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Polyurea coating and carbon fibre reinforced polymer reinforcing techniques were applied to retrofit a severely damaged urban utility tunnel (UUT). The blast responses of the retrofitted UUT were investigated through in-filed explosion experimental tests, and the displacements, strains, accelerations, and damage were compared. The retrofitted UUT exhibited comparable or even better blast resistance than the intact UUT. Although the polyurea coating was flexible, it exhibited excellent performance in improving the blast resistance of the damaged UUT. As the UUT reinforced with basalt fibre reinforce polymer (BFRP) bars has smaller damage compared with the UUT reinforced with steel bars, its retrofitting is simple, and the cost is low. The roof was simplified as an elastically simple support one-way slab. Euler beam theory was adopted to analyse the dynamic responses of UUT roof considering the interaction between soil and structure, which agree well with the experiments in the first three cases.

To improve corrosion-resistance of shallow-buried concrete urban utility tunnels (UUTs), basalt fiber reinforced polymer (BFRP) bars are applied to reinforce UUTs. As the UUT must have excellent survival capability under accidental explosions, a shallow-buried BFRP bars reinforced UUT (BBRU) was designed and constructed. Repetitive blast experiments were carried out on this BBRU. Dynamic responses, damage evolutions and failure styles of the BBRU under repetitive explosions were revealed. The tunnel roof is the most vulnerable component and longitudinal cracks develop along the tunnel. When the scaled distance is larger than 1.10 m/kg1/3, no cracks are observed in the experiments. When the BBRU is severely damaged, there are five cracks forming and developing along the roof. The roof is simplified as a clamped-supported one-way slab, proved by the observation that the maximum strain of the transverse bar is much larger than that of the longitudinal bar. Dynamic responses of the roof slab are predicted by dynamic Euler beam theory, which can consistently predict the roof displacement under large-scaled-distance explosion. Compared with the UUT reinforced with steel bars, the BBRU has advantages in blast resistance with smaller deflections and more evenly-distributed cracks when the scaled distance is smaller than 1.260 m/kg1/3 and the steel bars enter plastic state. Longer elastic defamation of the BFRP bars endows the UUT more excellent blast resistance under small-scaled-distance explosions.

A new 2D phosphorescence lead metal cluster-based coordination polymer (CP) [Pb4(μ2-OH) (μ3-OH) (μ4-O) (3-qlc)4]n (1; 3-qlc ​= ​3-quinolinecarboxylate) has been successfully synthesized by solvothermal reaction. CP 1 is a robust Pb(II) CP constructed by a rare [Pb8(μ2-OH)2 (μ3-OH)2 (μ4-O)2(COO)8] cluster units and 3-qlc ligands. The bulky clusters provide architectural stability to the framework of 1. Interestingly, CP 1 exhibited almost pure room-temperature orange phosphorescence with absolute phosphorescence quantum yields of 3.3% and a phosphorescence lifetime of 1.52 ​ms benefiting from the restriction of molecular vibrations/rotations of organic luminogens (3-qlc) and the heavy-atom effect of Pb(II).

In this paper, N ( N = 2 , 3 ⋯ ) coupled nonlinear Schrodinger equations with variable coefficients have been studied via the Darboux transformation, which have been used to describe the interaction among nonlinear optics and other interdisciplinary subjects. Higher-order semi-rational solutions have been attained. As an example, it has been discussed the propagation and interaction of rogue wave and soliton for the 3 coupled nonlinear Schrodinger equations with variable coefficients: one- and two-order solitons with rogue waves have been discussed.

Ultra-short pulse waves in the nonlinear optical fibers can be described by a two-component derivative nonlinear Schrodinger equation (cDNLS). Via theories of ordinary differential equation, general solutions of Lax pairs for cDNLS are attained, so analytic solutions describing different waveforms of cDNLS are obtained by virtue of Darboux transformation. Wave-type conversion is discussed: Fusion and fission of breather are gotten; Breather divide into breather and rogue wave is attained, i.e., breather splits up two breathers while one of which convert to rogue wave; Breather convert to bell shape soliton and rogue wave is obtained; Higher-order rogue-wave-breather is attained.

A series of Cu–Zn–Al–Zr precursor materials are prepared by coprecipitation at different pH values (6.0–11.0) and treated under hydrothermal condition. Zincian malachite is formed as the main phase at the low pH of 6.0 and 7.0, and is replaced by hydrotalcite-like phases with increasing the pH. After calcination and reduction of precursors, Cu/ZnO/Al2O3/ZrO2 catalysts are obtained and tested for methanol synthesis from CO2 hydrogenation at the reaction temperature of 463 K. With increasing pH, the Cu particle size first increases until pH 9.0 and then decreases. Compared with the sample resulting from well-crystallized zincian malachite (pH 7.0), the catalysts derived from phase-pure hydrotalcite-like precursors (pH ≥ 9.0) exhibit lower BET specific surface area and lower specific Cu surface area. In addition, due to the smaller of Cu particle size and the stronger interaction among Cu and ZnO, the catalytic activity for the Cu/ZnO/Al2O3/ZrO2 catalysts via the hydrotalcite-like precursors is higher than that for the catalysts derived from zincian malachite precursors at low reaction temperature. A maximum CH3OH yield of 0.087 g gcat−1 h−1 with the CO2 conversion of 10.7% and the CH3OH selectivity of 81.8% at 463 K and 5.0 MPa is obtained over the Cu/ZnO/Al2O3/ZrO2 catalyst prepared at pH 9.0.

To develop corrosion resistant arches in waterfront protective engineering, basalt fiber reinforced polymer (BFRP) bars and hybrid BFRP-steel bars are applied to build concrete arches to replace traditional steel bars. Four types of arches with different reinforcements were designed and casted for the in-field explosion experiment. The scaled distance changes from 0.542 m/kg1/3 to 0.108 m/kg1/3 for a total of 14 explosion tests. The arches suffer five levels of damage, from none damage, slight damage, medium damage, severe damage and complete collapse, judged from cracks and spalling at the vault. The exploded arches were also compressed quasi-statically to check their residual load carrying capacity, which is obviously reduced by severe spalling. In current experiments, the BFRP bars reinforced arch (BBRA) has comparable or even better blast-resistance than the steel bars reinforced arch (SBRA). A theoretical analysis based on improved finite differential method was proposed to predict the dynamic response of the BBRA. According to the research, BBRAs with excellent corrosion resistance and blast resistance could replace SBRAs in waterfront protective structures.

An integrated low-temperature nitriding process was carried out for Ti6Al4V to investigate its effect on microstructure and properties. The process was designed to enhance the nitriding kinetics in low-temperature (500 °C) nitriding by deformation, and to strengthen Ti6Al4V alloy by dispersion at the same time. Specimens of Ti6Al4V alloy were treated through the process of solid solution strengthening–cold deformation–nitriding at 500 °C. The white nitriding layer is formed after some time and then kept stable, changing little with the deformation degree and time. The effect of aging on substrate is significant. Surface hardness and substrate hardness increase with deformation increasing. The construction was investigated by XRD. The surface nitrides are TiN, Ti2N, Ti4N3–X and Ti3N1.29, and the nitrides in cross-section are Ti3N1.29 and TiN0.3. The wear tests of specimens after nitriding, aging and deformation were carried out, and the test data show that the nitrided pieces have the best wear resistance.

Kaolinite, one of the most ubiquitous clay minerals on the earth, is a hydrated aluminum disilicate with the composition of Al2Si2O5(OH)4, 1:1 dioctahedral and structurally asymmetric layers. This type of lamella mineral provides a platform to create artificially functional materials. Herein, we present a facile approach to prepare the glowing Kaolinites via a stepwise of intercalation of Kaolinite with N-Methyl imidazole (abbr. NMI) and Eu3+/Tb3+ nitrate salts in sequence, which are labeled as K-NMI-Eu and K-NMI-Tb, respectively, and characterized by microanalysis, thermogravimetric (TG), IR spectroscopy, powder X-ray diffraction techniques. Under ultraviolet irradiation, K-NMI-Eu and K-NMI-Tb emit the characteristic luminescence of Eu3+/Tb3+ ion with quantum yields of 25.5% (Eu3+) and 16.3% (Tb3+), respectively. We further fabricated the composite films of K-NMI-Eu with polyvinylidene fluoride (PVDF), K-NMI-Eu@PVDF-X (X = 1, 2, 5 and 10%, representing the mass percentage of K-NMI-Eu in film). The mechanical performances of composite films are almost the same as that of the pure PVDF film even if the X value is up to 10%. K-NMI-Eu@PVDF-10% emits intense red luminescence under ultraviolet irradiation at ambient condition, indicating that K-NMI-Eu is a good ultraviolet-converted-red light material potentially used for the agricultural light conversion film.

The hydrothermal reactions of 5-bromoisophthalic acid (H 2 BIPA) and metal salts in the presence of pyridine (py) result in three new coordination polymers, namely, M(BIPA)(py) 3 [M = Co(II) ( 1 ), Ni(II) ( 2 )] and Zn(BIPA)(py) 2 ·H 2 O ( 3 ), all of which have been characterized by single-crystal X-ray, elemental analysis, infrared spectroscopy, and thermogravimetric analysis. Compounds 1 and 2 are isostructural and contain 2 1 helical chains made up of metal ions and BIPA 2− ligand, the chains are further formed to the supramolecular structures by the π⋯π interactions between the adjacent parallel py rings. Compound 3 has a 1D chiral left-handed helical chain structure. It is notable that 3 is obtained by second order spontaneous resolution using achiral starting materials. Moreover, the solid-state CD spectrum of single crystals and powder samples of 3 is investigated. The nonlinear optical measurement shows that 3 displayed a second-harmonic-generation (SHG) response of 0.7 times that for urea.

Treatment of Ln(NO3)3 · 6H2O with 1, 2-phenylenedioxydiacetic acid (H2PDOA) in ethanol leads to the unusual 1-D double chain complexes {[Ln(PDOA)1.5 (H2O)3] · H2O}n (Ln = Sm (1), Eu (2), Dy (3)), in which the Ln3+ ions are linked by pentadentate and bideatate PDOA ligands in two different directions. The chain looks like a ladder containing two –Ln–O–C–O–Ln– chains and PDOA spacers, which has never been observed in the lanthanide carboxylate complexes, and they exhibit different photoluminescence properties.

A coordination polymer {[Tb 4 (3-SBA) 4 (OH) 4 (phen) 3 (H 2 O) 3 ] · 7H 2 O} n (3-SBA = 3-sulfobenzoate, phen = 1,10-phenanthroline) was synthesized and structurally characterized. The complex contains cubane-like clusters, [Tb 4 (μ 3 -OH) 4 (phen) 3 (H 2 O) 3 ] 8+ , which are further linked through 3-SBA ligands to form a 2-D grid-like network structure with topology of (3 3 , 4 4 , 5 3 ). The complex exhibits strong photoluminescence of the Tb 3+ ion.

Two complexes {[Dy2(4-SBA)3(phen)2(H2O)4] · 2H2O}n (1) and {[Eu2(4-SBA)3(phen)2(H2O)2]}n (2) (4-SBA = 4-sulfobenzoate, phen = 1,10-phenanthroline) were synthesized and their structures were determined by X-ray crystallography. The 1 has a 1-D chain structure by bidentate and tridentate 4-SBA ligands as linkages and 3-D network was formed by strong hydrogen bonds. The 2 has a 2-D network structure by tridentate and tetradentate 4-SBA ligands as linkages. The luminescence properties and thermal stability of the two complexes were investigated.

Apelin is an endogenous depressor peptide for the G protein-coupled APJ receptor. Our hypothesis is that apelin is a venodilator, and it reduces mean circulatory filling pressure (MCFP; index of venous tone). Dose–response curves of apelin (10, 20 and 40 nmol/kg) or vehicle (0.9% NaCl) were constructed in two groups each of conscious, unrestrained rats: unblocked rats and rats pretreated with mecamylamine (Mec; ganglionic blocker) and noradrenaline (NA; to restore vascular tone). The vehicle had no effects in the unblocked or ganglionic-blocked rats. Apelin decreased mean arterial pressure (MAP) and increased heart rate (HR), but it did not alter mean circulatory filling pressure in the unblocked rats. In the ganglionic-blocked rats, apelin did not alter heart rate but decreased mean arterial pressure and mean circulatory filling pressure. These results show that apelin is an arterial and venous dilator in vivo. The depressor effect of apelin is accompanied by tachycardia which is abolished by ganglion blockade.