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Geosynchronous orbit satellite is usually the first early warning equipment to catch ballistic missile launches in actual combat. However, the detection information it provides is lack of dimension, which makes the traditional target guidance method hard to be directly applied on the target guidance for low-orbit satellite. Aiming at this point, this paper studies the target guidance method for low-orbit satellite by geosynchronous orbit satellite. First, based on the altitude constraint of infrared radiation during the launch and active flight of the ballistic missile, the azimuth and pitch detection ranges of the infrared sensor of the low-orbit satellite are calculated with the guidance of one geosynchronous orbit satellite. Then, the detection distance of the infrared sensor of the low-orbit satellite is modeled and calculated, which leads to a successful target detection for the low-orbit satellite. Finally, the effectiveness and accuracy of this method are verified through a numerical simulation experiment.

The rise of porcelain industry in northern China and the subsequent emergence of white porcelain production during the Northern dynasties (386–581 CE) played a pivotal role in shaping the historical trajectory of Chinese ceramics. Xing kiln is one of China's earliest and most representative white porcelain kilns. Herein, we investigated 23 porcelain sherds from the Neiqiu Xing kiln site during the late Northern dynasties and the early Sui dynasty (550–600 CE) from the perspective of firing temperature, firing atmosphere, and microstructure using a dilatometer, X‐ray photoelectron spectroscopy, and scanning electron microscopy. The results show that the early Xing porcelains were fired at high firing temperatures exceeding 1200°C with a reducing flame, and the adjustment of temperature promotes the emergence of early white porcelain. Moreover, the higher firing temperature of early Xing porcelain leads to the dominance of a glassy phase within the glaze, and the high bonding strength of the glaze and body caused by the body–glaze interaction layer formed with dense anorthite crystals. Overall, these findings provide valuable insights into the firing technology in the Xing kiln and even in North China during the late sixth century. [ABSTRACT FROM AUTHOR]

Dalian Island, located in the northwest of Pingtan County, Fujian Province, China, has been an important junction on the Maritime Silk Road since the Tang dynasty. This study focuses on sauce-glazed ceramic ware from the Song dynasty salvaged from the waters near Dalian Island Wharf. The composition, phase attributes, and microstructures of the marine organism remains attached to the ceramic ware were analyzed using an optical microscope, scanning electron microscope, and micro-Raman spectrometer to investigate the influence of marine organisms on the degradation of the ceramic ware. Long-term abrasion by sea wave-borne debris led to the increased surface roughness and wettability of the ceramic ware, facilitating the attachment of marine organisms. Differences in surface roughness between the inner and outer walls led to varying levels of biomass. Coralline algae secreted inducers to attract the larvae of macrofoulers. The attachment of different types of marine organisms had varying effects on the degradation of the ceramic ware. Firmly attached unitary organisms could alleviate the scouring of sea wave-borne debris and hinder the intrusion of foreign pollutants, thereby playing a 'bio-protective' role. In contrast, the group skeletons of modular organisms could reinforce the mechanically damaged surface but failed to block the intrusion of iron rust and other pollutants, resulting in chemical alterations of the glaze. Therefore, the specific species of the attached marine organisms should be considered in subsequent conservation efforts. [ABSTRACT FROM AUTHOR]

As the criterion used by archaeologists for determining early white porcelain is quite ambiguous, the origin of Chinese white porcelain remains a point of disagreement. In this study, we systematically investigate 61 typical Xing porcelains of the late Northern dynasties to the early Sui dynasty (550–600 CE) using spectrophotometer, X‐ray fluorescence (XRF), scanning electron microscopy (SEM), and X‐ray powder diffraction (XRD), and analyze the differences between early white porcelain and celadon of Xing kiln in terms of their whiteness and raw materials characteristic. The results show that early white porcelain is a new type of ware that differs from celadon, which can be distinguished by whiteness, with a whiteness greater than 8% being early white porcelain and a whiteness less than 8% being celadon. It is assumed that the ancient potters created the whiter wares based on celadon by improving the glaze and selecting new raw materials for the body, but the production of this type of ware was short lived and subsequently refined in the Sui dynasty (581–618 CE) owing to the limited improvement in whiteness. [ABSTRACT FROM AUTHOR]