Construction of Asymmetrical Hexameric Biomimetic Motors with Continuous Single‐Directional Motion by Sequential Coordination

The significance of bionanomotors in nanotechnology is analogous to mechanical motors in daily life. Here the principle and approach for designing and constructing biomimetic nanomotors with continuous single‐directional motion are reported. This bionanomotor is composed of a dodecameric protein channel, a six‐pRNA ring, and an ATPase hexamer. Based on recent elucidations of the one‐way revolving mechanisms of the phi29 double‐stranded DNA (dsDNA) motor, various RNA and protein elements are designed and tested by single‐molecule imaging and biochemical assays, with which the motor with active components has been constructed. The motor motion direction is controlled by three operation elements: (1) Asymmetrical ATPase with ATP‐interacting domains for alternative DNA binding/pushing regulated by an arginine finger in a sequential action manner. The arginine finger bridges two adjacent ATPase subunits into a non‐covalent dimer, resulting in an asymmetrical hexameric complex containing one dimer and four monomers. (2) The dsDNA translocation channel as a one‐way valve. (3) The hexameric pRNA ring geared with left‐/right‐handed loops. Assessments of these constructs reveal that one inactive subunit of pRNA/ATPase is sufficient to completely block motor function (defined as K = 1), implying that these components work sequentially based on the principle of binomial distribution and Yang Hui's triangle.     

Highly Efficient p‐i‐n Perovskite Solar Cells Utilizing Novel Low‐Temperature Solution‐Processed Hole Transport Materials with Linear π‐Conjugated Structure

Alternative low‐temperature solution‐processed hole‐transporting materials (HTMs) without dopant are critical for highly efficient perovskite solar cells (PSCs). Here, two novel small molecule HTMs with linear π‐conjugated structure, 4,4′‐bis(4‐(di‐p‐toyl)aminostyryl)biphenyl (TPASBP) and 1,4′‐bis(4‐(di‐p‐toyl)aminostyryl)benzene (TPASB), are applied as hole‐transporting layer (HTL) by low‐temperature (sub‐100 °C) solution‐processed method in p‐i‐n PSCs. Compared with standard poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonic acid) (PEDOT:PSS) HTL, both TPASBP and TPASB HTLs can promote the growth of perovskite (CH₃NH₃PbI₃) film consisting of large grains and less grain boundaries. Furthermore, the hole extraction at HTL/CH₃NH₃PbI₃ interface and the hole transport in HTL are also more efficient under the conditions of using TPASBP or TPASB as HTL. Hence, the photovoltaic performance of the PSCs is dramatically enhanced, leading to the high efficiencies of 17.4% and 17.6% for the PSCs using TPASBP and TPASB as HTL, respectively, which are ≈40% higher than that of the standard PSC using PEDOT:PSS HTL.     

Alumina‐Supported CoFe Alloy Catalysts Derived from Layered‐Double‐Hydroxide Nanosheets for Efficient Photothermal CO2 Hydrogenation to Hydrocarbons

A series of novel CoFe‐based catalysts are successfully fabricated by hydrogen reduction of CoFeAl layered‐double‐hydroxide (LDH) nanosheets at 300–700 °C. The chemical composition and morphology of the reaction products (denoted herein as CoFe‐x) are highly dependent on the reduction temperature (x). CO₂ hydrogenation experiments are conducted on the CoFe‐x catalysts under UV–vis excitation. With increasing LDH‐nanosheet reduction temperature, the CoFe‐x catalysts show a progressive selectivity shift from CO to CH₄, and eventually to high‐value hydrocarbons (C₂₊). CoFe‐650 shows remarkable selectivity toward hydrocarbons (60% CH₄, 35% C₂₊). X‐ray absorption fine structure, high‐resolution transmission electron microscopy, Mössbauer spectroscopy, and density functional theory calculations demonstrate that alumina‐supported CoFe‐alloy nanoparticles are responsible for the high selectivity of CoFe‐650 for C₂₊ hydrocarbons, also allowing exploitation of photothermal effects. This study demonstrates a vibrant new catalyst platform for harnessing clean, abundant solar‐energy to produce valuable chemicals and fuels from CO₂.     

The effect of heat treatment on superconductivity of Zn‐doped YBa2Cu3‐xZnxO7‐y

YBa₂Cu_3‐xZn_xO_7‐y compounds with x = 0, 0.05, 0.15, and 0.30 have been synthesized by standard solid state reaction method. The crystal structure, lattice parameters, and oxygen content are not changed by the substitution of Zn for Cu since both valence state and ionic radius are almost identical for Zn and Cu elements in YBa₂Cu_3‐xZn_xO_7‐y. However, the superconducting transition temperature T_c decreases with the increase of Zn content, reflecting the T_c‐suppression effect of Zn substitution. Heat treatment experiments indicate that the heat treatment at low temperature is beneficial to improve the superconductivity of the sample. But T_c decreases with the increase of annealing temperature when the treatment temperature is above 300°C, and finally the superconductivity disappears at approximately 920°C, 700°C and 550°C for the samples with x = 0.0, 0.05 and 0.15, respectively. Our experiments indicate that the superconductivity of the sample with higher Zn content is more sensitive to the oxygen content, and a small decrease in the oxygen content can lead to a considerable decrease of T_c.     

Graphene‐Encapsulated FeS2 in Carbon Fibers as High Reversible Anodes for Na+/K+ Batteries in a Wide Temperature Range

Developing low cost, long life, and high capacity rechargeable batteries is a critical factor towards developing next‐generation energy storage devices for practical applications. Therefore, a simple method to prepare graphene‐coated FeS₂ embedded in carbon nanofibers is employed; the double protection from graphene coating and carbon fibers ensures high reversibility of FeS₂ during sodiation/desodiation and improved conductivity, resulting in high rate capacity and long‐term life for Na⁺ (305.5 mAh g^?1 at 3 A g^?1 after 2450 cycles) and K⁺ (120 mAh g^?1 at 1 A g^?1 after 680 cycles) storage at room temperature. Benefitting from the enhanced conductivity and protection on graphene‐encapsulated FeS₂ nanoparticles, the composites exhibit excellent electrochemical performance under low temperature (0 and ?20 °C), and temperature tolerance with stable capacity as sodium‐ion half‐cells. The Na‐ion full‐cells based on the above composites and Na₃V₂(PO₄)₃ can afford reversible capacity of 95 mAh g^?1 at room temperature. Furthermore, the full‐cells deliver promising discharge capacity (50 mAh g^?1 at 0 °C, 43 mAh g^?1 at ?20 °C) and high energy density at low temperatures. Density functional theory calculations imply that graphene coating can effectively decrease the Na⁺ diffusion barrier between FeS₂ and graphene heterointerface and promote the reversibility of Na⁺ storage in FeS₂, resulting in advanced Na⁺ storage properties.     

Three‐dimensional analyses of unified characterization parameter of in‐plane and out‐of‐plane creep constraint

Based on extensive three‐dimensional finite element analyses, the unified characterization parameter A_c of in‐plane and out‐of‐plane creep constraint based on crack‐tip equivalent creep strain for three specimen geometries (C(T), SEN(T) and M(T)) were quantified for 316H steel at 550 °C and steady‐state creep. The distributions of the parameter A_c along crack fronts (specimen thickness) were calculated, and its capability and applicability for characterizing a wide range of in‐plane and out‐of‐plane creep constraints in different specimen geometries have been comparatively analysed with the constraint parameters based on crack‐tip stress fields (namely R*, h and T_Z). The results show that the parameter A_c in the centre region of all specimens appears uniform distribution and lower value (higher constraint), and in the region near free surface it shows protuberant distribution and higher value (lower constraint). The parameter A_c can simultaneously and effectively characterize a wide range of in‐plane and out‐of‐plane creep constraints, while the parameters R*, h and T_Z based on crack‐tip stress fields cannot achieve this. The different capabilities of these parameters for characterizing in‐plane and out‐of‐plane creep constraints originate from their underlying theories. The parameter A_c may be useful for accurately characterizing the overall constraint level composed of in‐plane and out‐of‐plane constraints in actual high‐temperature components, and it may be used in creep life assessments for improving accuracy.     

High strain rate superplasticity in powder metallurgy aluminium alloy 6061 + 20 vol.-%SiCpcomposite with relatively large particle size

Abstract

The possibility of high strain rate superplasticity (HSRS) was examined over a wide range of temperatures in a powder metallurgy aluminium alloy 6061/SiC_p composite with a relatively large SiC particle size of ~8 μm. A maximum tensile elongation of 350% was obtained at 600°C and 10^-2 s^-1. Tensile elongations over 200% were obtained in a narrow temperature range between 590 and 610°C at high strain rates of 10^-2 and 10^-1 s^-1. The current testing temperature range could be divided into two regions depending on the rate-controlling deformation mechanism. Region I is in the lower temperature range from 430 to 490°C, where lattice diffusion controlled dislocation climb creep (n = 5) is the rate-controlling deformation process, and region II is in the higher temperature range from 520 to 610°C, where lattice diffusion controlled grain boundary sliding controls the plastic flow. An abnormally large increase in activation energy was noted at temperatures above 590°C, where large tensile elonga tions over 200% were obtained at high strain rates. This increase in activation energy and high tensile ductility may be explained in terms of presence of a liquid phase created by partial melting, but such evidence could not be provided by the current differential scanning calorimetry (DSC) test. This may be because the DSC is not sensitive enough to detect the small amount of liquid phase.     

A Polymer Encapsulation Strategy to Synthesize Porous Nitrogen‐Doped Carbon‐Nanosphere‐Supported Metal Isolated‐Single‐Atomic‐Site Catalysts

A novel polymer encapsulation strategy to synthesize metal isolated‐single‐atomic‐site (ISAS) catalysts supported by porous nitrogen‐doped carbon nanospheres is reported. First, metal precursors are encapsulated in situ by polymers through polymerization; then, metal ISASs are created within the polymer‐derived p‐CN nanospheres by controlled pyrolysis at high temperature (200–900 °C). Transmission electron microscopy and N₂ sorption results reveal this material to exhibit a nanospheric morphology, a high surface area (≈380 m² g^?1), and a porous structure (with micropores and mesopores). Characterization by aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy and X‐ray absorption fine structure confirms the metal to be present as metal ISASs. This methodology is applicable to both noble and nonprecious metals (M‐ISAS/p‐CN, M = Co, Ni, Cu, Mn, Pd, etc.). In particular, the Co‐ISAS/p‐CN nanospheres obtained using this method show comparable (E_1/2 = 0.838 V) electrochemical oxygen reduction activity to commercial Pt/C with 20 wt% Pt loading (E_1/2 = 0.834 V) in alkaline media, superior methanol tolerance, and outstanding stability, even after 5000 cycles.     

A High‐Temperature Na‐Ion Battery: Boosting the Rate Capability and Cycle Life by Structure Engineering

High‐temperature sodium ion batteries (SIBs) have drawn significant heed recently for large‐scale energy storage. Yet, conventional SIBs are in the depths of inferior charge/discharge efficiency and cyclability at elevated temperatures. Rational structure design is highly desirable. Hence, a 3D hierarchical flower architecture self‐assembled by carbon‐coated Na₃V₂(PO₄)₃ (NVP) nanosheets (NVP@C‐NS‐FL) is fabricated via a microwave‐assisted glycerol‐mediated hydrothermal reaction combined with a post heat‐treatment. The growth mechanism of NVP@C‐NS‐FL is systematically investigated, by forming a microspherical glycerol/polyglycerol‐NVP complex initially and then converting into flower‐like architecture during the subsequent annealing at a low temperature ramping rate. Benefiting from the integrated structure, fast Na⁺ transportation, and highly effective heat transfer, the as‐obtained NVP@C‐NS‐FL exhibits an excellent high‐temperature SIB performance, e.g., 65 mAh g^?1 (100 C) after 1000 cycles under 60 °C. When coupled with NaTi₂(PO₄)₃ anode, the full cell can still display superior power capability of 1.4 kW kg^?1 and long‐term cyclability (2000 cycles) under 60 °C.     

Charge Transport Through a Cardan‐Joint Molecule

The charge transport through a single ruthenium atom clamped by two terpyridine hinges is investigated, both experimentally and theoretically. The metal‐bis(terpyridyl) core is equipped with rigid, conjugated linkers of para‐acetyl‐mercapto phenylacetylene to establish electrical contact in a two‐terminal configuration using Au electrodes. The structure of the [Ru^II( L )₂](PF₆)₂ molecule is determined using single‐crystal X‐ray crystallography, which yields good agreement with calculations based on density functional theory (DFT). By means of the mechanically controllable break‐junction technique, current–voltage (I–V), characteristics of [Ru^II( L )₂](PF₆)₂ are acquired on a single‐molecule level under ultra‐high vacuum (UHV) conditions at various temperatures. These results are compared to ab initio transport calculations based on DFT. The simulations show that the cardan‐joint structural element of the molecule controls the magnitude of the current. Moreover, the fluctuations in the cardan angle leave the positions of steps in the I–V curve largely invariant. As a consequence, the experimental I–V characteristics exhibit lowest‐unoccupied‐molecular‐orbit‐based conductance peaks at particular voltages, which are also found to be temperature independent.     

WO3 Nanofiber‐Based Biomarker Detectors Enabled by Protein‐Encapsulated Catalyst Self‐Assembled on Polystyrene Colloid Templates

A novel catalyst functionalization method, based on protein‐encapsulated metallic nanoparticles (NPs) and their self‐assembly on polystyrene (PS) colloid templates, is used to form catalyst‐loaded porous WO₃ nanofibers (NFs). The metallic NPs, composed of Au, Pd, or Pt, are encapsulated within a protein cage, i.e., apoferritin, to form unagglomerated monodispersed particles with diameters of less than 5 nm. The catalytic NPs maintain their nanoscale size, even following high‐temperature heat‐treatment during synthesis, which is attributed to the discrete self‐assembly of NPs on PS colloid templates. In addition, the PS templates generate open pores on the electrospun WO₃ NFs, facilitating gas molecule transport into the sensing layers and promoting active surface reactions. As a result, the Au and Pd NP‐loaded porous WO₃ NFs show superior sensitivity toward hydrogen sulfide, as evidenced by responses (R_air/R_gas) of 11.1 and 43.5 at 350 °C, respectively. These responses represent 1.8‐ and 7.1‐fold improvements compared to that of dense WO₃ NFs (R_air/R_gas = 6.1). Moreover, Pt NP‐loaded porous WO₃ NFs exhibit high acetone sensitivity with response of 28.9. These results demonstrate a novel catalyst loading method, in which small NPs are well‐dispersed within the pores of WO₃ NFs, that is applicable to high sensitivity breath sensors.     

Composition‐Graded Cesium Lead Halide Perovskite Nanowires with Tunable Dual‐Color Lasing Performance

Cesium lead halide (CsPbX₃) perovskite has emerged as a promising low‐threshold multicolor laser material; however, realizing wavelength‐tunable lasing output from a single CsPbX₃ nanostructure is still constrained by integrating different composition. Here, the direct synthesis of composition‐graded CsPbBr_xI_3?x nanowires (NWs) is reported through vapor‐phase epitaxial growth on mica. The graded composition along the NW, with an increased Br/I from the center to the ends, comes from desynchronized deposition of cesium lead halides and temperature‐controlled anion‐exchange reaction. The graded composition results in varied bandgaps along the NW, which induce a blueshifted emission from the center to the ends. As an efficient gain media, the nanowire exerts position‐dependent lasing performance, with a different color at the ends and center respectively above the threshold. Meanwhile, dual‐color lasing with a wavelength separation of 35 nm is activated simultaneously at a site with an intermediate composition. This position‐dependent dual‐color lasing from a single nanowire makes these metal halide perovskites promising for applications in nanoscale optical devices.     

Multilayer Lead‐Free Ceramic Capacitors with Ultrahigh Energy Density and Efficiency

The utilization of antiferroelectric (AFE) materials is thought to be an effective approach to enhance the energy density of dielectric capacitors. However, the high energy dissipation and inferior reliability that are associated with the antiferroelectric–ferroelectric phase transition are the main issues that restrict the applications of antiferroelectric ceramics. Here, simultaneously achieving high energy density and efficiency in a dielectric ceramic is proposed by combining antiferroelectric and relaxor features. Based on this concept, a lead‐free dielectric (Na_0.5Bi_0.5)TiO₃‐x(Sr_0.7Bi_0.2)TiO₃ (NBT‐xSBT) system is investigated and the corresponding multilayer ceramic capacitors (MLCCs) are fabricated. A record‐high energy density of 9.5 J cm^?3, together with a high energy efficiency of 92%, is achieved in NBT‐0.45SBT multilayer ceramic capacitors, which consist of ten dielectric layers with the single‐layer thickness of 20 µm and the internal electrode area of 6.25 mm². Furthermore, the newly developed capacitor exhibits a wide temperature usage range of ‐60 to 120 °C, with an energy‐density variation of less than 10%, and satisfactory cycling reliability, with degradation of less than 8% over 10⁶ cycles. These characteristics demonstrate that the NBT‐0.45SBT multilayer ceramic is a promising candidate for high‐power energy storage applications.     

Fabrication of Millimeter‐Scale,Single‐Crystal One‐Third‐Hydrogenated Graphene with Anisotropic Electronic Properties

Periodically hydrogenated graphene is predicted to form new kinds of crystalline 2D materials such as graphane, graphone, and 2D C_xH_y, which exhibit unique electronic properties. Controlled synthesis of periodically hydrogenated graphene is needed for fundamental research and possible electronic applications. Only small patches of such materials have been grown so far, while the experimental fabrication of large‐scale, periodically hydrogenated graphene has remained challenging. In the present work, large‐scale, periodically hydrogenated graphene is fabricated on Ru(0001). The as‐fabricated hydrogenated graphene is highly ordered, with a √3 × √3/R30° period relative to the pristine graphene. As the ratio of hydrogen and carbon is 1:3, the periodically hydrogenated graphene is named “one‐third‐hydrogenated graphene” (OTHG). The area of OTHG is up to 16 mm². Density functional theory calculations demonstrate that the OTHG has two deformed Dirac cones along one high‐symmetry direction and a finite energy gap along the other directions at the Fermi energy, indicating strong anisotropic electrical properties. An efficient method is thus provided to produce large‐scale crystalline functionalized graphene with specially desired properties.     

Breathable Nanowood Biofilms as Guiding Layer for Green On‐Skin Electronics

Thin‐film electronics are urged to be directly laminated onto human skin for reliable, sensitive biosensing together with feedback transdermal therapy, their self‐power supply using the thermoelectric and moisture‐induced‐electric effects also has gained great attention (skin and on‐skin electronics (On‐skinE) themselves are energy storehouses). However, “thin‐film” On‐skinE 1) cannot install “bulky” heatsinks or sweat transport channels, but the output power of thermoelectric generator and moisture‐induced‐electric generator relies on the temperature difference (?T ) across generator and the ambient humidity (AH), respectively; 2) lack a routing and accumulation of sweat for biosensing, lack targeted delivery of drugs for precise transdermal therapy; and 3) need insulation between the heat‐generating unit and heat‐sensitive unit. Here, two breathable nanowood biofilms are demonstrated, which can help insulate between units and guide the heat and sweat to another in‐plane direction. The transparent biofilms achieve record‐high transport_///transport_⊥ (//: along cellulose nanofiber alignment direction, ⊥: perpendicular direction) of heat (925%) and sweat (338%), winning applications emphasizing on ?T/AH‐dependent output power and “reliable” biosensing. The porous biofilms are competent in applications where “sensitive” biosensing (transporting_// sweat up to 11.25 mm s^?1 at the 1st second), “insulating” between units, and “targeted” delivery of saline‐soluble drugs are of uppermost priority.     

Low‐cycle fatigue of IN 718: Effect of waveform

The influence of various strain waveforms on the low‐cycle fatigue of IN 718 tested at 650°C has been investigated. The straining paths are accompanied by dwell‐induced creep component(s) or unequal strain distribution in different portions of cycles reducing strength of material. The investigation intends to clarify mainly mechanistic aspects of relaxation‐fatigue interaction. Features of time‐dependent effect induced by nonpeak dwell and the same accompanied by peak dwell, slow unloading from the peak to a lower strain, and different loading and unloading rates are compared in terms of stress amplitude responses, mean stress relaxation, hysteresis loops, life, and damage parameter D_C‐F. Softening is common in all the cases, and degree of softening varies linearly with life. The energy‐based life prediction model has been found to work well for the data, and we have introduced energy fraction–based approach to observe simultaneous contribution from both creep and fatigue on life.     

Crystal Facet Induced Single‐Atom Pd/CoxOy on a Tunable Metal–Support Interface for Low Temperature Catalytic Oxidation

Atomic dispersed metal sites in single‐atom catalysts are highly mobile and easily sintered to form large particles, which deteriorates the catalytic performance severely. Moreover, lack of criterion concerning the role of the metal–support interface prevents more efficient and wide application. Here, a general strategy is reported to synthesize stable single atom catalysts by crafting on a variety of cobalt‐based nanoarrays with precisely controlled architectures and compositions. The highly uniform, well‐aligned, and densely packed nanoarrays provide abundant oxygen vacancies (17.48%) for trapping Pd single atoms and lead to the creation of 3D configured catalysts, which exhibit very competitive activity toward low temperature CO oxidation (100% conversion at 90 °C) and prominent long‐term stability (continuous conversion at 60 °C for 118 h). Theoretical calculations show that O vacancies at high‐index {112} facet of Co_xO_y nanocrystallite are preferential sites for trapping single atoms, which guarantee strong interface adhesion of Pd species to cobalt‐based support and play a pivotal role in preventing the decrement of activity, even under moisture‐rich conditions (≈2% water vapor). The progress presents a promising opportunity for tailoring catalytic properties consistent with the specific demand on target process, beyond a facile design with a tunable metal–support interface.     

Wafer Scale Solventless Adhesive Bonding with iCVD Polyglycidylmethacrylate: Effects of Bonding Parameters on Adhesion Energies

Initiated chemical vapor deposition (iCVD) polyglycidylmethacrylate (PGMA) thin films are investigated as adhesives for wafer‐scale bonding of 300 mm silicon substrates and demonstrated to form highly uniform, void‐free bond interfaces. The effects of bonding temperature and pressure on critical adhesion energy (G_c) between iCVD PGMA and silicon are studied using the four‐point bend technique. G_c values can be varied over an order of magnitude (0.59–41.6 J m⁻²) by controlling the bonding temperature and the observed dependence is attributed to changes in the physical (diffusion) and chemical (crosslinking) properties of the film. Thermal degradation studies using spectroscopic ellipsometry reveal that the iCVD PGMA films can crosslink when annealed above 120 °C in air. Further, changes in polymer behavior associated with annealing temperature are demonstrated to influence the crack propagation interface between the bonded substrates. These findings demonstrate the feasibility of iCVD polymer films for both temporary “thermoplastic,” and permanent “thermoset” bonding with potential applications in 3D integrated circuit technologies.     

Discovery of Rapid and Reversible Water Insertion in Rare Earth Sulfates: A New Process for Thermochemical Heat Storage

Thermal energy storage based on chemical reactions is a prospective technology for the reduction of fossil‐fuel consumption by storing and using waste heat. For widespread application, a critical challenge is to identify appropriate reversible reactions that occur below 250 °C, where abundant low‐grade waste heat and solar energy might be available. Here, it is shown that lanthanum sulfate monohydrate La₂(SO₄)₃?H₂O undergoes rapid and reversible dehydration/hydration reactions in the temperature range from 50 to 250 °C upon heating/cooling with remarkably small thermal hysteresis (<50 °C), and thus it emerges as a new candidate system for thermal energy storage. Thermogravimetry and X‐ray diffraction analyses reveal that the reactions proceed through an unusual mechanism for sulfates: water is removed from, or inserted in La₂(SO₄)₃?H₂O with progressive change in hydration number x without phase change. It is also revealed that only a specific structural modification of La₂(SO₄)₃ exhibits this reversible dehydration/hydration behavior.     

Inhibition of microbial growth in ready‐to‐eat food stored at ambient temperature by modified atmosphere packaging

This study was undertaken to develop a modified atmosphere package to control microbial growth in ready‐to‐eat (RTE) products stored at ambient temperature. Ethanol and/or limonene associated with modified atmosphere (CO₂ : O₂ : N₂ = 30% : 5% : 65%) was used to inhibit the growth of total air‐borne microorganisms and Escherichia coli in RTE products stored at 25°C. The results indicated that 0.05% ethanol vapour in the headspace was effective to inhibit the growth of air‐borne microorganisms and E. coli at 25°C for 72 h in a model study, and the effectiveness was related to ethanol content. Both 73 ppm limonene and 0.05% ethanol vapour enhanced the bacteriostatic effect of modified atmosphere in RTE sushi roll products, and no off‐flavour was detected using this formulated gas; however, no significant inhibitory effect was observed for RTE cold noodle products. This study concludes that combinations of carbon dioxide, ethanol or limonene vapours are effective to inhibit microbial growth in RTE food at ambient temperature, and the outcome may be due to the hurdle effect. Copyright © 2003 John Wiley & Sons, Ltd.