Research on Modeling of Cutting Parts Based on Solidworks

The article elaborates the significance of the cutting feature in different ways, the shape structure and modeling approach of cutting feature are analyzed through examples. The modeling method is summarized: 1) According to the projection relation, the wire frame is separated. According to the projection of view, the positional relation of each plane is analysed, the corresponding plane of the wireframe is determined the shape of the cut is clarified. This is the key to deciding whether the modeling can be completed successfully. 2) By imagining the shape, the position and order are determined. By line-plane analysis and dimensioning, the cutting position and order of the surface are determined, and the shape and structure after cutting are clarified. This is an important basis for rapid modelling. 3)Thinking overall. Repeatedly compare the shape with the views, and comprehensively check to ensure that the feature position of the shape is clear, the shape is accurate, and the structure is complete.

A Novel Attention-Based Network for Fast Salient Object Detection

In the current salient object detection network, the most popular method is using U-shape structure. However, the massive number of parameters leads to more consumption of computing and storage resources which are not feasible to deploy on the limited memory device. Some others shallow layer network will not maintain the same accuracy compared with U-shape structure and the deep network structure with more parameters will not converge to a global minimum loss with great speed. To overcome all of these disadvantages, we propose a new deep convolution network architecture with three contributions: (1) using smaller convolution neural networks (CNNs) to compress the model in our improved salient object features compression and reinforcement extraction module (ISFCREM) to reduce parameters of the model. (2) introducing channel attention mechanism to weigh different channels for improving the ability of feature representation. (3) applying a new optimizer to accumulate the long-term gradient information during training to adaptively tune the learning rate. The results demonstrate that the proposed method can compress the model to 1/3 of the original size nearly without losing the accuracy and converging faster and more smoothly on six widely used datasets of salient object detection compared with the others models. Our code is published in https://gitee.com/binzhangbinzhangbin/code-a-novel-attention-based-network-for-fast-salientobject-detection.git

Keanekaragaman Dan Dominansi Pohon Penyusun Hutan Lindung Di Pulau Marsegu Kabupaten Seram Bagian Barat

Maluku is known as an archipelago and has high biodiversity. One of the many islands in Maluku that has biological natural resources is Marsegu Island in the West Seram district. Marsegu Island has a very high diversity of marine resources, various types of birds and various vegetation diversity of trees. The diversity of trees in vegetation shows a variety of compositions, both variations in shape, structure or morphology, color, number, and other characteristics of plants in an area. Tree vegetation is the main constituent of forest areas and has an important function in water management, germplasm reserves, life support, development resources and sources of foreign exchange. This study aims to determine the diversity and dominance of protected forest trees on Marsegu Island, West Seram district. The method used in this research is the belt transect method. Furthermore, the tree species were identified based on the identification book. Data were analyzed using the diversity index formula from Shannon-Wienner and Simpson dominance index. The results of research conducted in the eastern and western parts of Marsegu Island found 22 species of trees as the protected forest on Marsegu Island. The Diversity Index at both stations is in the medium category with the results obtained that the east station is 2.2652 while the west station is 2.3761 and is in a stable condition, while the Dominance Index at both stations is low with the results obtained that the eastern station is 0.1618 while the west 0.1135 and no species dominates.

The structure of the Milky Way based on unWISE 3.4 μm integrated photometry

ABSTRACT We present a detailed analysis of the Galaxy structure using an unWISE wide-field image at $3.4\,\mu$m. We perform a 3D photometric decomposition of the Milky Way taking into account (i) the projection of the Galaxy on the celestial sphere and (ii) that the observer is located within the Galaxy at the solar radius. We consider a large set of photometric models starting with a pure disc model and ending with a complex model that consists of thin and thick discs plus a boxy-peanut-shaped bulge. In our final model, we incorporate many observed features of the Milky Way, such as the disc flaring and warping, several overdensities in the plane, and the dust extinction. The model of the bulge with the corresponding X-shape structure is obtained from N-body simulations of a Milky Way-like galaxy. This allows us to retrieve the parameters of the aforementioned stellar components, estimate their contribution to the total Galaxy luminosity, and constrain the position angle of the bar. The mass of the thick disc in our models is estimated to be 0.4–1.3 of that for the thin disc. The results of our decomposition can be directly compared to those obtained for external galaxies via multicomponent photometric decomposition.

On the centennials of the discoveries of the hydrogen bond and the structure of the water molecule: the short life and work of Eustace Jean Cuy (1897–1925)

The bent structure of the water molecule, and its hydrogen-bonding properties, arguably rank among the most impactful discoveries in the history of chemistry. Although the fact that the H—O—H angle must deviate from linearity was inferred early in the 20th century, notably from the existence of the electric dipole moment, it was not clear what that angle should be and why. One hundred years ago, a young PhD student at the University of California, Berkeley, Eustace J. Cuy, rationalized the V-shape structure of a water molecule using the Lewis theory of a chemical bond, i.e. a shared electron pair, and its tetrahedral stereochemistry. He was inspired, in part, by the proposal of a weak (hydrogen) bond in water by two colleagues at Berkeley, Wendell Latimer and Worth Rodebush, who published their classic paper a year earlier. Cuy went on to suggest that other molecules, notably H2S and NH3, have similar structures, and presciently predicted that this architecture has broader consequences for the structure of water as a liquid. This short, but brilliant paper has been completely forgotten, perhaps due to the tragic death of the author at the age of 28; the hydrogen-bond study is also rarely recognized. One of the most impactful publications on the structure of liquid water, a classic treatise published in 1933 by John Bernal and Ralph Fowler, does not mention either of the two pioneering papers. In this essay, the background for the two discoveries is described, including the brief history of Lewis's research on the nature of the chemical bond, and the history of the discovery of the hydrogen bond, which inspired Cuy to look at the structure of the water molecule. This is – to the best of the author's knowledge – the first biographical sketch of Eustace J. Cuy.

Investigation and Computational Modelling of Variable TEG Leg Geometries

In this work, computational modelling and performance assessment of several different types of variable thermoelectric legs have been performed under steady-state conditions and the results reviewed. The study conducted has covered geometries, not previously analysed in the literature, such as Cone-leg and Diamond-leg, based on the corresponding thermoelectric generator leg shape structure. According to the findings, it has been demonstrated that the inclusion of a variable cross-section can have an impact on the efficiency of a thermoelectric generator. It has been concluded that the Diamond configuration generated a slightly larger voltage difference than the conventional Rectangular geometry. In addition, for two cases, Rectangular and Diamond configurations, the voltage generated by a TEG module consisting of 128 pairs of legs was analysed. As thermal stress analysis is an important factor in the selection of TEG leg geometries, it was observed based on simulations that the newly implemented Diamond-leg geometry encountered lower thermal stresses than the traditional Rectangular model, while the Cone-shape may fail structurally before the other TEG models. The proposed methodology, taking into account the results of the simulation carried out, provides guidance for the development of thermoelectric modules with different forms of variable leg geometry.

Research on the Mechanisms of Internal Gear Honing by use of Cone-shape Honing Wheel with Tool Tilt Angle

Ring gear is an important transmission component, but restricted by its ring-shape structure, the tooth surfaces are pretty hard to be finished after heat treatment. Honing is the most commonly used finishing technique for external gear, but for ring gear, it is inconvenient. In this paper, a new type of cone-shape honing wheel is proposed and the honing mechanism is studied for improving the honing performance of ring gear. First of all, the mathematical model of the honing technology by use of cone-shape honing wheel is built, and the merits of the new honing method are discussed. Then, the contact conditions between the honing wheel and the work gear are analyzed, and it is found that the tool tilt angle of the honing wheel has good influences on the honing mark distribution of the work gear. Finally, the honing simulations for ring gear by use of cone-shape honing wheel are carried out, by which the feasibility of the new honing technique are verified.

Structural Analysis and Whole Genome Mapping of a New Type of Plant Virus Subviral RNA: Umbravirus-Like Associated RNAs

We report the biological and structural characterization of umbravirus-like associated RNAs (ulaRNAs), a new category of coat-protein dependent subviral RNA replicons that infect plants. These RNAs encode an RNA-dependent RNA polymerase (RdRp) following a −1 ribosomal frameshift event, are 2.7–4.6 kb in length, and are related to umbraviruses, unlike similar RNA replicons that are related to tombusviruses. Three classes of ulaRNAs are proposed, with citrus yellow vein associated virus (CYVaV) placed in Class 2. With the exception of CYVaV, Class 2 and Class 3 ulaRNAs encode an additional open reading frame (ORF) with movement protein-like motifs made possible by additional sequences just past the RdRp termination codon. The full-length secondary structure of CYVaV was determined using Selective 2’ Hydroxyl Acylation analyzed by Primer Extension (SHAPE) structure probing and phylogenic comparisons, which was used as a template for determining the putative structures of the other Class 2 ulaRNAs, revealing a number of distinctive structural features. The ribosome recoding sites of nearly all ulaRNAs, which differ significantly from those of umbraviruses, may exist in two conformations and are highly efficient. The 3′ regions of Class 2 and Class 3 ulaRNAs have structural elements similar to those of nearly all umbraviruses, and all Class 2 ulaRNAs have a unique, conserved 3′ cap-independent translation enhancer. CYVaV replicates independently in protoplasts, demonstrating that the reported sequence is full-length. Additionally, CYVaV contains a sequence in its 3′ UTR that confers protection to nonsense mediated decay (NMD), thus likely obviating the need for umbravirus ORF3, a known suppressor of NMD. This initial characterization lays down a road map for future investigations into these novel virus-like RNAs.