Search

Despite the widespread utilization of Lithium-ion batteries (LIBs), concerns regarding safety during operation persist owing to accidents and potential risks of fires and explosions. To comprehend the thermal dynamics that underlie severe LIB incidents, calorimetry tests have been prevalently employed for over three decades to examine the exothermic/endothermic behavior, reaction kinetics, and thermal interactions among LIB materials. There exists a substantial volume of calorimetry test results on various LIB electrodes, electrolytes, and other components. However, this data showcases low consistency, yielding an unreliable database that obstructs a thorough understanding of LIB thermal behavior. In this research, a comparative analysis of differential scanning calorimetry (DSC) results from materials utilized in the most commercialized LIB systems is conducted. The analysis unveils notable discrepancies in DSC data amassed by different researchers, identifies five predominant causes of data inconsistency, proposes a standardized DSC operational procedure, and generates a set of self-consistent data. Subsequently, an intrinsic safety spectrum is delineated and compared with X-ray diffraction (XRD) outcomes to elucidate the correlation between the crystal lattice structure and the thermal behavior of the material. This work aids in the formation of a comparative DSC database, utilizing the vast but inconsistent literature data. Moreover, it clarifies the linkage between the material structure and thermal behavior, facilitating data-driven thermal analysis of LIBs.

Abstract Carbon nanotube (CNT) film photo‐thermoelectric (PTE) imagers are suitable for non‐destructive inspection techniques owing to their functionalities. Simultaneously, their practical application remains a crucial bottleneck due to low yield handling in the device fabrication (e.g., disconnections between photo absorbent channels and readout electrodes). However, studies clarifying the above malfunction mechanism and associated dominant factors in device handling, such as specific fabrication or material selection steps, still need to be completed. To address this issue, this work introduces all‐screen‐coatable fabrication techniques for CNT film PTE imagers to enhance their physical and thermal durabilities. First, this work determined that the transfer of CNT films on supporting substrates dominantly governs the mechanical robustness of the channels and that thermal curing in the subsequent fabrication process is an essential factor in the yields of channel‐electrode connections. The proposed approach ensures a transfer‐free direct coating of the CNT film on diverse substrates and is sufficiently durable against thermal curing‐induced disconnections at the channel‐electrode interfaces. The screen‐coating technique is also available for whole device materials of solution‐processable CNT film PTE imagers, simplifying fabrication processes. All‐screen‐coatable CNT film PTE imagers synergize their inherent functional sensing and high‐yield operations toward versatile applications.

The use of imager devices to supplement broadband photo-monitoring technology has enabled multi-functional sensing capability relevant to internet of things-related applications. Here, the authors report a robotassisted imager-implanted broadband photo-monitoring sensing platform.

The photo-thermoelectric (PTE) effect in electronic materials effectively combines photo-absorption-induced local heating and associated thermoelectric conversion for uncooled and broadband photo-detection. In particular, this work comprehensively summarizes the operating mechanism of carbon nanotube (CNT)-film-based PTE sensors and ubiquitous non-destructive inspections realized by exploiting the material properties of CNT films. Formation of heterogeneous material junctions across the CNT-film-based PTE sensors, namely photo-detection interfaces, triggers the Seebeck effect with photo-absorption-induced local heating. Typical photo-detection interfaces include a channel–electrode boundary and a junction between P-type CNTs and N-type CNTs (PN junctions). While the original CNT film channel exhibits positive Seebeck coefficient values, the material selections of the counterpart freely govern the intensity and polarity of the PTE response signals. Based on these operating mechanisms, CNT film PTE sensors demonstrate a variety of physical and chemical non-destructive inspections. The device aggregates broad multi-spectral optical information regarding the targets and reconstructs their inner composite or layered structures. Arbitrary deformations of the device are attributed to the macroscopic flexibility of the CNT films to further monitor targets from omni-directional viewing angles without blind spots. Detection of blackbody radiation from targets using the device also visualizes their behaviors and associated changes.

As flexible wearable sensors and imagers are receiving attention from diverse social sectors, the freely attachable photothermoelectric (PTE) conversion technique should be evaluated to develop a highly usable safety sensor network. Although carbon nanotube (CNT)‐related materials should be effective, the key parameters/structures that maximize PTE conversion have not been clarified, thus hindering optimum device design and practical use. Herein, the flexible, sensitive broadband photodetection operation based on a coupling configuration between the CNT film photo/heat/electron channel and metal electrode is evaluated. Experimental PTE measurements and steady‐state thermal distribution simulations reveal that a series coupling of a p‐type CNT film channel and a highly negative Seebeck coefficient counter metal electrode facilitate superior photodetection performances than those of a parallel coupling configuration. Furthermore, subsequent device designs provide sensitive broadband photodetection from the millimeter‐wave to visible light wavelength regions with a minimum noise equivalent power of 5 pWHz−1/2 in an uncooled nonvacuum condition. Simultaneously, the mechanical flexibility of the proposed photodetector allows for its use in freely attachable sheet imager applications on curvilinear objects, and the nondestructive 3D photomonitoring of a defective intricately bent sample is demonstrated.

The paper analyzed dust source and dust generating characteristics in fully mechanized face and emphatically introduced methods of spraying for dust suppression applied in processes of shearer mining, support moving, coal caving, crusher working, coal transshipping and dust-catched water curtain. The practical application in Changcun Coal Mine verified effectiveness of the technology of spraying for dust suppression.

According to the characteristics of different symbolic gases produced in different periods of spontaneous combustion of coal, gas chromatography was applied to make qualitative and quantitative analysis for gas samples in mined-out area of one coal mine, the components and the change of content of the symbolic gases were used to forecast condition of coal spontaneous combustion. It establishes a foundation for taking appropriate preventive measure in advance.

Abstract Background Traffic-related air pollution especially in highly socioeconomically developed megacity is usually considered as a severe problem leading to inevitable adverse health outcomes. This study aimed to investigate the associations between traffic-related air pollutants with risk of dry eye disease (DED) outpatient visits in a megacity (Guangzhou) along the subtropical coast in South China. Methods Daily data on DED outpatient visits and environmental variables from 1 January 2014 to 31 December 2020 in Guangzhou were obtained. A time-series study using a quasi-Poisson generalized linear model (GLM) combined with distributed lag non-linear model (DLNM) was adopted. Subgroup analyses stratified by age, gender, and season were conducted. Results Totally, 27, 828 DED cases were identified during the study period including 2557 days. Daily number of outpatient visits for DED ranged from 0 to 41. An increase of 10 μg/m3 in PM2.5, NO2 and SO2 concentration was associated with 3.1%, 5.9% and 17.4% increase in the risk of DED outpatient visits, respectively (RRPM2.5 = 1.031, 95%CI: 1.004–1.059, lag 0–11 day; RRNO2 = 1.059, 95% CI: 1.027–1.092, lag0-14 day; RRSO2 = 1.174, 95% CI: 1.036–1.330, lag0-13 day). Subgroup analyses indicated that the effects of PM2.5 exposure on the risk of DED outpatient visits remained significant in aged

[Purposes] The evolution of the Arctic sea ice melt pond includes the morphological change in the horizontal direction and the structural evolution in the vertical direction, but there is a few observation equipment for the vertical structure of the melt pond. In view of the problems existing in the observation of the Arctic sea ice melt pond, an automatic observation system for the vertical temperature profile of melt pond is designed. [Methods] The system is composed of observation module, power supply module, data acquisition module, data transmission module, and auxiliary module. [Findings] This system can realize continuous automatic observation of the atmosphere, snow, sea ice, melt pond, and upper ocean. The system can also provide on-site data for the verification of the results of the melt pond model, improving China’s ability to observe the rapid changes of the Arctic sea ice, and has important engineering application value.

Abstract Background Retinal artery occlusions are rare amongst young adults, and relevant risk factors and etiology remain unclear. In this report, we present a case of central retinal artery occlusion (CRAO) as the initial manifestation of mixed connective tissue disease (MCTD) in a young woman. Case presentation A 22-year-old female presented to the emergency department with a sudden decrease in visual acuity in her right eye for 1 hour. She reported a similar episode in her left eye five years prior, which resolved spontaneously after 2 hours. Initially misdiagnosed with optic neuritis in the right eye at another hospital, she was referred to our institution the following day. Clinical examination revealed a CRAO in her right eye. A detailed medical history revealed that she had developed livedo reticularis (LR) on both lower limbs five years ago, which had been overlooked and untreated. Further rheumatologic history, hematologic tests, and an autoimmune work-up confirmed a diagnosis of mixed connective tissue disease (MCTD). Conclusion In young patients presenting with CRAO, further examinations should be conducted to investigate systemic disease or an embolic source to prevent future sequelae.

Objective Yuncheng Salt Lake, located within the core area of the Fenwei Graben System in the south-central part of the North China Craton, is the earliest known salt lake in China and worldwide. The formation and evolution of the Yuncheng Salt Lake are closely related to the Cenozoic tectonic domains of the coastal Pacific in eastern China and the Qinghai-Tibet Plateau in western China. However, there are many debates regarding the spatiotemporal processes and key timing associated with these two domains in the Yuncheng Salt Lake. Additionally, the salt lake is rich in sodium, magnesium, chloride, and sulfate ions; however the sources of these saline ions remain unclear. Methods This study investigated the major changes in the Cenozoic tectonic geomorphology of the Yuncheng Basin and its surrounding areas, focusing on the evolution of the Cenozoic river-lake system to establish the formation and evolution stages of the Yuncheng Salt Lake. This study combined the tectonic background and geochemical element analysis of typical strata in the adjacent Zhongtiao Mountains to identify the main sources of saline ions in the Yuncheng Salt Lake. Results At the boundary between the Paleogene and Neogene, there was a widespread angular unconformity across the central and eastern parts of the North China Craton. This unconformity affected the Weihe Basin in the Fenwei Graben System to the west, and not the northeastern edge of the Qinghai-Tibet Plateau, which connects to the western North China Craton. This indicates that the tectonic forces during this period originated mainly from the coastal Pacific tectonic domain of the eastern North China Craton. In the mid-Miocene, a widespread unconformity along the northeastern edge of the Qinghai-Tibet Plateau connect to the western North China Craton. The northeastward uplift and expansion of the Qinghai-Tibet Plateau affected caused the Ordos Basin to rotate counterclockwise, initiating the formation of the Shanxi Graben System within the Fenwei Graben System. The Cenozoic evolution of the Yuncheng Salt Lake is the result of the interaction between the two major tectonic domains of eastern and western China. Before the mid-Miocene, the coastal Pacific tectonic domain predominantly controlled the region. Subsequently, the long-distance effects of northeastward uplift and expansion of the Qinghai-Tibet Plateau began to influence the Yuncheng Salt Lake. The Jixian System Longjiayuan Formation in the Zhongtiao Mountain area is composed of marine carbonate deposits that is the primary source of magnesium ions for the salt lake, with an average magnesium oxide content of 20.92%. The Paleogene Pinglu Group, an arid lake basin deposit rich in gypsum layers, provids sodium, chloride, and sulfate ions to the salt lake, with an average sodium oxide content of up to 2.6%. Conclusion This study suggested that approximatedly 700000 years ago, during the transition between the early and middle Pleistocene, the Yellow River flowed eastward into the sea through the Sanmenxia Gorge, leading to the disappearance of the Sanmen paleolake and the initial formation of the Yuncheng Salt Lake. Approximately 70000 years ago, during the mid-late Pleistocene, the Fen River changed its course and left the Yuncheng Basin, transforming the salt lake from an open to a closed system, ultimately forming the Yuncheng Salt Lake. Subsequently, under the continuous influence of the fault at the northern edge of the Zhongtiao Mountains, a large sedimentary depression formed, accumulating a large amount of saline minerals. Natural salt lake is formed over long periods of precipitation and evaporation. Currently, the saline ions of the Yuncheng Salt Lake mainly originate from adjacent sedimentary strata in the Zhongtiao Mountains and deep mineralization layers. The major fault controlling the salt lake provides the upward migration and injection of saline substances from deep mineralization layers into the salt lake. The marine high-magnesium dolomite of the Longjiayuan Formation of the Mesoproterozoic Jixian System in the Zhongtiao Mountains is a major source of magnesium ions for the salt lake. Significance The research findings provide fundamental geological evidence for the implementation of an ecological protection strategy to restore the lake by reducing salt levels in Yuncheng Salt Lake.