A Density Control Based Adaptive Hexahedral Mesh Generation Algorithm

A density control based adaptive hexahedral mesh generation algorithm for three dimensional models is presented in this paper. The first step of this algorithm is to identify the characteristic boundary of the solid model which needs to be meshed. Secondly, the refinement fields are constructed and modified according to the conformal refinement templates, and used as a metric to generate an initial grid structure. Thirdly, a jagged core mesh is generated by removing all the elements in the exterior of the solid model. Fourthly, all of the surface nodes of the jagged core mesh are matching to the surfaces of the model through a node projection process. Finally, the mesh quality such as topology and shape is improved by using corresponding optimization techniques

Garnierite mineralization from a serpentinite-derived lateritic regolith, Sulawesi Island, Indonesia: Mineralogy, geochemistry and link to hydrologic flow regime

Garnierite represents a significant nickel ore in many lateritic Ni deposits worldwide. To gain a better understanding of its nature and origin, a well-developed garnierite-hosting transect from the Kolonodale area of East Sulawesi, Indonesia, has been investigated using field geology, mineralogy and geochemical data. Garnierite occurs mainly in veins in the lower saprolite of a serpentinite-derived regolith. Mineralogically, it can be determined as an intimate mixture of Ni-rich serpentine-like (lizardite-Nepouite) and talc-like (kerolite-pimelite) phases. Results of EMP analyses indicate that Ni is preferentially enriched in the talc-like phases rather than the serpentine-like phases. A sequential precipitation of mineral phases progressively enriched in Ni and Si to form garnierite during weathering is suggested. The Ni-lizardite (2.63-8.49 wt% Ni) with elevated Fe (4.02-6.44 wt %) may have been inherited from saprolite in a first instance and enriched in Ni by cation exchange processes. Newly precipitated minerals are kerolite-pimelite (7.84-23.54 wt% Ni) and then followed by Ni-free quartz. Minor amount of Nepouite (23.47-28.51 wt% Ni) occur in laths along shrinkage cracks of previously formed minerals, indicating a late stage paragenetic sequence. With emphasis on a hydrologic consideration, indicators of a preferential flow regime are identified in the garnierite-hosting regolith, including: (i) non-uniform pattern of the garnierite field occurrence, (ii) syn-weathering active nature of the garnierite-hosting structures, (iii) close relationship between the garnierite occurrence and vertical FeeMn oxides pipes as well as FeeMn oxides patched areas, and (iv) specific physico-chemical property of the garnierite location with higher organic matter concentrations but lower pH values compared to surroundings. It is proposed that the origin of garnierite is closely linked to a preferential flow of oversaturated solutions through accessible conduits in the regolith. Garnierite features as colloidal nature, high organic matter and low pH are key-parameters in metal transport and deposition

BeiDou Satellites Assistant Determination by Receiving Other GNSS Downlink Signals

GNSS’s orbit determinations always rely on ground station or intersatellite links (ISL). In the emergency of satellite-to-ground links and ISL break-off, BeiDou navigation satellite system (BDS) satellites cannot determine their orbits. In this paper, we propose to add a spaceborne annular beam antenna for receiving the global positioning system (GPS) and global navigation satellite system (GLONASS) signals; therefore, the BDS satellites may be capable of determining their orbits by GPS/GLONASS signals. Firstly, the spectrum selection, the power isolation, the range of Doppler frequency shift, and changing rate are taken into account for the feasibility. Specifically, the L2 band signals are chosen for receiving and processing in order to prevent the overlapping of the receiving and transmitting signals. Secondly, the minimum number of visible satellites (MNVS), carrier-to-noise ratio (C/N0), dilution of precision (GDOP), and geometric distance root-mean-square (gdrms) are evaluated for acquiring the effective receiving antennas’ coverage ranges. Finally, the scheme of deploying 3 receiving antennas is proved to be optimal by analysis and simulations over the middle earth orbit (MEO), geostationary earth orbit (GEO), and the inclined geosynchronous satellite orbit (IGSO). The antennas’ structures and patterns are designed to draw a conclusion that installing GPS and GLONASS receivers on BDS satellites for emergent orbits determination is cost-effective

Possible Luttinger liquid behavior of edge transport in monolayer transition metal dichalcogenide crystals.

In atomically-thin two-dimensional (2D) semiconductors, the nonuniformity in current flow due to its edge states may alter and even dictate the charge transport properties of the entire device. However, the influence of the edge states on electrical transport in 2D materials has not been sufficiently explored to date. Here, we systematically quantify the edge state contribution to electrical transport in monolayer MoS2/WSe2 field-effect transistors, revealing that the charge transport at low temperature is dominated by the edge conduction with the nonlinear behavior. The metallic edge states are revealed by scanning probe microscopy, scanning Kelvin probe force microscopy and first-principle calculations. Further analyses demonstrate that the edge-state dominated nonlinear transport shows a universal power-law scaling relationship with both temperature and bias voltage, which can be well explained by the 1D Luttinger liquid theory. These findings demonstrate the Luttinger liquid behavior in 2D materials and offer important insights into designing 2D electronics

Co-sensitization and cross-reactivity of Blomia tropicalis with two Dermatophagoides species in Guangzhou, China

Around 85.50% of patients were sensitized to Der p, 85.37% of patients were sensitized to Der f, and 71.54% of patients were sensitized to Blo t. Further, 70.14% of patients were co-sensitized to Blo t, Der p, and Der f, and only seven patients were sensitized solely to Blo t. With increasing sIgE levels for Blo t, the positive rates of severe-level (class 5-6) co-sensitization to Der p or Der f significantly increased. Blo t was moderately associated with Der p and Der f, with correlation coefficients of 0.6998 and 0.6782, respectively. Der p and Der f inhibited IgE binding to Blo t more strongly than Blo t inhibited IgE binding to Der p or Der f in the patient groups CBlo t  < CDer p and CBlo t  < CDer f .Open Project of State Key Laboratory of Respiratory Disease [SKLRD-OP-201803, SKLRD-OP-201809]; Science and Technology Innovation Committee Project of Guangzhou [201831802]; Bureau of traditional Chinese Medicine Scientific Research Project of Guangdong [20192048]; National Natural Science Foundation of China [81601394, 81802076, 81871736]Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

6-Gingerol Activates PI3K/Akt and Inhibits Apoptosis to Attenuate Myocardial Ischemia/Reperfusion Injury

6-Gingerol (6-G) is known to alleviate myocardial ischemia/reperfusion injury. However, the underlying molecular mechanisms of 6-G myocardial protection are not known. In this study, the protective effect of 6-G on ischemia/reperfusion (I/R) damage and whether such a mechanism was related to apoptosis inhibition and activation of phosphoinositide 3-kinases (PI3K)/serine/threonine kinase (Akt) signaling pathway were investigated. Rats were subjected to I/R in the presence or absence of 6-G and the changes of cardiac function, infarct size and histopathological changes, and the levels of cardiac troponin T, creatine kinase-MB, and myocardial apoptosis were examined. The expression of caspase-3, PI3K, p-Akt, and Akt was also determined. We found that 6-G (6 mg/kg) pretreatment significantly improved heart function and ameliorated infarct size and histopathological changes and cardiac troponin T and creatine kinase-MB levels induced by I/R. Moreover, pretreatment with 6-G significantly inhibited myocardial apoptosis and caspase-3 activation induced by I/R. 6-G also upregulated expression of PI3K, p-Akt, and Akt in myocardial tissues. Taken together, these findings suggest that 6-G inhibits apoptosis and activates PI3K/Akt signaling in response to myocardial I/R injury as a possible mechanism to attenuate I/R-induced injury in heart. These results might be important for developing novel strategies for preventing myocardial I/R injury

Switchable chiral transport in charge-ordered kagome metal CsV3Sb5

When electric conductors differ from their mirror image, unusual chiral transport coefficients appear that are forbidden in achiral metals, such as a non-linear electric response known as electronic magnetochiral anisotropy (eMChA)$^{1–6}$. Although chiral transport signatures are allowed by symmetry in many conductors without a centre of inversion, they reach appreciable levels only in rare cases in which an exceptionally strong chiral coupling to the itinerant electrons is present. So far, observations of chiral transport have been limited to materials in which the atomic positions strongly break mirror symmetries. Here, we report chiral transport in the centrosymmetric layered kagome metal CsV$_{3}$Sb$_{5}$ observed via second-harmonic generation under an in-plane magnetic field. The eMChA signal becomes significant only at temperatures below $${T}^{{\prime} }\approx$$ 35 K, deep within the charge-ordered state of CsV$_{3}$Sb$_{5}$ (T$_{CDW}$ ≈ 94 K). This temperature dependence reveals a direct correspondence between electronic chirality, unidirectional charge order$^{7}$ and spontaneous time-reversal symmetry breaking due to putative orbital loop currents$^{8–10}$. We show that the chirality is set by the out-of-plane field component and that a transition from left- to right-handed transport can be induced by changing the field sign. CsV$_{3}$Sb$_{5}$ is the first material in which strong chiral transport can be controlled and switched by small magnetic field changes, in stark contrast to structurally chiral materials, which is a prerequisite for applications in chiral electronics

Switchable chiral transport in charge-ordered kagome metal CsV3Sb5

When electric conductors differ from their mirror image, unusual chiral transport coefficients appear that are forbidden in achiral metals, such as a non-linear electric response known as electronic magnetochiral anisotropy (eMChA)1–6 . Although chiral transport signatures are allowed by symmetry in many conductors without a centre of inversion, they reach appreciable levels only in rare cases in which an exceptionally strong chiral coupling to the itinerant electrons is present. So far, observations of chiral transport have been limited to materials in which the atomic positions strongly break mirror symmetries. Here, we report chiral transport in the centrosymmetric layered kagome metal CsV3Sb5 observed via second-harmonic generation under an in-plane magnetic field. The eMChA signal becomes significant only at temperatures below T′≈ 35 K, deep within the charge-ordered state of CsV 3Sb5 (TCDW ≈ 94 K). This temperature dependence reveals a direct correspondence between electronic chirality, unidirectional charge order7 and spontaneous time-reversal symmetry breaking due to putative orbital loop currents8–10 . We show that the chirality is set by the out-of-plane field component and that a transition from left- to right-handed transport can be induced by changing the field sign. CsV3Sb5 is the first material in which strong chiral transport can be controlled and switched by small magnetic field changes, in stark contrast to structurally chiral materials, which is a prerequisite for applications in chiral electronics.This work was funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (MiTopMat, grant agreement no. 715730, and PARATOP, grant agreement no. 757867). This project received funding by the Swiss National Science Foundation (grant no. PP00P2_176789). M.G.V., I.E. and M.G.-A. acknowledge the Spanish Ministerio de Ciencia e Innovacion (grant PID2019-109905GB-C21). M.G.V., C.F. and T.N. acknowledge support from FOR 5249 (QUAST) lead by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation). This work has been supported in part by Basque Government grant IT979-16. This work was also supported by the European Research Council Advanced Grant (no. 742068) ‘TOPMAT’, the Deutsche Forschungsgemeinschaft (Project-ID no. 247310070) ‘SFB 1143’ and the DFG through the Würzburg–Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter ct.qmat (EXC 2147, Project-ID no. 390858490). Open access funding provided by Max Planck Society