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A modified, bilingual Attitudes Toward Mathematics Inventory (ATMI) instrument was administered to 1,258 high school students in South Texas in an NSF-funded project on informal learning of mathematics and near peer mentoring. We explore students’ survey response behaviors and examine the existence of careless and insufficient effort (CIE) responses. This is empirical research for handling the challenge of CIE responses that leads to improved survey data quality, thus eventually validating the intervention effect of the mathematical informal learning project. 

Research in mentoring has shown that students may at times be more willing and able to absorb information that is delivered to them by their near-peers, rather than by traditional figures of authority, like teachers and professors. In this study, underrepresented minority high school students participated in an informal learning experience that was led by college students who were near-peers to the high schoolers. Students were engaged by participating in interactive MathShows, following a Math Social Media Campaign, and attending a summer Math Internship. Participants in the quantitative component of the study included N = 559 U.S. high schoolers who were from predominantly (99%) Hispanic ethnic backgrounds. The qualitative component of the study involved another 19 students from the same school. The mixed methods study addresses associations between high schoolers’ attitudes toward mathematics and their identity alignment, as well as classes of reasons that students gave for their identity alignment. Interactions with the college near-peers that occurred during the experiential learning intervention are also discussed. Results of this study address the goal of broadening participation of underrepresented student groups in STEM careers. 

Abstract Paper-based electrochemical sensors provide the opportunity for low-cost, portable and environmentally friendly single-use chemical analysis and there are various reports of surface-functionalized paper electrodes. Here we report a composite paper electrode that is fabricated through designed papermaking using cellulose, carbon fibers (CF), and graphene oxide (GO). The composite paper has well-controlled structure, stable, and repeatable properties, and offers the electrocatalytic activities for sensitive and selective chemical detection. We demonstrate that this CF/GO/cellulose composite paper can be reduced electrochemically using relatively mild conditions and this GO reduction confers electrocatalytic properties to the composite paper. Finally, we demonstrate that this composite paper offers sensing performance (sensitivity and selectivity) comparable to, or better than, paper-based sensors prepared by small-batch surface-modification (e.g., printing) methods. We envision this coupling of industrialized papermaking technologies with interfacial engineering and electrochemical reduction can provide a platform for single-use and portable chemical detection for a wide range of applications. 

Abstract Self‐assembled materials with complex nanoscale and mesoscale architecture attract considerable attention in energy and sustainability technologies. Their high performance can be attributed to high surface area, quantum effects, and hierarchical organization. Delineation of these contributions is, however, difficult because complex materials display stochastic structural patterns combining both order and disorder, which is difficult to be consistently reproduced yet being important for materials' functionality. Their compositional variability make systematic studies even harder. Here, a model system of FeSe₂“hedgehog” particles (HPs) was selected  to gain insight into the mechanisms of charge storage n complex nanostructured materials common for batteries and supercapacitors. Specifically, HPs represent self‐assembled biomimetic nanomaterials with a medium level of complexity; they display an organizational pattern of spiky colloids with considerable disorder yet non‐random; this patternt is consistently reproduced from particle to particle. . It was found that HPs can accommodate ≈70× greater charge density than spheroidal nano‐ and microparticles. Besides expanded surface area, the enhanced charge storage capacity was enabled by improved hole transport and reversible atomic conformations of FeSe₂layers in the blade‐like spikes associated with the rotatory motion of the Se atoms around Fe center. The dispersibility of HPs also enables their easy integration into energy storage devices. HPs quadruple stored electrochemical energy and double the storage modulus of structural supercapacitors. 

Abstract Photonic crystals (PCs) constructed from colloidal building blocks have attracted increasing attention because their brilliant structural colors may find broad applications in paints, sensors, displays, and security devices. However, producing high‐quality structural colors on flexible substrates such as textiles in an efficient and scalable manner remains a challenge. Here a robust and ultrafast approach to produce industrial‐scale colloidal PCs by the shear‐induced assembly of liquid colloidal crystals of polystyrene beads pre‐formed spontaneously over a critical volume fraction is demonstrated. The pre‐crystallization of colloidal crystals allows their efficient assembly into large‐scale PCs on flexible fabric substrates under shear force. Further, by programming the wettability of the fabric substrate with hydrophilic–hydrophobic regions, this shear‐based assembly strategy can conveniently generate pre‐designed patterns of complex structural colors. This assembly strategy brings structural coloration to flexible fabrics at a scale suitable for commercial applications; therefore, it holds the potential to revolutionize the coloration technology in the textile industry.