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Designing and constructing advanced heterojunction architectures are desirable for boosting CO2 photoreduction performance of semiconductor photocatalysts. Herein, we have prepared hierarchical ZnS@ZnIn2S4 core-shell cages with controlled particle sizes using sequential synthesis of Zeolitic imidazolate (ZIF-8) polyhedrons, ZnS cages, and ZnIn2S4 nanosheets on the ZnS polyhedron cages. ZIF-8 polyhedrons are firstly synthesized by a liquid-phase approach. The subsequent sulfidation of the ZIF-8 polyhedrons results in the formation of ZnS polyhedron cages, which act as substrates for fabricating ZnS@ZnIn2S4 core-shell cages by growing ZnIn2S4 nanosheets. The size of ZnS cages can be tuned to optimize CO2 photoreduction performance of hierarchical ZnS@ZnIn2S4 core-shell cages. The synergy of the unique hierarchical core-shell cage-like structure and heterojunction composition endows the hybrid catalyst high incident light utilization, abundant active sites, and effective separation of photoexcited charge carriers. Benefiting from these advantages, the optimized hierarchical ZnS@ZnIn2S4 core-shell cages exhibit enhanced performance for CO2 photoreduction with the CO yield of 87.43 μmol h−1g−1 and 84.3% selectivity, which are much superior to those of single ZnIn2S4 or ZnS. Upon Au decoration, the CO2 photoreduction performance of ZnS@ZnIn2S4 core-shell cages is further enhanced because of the Schottky junctions and surface plasmon resonance effect.

Here, we describe the fabrication of surface oxygen vacancy-enriched ZnFe2O4@TiO2 double-shell hollow heterostructure nanospheres (ZnFe2O4@H-TiO2-x) coupled with spatially separated CoOx and Au-Cu bimetallic cocatalysts. The ZnFe2O4@TiO2 heterojunction and spatially separated dual cocatalysts can significantly promote the separation of photoinduced charge carriers. Combined with the unique hollow double-shell heterostructure characteristics and improved surface state properties, the hybrid nanospheres can efficiently adsorb and activate CO2 molecules. These advantages cause the optimized catalyst to exhibit remarkably higher gas-phase photocatalytic CO2 reduction activity than the control CoOx/ZnFe2O4/Au-Cu and ZnFe2O4@H-TiO2-x double-shell hollow nanospheres loaded with a single cocatalyst. Meanwhile, the Au-Cu bimetal effect boosts the CO2 conversion rate and CH4 selectivity. The optimized hybrid catalyst with a Au/Cu ratio of 1:1 provides a CH4 yield of 21.39 μmol g−1 h−1 with 93.8% selectivity. This work provides a rational photocatalyst design to improve CO2 conversion and CH4 selectivity.

Rational component control and architectural design benefit to charge transport/separation and light absorption of photoelectrochemical (PEC) photoanodes. Here, α-Fe2O3/SnS2 nanorod/nanosheet core/shell heterostructure nanoarrays were fabricated through two steps including the synthesis of α-Fe2O3 nanorod arrays and the subsequent loading of SnS2 nanosheets on the α-Fe2O3 nanorods via a hydrothermal route. The formed hierarchical nanorod/nanosheet core/shell nanostructure makes SnS2 nanosheets have good adhesion to the α-Fe2O3 nanorod array substrate with strong interfacial contact. The optimized α-Fe2O3/SnS2 photoanode exhibited improved PEC performance than the pristine α-Fe2O3 nanorod photoanode due to the accelerated charge separation and increased active sites. Moreover, the decoration of Cu2O nanoparticles further improves the water splitting performance and incident photon to current efficiency. This work delivers a rational strategy to prepare nanostructures with remarkable photoelectrochemical performance.

Brittleness is a crucial parameter of rock mass and the key indicator in rock engineerings, such as rockburst prediction, tunnelling machine borehole drilling, and hydraulic fracturing. To solve the problem of using present brittleness indexes, the existing rock brittleness indexes were firstly summarised in this paper. Then, a brittleness index (BL), which considers the ratio of stress drop rate and stress increase rate and the peak stress, was proposed. This new index has the advantage of simplifying the acquisition of key parameters and avoiding dimensional problems, as well as taking the complete stress-strain curves into account. While applying the BL, the peak strain is used to describe the difficulty of brittle failure before the peak point, and the ratio of stress drop to strain increase can reflect the stress drop rate without dimension problem. In order to verify the applicability of BL, through the PFC2D, the microparameters and confining pressure were changed to model different types of rock numerical specimens and different stress condition. The results show that the BL can well reflect and classify the brittleness characteristics of different rock types and characterise the constraint of confining pressure on rock brittleness. Moreover, the influence of microparameter on macroparameter was studied. In order to further verify the reliability of the brittleness index (BL), this study conducted uniaxial and triaxial compression tests (30 MPa) on marble, sandstone, limestone, and granite under different confining pressure.

Rationally designed architecture and smart components of catalysts can greatly accelerate the hydrogen evolution reaction in photoelectrochemical water splitting. Herein, hierarchical NiS quantum dots decorated CuO nanowires@ZnFe2O4 nanosheets core/shell nanoarrays were prepared by a viable multi-step synthesis approach. First, CuO nanowire arrays were prepared through the thermal treatment of copper mesh. Then, CuO@ZnO core/shell nanowire arrays were prepared via an impregnation-calcination process. Next, the CuO nanowire arrays with different ZnFe2O4 nanosheet contents were prepared through wet chemical reaction and subsequent thermal treatment. The further NiS quantum dots decoration was realized through a chemical bath deposition. The CuO nanowire arrays covered with ZnFe2O4 porous nanosheets not only offer abundant active sites to react with the electrolyte but also improve visible light utilization. Moreover, the hierarchical nanoarray structure provides a direct electron transport pathway with a graded interface for better charge flow. As a result, remarkably enhanced photoelectrochemical performance and excellent cycling stability were obtained for the CuO@ZnFe2O4 nanoarray photocathodes due to the synergistic effects of ideal components and hierarchical nanoarray structure. Additionally, the further NiS decoration makes CuO@ZnFe2O4 exhibit a significantly enhanced photocathodic current density.

Cementation factor and saturation exponent are important indexes for oil reservoirs evaluation. In order to facilitate the quantitative analysis of oil reservoirs accurately, a method of calculating cementation factor and saturation exponent by resistivity was proposed. Taking the silty clay (cohesive soil) samples in Changchun as an example, the resistivity expressions of cohesive soil was derived. Combined with the moisture content, porosity, and resistivity of the samples, the cementation factor and saturation exponent were calculated by multivariate fitting of resistivity formula of silty clay from two boreholes in Changchun. Results revealed that the dispersion of cementation factor and saturation exponent calculated by resistivity method is very small, and R2 of the independent analysis are all above 0.95. The comprehensive analysis showed that it is accurate and simple to determine the cementation factor and saturation exponent by the derived resistivity expression and multiple regression analysis, which provides a theoretical basis for further calculation of oil reservoirs.

Designing and constructing advanced heterojunction architectures are desirable for boosting CO

Fabricating efficient photocatalysts with rapid charge carrier separation and high visible light harvesting is an advisable strategy to improve CO

Brittleness plays an important role in the brittle failure process of rocks, and is also one of the important mechanical properties of rocks and a key indicator in rock engineering such as hydraulic fracturing, tunnelling machine borehole drilling and rockburst prediction. Therefore, aiming at the applicability of the brittleness index, this paper summarizes and analyzes the existing brittleness indices based on different experimental methods. Through analysis, it is found that many of the existing methods have their limitations. On the other hand, the brittleness evaluation method based on the stress s-strain curve makes it easier to obtain key parameters and quantify them. Therefore, this paper also adopts this practically widely used method. It proposes a brittleness index based on the post-peak stress drop rate of the rock stress-strain curve and the difficulty of brittle failure, verifies by the traditional triaxial surrounding rock pressure test the accuracy and superiority of BL and further explores the differences between the brittleness indices B8, B11, B12 and BL. Finally, the brittleness index BL and B13 are further contrasted by the existing experimental data.

Due to the limitation in the prediction of the foundation pit settlement, this paper proposed a new methodology which takes advantage of the grey Verhulst model and a genetic algorithm. In the previous study, excavation times are often the only factor to predict the settlement, which is mainly because the correspondence between real-time excavation depth and the excavation time is hard to determine. To solve this issue, the supporting times are precisely recorded and the excavation depth rate can be obtained through the excavation time length and excavation depth between two adjacent supports. After the correspondence between real-time excavation depth and the excavation time is obtained, the internal friction angle, cohesion, bulk density, Poisson’s ratio, void ratio, water level changes, permeability coefficient, number of supports, and excavation depth, which can influence the settlement, are taken to be considered in this study. For the application of the methodology, the settlement monitoring point of D4, which is near the bridge pier of the highway, is studied in this paper. The predicted values of the BP neural network, GA-BP neural network, BP neural network optimized by the grey Verhulst model, and GA-BP neural network optimized by the grey Verhulst model are detailed compared with the measured values. And the evaluation indexes of RMSE, MAE, MSE, MAPE, and R 2 are calculated for these models. The results show that the grey Verhulst model can greatly improve the consistency between predicted values and measured values, while the accuracy and resolution is still low. The genetic algorithm (GA) can greatly improve the accuracy of the predicted values, while the GA-BP neural network shows low reflection to the fluctuation of measured values. The GA-BP neural network optimized by the grey Verhulst model, which has taken the advantages of GA and the grey Verhulst model, has extremely high accuracy and well consistency with the measured values.

Thermal conductivity is a critical parameter playing an important role in the heat transfer process in thermal engineering and enormous other engineering fields. Thus, the accurate acquisition of thermal conductivity has significant meaning for thermal engineering. However, compared to density test, moisture content test, and other physical property tests, the thermal conductivity is hard and expensive to acquire. Apparently, it has great meaning to accurately predict conductivity around a site through easily accessible parameters. In this paper, 40 samples are taken from 37 experimental points in Changchun, China, and the BPNN optimized by genetic algorithm (GA-BPNN) is used to evaluate the thermal conductivity by moisture content, porosity, and natural density of undisturbed soil. The result is compared by two widely used empirical methods and BPNN method and shows that the GA-BPNN has better prediction ability for soil thermal conductivity. The impact weight is obtained through mean impact value (MIV), where the natural density, moisture content, and porosity are 30.98%, 55.57%, and 13.45%, respectively. Due to high complexity of different parameter on thermal conductivity, some remolded soil specimens are taken to study the influence of individual factors on thermal conductivity. The correlations between moisture content and porosity with thermal conductivity are studied through control variable method. The result demonstrates that the impact weight of moisture content and porosity can be explained by remolded soil experiment to some extent.

Developing integrated photocatalysts with advanced structures and desired components is an effective strategy for promoting solar-to-chemical energy conversion. Herein, a novel sulfur-doped In2O3-CeO2 hollow hexagonal prism with a thin carbon coating (S-C/In2O3-CeO2 HHP) is synthesized by directly pyrolyzing Ce-doped In-Materials of Institute Lavoisier-68 (In-MIL-68) hexagonal prism metal–organic frameworks under N2 atmosphere in the presence of sulfur powder, showing excellent photocatalytic carbon dioxide (CO2) reduction efficiency. This synthetic strategy realizes the regulation of structure, components, and surface defects of the final products. The synergistic effects of hollow porous hexagonal prism structure, In2O3-CeO2 heterojunction, and surface defects exhibit advantageous features for CO2 photoreactions with accelerated transfer and separation of charge carriers, enhanced visible-light utilization and CO2 chemisorption ability, and enlarged catalytic active sites. Benefiting from these advantages, the obtained optimized S-C/In2O3-CeO2 HHP exhibits superior gas phase photocatalytic performance for the conversion of CO2 into CH4 and CO, yielding a CH4 yield of 60.6 μmol g−1h−1 and a selectivity of 92.4% under AM1.5 irradiation without noble metal and organic photosensitizer. This work presents a strategy for the rational design and fabrication of efficient photocatalysts with advanced hollow architectures.

Fabricating efficient photocatalysts with rapid charge carrier separation and high visible light harvesting is an advisable strategy to improve CO2 reduction performance. Herein, hierarchical Co0.85 Se-CdSe/MoSe2 /CdSe cages with sandwich-like heterostructure are prepared to act as efficient photocatalysts for CO2 reduction. In this study, the structure and composition of the final products can be regulated through the cation-exchange reaction in the presence of ascorbic acid. In the Co0.85 Se-CdSe/MoSe2 /CdSe cages, MoSe2 nanosheets function as a bridge to integrate Co0.85 Se-CdSe and CdSe on both sides of the MoSe2 nanosheet shell into a sandwich-like heterostructured catalyst system, which possesses multiple positive merits for photocatalysis, including accelerated transport and separation of photogenerated carriers, improved visible light utilization, and increased catalytic active sites. Thus, the optimized Co0.85 Se-CdSe/MoSe2 /CdSe cages exhibit remarkable visible-light photocatalytic performance and outstanding stability for CO2 reduction with a high CO average yield of 15.04 µmol g-1 h-1 and 90.14% selectivity, which are much higher than those of other control samples including single-component catalysts and binary hybrid catalysts. This study provides a promising way for the design and fabrication of high-efficiency photocatalysts.

Amygdalus triloba (Rosaceae; previously Prunus triloba) is a deciduous, flowering shrub that is widely used in the greening and beautification of lawns, parks and courtyards in China. In late May 2019, a leaf spot disease of A. triloba was observed on approximately 35% of plants in the Xinjiang Alaer city (40˚33'20''N, 81˚17'19''E). The disease symptoms began as small, suborbicular, brown spots on the leaves. As the disease progressed, the spots enlarged and coalesced into large necrotic areas and resulted in premature defoliation. Leaf sections (5 x 5 mm) from infected leaves were surface - sterilized with 75% ethanol for 30 s and 0.1% HgCl2 for 1 min, rinsed three times in sterile distilled water and then incubated on potato dextrose agar (PDA). Fifteen fungal isolates showing similar morphological characteristics were obtained by single-spore isolation. On the PDA plates, all fungal colonies had a dark olive color with loose, cottony mycelium. On the potato carrot agar, the fungus formed unbranched spore chains, but occasionally formed one or two lateral branches. Conidiophores were short, hazel-colored, septae, arising singly, and measuring 15.1 to 61.8 × 1.8 to 4.2 µm (35.2 ± 1.4 × 2.3 ± 0.1 µm, n = 50). Mature conidia were ellipsoidal to ovoid with a short conical beak at the tip, light brown with zero to three longitudinal septa and one to five transverse septa, and measuring 19.3 to 30.8 × 7.2 to 12.5 µm (21.8 ± 0.3 × 9.5 ± 0.2 µm, n = 50). Based on the cultural and morphological traits, the pathogen was preliminary identified as Alternaria tenuissima (Simmons 2007). Genomic DNA was extracted from the representative isolate YALAR-1, and the internal transcribed spacer (ITS) region, the partial coding sequence of endopolygalacturonase (endoPG), the glyceradehyde -3- phosphate dehydrogenase (GAPDA), the partial region of the histone 3 (H3) genes were amplified using primers ITS1/ITS4 (White et al. 1990), PG2b/PG3a (Andrew et al. 2009), GDF1/GDR1 (Berbee et al. 1999) and H3-1a/H3-1b (Glass and Donaldson 1995), respectively. The amplicons were sequenced and deposited in GenBank [MT459807 (ITS), MT459808 (endoPG), MT459805 (GAPDA), MT459806 (H3)]. MegaBLAST analyses revealed that our ITS, endoPG, GAPDA, and H3 sequences were 99-100% identical to those of A. tenuissima isolates in GenBank [AF347032 (ITS), KP124026 (endoPG), AY278809 (GAPDA), KF997086 (H3)], confirming the identity of the pathogen as A. tenuissima. Pathogenicity tests were performed by inoculating the fungus onto healthy, mature leaves of A. triloba in the field. Twenty five leaves (five leaves/plant) were sprayed with spore suspensions (1 × 106 spores/ml) of each fungal pathogen, and the same number of leaves were sprayed with distilled water as controls. Inoculated and control leaves were covered with clear plastic bags for 3 days. The experiment was repeated three times. Twelve days after inoculation, the observed symptoms were similar to the original symptoms and the same fungal pathogen was reisolated from the inoculated leaves and identified as A. tenuissima based on morphological features and sequence analysis. The control leaves remained asymptomatic and no fungus was isolated from these leaves. Previously, a leaf spot of A. triloba caused by Alternaria brassicae was reported in Dalian, China (Xie et al. 2017). In order to control this disease effectively, further studies are needed on the biology and ecology of A. tenuissima and A. brassicae respectively. To our knowledge, this is the first report of A. tenuissima associated with leaf spot disease on A. triloba in China. In late September 2020, the diseased plant rate increased to 38% in Alaer city. If the disease control and prevention is neglected, the landscape of Alaer city will be affected seriously. So, in order to effectively control the spread of the disease, it is urgent now to study the sensitivity of pathogen to fungicide and carry out the field efficacy trials. References: Andrew, M., et al. 2009. Mycologia. 101:95. Berbee, M. L., et al. 1999. Mycologia. 91:964. Glass, N. L., and Donaldson, G. C. 1995. Appl. Environ. Microbiol. 61:1323. Simmons, E. G. 2007. Alternaria: An Identification Manual. CBS Fungal Biodiversity Centre, Utrecht, The Netherlands. White, T. J., et al. 1990. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Xie, Y., et al. 2017. Liaoning Agricultural Sciences. 6: 73.

As the important part of historical relics, ancient architectural sites contain an amount of cultural information, which are of great significance for the future development of mankind. But improper prospection methods will lead irreversible damage to the existing architectural sites. Therefore, appropriate detection methods have significant meaning in archeological prospection and cultural relic protection. At present, there are many methods to explore ancient architectural sites, among which three-dimensional electrical resistivity tomography (ERT) methods are gradually popularized, because of its advantages of non-destructive, high efficiency, economic and deep prospection. But there are too many electrode arrays, such as Wenner array, Schlumberger array, dipole-dipole array and pole-pole array. First, this paper briefly introduces the application status of ERT. Then, a simple geoelectric model is constructed, and the inversion results are obtained with different arrays. The comparison of the inversion results for 4 electrode arrays shows that the dipole-dipole array gives the highest resolution. And, a more complex geoelectric model is constructed and compared with the results of the inversion. The results show that conclusions have a good consistency. And, this paper shows that Wenner method and Schlumberger array have high resolution in archeological prospection.

In order to test the performance of the LVIB-15 self-propelled light electro-hydraulic servo vibrator developed by Jilin University, a comparative test was conducted on different excitation conditions of a hard pavement and sandy road in Chaganhua town, Jilin Province, China. The optimum scanning frequency was determined by comparing different scanning frequencies. And seismic exploration with a length of 1.2 km was completed. The results show that the reflections were very clear and had good consistency. The signal-to-noise ratio of seismic signal was very high, reaching a reflector of 1400 ms, proving that the seismic data of vibroseis had high accuracy and reliable results and it meets the demand of geophysical prospecting.