Curved-beams can be used to design modular multistable metamaterials(MMMs)with reprogrammable material properties,i.e.,programmable curved-beam periodic structure(PCBPS),which is promising for controlling the elastic ...Curved-beams can be used to design modular multistable metamaterials(MMMs)with reprogrammable material properties,i.e.,programmable curved-beam periodic structure(PCBPS),which is promising for controlling the elastic wave propagation.The PCBPS is theoretically equivalent to a spring-oscillator system to investigate the mechanism of bandgap,analyze the wave propagation mechanisms,and further form its geometrical and physical criteria for tuning the elastic wave propagation.With the equivalent model,we calculate the analytical solutions of the dispersion relations to demonstrate its adjustability,and investigate the wave propagation characteristics through the PCBPS.To validate the equivalent system,the finite element method(FEM)is employed.It is revealed that the bandgaps of the PCBPS can be turned on-and-off and shifted by varying its physical and geometrical characteristics.The findings are highly promising for advancing the practical application of periodic structures in wave insulation and propagation control.展开更多
Welding deformation often brings about manufacturing problems such as dimensional inaccuracies during assembly and reduces fabrication efficiency.Prediction and controlling welding deformation can help to improve the ...Welding deformation often brings about manufacturing problems such as dimensional inaccuracies during assembly and reduces fabrication efficiency.Prediction and controlling welding deformation can help to improve the quality of welded structures.In this paper,the welding deformation of propeller base struc-tures is predicted by means of numerical approaches and mechanical constraints are proposed to control deformations in welding process.Thermal elasto-plastic finite element method(TEP FEM)is employed to simulate welding process of the base structure.Computed accuracy of welding deformation by TEP FEM analysis is verified by comparing with experimental data of tee joint welding.Results show that welding deformations of the base mainly comprise out-of-plane distortion of ring fringe and radial distortion of cylindrical plate.Exerting mechanical constraints of fixed points at fringe and rigid supports inside cylin-der can decrease out-of-plane and radial distortions effectively.The numerical approach adopted in this article can serve as an effective tool to optimize welding process planning in integrated design method.展开更多
The optimal design and effectiveness of three control systems,tuned viscous mass damper(TVMD),tuned inerter damper(TID)and tuned mass damper(TMD),on mitigating the seismic responses of base isolated structures,were sy...The optimal design and effectiveness of three control systems,tuned viscous mass damper(TVMD),tuned inerter damper(TID)and tuned mass damper(TMD),on mitigating the seismic responses of base isolated structures,were systematically studied.First,the seismic responses of the base isolated structure with each control system under white noise excitation were obtained.Then,the structural parameter optimizations of the TVMD,TID and TMD were conducted by using three different objectives.The results show that the three control systems were all effective in minimizing the root mean square value of seismic responses,including the base shear of the BIS,the absolute acceleration of structural SDOF,and the relative displacement between the base isolation floor and the foundation.Finally,considering the superstructure as a structural MDOF,a series of time history analyses were performed to investigate the effectiveness and activation sensitivity of the three control systems under far field and near fault seismic excitations.The results show that the effectiveness of TID and TMD with optimized parameters on mitigating the seismic responses of base isolated structures increased as the mass ratio increases,and the effectiveness of TID was always better than TMD with the same mass ratio.The TVMD with a lower mass ratio was more efficient in reducing the seismic response than the TID and TMD.Furthermore,the TVMD,when compared with TMD and TID,had better activation sensitivity and a smaller stroke.展开更多
The title zinc（Ⅱ） complex salt [Zn（H2O）6]（ClO4）2-（PNOS）4, where PNOS is derived from picolinaldehyde N-oxide with semicarbazone, has been prepared and structurally characterized by X-ray single-crystal analys...The title zinc（Ⅱ） complex salt [Zn（H2O）6]（ClO4）2-（PNOS）4, where PNOS is derived from picolinaldehyde N-oxide with semicarbazone, has been prepared and structurally characterized by X-ray single-crystal analysis. It crystallizes in triclinic, space group PI with a = 7.529（3）, b = 10.206（4）, c = 14.678（6）A, a = 86.293（6）, β= 87.686（7）, γ= 81.382（6）°, C28H44Cl2N16O22Zn, Mr = 1093.06, V = 1112.3（8） ,A^3 Z = 1, Dc = 1.632 g/cm^3, S = 1.089, μ（MoKa） = 0.773 mm^-1, F（000） = 564, the final R = 0.0438 and wR = 0.1076 for 3888 independent reflections with Rint = 0.0224. The crystal structure possesses a [Zn（H2O）6]^2＋ cation, two ClO4^- anions and four PNOSs. In the crystal structure, Zn^2＋ cation is located at the symcenter and coordinated by six water molecules. In [Zn（H2O）6]^2＋, an elongate octahedral complex cation, the average Zn-O bond length is 2.087（2） A. There exist a lot of H bonds in the structure, linking the cation [Zn（H2O）6]^2＋, anion ClO4^- and PNOS to form a 3D network.展开更多
It is regretted that the author corrections requested at the proof stage were not made accurately. There are some incorrect typings in two equations which will lead to inaccurate results if readers perform calculation...It is regretted that the author corrections requested at the proof stage were not made accurately. There are some incorrect typings in two equations which will lead to inaccurate results if readers perform calculations directly展开更多
A compact structured illumination chip based on integrated optics is proposed and fabricated on a silicon-on- insulator platform. Based on the simulation of Caussian beam interference, we adopt a chirped diffraction g...A compact structured illumination chip based on integrated optics is proposed and fabricated on a silicon-on- insulator platform. Based on the simulation of Caussian beam interference, we adopt a chirped diffraction grating to achieve a specific interference pattern. The experimental results match well with the simulations. The portability and flexibility of the structured illumination chip can be increased greatly through horizontal encapsulation. High levels of integration, compared with the conventional structured illumination approach, make this chip very compact, with a footprint of only around 1 mm2. The chip has no optical lenses and can be easily combined with a microfluidic system. These properties would make the chip very suitable for portable 3D scanner and compact super-resolution microscopy applications.展开更多
A combined structure with the unit cell consisting of four sub-units with 90° rotation in turn is designed. Each of sub-units is composed of two gold rods in transverse arrangement and one gold rod in longitudina...A combined structure with the unit cell consisting of four sub-units with 90° rotation in turn is designed. Each of sub-units is composed of two gold rods in transverse arrangement and one gold rod in longitudinal arrangement. Simulating electromagnetic responses of the structure, we verify that the structure exhibits the double Fano resonances, which originate from the coupling between magnetic quadrupoles and electric dipoles and the coupling between electric quadrupoles and electric dipoles. Simulation results also demonstrate that the structure is polarization-insensitive and shows an analogue of electromagnetically induced transparency at the two Fano resonances. Such a plasmonic structure has potential applications in photoelectric elements.展开更多
In this paper, an asymmetric array structure of space laser communication receiver is proposed. This structure can greatly reduce alignment requirement, and lighten the signal strength jitter caused by atmospheric tur...In this paper, an asymmetric array structure of space laser communication receiver is proposed. This structure can greatly reduce alignment requirement, and lighten the signal strength jitter caused by atmospheric turbulence. A prototype of the proposed structure is fabricated and a 2.5 Mbit/s on-off keying(OOK) modulated demonstration link over 40 m free space is built. This asymmetric array structure can effectively collect optical signal while rotating in a window angle of ±17°, and the bit error ratio(BER) keeps zero.展开更多
The functionalized calix[4]pyrrole meso-substituted Schiff bases were conveniently prepared by four- step synthetic route. Furthermore, the nickel and copper complexes of calix[4]pyrrole meso-substituted Schiff base w...The functionalized calix[4]pyrrole meso-substituted Schiff bases were conveniently prepared by four- step synthetic route. Furthermore, the nickel and copper complexes of calix[4]pyrrole meso-substituted Schiff base with 1：2 stoichiometry were obtained. The crystal structures of the calix[4]pyrroles and their metal complexes were determined by X-ray diffraction.展开更多
The regioselective syntheses of novel p-tert-butylcalix[4]arenes with functional aldehyde and dithiocarbazate Schiff base groups were carried out. p-tert-Butylcalix[4]arene was alkylated with o-, p-（ω-chloroalkoxy）...The regioselective syntheses of novel p-tert-butylcalix[4]arenes with functional aldehyde and dithiocarbazate Schiff base groups were carried out. p-tert-Butylcalix[4]arene was alkylated with o-, p-（ω-chloroalkoxy）- benzaldehydes in the system of K2CO3/KI/CH3CN to give calixarene 1,3-dialdehydes. Then the condensation reactions of active calixarene aldehydes with S-methyl and S-benzyldithiocarbazate, calixarene sulfur-containing Schiff bases were efficiently obtained in satisfied yields. The single crystal analysis of the four representative products shows that calixarene aldehydes and Schiff bases exist in cone conformation and there are interesting intermolecular hydrogen-bands and π...π interaction in the crystals.展开更多
A high-efficiency green phosphorescent organic light emitting diode with a simplified structure is achieved that is free of a hole transport layer. The design of this kind of device structure not only saves the consum...A high-efficiency green phosphorescent organic light emitting diode with a simplified structure is achieved that is free of a hole transport layer. The design of this kind of device structure not only saves the consumption of organic materials but also greatly reduces the structural heterogeneities and effectively facilitates the charge injection into the emissive layer. The resulting green phosphorescent organic light-emitting diodes （PHOLEDs） exhibit higher electroluminescent efficiency. The maximum external quantum efficiency and current efficiency reach 23.7% and 88 cd/A, respectively. Moreover the device demonstrates satisfactory stability, keeping 23.7% and 88cd/A, 22% and 82cd/A, respectively, at a luminance of 100 and 1000cd/m2. The working mechanism for achieving high efficiency based on such a simple device structure is discussed correspondingly. The improved charge carrier injection and transport balance are proved to prominently contribute to achieve the high efficiency and great stability at high luminance in the green PHOLEDs.展开更多
A distance measure that infers to indicate the evolutionary relationship of protein structures has been developed based on spatial preference factors of residues. The spatial preference factor is a reflection of the e...A distance measure that infers to indicate the evolutionary relationship of protein structures has been developed based on spatial preference factors of residues. The spatial preference factor is a reflection of the environment of residues in tertiary structure. Compared with the phyletic relationships derived from sequence homologies and three-dimensional structures, we find that the two lines of evolution are similar in general. This approach is applied to a group of glins here.展开更多
After synthesis of an asymmetric tetradentate ONN＇O＇ Schiff base ligand （H2L） followed by reaction of the synthesized H2L with an equimolar mixture of methanolic solutions of the VO（acac）2, a new oxidovanadium...After synthesis of an asymmetric tetradentate ONN＇O＇ Schiff base ligand （H2L） followed by reaction of the synthesized H2L with an equimolar mixture of methanolic solutions of the VO（acac）2, a new oxidovanadium（IV） Schiff base complex （VOL） was synthesized. The Schiff base ligand and its complex were characterized by FT-IR and UV-vis spectra and C, H, N analysis, The crystal structure of VOL was also determined by single crystal X-ray analysis. The VOL complex crystallizes in monoclinic space group Cc. The Schiffbase ligand acts as a tetradentate ligand through its two＇iminic nitrogens and two phenolic and acetylacetonate oxygens. Thermogravimetric analysis of the VOL showed that it decomposes in two steps and converts to mixed vanadium oxides at 477℃. In addition, thermal decomposition of the VOL complex in air at 660 ℃ leads to formation of V2O5 nanoparticles with the average size estimated from XRD 49 nm. The catalytic activity of the VOL complex was investigated in the epoxidation reaction and different reaction parameters were optimized. The results showed that the cyclic alkenes were efficiently converted to the corresponding epoxides, whereas the VOL did not appreciably convert the linear alkenes.展开更多
A new chain-like coordination polymer, namely, [CuL]n （1, Na2L = 2-[（2-hydroxy- benzylidene）-amino]-benzenesulfonic acid sodium salt）, has been synthesized and characterized by single-crystal X-ray diffraction, IR...A new chain-like coordination polymer, namely, [CuL]n （1, Na2L = 2-[（2-hydroxy- benzylidene）-amino]-benzenesulfonic acid sodium salt）, has been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy and elemental analysis. Complex 1 crystallizes in monoclinic system, space group P21/c with a = 9.2296（16）, b = 10.4754（18）, c = 12.200（2） A, β = 102.392（2）°, V = 1152.0（3）A3, CI3H9CuNOaN, Mr = 338.83, Dc = 1.953 g/cm3, Z = 4, F（000） = 684, p = 2.089 mm-1, the final R = 0.0376 and wR = 0.0956. X-ray diffraction analyses indicate that 1 displays a square-pyramidal metal center with NO4 donor sets. The sulfonate-derived Schiff base serves as a common N,O,O＇-tridentate and a unique O-bridged ligand connecting the metals. Dinuclear copper complexes serve as secondary building blocks （SBUs） to construct an unusual 2D coordination network. In the crystal, the components form a stable 3D supramolecular architecture by C-H...O interactions and to-stacking展开更多
We investigate the memory properties of the ITO/graphene oxide/Al diodes. It is found that the devices show different memory behaviors with the diverse geometry and thickness of Al. When the thickness of the Al electr...We investigate the memory properties of the ITO/graphene oxide/Al diodes. It is found that the devices show different memory behaviors with the diverse geometry and thickness of Al. When the thickness of the Al electrode is relatively thick, the device of the cross-point Al electrode shows a three-level memory effect, and the counterpart device of the cross-bar Al electrode exhibits a volatile static random access memory effect. When the thickness of the AI electrode is thinner, the above devices demonstrate a flash memory effect. The different memory behaviors of ITO/GO/AI diodes are ascribed to the mode and degree of reduction and oxidation of GO.展开更多
An efficient method for the synthesis of some difunctionalized copillar[5]arene Schiff bases from condensation of salicylaldehyde and its 5-chloro,5-bromo,3,5-di（t-butyl） substituted derivatives with corresponding d...An efficient method for the synthesis of some difunctionalized copillar[5]arene Schiff bases from condensation of salicylaldehyde and its 5-chloro,5-bromo,3,5-di（t-butyl） substituted derivatives with corresponding diamino-functionalized copillar[5]arene,which were prepared by Gabriel reaction according to the reported method.Single-crystals of six copillar[5]arenes were determined by X-ray diffraction.An ORTEP of compounds showed that the two chains units of Schiff base exist in the outside of the cavity of pillar[5]arene.Furthermore,the complexing ability of these Schiff bases to transition metal ions were investigated by UV and fluorescence spectroscopy.展开更多
Two new mononuclear complexes, namely [Co（L）2]（1） and [Mn（L）2]（2）（HL = N-（3-methylsalicylidene）tryptamine）, have been synthesized by the reactions of the ligand with cobalt acetate or manganese acetate in ...Two new mononuclear complexes, namely [Co（L）2]（1） and [Mn（L）2]（2）（HL = N-（3-methylsalicylidene）tryptamine）, have been synthesized by the reactions of the ligand with cobalt acetate or manganese acetate in anhydrous ethanol. The crystal structures of the complexes were characterized by IR spectrum, elemental analysis, PXRD and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 23.146（2）, b = 9.4864（10）, c = 13.9261（15）A, β = 102.898（2）°, V = 2980.6（5） ？3, Z = 4, Dc = 1.367 g/cm3, F（000） = 1284 and μ = 0.616 mm^-1. Complex 2 crystallizes in monoclinic, space group P21/n, with a = 14.807（11）, b = 13.118（10）, c = 16.663（13） A, β = 111.237（14）°, V = 3017（4） A^3, Z = 4, Dc = 1.342 g/cm^3, F（000） = 1276 and μ = 0.477 mm-1. The units of complex 1 are linked by intermolecular N–H…π hydrogen bonds into infinite 1D chains, which are further extended into a 3D supramolecular structure by a series of π···π stacking interactions. The units of complex 2 are linked by intermolecular N–H…π hydrogen bonds and C–H…π hydrogen bonds into an infinite 3D supramolecular structure. Meanwhile, the antibacterial activities of the ligand and its complexes have been tested against four kinds of bacteria. The results show that the three compounds all have excellent antibacterial activities and that 1 and 2 possess stronger inhibiting effects against the bacteria than the Schiff base.展开更多
A knowledge based company is the microcosmic foundation of the knowledge economy, the design of its organization structure should amplify the company competence to be agile to the knowledge elements. This paper expoun...A knowledge based company is the microcosmic foundation of the knowledge economy, the design of its organization structure should amplify the company competence to be agile to the knowledge elements. This paper expounds an interior market network structure which is fit for the company intellectual capital operation, and analyses this organization pattern about the reasons of existence, the effectiveness of growing up in scale, the economies of knowledge distribution and the efficiency of operation, and it will provide some beneficial theoretical guidance about how can a company improve its competition competence in the knowledge environment through organization innovation.展开更多
Rapid increases in Carbon dioxide(CO_(2))levels could trigger unpredictable climate change.The assessment of spatiotempor-al variation and influencing factors of CO_(2) concentration are helpful in understanding the s...Rapid increases in Carbon dioxide(CO_(2))levels could trigger unpredictable climate change.The assessment of spatiotempor-al variation and influencing factors of CO_(2) concentration are helpful in understanding the source/sink balance and supporting the formu-lation of climate policy.In this study,Greenhouse Gases Observing Satellite(GOSAT)data were used to explore the variability of CO_(2) concentrations in China from 2009 to 2020.Meteorological parameters,vegetation cover,and anthropogenic activities were combined to explain the increase in CO_(2) concentration,using pixel-based correlations and Covariance Based Structural Equation Modeling(CB-SEM)analysis.The results showed that the influence of vertical CO_(2) transport diminished with altitude,with a distinct inter-annual in-crease in CO_(2) concentrations at 17 vertical levels.Spatially,the highest values were observed in East China,whereas the lowest were observed in Northwest China.There were significant seasonal variations in CO_(2) concentration,with maximum and minimum values in spring(April)and summer(August),respectively.According to the pixel-based correlation analysis,the near-surface CO_(2) concentration was positively correlated with population(r=0.99,P<0.001),Leaf Area Index(LAI,r=0.95,P<0.001),emissions(r=0.91,P<0.001),temperature(r=0.60,P<0.05),precipitation(r=0.34,P>0.05),soil water(r=0.29,P>0.05),nightlight(r=0.28,P>0.05);and negatively correlated with wind speed(r=−0.58,P<0.05).CB-SEM analysis revealed that LAI was the most important con-trolling factor explaining CO_(2) concentration variation(total effect of 0.66),followed by emissions(0.58),temperature(0.45),precipita-tion(0.30),wind speed(−0.28),and soil water(−0.07).The model explained 93% of the increase in CO_(2) concentration.Our results provide crucial information on the patterns of CO_(2) concentrations and their driving mechanisms,which are particularly significant in the context of climate change.展开更多
A new silver（Ⅰ） compound 6 （[Ag6L66]·4DMF） containing thiosemicarbazone with the group of 2-chloro-1-benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental anal...A new silver（Ⅰ） compound 6 （[Ag6L66]·4DMF） containing thiosemicarbazone with the group of 2-chloro-1-benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. The title compound 6 crystallizes in monoclinic, space group C2/c with a = 26.9236（18）, b = 15.2553（8）, c = 24.6237（13） , β = 103.0680（10）°, V = 9851.7（10）3, C58H66Ag6Cl6N20O3S6, Mr = 2143.59, Dc = 1.445 g/cm3, μ（MoKα） = 1.503 mm-1, F（000） = 4232, Z = 4, the final R = 0.0565 and wR = 0.1654 for 5831 observed reflections （Ⅰ 〉 2σ（Ⅰ））. Similar to the structure of the compounds we have reported, compound 6 also exhibits a hexanuclear silver（Ⅰ） cluster. In the cluster, the S atom of ligand L6 （L6 = 2-chloro-1-benzaldehyde thiosemicarbazone） served as a triply bridged chelator to connect the six silver atoms into a Ag6L66 cluster. The luminescence property of compound 6 was investigated at room temperature and compared with other similar compounds in order to find the factors influencing their luminescent property.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12172012 and 11802005)。
文摘Curved-beams can be used to design modular multistable metamaterials(MMMs)with reprogrammable material properties,i.e.,programmable curved-beam periodic structure(PCBPS),which is promising for controlling the elastic wave propagation.The PCBPS is theoretically equivalent to a spring-oscillator system to investigate the mechanism of bandgap,analyze the wave propagation mechanisms,and further form its geometrical and physical criteria for tuning the elastic wave propagation.With the equivalent model,we calculate the analytical solutions of the dispersion relations to demonstrate its adjustability,and investigate the wave propagation characteristics through the PCBPS.To validate the equivalent system,the finite element method(FEM)is employed.It is revealed that the bandgaps of the PCBPS can be turned on-and-off and shifted by varying its physical and geometrical characteristics.The findings are highly promising for advancing the practical application of periodic structures in wave insulation and propagation control.
文摘Welding deformation often brings about manufacturing problems such as dimensional inaccuracies during assembly and reduces fabrication efficiency.Prediction and controlling welding deformation can help to improve the quality of welded structures.In this paper,the welding deformation of propeller base struc-tures is predicted by means of numerical approaches and mechanical constraints are proposed to control deformations in welding process.Thermal elasto-plastic finite element method(TEP FEM)is employed to simulate welding process of the base structure.Computed accuracy of welding deformation by TEP FEM analysis is verified by comparing with experimental data of tee joint welding.Results show that welding deformations of the base mainly comprise out-of-plane distortion of ring fringe and radial distortion of cylindrical plate.Exerting mechanical constraints of fixed points at fringe and rigid supports inside cylin-der can decrease out-of-plane and radial distortions effectively.The numerical approach adopted in this article can serve as an effective tool to optimize welding process planning in integrated design method.
基金National Key Research and Development Program of China under Grant No.2017YFC0703600 and No.2017YFC0703604。
文摘The optimal design and effectiveness of three control systems,tuned viscous mass damper(TVMD),tuned inerter damper(TID)and tuned mass damper(TMD),on mitigating the seismic responses of base isolated structures,were systematically studied.First,the seismic responses of the base isolated structure with each control system under white noise excitation were obtained.Then,the structural parameter optimizations of the TVMD,TID and TMD were conducted by using three different objectives.The results show that the three control systems were all effective in minimizing the root mean square value of seismic responses,including the base shear of the BIS,the absolute acceleration of structural SDOF,and the relative displacement between the base isolation floor and the foundation.Finally,considering the superstructure as a structural MDOF,a series of time history analyses were performed to investigate the effectiveness and activation sensitivity of the three control systems under far field and near fault seismic excitations.The results show that the effectiveness of TID and TMD with optimized parameters on mitigating the seismic responses of base isolated structures increased as the mass ratio increases,and the effectiveness of TID was always better than TMD with the same mass ratio.The TVMD with a lower mass ratio was more efficient in reducing the seismic response than the TID and TMD.Furthermore,the TVMD,when compared with TMD and TID,had better activation sensitivity and a smaller stroke.
基金Natural Science Foundation and Education Department Foundation of Guangxi Province
文摘The title zinc（Ⅱ） complex salt [Zn（H2O）6]（ClO4）2-（PNOS）4, where PNOS is derived from picolinaldehyde N-oxide with semicarbazone, has been prepared and structurally characterized by X-ray single-crystal analysis. It crystallizes in triclinic, space group PI with a = 7.529（3）, b = 10.206（4）, c = 14.678（6）A, a = 86.293（6）, β= 87.686（7）, γ= 81.382（6）°, C28H44Cl2N16O22Zn, Mr = 1093.06, V = 1112.3（8） ,A^3 Z = 1, Dc = 1.632 g/cm^3, S = 1.089, μ（MoKa） = 0.773 mm^-1, F（000） = 564, the final R = 0.0438 and wR = 0.1076 for 3888 independent reflections with Rint = 0.0224. The crystal structure possesses a [Zn（H2O）6]^2＋ cation, two ClO4^- anions and four PNOSs. In the crystal structure, Zn^2＋ cation is located at the symcenter and coordinated by six water molecules. In [Zn（H2O）6]^2＋, an elongate octahedral complex cation, the average Zn-O bond length is 2.087（2） A. There exist a lot of H bonds in the structure, linking the cation [Zn（H2O）6]^2＋, anion ClO4^- and PNOS to form a 3D network.
文摘It is regretted that the author corrections requested at the proof stage were not made accurately. There are some incorrect typings in two equations which will lead to inaccurate results if readers perform calculations directly
基金Supported by the National Natural Science Foundation of China under Grant No 61334008the National High-Technology Research and Development Program of China under Grant No 2015AA016904the Instrument Developing Project of the Chinese Academy of Sciences under Grant No YZ201301
文摘A compact structured illumination chip based on integrated optics is proposed and fabricated on a silicon-on- insulator platform. Based on the simulation of Caussian beam interference, we adopt a chirped diffraction grating to achieve a specific interference pattern. The experimental results match well with the simulations. The portability and flexibility of the structured illumination chip can be increased greatly through horizontal encapsulation. High levels of integration, compared with the conventional structured illumination approach, make this chip very compact, with a footprint of only around 1 mm2. The chip has no optical lenses and can be easily combined with a microfluidic system. These properties would make the chip very suitable for portable 3D scanner and compact super-resolution microscopy applications.
基金Supported by the National Innovative Projects for College Students under Grant No 201310320025the National Natural Science Foundation of China under Grant Nos 61401182 and 61372057the Priority Academic Program Development of Jiangsu Higher Education Institutions of China
文摘A combined structure with the unit cell consisting of four sub-units with 90° rotation in turn is designed. Each of sub-units is composed of two gold rods in transverse arrangement and one gold rod in longitudinal arrangement. Simulating electromagnetic responses of the structure, we verify that the structure exhibits the double Fano resonances, which originate from the coupling between magnetic quadrupoles and electric dipoles and the coupling between electric quadrupoles and electric dipoles. Simulation results also demonstrate that the structure is polarization-insensitive and shows an analogue of electromagnetically induced transparency at the two Fano resonances. Such a plasmonic structure has potential applications in photoelectric elements.
基金supported by the National Natural Science Foundation of China (Nos.61674142 and 62041502)。
文摘In this paper, an asymmetric array structure of space laser communication receiver is proposed. This structure can greatly reduce alignment requirement, and lighten the signal strength jitter caused by atmospheric turbulence. A prototype of the proposed structure is fabricated and a 2.5 Mbit/s on-off keying(OOK) modulated demonstration link over 40 m free space is built. This asymmetric array structure can effectively collect optical signal while rotating in a window angle of ±17°, and the bit error ratio(BER) keeps zero.
基金financially supported by the National Natural Science Foundation of China (No.21172190)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The functionalized calix[4]pyrrole meso-substituted Schiff bases were conveniently prepared by four- step synthetic route. Furthermore, the nickel and copper complexes of calix[4]pyrrole meso-substituted Schiff base with 1：2 stoichiometry were obtained. The crystal structures of the calix[4]pyrroles and their metal complexes were determined by X-ray diffraction.
基金Supported by the National Natural Science Foundation of China(No.20672091)the Jiangsu Provincial Key Program of Physical Chemistry in Yangzhou University,China
文摘The regioselective syntheses of novel p-tert-butylcalix[4]arenes with functional aldehyde and dithiocarbazate Schiff base groups were carried out. p-tert-Butylcalix[4]arene was alkylated with o-, p-（ω-chloroalkoxy）- benzaldehydes in the system of K2CO3/KI/CH3CN to give calixarene 1,3-dialdehydes. Then the condensation reactions of active calixarene aldehydes with S-methyl and S-benzyldithiocarbazate, calixarene sulfur-containing Schiff bases were efficiently obtained in satisfied yields. The single crystal analysis of the four representative products shows that calixarene aldehydes and Schiff bases exist in cone conformation and there are interesting intermolecular hydrogen-bands and π...π interaction in the crystals.
基金Supported by the Nanjing University of Telecommunication and Posts under Grant No NY212010the National Natural Science Foundation of China under Grant Nos 91233117,50973104 and 51333007+2 种基金the Natural Science Fund of Jiangsu Province under Grant No BK2012834the National Basic Research Program of China under Grant No 2015CB932200the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘A high-efficiency green phosphorescent organic light emitting diode with a simplified structure is achieved that is free of a hole transport layer. The design of this kind of device structure not only saves the consumption of organic materials but also greatly reduces the structural heterogeneities and effectively facilitates the charge injection into the emissive layer. The resulting green phosphorescent organic light-emitting diodes （PHOLEDs） exhibit higher electroluminescent efficiency. The maximum external quantum efficiency and current efficiency reach 23.7% and 88 cd/A, respectively. Moreover the device demonstrates satisfactory stability, keeping 23.7% and 88cd/A, 22% and 82cd/A, respectively, at a luminance of 100 and 1000cd/m2. The working mechanism for achieving high efficiency based on such a simple device structure is discussed correspondingly. The improved charge carrier injection and transport balance are proved to prominently contribute to achieve the high efficiency and great stability at high luminance in the green PHOLEDs.
文摘A distance measure that infers to indicate the evolutionary relationship of protein structures has been developed based on spatial preference factors of residues. The spatial preference factor is a reflection of the environment of residues in tertiary structure. Compared with the phyletic relationships derived from sequence homologies and three-dimensional structures, we find that the two lines of evolution are similar in general. This approach is applied to a group of glins here.
基金the Damghan UniversityGolestan University for financial supportsupported by the project 14-03276S of the Czech Science Foundation
文摘After synthesis of an asymmetric tetradentate ONN＇O＇ Schiff base ligand （H2L） followed by reaction of the synthesized H2L with an equimolar mixture of methanolic solutions of the VO（acac）2, a new oxidovanadium（IV） Schiff base complex （VOL） was synthesized. The Schiff base ligand and its complex were characterized by FT-IR and UV-vis spectra and C, H, N analysis, The crystal structure of VOL was also determined by single crystal X-ray analysis. The VOL complex crystallizes in monoclinic space group Cc. The Schiffbase ligand acts as a tetradentate ligand through its two＇iminic nitrogens and two phenolic and acetylacetonate oxygens. Thermogravimetric analysis of the VOL showed that it decomposes in two steps and converts to mixed vanadium oxides at 477℃. In addition, thermal decomposition of the VOL complex in air at 660 ℃ leads to formation of V2O5 nanoparticles with the average size estimated from XRD 49 nm. The catalytic activity of the VOL complex was investigated in the epoxidation reaction and different reaction parameters were optimized. The results showed that the cyclic alkenes were efficiently converted to the corresponding epoxides, whereas the VOL did not appreciably convert the linear alkenes.
基金Supported by Guangxi Provincial Department of Education(No.YB2014333)the Scientific research and technological development project of Guilin(No.20110330)+2 种基金the Project of Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources(Guangxi Normal University)Ministry of Education of China(CMEMR2011-13)Key Subjects of Universities in Guangxi Province Applied Chemistry(2007<20>)
文摘A new chain-like coordination polymer, namely, [CuL]n （1, Na2L = 2-[（2-hydroxy- benzylidene）-amino]-benzenesulfonic acid sodium salt）, has been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy and elemental analysis. Complex 1 crystallizes in monoclinic system, space group P21/c with a = 9.2296（16）, b = 10.4754（18）, c = 12.200（2） A, β = 102.392（2）°, V = 1152.0（3）A3, CI3H9CuNOaN, Mr = 338.83, Dc = 1.953 g/cm3, Z = 4, F（000） = 684, p = 2.089 mm-1, the final R = 0.0376 and wR = 0.0956. X-ray diffraction analyses indicate that 1 displays a square-pyramidal metal center with NO4 donor sets. The sulfonate-derived Schiff base serves as a common N,O,O＇-tridentate and a unique O-bridged ligand connecting the metals. Dinuclear copper complexes serve as secondary building blocks （SBUs） to construct an unusual 2D coordination network. In the crystal, the components form a stable 3D supramolecular architecture by C-H...O interactions and to-stacking
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB723402 and 2014CB648300the National Natural Science Foundation of China under Grant Nos 61204095 and 61475074+3 种基金the National Science Fund for Excellent Young Scholars under Grant No 21322402the Natural Science Foundation of Jiangsu Province under Grant No BK2012431,the Natural Science Foundation of the Education Committee of Jiangsu Province under Grant No 14KJB510027the Ministry of Education of China under Grant No IRT1148the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘We investigate the memory properties of the ITO/graphene oxide/Al diodes. It is found that the devices show different memory behaviors with the diverse geometry and thickness of Al. When the thickness of the Al electrode is relatively thick, the device of the cross-point Al electrode shows a three-level memory effect, and the counterpart device of the cross-bar Al electrode exhibits a volatile static random access memory effect. When the thickness of the AI electrode is thinner, the above devices demonstrate a flash memory effect. The different memory behaviors of ITO/GO/AI diodes are ascribed to the mode and degree of reduction and oxidation of GO.
基金financially supported by the National Natural Science Foundation of China (Nos. 21172190, 21372192)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘An efficient method for the synthesis of some difunctionalized copillar[5]arene Schiff bases from condensation of salicylaldehyde and its 5-chloro,5-bromo,3,5-di（t-butyl） substituted derivatives with corresponding diamino-functionalized copillar[5]arene,which were prepared by Gabriel reaction according to the reported method.Single-crystals of six copillar[5]arenes were determined by X-ray diffraction.An ORTEP of compounds showed that the two chains units of Schiff base exist in the outside of the cavity of pillar[5]arene.Furthermore,the complexing ability of these Schiff bases to transition metal ions were investigated by UV and fluorescence spectroscopy.
基金supported by the National Natural Science Foundation of China(No.21272008)the Natural Science Industry-University-Research Foundation of Suzhou University(2015hx014)
文摘Two new mononuclear complexes, namely [Co（L）2]（1） and [Mn（L）2]（2）（HL = N-（3-methylsalicylidene）tryptamine）, have been synthesized by the reactions of the ligand with cobalt acetate or manganese acetate in anhydrous ethanol. The crystal structures of the complexes were characterized by IR spectrum, elemental analysis, PXRD and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 23.146（2）, b = 9.4864（10）, c = 13.9261（15）A, β = 102.898（2）°, V = 2980.6（5） ？3, Z = 4, Dc = 1.367 g/cm3, F（000） = 1284 and μ = 0.616 mm^-1. Complex 2 crystallizes in monoclinic, space group P21/n, with a = 14.807（11）, b = 13.118（10）, c = 16.663（13） A, β = 111.237（14）°, V = 3017（4） A^3, Z = 4, Dc = 1.342 g/cm^3, F（000） = 1276 and μ = 0.477 mm-1. The units of complex 1 are linked by intermolecular N–H…π hydrogen bonds into infinite 1D chains, which are further extended into a 3D supramolecular structure by a series of π···π stacking interactions. The units of complex 2 are linked by intermolecular N–H…π hydrogen bonds and C–H…π hydrogen bonds into an infinite 3D supramolecular structure. Meanwhile, the antibacterial activities of the ligand and its complexes have been tested against four kinds of bacteria. The results show that the three compounds all have excellent antibacterial activities and that 1 and 2 possess stronger inhibiting effects against the bacteria than the Schiff base.
基金This paper is supported by the Philosophy and Social Science Foundation ofGuangxi （No.05FJY034）.
文摘A knowledge based company is the microcosmic foundation of the knowledge economy, the design of its organization structure should amplify the company competence to be agile to the knowledge elements. This paper expounds an interior market network structure which is fit for the company intellectual capital operation, and analyses this organization pattern about the reasons of existence, the effectiveness of growing up in scale, the economies of knowledge distribution and the efficiency of operation, and it will provide some beneficial theoretical guidance about how can a company improve its competition competence in the knowledge environment through organization innovation.
基金Under the auspices of National Natural Science Foundation of China(No.41871193,U1910207)Program for the Philosophy and Social Science of Shanxi Province(No.2023YJ107)。
文摘Rapid increases in Carbon dioxide(CO_(2))levels could trigger unpredictable climate change.The assessment of spatiotempor-al variation and influencing factors of CO_(2) concentration are helpful in understanding the source/sink balance and supporting the formu-lation of climate policy.In this study,Greenhouse Gases Observing Satellite(GOSAT)data were used to explore the variability of CO_(2) concentrations in China from 2009 to 2020.Meteorological parameters,vegetation cover,and anthropogenic activities were combined to explain the increase in CO_(2) concentration,using pixel-based correlations and Covariance Based Structural Equation Modeling(CB-SEM)analysis.The results showed that the influence of vertical CO_(2) transport diminished with altitude,with a distinct inter-annual in-crease in CO_(2) concentrations at 17 vertical levels.Spatially,the highest values were observed in East China,whereas the lowest were observed in Northwest China.There were significant seasonal variations in CO_(2) concentration,with maximum and minimum values in spring(April)and summer(August),respectively.According to the pixel-based correlation analysis,the near-surface CO_(2) concentration was positively correlated with population(r=0.99,P<0.001),Leaf Area Index(LAI,r=0.95,P<0.001),emissions(r=0.91,P<0.001),temperature(r=0.60,P<0.05),precipitation(r=0.34,P>0.05),soil water(r=0.29,P>0.05),nightlight(r=0.28,P>0.05);and negatively correlated with wind speed(r=−0.58,P<0.05).CB-SEM analysis revealed that LAI was the most important con-trolling factor explaining CO_(2) concentration variation(total effect of 0.66),followed by emissions(0.58),temperature(0.45),precipita-tion(0.30),wind speed(−0.28),and soil water(−0.07).The model explained 93% of the increase in CO_(2) concentration.Our results provide crucial information on the patterns of CO_(2) concentrations and their driving mechanisms,which are particularly significant in the context of climate change.
基金supported by the National Science and Technology Support Program (2012BAC12B03)the Postdoctoral Science Foundation of Central South Universitythe Fundamental Research Funds for the Central Universities (No. 2012QNZT001)
文摘A new silver（Ⅰ） compound 6 （[Ag6L66]·4DMF） containing thiosemicarbazone with the group of 2-chloro-1-benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. The title compound 6 crystallizes in monoclinic, space group C2/c with a = 26.9236（18）, b = 15.2553（8）, c = 24.6237（13） , β = 103.0680（10）°, V = 9851.7（10）3, C58H66Ag6Cl6N20O3S6, Mr = 2143.59, Dc = 1.445 g/cm3, μ（MoKα） = 1.503 mm-1, F（000） = 4232, Z = 4, the final R = 0.0565 and wR = 0.1654 for 5831 observed reflections （Ⅰ 〉 2σ（Ⅰ））. Similar to the structure of the compounds we have reported, compound 6 also exhibits a hexanuclear silver（Ⅰ） cluster. In the cluster, the S atom of ligand L6 （L6 = 2-chloro-1-benzaldehyde thiosemicarbazone） served as a triply bridged chelator to connect the six silver atoms into a Ag6L66 cluster. The luminescence property of compound 6 was investigated at room temperature and compared with other similar compounds in order to find the factors influencing their luminescent property.
