Salicylaldehyde imine transition metal catalyst is a kind of olefin polymerization catalyst that is widely used in the coordination of salicylaldehyde imine ligand and pre-transition metal. Salicylaldehyde imine ligands have the characteristic of easily inserting different substituents via organic synthesis. Therefore, the regulation of the polymerization activity, polymerization product, and product distribution can be achieved by changing the steric hindrance effect, the electronic effect, and the number of metal active sites near the catalytic active center. The development status of the transition metal catalyst of salicylaldehyde imide was summarized in this paper. The influence of the ligand structure of the salicylaldehyde imide transition metal catalyst on the catalytic performance, which involved the high selectivity of ethylene trimerization, ethylene/α-olefin, polar monomer copolymerization, ethylene polymerization production, ultra-high molecular weight polyethylene, and many other areas of olefin polymerization, was elaborated, providing references for further study and industrial applications of this catalyst.
The developmental dilemma of infant and toddler care is examined from a family perspective, and in-depth analyses of infant and toddler care are conducted using Family Systems Theory and Cultural Capital Theory,which are essential to the holistic development of children, the balance between family and work, and the sustainable development of society and the economy.The developmental dilemmas of infant and toddler care are discussed in depth from the family perspective, and solutions are proposed accordingly. By applying family systems theory and cultural capital theory to analyze the root causes and influencing factors of the problem, it provides useful thoughts and suggestions for improving infant and toddler care practices.
To deal with problems of traditional geographic information collection, such as low real-time, poor authenticity of the data, and unclear description of detailed areas, a design scheme of remote sensing-based geographic information system is proposed. The system mainly consists of information collection, imaging processing, data storage management, scene control and data transmission module. By use of remote sensing technology, the reflected and radiated electromagnetic waves of the target area are collected from a long distance to form an image, and the hue–intensity–saturation (HIS) transformation method is used to enhance the image definition. Weighted fusion algorithm is adopted to process the details of the image. The spatial database stores and manages the text and image data respectively, and establishes the attribute self-correlation mechanism to render the ground objects in the picture with SketchUp software. Finally, using RS422 protocol to transmit information can achieve the effect of multi-purpose, and enhance the anti-interference of the system. The experimental results show that the practical experience of the proposed system is excellent, the geographic information image presented is clear, and the edge details are clearly visible, which can provide users with effective geographic information data.
China's famous educator Mr. Tao Xingzhi once said that "education is the first, observation first", only scientific and effective observation can change the teachers' narrow understanding of kindergarten curriculum. From the observation record to the derived "Little Secrets in the Toilet" garden-based course, the original is just an ordinary life segment, become warm, have curriculum awareness. With an observational perspective, the teachers capture the interests and needs of the children in their lives, understand their experience levels, and provide valuable learning growth points. At the same time, in the activity, teachers reflect on their own educational content, organization mode and environment creation, and make dynamic adjustment and transformation, which promotes the development of children and improves teachers' leadership in the curriculum.
The combination of polybutylene terephthalate (PBT) and polyamide 6 (PA6) plastic mixture was taken from waste from the table production process along with carbon black (CB) reinforcement with the desire to create a potential plastic mixture widely used in many fields. The PBT/PA6/CB mix is created by injection molding with a CB weight ratio of 0%, 4%, 8%, and 12%. This study has shown the change in plastic’s mechanical properties when adding CB to the mixture by testing the unnotched impact toughness according to ASTM D256 standards. Research results show that the unnotched impact toughness was gradually reduced when increasing the CB content in the mixture from 0% to 12% CB. Specifically, at 0% CB, the resulting unnotched impact toughness was 12.85 kJ/m2, reduced to 4.78 kJ/m2.
Objective: To evaluate the clinical and radiographic results and complications of arthroscopic subcapital realignment osteotomy for the treatment of chronic and stable proximal femoral epiphysiolysis (PFE) in an initial series of patients. According to the literature review, the study presents the first description of an arthroscopic technique of this type of osteotomy. Methods: Between June 2012 and December 2014, seven patients underwent arthroscopic subcapital realignment osteotomy for the treatment of chronic, stable PFE. The mean age of the patients was 11 years and four months. Minimum follow-up ranged from 6 to 36 months (mean, 16.5 months). Patients were clinically evaluated according to the Harris Hip Score modified by Byrd and radiographically according to Southwick’s quantitative classification and the epiphyseal-diaphyseal angle. Postoperative complications were analyzed. Results: With regard to the evaluation of the Harris Hip Score Modified by Byrd clinical score, a preoperative mean of 35.8 points and a postoperative mean of 97.5 points were observed (p < 0.05). Radiographically, five patients were classified as Southwick grade II and two as grade III. A mean correction of the epiphyseal-diaphyseal angle of 40° was observed. There were no immediate postoperative complications. One patient developed avascular necrosis of the femoral head, without collapse or chondrolysis at the last follow-up (22 months). Conclusion: The arthroscopic technique presented by the authors for the treatment of chronic, stable PFE resulted in clinical and radiographic improvement of the patients in this initial series.
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