自适应机翼的发展现状及其关键技术研究

综述了近二十年来国内外自适应机翼技术的研究现状以及该领域需要解决的关键技术,对未来这一技术的发展和应用进行了展望。     

One-Component Artificial Gustatory System Based on Hydrogen-Bond Organic Framework for Discrimination of Versatile Analytes

Hydrogen-bond organic frameworks (HOFs) with excellent structural and luminescent properties have emerged as a promising material for the construction of fluorescence sensors. However, designing a facile, universal and high throughput sensor with multiplex detection capacity still remains challenging. Herein, a one-component sensor array is constructed that mimics natural gustatory system for accurate and high-throughput discrimination and identification of versatile analytes. HOF as a single sensing element greatly simplifies the probe preparation in sensor array and detection procedure. Metal ions, proteins and bacteria as the model targets are rapid and accurately discriminated, presenting the universality of the system. Particularly, the system is successfully used for the classification of antibiotic mechanisms. The study expands the application scope of HOFs and provides a facile and universal system for sensing applications.     

蓝牙的未来

如今蓝牙技术已经有了非常广泛的应用,但仍面临一些问题。文中就蓝牙目前应用方面遇到的蓝牙与WLAN之间的干扰问题、蓝牙的传输速率问题以及蓝牙安全机制方面进行了深入分析,介绍了目前针时此类问题的一些最新技术和研究成果,以及蓝牙未来的发展前景。     

Tailoring Anion Association Strength Through Polycation-Anion Coordination Mechanism in Imidazole Polymeric Ionic Liquid-Based Artificial Interphase toward Durable Zn Metal Anodes

Artificial interface layer engineering is an efficacious modification strategy for protecting zinc anode from dendrite growth and byproducts formation. However, the high bulk ionic conductivity of most artificial interfacial layers is mainly contributed by the movement of anions (SO₄²⁻), which is the source of parasitic reactions on zinc anode. Herein, a high zinc ion donor transition (σZn²⁺ = 3.89 × 10⁻² S cm⁻¹) imidazole polymeric ionic liquid interface layer (1-carboxymethyl-3-vinylimidazolium bromide monomer, CVBr) for Zn metal protection is designed. The N⁺ atom of imidazole rings is connected by chains to form the cavities and the anions are confined within these cavities. Thus, the hindering effect of surrounding units on the anions leads to the subdiffusive regime, which inhibits the diffusion of SO₄²⁻ in interface and increases Zn²⁺ transference number. Besides, the polycation-anion coordination mechanism of PolyCVBr ensures accelerated Zn²⁺ transition and realizes rapid internal Zn²⁺ migration channel. As a result, the Zn@CVBr||AM symmetry cells deliver high bulk ionic conductivity (4.42 × 10⁻² S cm⁻¹) and high Zn²⁺ transference number (tZn²⁺ = 0.88) simultaneously. The Zn@CVBr||AM-NaV₃O₈ pouch cells display the capacity retention of 88.9% after 190 cycles under 90° bending, verifying their potential practical application.     

“Ship‐in‐a‐Bottle” Growth of Noble Metal Nanostructures

Noble metal nanostructures are grown inside hollow mesoporous silica microspheres using “ship‐in‐a‐bottle” growth. Small Au seeds are first introduced into the interior of the hollow microspheres. Au nanorods with synthetically tunable longitudinal plasmon wavelengths and Au nanospheres are obtained through seed‐mediated growth within the microspheres. The encapsulated Au nanocrystals are further coated with Pd or Pt shells. The microsphere‐encapsulated bimetallic core/shell nanostructures can function as catalysts. They exhibit high catalytic performance and their stability is superior to that of the corresponding unencapsulated core/shell nanostructures in the catalytic oxidation of o‐phenylenediamine with hydrogen peroxide. Therefore, these hollow microsphere‐encapsulated metal nanostructures are promising as recoverable and efficient catalysts for various liquid‐phase catalytic reactions.     

Transition‐Metal‐Free Magnesium‐Based Batteries Activated by Anionic Insertion into Fluorinated Graphene Nanosheets

Considering resource abundance, high volumetric energy density, and safer anodic electroplating, the Mg‐based battery is thought to be one of the most promising systems beyond current Li‐ion batteries. However, the development of Mg batteries is hindered by the narrow electrochemical window of electrolytes as well as by inapplicable cathode frameworks. In this work, it is proposed, for the first time, to utilize a fast surface redox process to replace sluggish lattice migration for improving the kinetics of Mg batteries. Taking fluorinated graphene nanosheets (FGSs) as model material, a reversible capacity higher than 100 mAh g^?1 is achieved in a pseudocapacitance behavior from 2.75 to 0.5 V. Different from traditional storage mechanisms, this proof‐of‐concept Mg/FGS system is activated by a prior anionic process followed by reversible cationic storage. The dilution of charge density by forming large‐sized monovalent complex cations and the easy access to surface redox sites are responsible for the negligible voltage polarization without an evident MgF₂ nucleation phenomenon.     

Salt‐Assisted Synthesis of 2D Materials

2D materials have demonstrated good chemical, optical, electrical, and magnetic characteristics, and offer great potential in numerous applications. Corresponding synthesis technologies of 2D materials that are high‐quality, high‐yield, low‐cost, and time‐saving are highly desired. Salt‐assisted methods are emerging technologies that can meet these requirements for the fabrication of 2D materials. Herein, the recent process for the salt‐assisted synthesis of 2D materials and their typical applications are summarized. First, the properties of salt crystals and molten salts are briefly introduced, and then some examples of 2D materials synthesis with the assistance of salt as well as their representative applications are presented. The underlying mechanisms of salts with different states on the formation of 2D morphology are discussed to aid in the rational design of synthetic route of 2D materials. At last, the challenges and future perspectives for salt‐assisted methods are briefly described. This review provides guidance for the controllable synthesis of 2D materials based on the salt‐assisted approaches.     

Characterization of current transport in ferroelectric polymer devices

We report the charge injection characteristics in poly(vinylidene fluoride-trifluoroethylene), P(VDF-TrFE), as a function of electrode material in metal/ferroelectric/metal device structures. Symmetric and asymmetric devices with Al, Ag, Au and Pt electrodes were fabricated to determine the dominant carrier type, injection current density, and to propose transport mechanisms in the ferroelectric polymer. Higher work function metals such as Pt are found to inject less charges compared to lower work function metals, implying n-type conduction behavior for P(VDF-TrFE) with electrons as the dominant injected carrier. Two distinct charge transport regimes were identified in the P(VDF-TrFE) devices; a Schottky-limited conduction regime for low to intermediate fields (E < 20 MV/m), and a space-charge limited conduction (SCLC) regime for high fields (20 < E < 120 MV/m). Implication of these results for degradation in P(VDF-TrFE) memory performance are discussed.     

Extraction of physical Schottky parameters using the Lambert function in Ni/AlGaN/GaN HEMT devices with defined conduction phenomena

Electrical characterization analyses are proposed in this work using the Lambert function on Schottky junctions in GaN wide band gap semiconductor devices for extraction of physical parameters. The Lambert function is used to give an explicit expression of the current in the Schottky junction. This function is applied with defined conduction phenomena, whereas other work presented arbitrary (or undefined) conduction mechanisms in such parameters'' extractions. Based upon AlGaN/GaN HEMT structures, extractions of parameters are undergone in order to provide physical characteristics. This work highlights a new expression of current with defined conduction phenomena in order to quantify the physical properties of Schottky contacts in AlGaN/GaN HEMT transistors.     

In Situ Liquid-Cell TEM Observation of Multiphase Classical and Nonclassical Nucleation of Calcium Oxalate

Calcium oxalate (CaOx) is the major phase in kidney stones and the primary calcium storage medium in plants. CaOx can form crystals with different lattice types, water contents, and crystal structures. However, the conditions and mechanisms leading to nucleation of particular CaOx crystals are unclear. Here, liquid-cell transmission electron microscopy and atomistic molecular dynamics simulations are used to study in situ CaOx nucleation at different conditions. The observations reveal that rhombohedral CaOx monohydrate (COM) can nucleate via a classical pathway, while square COM can nucleate via a non-classical multiphase pathway. Citrate, a kidney stone inhibitor, increases the solubility of calcium by forming calcium-citrate complexes and blocks oxalate ions from approaching calcium. The presence of multiple hydrated ionic species draws additional water molecules into nucleating CaOx dihydrate crystals. These findings reveal that by controlling the nucleation pathways one can determine the macroscale crystal structure, hydration state, and morphology of CaOx.