Practical Picture Processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051700 ◽

1974 ◽

Vol 32 ◽

pp. 338-339

Author(s):

T. A. Welton

Keyword(s):

Radiation Damage ◽

Coherence Length ◽

Spatial Information ◽

State Of The Art ◽

Coherent Radiation ◽

The State ◽

Energy Spread ◽

Electron Micrograph ◽

Picture Processing ◽

Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

Download Full-text

High- T c superconductors tailored on the nanometre-scale

Philosophical Transactions of the Royal Society of London Series A Physical and Engineering Sciences ◽

10.1098/rsta.1995.0107 ◽

1995 ◽

Vol 353 (1703) ◽

pp. 377-385 ◽

Cited By ~ 1

Keyword(s):

Josephson Junction ◽

Coherence Length ◽

State Of The Art ◽

The State ◽

Special Focus ◽

Length Scale ◽

Considerable Effort ◽

New Concepts

High- T c superconductors are characterized by an unusually small coherence length, which amounts to a few angstroms only. As the coherence length is the length scale in which a superconductor has to be structured to achieve Josephson junction behaviour, considerable effort has been devoted by many groups to modify high- T c films in the nanometre scale. Because the high- T c cuprates do not lend themselves for nanostructuring, new concepts have to be developed to achieve this goal. These developments will be discussed and an overview of the state of the art of the field will be presented with a special focus on the ultimate limitations of nanoscale structuring of superconductors.

Download Full-text

A 150 kV High-Coherence Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052079 ◽

1974 ◽

Vol 32 ◽

pp. 412-413

Author(s):

R. E. Worsham ◽

W. W. Harris ◽

J. E. Mann ◽

E. G. Richardson ◽

N. F. Ziegler

Keyword(s):

Coherence Length ◽

Spatial Information ◽

Spherical Aberration ◽

Wiener Filter ◽

Energy Spread ◽

Filter Function ◽

Resolution Level ◽

High Coherence ◽

Illuminating Beam ◽

Transmission Microscope

Welton has shown that if the illuminating beam in a conventional transmission microscope column has a transverse coherence length of 5°0 Å, or greater, and an energy spread ≤0.2 eV(rms), spatial information at the 0.5 Å resolution level would be attenuated by a factor of 2 and 1 Å information essentially unimpaired. The untreated micrographs, which would show a complex set of fringes with detail down to about 2.5 Å as set by spherical aberration, would require the application of a Wiener filter function to bring out the existing finer details. This microscope was designed to produce the high coherence required, to permit this method of correction for the spherical aberration, and to be limited in no other way in resolution down to <1Å.

Download Full-text

A synchrotron-based kilowatt-level radiation source for EUV lithography

10.21203/rs.3.rs-1001917/v1 ◽

2021 ◽

Author(s):

Bocheng Jiang ◽

Chao Feng ◽

Changliang Li ◽

Zhenghe Bai ◽

Weishi Wan ◽

...

Keyword(s):

Radiation Source ◽

Electron Bunch ◽

State Of The Art ◽

Average Power ◽

Coherent Radiation ◽

The State ◽

Angular Dispersion ◽

Laser Technologies ◽

Euv Lithography

Abstract A compact damping ring with limited circumference of about 160 m is proposed for producing kilowatt-level coherent EUV radiation. The electron bunch in the ring is modulated by a 257nm wavelength laser with the help of the angular dispersion induced micro-bunching method [C. Feng and Z. Zhao, Sci. Rep. 7, 4724 (2017)]. Coherent radiation at 13.5 nm with an average power of about 2.5 kW can be achieved with the state-of-the-art accelerator and laser technologies.

Download Full-text

Classification of Hyperspectral Image Based on Double-Branch Dual-Attention Mechanism Network

10.20944/preprints201912.0059.v1 ◽

2019 ◽

Author(s):

Li Rui ◽

Zheng Shunyi ◽

Duan Chenxi ◽

Yang Yang ◽

Wang Xiqi

Keyword(s):

Spatial Information ◽

Hyperspectral Image ◽

State Of The Art ◽

Empirical Studies ◽

The State ◽

Attention Mechanism ◽

Spatial Features ◽

Better Than

In recent years, more and more researchers have gradually paid attention to Hyperspectral Image (HSI) classification. It is significant to implement researches on how to use HSI's sufficient spectral and spatial information to its fullest potential. To capture spectral and spatial features, we propose a Double-Branch Dual-Attention mechanism network (DBDA) for HSI classification in this paper, Two branches aer designed to extract spectral and spatial features separately to reduce the interferences between these two kinds of features. What is more, because distinguishing characteristics exist in the two branches, two types of attention mechanisms are applied in two branches above separately, ensuring to exploit spectral and spatial features more discriminatively. Finally, the extracted features are fused for classification. A series of empirical studies have been conducted on four hyperspectral datasets, and the results show that the proposed method performs better than the state-of-the-art method.

Download Full-text

Gated Autoencoder Network for Spectral–Spatial Hyperspectral Unmixing

Remote Sensing ◽

10.3390/rs13163147 ◽

2021 ◽

Vol 13 (16) ◽

pp. 3147

Author(s):

Ziqiang Hua ◽

Xiaorun Li ◽

Jianfeng Jiang ◽

Liaoying Zhao

Keyword(s):

Real World ◽

Spatial Information ◽

State Of The Art ◽

The State ◽

Spectral Unmixing ◽

Experimental Results ◽

Spectral Information ◽

Hyperspectral Unmixing ◽

Spatial Features ◽

Gating Mechanism

Convolution-based autoencoder networks have yielded promising performances in exploiting spatial–contextual signatures for spectral unmixing. However, the extracted spectral and spatial features of some networks are aggregated, which makes it difficult to balance their effects on unmixing results. In this paper, we propose two gated autoencoder networks with the intention of adaptively controlling the contribution of spectral and spatial features in unmixing process. Gating mechanism is adopted in the networks to filter and regularize spatial features to construct an unmixing algorithm based on spectral information and supplemented by spatial information. In addition, abundance sparsity regularization and gating regularization are introduced to ensure the appropriate implementation. Experimental results validate the superiority of the proposed method to the state-of-the-art techniques in both synthetic and real-world scenes. This study confirms the effectiveness of gating mechanism in improving the accuracy and efficiency of utilizing spatial signatures for spectral unmixing.

Download Full-text