Comparison of Photosynthetic Adaptability Between Kobresia humilis and Polygonum viviparum on Qinghai Plateau

The chlorophyll fluorescence parameters of Kobresia humilis Serg. and Polygonum viviparum L. grown at two different altitudes (3?200 m, 3?980 m) were measured and the ultrastructure of chloroplasts were observed for studying the photosynthetic adaptability of plants to the influences of stress conditions in alpine environment. Rfd _values, the vitality index, in leaves of K. humilis and P.viviparum grown at 3?980 m were higher than those at 3?200 m. The higher ratio of F v/F o and F v/F m in leaves of K. humilis and P.viviparum indicated that the rate of photosynthetic conversion of light energy increased at higher altitude. Ratios of F v/F o and F v/F m and Rfd _values in K.humilis were higher than that in P.viviparum grown at the same altitude. There were more irregular chloroplasts in leaves of both species grown at higher altitude. Many irregular chloroplasts such as swollen thylakoid, deformed chloroplast envelope, were observed in P.viviparum grown at 3?980 m, but few in K. humilis . These results were discussed in relation to the photosynthetic adaptability of alpine plants and the different adaptive competence between K.humilis and P.viviparum .

Effects of Doubled_CO_2 Concentration on Ultrastructure, Supramolecular Architecture and Spectral Characteristics of Chloroplasts from Wheat

Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.

Neutral Dissociation of Superexcited Nitric Oxide Induced by Intense Laser Fields

Superexcited states of NO molecule and their neutral dissociation processes have been studied both experimentally and theoretically. Neutral excited N^＊ and O^＊ atoms are detected by fluorescence spectroscopy for the NO molecule upon interaction with 800 nm intense laser radiation of duration 60 fs and intensity 0.2 PW/cm^2. Intense laser pulse causes neutral dissociation of superexcited NO molecule by way of multiphoton excitation, which is equivalent to single photon excitation in the extreme-ultraviolet region by synchrotron radiation. Potential energy curves （PECs） are also built using the calculated superexcited state of NO^＋. In light of the PECs, direct dissociation and pre-dissociation mechanisms are proposed respectively for the neutral dissociation leading to excited fragments N^＊ and O^＊.

Influence of laser treatment on the fatigue of notched bar

Fatigue cutting is a new approach for separating material. Man-made fatigue can be realized by applying a rotating bending load to a notched bar. To better utilize the new method, laser treatment is adopted in this study. After laser radiation at the notch root, the fatigue cycle of the bar drops dramatically. Based on the experimental result, we draw the conclusion that the fatigue of the bar is influenced by the shape of the hardened area. A hardened area that has a small axial dimension and a relatively large radial dimension facilitates the fatigue. The desirable hardened area can be obtained by controlling the laser treatment parameters.

Theoretical Study on First Hyperpolarizabilities of End-Capped Triply Branched Dendrimers

A series of end-capped triply branched dendritic chromophores have been studied by means of density functional theory calculations. It is found that the second order nonlinear optical properties of the end-capped dendrimers are strongly dependent on the mutual orientations of the three chromophores, numbers of caps and the conjugation length of the ehromophores. Large enhancement of the first hyperpolarizability can be obtained when dipole moments of three branches in the dendrimers are highly parallelized.

Photocatalytic Activity of Hierarchical Flower-Like TiO_(2) Superstructures with Dominant {001} Facets

The fabrication of well defined hierarchical structures of anatase TiO_(2) with a high percentage of reactive facets is of great importance and challenging.Hierarchically flower-like TiO_(2) superstructures(HFTS)self-assembled from anatase TiO_(2) nanosheets with exposed{001}facets(up to 87%)were synthesized by a simple alcohothermal strategy in a HF-H_(2)O-C_(2)H_(5)OH mixed solution using titanate nanotubes as precursor.The samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,and N2 adsorption-desorption isotherms.The photocatalytic activity was evaluated by the photocatalytic oxidation decomposition of acetone in air and methyl orange in aqueous solution under UV illumination.The photocatalytic activity of HFTS was much higher than that of commercial Degussa P25 and tabular-shaped anatase TiO_(2) obtained using pure water as the synthesis medium.The enhancement in photocatalytic activity was related to several factors,including the hierarchically porous structure,exposed{001}facets,and increased light harvesting ability.The HFTS was also of interest for use in solar cells,photocatalytic H_(2) production,optoelectronic devices,sensors,and catalysis.

N = 4 Supersymmetric Morse Oscillator and Its Spectrum-Generating Algebra

In this paper N = 4 supersymmetry of generalized Morse oscillators in one dimension is studied. Both bound states and scattering states of its four superpartner Hamiltonians are analyzed by using unitary irreducible representations of the noncompact Lie algebra su(1,1). The spectrum-generating algebra governing the Hamiltonian of the N = 4 supersymmetric Morse oscillator is shown to be connected with the realization of Lie superalgebra osp(1,2)or B(0,1) in terms of the variables of a supersymmetric two-dimensional harmonic oscillator.

Simulation of Novel Tunable Nonlinear Chirped Fiber Bragg Grating

A novel tunable chirped fiber Bragg grating technology is proposed and simulated numerically by Matlab. If we adhere a uniform fiber grating with super magnetostrictive film and expose them in a non-uniform magnetic field, the period of the grating can be changed with the strain imposed on it by the magnetostrictive effect .The chirped characteristics can be tuned by changing the magnetic filed which is very flexible in designing.

Stainless steel anisotropic superhydrophobic surfaces fabrication with inclined cone array via laser ablation and post annealing treatment

Metal superhydrophobic surfaces with anisotropic wettability and adhesion have become more and more important due to their promising applications. Herein, we report a new fabrication strategy through a combination of pulsed laser ablation and low-temperature annealing post-processing. An inclined cone structure array is made on stainless steel surfaces, and then 120 °C low-temperature annealing is applied. Such surface displays excellent mechanical durability and anisotropic superhydrophobicity. It is demonstrated experimentally that the contact angle of water droplets on the surface is different along the parallel(167° ±2°) and perpendicular directions(157° ±2°) of the inclined cone structure. The sliding behaviors of water droplets and mechanical durability of the inclined cone structures are studied. These surfaces obtained in a short time with environmentally friendly fabrication can be applied in industries for water harvesting, droplet manipulation, and pipeline transportation.

Ultrasonic synthesis of Zn-doped CdO nanostructures and their optoelectronic properties

The effect of Zn dopant on the growth of cadmium oxide （CdO） nanostructures through a sonochemical method wasinvestigated. The X-ray diffraction （XRD） patterns of the nanoparticles show CdO cubic structures for the produced samples. Fieldemission scanning electron microscope （FESEM） images reveal that morphologies of the samples change, when they are doped withZn atoms, and their sizes reduce. Room temperature photoluminescence （PL） and UV-Vis spectrometers were used to study opticalproperties of the samples. Evaluation of optical properties indicates that different emission bands result from different transitions andthe value of CdO energy band gap increases due to doping. Studies of electrical properties of the nanostructures demonstrate that Zndopant enhances electrical conductivity and photocurrent generation as the result of light illumination on the nanostructures due toimproved density of photo-generated carriers. Considering the obtained outcomes, Zn dopant can alter the physical property of theCdO nanostructures.

SGC Switching Between Subluminal to Superluminal Propagation in V-Type Atom

For a V-type three-level atomic system with two closely spaced upper levels, we investigate the light pulse propagation properties with only one laser field. Due to spontaneously generated coherence, the group velocity of the light pulse can be changed from subluminal to superluminal. The effects of the field intensity and the two-upper level splitting on the group velocity are also shown. At last, an analytical expression for the group velocity is given in the case of a weak field.

MOSSBAUER SPECTROSCOPY OF HIGH T_c YBa_2 (Cu_(3-x)Fe_x )O_y

YBa2(Cu3-xFex)Oy (x is 0.001, 0.005, 0.01, 0.1 and 0.3 respectively), of whichCu is replaced with 57Fe are studied using M0ssbauer spectroscopy to understand thecrystal lattice property, the effects of the replacement on superconductivity of theHigh To materials.

Statistical Behaviors of Quantum Spectra in Superheavy Nuclei

From the point of view of the interplay between order and chaos, the most regular single-particle motion of neutrons has been found in the superheavy system with and based on the Skyrme–Hartree–Fock model and in the system with and based on the relativistic mean-field model. It has been shown that the statistical analysis of spectra can give valuable information about the stability of suprheavy systems. In addition it may yield deep insight into the single-particle motion in the mean field formed by the superheavy system.

Magnetic and optical properties of zinc chromite nanostructures prepared by microwave method

The nanostructures of zinc chromite（Zn Cr2O4） were fabricated by the microwave method. It was shown that the well-crystallized spinel structure is formed after annealing at 700 °C. The influence of reaction time and irradiation power of oven on the size and shape of the as-prepared Zn Cr2O4 samples was studied. The synthesized samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, energy dispersive X-ray（EDX）, transmission electron microscopy（TEM）, diffuse reflectance spectroscopy（DRS）, photoluminescence（PL） spectroscopy, Fourier transform infrared（FTIR） spectra and vibrating sample magnetometry（VSM）, respectively. The optical band gap calculated using DRS was found to be 3.50 e V for Zn Cr2O4 nanostructures. Photoluminescence measurements also confirmed this result.

Synthesis, Structure and Fluorescent Property of a Cadmium (II) Polymer

A new cadmium(II) coordination polymer with benzenetricarboxylate{Cd2- (Htma)2(H2O)2}}n 1 (Htma = 1-carboxybenzene-2,4-dicarboxylate) has been synthesized by hydro- thermal reaction. 1 crystallizes in triclinic, space group P?with a = 6.9990(8), b = 7.0564(8), c = 10.096(1) ? = 83.438(1), = 86.357(2), = 69.233(2)? V = 463.02(9) 3, Dc = 2.428 g/cm3, F(000) = 328, Mr = 677.08, m(MoKa) = 2.382 mm-1, Z = 1, the final R = 0.0284 and wR = 0.0772 for 1540 observed reflections (I≥2s(I)). The structure of 1 consists of centrosymmetric dinuclear units with all metal centers being six-coordinated, which adopt a distorted octahedral configuration and lead to the formation of three-dimensional microporous framework with size of about 3 ??8 ? Fluoerescent measurement showed that 1 exhibits intense fluorescent emission.

Preliminary Feasibility Study on Application of Very Large Scale-Photovoltaic Power Generation in China

Some energy experts believe that solar energy photovoltaic power generation is hopeful to be applied in a large amount and possesses a certain proportion in the structure of energy in the future. In this paper, based on the forecasting of electric load demand and energy structure of power generation in the middle of 21 century, the pictures of VLS-PV power genera- tion is composed, the operation characteristic of VLS-PV power generation and the adaptability of electric power grid for it is analyzed, the ways for transmitting large amount of PV power and the economic and technical bottlenecks for applying VLS-PV power generation are discussed. Finally, the steps and suggestions for developing VLS-PV power generation and its electric power system in China are proposed.

Superlinear Convergence of a Smooth Approximation Method for Mathematical Programs with Nonlinear Complementarity Constraints

Mathematical programs with complementarity constraints(MPCC) is an important subclass of MPEC.It is a natural way to solve MPCC by constructing a suitable approximation of the primal problem.In this paper,we propose a new smoothing method for MPCC by using the aggregation technique.A new SQP algorithm for solving the MPCC problem is presented.At each iteration,the master direction is computed by solving a quadratic program,and the revised direction for avoiding the Maratos effect is generated by an explicit formula.As the non-degeneracy condition holds and the smoothing parameter tends to zero,the proposed SQP algorithm converges globally to an S-stationary point of the MPEC problem,its convergence rate is superlinear.Some preliminary numerical results are reported.

SUSY QCD Impact on Top-Pair Production Associated with a Z^0-Boson at a Photon-Photon Collider

The top-pair production in association with a Z^0-boson at a photon-photon collider is an important process in probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics. We describe the impact of the complete supersymmetric QCD （SQCD） next-to-leading order （NLO） radiative corrections on this process at a polarized or unpolarized photon collider, and make a comparison between the effects of the SQCD and the standard model （SM） QCD. We investigate the dependence of the lowest-order （LO） and QCD NLO corrected cross sections in both the SM and minimal supersymmetric standard model （MSSM） on colliding energy √s in different polarized photon collision modes. The LO, SM NLO, and SQCD NLO corrected distributions of the invariant mass of tt^--pair and the transverse momenta of final Z^0-boson are presented. Our numerical results show that the pure SQCD effects in γγ →tt^- Z^0 process can be more significant in the ＋＋ polarized photon collision mode than in other collision modes, and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to -1.89% when √s goes up from 500 GeV to 1.5 TeV.

Preparation of Ultrafine SiO2 Powder from Rice Husk and Properties of Its Infrared Spectrum

This paper discussed impact of temperature on the size distribution in preparing ultrafine silica from rice husk.The samples prepared were analyzed with infrared spectrum,and the relation between the particle size and intensity of characteristic absorption peak of IR at center around 1 100 cm-1 was disscussed with the baseline method.Results show that when the temperature is 650 ℃ and roasting time is 11 h,at optimal reaction conditions,the size distribution of the ultrafine silica powder prepared is relatively concentrated,and the average particle size is 199.5 nm.Moreover,the characteristic absorption band of IR is broadening gradually along with particle size decreasing.

Development and Application of Ultrafast Circular Dichroism Spectroscopy Techniques

Chirality hold broad applications in life sciences,quantum devices,and various other areas.Traditionally,molecular chirality can be characterized by using steady-state circular dichroism spectroscopy.However,the techniques that can characterize excited state chirality are progressively capturing the public interest as it can provide the dynamic information for chirality generation and transfer.In this review,we focus on the theoretical background and the developmental history of femtosecond time-resolved circular dichroism spectroscopy(TRCD)techniques around the world.Additionally,we provide examples to showcase the utility of these techniques in the analysis of the dynamical molecular chemical structures,the investigation of molecular chirality generation,and the detection of electron spin dynamics in semiconductor quantum dots.