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The current proliferation of mobile robots spans ecological monitoring, warehouse management and extreme environment exploration, to an individual consumer's home

A critical aspect of toxicity evaluation is developmental and reproductive toxicity (DART) testing. Traditionally, DART testing has been conducted in vivo in mammalian model systems. New legislation aimed at reducing animal use and the prohibitive costs associated with DART testing, together with a need to understand the genetic pathways underlying developmental toxicity means there is a growing demand for alternative model systems for toxicity evaluation. Here we explore the potential of the eukaryotic social amoeba Dictyostelium discoideum, which is already widely used as a simple model system for cell and developmental biology, as a potential nonanimal model for DART testing. We developed assays for high-throughput screening of toxicity during D. discoideum growth and development. This allowed the toxicity of a broad range of test compounds to be characterized, which revealed that D. discoideum can broadly predict mammalian toxicity. In addition, we show that this system can be used to perform functional genomic screens to compare the molecular modes of action of different compounds. For example, genome-wide screens for mutations that affect lithium and valproic acid toxicity allowed common and unique biological targets and molecular processes mediating their toxicity to be identified. These studies illustrate that D. discoideum could represent a predictive nonanimal model for DART testing due to its amenability to high-throughput approaches and molecular genetic tractability.

Soft robotics aims at creating systems with improved performance of movement and adaptability in unknown, challenging, environments and with higher level of safety during interactions with humans. This Roadmap on Soft Robotics covers selected aspects for the design of soft robots significantly linked to the area of multifunctional materials, as these are considered a fundamental component in the design of soft robots for an improvement of their peculiar abilities, such as morphing, adaptivity and growth. The roadmap includes different approaches for components and systems design, bioinspired materials, methodologies for building soft robots, strategies for the implementation and control of their functionalities and behavior, and examples of soft-bodied systems showing abilities across different environments. For each covered topic, the author(s) describe the current status and research directions, current and future challenges, and perspective advances in science and technology to meet the challenges., Multifunctional Materials, 5 (3), ISSN:2399-7532

We present a methodology for designing, fabricating, and controlling rolling membrane-driven tensegrity robots. This methodology is enabled by pneumatic membrane actuators and a generalized path planning algorithm for rolling polyhedra. Membrane actuators are planar, assembled in a scalable fashion, and amenable to arbitrary geometries. Their deformation trajectories can be tuned by varying the stacking sequence and orientation of layers of unidirectional lamina placed on their surfaces. We demonstrate the application of the same set of membrane actuators consisting of polygonal faces of Platonic Solids to create polyhedral tensegrity variants. Three specific tensegrities in the forms of cube, dodecahedron, and rhombicuboctahedron are chosen to demonstrate the path planning algorithm, though the algorithm is generalizable to any uniform or non-uniform n-sided polyhedra. The membrane-driven tensegrities are able to roll in unique trajectories and circumvent obstacles contingent on the distribution and types of polygons which constitute their faces.

The emerging generation of robots composed of soft materials strives to match biological motor adaptation skills via shape-shifting. Soft robots often harness volumetric expansion directed by strain limiters to deform in complex ways. Traditionally, strain limiters have been inert materials embedded within a system to prescribe a single deformation. Under changing task demands, a fixed deformation mode limits adaptability. Recent technologies for on-demand reprogrammable deformation of soft bodies, including thermally activated variable stiffness materials and jamming systems, presently suffer from long actuation times or introduce unwanted bending stiffness. We present fibers that switch tensile stiffness via jamming of segmented elastic fibrils. When jammed, tensile stiffness increases more than 20× in less than 0.1 s, but bending stiffness increases only 2×. When adhered to an inflating body, jamming fibers locally limit surface tensile strains, unlocking myriad programmable deformations. The proposed jamming technology is scalable, enabling adaptive behaviors in emerging robotic materials that interact with unstructured environments.

Background Genomes can be sequenced with relative ease, but ascribing gene function remains a major challenge. Genetically tractable model systems are crucial to meet this challenge. One powerful model is the social amoeba Dictyostelium discoideum, a eukaryotic microbe widely used to study diverse questions in the cell, developmental and evolutionary biology. Results We describe REMI-seq, an adaptation of Tn-seq, which allows high throughput, en masse, and quantitative identification of the genomic site of insertion of a drug resistance marker after restriction enzyme-mediated integration. We use REMI-seq to develop tools which greatly enhance the efficiency with which the sequence, transcriptome or proteome variation can be linked to phenotype in D. discoideum. These comprise (1) a near genome-wide resource of individual mutants and (2) a defined pool of ‘barcoded’ mutants to allow large-scale parallel phenotypic analyses. These resources are freely available and easily accessible through the REMI-seq website that also provides comprehensive guidance and pipelines for data analysis. We demonstrate that integrating these resources allows novel regulators of cell migration, phagocytosis and macropinocytosis to be rapidly identified. Conclusions We present methods and resources, generated using REMI-seq, for high throughput gene function analysis in a key model system.

Inextensible material inflatables, such as those made from heat-sealable fabric or Mylar, are lightweight, robust, and easily packed into compact spaces and self-deployed. They are commonly made by heat-pressing two sheets together to seal them along a desired curvilinear path. Upon inflation, the sheets wrinkle about the constraints imposed by the seals, giving rise to fascinating and functional shapes. In previous literature, once an inflatable has been manufactured, it can only attain a single inflated shape. Changing task demands of the real world motivate adaptive inflatables that are not fixed to a single deformation. Herein we present a method for creating inflatables that rapidly switch between multiple deformation modes. By patterning conductive fabric on the surface, we bestow the ability to locally form or remove seals during real-time operation. Namely, pulling a vacuum to supply compression force and locally Joule heating regions of the conductive fabric mimics the action of a heat press. Furthermore, we present a finite element model to aid in the analysis and inverse design of inextensible inflatables. Together, the reconfigurable inflatables and inverse model unlock a vast array of programmed inflated shapes with a single enclosed volume.

Amphibious robots capable of transition from aquatic to terrestrial locomotion face significant challenges associated with propulsive efficacy in each environment. Conventionally, amphibious robots have utilized separate systems for aquatic and terrestrial locomotion, such as rotors and wheels, respectively. Recent approaches have attempted to consolidate the propulsive mechanism footprint and complexity in hopes of creating systems that mirror the performance and adaptability of living organisms. The crux of such a bioinspired design philosophy lies in integrating hydrodynamic profiles and terrestrial mobility, two seemingly antithetical features, into a cohesive robot architecture. State-of-the-art amphibious robots approach this challenge in a variety of ways and can be sorted into four distinct categories based on their locomotion mechanisms and body plans: (1) wheeled, (2) legged, (3) undulating, and (4) soft. This chapter surveys existing amphibious robots under each category, identifies seminal designs, and briefly examines them. We then synthesize findings from the survey to highlight open avenues of research for the continued development of amphibious robots. Lastly, we discuss our ongoing research developing a variable stiffness morphing limb as a potential next-generation propulsor for amphibious robots.

Current robotic terrain mapping techniques require expensive sensor suites to construct an environmental representation. In this work, we present a cube-shaped robot that can roll through unstructured terrain and construct a detailed topographic map of the surface that it traverses in real time with low computational and monetary expense. Our approach devolves many of the complexities of locomotion and mapping to passive mechanical features. Namely, rolling movement is achieved by sequentially inflating latex bladders that are located on four sides of the robot to destabilize and tip it. Sensing is achieved via arrays of fine plastic pins that passively conform to the geometry of underlying terrain, retracting into the cube. We developed a topography by shade algorithm to process images of the displaced pins to reconstruct terrain contours and elevation. We experimentally validated the efficacy of the proposed robot through object mapping and terrain locomotion tasks.

Ternary transition metal sulfide hollow structures are promising materials for energy storage and conversion applications. However, their synthetic methods are rather complicated and time-consuming. In this work, for the first time, with FeNi2S4 hollow balloons (FNSH) as the quintessential example, a template-free solvothermal method has been developed to synthesize ternary transition metal sulfide hollow balloons. The corresponding formation mechanism is deeply investigated, and the main factors affecting the formation of the hollow balloons are confirmed to be reaction time and temperature. FNSH/graphene aerogel (FNSH/GA) is further fabricated, which has been proven to be a highly efficient electrocatalyst for the oxygen evolution reaction (OER). The FNSH/GA exhibits excellent performance for the OER with a small overpotential of 273 mV at 10 mA cm−2 in 1.0 M KOH, which is even superior to the typical RuO2 catalyst. Furthermore, the FNSH/GA maintains the excellent performance for the OER even after a 10 h chronoamperometric test. Moreover, the synthetic method is universal and can be widely extended to other ternary transition metal sulfide hollow balloons.

Herein, N doped graphene quantum dots-interspersed Cadmium tungstate (CdWO4) nanorods (N-GQDs-CdWO4) were synthesized via decorating the N-GQDs on the surface of CdWO4 nanorods in three steps. The morphological and structural properties of the N-GQDs-CdWO4 nanorods were thoroughly investigated by X-ray diffraction spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier Transform infrared spectroscopy, Raman spectroscopy, and ultraviolet–visible spectroscopy. Based on imaging techniques, it became clear that the N-GQDs decorated on the surface of CdWO4 nanorods formed a heterostructure. This nanocomposite exhibits enhanced photoelectrochemical performances—more than four times those of bare CdWO4. In addition, the nanocomposite's photocatalytic activity under ultra-violet light irradiation was almost six fold that of bare CdWO4. We studied the mechanism governing its exceptional performance. It indicates that the existence of a heterostructure induces a synergistic effect between the N-GQDs and CdWO4 nanorods that bolsters photoelectric performance. Our work provides a feasible method to synthesize 0D/3D nanocomposites with enhanced photoelectrochemical performances, and offers a solution to rectify current solar energy shortfalls.

High-performance active materials for energy-storage and energy-conversion applications require a novel class of electrodes: ones with a structure conducive to conductivity, large specific surface area, high porosity, and mechanical robustness. Herein, we report the design and fabrication of a new ternary hybrid aerogel. The process entails an in situ assembly of 2D WSe2 nanosheets and NiFe-LDH nanosheets on a 3D N,S-codoped graphene framework, accomplished by a facile hydrothermal method and electrostatic self-assembly technology. The obtained nanocomposite architecture maximizes synergistic effects among its three 2D-layer components. To assess the performance of this hybrid material, we deployed it as an advanced electrode in overall water splitting and in a supercapacitor. Results in both scenarios attest to its excellent electrochemical properties. Specifically, serving as a catalyst in an oxygen evolution reaction, our nanocomposite requires overpotentials of 1.48 and 1.59 V to obtain current densit...

Developing efficient visible-light-driven photocatalysts will advance alternative energy technologies, ultimately curbing the environmental pollution associated with fossil fuels. In this work, Bi2S3/Bi2MoO6 photocatalysts with a heterogeneous cookie-like structure were prepared for the first time by in-situ anion exchange at relatively low temperatures. The catalysts exhibited enhanced photocatalytic activity, which we attributed to the photocurrent response, a diminished recombination rate of photogenerated electron-hole pairs, and the existence of a large heterojunction interface. These governing factors were discerned by photoelectrochemical measurements, calculated energy band positions and photoluminescence spectra. Bi2S3/Bi2MoO6 nanocomposites also exhibit better performance in response to gas than bare Bi2MoO6 according to gas sensing tests. Our work, in relaying a feasible method to synthesize Bi2S3/Bi2MoO6-based heterojunction superstructures, and documents a universal preparation method of synthetic heterogeneous complexes, and provides necessary groundwork for the development of next generation semiconductor photocatalytic technology and gas sensor.

Fabrication of stable, efficient, and inexpensive bifunctional electro-catalysts for water splitting has become increasingly attractive. Herein, for the first time, the direct growth of Mo-doped Ni3S2 on Ni foams using sodium molybdate as the Mo source at different temperatures is demonstrated. Effects of temperature on the morphology and water splitting performance of Mo-doped Ni3S2 were discussed in detail. It is found that the atomic stoichiometric ratios of Mo and Ni can be controlled by the adjusting of reaction temperature, while the obtained electro-catalysts demonstrate various morphologies, capacitances and chemisorption free energies of hydrogen, which lead to different current densities and hydrogen evolution efficiencies. The electro-catalyst synthesized at 200 °C (200-SMN/NF) demonstrates the best regular morphology and electrochemical properties. When employed in oxygen evolution reactions, 200-SMN/NF demonstrates a low over-potential of 180 mV at 100 mA cm−2. Adapting it as a bifunctional electro-catalyst, a current density of 10 mA cm−2 at a very low cell voltage of 1.53 V and cycling lifespan of more than 15 h was delivered. Further results indicated elevated hydrogen evolution reaction activity, consisting of a moderate 278 mV over-potential at a 100 mA cm−2 hydrogen production current density, a small 72.9 mV dec−1 Tafel slope, and a superior current density compared to that of precious catalyst Pt/C (40%) after −0.53 V. These results underscore the fact that 200-SMN/NF is a high-performance, precious-metal-free electro-catalyst, and provide the foundation for exciting opportunities in water splitting applications.

Most robots operate either exclusively on land or in water. Toward building an amphibious legged robot, we present a morphing limb that can adapt its structure and stiffness for amphibious operation. We draw inspiration for the limb's design from the morphologies of sea turtle flippers and land-faring tortoise legs. Turtles and tortoises have rigid hulls that can be emulated in amphibious robots to provide a convenient, protected volume for motors, electronics, power supply, and payloads. Each of these animals' limbs are tailored for locomotion in their respective environments. A sea turtle flipper has a streamlined profile to reduce drag, making it apt for swimming. A land tortoise leg boasts a strong, expanded cross-section conducive to load-bearing. We capture the morphological advantages of both animals' limbs in our morphing limb via a variable stiffness composite coupled to a pneumatic actuator system that enables on-demand transitions between leg and flipper configurations. We control the degree of stiffness of the limb by varying electrical input to flexible heaters bound to the thermally responsive variable stiffness composite. The proposed morphing amphibious limb design is promising for enabling the next generation of hybrid soft-rigid robots to adapt to unstructured environments.

Compliant, continuum structures allow living creatures to perform complex tasks inaccessible to artificial rigid systems. Although advancements in hyper-elastic materials have spurred the development of synthetic soft structures (i.e., artificial muscles), these structures have yet to match the precise control and diversity of motions witnessed in living creatures. Cephalopods tentacles, for example, can undergo multiple trajectories using muscular hydrostat, a structure consisting of aggregated laminae of unidirectional muscle fibers. Here, we present a self-adhesive composite lamina inspired by the structural morphology of the muscular hydrostat, which adheres to any volumetrically expanding soft body to govern its motion trajectory. The composite lamina is stretchable only in one direction due to inextensible continuous fibers unidirectionally embedded within its hyper-elastic matrix. We showcase reconfiguration of inflation trajectories of two- and three-dimensional soft bodies by simply adhering laminae to their surfaces., Soft actuators are typically confined to a single, predetermined deformation trajectory. Here, the authors report on a bioinspired self-adhesive material which can be attached, detached, and re-attached to expanding soft bodies to render reconfigurable and controllable deformation trajectories.

Herein, we describe the preparation and testing of Co-doped FeSe2 hybridized with graphene (Fe1-xCoxSe2/RGO), a high-active yet stable electrocatalyst for hydrogen evolution reactions (HERs) in acidic solutions. First, we systematically analyze the composition and morphology of Fe1-xCoxSe2/RGO and attribute its excellent electrochemical performance to its unique architecture-a base of highly conductive graphene with fully exposed active edges that enhances conductivity and facilitates ion/electron transfer. Our experimental measurements indicate elevated HER activity with a moderate overpotential of ∼166 mV at a hydrogen production current density of 10 mA cm(-2), a small Tafel slope of ∼36 mV dec(-1), and long cycling lifespan more than 20 h. The promising results, in addition to the fact that Fe1-xCoxSe2/RGO is a high-performance, precious-metal-free electrocatalyst, pave the way for exciting opportunities in renewable hydrogen production applications.

In this paper, we described a simple two–step method for preparing needle-like CoNi 2 S 4 /CNT/graphene nanocomposite with robust connection among its ternary components. The prepared CoNi 2 S 4 /CNT/graphene nanocomposite has been thoroughly characterized by spectroscopic (Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy), X-ray diffraction and thermogravimetric analysis. Microscopy techniques (scanning electron microscopy–energy dispersive spectroscopy and transmission electron microscopy) were employed to probe the morphological structures. The electrochemical properties of the as-prepared 3D architectures were investigated with three and two-electrode systems. In addition to its high specific capacitance (710 F g −1 at 20 A g −1 ), after charging–discharging for 2000 cycles, the electrode still maintained the capacity retention of about 82%. When used as the active electrode material for supercapacitors, the fabricated CoNi 2 S 4 –g–CNT nanostructure exhibited excellent specific capacitance and good rate capability, making it a promising candidate for next-generation supercapacitors.

Few-layered polyelectrolyte functionalized MoS2 nanosheets were obtained for the first time through in situ polymerization of MoS2 nanosheets with poly(acrylic acid) and poly(acrylamide), both of which demonstrated excellent dispersibility and stability in water. After designing and optimizing the components of this series of polyelectrolyte functionalized MoS2 nanosheets, by exploiting the electrostatic interactions present in the modified MoS2 nanosheets, we further created a series of layer-by-layer (LBL) self-assembling MoS2-based films. To this end, uniform MoS2 nanosheet-based LBL films were precisely deposited on substrates such as quartz, silicon, and ITO. The polyelectrolyte functionalized MoS2 nanosheet assembled LBL film-modified electrodes demonstrated enhanced electrocatalytic activity for H2O2. As such, they are conducive to efficient sensors and advanced biosensing systems.

The search for safe and efficient energy storage systems continues to inspire researchers to develop new energy storage materials with excellent performance. Graphene-based three-dimensional (3D) nanostructures are interesting to supercapacitors (SCs) because of their high surface area, ample number of active sites, and good conductivity. This combination of attributes allows for full utilization capacitance of active electrode materials. Herein, three-dimensional CuCo2S4–g–CNT structure was fabricated successfully with the hydrothermal method. Serving as the active electrode, CuCo2S4–g–CNT demonstrated a remarkable specific capacitance (504 F g−1 at the current density of 10 A g−1). Moreover, the as-obtained CuCo2S4–g–CNT hybrid electrode is robust, exhibiting exceptional cycle life, as revealed by galvanostatic charge–discharge studies (retaining 92.3% after 2000 cycles). Its durability is mainly due to the synergistic effects of CuCo2S4, graphene and CNTs. These unique nano-architectures demonstrate potential applications in energy storage electrodes and may indeed spur a new generation of hybrid SCs to bridge the energy gap between SCs and chemical batteries.

Ternary electrode materials based on graphene, FeNi2S4, and transition metal dichalcogenides (TMDs) were obtained via a one-pot synthesis method. Compared to binary materials, FeNi2S4–graphene (g)–2D-TMD nanocomposites exhibited better performance, which is a direct consequence of their unique ternary structures and the induced synergistic effect among their three components—ultrathin TMD nanosheets, highly conductive graphene networks, and FeNi2S4 nanoparticles. With the fabricated materials, we constructed electrodes to assess the electrochemical performance. The results are promising: the materials exhibited rapid electron and ion transport rates and large electroactive surface areas, testifying to their excellent electrochemical properties. In particular, the FeNi2S4–g–MoSe2 electrode demonstrated a maximum specific capacitance of 1700 F g−1 at a current density of 2 A g−1 (8.5 F cm−2 at a current density of 10 mA cm−2) and a capacitance retention of approximately 106% after 4000 cycles at a charge–discharge current density of 2 A g−1. These electrochemical results indicate that the ternary composite, FeNi2S4–g–MoSe2, is a promising candidate electrode material for high-performance supercapacitors.

Dual-functional electrocatalysts have recently been reported to improve the conversion and storage of energy generated from overall water splitting in alkaline electrolytes. Herein, for the first time, a shape-controlled synthesis of starfish-like Co–Ni–S nanosheets on three-dimensional (3D) hierarchically porous nickel foams (Co–Ni–S/NF) via a one-step hydrothermal method was developed. The influence of reaction time on the nanosheet structure and properties was intensively studied. After 11 h reaction, the Co–Ni–S/NF-11 sample displays the most regular structure of nanosheets and the most outstanding electrochemical properties. As to water splitting, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) required overpotentials of 284.3 and 296 mV, respectively, to provide a current density of 100 mA cm–2. The marvelous electrochemical performance can be attributed to the conductive networks of 3D layered porous nickel skeletons that are highly interconnected, which provided a large speci...

In Book One, Chapter Six, of Finnegans Wake , Shaun adopts the guise of Professor Jones in order to present a lecture on the relationship between time and space. The first half of that lecture considers that relationship from a philosophical perspective and the second from an anthropological. This lecture is challenging for the reader because Shaun, in attempting to convey the immensity of his erudition, throws in a vast number of references to different thinkers. Allusions are made to Bergson, Einstein, Spinoza, and Hegel. The situation is further complicated by the fact that Shaun’s adopted character of Professor Jones represents Joyce’s friend/adversary Wyndham Lewis. The purpose of this article is to offer a reading of the first half of Shaun’s lecture. This reading focuses on how the numerous ideas and thinkers referenced in that section are related to one another. In examining the lecture’s connections, the article shows how Joyce uses Professor Jones’s discourse to explore the notion of opposition.

High-performance active materials for energy-storage and energy-conversion applications require a novel class of electrodes: ones with a structure conducive to conductivity, large specific surface area, high porosity, and mechanical robustness. Herein, we report the design and fabrication of a new ternary hybrid aerogel. The process entails an in situ assembly of 2D WSe

Synthesis of highly efficient and robust catalysts with earth-abundant resources for overall water splitting is essential for large-scale energy conversion processes. Herein, a series of highly active and inexpensive Co–Ni–P films were fabricated by a one-step constant current density electrodeposition method. These films were demonstrated to be efficient bifunctional catalysts for both H2 and O2 evolution reactions (HER and OER), while deposition time was deemed to be the crucial factor governing electrochemical performance. At the optimal deposition time, the obtained Co–Ni–P-2 catalyst performed remarkably for both HER and OER in alkaline media. In particular, it requires −103 mV overpotential for HER and 340 mV for OER to achieve the current density of 10 mA cm–2, with corresponding Tafel slopes of 33 and 67 mV dec–1. Moreover, it outperforms the Pt/C//RuO2 catalyst and only needs −160 mV (430 mV) overpotential for HER (OER) to achieve 200 mA cm–2 current density. Co–Ni–P electrodes were also conducte...

Transition metal dichalcogenides, MX2 (M = Fe, Co, Ni, X = S, Se, Te), have been proven to be promising substitutes for noble metals in hydrogen evolution reactions (HERs). However, forthright comparisons of metal sulfides, metal selenides, and metal tellurides are rarely conducted, let alone the mechanism of the important role of their non-metal ligands. In this paper, we report the pilot study of a controllable method for the preparation of a series of NiX2 (X = S, Se, Te) nanosheets via a facile anion-exchange reaction. Consequently, the HER activities and stabilities of NiS2, NiSe2, and NiTe2 nanosheets were tested in both acid and alkaline solutions. The required overpotentials to reach 10 mA cm−2 in 0.5 M H2SO4 for NiS2, NiSe2, and NiTe2 were 213, 156, and 276 mV, respectively. The best performance of NiSe2 was also confirmed in 1 M KOH. Besides NiS2 and NiTe2 nanosheets, the HER properties of NiSe2 nanosheets are superior to most of the available nickel catalysts. Interestingly, the results from electrochemical measurements were found to be fully consistent with the data based on density function theory calculation. Among various factors that might influence the HER activities of nickel dichalcogenides, the free energies of hydrogen adsorption and conductivities have played important roles.

Direct liquid phase exfoliation (LPE) is generally regarded as an effective and efficient methodology for preparing single- to few-layered nanosheets on a large scale. Based on a previous finding that the polar and dispersive components of surface tension can be used as critical parameters for screening suitable solvents for LPE, in this study, we conducted in-depth research on direct LPE of two-dimensional (2D) materials by the extensive LPE of a series of 2D materials and the thorough comparison of their surfaces properties and LPE efficiencies. We rationally developed the surface tension component matching (STCM) theory, and in nature, its key point lies in the close ratio of polar to dispersive components (P/D) between the solvents and the aimed 2D materials. To this end, the surface tension components ratio is demonstrated to be an effective parameter for screening LPE solvents. In addition to the optimization of the LPE process for these 2D materials, this work has further greatly enlarged the comprehensive library for the solvent and 2D material matching pairs based on the improved STCM theory.

Developing efficient visible-light-driven photocatalysts will advance alternative energy technologies, ultimately curbing the environmental pollution associated with fossil fuels. In this work, Bi

A facile route toward functionalized amphiphilic layered transition-metal dichalcogenide nanosheets through in situ polymerization of polystyrene-polyacrylamide copolymers is established. The attachment of copolymers greatly affects their dispersibility in different kinds of solvents. Surface-tension components, polarity, and coordination effects of the copolymer are found to be the main factors affecting the dispersibility.

This study describes a comparative investigation on the heterogeneous versus homogeneous nature of the Pd-catalyzed Suzuki-Miyaura cross-coupling reaction mechanism with specific magnetic hierarchical core-shell and yolk-shell structures. The hierarchical core-shell Fe3 O4 @SiO2 -Pd@mCeO2 (m=mesoporous) catalyst contains a core of nonporous silica-sheltered magnetite (Fe3 O4 ) nanoparticles (NPs), a transition layer of active palladium (Pd) NPs, and an outer shell of porous ceria (CeO2 ). The magnetic yolk-shell Fe3 O4 @h-Pd@mCeO2 (h=hollow) catalyst was prepared by selectively etching the nonporous silica interlayers. Notably, the results of the hot-filtration heterogeneity test, the effect of Pd concentration, and solid-phase poisoning, indicate that the two kinds of catalysts function in Pd-catalyzed Suzuki-Miyaura cross-coupling reactions through different catalytic mechanisms. Moreover, both catalysts demonstrated better catalytic activity than the Fe3 O4 @SiO2 -Pd catalyst. This finding can be ascribed to the outermost CeO2 shell having a high concentration of trivalent cerium and oxygen vacancies, which gives rise to the increased electron density of Pd NPs, and a faster rate-determining step in the oxidative addition reaction for the Suzuki reaction. In addition, we propose a feasible mechanism elucidating the synergistic effect between the supporting CeO2 and active species.

Precise control of the electronic surface states of two-dimensional (2D) materials could improve their versatility and widen their applicability in electronics and sensing. To this end, chemical surface functionalization has been used to adjust the electronic properties of 2D materials. So far, however, chemical functionalization has relied on lattice defects and physisorption methods that inevitably modify the topological characteristics of the atomic layers. Here we make use of the lone pair electrons found in most of 2D metal chalcogenides and report a functionalization method via a Lewis acid-base reaction that does not alter the host structure. Atomic layers of n-type InSe react with Ti(4+) to form planar p-type [Ti(4+)n(InSe)] coordination complexes. Using this strategy, we fabricate planar p-n junctions on 2D InSe with improved rectification and photovoltaic properties, without requiring heterostructure growth procedures or device fabrication processes. We also show that this functionalization approach works with other Lewis acids (such as B(3+), Al(3+) and Sn(4+)) and can be applied to other 2D materials (for example MoS2, MoSe2). Finally, we show that it is possible to use Lewis acid-base chemistry as a bridge to connect molecules to 2D atomic layers and fabricate a proof-of-principle dye-sensitized photosensing device.

In Finnegans Wake Notebook VI.B.8 Joyce famously observed that Flaubert treats language “as a kind of despair.” This quotation has frequently been used to assert the connection between Joyce's final work and Bouvard and Pecuchet. It is in stressing the ubiquity of intertextuality, the futility of the quest for originality, the hypocrisy of the artist, that Joyce is most Flaubertian. But for this reading to function as an all-encompassing description of Flaubert's artistic beliefs, La Tentation de Saint Antoine must be eliminated from his oeuvre. Ezra Pound, in an attempt to limit the Tentation's influence within Ulysses, claimed that Joyce had swallowed it whole within one episode, “Circe.” Given how Finnegans Wake pushes the limits of intertextuality even harder than Joyce's previous work, one might expect it to be more Bouvardian, more Pecuchetian, more despairing. In this essay I intend to show how, in order to properly understand how Flaubert influenced the Wake, one must consider the Tentation. I will look at how Flaubert's saint relates to the St. Patrick of the Wake's final chapter. St. Patrick's debate with Archdruid Berkeley touches on many issues which are key to the Tentation: the relationship between form and matter, the limits of perception, the power of faith. Just as the debate is decided by a burst of heavenly light, so the Tentation closes with St. Anthony gazing up at the sun and seeing the face of Christ.