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High-tech industrial agglomeration is conducive to boosting technological progress, promoting industrial structure upgrading and realizing economic transformation, and certainly affects the overall industrial environmental efficiency. However, few recent studies have focused on its impact on industrial environmental efficiency from a green perspective. In the context of promoting the development of green economy, it is of great significance to clarify the links between high-tech industrial agglomeration and industrial environmental efficiency. In this research, we first analyzed the theoretical mechanism of the impact of high-tech industrial agglomeration and its spatial spillover effects on industrial environmental efficiency and then made an empirical analysis based on the panel data of 29 provinces and cities in China from 2003 to 2016. During the research, Super-DEA method, ESDA method and spatial Dubin model are used. The result shows that: (1) There is a significant spatial positive correlation between China's industrial environmental efficiency and high-tech industrial agglomeration; (2) high-tech industrial agglomeration has improved the local industrial productivity and industrial technology level through scale effects and technical effects, which has accordingly significantly enhanced the corresponding environmental efficiency; (3) through the association of regional industries, the cross-regional cooperation of enterprises and the formation of innovation networks, high-tech industrial agglomeration promotes the spillover of knowledge and technology among regions, improves the level of industrial technology in neighboring regions, and enhances the industrial environmental efficiency in neighboring regions. All these three is helpful to re-evaluate the development mode of high-tech industry agglomeration and to formulate relevant government policies. [ABSTRACT FROM AUTHOR]

Photonic materials designed at wavelength scales have enabled a range of emerging energy technologies, from solid-state lighting to efficient photovoltaics that have transformed global energy landscapes. Daytime passive radiative cooling materials shed heat from the ground to the cold universe by taking advantage of the terrestrial thermal radiation that is as large as the renewable solar energy. Newly developed photonic materials permit subambient cooling under direct sunshine, and their applications are expanding rapidly enabled by scalable manufacturing. We review here the recent advancement of daytime subambient radiative cooling materials, which allow energy-efficient cooling and are paving the way toward technologies that harvest the coldness from the universe as a new renewable energy source. [ABSTRACT FROM AUTHOR]

The existing differential privacy for social network graphs data published method is mainly focused on graph synthesis. But the privacy budget is set by data owner without adequate consideration of the differences in privacy requirements between individual users. And it published a topology data of social network data, which does not combine the independent attribute information and attribute information of the individual user with the correlation of edge information. This paper researches the influence of both social network attribute graph node properties and the correlation of edge information under the condition of considering the user privacy requirements, thus a social network attributes graphs algorithm is proposed under personalized differential privacy, which is for the independent attribute information between users. Since the node properties do not match the data type, our proposed mode will make the data partitioning in the data set, and it also divides and calculates the probability according to the node attribute distribution query function. Finally, through two real social network data sets, our proposed algorithms will execute for experimental comparison, and are verified they validity and usability through the experimental results. [ABSTRACT FROM AUTHOR]

Association Link Network (ALN) can organize massive news data to support many intelligent Web applications. The degree estimating can facilitate the rapid positioning of Web resources in ALN. In our prior work, we have well studied the degree estimating of out-degree of nodes in ALN. In this paper, we proposed an automatic estimating method of the in-degree of nodes in ALN to further reduce the searching scope for the rapid positioning. First, we explore the main factors of forming the in-degree of any one node from semantic feature view by qualitative analysis. Then, based on the result of qualitative analysis, we propose the model for estimating the in-degree of any one node in ALN, including the method framework, the first automatic estimating method and its further optimization method. Experimental results show that the proposed estimating method as well as the optimization method have a high precision. [ABSTRACT FROM AUTHOR]

China and Thailand are traditional agricultural countries, geographically near to each other, large differences in natural conditions and climates, agricultural trade between the two countries is pretty developed. In recent years, with a higher productivity and a more sophisticated opening-up policy, Sino-Thailand bilateral trade in agricultural products has kept steadily growing. However, there are still many problems such as a great similarity in exports, concentration of export market, low price competition and so on. Based on the international market position, trade structure of agricultural products, trade geography direction and others, using the latest product similarity index, market similarity index, trade complement index to analyze the competition and complement of agricultural products between China and Thailand in the international agricultural trade, also analyze the bilateral relations between the two countries in agricultural trade. Conclusions show that the trade complement does exist in agricultural product trade between China and Thailand, the market similarity is greater than the product similarity in agricultural product trade between China and Thailand. In the world agricultural product market, Thailand maintains its competitive advantage over China in general terms. However, Thai agricultural products much differ from those of China which lead to a low competition of farm products between China and Thailand in the global market. Conversely, in Sino-Thailand bilateral agricultural trade, competition plays the major role while complement, a minor one. This paper gives out some suggestions based on the analysis of several factors affecting the Sino-Thai trade in agricultural products. For example, make full use of comparative advantages; carry on strategic adjustment and others. This promotion of stable development of Sino-Thai trade in agricultural products is of great practical significance. [ABSTRACT FROM AUTHOR]

Along with the further development of China - ASEAN Free Trade Area, the economic cooperation between China and Thailand has become more and more frequent,China-ASEAN cooperation in service areas has once again become the focus of regional economic cooperation. Therefore, it is of great realistic significance to study in depth how service trade of the two countries leads the development of their economic growth. Based on Balassa export extended aggregate production function under the open economy condition, introduce export and import variable into C-D production function to establish a new model including import and export variables. Using 1990-2011 panel data on trading in services and SUR method to make an empirical analysis on the contribution rate to economic growth of the service trade in China and Thailand by empirical analysis. To compare the differences of the contribution of classification of service trade to economic growth between China and Thailand, relevant models were constructed to analyze the contribution of transport services trade, tourism service trade and other services to economic growth. Studies concluding that there is a significant difference in promoting of Sino-Thai bilateral trade in service imports and exports to economic growth, the contribution of bilateral service trade exports is more than imports. The contribution of China's total volumes of import and export service trade and exports to economic growth is greater than Thailand, and in the contribution of total volumes of import service trade to economic growth, Thailand overall is higher than China due to the difference of output elasticity. So China's economic development is more susceptible to global environmental degradation and international financial crisis and other factors, the study's conclusions provide the important theory guidance of further development of national policy and industrial policy of Chinese to Thai trade services. [ABSTRACT FROM AUTHOR]

The stabilized finite element method based on local projection stabilization is applied to discretize the Stokes eigenvalue problems, then the corresponding stability and convergence properties are given. Furthermore, we use a postprocessing technique to accelerate the convergence rate of the eigenpair approximations. The postprocessing strategy contains solving an additional Stokes source problem in an augmented finite element space which can be constructed either by refining the mesh, or increasing the order of finite element space. Numerical tests are also provided to confirm the theoretical results. [ABSTRACT FROM AUTHOR]

Thermodynamically driven self-assembly offers a direct route to organize individual nanoscopic components into three-dimensional structures over a large scale. The most thermodynamically favourable configurations, however, may not be ideal for some applications. In plasmonics, for instance, nanophotonic constructs with non-trivial broken symmetries can display optical properties of interest, such as Fano resonance, but are usually not thermodynamically favoured. Here, we present a self-assembly route with a feedback mechanism for the bottom-up synthesis of a new class of symmetry-breaking optical metamaterials. We self-assemble plasmonic nanorod dimers with a longitudinal offset that determines the degree of symmetry breaking and its electromagnetic response. The clear difference in plasmonic resonance profiles of nanorod dimers in different configurations enables high spectra selectivity. On the basis of this plasmonic signature, our self-assembly route with feedback mechanism promotes the assembly of desired metamaterial structures through selective excitation and photothermal disassembly of unwanted assemblies in solution. In this fashion, our method can selectively reconfigure and homogenize the properties of the dimer, leading to highly monodispersed aqueous metamaterials with tailored symmetries and electromagnetic responses. [ABSTRACT FROM AUTHOR]

Abstract: A unified strategy to derive metric tensors in two and three spatial dimensions for the interpolation error and its gradient in norm is presented. It generates anisotropic adaptive meshes as quasi-uniform ones in the corresponding metric space, which is defined by a metric tensor being computed based on error estimates in different norms. Numerical results show that the corresponding convergence rates for several typical problems are almost optimal. [Copyright &y& Elsevier]

We theoretically demonstrate coherent control over propagation of surface plasmon polaritons (SPP), at both telecommunication and visible wavelengths, on a metallic surface adjacent to quantum coherence (phaseonium) medium composed of three-level quantum emitters (semiconductor quantum dots, atoms, rare-earth ions, etc.) embedded in a dielectric host. The coherent drive allows us to provide sufficient gain for lossless SPP propagation and also lowers the pumping requirements. In case of lossy propagation, an order of magnitude enhancement in propagation length can be achieved. Optical control over SPP propagation dynamics via an external coherent drive holds promise for quantum control in the field of nanophotonics. [ABSTRACT FROM AUTHOR]

With unprecedented ability to localize electromagnetic field in time and space, the nanometer scale laser promises exceptionally broad scientific and technological innovation. However, as the laser cavity becomes subwavelength, the diffraction of light prohibits the directional emission, so-called the directionality, one of the fundamental attributes of the laser. Here, we have demonstrated a deep subwavelength waveguide embedded (WEB) plasmon laser that directs more than 70% of its radiation into an embedded semiconductor nanobelt waveguide with dramatically enhanced radiation efficiency. The unique configuration of WEB plasmon laser naturally integrates photonic and electronic functionality allowing both efficient electrical modulation and wavelength multiplexing. We have demonstrated a plasmonic circuit integrating five independently modulated multicolored plasmon laser sources multiplexed onto a single semiconductor nanobelt waveguide, illustrating the potential of plasmon lasers for large scale, ultradense photonic integration. [ABSTRACT FROM AUTHOR]

Photoacoustic imaging, an acoustic imaging modality with potentially optical resolution in an optical turbid medium, has attracted great attention. However, the convergence of wavefront optimization and raster scanning in computational photoacoustic imaging leads to the challenge of fast mapping, especially for a spatial resolution approaching the acoustic deep-subwavelength regime. As a sparse sampling paradigm, compressive sensing has been applied in numerous fields to accelerate data acquisition without significant quality losses. In this work, we propose a dual-compressed approach for photoacoustic surface tomography that enables high-efficiency imaging with 3D spatial resolution unlimited by the acoustics in a turbid environment. The dual-compressed photoacoustic imaging with single-pixel detection, enabled by spatially optical modulation with synchronized temporally photoacoustic coding, allows decoding of the fine optical information from the modulated acoustic signal even when the variance of original photoacoustic signals is weak. We perform a proof-of-principle numerical demonstration of dual-compressed photoacoustic imaging, that resolves acoustic sub-acoustic-wavelength details with a significantly reduced number of measurements, revealing the potential for dynamic imaging. The dual-compressed concept, which transforms unobtrusive spatial difference into spatio-temporal detectable information, can be generalized to other imaging modalities to realize efficient, high-spatial-resolution imaging. [ABSTRACT FROM AUTHOR]

Thanks to recent advances in nanophotonics and scalable manufacturing of metamaterials, radiative sky cooling has emerged as a "self-reliant" cooling technology with various potential applications. However, not every region across the globe is well suited for the adoption of radiative cooling technologies, depending on the local climate, population density, cooling demand, air conditioning saturation, economic prosperity, etc. Because the atmospheric downward longwave radiation, especially the portion from the atmospheric window (8–13 µm), is substantially affected by weather conditions, the performance of a well-designed radiative cooler can be vastly different across regions and seasons. Here, we first map the global radiative sky cooling potential in the form of net cooling power density. We then further evaluate it based on the global population density and cooling demand. In terms of the adjusted potential, we show that geographically and demographically "transitional" regions, located between wet and dry climates as well as sparsely and densely populated regions, are better suited for the adoption of radiative cooling technologies because of their temperate climate and moderate population density. Even in densely populated and humid regions, the cumulative impact and other accompanying benefits must not be ignored. [ABSTRACT FROM AUTHOR]

Abstract: This paper derives a general procedure to produce an asymptotic expansion for eigenvalues of the Stokes problem by mixed finite elements. By means of integral expansion technique, the asymptotic error expansions for the approximations of the Stokes eigenvalue problem by Bernadi–Raugel element and element are given. Based on such expansions, the extrapolation technique is applied to improve the accuracy of the approximations. [Copyright &y& Elsevier]

China has the largest antimony (Sb) reserves and Sb production and consumption levels in the world. The Sb emissions from PET products have caused great concern regarding human health and environmental risks with the widespread use of Sb-containing polyethylene terephthalate (PET) products in China. However, the main sources and magnitude of Sb risks in the PET life cycle for humans and the environment are unknown. Therefore, the PET cycle is constructed. And we further quantified the Sb flow and emissions in the PET life cycle and mass ranges of Sb entering the biosphere in each stage. The results show that in the PET life cycle, Sb emissions and risks are the highest in the manufacturing and use stage, especially in the fiber manufacturing and use stage, which is much higher than that of PET bottles, film, and engineering plastics. The Sb emissions and risks in the production stage are only next to that in the manufacturing and use stage, and a large amount of Sb directly enters the biosphere in this stage. It is worth noting that thousands of tons of Sb enter the biosphere in the reclamation and market trade stage. The study reveals the Sb emissions and risks during the PET life cycle and provides suggestions for Sb management in the PET life cycle to reduce the risks of Sb to humans and the environment. Image 1 • We analyzed the flow and environmental release of Sb from PET products in China. • In the life cycle of PET, Sb emission mainly comes from the M&U stages. • During the M&U stage, a total of 4.6–5.9 Gg of Sb entered the biosphere. • Sb leaching and exposure from PET products should be taken seriously. [ABSTRACT FROM AUTHOR]

The authors discuss the aspects of light propagation and the unidirectional invisibility from exceptional points that combined states of an open system in photonic media. They are critical on the concept of the magic cloak worn by the fictional wizard Harry Potter, which makes him invisible due to the reciprocity of light. They comment on the use of photonic crystals in manipulating the light propagation and in controlling light-matter interactions.

Thermoelectric cooling suffers from low energy conversion efficiency (i.e., COP) which is a major bottleneck that hurdles its wide application, especially for large-scale systems. The COP of thermoelectric cooling system can be improved by integrating with other technologies. Due to its "free" nature, radiative sky cooling technology can potentially be integrated with thermoelectric cooling to obtain much higher system COP. This study introduces a novel radiative sky cooling-assisted thermoelectric cooling (RSC-TEC) system. The system has four different working modes under different operating conditions. A case study has been conducted for a two-story residential building that has 223 m2 living zone area located in Los Angeles, USA. Sensitivity analysis is first performed to size the system parameters. It is shown that the RSC-TEC system with a 0.83 m3 cold storage tank, 32 m2 radiative cooling surface area, and 101 thermoelectric modules (Laird ZT8-12), could achieve annual cooling COP of 1.87. Further analysis showed that daytime and nighttime cooling of the radiative sky cooling subsystem contribute to 55.0% and 45.0% of annual cold generation (heat dissipation) respectively, which indicates the critical importance of daytime cooling. The RSC-TEC system demonstrates a potential solution for large-scale adoption of the thermoelectric cooling technology. • A radiative sky cooling assisted thermoelectric cooling (RSC-TEC) system is proposed. • Sensitivity analysis is performed to size the system parameters. • Annual building energy simulation is conducted with EnergyPlus and MATLAB. • Annual cooling COP of 1.87 is achieved in a two-story residential building. • The RSC-TEC system demonstrates a potential solution for the wide adoption of thermoelectric cooling technology. [ABSTRACT FROM AUTHOR]

A high resolution surface plasmon resonance sensor is proposed and demonstrated by measuring the plasmon resonance enhanced Goos-Hänchen effect at attenuated total internal reflection. The giant Goos-Hänchen shift results from the singular phase retardation at the resonance which leads to the superior sensitivity of the sensor. [ABSTRACT FROM AUTHOR]

Near-field two-photon optical lithography is demonstrated by using ∼120 fs laser pulses at 790 nm in an apertureless near-field optical microscope, which produces lithographic features with ∼70 nm resolution. The technique takes advantage of the field enhancement at the extremity of a metallic probe to induce nanoscale two-photon absorption and polymerization in a commercial photoresist, SU-8. Even without optimization of the resist or laser pulses, the spatial resolution of this technique is as high as λ/10, nearly a factor of 2 better than techniques based on far field two-photon lithography. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Efficient and accurate simulation of ground penetrating radar (GPR) in the open region helps immensely in both grasping the features of echoes and facilitating the interpretation of real GPR data. Due to the limitation of the computer model, however, the strong artificial boundary reflections, especially the low-frequency propagating waves encountered at the late stage of simulation greatly affect the simulation accuracy of GPR. This paper presents an innovative optimized unsplit-field convolutional perfectly matched layer (UCPML) based on rotated staggered grid (RSG) scheme to truncate the finite-difference time-domain (FDTD) lattices. Rather than obey the sharp variation based on an ${m}$ th-order polynomial, the optimized approach employs a novel optimized term and an adjustment factor to seek a gentle variation on optimal constitutive coefficients. This guarantees that the determination of optimal constitutive coefficients can be less influenced by the order of polynomial and especially, to improve the absorptive performance on low-frequency propagating waves. The calculating efficiency and accuracy of the RSG-FDTD scheme, as well as the absorbing performance of the optimized UCPML, are verified by two numerical examples. In particular, the analysis of the amplitude-frequency features of low-frequency clutters at steady state of the electromagnetic (EM) field and the corresponding global reflection error in the time–frequency domain is also presented. [ABSTRACT FROM AUTHOR]

Purpose: Serum-derived extracellular vesicles (EVs) have been reported to play an important role in non-small cell lung cancer (NSCLC). The current study sought to explore the effect of serum-EVs delivering m6A methylation regulator heterogeneous nuclear ribonucleoprotein C (HNRNPC) on the development of NSCLC through the regulation of discs large-associated protein 5 (DLGAP5). Methods: NSCLC-related RNA-Seq and clinical data were first obtained from the TCGA database to screen differentially expressed m6A-related regulators, which were intersected with the differential genes in NSCLC-related microarray GSE43458 obtained from the GEO database for survival analysis and clinical correlation analysis. Correlation between HNRNPC and DLGAP5 expression was evaluated. Serum-EVs were isolated and identified, and the uptake of EVs by A549 cells was visualized using fluorescence microscopy. In vivo xenograft tumor models and tumor metastasis models were constructed in nude mice to observe growth and metastasis of NSCLC cells. Results: HNRNPC was associated with poor prognosis and metastasis of NSCLC, and further implicated in the regulation of DNA replication and cell cycle-related pathways. HNRNPC might promote the growth and metastasis of NSCLC by identifying m6A modification of DLGAP5 mRNA. Serum-EVs delivered HNRNPC to NSCLC cells in vitro. In vivo experimentation further confirmed that serum-EVs could deliver HNRNPC to promote the growth and metastasis of NSCLC cells in nude mice. Conclusions: Our findings highlight that serum-EVs can deliver HNRNPC to NSCLC cells, wherein HNRNPC recognizes the m6A modification of DLGAP5 mRNA, thus ultimately promoting NSCLC growth and metastasis. [ABSTRACT FROM AUTHOR]

One-dimensional nonlinear optical edge states of a single atomic membrane of MoS2 epitaxially grown by chemical vapor deposition are observed by second harmonic generation measurements. [ABSTRACT FROM AUTHOR]

Conversion of solar energy into chemical energy through natural photosynthesis plays a crucial role in sustainable energy transformation, bioresource production, and CO2 biofixation. Nevertheless, the overall solar energy to chemical energy (biomass) conversion efficiency in the photosynthetic organisms is still unsatisfactory because of their inefficient utilization of solar light. Here, a photonic method to improve photosynthesis of a unicellular green microalga, Chlamydomonas reinhardtii, a photosynthetic organism model is reported. For this purpose, an easy‐to‐fabricate microphotonic film is developed to improve the spectral quality of solar light reaching the microalgae through photon management (i.e., simultaneous solar spectral conversion and directional fluorescent emission). This study demonstrates that the short‐term oxygen evolution rate and the long‐duration biomass production of microalgae in 200‐mL laboratory photobioreactors are enhanced by a factor of 38% and 54%, respectively. In 5000‐mL scaled‐up bubble column photobioreactors placed outdoor under natural sunlight and weather conditions, the biomass yield is improved by more than 20% when compared to the control experiments conducted in parallel in an optically clear bubble column photobioreactor. Based on such experimental observations, the work here demonstrates the potential of photon management for promoting the solar energy‐to‐biomass conversion process of microalgae and other photosynthetic organisms. [ABSTRACT FROM AUTHOR]

The piecewise quadratic polynomial collocation is used to approximate the nonlocal model, which generally leads to a nonsymmetric indefinite system (Chen et al. (2021) [5]). In this case, the discrete maximum principle is not satisfied, which might be trickier for the stability analysis of the high-order numerical schemes (D'Elia et al. (2020) [10] ; Leng et al. (2021) [26]). Here, we present a modified (shifted-symmetric) piecewise quadratic polynomial collocation for solving the linear nonlocal diffusion model, which leads to a symmetric positive definite system and satisfies the discrete maximum principle. Using Faulhaber's formula and Riemann zeta function, the perturbation error for symmetric positive definite system and nonsymmetric indefinite system are given. Then rigorous convergence analysis for the nonlocal models are provided under the general horizon parameter δ = O (h β) , with β ≥ 0. More concretely, the global error is O (h min ⁡ { 2 , 1 + β } ) if δ is not set as a grid point, while it recovers O (h max ⁡ { 2 , 4 − 2 β } ) when δ is set as a grid point. We also prove that the shifted-symmetric scheme is asymptotically compatible, which has the global error O (h min ⁡ { 2 , 2 β } ) as δ , h → 0. The numerical experiments (including two-dimensional case) are performed to verify the convergence. [ABSTRACT FROM AUTHOR]

In this paper we analyze the stream function-vorticity-pressure method for the Stokes eigenvalue problem. Further, we obtain full order convergence rate of the eigenvalue approximations for the Stokes eigenvalue problem based on asymptotic error expansions for two nonconforming finite elements, Q and EQ. Using the technique of eigenvalue error expansion, the technique of integral identities and the extrapolation method, we can improve the accuracy of the eigenvalue approximations. [ABSTRACT FROM AUTHOR]

• Novel design of a dynamic solar modulative smart window component. • Control of solar modulation performance of smart window components. • Correlation study between hydrogel film and IR-reflective coatings. • Monitoring space cooling annual saving with application of smart window component. Energy-efficient smart windows with dynamic modulation of solar heat gain in response to external stimulus such as ambient temperature variation have been of great interest. However, when a smart window technology is implemented over a commercial glazing system, its performance could be dramatically influenced by the pre-installed low-e coating. An implementable smart window component made of thermo-response hydrogel for dynamic solar modulation, either prefabricated with window structures for newly constructed building application or manufactured into a film for existing building retrofit, has been rationally designed in this work. An IR-reflective coating was integrated with the as-synthesized hydrogel film and the ultimate solar regulation performance has been evaluated. Compared to the bare hydrogel sample, the total light modulation ability from the hydrogel film with IR-reflective coating was tapered by 0.9–5.4% due to the blockage of a portion of IR radiation before transmitting through the hydrogel layer. This additional NIR blocking effect allows this window design preferably suitable for hot weather with high solar radiation. Annual energy simulations to a prototype commercial building have shown the thermo-responsive hydrogel window component prepared in this work yields annual space cooling energy savings of up to 8.1% for Tucson, AZ, USA, which gives a 30.6 kWh/yr·m2 cooling energy savings per square meter of window glass. [ABSTRACT FROM AUTHOR]

Background: Non-small cell lung cancer (NSCLC) is a common type of lung cancer. Extracellular vehicles (EVs) are nano-sized particles containing proteins, lipids, and miRNAs secreted by various cells, which play important roles in the development of lung cancer by regulating a wide range of signaling pathways. This study focused on elucidating a potential mechanism by which EVs promote the development of NSCLC.Methods: Expression levels of miR-744, SUV39H1, Smad9, and BMP4 in clinical tissue samples of NSCLC patients and cell lines were quantified by RT-qPCR and/or western blot analysis. The interaction between SUV39H1 and miR-744 was identified by dual-luciferase reporter assay. miR-744, SUV39H1, and BMP4 expression levels were modulated in A549 and H460 cells, in order to evaluate their effects on cell proliferation, colony formation and cell cycle. A NSCLC xenograft mouse model was used to verify the in vitro findings. NSCLC cell-derived EVs and normal bronchial epithelial cell-derived EVs were isolated and their roles in NSCLC development were evaluated in vivo and in vitro.Results: miR-744 expression was lower in cancer cell-derived derived EVs than in normal lung epithelial cell-derived EVs. Reduced miR-744 expression in EVs upregulated SUV39H1 in NSCLC cells and further increased BMP4 levels to promote NSCLC development. BMP4 was upregulated in NSCLC cells upon suppression of Smad9 mediated by SUV39H1. Reduced miR-744 expression transferred from cancer cell-derived EVs into NSCLC cells enhanced cancer development.Conclusion: Overall, our findings unveiled a mechanism whereby miR-744 delivered by NSCLC-derived EVs upregulated SUV39H1, activating the Smad9/BMP9 axis and thus promoted cancer development. [ABSTRACT FROM AUTHOR]

• Radiative sky cooling is integrated with attic ventilation to reduce attic temperature. • Daytime sub-ambient air cooling up to 5°C (with an air flow rate) is experimentally demonstrated under direct sunlight. • Attic temperature can be reduced by 15.5-21°C on typical summer day compared to shingle roof. • Substantial annual cooling energy saving can be achieved with different attic insulations at different locations compared to shingle roof. The building attic usually subjects to substantial solar heat gain and has much higher temperature compared to the conditioned living space during the day, especially in summer and in hot areas. Reducing attic temperature can reduce cooling energy consumption in buildings. However, conventional techniques such as cool roof or attic ventilation, suffer from either heating penalty in winter or limited attic temperature reduction. In this work, a new roof-integrated radiative air-cooling system is introduced, which couples radiative sky cooling with attic ventilation to reduce attic temperature. A radiative air cooler with 1.08 m2 surface area is constructed using a recently developed daytime radiative sky cooling metamaterial [Zhai et al., Science 355, pp. 1062–1066, 2017]. Experimental tests show that sub-ambient air cooling is achieved throughout 24-h day-and-night cycle in a summer day with clear sky conditions. Depending on air flow rates, measured sub-ambient temperature reductions of air are 5–8°C at night and 3–5°C at noon under direct sunlight, respectively. An in-house model is first developed for the radiative air-cooling system, the model is then coupled with EnergyPlus to study annual energy saving of buildings. The performance of the radiative air-cooling system is compared with three reference systems: shingle roof, attic ventilation, and cool roof. Results show that for a single-family house, attic temperature can be substantially reduced by 15.5–21.0°C, varying with attic insulation level, compared to shingle roof on typical summer days. Compared to a shingle roof (solar reflectance 0.25, thermal emittance 0.9) residential building with attic insulations of R-30 (RSI-5.28), R-10 (RSI-1.76), and R-0.8 (RSI-0.14), the roof-integrated radiative air-cooling system can achieve annual cooling energy savings of 0.4–1.5 kWh/m2 (4.6–18.8%), 1.2–3.6 kWh/m2 (10.2–41.4%), and 3.7–11.8 kWh/m2 (26.5–76.1%) respectively. [ABSTRACT FROM AUTHOR]

Radiative cooling technology dissipates heat to outer space through the atmospheric window. A radiative cooling membrane possessing spectrum-selective optical properties has been installed on the grain storage warehouses in Hangzhou, China for a field testing. The long-term measurement results show notable decreases in headspace temperature and grain temperature by as much as 9.8 °C and 4 °C, respectively. A building model is created with measurement data and extended to seven grain storage ecological zones to assess potential electricity savings and temperature reductions without air conditioning. For cases with air conditioners, a total electricity saving of 573 GWh/yr is expected if applied nationwide. Without air conditioners, the temperature could decrease by 5.1–9.9 °C and 3.8–6.9 °C for headspace and grain respectively when ambient temperature exceeds 25 °C, thus upgrading the grain storage levels in different grain storage ecological zones. The linear correlation between the cooling-degree-day values set at 18 °C and the electricity consumption was developed, and extended to a global map. It reveals that in areas with values less than 1000 °C d, radiative cooling technology can maintain quasi-low storage temperatures, eliminating the need for air conditioning. [Display omitted] [ABSTRACT FROM AUTHOR]

• Improved model developed to evaluate a metamaterial-based new cool roof performance. • The model incorporates the spectrum selective approach for radiative sky cooling. • Experiments of the metamaterial-based cool roof are conducted on reduced-size building. • The metamaterial-based cool roof can significantly reduce roof-induced cooling load. A new cool roof with potential to generate significant energy savings in buildings has been developed from a metamaterial film named as RadiCold. Considering that the RadiCold film has unique optical and thermal characteristics and the current Roof Thermal Transfer Value model neglecting the effect of roof thermal mass that may lead to overestimating the cooling load from roofs, this work developed an improved Roof Thermal Transfer Value model and validated the model for both RadiCold cool roof and traditional roofing structures. Data from the reduced-size model building experiments showed that the improved Roof Thermal Transfer Value model can accurately describe the heat gains or losses via the roofs. Under real-world weather conditions in the United States (Tucson AZ, Los Angeles, CA, and Orlando FL), the improved Roof Thermal Transfer Value model has been applied to three types of roof exterior finishing: shingle, Thermoplastic Polyolefin (a cool roof material) and RadiCold. In a typical meteorology year, the modeling results show that the shingle and Thermoplastic Polyolefin roof transfer 78.9–294.1 kWh/(m2·yr) and 8.5–128.2 kWh/(m2·yr) of heat into the building space, respectively, but the RadiCold cool roof dissipates 137.6–268.7 kWh/(m2·yr) of heat from the building space to outdoor environment (e.g., sky). The cooling load reduction from utilizing RadiCold cool roof results in cooling electricity savings of 113.0–143.9 kWh/(m2·yr) compared to the shingle roof and 88.0–92.4 kWh/(m2·yr) compared to the Thermoplastic Polyolefin roof for the three analyzed locations with an assumed air conditioning system's coefficient of performance of 3.0. [ABSTRACT FROM AUTHOR]

Radiative sky cooling cools an object on the earth by emitting thermal infrared radiation to the cold universe through the atmospheric window (8–13 μm). It consumes no electricity and has great potential to be explored for cooling of buildings, vehicles, solar cells, and even thermal power plants. Radiative sky cooling has been explored in the past few decades but limited to nighttime use only. Very recently, owing to the progress in nanophotonics and metamaterials, daytime radiative sky cooling to achieve subambient temperatures under direct sunlight has been experimentally demonstrated. More excitingly, the manufacturing of the daytime radiative sky cooling material by the roll-to-roll process makes large-scale deployment of the technology possible. This work reviews the fundamental principles of radiative sky cooling as well as the recent advances, from both materials and systems point of view. Potential applications in different scenarios are reviewed with special attention to technology viability and benefits. As the energy situation and environmental issues become more and more severe in the 21st century, radiative sky cooling can be explored for energy saving in buildings and vehicles, mitigating the urban heat island effect, resolving water and environmental issues, achieving more efficient power generation, and even fighting against the global warming problem. [ABSTRACT FROM AUTHOR]

Reducing human reliance on energy-inefficient cooling methods such as air conditioning would have a large impact on the global energy landscape. By a process of complete delignification and densification of wood, we developed a structural material with a mechanical strength of 404.3 megapascals, more than eight times that of natural wood. The cellulose nanofibers in our engineered material backscatter solar radiation and emit strongly in mid-infrared wavelengths, resulting in continuous subambient cooling during both day and night. We model the potential impact of our cooling wood and find energy savings between 20 and 60%, which is most pronounced in hot and dry climates. [ABSTRACT FROM AUTHOR]

Surfaces with tunable topological features enable important applications, such as optical devices, precision metrology, adhesion, and wetting. In this study, we demonstrate a facile method to fabricate and control the surface morphologies by combining thin film wrinkling and thermal expansion. This approach utilizes self-assembled surface wrinkling induced by shape recovery of shape memory polymers (SMPs) and localized thermal expansion caused by Joule heating. Recovering the prestrain in the SMP substrate induces global wrinkling of the thin film on the substrate. Joule heating in the SMP by a heating wire embedded in the substrate induces thermal expansion of the substrate in a localized area, which leads to the disappearance of the wrinkling pattern. This effect is reversed when heating is stopped, leading to reversible and repeatable tuning of the surface morphology in a controllable localized surface region. With metal coating, the SMP surface can be switched from specular to diffuse reflectance in response to external Joule heating. Finally, we demonstrate a smart micromirror device with its diffuse reflectance tunable between 13.5% and 81.9% in the visible light region. This approach provides a method to modulate surface diffusivity by controlling its surface morphologies, with potential applications in optical display and optical microelectromechanical systems devices. [ABSTRACT FROM AUTHOR]

The importance of matrix micromechanics is increasingly recognized in cardiovascular research due to the intimate role they play in local vascular cell physiology. However, variations in micromechanics among arterial layers (i.e. intima, media, adventitia), as well as dependency on local matrix composition and/or structure, anatomical location or developmental stage remain largely unknown. This study determined layer-specific stiffness in elastic arteries, including the main pulmonary artery, ascending aorta, and carotid artery using atomic force indentation. To compare stiffness with age and frozen processing techniques, neonatal and adult pulmonary arteries were tested, while fresh (vibratomed) and frozen (cryotomed) tissues were tested from the adult aorta. Results revealed that the mean compressive modulus varied among the intima, sub-luminal media, inner-middle media, and adventitia layers in the range of 1–10 kPa for adult arteries. Adult samples, when compared to neonatal pulmonary arteries, exhibited increased stiffness in all layers except adventitia. Compared to freshly isolated samples, frozen preparation yielded small stiffness increases in each layer to varied degrees, thus inaccurately representing physiological stiffness. To interpret micromechanics measurements, composition and structure analyses of structural matrix proteins were conducted with histology and multiphoton imaging modalities including second harmonic generation and two-photon fluorescence. Composition analysis of matrix protein area density demonstrated that decrease in the elastin-to-collagen and/or glycosaminoglycan-to-collagen ratios corresponded to stiffness increases in identical layers among different types of arteries. However, composition analysis was insufficient to interpret stiffness variations between layers which had dissimilar microstructure. Detailed microstructure analyses may contribute to more complete understanding of arterial micromechanics. [ABSTRACT FROM AUTHOR]

Highlights • A kW-scale day-night radiative sky cooling system is demonstrated. • Daytime and nighttime cooling strategies based on optimum flow rates are investigated through modeling. • Daytime and nighttime cold water generation tests are conducted. • Predictive modeling of the system annual cooling performance is carried out. Abstract With the advancement in sub-ambient cooling of water during daytime under the sun with scalable-manufactured radiative cooling metamaterials, the challenge for applications lies in design and building of large-scale radiative cooling systems. Here, we present a kW-scale, 24-hour continuously operational, radiative sky cooling system, with both experimental study and detailed modeling. We first quantitatively show how water flow rate directly affects the system cooling power and inversely affects the water temperature drop. A day-and-night stagnant (flow rate = 0 L/(min·m2)) water cooling test of the system shows a consistent sub-ambient water temperature drop of 5–7 °C. A daytime cooling test of the system at a low flow rate of 0.227 L/(min·m2) yields a maximum sub-ambient temperature drop of 4.0 °C with an average net cooling power of around 80 W/m2. Further modelling for a typical metrological year (in Phoenix, Arizona) shows that the system could generate as much as 350 kWh cold (or 26 kWh/m2) with a sub-ambient temperature drop of 4–5 °C at a low flow rate of 0.1 L/(min·m2) during a typical summer month. The cold generated could be used to assist AC systems in regions or seasons with high ambient temperatures. [ABSTRACT FROM AUTHOR]

Shape memory polymers (SMPs) can remember different shapes and can be recovered to their permanent shapes from temporary shapes with appropriate stimuli, such as heat, humidity, and electrical field. Using programmed thermal responsive SMPs as substrates, we demonstrate a self-assembly fabrication method for programmable surface wrinkling within a highly confined area that is accurately controllable. Different from global wrinkling reported in most of the literature, Joule heating through a heating wire embedded in the SMP substrate leads to temperature increase and thus recovery in a highly confined area of the SMP substrate, inducing localized wrinkling of the stiff thin film on SMPs. The patterns show good sinusoidal profiles, with the wrinkling wavelength and amplitude decreasing gradually with the distance from the heat source. The surface wrinkling area can be accurately tuned by controlling the heat input, such as power and duration. Based on this unique surface wrinkling phenomenon, we demonstrate a nonuniform reflective optical grating device, whose peak wrinkling wavelength and amplitude decrease gradually away from the heat source. This study offers a simple method to fabricate programmable localized wrinkling patterns, with potential applications in surface engineering, advanced manufacturing, optical gratings, and other demanding areas. [ABSTRACT FROM AUTHOR]

Passive radiative cooling draws heat from surfaces and radiates it into space as infrared radiation to which the atmosphere is transparent. However, the energy density mismatch between solar irradiance and the low infrared radiation flux from a near-ambient-temperature surface requires materials that strongly emit thermal energy and barely absorb sunlight. We embedded resonant polar dielectric microspheres randomly in a polymeric matrix, resulting in a metamaterial that is fully transparent to the solar spectrum while having an infrared emissivity greater than 0.93 across the atmospheric window. When backed with a silver coating, the metamaterial shows a noontime radiative cooling power of 93 watts per square meter under direct sunshine. More critically, we demonstrated high-throughput, economical roll-to-roll manufacturing of the metamaterial, which is vital for promoting radiative cooling as a viable energy technology. [ABSTRACT FROM AUTHOR]

• A novel type of socket connection with specific shear keys was proposed. • Reliability of the proposed connection was verified through cyclic loading tests. • The configuration details of the connection were discussed. • The smallest embedment depth of the socket connection was explored. Socket connections have been widely used in accelerated bridge construction (ABC) for their construction convenience while the reliability of the connections under seismic load and the appropriate embedment depth become the main concerns of engineers and researchers. In this study, a novel type of socket connection with specific shear keys and inner and outer filled reinforced concrete was proposed for hollow concrete columns (HCCs). Cyclic loading tests of five specimens with the proposed socket connections were conducted to investigate their reliability. The results showed that all specimens failed in flexural failure of the HCC piers, identical with cast-in-place (CIP) connections, and had adequate ductility and energy dissipation capacity. The configuration details could be further simplified and the embedment depth could be 0.325 times the column diameters (0.325 D o) for the proposed socket connection according to the tests. The behavior model for the socket connections is also proposed. [ABSTRACT FROM AUTHOR]

The present work aims to investigate the effects of the addition of waste cooking oil (WCO) on heavy crude oil biodegradation and microbial enhanced oil recovery (MEOR) using Pseudomonas sp. SWP-4. Growth kinetics show Pseudomonas sp. SWP-4 had a maximum dry cell weight of 1.73 g/L and cell-surface hydrophobicity of 62.4% against n -hexadecane when degraded the crude oil with the addition of WCO. The maximum rhamnolipid concentration was 6.87 g/L, and the culture broth exhibited a higher emulsification efficiency of 58.3% on n -hexadecane and reduced the surface tension of broth to 22.7 mN/m. Meanwhile, Pseudomonas sp. SWP-4 reduced the viscosity of crude oil from 26,300 mPa s to 550 mPa s (40 °C) and successfully degraded most of the n -alkanes. Furthermore, the fluidity of oil had been well improved after degradation. It can be concluded that not only could WCO stimulate the bacterial growth, but also it could enhance the crude oil degradation. Core displacement experiment demonstrates the efficiency of water flooding was just 5.8%, but the microbial flooding produced by Pseudomonas sp. SWP-4 with the addition of WCO effectively improved the oil recovery further with an additional oil recovery efficiency of 24.4%. [ABSTRACT FROM AUTHOR]

The present work aims to produce rhamnolipid from waste cooking oil (WCO) using a newly isolated bacterium named Pseudomonas SWP-4. SWP-4 was a high-yield strain that could accumulate rhamnolipid steadily even in decline phase and gave a maximum rhamnolipid yield of 13.93 g/L and WCO utilization percent around 88%. The critical micelle concentration of the produced rhamnolipid was only 27 mg/L and its emulsification index against n -hexadecane reached around 59%. Moreover, it reduced the surface tension of water from 71.8 mN/m to 24.1 mN/m and the interfacial tension against n -hexadecane from 29.4 mN/m to 0.9 mN/m. Results of biosurfactant stability show the rhamnolipid was effective when the salinity was lower than 8% and pH value ranged from 4 to 10, and it was quite thermostable based on thermal gravity analysis. Furthermore, it maintained high surface activity even after incubation under extreme conditions i.e. , pH of 4.0, salinity of 8% and temperature of 80 °C for half a month. Based on free fatty acids metabolism analysis, Pseudomonas SWP-4 consumed palmitic acid, oleic acid and linoleic acid chiefly. All these characteristics demonstrate bioconversion and biodegradation of WCO by Pseudomonas SWP-4 is a promising and commercial way of rhamnolipid production and waste treatment. [ABSTRACT FROM AUTHOR]

The discovery of optical second harmonic generation in 1961 started modern nonlinear optics. Soon after, R. C. Miller found empirically that the nonlinear susceptibility could be predicted from the linear susceptibilities. This important relation, known as Miller's Rule, allows a rapid determination of nonlinear susceptibilities from linear properties. In recent years, metamaterials, artificial materials that exhibit intriguing linear optical properties not found in natural materials, have shown novel nonlinear properties such as phase-mismatch-free nonlinear generation, new quasi-phase matching capabilities and large nonlinear susceptibilities. However, the understanding of nonlinear metamaterials is still in its infancy, with no general conclusion on the relationship between linear and nonlinear properties. The key question is then whether one can determine the nonlinear behaviour of these artificial materials from their exotic linear behaviour. Here, we show that the nonlinear oscillator model does not apply in general to nonlinear metamaterials. We show, instead, that it is possible to predict the relative nonlinear susceptibility of large classes of metamaterials using a more comprehensive nonlinear scattering theory, which allows efficient design of metamaterials with strong nonlinearity for important applications such as coherent Raman sensing, entangled photon generation and frequency conversion. [ABSTRACT FROM AUTHOR]

Piezoelectricity allows precise and robust conversion between electricity and mechanical force, and arises from the broken inversion symmetry in the atomic structure. Reducing the dimensionality of bulk materials has been suggested to enhance piezoelectricity. However, when the thickness of a material approaches a single molecular layer, the large surface energy can cause piezoelectric structures to be thermodynamically unstable. Transition-metal dichalcogenides can retain their atomic structures down to the single-layer limit without lattice reconstruction, even under ambient conditions. Recent calculations have predicted the existence of piezoelectricity in these two-dimensional crystals due to their broken inversion symmetry. Here, we report experimental evidence of piezoelectricity in a free-standing single layer of molybdenum disulphide (MoS2) and a measured piezoelectric coefficient of e11 = 2.9 × 10-10 C m−1. The measurement of the intrinsic piezoelectricity in such free-standing crystals is free from substrate effects such as doping and parasitic charges. We observed a finite and zero piezoelectric response in MoS2 in odd and even number of layers, respectively, in sharp contrast to bulk piezoelectric materials. This oscillation is due to the breaking and recovery of the inversion symmetry of the two-dimensional crystal. Through the angular dependence of electromechanical coupling, we determined the two-dimensional crystal orientation. The piezoelectricity discovered in this single molecular membrane promises new applications in low-power logic switches for computing and ultrasensitive biological sensors scaled down to a single atomic unit cell. [ABSTRACT FROM AUTHOR]

Wedemonstrate an all-dielectric quantum electrodynamical nanowire-slabsystem with a single emitter that concentrates the extremely intenselight at the scale of 10 × 75 nm2. The quantum dotexhibits a record high 31-fold spontaneous decay rate enhancement,its optical saturation and blinking are strongly suppressed, and 80%of emission couples into a waveguide mode. [ABSTRACT FROM AUTHOR]

[Display omitted] • A nacre-inspired "rigid-and-soft" interphase was constructed between GO and epoxy. • The grafting layer number of GO was modulated to adjust the interphase. • The interphase showed synergistic effect in interfacial and mechanical properties. • Nanocomposites exhibited enhanced mechanical properties under extreme conditions. The interphase structure plays a significant role in the interfacial interactions and mechanical properties of epoxy-based nanocomposites. Inspired by the nacre's structure, a "rigid-and-soft" multilayer interphase was constructed between functionalized graphene oxide (GO) and epoxy matrix through grafting rigid polydopamine (PDA) and flexible polyetheramine D230 alternatively on GO surfaces. The structural and morphological characteristics of modified GO (MGO) with various numbers of grafted layers were characterized. The dispersion of MGO in epoxy matrix was investigated. The mechanical properties of nanocomposites at room temperature (RT) and liquid nitrogen temperature (LNT) were evaluated. MGO with three layers of PDA/D230 (MGO-L 3) endowed the nanocomposites with the highest mechanical properties, owing to the "rigid-and-soft" interphase which can synergistically enhance the stress transfer and accelerate the energy dissipation. At RT, nanocomposites showed the maximum increment of 25.8% in tensile strength and 13.0% in elongation at break compared to neat epoxy. At LNT, the corresponding increments could reach 6.8% and 23.1%, respectively. The influence of the "rigid-and-soft" interphase on the mechanical properties of MGO/epoxy nanocomposites under thermal cycling were investigated as well. Based on the fracture morphology, the toughening mechanisms of MGO at RT and LNT were both disclosed. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenide (TMDC) monolayers have recently emerged as an important class of two-dimensional semiconductors with potential for electronic and optoelectronic devices. Unlike semi-metallic graphene, layered TMDCs have a sizeable bandgap. More interestingly, when thinned down to a monolayer, TMDCs transform from indirect-bandgap to direct-bandgap semiconductors, exhibiting a number of intriguing optical phenomena such as valley-selective circular dichroism, doping-dependent charged excitons and strong photocurrent responses. However, the fundamental mechanism underlying such a strong light-matter interaction is still under intensive investigation. First-principles calculations have predicted a quasiparticle bandgap much larger than the measured optical gap, and an optical response dominated by excitonic effects. In particular, a recent study based on a GW plus Bethe-Salpeter equation (GW-BSE) approach, which employed many-body Green's-function methodology to address electron-electron and electron-hole interactions, theoretically predicted a diversity of strongly bound excitons. Here we report experimental evidence of a series of excitonic dark states in single-layer WS2 using two-photon excitation spectroscopy. In combination with GW-BSE theory, we prove that the excitons are of Wannier type, meaning that each exciton wavefunction extends over multiple unit cells, but with extraordinarily large binding energy (∼0.7 electronvolts), leading to a quasiparticle bandgap of 2.7 electronvolts. These strongly bound exciton states are observed to be stable even at room temperature. We reveal an exciton series that deviates substantially from hydrogen models, with a novel energy dependence on the orbital angular momentum. These excitonic energy levels are experimentally found to be robust against environmental perturbations. The discovery of excitonic dark states and exceptionally large binding energy not only sheds light on the importance of many-electron effects in this two-dimensional gapped system, but also holds potential for the device application of TMDC monolayers and their heterostructures in computing, communication and bio-sensing. [ABSTRACT FROM AUTHOR]

Active heat flow control is essentialfor broad applications ofheating, cooling, and energy conversion. Like electronic devices developedfor the control of electric power, it is very desirable to developadvanced all-thermal solid-state devices that actively control heatflow without consuming other forms of energy. Here we demonstratetemperature-gated thermal rectification using vanadium dioxide beamsin which the environmental temperature actively modulates asymmetricheat flow. In this three terminal device, there are two switchablestates, which can be regulated by global heating. In the “Rectifier”state, we observe up to 28% thermal rectification. In the “Resistor”state, the thermal rectification is significantly suppressed (<1%).To the best of our knowledge, this is the first demonstration of solid-stateactive-thermal devices with a large rectification in the Rectifierstate. This temperature-gated rectifier can have substantial implicationsranging from autonomous thermal management of heating and coolingsystems to efficient thermal energy conversion and storage. [ABSTRACT FROM AUTHOR]

Remotely manipulating a large numberof microscopic objects isimportant to soft-condensed matter physics, biophysics, and nanotechnology.Optical tweezers and optoelectronic tweezers have been widely usedfor this purpose but face critical challenges when applied to nanoscaleobjects, including severe photoinduced damages, undesired ionic convections,or irreversible particle immobilization on surfaces. We report herethe first demonstration of a lipid bilayer-integrated optoelectronictweezers system for simultaneous manipulation of hundreds of 60 nmgold nanoparticles in an arbitrary pattern. We use a fluid lipid bilayermembrane with a ∼5 nm thickness supported by a photoconductiveelectrode to confine the diffusion of chemically tethered nanoparticlesin a two-dimensional space. Application of an external a.c. voltagetogether with patterned light selectively activates the photoconductingelectrode that creates strong electric field localized near the surface.The field strength changes most significantly at the activated electrodesurface where the particles tethered to the membrane thus experiencethe strongest dielectrophoretic forces. This design allows us to efficientlyachieve dynamic, reversible, and parallel manipulation of many nanoparticles.Our approach to integrate biomolecular structures with optoelectronicdevices offers a new platform enabling the study of thermodynamicsin many particle systems and the selective transport of nanoscaleobjects for broad applications in biosensing and cellular mechanotransductions. [ABSTRACT FROM AUTHOR]

The extraordinary electronic properties of graphene provided the main thrusts for the rapid advance of graphene electronics. In photonics, the gate-controllable electronic properties of graphene provide a route to efficiently manipulate the interaction of photons with graphene, which has recently sparked keen interest in graphene plasmonics. However, the electro-optic tuning capability of unpatterned graphene alone is still not strong enough for practical optoelectronic applications owing to its non-resonant Drude-like behaviour. Here, we demonstrate that substantial gate-induced persistent switching and linear modulation of terahertz waves can be achieved in a two-dimensional metamaterial, into which an atomically thin, gated two-dimensional graphene layer is integrated. The gate-controllable light-matter interaction in the graphene layer can be greatly enhanced by the strong resonances of the metamaterial. Although the thickness of the embedded single-layer graphene is more than six orders of magnitude smaller than the wavelength (