The Cauchy 5 Small, Low-Volume Lunar Shield Volcano:Evidence for Volatile Exsolution-Eruption Patterns and Type 1/Type 2 Hybrid Irregular Mare Patch Formation

The lunar shield volcano Cauchy 5, sitting at the low diameter‐height‐volume end of the population, is the only known example containing two different types of Irregular Mare Patches (IMPs) in very close association: (1) the pit crater interior Type 1 IMP composed of bleb‐like mounds surrounded by a hummocky and blocky floor unit and (2) Type 2 IMPs, small, often optically immature pits less than ~5 m deep, located on the generally block‐deficient shield flanks. A four‐phase lunar magma ascent/eruption model predicts that during a relatively brief eruption, low magma rise rates maximize volatile exsolution in lava filling the pit crater. Bubble‐rich magmas overtop the pit crater and form extremely vesicular flows on the shield flanks. Exposure of the flanking flows to vacuum produces a fragmental layer of exploded glassy bubble walls. Subsequent second boiling upon cooling of the flanking flow interiors releases additional volatiles which migrate and collect, forming magmatic foams and gas pockets. As magma rise rates slow, trapped gas and magmatic foam build up below the cooling pit crater floor. Magmatic foams are extruded to form Type 1 IMP deposits. Type 2 IMPs on the flanks are interpreted to be due primarily to subsequent impacts causing collapse of the flow surface layer into the extremely vesicle‐ and void‐rich flow interior. Anomalously young pit crater floor/shield flank crater retention ages compared with surrounding maria ages may be due to effects of Cauchy 5 substrate characteristics (extreme micro‐ and macroporosity, foamy nature, and glassy auto‐regolith) on superposed crater formation and retention

An improved diameter bound for finite simple groups of Lie type

© 2019 London Mathematical Society For a finite group (Formula presented.), let (Formula presented.) denote the maximum diameter of a connected Cayley graph of (Formula presented.). A well-known conjecture of Babai states that (Formula presented.) is bounded by (Formula presented.) in case (Formula presented.) is a non-abelian finite simple group. Let (Formula presented.) be a finite simple group of Lie type of Lie rank (Formula presented.) over the field (Formula presented.). Babai's conjecture has been verified in case (Formula presented.) is bounded, but it is wide open in case (Formula presented.) is unbounded. Recently, Biswas and Yang proved that (Formula presented.) is bounded by (Formula presented.). We show that in fact (Formula presented.) holds. Note that our bound is significantly smaller than the order of (Formula presented.) for (Formula presented.) large, even if (Formula presented.) is large. As an application, we show that more generally (Formula presented.) holds for any subgroup (Formula presented.) of (Formula presented.), where (Formula presented.) is a vector space of dimension (Formula presented.) defined over the field (Formula presented.)

Multi-objective optimization coordination for urban arterial roadway based on operational-features

In this paper, a new coordinated control model is proposed based on the vehicular operational features, and a multi-objective optimization algorithm NSGA-II is employed to the model for the operation of the vehicle traveling on an urban arterial road taking three evaluation indexes into consideration as the average vehicle delay, the queue length, and the vehicle exhaust emission. A numerical experiment was made in an urban arterial road with three intersections on VISSIM for the proposed strategy, and the simulation results were compared with two commonly used pre-timed methods: Webster’s method and MAXBAND coordinated control method to verify the effectiveness of the proposed strategy in dealing with the unbalanced traffic volume condition, and it proved its advantages in designing and managing traffic systems more efficiently

State estimation for discrete-time neural networks with Markov-mode-dependent lower and upper bounds on the distributed delays

Copyright @ 2012 Springer VerlagThis paper is concerned with the state estimation problem for a new class of discrete-time neural networks with Markovian jumping parameters and mixed time-delays. The parameters of the neural networks under consideration switch over time subject to a Markov chain. The networks involve both the discrete-time-varying delay and the mode-dependent distributed time-delay characterized by the upper and lower boundaries dependent on the Markov chain. By constructing novel Lyapunov-Krasovskii functionals, sufficient conditions are firstly established to guarantee the exponential stability in mean square for the addressed discrete-time neural networks with Markovian jumping parameters and mixed time-delays. Then, the state estimation problem is coped with for the same neural network where the goal is to design a desired state estimator such that the estimation error approaches zero exponentially in mean square. The derived conditions for both the stability and the existence of desired estimators are expressed in the form of matrix inequalities that can be solved by the semi-definite programme method. A numerical simulation example is exploited to demonstrate the usefulness of the main results obtained.This work was supported in part by the Royal Society of the U.K., the National Natural Science Foundation of China under Grants 60774073 and 61074129, and the Natural Science Foundation of Jiangsu Province of China under Grant BK2010313

Singular Effects of Spin-Flip Scattering on Gapped Dirac Fermions

We investigate the effects of spin-flip scattering on the Hall transport and spectral properties of gapped Dirac fermions. We find that in the weak scattering regime, the Berry curvature distribution is dramatically compressed in the electronic energy spectrum, becoming singular at band edges. As a result the Hall conductivity has a sudden jump (or drop) of $e^2/2h$ when the Fermi energy sweeps across the band edges, and otherwise is a constant quantized in units of $e^2/2h$. In parallel, spectral properties such as the density of states and spin polarization are also greatly enhanced at band edges. Possible experimental methods to detect these effects are discussed

Challenges in multi-scale hard rock behaviour evaluation at deep underground excavations

As a consequence of rapid growing trend of resource extraction in world, depth of excavations for resource exploitation increases. Eventually excavations faces with transition from low stress to high stress condition. In this paper, comprehensive aspects on rock behaviour at deep underground excavation were investigated. The state of art of rock behaviour at micro- meso- and macro-scale were discussed and relevant challenges along with achieved knowledge, experiences, and research results were presented. At micro-scale, research results revealed that, apart from chemical bonding, rock behaviour significantly influenced by deficiencies such as; particle-crystal boundaries, heterogeneity, pores and micro-cracks, which reduces the rock strength 2-3 order of magnitude. Granite SEM images proves the deficiencies between crystals, micro-cracks and pores at each crystal, and weakness and foliation of mica components. When stresses applied on specimen, new tensile cracks nucleated and initiated from the edge of existing micro-cracks, and rate of crack propagation depends on the differential stress level. At meso-scale, true triaxial testing makes it possible to apply different stress paths in the ranges of ground in situ stresses, concentrated stresses and even dynamic loads. Careful assessment of the full stress–strain curves of the true triaxial test results of granite and conventional triaxial test results of Marble shows that rock mechanical properties such as magnitude of linear elasticity, ductility domain, peak strength value, ranges of brittleness, and residual strength level significantly differs with changing confining stresses. The rock stress – strain behaviour variation were categorised to four distinct stages consisting; 1) Elastic-stable micro-cracking, 2) Stable - unstable micro-cracking, 3) Unstable micro-cracking-brittle failure, and 4) Brittle failure-residual strength. The ranges of rock behaviour at each stage with different confining stresses were illustrated, which could be used as input for mechanical parameters in design analysis. At macro-scale, counteraction between ‘Rock Mass Composition (RMC)’, ‘Active Stress Condition (ASC)’, and ‘Excavation Method, Size and Orientation (EMSO)’ to estimate the ‘Rock Mass Behaviour (RMB)’ were discussed and presented as a verbal equation. To reduce the sudden failure risk, a micro-seismic monitoring system were designed and implemented for perdition and warning of failure and evacuation in timely manner. To verify the presented approaches, rock mass behaviour and failure mechanisms were illustrated in a deep gold mine in Western Australia. To manage the ground behaviour; considering the static and dynamic loading and interlocked nature of rock masses at deep underground excavations, the ratio of “Ground energy demand” to “support energy absorption capacity” is mostly used for stability evaluation. Finally, it should be noted that, the geomechanics at general and deep underground geomechanics specifically is a developing field due to incapability to achieve proper ground characteristics, huge number of variables and their coupled interactions, and incompetence in analysis them properly. Therefore, the results from current analysis should not be taken as granted and always solid engineering judgement must involve in interpretation and design. It is also hoped that future development in sophisticated ground exploration technologies along with advances in computation science will assist geomechanics engineers to mature their knowledge of rock mass behaviour and safe and economic design in engineering activities

Key region of laminin receptor 1 for interaction with human period 1

The 67 kDa laminin receptor 1 (Lamr1) is a novel protein that interacts with human circadian clock protein period 1 (hPer1). We confirmed the interaction between hPer1 and complete Lamr1 (295 amino acids) through yeast two-hybrid system in the present study. And we identified the interaction between hPer1 and hLamr11-190/hLamr1201-295 with yeast two-hybrid system. The results showed that hPer1 could interact with two partial Lamr1, which each contained a laminin-binding region, suggesting that both two partial sequences contained the binding region for hPer1. To define the key region of Lamr1 to interact with hPer1, pGADT7-Rec/hLamr11-190 was mutated with the palindromic sequence LMWWML, part LMW and WML, respectively. With yeast two-hybrid system, we found that hPer1 could not interact with Lamr1 mutated with LMWWML and LMW, but could interact with Lamr1 mutated with WML. It suggested that the palindromic sequence LMWWML in peptide G of Lamr1, especially LMW of it, was necessary for the interaction. Although, the palindromic sequence LMWWML is just the actual binding site for laminin. Together, these findings suggested that hPer1 might interact with Lamr1 by occupying the laminin-binding sites. It will be beneficial for studying the mechanism of hPer1 interaction with Lamr1.Key words: Laminin receptor 1 (Lamr1), human circadian clock protein period 1 (hPer1), interaction, yeast twohybrid, key region