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Cr3+-doped near-infrared (NIR) afterglow phosphors have received wide recognition in the optical storage field because of the high signal-to-noise ratio and broad excitation spectra. In this article, the high-temperature TL intensity of ZnGa2O4:Cr3+ afterglow glass ceramic (ZGO:Cr3+ GC) was enhanced via partial hetero-valence substitution of Ge for Ga, demonstrating the tunability of the trapped electron levels in ZGO:Cr3+ GC. The persistent luminescence phosphor ZGO:Cr3+ GC exhibits a zero-phonon lines emission peaking at 698 nm, attributing to the 2E→4A2g transition of Cr3+ ions. Moreover, the trap levels in Zn-Ga-Ge-O:Cr3+ glass ceramic (ZGGO:Cr3+ GC) are deeper than those of the Ge-free one and the captured electrons in deeper levels cannot be released only by the ambient thermal energy, thus the optical storage capacity of ZGGO:Cr3+ GC is much larger. By means of an additional 980 nm laser photostimulation, an intense NIR emission could be obtained. In consequence, ZGGO:Cr3+ GC has a promising application prospect in optical information storage field.

Two novel nitrogen-doped, hexa-peri-hexabenzocoronene (HBC)-based nanographenes (NGs) 1 and 2 bearing an azepine and an azocine at the fjord region, respectively, were synthesized and characterized. Notably, structure 1 was synthesized by Diels-Alder reaction of cyclic alkene and tetrachlorothiophene-S,S-dioxide, followed by Suzuki-Miyaura cross-coupling and Scholl-type reactions, which represents a modified strategy to construct NGs. The azo-heptagon-embedded NG 1 leads to a saddle shape, and the azo-octagon-embedded NG 2 exhibits a distorted saddle-helix conformation with the largest torsion angle recorded so far in [5]helicenes. As a result, the different structural topographies for NGs 1 and 2 lead to significant changes in the optical properties including UV absorption and fluorescent emission. Additionally, the 8π-heterocycles azepine and azocine in the NGs 1 and 2 exhibited obvious antiaromatic properties.

Waterborne elastic polyester (WEP) with different content of hard polyester was applied in the maize starch (MS) based composites (MS/WEP) via solution casting method. The effects of WEP with different contents of hard polyester on the structure and properties of starch were studied by Fourier transform infrared, X-ray diffraction, ultraviolet-visible, tensile test, differential scanning calorimeter, thermogravimetric analysis and moisture measurement. The experimental results show that the addition of WEP does not change the crystalline type of starch, and only reduces the crystallinity of starch. And the structure and properties of MS/WEP are related to not only the content of starch but also the microstructure of WEP or the content of hard polyester in WEP. Waterborne elastic polyester with 30wt% hard polyester (WEP30) has the best modification effect on the maize starch among all the WEPs. For example, MS/WEP30 film has the optimum toughness, aging resistance and transmittance, the lowest crystallinity and glass transition temperature among all the MS/WEP films, and the lower moisture content. It is related to the compatibility between starch and WEP, resulting from the number of physical crosslinking points in WEP.

Waste tire pyrolysis residue (WTPR) is a solid byproduct with high carbon content. Herein, WTPR was utilized in the preparation of WTPR water slurry (WTPRWS) to achieve resource utilization. Three dispersants (sodium ligninsulfonate [SL], hexadecyltrimethylammonium chloride [CTAC], and NP-40 substitute octylphenoxypolyethoxyethanol [NP-40]) were used in slurry preparation to improve the performance of WTPRWS. Results showed that the surface prpperties of WTPR had changed after dispersant adsorption through the analyses of FTIR, SEM–EDS, and XPS. The Langmuir equation was highly applicable for fitting the adsorption kinetics of the dispersants, and the adsorption quantity of NP40 was greater. NP40 exhibited better viscosity-reducing and stabilizing abilities in WTPRWS than the other dispersants. Meanwhile, shear-thinning characteristics were exhibited by all samples, especially the NP40 WTPRWS sample, which had the smallest yield stress. Moreover, the wetting properties and zeta potentials of WTPR before and after dispersant adsorption were analyzed.

The mechanical properties of an austenite-based Fe-Mn-Al-C lightweight steel were improved by co-precipitation of nanoscale Cu-rich and κ-carbide particles. The Fe-28Mn-9Al-0.8C-(0,3)Cu (wt.%) strips were near-rapidly solidified and annealed in the temperature range from 500 °C to 700 °C. The microstructure evolution and mechanical properties of the steel under different annealing processes were studied. Microstructural analysis reveals that nanoscale κ-carbides and Cu-rich particles precipitate in the austenite and ferrite of the steel in this annealing temperature range. Co-precipitation of nanoscale Cu-rich particles and κ-carbides provides an obvious increment in the yield strength. At the annealing temperature of 600 °C, both the yield strength and ultimate tensile strength of Fe-28Mn-9Al-0.8C-3Cu (wt.%) steel strip are the highest. The total elongation is 25%, which is obviously higher than that of Cu-free steel strips, for the addition of Cu reduces the large sized κ-carbides precipitated along austenite/ferrite interfaces. When the annealing temperature rises to 700 °C, the strength and ductility of the two steel strips deteriorate due to the formation of massive intergranular κ-carbides precipitated along austenite/ferrite interfaces. It can be concluded that a proper co-precipitation of Cu-rich particles and κ-carbides would improve the properties of austenite-based Fe-Mn-Al-C steel.

The intense zero phonon line (ZPL) of the Mn4+:2E→4A2 transition can further promote the color rendering and luminous efficiency for high-quality white-emitting diodes (w-LEDs). In this article, a Mn4+-activated K3TaOF6 oxyfluoride red phosphor was synthesized via a facile two-step method. Its phase and morphology were characterized by X-ray diffraction, SEM and TEM. The as-prepared K3TaOF6:Mn4+ exhibits an intense absorption of blue light and a strong emission band peaking at 628 nm with a color purity as high as 96.4%. Attributed to the distorted octahedral coordination environment of Mn4+ ions, an intense ZPL emission was detected at 620 nm. By theoretical calculation, Mn4+ ions in the K3TaOF6 host experience a strong crystal field. In addition, the temperature-dependent PL and thermoluminescence (TL) spectra suggest that thermal ionization dominates the thermal quenching phenomenon in this phosphor.

Amorphous metal oxides are provided with tremendous merits in energy storage devices for their high structural disorder and excellent electrochemical activity. Unfortunately, hindered by the large inherent resistance, their electrochemical performance under high mass loading is unsatisfactory. Herein, an effective strategy for the branch–leaf structure is proposed to fabricate novel high mass loading electrode materials with the capability of high-speed charge transport and excellent capacitance performance. Under the synergistic effect of the branch–leaf structure, the NiMnOx/TiN/CC electrode under 10.12 mg cm−2 mass loading shows 4882 mF cm−2 areal capacitance at 5 mA cm−2, high-speed charge transfer capability, and great rate performance. It is the first time that the excellent performance of supercapacitors has been achieved in high mass loading amorphous metal oxides. Moreover, the assembled asymmetric supercapacitor device exhibits extreme power and energy density (0.65 W h cm−2 at 5.3 W cm−2), which are superior to those of most state-of-the-art supercapacitors. A novel path has been opened up for the application of energy storage devices with high mass loading of amorphous materials.

Mn4+-activated oxide-fluoride phosphors are attractive for application in a wide range of solid-state lighting devices because of their distinct red emission at about 630 nm and the abundant storage of Mn ions. However, the zero-phonon line (ZPL) of Mn4+ ions is too weak to be detected in most host materials due to the magnetic dipole nature. In this article, we introduce a co-precipitation method for synthesizing a Mn4+-doped oxyfluoride perovskite KNaMoO2F4 phosphor containing [MoO2F4]2− building units. The electron paramagnetic resonance (EPR) spectra are consistent with the presence of a MnF62− species at g = 1.991. The KNaMoO2F4:0.01Mn4+ phosphor exhibits strong absorption under blue light and an internal quantum yield (IQE) of 65.8%. Attributed to the distorted octahedral environment of the Mn4+ ions, visible ZPL emission was detected at 625 nm. Based on theoretical calculations, the Mn4+ ions in the KNaMoO2F4 host exist in a strong crystal field with a high Dq/B value of ∼3.86. A series of photoluminescence-dependent low-temperature spectra indicates that the Mn4+ emissive state experiences weak electron–phonon interactions upon calculating the Huang–Rhys factor. Benefiting from the ZPL, a warm white-light-emitting diode is achieved using YAG:Ce3+ and KNaMoO2F4:Mn4+ as color converters, in which the color rendering index was Ra = 83.5 and CCT = 4490 K.

In this study, oxidized starch (OCS) with different carboxyl content was prepared by the dry method, with H2O2 as the oxidant and CuCl2 as the catalyst. The optimum conditions were obtained by an orthogonal experiment, under the carboxyl and carbonyl content of 0.6813 and 1.0416% respectively. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction and gel permeation chromatography characterized the structures of OCS, and the thermal, gelatinization, viscosity property and its viscosity stability were measured. The results demonstrated that the crystallinity decreased slightly and the A-type crystal remained unchanged after oxidation, and the molecular weight of OCS decreased greatly. The thermal decomposition temperature, apparent viscosity and setback viscosity also decreased. With the increase of carboxyl content in OCS, the cold-water solubility and paste transparency of OCS paste increased gradually, while the viscosity of OCS paste decreased, and the viscosity stability displayed a trend of first increasing and then reducing. The OCS obtained by a kneader had low solution viscosity and high viscosity stability, suitable for sizing high count warp yarns.

In order to explore the high-temperature pyrolysis behavior and mechanism, two different rank coals (Shenhua bituminous coal and Baiyinhua lignite coal) were pyrolyzed in fixed-bed and drop tube furnace (DTF) reactors. Pyrolysis gas production was online quantified by a drainage method while the gas composition was detected by the gas chromatography. The physical and chemical characteristics of pyrolysis char were observed by N2 absorption and FTIR. Results show that pyrolysis gas release rate and total production increase with the higher temperature. The gas production of SH coal (618–749 ml/g) is always higher than that of BYH coal (418–510 ml/g) due to its higher volatile content. The main high-temperature pyrolysis gas products are H2 (∼50% vol), CO, CH4 and CO2. Carbon-reduction reaction at high temperatures can further form H2 and CO while the rupture of aromatic heterocyclic ring can generate CH4. High-temperature pyrolysis can greatly remove the coal moisture, develop their pore structures, crack the chemical functional groups (O–H, –CH3, C O, C–O, etc.) and upgrade the coal rank. Different coal structures and pyrolysis heating rates result in various gas evolution and char formation behaviors. Higher heating rate can help to quickly generate large amounts of free radicals and change the pyrolysis behaviors.

A green and efficient procedure for the preparation of valuable 2,3-dihydrofurans and benzoxazines has been achieved through halocyclization of olefinic 1,3-dicarbonyls or olefinic amides. This protocol could be conducted under catalyst-, base-, and oxidant-free conditions in aqueous media open to the air at room temperature with good to excellent yields. Notably, the practicality of this method is further highlighted by gram-scale reactions in good yields.

Tb (oct-phe)3·H2O and Eu (oct-phe)3·H2O were prepared by chemical reaction in solution. The molecular formula of the complex was determined by elemental analysis and FT-IR. The optical properties of rare earth complexes were further tested by ultraviolet-visible-infrared absorption measurements. The results show that the optical absorption performance is better in the wavelength range of 200-300 nm. The luminescent properties of the rare earth complexes in the wavelength range of 450-750 nm were tested. It was found that the rare earth (Eu, Tb) complexes of octylphenylalanine have good luminescent properties.

The ability of perceiving external pressures and conducting corresponding signals is one of the important functions of flexible electronics, which has been widely studied in electronic skin, prosthetics, robotics, healthcare, human-machine interfaces, etc. Pressure sensor should not be limited to the detection of unidirectional pressure. Here, a leather-based electronic pressure sensor and corresponding arrays with bidirectional sensing capability are demonstrated. The sensor/arrays consisting of two pieces of stacked leather both modified with acidified carbon nanotubes (a-CNTs) can achieve multi-level response to pressure over a broad working range and sense pulling force opposite to pressure. With polyurethane mixed with ferriferrous oxide (Fe3O4) powder being applied to their upper surface, the resistive sensor/individual units of arrays can also detect the magnetic field because of the contactless pulling force generated by the magnetized Fe3O4. Being able to sense pressure, pulling force and magnetic field, the leather-based electronic bidirectional pressure sensor and corresponding arrays with good performance not only exhibit potential for mass production and their broad application prospects, but also provide a new insight for the development of flexible electronics.

The influence of Mn doping on structural, optical, and magnetic behaviors of Mn-doped zinc stannate (ZTO) nanostructures was investigated. Pure and Mn (atomic ratios of 1, 3, and 5%)-doped high-qua...

Dexmedetomidine (Dex) works as a crucial agent for the treatment of intestinal ischemia/reperfusion (I/R), but its mechanism remains unclear. Recent articles demonstrated the pivotal role of Janus kinase/signal transducer and activator of transcription (JAK2/STAT3) signalling in I/R. Therefore, it is reasonable to explore the associated mechanism of JAK2/STAT3 signalling in Dex treatment. The study purpose was to evaluate the JAK2/STAT3 signalling regulatory mechanisms of Dex in preventing I/R. Anaesthetized rats were subjected to superior mesenteric artery occlusion consisting of 1 h of ischemia and 2 h of reperfusion while served as controls. Animals received subcutaneous administration of 50 μg/kg Dex, JAK1 and JAK2 inhibitor, Ruxolitinib, selective JAK2 inhibitor, 10 mg/kg AG490 or STAT inhibitor and 0.4 mg/kg rapamycin; or Dex-treatment in the presence of α2-adrenoceptor antagonists Atip or Dex-treatment alone after I/R. Injury was scored histologically, apoptosis was detected via the apoptotic mediators caspase-3 and Bcl-2/Bax and the degree of activation of the JAK/STAT pathway was evaluated. Dex inhibited I/R injury by decreasing apoptosis significantly with rescue of cleaved caspase-3 and the Bcl-2/Bax ratio. Furthermore, phosphorylation of JAK2, STAT1 and STAT3 was affected, suggesting the involvement of activated JAK/STAT in response to Dex. Meanwhile, the JAK2 or STAT inhibitors AG490 and rapamycin, but not Ruxolitinib, exhibited a similar but even greater JAK2 and STAT3 regulatory effect, thus leading to a greater benefit. JAK2/STAT3 activation is crucial to the diminishing effect of Dex on mesenteric I/R injury; however, the efficacy and timing of Dex administration should be considered in clinical practice.

The stress-strain relationship of single fiber and fiber bundle based on the different strain distribution functions of single fiber, including rectangular distribution, normal distribution and Wei...

To reveal the influence of pore structure of coal on the characteristics of coal dust generation during roadheader cutting, a self-developed coal cutting system was used to generate dust. A low field nuclear magnetic resonance was utilized to measure the pore system of coal. Results show that the porosity had negative correlations with the cumulative proportions of both respirable dust and fine particulate matter (PM2.5), but the positive influence on the mass ratio of dust generation (MRD) of total dust and slight effect on MRD of respirable dust and PM2.5 were observed. The correlations of the fractal dimension (Df) of pore structure on dust generation were inverse compared with that of porosity. The negative relationship between porosity and Df was the reason for the opposite correlations. This study can provide basic support for the estimate of dust hazard and the development of dust control technologies.

As dust is one of the main hazards generated by coal cutting, understanding the properties of dust generation is essential for preventing and controlling its propagation. This paper therefore aims to investigate the influence of coal brittleness on dust generation. A system was devised to produce dust and the density, uniaxial compressive strength, and Brazilian tensile strength of dust samples were then measured. The results showed that the cumulative proportions of fine particulate matter and respirable dust increased with brittleness, while a declining trend was observed from the mass ratio of total dust to coal sample. B14 (half of the product of compressive and tensile strength) had the strongest correlation with the properties of dust generation, and accounted for more than 95% of B15 (half of the sum of compressive and tensile strength).

The diluted magnetic semiconductor (DMS) is an important system for realizing room-temperature ferromagnetism. In the DMS, the exchange interactions between the spins of the carrier or exciton and ...

Printing methods are potential strategies to realize the fabrication of flexible electronics on a large scale with low cost, and have been widely adopted to fabricate flexible electronic whiskers (e-whiskers). However, the sensors fabricated by these methods are typically fragile to surface damage as their conductive pattern is exposed on the surface. Here, conductive ink formed by zero-dimensional conductive nanomaterials, is used to write on leather to fabricate a leather-based e-whisker. Owing to the porosity of leather, the ink can permeate into the leather and form a three-dimensional conductive pathway. The good mechanical properties and special structure of leather enable the sensor to have good performance in tape tests, abrasion tests and washing tests. Furthermore, when scanning the surface of a substrate, the leather-based e-whisker is sensitive enough to detect a height difference of 50 μm, which makes it capable of surface texture detection, spatial distribution mapping, and wind mapping, etc.

Single-layer 1T-TaSe2 has recently been found to host a Mott insulating ground state entwined with a commensurate charge density wave (CDW). However, the interplay between the CDW order and the Mott state remains unclear and elusive. Using first-principles calculations, we show that the CDW order with Star of David lattice distortions induces the formation of two different types of Ta-d orbitals (one is localized and the other is extended), and the Mott insulating state is brought on by the electron correlation in the localized orbital which is separated from the extended orbitals in energy. Interestingly, when a compressive biaxial strain is applied on monolayer 1T-TaSe2, the Mott insulating phase will first transform into a charge-transfer insulating phase and then into a normal metallic phase with increasing strain. The CDW always persists and is even enhanced under the strain, indicating that the Mottness collapse is unexpectedly not at the expense of suppression of the long-range CDW order. We further reveal that the realization of metallization in the CDW phase occurs because the localized orbital is immersed into the extended-orbital-spanned Fermi sea and its Hubbard splitting is quenched by orbital hybridization. Our findings may provide significant implications for fine control over correlated electronic states, possessing potential applications in ultrafast resistive switching.

The ever-increasing development of flexible and wearable electronics has imposed unprecedented demand on flexible batteries of high energy density and excellent mechanical stability. Rechargeable lithium (Li) metal battery shows great advantages in terms of its high theoretical energy density. However, the use of Li metal anode for flexible batteries faces huge challenges in terms of its undesirable dendrite growth, poor mechanical flexibility, and slow fabrication speed. Here, a highly scalable Li-wicking strategy is reported that allows ultrafast fabrication of mechanically flexible and electrochemically stable Li metal anodes. Through the rational design of the interface and structure of the wicking host, the mean speed of Li-wicking reaches 10 m2 min-1 , which is 1000 to 100 000 fold faster than the reported electrochemical deposition or thermal infusion methods and meets the industrial fabrication speed. Importantly, the Li-wicking process results in a unique 3D Li metal structure, which not only offers remarkable flexibility but also suppresses the dendrite formation. Paring the Li metal anode with lithium-iron phosphate or sulfur cathode yields flexible full cells that possess a high charging rate (8.0 mA cm-2 ), high energy density (300-380 Wh kg-1 ), long cycling stability (over 550 cycles), and excellent mechanical robustness (500 bending cycles).

In this paper, hydrogen adsorption in metal-organic framework MIL-101(Cr) is investigated through a combination of sorption experiments, modeling of experimental isotherms, differential scanning calorimetry (DSC), neutron scattering, in situ synchrotron powder X-ray diffraction, and molecular simulations. The molecular simulations at 77 K for H2 adsorption in the material show excellent correspondence with excess uptakes determined from experimental isotherms. The simulations also indicate that H2 adsorption at a low pressure is mainly located in the 0.7 nm supertetrahedron and that, with increasing pressure, H2 starts to accumulate in the small (2.9 nm) and large (3.4 nm) cages. The inelastic neutron scattering results show that, in contrast to reports for hydrogen adsorption under the same conditions for microporous carbons, there is no solid-like H2 or any higher density H2 phases adsorbed in the pores of MIL-101(Cr). This indicates that, with increasing pressures, the adsorbed density of the MIL-101(Cr) remains constant but the volume of adsorbate increases and that higher densities for adsorbed hydrogen require pore sizes smaller than 0.7 nm, which is the size of the smallest pore in MIL-101(Cr). The enthalpies of adsorption are also investigated for this material using simulations, the Clapeyron equation applied to the isosteres and DSC, with the direct calorimetric method showing good agreement at zero coverage with the other two methods. The simulations and the Clapeyron equation are also in good agreement up to 6 wt % coverage.

The formation of CH4 hydrate in a mesoporous metal-organic framework MIL-101 is investigated by microsecond molecular dynamics simulations. CH4 hydrate is observed to form preferentially in the outer space of MIL-101 cavities rather than inside the cavities; only when the hydrate formation is nearly complete in the outer space can stable hydrate form in MIL-101 cavities. The underlying reason is revealed to be the easy dissociation of small hydrate clusters formed in the nanospace of the cavities, because of the diffusion of CH4 molecules out of the cavities into the outer space. Compared with dry MIL-101, the CH4 storage capacity of H2O-saturated MIL-101 is drastically reduced as the cavities are occupied by H2O. When oversaturated with H2O, however, extra H2O molecules in the outer space of the cavities can form considerable CH4 hydrate, significantly promoting CH4 storage capacity. This study provides important mechanistic insights into the formation mechanism and process of CH4 hydrate in MIL-101 and will facilitate the design of emerging materials for energy storage.

Pressure sensor can be applied in a wide range of fields, such as voice recognition, human motions detection and artificial electronic skin, the sensing of which is greatly influenced by the flexibility and stretchability of substrate materials. Here, based on the piezoresistive effect, new kinds of flexible pressure sensors have been realized from a pair of flexible and biocompatible collagen films: one is coated by silver nanowires (Ag NWs) and the other by interdigital electrode, respectively. The collagen films are regenerated from leather waste and could bring economic benefits to society. The prepared pressure sensors are applied for voice recognition and human motion detection. Graphical abstract A flexible pressure sensor based on two layers of regenerated collagen films coated silver nanowires (Ag NWs) and interdigital electrodes respectively are obtained. The flexible collagen films are prepared by dissolving leather waste into ionic liquid, [BMIM]Cl. The fabricated pressure sensor displays potential applications in voice recognition and human physical motion detection, such as finger and wrist bending-releasing, which are expected to access the training data of athletes, monitor some physical activities of patients synchronously and act as a voice recognition device.

In this work, the novel, interconnected and self-assembled nanocomposite of porous hollow Cu7S4/CuS and nitrogen-doped reduced graphene oxide (Cu7S4/CuS@nGO) has been designed and synthesized successfully via a simple solvothermal process. An efficiently synthetic approach to selectively manufacture different morphologies of Cu7S4/CuS has been investigated by only controlling the hydrothermal temperature. The images of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicate the temperature-dependent evolution of structures and morphologies of the samples. Considering the efficient morphology of Cu7S4/CuS(synthesized at 210 °C) with the porous hollow spherical structure, we speculate it should have good photoelectric properties, such as wide UV–vis absorption spectra, and its performance should be enhanced with further treatment like being encapsulated with nitrogen-doped reduced graphene oxide. In order to investigate the photoelectric properties of the Cu7S4/CuS and Cu7S4/CuS@nGO nanocomposites, they have been used as the counter electrodes (CE) in the dye-sensitized solar cells (DSSC). It is demonstrated that the Cu7S4/CuS@nGO nanocomposite not only shows the best photoelectric performance, whose power conversion efficiency is 9.14% (much higher than those of the devices with Pt, Cu7S4/CuS and nGO as CEs), but possesses remarkable electrochemical stability as well.

This article presents a leather-based respiration sensor based on the ionic conductivity change of leather, caused by humidity variation during breathing. Leather was applied as a flexible substrate due to its biocompatibility, hydroscopicity, porosity, and ionic conductivity. Printing method was employed to fabricate the sensor, which could convert human respiration to electrical signals. By combining the leather with silver nanowires (AgNWs), data about human respiration rate, respiration depth, and respiration pattern can be acquired easily through a noninvasive way. Such sensor could work tens of hours consecutively due to the unique properties of leather.

Octanoyl alanine ligands and metal ions (Mg2+, Ca2+) form metal complexes of octanoyl alanine through chemical coordination bonds [1]. According to the acid base reaction and the Lewis acid-base theory[2], the molecule or ion of the central atom or ion (collectively called the central atom) and the ligand (called ligand) around it, completely or partially by the coordination bond to form metal complex. These octanoyl alanine complexes are soluble in water and easily ionize into internal coordination ions and external ions, while the ligands and central atoms do not ionize in the inner boundary. The octanoyl alanine magnesium and calcium complexes belongs to the amino acid metal complexes, which can be widely used in daily life, industrial production and life science in the future application. Recently, with the rapid development of amino acid metal complexes [3-7], it is not only associated with inorganic compounds and organometallic compounds, but also overlaps with the chemistry, coordination catalysis and molecular biology of the current chemical frontiers [8-10]. In this paper, [C10H20NCO3]2M type metal complexes prepared by combining octanoyl alanine ligand with metal ions containing functional group COOH, the influence of water content on the DSC curve and surface morphology of metal complexes was studied, and the information of the diversified structure state of the materials complex can be obtained.

To obtain high efficient and lightweight microwave (MW) absorption material, a novel composite RGO/PANI/BaNd0.2Sm0.2Fe11.6O19 (BNSF) was successfully synthesized. The RGO/PANI composite was synthesized by an in-situ polymerization, the BNSF was obtained via a chemical co-precipitation method and the RGO/PANI/BNSF ternary nanocomposite was fabricated through high energy ball mill. The phase composition, microstructure and MW absorption performance of samples were investigated and discussed. The results exhibited not only an excellent composite structure, but also an outstanding MW absorption performance. The RGO/PANI/BNSF nanocomposites exhibited excellent MW absorption property with 30 wt.% of BNSF, the minimum reflection loss (RL) could reach −50.5 dB at 13.68 GHz with the thickness of 2.90 mm. Meanwhile, the introduction of multiple polarization and relaxation in ternary composite were responsible for the enhancement of microwave attenuation and a broad effective absorption bandwidth (6.8 GHz). Based on the above results, we confirmed that the RGO/PANI/BNSF composite will have a considerable prospect in the electromagnetic interference shielding field.

A novel hybrid material with excellent microwave absorption property has been designed by decorating reduced graphene oxide with Ba Tb0.2Eu0.2Fe11.6O19/PANI composite, and the effect of graphene content on microwave absorption property has been investigated. The microstructure of the composite is characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, field emission scanning electron microscope, transmission electron microscope and Raman spectroscopy. The mechanism of microwave absorption is discussed minutely. The result shows that the ternary nanocomposites demonstrate unexceptionable microwave absorption property due to its special nanostructures and synergistic effect among BaTb0.2Eu0.2Fe11.6O19, PANI and RGO. The minimum reflection loss can reach − 60.9 dB at 16.4 GHz with a thickness of only 1.95 mm, and the corresponding effective absorption bandwidth (below − 10 dB) is 4.2 GHz. BaTb0.2Eu0.2Fe11.6O19/PANI/RGO composite can be one of the most promising microwave absorption materials.

A fluorescent D–A–D′ triad (1), composed of monocarbaborane, benzothiadiazole and triphenylamine, was synthesized. By replacing monocarbaborane with phenyl (Ph), p-methoxyphenyl (PMP) or 4-pyridinyl (Py), three analogs (2, 3, and 4) were prepared for comparison. Monocarbaborane is an electron donating group based on the comparative analysis of NMR spectra and the systematic investigation of their photophysical properties. Triad 1 emits bright-yellow light in THF solution with the highest quantum yield and the longest decay time among these compounds. It tends to form nanoparticles in aqueous THF solution. The in situ generated nanoparticles might be used to detect silver ions with high sensitivity and high selectivity. By holding the molecules via multiple CH⋯π interactions and electrostatic forces between the tetraethylammonium cation and the cage, a sheet-like arrangement of 1 is formed in the solid state with the smallest crystal density that provides the maximal possibility of mechanofluorochromism from the crystalline to the ground form. Moreover, by doping 1 in PVK, a white OLED is obtained.

In order to study the high-temperature pyrolysis behavior of bituminous coal in the drop tube furnace (DTF) and better utilization of the obtained char, a typical Shenhua bituminous coal (SH) was pyrolyzed in a DTF at the temperatures of 1000–1300 °C (100 °C increments). The obtained char was then characterized using BET and FTIR methods, while its combustion, gasification and pollutant emission characteristics were explored by a thermogravimetric analyzer and online flue gas analyzer. Results show that higher pyrolysis temperature leads to more CO and less CH4 for the increased free radical rearrangement by high heating rate and carbon reduction reactions at high temperatures. Pyrolysis generally decomposes the functional groups, increases the volume of char pores, and upgrades the rank of coal. The combustion activation energy increases from 22.99 kJ/mol to 27.42 kJ/mol and the gasification is hindered with the higher pyrolysis temperature. It is notable that the NOx and SO2 emissions of the obtained char combustion are both below 30 mg/s-MJ. High-temperature pyrolysis can enhance the evolution of NH3 and HCN as volatiles, thus decreasing the NOx formation in further char combustion stages while partly decomposing the organic and inorganic sulfur compounds to impact the SO2 emission.

The confined laser shock peening (LSP) is an innovative surface treatment technique designed to improve the fatigue performance of materials by imparting compressive residual stresses into materials. A 3D finite element model was developed to predict the surface residual stress and plastically affected depth of the TC11 titanium alloy after LSP. The modeling procedure consists of two successive explicit analysis steps. The performance of finite element model was verified by comparing simulated results with the experimental data. With the validated finite element model, the influence of the process parameters (LSP path, thickness of the sample, number of impacts) was investigated on the surface residual stress and plastically affected depth of the TC11 titanium alloy after LSP. Some simulated results can be used to mentor the optimization of the process parameters of LSP.

We calculate the electronic, thermal and mechanical properties of antimonene with different oxygen compositions (Sb, 2Sb O and 2Sb 2O). Results show that the band gaps gradually decrease with the increase of the oxidation degree. We also study the lattice thermal conductivities of the three materials and find that the oxidation would greatly reduce the lattice thermal conductivity k of antimonene which is due to the decline of corresponding phonon lifetime. In addition, oxidation reduces the stiffness of antimonene. Our work provides a new perspective for the adjustment of thermal transport which will facilitate the design of thermal materials.

In this work, a photocatalyst with a built-in p–n–n tandem heterostructure is designed and fabricated by combining CdS with n-type WS2 nanosheets and p-type CoP nanoparticles. The p–n–n tandem heterostructure allows different favorable properties from each participating compound to be combined, prolonging the lifetimes of photogenerated electrons, providing surface redox sites and increasing the photostability. Photocatalytic hydrogen evolution activity of CoP/CdS/WS2 without using sacrificial agents is measured to be 9.16 μmol g−1 h−1. Moreover, it can be used as a bifunctional photocatalyst for degrading pollutants and producing hydrogen at the same time (43.51 μmol g−1 h−1). This work opens a new way for designing efficient photocatalysts without using sacrificial agents and combining energy conversion with environmental remediation effectively.

Based on energy band engineering theory, a p–n homojunction of metal oxides was designed to overcome the recombination of photogenerated carriers and inappropriate hydrogen adsorption energy. A novel p–n tungsten oxide homojunction was successfully synthesized by tuning oxygen vacancies and phosphorus-doping. Based on the synergies of Mxenes, a Vis-NIR light-enhanced electrocatalytic hydrogen evolution system was accomplished with a small overpotential of 44 mV (at 10 mA cm−2) and a low Tafel slope of 41 mV dec−1, which performed much more efficiently than in darkness and comparably to noble-metal catalysts (Pt and Pt/C). Moreover, the as-synthesized samples offered a distinct advantage of long-term stability for more than 24 h both with and without light irradiation. The design philosophy of p–n homojunctions opens a prospect of utilizing light-activated metal oxides to integrate catalysis with solar energy and electrical energy.

With needle coke (NC) as an initial material, large-sized graphene was successfully prepared through an oxidation–exfoliation–thermal reduction process. The prepared graphene was characterized by S...

A combined conventional and microwave drying process for Ximeng lignite was investigated in this paper. Samples were firstly dehydrated by hot air to achieve a conversion moisture content, and then were managed to final moisture content by microwave drying. Results showed that the drying rate was significantly improved in the decreasing rate period by microwave drying, approximately 3–5 times faster than that of conventional drying. Finally, the orthogonal test was used to clarify the effects of each factor on the energy consumption, and the magnitude ranking order was conversion moisture content > microwave power > hot air temperature.

Flexible polyurethane foam (FPUF) has been considered as an excellent material in many fields, such as furniture and electromagnetic interference (EMI) shielding products due to its lightweight and flexibility. However, there is a severe fire hazard problem for FPUF that makes it unsuitable to be used in practical. Herein, a facile method was to prepare anti-dripping FPUF via electroless plating at ambient temperature. The silver nanoparticles (SNPs) were in-situ grown on the surface along with the polydopamine (PDA) as an adhesive and template (SNP@PDA@FPUF). As a result, these FPUFs show outstanding fire safety and anti-dripping capacity, and the heat release rate reduced 80.92%. Furthermore, the amounts of carbon oxide (CO) and carbon dioxide (CO2) decreased 75.01% and 22.4%, respectively. Above all, the EMI shielding effectiveness (SE) accomplished almost 120 dB as the increasing electroless time with a low density of 0.051 g/cm3. Furthermore, the specific EMI SE (SSE) and the absolute EMI SE (SSE/t) accomplished 2630.98 dB·cm3/g and 2434 dB·cm2/g, respectively, which was far beyond the commercial request. Therefore, this work may provide a facile way to prepare low density and EMI shielding products with high fire safety for next generation electronic products.

Porous air journal bearings (PAJBs) with O-rings mounted are regarded as a potential choice to offer air levitation with a large load capacity and optimal start/stop characteristics, which are required in small-sized and high-efficiency turbomachinery. However, the coupling of the mechanical properties of the O-rings and lubrication induces strong nonlinear characteristics, thereby affecting the dynamic responses of the rotor. In this study, a numerical model, which is obtained by coupling the excitation frequency-influenced stiffness and damping characteristics of O-rings, Darcy’s laws, air motion equations, and rotor and bearing motion equations, is presented. The numerical model can efficiently reflect the influences of the actual mechanical property of O-rings and the coupling between aerodynamic and aerostatic effects on the performance of a rotor-PAJB system (RPS). The model is well verified by experimental results. The effects of different system parameters on the performance of the RPS are studied by analyzing bifurcation diagrams, orbit, Poincare maps, and fast Fourier transform plots. Results show that the rotor motion is changed between periodic and quasi-periodic with the variation in rotational speed, external supply pressure, bearing clearance, and porous permeability. With O-rings mounted, the stability of the RPS can be increased to hinder the rotor motion from changing from periodic to quasi-periodic. The effectiveness in increasing the stability of the RPS for the O-rings with styrene butadiene rubber as the material is better than that with nitrile butadiene rubber but weaker than that with methyl vinyl silicone rubber. Moreover, only a limited number of O-rings have enhancing effects on the stability of the RPS.

Designing photo‐responsive host–guest systems can provide versatile supramolecular tools for constructing smart systems and materials. We designed photo‐responsive macrocyclic hosts, modulated by light‐driven molecular rotary motors enabling switchable chiral guest recognition. The intramolecular cyclization of the two arms of a first‐generation molecular motor with flexible oligoethylene glycol chains of different lengths resulted in crown‐ether‐like macrocycles with intrinsic motor function. The octaethylene glycol linkage enables the successful unidirectional rotation of molecular motors, simultaneously allowing the 1:1 host–guest interaction with ammonium salt guests. The binding affinity and stereoselectivity of the motorized macrocycle can be reversibly modulated, owing to the multi‐state light‐driven switching of geometry and helicity of the molecular motors. This approach provides an attractive strategy to construct stimuli‐responsive host–guest systems and dynamic materials., Motorized macrocycles have been successfully synthesized by combining molecular motors with crown ether macrocycles, enabling unique photo‐switchable host–guest systems controlled by the multi‐stable unidirectional rotation of molecular motors. The switchable chiral cavity can be also used for the enantioselective recognition of guests.

Nb 2 AlC is a kind of ternary ceramic material whose special crystal structure makes it both the advantages of metal and ceramics. And it has good electrical conductivity and strong stability at room temperature. In this article, the saturable absorption of Nb 2 AlC based thin film have been investigated, showing that it has saturated light intensity of 0.21 MW/cm 2 and the modulation depth of 2.62%. Noise-like mode locked and Q-switched pulses output based on Nb 2 AlC thin film have been achieved in erbium-doped fiber laser cavity. The narrowest width of noise-like mode-locked pulses' envelope is 13 ns, the maximum single pulse energy is 1.5 nJ, and the full width at half-maximum (FWHM) of the narrowest coherent spike is 2.34 ps. The minimum pulse width of the Q-switched pulse is 8.6 μs and the maximum single pulse energy is 66 nJ. As far as we know, this is the first report of Nb 2 AlC's application in ultrafast optics.

In this work, a novel phosphine oxide-containing hyperbranched polyol (POCHP) was synthesized. Then POCHP and/or expandable graphite (EG) were incorporated into rigid polyurethane foam (RPUF). EG increases foam density and deteriorates compressive strength and thermal conductivity, but POCHP has opposite effects. A 12.8% improvement of compressive strength and slightly decreased density and thermal conductivity are achieved by ERPUF50 containing POCHP and EG. And it reaches a limited oxygen index of 30.0% and UL-94 V-0 rating with immediate self-extinguishing behavior after removing flame. The peak heat release rate, total heat release and total smoke production of ERPUF50 are reduced by 71.1%, 52.2% and 71.1% respectively via bi-phase flame retardant mechanisms. Interesting phenomena were observed that POCHP promotes the intumescence of EG after combustion. The results of combustion gas analysis reveal that single POCHP or EG reduces the production of CO but increases the generation of NOx. ERPUF50 exhibits a 52% decrement of CO and an unexpected 40% diminishment of NOx. ERPUF50 with excellent comprehensive properties can not only be used as fire safe thermal insulation material with high physical performances, but also significantly reduce the release of contaminative smoke, CO and NOx in fires and waste RPUF disposal by combustion.

Afterglow imaging that detects photons after cessation of optical excitation avoids tissue autofluorescence and thus possesses higher sensitivity than traditional fluorescence imaging. Purely organic molecules with room-temperature phosphorescence (RTP) have emerged as a new library of benign afterglow agents. However, most RTP luminogens only emit visible light with shallow tissue penetration, constraining their in vivo applications. This study presents an organic RTP nanoprobe (mTPA-N) with emission in the NIR range for in vivo afterglow imaging. Such a probe is composed of RTP molecule (mTPA) as the phosphorescent generator and an NIR-fluorescent dye as the energy acceptor to enable room-temperature phosphorescence resonance energy transfer (RT-PRET), ultimately resulting in redshifted phosphorescent emission at 780 nm. Because of the elimination of background noise and redshifted afterglow luminescence in a biologically transparent window, mTPA-N permits imaging of lymph nodes in living mice with a high signal-to-noise ratio. This study thus opens up a universal approach to develop organic RTP luminogens into NIR afterglow imaging agents via construction of RT-PRET.

There are varied spin states in dilute magnetic semiconductors, and carriers are not the only elementary excitations that carry the spin. This article reports a study of spin interactions in excitons of ZnSe:NiI(II) nanostructures. High-quality ZnSe:NiI(II) nanobelts (NBs) prepared by chemical vapor deposition show a zinc blende structure by x-ray diffraction and Raman spectroscopy. The temperature-dependent photoluminescence spectra of doped NBs show independent free exciton (FX) and exciton magnetic polaron (EMP) peaks at room temperature with ferromagnetically coupled Ni ions. A single-mode lasing profile was obtained with femtosecond laser excitation due to condensation of EMPs over a threshold. The luminescence lifetimes at different pump powers indicated different relaxation profiles, confirming the formation of coherent EMP aggregates. At a slightly higher dopant concentration, a weak peak at the high-energy side of the FX peak showed up separately at low temperature; this should be the magnetic polaron emission band from the antiferromagnetically coupled Ni(II) pair binding with a FX (antiferromagnetic magnetic polaron). These results illustrate the typical spectroscopic characteristics of spin-spin magnetic coupling, exciton-spin or phonon interactions in dilute magnetic semiconductor nanostructures, showing that their different coupled spin types could work as exciton binders for their collective excitons, with possible use in spin nanophotonic devices and quantum modulations.

In the reaction of photocatalytic water splitting, oxygen production has been the rate-limiting step, and the side-reactions caused by excessive oxidation capacity have become important factors affecting oxygen production. C3N4 was doped by phosphorus (P) to controllably reduce its oxidation performance while narrowing the band gap, so as to improve its light absorption ability and reduce the side-reactions caused by excessive oxidation capacity. Due to the much higher reducibility, C3N4 has been identified as an ideal carrier for this design philosophy, which can make up the power lack of producing O2 induced by the reduced oxidation capacity while P being doped. Successively, via adjusting the relationship between the overall water splitting activity and energy band structure of the catalyst, it was proved that the regulation of oxidation capacity has an important effect on the photocatalytic water splitting. The photocatalytic H2 and O2 evolution rates were 0.67 and 0.27 μmol h−1, respectively. This research will provide a new idea to improve the performance of overall water splitting with energy band structure regulation in the future.

The effect of hindered amine light stabilizer on free radical quenching can be combined with the cross-linked polyphosphazene containing P N structure to improve the flame retardant efficiency of titanium carbide (Ti3C2TX) in both gas phase and condensed phase. Here, a hindered amine and polyphosphazene modified Ti3C2TX (Ti3C2TX@PHbP-PHC) was obtained. With the loading of Ti3C2TX@PHbP-PHC in the bismaleimide resin (BMI) increased to 2 wt%, an 43% reduction was achieved in the peak heat release rate (PHRR), and a 47% reduction in the total heat release rate (THR). Meanwhile, the total gaseous products and total smoke production (TSP) exhibited a similar decreasing trend. Furthermore, 0.5 wt% BMI system exhibited the highest storage modulus (2629 MPa) and impact strength (13.7 MPa), which were 21% and 76% higher than pure BMI, respectively. Therefore, the developed functionalized Ti3C2TX can be effectively used in BMI matrix, thereby providing reliable source material for the design of high-performance BMI resins that meet various application scenarios.

Photocatalytic nitrogen fixation is a promising method for solar energy storage. In order to improve the efficiency of photocatalysis, it is necessary to accelerate the transfer of photogenerated electron-holes and inhibit their recombination. Based on energy band engineering theory, the band gap of CN is changed by adjusting the doping proportion of B element so as to better match the energy band of WO3, and the optimal energy band state is achieved. The change of the band of CN is studied in depth while introducing B. The WO3/B-CN photocatalytic system can effectively improve the separation efficiency and prolong the life of photogenerated carriers. The quantum efficiency of the photocatalyst material for nitrogen fixation at 400 nm is 0.71%. The yield of NH3 under visible light is 450.94 μmol g-1 h-1. This study has important guiding significance for the design of high efficiency photocatalysts in photocatalytic nitrogen fixation.