Facile construction of fully sp2-carbon conjugated two-dimensional covalent organic frameworks containing benzobisthiazole units

Developing a facile strategy for the construction of vinylene-linked fully π-conjugated covalent organic frameworks (COFs) remains a huge challenge. Here, a versatile condition of Knoevenagel polycondensation for constructing vinylene-linked 2D COFs was explored. Three new examples of vinylene-linked 2D COFs (BTH-1, 2, 3) containing benzobisthiazoles units as functional groups were successfully prepared under this versatile and mild condition. The electron-deficient benzobisthiazole units and cyano-vinylene linkages were both integrated into the π conjugated COFs skeleton and acted as acceptor moieties. Interestingly, we found the construction of a highly ordered and conjugated D-A system is favorable for photocatalytic activity. BTH-3 with benzotrithiophene as the donor with a strong D-A effect exhibited an attractive photocatalytic HER of 15.1 mmol h−1g−1 under visible light irradiation.

Improvement of Oracle Bone Inscription Recognition Accuracy: A Deep Learning Perspective

Deep learning techniques have been successfully applied in handwriting recognition. Oracle bone inscriptions (OBI) are the earliest hieroglyphs in China and valuable resources for studying the etymology of Chinese characters. OBI are of important historical and cultural value in China; thus, textual research surrounding the characters of OBI is a huge challenge for archaeologists. In this work, we built a dataset named OBI-100, which contains 100 classes of oracle bone inscriptions collected from two OBI dictionaries. The dataset includes more than 128,000 character samples related to the natural environment, humans, animals, plants, etc. In addition, we propose improved models based on three typical deep convolutional network structures to recognize the OBI-100 dataset. By modifying the parameters, adjusting the network structures, and adopting optimization strategies, we demonstrate experimentally that these models perform fairly well in OBI recognition. For the 100-category OBI classification task, the optimal model achieves an accuracy of 99.5%, which shows competitive performance compared with other state-of-the-art approaches. We hope that this work can provide a valuable tool for character recognition of OBI.

Overview of Manually Operated Paddy Transplanter

Agriculture is the most important sector in the Indian economy. It is the most important source of employment for most of the country’s labor force. In 2012, about 49% of the labor force was engaged in agriculture. The highest proportion of these is in the rice sector. Rice is the country’s main stable food. The release of labor to sectors other than agriculture is important to the development of the country. The mechanization of rice fields has played an important role in liberating labor. Feeding a growing population is a huge challenge. The import of rice will cause the country’s economy to drain. The mechanization of the rice sector will lead to higher productivity and release labor to other sectors. The goal of the project is to design a rice transplanting mechanism for small farmers in the country to transplant rice seedlings.

Market Volatility, Digital Transformation and Innovation changed the way of competition

The world is rapidly changing. As a result, organizations have to find new ways to compete with close competitors. It is challenging to use traditional methods and ways. Advertising and price war are not gaining sustainable competitive advantage further. Most past researches mentioned that Innovation is the key to future success. Furthermore, it is required to transform to digitalization. It provides new insight into the organization. Market volatility is a huge challenge to the organization. However, it can be managed with digitalization and Innovation.

Practical Align Overview of the Main Frameworks Used by the Companies to Prevent Cyber Incidents

Among the biggest cybercrime or information security challenges, the information security professionals must be up to date with the new risks, cases, and different ways of attacks. Being up to date in this complex and aggressive scenario is a huge challenge and is a necessity to the security professional to fight against the cybercriminals. Additionally, based on this standard of requisites to start an information security program, an immature professional may be confused on the different frameworks used by the industries, mainly ISO/IEC 27000 family, NIST 800-53, NIST Cybersecurity Framework, COBIT, etc. This chapter will help the information security professional to decide where is important to focus efforts, to decide what is feasible and which control does not demand any additional investment. Additionally, this grade helps the InfoSec professionals to compare the information security maturity level within the companies and between the companies, comparing with benchmarks.

Size-controlled, hollow and hierarchically porous Co2Ni2 alloy nanocubes for efficient oxygen reduction in microbial fuel cells

Uniform, hollow-structure and hierarchically porous materials often produce surprisingly outstanding electrocatalytic performance. Besides, fabrication of highly active and stable non-noble metal-based alloys remains a huge challenge. Herein, a facile synthetic...

A hyperbranched polymer elastomer-based pressure sensitive adhesive

Creation of pressure sensitive adhesives (PSAs) with instantly tough adhesion to diverse materials in harsh conditions remains a huge challenge. Here, we report a versatile strategy for designing a hyperbranched...

Micro-Expression Recognition Based on Pixel Residual Sum and Cropped Gaussian Pyramid

Facial micro-expression(ME) recognition has great significance for the progress of human society and could find a person's true feelings. Meanwhile, ME recognition faces a huge challenge, since it is difficult to detect and easy to be disturbed by the environment. In this article, we propose two novel preprocessing methods based on Pixel Residual Sum. These methods can preprocess video clips according to the unit pixel displacement of images, resist environmental interference, and be easy to extract subtle facial features. Furthermore, we propose a Cropped Gaussian Pyramid with Overlapping(CGPO) module, which divides images of different resolutions through Gaussian pyramids and crops different resolutions images into multiple overlapping subplots. Then, we use a convolutional neural networks of progressively increasing channels based on the depthwise convolution to extract preliminary features. Finally, we fuse preliminary features and make position embedding to get the last features. Our experiments show that the proposed methods and model have better performance than the well-known methods.

Special Issue: From Host–Pathogen Interaction to Host-Directed Therapies

Despite the enormous progress made in the last few decades, infectious diseases still represent a huge challenge to human society and health systems, as evidenced by the recent SARS-CoV-2 pandemic [...]

Hierarchical living assembly: fabrication and visualization of multiblock microstructures

Nature possesses a powerful ability to assemble multiple complex structures to fabricate hierarchical biological structures in a living-assembled way. However, it is still a huge challenge for artificial systems to fabricate and characterize hierarchical living assemblies with well-defined and controllable but complex structures. In this work, we proposed a new concept for the fabrication of multiblock fluorescent microcolumns, which relies on the cooperation between the controllable host–guest complexation based on cucurbit[8]uril (CB[8]) and the living assembly of nanotubular supramolecular polymers composed of CB[8] and NaBr in aqueous solution. By using the complexation of CB[8] with different guest numbers of luminogens with aggregation-induced emission (AIEgens) characteristics, and the difference in affinity between CB[8] and different types of AIEgens, the concentration-controlled and self-sorting-controlled sequential living assembly are realized, respectively. Correspondingly, multiblock fluorescent microcolumns with different fluorescence emission are fabricated, and the molecular structure of each fluorescent block is analyzed by single crystal X-ray diffraction measurement. In addition, the living assembly of multiblock fluorescent microcolumns is visualized, understood, and regulated with the aid of AIEgens. The method developed here is expected to be extended to more guest molecules of CB[8] and also provides a referential crystallization method for CB[8]-based complexes.