@article{9257,
abstract = {The inverse problem of designing component interactions to target emergent structure is fundamental to numerous applications in biotechnology, materials science, and statistical physics. Equally important is the inverse problem of designing emergent kinetics, but this has received considerably less attention. Using recent advances in automatic differentiation, we show how kinetic pathways can be precisely designed by directly differentiating through statistical physics models, namely free energy calculations and molecular dynamics simulations. We consider two systems that are crucial to our understanding of structural self-assembly: bulk crystallization and small nanoclusters. In each case, we are able to assemble precise dynamical features. Using gradient information, we manipulate interactions among constituent particles to tune the rate at which these systems yield specific structures of interest. Moreover, we use this approach to learn nontrivial features about the high-dimensional design space, allowing us to accurately predict when multiple kinetic features can be simultaneously and independently controlled. These results provide a concrete and generalizable foundation for studying nonstructural self-assembly, including kinetic properties as well as other complex emergent properties, in a vast array of systems.},
author = {Goodrich, Carl Peter and King, Ella M. and Schoenholz, Samuel S. and Cubuk, Ekin D. and Brenner, Michael P.},
issn = {1091-6490},
journal = {Proceedings of the National Academy of Sciences},
number = {10},
publisher = {National Academy of Sciences},
title = {{Designing self-assembling kinetics with differentiable statistical physics models}},
doi = {10.1073/pnas.2024083118},
volume = {118},
year = {2021},
}
@article{9301,
abstract = {Electrodepositing insulating lithium peroxide (Li2O2) is the key process during discharge of aprotic Li–O2 batteries and determines rate, capacity, and reversibility. Current understanding states that the partition between surface adsorbed and dissolved lithium superoxide governs whether Li2O2 grows as a conformal surface film or larger particles, leading to low or high capacities, respectively. However, better understanding governing factors for Li2O2 packing density and capacity requires structural sensitive in situ metrologies. Here, we establish in situ small- and wide-angle X-ray scattering (SAXS/WAXS) as a suitable method to record the Li2O2 phase evolution with atomic to submicrometer resolution during cycling a custom-built in situ Li–O2 cell. Combined with sophisticated data analysis, SAXS allows retrieving rich quantitative structural information from complex multiphase systems. Surprisingly, we find that features are absent that would point at a Li2O2 surface film formed via two consecutive electron transfers, even in poorly solvating electrolytes thought to be prototypical for surface growth. All scattering data can be modeled by stacks of thin Li2O2 platelets potentially forming large toroidal particles. Li2O2 solution growth is further justified by rotating ring-disk electrode measurements and electron microscopy. Higher discharge overpotentials lead to smaller Li2O2 particles, but there is no transition to an electronically passivating, conformal Li2O2 coating. Hence, mass transport of reactive species rather than electronic transport through a Li2O2 film limits the discharge capacity. Provided that species mobilities and carbon surface areas are high, this allows for high discharge capacities even in weakly solvating electrolytes. The currently accepted Li–O2 reaction mechanism ought to be reconsidered.},
author = {Prehal, Christian and Samojlov, Aleksej and Nachtnebel, Manfred and Lovicar, Ludek and Kriechbaum, Manfred and Amenitsch, Heinz and Freunberger, Stefan Alexander},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
keywords = {small-angle X-ray scattering, oxygen reduction, disproportionation, Li-air battery},
number = {14},
publisher = {National Academy of Sciences},
title = {{In situ small-angle X-ray scattering reveals solution phase discharge of Li–O2 batteries with weakly solvating electrolytes}},
doi = {10.1073/pnas.2021893118},
volume = {118},
year = {2021},
}
@article{9443,
abstract = {Endoplasmic reticulum–plasma membrane contact sites (ER–PM CS) play fundamental roles in all eukaryotic cells. Arabidopsis thaliana mutants lacking the ER–PM protein tether synaptotagmin1 (SYT1) exhibit decreased PM integrity under multiple abiotic stresses, such as freezing, high salt, osmotic stress, and mechanical damage. Here, we show that, together with SYT1, the stress-induced SYT3 is an ER–PM tether that also functions in maintaining PM integrity. The ER–PM CS localization of SYT1 and SYT3 is dependent on PM phosphatidylinositol-4-phosphate and is regulated by abiotic stress. Lipidomic analysis revealed that cold stress increased the accumulation of diacylglycerol at the PM in a syt1/3 double mutant relative to wild-type while the levels of most glycerolipid species remain unchanged. In addition, the SYT1-green fluorescent protein fusion preferentially binds diacylglycerol in vivo with little affinity for polar glycerolipids. Our work uncovers a SYT-dependent mechanism of stress adaptation counteracting the detrimental accumulation of diacylglycerol at the PM produced during episodes of abiotic stress.},
author = {Ruiz-Lopez, N and Pérez-Sancho, J and Esteban Del Valle, A and Haslam, RP and Vanneste, S and Catalá, R and Perea-Resa, C and Van Damme, D and García-Hernández, S and Albert, A and Vallarino, J and Lin, J and Friml, Jiří and Macho, AP and Salinas, J and Rosado, A and Napier, JA and Amorim-Silva, V and Botella, MA},
issn = {1040-4651},
journal = {Plant Cell},
publisher = {American Society of Plant Biologists},
title = {{Synaptotagmins at the endoplasmic reticulum-plasma membrane contact sites maintain diacylglycerol homeostasis during abiotic stress}},
doi = {10.1093/plcell/koab122},
year = {2021},
}
@article{9447,
abstract = {Lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) based water-in-salt electrolytes (WiSEs) has recently emerged as a new promising class of electrolytes, primarily owing to their wide electrochemical stability windows (~3–4 V), that by far exceed the thermodynamic stability window of water (1.23 V). Upon increasing the salt concentration towards superconcentration the onset of the oxygen evolution reaction (OER) shifts more significantly than the hydrogen evolution reaction (HER) does. The OER shift has been explained by the accumulation of hydrophobic anions blocking water access to the electrode surface, hence by double layer theory. Here we demonstrate that the processes during oxidation are much more complex, involving OER, carbon and salt decomposition by OER intermediates, and salt precipitation upon local oversaturation. The positive shift in the onset potential of oxidation currents was elucidated by combining several advanced analysis techniques: rotating ring-disk electrode voltammetry, online electrochemical mass spectrometry, and X-ray photoelectron spectroscopy, using both dilute and superconcentrated electrolytes. The results demonstrate the importance of reactive OER intermediates and surface films for electrolyte and electrode stability and motivate further studies of the nature of the electrode.},
author = {Maffre, Marion and Bouchal, Roza and Freunberger, Stefan Alexander and Lindahl, Niklas and Johansson, Patrik and Favier, Frédéric and Fontaine, Olivier and Bélanger, Daniel},
issn = {0013-4651},
journal = {Journal of The Electrochemical Society},
keywords = {Renewable Energy, Sustainability and the Environment, Electrochemistry, Materials Chemistry, Electronic, Optical and Magnetic Materials, Surfaces, Coatings and Films, Condensed Matter Physics},
number = {5},
publisher = {IOP Publishing},
title = {{Investigation of electrochemical and chemical processes occurring at positive potentials in “Water-in-Salt” electrolytes}},
doi = {10.1149/1945-7111/ac0300},
volume = {168},
year = {2021},
}
@article{9465,
abstract = {Given a locally finite set 𝑋⊆ℝ𝑑 and an integer 𝑘≥0, we consider the function 𝐰𝑘:Del𝑘(𝑋)→ℝ on the dual of the order-k Voronoi tessellation, whose sublevel sets generalize the notion of alpha shapes from order-1 to order-k (Edelsbrunner et al. in IEEE Trans Inf Theory IT-29:551–559, 1983; Krasnoshchekov and Polishchuk in Inf Process Lett 114:76–83, 2014). While this function is not necessarily generalized discrete Morse, in the sense of Forman (Adv Math 134:90–145, 1998) and Freij (Discrete Math 309:3821–3829, 2009), we prove that it satisfies similar properties so that its increments can be meaningfully classified into critical and non-critical steps. This result extends to the case of weighted points and sheds light on k-fold covers with balls in Euclidean space.},
author = {Edelsbrunner, Herbert and Nikitenko, Anton and Osang, Georg F},
issn = {14208997},
journal = {Journal of Geometry},
number = {1},
publisher = {Springer Nature},
title = {{A step in the Delaunay mosaic of order k}},
doi = {10.1007/s00022-021-00577-4},
volume = {112},
year = {2021},
}
@inproceedings{9464,
abstract = {We firstly introduce the self-assembled growth of highly uniform Ge quantum wires with controllable position, distance and length on patterned Si (001) substrates. We then present the electrically tunable strong spin-orbit coupling, the first Ge hole spin qubit and ultrafast operation of hole spin qubit in the Ge/Si quantum wires.},
author = {Gao, Fei and Zhang, Jie Yin and Wang, Jian Huan and Ming, Ming and Wang, Tina and Zhang, Jian Jun and Watzinger, Hannes and Kukucka, Josip and Vukušić, Lada and Katsaros, Georgios and Wang, Ke and Xu, Gang and Li, Hai Ou and Guo, Guo Ping},
booktitle = {2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021},
isbn = {9781728181769},
location = {Virtual},
publisher = {IEEE},
title = {{Ge/Si quantum wires for quantum computing}},
doi = {10.1109/EDTM50988.2021.9420817},
year = {2021},
}
@article{9469,
abstract = {In this paper, we consider reflected three-operator splitting methods for monotone inclusion problems in real Hilbert spaces. To do this, we first obtain weak convergence analysis and nonasymptotic O(1/n) convergence rate of the reflected Krasnosel'skiĭ-Mann iteration for finding a fixed point of nonexpansive mapping in real Hilbert spaces under some seemingly easy to implement conditions on the iterative parameters. We then apply our results to three-operator splitting for the monotone inclusion problem and consequently obtain the corresponding convergence analysis. Furthermore, we derive reflected primal-dual algorithms for highly structured monotone inclusion problems. Some numerical implementations are drawn from splitting methods to support the theoretical analysis.},
author = {Iyiola, Olaniyi S. and Enyi, Cyril D. and Shehu, Yekini},
issn = {10294937},
journal = {Optimization Methods and Software},
publisher = {Taylor and Francis},
title = {{Reflected three-operator splitting method for monotone inclusion problem}},
doi = {10.1080/10556788.2021.1924715},
year = {2021},
}
@article{9470,
abstract = {A key step in understanding the genetic basis of different evolutionary outcomes (e.g., adaptation) is to determine the roles played by different mutation types (e.g., SNPs, translocations and inversions). To do this we must simultaneously consider different mutation types in an evolutionary framework. Here, we propose a research framework that directly utilizes the most important characteristics of mutations, their population genetic effects, to determine their relative evolutionary significance in a given scenario. We review known population genetic effects of different mutation types and show how these may be connected to different evolutionary outcomes. We provide examples of how to implement this framework and pinpoint areas where more data, theory and synthesis are needed. Linking experimental and theoretical approaches to examine different mutation types simultaneously is a critical step towards understanding their evolutionary significance.},
author = {Berdan, Emma L. and Blanckaert, Alexandre and Slotte, Tanja and Suh, Alexander and Westram, Anja M and Fragata, Inês},
issn = {1365294X},
journal = {Molecular Ecology},
number = {12},
pages = {2710--2723},
publisher = {Wiley},
title = {{Unboxing mutations: Connecting mutation types with evolutionary consequences}},
doi = {10.1111/mec.15936},
volume = {30},
year = {2021},
}
@article{9467,
abstract = {Turbulence in the flow of fluid through a pipe can be suppressed by buoyancy forces. As the suppression of turbulence leads to severe heat transfer deterioration, this is an important and undesirable phenomenon in both heating and cooling applications. Vertical flow is often considered, as the axial buoyancy force can help drive the flow. With heating measured by the buoyancy parameter 𝐶, our direct numerical simulations show that shear-driven turbulence may either be completely laminarised or it transitions to a relatively quiescent convection-driven state. Buoyancy forces cause a flattening of the base flow profile, which in isothermal pipe flow has recently been linked to complete suppression of turbulence (Kühnen et al., Nat. Phys., vol. 14, 2018, pp. 386–390), and the flattened laminar base profile has enhanced nonlinear stability (Marensi et al., J. Fluid Mech., vol. 863, 2019, pp. 50–875). In agreement with these findings, the nonlinear lower-branch travelling-wave solution analysed here, which is believed to mediate transition to turbulence in isothermal pipe flow, is shown to be suppressed by buoyancy. A linear instability of the laminar base flow is responsible for the appearance of the relatively quiescent convection driven state for 𝐶≳4 across the range of Reynolds numbers considered. In the suppression of turbulence, however, i.e. in the transition from turbulence, we find clearer association with the analysis of He et al. (J. Fluid Mech., vol. 809, 2016, pp. 31–71) than with the above dynamical systems approach, which describes better the transition to turbulence. The laminarisation criterion He et al. propose, based on an apparent Reynolds number of the flow as measured by its driving pressure gradient, is found to capture the critical 𝐶=𝐶𝑐𝑟(𝑅𝑒) above which the flow will be laminarised or switch to the convection-driven type. Our analysis suggests that it is the weakened rolls, rather than the streaks, which appear to be critical for laminarisation.},
author = {Marensi, Elena and He, Shuisheng and Willis, Ashley P.},
issn = {14697645},
journal = {Journal of Fluid Mechanics},
publisher = {Cambridge University Press},
title = {{Suppression of turbulence and travelling waves in a vertical heated pipe}},
doi = {10.1017/jfm.2021.371},
volume = {919},
year = {2021},
}
@article{9468,
abstract = {Motivated by the successful application of geometry to proving the Harary--Hill conjecture for “pseudolinear” drawings of $K_n$, we introduce “pseudospherical” drawings of graphs. A spherical drawing of a graph $G$ is a drawing in the unit sphere $\mathbb{S}^2$ in which the vertices of $G$ are represented as points---no three on a great circle---and the edges of $G$ are shortest-arcs in $\mathbb{S}^2$ connecting pairs of vertices. Such a drawing has three properties: (1) every edge $e$ is contained in a simple closed curve $\gamma_e$ such that the only vertices in $\gamma_e$ are the ends of $e$; (2) if $e\ne f$, then $\gamma_e\cap\gamma_f$ has precisely two crossings; and (3) if $e\ne f$, then $e$ intersects $\gamma_f$ at most once, in either a crossing or an end of $e$. We use properties (1)--(3) to define a pseudospherical drawing of $G$. Our main result is that for the complete graph, properties (1)--(3) are equivalent to the same three properties but with “precisely two crossings” in (2) replaced by “at most two crossings.” The proof requires a result in the geometric transversal theory of arrangements of pseudocircles. This is proved using the surprising result that the absence of special arcs (coherent spirals) in an arrangement of simple closed curves characterizes the fact that any two curves in the arrangement have at most two crossings. Our studies provide the necessary ideas for exhibiting a drawing of $K_{10}$ that has no extension to an arrangement of pseudocircles and a drawing of $K_9$ that does extend to an arrangement of pseudocircles, but no such extension has all pairs of pseudocircles crossing twice.
},
author = {Arroyo Guevara, Alan M and Richter, R. Bruce and Sunohara, Matthew},
issn = {08954801},
journal = {SIAM Journal on Discrete Mathematics},
number = {2},
pages = {1050--1076},
publisher = {Society for Industrial and Applied Mathematics},
title = {{Extending drawings of complete graphs into arrangements of pseudocircles}},
doi = {10.1137/20M1313234},
volume = {35},
year = {2021},
}