In oil and gas exploration, rock sample identification is a basic and important work. At present, the methods of rock sample identification mainly include gravity and magnetism, well logging, ...earthquake, remote sensing, electromagnetism, geochemistry, hand sample, and thin section analysis. Most of these methods for lithology identification are based on manual identification methods, which require a certain professional background and rich identification experience. Based on the deep learning method, this paper constructs the intelligent recognition model of cuttings lithology in logging work, which can realize the automatic recognition of rock images. The pre-training model is VGG16, and the parameters in the pre-training model are frozen and fine-tuned by the method of transfer learning, and finally the rock image identification based on vgg16 is realized. The accuracy of the trained model was 98% in the training set and 86% in the validation set. The experimental results show that the deep learning model based on transfer learning and vgg16 proposed in this paper has strong applicability to cuttings data and can distinguish rock types well. The intelligent lithology identification method proposed in this paper has good generalization performance and can be used for rapid intelligent identification of rock lithology in geology, well logging, power fault inspection, water conservancy and other projects.
Tin‐based halide perovskite materials have been successfully employed in lead‐free perovskite solar cells, but the overall power conversion efficiencies (PCEs) have been limited by the high carrier ...concentration from the facile oxidation of Sn2+ to Sn4+. Now a chemical route is developed for fabrication of high‐quality methylammonium tin iodide perovskite (MASnI3) films: hydrazinium tin iodide (HASnI3) perovskite film is first solution‐deposited using presursors hydrazinium iodide (HAI) and tin iodide (SnI2), and then transformed into MASnI3 via a cation displacement approach. With the two‐step process, a dense and uniform MASnI3 film is obtained with large grain sizes and high crystallization. Detrimental oxidation is suppressed by the hydrazine released from the film during the transformation. With the MASnI3 as light harvester, mesoporous perovskite solar cells were prepared, and a maximum power conversion efficiency (PCE) of 7.13 % is delivered with good reproducibility.
High‐quality, pinhole‐free CH3NH3SnI3 films are achieved from pristine NH2NH3SnI3 perovskite, and the oxidation of Sn2+ to Sn4+ can be efficiently suppressed owing to the reduction agent hydrazine generated inside the films in the conversion. With the CH3NH3SnI3 film as light absorber, mesoporous MASnI3 perovskite solar cells were fabricated with a maximum PCE of 7.13 %.
In the context of frequent occurrences of disasters worldwide, disaster-coping capability is imperative for risk reduction and contemporary emergency management. The global COVID-19 pandemic since ...2020 has further highlighted the significance of resilience construction at different geographical scales. Overall, the conceptual cognition of resilience in disaster management covers multiple elements and has diverse yielding on regional assessment. This study assesses the local resilience to the public health disaster at the prefecture-level cities, focusing on two dimensions consisting of vulnerability and capability in the targeted provincial region of Jiangsu in China. To this end, based on the vulnerability-capability framework, the Rough Analytic Hierarchy Process (RAHP) method was applied to the resilience assessment. Drawing upon the criteria derived from literature, the criteria weights were determined with the RAHP method and we assessed urban resilience with census data. In addition, the hierarchical factors contributing to urban resilience were determined using robustness analysis. This research provides constructive ideas for regional disaster reduction and contributes to the government's capability to improve urban resilience.
A sensitive, fast and comprehensive method for the quality assessment of Semen Ziziphi Spinosae (SZS) standard decoction with characterization of its chemical components was developed and validated. ...UPLC-Q/TOF-MS/MS system was used to identify thirty-six chemical components of SZS standard decoction which included nucleosides, phenolic acids, alkaloids, and flavonoids. Furthermore, a UPLC-PDA method was validated to simultaneously determine adenosine, protocatechuic acid, magnoflorine, catechin, protocatechin, vicenin II, spinosin, kaempferol-3-rutinoside, and 6'''-feruloylspinosin which represent four species of characteristic compounds. The qualitative method had been validated according to Chinese Pharmacopoeia (2015 edition) in terms of lineary, repeatability, recovery and stability for all analytes, with the results showing good precision, accuracy and stability. In conclusion, the method using UPLC combined with MS and PDA provided a novel way for the standardization and identification of SZS standard decoction, and also offered a basis for qualitative analysis and quality assessment of the preparations for SZS standard decoction.
Given the direct association with malignant ventricular arrhythmias, cardiotoxicity is a major concern in drug design. In the past decades, computational models based on the quantitative ...structure-activity relationship have been proposed to screen out cardiotoxic compounds and have shown promising results. The combination of molecular fingerprint and the machine learning model shows stable performance for a wide spectrum of problems; however, not long after the advent of the graph neural network (GNN) deep learning model and its variant (e.g., graph transformer), it has become the principal way of quantitative structure-activity relationship-based modeling for its high flexibility in feature extraction and decision rule generation. Despite all these progresses, the expressiveness (the ability of a program to identify non-isomorphic graph structures) of the GNN model is bounded by the WL isomorphism test, and a suitable thresholding scheme that relates directly to the sensitivity and credibility of a model is still an open question.
In this research, we further improved the expressiveness of the GNN model by introducing the substructure-aware bias by the graph subgraph transformer network model. Moreover, to propose the most appropriate thresholding scheme, a comprehensive comparison of the thresholding schemes was conducted.
Based on these improvements, the best model attains performance with 90.4% precision, 90.4% recall, and 90.5% F1-score with a dual-threshold scheme (active:
; non-active:
). The improved pipeline (graph subgraph transformer network model and thresholding scheme) also shows its advantages in terms of the activity cliff problem and model interpretability.
The evolution of the head was one of the key events that marked the transition from invertebrates to vertebrates. With the emergence of structures such as eyes and jaws, vertebrates evolved an active ...and predatory life style and radiated into diversity of large-bodied animals. These organs are moved by cranial muscles that derive embryologically from head mesoderm. Compared with other embryonic components of the head, such as placodes and cranial neural crest cells, our understanding of cranial mesoderm is limited and is restricted to few species.
Here, we report the expression patterns of key genes in zebrafish head mesoderm at very early developmental stages. Apart from a basic anterior-posterior axis marked by a combination of
and
expression, we find that most gene expression patterns are poorly conserved between zebrafish and chick, suggesting fewer developmental constraints imposed than in trunk mesoderm. Interestingly, the gene expression patterns clearly show the early establishment of medial-lateral compartmentalisation in zebrafish head mesoderm, comprising a wide medial zone flanked by two narrower strips.
In zebrafish head mesoderm, there is no clear molecular regionalisation along the anteroposterior axis as previously reported in chick embryos. In contrast, the medial-lateral regionalisation is formed at early developmental stages. These patterns correspond to the distinction between paraxial mesoderm and lateral plate mesoderm in the trunk, suggesting a common groundplan for patterning head and trunk mesoderm. By comparison of these expression patterns to that of amphioxus homologues, we argue for an evolutionary link between zebrafish head mesoderm and amphioxus anteriormost somites.
Budding uninhibited by benzimidazole-related 1 (BUBR1) is a central molecule of the spindle assembly checkpoint. Germline mutations in the budding uninhibited by benzimidazoles 1 homolog beta gene ...encoding BUBR1 cause premature chromatid separation (mosaic variegated aneuploidy) PCS (MVA) syndrome, which is characterized by constitutional aneuploidy and a high risk of childhood cancer. Patients with the syndrome often develop Dandy-Walker complex and polycystic kidneys; implying a critical role of BUBR1 in morphogenesis. However, little is known about the function of BUBR1 other than mitotic control. Here, we report that BUBR1 is essential for the primary cilium formation, and that the PCS (MVA) syndrome is thus a novel ciliopathy. Morpholino knockdown of bubr1 in medaka fish also caused ciliary dysfunction characterized by defects in cerebellar development and perturbed left-right asymmetry of the embryo. Biochemical analyses demonstrated that BUBR1 is required for ubiquitin-mediated proteasomal degradation of cell division cycle protein 20 in the G0 phase and maintains anaphase-promoting complex/cyclosome-CDC20 homolog 1 activity that regulates the optimal level of dishevelled for ciliogenesis.
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•PAN-APS membrane was prepared by electrospinning.•In-situ grown SiO2 nanocoating was developed to prepare SiO2@PAN membrane.•The surface was coated with environmentally friendly ...non-fluorosilicate.•SiO2@PAN membrane showed excellent waterproof and breathable performance.•SiO2@PAN membrane exhibited light-shielding performance.
Waterproof and breathable (W&B) materials with light-shielding properties are expected to provide new choices for outdoor clothing. Herein, SiO2@PAN nanofibrous membranes were fabricated by a facile and eco-friendly strategy. Firstly, amino-silane modified polyacrylonitrile (PAN-APS) nanofibrous membranes were prepared by electrospinning. Subsequently, a hierarchical rough structure and robust superhydrophobic surface were formed by a one-step in-situ growing SiO2 and coating with hexadecyltrimethoxysilane (HDTMS). The results showed that SiO2@PAN nanofibrous membranes displayed durable water repellency (the water contact angle above 150° and the sliding angle of about 5.3°), and high breathability (the air permeability of 47.23 mm/s and the moisture permeability of 3.92 kg·m−2·d-1). And SiO2@PAN nanofibrous membranes had a certain durability, which water repellency could maintain even after mechanical abrasion, or after 24 h of immersion in acid-base solutions with pH values of 1, 4, 7, 10 and 13. Moreover, SiO2@PAN nanofibrous membranes showed light-shielding properties. After 10 min exposure to sunlight irradiation, the surface temperature of SiO2@PAN membrane was about 10 °C lower than that of PAN membrane and 20 °C lower than the temperature of the surface without covering membrane. This work provides a promising candidate for protective clothing.
Heat insulation and solar energy use are attractive strategies to cope with the serious and external cold environment. Here, silver nanowires (AgNWs) with high purity and aspect ratio were ...synthesized by polyol method and PVDF/AgNWs nanofiber membranes were prepared by electrostatic spinning. We investigated the warmth retention properties of nanofiber membranes using a heating table and simulated sunlight as the heat source, respectively. The results showed that the nanofiber membrane doped with 2 wt % AgNWs had a high porosity of 84% and thus a low thermal conductivity of 18 mW m−1 K−1. Meanwhile the nanofiber membrane exhibited stable and long-lasting heat insulation behaviors and the surface temperature of the fiber membrane could reach nearly 43 °C after 5 min of irradiation with a 100 mW cm−2 light intensity and about 70 °C after 2 min of irradiation with a 300 mW cm−2 light intensity. In addition, the nanofiber membrane showed hydrophobicity with a water contact angle of 138° and breathability with air permeability of 75 mm s−1. The stress and strain of the nanofiber membrane was 3.6 Mpa and 211.3% respectively.
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•AgNWs with high purity and aspect ratio were synthesized by polyol method.•Warmth retention properties of PVDF/AgNWs nanofiber membranes was investigated.•The membranes had good hydrophobicity and air permeability.•The membranes exhibited stable and lasting warmth retention properties.•PVDF/AgNWs nanofiber membrane can convert sunlight into thermal energy.
The medaka, Oryzias latipes, a small egg-laying freshwater fish, is one of the three vertebrate model organisms in which genome-wide phenotype-driven mutant screens have been carried out. Despite a ...number of large-scale screens in zebrafish, a substantial number of mutants with new distinct phenotypes were identified in similar large-scale screens in the medaka. This observed difference in phenotype is due to the two species having a unique combination of genetic, biological and evolutional properties. The two genetic models share a whole-genome duplication event over that of tetrapods; however, each has independently specialized or lost the function of one of the two paralogues. The two fish species complement each other as genetic systems as straightforward comparison of phenotypes, ease of side-by-side analysis using the same techniques and simple and inexpensive husbandry of mutants make these small teleosts quite powerful in combination. Furthermore, both have draft genome sequences and bioinformatic tools available that facilitate further genetic dissection including whole-genome approaches. Together with the gene-driven approach to generate gene knockout mutants of the fish models, the two fish models complement the mouse in genetically dissecting vertebrate genome functions. The external embryogenesis and transparent embryos of the fish allow systematic isolation of embryonic lethal mutations, the most difficult targets in mammalian mutant screens. This chapter will describe how to work with both medaka and zebrafish almost as one species in a lab, focusing on medaka and highlighting the differences between the medaka and zebrafish systems.
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