Activated carbon fibers (ACFs) are highly efficient adsorbents for liquid and gaseous phases due to their tunable porosity, high surface area, and rapid adsorption kinetics. While polyacrylonitrile (PAN)-based ACFs are widely studied, the fundamental mechanisms governing nitrogen transformation and porosity evolution during chemical activation remain poorly understood. This study examines the structural, mechanical, chemical, and textural modifications in nitrogen-rich PAN-derived CFs during KOH activation, utilizing nitrogen contents and functionalities as indicators of the activation process. ACFs and crushed ACFs were prepared from pure PAN fibers by stabilization, carbonization, and KOH activation with different ratios at 600–900 °C. Aggressive activation conditions drastically reduced the nitrogen content and selectively decomposed specific nitrogen functionalities: pyridinic N diminished sharply, graphitic N remained comparatively stable, and pyrrolic N and pyridone species collapsed at higher temperatures. Structural and textural analyses revealed a correlation between increased disorder and lattice change, leading to the formation of a more uniform porous network in the crushed samples. However, this enhanced porosity came at the cost of mechanical integrity, as shown by reduced tensile strength and modulus. This study clarifies the relationship between activation parameters and the final properties of PAN-ACFs, providing a foundation for the optimized synthesis of these materials.

This study investigates the Dunhuang medallion patterns of the Tang Dynasty as its primary focus, conducting a systematic analysis of their morphological structures and color characteristics across four distinct historical phases, from the Early to the Late Tang periods. It also elucidates the evolution of patterns, tracing their transformation from the Early Tang's “cross” structure to the Middle-Late Tang's “six-partition” structure. Additionally, it interprets the sociological and cultural significance embedded within this progression. The study integrates shape grammar theory to create a layered deconstruction framework for pattern analysis based on split grammar principles and proposes an innovative design methodology that includes four deduction rules: generative, modifying, inherited, and derivative. New patterns are generated through vectorized extraction and regularized deduction, preserving traditional elements while aligning with modern aesthetics. The method's feasibility and utility were validated through a practical case using the design on a silk scarf, completing a research cycle of “analysis-extraction-derivation-validation.” Research shows that shape grammar provides a systematic method for innovating traditional patterns, while the resulting framework opens new avenues for reinterpreting cultural heritage.

This study examined impact of agricultural cooperative membership on technical efficiency, income, and costs of coffee farmers in Southern Shan State, Myanmar. Using stochastic frontier analysis (SFA) and propensity score matching (PSM) methods, this study estimated average treatment effect on the treated of agricultural cooperative participation. Results showed that technical efficiency, total income, and total variable costs were significantly higher for cooperative members than for comparable non-members. However, net income of members is not significantly different from that of comparable non-members.