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This paper mainly proposes a technical route of user profiling based on multi-view clustering and constructs a multidimensional and multi-view reader feature system based on reader behavior data. According to the constructed reader feature system and the defects of the classical K-means algorithm in multi-view clustering, a multi-view dichotomous K-means algorithm based on Marxian distance is proposed. Using the proposed algorithm for multi-view clustering of readers, the user portrait features of readers can be obtained, and finally, a university library user portrait system is designed and implemented. By analyzing the behavior of college students through the user portrait technique, we get that the most preferred book genre of college students is literature accounting for 71.45%, followed by science and history with 57.64% and 51.37%, respectively. The most popular form of reading promotion among college students is classical film and television exhibitions, accounting for 63.73%, followed by lectures by celebrities and experts, accounting for 60.91%. The highest influence on college students going to the library is too many spare time activities, accounting for 64.38%, and not choosing books, accounting for 36.95%. These data can help libraries understand readers’ needs and provide help for reading accurate recommendations and services based on readers’ user profiles.

为了研究焙炒对植物油品质的影响，以油菜籽、亚麻籽、花生、葵花籽和芝麻为原料，经焙炒处理后采用液压压榨法制油（热榨油），分析植物油的理化指标（酸值、过氧化值、水分及挥发物、色泽）、主体组分（脂肪酸组成及含量、甘三酯组成及含量、挥发性组分）和总酚含量，并与未焙炒处理直接压榨制取的油（冷榨油）作对比。结果表明：热榨油酸值和过氧化值显著高于冷榨油（p0.05）；热榨油中醇类、醛类和酸类等挥发性组分较少，但杂环类物质较多；热榨菜籽油、亚麻籽油、花生油、葵花籽油和芝麻油总酚含量分别是其冷榨油的1.38、1.57、1.51、1.80倍和1.27倍。因此，焙炒对植物油品质影响较大，应根据生产需要选择合适的预处理方式。 In order to study the effect of roasting on the quality of vegetable oils, rapeseed, flaxseed, peanut, sunflower seed and sesame were used as raw materials, and the oils were obtained by hydraulic pressing after roasting(hot pressed oil). The physicochemical indexes (acid value, peroxide value, moisture and volatile, color), main components (fatty acid composition and content, triglyceride composition and content, volatile components) and total phenols of the five hot pressed vegetable oils were analyzed and compared with those of the oils direct pressed with unroasted oilseeds(cold pressed oil). The results showed that the acid value and peroxide value of hot pressed oils were significantly higher than those of cold pressed oils (p0.05). The hot pressed oils contained less volatile components, such as alcohols, aldehydes and acids, but more heterocyclic substances. The contents of total phenols in hot pressed rapeseed oil, flaxseed oil, peanut oil, sunflower seed oil and sesame oil were 1.38, 1.57, 1.51, 1.80, 1.27 times of the cold pressed oil, respectively. Therefore, roasting has a great influence on the quality of vegetable oil, and an appropriate pretreatment method should be selected according to production needs.

Single-molecule detection can reveal time trajectories and reaction pathways of individual intermediates/transition states in chemical reactions and biological processes, which is of fundamental importance to elucidate their intrinsic mechanisms. We present a reliable, label-free single-molecule approach that allows us to directly explore the dynamic process of basic chemical reactions at the single-event level by using stable graphene-molecule single-molecule junctions. These junctions are constructed by covalently connecting a single molecule with a 9-fluorenone center to nanogapped graphene electrodes. For the first time, real-time single-molecule electrical measurements unambiguously show reproducible large-amplitude two-level fluctuations that are highly dependent on solvent environments in a nucleophilic addition reaction of hydroxylamine to a carbonyl group. Both theoretical simulations and ensemble experiments prove that this observation originates from the reversible transition between the reactant and a new intermediate state within a time scale of a few microseconds. These investigations open up a new route that is able to be immediately applied to probe fast single-molecule physics or biophysics with high time resolution, making an important contribution to broad fields beyond reaction chemistry.

A topological phase transition in high-temperature superconductor FeTe1−xSex, occurring at a critical range of Se concentration x, underlies their intrinsic topological superconductivity and emergence of Majorana states within vortices. However, how Se concentration and distribution determine the electronic states, particularly the presence or absence of Majorana states, in FeTe1−xSex remains unclear. In this study, we combine density functional theory calculations with pz–dxz/yz-based analysis and Wannier-based Hamiltonian analysis to systematically explore the electronic structures of diverse FeTe1−xSex compositions. Our investigation reveals a nonlinear variation of the spin–orbit coupling (SOC) gap between pz and dxz/yz bands in response to the Se concentration x, with the maximum gap occurring at x = 0.5. The pz–pz and dx2−y2–pz interactions are found to be critical for pd band inversion. Furthermore, the distribution of Se significantly modulates the SOC gap, thereby influencing the emergence of Majorana states within local vortices. [ABSTRACT FROM AUTHOR]