Orientational Correlation Research Articles

How Far Is "Bulk Water" from Interfaces? Depends on the Nature of the Surface and What We Measure.

Using systematic molecular dynamics (MD) simulations, we revisit the question: At what distance from an interface do the properties of "bulk water" get recovered? We have considered three different kinds of interfaces: nonpolar (hydrophobic; isooctane-water interface), charged (negative; AOT bilayer), and polar (zwitterionic; POPC bilayer). In order to interrogate the extent of perturbation of the interfacial water molecules as a function of the distance from the interface, we utilize a diverse range of structural and dynamical parameters. To capture the structural perturbations, we look into local density (translational order), local tetrahedral order parameter, and dipolar orientation of the water molecules. We also explore the anisotropic diffusion of the water molecules in the direction perpendicular to the interface as well as the planar diffusion parallel to the interface in a distance dependent manner. In addition, the orientational time correlation functions have been computed to understand the extent of slowdown in the rotational dynamics. As expected, the electrostatic field emanating from the charged AOT interface seems to have the highest long-range effect on the orientational order and dynamics of the water molecules, whereas specific interactions like hydrogen bonding and electrostatic interaction lead to significant trapping and kinetic slowdown for both AOT and POPC (zwitterionic) very close to the interface. Our analysis highlights that not only the length-scale of perturbation depends on the nature of the interfaces and specific interactions but also the type of water property that we measure/calculate. Different water properties seem to have widely different length-scale of perturbation. Orientational order parameters seem to be perturbed to a much longer length-scale as compared to translational order parameters. The global orientational order of water can be perturbed even up to ∼4-5 nm near the negatively charged AOT surface in the absence of any extra electrolyte. This observation has significant implication toward the interpretation of experimental measurements as well since different spectroscopic techniques would probe different parameters or water properties with possible mutual disagreement and inconsistency between different types of measurements. Thus, our study provides a broader and unifying perspective toward the aspect of "context dependent" structural and dynamical perturbation of "interfacial water".

Correlated orientations of the axes of large quasar groups on Gpc scales

ABSTRACT Correlated orientations of quasar optical and radio polarization, and of radio jets, have been reported on Gpc scales, possibly arising from intrinsic alignment of spin axes. Optical quasar polarization appears to be preferentially either aligned or orthogonal to the host large-scale structure, specifically large quasar groups (LQGs). Using a sample of 71 LQGs at redshifts 1.0 ≤ z ≤ 1.8, we investigate whether LQGs themselves exhibit correlated orientation. We find that LQG position angles (PAs) are unlikely to be drawn from a uniform distribution (p-values 0.008 ≲ p ≲ 0.07). The LQG PA distribution is bimodal, with median modes at $\bar{\theta }\sim 45\pm 2^{\circ }, 136\pm 2^{\circ }$, remarkably close to the mean angles of quasar radio polarization reported in two regions coincident with our LQG sample. We quantify the degree of alignment in the PA data, and find that LQGs are aligned and orthogonal across very large scales. The maximum significance is $\simeq 0.8{{\ \rm per\ cent}}$ (2.4σ) at typical angular (proper) separations of ∼30° (1.6 Gpc). If the LQG orientation correlation is real, it represents large-scale structure alignment over scales larger than those predicted by cosmological simulations and at least an order of magnitude larger than any so far observed, with the exception of quasar-polarization/radio-jet alignment. We conclude that LQG alignment helps explain quasar-polarization/radio-jet alignment, but raises challenging questions about the origin of the LQG correlation and the assumptions of the concordance cosmological model.

Ground state of asymmetric tops with DMRG: Water in one dimension.

We propose an approach to compute the ground state properties of collections of interacting asymmetric top molecules based on the density matrix renormalization group method. Linear chains of rigid water molecules of varying sizes and density are used to illustrate the method. A primitive computational basis of asymmetric top eigenstates with nuclear spin symmetry is used, and the many-body wave function is represented as a matrix product state. We introduce a singular value decomposition approach in order to represent general interaction potentials as matrix product operators. The method can be used to describe linear chains containing up to 50 water molecules. Properties such as the ground state energy, the von-Neumann entanglement entropy, and orientational correlation functions are computed. The effect of basis set truncation on the convergence of ground state properties is assessed. It is shown that specific intermolecular distance regions can be grouped by their von-Neumann entanglement entropy, which in turn can be associated with electric dipole-dipole alignment and hydrogen bond formation. Additionally, by assuming conservation of local spin states, we present our approach to be capable of calculating chains with different arrangements of the para and ortho spin isomers of water and demonstrate that for the water dimer.

Intermolecular correlations of liquid and glassy CS2 studied by synchrotron radiation x-ray diffraction.

How is the orientation of molecular liquids ordered on cooling? What are the basic structures of molecular glasses, e.g., close to the crystalline structure or some special structures such as icosahedral cluster? These are long-standing questions in liquid and glass physics. We have constructed a novel cryostat to prepare simple molecular glasses by vapor deposition and performed in situ synchrotron radiation x-ray diffraction experiments. The glassy state of a simple molecule CS2, which cannot be vitrified by normal liquid quenching, was successfully prepared with this instrument, and its diffraction data were collected in a wide Q-range of 0.16-25.7 Å-1 with a high-energy diffractometer at BL04B2, SPring-8. The diffraction data of liquid CS2 were also recorded in a wide temperature range of 160-300K. These diffraction data were analyzed with molecular dynamics simulations and reverse Monte Carlo modelings to investigate orientational correlation. From the obtained 3D structure models, the orientational correlation between neighboring CS2 molecules was investigated quantitatively as a function of temperature. At room temperature, the parallel and T-shaped arrangements are preferred for the nearest neighbor correlation. On cooling, these arrangements are developed gradually, and its rate became prominent below the melting temperature (162K). In the glassy state, the slipped-parallel arrangement is dominant as well as the T-shaped arrangement. Both arrangements appear in the CS2 crystal, indicating that the structure of glassy CS2 is close to that of crystalline CS2.

Structural defects of monolayer wet particles during melting under vertical vibration.

The evolution of structural defects during phase transition is of great significance to the understanding of the mechanism of solid-liquid transition. However, the current research on topological defects still uses the pair-correlation function and the orientational order correlation function, so it is difficult to quantify the detailed changes of structural defects locally. In this paper, the local volume fraction is proposed as a key parameter to accurately quantify the variation of structural defects. The experimental results indicate that the evolution of structural defects in the particle system is caused by the decrease of local volume fraction, so the critical value of phase transition could be determined by the minimum local volume fraction ϕ_{min}. Furthermore, according to the evolution law of structural defects, it can be deduced that the phase transition is continuous, which is consistent with the Kosterlitz-Thouless-Halperin-Nelson-Young theory. Therefore, the quantitative analysis of structural defects by using local volume fraction can help make the mechanism of solid-liquid phase transformation clearer.

Психологические характеристики деятельности, традиционные ценности и ценности безопасности вузовской молодежи в контексте инновативности

Exploring value orientations and psychological characteristics of activity in students in the context of their innovativeness is relevant in connection with the society's social demands and the specifics of personal and professional development of this category of young people. Such a study is significant, since it is students who are potential and active subjects of various social transformations, the most intellectually advanced and creative part of youth. The study focused on correlation and regression analyses of value orientations and psychological characteristics of activity among university students in Tomsk (N = 419). In the study the following research instruments were used: Sh. Schwartz's Portrait Values Questionnaire-Revised (modified by K.V. Sugonyaev); R. Inglehart's World Values Survey (adapted by R.K. Khabibulin); N.M. Lebedeva and A.N. Tatarko's Self-Assessment of Personality's Innovative Qualities; E.Yu. Mandrikova's Self-Organization of Activity Questionnaire; the Differential Test of Reflexivity (D.A. Leontiev); the Satisfaction with Life Scale (E. Diener; adapted by D.A. Leontiev and E.N. Osin); the Index of Personal Readiness for Activity (S.A. Bogomaz, I.V. Atamanova); the Change Response Styles Questionnaire (T.Yu. Bazarov, M.P. Sycheva); the Academic Motivation Scales questionnaire (T.O. Gordeeva, O.A. Sychev and E.N. Osin, based on the R. Vallerand Academic Motivation Scale). Regression analysis has shown that the leading psychological characteristics of activity in university youth in the context of innovativeness are “Index of innovativeness”, “Index of personal readiness for activity” and “Implementing style of responding to changes”. The regression analysis results indicate that the innovative style of responding to changes is not preferable among students when assessing their innovativeness. The study conducted revealed the ambivalence of the relationship between university youth's traditional values, safety values and their psychological characteristics of activity. This fact may indicate that current societal transformations inevitably affect personality characteristics of young people, showing that values ensuring the society's stability and security, the absence of chaos are important for them, as well as the significance of development, expansion of opportunities for self-realization, socio-cultural transformations. The study findings show the need for taking into account the degree of manifestation of psychological parameters in question and their ratio in students to ensure their personal and socio-cultural development. Investigating students' psychological characteristics can be used as guidelines for developing various programs of psychological and pedagogical support for their personal and professional development during their studies at university, searching for models of training specialists that meet the current requirements.

Characterization of orientation correlation kinetics: chiral-mesophase domains in suspensions charged DNA-rods

Bacteriophage DNA fd-rods are long and stiff rod-like particles which are known to exhibit a rich equilibrium phase behavior. Due to their helical molecular structure, they form the stable chiral nematic (N*) mesophases. Very little is known about the kinetics of forming various phases with orientations. The present study addresses the kinetics of chiral-mesophases and N*-phase, by using a novel image-time correlation technique. Instead of correlating time-lapsed real-space microscopy images, the corresponding Fourier images are shown for time-correlated averaged orientations. This allows to unambiguously distinguish to detect the temporal evolution of orientations on different length scales, such as domain sizes (depending on their relative orientations), and the chiral pitch within the domains. Kinetic features are qualitatively interpreted in terms of replica symmetry breaking of elastic deformations in the orthogonal directional axes of chiral-mesophase domains, as well by the average twist angle and the order parameter. This work can be interesting for characterizing other types of charged rods, mimicking super-cooled liquids and orientation glasses.

Assessment of Recent Flow, and Calving Rate of the Perito Moreno Glacier Using LANDSAT and SENTINEL2 Images

We mapped flow velocity and calving rates of the iconic Perito Moreno Glacier (PMG), belonging to the Southern Patagonian Icefield (SPI) in the Argentinian Patagonia. We tracked PMG from 2001 to 2017, focusing mostly upon the latest images from 2016–2017. PMG delivers about ca. 106 m3 day−1 of ice in the Lago Argentino, and its front periodically reaches the Peninsula Magallanes. Therein, the PMG causes an ice-dam, clogging Brazo Rico channel, and lifting water level by about 10 m, until ice-dam failure, normally occurring in March. Here, we used 36 pairs of satellite images with a resolution of 10 m (SENTINEL2, visible, 9 pairs of images) and 15 m (LANDSAT imagery, panchromatic, 27 pairs of images) to calculate surface velocity (VS). We used Orientation Correlation technique, implemented via the ImGRAFT® TemplateMatch tool. Calving rates were then calculated with two methods, namely, (i) M1, by ice flow through the glacier front, and (ii) M2, by ice flow at 7.5 km upstream of the front minus ablation losses. Surface velocity ranged from about 4 m day−1 in the accumulation area to about 2 m day−1 in the calving front, but it is variable seasonally with maxima in the summer (December–January–February). Calving rate (CRM) ranges from 7.72 × 105 ± 32% to 8.76 × 105 ± 31% m3 day−1, in line with recent studies, also with maxima in the summer. We found slightly lower flow velocity and calving rates than previously published values, but our estimates cover a different period, and a generally large uncertainty in flow assessment suggests a recent overall stability of the glacier.

Laser additive manufacturing of pure molybdenum using freeze-dry pulsated orifice ejection method-produced powders

Preparing appropriate initial powders is a key factor in using laser powder bed fusion (L-PBF) for high-performance refractory materials. In this study, we developed a novel technology, the freeze-dry pulsated orifice ejection method (FD-POEM), for producing spherical molybdenum powders with controllable particle size and distribution and good flowability without melting. The Mo powders, which had unique mesh-structures, exhibited higher laser absorptivity than the dense ones. Pure Mo builds were fabricated using L-PBF. Fine MoO2 particles were formed and uniformly distributed along the grain boundaries and inside the equiaxed grains. High-resolution transmission electron microscopy revealed an interfacial orientation correlation between Mo [1 -1 -1]//MoO2 [0–1 0] and Mo (1 1 0)//MoO2 (0–1 2). The Vickers hardness of the Mo build increased compared to that of pure Mo owing to grain refinement and the oxide-dispersion-strengthening effect of in-situ MoO2. This study provides the basis for powder fabrication using FD-POEM and the processability of Mo parts via L-PBF in ultrahigh-temperature applications.

On regular and random two-dimensional packing of crosses

Packing problems, even of objects with regular geometries, are in general non-trivial. For few special shapes, the features of crystalline as well as random, irregular two-dimensional (2D) packing structures are known. The packing of 2D crosses does not yet belong to the category of solved problems. We demonstrate in experiments with crosses of different aspect ratios (arm width to length) which packing fractions are actually achieved by random packing, and we compare them to densest regular packing structures. We determine local correlations of the orientations and positions after ensembles of randomly placed crosses were compacted in the plane until they jam. Short-range orientational order is found over 2 to 3 cross lengths. Similarly, correlations in the spatial distributions of neighbors extend over 2 to 3 crosses. There is no simple relation between the geometries of the crosses and the peaks in the spatial correlation functions, but some features of the orientational correlations can be traced to typical local configurations.

Topological phase transitions in two-dimensional bent-core liquid crystal models.

Two-dimensional liquid crystal (LC) models of interacting V-shaped bent-core molecules with two rigid rodlike identical segments connected at a fixed angle (θ=112^{∘}) are investigated. The model assigns equal biquadratic tensor coupling among constituents of the interacting neighboring molecules on a square lattice, allowing for reorientations in three dimensions (d=2,n=3). We find evidence of two temperature-driven topological transitions mediated by point disclinations associated with the three ordering directors, condensing the LC medium successively into uniaxial and biaxial phases. With Monte Carlo simulations, temperature dependencies of the system energy, specific heat, orientational order parameters, topological order parameters, and densities of unbound topological defects of the different ordering directors are computed. The high-temperature transition results in topological ordering of disclinations of the primary director, imparting uniaxial symmetry to the phase. The low-temperature transition precipitates simultaneous topological ordering of defects of the remaining directors, resulting in biaxial symmetry. The correlation functions, quantifying spatial variations of the orientational correlations of the molecular axes show exponential decays in the high-temperature (disordered) phase, and power-law decays in the low-temperature (biaxial) phase. Differing temperature dependencies of the topological parameters point to a significant degree of cross coupling among the uniaxial and biaxial tensors of interacting molecules. This simplified Hamiltonian leaves θ as the only free model parameter, and the system traces a θ-dependent trajectory in a plane of the phenomenological parameter space.

Vortex clustering, polarisation and circulation intermittency in classical and quantum turbulence

The understanding of turbulent flows is one of the biggest current challenges in physics, as no first-principles theory exists to explain their observed spatio-temporal intermittency. Turbulent flows may be regarded as an intricate collection of mutually-interacting vortices. This picture becomes accurate in quantum turbulence, which is built on tangles of discrete vortex filaments. Here, we study the statistics of velocity circulation in quantum and classical turbulence. We show that, in quantum flows, Kolmogorov turbulence emerges from the correlation of vortex orientations, while deviations—associated with intermittency—originate from their non-trivial spatial arrangement. We then link the spatial distribution of vortices in quantum turbulence to the coarse-grained energy dissipation in classical turbulence, enabling the application of existent models of classical turbulence intermittency to the quantum case. Our results provide a connection between the intermittency of quantum and classical turbulence and initiate a promising path to a better understanding of the latter.

Model of metameric locomotion in smooth active directional filaments with curvature fluctuations

Locomotion in segmented animals, such as annelids and myriapods (centipedes and millipedes), is generated by a coordinated movement known as metameric locomotion, which can be also implemented in robots designed to perform specific tasks. We introduce a theoretical model, based on an active directional motion of the head segment and a passive trailing of the rest of the body segments, in order to formalize and study the metameric locomotion. The model is specifically formulated as a steered Ornstein-Uhlenbeck curvature process, preserving the continuity of the curvature along the whole body filament, and thus supersedes the simple active Brownian model, which would be inapplicable in this case. We obtain the probability density by analytically solving the Fokker-Planck equation pertinent to the model. We also calculate explicitly the correlators, such as the mean-square orientational fluctuations, the orientational correlation function and the mean-square separation between the head and tail segments, both analytically either via the Fokker-Planck equation or directly by either solving analytically or implementing it numerically from the Langevin equations. The analytical and numerical results coincide. Our theoretical model can help understand the locomotion of metameric animals and instruct the design of metameric robots.

Orientational Correlations in Active and Passive Nematic Defects.

We investigate the emergence of orientational order among +1/2 disclinations in active nematic liquid crystals. Using a combination of theoretical and experimental methods, we show that +1/2 disclinations have short-range antiferromagnetic alignment, as a consequence of the elastic torques originating from their polar structure. The presence of intermediate -1/2 disclinations, however, turns this interaction from antialigning to aligning at scales that are smaller than the typical distance between like-sign defects. No long-range orientational order is observed. Strikingly, these effects are insensitive to material properties and qualitatively similar to what is found for defects in passive nematic liquid crystals.

The role of fluorination during the physicochemical erosion of yttria in fluorine-based etching plasmas

A physicochemical mechanism acting between the reactive plasma and the material surface controls the erosion of polycrystalline ceramics in fluorine containing etching plasmas. In this study, a Y2O3/YOF composite was exposed to a fluorine etching plasma. Relocalization enables the direct correlation of crystalline orientation with material response. Our study reveals an orientation dependent surface fluorination of Y2O3, which controls the etching resistance and morphology formation. Orientations near the low index planes (001), (010) and (100) exhibit the lowest stability due to a homogeneous surface reaction. The presented results help to extend the mechanistic understanding of the plasma-material interaction of Y2O3.

Intermolecular interaction network in liquid acetone

Molecular dynamics simulations, employing the transferable potentials for phase equilibria-united atom force field, have been performed to explore the structural features of liquid acetone. Topological and dynamical network analyses have been performed on the intermolecular interaction (IMI) networks, which are constructed based on a set of pair energy cutoffs. Topological analysis revealed that the acetone pairs interacting stronger than −10 kJ/mol exist as isolated pairs in a sense that the members of the pair do not interact with other molecules with an energy smaller than −10 kJ/mol. As such, those strongly interacting pairs do not constitute a three-dimensional extended network. As the pair interaction energy cutoff becomes larger than −10 kJ/mol, the IMI network starts to become a three-dimensional extended network and its connectivity increases gradually. Dynamical analysis revealed that the decay function for intermolecular interaction lifetimes is characterized by a nonexponential decay for all the IMI networks such that it decays faster at short-times in comparison to the longer-times. Yet, the duration of the intermolecular interactions can go beyond 1.0 ps for the pairs with the interaction energies larger than −6 kJ/mol. Furthermore, the orientational correlations in the liquid acetone have been examined for a more detailed picture of its structure. It is clearly shown that as the distance between the carbonyl carbons of the two acetones gets smaller, (i) they tend to adopt an anti-parallel dipole orientation, (ii) the planes of the acetones tend to adopt a parallel orientation, and, (iii) such acetone pairs particularly interact more strongly. In the light of these findings, two dimeric structures, stack-type and planar-type, are highlighted. Using density functional theory (DFT) at the mPW2PLYP/def2-TZVP level, the interaction energy in the gas-phase is computed to be −19.85 kJ/mol for the stack-type dimer, which is more stable than the planar-type dimer by 7.7 kJ/mol. Both the gas-phase DFT interaction energy and the computed acetone dipole moment, 2.97 D, are in great agreement with the corresponding experimental data. Furthermore, in accordance with the gas-phase results, the stack-type dimers are found to be more stable than the planar-type dimers also in the liquid-phase as revealed from both the liquid-phase DFT interaction energies and the MD based mean interaction energies. Finally, trimeric structure search in the simulated liquid acetone revealed that of all trimers, 94% belongs to the chain-like trimers, while the remaining 6% belongs to the cyclic trimers.

Atomic simulation of the effect of orientation on tensile/compressive properties in nickel-based single crystal superalloys

Nickel-based single crystal superalloys reveal obvious anisotropy and orientation correlation. Choosing the orientation with the best mechanical properties is beneficial to prolong its service life. In this paper, the effects of crystal orientation on the plastic deformation and mechanical properties of the nickel-based single crystal two-phase model under uniaxial tension/compression were simulated by molecular dynamics. The microstructure evolution and dislocation movement are studied through stress-strain response and structural changes of the two phases with different crystal orientations. In addition, the typical dislocation structures are analyzed, it is found that the yield stress of different orientation models is: [111] > [001] > [011]. Different orientation models all show tension/compression asymmetry and the [001] orientation is the most obvious. The results showed that the evolution of dislocation and stacking faults is one of the reasons which causes the crystal anisotropy.

СПРЯМОВАНІСТЬ У СПІЛКУВАННІ ЯК ОСОБИСТІСНИЙ РЕСУРС ЕФЕКТИВНОЇ МІЖОСОБИСТІСНОЇ ВЗАЄМОДІЇ

The results of an empirical study of the influence of different types of orientation in communication on the formation of personal resource of interpersonal interaction are presented in the article. The analysis of the results of the study consisted of three successive steps to test the hypothesis that the type of orientation in communication affects the formation of the personal resource of interpersonal interaction. First, it is the clarification of the general trends in the manifestation of different types of communication orientation in modern youth. Second, it is the establishing the nature of the relationship between the types of communication orientation with the personal components of interpersonal interaction. Third, it is the comparison of groups studied by different types of orientation in communication. As a result of the study, it was determined that three tendencies are most common in the communication of modern youth: a) to build it on mutual trust, respect, mutual understanding and openness; b) focus efforts on voluntary and selfless centering on the partner; c) treat partners as a means, an object of covert manipulation. It is established in the process of correlation analysis that all types of communication orientation in some way affect the formation of the personal resource of interpersonal interaction. This is most evident in the direct links of alterocentric tendencies with motivational, emotional, cognitive components and the general indicator of the effectiveness of interpersonal interaction; as well as in the negative links of authoritarian and indifferent orientation with motivation, emotional and volitional regulation, and as a consequence, the personal basis of interpersonal interaction in general. Furthermore, the direct correlations of dialogic orientation of communication with the motivational component, manipulative and conformal orientation with the cognitive component of interpersonal interaction were revealed. It was found by comparing groups of subjects with the dominance of different types of orientation in communication, that the alterocentric type more than other types contributes to the highest manifestation of personal resource of interpersonal interaction, manifested both at the level of all its components and overall efficiency of this process. Authoritarian type leads to a deficient nature of the formation of personal resources, which reduces the effectiveness of interpersonal interaction. Dialogic orientation of communication is characteristic of young people with a moderate formation of all components of interpersonal interaction. A feature of young people with a predominance of conformal type of orientation is high self-confidence, independence, endurance and self-control. The dominance of the indifferent type leads to a lack of communication skills, and therefore representatives of this type often distort the feelings of partners; they do not know how to negotiate.

Long-range decay of pair correlations and nematic ordering in a two-dimensional system of Gay-Berne mesogens

Isothermal-isobaric(NPT) Monte-Carlo simulation has been used to investigate the nature of pair-correlations and ordering in a two-Dimensional system of soft ellipses with aspect ratio κ=3 interacting via the Gay-Berne potential. The system is found to exhibit an isotropic phase (with exponential decay of orientational correlations) and a nematic phase (with algebraic decay of orientational correlations) as we suitably change temperature and pressure. The large distance decay exponent of the orientational correlations is found to converge around an universal value of 0.5 with the increase in pressure along an isotherm. The algebraic decay of orientational correlation in the low temperature phase shows that the nematic lacks true-long range orientational order. This has been substantiated by the system size dependence of the nematic order parameter. We have found the emergence of localized nematic patches separated by disclinations on increasing the pressure in the isotropic phase. No abrupt change is observed in pressure-density plot corresponding to the isotherms studied in this work.

Observation of the Pinning-Induced Crystal-Hexatic-Glass Transition in Two-Dimensional Colloidal SuspensionsSupported by the National Natural Science Foundation of China (Grant Nos. 12074275, 11704269, and 11704270), the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant Nos. 20KJA150008 and 17KJB140020), and the PAPD Program of Jiangsu Higher Education Institutions.

Identification of the glass formation process in various conditions is of importance for fundamental understanding of the mechanism of glass transitions as well as for developments and applications of glassy materials. We investigate the role of pinning in driving the transformation of crystal into glass in two-dimensional colloidal suspensions of monodisperse microspheres. The pinning is produced by immobilizing a fraction of microspheres on the substrate of sample cells where the mobile microspheres sediment. Structurally, the crystal-hexatic-glass transition occurs with increasing the number fraction of pinning ρ pinning, and the orientational correlation exhibits a change from quasi-long-range to short-range order at ρ pinning = 0.02. Interestingly, the dynamics shows a non-monotonic change with increasing the fraction of pinning. This is due to the competition between the disorder that enhances the dynamics and the pinning that hinders the particle motions. Our work highlights the important role of the pinning on the colloidal glass transition, which not only provides a new strategy to prevent crystallization forming glass, but also is helpful for understanding of the vitrification in colloidal systems.