bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperbranched polymer for light‐emitting applications
Authors: Wang Haiqiao , Qiu Teng , Song Na , Li Xiaoyu 
Published: June 2010

AbstractA light‐emitting partially conjugated hyperbranched polymer (2,5‐dimethoxy‐substituted hyperbranched poly(p‐phenylene vinylene), MOHPV) based on rigid fluorescent conjugated segments, 2,5‐dimethoxy‐substituted distyrylbenzene (a derivative of oligo‐poly(p‐phenylene vinylene)), and flexible non‐conjugated spacers, trioxymethylpropane, was synthesized via an A2 + B3 approach. The weight‐average molecular weight was 2.48 × 104 g mol−1. The introduction of two methoxy groups into central rings of the oligo‐poly(p‐phenylene vinylene) imparted to MOHPV better solubility in common organic solvents and processability than its analogues reported in our previous work, especially the fully conjugated hyperbranched polymers. The effect of the molar ratio of monomer A2 to monomer B3 on the molecular weight and molecular weight distribution was investigated. A single‐layer light‐emitting diode was fabricated employing MOHPV as an emitter. A double‐layer light‐emitting diode was also fabricated by doping an electron transport material, 2‐(4‐biphenylyl)‐5‐phenyl‐1,3,4‐oxadiazole, into the emitting layer and inserting a thin layer of tri(8‐hydroxyquinoline)aluminium as electron‐transporting/hole‐blocking layer. A maximum luminance of 1500 cd m−2 at 12 V and a maximum electroluminescence efficiency of 1.38 cd A−1 at 14 mA cm−3, which are approximately 43.5 and 12.9 times greater, respectively, than those of the single‐layer device, were achieved. The synthetic simplicity, excellent solubility and solution processability, and less of a propensity to aggregation make MOHPV a novel type of emitter for polymer light‐emitting displays. Copyright © 2010 Society of Chemical Industry
The Botrytis cinerea early secretome
Authors: Espino José J. , Gutiérrez‐Sánchez Gerardo , Brito Nélida , Shah Punit , Orlando Ron , González Celedonio 
Published: June 2010

AbstractThe extracellular proteome, or secretome, of phytopathogenic fungi is presumed to be a key element of their infection strategy. Especially interesting constituents of this set are those proteins secreted at the beginning of the infection, during the germination of conidia on the plant surfaces or wounds, since they may play essential roles in the establishment of a successful infection. We have germinated Botrytis cinerea conidia in conditions that resemble the plant environment, a synthetic medium enriched with low molecular weight plant compounds, and we have collected the proteins secreted during the first 16 h by a double precipitation protocol. 2‐D electrophoresis of the precipitated secretome showed a spot pattern similar for all conditions evaluated and for the control medium without plant extract. The proteins in 16 of these spots were identified by PMF and corresponded to 11 different polypeptides. Alternative determination of secretome composition by LC‐MS/MS of tryptic fragments rendered a much larger number, 105 proteins, which included all previously identified by PMF. All proteins were functionally classified according to their putative function in the infection process. Key features of the early secretome include a large number of proteases, the abundance of proteins involved in the degradation of plant defensive barriers, and plenty of proteins with unknown function.
Enhancement through sensitization of VUV‐excited luminescence in red‐emitting pentaborate phosphors
Authors: Mikhailik V. B. , Kraus H. 
Published: June 2010

AbstractWe studied the feasibility of using sensitization for the improvement of the VUV‐to‐visible conversion efficiency of red‐emitting pentaborate phosphor. It is shown that Tb3+ ions that exhibit a strong absorption throughout the 160–230 nm wavelength range facilitate enhancement of Eu3+ emission in TbMgB5O10–Eu at excitation in this spectral range. The maximum increase of the Eu3+ emission efficiency in a pentaborate host at excitation with 150 nm photons is ca.10%. It is also shown that substitution of Zn for Mg in Gd(Mg,Zn)B5O10–Mn phosphor results in strong (up to 2.4 times) enhancement of the intensity of Mn2+ emission. A possible reason for the observed host sensitization effect is discussed.
Some observations of the optical properties of clouds. I: Stratocumulus
Authors: Foot J. S. 
Published: June 2010

AbstractAircraft measurements of broad‐band solar irradiances together with radiance measurements in the 1‐2 to 2‐1 μm region are presented for a stratocumulus sheet. Measurements of the solar albedo and cloud physics parameters indicate that the cloud was very uniform and optically thick. Broad‐band observations of albedo agreed well with calculations but observed absorption was about double the model values. Narrow‐band observations of vertical reflectance at three wavelengths suggested a marked increase in effective cloud droplet radius along the cloud, which was not observed. Some evidence that the discrepancy might be due to cloud top unevenness is presented.
A simple model for surface stress and low‐level flow in the tropical atmosphere driven by prescribed heating
Authors: Neelin J. David 
Published: June 2010

AbstractA simple model is developed for time‐mean, large‐scale flow in the tropical boundary layer forced by vertical velocity at the top of the boundary layer. The model is formulated as an integral over the boundary layer and is closed by assuming the stress to be proportional to the boundary layer mass transport. Since vertical velocity is closely related to diabatic heating in the tropics, the model can also be forced by latent heating as measured by precipitation. In this case, the model can be made equivalent to the widely used Matsuno–Gill model by adding a Newtonian cooling term. This term can be shown to have little effect on the zonally asymmetric component of the flow and, in its absence, the boundary layer flow is decoupled from the flow at upper levels. It is suggested that the success of the Gill model for low‐level flow is due to this effective decoupling. The model is quite successful at simulating GCM results for both the total climatology and El NiTo anomalies. A second model, which takes into account some effects of vertical structure in the boundary layer, is also presented. The zonally symmetric component of the flow is shown to be poorly reproduced in these models.
Retrieval of energy spectra from measured data for assimilation into a wave model
Authors: Thomas J. P. 
Published: June 2010

AbstractSome results are presented from experiments on modifying modelled wave energy spectra, using reported integrated wave and wind data from three North Sea stations over a six‐month winter period. The resulting spectra are verified against measured spectra from the same stations. Significant improvements are seen in individual cases and in statistical comparisons of spectral parameters over the whole period. Future developments and the problems to be overcome in implementing an operational wave model data assimilation system are discussed.
A comparative study of atmospheric and laboratory‐analogue numerical tornado‐vortex models
Authors: Howells Peter A. C. , Rotunno Richard , Smith Roger K. 
Published: June 2010

AbstractA detailed sensitivity study of a tornado‐vortex model developed by Howells and Smith is presented in order to draw a comparison between the results of various axisymmetric models that purport to simulate laboratory and tornadic vortices. The model incorporates a stretched finite‐difference mesh in both radial and vertical directions and this provides for an increase in resolution in the vicinity of the vortex core and lower‐boundary layer. The development of the vortex is studied for different values of two key parameters. These are the ratio of the applied tangential velocity to the mean vertical velocity (the swirl ratio) and the Reynolds' number based on the eddy diffusivity coefficient, the mean radial velocity, and the radius of the domain. Most of the simulations are for a no‐slip lower boundary, but a few free‐slip experiments are presented for comparison. These serve to highlight the importance of the radial inflow jet for the no‐slip case.Emphasis is placed in the no‐slip experiment on the relative importance of the primary meridional circulation associated directly with the applied forcing, and the secondary circulation induced by the lower‐boundary layer. For weak applied swirl (tangential) velocity (1ms−1), the secondary circulation is relatively weak and the maximum tangential velocity is associated with the convergence produced by the primary circulation. Accordingly, this maximum occurs at a substantial height above the lower boundary. For moderate applied swirl velocity (4ms−1), the secondary circulation is manifest as a strong radial inflow jet near the lower boundary. This jet advects rotating air close to the axis. The flow that evolves is dependent on the magnitude of the eddy turbulent diffusivity coefficient. For a relatively low diffusivity coefficient (10m2s−1), a large amplitude centrifugal wave forms and breaks violently near the corner region. At higher values (20m2s−1), a quasi‐steady toroidal vortex develops in the region where the stream surfaces expand, and the maximum swirl velocity is found to occur at low levels near the corner region. This breakdown feature is advected out of the domain when the diffusivity coefficient is increased to 30m2s−1. When the simulations are performed using high imposed swirl velocities (10ms−1), a very intense vortex forms with maximum tangential velocity exceeding 55ms−1, despite the frictional losses near the ground. This is considerably stronger than the equivalent free‐slip vortex which attains a maximum tangential velocity of 44ms−1. Although many of these results have been obtained in past numerical studies, a clear demonstration of the importance of the secondary circulation as compared with the primary circulation has not been forthcoming due to a wide variety of experimental configurations and external parameters.
A line‐by‐line investigation of solar radiative effects in vertically inhomogeneous low clouds
Authors: Ramaswamy V. , Li J. 
Published: June 2010

AbstractUsing a detailed line‐by‐line, multiple‐scattering solar radiative‐transfer model, the influences due to cloud internal inhomogeneity in the vertical upon the solar radiative transfer are investigated. In particular, the consequences due to non‐uniform vertical profiles of liquid water and droplet sizes within low clouds are explored in a systematic manner. The fine structure of the spectral overlap between the water droplet and water vapour optical properties, and its effects upon the radiation absorbed within the cloud layer and that reflected at the top of the cloud, are discussed. Without consideration of the in‐cloud water vapour, a vertically inhomogeneous cloud with properties resembling those observed absorbs more solar radiation than an equivalent homogeneous cloud. However, consideration of the effects of the in‐cloud vapour, while still leading to a slightly greater absorption for the inhomogeneous case, partly offsets the difference introduced by the vertical distribution of the drop microphysics. The vertical distribution of cloud heating rate is changed substantially because of the inhomogeneity in the microphysics, with the heating rate in the top region of the cloud nearly 50% more than that due to an equivalent vertically homogeneous cloud. Vertical inhomogeneity of cloud microphysics has little influence on the broadband solar albedo, but can cause significant decreases of the cloud reflectance at specific near‐infrared wavelengths i.e. wavelengths greater than 1 μm, (equivalently, wave numbers less than 10000 cm−1).
Adjoint sensitivity of an idealized extratropical cyclone with moist physical processes
Authors: Langland Rolf H. , Elsberry Russell L. , Errico Ronald M. 
Published: June 2010

AbstractAn adjoint model (MAMS1) that includes parametrizations for convective (subgrid‐scale), and non‐convective (grid‐scale) precipitation, and surface latent‐heat flux is used to investigate an idealized extratropical cyclogenesis. The adjoint sensitivity information demonstrates the effects that perturbations of model variables and parameters at various times during the cyclone life cycle have on forecast cyclone intensity. For a nonlinear trajectory that includes precipitation processes and surface latent‐heat flux, the accuracy of the tangent‐linear and adjoint model is much higher when moist physical processes are included. Inclusion of moist processes in the adjoint model increases sensitivity magnitude compared with sensitivity obtained with a dry adjoint model, but does not alter the primary spatial pattern of sensitivity.The larger cyclone deepening rates that occur with the inclusion of moisture are related to latent‐heat release from condensation of water vapour in areas of the middle and lower troposphere (the warm‐front region) that are strongly sensitive to temperature perturbations in both dry and moist cyclone simulations. The effects of diabatic heating on cyclone development are interpreted as a reinforcement of dry baroclinic instability, and not a separate development mechanism (which would have a unique non‐baroclinic sensitivity signature). The sensitivity patterns explain why favourably positioned latent‐heat release is an ingredient that can lead to explosive baroclinic development. Cyclone intensity is very sensitive to the vertical distribution of temperature perturbations, so this feature of diabatic heating is critical to the cyclone forecast.An increase in the transfer coefficient, CE, for the surface latent‐heat flux can intensify the cyclone by adding moisture to the lower troposphere in the cyclone warm sector before the release of latent heat by precipitation processes. Perturbations of CE have more effect on cyclone intensity than perturbations of the transfer coefficients involved in surface sensible‐heat flux and surface stress during most of the cyclone life cycle.
Resolution of compositional backscattered electron profiles of single interfaces in the scanning electron microscope
Authors: Konkol A. 
Published: June 2010

AbstractA new method is proposed for the calculation of the lateral resolution of the compositional backscattered electron (BSE) profiles of bulk cross sections of single interfaces in the scanning electron microscope (SEM). The method is based on Niedrig's combined analytical model for electron backscattering and Doig and Flewitt's empirical expression for beam broadening. Experimentally determined lateral resolution values measured on BSE profiles of abrupt interfaces using three different SEMs are very closely reproduced by the calculated values. Based on this new method, the optimum SEM parameters can be determined to enable the measurement of the best resolution BSE profiles with low noise, so that the earlier proposed deconvolution method (Konkol et al. 1994) could be used at optimum conditions.
Real color cathodoluminescence scanning electron microscopy—A new effective method for study of SiC materials and devices
Authors: Saparin G. V. , Mokhov E. N. , Obyden S. K. , Roenkov A. D. 
Published: June 2010

AbstractColor cathodoluminescence scanning electron microscopy (CCL‐SEM) studies prove the correctness of available information concerning space distribution of luminescence centers in SiC layers. Established facts may be applied for investigation of the polytypism, space distribution of impurities, and native defects induced during growth by high‐energy particles radiation or by diffusion, as well as by the mechanisms of crystal formation. This paper presents a short survey of diagnostic availability of the CCL‐SEM technique for inspection of the SiC materials and devices.
Practical method for noise removal in scanning electron microscopy
Authors: Oho Eisaku , Ichise Norihiko , Martin William H. , Peters Klaus‐Ruediger 
Published: June 2010

AbstractA new smoothing filter has been developed for noise removal of scanning electron microscopy (SEM) images. We call this the complex hysteresis smoothing (CHS) filter. It is much easier to use for SEM operators than any other conventional smoothing filter, and it rarely produces processing artifacts because it does not utilize a definite mask (which usually has processing parameters of size, shape, weight, and the number of iterations) like a common averaging filter or a complicated filter shape in the Fourier domain. Its criterion for distinguishing noise depends simply on the amplitude of the SEM signal. When applied to several images with different characteristics, it is shown that the present method has a high performance with some original advantages.
Color cathodoluminescence‐scanning electron microscopy study of the 4H‐SiC heteroepitaxial layers grown by sublimation “sandwich method”
Authors: Mokhov E. N. , Roenkov A. D. , Saparin G. V. , Obyden S. K. 
Published: June 2010

AbstractThe color cathodoluminescence scanning electron microscopy (CCL‐SEM) technique was used for the study of the 4H‐SiC epitaxial layers grown by sublimation “sandwich method” on the 6H‐ or 21R substrates. Elements of the BIY group were introduced for polytype transformations. The method makes it possible to control the polytype in thin layers (0.1–2 μam). The effect of supersaturation and the growth rate on 4H polytype formation have been studied. It was shown that the probability of polytype transformation depends on the configuration of the substrate surface. At low supersaturation, 4H polytype nuclei arise predominantly on projected areas of the (0001)C substrate surface, which had no growth centers such as screw dislocations.
Proper acquisition and handling of scanning electron microscopy images using a high‐performance personal computer
Authors: Oho Eisaku , Ichise Norihiko , Ogashiwa Takeshi 
Published: June 2010

AbstractThe modern high‐performance personal computer (PC) has very recently expanded the range of utilization of digital scanning electron microscopy (SEM) images, and the PC will be used increasingly with SEMs. However, the image quality of digital SEM images may be considerably influenced by scanning and digitization conditions. In particular, the effects of the aliasing error peculiar to digital data are often serious in the low‐magnification acquisition (undersampling) of SEM images, and moreover even a high‐magnification image (oversampling) is disturbed by the undersampled noise (a sort of aliasing error). Furthermore, the signal‐to‐noise ratio of a digitized SEM image is closely related to the performance of the analog‐to‐digital converter. To prevent a flood of low‐quality digital images with artifacts by the aliasing and additional noise, we propose a method using very high‐density sampling (scanning). In addition, we will discuss how to handle digital SEM images from the point of view of the sampling and quantization.
Scanning electron microscope design for quantitative multicontrast
Authors: Khursheed A. 
Published: June 2010

AbstractConceptual designs of scanning electron microscopes (SEMs) using a time‐of‐flight electron spectrometer are presented. The procedure for making quantitative measurements with such SEMs is shown to be much simpler and versatile than using conventional SEMs. SEMs which use an electron time‐of‐flight spectrometer are able to operate as multicontrast analytical probes, capable of simultaneously quantifying surface topography, voltage, and material type. In addition, it is demonstrated that these SEMs can be designed to have high spatial resolution, good signal‐to‐noise characteristics, and to be of compact table‐top size.
Transmission and double reflection imaging applications with the confocal scanning laser transmission microscope
Authors: Damaskinos S. , Dixon A. E. , Uesaka T. 
Published: June 2010

AbstractThe confocal scanning laser transmission and double‐reflection microscope (CSLTM) has been used in two completely different applications to illustrate some of its unique capabilities. In the first application, the CSLTM was used in reflection and transmission modes to image neurons in a Golgi‐stained specimen. Images that show the advantages of having both modes of operation on the same microscope are presented and discussed. In the second application, the microscope was used in fluorescence to image fibers in paper. The unique property of the CSLTM that enables imaging both the top and the bottom of a specimen was used to image fluorescence emissions from both sides of a sheet of paper, effectively doubling the depth inside the specimen at which one can produce high contrast images.
An all‐digital method for accurate measurements of mechanical deformations
Authors: Amar Najet Ben , Beghdadi Azeddine , De Lesegno Patrick Viaris 
Published: June 2010

AbstractIn this paper, an experimental analysis method based on image treatment techniques for the quantitative evaluation of some polycrystal material deformations is presented. This method has been successfully developed for this purpose by adapting and developing algorithms suitable for the images under study. Details of the whole process as applied to a typical example are described and discussed.
Effects of tip‐sample forces and humidity on the imaging of DNA with a scanning force microscope
Authors: Yang Gouliang , Vesenka James P. , Bustamante Carlos J. 
Published: June 2010

AbstractWe have investigated the effects of tip‐sample forces and relative humidity when using a scanning force microscope (SFM) to image DNA molecules adsorbed on fresh mica. As the force between the tip and the sample increases, the apparent height of the DNA molecules decreases. After being imaged with high forces, the DNA molecules recover partially in their apparent height, indicating that a plastic deformation of the DNA has been induced by the scanning tip. At low humidities, DNA molecules can be imaged with a force up to 150 nN during the scanning without obvious damages. At higher humidities, however, the DNA molecules can be dissected or swept away by the tip even at a tip‐sample force of 30 nN. The net force between the tip and the molecules is the vector sum of several forces, the dominant components of which are the elastic force due to the cantilever bending and the capillary force resulting from the water meniscus formed between the tip and the sample surface. When the relative humidity of the imaging environment is increased, the capillary force becomes stronger.
Some limitations of surface profile reconstruction in scanning electron microscopy
Authors: Czepkowshi T. , Słówko W. 
Published: June 2010

AbstractThis paper is a contribution to development of electron beam profilography based on the so called “shape from shading” technique. A new formula of signal processing in a two detector system has been proposed. The formula en be applied to all the signals showing Lambert's angular distribution. The signal processing may be realized in “real time” in a simple analog processing system. However, an accuracy of the profiles is limited by numerous errors, mainly by shadowing effects. As the shadowing causes disturbances of the signal flow, a proper design of the detection system is necessary to reduce the errors.
An on‐pole‐piece‐tip deflector for high‐resolution, low‐voltage scanning electron microscopes
Authors: Zhao Yan , Khursheed Aniam 
Published: June 2010

AbstractA proposal to enlarge the field of view of low‐voltage, high‐resolution scanning electron microscopes is presented in this paper. The proposal is based upon mounting primary beam deflectors onto the pole tip of the objective lens. Simulation results show that this compact arrangement of beam deflection should widen the present attainable field of view at probe resolutions < 5 nm by over an order of magnitude.