Effect of Injection Phenomena on Electrical Properties of pSi--nSi1--xSnx Heterojunctions

We studied the current-voltage characteristic of pSi--nSi1--xSnx structures in the temperature range of 293--393 K so as to find out the role of injection phenomena during electrical property formation in pSi--nSi1--xSnх heterojunctions derived from the Si1--xSnx (0 ≤ x ≤ 0.04) solid solution. We established that the current-voltage characteristic of such heterojunctions consists of two typical segments. We determined that an exponential function describes the first current-voltage characteristic segment well. In all current-voltage characteristics the exponential curve is followed by sublinear segments that do not depend on temperature. We show that the theory of injection depletion effect describes these segments well. We used the sublinear segment of the current-voltage characteristic to determine the value of the parameter a, which can be employed to calculate deep level impurity concentration leading to the appearance of the sublinear segment. We prove that the structure under investigation may be considered to be a pSi--nSi1--xSnx--n+Si1--xSnx (0 ≤ x ≤ 0.04) junction with a high-resistance nSi1--xSnx layer. The analysis results make it possible to conclude that charge carrier dissipation on both complex aggregates and nanoinclusions plays a significant role in forming electrophysical properties in the Si1--xSnx (0 ≤ x ≤ 0.04) solid solution and that epitaxial films of Si1--xSnx (0 ≤ x ≤ 0.04) solid solutions derived on silicon substrates are efficient promising materials for developing diodes operating under double injection

Elimination of End effects in LMD Based on LSTM Network and Applications for Rolling Bearing Fault Feature Extraction

Local mean decomposition (LMD) is widely used in the area of multicomponents signal processing and fault diagnosis. One of the major problems is end effects, which distort the decomposed waveform at each end of the analyzed signal and influence feature frequency. In order to solve this problem, this paper proposes a novel self-adaptive waveform point extended method based on long short-term memory (LSTM) network. First, based on existing signal points, the LSTM network parameters of right and left ends are trained; then, these parameters are used to extend the waveform point at each end-side of signal; furthermore, the corresponding parameters are adaptively updated. The proposed method is compared with the characteristic segment extension and the traditional neural network extension methods through a simulated signal to verify the effectiveness. By combing the proposed method with LMD, an improved LMD algorithm is obtained. Finally, application of rolling bearing fault signal is carried out by the improved LMD algorithm, and the results show that the feature frequencies of the rolling bearing’s ball and inner and outer rings are successfully extracted.

Sequence of pNL194, a 79.3-Kilobase IncN Plasmid Carrying the blaVIM-1 Metallo-β-Lactamase Gene in Klebsiella pneumoniae

ABSTRACT The nucleotide sequence of pNL194, a VIM-1-encoding plasmid, is described in this study. pNL194 (79,307 bp) comprised an IncN-characteristic segment (38,940 bp) and a mosaic structure (40,367 bp) including bla VIM-1, aacA7, aadA1, aadA2, dfrA1, dfrA12, aphA1, strA, strB, and sul1. Tn1000 or Tn5501 insertion within fipA probably facilitated recruitment of additional mobile elements carrying resistance genes.

A common precursor for glia and neurons in the embryonic CNS of Drosophila gives rise to segment-specific lineage variants

The nervous system consists of two classes of cells, neurons and glia, which differ in morphology and function. They derive from precursors located in the neurogenic region of the ectoderm. In this study, we present the complete embryonic lineage of a neuroectodermal precursor in Drosophila that gives rise to neurons as well as glia in the abdominal CNS. This lineage is conserved among different Drosophila species. We show that neuronal and glial cell types in this clone derive from one segregating precursor, previously described as NB1-1. Thus, in addition to neuroblasts and glioblasts, there exists a third class of CNS precursors in Drosophila, which we call neuroglioblasts. We further show that the NB 1–1 lineage exhibits characteristic segment-specific differences on the cellular level.

Analysis of the gooseberry locus in Drosophila embryos: gooseberry determines the cuticular pattern and activates gooseberry neuro

The segment-polarity class of segmentation genes in Drosophila are primarily involved in the specification of sub-segmental units. In addition, some of the segment-polarity genes have been shown to specify cell fates within the central nervous system. One of these loci, gooseberry, consists of two divergently transcribed genes, gooseberry and gooseberry neuro, which share a paired box as well as a paired-type homebox. Here, the expression patterns of the two gooseberry gene products are described in detail. The gooseberry protein appears in a characteristic segment-polarity pattern of stripes at gastrulation and persists until head involution. It is initially restricted to the ectodermal and neuroectodermal germ layer, but is later detected in mesodermal and neuronal cells as well. The gooseberry neuro protein first appears during germ band extension in cells of the central nervous system and also, much later, in epidermal stripes and in a small number of muscle cells. P-element-mediated transformation with the gooseberry gene has been used to demonstrate that gooseberry transactivates gooseberry neuro and is sufficient to rescue the gooseberry cuticular phenotype in the absence of gooseberry neuro.

On the theory of polymer crystallization

The systematic pleating of polymer molecules in their crystallization, in segments of a length of the order of 100 A, which depends on the crystallization temperature, is interpreted in terms of the kinetics of crystal growth. The theory begins with but departs from a theory proposed by Lauritzen & Hoffman, in which the statistical probability of a bend occurring somewhere gives a factor disfavouring long segments, and the probability of a deposited chain coming off again gives a factor disfavouring short segments, the two defining an optimum segment length. A basic analysis of ‘nucleation theory’ is included in this paper (and in an appendix) to clarify the points of departure. Whereas the Lauritzen-Hoffman theory postulates that successive fold segments are of the same length as the first on a crystal face, this paper shows that there must be considerable fluctuation in length from segment to segment. An approximate calculation of these fluctuations indicates that (within a specific range of supercoolings) there is a characteristic segment length l * such that after shorter segments than l * the next fluctuation is more likely to be to a longer one, and after longer segments than l * the next fluctuation is likely to be to a shorter one: so that l * defines a stable mean strip - width into which the chain molecule folds. The next strip of crystal deposited on this one has a narrow er corresponding stable width. With successive strips depositing on each other, within a certain specific range of supercooling, the strip widths converge to a stable value l **, which depends on temperature in the observed manner. For smaller supercoolings the strip width converges to a value too narrow for any further growth to occur. At larger supercoolings multiple nucleation of crystals within the same molecular chain is considered to change the mode of crystallization— dendrites rather than tabular crystals are in fact observed at these lower temperatures. Though the theory is approximate, acceptable parameters give satisfactory agreement with observation.