Dichromate capture: A 3D cationic metal–organic framework consisting of distorted octahedral and tetrahedral cages was constructed by using AgI and 4,4′‐bis(1,2,4‐triazole). The complex exhibits fast ...exchange, high trapping capacity, and good selectivity for Cr2O72− through single‐crystal to single‐crystal transformation. The complex also features a bluish violet luminescence that is distinctly quenched after Cr2O72− exchange.
With the rapid development of computer technology and network communication technology, copyright protection caused by widely spread digital media has become the focus of attention in various fields. ...For digital media watermarking technology research emerge in endlessly, but the results are not ideal. In order to better realize the copyright identification and protection, based on the embedded intelligent edge computing detection technology, this paper studies the zero watermark copyright protection algorithm of digital media. Firstly, this paper designs an embedded intelligent edge detection module based on Sobel operator, including image line buffer module, convolution calculation module and threshold processing module. Then, based on the embedded intelligent edge detection module, the Arnold transform of image scrambling technology is used to preprocess the watermark, and finally a zero watermark copyright protection algorithm is constructed. At the same time, the robustness of the proposed algorithm is tested. The image is subjected to different proportion of clipping and scaling attacks, different types of noise, sharpening and blur attacks, and the detection rate and signal-to-noise ratio of each algorithm are calculated respectively. The performance of the watermark image processed by this algorithm is evaluated subjectively and objectively. Experimental data show that the detection rate of our algorithm is the highest, which is 0.89. In scaling attack, the performance of our algorithm is slightly lower than that of Fourier transform domain algorithm, but it is better than the other two algorithms. The Signal to Noise Ratio of the algorithm is 36.854% in P6 multiplicative noise attack, 39.638% in P8 sharpening edge attack and 41.285% in fuzzy attack. This shows that the algorithm is robust to conventional attacks. The subjective evaluation of 33% and 39% of the images is 5 and 4. The mean values of signal to noise ratio, peak signal to noise ratio, mean square error and mean absolute difference are 20.56, 25.13, 37.03 and 27.64, respectively. This shows that the watermark image processed by this algorithm has high quality. Therefore, the digital media zero watermark copyright protection algorithm based on embedded intelligent edge computing detection is more robust, and its watermark invisibility is also very superior, which is worth promoting.
One-dimensional (1D) semiconductor nanostructure has been widely used for gas sensor devices. In this work, a high performance gas sensor based on Au-functionalized ZnO nanorods was fabricated. Au ...nanoparticles were successfully immobilized onto the surface of ZnO nanorods to serve as a sensitizer by a facile solution reduction process. The hybrid Au/ZnO nanorods have been systematically characterized by XRD, SEM, EDS, TEM and optical absorption spectrum. Gas sensing tests reveal that the Au/ZnO sensor has remarkably enhanced performance compared to pure ZnO. It could detect ethanol gas in a wide concentration range with very high response, fast response–recovery time, good selectivity and stable repeatability. The possible sensing mechanism is discussed. The superior sensing features indicate the present Au/ZnO nanorods are promising for gas sensors.
Chemiresistive gas sensors with high sensitivity, selectivity and reliable fabrication potency for specific gas have been now expected for many applications. A highly sensitive and selective ...nanostructured triethylamine (TEA) gas sensor has been fabricated successfully by designing PN heterojunction consisting of ZnO nanosheets and NiO nanoparticles. The ZnO nanosheets directly grew on Al2O3 ceramic tubes by introducing a seed layer with a simple and cost-effective hydrothermal method. By employing pulsed laser deposition (PLD) method, the construction of NiO/ZnO PN heterojunction is highly controllable and reproducible. In comparison with ZnO nanosheet, the NiO/ZnO nanoparticle/nanosheet heterojunction exhibits much better sensing property to TEA gas. The depletion layer formed at the PN junction interface in NiO/ZnO sensor can greatly increase the resistance in air and decrease the resistance in TEA gas. Due to the general working principle and controllable growth strategy, this study provides a way for design and fabrication of the chemiresistive gas sensors with high performance.
Designer self‐assembling peptides form the entangled nanofiber networks in hydrogels by ionic‐complementary self‐assembly. This type of hydrogel has realistic biological and physiochemical properties ...to serve as biomimetic extracellular matrix (ECM) for biomedical applications. The advantages and benefits are distinct from natural hydrogels and other synthetic or semisynthetic hydrogels. Designer peptides provide diverse alternatives of main building blocks to form various functional nanostructures. The entangled nanofiber networks permit essential compositional complexity and heterogeneity of engineering cell microenvironments in comparison with other hydrogels, which may reconstruct the tumor microenvironments (TMEs) in 3D cell cultures and tissue‐specific modeling in vitro. Either ovarian cancer progression or recurrence and relapse are involved in the multifaceted TMEs in addition to mesothelial cells, fibroblasts, endothelial cells, pericytes, immune cells, adipocytes, and the ECM. Based on the progress in common hydrogel products, this work focuses on the diverse designer self‐assembling peptide hydrogels for instructive cell constructs in tissue‐specific modeling and the precise oncology remodeling for ovarian cancer, which are issued by several research aspects in a 3D context. The advantages and significance of designer peptide hydrogels are discussed, and some common approaches and coming challenges are also addressed in current complex tumor diseases.
Designer self‐assembling peptides are favorable building blocks compared to other hydrogels, which mimic 3D extracellular matrix at the nanometer scale by bioengineering nanotechnology. In 3D cell cultures, various cell constructs are fabricated by this kind of hydrogels in tissue engineering and regenerative medicine. Herein, the precise oncology remodeling is addressed by several main aspects involved in ovarian cancer.
The eastern Tibetan Plateau (TP) is a climatically sensitive area affected by the Indian Summer Monsoon (ISM). A new pollen record from a lacustrine sediment in Mao County shows that the study area ...was covered mainly by shrubs and herbs during the last deglaciation, indicating open and sparse forest grasslands. Hydrophilous herbs were mainly dominated by Cyperaceae, Poaceae, Myriophyllum, Polygonum and Typha, and they gradually increased from 18.7 to 16.8 ka, suggesting a transition to a more humid climate. This corresponds to climate cooling over the same period. From 16.8 to 14.6 ka, hydrophilous herbs continued to increase, coincident with a general ameliorating trend indicated by δ18O records from East Asia. Between 14.6 and 14.0 ka, the mean content of hydrophilous herbs reached peak in the sequence, corresponding to relatively high δ18O values during this period. From ~14.0 to 12.9 ka, the abundance of hydrophilous herbs decreased significantly. Over the same period, the Greenland ice core shows a decrease in δ18O and low-latitude cave stalagmites in China record an increase in δ18O. This implies that longitudinal temperature gradients increased and drove the southward retreat of the ISM, which in turn drove a continuous decrease in the abundance of hydrophilous herbs in the study area. From 12.9 to 11.6 ka, the mean content of hydrophilous herbs decreased to the lowest (8.3%) in the whole sequence, indicating a cold and dry climate in the study area. A positive shift in δ18O records during 11.6-10.6 ka was matched by a significant increase in the abundance of hydrophilous herbs in the study area, indicating a warm and humid climate trending. Hence, the ISM has had a significant impact on the climate of the eastern TP since the onset of deglaciation around ~16.8 ka.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Two-dimensional (2D) semiconductors beyond graphene represent the thinnest stable known nanomaterials. Rapid growth of their family and applications during the last decade of the twenty-first century ...have brought unprecedented opportunities to the advanced nano- and opto-electronic technologies. In this article, we review the latest progress in findings on the developed 2D nanomaterials. Advanced synthesis techniques of these 2D nanomaterials and heterostructures were summarized and their novel applications were discussed. The fabrication techniques include the
state-of-the-art
developments of the vapor-phase-based deposition methods and novel van der Waals (vdW) exfoliation approaches for fabrication both amorphous and crystalline 2D nanomaterials with a particular focus on the chemical vapor deposition (CVD), atomic layer deposition (ALD) of 2D semiconductors and their heterostructures as well as on vdW exfoliation of 2D surface oxide films of liquid metals.
Supply risk is one of the most important enterprise risks. Dual sourcing and backup production are the two operational strategies that firms most commonly use to mitigate supply risk. The base model ...examines the strategic use of dual sourcing and backup supply options in a two-stage dynamic programming model for one period. In the first stage the firm decides whether to employ single or dual sourcing for primary supply and whether to reserve backup option. In the second stage, if backup option has been reserved, the firm decides the backup production quantity after observing the realized primary delivery. The optimal sourcing strategies are separately characterized under deterministic and uncertain demand. The results show that dual sourcing coexists with backup production when the two primary suppliers have similar and moderate reliabilities and the backup reservation cost is relatively small. When the reliabilities of the two primary suppliers differ significantly, dual sourcing and backup can become mutually exclusive strategies. Furthermore, the existence of the backup production option decreases the probability of selecting dual sourcing; compared with deterministic demand, uncertain demand increases the area of coexistence of dual sourcing and backup production. In particular, when the firm employs dual sourcing, backup production is activated under deterministic demand only when both primary suppliers fail, while can be activated under uncertain demand when one of the primary suppliers fails. We extend the base model to a two-period structure where the reliability of one primary supplier is uncertain, and the firm updates its assessment of supplier reliability based on the delivery in previous period. Based on Bayesian forecast-updating approach, we find that reliability learning weakly increases the area of coexistence of dual sourcing and backup, and weakly decreases the probability of contingent backup production in the coexistence area.
•The interaction between dual sourcing and backup production is examined.•Dual sourcing can coexist with or exclude backup production.•Backup production decreases the probability of the application of dual sourcing.•Uncertain demand increases the area of coexistence of two instruments.•Reliability learning weakly increases the area of coexistence.
Concrete bridge crack detection is critical to guaranteeing transportation safety. The introduction of deep learning technology makes it possible to automatically and accurately detect cracks in ...bridges. We proposed an end-to-end crack detection model based on the convolutional neural network (CNN), taking the advantage of atrous convolution, Atrous Spatial Pyramid Pooling (ASPP) module and depthwise separable convolution. The atrous convolution obtains a larger receptive field without reducing the resolution. The ASPP module enables the network to extract multi-scale context information, while the depthwise separable convolution reduces computational complexity. The proposed model achieved a detection accuracy of 96.37% without pre-training. Experiments showed that, compared with traditional classification models, the proposed model has a better performance. Besides, the proposed model can be embedded in any convolutional network as an effective feature extraction structure.
Abstract Enhancing infrared images is essential for detecting wind turbine blades using infrared technology. This paper introduces an Infrared Image Enhancement Method based on Adaptive Iterative ...Cutoff Threshold Difference Multi-Scale Top-Hat Transformation (AICT-DMTH) to address the challenge of low image clarity in infrared detection. The method involves performing a black-white difference top-hat transformation by utilizing structural elements of varying scales for dilation and erosion. Additionally, an iterative threshold method is applied to extract more detailed image features, followed by setting a cutoff constant to determine the final scale of the structural element. The effectiveness of the proposed method is evaluated both qualitatively and quantitatively, with infrared images from laboratory and wind farm settings enhanced and compared against existing methods. The experimental results indicate that the proposed method significantly improves the clarity of infrared images, demonstrating robustness in enhancing images from various environments.
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