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With the development of The Times, the Internet industry has gradually penetrated all aspects of our daily life, especially in the field of pan-entertainment, among which the video industry is the gathering place of the Internet industry. Long video websites include iQiyi, Youku, and Tencent, while short video websites include Douyin and Kuaishou. Bilibili, an especially popular video website in recent years, has attracted many young people as its users. Bilibili, as a video website with both long and short videos, mainly focuses on PUGC content but also has rich self-made content. It has strong competition from many video websites, but it also successfully occupies a considerable part of the market with its unique content ecology and bullet screen culture. This paper will analyze the external and internal competition pattern of Bilibili, then analyze its differentiated competition strategy and competitive advantages, and finally put forward suggestions and prospects for its future development direction.

Wudalianchi is a typical continental Cenozoic volcanic group rich in potassic volcanic rocks (Northeast China). Five hydrologically connected barrier lakes (Lakes 5 to 1) and upwelling cold mineral springs occur, forming a complex lake-groundwater system. Clarifying the water-source contributions and the role of water-rock interactions in the hydrological cycling for barrier lakes remains a challenge from scientific and engineering perspectives. In this study, seasonal variations of multiple isotopes were analyzed. δ18O and δD data indicate that the Wudalianchi lakes were mainly fed by mineral springs. The values, however, were greatly influenced by precipitation (rain and snow) and varying evaporation intensities. In contrast, 87Sr/86Sr ratios varied little between seasons (0.70701–0.7079), suggesting similar water-rock interactions through time. Nonetheless, Sr isotopic mixing models suggested that shallow mineral springs generally contributed >50% of the water to lower reaches. In contrast, the upstream wetland contributed >50% to Lake 5 and decreased down-valley (10.3–53.6%). Calculations based on the δ18O and δD Rayleigh fractionation equation suggest that evaporation in upper reaches was higher than the lower reaches. The evaporation in July was generally higher than in October. This study demonstrates the homogenous water-rock interactions and the associated water mixing effects on the terrestrial volcanic area. HIGHLIGHTS 87Sr/86Sr ratios varied little across seasons; δD and δ18O varied significantly.; δD and δ18O values of lakes were impacted by evaporation and precipitation.; Four endmember sources were identified by geochemical and isotopic data.; Shallow mineral springs and wetland water contributed most to lake waters.; Water-rock interaction and water mixing effect were highlighted in terrestrial volcanic area in eastern China.

Steel-bamboo composite I-beams are made of cold-formed thin-walled steel and bamboo-based panels using a structural adhesive. In the structural analysis of these beams, the mechanical properties are considered to be those of integrated beams; however, the effect of slip at the steel-bamboo interface could lead to differences between analytical and experimental results. To investigate flexural behavior, nine steel-bamboo composite I-beams were subjected to monotonic static loadings with two-point symmetric concentrated loads. According to the theory of elementary beam deformation and the differential relationship between interface slip and strain, the equations for calculating the mid-span deflection and flexural capacity of composite beams were established. A comparison between the calculated and experimental results show that steel-bamboo composite I-beams have high bearing capacity and stiffness and the failure modes exhibit ductility, which can be considered in practical engineering applications. Comparing the theoretical results with and without the inclusion of the slip effect, using a transformed section method, it is seen that the mid-span deflection of composite beams with interface slip effect is closer to the real deflection with an increase in accuracy that ranges from 2.64% to 5.95%. The slip effect reduces the stiffness and weakens the flexural capacity of composite beams. The average error between the calculated results with bond-slip and the experimental results is within 10%. Thus, the results of this study serve as a reference for the future design and application of steel-bamboo composite structures.

Cloud computing is introducing many huge changes to people's lifestyle and working pattern recently for its multitudinous benefits. However, the security of cloud computing is always the focus of numerous potential cloud customers, and a big barrier for its widespread applications. In this paper, to facilitate customers to understand the security status quo of cloud computing and contribute some efforts to improving the security level of cloud computing, we surveyed the existing popular security models of cloud computing, e.g. multiple-tenancy model, risk accumulation model, cube model of cloud computing, and summarized the main security risks of cloud computing deriving from different organizations. Finally, we gave some security strategies from the perspective of construction, operation and security incident response to relieve the common security issues of cloud computing.