This study presents an in-depth analysis of ground-level ozone (O3) episodes in Shenyang from May to July 2019, utilizing advanced source apportionment modeling techniques: Ozone Source Apportionment Technology (OSAT), Geographic Ozone Assessment Technology (GOAT), and the High-order Decoupling Direct Method (HDDM). The research aimed to characterize the sources of O3 and assess the potential impact of emission reduction strategies on O3 concentrations. The results demonstrate that reducing emissions of both NOx and VOCs can lower O3 levels, with VOC controls proving to be more effective. During the ozone season, regional transport was identified as the dominant contributor to pollution, accounting for approximately 90% of the total, while local sources (sources within Shenyang's administrative boundary) contributed only about 10%. On days with severe pollution, the long-range transport of O3 precursors was found to be the primary driver of Maximum Daily 8 h average O3 (MDA8 O3) exceedances in Shenyang. This study indicates that local measures alone are insufficient to eliminate O3 exceedances; for instance, in some scenarios, even with a simultaneous 60% reduction in both local anthropogenic VOCs and NOx emissions, MDA8 O3 levels would not meet the national standard of 160 & micro;g & centerdot;m-3. Therefore, effective mitigation strategies must include regionally coordinated, time-dependent controls. This study also highlights that local industrial and mobile sources contribute to over 70% of ozone formation, suggesting that targeting these sectors could yield the most significant local benefits. This research underscores the need for a comprehensive approach to O3 management, combining both local and regional efforts to address the complex issue of ground-level ozone pollution.

In order to obtain samples with high color purity, we first proposed a novel spectral-clipping approach. In this technique, the incorporation of ions with spectral regulation characteristics, through the energy level transition, the absorption of variegated peaks in the sample reflection spectrum and the selective emission of the desired color or specific band can be achieved. Taking Eu-doped Cr-ZrSiO4 green ceramic pigment as an example, and its crystal structure, diffuse reflectance spectrum, and color characteristics were systematically investigated. Firstprinciples band calculations were performed on (Eu,Cr)-ZrSiO4 supercells to elucidate the effect of co-doping on the electronic structure and optical properties. Structural and spectral analyses demonstrate that Eu doping effectively eliminates stray colors, yielding a pure green color (L* = 76.26, a* = -7.9, b* = 12.17) and significantly enhancing the near-infrared reflectance, which reaches 90.36 % in the 700-2500 nm wavelength range. The spectral-clipping approach shows promising potential for applications in pigments and phosphor materials.

Efficient membrane concentration of sulfate-based rare-earth leachates is severely restricted by high osmotic pressure and inorganic scaling caused by coexisting Ca2+ and Mg2+. In this study, a complexation-assisted nanofiltration (NF) strategy was developed to achieve high-flux concentration and anti-scaling separation through ion-speciation regulation. Systematic screening identified diethylenetriaminepentaacetic acid (DTPA) as the optimal complexing agent, which selectively coordinates multivalent cations to form hydrophilic, negatively charged complexes with enlarged hydrated size. The reduced free-ion concentration lowers the solution osmotic pressure and suppresses the supersaturation-driven crystallization of CaSO₄ and MgSO₄. Coupled with the NF10 membrane, the process achieved rejections of 97.67% for La3+ (representative rare earth ion), 95.09% for Ca2+, and 97.18% for Mg2+, while maintaining stable operation during eight-fold concentration with negligible flux decline. Fouling analysis showed that DTPA complexation effectively inhibited irreversible inorganic fouling and shifted the dominant filtration resistance from pore blockage to mild concentration polarization. SEM-EDS and FTIR characterizations further confirmed the substantial suppression of sulfate scale deposition on the membrane surface. To demonstrate process applicability, a coupled decomplexation–extraction step using P507 enabled efficient recovery of rare-earth ions, and the regenerated DTPA maintained stable separation performance over four reuse cycles. This work provides an effective membrane-based route for the high-flux concentration and sustainable recovery of rare-earth resources from sulfate leachates.

Hexagonal boron nitride (hBN) ceramics suffer from poor sinterability and weak mechanical properties, primarily due to their intrinsic layered structure. To address this issue, a novel strategy is established using hBN powders with varying particle sizes as the main raw material. Specifically, granular SiC is introduced to fill the polygonal pores between the flaky hBN grains, and trace amounts of ZrO2 are incorporated through ball milling. The SiC/hBN-ZrO2 composites, with SiC contents ranging from 0 to 15 wt %, are prepared by hot-pressing sintering at 1800 degrees C under a pressure of 50 MPa. The composite containing 15 wt % SiC exhibits the best overall properties: a relative density of 97.5 %, Vickers hardness of 0.67 GPa, flexural strength of 247 MPa, compressive strength of 231.99 MPa, and fracture toughness of 3.15 MPa m1/2, significantly outperforming pure hBN ceramics. Microstructural analysis and finite element simulations reveal that the granular SiC filling effectively reduces the intrinsic crack size and maximum stress by 51.7 % and 81.6 %, respectively, by eliminating the polygonal pores, thereby contributing to the enhanced mechanical properties. This strategy offers a promising approach for improving the densification and mechanical performance of layered ceramics.

One-dimensional (1D) structures, such as nanowires, whiskers and fibers, have attracted extensive attentions for their potential as reinforcements for advanced composite materials. To achieve uniform dispersion of 1D structures in the matrix and to materialize strong interface bonding between them and the matrix are the two most challenging tasks for preparing high-performance composite materials. For hexagonal boron nitride (h-BN) ceramics are naturally weak, in this work, SiC nanowires were introduced into BN powders via in-situ grown on a catalyst using chemical vapor deposition (CVD) technology and this technology ensured the uniform dispersion of SiC nanowires in later h-BN ceramics. High performance h-BN composite ceramics were fabricated by spark plasma sintering from as-prepared powder mixture of h-BN and SiC nanowires doped with cubic boron nitride (c-BN). The onion-like h-BN structures, freshly derived from c-BN, were activatory during the sintering process, facilitating the SiC nanowires firmly anchored onto the h-BN grains. These SiC nanowires were thus well distributed and strongly bonded with h-BN matrix, significantly improving the mechanical properties of h-BN ceramics by stopping and deflecting the extension of cracks. Optimal composite performance was achieved when SiC nanowires were grown with a catalyst mass ratio of 5.50 wt%, and the density, Young's modulus and flexural strength of the sample reached 2.29 g/cm3, 35 GPa, and 171 MPa, respectively. This study demonstrates a new combination strategy for the preparation of high-performance h-BN composite ceramics, and will further promote the development and application of h-BN ceramics.

Glassy carbon (GC) with biocompatibility provides an alternative as a promising tissue implant. However, various defects would exist due to the complex preparation process of GC via the thermal decomposition of the resins, severely weakening the as-produced GCs. Powder metallurgy for fabricating GC bulks, which was unsuccessful due to the inertness of GC powder, has been materialized in this work, where nanodiamond (ND) is used as a sintering aid. Nano carbon onion generated during ND to graphite phase transformation forms a semicoherent interface with GC matrix to improve the density and mechanical properties of GC. The as-prepared GC bulks possess a density of 90.26 %, a bending strength of 69.79 MPa and a compressive strength of 72.93 MPa, matching well with human bone. And its good machinability enables its complex structure as requested. The in vitro cell experiment results demonstrate that as-prepared GC is noncytotoxic and conducive to the adhesion and proliferation of cells, showing its natural biocompatibility. This research pioneers an innovative strategy for bioGC bulk preparation, furthering its application potential in the medical field.

The aim of this study was to modify strain hardening cementitious composite (SHCC) using MXene nanosheets to further enhance its strength and ductility. The results showed that the addition of 0.03 wt% MXene nanosheets increased the compressive strength and tensile strain of SHCC by 18.04% and 88.18%, respectively. The mechanism of MXene nanosheets in improving the mechanical properties of SHCC was revealed by single fiber pullout test, micromechanical analysis, microstructure analysis and finite element analysis. Firstly, MXene nanosheets fill the pores inside the matrix, reduce the porosity of the matrix, disperse the stress, and inhibit the crack propagation, thus improving the compressive properties of SHCC. Secondly, when MXene nanosheets adhered to the fiber surface, they modified the interfacial properties between the fiber and the matrix, preventing fiber pullout and consequently improving the tensile ductility of SHCC.

One-dimensional (1D) structures, such as carbon nanotubes and carbon fibers, used as reinforcements in advanced carbon materials, have been greatly appreciated but facing with some significant challenges of dispersion and interfacial bonding. We utilized electrospinning technology to create a new 1D nanofiller. This material is a superfine fiber composed of polyacrylonitrile (PAN) with a high nanodiamond (ND) content of 75%, which is referred to as PDNF. During the preparation process, these nanofillers were blended with natural flake graphite (NFG) through electro-spraying. The as-prepared mixture served as the precursor powder sintered into NFG-based high-strength bulk graphite (HPG). During spark plasma sintering at 1800 °C, fibrous PDNF undergoes a phase transformation of diamond to graphite, with onion carbon pinning into and markedly reducing cleavage along the (002) plane of NFG, foundational to the high strength of NFG-based HPG. The PDNF's fiber-like structure and NFG's flake structure greatly increase the interfacial area between the matrix and reinforcement. Furthermore, the PDNF excels at blunting and deflecting cracks, thus bolstering the NFG-based HPG's overall resistance to crack propagation. The density, Young's modulus, and flexural strength of the as-prepared NFG-based HPG achieve 1.65 g/cm3, 17.4 GPa, and 145 MPa, respectively. Most importantly, this process can be a general approach for other high-performance composite materials.

Ozone deposition velocity with a daily mean of 0.49 cm s−1 was observed in the Tibetan Plateau and rationalized by local meteorological and soil conditions. Our research suggested widespread ozone deposition velocity over soil of 0.1–0.7 cm s−1.

The influence of pulse time delay (PTD) caused by the large-diameter lens on the spatiotemporal characteristics of a broadband laser focal spot is studied to design a high-energy laser system. To this end, diffraction transmission theory of broadband lasers in lenses, which is used in high-energy petawatt laser system with multi-pass amplified structure, is employed. It is found that when the aperture of the broadband laser reaches 360 mmx360 mm, the maximum PTD caused by the lens is approximately 2. 5 ps. The spatiotemporal coupling effect peaks when the pulse width is 0. 5 ps under the Fourier-transform-limit bandwidth of 3. 2 nm and the beam quality is 1 diffraction-limited (DL). The time waveform is distorted, and the focal spot size corresponding to 90% energy concentration is doubled. However, when the compressed pulse width is more than 1 ps or the far-field beam quality is >= 5 DL, the spatiotemporal coupling effect weakens, and the influence of the PTD on focus can be neglected. The research results provide an important theoretical basis for the lens chromatic aberration compensation and fosus performance improvement of domestic high-energy petawatt laser systems.

Superhydrophobic materials have found extensive applications in everyday life and various industries due to their outstanding attributes such as waterproofing, exceptional anti-corrosion and self-cleaning capabilities. Nonetheless, their limited mechanical stability hinders their widespread use on ceramic surfaces. This study aims to address these limitations by employing industrial waste porcelain powder as a raw material and co-firing technology to create a micro-rough structure on ceramic surfaces. Furthermore, the impact of this rough structure on the wear resistance and hydrophobicity of the hydrophobic coating is investigated using the finite element method. The results indicate that the mechanical stability of the hydrophobic coating experiences a more pronounced enhancement with increasing distribution density of the micron rough structure of waste porcelain powder (WPPMRS). A dense rough structure does not only reduce its concentrated stress and improve its anti-wear ability, but also reduce the concentrated stress of hydrophobic coating to improve the protection of the coating. As a result, it substantially enhances the mechanical properties and stability of the hydrophobic coating. This work will provide valuable insights into the utilization of waste porcelain powder in sustainable superhydrophobic ceramics.

High performance graphites (HPGs) are a key material in modem industries; however, prevailing HPGs are short of comprehensive properties in many aspects, i.e., a specific property of HPGs is always achieved at the cost of other properties. And the production of HPGs is highly costly and causes severe environmental problems. Current HPGs are derived from various carbonaceous precursors, excluding nature flake graphite (NFG), the best graphite source. Typically, NFG-based bulk graphite has poor mechanical properties because NFG is difficult to sinter. Here we report the preparation and comprehensive properties of a new family of universal HPGs (U-HPGs) that can be mass-produced with moderate conditions by sintering NFG slightly mixed with diamond, where units of onion carbon (OC) with NFG (OC@NFG) act as building blocks. OC@NFG creates a strong interfacial network between the NFGs, giving the U-HPGs outstanding strength and moderate hardness. With U-HPGs being more than 93 % graphitization, the flexural strength exceeds 100 MPa, far superior to mainstream commercial graphites. OC@NFG also bestows U-HPGs with excellent thermal conductivity(>125 W m(-1) K-1 at room temperature). For such structure provides a 3D path for electrons inside U-HPGs, the as-produced material has significant electronical conductivity. This work presents new insights into this old yet important material and allows for innovative design of HPGs for various applications.

Large-aperture gratings have significant applications in inertial confinement fusion, immersion lithography manufacturing and astronomical observation. Currently, it is challenging and expensive to manufacture sizable monolithic gratings. Therefore, tiled multiple small-aperture gratings are preferred. In this study, the impact of seam phase discontinuity on the modulation of the laser beam field was explored based on the measurement results of the Shenguang-II laser large-aperture multi-exposure-tiled grating. An innovative method for accurately calculating the phase jump of multi-exposure-tiled grating seams was proposed. An intensive electromagnetic field analysis was performed by applying rigorous coupled-wave analysis to a reasonably constructed micrometer-level periodic grating seam structure, and the phase jump appearing in millimeter-scale seams of large-aperture tiled gratings was obtained accurately.

Bioinspired interfacial structures in materials, such as nacre-inspired masonry structures and bionic mechanical interlocking structures, can produce unique effects that enable unprecedented material mechanical properties. However, the smooth interface in ceramic materials is known to elicit weakening effects on mechanical properties, easily causing catastrophic damage in industrial production. Here, inspired by the suture structure of fish, zirconia-toughed alumina (ZTA) is fabricated with a bioinspired suture structure interface by introducing a graphene nanosheet (GNS) through tailoring the interfacial atomic diffusive rate on a ZTA composite, and its effect on fracture strength is measured. The results show that the flexural strength of ZTA modified by 0.14% GNS is 865.4 MPa, which is 60.2% higher than that of ZTA without GNS modification. Subsequently, the local grain boundary slip resistance on the suture interface is calculated using finite element simulation, which reveals that the suture interface of the Al2O3 matrix had higher resistance values than the smooth interface under applied load, which could improve the hardness, flexural strength, and fracture toughness. This unique suture interface intensifies the interface strength and essentially improves the force transmission. This work provides guidance for bionic optimization of the grain boundary structure of structural ceramics and a new idea for the structural design of high-strength and -toughness ceramics.

Carbon fiber (CF) is commonly employed to enhance the mechanical properties, electrical conductivity, and electromagnetic absorption properties of cementitious composites. However, its weak interfacial bonding with the matrix limits its application in such composites. In this study, boron nitride (BN) nanosheets were synthesized via the solid-state reaction and used to modify CF surface. The flexural and compressive strengths of cementitious composites incorporating BN nanosheets coated CF (BN@CF) increased by 18.45% and 29.38%, respectively, with CF doping at only 0.2 wt%. Isothermal calorimetry and TGA results revealed that BN nanosheets on CF surface would provide nucleation sites for the formation of C-S-H and CH. The microstructure and bonding properties of BN@CF were characterized using SEM/EDS, FTIR, XPS, finite element analysis, and single fiber pullout test. The results showed that the significant improvement of interfacial properties between the fiber and the matrix contributed to the increase of mechanical properties of cementitious composites. These findings provide an effective strategy for the strength development of CF-reinforced cementitious composites.

Superconductivity has been one of the focal points in medium and high -entropy alloys (MEAs-HEAs) since the discovery of the body -centered cubic (bcc) HEA superconductor in 2014. Until now, the superconducting transition temperature (Tc) of most MEA and HEA superconductors has not exceeded 10 K. Here, we report a TaNbHfZr bulk MEA superconductor crystallized in the BCC structure with a Tc of 15.3 K which set a new record. During compression, Tc follows a dome -shaped curve. It reaches a broad maximum of roughly 15 K at around 70 GPa before decreasing to 9.3 K at 157.2 GPa. First -principles calculations attribute the dome -shaped curve to two competing effects, that is, the enhancement of the logarithmically averaged characteristic phonon frequency omega log and the simultaneous suppression of the electron -phonon coupling constant lambda. Thus, TaNbHfZr MEA may have a promising future for studying the underlying quantum physics, as well as developing new applications under extreme conditions.

Highly robust ceramics materials are promising materials for applications in the automobile, aerospace, and ceramic cutting tool industries. However, conventional ceramics are typically brittle, which limits their suitability for advanced applications. In this study, with zeolite imidazolium salt skeleton-8 (ZIF-8) as a carbon source, discharge plasma sintering is used to create carbon nanonetworks derived from metal-organic frameworks (MOFs) in situ on the grain boundaries of zirconia-toughened alumina (ZTA) ceramic. ZTA exhibits maximum bending strength (719 +/- 20.5 MPa) and fracture toughness (7.91 +/- 0.7 MPa m(1/2)) at MOF concentrations of 1.0 wt% and 2.0 wt%, respectively, which are 1.37 and 1.88 times higher than that of the unmodified sample. This demonstrates that the MOF-derived carbon nanonetworks significantly improve the mechanical properties of the ceramic. The finite element analysis results indicate that the carbon nanonetworks can effectively disperse the stress inside the material and transfer the concentrated stress from the internal defects to the two-phase grain boundary on the surface of the sample, thereby contributing to strengthening and toughening. Overall, this work validates that the in situ production of carbon nanonetworks from MOFs is an effective strategy to enhance the mechanical properties of ZTA ceramics. Moreover, it offers new approaches for reinforcing and toughening other ceramic materials.

In August 2020, the observations of total peroxy radical concentrations were carried out in the western suburb site of Hefei using a peroxy radical chemical amplifier (PERCA) instrument. The ozone production and its sensitivity were characterized with the measured O3 and its precursors. The results showed that the daily variation in total peroxy radical concentrations exhibited an obvious convex tend, with the highest value at approximately 12:00; the average peak peroxy radical concentration was 43.8×10-12; and the concentrations of the peroxy radical and ozone were driven by strong solar radiation and high temperature. The photochemical ozone production rate could be determined with peroxy radical and NO concentration. The average ozone peak production rate in summer was 10.6×10-9 h-1, which was more sensitive to NO concentration. Based on the ratio of the radical loss rate due to reactions with NOx to the radical loss rate (Ln/Q), the characteristics of O3 production in the western suburb of Hefei in summer were analyzed. The results showed that O3 production sensitivity varied greatly during the day. The summer O3 production regime shifted from the VOC-sensitive chemistry in the early morning to NOx-sensitive chemistry in the afternoon, and this regime transition typically occurred in the morning.

Ferroelectricity and superconductivity are prominent yet distinct quantum phenomena; materials exhibiting both of these phenomena are rare and of great fundamental and practical interest. Here, combining ab initio calculations and in situ measurements, we show that ferroelectric SnPS3 turns into a superconductor under pressure at 31.7 GPa, accompanied by a structural phase transition. Electronic band structure calculations reveal a partial flat band near the Fermi energy in compressed SnPS3, suggesting correlation effects as a possible origin of the observed superconducting state. The discovery of a pressure-induced ferroelectric-to-superconductor transition in SnPS3 raises the prospect of establishing this intriguing quantum phenomenon among a large class of metal phosphorous trichalcogenides, thereby broadening the material basis to elucidate the underlying physics.

Carbon materials are important but find little application in bending components due to their unsatisfy-ing bending strength (30 0-50 0 MPa). To fabricate carbon composites of high bending strength is a tough task, even using carbon fibers (CFs) structures as reinforcements. Here we report lamellar carbon composites of ultra-high bending strength (> 1.2 GPa) produced from CFs cloths coated with nano-diamond (ND) particles by spark plasma sintering (SPS). When NDs are sandwiched between CFs cloths, some ND particles penetrate into interstices between CFs. During the sintering, the ND particles are transformed into graphite onions; this transformation is associated with an active state of carbon atoms participating in the change. As a result, the carbon onions strongly bond the CFs together, helping consolidate the com-pacts into strong lamellar carbon composite bulks. The produced graphite onions from the NDs located at crossings of CFs tows form a robust mortise and tenon structure, which helps the bending strength of the lamellar composite from the compact of 40 wt.% NDs exceed 1.2 GPa. The as-prepared compos-ite possesses the highest specific bending strength of all current high temperature structural materials reported so far. This work may pave a new way for high performance carbon materials. (C) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.