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In-memory computing represents an effective method for modeling complex physical systems that are typically challenging for conventional computing architectures but has been hindered by issues such as reading noise and writing variability that restrict scalability, accuracy, and precision in high-performance computations. We propose and demonstrate a circuit architecture and programming protocol that converts the analog computing result to digital at the last step and enables low-precision analog devices to perform high-precision computing. We use a weighted sum of multiple devices to represent one number, in which subsequently programmed devices are used to compensate for preceding programming errors. With a memristor system-on-chip, we experimentally demonstrate high-precision solutions for multiple scientific computing tasks while maintaining a substantial power efficiency advantage over conventional digital approaches. 

Porphyry ore deposits, Earth’s most important resources of copper, molybdenum, and rhenium, are strongly associated with felsic magmas showing signs of high-pressure differentiation and are usually found in places with thickened crust (>45 kilometers). This pattern is well-known, but unexplained, and remains an outstanding problem in our understanding of porphyry ore deposit formation. We approach this problem by investigating the oxidation state of magmatic sulfur, which controls the behavior of ore-forming metals during magma differentiation and magmatic-hydrothermal transition. We use sulfur in apatite to reconstruct the sulfur oxidation state in the Gangdese batholith, southern Tibet. We find that magma sulfate content increased abruptly after India-Eurasia collision. Apatite sulfur content and the calculated magma S 6+ /ΣS ratio correlate with whole-rock dysprosium/ytterbium ratio, suggesting that residual garnet, favored in thickened crust, exerts a first-order control on sulfur oxidation in magmatic orogens. Our findings link sulfur oxidation to internal petrogenic processes and imply an intrinsic relationship of magma oxidation with synmagmatic crustal thickening. 

Abstract Sustainable urban systems (SUS) science is a new science integrating work across established and emerging disciplines, using diverse methods, and addressing issues at local, regional, national, and global scales. Advancing SUS requires the next generation of scholars and practitioners to excel at synthesis across disciplines and possess the skills to innovate in the realms of research, policy, and stakeholder engagement. We outline key tenets of graduate education in SUS, informed by historical and global perspectives. The sketch is an invitation to discuss how graduates in SUS should be trained to engage with the challenges and opportunities presented by continuing urbanization.