Feature-Based Fusion of Dual Band Infrared Image Using Multiple Pulse Coupled Neural Network

To improve the quality of the infrared image and enhance the information of the object,a dual band infrared image fusion method based on feature extraction and a novel multiple pulse coupled neural network(multi-PCNN)is proposed.In this multi-PCNN fusion scheme,the auxiliary PCNN which captures the characteristics of feature image extracting from the infrared image is used to modulate the main PCNN,whose input could be original infrared image.Meanwhile,to make the PCNN fusion effect consistent with the human vision system,Laplacian energy is adopted to obtain the value of adaptive linking strength in PCNN.After that,the original dual band infrared images are reconstructed by using a weight fusion rule with the fire mapping images generated by the main PCNNs to obtain the fused image.Compared to wavelet transforms,Laplacian pyramids and traditional multi-PCNNs,fusion images based on our method have more information,rich details and clear edges.

碳含量对高硅高铝钢组织及石墨粒子析出行为的影响

石墨易切削钢因具有低成本、环保及优良可切削性等优点,近年来引起了国内外冶金和材料学者的广泛关注。本工作采用金相显微镜、扫描电镜和能谱分析仪等方法,系统研究了两种碳含量(0.20wt%和0.52wt%)对1.9wt%Si-1.1wt%Al高硅高铝钢热轧-淬火-回火过程组织变化及回火后石墨粒子析出行为的影响。结果表明,0.20wt%C的实验钢热轧→920℃淬火→回火后的组织演变为铁素体+珠光体→铁素体+“小岛”状贝氏体→铁素体+石墨粒子+少量渗碳体,而0.52wt%C的实验钢热轧→920℃淬火→回火后的组织演变为铁素体+珠光体→马氏体→铁素体+石墨粒子+少量渗碳体。在相同回火温度下,相比0.20wt%C的实验钢,0.52wt%C的实验钢中石墨粒子的数量更多、尺寸更大且更多以晶界形核方式析出。当回火温度从680℃提高至710℃,0.20wt%C的实验钢晶界上析出的石墨粒子密度从2337个/mm^(2)降至1710个/mm^(2),其平均尺寸从1.50 2μm增大至2.27μm;0.52wt%C的实验钢晶界上析出的石墨粒子密度从5244个/mm^(2)降至1938个/mm,其平均尺寸从2.36μm增大至3.45μm。钢中碳含量从0.20wt%增加至0.52wt%,可有效促进实验钢回火过程石墨粒子的形核和长大。相比710℃回火,680℃回火后的实验钢中石墨粒子数量更多且分布更为均匀,更有利于其整体切削性能的提高。

Dynamics of thinning and destruction of the continental cratonic lithosphere: Numerical modeling

Thinning of the cratonic lithosphere is common in nature, but its destruction is not. In either case, the mechanisms for both thinning and destruction are still widely under debate. In this study, we have made a review on the processes and mechanisms of thinning and destruction of cratonic lithosphere according to previous studies of geological/geophysical observations and numerical simulations, with specific application to the North China Craton(NCC). Two main models are suggested for the thinning and destruction of the NCC, both of which are related to subduction of the oceanic lithosphere. One is the "bottom-up" model, in which the deeply subducting slab perturbs and induces upwelling from the hydrous mantle transition zone(MTZ). The upwelling produces mantle convection and erodes the bottom of the overriding lithosphere by the fluid-meltperidotite reaction. Mineral compositions and rheological properties of the overriding lithospheric mantle are changed, allowing downward dripping of lithospheric components into the asthenosphere. Consequently, lithospheric thinning or even destruction occurs. The other is the "top-down" model, characterized by the flat subduction of oceanic slab beneath the overriding cratonic lithosphere. Dehydration reactions from the subducting slab would significantly hydrate the lithospheric mantle and decrease its rheological strength. Then the subduction angle may be changed from shallow to steep, inducing lateral upwelling of the asthenosphere. This upwelling would heat and weaken the overriding lithospheric mantle, which led to the weakened lithospheric mantle dripping into the asthenosphere. These two models have some similarities, in that both take the subducting oceanic slab and relevant fluid migration as the major driving mechanism for thinning or destruction of the overriding cratonic lithosphere. The key difference between the two models is the effective depth of the subducting oceanic slab. One is stagnation and flattening in the MTZ, whereas the other is flat subduction at the bottom of the cratonic lithosphere. In the NCC, the eastern lithosphere was likely affected by subduction of the Izanagi slab during the Mesozoic, which would have perturbed the asthenosphere and the MTZ, and induced fluid migration beneath the NCC lithosphere. The upwelling fluid may largely have controlled the reworking of the NCC lithosphere. In order to discuss and analyze these two models further, it is crucial to understand the role of fluids in the subduction zone and the MTZ. Here, we systematically discuss phase transformations of hydrous minerals and the transport processes of water in the subduction system. Furthermore, we analyze possible modes of fluid activity and the problems to explore the applied feasibility of each model. In order to achieve a comprehensive understanding of the mechanisms for thinning and destruction of cratonic lithosphere, we also consider four additional possible dynamic models: extension-induced lithospheric thinning, compression-induced lithospheric thickening and delamination, large-scale mantle convection and thermal erosion, and mantle plume erosion. Compared to the subduction-related models presented here, these four models are primarily controlled by the relatively simple and single process and mechanism(extension, compression, convection, and mantle plume, respectively), which could be the secondary driving mechanisms for the thinning and destruction of lithosphere.

OGP: A Repository of Experimentally Characterized O-glycoproteins to Facilitate Studies on O-glycosylation

Numerous studies on cancers, biopharmaceuticals, and clinical trials have necessitated comprehensive and precise analysis of protein O-glycosylation. However, the lack of updated and convenient databases deters the storage of and reference to emerging O-glycoprotein data. To resolve this issue, an O-glycoprotein repository named OGP was established in this work.It was constructed with a collection of O-glycoprotein data from different sources. OGP contains 9354 O-glycosylation sites and 11,633 site-specific O-glycans mapping to 2133 O-glycoproteins, and it is the largest O-glycoprotein repository thus far.Based on the recorded O-glycosylation sites, an O-glycosylation site prediction tool was developed. Moreover, an OGP-based website is already available(http://www.oglyp.org/). The website comprises four specially designed and user-friendly modules:statistical analysis, database search, site prediction, and data submission. The first version of OGP repository and the website allow users to obtain various O-glycoprotein-related information, such as protein accession Nos., O-glycosylation sites,O-glycopeptide sequences, site-specific O-glycan structures, experimental methods, and potential O-glycosylation sites.O-glycosylation data mining can be performed efficiently on this website, which will greatly facilitate related studies. In addition, the database is accessible from OGP website(http://www.oglyp.org/download.php).