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Collision detection capabilities of industrial manipulator is essential for ensuring the human safety during human machine collaboration. The payload variations will significantly decrease the detection accuracy and sensitivity. However, difficulty in parameter tuning of time-variant threshold and time-consuming training procedure make existed collision detection methods not easily generalized to industrial manipulator systems with payload variation. This paper presents an adaptive collision detection algorithm for six-axis industrial manipulator with accurate payload estimation. Specifically, the unknown payload is estimated online through a generalized momentum-based indirect adaptation law. Compared to existed adaptive collision detection algorithms, the joint acceleration is not needed in the adaptation law, which makes the algorithm easy to be applied to industrial manipulator systems. Based on the estimated payload, a generalized momentum external force observer is developed to estimate the external collision force. Finally, the collision detection can be realized by comparing the estimated collision force with constant threshold values. Comparative simulations and experiments indicate that the proposed adaptive collision detection method can achieve accurate and robust detection under different loads. [ABSTRACT FROM AUTHOR]

This study systematically studied the moisture characteristic curves, water‐holding capacity, and infiltration performance of different particle sizes of gangue in Nanliang coal mine and Dahaize coal mine by comprehensively using numerical simulation and measured data. The HYDRUS model was used to fit the measured moisture characteristic curve, determine the relevant soil parameters, and perform numerical simulations through the set boundary conditions to verify the reliability of the model. The results show that as the particle size of the gangue increases, the saturated water content gradually decreases, and the gangue with a smaller particle size exhibits a superior water‐holding capacity. In terms of wetting front migration, the migration distance of gangue with different particle sizes changes with time in a power function relationship, and the migration speed of gangue with a particle size of 1.25–2.5 mm is the fastest. Infiltration experiments show that gangue with a smaller particle size has a higher infiltration rate and a longer saturation time. The influence of coal gangue particle size on the water retention capacity and permeability of coal gangue is greater than the influence of coal gangue type on the water retention capacity and permeability of coal gangue. The gangue of Nanliang coal mine shows significant advantages in moisture characteristics, and its water‐holding capacity and infiltration performance are significantly better than those of Dahaize coal mine. This study systematically quantified the effects of different particle sizes of coal gangue on soil water retention characteristics, providing a new theoretical basis for its application in soil improvement. By combining numerical simulation and measured data verification methods, the accuracy and reliability of the research results were improved, providing an important reference for similar studies in the future. In addition, the significant effects of coal gangue particle size on soil wetting front migration speed and profile water content were revealed, providing new insights and basis for optimizing water resource management strategies. [ABSTRACT FROM AUTHOR]

Cuttage is the main propagation method of tea plant cultivars in China. However, some tea softwood cuttings just form an expanded and loose callus at the base, without adventitious root (AR) formation during the propagation period. Meanwhile, exogenous auxin could promote the AR formation of tea plant cuttings, but the regulation mechanism has not yet explained clearly. We conducted this study to elucidate the regulatory mechanism of exogenous auxin-induced adventitious root (AR) formation of such cuttings. The transcriptional expression profile of non-rooting tea calluses in response to exogenous IBA and NAA was analyzed using ONT RNA Seq technology. In total, 56,178 differentially expressed genes (DEGs) were detected, and most of genes were significantly differentially expressed after 12 h of exogenous auxin treatment. Among these DEGs, we further identified 80 DEGs involved in the auxin induction pathway and AR formation. Specifically, 14 auxin respective genes (ARFs, GH3s, and AUX/IAAs), 3 auxin transporters (AUX22), 19 auxin synthesis- and homeostasis-related genes (cytochrome P450 (CYP450) and calmodulin-like protein (CML) genes), and 44 transcription factors (LOB domain-containing protein (LBDs), SCARECROW-LIKE (SCL), zinc finger protein, WRKY, MYB, and NAC) were identified from these DEGs. Moreover, we found most of these DEGs were highly up-regulated at some stage before AR formation, suggesting that they may play a potential role in the AR formation of tea plant cuttings. In summary, this study will provide a theoretical foundation to deepen our understanding of the molecular mechanism of AR formation in tea cuttings induced by auxin during propagation time. [ABSTRACT FROM AUTHOR]

In order to study the law of ground pressure appearance in the face with large mining height in shallow coal seam and determine its reasonable working resistance of support, the 5-2 coal 503 working face of Daliuta Coal Mine in Shendong is selected as the research object. The law of ground pressure appearance in the face with large mining height in shallow coal seam is studied through the thin plate theory and the field measured ground pressure data, and the support resistance is calculated by combining two different theoretical calculation formulas force analysis. The results show that the initial step distance of 52503 working face is 64.4 m, which is basically consistent with 61.7 m calculated based on thin plate theory; the periodic weighting step fluctuates between 7.65 m and 29.75 m during the normal mining period, with an average of 19.16 m, a dynamic load coefficient of 1.45-1.57, an average of 1.50, which shows a strong mine pressure; during the weighting period, the support resistance along the inclined direction of the working face presents a “convex” type among them, the lower support resistance of the working face is about 69.8% of the middle part, and the upper support resistance of the working face is about 66.5% of the middle part; the working resistance calculated based on the two support strength theories is 17 871 kN and 19 890 kN respectively, which is smaller than the ZY21000/36.5/70D hydraulic support with the rated working resistance of 21 000 kN, which can meet the support requirements of the roof pressure above the working face.

In order to study the influence of the aspect ratio of the short-wall filling roadway on the stability of surrounding rock, the theory of numerical analysis and numerical simulation were used to analyze the principle of cooperative roof control of the short-wall filling roadway. The change laws of the stability of surrounding rock under different aspect ratios are presented.Research indicates that: when the height of the roadway is fixed, the maximum approach of the top floor and the two sides increases slowly with the increase of the width to height ratio and then decreases slightly, and then increases rapidly after the width to height ratio is greater than 1.0. And when the width to height ratio of the roadway is 1.0, the deformation of the panel per unit area is the smallest, which is most beneficial to the stability of the surrounding rock of the panel. Combined with the specific conditions of Bailiang Xusheng Coal Mine, the reasonable width-to-height ratio of the short-wall filling roadway was determined to be 1.0, and a specific support scheme was given based on the asymmetric deformation characteristics of the roof.

Nanostructural contact sites formed by interorganelle membrane contacts, including mitochondria and lysosome contacts (MLC), facilitate the exchange of substances during various life processes. However, existing bioanalytical technologies have yet to provide accurate information on the exchange of substances, as these techniques exhibit limited spatial and temporal resolution. To address this limitation, a strategy is proposed that combines fluorescence resonance energy transfer (FRET) probes with high spatial resolution detection and super‐resolution microscopes (SRM) that feature time‐resolved imaging. Specifically, a proof‐of‐concept approach is presented for monitoring H+ fluctuations during MLC with a spatial H+ biosensor targeting lysosomes, BDP‐RhB. The biosensor comprises H+‐sensitive rhodamine B as a FRET acceptor connected by a flexible chain to a BODIPY derivative as a donor. The acidity of MLC sites may vary, influencing the spatial distance of the flexible chain and causing a fluorescence transition in BDP‐RhB. Consequently, the spatial distribution of H+ can be identified using SRM. Furthermore, an algorithm has been developed to screen and identify potential compounds that control substance exchange in the MLC. Collectively, this work presents the dynamic of H+ in lysosomes within living cells, which provides a drug screening tool for studying substance exchange through interorganelle membrane contacts. [ABSTRACT FROM AUTHOR]

This article discusses the development of a novel pH probe called Mem-C0C18 for quantitative monitoring of cell surface pH using fluorescence lifetime imaging. The surface pH of tumor cells is lower than that of normal cells due to the production of acidic metabolites. The probe targets the plasma membrane and accurately measures pH changes using fluorescence lifetime imaging. The article provides details on the molecular design of the probe, its spectral properties, establishment of standard curves, and its application in evaluating the effects of extracellular fluid acidity and glycolysis on cell surface pH. The probe shows promise as a tool for studying pH fluctuations in the cell membrane. [Extracted from the article]