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The development of photocatalytic nano-purifiers with high electrons and holes separation efficiency and high-photocatalytic activity is essential in treating water and air pollution. In this paper, novel nano-purifiers with S-scheme faceted heterojunction created between BiOCl nanosheets (110) facets and TiO2hollow nanocubes (001) facets were successfully fabricated. In nano-purifiers, BiOCl nanosheets are enriched with oxygen vacancies capable of trapping electrons, which synergize with the unique S-scheme faceted heterojunction charge transfer mechanism to facilitate carrier separation and migration to a large extent. Herein, BiOCl(110) nanosheets/TiO2(001) hollow nanocubes nano-purifiers (BTHNs) were significantly enhanced in photocatalytic treatment of water and air pollution and were not inferior to other cleaning agents. The obtained 15BTHNs showed the best photocatalytic purification ability among the same series of products. 15BTHNs could degrade 99.9% of RhB in 70 min, which was 25 times higher than that of pure THNs, and effectively removed 44.8% of NO. Moreover, the reduction rate of Cr (Ⅵ) for 15BTHNs reached 99.9% in 90 min, with a kinetic constant 21.5 times higher than that of pure THNs. Active species trapping experiments revealed that four active species of BTHNs contributed to the RhB oxidation reaction in the following order:·OH>h+>·O2->e-, and the contribution rates of 15BTHNs were 45.0%, 38.0%, 12.3%, and 4.7%, respectively. The appropriate ratios of oxidizing TiO2to reducing BiOCl in 15BTHNs allowed the generated active species to be fully utilized, achieving oxidation-reduction equilibrium as well as improving the photocatalytic efficiency. This work reveals that the S-scheme faceted heterojunction formed in the BiOCl/TiO2nano-purifier was a progressing approach for water and air cleaning.

The Liwu copper–zinc mining area has a complex topographical environment. Using traditional prospecting methods, it is difficult and costly to carry out traditional prospecting research on a large scale. This study used portable X-ray fluorescence (pXRF) spectrometry and hyperspectral imaging for analysing rock samples in the B2ore body of the Liwu copper–zinc deposit. The hyperspectral imaging data and the measured indoor spectral characteristic curve of the same lithological rock have a certain similarity. The absorption or reflection characteristics in the same waveband were similar. The main elements were Cu and Zn in the ore body, Pb which was obviously brought out, and Cd, Sn and Sb which were brought in. It is believed that the mass migration of Cd, Sn, Sb and Pb elements plays an important role in the precipitation and enrichment of Cu and Zn elements. This method can be used to quickly determine element migration. The combination of the two analytical methods of pXRF and hyperspectral analysis, the low requirements of the work site and the fast and efficient characteristics, mean this method has unique advantages in analysing and monitoring environmental pollution, rock and mineral analysing and prospecting.

Ti3+self-doped anatase three-dimensional (3D) TiO2hollow nanoboxes were synthesized viaa topological transformation process involving template participation by a facile one-pot hydrothermal treatment with an ethanol solution of zinc powder and TiOF2. It is worth noting that the 3D TiO2hollow nanoboxes are assembled from six single-crystal nanosheets and have dominant exposure of the {001} facets. It is found from EPR spectra that adding zinc powder is an environment-friendly and effective strategy to introduce Ti3+and oxygen vacancy (Ov) into the bulk of 3D hollow nanoboxes rather than the surface, which is responsible for their enhanced visible photocatalytic properties. The photocatalytic activity was evaluated by measuring the formation rate of hydroxide free radicals using 7-hydroxycoumarin as a probe. The sample prepared with zinc/TiOF2mass ratio of 0.25 exhibited the highest RhB photodegradation activity under visible-light irradiation with a degradation rate of 96%, which is 4.0-times higher than that of pure TiO2. The results suggest a novel approach to construct in-situ3D hierarchical TiO2hollow nanoboxes doped with Ti3+and Ovwithout introducing any impurity elements for superior visible-light photocatalytic activity.

The creep properties of Ni-based bicrystal specimens with low- to medium-angle grain boundaries are investigated at 1100°C and 130?MPa with two misorientation angles prepared by double-seed solidification. Experimental results show that the angle of the grain boundary with respect to the stretching direction has a strong effect on creep life. Molecular dynamics simulations show that the effect of the grain boundary on the neighbouring dislocation density is related to the grain boundary angle. A creep constitutive model with the grain boundary angle and the initial damage rate can be adopted to describe the creep damage evolution. The model is then modified according to the molecular dynamics simulation and experimental results to give more accurate predictions of creep life.

The creep properties of Ni-based bicrystal specimens with low- to medium-angle grain boundaries are investigated at 1100°C and 130 MPa with two misorientation angles prepared by double-seed solidification. Experimental results show that the angle of the grain boundary with respect to the stretching direction has a strong effect on creep life. Molecular dynamics simulations show that the effect of the grain boundary on the neighbouring dislocation density is related to the grain boundary angle. A creep constitutive model with the grain boundary angle and the initial damage rate can be adopted to describe the creep damage evolution. The model is then modified according to the molecular dynamics simulation and experimental results to give more accurate predictions of creep life.

Hierarchical TiO2hollow nanoboxes (TiO2-HNBs) assembled from TiO2nanosheets (TiO2-NSs) show improved photoreactivity when compared with the building blocks of discrete TiO2-NSs. However, TiO2-HNBs can only be excited by ultraviolet light. In this paper, visible-light-responsive N and S co-doped TiO2-HNBs were prepared by calcining the mixture of cubic TiOF2and methionine (C5H11NO2S), a N- and S-containing biomacromolecule. The effect of calcination temperature on the structure and performance of the TiO2-HNBs was systematically studied. It was found that methionine can prevent TiOF2-to-anatase TiO2phase transformation. Both N and S elements are doped into the lattice of TiO2-HNBs when the mixture of TiOF2and methionine undergoes calcination at 400 °C, which is responsible for the visible-light response. When compared with that of pure 400 °C-calcined TiO2-HNBs (T400), the photoreactivity of 400 °C-calcined methionine-modified TiO2-HNBs (TM400) improves 1.53 times in photocatalytic degradation of rhodamine-B dye under visible irradiation (λ> 420 nm). The enhanced visible photoreactivity of methionine-modified TiO2-HNBs is also confirmed by photocatalytic oxidation of NO. The successful doping of N and S elements into the lattice of TiO2-HNBs, resulting in the improved light-harvesting ability and efficient separation of photo-generated electron-hole pairs, is responsible for the enhanced visible photocatalytic activity of methionine-modified TiO2-HNBs. The photoreactivity of methionine modified TiO2-HNBs remains nearly unchanged even after being recycled five times, indicating its promising use in practical applications.

The microstructure of as-cast and as-HIPed (hot isostatic pressed) K403 superalloy was investigated using a scanning electron microscopy (SEM), as component analysis was conducted by energy dispersive x-ray spectrometer (EDS). It was found that the microstructure of the alloy was improved significantly through HIP. Firstly, the microporosity and micropores in as-cast alloy were ameliorated effectively and the morphology of grains tended to be uniform. Moreover, the morphology of carbides at grain boundaries transformed from thread-like to granular. Uppermost, the size, shape and volume fraction of γ′ phase were significantly optimized and γ′ precipitates in two different sizes were generated in matrix. Nanoindentation experiment was then carried out to obtain the nanohardness and elastic modulus of as-cast and as-HIPed K403 superalloy. The results revealed an obvious increase in both nanohardness and elastic modulus after HIP. Conclusions could be drawn from the research that HIP could improve the microstructure of as-cast K403 superalloy, which could enhance the mechanical properties of the alloy positively.