Two dimensional MoS_(2) finding its way towards constructing high-performance alkaline recovery membranes

The available alkaline recovery membranes are currently dominated by polymeric materials,but they suffer from a permeation-selectivity trade-off and inferior chemical resistance.Robust two dimensional(2D) lamellar membranes with sub-nanometer wide channels are promising candidates for discerning OH^(-)and other anions.Here,we report the development of alkaline recycling membranes through stacking MoS_(2) nanosheets.Benefiting from the ordered and narrow 2D channels,MoS_(2) membranes show excellent alkaline recovery performances.The OH^(-)dialysis coefficient (U_(OH)-) and separation factor (S)towards simulated OH^(-) and WO_(4)^(2-) across the 500 nm thick MoS_(2) laminates reach 6.9×10^(-3)m·h^(-1)and 34.3 respectively.Furthermore,the chemical environments of MoS_(2) laminates were modulated by intercalating ionic poly(sodium 4-styrene sulfonate)(PSS@MoS_(2)).The U_(OH)-and S values of PSS@MoS_(2) membrane further improve to 11.7×10^(-3)m·h^(-1)and 49.8 respectively.Besides,both MoS_(2) and PSS@MoS_(2) membranes exhibit promising stability.

Theoretical Predition of Two-dimensional SiGeP_(2)by the Global Optimization Method

The well-developed particle-swarm optimization method together with density functional theory calculations were employed to search lowest-energy geometric structures of two-dimensional(2D)SiGeP_(2).Two newly found structures(P3m1 and Pmm2)are predicted.The unbiased global search reveals that the two lowest-energy structures are honeycomb lattices with robust dynamical stabilities.A more accurate Heyd-Scuseria-Ernzerhof(HSE06)hybrid functional is used to estimate the band structures of SiGeP_(2),which indicates that both the structures are semiconductors with indirect band-gap energies 1.80 e V for P3m1 and1.93 e V for Pmm^(2),respectively.Using the deformation potential theory,the P3m1-SiGeP_(2)is predicted to have high electron mobilities(6.4×10^(4)along zigzag direction and 2.9×10^(3)cm^(2)·V^(-1)·s^(-1)along armchair direction,respectively)and hole electron mobilities(1.0×10^(3)along zigzag direction and 2.5×10^(3)cm^(2)·V^(-1)·s^(-1)along armchair direction,respectively),which can be comparable with that of phosphorene and show anisotropic character in-plane.In addition,to estimate the elastic limit of SiGeP_(2),we also calculated the surface tension of SiGeP_(2)as a function of tensile strain.Our results show that the 2D SiGeP_(2)may be good candidaticates for applications in nanoelectronic devices.

Event-triggered robust guaranteed cost control for two-dimensional nonlinear discrete-time systems

An event-triggered scheme is proposed to solve the problems of robust guaranteed cost control for a class of two-dimensional(2-D)discrete-time systems.Firstly,an eventtriggered scheme is proposed for 2-D discrete-time systems with parameter uncertainties and sector nonlinearities.Then,according to the Lyapunov functional method,the sufficient conditions for the existence of event-triggered robust guaranteed cost controller for 2-D discrete-time systems with parameter uncertainties and sector nonlinearities are given.Furthermore,based on the sufficient conditions and the linear matrix inequality(LMI)technique,the problem of designing event-triggered robust guaranteed cost controller is transformed into a feasible solution problem of LMI.Finally,a numerical example is given to demonstrate that,under the proposed event-triggered robust guaranteed cost control,the closed-loop system is asymptotically stable and fewer communication resources are occupied.

Review on the Studies about Rapeseed by Two-dimensional Gel Electrophrosis

As rapeseed is a major oil crop with high quality vegetable oil and feed protein in China and the two-dimensional gel electrophoresis （2-DE） is an efficient technique for investigating protein expression, this paper reviews the innovations in 2-DE and its application in the studies of rapeseed. We conclude that 2-DE has provided much valuable information on rapeseed, and it will do more for rapeseed proteomic research in the near future with the technology innovations.

THE CALCULATION OF THE VOLUME INTEGRAL IN BEM OF TWO DIMENSIONAL ELASTICITY

In this paper, a method of transforming volume integrals to boundary integrals is given for complicated loadings such as a i(y)x i and b i(x)y i . In the present method the volume integrals are approximately transformed to boundary integrals.

CALCULATION OF TWO-DIMENSIONAL PARABOLIC STABILITY EQUATIONS

Two dimensional parabolic stability equations (PSE) are numerically solved using expansions in orthogonal functions in the normal direction.The Chebyshev polynomials approximation,which is a very useful form of orthogonal expansions, is applied to solving parabolic stability equations. It is shown that results of great accuracy are effectively obtained.The availability of using Chebyshev approximations in parabolic stability equations is confirmed.

Coherent Exciton-Phonon Coupling in CdSe/ZnS Nanocrystals Studied by Two-Dimensional Electronic Spectroscopy

Coherent exciton-phonon coupling in CdSe/ZnS nanocrystals have been investigated by temperature-dependent two-dimensional electronic spectroscopy （2DES） measurements. Benefiting from the ability of 2DES to dissect assembles in nanocrystal films, we have dearly identified experimental evidences of coherent coupling between exciton and phonon in CdSe/ZnS nanocrystals. In time domain, 2DES signals of excitonic transitions beat at a frequency resonant to a longitudinal optical phonon mode; in energy domain, phonon side bands are distinct at both Stokes and anti-Stokes sides. When temperature increases, phonon-induced exciton dephasing is observed with dramatic broadening of homogeneous linewidth. The results suggest exciton-phonon coupling is essential in elucidating the quantum dynamics of excitonic transitions in semiconductor nanocrystals.

Flag-transitive point-primitive 2-(v,k,4) symmetric designs and two dimensional classical groups

Let D be a 2-（v, k, 4） symmetric design and G be a flag-transitive point-primitive automorphism group of D with X ≥G ≤Aut（X） where X ≌ PSL2（q）.Then D is a 2-（15,8,4） symmetric design with X = PSL2（9） and Xx = PGL2（3） where x is a point of D.

CONTROL OF TWO DIMENSIONAL JETS USING MINIATURE ZERO MASS FLUX JETS

Zero mass flux jets, synthesized by acoustic actuators, have been used for the purpose of jet mixing enhancement and jet vectoring. Zero mass flux jets composed of entirely entrained fluid allow momentum transfer into the embedding flow. In the present experiments, miniature scale high aspect ratio actuator jets are placed along the long sides and near the exit plane of a primary two dimensional jet. In different modes, the primary jet can be vectored either towards or away from the actuator jets and the jet mixing is enhanced. The disturbance of the excitation frequency is developed while the unstable frequency of the primary jet is completely suppressed.

Recent advances in two-dimensional nanomaterials-based electrochemical sensors for environmental analysis

With the rapidly increased concerns in environmental pollution, there have been urgent needs to develop fast, sensitive, low-cost and multiplexed sensing devices for the detection of environmental pollutants. Two-dimensional(2D) nanomaterials hold great promise due to their unique chemical and physical properties, which have been extensively employed to monitor the environmental pollutants combined with different detection techniques. In this review, we summarize recent advances in 2D nanomaterials-based electrochemical sensors for detecting heavy metal ions, organic compounds, pesticides, antibiotics and bacteria. We also discuss perspectives and challenges of 2D nanomaterials in environmental monitoring.

Elastic Wave Scattering by Two-Dimensional Periodical Array of Cylinders

We extend the multiple-scattering theory (MST) for elastic wave scattering and propagating in two-dimensional composite. The formalism for the band structure calculation is presented by taking into account the full vector character of the elastic wave. As a demonstration of application of the formalism we calculate the band structure of elastic wave propagating in a two-dimensional periodic arrangement of cylinders. The results manifest that the MST shows great promise in complementing the plane-wave (PW) approach for the study of elastic wave.

Detection of Electronic Coherence via Two-Dimensional Electronic Spectroscopy in Condensed Phase

Two dimensional Fourier transforrn electronic spectroscopy （2DES） in the visible region enables direct observation of complex dynamics of molecules including quantum coherence in the condensed phase. This review aims to provide a bridge between the principles and intuitive physical description of 2DES for tutorial purpose. Special emphasis is laid upon how 2DES circumvents the restrictions from both uncertainty principle and the wave-packet collapse during the coherent detection, leading to the successful detection of the coherence in terms of energy difference between the eigenstates showing as the quantum beats; then upon the possible mixing among the pure electronic transition, single-rnode and multi-mode coupled vibronic transition leading to the observed beating phenomena. Finally, recent ad- vances in experimentally distinguishing between the electronic coherence and the vibrational coherence are briefly discussed.

TWO DIMENSIONAL MELLIN TRANSFORM IN QUANTUM CALCULUS

In this article, we introduce the two dimensional Mellin transform M4（f）（s,t）, give some properties, establish the Paley-Wiener theorem and Plancherel formula, present the Hausdorff-Young inequality, and find several applications for the two dimensional Mellin transform.

FACE RECOGNITION USING TWO DIMENSIONAL LAPLACIAN EIGENMAP

Recently, some research efforts have shown that face images possibly reside on a nonlinear sub-manifold. Though Laplacianfaees method considered the manifold structures of the face images, it has limits to solve face recognition problem. This paper proposes a new feature extraction method, Two Dimensional Laplacian EigenMap （2DLEM）, which especially considers the manifold structures of the face images, and extracts the proper features from face image matrix directly by using a linear transformation. As opposed to Laplacianfaces, 2DLEM extracts features directly from 2D images without a vectorization preprocessing. To test 2DLEM and evaluate its performance, a series of ex- periments are performed on the ORL database and the Yale database. Moreover, several experiments are performed to compare the performance of three 2D methods. The experiments show that 2DLEM achieves the best performance.

TWO DIMENSIONAL SUPERSONIC SHOCK TUNNEL AND ITS APPLICATION

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Temperature Dependence of Polarizability and Dispersion in Three,Two and One Dimensional Electron Gases

Both temperature dependence of polarizability and plasmon dispersion in unmagnetized metal （or semiconductor） electron gases are investigated in this paper. It is obtained that, with a continuous variation of temperature in a large region, the polarizability and dispersion change non-monotonously. The static polarizability X（q, w =0, μ, T） and dispersion wp（q, T） for finite T in three, two and one dimensional electron gases are calculated numerically. In addition, dispersion relation w（q） at a definite temperature （T ≠0） is similar to that at T = 0.

Analysis of one dimensional and two dimensional 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.

Hurst's Analysis to Detect Fluctuation of the Jet in A Two-Dimensional Fluidized Bed

The experimental study of vertical jet in a two dimensional fluidized bed is presented. The time series of vertical jet penetration depth are acquired by image processing. The fluctuation of jet which is studied by means of Hurst's analysis becomes weaker with increase in jet velocity, fluidization number, particle diameter and static bed height. They are found that the signal is persistent and the fractal dimensional of vertical jet is between 1.19 and 1.64.

ON TWO DIMENSIONAL STANCU- MUHLBACH OPERATOR

In this paper, the twodirnensional Stancu - Muhlbach operator and Beta operator are introduced , and their approximation properties are discussed.

TWO DIMENSIONAL NUMERICAL CALCULATION FOR SALT WATER INTRUSION AT ESTUARIES

Based on 2-dimensional vertically governing equations of salt water intrusion at estuaries, a method is obtained, which can predict quantitatively current velocity and salinity distribution along depth when the intrusion occurs. The volume-controlling method proposed by Patanker and Spalding is used to form the computational pattern and the Power- Law Scheme is used as the diversion pattern of the diffusion term. The comparison between the computational results and the measured ones gives a satisfactory agreement.