•The seismic failure behavior of a precast RC frame-shear wall structure using full/half grout sleeve connections is reported.•The different seismic performances of the precast RC frame-shear wall ...structure and cast-in-situ RC frame-shear wall structure are explored.•The seismic behavior of the precast RC frame-shear-wall structure is analyzed by simulation.
To investigate the seismic behavior of precast RC frame–shear wall structures using full/half grout sleeve connections, two RC frame–shear wall structure specimens were constructed and tested under cyclic loadings: the first specimen was a precast RC frame–shear wall structure (Specimen PCFW), and the second specimen was a conventional RC frame–shear wall structure (Specimen RCFW) cast in situ. The seismic performance of Specimens PCFW and RCFW including the failure modes, hysteretic responses, and energy dissipation capacities was investigated. Furthermore, the mechanical behavior of Specimen PCFW was numerically simulated using the OpenSees software. The test results show that the crack distribution of Specimen PCFW is more dispersed than that of Specimen RCFW. In particular, few cracks appear in the area of full/half grout sleeves in Specimen PCFW. However, the damage to the concrete around the half grout sleeves of the side columns in the shear wall of Specimen PCFW in the 1st story was more severe than that in the corresponding region of Specimen RCFW for a less thick concrete cover. Compared to Specimen RCFW, Specimen PCFW exhibits higher lateral bearing capacity, better energy dissipation ability, and slightly lower ductility. In addition, assuming the equivalent principle of rebar area, the mechanical behavior of Specimen PCFW can be effectively simulated using the nonlinear multilayer shell element in the OpenSees software.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper compares the performance of five popular machine learning methods, namely, particle swarm optimization–extreme learning machine (PSO–ELM), particle swarm optimization–kernel extreme ...learning machine (PSO–KELM), particle swarm optimization–support vector machine (PSO–SVM), particle swarm optimization–least squares support vector machine (PSO–LSSVM), and long short-term memory neural network (LSTM), in the prediction of reservoir landslide displacement. The Baishuihe, Shuping, and Baijiabao landslides in the Three Gorges reservoir area of China were used for case studies. Cumulative displacement was decomposed into trend displacement and periodic displacement by the Hodrick–Prescott filter. The double exponential smoothing method and the five machine learning methods were used to predict the trend and periodic displacement, respectively. The five machine learning methods are compared in three aspects: highest single prediction accuracy, mean prediction accuracy, and prediction stability. The results show that no method performed the best for all three aspects in the three landslide cases. LSTM and PSO–ELM achieved better single prediction accuracy, but worse mean prediction accuracy and stability. PSO–KELM, PSO–LSSVM, and PSO–SVM always yielded consistent predictions with slight variations. On the whole, PSO–KELM and PSO–LSSVM are recommended for their superior mean prediction accuracy and prediction stability.
•The performances of machine learning methods depend on the selected evaluation index and reservoir landslide case.•Using single prediction accuracy for evaluating the superiority of machine learning methods may be unreliable.•PSO-KELM and PSO-LSSVM are recommended for their superior mean prediction accuracy and prediction stability.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Geohazards, such as landslides, rock avalanches, debris flow, ground fissures, and ground subsidence, pose significant threats to people’s lives and property ...
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Sawdust, rice husk, and mushroom residues are commonly used as bulking agents during manure composting; this work evaluated their potentiality for enhancing the removal of antibiotics and antibiotic ...resistance genes (ARGs) under a temperature-consistent condition. Results indicated that the addition of all the compost-bulking agents increased antibiotic removal in swine manure with increasing rates of 14.9%–33.4%; however they showed less effect on the reduction of residual antibiotics in chicken manure where fluoroquinolone (FQs) antibiotics are the dominant antibiotics, partly owing to the weak promoting effects of bulking agents on FQs degradation. The addition of bulking agents somehow hindered the reduction of ARGs within swine manure, whereas there were obvious reductions in the total relative abundance of ARGs in chicken manure with bulking agents added. Among the three bulking agents, sawdust was the most efficient enhancer for antibiotic removal in both manures, and rice husk exhibited the best performance on ARGs reduction in chicken manure. The relationship between antibiotics, ARGs and bacteria communities was subsequently delineated. Proteobacteria was proposed to play key roles on the effect of bulking agent addition on antibiotics and ARGs in swine manure. Particularly, the increased Xanthomonadaceae contributed much to the promoted antibiotic degradation as well as the high level of ARGs in swine manure with sawdust added. By contrast, the changes in dominant bacterial families by the addition of bulking agents into chicken manure were not strong enough to effectively enhance antibiotic removal, but largely influenced the ARGs abundance. The large reductions of Paenibacillaceae and Staphylococcaceae by rice husk addition were closely related to the reduced ARGs in chicken manure with rice husk added.
Display omitted
•Bulking agents enhance antibiotics and ARGs removal without affecting temperature.•The effects of bulking agents on antibiotics and ARGs fates vary with manure types.•Sawdust is the most efficient enhancer for antibiotic removal in manures.•Rice husk added into chicken manure effectively reduces ARGs.•Antibiotics degrading and ARGs carrying responders to bulking agents were identified.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The accurate determination of crack initiation stress (CI) is significant for understanding rock deformation and failure. In this paper, a new concept is introduced, namely the relative compression ...strain response (RCSR), which represents the compressive deformation of the rock before dilatancy of the rock is introduced. An RCSR-based method for determining CI is proposed and compared with existing methods, i.e., (1) the volumetric strain (VS) method, (2) the lateral strain (LS) method, (3) the crack volumetric strain (CVS) method, (4) the cumulative acoustic emission hit tangent (CAEHT) method, and (5) the lateral strain response (LSR) method. Data for the comparison are collected from 227 uniaxial compression test and 222 compression test for diverse rock types. The comparison results show that, the CI determined using the proposed method is in good agreement with that determined using the existing methods. The CI values determined using different methods are similar, at approximately 0.5 of uniaxial compressive strength (UCS). The ratio of CI to peak strength (PS) is approximately 0.55 under triaxial compression, which is greater than the CI/UCS ratio. According to the analysis of variance (ANOVA), there is no statistical difference among the existing methods. Compared with the exisiting methods, the proposed method has advantages of avoiding users judgment subjectivity Thus, the RCSR method can be employed to determine the CI under uniaxial and triaxial compression.
•The relative compression strain response (RCSR) method to determine the CI is proposed.•An amount of uniaxial and triaxial compression tests for different rock samples data from the literature were collected.•The CI/UCS ratio in uniaxial compression and the CI/PS ratio in triaxial compression are analyzed.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Geohazard prevention and mitigation are highly complex and remain challenges for researchers and practitioners. Artificial intelligence (AI) has become an effective tool for addressing these ...challenges. Therefore, for decades, an increasing number of researchers have begun to conduct AI research in the field of geohazards leading to rapid growth in the number of related papers. This has made it difficult for researchers and practitioners to grasp information on cutting-edge developments in the field, thus necessitating a comprehensive review and analysis of the current state of development in the field. In this study, a comprehensive scientometric analysis appraising the state-of-the-art research for geohazard was performed based on 9226 scientometric records from the Web of Science core collection database. Multiple types of scientometric techniques, including coauthor analysis, co-citation analysis, and cluster analysis were employed to identify the most productive researchers, institutions, and hot research topics. The results show that research related to the application of AI in the field of geohazards experienced a period of rapid growth after 2000, with major developments in the field occurring in China, the United States, and Italy. The hot research topics in this field are ground motion, deep learning (DL), and landslides. The commonly used AI algorithms include DL, support vector machine (SVM), and decision tree (DT). The obtained visualization on research networks offers valuable insights and an in-depth understanding of the key researchers, institutions, fundamental articles, and salient topics through animated maps. We believe that this scientometric review offers useful reference points for early-stage researchers and provides valuable in-depth information to experienced researchers and practitioners in the field of geohazard research. This scientometric analysis and visualization are promising for reflecting the global picture of AI-based geohazard research comprehensively and possess potential for the visualization of the emerging trends in other research fields.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
•Continuous applications of organic materials increased the C and N fraction content.•Rice straw greatly increased the soil organic C and dissolved organic C content.•Pig manure greatly increased ...soil microbial biomass N and dissolved total N content.
Soil organic carbon (C) and nitrogen (N) pools are the most important soil components, and their characteristics directly or indirectly determine the stability of the soil structure and the soil fertility. Using a rice fields experiment in the coastal areas of Southeast China, how a long-term (10 years) continuous application of organic materials consisting of green manure (Chinese milk vetch), pig manure, and rice straw affected the soil C and N fractions were studied. The results showed that 10-year continuous applications of organic materials to the paddy fields significantly increased the C fraction content in terms of parameters such as the soil organic C (SOC), microbial biomass C (MBC), and active organic C (AOC). It also increased the soil N fraction content, including the soil total N (TN), dissolved total N (DTN), microbial biomass N (MBN), and active N. The rice straw return had the most significant effect in relation to increasing the SOC and dissolved organic C (DOC), with 23.9% and 42.3% increases, respectively, compared to applying chemical fertilizer alone. Organic pig manure had the most significant effect on the soil MBN and DTN, with 49.3% and 50.7% increases, respectively, compared to the application of chemical fertilizer alone. MBC and MBN are the primary components of soil AOC and active N, respectively. The application of organic materials increased the ratio of soil MBC and AOC to SOC, as well as the ratio of MBN, DTN, and active N to the soil TN. Our findings indicated that long-term applications of organic materials could improve and enhance paddy soil fertility and promote increased rice yields.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Active deformation is ongoing in the southeastern margin of the Tibetan Plateau due to the collision of the Indian and Eurasian continents. While large-scale motion of the surface occurs, the nature ...of deformation at depth remains unresolved. We construct new lithospheric seismic anisotropic (radially and azimuthally) and shear-wave velocity models using fundamental-mode Rayleigh- and Love-wave phase velocity at periods of 20–100 s obtained from the ChinArray experiment to constrain the deformation style of the crust and upper mantle in the southeastern margin of the Tibetan Plateau. The results show that the uppermost mantle (Moho-90 km) underneath the Tibetan Plateau and northwestern part of the western Yangtze block are characterized with NE-SW oriented azimuthal anisotropy, prominent slow velocity and negative radial anisotropy (VSH < VSV). We interpret that this seismic pattern reflects the southeastward extrusion of the Tibetan uppermost mantle that may thermally erode the northwestern edge and result in the vertically coherent fabric due to the barriers of the left strong Emeishan large igneous province (i.e., south of the western Yangtze block) dominated by the high shear wave velocities. Low velocity anomaly, N-S trending azimuthal anisotropy, and negative radial anisotropy in the uppermost mantle beneath the eastern Yangtze block are most probably associated with vertical migration of hot mantle material from the lithosphere delamination and/or a branch of the Hainan plume.
•New lithospheric seismic anisotropic (radially and azimuthally) and shear-wave velocity models of the southeastern margin of the Tibetan plateau are constructed using fundamental-mode Rayleigh- and Love-wave phase velocity at periods of 20-100 s obtained from the ChinArray experiment.•The southeastward extrusion of the Tibetan uppermost mantle may thermally erode the northwestern edge of the western Yangtze block and result in the vertically coherent fabric due to the barriers of the left strong Emeishan large igneous province.•Low velocity anomaly, N-S trending azimuthal anisotropy, and negative radial anisotropy in the uppermost mantle beneath the eastern Yangtze block are most probably associated with vertical migration of hot mantle material from the lithosphere delamination and/or a branch of the Hainan plume.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
Overuse of nitrogen (N) fertilizer has led to low N use efficiency (NUE) and high N loss in single rice cropping systems in southeast China. Application of controlled-release urea (CRU) is ...considered as an effective N fertilizer practice for improving crop yields and NUE. Here, field experiments were conducted during 2015–2017 to assess the effects of two CRUs (resin-coated urea (RCU) and polyurethane-coated urea (PCU)) on rice yields, NUE and soil fertility at two sites (Lincheng town (LC) and Xintang town (XT)). Four treatments were established at each site: (1) control with no N application (CK), (2) split application of conventional urea (U, 270 kg N ha
−1
), (3) single basal application of RCU (RCU, 216 kg N ha
−1
), and (4) single basal application of PCU (PCU, 216 kg N ha
−1
). The N application rate in the CRU treatment compared to the U treatment was reduced by 20%. However, the results showed that, compared to split application of urea, single basal application of CRU led to similar rice grain yields and aboveground biomass at both sites. No significant difference in the N uptake by rice plant was observed between the U and CRU treatments at either site. There were no significant differences in the N apparent recovery efficiency (NARE) among the U, RCU and PCU treatments, with the exception of that in XT in 2015. Compared to application of U, application of CRU increased the N agronomic efficiency (NAE) and N partial factor productivity (NPFP) by 17.4–52.6% and 23.4–29.8% at the LC site, and 15.0–84.1% and 23.2–33.4% at the XT site, respectively, during 2015–2017. Yield component analysis revealed that greater rice grain yield in response to N fertilizer was attributed mainly to the number of panicles per m
2
, which increased in the fertilized treatments compared to the CK treatment. The application of CRU did not affect the soil fertility after rice harvest in 2016. Overall, these results suggest that single basal application of CRU constitutes a promising alternative N management practice for reducing N application rates, time- and labor-consuming in rice production in southeast China.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Highly selective binding of basic amino acids, i.e. lysine, arginine, and histidine, by a negatively charged carboxylatopillar5arene (CP5A) is reported. And the complexation behavior of the CP5A host ...towards lysine metabolites including cadaverine (Cad), acetyl-l-lysine (AcLys) and trimethyl-l-lysine (TMLys) is also described.
PDF
