On a Class of Two Dimensional Singular Integral Equations

We mainly consider a class of two dimensional normal type singular integral equations, the solutions as well as the conditions of solvability of which are obtained .The methods used consist of transferring them to several one dimensional Riemann boundary value problems, and then solving the latter.

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.

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.

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.

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.

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.

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.

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.

TWO DIMENSIONAL PROPERTIES OF REVERSED DUCKWEED AMPHIPHILIC POLYMER

The surface pressure-Area isotherms of Reversed Duckweed amphiphili polymer were examined in view of their chemical structure and two- dimentional properties of polymer monolayer were studied.

Two-dimensional PtRu Nanoclusters Carbon Based Electrocatalysts for Methanol Oxidation

A novel method to prepare an electrocatalyst with a new structure and high catalytic performance was reported. Two-dimensional（2 D） PtRu nanoclusters have been successfully deposited on graphene oxide and carbon black supports. Compared with the commercial 3 D E-TEK PtRu samples, the prepared 2 D PtRu composites have larger electrochemically active surface area and display much higher catalytic activity toward methanol oxidation reaction. The preparation method mainly includes the following procedures： oxidation of carbon matrix, Pb^（2＋） adsorption on the surface of carbon support, Pb^（2＋） electrochemical reduction and galvanic displacement of Pb^0 by Pt^（2＋） and Ru^（3＋）. The method developed in this study could be viable for solving the problem of low electrocatalytic activity in direct methanol fuel cell anodes.

The Instability of Terahertz Plasma Waves in Two Dimensional Gated and Ungated Quantum Electron Gas

The instability of terahertz（THz）plasma waves in two-dimensional（2D）quantum electron gas in a nanometer field effect transistor（FET）with asymmetrical boundary conditions has been investigated.We analyze THz plasma waves of two parts of the 2D quantum electron gas：gated and ungated regions.The results show that the radiation frequency and the increment（radiation power）in 2D ungated quantum electron gas are much higher than that in 2D gated quantum electron gas.The quantum effects always enhance the radiation power and enlarge the region of instability in both cases.This allows us to conclude that 2D quantum electron gas in the transistor channel is important for the emission and detection process and both gated and ungated parts take part in that process.

Evaluation of Atrial Septal Defect Using Real-time Three-dimensional Echocardiography:Comparison with Surgical Findings

The present study evaluated the application of three dimensional echocardigraphy （3DE） in the diagnosis of atrial septal defect （ASD） and the measurement of its size by 3DE and compared the size with surgical findings. Two-dimensional and real-time three dimensional echocardiography （RT3DE） was performed in 26 patients with atrial septal defect, and the echocardiographic data were compared with the surgical findings. Significant correlation was found between defect diameter by RT3DE and that measured during surgery （r=0.77, P〈0.001）. The defect area changed significantly during cardiac cycle. Percentage change in defect size during cardiac cycle ranged from 6%-70%. Our study showed that the size and morphology of atrial septal defect obtained with RT3DE correlate well with surgical findings. Therefore, RT3DE is a feasible and accurate non-invasive imaging tool for assessment of atrial septal size and dynamic changes.

Research Progress of Two-d imensional Matrix Detectors in IMRT Dose Verification

With the continuous development of science and technolog ies in China,radiotherapy technology in medical field has been very significant ly developing,and intensity modulated radiation therapy(IMRT)technology has been the most widely used.This paper first introduces the components and types of two-dimensional matrix detector,two-dimensional ionization chamber matrix detector and two-dimensional semiconductor matrix detector,then analyzes the dosimetric characteristics of the two-dimensional matrix detector.In the end,the various applications of the two-dimensional matrix detector are analyzed and discussed in detail.The paper aims to promote the two-dimensional matrix detector’s development in the field of radiotherapy in China.

胰腺癌血浆蛋白质组学研究

目的利用双向电泳(2-DE)的方法进行胰腺癌的比较蛋白质组学研究,寻找和鉴定与胰腺癌相关或特异的生物标志分子。方法选择12例胰腺癌患者以及与之性别年龄匹配的12例正常人和10例慢性胰腺炎患者的血浆标本进行研究。对去除ALB和IgG等预分离方法进行探索,确定最佳的血浆2-DE方案。通过比较胰腺癌(术前、术后)、正常人和慢性胰腺炎患者的血浆2-DE图谱,寻找差异蛋白并进行质谱鉴定。结果去除ALB和IgG以及超滤的预处理仅使血浆2-DE图谱的局部分辨率提高。共发现并鉴定了5种与胰腺癌或慢性胰腺炎相关的差异蛋白:Haptoglobin(Hp),Hemoglobin(Hb),α1-antitrypsin(α1AT),Immunoglobin J chain(Ig J) and Leucine-rich α2-glycoprotein(LRG)。Hp β链在胰腺癌患者中轻度升高,胰腺癌患者的Hp2-2表型的比例高于正常人,而缺少Hp1-1表型。胰腺癌和慢性胰腺炎患者的血浆Hb高于正常人。α1AT的变化趋势为慢性胰腺炎>胰腺癌>正常人。慢性胰腺炎患者的IgJ链高于胰腺癌患者和正常人,可能来源于血分泌型IgA(sIgA)。胰腺癌患者的LRG水平较正常人和慢性胰腺炎轻度升高。术后Hp、α1AT和LRG均明显升高,未发现术后明显下降的蛋白。结论去除ALB和IgG以及超滤去除大分子的预处理方法对于血浆蛋白的差异比较并无太大优势,但在质谱鉴定方面可以与未处理的方法互相补充。在发现的5种差异蛋白中,Hp的表型、Hb、IgJ链和LRG与胰腺癌或慢性胰腺炎的关系在以往的文献中未见报道,这些差异蛋白对于胰腺癌或慢性胰腺炎的意义及诊断价值还需要进一步的验证。