Under extreme heterogeneous loading conditions in the deep sea, obtaining well-preserved and stratigraphically coherent cores is a critical challenge that requires urgent resolution. Current methods cannot directly determine the preservation of core stratigraphic information or the sampling behaviour of drill bits through experimentation. Consequently, a new evaluation method for angular velocity-based stratigraphic preservation, which is grounded in Discrete Element Method (DEM) theory, is proposed. Simulation modelling uses the Hertz–Mindlin contact model to construct a multi-scale geotechnical–drill string numerical coupling model. The drill string structure is simplified while incorporating actual geometric dimensions and material properties. By simulating and extracting particle angular velocity data under various operating conditions, a correlation is established between particle motion characteristics and the stratigraphic preservation status. Experiments were conducted on a customised drilling rig platform using specimens with deep-sea geomechanical properties consistent with the simulations. Drilling tools with multiple inner diameter specifications were configured, and multiple variable combinations of the rotational speed and feed rate were set. The degree of bedding preservation in the sampled cores was recorded synchronously. The study clarified the relationship between particle angular velocity and bedding preservation, identifying the influence patterns of parameters such as the tool inner diameter, rotational speed, and feed rate on bedding preservation. Results indicate that when the rotational speed exceeds 200 rpm and the feed rate falls below 0.018 m/s, stratigraphic distortion significantly increases; the drill bit inner diameter exhibits a non-linear negative correlation with core disturbance. This study provides theoretical underpinnings and experimental evidence for multi-parameter process optimisation in maintaining stratigraphic integrity during deep-sea submersible coring operations.

Design and testing of a timber-steel hybrid beam string structure

Dynamic collapse mechanism and collapse resistance assessment of in-service prestressed truss string structures subjected to thunderstorm downbursts

A novel vibration control method for double rhombic-strut beam string structures by frequency-tuning and stiffness-adjustment

Structural stress analysis of a swimming pool with a beam string structure under the temperature effect

Abstract We define the notion of adjustment for strict Lie 2-groups and provide the complete cocycle description for non-Abelian gerbes with connections whose structure 2-group is an adjusted 2-group. Most importantly, we depart from the common fake-flat connections and employ adjusted connections. This is an important generalisation that is needed for physical applications especially in the context of supergravity. We give a number of explicit examples; in particular, we lift the spin structure on S^4, corresponding to an instanton-anti-instanton pair, to a string structure, a 2-group bundle with connection. We also outline how categorified forms of Bogomolny monopoles known as self-dual strings can be obtained via a Penrose-Ward transform of string bundles over twistor space.

Solution electrospinning produces not only round fibersbut alsomany unexpected features, e.g., ribbons, nets, and fibers with beads,barbs, or branches along the fiber length. These diversified featuresare observed in the electrospun fibers of poly­(vinyl alcohol), Nylon-6,poly­(N-isopropylacrylamide), ultrahigh-molecular-weightpolystyrene, and ultrahigh-molecular-weight polyethylene in this study.All these unique features could be realized through our recent discoveriesthat flow-induced phase separation occurs in the jet to develop polymer-richphases of hierarchical string structures with various diameters. Subsequently,lateral association (or fasciation) of the hierarchical strings ensuesand creates assembled strings of different kinds, which are splitfrom the phase-separated jet and evolve into as-spun features aftersolvent evaporation. Our results indicate that flow-induced phaseseparation in jets cannot be overlooked and is likely to unify theformation mechanism of all diversified morphologies of electrospunproducts.

Multi-objective optimization control of a novel adaptive beam string structure with double rhombic struts: Experimental and simulation studies

Analysis of wind-induced vibration and collapse failure of prestressed truss string structures under thunderstorm downbursts

With the acceleration of urbanization, the number of deep foundation pit projects is increasing, and the limitations of traditional support systems in large-span and complex environments are gradually highlighted. As a new type of support form, the prestressed beam string internal support system has been more and more widely used in foundation pit engineering due to its advantages of high stiffness, large span and strong controllability. This paper systematically reviews the development history, structural composition and working mechanism of the internal support system of prestressed beam string structure, and summarizes the mechanical performance analysis, influencing factors, engineering application cases and existing problems. By integrating the relevant research results at home and abroad, the mechanical properties of the system in terms of load transfer, deformation control and stability are revealed. The effects of prestress level, geometric parameters, material properties and other factors on its performance are discussed, and its practical application effect is analyzed in combination with typical engineering cases. Finally, in view of the shortcomings of the current research, the future research direction is proposed, which provides a reference for the further development and engineering application of the system.

This paper examines the string structure of the bass guitar and shows how technological advancements can end up limiting talent instead of improving it. The main objective is to show how scientific innovation can help overcome challenges associated with music production and performance. The study also outlines how different African musicians have dealt with this challenge before proposing a technical solution through the development of a convertible Bass Guitar, to be developed by the researcher and an Engineering graduate at the University of Nairobi, leading to a Kenyan solution to a global musical dilemma. When published, it is the researcher’s conviction that the innovation can be replicated anywhere in the world. To share the researcher’s story and suggestions as summarised in this paper, I read several publications on the history and techniques of playing the bass guitar, but also interviewed eight key Sebene players who have played for between eleven and thirty-two years.

The high-altitude assembly and tensioning construction of large-span beam string structures (BSS) offers numerous advantages, including structural simplicity, clear force transmission, minimal deformation, strong stability, structural adaptability, self-balancing capability, and ease of construction. However, it also presents technical challenges such as complex loading behavior, difficult deformation control, and high precision requirements during construction. This paper, based on the practical application in the Lingshui Gymnasium project in Hainan, employs a combination of theoretical analysis, numerical calculation, and in-situ testing to investigate the mechanical response characteristics of large-span BSS roofs. Under self-weight, the displacement of the support scaffolding causes the mid-span deflection on the left side of the beam-string to be greater than that on the right side. After the staged tensioning is completed, the mid-span of the beam-string exhibits an upward arching phenomenon. Under the standard combination of dead load and live load, the maximum deflection occurs at the mid-span of the beam-string, with a deflection-to-span ratio of 1/423, which meets the serviceability requirements. In terms of the improvement and innovation of construction technology, the supporting tire frame, tension cable, gusset, early warning and other aspects have been improved and innovated, and these improvements provide support for the improvement of the construction technology of the large-span tensioned string girder structure as well as the development and scientific and technological progress of the industry.

Alzheimer’s disease (AD) affects a significant portion of humanity’s elderly population across the globe. Recent studies have identified Amyloid-Beta 42 (Aβ42) as a key biomarker for AD. In this research, we examined the feasibility of using string-shaped electrodes to develop a potentially wearable biosensor for the early detection of AD. Two types of flexible electrochemical electrodes were fabricated using a commercial thread (25% cotton-75% polyester) and an electrospun nanofiber-based string. Decorating the strings with either gold or SiC nanoparticles, several different electrodes were tested to explore their responses to Aβ42. Our results show that the nanofiber-based electrode decorated with gold nanoparticles had the highest sensitivity of 1.71 µA/pg.cm and the best limit of detection (LoD) of 8.36 pg/mL. These findings highlight the importance of the string structure in designing highly sensitive sensors.

Amplification mechanism of double rhombic struts in adaptive beam string structures

Performance, strategy, and evaluation of truss string structure based on active control

Investigation on the progressive collapse resistance and failure mechanism of truss string structure with alternate cables

ABSTRACTIn this study, we have fabricated the efficient luminescent solar concentrators (LSCs) with the chemical raw materials of B2O3–SiO2–ZnO, Cs2BIBIIIX6, and copper‐based halide, and after integrating with the silicon‐based solar cell, the optoelectronic conversion efficiency of this device with the area of 32 × 32 cm2 could achieve the high value as 10.89%. Due to the high absorptance and transmittance of LSCs, these devices are very suitable for the application of building integrated photovoltaic (BIPV). A simulation model of the photovoltaic roof system was constructed with PVsyst software by using the 32 × 32 cm2 LSCs as the basic unit. In addition, the performance of photovoltaic roof systems with varied string structures, assembled angles (0° and 30°) and operating status of LSCs are explored, these results indicate that the best string structure of the LSCs working at different operating status. Moreover, the annual power generation capacity of the photovoltaic roof system assembled at 0° could achieve 22,152 kWh, which is 4.70% higher than that of the photovoltaic roof system assembled at 30°. These results could give a reference for the practical construction and optimization of BIPV.

Reciprocal structures represent a category of spatial structural systems characterized by mutually supporting connections between components, which are primarily employed in roof systems and spatial frameworks. Insufficient stiffness is a critical challenge for the practical application of reciprocal structures in engineering. This study introduces a new cable-supported reciprocal structure, which integrates rigid beams and flexible cables through struts, inspired by the construction principles of beam string structures. By optimizing the force transfer path, the overall performance of the structure is improved. Through finite element analysis, a comprehensive investigation was conducted on the static behavior and parametric analysis of this new reciprocal structure. The research results show that the rational determination of key parameters, including the rise/span ratio, strut height, and cable length, demonstrates significant efficacy in reducing the maximum displacement of this new reciprocal structure under uniformly distributed load. The stiffness of the new cable-supported reciprocal structure increases by 17% compared to that of the general reciprocal structure, while the total steel consumption decreases by 12%. The proposed new cable-supported reciprocal structure presents an innovative and viable configuration within the domain of reciprocal structures.

Abstract In order to develop a suitable method for applying prestress in large‐span emergency bridges with a tensegrity beam structure, this paper proposes a prestress application method based on diamond strut mechanism. The 92 meters long span emergency bridge is taken as the research background. The bridge is a lightweight and high‐load emergency bridge equipment, which can quickly restore traffic after traffic interruption caused by natural disasters or sudden emergency rescue situations. Compared with the existing tensioning method and strut rotation method, this method can save 97% and 74% of the external force requirements, respectively, while providing the same top bracing force. Only a 3t lever hoist can complete the application of prestress. And existing methods require heavy hydraulic equipment or traction machine. Therefore, this method is more convenient and labor‐saving than the traditional method of prestressing. A 1:1 scale strut mechanism test piece was designed and made. Prestress application tests and strut mechanism loading tests were conducted. The test results show that: the prestressing application method based on the top brace of diamond strut is simple and fast, and can meet the demand of 160kN pre‐top brace force; from the load‐displacement curve from zero to the maximum internal force of 620KN of the struts under the full bridge through‐loaded condition. The bracing structure has consistently remained within the linear elastic phase, and the structural safety requirements are met.

Increasing the span of large wooden structures raises the risk of brittle failure in the glulam beams’ tensile zone, while the compressive zone materials remain underutilized, resulting in suboptimal structural efficiency and material wastage when constructing large-span wooden roof systems solely with wooden components. The steel-wood composite beam-string structure is a suitable solution for such needs. However, there is still a gap in research regarding the overall mechanical performance of steel-wood composite beam-string structures on a larger scale, with limited attention given to studying their mechanical properties and force mechanisms comprehensively. This paper introduces a steel-wood composite beam-string structure based on a practical engineering project of the Capital Museum East Branch. It includes a detailed analysis of forces and structural calculations, along with static loading tests on a glulam curved beam roof system using beam-string structures. Structural analysis shows that, under frequently occurred earthquake, the maximum inter-story drift of the overall structure is 1/370, with the stress ratio of most components below 0.8. Experimental results indicate that when the load increases to twice the design load, there is a tendency for separation at the connection, but significant damage is not observed. The cross-section generally satisfies the assumption of a plane section. The pre-stressed strands set at the bottom of the wooden beams strengthen the tension zone of the beams, causing the neutral axis of the beams to generally shift towards the tension zone. The experimental findings will inform the museum project and provide useful design insights for similar steel-wood composite beam-string structures.