Force and deformation characteristics during the reconstruction and expansion of shallow single-tube tunnels into large-span multiarch tunnels

At present, there are an ever-increasing number of tunnel expansion projects in China. Studying the mechanical properties of the expanded tunnels is of great significance for guiding their safe construction. Through model testing and numerical simulation, the mechanical properties of a double-arch tunnel constructed through the expansion of the middle pilot heading from an existing single-tube tunnel were studied. The variation characteristics of the surface subsidence, surrounding rock stress, and stress and strain of the middle partition wall and lining during the tunnel reconstruction and expansion were investigated. The mechanism for transferring stress and strain between the left and right tunnel tubes was studied by a numerical simulation method. The results showed that the surface subsidence caused by the excavation of the left (i.e., the subsequent) tunnel tube was larger, and the maximum surface subsidence occurred at the right (i.e., the first) tunnel tube. The surrounding rock on the middle wall was the sensitive part of the tunnel excavation, the stress of the surrounding rock at the left spandrel of the right tunnel tube fluctuated and exhibited the most complex variation, and the stress of the surrounding rock at the right spandrel of the left tunnel tube exhibited the largest variation. The excavation of the left tunnel tube had a great influence on the forces of the middle partition wall and the lining structure of the right tunnel tube, the middle partition wall was subjected to eccentric compression towards the left tunnel tube, and the stress at the left spandrel under the initial support of the right tunnel tube exhibited complex variations. The excavation of the left and right tunnel tubes had a great influence on the stability of the surrounding rock, as well as on the force-induced deformation of the middle partition wall and the support structure, within the width of the single tunnel tube span behind the tunnel working face. Due to the different construction sequences, the stress and strain at the symmetric measurement points of the middle partition wall, as well as the left and right tunnel support structures, were very different

Advancements in AI-driven multilingual comprehension for social robot interactions: An extensive review

In the digital era, human-robot interaction is rapidly expanding, emphasizing the need for social robots to fluently understand and communicate in multiple languages. It is not merely about decoding words but about establishing connections and building trust. However, many current social robots are limited to popular languages, serving in fields like language teaching, healthcare and companionship. This review examines the AI-driven language abilities in social robots, providing a detailed overview of their applications and the challenges faced, from nuanced linguistic understanding to data quality and cultural adaptability. Last, we discuss the future of integrating advanced language models in robots to move beyond basic interactions and towards deeper emotional connections. Through this endeavor, we hope to provide a beacon for researchers, steering them towards a path where linguistic adeptness in robots is seamlessly melded with their capacity for genuine emotional engagement

Invented spelling in English and pinyin in multilingual L1 and L2 Cantonese Chinese speaking children in Hong Kong

This research examined the relations among Cantonese phonological awareness, invented spelling in Pinyin (in Mandarin), and invented English spelling in 29 first language (L1) and 34 s language (L2) Cantonese-speaking second and third graders in Hong Kong. The purpose of this study was to understand how phonological awareness skills across languages are associated in multilinguals. We compared the phonological skills in the two groups (i.e., L1 and L2 Chinese speaking children) for the three official languages (i.e., Cantonese, Mandarin, and English) spoken in Hong Kong. The two groups did not differ on Cantonese phonological awareness, Mandarin Pinyin invented spelling, or English invented spelling, but the L1 group performed significantly better than the L2 group on Mandarin Pinyin tone skills, with non-verbal intelligence and grade level statistically controlled. In both groups, all three of the phonological sensitivity measures were significantly correlated with one another. With group, grade, and nonverbal IQ statistically controlled, only Mandarin Pinyin invented spelling but not Cantonese phonological awareness uniquely explained English invented spelling performance. In contrast, Pinyin invented spelling was uniquely explained by both English invented spelling and Cantonese phonological awareness skills. Results highlight some phonological transfer effects across languages

Experimental investigation of the tip based micro/nano machining

Based on the self-developed three dimensional micro/nano machining system, the effects of machining parameters and sample material on micro/nano machining are investigated. The micro/nano machining system is mainly composed of the probe system and micro/nano positioning stage. The former is applied to control the normal load and the latter is utilized to realize high precision motion in the xy plane. A sample examination method is firstly introduced to estimate whether the sample is placed horizontally. The machining parameters include scratching direction, speed, cycles, normal load and feed. According to the experimental results, the scratching depth is significantly affected by the normal load in all four defined scratching directions but is rarely influenced by the scratching speed. The increase of scratching cycle number can increase the scratching depth as well as smooth the groove wall. In addition, the scratching tests of silicon and copper attest that the harder material is easier to be removed. In the scratching with different feed amount, the machining results indicate that the machined depth increases as the feed reduces. Further, a cubic polynomial is used to fit the experimental results to predict the scratching depth. With the selected machining parameters of scratching direction d3/d4, scratching speed 5 μm/s and feed 0.06 μm, some more micro structures including stair, sinusoidal groove, Chinese character ‘田’, ‘TJU’ and Chinese panda have been fabricated on the silicon substrate

A unified element stiffness matrix model for variable cross-section flexure hinges in compliant mechanisms for micro/nano positioning

This paper presents a unified analytical model of element stiffness matrix for variable cross-section flexure hinges in plane deformation which is most frequently employed in planar-motion compliant mechanisms for micro/nano positioning. The unified analytical model is derived for flexure hinges in plane deformation based on the principle of virtual work. The derivation is generalized such that it can be applied to various geometries. To optimize and simplify element stiffness matrix model, four coefficients with curve integral are introduced. The results of the analysis were validated in part by modeling several previously investigated configurations, namely flexible beam hinge and right circular hinge. To further validate the proposed analytical model, finite element analysis and experimental testing were used. And the experimental testing shows the proposed unified model is more precise than pseudo-rigid-body method. The proposed model provides a concise and generalized solution to derive the element stiffness matrices of flexible hinges in plane deformation, which will have excellent applications in design and analysis of variable cross-section flexible hinges in compliant mechanisms

Propyl 4-hydroxy­benzoate

There are two mol­ecules in the asymmetric unit of the title compound, C10H12O3. In the crystal, mol­ecules are linked by O—H⋯O hydrogen bonds into chains running along [010]. Adjacent chains are joined together by weak π–π inter­actions between benzene rings [centroid–centroid distance = 4.040 (2) Å]

Attentional biases and daily game craving dynamics: An ecological momentary assessment study

Background and aims: Theories posit that the combination of external (e.g. cue exposure) and internal (e.g. attention biases) factors contributes to the development of game craving. Nevertheless, whether different components of attentional biases (namely, engagement bias and disengagement bias) play separate roles on game craving has not been fully elucidated. We aimed to examine the associations between two facets of attentional biases and game craving dynamics under a daily life setting. Methods: Participants (110 regular internet game players) accomplished the modified attentional assessment task in the laboratory, after which they entered a 10-day ecological momentary assessment (EMA) to collect data on their momentary game craving and occurrence of game-related events at five different time points per day. Results: We found that occurrence of game-related events was significantly associated with increased game craving. Moreover, attentional disengagement bias, instead of engagement bias, bore on the occasional level variations of game craving as moderating variables. Specifically, attentional disengagement bias, not engagement bias, was associated with a greater increase in game craving immediately after encountering a game-related event; however, neither attentional engagement bias nor disengagement bias was associated with the craving maintenance after a relatively long period. Discussion and conclusions: The present study highlights the specific attentional processes involved in game craving dynamics, which could be crucial for designing interventions for attentional bias modification (ABM) in Internet Gaming Disorder (IGD) populations