V-Shaped Monopole Antenna with Chichena Itzia Inspired Defected Ground Structure for UWB Applications

Due to rapid growth in wireless communication technology,higher bandwidth requirement for advance telecommunication systems,capable of operating on two or higher bands with higher channel capacities and minimum distortion losses is desired.In this paper,a compact Ultra-Wideband(UWB)V-shaped monopole antenna is presented.UWB response is achieved by modifying the ground plane with Chichen Itzia inspired rectangular staircase shape.The proposed V-shaped is designed by incorporating a rectangle,and an inverted isosceles triangle using FR4 substrate.The size of the antenna is 25 mm×26 mm×1.6 mm.The proposed V-shaped monopole antenna produces bandwidth response of 3 GHz Industrial,Scientific,and Medical(ISM),Worldwide Interoperability for Microwave Access(WiMAX),(IEEE 802.11/HIPERLAN band,5G sub 6 GHz)which with an additional square cut amplified the bandwidth response up to 8 GHz ranging from 3.1 GHz to 10.6 GHz attaining UWB defined by Federal Communications Commission(FCC)with a maximum gain of 3.83 dB.The antenna is designed in Ansys HFSS.Results for key performance parameters of the antenna are presented.The measured results are in good agreement with the simulated results.Due to flat gain,uniform group delay,omni directional radiation pattern characteristics and well-matched impedance,the proposed antenna is suitable for WiMAX,ISM and heterogeneous wireless systems.

ASYMMETRICAL STRUCTURES OF THE TEMPERATURE AND HUMIDITY OF TROPICAL CYCLONES

Based on NCEP/CFSR 0.5° reanalysis data and the best track data from the Japan Tokyo Typhoon Center,composite and comparative analyses demonstrate the asymmetrical structures of the temperature and humidity in tropical cyclones over the Western North Pacific and the South China Sea from 1979 to 2010.The results are shown as follows.(1) With intensifying tropical cyclones,the flow field tends to become gradually more axisymmetric;however,the asymmetry of the specific humidity in the outer regions is more obvious.(2) In general,tropical cyclones have a non-uniform,vertical, "double warm-core" structure.The "warm-cores" in the lower level of weak tropical cyclones and in the higher level of strong tropical cyclones are the stronger of the two.(3) The distribution area of a "warm-core" is enhanced with cyclone intensification and tends to become more axisymmetric.At 200 hPa,the "warm-core" of a weak cyclone has a weak anticyclone in the center,whereas that of a strong cyclone has a weak cyclone in the center.(4)The "wet-core" of a tropical cyclone is primarily located in the lower level(700-850 hPa).With the cyclone's intensification,the intensity of the "wet-core" increases and the scope of the 0.8 g kg^(-1) specific humidity anomaly tends to expand to higher levels.(5) With the cyclone's deepening,the pseudo-equivalent potential temperature at different levels in different regions increases.In addition,the largest warming rates at each intensity level in the different regions occur in the core area,followed in turn by the envelope and outer areas.

AN ANALYSIS OF THE ASYMMETRICAL STRUCTURE OF TYPHOON AERE'S PRECIPITATION

The structural characteristics of 2004 typhoon Aere's precipitation are analyzed using the high-resolution data from the Tropical Rainfall Measuring Mission(TRMM) of the National Aeronautics Space Administration(NASA).It is found that the typhoon's characteristics vary at different stages of its development.To analyze the asymmetric causation of precipitation distribution,data from the National Center for Environmental Prediction(NCEP) reanalysis are used to calculate the vertical integral of the water vapor flux vector.The results show that because of this process,along with the unique phenomenon of twin-typhoon circulation,the easterly air current of the typhoon's northern side and the southwesterly air current of its southern side play a joint role in transporting water vapor.Furthermore,its transport effects vary greatly at the different stages of development,showing the peculiarity of the water source for this typhoon process.The distributions of the typhoon convection area—characterized by heavy precipitation and a maximum-value area of the water vapor flux,as well as a strong ascending-motion area—differ at different stages of the typhoon's development.The non-uniform distribution of water vapor flux and the vertical motion bring about asymmetrical distribution of the typhoon precipitation.

Stable single longitudinal mode erbium-doped silica fiber laser based on an asymmetric linear three-cavity structure

We present a stable linear-cavity single longitudinal mode （SLM） erbium-doped silica fiber laser. It consists of four fiber Bragg gratings （FBGs） directly written in a section of photosensitive erbium-doped fiber （EDF） to form an asymmetric three-cavity structure. The stable SLM operation at a wavelength of 1545.112 nm with a 3-dB bandwidth of 0.012 nm and an optical signal-to-noise ratio （OSNR） of about 60 dB is verified experimentally. Under laboratory conditions, the performance of a power fluctuation of less than 0.05 dB observed from the power meter for 6 h and a wavelength variation of less than 0.01 nm obtained from the optical spectrum analyzer （OSA） for about 1.5 h are demonstrated. The gain fiber length is no longer limited to only several centimeters for SLM operation because of the excellent mode-selecting ability of the asymmetric three-cavity structure. The proposed scheme provides a simple and cost-effective approach to realizing a stable SLM fiber laser.

Structured illumination microscopy based on asymmetric three-beam interference

Structured illumination microscopy(SIM)is a rapidly developing super-resolution technology.It has been widely used in various application fields of biomedicine due to its excellent two-and three-dimensional imaging capabilities.Furthermore,faster three-dimensional imaging methods are required to help enable more research-oriented living cell imaging.In this paper,a fast and sensitive three-dimensional structured illumination microscopy based on asymmetric three-beam interference is proposed.An innovative time-series acquisition method is employed to halve the time required to obtain each raw image.A segmented half-wave plate as a substantial linear polarization modulation method is applied to the three-dimensional SIM system for the first time.Although it needs to acquire 21 raw images instead of 15 to reconstruct one super-resolution image,the SIM setup proposed in this paper is 30%faster than the traditional spatial light modulator-SIM(SLM-SIM)in imaging each super-resolution image.The related theoretical derivation,hardware system,and verification experiment are elaborated in this paper.The stable and fast 3D super-resolution imaging method proposed in this paper is of great significance to the research of organelle interaction,intercellular communication,and other biomedical fields.

Bcklund Transformation and Localized Coherent Structure for the (2+1)-Dimensional Asymmetric Nizhnik-Novikov-Veselov Equation

This article is concerned with the extended homogeneous balance method for studying the abundant localized solution structure of the (2+1) dimensional asymmetric Nizhnik Novikov Veselov equation. A B a¨ cklund transformation was first obtained, and then the richness of the localized coherent structures was found, which was caused by the entrance of two variable separated arbitrary functions, in the model. For some special choices of the arbitrary functions, it is shown that the localized structures of the model may be dromions, lumps, and ring solitons.

Seismic Responses of Asymmetric Base-Isolated Structures under Near-Fault Ground Motion

An inter-story shear model of asymmetric base-isolated structures incorporating deformation of each isolation bearing was built, and a method to simultaneously simulate bi-directional near-fault and far-field ground motions was proposed. A comparative study on the dynamic responses of asymmetric base-isolated structures under near-fault and far-field ground motions were conducted to investigate the effects of eccentricity in the isolation system and in the superstructures, the ratio of the uncoupled torsional to lateral frequency of the superstructure and the pulse period of near-fault ground motions on the nonlinear seismic response of asymmetric base-isolated structures. Numerical results show that eccentricity in the isolation system makes asymmetric base-isolated structure more sensitive to near-fault ground motions, and the pulse period of near-fault ground motions plays an import role in governing the seismic responses of asymmetric base-isolated structures.

Asymmetric structure of atomic above-threshold ionization spectrum in two-color elliptically polarized laser fields

According to the frequency-domain theory, we investigate the asymmetric structure of above-threshold ionization(ATI) spectrum of an atom in two-color elliptically polarized(EP) laser fields. When both laser fields are linearly polarized(LP), the spectrum shows that the multi-plateau structure is symmetric about the emitted angle of electron at π/2, while the spectrum becomes asymmetric and shifts rightwards with the increase of the EP degree of the IR laser field. Since the total ATI process is regarded as including direct ATI and the rescattering ATI, we analyze the spectrum structure of direct ATI and rescattering ATI separately. Using the saddle-point approximation, we find that for direct ATI, the fringes on the spectrum are mainly attributed to the fact that the ionization probability becomes very small when the direction of emitted electrons is perpendicular to the direction of the XUV laser polarization;while for the rescattering ATI, the interference fringes on the spectrum mainly come from the superposition of the waist structures on the spectra of all sub-channels.

NUMERICAL EXPERIMENTS OF THE INFLUENCE OF DIABATIC HEATING ON TROPICAL CYCLONE ASYMMETRIC STRUCTURE

Using the barotropic volticity equation that contains forcing from diabatic heating with appropriate parameterization. a number of numerical experiments are conducted for the tropical cyclone that is initially symmetric The result shows that the diabatic heating has important effects on the asymmetric structure in addition to the roll of the β term and nonlinear advection term in its formation. It again confirms the conclusion that the diabatic heating is a possible mechanism responsible for such structures in the tropical cyclone.

A NUMERICAL ANALYSIS ON TYPHOON ASYMMETRIC STRUCTUREAND MOTION

Five prediction experiments are carried out with two typhoons in 1992 using a limited -arca primitiveequations and two-way interactive model in a movable ,nested mesh. The result indicates good agreementin terms of motion between the prediction and observation. Studying the asymmetric structure in the cas-es selected, a close link is uncovered between the temporal evolutions of the structure and the track of motion in a tropical cyclone. Understanding of real asymmetric structure will help to improve the skill offorecasting tropical cyclones.

Effect of the asymmetric geometry on the wake structures of a pitching foil

The two-dimensional wake produced by a time-periodic pitching foil with the asymmetric geometry is investigated in the present work. Through numerically solving nonlinear Navier–Stokes equations, we discuss the relationship among the kinematics of the prescribed motion, the asymmetric parameter K ranged as-1 ≤ K ≤ 1, and the types of the wakes including the mP＋nS wake, the B′enard–von K′arm′an wake, the reverse B′enard–von K′arm′an wake, and the deviated wake.Compared with previous studies, we reveal that the asymmetric geometry of a pitching foil directly affects the foil＇s wake structures. The numerical results show that the reverse B′enard–von K′arm′an wake is easily deviated at K 〈 0, while the symmetry-breaking of the reverse B′enard–von K′arm′an wake is delayed at K 〉 0. Through the vortex dynamic method,we understand that the initial velocity of the vortex affected by the foil＇s asymmetry plays a key role in the deviation of the reverse B′enard–von K′arm′an wake. Moreover, we provide a theoretical model to predict the wake deviation of the asymmetric foil.

Synthesis and Crystal Structure of (R)-4-Hydroxymethyl-2-thioxo Thiazolidine and Its Asymmetric Catalysis

（R）-4-Hydroxymethyl-2-thioxo thiazolidine as a new chiral catalyst in the asymmetric addition of diethylzinc to benzaldehyde was synthesized from （R）-4-hydroxymethyl-2-thioxo thiazolidine carboxylic acid and its crystal structure was determined by X-ray diffraction method. The compound was crystallized in the orthorhombic system, space group P212121 with unit cell dimensions a=0.67253（12） nm; b=0.89164（17） nm; c=1.06146（19） nm, volume 0.6365（2） nm^3; Z=4, calculated denisity 1.557 Mg/m^3; absorption coefficient 0.733 mm^-1; F（000）=312. The X-ray crystal structure analysis reveals that the compound has a thione group.

The role of viscoelastic damping on retrofitting seismic performance of asymmetric reinforced concrete structures

The primary purpose of this research is to improve the seismic response of a complex asymmetric tall structure using viscoelastic(VE) dampers. Asymmetric structures have detrimental effects on the seismic performance because such structures create abrupt changes in the stiffness or strength that may lead to undesirable stress concentrations at weak locations. Structural control devices are one of the effective ways to reduce seismic impacts, particularly in asymmetric structures. For passive vibration control of structures, VE dampers are considered among the most preferred devices for energy dissipation. Therefore, in this research, VE dampers are implemented at strategic locations in a realistic case study structure to increase the level of distributed damping without occupying significant architectural space and reducing earthquake vibrations in terms of story displacements(drifts) and other design forces. It has been concluded that the seismic response of the considered structure retrofitted with supplemental VE dampers corresponded well in controlling the displacement demands. Moreover, it has been demonstrated that seismic response in terms of interstory drifts was effectively mitigated with supplemental damping when added up to a certain level. Exceeding the supplemental damping from this level did not contribute to additional mitigation of the seismic response of the considered structure. In addition, it was found that the supplemental damping increased the total acceleration of the considered structure at all floor levels, which indicates that for irregular tall structures of this type, VE dampers were only a good retrofitting measure for earthquake induced interstory deformations and their use may not be suitable for acceleration sensitive structures. Overall, the research findings demonstrate how seismic hazards to these types of structures can be reduced by introducing additional damping into the structure.

SYNTHESIS AND STRUCTURE OF AN ASYMMETRIC TRICOBALT COMPOUND Co_3(o-HOC_6H_4S)_2(o-OC_6H_4S)_2(PEt_3)_3

Compound Co_3(o-HOC_6H_4S)_2(o-OC_6H_4S)_2(PEt_3)_3 was obtained by reaction of CoCl_2, o-HOC_6H_4SH(H_2mD)and PEt_3 in ethanol in the presence of NaOCH_3.The three Co atoms are triangularly arranged and asymmetrically bridged by four S and one O atoms from the four H_2mp ligands and terminally ligated by one O and three P atoms.Two free hydroxyl groups form two internal hydrogen bonds with adjacent oxo donor atoms.

Probing the structure of multi-center molecules with odd–even high harmonics

We study high-order harmonic generation(HHG)from multi-center asymmetric linear molecules numerically and analytically.Our simulations show that odd and even HHG spectra of the asymmetric multi-center system respond differently to the change of the molecular structure.Specifically,when the internuclear distances between these nuclei of the molecule have a small change,the odd spectra usually do not change basically,but the even spectra differ remarkably.Based on this phenomenon,a simple procedure is proposed to probe the positions of these nuclei with odd–even HHG.Our results shed light on attosecond probing of the structure of multi-center molecules using HHG.

Synthesis, Crystal Structure and Hydrogenation Catalysis of a CF_3-BINAP(O)-Rh-COD Complex

The complex [（CF3-BINAP（O））Rh（COD）][ClO4]·Et2O （2, CFa-BINAP（O） = 2- {bis[3,5-bis（trifluoromethyl）phenyl]phosphino } -2 ＇- {bis [3,5-bis（trifluoromethyl）phenyl]phosphinyl } -1,1、-binaphthyl, COD = 1,5-cyclooctadiene） was obtained directly from the reaction of CF3- BINAP（O） ligand with [Rh（COD）][C104]. Complex 2 has been characterized by single-crystal X-ray diffraction. The crystal adopts space group P21/n with a = 19.0727（4）, b = 15.6275（4）, c = 22.3039（6） A, fl = 112.3570（10）°, V= 6148.2（3） A3, Z = 4, Dc = 1.693 g/cm3, F（000） = 3144, μ（MoKa） = 0.500 mm-1, the final R = 0.0947 and wR = 0.2501. Structural studies reveal that Rh（I） is coordinated by one oxygen and one phosphorus in the same ligand. Asymmetric hydrogenation of acetami- docinnamic acid with compound 2 was also evaluated.

Synthesis,Crystal Structure and Heterogeneous Catalysis of a New Chiral Manganese Coordination Polymer Based on the Schiff-base Ligand

A homochrial manganese（Ⅲ） complex（1） derived from chiral salen ligand（1 R,2 R）-（-）-1,2-diphenylethane-1,2-diamine-N,N？-bicarboxyl-salicylidene） has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism（CD）,powder and single-crystal X-ray crystallography.It crystallizes in orthorhombic,space group P212121 with a = 9.108（3）,b = 16.431（5）,c = 26.531（6） A,V = 3970.4（19） A^3,Z = 4,Dc = 1.248 g/cm^3,F（000） = 1568,Mr = 745.73,μ = 0.383 mm^-1,the final GOOF = 0.957,R = 0.0631 and wR = 0.1079 for 13250 observed reflections with I 〉 2σ（I）.The coordination polymer 1 possesses a 1 D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand（Mn-salen）,and the polymeric chains are further assembled into a 3D supramolecular network structure via strong intermolecular hydrogen bonding interactions between adjacent zigzag chains.As a heterogeneous catalyst,1 was used as an efficient heterogeneous catalyst for the asymmetric olefin epoxidation.

12.6μm-Thick Asymmetric Composite Electrolyte with Superior Interfacial Stability for Solid-State Lithium-Metal Batteries

Solid-state lithium metal batteries(SSLMBs)show great promise in terms of high-energy-density and high-safety performance.However,there is an urgent need to address the compatibility of electrolytes with high-voltage cathodes/Li anodes,and to minimize the electrolyte thickness to achieve highenergy-density of SSLMBs.Herein,we develop an ultrathin(12.6μm)asymmetric composite solid-state electrolyte with ultralight areal density(1.69 mg cm^(−2))for SSLMBs.The electrolyte combining a garnet(LLZO)layer and a metal organic framework(MOF)layer,which are fabricated on both sides of the polyethylene(PE)separator separately by tape casting.The PE separator endows the electrolyte with flexibility and excellent mechanical properties.The LLZO layer on the cathode side ensures high chemical stability at high voltage.The MOF layer on the anode side achieves a stable electric field and uniform Li flux,thus promoting uniform Li^(+)deposition.Thanks to the well-designed structure,the Li symmetric battery exhibits an ultralong cycle life(5000 h),and high-voltage SSLMBs achieve stable cycle performance.The assembled pouch cells provided a gravimetric/volume energy density of 344.0 Wh kg^(−1)/773.1 Wh L^(−1).This simple operation allows for large-scale preparation,and the design concept of ultrathin asymmetric structure also reveals the future development direction of SSLMBs.

Synthesis and Crystal Structure of Chiral 4-Hydroxy-4-butyrolactam Fused Aziridine

A novel compound of chiral 4-hydroxy-4-butyrolactam fused aziridine was synthesized via tandem nucleophilic displacement reaction under mild condition. Its structure was determined by IR, 1H NMR, elemental analysis and X-ray diffraction. The crystal of the new compound is of orthorhombic, space group P212121 with a = 6.4246（6）, b = 13.5081（13）, c = 18.6399（18） A, Mr = 278.39, Z = 4, V = 1617.6（3）A^3, Dc = 1.143 g/cm^3, p（MoKa） = 0.075 mm^-1, F（000） = 608, the final R = 0.0297 and wR = 0.0679.

Synthesis and Structure of Mixed Distannoxane Dimers [ClR_2SnOSnR'_2Cl]_2

Mixed distannoxane dimers [ClR2SnOSnR'2Cl]2 were synthesized by the reaction of R2SnO (R = Bu, Pr) and R2SnCl2 (R = Me, Ph, Cy, Oct). The crystal structures of compound 1 and 5 show they are ladder-type dimers that contain a central planar Sn2O2 four-membered ring. Both endo- and exo-Sn atoms are five-coordinate.