A family of merit functions are proposed, which are the generalization of several existing merit functions. A number of favorable properties of the proposed merit functions are established. By using these properties, ...A family of merit functions are proposed, which are the generalization of several existing merit functions. A number of favorable properties of the proposed merit functions are established. By using these properties, a merit function method for solving nonlinear complementarity problem is investigated, and the global convergence of the proposed algorithm is proved under some standard assumptions. Some preliminary numerical results are given.展开更多
Food additive is a double-edged sword. It has merits and demerits. Food additives have such merits as improving sensory properties of foods,preventing deterioration and extending the shelf life,increasing varieties of...Food additive is a double-edged sword. It has merits and demerits. Food additives have such merits as improving sensory properties of foods,preventing deterioration and extending the shelf life,increasing varieties of foods,enhancing convenience of foods,facilitating food processing,and satisfying other demands. However,excessive and illegal use of food additives will exert adverse influence on food security.Therefore,it is required to take proper measures to bring merits of food additives into full play,and get rid of their demerits.展开更多
We investigate the sensitivity and figure of merit （FOM） of a localized surface plasmon （LSP） sensor with gold nanograting on the top of planar metallic film. The sensitivity of the localized surface plasmon senso...We investigate the sensitivity and figure of merit （FOM） of a localized surface plasmon （LSP） sensor with gold nanograting on the top of planar metallic film. The sensitivity of the localized surface plasmon sensor is 317 nm/RIU, and the FOM is predicted to be above 8, which is very high for a localized surface plasmon sensor. By employing the rigorous coupled-wave analysis （RCWA） method, we analyze the distribution of the magnetic field and find that the sensing property of our proposed system is attributed to the interactions between the localized surface plasmon around the gold nanostrips and the surface plasmon polarition on the surface of the gold planar metallic film. These findings are important for developing high FOM localized surface plasmon sensors.展开更多
Figure of merit analysis is a general methodology used to evaluate whether a hybrid power plant could produce more power than two stand-alone power plants. In this paper, the assessment methodology using figure of mer...Figure of merit analysis is a general methodology used to evaluate whether a hybrid power plant could produce more power than two stand-alone power plants. In this paper, the assessment methodology using figure of merit analysis was re-examined for a hybrid solar-geothermal power plant. A new definition of the figure of merit was introduced specifically for a solar boosted geothermal plant to include both the technical and economic factors. The new definition was then applied in a case study of a hypothetical demonstration hybrid solar-geothermal power plant in Australia. The power plant was considered to have a typical net power output of 2.2 MW with a solar energy fraction of 27%. The analysis was performed to compare the power output and capital cost of the hybrid plant with the state-of-the-art (SoA) and existing stand-alone solar and geothermal plants. Based on the new definition, the hybrid plant was found to generally outperform the two existing stand-alone plants. Moreover, at an ambient temperature of 5 °C, the hybrid plant was found to outperform the SoA stand-alone plants when the geothermal temperature was greater than 150 °C. For geothermal temperature of 180 °C on the other hand, the hybrid plant outperformed the SoA stand-alone plants at ambient temperatures lower than 33 °C.展开更多
Aristotle's Poetics represents the first major work of literature criticism. In this masterpiece,Aristotle expresses his literary and aesthetical theories. By introducing the merits in Aristotle's Poetics,this...Aristotle's Poetics represents the first major work of literature criticism. In this masterpiece,Aristotle expresses his literary and aesthetical theories. By introducing the merits in Aristotle's Poetics,this thesis tends to reveal Aristotle's large and enduring influence on modern literary criticism.展开更多
Under some assumptions, the solution set of a nonlinear complementarity problem coincides with the set of local minima of the corresponding minimization problem. This paper uses a family of new merit functions to deal...Under some assumptions, the solution set of a nonlinear complementarity problem coincides with the set of local minima of the corresponding minimization problem. This paper uses a family of new merit functions to deal with nonlinear complementarity problem where the underlying function is assumed to be a continuous but not necessarily locally Lipschitzian map and gives a descent algorithm for solving the nonsmooth continuous complementarity problems. In addition, the global convergence of the derivative free descent algorithm is also proved.展开更多
Dr. Samuel M. Cohen of the University of Nebraska Medical Center, who has recently published in the Journal of Environmental Sciences （Cohen et al., 2016）, is the recipient of the Merit Award from the Society of Tox...Dr. Samuel M. Cohen of the University of Nebraska Medical Center, who has recently published in the Journal of Environmental Sciences （Cohen et al., 2016）, is the recipient of the Merit Award from the Society of Toxicology （USA）. ＂The Merit Award is presented to a member of the Society of Toxicology in recognition of distinguished contributions to toxicology throughout an entire career in areas such as research, teaching, regulatory activities, consulting and service to the Society＂ （SOT, 2016a）. Dr. Cohen is professor at the University of Nebraska Medical Center, Omaha, Nebraska. He serves in the Depart- ment of Pathology and Microbiology, as well as the Eppley Institute for Research in Cancer. He also is staff pathologist with Nebraska Medicine, the Nebraska Orthopedics Hospital in Omaha. and the Bellevue Medical Center.展开更多
A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition techniq...A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.展开更多
In a recent issue of the Journal of Sport and Health Science,García-Pinillos et al.~1 reviewed evidence on the effects of highintensity intermittent training(interval training)(HIIT)on muscular and performance ad...In a recent issue of the Journal of Sport and Health Science,García-Pinillos et al.~1 reviewed evidence on the effects of highintensity intermittent training(interval training)(HIIT)on muscular and performance adaptations in recreational runners.展开更多
The beam pointing is the most crucial issue for beam combining to achieve high energy laser output. In order to meet the turbulence situation, a beam pointing method that cooperates with the stochastic parallel gradie...The beam pointing is the most crucial issue for beam combining to achieve high energy laser output. In order to meet the turbulence situation, a beam pointing method that cooperates with the stochastic parallel gradient descent(SPGD) algorithm is proposed. The power-in-the-bucket(PIB) is chosen as the merit function, and its radius changes gradually during the correction process. The linear radius and the exponential radius are simulated. The results show that the exponential radius has great promise for beam pointing.展开更多
With growing tendency and widespread application, TBLT has attracted considerable attention from educator teachers,theorists and researchers. The paper commences by offering some influential definitions of‘task',...With growing tendency and widespread application, TBLT has attracted considerable attention from educator teachers,theorists and researchers. The paper commences by offering some influential definitions of‘task', varying classifications of differ-ent types of task, and criteria for judging a task. Then, compared with teaching approaches before the emergence of CLT, TBLT isnew and has many distinct merits. Meanwhile, since it is a newly-established approach, some problems and difficulties in comple-menting TBLT are inevitable. A number of genuine issues raised in Asian language teaching classrooms are examined.展开更多
Piezoelectric MEMS speakers,an emerging technology with great promise,face significant challenges in performance evaluation and rational design.Their broadband nature means that responses at every frequency point acro...Piezoelectric MEMS speakers,an emerging technology with great promise,face significant challenges in performance evaluation and rational design.Their broadband nature means that responses at every frequency point across the whole operating bandwidth contribute to performance,yet there is no widely recognized weighting approach for fair evaluation.This absence of quantitative criteria makes objective comparisons of different designs difficult,slowing the adoption of new design concepts;and it leads to ambiguous design goals without response balance across frequency bands.Additionally,the current design methods rely on labor-intensive simulations,further prolonging the development process.To address these challenges,two figures of merit(FOMs)obtained via theoretical deduction are proposed in this study.These FOMs facilitate the evaluation of key metrics,such as sound pressure level and energy efficiency over a wide frequency range,enabling quantitative comparisons among various speaker designs.On the basis of FOMs,the design process can be simplified into a single-objective optimization problem,significantly streamlining the speaker design.Using this method,piezoelectric MEMS speakers with ultra-high FOMs and superior performance are demonstrated.The normalized SPLs at 1 and 10 kHz reach an impressive 76.6 and 86.6 dB/mm^(2)/V_(rms),respectively,with normalized sensitivities of 91.2 and 91.5 dB/mm2/mW.This achievement validates our FOM theory,representing a notable advancement in the field.展开更多
A model of a novel 1-3-type composite containing two ferroelectric components is put forward.In this composite,ferroelectric single crystal(SC)rods and ferroelectric ceramic rods are distributed in a polymer matrix.Fo...A model of a novel 1-3-type composite containing two ferroelectric components is put forward.In this composite,ferroelectric single crystal(SC)rods and ferroelectric ceramic rods are distributed in a polymer matrix.For a lead-free 1-1-3 composite based on domain-engineered[Li_(x)(K_(1-y)Na_(y))_(1-x)](Nb_(1-z)Ta_(z))O_(3):Mn SC,effective piezoelectric coeficients d_(3j)^(*);and g_(3j)^(*)and energy-harvesting figures of merit(FOMs)d_(3j)^(*)g_(3j)^(*),are studied taking an active influence of the feroelectric components into account.In a new m-m_(c)diagram,regions of volume fractions of SC(m)and ceramic(m_(c))are determined where FOM d_(33)^(*)g_(33)^(*)changes from 6.10^(-11)to 9·10^(-11)Pa^(-1).Efective parameters of the 1-1-3 and related 1-0-3 composites are compared,and consistency is shown.The large longitudinal piezoelectric coefficient g_(33)^(*)and FOM d_(33)^(*)g_(33)^(*)of the lead-free 1-1-3 composite are to be of interest in piezoelectric sensoricsand energy harvesting.展开更多
High phase accuracy and figure of merit(FOM)of quadrature signals are essential for integrated systems,including quadrature amplitude modulation(QAM)communications and multi-input multi-output(MIMO)radar.However,the t...High phase accuracy and figure of merit(FOM)of quadrature signals are essential for integrated systems,including quadrature amplitude modulation(QAM)communications and multi-input multi-output(MIMO)radar.However,the traditional quadrature oscillators often struggle to meet the stringent requirements of high FOM and high quadrature phase accuracy simultaneously.To address this challenge,we propose a spoof surface plasmon polariton(SPP)metawaveguide(Meta)to design on-chip rotary traveling-wave oscillator(RTWO).By leveraging the advanced dispersion manipulation capability of Meta,the physical and electrical lengths of transmission line(TL)are effectively decoupled,thereby overcoming the limitations associated with the unequal electrical lengths of inner and outer loops of the resonator,which is difficult to achieve in the conventional RTWOs.Based on the design methodology,we realize a Meta-RTWO using the 65 nm CMOS technology and achieve a measured FOM of 188.5 dBc/Hz and a phase error of approximately 0.21°.These metrics surpass those of the traditional oscillators fabricated even by more advanced 28 nm CMOS processes.This study demonstrates that Meta-RTWO achieves a significant improvement in both output signal quadrature accuracy and FOM under process limitations without using additional phase adjustment structures.展开更多
A well-functioned society depends on its ability to nurture,attract,and deploy talents in critical sectors.However,the implementation of some meritocratic principles to allocate positions often leads to unjust social ...A well-functioned society depends on its ability to nurture,attract,and deploy talents in critical sectors.However,the implementation of some meritocratic principles to allocate positions often leads to unjust social hierarchies.Is there,then,a solution to meritocracy’s dysfunctional hierarchical effects?This paper attempts to answer this by drawing on the real-world cases of Singapore and the USA to investigate the relationship of toxic social hierarchies with meritocracy.It proposes three solutions to curb the unjustifiable social stratifications and the erosion of social cooperation often associated with social meritocracy.These reflections could help to shed light on the grounds for the ongoing debates on social hierarchies and provide valuable insights into how to weigh up existing socio-political structures.展开更多
CMOS platforms with a high nonlinear figure of merit are highly sought after for high photonic quantum efficiencies, enabling functionalities not possible from purely linear effects and ease of integration with CMOS e...CMOS platforms with a high nonlinear figure of merit are highly sought after for high photonic quantum efficiencies, enabling functionalities not possible from purely linear effects and ease of integration with CMOS electronics. Silicon-based platforms have been prolific amongst the suite of advanced nonlinear optical signal processes demonstrated to date. These include crystalline silicon, amorphous silicon, Hydex glass, and stoichio- metric silicon nitride. Residing between stoichiometric silicon nitride and amorphous silicon in composition, silicon-rich nitride films of various formulations have emerged recently as promising nonlinear platforms for high nonlinear figure of merit nonlinear optics. Silicon-rich nitride films are compositionally engineered to create bandgaps that are sufficiently large to eliminate two-photon absorption at telecommunications wavelengths while enabling much larger nonlinear waveguide parameters （5x-500x） than those in stoichiometric silicon uitride. This paper reviews recent developments in the field of nonlinear optics using silicon-rich nitride platforms, as well as the outlook and future opportunities in this burgeoning field.展开更多
Monolayer boron-based materials are of current interests due to its polymorphism.Herein,motivated by the recent experimental synthesis of semiconducting hydrogenatedαʹ-borophene and the regulation of the physical pro...Monolayer boron-based materials are of current interests due to its polymorphism.Herein,motivated by the recent experimental synthesis of semiconducting hydrogenatedαʹ-borophene and the regulation of the physical properties in layered materials by surface functionalization,we study the thermal and electronic properties ofαʹ-borophene with three different types of gas functional groups(H,F,and Cl)based on first-principles and Boltzmann transport theory.It is found thatαʹ-borophene can be well stabilized by fluorination and chlorination and maintain the semiconductor nature.More interestingly,when hydrogen is replaced with fluorine or chlorine,the lattice thermal conductivity changes from 24.3 to 5.2 or 0.73 W/(m·K)along armchair direction at 300 K,exhibiting a huge reduction by two orders of magnitude.The main reason is the decrease of both phonon group velocities and acoustic phonon relaxation time resulting from the strong phonon mode softening due to the weaken B-B bond strength and heavier atomic mass of fluorine and chlorine.Consequently,the chlorinatedαʹ-borophene exhibits a high thermoelectric figure of merit~2 at 300 K along armchair direction.Our study illustrates the importance of the modulation of transport properties by gas functional groups,which may promote the thermoelectric application of boron-based materials.展开更多
Bi2S3-xSex/poly(methyl methacrylate)(PMMA)nanocomposite films were prepared using microwave assisted synthesis with different compositions of x.Crystal structure,surface morphology,and optical properties were investig...Bi2S3-xSex/poly(methyl methacrylate)(PMMA)nanocomposite films were prepared using microwave assisted synthesis with different compositions of x.Crystal structure,surface morphology,and optical properties were investigated to characterize the prepared nanocomposite films.The crystallinity and optical band gap of the prepared Bi2S3-xSex/PMMA were affected by x.The prepared samples showed a blue shift in the absorption edge.The laser power dependent nonlinear refraction and absorption of Bi2S3-xSex/PMMA nanocomposite films were investigated by using the Z-scan technique.The optical nonlinearity of the nanocomposite films exhibited switchover from negative nonlinear refraction to positive nonlinear refraction to negative nonlinear refraction effects,and from saturable absorption to reverse saturable absorption to saturable absorption with an increase and decrease in the composition.An interesting all-optical figure of merit was reported to assess the nanocomposite films for a practical device.It was calculated that the device all-figures of merit were based on the nonlinear response,which is important for the all-optical switching device.The results demonstrate that the optimized all-optical figures of merit can be achieved by adjusting the composition and input laser power,which can be used for the design of different all-photonic devices,and the results of nonlinear switching behavior can open new possibilities for using the nanocomposite films in laser Q-switching and mode-locking.展开更多
At first, we systematically sum up and deduce the figure of merit of the compensator using linearly chirped fiber gratings. Secondly, we solve the Reccatti differential equation by the Runge Kutta method and calcul...At first, we systematically sum up and deduce the figure of merit of the compensator using linearly chirped fiber gratings. Secondly, we solve the Reccatti differential equation by the Runge Kutta method and calculate the reflectivity and dispersion of the linearly chirped fiber gratings to obtain the figure of merit numericallu.On the other hand, we also discuss the figure of merit under the circumstances of three kinds of coupling coefficients and compare them Finally, we present one kind of perfect design of the compensator using the Gauss coupling function, and simply discuss the method to realize the Gauss coupling function in the fabrication of linearly chirped fiber gratings in this paper.展开更多
基金Supported by the National Natural Science Foundation of China(10871144)the Natural Science Foundation of Tianjin(07JCYBJC05200)
文摘A family of merit functions are proposed, which are the generalization of several existing merit functions. A number of favorable properties of the proposed merit functions are established. By using these properties, a merit function method for solving nonlinear complementarity problem is investigated, and the global convergence of the proposed algorithm is proved under some standard assumptions. Some preliminary numerical results are given.
文摘Food additive is a double-edged sword. It has merits and demerits. Food additives have such merits as improving sensory properties of foods,preventing deterioration and extending the shelf life,increasing varieties of foods,enhancing convenience of foods,facilitating food processing,and satisfying other demands. However,excessive and illegal use of food additives will exert adverse influence on food security.Therefore,it is required to take proper measures to bring merits of food additives into full play,and get rid of their demerits.
基金Project supported by the National Key Research Program of China(Grant No.2011ZX01015-001)
文摘We investigate the sensitivity and figure of merit （FOM） of a localized surface plasmon （LSP） sensor with gold nanograting on the top of planar metallic film. The sensitivity of the localized surface plasmon sensor is 317 nm/RIU, and the FOM is predicted to be above 8, which is very high for a localized surface plasmon sensor. By employing the rigorous coupled-wave analysis （RCWA） method, we analyze the distribution of the magnetic field and find that the sensing property of our proposed system is attributed to the interactions between the localized surface plasmon around the gold nanostrips and the surface plasmon polarition on the surface of the gold planar metallic film. These findings are important for developing high FOM localized surface plasmon sensors.
文摘Figure of merit analysis is a general methodology used to evaluate whether a hybrid power plant could produce more power than two stand-alone power plants. In this paper, the assessment methodology using figure of merit analysis was re-examined for a hybrid solar-geothermal power plant. A new definition of the figure of merit was introduced specifically for a solar boosted geothermal plant to include both the technical and economic factors. The new definition was then applied in a case study of a hypothetical demonstration hybrid solar-geothermal power plant in Australia. The power plant was considered to have a typical net power output of 2.2 MW with a solar energy fraction of 27%. The analysis was performed to compare the power output and capital cost of the hybrid plant with the state-of-the-art (SoA) and existing stand-alone solar and geothermal plants. Based on the new definition, the hybrid plant was found to generally outperform the two existing stand-alone plants. Moreover, at an ambient temperature of 5 °C, the hybrid plant was found to outperform the SoA stand-alone plants when the geothermal temperature was greater than 150 °C. For geothermal temperature of 180 °C on the other hand, the hybrid plant outperformed the SoA stand-alone plants at ambient temperatures lower than 33 °C.
文摘Aristotle's Poetics represents the first major work of literature criticism. In this masterpiece,Aristotle expresses his literary and aesthetical theories. By introducing the merits in Aristotle's Poetics,this thesis tends to reveal Aristotle's large and enduring influence on modern literary criticism.
基金Supported by the National Science foundation of China(10671126, 40771095)the Key Project for Fundamental Research of STCSM(06JC14057)+1 种基金Shanghai Leading Academic Discipline Project(S30501)the Innovation Fund Project for Graduate Students of Shanghai(JWCXSL0801)
文摘Under some assumptions, the solution set of a nonlinear complementarity problem coincides with the set of local minima of the corresponding minimization problem. This paper uses a family of new merit functions to deal with nonlinear complementarity problem where the underlying function is assumed to be a continuous but not necessarily locally Lipschitzian map and gives a descent algorithm for solving the nonsmooth continuous complementarity problems. In addition, the global convergence of the derivative free descent algorithm is also proved.
文摘Dr. Samuel M. Cohen of the University of Nebraska Medical Center, who has recently published in the Journal of Environmental Sciences （Cohen et al., 2016）, is the recipient of the Merit Award from the Society of Toxicology （USA）. ＂The Merit Award is presented to a member of the Society of Toxicology in recognition of distinguished contributions to toxicology throughout an entire career in areas such as research, teaching, regulatory activities, consulting and service to the Society＂ （SOT, 2016a）. Dr. Cohen is professor at the University of Nebraska Medical Center, Omaha, Nebraska. He serves in the Depart- ment of Pathology and Microbiology, as well as the Eppley Institute for Research in Cancer. He also is staff pathologist with Nebraska Medicine, the Nebraska Orthopedics Hospital in Omaha. and the Bellevue Medical Center.
基金Supported by the Scientific Research Deanship of University of Dammam under Grant No 2014264
文摘A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.
文摘In a recent issue of the Journal of Sport and Health Science,García-Pinillos et al.~1 reviewed evidence on the effects of highintensity intermittent training(interval training)(HIIT)on muscular and performance adaptations in recreational runners.
基金supported by the Changchun Technology Project(No.2013270)
文摘The beam pointing is the most crucial issue for beam combining to achieve high energy laser output. In order to meet the turbulence situation, a beam pointing method that cooperates with the stochastic parallel gradient descent(SPGD) algorithm is proposed. The power-in-the-bucket(PIB) is chosen as the merit function, and its radius changes gradually during the correction process. The linear radius and the exponential radius are simulated. The results show that the exponential radius has great promise for beam pointing.
文摘With growing tendency and widespread application, TBLT has attracted considerable attention from educator teachers,theorists and researchers. The paper commences by offering some influential definitions of‘task', varying classifications of differ-ent types of task, and criteria for judging a task. Then, compared with teaching approaches before the emergence of CLT, TBLT isnew and has many distinct merits. Meanwhile, since it is a newly-established approach, some problems and difficulties in comple-menting TBLT are inevitable. A number of genuine issues raised in Asian language teaching classrooms are examined.
基金the funding from National Key Research and Development Program(No.2020YFB2008800)。
文摘Piezoelectric MEMS speakers,an emerging technology with great promise,face significant challenges in performance evaluation and rational design.Their broadband nature means that responses at every frequency point across the whole operating bandwidth contribute to performance,yet there is no widely recognized weighting approach for fair evaluation.This absence of quantitative criteria makes objective comparisons of different designs difficult,slowing the adoption of new design concepts;and it leads to ambiguous design goals without response balance across frequency bands.Additionally,the current design methods rely on labor-intensive simulations,further prolonging the development process.To address these challenges,two figures of merit(FOMs)obtained via theoretical deduction are proposed in this study.These FOMs facilitate the evaluation of key metrics,such as sound pressure level and energy efficiency over a wide frequency range,enabling quantitative comparisons among various speaker designs.On the basis of FOMs,the design process can be simplified into a single-objective optimization problem,significantly streamlining the speaker design.Using this method,piezoelectric MEMS speakers with ultra-high FOMs and superior performance are demonstrated.The normalized SPLs at 1 and 10 kHz reach an impressive 76.6 and 86.6 dB/mm^(2)/V_(rms),respectively,with normalized sensitivities of 91.2 and 91.5 dB/mm2/mW.This achievement validates our FOM theory,representing a notable advancement in the field.
基金supported by the Southern Federal University(research topic“Development and Materials-Science Substantiation of the Creation of Materials and Products Based on Piezoelectric Ceramics Using Additive Technologies,”Contract No.176/22-D,July 11 th,2022).
文摘A model of a novel 1-3-type composite containing two ferroelectric components is put forward.In this composite,ferroelectric single crystal(SC)rods and ferroelectric ceramic rods are distributed in a polymer matrix.For a lead-free 1-1-3 composite based on domain-engineered[Li_(x)(K_(1-y)Na_(y))_(1-x)](Nb_(1-z)Ta_(z))O_(3):Mn SC,effective piezoelectric coeficients d_(3j)^(*);and g_(3j)^(*)and energy-harvesting figures of merit(FOMs)d_(3j)^(*)g_(3j)^(*),are studied taking an active influence of the feroelectric components into account.In a new m-m_(c)diagram,regions of volume fractions of SC(m)and ceramic(m_(c))are determined where FOM d_(33)^(*)g_(33)^(*)changes from 6.10^(-11)to 9·10^(-11)Pa^(-1).Efective parameters of the 1-1-3 and related 1-0-3 composites are compared,and consistency is shown.The large longitudinal piezoelectric coefficient g_(33)^(*)and FOM d_(33)^(*)g_(33)^(*)of the lead-free 1-1-3 composite are to be of interest in piezoelectric sensoricsand energy harvesting.
基金supported by the National Natural Science Foundation of China under Grant Nos.62422106 and 62288101the Project on Frontier and Interdisciplinary Research Assessment,the Postdoctoral Fellowship Program of CPSF under Grant No.BX20240063the Jiangsu Funding Program for Excellent Postdoctoral Talent under Grant Number 2024ZB398.
文摘High phase accuracy and figure of merit(FOM)of quadrature signals are essential for integrated systems,including quadrature amplitude modulation(QAM)communications and multi-input multi-output(MIMO)radar.However,the traditional quadrature oscillators often struggle to meet the stringent requirements of high FOM and high quadrature phase accuracy simultaneously.To address this challenge,we propose a spoof surface plasmon polariton(SPP)metawaveguide(Meta)to design on-chip rotary traveling-wave oscillator(RTWO).By leveraging the advanced dispersion manipulation capability of Meta,the physical and electrical lengths of transmission line(TL)are effectively decoupled,thereby overcoming the limitations associated with the unequal electrical lengths of inner and outer loops of the resonator,which is difficult to achieve in the conventional RTWOs.Based on the design methodology,we realize a Meta-RTWO using the 65 nm CMOS technology and achieve a measured FOM of 188.5 dBc/Hz and a phase error of approximately 0.21°.These metrics surpass those of the traditional oscillators fabricated even by more advanced 28 nm CMOS processes.This study demonstrates that Meta-RTWO achieves a significant improvement in both output signal quadrature accuracy and FOM under process limitations without using additional phase adjustment structures.
基金the Research programme‘Ethics of Socially Disruptive Technologies’,the Gravitation programme of the Dutch Ministry of Education,Culture,and Science and the Netherlands Organization for Scientific Research,(Grant No.[024.004.031]).
文摘A well-functioned society depends on its ability to nurture,attract,and deploy talents in critical sectors.However,the implementation of some meritocratic principles to allocate positions often leads to unjust social hierarchies.Is there,then,a solution to meritocracy’s dysfunctional hierarchical effects?This paper attempts to answer this by drawing on the real-world cases of Singapore and the USA to investigate the relationship of toxic social hierarchies with meritocracy.It proposes three solutions to curb the unjustifiable social stratifications and the erosion of social cooperation often associated with social meritocracy.These reflections could help to shed light on the grounds for the ongoing debates on social hierarchies and provide valuable insights into how to weigh up existing socio-political structures.
基金MOE Academic Research Fund Tier 2 GrantNational Research Foundation Competitive Research Grant+3 种基金National Research Foundation Land and Liveability National Innovation Challenge GrantSUTD-MIT International Design CenterTemasek Laboratories grantNational Research Foundation,Prime Minister’s Office,Singapore,under its Medium Sized Centre Program
文摘CMOS platforms with a high nonlinear figure of merit are highly sought after for high photonic quantum efficiencies, enabling functionalities not possible from purely linear effects and ease of integration with CMOS electronics. Silicon-based platforms have been prolific amongst the suite of advanced nonlinear optical signal processes demonstrated to date. These include crystalline silicon, amorphous silicon, Hydex glass, and stoichio- metric silicon nitride. Residing between stoichiometric silicon nitride and amorphous silicon in composition, silicon-rich nitride films of various formulations have emerged recently as promising nonlinear platforms for high nonlinear figure of merit nonlinear optics. Silicon-rich nitride films are compositionally engineered to create bandgaps that are sufficiently large to eliminate two-photon absorption at telecommunications wavelengths while enabling much larger nonlinear waveguide parameters （5x-500x） than those in stoichiometric silicon uitride. This paper reviews recent developments in the field of nonlinear optics using silicon-rich nitride platforms, as well as the outlook and future opportunities in this burgeoning field.
基金This project is supported in part by the grants from the National Natural Science Foundation of China(Nos.12075168 and 11890703)the Science and Technology Commission of Shanghai Municipality(No.19ZR1478600).
文摘Monolayer boron-based materials are of current interests due to its polymorphism.Herein,motivated by the recent experimental synthesis of semiconducting hydrogenatedαʹ-borophene and the regulation of the physical properties in layered materials by surface functionalization,we study the thermal and electronic properties ofαʹ-borophene with three different types of gas functional groups(H,F,and Cl)based on first-principles and Boltzmann transport theory.It is found thatαʹ-borophene can be well stabilized by fluorination and chlorination and maintain the semiconductor nature.More interestingly,when hydrogen is replaced with fluorine or chlorine,the lattice thermal conductivity changes from 24.3 to 5.2 or 0.73 W/(m·K)along armchair direction at 300 K,exhibiting a huge reduction by two orders of magnitude.The main reason is the decrease of both phonon group velocities and acoustic phonon relaxation time resulting from the strong phonon mode softening due to the weaken B-B bond strength and heavier atomic mass of fluorine and chlorine.Consequently,the chlorinatedαʹ-borophene exhibits a high thermoelectric figure of merit~2 at 300 K along armchair direction.Our study illustrates the importance of the modulation of transport properties by gas functional groups,which may promote the thermoelectric application of boron-based materials.
文摘Bi2S3-xSex/poly(methyl methacrylate)(PMMA)nanocomposite films were prepared using microwave assisted synthesis with different compositions of x.Crystal structure,surface morphology,and optical properties were investigated to characterize the prepared nanocomposite films.The crystallinity and optical band gap of the prepared Bi2S3-xSex/PMMA were affected by x.The prepared samples showed a blue shift in the absorption edge.The laser power dependent nonlinear refraction and absorption of Bi2S3-xSex/PMMA nanocomposite films were investigated by using the Z-scan technique.The optical nonlinearity of the nanocomposite films exhibited switchover from negative nonlinear refraction to positive nonlinear refraction to negative nonlinear refraction effects,and from saturable absorption to reverse saturable absorption to saturable absorption with an increase and decrease in the composition.An interesting all-optical figure of merit was reported to assess the nanocomposite films for a practical device.It was calculated that the device all-figures of merit were based on the nonlinear response,which is important for the all-optical switching device.The results demonstrate that the optimized all-optical figures of merit can be achieved by adjusting the composition and input laser power,which can be used for the design of different all-photonic devices,and the results of nonlinear switching behavior can open new possibilities for using the nanocomposite films in laser Q-switching and mode-locking.
文摘At first, we systematically sum up and deduce the figure of merit of the compensator using linearly chirped fiber gratings. Secondly, we solve the Reccatti differential equation by the Runge Kutta method and calculate the reflectivity and dispersion of the linearly chirped fiber gratings to obtain the figure of merit numericallu.On the other hand, we also discuss the figure of merit under the circumstances of three kinds of coupling coefficients and compare them Finally, we present one kind of perfect design of the compensator using the Gauss coupling function, and simply discuss the method to realize the Gauss coupling function in the fabrication of linearly chirped fiber gratings in this paper.
