DUAL FUNCTIONALS OF SAID-BZIER TYPE GENERALIZED BALL BASES OVER TRIANGLE DOMAIN AND THEIR APPLICATION

A family of Said-Bézier type generalized Ball （SBGB） bases and surfaces with a parameter H over triangular domain is introduced,which unifies Bézier surface and Said-Ball surface and includes several intermediate surfaces. To convert different bases and surfaces,the dual functionals of bases are presented. As an application of dual functionals,the subdivision formulas for surfaces are established.

The Dual Functionals for the Generalized Ball Basis of Wang-Said Type and Basis Transformation Formulas

The generalized Ball curves of Wang-Said type with a position parameter L not only unify the Wang-Ball curves and the Said-Ball curves, but also include several useful intermediate curves. This paper presents the dual functionals for the generalized Ball basis of Wang-Said type. The relevant basis transformation formulae are also worked out.

Enhancement of the CO_(2)adsorption and hydrogenation to CH_(4)capacity of Ru–Na–Ca/γ–Al_(2)O_(3)dual function material by controlling the Ru calcination atmosphere

Integrated CO_(2)capture and utilization(ICCU)technology requires dual functional materials(DFMs)to carry out the process in a single reaction system.The influence of the calcination atmosphere on efficiency of 4%Ru-8%Na_(2)CO_(3)-8%CaO/γ-Al_(2)O_(3)DFM is studied.The adsorbent precursors are first co-impregnated onto alumina and calcined in air.Then,Ru precursor is impregnated and four aliquotes are subjected to different calcination protocols:static air in muffle or under different mixtures(10%H_(2)/N_(2),50%H_(2)/N_(2)and N_(2))streams.Samples are characterized by XRD,N_(2)adsorption-desorption,H_(2)chemisorption,TEM,XPS,H_(2)-TPD,H_(2)-TPR,CO_(2)-TPD and TPSR.The catalytic behavior is evaluated,in cycles of CO_(2)adsorption and hydrogenation to CH_(4),and temporal evolution of reactants and products concentrations is analyzed.The calcination atmosphere influences the physicochemical properties and,ultimately,activity of DFMs.Characterization data and catalytic performance discover the acccomodation of Ru nanoparticles disposition and basic sites is mostly influencing the catalytic activity.DFM calcined under N_(2)flow(RuNaCa-N_(2))shows the highest CH_(4)production(449μmol/g at 370℃),because a well-controlled decomposition of precursors which favors the better accomodation of adsorbent and Ru phases,maximizing the specific surface area,the Ru-basic sites interface and the participation of different basic sites in the CO_(2)methanation reaction.Thus,the calcination in a N_(2)flow is revealed as the optimal calcination protocol to achieve highly efficient DFM for integrated CO_(2)adsorption and hydrogenation applications.

Dual-functional pyrene implemented mesoporous silicon material used for the detection and adsorption of metal ions

A fluorescent active organic–inorganic hybrid material Py N-SBA-15 was synthesized by implementing pyrene derivatives into mesoporous SBA-15 silica.Py N-SBA-15 had detection and removal functionalities toward Al^(3+),Cu^(2+),and Hg^(2+).On the one hand,Py N-SBA-15 was used as a fluorescence sensor and displayed high sensitivity toward Al^(3+),Cu^(2+),and Hg^(2+)cations (limit of detection:8.0×10^(-7),1.1×10^(-7),and 2.9×10^(-6)mol·L^(–1),respectively) among various analytes with“turn-off”response.On the other hand,the adsorption studies for these toxic analytes (Cu^(2+),Hg^(2+),and Al^(3+)) showed that the ion removal capacity could reach up to 45,581,and 85 mg·g^(-1),respectively.Moreover,the Langmuir isotherm models were better fitted with the adsorption data,indicating that the adsorption was mono-layer adsorption.Kinetic analysis revealed that the adsorption process was well described by the pseudo-second-order kinetic model for Cu^(2+)and Hg^(2+)and pseudo-first-order kinetic model for Al^(3+).The prepared silica material could be reused in four recycles without significantly decreasing its adsorption capacity.Therefore,the Py N-SBA-15 material can serve as a promising candidate for the simultaneous rapid detection and efficient adsorption of metal ions.

Bioactive glass sol as a dual function additive for chitosan-alginate hybrid scaffold

Bioactive glass-chitosan-alginate hybrid scaffolds （BG-C-A scaffolds） were fabricated using BG sol as a dual function additive, which behaves as both bioactive inorganic phase to confer the bioactivity and cross-linker to improve the structural stability and mechanical properties. The microstructure, physicochemical and mechanical properties, in vitro bioactivity and cellular biocompatibility of the scaffolds were investigated. The results indicated that BG component was successfully incorporated into the BG-C-A scaffolds through a facile BG sol-immersing method and the original interconnected microstructure could be well preserved. The obtained BG-C-A scaffolds showed improved mechanical properties and structural stability as compared to C-A scaffolds. At the same time, they presented excellent in vitro bioactivity and cellular compatibility. All these results demonstrated that these BG-C-A scaffolds have promising potential for tissue engineering.

1,n-Thiosulfonylation using thiosulfonates as dual functional reagents

In recent years,the direct introduction of sulfonyl and sulfenyl groups into unsaturated substrates by using thiosulfonates as unique dual functional reagents has inarguably provided chemists a new platform for the diverse synthesis of important S-containing derivatives.These 1,n-thiosulfonylation reactions usually feature simple procedures,100%atom economy,and high regioselectivity.This review focuses on the recent advancements in the transformations of thiosulfonates through 1,n-thiosulfonylation involving the formation of two distinct C-S bonds under transition-metal-catalyzed or metal-free conditions,where thiosulfonates act as both a sulfonyl and a sulfenyl component.

Gold-catalyzed ketene dual functionalization and mechanistic insights:divergent synthesis of indenes and benzo[d]oxepines

An unprecedented gold-catalyzed ketene C=O/C=C bifunctionalization method has been developed.Mechanistic studies and density function theory(DFT)calculations indicate that the reaction is initiated by gold-catalyzed Wolff rearrangement of diazoketone to form the ketene intermediate,followed by intermolecular nucleophilic addition and terminated with two divergent cyclization processes via enol intermediates.In the case with alcohols as the nucleophiles,the reaction goes through a C-5-endodig carbocyclization to give the indene products;whereas,O-7-endo-dig cyclization occurs dominantly when indoles/pyrroles are used as the nucleophiles,delivering the 7-membered benzo[d]oxepines.In comparison with the well-documented cycloaddition and nucleophilic addition reactions,this cascade reaction features a novel reaction pattern for the ketene dual functionalization through addition with nucleophile and electrophile in sequence.

Facile wet-chemical fabrication of bi-functional coordination polymer nanosheets for high-performance energy storage and anti-corrosion engineering

Organic materials are of great interest in various applications owing to their intrinsic designability,molecular controllability,ease of synthesis,and ecological sustainability.In this work,a facile and mild wet-chemical strategy was carried out to construct a conjugated Ni-BTA coordination polymer via the π-d hybridization with 1,2,4,5-benzenetetramine(BTA)as π-conjugated ligands and Ni^(2+)as metallic centers,which exhibits a unique two-dimensional nanosheet-like structure with available active sites,sufficient electrochemical activity,and multi-electron redox capability.On the one hand,the as-prepared Ni-BTA coordination polymer as electrode material exhibits a rapid,reversible,and efficient energy storage behavior with a large reversible capacity of 198 mA·h·g^(-1)at 1 A·g^(-1) and a high-rate capability of 150 mA·h·g^(-1) at 20 A·g^(-1) in alkali-ion aqueous electrolyte,which are further demonstrated by the in-situ Raman investigation.On the other hand,the Ni-BTA coordination polymer as anti-corrosion additive was introduced into the epoxy resin to achieve a Ni-BTA epoxy coating,which shows a long-term anticorrosion performance with a low corrosion rate of 4.62×10_(-6) mm·a^(-1) and a high corrosion inhibition efficiency of 99.86%,suggesting its great engineering potential as the bi-functional organic material for high-performance energy storage and corrosion protection.

A DUAL-RELAX PENALTY FUNCTION APPROACH FOR SOLVING NONLINEAR BILEVEL PROGRAMMING WITH LINEAR LOWER LEVEL PROBLEM

The penalty function method, presented many years ago, is an important nu- merical method for the mathematical programming problems. In this article, we propose a dual-relax penalty function approach, which is significantly different from penalty func- tion approach existing for solving the bilevel programming, to solve the nonlinear bilevel programming with linear lower level problem. Our algorithm will redound to the error analysis for computing an approximate solution to the bilevel programming. The error estimate is obtained among the optimal objective function value of the dual-relax penalty problem and of the original bilevel programming problem. An example is illustrated to show the feasibility of the proposed approach.

Phase composition, transition and structure stability of functionally graded cemented carbide with dual phase structure

The phase composition, phase transition and phase structure transformation of the wire-cut section of functionally graded WC-Co cemented carbide with dual phase structure were investigated by XRD phase analysis. It is shown that the composition of η phase in the core zone is Co_3W_3C (M_6 C type). The structure of cobalt based solid solution binder phase is fcc type. At the cooling stage of the sintering process, the phase transition of η phase, i.e. M_6C→M_12C and the martensitic phase transition of the cobalt based solid solution binder phase, i.e. fcc→hcp are suppressed, which facilitates the strengthening of the alloy. Because the instantaneous temperature of the discharge channel is as high as 10 000 ℃ during the wire cutting process, the processed surface is oxidized. Nevertheless, the oxide layer thickness is in micro grade. In the oxide film, η phase is decomposed into W_2C and CoO, and cobalt based solid solution binder is selectively oxidized, while WC remains stable due to the existence of carbon containing liquid organic cutting medium.

Characterization of functionally graded ZrO_2 thermal barrier coatings sprayed by supersonic plasma spray with dual powder feed ports

The functionally graded thermal barrier coatings （FG-TBCs） with 80%ZrO2-13%CeO2-7%Y2O3 （C-YSZ）/NiCoCrAlY were prepared using a recently developed supersonic plasma spraying（S-PS） with dual powder feed ports system. The thermal shock experiment of FG-TBCs specimens was carried out by means of the automatic thermal cycle device, in which the samples were heated to 1200℃ by oxygen-acetylene flame jet then water-quenched to ambient temperature. The temperature—time curves of specimens and photographs can be watched on-line and recorded by a computer during the test. The results show that the totally 1mm-thick FG-TBCs have excellent thermal shock resistance due to the fact that the coatings have no any peeling-off after 200 thermal cycles. The microstructures and morphologies of FG-TBCs were characterized and analyzed by SEM.

Perturbation Theory for Dual Cosine Function（Ⅱ）—Time－dependent Perturbation in the Sun－reflexive Case

ＰｅｒｔｕｒｂａｔｉｏｎＴｈｅｏｒｙｆｏｒＤｕａｌＣｏｓｉｎｅＦｕｎｃｔｉｏｎ（Ⅱ）—Ｔｉｍｅ－ｄｅｐｅｎｄｅｎｔＰｅｒｔｕｒｂａｔｉｏｎｉｎｔｈｅＳｕｎ－ｒｅｆｌｅｘｉｖｅＣａｓｅＤｉｎｇＴｉａｎｂｉａｏ（丁天彪）（ＮｏｒｔｈＣｈｉｎａＩｎｓｔｉｔ...

Standard Dual Quaternion Optimization and Its Applications in Hand-Eye Calibration and SLAM

Several common dual quaternion functions,such as the power function,the magnitude function,the 2-norm function,and the kth largest eigenvalue of a dual quaternion Hermitian matrix,are standard dual quaternion functions,i.e.,the standard parts of their function values depend upon only the standard parts of their dual quaternion variables.Furthermore,the sum,product,minimum,maximum,and composite functions of two standard dual functions,the logarithm and the exponential of standard unit dual quaternion functions,are still standard dual quaternion functions.On the other hand,the dual quaternion optimization problem,where objective and constraint function values are dual numbers but variables are dual quaternions,naturally arises from applications.We show that to solve an equality constrained dual quaternion optimization(EQDQO)problem,we only need to solve two quaternion optimization problems.If the involved dual quaternion functions are all standard,the optimization problem is called a standard dual quaternion optimization problem,and some better results hold.Then,we show that the dual quaternion optimization problems arising from the hand-eye calibration problem and the simultaneous localization and mapping(SLAM)problem are equality constrained standard dual quaternion optimization problems.

Poly (N-Isopropyl Acrylamide-<i>Co</i>-Vanillin Acrylate) Dual Responsive Functional Copolymers for Grafting Biomolecules by Schiff’s Base Click Reaction

This article reports on the synthesis of acrylate monomer from renewable material. Vanillin was selected to be the start material to produce new monomer called vanillin acrylate and abbreviated by (VA). It has been successfully investigated by 1H, 13C NMR, IR and UV and all results were in logic state. The next step was to synthetize three different thermo-responsive functional copolymers by incorporation of three different molar ratios of vanillin acrylate (10, 20, 30 mol%) with N-Isopropylacrylamide via free radical polymerization by AIBN as initiator in solution. All copolymers were deduced by 1NMR and IR and all showed the presence of aldehyde group. The copolymer was used for grafting of tryptophan and β-alanine through the chemical link between amino group and the active aldehyde group by click reactions to form Schiff’s base imine compounds. Moreover, polymers were also elucidated by 1HNMR, IR and UV, Size Exclusion Chromatography (SEC) was used for the molecular weight determination, differential scanning calorimeter (DSC) for glass temperature of solid polymers, XRD for crystallinity. UV-vis Spectroscopy was used for the determination of phase separation or the lower critical solution temperature (Tc) of polymers solution not only in deionized water but in pH5 and pH11. The mount of conversation and linked amino acid was determined by UV-vis Spectroscopy.

Green’s Function Solution for the Dual-Phase-Lag Heat Equation

The present work is devoted to define a generalized Green’s function solution for the dual-phase-lag model in homogeneous materials in a unified manner .The high-order mixed derivative with respect to space and time which reflect the lagging behavior is treated in special manner in the dual-phase-lag heat equation in order to construct a general solution applicable to wide range of dual-phase-lag heat transfer problems of general initial-boundary conditions using Green’s function solution method. Also, the Green’s function for a finite medium subjected to arbitrary heat source and arbitrary initial and boundary conditions is constructed. Finally, four examples of different physical situations are analyzed in order to illustrate the accuracy and potentialities of the proposed unified method. The obtained results show good agreement with works of [1-4].

太赫兹各向异性超材料极化调控器设计与实现

电磁波极化特性会影响无线通信系统的性能,随着电磁场与微波技术的广泛应用,为满足信息传输和信息获取需求,电磁波极化特性的自由调控变得非常重要,在无线通信和雷达目标识别技术领域,都是通过改变极化状态来实现极化自由调控,随着波长的变短,相比微波通信,太赫兹通信具备频谱资源更丰富、传输速率更高的优势,但传统结构的极化调控器因存在各种缺陷,在太赫兹频段中的应用具有一定的局限性。针对这个问题,利用各向异性超材料设计了一款可用于太赫兹频段的双功能极化调控器,首先采用坐标分解法分析了器件的双功能极化调控特性,分析结果表明所设计的调控器既可以实现线极化波调控,又可以实现圆极化波调控,具备双功能调控特点;然后采用表面电流法分析了调控器的极化转换机理,仿真结果表明调控器具有4个谐振点,超材料单元结构中发生的四阶电磁谐振叠加,使得调控器工作频带宽,且极化转化效率高,在0.45~1.152 THz的频带内效率可高达90%以上;最后还分析了器件的不同参数对器件性能的影响,提出了调控器性能的优化思路和调控器的实际使用条件。通过对结构参数的分析,发现结构参数的变化会影响调控器工作时的频带宽度和谐振点的分布位置,调控器性能与自身工作频带宽度存在互斥关系,工作频带变宽,调控器性能变差,工作频带变窄,调控器性能变好,在调控器的实际应用过程中,为获取满意的调控特性,要根据具体的调控要求对结构参数进行优化调整;通过对入射角和方位角的分析,发现调控器性能对入射角的变化非常敏感,并指出在使用调控器时,它的摆放位置方向要满足入射波在调控器中的投影与调控器边沿保持平行。与现有工作相比,所设计的调控器性能更高效,结构更简单,并且双功能特性使器件的使用更加便捷和多样化,该工作为太赫兹极化转化器的发展和应用提供了理论参考。

Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation A functional MRI study

We performed functional MRI examinations in six right-handed healthy subjects.During functional MRI scanning,transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation.This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions.Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation.These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation.

可重构智能表面辅助双功能雷达通信系统的联合波束优化

双功能雷达通信系统(DFRC)是有效解决未来网络频谱资源拥挤问题的理想技术之一,该文引入了可重构智能表面(RIS)技术,旨在提升用户的加权和速率和系统的探测性能。首先在雷达功率约束和可重构智能表面的恒定模约束以及通信的整体功率预算下,构建了通信用户的加权和速率和系统探测性能最大化的优化模型。通过联合优化基站的主动波束和可重构智能表面的无源被动波束形成,该文设计了一种有效的基于加权最小均方误差、分式规划和流形优化的交替优化算法,将非凸优化问题转化为两个子问题并利用迭代进行求解。仿真结果表明,所提方案对解决该问题的有效性和对用户加权和速率在较低迭代次数下达到收敛,并且可使用户的加权和速率上限提升0.86 bit/(s·Hz)和使系统探测更具方向性。

广东在“双循环”战略中的功能与路径选择

如何实现“双循环”新发展格局大战略是我国经济发展亟待解决的问题,广东历来是全国改革开放的前沿阵地,理应承担起积极构建“双循环”新发展格局的重任。首先,基于广东历史区位,分析广东省在“双循环”新格局中的功能。然后,基于马克思的社会再生产理论,从生产、分配、流通、消费和外贸方面,分析了广东构建“双循环”新格局中的优势和劣势。最后,从投资、创新、收入、保障、物流、消费等方面提出广东省构建“双循环”新格局的实践路径。