42 research outputs found

    Elastoplastic Solution of Cylindrical Cavity Expansion in Unsaturated Offshore Island Soil Considering Anisotropy

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    An elastoplastic analysis scheme for the cylindrical cavity expansion in offshore islands unsaturated soils considering anisotropy is established. The hydraulic properties and anisotropy caused by stress of unsaturated soils are coupled in an elastoplastic constitutive matrix for unsaturated soil to obtain the governing equations for the cylindrical cavity expansion problem, with an analytical solution that utilizes the original hydro-mechanical state of the soil as the initial conditions. Through a comparative analysis with other analytical solutions, the effectiveness of the new solution is verified. Moreover, the swelling response of the cylindrical cavity expansion in unsaturated soils is examined by systematically analyzing different parameters of the surrounding soil. The findings reveal that the development and rate of anisotropy in normal consolidated soil and over-consolidated soil exert a significant impact on the soil’s mechanical characteristics. Nevertheless, the alteration in the model constant h has little effect on the soil’s mechanical characteristics. The analytical solution introduces anisotropy and broadens the expansion theory of unsaturated soils to yield a more comprehensive theoretical framework for the comprehensive analysis of offshore islands’ unsaturated soils

    Elemental Stoichiometry (C, N, P) of Soil in the Wetland Critical Zone of Dongting Lake, China: Understanding Soil C, N and P Status at Greater Depth

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    Earth’s critical zone is defined as a plant–soil–water system, which covers a wide area and has a large vertical thickness, but the soil elemental stoichiometry characteristics of the critical zone at different depths are still unclear. In this study, the spatial distribution of soil carbon (C), nitrogen (N) and phosphorus (P) in the critical zone of a typical wetland in Dongting Lake, China, and their ecological chemometric characteristics were analyzed. The results indicated that: (1) the average C, N and P contents were 18.05, 0.86 and 0.52 g/kg, respectively, with a decreasing trend from the surface to the deeper layers. The soil is relatively rich in C and P, while N is the main element limiting plant growth and development. (2) The mean values of soil C/N, N/P and C/P were 21.1, 1.7 and 35.4 respectively, with the C/N ratio and C/P ratio showing a trend of increasing and then decreasing in the vertical direction and reaching a maximum at a depth of 2–5 m below ground. (3) According to the correlation results, C, N and P in soils are coupled and influenced by each other (p < 0.001), and pH, infiltration coefficient and human activities are closely related to the spatial distribution of C, N and P. (4) Stable Redfield ratios (1:1.6:35.4) may exist in lake wetland soils, and future studies should be conducted for complete systems of the same type of wetlands. The results of the study will provide a theoretical basis for the sustainable development and scientific management of lake wetlands

    A Detection Method for Pavement Cracks Combining Object Detection and Attention Mechanism

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    Several deep learning techniques have been used to detect pavement cracks for the partial replacement of inefficient traditional inspections. However, the extensively varying real-world situations limit the detection accuracy. While many existing studies utilized the attention modules in pavement crack detection to improve model performance, few studies considered the impact of “how” and “where” to add attention modules on model performance, namely the module optimization. Combined with the attention mechanism, a new pavement crack detection method was proposed based on the You Only Look Once 5th version (YOLOv5) in this paper. Considering two adding ways and three adding positions, the spatial and channel squeeze and excitation (SCSE) module and convolutional block attention module (CBAM) were used to build a total of 12 different attention models for the cracking detection. Each model was trained on 3248 images, and the weight with the best performance on the validation set was saved for testing. The test results show that the [email protected]:0.95 of the best attention model is improved by nearly 6.7% compared to the original model without the attention mechanism. In addition, it can process images at 13.15ms/pic while maintaining 94.4% precision, fully meeting the needs of real-time detection. Compared with the existing pavement crack detection methods, the advantages of the proposed method include a great detection speed, high accuracy, and good robustness

    Application of FRP Bolts in Monitoring the Internal Force of the Rocks Surrounding a Mine-Shield Tunnel

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    Monitoring the internal force of the rocks surrounding a mine-shield tunnel for the initial support of a mine-shield tunnel, in complex geological and hydrological environments, requires bolts with specific features such as high tensile strength, low shear strength, good insulation and resistance to corrosion. As such, internal force monitoring has become an important issue in safety monitoring for such tunneling projects. In this paper, the adaptability of a mine-shield tunnel project in a corrosive environment is investigated. A fiberglass reinforced plastic (FRP) bolt with high tensile strength, low shear strength, resistance to fatigue, non-conductivity and resistance to corrosion is used as a probe in tandem with an anchor-head dynamometer to monitor the internal force of the rocks surrounding a mine-shield tunnel for initial support. Additionally, solar energy collection technology is introduced to create a remote monitoring system. Using a 2.5 km long railway tunnel located in the northeast of the Pearl River Delta of China as a case study, the present study shows that, compared with a conventional steel bolt, the FRP bolt has advantages, such as avoidance of the risks associated with the shield machine, insulation and resistance to corrosion. As a probe, the response of the FRP bolt to events such as a blasting vibration and a construction disturbance that results in internal changes in the surrounding rock demonstrates a clear pattern that is appropriate for monitoring the internal force of the rocks surrounding a mine-shield tunnel in a corrosive environment. FRP bolt-based monitoring not only provides new technological support for controlling the risk involved in the initial support of a mine-shield tunnel but can also be widely deployed in projects with special requirements for disassembly, conductivity and corrosion

    Quality properties and expression profiling of protein disulfide isomerase genes during grain development of three spring wheat near isogenic lines

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    Three wheat glutenin near isogenic lines (NILs) CB037A, CB037B and CB037C were used to investigate their quality properties and the transcriptional expression profiles of PDI gene family during grain development. Our purpose is to understand the relationships between the dynamic expression of different PDI genes and glutenin allelic compositions related to gluten quality. The results showed that glutenin allelic variations had no significant effects on main agronomic traits and yield performance, but resulted in clear gluten quality changes. CB037B with 5+ 10 subunits had higher glutenin macropolymer (GMP) content and better breadmaking quality than CB037A with 2+ 12 while the lack of Glu-B3h encoding one abundant B-subunit in CB037C significantly reduced GMP content, dough strength and breadmaking quality. The dynamic expression patterns of eight protein disulfide isomerase (PDI) genes during grain development detected by quantitative real-time polymerase chain reaction (qRT-PCR) showed the close correlations between higher expression levels of PDI3-1, PDI5-1 and PDI8-1 and the presence of 5+ 10 subunits. Meanwhile, Glu-B3h silence resulted in significant decrease of expression levels of five PDI genes (PDI3-1, PDI5-1, PDI6-1, PDI7-2 and PDI8-1), suggesting the vital roles of certain PDI genes in glutenin and GMP synthesis and gluten quality formation

    Strategy for aesthetic photography recommendation via collaborative composition model

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    In this study, the authors propose a collaborative composition model for automatically recommending suitable positions and poses in the scene of photography taken by amateurs. By analysing aesthetic‐aware features, the authors' strategy jointly takes attention and geometry composition into account to learn the aesthetic manifestation knowledge of professional photographers. Firstly, aesthetic composition representation exploits the strength of visual saliency to explicitly encode the spatial correlation of the professional photos. Secondly, ℓ2 regularised least square is adopted to constrain the representation coefficients, which provides a fast solution in selecting aesthetic candidates collaboratively. In addition, a novel confidence measure scheme is further designed based on reconstruction errors and the reference photos are updated adaptively according to the composition rules. Both qualitative and quantitative evaluations show that the model performs well for the portrait photographing recommendation

    Quality properties and expression profiling of protein disulfide isomerase genes during grain development of three spring wheat near isogenic lines

    No full text
    Three wheat glutenin near isogenic lines (NILs) CB037A, CB037B and CB037C were used to investigate their quality properties and the transcriptional expression profiles of PDI gene family during grain development. Our purpose is to understand the relationships between the dynamic expression of different PDI genes and glutenin allelic compositions related to gluten quality. The results showed that glutenin allelic variations had no significant effects on main agronomic traits and yield performance, but resulted in clear gluten quality changes. CB037B with 5+10 subunits had higher glutenin macropolymer (GMP) content and better breadmaking quality than CB037A with 2+12 while the lack of Glu-B3h encoding one abundant B-subunit in CB037C significantly reduced GMP content, dough strength and breadmaking quality. The dynamic expression patterns of eight protein disulfide isomerase (PDI) genes during grain development detected by quantitative real-time polymerase chain reaction (qRT-PCR) showed the close correlations between higher expression levels of PDI3-1, PDI5-1 and PDI8-1 and the presence of 5+10 subunits. Meanwhile, Glu-B3h silence resulted in significant decrease of expression levels of five PDI genes (PDI3-1, PDI5-1, PDI6-1, PDI7-2 and PDI8-1), suggesting the vital roles of certain PDI genes in glutenin and GMP synthesis and gluten quality formation

    Genetic Mapping and Candidate Gene Prediction of a QTL Related to Early Heading on Wild Emmer Chromosome 7BS in the Genetic Background of Common Wheat

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    Heading date (HD) is an essential agronomic objective in wheat conventional breeding. Field experiments from several years and locations indicated that the chromosome arm substitution line (CASL) of wild emmer chromosome 7BS in the genetic background of common wheat var. Chinese Spring (CS) always showed a substantially earlier HD than CS planted in different seasons; usually about 8 d earlier than CS grown under a normal autumn sowing season. CASL7BS consistently showed a much earlier HD than CS when treated for vernalization under a long or short photoperiod and then grown under a short or long photoperiod in the growth room. CASL7BS showed faster spike development than CS at the stages before the glume stage when grown under long days, and depicted relatively rapid growth at all stages when grown under short days. To map the early gene in CASL7BS, F2 plants from the cross of CASL7BS and CS were planted in the field and growth room, forming two mapping populations (P1 and P2, respectively). According to the HD distribution of P1, the HD was most likely regulated by a dominant gene. A QTL was detected consistently in the distal region of about 8.94 cM flanked by C268 and C309 with LOD scores of 5–8, explaining 9.14 and 12.35% of the phenotypic variation in the two mapping populations. The QTL was further narrowed down to an interval between ZAFU058724 and ZAFU061354 of 58–61 Mb based on the HD and genotype of F3 and F4 families. A total of 41 genes were located in this region, and eleven of them were thought to be the candidate genes based on the gene functions. According to the HD and mapping location, the QTL identified in this study was a new gene associated with flowering, which will be helpful in understanding the mechanism of wheat flowering and for breeding an early wheat variety
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