194 research outputs found

    Degradation of Toxic Organic Contaminants by Graphene Cathode in an Electro‐Fenton System

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    A novel composite electrode was constructed by pressing graphene and CuO, using a cathode in an electro‐Fenton (EF) system. Cyclic voltammetry, charge/discharge curve and electrochemical impedance spectroscopy (EIS) were used to characterize the composite electrode. The degradation of a toxic organic contaminant, Terramycin, by EF system was studied in an undivided electrolysis cell. The possible degradation products of Terramycin were studied by a Fourier transform‐infrared spectrum, and the findings showed that the structure of Terramycin was damaged. The variations of hydrogen peroxide and the relative content of hydroxyl radical (.OH) during the degradation process were traced by enzyme catalysis method and fluorescence spectrometry. The results showed that the electro‐catalytic degradation of Terramycin occurred by an ·OH radical mechanism. More importantly, this as‐prepared cathode was very stable and could be reused without any catalytic activity decrease, suggesting its potential application in the wastewater treatment

    Observation of Higher Order Nodal Line Semimetal in Phononic Crystals

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    Higher-order topological insulators and semimetals, which generalize the conventional bulk-boundary correspondence, have attracted extensive research interest. Among them, higher-order Weyl semimetals feature two-fold linear crossing points in three-dimensional (3D) momentum space, 2D Fermi-arc surface states, and 1D hinge states. Higher-order nodal-point semimetals possessing Weyl points or Dirac points have been implemented. However, higher-order nodal-line or nodal-surface semimetals remain to be further explored in experiments in spite of many previous theoretical efforts. In this work, we realize a second-order nodal-line semimetal in 3D phononic crystals. The bulk nodal lines, 2D drumhead surface states guaranteed by Zak phases, and 1D flat hinge states attributed to kz-dependent quadrupole moments, are observed in simulations and experiments. Our findings of nondispersive surface and hinge states may promote applications in acoustic sensing and energy harvesting.Comment: accepted for publication in PR

    How single-cell techniques help us look into lung cancer heterogeneity and immunotherapy

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    Lung cancer patients tend to have strong intratumoral and intertumoral heterogeneity and complex tumor microenvironment, which are major contributors to the efficacy of and drug resistance to immunotherapy. From a new perspective, single-cell techniques offer an innovative way to look at the intricate cellular interactions between tumors and the immune system and help us gain insights into lung cancer and its response to immunotherapy. This article reviews the application of single-cell techniques in lung cancer, with focuses directed on the heterogeneity of lung cancer and the efficacy of immunotherapy. This review provides both theoretical and experimental information for the future development of immunotherapy and personalized treatment for the management of lung cancer

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    The tunable wettability in multistimuli-responsive smart graphene surfaces

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    The tunable wettability of smart graphene films onto stainless steel substrates with a multi-response to different environmental stimuli has been investigated including light irradiation, pH, electric field, and annealing temperature. Conductive graphene film exhibited the controllable transition from water-repellent to water-loving characteristic in response to different environment fields, which primarily resulted from the morpho-chemically synergistic effect as well as the restoration of electronic stucture. Based on the fundamental theories of wettability, mechanisms in switching from hydrophobicity to hydrophilicity for smart graphene surface including thermal chemistry, electrostatic, photo-induced surface chemistry, solvent, and pH methods were presented

    Language Development for English-Medium Instruction: A Longitudinal Perspective on the Use of Cohesive Devices by Chinese English Majors in Argumentative Writing

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    In alignment with a strong increase of fully or partially English-taught programmes worldwide, intense research interest has been drawn to English as a medium of instruction (EMI) in higher education. In the meanwhile, much research has been done concerning cohesion and coherence in second language writing, which reveals that the appropriate use of cohesive devices will ultimately lead to text coherence. This study adopts a longitudinal perspective to examine the use of cohesive devices by Chinese English majors in argumentative writing in the EMI context. Thirty-one second-year Chinese English majors participated in this study. They were given three writing prompts at the initial, middle, and final time-points of one academic year, respectively. Altogether, 93 argumentative writings were collected, and 30 cohesion indices were selected and investigated at local, global and text levels via two automatic computational tools: Coh-Metrix and TAACO. The major findings of the study indicate (1) Chinese English majors were capable of a variety of cohesive devices in their writing. They tended to use local cohesive devices, especially connectives, more than global and text cohesive devices; (2) Most of the cohesion indices demonstrated growth. Of the 30 selected cohesion indices, 13 presented significant development over one academic year, and among them, 3 were at local level, 10 at global level and 3 at text level. Informed of the possible learning trajectories of cohesive devices, teachers may be guided to focus on their teaching in some specific areas of cohesion, and students may be more aware of what contributes to their writing performance and what to emphasize when writing in English

    Synthesis of a new orthorhombic form of diamond in varying-C VN films: Microstructure, mechanical and tribological properties

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    Synthesis of a new orthorhombic form of diamond in varying-C VN films: Microstructure, mechanical and tribological propertie

    A feasible multilayer structure design for solid lubricant coatings in a lunar environment

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    Solid lubricant coatings have received considerable research attention in space applications owing to their remarkably improved tribological characteristics. But their service life is seriously restricted by the harsh environment, such as high vacuum and abrasive wear. In this paper, a novel design of carbon-based multilayer (MoS2/DLC multilayer) coatings was reported to clarify the friction and wear behavior in high vacuum conditions with and without simulated lunar-dust (SLD). Compared with pure DLC or MoS2 coatings, the multilayer coating showed excellent tribological performance with a low friction coefficient of 0.02 and a wear rate of similar to 6.5 x 10(-6) mm(3) N-1 m(-1). What is particularly interesting is that the wear volume of MoS2/DLC multilayer coatings with the increase of time is in accordance with the Archard linear law, regardless of the condition with or without SLD. Moreover, the surface morphology and composition of wear tracks and scars reveal that the long life of carbon-based multilayer coatings cannot be explained solely by excellent mechanical performance, and is also attributed to the formation of ridge layers as third body reservoirs and a tribo-induced composite transfer layer containing SLD nanoparticles and coating materials

    The Productivity, Economic Structure and Middle-income Trap— Can China Avoid this Trap?

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    This paper establishes an economic model to directly study the effects of the labor ratio, economic structure and productivity of a country on its economic growth. The model analysis also indicates the relevancy and importance of the stable exchange and inflation rates to the economic success of a nation. Using data from selected countries over the particular years, this paper explores and explains why some economies have successfully passed through the middle-income trap, while others fell in. The paper then compares China’s relevant data with that of others, and discusses challenges and problems China faces and how it can avoid this middle-income trap
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