The synthesis of urea fertilizer is currently the largest CO 2 conversion process by volume in the industry. In this process, ammonium carbamate is an intermediate en route to urea formation. We determined that the tetraammineaquacopper(II) sulfate complex, [Cu(NH 3 ) 4 (OH 2 )]SO 4 , catalyzed the formation of urea from ammonium carbamate in an aqueous solution. A urea yield of up to 18 ± 6% was obtained at 120 °C after 15 h and in a high-pressure metal reactor. No significant urea formed without the catalyst. The urea product was characterized by Fourier transform infrared (FT-IR), powder X-ray diffraction (PXRD), and quantitative 1 H{ 13 C} NMR analyses. The [Cu(NH 3 ) 4 (OH 2 )]SO 4 catalyst was then recovered at the end of the reaction in a 29% recovery yield, as verified by FT-IR, PXRD, and quantitative UV−vis spectroscopy. A precipitation method using CO 2 was developed to recover and reuse 66 ± 3% of Cu(II). The catalysis mechanism was investigated by the density functional theory at the B3LYP/6-31G** level with an SMD continuum solvent model. We determined that the [Cu(NH 3 ) 4 ] 2+ complex is likely an effective catalyst structure. The study of the catalysis mechanism suggests that the coordinated carbamate with [Cu(NH 3 ) 4 ] 2+ is likely the starting point of the catalyzed reaction, and carbamic acid can be involved as a transient intermediate that facilitates the removal of an OH group. Our work has paved the way for the rational design of catalysts for urea synthesis from the greenhouse gas CO 2 .

The Japanese lesson study (JLS) model for curriculum development has seen limited application to middle school science classrooms. The JLS model was used to develop and refine three hands-on activities focused on four major eighth grade science topics from the California curriculum. Prior assessments of these topics showed limited understanding by students at a suburban school with a predominanty underrepresented population in science. Quantitative assessment of student understanding along with observations of the students’ capacity to conduct careful investigations found a large, gender-independent increase in understanding, as well as improved state-mandated test scores. Informal “local proof” assessment resulted in expansion of the JLS model into other grade levels and disciplinary subjects. This led to multiyear school-site reform and recognition outcomes.

Physical weathering in cold, steep bedrock hillslopes occurs at rates that are thought to depend on temperature, but our ability to quantify the temperature‐dependence of erosion remains limited when integrating over geomorphic timescales. Here, we present results from a 1D numerical model of in‐situ cosmogenic 10Be, 14C, and 3He concentrations that evolve as a function of erosion rate, erosion style, and ground surface temperature. We used the model to explore the suitability of these nuclides for quantifying erosion rates in areas undergoing non‐steady state erosion, as well as the relationship between bedrock temperature, erosion rate, and erosional stochasticity. Our results suggest that even in stochastically eroding settings, 10Be‐derived erosion rates of amalgamated samples can be used to estimate long‐term erosion rates, but infrequent large events can lead to bias. The ratio of 14C to 10Be can be used to evaluate erosional stochasticity, and to determine the offset between an apparent 10Be‐derived erosion rate and the long‐term rate. Finally, the concentration of 3He relative to that of 10Be, and the paleothermometric interpretations derived from it, are unaffected by erosional stochasticity. These findings, discussed in the context of bedrock hillslopes in mountainous regions, indicate that the 10Be‐14C‐3He system in quartz offers a method to evaluate the temperature‐sensitivity of bedrock erosion rates in cold, high‐alpine environments.

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<p>Erosion rates in cold, bedrock hillslopes where temperatures are below freezing for a considerable portion of the year are believed to be set by frost-cracking. Nevertheless, numerous studies from the European Alps have shown that permafrost thaw-induced rockfalls can contribute non-trivially to long-term erosion rates.</p> <p>Here, we report 27 new bedrock hillslope erosion rates from across the European Alps estimated using <em>in-situ</em> cosmogenic <sup>10</sup>Be. Samples were collected from bedrock hillslopes as well as talus slopes with identifiable (steep, bedrock) source areas using amalgamated sampling techniques. Our sites range in elevation from 2700 m to 4040 m, and consist of a range of lithologies, bedrock temperature conditions, and deglaciation histories. Furthermore, several of our selected sites include hillslopes wherein erosion rates have been previously estimated by others using methods other than <em>in-situ </em>cosmogenic nuclides. We explore how our rates vary against these previously derived rates, which may integrate over shorter (or, in exceptional cases, longer) timescales.</p> <p>Preliminary calculations yield <sup>10</sup>Be-based erosion rates ranging from 0.1 mm yr<sup>-1</sup> to 2.7 mm yr<sup>-1</sup> and show no apparent correlation with elevation, aspect, or bedrock thermal conditions. In addition to erosion rates, we likewise calculate site-specific frost-cracking intensities using modern ground surface temperatures and modelled paleoclimatic conditions. Comparing the calculated frost-cracking intensities against our erosion rates inferred using <sup>10</sup>Be suggests that frost-cracking alone is likely not the rate-limiting erosion rates in cold, high-Alpine bedrock hillslopes.</p>