Hybrid Alignment Research Articles

Research on the Application of Natural Language Processing Technology in English Translation Quality Control

Abstract Machine translation is an important research area in natural language processing. In this paper, we propose an innovative fusion translation model that combines the slicing method and the alignment method and select articles from different domains for experiments to explore the translation effects of the proposed method. The experiments show that the proposed CRF sequence annotation cut-scoring method performs excellently, with F-values of 86.7%, 89.0%, and 87.4% for the three domains of computer science, civil engineering, and medicine, respectively. The hybrid alignment method based on the length and lexical information also performs well, both in terms of correctness and recall and the hybrid alignment method is able to obtain better results than the length or lexical information methods alone. Putting the proposed method into the translation accuracy test, the BLEU score of the cut-and-align fusion translation model is improved to 11.08, while the NIST score is improved to 3.6468, which is a significant improvement in the translation quality of English.

Advanced Light: Liquid Crystals-Based Ultra-Broadband Polarization Rotator for Functional Smart Devices.

A novel ultra-broadband polarization rotator with advanced angular adjustability is proposed for functional devices such as displays and smart windows. The new solution offers dynamic control of light polarization across a broad range of wavelengths, encompassing the complete visible spectrum, ultraviolet and near-infrared. Moreover, it boasts a smaller footprint, faster response times, and lower dispersion compared to conventional rotators. The findings are remarkable in that they show that as the viewing angle increases, the hybrid alignment takes on a twist-like configuration, with the polarization rotation angle determined by the spatial variation in the twist angle. This intriguing behavior leads to an improved range of angular adjustability, as the effective polarization rotation depth is extended. The improved angular adjustability of reconfigurable smart devices surpasses the limitations of traditional polarization rotators, unlocking new innovative possibilities. For example, the rotator plays a crucial role in display technologies, allowing for effective control of viewing angles and minimizing reflection from disturbing external light. Similarly, in smart windows, it optimizes energy conservation by regulating direct sunlight transmission while ensuring clear visibility in normal conditions. It is believed that the proposed advanced ultra-broadband polarization rotator is a significant step forward in the development of reconfigurable smart devices.

Surface confinement of vertically aligned liquid crystals between flexible silver nanoparticles hybridized polyimide thin layers

Alignment of liquid crystals (LCs) has emerged as an essentially fundamental approach for exploring the electro-optical performance and fabricating novel LC devices. Growing evidence suggests that the surface wettability of the alignment layer plays a key role in tuning the tilt angles of LCs. In this work, silver (Ag) nanoparticles (d ≤ 100 nm) are blended in polyimide (PI) by a wide range of concentration from 0.1% to 1.0% to tune surface wettability and align LCs. Ag nanoparticles agglomerate and result in a bumpy surface topology and somewhat reduce the transparency of hybrid thin layer to 85.1% by 1.0% doping because of their shielding effect. Nevertheless, Ag nanoparticle agglomerates change the thickness of hybrid thin layers less, and the hybrid thin layers are ∼96 nm thick like a pure PI thin layer. LCs are vertically aligned on hybrid thin layers after rubbing. Benefit from the declined anchoring energy and the outstanding surface plasmon polariton (SPP) of Ag nanoparticles, the external electric field to switch LCs is substantial boosted, and hence remarkably diminish the operating voltage and likewise notably shorten the response time. In particular, LCs that vertically aligned between PI hybrid alignment layers by 0.5% doping could be electrically switched to become planner at 3.38 V and go back to their original vertical alignment state within 73.21 ms. Ag nanoparticles agglomerates in hybrid thin layers also fairly hinder the drift of LCs when cells are mechanically bent with various radii. The hybrid alignment layers cell that blended with 0.5% Ag nanoparticles could be bent under 1500 mm without any new evident light leakages and fluctuating electro-optical characteristics. These results indicate the promising applications of PI hybrid thin layers blended with Ag nanoparticles for flexible LC devices.

ESA: An efficient sequence alignment algorithm for biological database search on Sunway TaihuLight

In computational biology, biological database search has been playing a very important role. Since the COVID-19 outbreak, it has provided significant help in identifying common characteristics of viruses and developing vaccines and drugs. Sequence alignment, a method finding similarity, homology and other information between gene/protein sequences, is the usual tool in the database search. With the explosive growth of biological databases, the search process has become extremely time-consuming. However, existing parallel sequence alignment algorithms cannot deliver efficient database search due to low utilization of the resources such as cache memory and performance issues such as load imbalance and high communication overhead. In this paper, we propose an efficient sequence alignment algorithm on Sunway TaihuLight, called ESA, for biological database search. ESA adopts a novel hybrid alignment algorithm combining local and global alignments, which has higher accuracy than other sequence alignment algorithms. Further, ESA has several optimizations including cache-aware sequence alignment, capacity-aware load balancing and bandwidth-aware data transfer. They are implemented in a heterogeneous processor SW26010 adopted in the world’s 6th fastest supercomputer, Sunway TaihuLight. The implementation of ESA is evaluated with the Swiss-Prot database on Sunway TaihuLight and other platforms. Our experimental results show that ESA has a speedup of 34.5 on a single core group (with 65 cores) of Sunway TaihuLight. The strong and weak scalabilities of ESA are tested with 1 to 1024 core groups of Sunway TaihuLight. The results show that ESA has linear weak scalability and very impressive strong scalability. For strong scalability, ESA achieves a speedup of 338.04 with 1024 core groups compared with a single core group. We also show that our proposed optimizations are also applicable to GPU, Intel multicore processors, and heterogeneous computing platforms.

Manipulating the Switching of Liquid Crystals by Interfacial Nanotips Penetrating Polyimide Hybrid Alignment Layers

Liquid crystals (LCs) are an active area of interest for electro-optical devices, and the alignment of LCs has emerged as an extremely essential issue for LC devices. Evidence suggests that the surface topology of alignment layers plays a key role in both tuning the tilt angles and modulating the switching of LCs. Herein, nanotips are constructed by self-assembly of two different two-dimensional (2D) nanoflakes in PI hybrid alignment layers to modulate the switching of LCs. Both MoS2 nanotips and Ti3C2Tx MXene nanotips were observed on hybrid thin layers, but MoS2 nanotips are much thinner and taller. The hybrid thin layers are highly transparent, and the nanotips penetrating the hybrid layers roughened the surface but moderately declined the surface energy. LCs are strongly anchored on hybrid alignment layers, and the nanotips were found to topologically hinder the in-plane switching of LCs and hence accelerate the rewriting speed of optical data. Besides the accelerated optical rewriting speed, the surface plasmon–polariton (SPP) of nanoflakes also substantially boosted the external electric field to switch LCs and hence remarkably diminished the operating voltage and likewise sufficiently shortened the response time. In particular, the optical rewriting time of LCs that homogeneously aligned on hybrid alignment layers with 0.5% MoS2 nanoflakes doping has been deduced to as short as 43.36 s, which is a decrease of 37.81% compared to that of PI alignment layers cell; LCs can be electrically driven to switch optical data at 2.51 V and return to their original alignment state within 24.142 ms. These results signify the promising applications of hybrid thin layers for both traditional LC devices and optical rewritable LC devices.

Monomolecular vertical alignment layer with room temperature processibility for flexible liquid crystal displays

In this article, we disclose a vertical alignment material using alkylphosphonic acid for liquid crystals that only requires simple room temperature treatments to secure good vertical alignment for liquid crystals. Alkylphosphonic acid forms a monomolecular layer on the substrate providing strong vertical alignment. The proposed alignment layer shows decent electro-optical properties, such as high voltage holding ratio, low residual direct current voltage, low image sticking parameter, etc. Later, we combine the alkylphosphonic acid with photo-rewritable azo-dye to fabricate a hybrid alignment of nematic cells and study its stability and anchoring energy. The material shows great compatibility with flexible substrates. Thus, the proposed alignment layer of alkylphosphonic acid can potentially find application as the alignment layer for flexible liquid crystal displays.

Electrically Tunable Microlens Array Enabled by Polymer‐Stabilized Smectic Hierarchical Architectures

AbstractLiquid crystals (LCs) are key functional materials that are broadly adopted in various fields due to their stimuli‐responsiveness. Recently, LCs with hierarchical architectures have brought new effects to optics and attracted intensive attention. In smectic A phase, the parallel molecular layers are periodically wrapped to form toric focal conic domains (TFCDs) under antagonistic boundary conditions (i.e., hybrid alignment conditions). TFCD shows great potential in nanofabrication and integral imaging. However, the arbitrary tailoring of TFCD is still challenging, and the robustness of hierarchical configuration hinders the tunability. Here, a radial alignment lattice is adopted to guide the local orientation of LCs and thus facilitates predefining the lattice symmetry and domain size of TFCDs. By introducing polymer stabilization and optimizing the composition, the sample simultaneously maintains the director distribution inside smectic layers and possesses the stimuli‐responsiveness of nematic phase at room temperature. By this means, microlens arrays are demonstrated with reversible electrical tunability. The strategy can be extended to other smectic configurations and may upgrade existing dynamic optics.

Generation of a focused optical vortex beam using a liquid crystal spiral zone plate.

Optical vortices (OVs) with orbital angular momenta show promise for various optical applications. Spiral zone plates (SZPs) can generate a focused OV and are thus used in applications like edge-enhanced imaging. However, conventional SZPs have low diffraction efficiency because they operate based on amplitude modulation. This study proposes a liquid crystal spiral zone plate (LCSZP) that operates based on phase modulation and demonstrates the generation of a focused OV with high efficiency and electric tunability. The LCSZP has no threshold voltage owing to its homeotropic/planar hybrid alignment regions, and it can find applications in imaging, laser processing, and optical manipulation.

Photo-patterned memory state based on nematic-silica-dye suspension

The influence of photoalignment on the memory state of nematic liquid crystals (LCs) doped with silica nanoparticles and azo dyes was studied. The memory state of the LC sample with hybrid alignment was realized with electrophoretically controlled silica nanoparticles, which accumulated on the homogeneously aligned side of the LC sample to stabilize the vertical orientation of LC molecules through a pulse voltage with appropriate polarity. When the photoalignment was executed on the LCs in the hybrid orientation, the adsorbed azo dyes screened the effect of vertical orientation supported by silica networks. The hybrid LC orientation was stabilized because the adsorbents of azo dyes on the substrate provided a stronger surface homogeneous alignment. When the LCs in the memory state of vertical alignment were illuminated, their vertical orientation was maintained by the adsorbed azo dyes that suppressed the electrophoretic movement of the silica nanoparticles. The study also demonstrates a simple display with hidden images by utilizing these results.

Active nematic flows confined in a two-dimensional channel with hybrid alignment at the walls: A unified picture

We study active nematic fluids confined in narrow channels with a conflicting anchoring at the walls. In this configuration flows are sustained even in the zero activity limit. We use a numerical approach to span a wide portion of parameter space and provide a unified picture of this system beyond the limiting regime explored previously, which stresses the key role played by the activity and the flow aligning parameter. We also show that solutions depend on two dimensionless parameters and present examples of biaxial solutions and the parameter values for which they are observed.

Vanadium Dioxide Nanoparticle Doped Polyimide Hybrid Alignment Layers for Flexible Liquid Crystal Displays

In this paper, a flexible liquid crystal display (LCD) is developed by applying hybrid alignment layers made of vanadium dioxide (VO2) nanoparticles and homeotropic-polyimide (h-PI) onto colorless plastic substrates, and the proposed hybrid thin layers with randomly embedded agglomerated VO2 nanoparticles exhibit a transparency over 85% at 550 nm including the substrate and a strong surface irregularity. After rubbing, liquid crystals (LCs) are vertically aligned between the hybrid thin layers with a tilt angle of ∼90°, and due to the significant surface plasmon polariton (SPP) of VO2 nanoparticles, the switch of LCs under the external electrical field has been remarkably accelerated. The operating voltage to switch LCs in a 5 μm cell assembled using a pair of 0.5% VO2 nanoparticle doped h-PI hybrid alignment layers has been reduced to 3.536 V, and simultaneously, the decaying time is also shortened more than 18%. Notably, the vertical alignment of LCs was also stabilized under bending thanks to the use of undulating hybrid alignment layers. The fabricated flexible LC cell using 0.5% VO2 nanoparticle doped h-PI alignment layers yielded good flexibility at a bending radius of 1500 mm without aggravated light leakages and deduced electro-optical performance, and the VO2 agglomerates hindering the slide of LCs by providing adequate obstructions are believed as the main contributors in firmly stabilizing the vertical alignment of LCs during bending. Compared to micropatterned substrates, ultrathin VO2 nanoparticle doped h-PI alignment layers employed in flexible LC cells demonstrating their priorities in easy investigation and displaying quality improvement are emerging, highly appreciated, and of great interest for the potential applications in flexible LCDs.

Hydrodynamics of fringing-field induced defects in nematic liquid crystals

Consumer demand for high resolution and high refresh-rate displays has naturally led to the fabrication of liquid crystal displays with ever smaller pixels. As a consequence, fringing fields between adjacent pixels grow in magnitude, leading to abrupt changes in orientation. Electric field strengths above some threshold can lead to order melting and, in turn, disclinations. This paper presents accurate modeling of disclinations induced by fringing fields due to interdigitated electrodes in a nematic liquid crystal calculated by means of the Landau–de Gennes theory. Disclination paths are determined while taking into account the flow of the liquid crystal. Making use of interdigitated electrodes, precise electrical control over the creation and positioning of defects is demonstrated for homeotropic, planar, hybrid, and in-plane surface alignments.

Interplay of Active Stress and Driven Flow in Self-Assembled, Tumbling Active Nematics

Lyotropic chromonic liquid crystals (LCLCs) are a special type of hierarchical material in which self-assembled molecular aggregates are responsible for the formation of liquid crystal phases. Thanks to its unusual material properties and bio compatibility, it has found wide applications including the formation of active nematic liquid crystals. Recent experiments have uncovered tumbling character of certain LCLCs. However, how tumbling behavior modifies structure and flow in driven and active nematics is poorly understood. Here, we rely on continuum simulation to study the interplay of extensile active stress and externally driven flow in a flow-tumbling nematic with a low twist modulus to mimic nematic LCLCs. We find that a spontaneous transverse flow can be developed in a flow-tumbling active nematic confined to a hybrid alignment cell when it is in log-rolling mode at sufficiently high activities. The orientation of the total spontaneous flow is tunable by tuning the active stress. We further show that activity can suppress pressure-driven flow of a flow-tumbling nematic in a planar-anchoring cell but can also promote a transition of the director field under a pressure gradient in a homeotropic-anchoring cell. Remarkably, we demonstrate that the frequency of unsteady director dynamics in a tumbling nematic under Couette flow is invariant against active stress when below a threshold activity but exhibits a discontinuous increase when above the threshold at which a complex, periodic spatiotemporal director pattern emerges. Taken together, our simulations reveal qualitative differences between flow-tumbling and flow-aligning active nematics and suggest potential applications of tumbling nematics in microfluidics.

Ultra-Low Driving Voltage in Quasi-Twisted Nematic Mode Using Weak / Strong Anchoring Hybrid Alignment Surface

Ultra-Low Driving Voltage in Quasi-Twisted Nematic Mode Using Weak / Strong Anchoring Hybrid Alignment Surface

Laser beam steering in a variable gradient index nematic liquid crystal structure

We have fabricated a parallel slab of nematic liquid crystal with hybrid alignment that provides “longitudinal” gradient of refractive index for the extraordinary polarized beam. This in turn generates continuously changing angular separation between ordinary and extraordinary beams while propagating inside the slab, like the optical mirage effect. For the moment the output separation angle is not large (below 1°), but it can be further optimized to obtain larger separation angles and consequently more effective electrical control.

All-optical switching of a dye-doped liquid crystal plasmonic metasurface.

A switchable metasurface composed of plasmonic split ring resonators and a dye-doped liquid crystal is developed. The transmission of the metasurface in the infrared spectral range can be changed by illuminating the dye-doped liquid crystal with light in the visible spectral range. The effect is particularly efficient in the case of hybrid alignment of the liquid crystal, i. e. alignment of the director perpendicular to the surface on one substrate and parallel alignment on the counter substrate. This all-optical switching effect can be attributed to the behavior described in earlier works as colossal optical nonlinearity or surface-induced nonlinear optical effect.

Design and application of a hybrid alignment platform for a double-sided hot embossing process

Hot embossing is a novel technique for the cost-effective production of micro-parts. Misalignment between the top and bottom surfaces of a product that has double-sided microstructures reduces its functions. Most solutions involve repairing or reproducing the embossing mold, which increases the cost for the molding process. This study proposes a hybrid alignment platform that allows accurate positioning and angular alignment for the embossing processes. The hybrid alignment platform includes two units. The upper unit allows angular adjustment using a precision rotary table. The lower unit allows positional adjustment using two orthogonal micrometers. Calibration tests are conducted for a series of adjustment steps along the X, Y and C axis. Only one alignment step is necessary for each axis. The alignment platform allows rapid positioning and increases replicability. The hybrid mold adjustment platform is used to resolve a problem with gear misalignment and the problem of eccentricity in the production of micro-gears is effectively resolved.

Louver Function in Hybrid Aligned Reverse Mode Using Dual Frequency Liquid Crystal

We have proposed reverse mode liquid crystal (LC) cells with a hybrid alignment nematic (HAN). A dual frequency LC which has positive and negative dielectric anisotropies and a reactive mesogen were used to prepare the cell. The reverse mode HAN cell has a transparent state at any incident angle in the voltage off state. The cell scattered a normal incident light by the voltage application and the transmittance, however, becomes high at a certain oblique incident angle like a louver of a window shutter. Such an incident angle can be switched by the frequency of applied voltage since the reoriented LC director changes from perpendicular to parallel to the substrate. Moreover, the incident angle switching was theoretically analyzed using conditions of refractive index matching and mismatching between the LC and the reactive mesogen.

P‐153: Improved Flexoelectric Coefficient Measurement by Means of Transmission Ellipsometry

Improved method in measuring the sum and difference of two flexoelectric coefficient e11 and e33 by means of transmission ellipsometry was devised. Planar alignment region and hybrid alignment region are fabricated in one cell of nematic liquid crystal, so as to be firstly determined the cell gap and then be estimated e11+e33 Accuracy was improved by measuring e11−e33 with using the same sample cell.

Real-time generation of dynamically patterned cholesteric liquid crystal fingerprint textures based on photoconductive effect

We present a convenient approach to facilitate the real-time generation of updatable dynamically patterned cholesteric liquid crystal (CLC) fingerprint textures based on photoconductive effect. The photoconductive Bi12SiO20 (BSO) substrate acts as virtual electrode to obtain the desired states of CLCs by both electric and light fields. Owing to different boundary conditions, the switching of four states; that is, planar, fingerprint, metastable, and homeotropic states, and the rotation of fingerprint stripes can be achieved in planar alignment (PA) cell and hybrid alignment (HA) cell, respectively. With the aid of a digital micro-mirror (DMD)-based exposure system, binary and gray-scale images were successfully written and updated by light upon suitable voltages. This work provides an alternative approach to photoaddress CLC fingerprint patterns, without needing special photoalignment agents or photoresponsitive chiral dopants. We expect that it could be employed in the manipulation of nano/micro-objects by light.