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Trigoniids, often regarded as the ‘cockles’ of the Mesozoic, inhabit several ecological niches owing to their morphological plasticity. Employing geometric morphometrics, we examined the shape evolution of nine Trigoniidae species from the Middle Jurassic to the Early Cretaceous in the Kutch basin. There appears to be a significant temporal shift in the shape of the genera Trigonia, Opisthotrigonia, and Indotrigonia. While Trigonia exhibits a shift from the sub-triangular to sub-ovate forms in the Middle–Upper Jurassic, Opisthotrigonia shows a change from the sub-rostrate to sub-ovate forms in the Upper Jurassic to Early Cretaceous. A reduction along the anterior–posterior direction is also evident in Indotrigonia. Compared with depositional environments, it appears that sub-triangular forms are adapted to low-energy depositional settings to minimize the shell-induced current vorticity through increased surface area of the posterior tip, whereas the relatively more streamlined rostrate/sub-rostrate shapes reduce exhumation in high-energy environments. However, this association between the depositional environment and trigoniid shapes cannot entirely explain the observed long-term trend, as sub-triangular forms are also found in an oolitic substrate, or sub-ovate shapes are prevalent across different substrates. Research highlights: The Trigoniidae family exhibits morphological adaptability to diverse environmental niches. Landmark morphometric analysis reveals a significant shift from sub-triangular or sub-rostrate to sub-ovate shapes within all three genera over time. Tectonic instability and environmental changes in the Kutch basin play a pivotal role in shape variation. Rapid changes in substrate and energy conditions partially influence shape changes, with sub-triangular forms in low-energy and sub-rostrate in high-energy settings. [ABSTRACT FROM AUTHOR]

Background and Aims The size and shape of reproductive structures is especially relevant in evolution because these characters are directly related to the capacity for pollination and seed dispersal, a process that plays a basic role in evolutionary patterns. The evolutionary trajectories of reproductive phenotypes in gymnosperms have received special attention in terms of pollination and innovations related to the emergence of the spermatophytes. However, variability of reproductive structures, evolutionary trends and the role of environment in the evolution of cycad species have not been well documented and explored. This study considered this topic under an explicitly phylogenetic and evolutionary approach that included a broad sampling of reproductive structures in the genus Ceratozamia. Methods We sampled 1400 individuals of 36 Ceratozamia species to explore the evolutionary pattern and identify and evaluate factors that potentially drove their evolution. We analysed characters for both pollen and ovulate strobili within a phylogenetic framework using different methods and characters (i.e. molecular and both quantitative and qualitative morphological) to infer phylogenetic relationships. Using this phylogenetic framework, evolutionary models of trait evolution for strobilar size were evaluated. In addition, quantitative morphological variation and its relation to environmental variables across species were analysed. Key Results We found contrasting phylogenetic signals between characters of pollen and ovulate strobili. These structures exhibited high morphological disparity in several characters related to size. Results of analyses of evolutionary trajectories suggested a stabilizing selection model. With regard to phenotype–environment, the analysis produced mixed results and differences for groups in the vegetation type where the species occur; however, a positive relationship with climatic variables was found. Conclusions The integrated approach synthesized reproductive phenotypic variation with current phylogenetic hypotheses and provided explicit statements of character evolution. The characters of volume for ovulate strobili were the most informative, and could provide a reference for further study of the evolutionary complexity in Ceratozamia. Finally, heterogeneous environments, which are under changing weather conditions, promote variability of reproductive structures. [ABSTRACT FROM AUTHOR]

The Cs content and the amount of oleic acid in the reaction system can be varied, and controllable structural features are achieved by adjusting the reaction time and precursor:ligand ratio. [Display omitted] The correlation between structural transformation and optical characteristics of cesium lead bromide (CsPbBr 3) nanocrystals (NCs) suggests insights into their growth mechanism and optical performance. Systematic control of reaction parameters led to the successful fabrication of on-demand shape-morphing CsPbBr 3 NCs. Transmission electron microscopy observations showed that the shape transformation from nanocubes to microcrystals could be accelerated by increasing the precursor:ligand molar ratio and reaction time. Further evidence for orthorhombic CsPbBr 3 NCs was obtained from their selected-area electron diffraction pattern, which exhibits a twin domain induced by the presence of large NCs. Likewise, we observed a substantial decrease in photoluminescence (PL) intensity of CsPbBr 3 due to surface decomposition or surface ligand loss resulting from increased size. In addition, fusion of smaller particles having other dimensionality induced the increase in the PL full-width at half maximum. In particular, existence of larger bulk material caused a reduction in the peak intensity in the absorption spectra and a trend of decreasing tendency in intensity of the absorption bands related to bromoplumbate species provided direct evidence of fully converted Cs-oleate. [ABSTRACT FROM AUTHOR]

Microbubble cleaning technology has the characteristics of environmental protection and low energy consumption and has been initially applied in the field of oil sludge cleaning. For the controllability of microbubbles in the cleaning process, this paper adopted the numerical simulation method to quantitatively study the growth and collapse mechanism of bubbles in the cleaning process, the influence law of flow field, and parameter changes on the dynamic behavior of bubbles from the perspective of micro-dynamics. It was found that the dynamic characteristics of the flow field around the bubble in the free field show a symmetrical distribution, while the motion of the fluid near the wall is blocked by the wall, and the flow field between the bubble and the wall becomes irregular. It was also found that the large amplitude pressure changes in microbubbles produced a "plastic hinge" alternating impact on the wall, the bubble collapse, and wall pulsation pressure change are mainly controlled by the driving pressure. The liquid temperature mainly affects the dynamic characteristics of the bubble by causing a change in the viscosity of the medium. Under the condition of Pd = 0.1 MPa and γ = 1.5, when the liquid viscosity decreases from 0.110 to 0.00314 Pa·s, the maximum pressure affected by the first bubble collapse increases from 200.71 to 317.74 Kpa. Compared with the bubble distribution, the impact of increasing the number of bubbles on the wall is more significant. Under the condition of γ = 1 and Pd = 0.1 MPa, compared with the single bubble, the pulse pressure of nine bubbles' collapse on the wall increases by 100 KPa. The research results can provide technical support for the development of microbubble cleaning technology. [ABSTRACT FROM AUTHOR]

Buddhism spread along the Silk Road, and its pagodas were introduced into Central Asia from India in the beginning, and then into Xinjiang, which evolved various pagodas, showing the characteristics of multi-culturalism, reflecting the epidemic of Buddhism in Xinjiang during the Han and Tang Dynasties and the evolution of pagodas under the influence of Chinese culture, and finally making the pagodas in Xinjiang an important component of Chinese-style pagodas. This paper makes a comparative analysis of the pagoda styles in Xinjiang to find the influencing factors, so as to reflect the exchange and mutual learning between different cultures. [ABSTRACT FROM AUTHOR]

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We have investigated the shape evolution and shape coexistence in the even-even neutron-rich isotopes of Yb, Hf, W, Os, and Pt and the isotones N = 110-122 in the A~190 within the microscopic-macroscopic Cranked Nilsson-Strutinsky framework. Here, we have focused on the potential energy surface (PES) calculations to detect shape variations with N and Z. The PESs in the ground state for low-lying energy show the presence of collective and non-collective bands. The results are comparable to the studies of others where the pairing correlation was also included. It is evident deformation changes in the isotopic and isotonic chains with increasing the neutron and proton number and the filling of closed shells. The qualitative consistency of our calculations without pairing correlations, especially on the position of the PES's minima, shows that the pairing force has no a considerable effect on the nuclear shape at least in the mass region A~190.

An understanding of nanocrystal shape evolution is significant for the design, synthesis, and applications of nanocrystals with surface-enhanced properties such as catalysis or plasmonics. Surface adsorbates that are selectively attached to certain facets may strongly affect the atomic pathways of nanocrystal shape development. However, it is a great challenge to directly observe such dynamic processes in situ with a high spatial resolution. Here, we report the anomalous shape evolution of Ag2O2 nanocrystals modulated by the surface adsorbates of Ag clusters during electron beam etching, which is revealed through in situ transmission electron microscopy (TEM). In contrast to the Ag2O2 nanocrystals without adsorbates, which display the near-equilibrium shape throughout the etching process, Ag2O2 nanocrystals with Ag surface adsorbates show distinct facet development during etching by electron beam irradiation. Three stages of shape changes are observed: a sphere-to-a cube transformation, side etching of a cuboid, and bottom etching underneath the surface adsorbates. We find that the Ag adsorbates modify the Ag2O2 nanocrystal surface configuration by selectively capping the junction between two neighboring facets. They prevent the edge atoms from being etched away and block the diffusion path of surface atoms. Our findings provide critical insights into the modulatory function of surface adsorbates on the shape control of nanocrystals.

As one of the characteristic typical patterns of the Ming Dynasty 1368 - 1644 A. D. the Sihe Ruyi cloud pattern has a distinguishing feature of the times on its artistic characteristics shape and form evolution. Its development and change reflect the social changes and the shift in aesthetic consciousness of the Ming Dynasty which has very important value of research and application. Most researchers have always focused on traditional cloud patterns and the study has been only limited to modeling features and cultural connotations. However there are few reports on the research of the Sihe Ruyi cloud pattern in the Ming Dynasty. There still lacks a necessary discussion for the systematical arrangement of pattern evolution and comparison of features in early middle and late Ming Dynasty. Given that this paper based on the physical sample pictures and relevant historical materials takes the Sihe Ruyi cloud pattern on fabrics and portraits of the Ming Dynasty as the research object combs and summarizes its development context analyzes and reveals the evolution process from four aspects including unit shape basic organization form color expression and fabric technology. The following conclusions are drawn about the shape and form evolution cultural connotation and development of the Sihe Ruyi cloud pattern in the Ming Dynasty i the unit modeling gradually became plump and rounded stable structure from loose free and simple structure. The range of motion angle and turning angle of the eddy curve gradually became smaller while the regularity roundness and symmetry gradually became stronger. The external profile of the Sihe Ruyi shape gradually evolved from a free and simple irregular triangle to a smooth flexible and changeable diamond shape. The lines gradually became more fluent with a larger size while the number of connecting cloud tails increased correspondingly. ii The organization form gradually diverged from simple rigorous and was enriched with the single pattern two-sided continuous pattern as well as the scattered overlapping and concatenated four-sided continuous pattern. In addition the combined composition enhanced the auspicious meaning. iii With the numerous and gorgeous style dispelling undertint plain one the color system gradually liberated from the rules of etiquette which has the rank system distinguishing noble and humble. There are two color types of ground and pattern homochromatic ground and pattern and heterochromatic ground and pattern. The ground has four main colors red blue yellow and green. In the meantime there are four color combinations for heterochromatic ground and pattern. iv The fabrics and craftsmanship have evolved from graded materials and single technique to being more luxury and exquisite. The main material which was more dependent on cotton or linen gradually tended to be more and more diversified. Silks satins and gauzes had indeed become a fairly common fabric. The chief crafts are jacquard Zhuanghua gold-thread-woven Zhicheng etc. v The Sihe Ruyi cloud pattern in the Ming Dynasty which means cosmopolitan world peace and happiness is the unity of formal beauty and auspicious cultural connotation. The pattern which evolved from the Duoyun pattern in the Yuan Dynasty gradually became the form of four-sided Douhe and three cloud tails. The style of four cloud tails of which the decorative effect was greatly increased was formed during the reign of Hongzhi and became a prescribed format after the Zhengde period. The emergence and evolution of the Sihe Ruyi cloud pattern were a concentrated reflection of production and living manners and aesthetic consciousness of the dress pattern in the Ming Dynasty. In this paper the evolution and formation process of the Sihe Ruyi cloud pattern of the Ming Dynasty was studied by comparative analysis and statistical analysis. The development track and artistic feature in each period of the Ming Dynasty was comprehensively explored from the four angles of unit modeling organizational form color expression and fabric technology. The formation causes and modern application of the Sihe Ruyi cloud pattern need to be further discussed and perfected. [ABSTRACT FROM AUTHOR]

Ecological gradients can drive adaptive phenotypic diversification, but the extent of local adaptation depends on the strength, temporal stability and spatial dimensions of selective forces at play. We examined diversification in morphology and life histories of a live-bearing fish (Poecilia mexicana) that has adapted to two concomitant gradients: differential light regimes and toxicity levels in and around a hydrogen sulphide-rich cave. Even though typical ranging distances of P. mexicana exceed the spatial dimensions of both gradients (few hundred metres), clines in head size, body depth, male and female lean mass, offspring size, fecundity and maternal provisioning strategies tracked both gradients. Comparison of two life-history samplings from 2007/2008 and 2014 revealed remarkable temporal stability, even though some degree of temporal variation was seen in fat content and investment into reproduction. Our study demonstrates how patterns of phenotypic gradient evolution can emerge when spatially and temporally stable, strong selection forces alter selective landscapes, resulting in alternate fitness optima of different locally adapted genotypes and impeding individuals' movement even at a spatial scale far below the species' potential lifetime ranging distance. This is further evidence for the role of active colonization and gradual adaptation to cave environments in the evolution of some cave organisms. [ABSTRACT FROM AUTHOR]

In this study, the ground-state properties of the platinum isotopic chain, 160-238Pt are studied within the covariant density functional theory. The calculations are carried out for a large number of eveneven Pt isotopes by using the density-dependent point-coupling and the density dependent meson-exchange effective interactions. Several ground-state properties such as the binding energy, separation energy and quadrupole deformation are discussed and compared with available experimental data, and with the predictions of some nuclear models such as the Relativistic Mean Field (RMF) model with NL3* functional and the Hartree Fock Bogoliubov (HFB) method with UNEDF0 Skyrme force. The shape phase transition for Pt isotopic chain is also studied. [ABSTRACT FROM AUTHOR]

A systematic study of the shape evolution in Ge (Z = 32), Se (Z = 34), Kr (Z = 36) and Sr (Z = 38) isotones for N = 70, and their neighboring isotones with N = 68 and N = 72 is presented. We use, in this investigation, the covariant density functional theory (CDFT) with the explicit Density Dependent Meson-Exchange (DD-ME2) and Density-Dependent Point-Coupling (DD-PC1) models. The finite range pairing interaction separable in coordinate space which was proposed by Tian et al. has been used to treat the pairing correlations. By investigating structural properties of nuclei under consideration, it is found that N = 70 isotones are, in generally, spheric. Furtheremore, the N = 70 can be considered as magic number. [ABSTRACT FROM AUTHOR]

This study aims to compare the shape evolution of the titanium carbide (TiC) particles in different systems after immersion in hydrofluoric acid (HF) solution for different times of 48 and 96 h. The TiC particles were synthesized via the mechanical allying method in three systems of Ti–C, Ti–Al–C, and Ti–Si–C. Results indicated the different shape evolutions for the prepared TiC particles in different systems after HF treatment. After 96 h immersion, the morphologies of spherical, cubic, and octahedron were respectively observed for Ti–C, Ti–Al–C, and Ti–Si–C systems. The lattice parameter values and the presence of impurities in the systems were introduced as the main reasons for the appearance of different morphologies of TiC particles in three systems. [ABSTRACT FROM AUTHOR]

The order Characiformes is one of the most diverse and widely distributed groups of fishes in cis-Andean basins. That diversity is reflected in the São Francisco River (Brazil), where approximately 1/3 of all described species belong to that order, with many being endemic and/or considered endangered. The great morphological diversity observed in this group has been the focus of several systematic, ecomorphological, and evolutionary studies. Here, we evaluated the morphological patterns of 39 species of Characiformes from the São Francisco River using geometric morphometric and comparative phylogenetic techniques to better understand how ecological factors can modulate morphological diversity. Our data produced a highly supported topology revealing two promoters that drive the diversity of the analyzed forms, one is associated with phylogenetic inheritance, while the other is modulated by habitat, generating similarities between phylogenetically distant species. The absence of any observed relationship between body shape and trophic niche may reflect phylogenetic inertia of food preferences and morphological characteristics. Our data highlights the importance of combined analysis of all available evidences for understanding the evolutionary routes of diverse groups, as is the case of the Characiformes of the São Francisco River. [ABSTRACT FROM AUTHOR]

The effects of hydrofluoric acid (HF) etching time on the morphology of the titanium carbide (TiC) particles with different stoichiometries were investigated. TiC particles with two C/Ti molar ratios of 0.5 and 1.0 were prepared by mechanical alloying. Then, the powders were immersed in the HF solution for different times of 48, 96, and 142 h. Results showed that the morphology of TiC particles greatly changed after HF etching. In general, a roughing phenomenon was observed as a function of the immersion time in the HF solution. The irregular shape of the TiC particles changed to the spherical shapes by increasing the HF etching time. However, the changing tendency of TiC particles with different stoichiometries was different. The shape of prepared powders with a C/Ti molar ratio of 1.0 was polyhedron at the initial stages of HF treatment, while the shape of prepared powders with a C/Ti molar ratio of 0.5 was near‐spherical. However, with increasing the immersion time, the shape of both samples changed to a spherical one. The degree of roughing phenomenon of the prepared powders with a C/Ti molar ratio of 0.5 was lower than that of the prepared powders with a C/Ti molar ratio of 1.0. [ABSTRACT FROM AUTHOR]

Morphological evolution is often assumed to be causally related to underlying patterns of ecological trait evolution. However, few studies have directly tested whether evolutionary dynamics of—and major shifts in—ecological resource use are coupled with morphological shifts that may facilitate trophic innovation. Using diet and multivariate cranial (microCT) data, we tested whether rates of trophic and cranial evolution are coupled in the radiation of New World bats. We developed a generalizable information‐theoretic method for describing evolutionary rate heterogeneity across large candidate sets of multirate evolutionary models, without relying on a single best‐fitting model. We found considerable variation in trophic evolutionary dynamics, in sharp contrast to a largely homogeneous cranial evolutionary process. This dichotomy is surprising given established functional associations between overall skull morphology and trophic ecology. We suggest that assigning discrete trophic states may underestimate trophic generalism and opportunism, and that this radiation could be characterized by labile crania and a homogeneous dynamic of generally high morphological rates. Overall, we discuss how trophic classifications could substantively impact our interpretation of how these dynamics covary in adaptive radiations. [ABSTRACT FROM AUTHOR]

Thick ($>4~\mu \text{m}$) germanium-on-nothing (GON) structures are fabricated by high-temperature annealing of microscale hole arrays under vacuum condition (830 to 910°C and $2\times 10 ^{-6}$ Torr). From annealing results obtained at various temperatures and durations, the annealing temperature of 890°C where practical annealing duration (< 60 min) is achieved is determined to be the optimum due to the surface detects noticeably found at 910°C. A prediction model for annealing duration is also proposed as a function of temperature from analysis of the annealing results. Interestingly, either single or double-stack GON structures result from hole arrays with the same aspect ratio of 12 but straight or curvy sidewalls. Key factors for realizing thick GON structures include the initial microscale hole array pattern, optimum annealing temperature, and relatively straight sidewall profiles (i.e., small arc angle, $\theta _{arc} < 1^{\circ }$) of hole arrays. [2021-0230] [ABSTRACT FROM AUTHOR]

MOF‐based one‐dimensional materials have received increasing attention in the nanophotonics field, but it is still difficult in the flexible shape evolution of MOF micro/nanocrystals for desired optical functionalities due to the susceptible solvothermal growth process. Herein, we report on the well‐controlled shape evolution of pure‐MOF microcrystals with optical waveguide and lasing performances based on a bottom‐up and top‐down synergistic method. The MOF microcrystals from solvothermal synthesis (bottom‐up) enable the evolution from microrods via microtubes to nanowires through a chelating agent‐assisted etching process (top‐down). The three types of MOF 1D‐microstructures with high crystallinity and smooth surfaces all exhibit efficient optical waveguide performance. Furthermore, MOF nanowire with lowest propagation loss served as low‐threshold pure‐MOF nanolasers with Fabry–Pérot resonance. These results advance the fundamental understanding on the controlled MOF evolution mechanism, and offer a valuable route for the development of pure‐MOF‐based photonic components with desired functionalities. [ABSTRACT FROM AUTHOR]

The diversity of the vertebrate cranial shape of phylogenetically related taxa allows conclusions on ecology and life history. As pleurodeline newts (the genera Echinotriton, Pleurodeles and Tylototriton) have polymorphic reproductive modes, they are highly suitable for following cranial shape evolution in relation to reproduction and environment. We investigated interspecific differences externally and differences in the cranial shape of pleurodeline newts via two‐dimensional geometric morphometrics. Our analyses also included the closely related but extinct genus Chelotriton to better follow the evolutionary history of cranial shape. Pleurodeles was morphologically distinct in relation to other phylogenetically basal salamanders. The subgenera within Tylototriton (Tylototriton and Yaotriton) were well separated in morphospace, whereas Echinotriton resembled the subgenus Yaotriton more than Tylototriton. Oviposition site choice correlated with phylogeny and morphology. Only the mating mode, with a random distribution along the phylogenetic tree, separated crocodile newts into two morphologically distinct groups. Extinct Chelotriton likely represented several species and were morphologically and ecologically more similar to Echinotriton and Yaotriton than to Tylototriton subgenera. Our data also provide the first comprehensive morphological support for the molecular phylogeny of pleurodeline newts. [ABSTRACT FROM AUTHOR]

Li–air batteries are limited to lab‐scale research owing to the uninterrupted formation of discharge products. In the case of Li–CO2 batteries, the increase in overpotential caused by Li2CO3 formation results in cell death. In this study, Cu2O crystals having three different types of shapes (i.e., cubic, octahedral, and rhombic) were synthesized to compare their catalytic activity toward CO2 reactions. The full‐cycle and long‐term stability test revealed that rhombohedral Cu2O facilitates Li2CO3 decomposition more efficiently than that of cubic and octahedral Cu2O. The cycle was extended to investigate the photocatalytic activity of the rhombic Cu2O by illuminating the cell. The repeated cycles to 1 h showed a maximum overpotential of 1.5 V, which is 0.5 V lower than that of the cell without illumination. A postmortem analysis of the cell after dividing the cycles into segments demonstrated interesting results concerning the role of light and Cu2O during the cell cycle. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a novel method for the automatic history matching of 3D reservoirs with two lithofacies. The method simultaneously estimates distributed geological reservoir properties and facies boundaries by combining the general Ensemble Kalman Filter (EnKF) strategy with the level set method for shape propagation in 3D. Each iteration of this novel Ensemble Kalman Filter-Level Set (EnKF-LS) scheme combines the update of the boundaries of two lithofacies, represented by associated level set functions, with an update of the corresponding parameter fields, namely porosity and permeability. A narrow band technique is employed for restricting the shape motion to a neighbourhood of the current interfaces. The proposed algorithm is tested on a synthetic 3D reservoir model which is a modification of the popular SPE10 model. We use an initial ensemble of porosity and permeability fields created by a multiple-point statistics-based algorithm for a channelized test case. We compared the proposed method with an implementation of the standard EnKF algorithm and showed that the proposed EnKF-LS scheme not only provides more adequate results for such a channelized structure, but also produces a better data fit than the standard EnKF approach. [ABSTRACT FROM AUTHOR]

Evolution of planar curves under a nonlocal geometric equation is investigated. It models the simultaneous contraction and growth of carbonate particles called ooids in geosciences. Using classical ODE results and a bijective mapping, we demonstrate that the steady parameters associated with the physical environment determine a unique, time-invariant, compact shape among smooth, convex curves embedded in ℝ2. It is also revealed that any time-invariant solution possesses D2 symmetry. The model predictions remarkably agree with ooid shapes observed in nature. [ABSTRACT FROM AUTHOR]

The phenomena of shape evolution and shape coexistence within the Molybdenum isotopic chain are investigated using the covariant density functional theory with the parameterizations DD-ME2 and DD-PC1. Furthermore, various ground state properties of this chain are investigated, including binding energy, two-neutron separation energy, charge radii, and two-neutron shell gap. A robust agreement is observed when comparing with the available experimental data. The ground state deformation of Mo isotopes evolves smoothly and correlates with the continuous and gradual changes observed in the physical properties. A noticeable phenomenon of shape coexistence can be observed in certain isotopes, marked by the simultaneous existence of both a triaxial and an oblate axial minimum. A pronounced and well-defined shell closure is prominently evident at the neutron magic number N = 82. [ABSTRACT FROM AUTHOR]

In the industrial systems for CO 2 gasification of biomass, a large amount of feedstock is presented as rod-shaped particles at different scales. The evolution of such particles during gasification remains unclear. This work investigated the overall gasification characteristics of single rod-shaped biomass char particle in a hot CO 2 /O 2 /H 2 O atmosphere and the intrinsic link between shape evolution and gasification characteristics. The overall gasification characteristics of the particle are discussed, including the influence of various inlet parameters and geometric parameters. The reaction intensity on the particle surface shows significant non-uniformity, which increases with the particle Reynolds number and oxygen concentration but decreases with increasing inlet temperature. The more the particle shape resembles a rod (aspect ratio ranging from 3:2 to 3:1), the more pronounced the non-uniformity of the surface temperature becomes (increasing by over five times). The intrinsic link between particle reaction properties and shape evolution was discussed using the dynamic mesh method. The shrinkage rate at the end of the particle is 1.73 times faster than that at the middle part. The non-uniformity of the surface temperature decreases by 6 % within 5 s, indicating that as the reaction proceeds, the reaction intensity on the particle surface tends to become more uniform. [Display omitted] • The gasification of a single rod-shaped char particle was modeled for 2-D and 3-D. • A transient model of particle shrinkage was developed using the dynamic mesh method. • The carbon consumption rate is faster at the ends of the particle than in the middle. • The rod-shaped particle gradually evolves into an ellipsoidal particle. [ABSTRACT FROM AUTHOR]

In the domain of fluid dynamics, the problem of shape optimization is relevant because is essential to increase lift and reduce drag forces on a body immersed in a fluid. The current state of the art in this aspect consists of two variants: (1) evolution from an initial guess, using optimization to achieve a very specific effect, (2) creation and genetic breeding of random individuals. These approaches achieve optimal shapes and evidence of response under parameter variation. Their disadvantages are the need of an approximated solution and / or the trial - and - error generation of individuals. In response to this situation, this manuscript presents a method which uses Fluid Mechanics indicators (e.g. streamline curvature, pressure difference, zero velocity neighborhoods) to directly drive the evolution of the individual (in this case a wing profile). This pragmatic strategy mimics what an artisan (knowledgeable in a specific technical domain) effects to improve the shape. Our approach is not general, and it is not fully automated. However, it shows to efficiently reach wing profiles with the desired performance. Our approach shows the advantage of application domain - specific rules to drive the optimization, in contrast with generic administration of the evolution.

In this work, the ground state properties of the platinum isotopic chain, 1 6 0 − 2 3 8 Pt are studied within the covariant density functional theory. The calculations are carried out for a large number of even–even Pt isotopes by using the density-dependent point-coupling and the density-dependent meson-exchange effective interactions. All ground state properties such as the binding energy, separation energy, two-neutron shell gap, root mean square (rms)-radii for neutrons and protons and quadrupole deformation are discussed and compared with available experimental data, and with the predictions of some nuclear models such as the Relativistic Mean Field (RMF) model with NL3 functional and the Hartree–Fock–Bogoliubov (HFB) method with SLy4 Skyrme force. The shape phase transition for Pt isotopic chain is also studied. Its corresponding total energy curves as well as the potential energy surfaces confirm the transition from prolate to oblate shapes at 1 8 8 Pt contrary to some studies predictions and in agreement with others. Overall, a good agreement is found between the calculated and experimental results wherever available. [ABSTRACT FROM AUTHOR]

In the domain of fluid dynamics, the problem of shape optimization is relevant because is essential to increase lift and reduce drag forces on a body immersed in a fluid. The current state of the art in this aspect consists of two variants: (1) evolution from an initial guess, using optimization to achieve a very specific effect, (2) creation and genetic breeding of random individuals. These approaches achieve optimal shapes and evidence of response under parameter variation. Their disadvantages are the need of an approximated solution and / or the trial - and - error generation of individuals. In response to this situation, this manuscript presents a method which uses Fluid Mechanics indicators (e.g. streamline curvature, pressure difference, zero velocity neighborhoods) to directly drive the evolution of the individual (in this case a wing profile). This pragmatic strategy mimics what an artisan (knowledgeable in a specific technical domain) effects to improve the shape. Our approach is not general, and it is not fully automated. However, it shows to efficiently reach wing profiles with the desired performance. Our approach shows the advantage of application domain - specific rules to drive the optimization, in contrast with generic administration of the evolution. [ABSTRACT FROM AUTHOR]

Abstract This work has investigated the shape evolution of the TiC particles after immersion in the hydrofluoric acid (HF) solutions at different times. The TiC particles were prepared by mechanical alloying of the Ti-Al-C system. The field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) patterns were used to study the phase and morphological evolution of the powders. In addition, the changes in the chemical composition of the solutions were investigated by atomic absorption spectroscopy (AAS). However, the relative intensity, X-ray diffraction full width at half maximum (FWHM) value and the position of the peaks were significantly changed after HF treatment. Results showed that the only detected phase in the XRD patterns of HF-treated samples was TiC. However, there were significant differences between the peaks of the XRD patterns. The results showed that the relative intensity of the (111) planes increased as a function of the immersion time up to 48 h. Moreover, the FWHM values of the peaks revealed that a recrystallization phenomenon occurred for TiC particles after immersion into the HF solutions. The FESEM observations demonstrated that with increasing the time of HF treatment the shape of TiC particles changed from near-spherical to the octahedron and finally cubic morphology. [ABSTRACT FROM AUTHOR]

Highlights • A novel plane-space polyhedral metamorphic mechanism is presented. • The isomorphism of the plane-space polyhedral metamorphic mechanism is investigated. • The position and velocity of joints of novel plane-space isomorphic metamorphic mechanism and the workspace of these mechanisms are compared and analyzed using screw theory. • The configuration expanded analysis of novel plane-space metamorphic mechanism is performed. • Three engineering application examples for the plane-space polyhedral metamorphic mechanism are introduced. Abstract This paper introduces the concept of isomorphism into the study of metamorphic mechanisms and presents the design of the isomorphic metamorphic mechanism, in which the structure is the same but the shape topology is different. A novel plane-space polyhedral metamorphic mechanism governed by the edge forming principle is developed. This mechanism is able to achieve the structural transformation between plane topology and space topology, and it has broad prospects for engineering application. The polyhedral metamorphic mechanism can be evolved into isomorphic mechanisms, like the spherical metamorphic mechanism and conical metamorphic mechanism, according to the scale relation between links. The evolution principle and movement conditions of the isomorphic mechanism are analyzed. The position and velocity of joints of novel plane-space isomorphism metamorphic mechanism and the workspace of these mechanisms are compared and analyzed using screw theory, and the configuration expanded analysis of novel plane-space metamorphic mechanism is performed. Finally, potential engineering applications are listed. The research results provide a reference for the reasonable choice of application configuration for such mechanisms. [ABSTRACT FROM AUTHOR]

• A novel hot embossing apparatus with an in-situ observation system is developed. • A method is proposed to dig up information about real-time filling ratio and shape evolution of PMMA microstructures. • Effects of process parameters on replication accuracy of PMMA microstructures are evaluated. • A general pattern of the central filling ration with time in the embossing stage is revealed. Hot embossing is a promising technology for mass production of PMMA microstructures due to its high efficiency, low cost, and high replication accuracy. However, the real-time filling deformation behavior of PMMA in hot embossing is rarely reported. In this study, a novel hot embossing equipment with an in-situ observation system is developed. Moreover, a characterization method is proposed to dig up information about the real-time central filling ratio and shape evolution of PMMA in microchannel mold cavity. Initially, a series of hot embossing experiments were conducted to evaluate the effects of process parameters on the replication accuracy of PMMA microstructures. After that, a general pattern of the real-time central filling ratio of PMMA microstructure in the embossing stage is proposed, where it increases continuously in a decreased rate, and finally reaches a steady-state value. Finally, the real-time shape evolution and average curvature of PMMA microstructures are studied by using the in-situ observation system. It is worth to mention that the in-situ observation method has the highlights of real-time and intuition, which is quite suitable for investigating macro/micro-scale deformation behavior of materials beyond PMMA. [ABSTRACT FROM AUTHOR]

We investigate the shape of monatomic high Cu islands on a Cu(111) surface by variable-temperature scanning tunneling microscopy between 110 K and 240 K. Low temperature dendrites evolve towards more compact shapes at increasing temperature; finally reaching the equilibrium shape of a hexagon with rounded corners. Time-lapsed imaging at increasing temperature reveals the onset of shape change to be at ≈170 K, corresponding to the onset of edge and corner diffusion of atoms along the island’s borders. Despite a substantial variation for individual islands at each temperature, the mean fractal dimension increases monotonously between 170 K up to 240 K, from the smallest to the largest values feasible for islands grown on surfaces.

Rotation-aligned isomeric states and associated oblate collective sequences are established in even Pt isotopes. Reduced E2 transition probabilities for the deexcitation of the 12+ isomers indicate an abrupt and unexpected quenching of oblate collectivity around neutron number N=120. Structure and shape evolution at high spin in the heaviest stable isotopes is found to be markedly different from observations in the lighter ones.

The aim of this study is to investigate the phase and morphological evolution of the prepared Ti 3 SiC 2 MAX phase powder after immersion in hydrofluoric acid (HF) solution for 24, 72, 96 and 120 h. The phase and morphological evolution of Ti 3 SiC 2 was analyzed using X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). XRD results revealed that after 24 h HF treatment the diffraction peaks of Ti 3 SiC 2 were fully disappeared and this treatment led to the decomposition of Ti 3 SiC 2 to TiC. XRD and EDS findings demonstrated that de-intercalation of Si layer occurred after HF treatment. Moreover, SEM images showed that the morphological shape of TiC particles significantly changed as a function of HF treatment times. In summary, the shape of TiC particles changed from the polyhedron to hexagonal, then to truncated octahedron, octahedron and cubic. [ABSTRACT FROM AUTHOR]

Abstract: Deposition around the microvias opening is crucial for desirable quality of metallic micro components and micro bumps in electroforming. This paper presents a numerical and experimental study of shape evolution of electrodeposition front on the extent of over-plating. Computational models based on kinetics of the electrode reaction are used to simulate the entire deposition process from start of deposition until the formation of bumps. The effects of the current density and microstructure geometries are discussed through analyzing the current density distribution along the transient cathode surface. When the current density is 4 A dm−2, the significant Ni craters are observed for microvias with diameters of 200 µm in the over-plating stage. The dent depths decrease as the current density and diameter decrease. For the 30 µm diameters, spherical structures in the over-plating stage form upon the photolithographic patterns for an applied current density of 1 A dm−2. Furthermore, the spherical surfaces enable the fabrication of hemispherical lenses with various curvature radii.Graphical Abstract: Spherical structures are obtained by electrodeposition into microcavities. A numerical and experimental study is carried out to study the mechanics of shape evolution. The polymeric microlenses are replicated through a combination of PDMS molding and UV curing. This process demonstrates the potential of this method in the fabrication of microlenses. [ABSTRACT FROM AUTHOR]

Ultrathin two-dimensional transition metal dichalcogenides (TMDCs) have shown significant potential for diverse applications in semiconductor industry. The controlled synthesis of TMDCs is a prerequisite for its potential application. Unfortunately, controllable synthesis is still a great challenge. Here, we report an experimental method to induce a broad range of morphologies in highly crystalline, monolayer MoSe 2 thin films by H 2 content engineering. A growth mechanism was proposed to clarify the formation process for variable-shaped MoSe 2 crystals. We attributed the evolution in morphologies to a result of the variable growth rates of two types of terminations that occur under different growth conditions. Our work provides a foundation for the controlled synthesis of MoSe 2, reveals the shape evolution of CVD-derived MoSe 2 and broadens the application range based on its shape-dependent properties. [ABSTRACT FROM AUTHOR]