This paper selects works of new generation migrant workers in partial enterprises in Guangzhou as the research samples, collects data by questionnaire surveys and makes the statistic analysis on date. As average value...This paper selects works of new generation migrant workers in partial enterprises in Guangzhou as the research samples, collects data by questionnaire surveys and makes the statistic analysis on date. As average values suggested, the psychological capital of new generation migrant workers is located in higher medium level. It exists positive relationship between education background and psychological capital. Finally, propose related suggestions from vertical and horizontal aspects such as from government to school and education funds to education form.展开更多
Capturing solar energy as heat for water treatment has become a substantial approach to obtain freshwater.To obtain higher performance,the understanding of the mechanism of how water molecules interact with the interf...Capturing solar energy as heat for water treatment has become a substantial approach to obtain freshwater.To obtain higher performance,the understanding of the mechanism of how water molecules interact with the interface is particularly fundamental,because the migration process of water molecules on the evaporation interface will directly affect the performance of the device.Herein we regulate the number of hydroxyl groups on the surface of reduced graphene oxide quantitatively,to study the effect of different wettability of interfaces on the performance of solar water generators.The water evaporation performance displays a volcanic shape as increasing wettability.Calculated by the computational chemistry method,deviation from proper wetting humidity is not conducive to the migration of water molecules from the surface.The double-edged sword effect of wettability on performances is clarified,and the surface energy density is the key to break through the limit by the finite element method.展开更多
Despite its apparently simple genetics,cystic fibrosis(CF) is a rather complex genetic disease.A lot of variability in the steps of the path from the cystic fibrosis transmembrane conductance regulator(CFTR) gene to t...Despite its apparently simple genetics,cystic fibrosis(CF) is a rather complex genetic disease.A lot of variability in the steps of the path from the cystic fibrosis transmembrane conductance regulator(CFTR) gene to the clinical manifestations originates an uncertain genotype- phenotype relationship.A major determinant of this uncertainty is the incomplete knowledge of the CFTR mutated genotypes,due to the high number of CFTR mutations and to the higher number of their combinations in trans and in cis.Also the very limited knowledge of functional effects of CFTR mutated alleles severely impairs our diagnostic and prognostic ability.The final phenotypic modulation exerted by CFTR modifier genes and interactome further complicates the framework.The next generation sequencing approach is a rapid,lowcost and high-throughput tool that allows a near complete structural characterization of CFTR mutated genotypes,as well as of genotypes of several other genes cooperating to the final CF clinical manifestations.This powerful method perfectly complements the new personalized therapeutic approach for CF.Drugs active on specific CFTR mutational classes are already available for CF patients or are in phase 3 trials.A complete genetic characterization has been becoming crucial for a correct personalized therapy.However,the need of a functional classification of each CFTR mutation potently arises.Future big efforts towards an ever more detailed knowledge of both structural and functional CFTR defects,coupled to parallel personalized therapeutic interventions decisive for CF cure can be foreseen.展开更多
Image paragraph generation aims to generate a long description composed of multiple sentences,which is different from traditional image captioning containing only one sentence.Most of previous methods are dedicated to...Image paragraph generation aims to generate a long description composed of multiple sentences,which is different from traditional image captioning containing only one sentence.Most of previous methods are dedicated to extracting rich features from image regions,and ignore modelling the visual relationships.In this paper,we propose a novel method to generate a paragraph by modelling visual relationships comprehensively.First,we parse an image into a scene graph,where each node represents a specific object and each edge denotes the relationship between two objects.Second,we enrich the object features by implicitly encoding visual relationships through a graph convolutional network(GCN).We further explore high-order relations between different relation features using another graph convolutional network.In addition,we obtain the linguistic features by projecting the predicted object labels and their relationships into a semantic embedding space.With these features,we present an attention-based topic generation network to select relevant features and produce a set of topic vectors,which are then utilized to generate multiple sentences.We evaluate the proposed method on the Stanford image-paragraph dataset which is currently the only available dataset for image paragraph generation,and our method achieves competitive performance in comparison with other state-of-the-art(SOTA)methods.展开更多
[PO_(4)]3-possesses small microscopic secondorder susceptibility and polarizability anisotropy,which inherently result in weak second-harmonic generation (SHG)and small birefringence.Herein,a new noncentrosymmetric ph...[PO_(4)]3-possesses small microscopic secondorder susceptibility and polarizability anisotropy,which inherently result in weak second-harmonic generation (SHG)and small birefringence.Herein,a new noncentrosymmetric phosphate,[C(NH_(2))3]3PO_(4)·2H_(2)O,was successfully designed and synthesized by a solution evaporation method.[C(NH_(2))3]3PO_(4)·2H_(2)O without metal ions is composed of planar conjugated guanidine cations and PO_(4)tetrahedrons,which are connected by hydrogen bonds,forming a three-dimensional network.Physical property measurements indicate that the title compound displays an SHG response of 1.5×KH_(2)PO_(4)(KDP) and a larger birefringence (0.055@546.1 nm)compared with most reported ultraviolet nonlinear optical phosphates.Furthermore,first-principles calculations reveal that theπ-conjugated planar[C(NH_(2))3]+cations and[PO_(4)]3-groups are responsible for its excellent linear and NLOproperties.展开更多
Deep-ultraviolet(UV)nonlinear optical(NLO)crystals with excellent performances are of great importance in laser science and technology.However,to design and synthesize an ideal deep-UV NLO material with a balance betw...Deep-ultraviolet(UV)nonlinear optical(NLO)crystals with excellent performances are of great importance in laser science and technology.However,to design and synthesize an ideal deep-UV NLO material with a balance between second harmonic generation(SHG)response and UV cut-off edge is still a huge challenge.Herein,a new oxy-borate BaYOBO_(3)(BaYBO)was designed and synthesized by substituting Be^(2+)with Y^(3+)from Sr_(2)Be_(2)B_(2(O_(7).The BaYBO features a stable three-dimensional framework and satisfies the property balance between a large SHG response(~2.6×KH_(2)PO_(4)KDP))and a short UV cut-off edge(<190 nm)as a promising deep-UV NLO candidate.The study of structure-property relationship indicates that the large SHG response of BaYBO is mainly attributed to the coplanar arrangement and large number density of BO_(3 )triangles.These results demonstrate that substituting Be^(2+)with Y^(3+)cations is also a feasible strategy for developing new deep-UV NLO crystals.展开更多
Conventional wisdom says that nonpolar structures do not favorably produce strong second-harmonic generation(SHG)responses since the polarization in their microscopic functional groups are counteracted.Herein,we repor...Conventional wisdom says that nonpolar structures do not favorably produce strong second-harmonic generation(SHG)responses since the polarization in their microscopic functional groups are counteracted.Herein,we report the first nonlinear optical thiosulfate,Na_(10)Cd(NO_(3))_(4)(SO_(3)S)_(4),which crystallizes in a nonpolar space group of P−4.However,this thiosulfate exhibits a strong SHG response of about 4.2 times that of the benchmark KH2PO4,which is larger than those of polar sulfates.According to first-principles calculations and a flexible dipole model,the SHG enhancement is mainly ascribed to the larger flexibility of the S=S bond in the SO_(3)S tetrahedra in comparison with the S–O bond in the SO4 tetrahedra.These findings indicate that constructing flexible bonds is an effective strategy to design highperformance nonlinear optical materials regardless of polarity.展开更多
This paper introduces a Monte Carlo scenario generation method based on copula theory for the stochastic optimal power flow （STOPF） problem with wind power. By using copula theory, the scenarios are simulated from m...This paper introduces a Monte Carlo scenario generation method based on copula theory for the stochastic optimal power flow （STOPF） problem with wind power. By using copula theory, the scenarios are simulated from multivariable joint distribution but only from their dependency matrix. Hence, the scenarios generated by proposed method can contain flail statistical information of multivariate. Here, the details of simu- lating scenarios for multi-wind-farm are explained with four steps： determine margin of one wind farm, fit the copulas, choose optimal copulas and simulate scenarios by Mote Carlo. Moreover, the producing process of scenarios is demonstrated by two adjacent actual wind farms in China. With the scenarios, the STOPF is con- verted into the same amount deterministic sub OPF models which can be solved by available technology per- fectly. Results using copula theory are compared against results from history samples based on two designs： IEEE 30-bus and IEEE 118-bus systems. The comparison results prove the accuracy of the proposed methodology.展开更多
Intra-organizational social media platforms are expected to help build a flexible corporate stage that facilitates employees'communication and leverages creative idea generation.However,whether and how these syste...Intra-organizational social media platforms are expected to help build a flexible corporate stage that facilitates employees'communication and leverages creative idea generation.However,whether and how these systems can expedite the creativity of employees remains unclear.This paper attempts to address the impacts of employees'social relationships on intra-organizational social media on their idea generation quantity and quality.Drawn upon the extant literature in the fields of information systems and organizational behavior,a theoretical model is postulated on the basis of analyzing the attributes of social ties and exchanged information content in light of a two-dimensional framework that juxtaposes boundary spanning and work relevance.The model is empirically tested using data obtained from two internal application systems of a large telecommunications company.Test results validate that employees'online social relationships with different attributes are discriminably associated with their group identification and proactive creativity.Meanwhile,proactive creativity and group identification both show the positive impacts on idea generation quantity,whereas only proactive creativity has a significant positive impact on idea generation quality.These findings contribute to the literature on intra-organizational social media and employee idea generation,by uncovering the links among employees'online social relationships,mental processes,and idea generation.展开更多
Metal iodates with a lone-pair containing I(V) that is in an asymmetric coordination geometry can form a diversity of unusual structures and many of them are promising new second homonic generation (SHG) materials. Th...Metal iodates with a lone-pair containing I(V) that is in an asymmetric coordination geometry can form a diversity of unusual structures and many of them are promising new second homonic generation (SHG) materials. They exhibit wide transparency wavelength regions, large SHG coefficients and high optical-damage thresholds as well as moderately high thermal stability. In this paper, the structures and properties of the metal iodates are reviewed. The combination of d0 transition-metal cations with the iodate groups afforded a large number of metal iodates, with cations covering alkali metal, alkaline earth and lanthanide elements. Many of them are noncentrosymmetric (NCS) and display excellent SHG properties due to the additive effects of polarizations from both types of the asymmetric units. Some lanthanide iodates are able to emit strong luminescence in the visible or near-IR regions. The use of transition metal ions with dn (n ≠ 0) electronic configuration into iodate systems can also induce the formation of NCS compounds when the lone pairs of the iodate groups are properly aligned. The dn transition metal cations are normally octahedrally coordinated or in a square-planar coordination geometry. Furthermore, the combination of two different types of lone-pair-containing cations is also an effective strategy to design new SHG materials.展开更多
Complex coordinated functional groups[MA_(x)B_(y)](M=Central coordination element;A,B=P,O,S,Se,F,Cl,Br or I)are composed of different types of anions A,B jointly linked to the same central cation M,which are in high p...Complex coordinated functional groups[MA_(x)B_(y)](M=Central coordination element;A,B=P,O,S,Se,F,Cl,Br or I)are composed of different types of anions A,B jointly linked to the same central cation M,which are in high potential to tune the physical properties of materials,e.g.,second-order susceptibility,energy gaps and birefringence.Recently,Compound containing complex coordinated functional groups have attracted great attention in the nonlinear optical(NLO)field and a large number of this type crystals exhibit promising NLO performance.However,the inherent relationship between ionic group structure and optical properties of complex coordinated NLO materials have not been systematically studied.This article systematically summarizes complex coordinated NLO materials in recent five years from the perspective of the internal relationship between crystal structure and optical properties.In addition,we propose the ideal combination and arrangement modes for structural building units,and also reveal the influence of complex coordinated functional groups[MA_(x)B_(y)]toward the NLO response,optical band gap and phase matching ability of complex coordinated NLO materials.展开更多
High-performance bi-functional materials are in urgent demand for the next-generation integrated optical devices.In this work,we successfully synthesized the first tricyanomelaminate with bi-functional optical respons...High-performance bi-functional materials are in urgent demand for the next-generation integrated optical devices.In this work,we successfully synthesized the first tricyanomelaminate with bi-functional optical responses,namely Cs_(3)C_(6)N_(9)•H_(2)O(I),from its analogue Na_(3)C_(6)N_(9)•3H_(2)O by a facile ion exchange method.In contrast to Na_(3)C_(6)N_(9)•3H_(2)O,I realizes an optimal arrangement of𝜋π-conjugated(C_(6)N_(9))3−anion groups in its crystal structure.As a result,the second-order nonlinear optical(NLO)response is greatly enhanced from nearly zero of Na_(3)C_(6)N_(9)•3H_(2)O to∼9.8×KH_(2)PO_(4)of I.Furthermore,I exhibits a giant linear optical anisotropic response(i.e.birefringence)of 0.52 at the wavelength of 550 nm.Both responses are almost the largest among the inorganic compounds ofπ-conjugated rings,which indicates that I has great potential as a bi-functional optical crystal.Structural and theoretical analyses reveal the microscopic origin of excellent optical properties.This work would attract a lot of interest to the persistently neglected potential of tricyanomelaminates as linear optical and NLO crystals.展开更多
基金Research for Social Support Mode of the New Migrant Workers Based on Psychological Capital, National Social Science Foundation （China）, No. 16BSH092.
文摘This paper selects works of new generation migrant workers in partial enterprises in Guangzhou as the research samples, collects data by questionnaire surveys and makes the statistic analysis on date. As average values suggested, the psychological capital of new generation migrant workers is located in higher medium level. It exists positive relationship between education background and psychological capital. Finally, propose related suggestions from vertical and horizontal aspects such as from government to school and education funds to education form.
基金funding from the National Natural Science Foundation of China(Nos.21871009 and 21527803)the Youth Science Foundation of Hubei University(No.202011303000002)China Postdoctoral Science Foundation(No.2018M641064).
文摘Capturing solar energy as heat for water treatment has become a substantial approach to obtain freshwater.To obtain higher performance,the understanding of the mechanism of how water molecules interact with the interface is particularly fundamental,because the migration process of water molecules on the evaporation interface will directly affect the performance of the device.Herein we regulate the number of hydroxyl groups on the surface of reduced graphene oxide quantitatively,to study the effect of different wettability of interfaces on the performance of solar water generators.The water evaporation performance displays a volcanic shape as increasing wettability.Calculated by the computational chemistry method,deviation from proper wetting humidity is not conducive to the migration of water molecules from the surface.The double-edged sword effect of wettability on performances is clarified,and the surface energy density is the key to break through the limit by the finite element method.
文摘Despite its apparently simple genetics,cystic fibrosis(CF) is a rather complex genetic disease.A lot of variability in the steps of the path from the cystic fibrosis transmembrane conductance regulator(CFTR) gene to the clinical manifestations originates an uncertain genotype- phenotype relationship.A major determinant of this uncertainty is the incomplete knowledge of the CFTR mutated genotypes,due to the high number of CFTR mutations and to the higher number of their combinations in trans and in cis.Also the very limited knowledge of functional effects of CFTR mutated alleles severely impairs our diagnostic and prognostic ability.The final phenotypic modulation exerted by CFTR modifier genes and interactome further complicates the framework.The next generation sequencing approach is a rapid,lowcost and high-throughput tool that allows a near complete structural characterization of CFTR mutated genotypes,as well as of genotypes of several other genes cooperating to the final CF clinical manifestations.This powerful method perfectly complements the new personalized therapeutic approach for CF.Drugs active on specific CFTR mutational classes are already available for CF patients or are in phase 3 trials.A complete genetic characterization has been becoming crucial for a correct personalized therapy.However,the need of a functional classification of each CFTR mutation potently arises.Future big efforts towards an ever more detailed knowledge of both structural and functional CFTR defects,coupled to parallel personalized therapeutic interventions decisive for CF cure can be foreseen.
基金supported in part by National Natural Science Foundation of China(Nos.61721004,61976214,62076078 and 62176246).
文摘Image paragraph generation aims to generate a long description composed of multiple sentences,which is different from traditional image captioning containing only one sentence.Most of previous methods are dedicated to extracting rich features from image regions,and ignore modelling the visual relationships.In this paper,we propose a novel method to generate a paragraph by modelling visual relationships comprehensively.First,we parse an image into a scene graph,where each node represents a specific object and each edge denotes the relationship between two objects.Second,we enrich the object features by implicitly encoding visual relationships through a graph convolutional network(GCN).We further explore high-order relations between different relation features using another graph convolutional network.In addition,we obtain the linguistic features by projecting the predicted object labels and their relationships into a semantic embedding space.With these features,we present an attention-based topic generation network to select relevant features and produce a set of topic vectors,which are then utilized to generate multiple sentences.We evaluate the proposed method on the Stanford image-paragraph dataset which is currently the only available dataset for image paragraph generation,and our method achieves competitive performance in comparison with other state-of-the-art(SOTA)methods.
基金supported by the National Natural Science Foundation of China (21975255,51890862,21921001 and U1605245)the National Key Research and Development Plan of Ministry of Science and Technology (2016YFB0402104)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB20000000)the Natural Science Foundation of Fujian Province (2019J01020758)Youth Innovation Promotion Association CAS (2019303)。
文摘[PO_(4)]3-possesses small microscopic secondorder susceptibility and polarizability anisotropy,which inherently result in weak second-harmonic generation (SHG)and small birefringence.Herein,a new noncentrosymmetric phosphate,[C(NH_(2))3]3PO_(4)·2H_(2)O,was successfully designed and synthesized by a solution evaporation method.[C(NH_(2))3]3PO_(4)·2H_(2)O without metal ions is composed of planar conjugated guanidine cations and PO_(4)tetrahedrons,which are connected by hydrogen bonds,forming a three-dimensional network.Physical property measurements indicate that the title compound displays an SHG response of 1.5×KH_(2)PO_(4)(KDP) and a larger birefringence (0.055@546.1 nm)compared with most reported ultraviolet nonlinear optical phosphates.Furthermore,first-principles calculations reveal that theπ-conjugated planar[C(NH_(2))3]+cations and[PO_(4)]3-groups are responsible for its excellent linear and NLOproperties.
基金supported by the National Natural Science Foundation of China(51972230,22071179,51890864,61835014,51802217,51890865)the Natural Science Foundation of Tianjin(20JCJQJC00060,19JCZDJC38200)+1 种基金Tianjin Science and Technology Plan Program(19ZYPTJC00070)the National Key R&D Program of China(2016YFB0402103)。
文摘Deep-ultraviolet(UV)nonlinear optical(NLO)crystals with excellent performances are of great importance in laser science and technology.However,to design and synthesize an ideal deep-UV NLO material with a balance between second harmonic generation(SHG)response and UV cut-off edge is still a huge challenge.Herein,a new oxy-borate BaYOBO_(3)(BaYBO)was designed and synthesized by substituting Be^(2+)with Y^(3+)from Sr_(2)Be_(2)B_(2(O_(7).The BaYBO features a stable three-dimensional framework and satisfies the property balance between a large SHG response(~2.6×KH_(2)PO_(4)KDP))and a short UV cut-off edge(<190 nm)as a promising deep-UV NLO candidate.The study of structure-property relationship indicates that the large SHG response of BaYBO is mainly attributed to the coplanar arrangement and large number density of BO_(3 )triangles.These results demonstrate that substituting Be^(2+)with Y^(3+)cations is also a feasible strategy for developing new deep-UV NLO crystals.
基金supported by the National Natural Science Foundation of China(nos.21833010,61975207,21921001,21971238,51872297,and 51890864)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(no.ZDBS-LY-SLH024)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(nos.XDB20010200 and XDB20000000)Fujian Institute of Innovation(no.FJCXY18010201)in Chinese Academy of Sciences,the National Key Research and Development Program of China(no.2019YFA0210400)Key Laboratory of Functional Crystals and Laser Tech-nology,TIPC,CAS(no.FCLT 202003)as well as Key Laboratory of New Processing Technology for Nonferrous Metal&Materials,Ministry of Education/Guangxi Key Laboratory of Optical and Electronic Materials and Devices(no.20KF-11).
文摘Conventional wisdom says that nonpolar structures do not favorably produce strong second-harmonic generation(SHG)responses since the polarization in their microscopic functional groups are counteracted.Herein,we report the first nonlinear optical thiosulfate,Na_(10)Cd(NO_(3))_(4)(SO_(3)S)_(4),which crystallizes in a nonpolar space group of P−4.However,this thiosulfate exhibits a strong SHG response of about 4.2 times that of the benchmark KH2PO4,which is larger than those of polar sulfates.According to first-principles calculations and a flexible dipole model,the SHG enhancement is mainly ascribed to the larger flexibility of the S=S bond in the SO_(3)S tetrahedra in comparison with the S–O bond in the SO4 tetrahedra.These findings indicate that constructing flexible bonds is an effective strategy to design highperformance nonlinear optical materials regardless of polarity.
基金supported by National Natural Science Foundation of China(Grant No.51277034,51377027)
文摘This paper introduces a Monte Carlo scenario generation method based on copula theory for the stochastic optimal power flow （STOPF） problem with wind power. By using copula theory, the scenarios are simulated from multivariable joint distribution but only from their dependency matrix. Hence, the scenarios generated by proposed method can contain flail statistical information of multivariate. Here, the details of simu- lating scenarios for multi-wind-farm are explained with four steps： determine margin of one wind farm, fit the copulas, choose optimal copulas and simulate scenarios by Mote Carlo. Moreover, the producing process of scenarios is demonstrated by two adjacent actual wind farms in China. With the scenarios, the STOPF is con- verted into the same amount deterministic sub OPF models which can be solved by available technology per- fectly. Results using copula theory are compared against results from history samples based on two designs： IEEE 30-bus and IEEE 118-bus systems. The comparison results prove the accuracy of the proposed methodology.
基金supported by the National Natural Science Foundation of China under Grant No.71902086.
文摘Intra-organizational social media platforms are expected to help build a flexible corporate stage that facilitates employees'communication and leverages creative idea generation.However,whether and how these systems can expedite the creativity of employees remains unclear.This paper attempts to address the impacts of employees'social relationships on intra-organizational social media on their idea generation quantity and quality.Drawn upon the extant literature in the fields of information systems and organizational behavior,a theoretical model is postulated on the basis of analyzing the attributes of social ties and exchanged information content in light of a two-dimensional framework that juxtaposes boundary spanning and work relevance.The model is empirically tested using data obtained from two internal application systems of a large telecommunications company.Test results validate that employees'online social relationships with different attributes are discriminably associated with their group identification and proactive creativity.Meanwhile,proactive creativity and group identification both show the positive impacts on idea generation quantity,whereas only proactive creativity has a significant positive impact on idea generation quality.These findings contribute to the literature on intra-organizational social media and employee idea generation,by uncovering the links among employees'online social relationships,mental processes,and idea generation.
基金financially supported by the National Natural Science Foundation of China(21827813,21921001,22175172,22075283,92161125,and U21A20508)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2020303 and 2021300)。
基金supported by the National Natural Science Foundation of China (20731006, 20825104 & 21003127)
文摘Metal iodates with a lone-pair containing I(V) that is in an asymmetric coordination geometry can form a diversity of unusual structures and many of them are promising new second homonic generation (SHG) materials. They exhibit wide transparency wavelength regions, large SHG coefficients and high optical-damage thresholds as well as moderately high thermal stability. In this paper, the structures and properties of the metal iodates are reviewed. The combination of d0 transition-metal cations with the iodate groups afforded a large number of metal iodates, with cations covering alkali metal, alkaline earth and lanthanide elements. Many of them are noncentrosymmetric (NCS) and display excellent SHG properties due to the additive effects of polarizations from both types of the asymmetric units. Some lanthanide iodates are able to emit strong luminescence in the visible or near-IR regions. The use of transition metal ions with dn (n ≠ 0) electronic configuration into iodate systems can also induce the formation of NCS compounds when the lone pairs of the iodate groups are properly aligned. The dn transition metal cations are normally octahedrally coordinated or in a square-planar coordination geometry. Furthermore, the combination of two different types of lone-pair-containing cations is also an effective strategy to design new SHG materials.
基金supported by National Natural Science Founda-tion of China(No.51972208).
文摘Complex coordinated functional groups[MA_(x)B_(y)](M=Central coordination element;A,B=P,O,S,Se,F,Cl,Br or I)are composed of different types of anions A,B jointly linked to the same central cation M,which are in high potential to tune the physical properties of materials,e.g.,second-order susceptibility,energy gaps and birefringence.Recently,Compound containing complex coordinated functional groups have attracted great attention in the nonlinear optical(NLO)field and a large number of this type crystals exhibit promising NLO performance.However,the inherent relationship between ionic group structure and optical properties of complex coordinated NLO materials have not been systematically studied.This article systematically summarizes complex coordinated NLO materials in recent five years from the perspective of the internal relationship between crystal structure and optical properties.In addition,we propose the ideal combination and arrangement modes for structural building units,and also reveal the influence of complex coordinated functional groups[MA_(x)B_(y)]toward the NLO response,optical band gap and phase matching ability of complex coordinated NLO materials.
基金the National Natural Science Foundation of China(22122507,21833010,61975207 and 21921001)the Youth Innovation Promotion of Chinese Academy of Sciences(Y202069)+1 种基金the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-SLH024)Fujian Institute of Innovation(FJCXY18010201)in Chinese Academy of Sciences。
文摘High-performance bi-functional materials are in urgent demand for the next-generation integrated optical devices.In this work,we successfully synthesized the first tricyanomelaminate with bi-functional optical responses,namely Cs_(3)C_(6)N_(9)•H_(2)O(I),from its analogue Na_(3)C_(6)N_(9)•3H_(2)O by a facile ion exchange method.In contrast to Na_(3)C_(6)N_(9)•3H_(2)O,I realizes an optimal arrangement of𝜋π-conjugated(C_(6)N_(9))3−anion groups in its crystal structure.As a result,the second-order nonlinear optical(NLO)response is greatly enhanced from nearly zero of Na_(3)C_(6)N_(9)•3H_(2)O to∼9.8×KH_(2)PO_(4)of I.Furthermore,I exhibits a giant linear optical anisotropic response(i.e.birefringence)of 0.52 at the wavelength of 550 nm.Both responses are almost the largest among the inorganic compounds ofπ-conjugated rings,which indicates that I has great potential as a bi-functional optical crystal.Structural and theoretical analyses reveal the microscopic origin of excellent optical properties.This work would attract a lot of interest to the persistently neglected potential of tricyanomelaminates as linear optical and NLO crystals.
