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As lithium (Li)‐ion batteries expand their applications, operating over a wide temperature range becomes increasingly important. However, the low‐temperature performance of conventional graphite anodes is severely hampered by the poor diffusion kinetics of Li ions (Li⁺). Here, zinc oxide (ZnO) nanoparticles are incorporated into the expanded graphite to improve Li⁺diffusion kinetics, resulting in a significant improvement in low‐temperature performance. The ZnO–embedded expanded graphite anodes are investigated with different amounts of ZnO to establish the structure‐charge storage mechanism‐performance relationship with a focus on low‐temperature applications. Electrochemical analysis reveals that the ZnO–embedded expanded graphite anode with nano‐sized ZnO maintains a large portion of the diffusion‐controlled charge storage mechanism at an ultra‐low temperature of −50 °C. Due to this significantly enhanced Li⁺diffusion rate, a full cell with the ZnO–embedded expanded graphite anode and a LiNi_0.88Co_0.09Al_0.03O₂cathode delivers high capacities of 176 mAh g⁻¹at 20 °C and 86 mAh g⁻¹at −50 °C at a high rate of 1 C. The outstanding low‐temperature performance of the composite anode by improving the Li⁺diffusion kinetics provides important scientific insights into the fundamental design principles of anodes for low‐temperature Li‐ion battery operation.

 

Metal-free carbon materials have emerged as cost-effective and high-performance catalysts for the production of hydrogen peroxide (H 2 O 2 ) through the two-electron oxygen reduction reaction (ORR). Here, we show that 3D crumpled graphene with controlled oxygen and defect configurations significantly improves the electrocatalytic production of H 2 O 2 . The crumpled graphene electrocatalyst with optimal defect structures and oxygen functional groups exhibits outstanding H 2 O 2 selectivity of 92–100% in a wide potential window of 0.05–0.7 V vs. reversible hydrogen electrode (RHE) and a high mass activity of 158 A g −1 at 0.65 V vs. RHE in alkaline media. In addition, the crumpled graphene catalyst showed an excellent H 2 O 2 production rate of 473.9 mmol gcat −1 h −1 and stability over 46 h at 0.4 V vs. RHE. Moreover, density functional theory calculations revealed the role of the functional groups and defect sites in the two-electron ORR pathway through the scaling relation between OOH and O adsorption strengths. These results establish a structure-mechanism-performance relationship of functionalized carbon catalysts for the effective production of H 2 O 2 . 

As more people turn to discretionary online tools to learn new skills such as computer programming, exploring how to better support a wide range of learners is becoming increasingly essential to train the next generation of highly skilled technology workers. In our prior work, users with high learner autonomy complained that most online resources they used to learn more programming did not provide them with the flexibility they preferred to navigate through learning materials, locking them into a set sequence of topics/concepts. To explore this, we implemented a level-jumping feature into an online educational programming game. We tested it with 350 new users, tracking their progress through the game for 7 days each. We found that those with high learner autonomy did use the level jumping feature more than those with low learner autonomy. We also found that males were more likely to use this new feature, regardless of learner autonomy level, compared to their female counterparts. Finally, we found that those with low learner autonomy ultimately completed more levels than their high autonomy counterparts, and that this was particularly true of female learners (who completed the most levels overall). Based on these findings, we believe that autonomous-supportive features such as flexible navigation may be beneficial to all users of online educational tools, and that encouraging its use by a wider group of users (particularly females), may increase positive effects. 

Antarctic terrestrial biodiversity faces multiple threats, from invasive species to climate change. Yet no large-scale assessments of threat management strategies exist. Applying a structured participatory approach, we demonstrate that existing conservation efforts are insufficient in a changing world, estimating that 65% (at best 37%, at worst 97%) of native terrestrial taxa and land-associated seabirds are likely to decline by 2100 under current trajectories. Emperor penguins are identified as the most vulnerable taxon, followed by other seabirds and dry soil nematodes. We find that implementing 10 key threat management strategies in parallel, at an estimated present-day equivalent annual cost of US$23 million, could benefit up to 84% of Antarctic taxa. Climate change is identified as the most pervasive threat to Antarctic biodiversity and influencing global policy to effectively limit climate change is the most beneficial conservation strategy. However, minimising impacts of human activities and improved planning and management of new infrastructure projects are cost-effective and will help to minimise regional threats. Simultaneous global and regional efforts are critical to secure Antarctic biodiversity for future generations. 

People often learn programming in face-to-face courses or online tutorials. Interactive computer tutors---systems that provide learning content interactively---are becoming more common in online tools such as those teaching computer programming. Studies have shown that teachers, interactive computer tutors, and the combination of both are efficient and effective in teaching programming. However, there is limited understanding of the comparative perspectives of learners learning from these two different sources. We conducted an exploratory study using semi-structured interviews and recruited 20 participants with programming experience from both teachers and interactive computer tutors. Speaking with our participants, we surfaced factors that learners like and dislike from the two learning resources and discussed the strengths and weaknesses between the two. Based on our findings, we discuss implications for designs that programming educators and interactive computer tutor developers can use to improve their teaching effectiveness. 

Many people are learning programming on their own using various online resources such as educational games. Unfortunately, little is known about how to keep online educational game learners motivated throughout their game play, especially if they become disengaged or frustrated with their task. Keeping online learners engaged is essential for learning programming, as it may have lasting effects on their views and self-efficacy towards computer science. To address this issue, we created a coarse-grained frustration detector that provided users with customized, adaptive feedback to help (re)engage them with the game content. We ran a controlled experiment with 400 participants over the course of 1.5 months, with half of the players playing the original game, and the other half playing the game with the frustration detection and adaptive feed- back. We found that the users who received the adaptive feedback when frustrated completed more levels than their counterparts who did not receive this customized feedback. Based on these findings, we believe that adaptive feedback is essential in keeping educational game learners engaged, and propose future work for researchers and designers of online educational games to better support their users.