Based on Marcuse’s thought of“one-dimensional person”,this paper discusses the influence of TV talent show on teenagers’socialization.By analyzing the characteristics of TV talent shows that emphasize individual c...Based on Marcuse’s thought of“one-dimensional person”,this paper discusses the influence of TV talent show on teenagers’socialization.By analyzing the characteristics of TV talent shows that emphasize individual competition and success,appearance and image,and instant satisfaction,it is pointed out that these characteristics are easy for teenagers to produce the mentality of pursuing fame and fortune,appearance,and instant satisfaction,ignoring the development of other important values and qualities.Therefore,we need to guide teenagers to maintain a critical attitude toward TV talent shows,and pay attention to cultivating their independent thinking and all-round development.展开更多
Smart hydrogels are environmentally sensitive hydrogels, which can produce a sensitive response to external stimuli, and often exhibit the characteristics of multi filed coupling. In this paper, a hydrogel rod under c...Smart hydrogels are environmentally sensitive hydrogels, which can produce a sensitive response to external stimuli, and often exhibit the characteristics of multi filed coupling. In this paper, a hydrogel rod under chemomechanical coupling was analytically studied based on a poroelastical model. The already known constitutive and governing equations were simplified into the one dimensional case, then two different boundary conditions were considered. The expressions of concentration, displacement,chemical potential and stress related to time were obtained in a series form. Examples illustrate the interaction mechanism of chemical and mechanical effect. It was found that there was a balance state in the diffusion of concentration and the diffusion process could lead to the expansion or the stress change of the hydrogel rod.展开更多
The analytical structures and the corresponding mathematical properties of the one dimensional and two dimensional fuzzy controllers are first investigated in detail. The nature of these two kinds of fuzzy controllers...The analytical structures and the corresponding mathematical properties of the one dimensional and two dimensional fuzzy controllers are first investigated in detail. The nature of these two kinds of fuzzy controllers is next probed from the perspective of control engineering. For the one dimensional fuzzy controller, it is concluded that this controller is a combination of a saturation element and a nonlinear proportional controller, and the system that employs the one dimensional fuzzy controller is the combination of an open-loop control system and a closedloop control system. For the latter case, it is concluded that it is a hybrid controller, which comprises the saturation part, zero-output part, nonlinear derivative part, nonlinear proportional part, as well as nonlinear proportional-derivative part, and the two dimensional fuzzy controller-based control system is a loop-varying system with varying number of control loops.展开更多
This paper shows that for a supercritical contact process in one dimension, if the initial distribution satisfies reasonable hypothesis, then the first hitting time of certain set with anomalous small density is asymp...This paper shows that for a supercritical contact process in one dimension, if the initial distribution satisfies reasonable hypothesis, then the first hitting time of certain set with anomalous small density is asymptotically exponentially distributed. We also show the similar result for the contact process on the finite set [0, N].展开更多
In this paper,we consider the one dimensional third order p-Laplacian equation(Фp(u″))′+h(t)f(t,u(t))=0 with integral boundary conditions u(0)-αu′(0)=∫_(0)^(1) g1(s)u(s)ds,u(1)+βu′(1)=∫_(0)^(1)g2(s)u(s)ds,u″...In this paper,we consider the one dimensional third order p-Laplacian equation(Фp(u″))′+h(t)f(t,u(t))=0 with integral boundary conditions u(0)-αu′(0)=∫_(0)^(1) g1(s)u(s)ds,u(1)+βu′(1)=∫_(0)^(1)g2(s)u(s)ds,u″(0)=0.By using kernel functions and the Avery-Peterson fixed point theorem,we establish the existence of at least three positive solutions.展开更多
Cu-Zn-Al alloy of one dimensional nano-structure was prepared and thestructure of obtained nano-material was characterized by transmission electron microscope (TEM). Itwas shown that there are non-linear oscillations ...Cu-Zn-Al alloy of one dimensional nano-structure was prepared and thestructure of obtained nano-material was characterized by transmission electron microscope (TEM). Itwas shown that there are non-linear oscillations on the surface of Cu-Zn-Al alloy and theconsanguineous connection exists between non-linear oscillation and the growth process of onedimensional nano-structure. The diameter of one dimensional nano-structure is about 40 nm, and theratio of length to diameter is over 40. Finally, the growth mechanism of one dimensionalnano-structure was also studied.展开更多
The reactions of 18 crown 6 with each of K 2(M=Zn, Hg; mnt=1,2 dicyanoethene 1,2 dithiolate, C 2S 2(CN) 2- 2) were studied and novel complexes [K(18 C 6)] 2[Zn(mnt) 2](1) and [K(18 C 6)] 2[Hg(mnt)...The reactions of 18 crown 6 with each of K 2(M=Zn, Hg; mnt=1,2 dicyanoethene 1,2 dithiolate, C 2S 2(CN) 2- 2) were studied and novel complexes [K(18 C 6)] 2[Zn(mnt) 2](1) and [K(18 C 6)] 2[Hg(mnt) 2](2) were characterized by elemental analysis, IR spectrum and X ray diffraction analysis. Complex 1 displays a one dimensional chain of [K(18 C 6)] 2[Zn(mnt) 2] bridged by K O interactions between adjacent [K(18 C 6)] + units. Complex 2 is also a one dimensional chain of [K(18 C 6)] 2[Hg(mnt) 2] bridged by K...S weak interactions between adjacent [K(18 C 6)] + and [Hg(mnt) 2] 2- .展开更多
The variation of effective stress ratio of stratfied soil with semi pervious boundaries and under cyclic loading was analyzed on the basis of Terzaghi's one dimensional consolidation assumptions. A solution by L...The variation of effective stress ratio of stratfied soil with semi pervious boundaries and under cyclic loading was analyzed on the basis of Terzaghi's one dimensional consolidation assumptions. A solution by Laplace Transform was obtained for the case when the soil was under time varied loading. With numerical inversion of Laplace Transform, some useful results were obtained for several kinds of commonly encountered loadings. The results can be meaningful in engineering practice.展开更多
One-dimensional (1D) ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their diverse current and futur...One-dimensional (1D) ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their diverse current and future technological applications. This article gives a comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods. We will cover the synthetic methodologies and the corresponding growth mechanisms, various nanostructures grown, their doping and alloying, and position-controlled growth on substrates. Finally, we will review their functional properties in catalysis, hydrophobic surface modification, sensing, and electronic, optical, optoelectronic, and energy harvesting devices.展开更多
Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and tw...Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and twodimensional graphene both possess remarkable mechanical properties. In the past years, a large amount of work have been done by using CNTs or graphene as building blocks for constructing novel, macroscopic, mechanically strong fibrous materials. In this review, we summarize the assembly approaches of CNT-based fibers and graphene-based fibers in chronological order, respectively. The mechanical performances of these fibrous materials are compared, and the critical influences on the mechanical properties are discussed. Personal perspectives on the fabrication methods of CNT-and graphene-based fibers are further presented.展开更多
Ni-rich oxides,LiNixMnyCozO2(NMC),are among leading candidates for cathode materials in Li-ion batteries.However,they are mostly fabricated by coprecipitation approach under complex conditions,which usually produces l...Ni-rich oxides,LiNixMnyCozO2(NMC),are among leading candidates for cathode materials in Li-ion batteries.However,they are mostly fabricated by coprecipitation approach under complex conditions,which usually produces large secondary particles composed of aggregated primary particles.Undesirable cation mixing and crack propagation upon cycling block ion and electron transport,result in fast capacity fading and poor rate capability.Herein,we present an ultrasound-triggered cation chelation and reassembly route for synthesizing one-dimensional precursor with homogeneous element distribution at the atomic level.This process is accomplished by the synergistic combination of ultrasound and surfactant,which can disperse reactants and remove hydration shells surrounding cations so as to accelerate chelating reaction,and then separate and assemble chelates into one dimensional structure.The whole synthesis time is only 20 min(8.9 min of ultrasonic working time)in an open vessel under natural ambient conditions.One-dimensional LiNi0.6Mn0.2Co0.2O2 has a high reversible capacity(184 mAh·g^−1 at 0.1 C)and long cycling stability(95.1%and 82.4%capacity retention for 100 and 1000 cycles,respectively).The short charging time of 76 s is realized at super high current rate of 20 C,which is very important to improve the competitiveness of electric vehicles relative to fuel vehicles.Our synthetic approach can provide a general strategy for the growth of mixed-metal-EDTA chelate precursors by changing the feeding ratio of Ni2+,Mn2+and Co2+cations in reaction for fabricating NMC cathode materials with other compositions.展开更多
A photonic heterostructure with multi-channel and sharp angular defect modes by combining two different one-dimensional defective photonic crystals is proposed. The filters designed on the basis of this heterostructur...A photonic heterostructure with multi-channel and sharp angular defect modes by combining two different one-dimensional defective photonic crystals is proposed. The filters designed on the basis of this heterostructure possess both functions of multi-channel narrow band filtering and sharp angular filtering. The channels, channel interval, and number of channels can be tuned by adjusting the geometric and physical parameters of the heterostuctures. This kind of filters will benefit the development of multi-channel interstellar or atmosphere optical communication.展开更多
Band structures of one-dimensional (1D) photonic crystals (PCs) containing dispersive left-handed metamaterials are studied theoretically. The results show that the structure possesses a type of photonic band gap ...Band structures of one-dimensional (1D) photonic crystals (PCs) containing dispersive left-handed metamaterials are studied theoretically. The results show that the structure possesses a type of photonic band gap originating from total internal reflection (TIR). In contrast to photonic band gaps corresponding to zero average refractive index and zero phase, the TIR gap exhibits sharp angular effect and has no polarization effect. It should also be noted that band structures of transverse electric (TE) and transverse magnetic (TM) mode waves are exactly the same in the PCs we studied.展开更多
Reactions of CuBr with equimolar PyHBr orγMePyHBr afforded two novel one dimensional bromocuprate?polymers{(PyH)_(3)[Cu_(3)Br_(6)]}_(∞)(1)and{(γMePyH)_(2)[Cu_(2)Br_(4)]}_(∞)(2),respectively.Both 1 and 2 were chara...Reactions of CuBr with equimolar PyHBr orγMePyHBr afforded two novel one dimensional bromocuprate?polymers{(PyH)_(3)[Cu_(3)Br_(6)]}_(∞)(1)and{(γMePyH)_(2)[Cu_(2)Br_(4)]}_(∞)(2),respectively.Both 1 and 2 were characterized by IR,elemental analysis,and X ray crystallography.Crystal data for 1:monoclinic,space group P2_(1)/n,a=0.93262(12)nm,b=1.3497(2)nm,c=1.9149(2)nm,β=93.465(7)°,V=2.4060(5)nm^(3),Z=4.Crystal data for 2:orthorhombic,space group Pbcm,a=0.8659(4)nm,b=1.5669(6)nm,c=1.2849(5)nm,V=1.7432(2)nm^(3),Z=4.The structure of 1 has a unique helical chain composed of units andμbromide anions while that of 2 shows a linear chain consisted of[Cu_(2)(μBr)_(2)]units bridged by pairs ofμBr atoms.CCDC:1,208412;2,208413.展开更多
The optimized method of extending the omni-photonic band gap (omni-PBG) was discussed based on analyzing the P-wave reflectivity characteristics in one-dimensional (1D) periodic multilayer film. A visible omnidire...The optimized method of extending the omni-photonic band gap (omni-PBG) was discussed based on analyzing the P-wave reflectivity characteristics in one-dimensional (1D) periodic multilayer film. A visible omnidirectional reflector with hybrid structure was designed using P-wave compensated overlapping in angle domain. The experimental result was in good agreement with the theoretical simulation.展开更多
1D europium coordination polymer wires were successfully prepared by reacting europium chloride with tributyl phosphate(TBP) at 160 oC for 12 h. The products were characterized by XRD,IR,TG,DTA,SEM,and EDS. SEM result...1D europium coordination polymer wires were successfully prepared by reacting europium chloride with tributyl phosphate(TBP) at 160 oC for 12 h. The products were characterized by XRD,IR,TG,DTA,SEM,and EDS. SEM results showed that the wires were with diameters ranging from several hundreds of nanometers to ~5 μm and lengths going up to several hundreds of micrometers. Influencing factors such as the dosage of reactants and reaction time on the preparation were systematically investigated. Strong emission centering at 590 nm was realized in the coordination polymer wires on excitation at 395 nm.展开更多
Transmission studies for one-dimensional photonic crystals (1DPCs) containing single-negative (SNG) materials inserted with multiple defects are presented. The numbers and positions of the defect modes inside zero...Transmission studies for one-dimensional photonic crystals (1DPCs) containing single-negative (SNG) materials inserted with multiple defects are presented. The numbers and positions of the defect modes inside zero-phase (zero-φeff) gap are found to be well characterized by effective medium theory.展开更多
The transmission properties of one-dimensional photonic crystals containing double-negative and single-negative materials are studied theoretically. A special kind of photonic band gap is found in this structure. This...The transmission properties of one-dimensional photonic crystals containing double-negative and single-negative materials are studied theoretically. A special kind of photonic band gap is found in this structure. This gap is invariant with scaling and insensitive to thickness fluctuation. But when changing the ratio of the thickness of two media, the width of the gap could be enlarged. The defect modes are analyzed by inducing a linear defect layer in the structure. It is found that the number of defect modes will increase when the thickness of the defect layer becomes larger.展开更多
Localized fields in the defect mode of one-dimensional photonic crystals with active impurity are studied with the help of the theory of spontaneous emission from two-level atoms embedded in photonic crystals. Numeric...Localized fields in the defect mode of one-dimensional photonic crystals with active impurity are studied with the help of the theory of spontaneous emission from two-level atoms embedded in photonic crystals. Numerical simulations demonstrate that the enhancement of stimulated radiation, as well as the phenomena of transmissivity larger than unity and the abnormality of group velocity close to the edges of photonic band gap, are related to the negative imaginary part of the complex effective refractive index of doped layers. This means that the complex effective refractive index has a negative imaginary part, and that the impurity state with very high quality factor and great state density will occur in the photonic forbidden band if active impurity is introduced into the defect layer properly. Therefore, the spontaneous emission can be enhanced, the amplitude of stimulated emission will be very large and it occurs most probably close to the edges of photonic band gap with the fundamental reason, the group velocity close to the edges of band gap is verv small or abnormal.展开更多
The characteristics of photonic forbidden bands, transmission gain and absorption of one-dimensional (ID) dual-periodical photonic crystals (PC) with a complex dielectric layer were studied by using the optical tr...The characteristics of photonic forbidden bands, transmission gain and absorption of one-dimensional (ID) dual-periodical photonic crystals (PC) with a complex dielectric layer were studied by using the optical transfer matrix (TM) method. The results show that the photonic band gap (PBG) of this structure is enlarged and many transmission resonance peaks appear in PBG. Large transmission gain for transmission peaks is obtained if the imaginary part of dielectric constant is negative. With the increase of the absolute value of the imaginary part, the transmission gain increases firstly and the transmittance gain gets to an apex. The imaginary parts of dielectric constant corresponding to transmission gain apex are different according to wavelength. However, the transmission ratio of resonance peaks is less than 1 if the imagi- nary part of dielectric constant is positive. The properties might be used to design multi-narrow-channel band filters and optical amplification devices synchronously.展开更多
文摘Based on Marcuse’s thought of“one-dimensional person”,this paper discusses the influence of TV talent show on teenagers’socialization.By analyzing the characteristics of TV talent shows that emphasize individual competition and success,appearance and image,and instant satisfaction,it is pointed out that these characteristics are easy for teenagers to produce the mentality of pursuing fame and fortune,appearance,and instant satisfaction,ignoring the development of other important values and qualities.Therefore,we need to guide teenagers to maintain a critical attitude toward TV talent shows,and pay attention to cultivating their independent thinking and all-round development.
基金financial supports from the National Natural Science Foundation of China (Grants 11472020, 11502007, and 11632005)Hong Kong Scholars Program (Grant XJ2016021)
文摘Smart hydrogels are environmentally sensitive hydrogels, which can produce a sensitive response to external stimuli, and often exhibit the characteristics of multi filed coupling. In this paper, a hydrogel rod under chemomechanical coupling was analytically studied based on a poroelastical model. The already known constitutive and governing equations were simplified into the one dimensional case, then two different boundary conditions were considered. The expressions of concentration, displacement,chemical potential and stress related to time were obtained in a series form. Examples illustrate the interaction mechanism of chemical and mechanical effect. It was found that there was a balance state in the diffusion of concentration and the diffusion process could lead to the expansion or the stress change of the hydrogel rod.
基金This project was supported by the fundation of the Academy of Finland (201353)
文摘The analytical structures and the corresponding mathematical properties of the one dimensional and two dimensional fuzzy controllers are first investigated in detail. The nature of these two kinds of fuzzy controllers is next probed from the perspective of control engineering. For the one dimensional fuzzy controller, it is concluded that this controller is a combination of a saturation element and a nonlinear proportional controller, and the system that employs the one dimensional fuzzy controller is the combination of an open-loop control system and a closedloop control system. For the latter case, it is concluded that it is a hybrid controller, which comprises the saturation part, zero-output part, nonlinear derivative part, nonlinear proportional part, as well as nonlinear proportional-derivative part, and the two dimensional fuzzy controller-based control system is a loop-varying system with varying number of control loops.
基金Supported in part by the National Natural Science Foundation of China.
文摘This paper shows that for a supercritical contact process in one dimension, if the initial distribution satisfies reasonable hypothesis, then the first hitting time of certain set with anomalous small density is asymptotically exponentially distributed. We also show the similar result for the contact process on the finite set [0, N].
基金supported by the National Natural Science Foundation of China(No.12071491)。
文摘In this paper,we consider the one dimensional third order p-Laplacian equation(Фp(u″))′+h(t)f(t,u(t))=0 with integral boundary conditions u(0)-αu′(0)=∫_(0)^(1) g1(s)u(s)ds,u(1)+βu′(1)=∫_(0)^(1)g2(s)u(s)ds,u″(0)=0.By using kernel functions and the Avery-Peterson fixed point theorem,we establish the existence of at least three positive solutions.
基金This work was financially supported by the National Climbing Programme of China (No. 1999-444)the Natural Science Foundation of Tianjin (No.003805611 and 033610611) the Center of Liuhui Application Mathematics of Nankai University and Tianjin Univers
文摘Cu-Zn-Al alloy of one dimensional nano-structure was prepared and thestructure of obtained nano-material was characterized by transmission electron microscope (TEM). Itwas shown that there are non-linear oscillations on the surface of Cu-Zn-Al alloy and theconsanguineous connection exists between non-linear oscillation and the growth process of onedimensional nano-structure. The diameter of one dimensional nano-structure is about 40 nm, and theratio of length to diameter is over 40. Finally, the growth mechanism of one dimensionalnano-structure was also studied.
文摘The reactions of 18 crown 6 with each of K 2(M=Zn, Hg; mnt=1,2 dicyanoethene 1,2 dithiolate, C 2S 2(CN) 2- 2) were studied and novel complexes [K(18 C 6)] 2[Zn(mnt) 2](1) and [K(18 C 6)] 2[Hg(mnt) 2](2) were characterized by elemental analysis, IR spectrum and X ray diffraction analysis. Complex 1 displays a one dimensional chain of [K(18 C 6)] 2[Zn(mnt) 2] bridged by K O interactions between adjacent [K(18 C 6)] + units. Complex 2 is also a one dimensional chain of [K(18 C 6)] 2[Hg(mnt) 2] bridged by K...S weak interactions between adjacent [K(18 C 6)] + and [Hg(mnt) 2] 2- .
文摘The variation of effective stress ratio of stratfied soil with semi pervious boundaries and under cyclic loading was analyzed on the basis of Terzaghi's one dimensional consolidation assumptions. A solution by Laplace Transform was obtained for the case when the soil was under time varied loading. With numerical inversion of Laplace Transform, some useful results were obtained for several kinds of commonly encountered loadings. The results can be meaningful in engineering practice.
文摘One-dimensional (1D) ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their diverse current and future technological applications. This article gives a comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods. We will cover the synthetic methodologies and the corresponding growth mechanisms, various nanostructures grown, their doping and alloying, and position-controlled growth on substrates. Finally, we will review their functional properties in catalysis, hydrophobic surface modification, sensing, and electronic, optical, optoelectronic, and energy harvesting devices.
基金supported by the National Natural Science Foundation of China (Nos. 21325417, 51533008)the MOST National Key Research and Development Plan (2016YFA0200200)+1 种基金the National Postdoctoral Program for Innovative Talents (No. BX201700209)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University (No. LK1403)
文摘Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and twodimensional graphene both possess remarkable mechanical properties. In the past years, a large amount of work have been done by using CNTs or graphene as building blocks for constructing novel, macroscopic, mechanically strong fibrous materials. In this review, we summarize the assembly approaches of CNT-based fibers and graphene-based fibers in chronological order, respectively. The mechanical performances of these fibrous materials are compared, and the critical influences on the mechanical properties are discussed. Personal perspectives on the fabrication methods of CNT-and graphene-based fibers are further presented.
基金This work was financially supported by the National Natural Science Foundation of China(No.51772337)Free Exploration Fund of State Key Laboratory of Optoelectronic Materials and Technologies of China(No.OEMT-2017-ZY-09).
文摘Ni-rich oxides,LiNixMnyCozO2(NMC),are among leading candidates for cathode materials in Li-ion batteries.However,they are mostly fabricated by coprecipitation approach under complex conditions,which usually produces large secondary particles composed of aggregated primary particles.Undesirable cation mixing and crack propagation upon cycling block ion and electron transport,result in fast capacity fading and poor rate capability.Herein,we present an ultrasound-triggered cation chelation and reassembly route for synthesizing one-dimensional precursor with homogeneous element distribution at the atomic level.This process is accomplished by the synergistic combination of ultrasound and surfactant,which can disperse reactants and remove hydration shells surrounding cations so as to accelerate chelating reaction,and then separate and assemble chelates into one dimensional structure.The whole synthesis time is only 20 min(8.9 min of ultrasonic working time)in an open vessel under natural ambient conditions.One-dimensional LiNi0.6Mn0.2Co0.2O2 has a high reversible capacity(184 mAh·g^−1 at 0.1 C)and long cycling stability(95.1%and 82.4%capacity retention for 100 and 1000 cycles,respectively).The short charging time of 76 s is realized at super high current rate of 20 C,which is very important to improve the competitiveness of electric vehicles relative to fuel vehicles.Our synthetic approach can provide a general strategy for the growth of mixed-metal-EDTA chelate precursors by changing the feeding ratio of Ni2+,Mn2+and Co2+cations in reaction for fabricating NMC cathode materials with other compositions.
基金This work was supported by the National Natural Science Foundation of China (No. 10274108)the National "973" Project of China (No. 2004CB719804)the National "863" Project of China (No. 2003AA311022)the Natural Science Foundation of Guangdong Province of China.
文摘A photonic heterostructure with multi-channel and sharp angular defect modes by combining two different one-dimensional defective photonic crystals is proposed. The filters designed on the basis of this heterostructure possess both functions of multi-channel narrow band filtering and sharp angular filtering. The channels, channel interval, and number of channels can be tuned by adjusting the geometric and physical parameters of the heterostuctures. This kind of filters will benefit the development of multi-channel interstellar or atmosphere optical communication.
基金the Shanghai Rising-Star Program(No.05QMX1459)the National Natural Science Foundation of China(No.60508018)
文摘Band structures of one-dimensional (1D) photonic crystals (PCs) containing dispersive left-handed metamaterials are studied theoretically. The results show that the structure possesses a type of photonic band gap originating from total internal reflection (TIR). In contrast to photonic band gaps corresponding to zero average refractive index and zero phase, the TIR gap exhibits sharp angular effect and has no polarization effect. It should also be noted that band structures of transverse electric (TE) and transverse magnetic (TM) mode waves are exactly the same in the PCs we studied.
文摘Reactions of CuBr with equimolar PyHBr orγMePyHBr afforded two novel one dimensional bromocuprate?polymers{(PyH)_(3)[Cu_(3)Br_(6)]}_(∞)(1)and{(γMePyH)_(2)[Cu_(2)Br_(4)]}_(∞)(2),respectively.Both 1 and 2 were characterized by IR,elemental analysis,and X ray crystallography.Crystal data for 1:monoclinic,space group P2_(1)/n,a=0.93262(12)nm,b=1.3497(2)nm,c=1.9149(2)nm,β=93.465(7)°,V=2.4060(5)nm^(3),Z=4.Crystal data for 2:orthorhombic,space group Pbcm,a=0.8659(4)nm,b=1.5669(6)nm,c=1.2849(5)nm,V=1.7432(2)nm^(3),Z=4.The structure of 1 has a unique helical chain composed of units andμbromide anions while that of 2 shows a linear chain consisted of[Cu_(2)(μBr)_(2)]units bridged by pairs ofμBr atoms.CCDC:1,208412;2,208413.
文摘The optimized method of extending the omni-photonic band gap (omni-PBG) was discussed based on analyzing the P-wave reflectivity characteristics in one-dimensional (1D) periodic multilayer film. A visible omnidirectional reflector with hybrid structure was designed using P-wave compensated overlapping in angle domain. The experimental result was in good agreement with the theoretical simulation.
基金Project supported by the China Postdoctoral Science Foundation (20100470841)the Natural Science Foundation of Jiangxi Province (2009GQH0057)
文摘1D europium coordination polymer wires were successfully prepared by reacting europium chloride with tributyl phosphate(TBP) at 160 oC for 12 h. The products were characterized by XRD,IR,TG,DTA,SEM,and EDS. SEM results showed that the wires were with diameters ranging from several hundreds of nanometers to ~5 μm and lengths going up to several hundreds of micrometers. Influencing factors such as the dosage of reactants and reaction time on the preparation were systematically investigated. Strong emission centering at 590 nm was realized in the coordination polymer wires on excitation at 395 nm.
文摘Transmission studies for one-dimensional photonic crystals (1DPCs) containing single-negative (SNG) materials inserted with multiple defects are presented. The numbers and positions of the defect modes inside zero-phase (zero-φeff) gap are found to be well characterized by effective medium theory.
基金the National Natural Science Foundation of China(No.60607005 and 60588502)the Science and Technology Bureau of Sichuan Province(2006z02-010-3)
文摘The transmission properties of one-dimensional photonic crystals containing double-negative and single-negative materials are studied theoretically. A special kind of photonic band gap is found in this structure. This gap is invariant with scaling and insensitive to thickness fluctuation. But when changing the ratio of the thickness of two media, the width of the gap could be enlarged. The defect modes are analyzed by inducing a linear defect layer in the structure. It is found that the number of defect modes will increase when the thickness of the defect layer becomes larger.
基金This work was supported by the Natural Science Foun-dation of Jiangsu Province under Grant No.BK2004059.
文摘Localized fields in the defect mode of one-dimensional photonic crystals with active impurity are studied with the help of the theory of spontaneous emission from two-level atoms embedded in photonic crystals. Numerical simulations demonstrate that the enhancement of stimulated radiation, as well as the phenomena of transmissivity larger than unity and the abnormality of group velocity close to the edges of photonic band gap, are related to the negative imaginary part of the complex effective refractive index of doped layers. This means that the complex effective refractive index has a negative imaginary part, and that the impurity state with very high quality factor and great state density will occur in the photonic forbidden band if active impurity is introduced into the defect layer properly. Therefore, the spontaneous emission can be enhanced, the amplitude of stimulated emission will be very large and it occurs most probably close to the edges of photonic band gap with the fundamental reason, the group velocity close to the edges of band gap is verv small or abnormal.
基金supported by the Natural Science Foundation of China (Nos. 50061001 and 50661001)the Science Foundation of Guangxi Province,China(Nos. 0991026,0832029 and 0639004)
文摘The characteristics of photonic forbidden bands, transmission gain and absorption of one-dimensional (ID) dual-periodical photonic crystals (PC) with a complex dielectric layer were studied by using the optical transfer matrix (TM) method. The results show that the photonic band gap (PBG) of this structure is enlarged and many transmission resonance peaks appear in PBG. Large transmission gain for transmission peaks is obtained if the imaginary part of dielectric constant is negative. With the increase of the absolute value of the imaginary part, the transmission gain increases firstly and the transmittance gain gets to an apex. The imaginary parts of dielectric constant corresponding to transmission gain apex are different according to wavelength. However, the transmission ratio of resonance peaks is less than 1 if the imagi- nary part of dielectric constant is positive. The properties might be used to design multi-narrow-channel band filters and optical amplification devices synchronously.