Finely preserved fossil assemblages (lagerstätten) provide crucial insights into evolutionary innovations in deep time. We report an exceptionally preserved Early Triassic fossil assemblage, the ...Guiyang Biota, from the Daye Formation near Guiyang, South China. High-precision uranium-lead dating shows that the age of the Guiyang Biota is 250.83 +0.07/-0.06 million years ago. This is only 1.08 ± 0.08 million years after the severe Permian-Triassic mass extinction, and this assemblage therefore represents the oldest known Mesozoic lagerstätte found so far. The Guiyang Biota comprises at least 12 classes and 19 orders, including diverse fish fauna and malacostracans, revealing a trophically complex marine ecosystem. Therefore, this assemblage demonstrates the rapid rise of modern-type marine ecosystems after the Permian-Triassic mass extinction.
In this work a quantum sorting algorithm with adaptable requirements of memory and circuit depth is introduced, and is used to develop a new quantum version of the classical machine learning ...algorithm known as k‐nearest neighbors (k‐NN). Both the efficiency and performance of this new quantum version of the k‐NN algorithm are compared to those of the classical k‐NN and another quantum version proposed by Schuld et al. Results show that the efficiency of both quantum algorithms is similar to each other and superior to that of the classical algorithm. On the other hand, the performance of the proposed quantum k‐NN algorithm is superior to the one proposed by Schuld et al. and similar to that of the classical k‐NN.
A quantum k‐NN (QK‐NN) is developed. Its efficiency and performance are compared to those of the classical k‐NN (CK‐NN) and another quantum version proposed by Schuld. The efficiency of both quantum algorithms is similar to each other but superior to that of the classical algorithm, while the performance of present QK‐NN algorithm is superior to that proposed by Schuld and similar to that of CK‐NN.
Thermo-elastic dissipation of microbeam resonators is studied by the generalized thermo-elasticity theory of Lord and Shulman's model. Explicit formulae of thermo-elastic damping and frequency shift ...have been derived. Influences of the beam height and aspect ratio are examined. The thermal relaxation time is determined by Chester's formula, where the phonon velocity is replaced by the flexural wave velocity in the microbeam. Numerical results show that the discrepancy between results of the present non-Fourier theory and classical ones increase with decrease of aspect ratio of the beam resonator. For fixed aspect ratios thermo-elastic damping tends to increase from lower vibration modes to higher modes.
Summary
The Chinese perch Siniperca knerii Garman, 1912 is an endemic perciform freshwater fish species mainly distributed in the Yangtze River and the Pearl River of China. To evaluate their genetic ...diversity in these rivers, microsatellite markers were used to assess the genetic structure and genetic variability among nine wild populations of S. knerii. In this study, the 12 loci used were polymorphic, with observed heterozygosity (Ho) ranging from 0.4079 to 0.8886 and polymorphism information content (PIC) ranging from 0.4511 to 0.7146. Results showed that six populations from the Yangtze River had a higher genetic diversity than those from the three Pearl River populations. The Bayesian STRUCTURE analysis recovered genetic clusters that matched localities perfectly or the kind of ecology environment with a significant Fst between them. The findings of this research should provide useful information for management and conservation of S. knerii stocks.
The grasshopper optimization algorithm (GOA) is a new meta-heuristic algorithm inspired by the behavior of grasshopper groups. Aiming at the shortcomings of poor development ability and low ...convergence accuracy of GOA, this paper introduces the gravity search operator into the optimization process of GOA to improve the grasshopper's global exploration and avoid falling into local optimum in advance. At the same time, a pigeon search operator-landmark operator is introduced to improve and balance the algorithm's exploration and development capabilities. In order to verify the validity of the improved algorithm, this paper will adopts the gravity search operator and a deterrent landmark operator hybrid grasshoppers algorithm (HGOA) with basic grasshopper algorithm (GOA), particle swarm optimization (PSO) algorithm, sine and cosine algorithm (SCA), moth-flame optimization (MFO) algorithm, salp swarm algorithm (SSA), and bat algorithm (BA) to optimize 28 test functions. And the analysis and comparison of the obtained statistical data results finally show that the proposed improved grasshopper algorithm has better optimization ability.
ABSTRACT
Although eclogites in the Belomorian Province have been regarded as Archean in age and among the oldest in the world, there are also multiple studies that have proposed a Paleoproterozoic ...age. Here, we present new data for the Gridino‐type eclogites, which occur as boudins and metamorphosed dykes within tonalite–trondhjemite–granodiorite gneisses. Zircon from these eclogites has core and rim structures. The cores display high Th/U ratios (0.18–0.45), negative Eu anomalies and strong enrichment in HREE, and have Neoarchean U–Pb ages of c. 2.70 Ga; they are interpreted to be magmatic in origin. Zircon cores have δ18O of 5.64–6.07‰ suggesting the possibility of crystallization from evolved mantle‐derived magmas. In contrast, the rims, which include the eclogite facies minerals omphacite and garnet, are characterized by low Th/U ratios (<0.035) and flat HREE patterns, and yield U–Pb ages of c. 1.90 Ga; they are interpreted to be metamorphic in origin. Zircon rims have elevated δ18O of 6.23–6.80‰, which was acquired during eclogite facies metamorphism. Based on petrography and phase equilibria modelling, we recognize a prograde epidote amphibolite facies mineral assemblage, the peak eclogite facies mineral assemblage and a retrograde high‐P amphibolite facies mineral assemblage. The peak metamorphic conditions of 695–755°C at >18 kbar for the Gridino‐type eclogites suggest an apparent thermal gradient of <39–42°C/kbar for the Lapland–Kola collisional orogeny.
Tensile strain along the cR axis in epitaxial VO sub(2) films raises the temperature of the metal insulator transition and is expected to stabilize the intermediate monoclinic M2 phase. We employ ...surface-sensitive x-ray spectroscopy to distinguish from the TiO sub(2) substrate and identify the phases of VO sub(2) as a function of temperature in epitaxial VO sub(2)/TiO sub(2) thin films with well-defined biaxial strain. Although qualitatively similar to our Landau-Ginzburg theory predicted phase diagrams, the M2 phase is stabilized by nearly an order of magnitude more strain than expected for the measured temperature window. Our results reveal that the elongation of the c sub()Raxis is insufficient for describing the transition pathway of VO sub(2) epitaxial films and that a strain induced increase of electron correlation effects must be considered.
Non-invasive in situ monitoring of catalyzed chemical reactions can show and probe the stability of the catalyst and ensure a high yield of the desired chemical processes. Infrared in situ ...measurement techniques in attenuated total reflection (ATR) and transmission mode were used to assess the feasibility of these methods and ultimately compare their ability to monitor and detect active or degrading catalyst species. Four different process configurations were used, namely (i) a stirred tank reactor equipped with ATR-IR; (ii) a continuously operated miniplant with ATR-IR; (iii) a continuously operated miniplant with transmission-IR; (iv) a stirred tank reactor equipped with transmission-IR. The established hydroformylation of a long-chain olefin catalyzed by a rhodium-phosphite catalyst was taken as a representative reaction. The potential for process monitoring in molecular catalysis was evaluated. Advanced chemometric analyses by Band Target Entropy Minimization (BTEM) were performed following spectral monitoring to obtain pure component spectra estimates as well as relative time-dependent concentration profiles. In general, this study showed that infrared measurements in transmission mode are able to detect active catalytic species and can follow deactivation phenomena in batch reactions and continuously operated miniplants. Apart from the substrates and products, a number of catalytic intermediates appear to be in equilibrium exchange at reaction conditions and hence the deconvolution of multispecies spectra exhibits superimpositions of these species. Quantum chemical calculations support the structural identification of measured vibrational spectra. This comparative study of ATR versus transmission and batch experiment versus continuously operated miniplant shows that transmission IR is capable of getting in-depth spectroscopic data that can be deconvoluted by BTEM. A distinct dosing strategy is important to get meaningful data on the molecular catalyst under process conditions. This study gives a unique perspective on in situ spectroscopic infrared investigations in molecular catalysis and future process control.
This paper presents an analytical study on evaluation of thermoelastic damping (TED) in micromechanical resonators operating as mass sensors by means of the thermal energy approach. Both ...quasi-one-dimensional model and two-dimensional model are proposed and analytical expressions of TED in infinite series form for micro-beam resonator-based mass sensors are derived. We apply the proposed models to examine effects of various factors on TED, such as the position of attached mass particle, boundary conditions, geometry of resonators and mode shape of vibration. Numerical results show that thermoelastic damping of micro-beam resonator-based mass sensors increases obviously with the increase of the mass ratio of the attached mass to mass of the resonator. Compared with results of TED obtained by 2-D model accounting for the two-dimensional thermal conduction in micro-beam resonators, the quasi-1-D model overestimates TED in the high frequency range, and underestimates TED in the low frequency range. Noticeable differences are observed in the results of TED between quasi-1-D model and 2-D model. We also obtain the expressions of mass sensitivity and minimum detectable mass imposed by thermomechanical noise process for resonant mass sensors of bridge and cantilever configurations.
•Evaluation of thermoelastic damping in micro-beam resonator-based mass sensors.•Development of quasi-1-D model and 2-D model by using thermal energy approach.•Presentation of expressions of mass sensitivity and minimum detectable mass.•Comparison between results of quasi-1-D model and those of 2-D model.•Examination of effects of mass ratio and position of attached mass particle on thermoelastic damping.
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