency heat pipe reaction equipment and high efficiency heat pipe heat exchange equipment are the developing di-rection of the heat pipe,and the complex heat pipe system is a new heat pipe idea that can satisfy the modern large heat pipe heat exchangeequipment and the high efficiency heat pipe heat exchange equipment.A new complex heat pipe system that is called double circulation con-trollable heat pipe system is advanced and several basic structure modes are given in this paper.The working principle and the basic character-istics about this special heat pipe system are also introduced and analyzed.展开更多
基金This work was supported by the NSF for Distinguished Young Scientist of China (20425104) and the NSF of Fujian Province (2005I017, A0420002)
文摘A new flexible double betaine L (L = 1,4-bis(pyridinio-4-carboxylato-N-methyl)benzene, C20H16N2O4) and its cadmium(Ⅱ) complex [Cd(H2O)aL(NO3)]NO3.H2O 1 were synthesized. Complex 1 was obtained by self-assembly reaction of [Cd(NO3)2]-4H2O and L in hot water,and its crystal structure was determined by single-crystal X-ray diffraction analysis. Crystallographic data for complex 1: C20H24CdN4O14.H2O, Mr = 674.85, monoclinic, space group P21/c, a =13.7854(3), b = 14.2820(3), c = 14.9188(4) ,A°, β = 116.418(1)°, V = 2630.5(1)A°^3, Z = 4, Dc= 1.704g/cm^3,/J(MoKα) = 0.911 mm^-1, F(000) = 1368, the final R = 0.0315 and wR = 0.0768 for 3637 observed reflections with I 〉 2σ(I). In complex 1, L acts as a monodentate ligand to link a Cd(Ⅱ) ion in a novel coordination mode of double betaines. The mononuclear [Cd(H2O)aL(NO3)] units are connected through intermolecular hydrogen bonds and π-π stacking reactions to generate a 3D network.
基金the National Natural Science Foundation of China(No.50273031)China Postdoctoral Science Foundation(No.20060400339).
文摘Various novel double metal cyanide (DMC) catalysts were successfully prepared by modifying the central metal (M) and one of cyanide ion (CN-) in Zna[M(CN)b]c complex. Such modifications have significant impact on the catalytic efficiency as well as the polymer selectivity for the reaction of PO/CO2. Zn-Ni(Ⅱ) DMC is a potential catalyst for alternating copolymerization of PO/CO2,and DMC catalysts based on Zn3[Co(CN)5X]2 (X = Br^- and N3^-) exhibit moderate efficiency for the production of polycarbonates.This research presents the preliminary exploration of novel DMC complex via chemical modification of its central metal and ligand.
文摘Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H-1-NMR analysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecular weight copolymers with various EO content were obtained and their values of molecular weight distribution (MWD) fell in the range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO+PO to initiator moles used, The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.
基金This work was financially supported by Liuhui Center for Applied Mathematics, Nankai and Tianjin Universities (No. H10114)
文摘A flexible double betaine 1,4-bis(pyridinil-4-carboxylato)-1,4-dimethylbenzene L has been used to generate two Cu(Ⅱ)-containing metal complexes that exhibit different polymeric structures: [Cu(H2O)2 L].2NO3 1 and [Cu(H2O)3 L].2Cl.H2O 2. The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1: triclinic, space group PT, a = 5.253(2), b = 7.406(3), c = 14.792(5) A, α = 84.195(5), β = 80.014(5), γ = 78.053(5)°, V= 553.2(3)A^3, Z = 1, F(000) = 293, Dc = 1.717 g/cm^3, the final R = 0.0385 and wR = 0.1079 for 1883 observed reflections (I 〉 2σ(I)); and those for 2: monoclinic, space group P21/c, a = 10.222(3), b = 25.287(7), c = 9.277(3)A, β = 93.572(5)°, V = 2393.2(12)A^3, Z = 4, F(000) = 1140, Dc = 1.540 g/cm^3, the final R = 0.0472 and wR = 0.0956 for 3204 observed reflections (I 〉2o(/)).
基金the financial supports of the National Science Foundation of the People's Republic of China(No.20704034)Provincial Natural Science Foundation of Zhejiang(No.Y4090047)
文摘Highly active calcium chloride(CaCl2) doped Zn-Co^Ⅲdouble metal-cyanide(Ca-DMC) catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield(54 kg polymer/g catalyst) at relative low temperature(80-115℃) toward ringopening polymerization(ROP) of propylene oxide(PO) than did DMC catalysts without modification.
基金The project supported by National Natural Science Foundation of China under Grant No. 10573004
文摘We propose to study the accelerating expansion of the universe in the double complex symmetric gravitational theory (DCSGT). The universe we live in is taken as the real part of the whole spacetime MC^4(J), which is double complex. By introducing the spatially flat FRW metric, not only the double Friedmann equations but also the two constraint conditions py = 0 and J^2 = 1 are obtained. Farthermore, using parametric DL(z) ansatz, we reconstruct the ω/(z) and V(Ф) for dark energy from real observational data. We find that in the two cases of J = i, pJ = 0, and J = ε, pJ≠0, the corresponding equations of state ω'(z) remain close to -1 at present (z = 0) and change from below -1 to above -1. The results illustrate that the whole spacetime, i.e. the double complex spacetime MC^4(J), may be either ordinary complex (J = i, pJ = 0) or hyperbolic complex (J = ε, pJ≠ 0). And the fate of the universe would be Big Rip in the future.
文摘The excited-state double-proton transfer (ESDPT) mechanism of 2-amino-3-methoxypyridine and acetic acid com- plex is studied by the density functional theory (DFT) and time-dependent DFT with CAM-B3LYP functional. The complex is connected through two different types of inter-molecular hydrogen bonds. After photo-excitation, both hydrogen bonds get strengthened, which can facilitate the ESDPT reaction. The scanned potential energy curve along the proton transfer coordinate indicates that the ESDPT reaction proceeds in a stepwise pattern.
文摘Image denoising is an important step in eliminating any noise impact in any image transmission process. Recently we presented two approaches for Bivariate based image denoising. They were Double Density Discrete Wavelet Transform (DD DWT) and Double Density Dual Tree Complex Wavelet Transform (DD CWT). In both techniques we decomposed noisy images with either DD DWT or DD CWT decompositions and then applied the Bivariate based denoising technique for noise removal. In this paper we propose an adaptive hybrid technique for Bivariate based image denoising that is based on the synthesis of DD-DWT bands or DD-CWT bands but with different weights, to deliver enhanced image features with less denoising impact especially around image edges, which is the most effected by noisy transmission channels. This proposed technique has been also enhanced by edge sharpening and Eigen analysis, as two separate stages. Simulation result comparisons have been performed between the proposed hybrid band adaptive DD-DWT and DD-CWT technique and the two primary techniques DD-DWT, DD- CWT, as well as other superior literature techniques such the original bivariate denoising technique with both original Complex Wavelet Transform and Double Density decompositions. This work in specific compares between Double Density DWT and Double Density CWT decompositions, proposes new filter design that suits each of them and proposes a hybrid technique between as will be shown.
基金Union Innovation Found of Jiangsu Province(No. BY2009149)
文摘This paper presents a novel scheme of high efficiency spreading spectrum modulation using double orthogonal complex sequences (DoCS). In this scheme, input data bit-stream is split into many groups with length M. Each group is then mapped into a word of width M and then utihzed to select one sequence from 2u-2 DoCS sequences each with length L. After that, the selected sequence is modulated on carrier in quadrature phase shift keying (QPSK) mode. In addition, a new method named forward phase correction (FPC) is put forward for carrier recovery. Theoretical analysis and bit-error-ratio(BER) experiment results indicate that the proposed scheme has better performance than the conventional direct sequence spread spectrum(DSSS) scheme both in bandwidth efficiency and processing gain of the receiver.
基金The project supported by the National Natural Science Foundation of China
文摘The double-double (or tetrad) effect of low molecular lanthanide complexes has been reportedsince the effect was discovered by Fidelis and Siekierski.However,so far no description concerning thedouble-double effect of macromolecular lanthanide complexes has been published in literature.We have been successful in preparing lanthanide complexes with styrene-acrylic acid copolymer,someof which exhibite high activitiest in butadiene polymerization.It was found that the complexes showedthe double-double effect as they were characterized.In the present paper,the SAAC·Ln IR spectra whichcharacterize the double-double effect have been discussed in detail.
文摘The double crush syndrome is described as an increased risk of distal nerve injury after a more proximal injury. This was a case series of two patients who developed Complex Regional Pain Syndrome under circumstances when a double crush phenomenon could have occurred. Both initially had spinal stenosis and subsequent spinal surgery. Both later had crush injuries to a unilateral lower extremity, which progressed to CRPS. There is no documented correlation between double crush syndrome and CRPS;however, these cases raise awareness about a heightened propensity for CRPS in such patients, which will lead to earlier, accurate diagnosis and treatment.
文摘Two new polymeric erbium(Ⅲ) complexes of two flexible double betaine ligands have been synthesized and characterized by X-ray analysis. In {[Er(L1)(H2O)4)Cl3 H2O}n (1) (L1 = 4, 4’ -trimethylenedipyridinio-N, N’-diacetate ), the erbium(Ⅲ) ions form a two-dimensional metal carboxylate layer in which each pair of Er(Ⅲ) atoms is bridged by two syn-anti μ-carboxylato-o,o’ groups, Adjacent layers arecross-linked through hydrogen bonds among aqua ligands, lattice water molecules andchloride ions to form a three-dimensional network. Complex l, C17 H28 N2 O9 ErC13 (Mr =676.0) is monoclinic, space group C2, with a= 27. 408(4), b= 9. 645 (3), c= 9. 423(2) A, p=1loo. 85(1)’, V=2446. 2(9) A’, Z=4, D=l. 836 g/cm’, F(OOO) =1332, μ(MoKa) = 38.06 cm-1, R=0. 048 for 2451 reflections with I>2σ(I). { [Er(L2 ) (H2O)4]Cl3. 5H2O}. (2) (L2=1, 3-bis (pyridinio-4-carboxylato) propane) comprises lanthanide carboxylate chains built from centrosymmetric dimeric units crosslinked by a pair of L2 ligands, discrete anions and lattice water molecules. In the dimeric unit of complex 2, each pair of metal ions is bridged by four syn-syn μ-carboxylatoO, O’ groups that are oriented nearly perpendicular to each other about the metal-metalaxis. The metal carboxylate chains of complex 2 are further cross-linked by hydrogenbonds to form a three-dimensional network. Complex 2, C15 H32 N2O13 ErCl3 (Mr=722.0) belongs to the monoclinic space group C2/m with a=16. 564 (3), b=15. 839(3), c=11. 792(4) , β=122. 27(1)°, V=2616(1), Z=4, Dc=1.833 g/cm3,F(000) =1436, μ (MoKa) = 35. 75 cm-1, R =0.043 for 2436 observed reflectionswithI>2σ(I).
文摘The title complex [Cd(IPA)L(H2O)]n(1,H2IPA = isophthalic acid,L = 1,4-bis(pyra-zole-1-ylmethyl)benzene) has been hydrothermally synthesized,and characterized by elemental analyses,IR spectroscopy,TGA and X-ray single-crystal diffraction.It crystallizes in the triclinic system,space group P1 with a = 9.3060(6),b = 10.2374(7),c = 11.9706(8) ?,α = 73.804(6),β = 77.883(5),γ = 85.942(5)°,V = 1070.7(1) ?3,Z = 2,C22H20CdN4O5,Mr = 532.82,Dc = 1.653 g/cm3,μ = 1.062 mm-1,λ(MoKα) = 0.71073 ?,F(000) = 536,R = 0.0392 and wR = 0.0640 for 3751 observed reflections with I 2σ(I).Crystal structure analysis showed that complex 1 has a 1D double chain structure,which is assembled together through strong O-H...O hydrogen bonding interactions between coordinated water molecules and carboxylate groups of isophthalate to form a 2D supramolecular network.In addition,the solid-state fluorescent spectrum of 1 exhibits strong emission at 364 nm.
基金funded by the National Science Centre,Poland CALSUB project no.2014/14/E/ST10/00321financial support has been provided by the Polish National Agency for Academic Exchange Scholarship PPN/IWA/2018/1/00030/U/00001 granted to C.Barnes。
文摘The Scandinavian Caledonides comprise nappe stacks of far-travelled allochthons that record closure of the Iapetus Ocean and subsequent continental collision of Baltica and Laurentia.The Seve Nappe Complex(SNC)of the Scandinavian Caledonides includes relics of the outermost Baltoscandian passive margin that were subducted to mantle depths.The earliest of the deep subduction events has been dated to ca.500-480 Ma.Evidence of this event has been reported from the northern exposures of the SNC.Farther south in the central and southern segments of the SNC,(ultra)high-pressure rocks have yielded younger ages in the range of ca.470-440 Ma.This study provides the first record of the early Caledonian event in the southern SNC.The evidence has been obtained by depth profiling of zircon grains that were extracted from the Tv?r?klumparna microdiamond-bearing gneiss.These zircon grains preserve eclogite facies overgrowths that crystallized at 482.6±3.8 Ma.A second,chemically-distinct zircon overgrowth records granulite facies metamorphism at 439.3±3.6 Ma,which corroborates previous geochronological evidence for granulite facies metamorphism at this time.Based on these results,we propose that the entire outer margin of Baltica was subducted in the late Cambrian to early Ordovician,but the record of this event may be almost entirely eradicated in the vast majority of lithologies by pervasive late Ordovician to early Silurian metamorphism.
基金Scientific Research from the Japan Society for the Promotion of Science to Suzuki K,No.15K09444
文摘The major histocompatibility complex(MHC) is the exclusive chaperone that presents intracellular antigens,either self or foreign to T cells.Interestingly,aberrant expression of MHC molecules has been reported in various autoimmune target tissues such as thyroid follicular cells in Grave's disease.Herein,we review the discovery of an unexpected effect of cytosolic doublestranded DNA(ds DNA),despite its origins,to induce antigen processing and presenting genes,including MHC molecules,in non-immune cells.Moreover,we highlight several recent studies that suggest cell injury endows thyroid epithelial cells with a phenotype of mature antigen presenting cells by inducing multiple antigen processing and presenting genes via releasing genomic DNA fragments into the cytosol.We discuss the possibility that such cytosolic ds DNA,in naked form without binding to histone proteins,might be involved in the development of cell damage-triggered autoimmune responses.We also discuss the possible molecular mechanism by which cytosolic ds DNA can induce MHC molecules.It is reasonable to speculate that cytosolic ds DNA-induced MHC class Ⅰ is partially due to an autocrine/paracrine effect of type Ⅰ interferon(IFN).While the mechanism of cytosolic ds DNA-induced MHC class Ⅱ expression appears,at least partially,distinct from that mediated by IFN-γ.Further in-depth are required to clarify this picture.
文摘Based on the analysis for the situation about heat pipe,this paper points out that high efficiency micro heat pipe,high temperaturelarge heat pipe,high efficiency heat pipe reaction equipment and high efficiency heat pipe heat exchange equipment are the developing di-rection of the heat pipe,and the complex heat pipe system is a new heat pipe idea that can satisfy the modern large heat pipe heat exchangeequipment and the high efficiency heat pipe heat exchange equipment.A new complex heat pipe system that is called double circulation con-trollable heat pipe system is advanced and several basic structure modes are given in this paper.The working principle and the basic character-istics about this special heat pipe system are also introduced and analyzed.