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In this review, the research reports on the dispersion processes of carbon nanotubes (CNTs) in aqueous cementitious materials are intensively introduced and summarized. The main processes for the CNTs dispersion in aqueous systems include high shear emulsification, ultrasonic treatment, covalent modification, and non-covalent modification. The influences of various factors on the dispersity of CNTs are evaluated, and the pros and cons of dispersion processes of CNTs are analyzed, along with the dispersion mechanism of CNTs in aqueous materials. Several novel techniques are also introduced, including arc thermal excitation and electromagnetic field-induced method, etc. In addition, the challenges when CNTs dispersion are further involved in cementitious alkali pore solution and the improvement means are also described in detail. And, the direct dispersion process (in situ growth process) of CNTs in cementitious materials has also been discussed in depth.

The strength damage and deformation failure of frozen soil–rock mixture (FSRM) often restrict the safety of the major engineering construction in cold areas or the spatial development of urban underground water-rich rock and soil masses. To investigate the uniaxial strength damage evolution and failure characteristics of FSRM under different loading rates (0.3, 0.6, 3, 6, 30, and 60 mm·min−1) in the quasi-static range, resistivity monitoring and image recognition technology were used to study the time-stress-volumetric strain-resistivity changes. The results indicate that the peak stress, peak strain, initial yield modulus, and tangential modulus of FSRM increase rapidly before increasing slowly as the loading rate increases, and there are critical loading rates and post-peak failure phenomenon. Three distinct types of failure modes, bulge failure, oblique shear failure, and fragmentation failure were observed at low (0.3–0.6 mm·min−1), medium (3–6 mm·min−1), and high loading rates (30–60 mm·min−1), respectively. The macroscopic failure of the FSRM at different loading rates arises from a combination of strain rate hardening of the strength and damage softening of the structure. To predict the stress-strain characteristics at various loading rates, a damage prediction model with a damage variable correction factor considering residual strength was employed based on the improved Duncan–Chang model and damage theory of electrical resistivity, and the predicted results were in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Dielectric ceramics have attracted significant attention in power electronic systems, owing to their exceptional charging and discharging speeds, as well as their high power density. However, simultaneously achieving a high recoverable energy density (Wrec) and high efficiency (η) in high‐voltage dielectric ceramics remains a challenge for applications where a high breakdown electric field (Eb) is required. In this study, high‐quality (1 – x)NaNbO3–xSr0.7Bi0.2(Mg1/3Nb2/3)O3 [(1 – x)NN–xSBMN] ceramics were prepared based on an optimization strategy combining phase structure with microstructural regulation. A quasilinear P–E loop with negligible hysteresis was realized in the ceramic with x = 0.4, excellent Wrec of 5.61 J/cm3, and high η of 85.1% obtained at a largely improved Eb of 710 kV/cm. To the best of our knowledge, the Eb of 710 kV/cm is one of the highest values achieved in dielectric ceramics to date. The noticeable reduction in grain size (∼0.95 µm) and increased bandgap improve the Eb to an ultra‐high level, which is a crucial factor in high energy storage density. The coexistence of a few antiferroelectric phases and the dominant paraelectric phase is the structural origin of the comprehensive energy‐storage performance improvement. Therefore, our research develops a unique approach to unleash the potential in NaNbO3‐based ceramics, holding great promise for application in high‐voltage dielectric capacitors. [ABSTRACT FROM AUTHOR]

Prior to enrolling in an English as a medium of instruction (EMI) institution, students must show an English proficiency level through meeting a benchmark on a standard English proficiency test, which is typically aligned with the Common European Framework of Reference for Languages (CEFR). Along with overall English proficiency, aural/written vocabulary level mastery could also predict students' success at EMI institutions, as students need adequate English vocabulary knowledge to comprehend lectures and course readings. However, aural/written vocabulary level mastery has yet to be clearly benchmarked to CEFR levels. Therefore, this study aimed to investigate the correlations between students' aural/written vocabulary level mastery and their CEFR levels. Forty undergraduate students in a Macau EMI university were recruited to take one English proficiency test and two vocabulary level tests (i.e., Listening Vocabulary Levels Test (LVLT) and the Updated Vocabulary Levels Test (UVLT)). Correlation analyses were conducted to explore the relationship between students' CEFR levels and their mastery of listening and reading vocabulary levels. A positive correlation was found between students' CEFR levels and their mastery of receptive aural vocabulary levels (ρ = 0.409, p = 0.009). Furthermore, a statistically significant positive correlation was found between students' CEFR levels and their mastery of receptive written vocabulary levels (ρ = 0.559, p < 0.001). Although positive correlations were observed, no clear pattern was identified regarding the relationship between students' CEFR levels and their mastery of aural/written vocabulary levels. Regression analyses were further conducted to determine the extent to which the combination of receptive aural and written vocabulary knowledge predicts the CEFR levels. The results indicated that the regression model that included only UVLT scores better predicted the CEFR levels. Given the positive correlations observed between students' CEFR levels and their mastery of vocabulary levels, this study's findings suggest the inclusion of aural/written vocabulary levels as additional indicators for ensuring student academic success in EMI institutions. Implications for EMI universities on student admissions, classroom teaching, and provision of additional English courses were provided. [ABSTRACT FROM AUTHOR]

Urbanization alters the thermal and dynamic environment of the local climate system, resulting in significant impacts on precipitation in both urban and adjacent areas. Nevertheless, there remains a significant gap in our understanding of urbanization‐induced effects on asymmetrical, symmetrical, and other precipitation patterns in urban agglomerations (UAs) with divergent background climates and geographic regions at different timescales. Specifically, this asymmetrical change pattern is characterized by an increase in heavy (or light) rainfall and a decrease in light (or heavy) rainfall. Here, we assessed the effects of urbanization on precipitation patterns across 18 UAs situated in diverse background climates and geographical areas in China at different timescales. The results demonstrate that urbanization predominantly alters precipitation patterns in UAs located in the humid region. Specifically, urbanization amplified asymmetrical changes in Yangtze River Delta, Pearl River Delta, Beibu Gulf, Middle Yangtze River, and Guanzhong, but exacerbated symmetrical changes in precipitation in some regions such as Chengdu‐Chongqing. Notably, the urbanization effect demonstrates greater significance at the hourly scale, as exemplified in the Yangtze River Delta, Pearl River Delta, and Middle Yangtze River, where the urban impact is nearly twice as pronounced when compared to the daily scale. Moreover, urbanization had either no effect or has a negative impact on precipitation patterns in UAs located within continental and arid regions. This is related to the intensity of urbanization, background climate and complex topography. This finding implies that urban managers should consider the impact of urbanization on precipitation patterns in different contexts to provide scientific guidance for urban planning. Plain Language Summary: China has undergone rapid urbanization in recent decades, resulting in increased heavy precipitation and decreased light precipitation in specific urban agglomerations. However, the influence of urbanization on different precipitation patterns (e.g., symmetric and asymmetric) at various timescales remains uncertain. This study investigates rainfall pattern changes across 18 urban agglomerations with diverse geographical locations and background climates. Our findings reveal that from 1961 to 2015, urbanization primarily modified precipitation patterns in humid regions, amplifying asymmetric changes in the Yangtze River Delta, Pearl River Delta, Middle Yangtze River, and Beibu Gulf. Importantly, in specific urban agglomerations, the impact of urbanization on precipitation is more pronounced at the hourly scale compared to the daily scale. Key Points: The influence of urbanization on precipitation change patterns at various time scales were investigated in 18 Urban Agglomerations in ChinaUrbanization has altered the precipitation patterns in the humid zone, amplifying heavy rainfall and suppressing light rainfall in the Yangtze River Delta, Pearl River Delta, Beibu Gulf regionsThe precipitation effect of urbanization exhibits a more pronounced variation on an hourly scale, being twice as substantial as on a daily scale in specific urban agglomerations [ABSTRACT FROM AUTHOR]