Search

Semantic segmentation technology is an important step in the interpretation of remote sensing images. High spatial resolution remote sensing images have clear features. Traditional image segmentation methods cannot fully represent the information in high spatial resolution images and tend to yield unsatisfactory segmentation accuracy. With the rapid development of deep learning, many researchers have tried to use deep learning algorithms for remote sensing image segmentation. This paper uses U-Net for multiclassification and binary classification of Gaofen-2 high spatial resolution remote sensing image data. Six types of features, which were build-up, farmland, water, meadow, forest and others, were labeled in the image. A “neighborhood voting” method was used to determine the category of uncertain pixels based on spatial heterogeneity and homogeneity. Through U-Net neural network multiclassification, the overall accuracy of the training data is 93.83%; the overall accuracy of the test data is 82.27%; and the test accuracy of the binary classification algorithm is 79.75%. The results show that the two models yield high accuracy and credibility in remote sensing image segmentation.

The highly ordered perpendicularly aligned cylindrical and lamellar microdomains within block copolymer (BCP) films have important applications in diverse fields. However, the fast normal orientation of self-assembled nanostructures on arbitrary substrates without tedious pre- and postprocessing has been a challenging issue in manufacturing miniaturized devices. Here, we outline the potential for extending the hierarchical self-assembly within azobenzene-containing PS-b-PMA(Az) films to inherently assist in the formation of normally aligned domains using a rapid thermal annealing process (140 °C for 5 min). Liquid crystalline (LC) mesogens in PS-b-PMA(Az) films self-assemble to form a parallelly aligned sematic phase after thermal annealing, as confirmed by grazing-incidence small-angle X-ray scattering (GISAXS), wide-angle X-ray diffraction (WAXD) and ultraviolet-visible (UV-vis) spectra. This sub-phase contributes to broadening of the PS-cylinder-phase window (0.083 ≤ fPS < 0.49) and ∼12 nm PS cylinder structures. Perpendicular cylinders or lamellae are observed on various substrates, such as silicon wafers, flexible polyethylene terephthalate (PET) sheets and conductive aluminum foils. Additionally, the good reactive ion etching (RIE) rate difference between the two blocks makes these BCPs more attractive for advancing the field of BCP lithographic applications for fabricating flexible microelectronic devices.

It is significantly challenging for state-of-the-art wearable electronics to stably monitor physicochemical signals under dynamic motions. Herein, a bending-insensitive, self-powered, and intrinsically flexible UV detector has been realized based on well-designed oriented composite fabrics, consisting of ionic liquid (IL)-containing liquid crystalline polymers (ILCPs) and piezoelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] nanogenerators. The novel composite fabrics establish effective UV illuminance-internal stress-electric signal conversion by coupling resistive and piezoelectric effects, with a fast response time of 190 ms. Particularly, benefiting from the intrinsic flexibility of composite fabrics, the ILCP/P(VDF-TrFE) device can maintain stable performance under dynamic bending even if the frequency is up to 2.5 Hz, with a bending insensitivity of less than 1% performance variation under 1.0 mW cm

Block copolymer (BCP) lithography, as one of the most promising techniques for the next-generation integrated circuits, has been extensively investigated in recent years. Among the diverse types of BCPs, liquid-crystalline BCPs (LC-BCPs) formed by incorporating LC moieties into the BCPs have become increasingly attractive because of the tunable alignment of the LC chains. This review highlights the control of the microdomain orientation of PEO-b-PMA(Az) thin films via novel and convenient processing methods, including micropore extrusion and the introduction of polydimethylsiloxane (PDMS). Meanwhile, the mechanisms of the microdomain alignment transition are clarified and are closely related to the soft shearing field and the change in the block surface energy. Furthermore, some new perspectives for future research on the self-assembly of LC-BCP thin films are outlined from the point of view of material design, orientation control, and technological innovation. The facile control of the microdomain orientation in the liquid-crystalline block copolymer (LC-BCP) thin films has been realized by means of micropore extrusion and introducing polydimethylsiloxane (PDMS), instead of complicated processes or costly apparatus. In extrusion process, the alignment can be recovered via ultrasonicating the extruded BCP solution or as-placing upon long-time thermal annealing.

Polymeric nanoparticles (NPs) containing liquid crystalline (LC) mesogens with tunable anisotropic morphologies have applications in various fields, but their preparation typically suffers from tedious and low-throughput approaches. Here we present an efficient route to the preparation of anisotropic morphologies of azobenzene-containing block copolymers (BCPs) at high solids content via a polymerization-induced hierarchical self-assembly in ethanol. Various anisotropic NPs, including cuboids, short belts, lamellae, and ellipsoidal vesicles, have been obtained in a remarkably broad range of BCP compositions. The NPs exhibit a smectic phase with ordered stripes when observed under TEM. This internal LC ordering plays a significant role on the formation of these intriguing anisotropic morphologies. Morphological transitions from anisotropic to isotropic spheres can be obtained upon UV illumination due to the photoresponsive properties of the azobenzene mesogens. This work significantly expands the scope of accessible morphologies in PISA and suggests that the under explored LC BCPs may have an impactful role in the PISA field.

Block copolymer (BCP) films with perpendicularly aligned cylindrical domains of high aspect ratio have important applications in diverse fields. However, an aspect ratio of the cylinders as high as 200 has rarely been reported so far. Here we demonstrate an efficient route to the formation of normally aligned P4VP cylinders with high aspect ratio surrounded by a matrix of azobenzene-containing block (PMA(Az)) via hierarchical self-assembly. A crisscross structure, consisting of parallelly aligned liquid crystalline (LC) layers and normally aligned self-assembly domains, is expected to assist the formation of well-defined nanostructures. The LC layers in the cylindrical films self-assemble to form smectic phase after solvent annealing, as confirmed by WAXD and UV-vis spectra. We found that the aspect ratio of the vertical P4VP cylinders is up to 200 and the film thickness reaches 6 μm. P4VP is a functional polymer, making this P4VP-b-PMA(Az) film more suitable for advanced filters, multi-nanochannels, nanolithography, and high-density storage media, etc.

Background Long non-coding RNA (lncRNA) plays important roles in many biological and pathological processes, including transcriptional regulation and gene regulation. As lncRNA interacts with multiple proteins, predicting lncRNA-protein interactions (lncRPIs) is an important way to study the functions of lncRNA. Up to now, there have been a few works that exploit protein-protein interactions (PPIs) to help the prediction of new lncRPIs. Results In this paper, we propose to boost the prediction of lncRPIs by fusing multiple protein-protein similarity networks (PPSNs). Concretely, we first construct four PPSNs based on protein sequences, protein domains, protein GO terms and the STRING database respectively, then build a more informative PPSN by fusing these four constructed PPSNs. Finally, we predict new lncRPIs by a random walk method with the fused PPSN and known lncRPIs. Our experimental results show that the new approach outperforms the existing methods. Conclusion Fusing multiple protein-protein similarity networks can effectively boost the performance of predicting lncRPIs.

Crosslinked liquid crystalline polymers (CLCPs) have garnered extensive attention in recent years for their significant values in the design of light-driven soft actuators. However, poor processabilities due to the insoluble and infusible crosslinked networks prevent their practical applications severely. In this study, a weldable azobenzene-containing CLCP is designed with photo- and humidity-responsive actuations, which enables a cut-and-weld process to 3D CLCP architectures. The tensile properties and stability are almost unchanged after welding, much better than those of the films pasted by common adhesive tapes. Meanwhile, the mechanisms of the welding process are clarified on the base of surface hydrogen bonding and further crosslinking. By taking advantage of the cut-and-weld process, a 3D "claw" integrated into a robotic arm is realized for grabbing millimeter-scale objects by remote control. This work enhances significantly not only the processability of CLCP films but also the utilization of leftover pieces, which provides an efficient approach to create functional 3D structures from film precursors for the potential application in the smart materials.

The orientation transition from perpendicular to parallel alignment of PEO cylindrical microdomains within PEO-b-PMA(Az) films has been demonstrated via introducing a small amount of polydimethylsiloxane (PDMS) into block copolymers (BCPs). The introduced PDMS can change the surface energy difference of the two blocks and induce a soft shearing force during the annealing process, which affects the alignment of PEO cylindrical domains synergically. With this understanding, the PDMS-assisted method can possibly be generalized to align a wide variety of other BCPs. The BCP films with controllable alignment can be used as lithographic nanotemplates to prepare nanowire arrays, which have enormous potential application in the field of integrated circuits.

Triboelectrification-enabled self-powered flexible electronic/optical systems have aroused a new surge of interest in recent years. All-in-one integration of such a system, which could significantly improve its adaptability, operability, and portability, still remains a challenge due to the absence of suitable architectures and integration schemes. Herein, a previously reported self-powered optical switch (OS) is thoroughly remolded and upgraded to a fully integrated contact-sliding-triboelectrification-driven dynamic optical transmittance modulator (OTM). The OTM is constructed with a multilayered structure, comprising a transparent triboelectrification top layer, a SiO2 -spaced polymer dispersed liquid crystal (PDLC) intermediate layer, and a flexible transparent conductive substrate. The working mechanism is that an alternating electric field can be induced once contact-sliding occurs upon the OTM, rendering the PDLC layer immediately switching its initial translucent state to an instantaneous transparent state. As such, a decent dimming range with the relative transmitted light intensity from 0.17 to 0.72 can be achieved at low mechanical thresholds of contact pressure (≈20 kPa) and sliding velocity (≈0.3 m s-1 ). Moreover, for practical applications, demonstrations of information covering and selective visualization are successfully implemented without any extra optical elements nor external power supplies, explicitly showing great potential for the OTM in various self-powered optical interactive applications.