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The risk of coal mine gas explosion seriously threatens the continuous safe production of coal mines, which in turn affects the national energy security, so it is important to prevent and control the coal mine gas risk. Current risk assessment methods are difficult to fully express the uncertainty in the assessment process, and calculating index weights is easy to deviate from reality. This study introduces Decision-making Trial and Evaluation Laboratory (DEMATEL) as well as the cloud model, and proposes a new coal mine gas explosion risk assessment model based on cloud integrated similarity and fuzzy DEMATEL. The model fully expresses the uncertainty in the whole risk assessment process and makes the index weights assignment more reasonable. It also combines the calculation of cloud integrated similarity to more accurately determine the risk level based on the advantage that the cloud model can visually display the risk status of the assessment object. An example study was conducted on a mine of a large state-owned coal mine enterprise in Shaanxi Province, China. The results show that the method helps coal mine enterprises to accurately assess gas explosion risks, identify weak links in risk prevention and control, and provide a powerful means for continuous improvement of risk management level. [ABSTRACT FROM AUTHOR]

[Display omitted] • A lightweight 3D CNN for MPM is proposed, which adopts the inception structure of GoogleNet and combines the idea of end-to-end learning. • The 3D geophysical and geological models are used to facilitate the ore-controlling representation. • The predicted results between the WofE and our proposed 3D CNN method for MPM are compared. With the continuous exploitation of surface and shallow mineral resources, the global demand for concealed ore deposit exploration is increasing. However, concealed mineral prospectivity modeling (MPM) requires significant efforts, particularly in terms of methods and technologies for three-dimensional modeling. In this study, we propose a lightweight three-dimensional convolutional neural network (3D CNN) for MPM, which adopts the inception structure of GoogleNet and combines the idea of end-to-end learning. We replace the fully connected layer in the conventional CNN with deconvolution, which can greatly reduce the required parameters during the training process and accelerate the convergence. The proposed method overcomes the disadvantage that other shallow machine learning methods cannot extract spatial neighborhood information, while it can extract cross-correlations among geological factors and generates less parameters by a lightweight network when facing massive data. Additionally, compared with the patch-wise method commonly used in previous studies, we use the pixel-wise method for end-to-end learning, which not only overcomes the drawbacks of random sampling but also considers the influence of each voxel when calculating the loss function. The three-dimensional multi-source geoscientific characteristics obtained from the geophysical inversion and 3D geological models are not discretized in order to promote effective CNN training while facilitating the ore-controlling representation. Comparing the predicted results between the 3D weight of evidence (WofE) and our proposed 3D CNN method for MPM, our proposed method and WofE delineated 100% of the known mineralization in high-favorability areas with voxel numbers of 70% and 95%, respectively. A case study of a structure-controlled hydrothermal gold deposit in the Sanhetun area of Heilongjiang Province demonstrates that the proposed 3D CNN method performs better than WofE in terms of prediction effectiveness and efficiency and effectively reveals the correlation between mineralization and adjacent ore-controlling characteristics. Moreover, the proposed 3D CNN method can simulate non-linear metallogenic processes and mine hidden relationships to reveal complex ore-controlling characteristics. In conclusion, the proposed 3D CNN method can reduce the exploration effort in 3D MPM, thus greatly improving the efficiency of discovering concealed ore deposits. [ABSTRACT FROM AUTHOR]

• The detailed design of the back supporting structure (BSS) of CFETR WCCB blanket has been presented. • Heat transfer Thermal-hydraulic analysis of the BSS has been carried out based on a global model of BSS and the attachment. • Mechanical assessment of the BSS and the attachment has been performed and results can meet the design requirements. China Fusion Engineering Test Reactor (CFETR) is a key step to realize the future demonstration fusion power plant and plays an important role in the roadmap of magnetic confinement fusion development in China. As an important in-vessel component, CFETR blanket back supporting structure (BSS) bridges the blanket modules onto the vacuum vessel, withstanding the gravity and electromagnetic loads and distributing the coolant into blanket modules. This paper presents the preliminary design of BSS for the CFETR WCCB blanket and the detailed design of the attachments between BSS and Vacuum Vessel. Based on the proposed design, a global model of BSS and the attachment for one sector has been established with ANSYS code. The thermal-hydraulic analysis has been conducted to assess the heat exchange and temperature distribution. The analyses of individual load conditions and the coupling analysis have been carried out to obtain the stress distribution and deformation. Based on the analyses results, the corresponding design targets and criterion have been met, indicating the feasibility of current BSS and the attachment design. The design and analyses of the BSS together with the attachments can not only provide good reference for the VV design but also provide guidance for design of flexible support used in the blanket pipe system. [ABSTRACT FROM AUTHOR]

In the context of global climate change, droughts pose a serious threat to agricultural development and food security. Assessing the vulnerability and risk of regions to drought is important for its prevention. In this paper, to understand the vulnerability of maize to drought in different regions of China and quantify its risk, 241 prefecture-level administrative regions (including prefecture-level cities, autonomous prefectures, prefectures, and leagues) in the five main maize-growing regions of China are used as study area. By using a method of global sensitivity analysis, the extended Fourier amplitude sensitivity test (EFAST), we chose two parameters that are most sensitive to maize yield to calibrate the AquaCrop model. We then used it to simulate the water stress of maize in the study area under different irrigation scenarios as well as the corresponding production. We defined the drought hazard index (DHI) as the daily average of the crop water stress indicator during the growing season, and used it to describe the intensity of droughts. Vulnerability curves (the function of the DHI and rate of yield loss) of the entire growth season and various stages of growth were also formulated. These were used to determine the loss of maize yield under four levels of risk (return periods of 5, 10, 20, and 50 years). The results showed the following: 1) the vulnerability curve of maize for the entire growing season was consistent with logistic function, and the coefficient of determination of the equation of regression was R 2 = 0.93. The rate of yield loss began increasing rapidly once the DHI had reached 0.2 and approached its maximum value when the DHI was 0.6. 2) The coefficients of determination of the results of regression in 14 scenarios, in which drought had occurred in different stages of growth, were between 0.28 and 0.92. Drought from the tasseling stage to the milk stage had the most significant negative effect on the maize yield, followed by the seventh leaf stage to the tasseling stage and the sowing stage to the seventh leaf stage. Drought from the milk stage to physiological maturity had the least negative effect on the maize yield. 3) Under all four risk levels, the DHI and the yield loss rate of maize in China decreased from the northwest to the southeast. The Northwest Irrigated Maize Region had the highest drought risk among the five maize-growing regions, followed by the North Spring Maize Region, the Huang-Huai-Hai Summer Maize Region, the South Hilly Maize Region, and the Southwest Mountain Maize Region. 4) The DHI calculated by the average method was more representative than that calculated using the accumulative method. Unlabelled Image • A new drought hazard index was proposed for building drought loss curves. • Drought vulnerability curves were built for five main maize-growing regions in China. • Yield loss curves of maize were built for droughts occurred in various growth stages. • Risk of maize yield loss for return periods of 5, 10, 20, and 50 years were assessed. • The drought risk of maize in China decreases from northwest to southeast. [ABSTRACT FROM AUTHOR]

Highlights • Cyclic tests were carried out based on the first rocking bridge in China. • Buckling-restrained plates were adopted to enhance its seismic performance. • Improved force-displacement model considering the compression depth was proposed. Abstract Seismic resilient structures with low structural damage and self-centering behavior after an earthquake are focus issues of current earthquake engineering. Unbonded pretensioned rocking columns offer advantages for accelerated bridge construction in seismic regions, which utilize column-uplifting mechanisms, high strength post-tensioning, and replaceable energy dissipation devices to enhance seismic performance and resilience. The experiment of three 1:3 scale unbonded, post-tensioned rocking bridge bents with different types of external replaceable energy dissipation devices subjected to quasi-static loading protocols, were carried out according to practical engineering demand in high-intensity earthquake regions. An improved analytical model was proposed for predicting the force-displacement relationship of the post-tensioned rocking bridge bent systems considering the neutral axis depth. Minimal physical damage was observed for the post-tensioned rocking bridge bent systems, which exhibit good energy dissipation and self-centering behavior. Especially, the external replaceable buckling-restrained plates dissipaters can be easily replaced if severely damaged subjected to higher than expected ground motions. The satisfactory analytical and experimental comparisons are presented as a validation of the reliability for the high-performance seismic-resistant bridge bent systems and the modelling techniques in this study. [ABSTRACT FROM AUTHOR]

Highlights: [•] The basic chromosome of Zingiber officinale was x =11, at least for the Chinese ginger. [•] The natural occurrence of a 2x-4x mixploid in ginger was found. [•] Phenotypic alterations occurred in response to changes in ginger ploidy level. [•] Single finger mass of Z. officinale was used as a key morphological character to distinguish mixploid from diploid. [•] A simple and convenient method of screening for mixploid in Z. officinale is available. [Copyright &y& Elsevier]

Deformation and failure of rocks under the loading effect is an energy-driven progressive process of damage evolution, and the abrupt energy release from rocks storing strain energy under high geostress conditions is a determinant inducing catastrophic effects. Therefore, studying the progressive fracture mechanism of rocks from the perspectives of energy accumulation and dissipation contributes to prediction and evaluation of catastrophic effects such as a rockburst. Fractured samples with different fracture dip angles were prepared using granite collected from the underground powerhouse (under maximum geostress of about 37.82 MPa) in Shuangjiangkou Hydropower Station in Dadu River Basin in China. By using these samples, the progressive failure characteristics and energy accumulation and evolution in fractured rocks during triaxial loading were studied under different stress conditions. In addition, the functional relationships of the crack initiation strength, damage strength, and peak strength of the fractured granite with the confining pressure and fracture dip angle in the loading process were established. The evolution of volumetric strain upon cracking corresponding to the peak stress with the confining pressure and fracture dip angle was discussed. Furthermore, the research explored the intrinsic relationships between the acoustic emission (AE) events and mechanical characteristics of the fractured granite during fracturing thereof. The correspondence of the AE count rate and cumulative energy count with various stages in the progressive failure of the rock was studied, and the evolution of the elastic strain energy and dissipated energy in the rock can be predicted based on the strength, deformation, and AE characteristics. Besides, effects of the confining pressure and the dip angle on the AE characteristic signals were investigated. Finally, the accumulation and evolution of the input energy, elastic strain energy, and dissipated energy of fractured granite in the pre-peak stage during triaxial loading were revealed using an energy analysis. Moreover, the relationships of the eigenvalues of elastic strain energy and dissipated energy of fractured granite with the confining pressure and fracture dip angle were determined. [ABSTRACT FROM AUTHOR]

• Seismic behavior of 1:3-scale UHPC-filled column-to-footing socket connection. • The difference of the cyclic response between the precast column and CIP column. • A FEM to consider the rotation effect of the column embedded in the footing. Accelerated bridge construction (ABC) has been paid great attention in China for the significant advantages compared with cast-in-place (CIP), such as higher construction speed, less environmental impact and structural members of higher quality. However, the reliability, durability and seismic behavior of the connection between prefabricated bridge column and the rest of the structure are primary factors that limit the application of the ABC in the moderate and high seismic zones. In this study, quasi-static experimental investigation of seismic performance of three 1:3-scale ultra-high performance concrete (UHPC)-filled socket reinforced concrete (RC) column-foundation connection specimens were conducted. A fiber-based finite element model is developed considering the rotation effect of the column embedded in the footing. The seismic behavior of the precast column specimens with UHPC-filled socket connection type was compared with that of CIP specimen. The experimental and numerical results show that the damage evolution, failure modes and hysteretic responses of the precast bridge column are equivalent with those of the CIP bridge column. Numerical analysis also validated that the finite element model(FEM) in this paper is adequate to predict seismic response of the precast column with UHPC-filled socket connection. The UHPC-filled socket connection is a reliable connection type in prefabricated column-foundation connection joint which is suitable for moderate and high seismic regions. [ABSTRACT FROM AUTHOR]

• Investigate and evaluate the ripple effect of WCCB blanket on TF ripple in CFETR. • CFETR TF ripple generated by WCCB blanket has been calculated. • Potential methods for reducing the TF ripple are studied in this paper. China Fusion Engineering Test Reactor (CFETR), the next fusion device in China, is proposed to bridge the gaps between ITER and the demonstration reactor (DEMO). The Water Cooled Ceramic Breeder (WCCB) blanket, one candidate option of breeding blanket conception for CFETR, impacts the toroidal field (TF) ripple in CFETR, as the reduced activation ferritic/martensitic (RAFM) steel was used as its structure material. The purpose of this paper is to investigate and evaluate the ripple effect of WCCB blanket on TF ripple in CFETR. An analysis is performed using three-dimensional finite element model with 16 TF coils and WCCB blanket modules. ANSYS code is employed for this study. The results indicated that the TF ripple was less than 0.5% at all points in target separatrix when it was estimated with TF coils only. We also calculated TF ripple in case of WCCB blanket modules and various port configuration schemes. It is found that TF ripple cannot meet the design requirements by the presence of WCCB blanket modules, even in difference port configuration. Discussions are made on the implication of the WCCB blanket modules and ports on TF ripple. Potential methods for reducing the TF ripple are studied in this paper. [ABSTRACT FROM AUTHOR]

Forest ecosystems play an increasingly important role in the global carbon cycle. However, knowledge on carbon exchanges, their spatio-temporal patterns, and the extent of the key controls that affect carbon fluxes is lacking. In this study, we employed 29-site-years of eddy covariance data to observe the state, spatio-temporal variations and climate sensitivity of carbon fluxes (gross primary productivity (GPP), ecosystem respiration (R eco ), and net ecosystem carbon exchange (NEE)) in four representative forest ecosystems in Yunnan. We found that 1) all four forest ecosystems were carbon sinks (the average NEE was − 3.40 tC ha − 1 yr − 1 ); 2) contrasting seasonality of the NEE among the ecosystems with a carbon sink mainly during the wet season in the Yuanjiang savanna ecosystem (YJ) but during the dry season in the Xishuangbanna tropical rainforest ecosystem (XSBN), besides an equivalent NEE uptake was observed during the wet/dry season in the Ailaoshan subtropical evergreen broad-leaved forest ecosystem (ALS) and Lijiang subalpine coniferous forest ecosystem (LJ); 3) as the GPP increased, the net ecosystem production (NEP) first increased and then decreased when the GPP > 17.5 tC ha − 1 yr − 1 ; 4) the precipitation determines the carbon sinks in the savanna ecosystem (e.g., YJ), while temperature did so in the tropical forest ecosystem (e.g., XSBN); 5) overall, under the circumstances of warming and decreased precipitation, the carbon sink might decrease in the YJ but maybe increase in the ALS and LJ, while future strength of the sink in the XSBN is somewhat uncertain. However, based on the redundancy analysis, the temperature and precipitation combined together explained 39.7%, 32.2%, 25.3%, and 29.6% of the variations in the NEE in the YJ, XSBN, ALS and LJ, respectively, which indicates that considerable changes in the NEE could not be explained by variations in the temperature and precipitation. Therefore, the effects of other factors (e.g., CO 2 concentration, N/P deposition, aerosol and other variables) on the NEE still require extensive research and need to be considered seriously in carbon-cycle-models. [ABSTRACT FROM AUTHOR]

Furrow irrigation, which can be combined with fertilisation by dissolving solid fertilisers in irrigation water, is the most common practice in vineyards in the Ningxia Hui Autonomous Region, and drip irrigation and fertigation have been employed in some areas. These irrigation methods and their corresponding fertilisation schemes may affect nitrous oxide (N 2 O) emissions from the soil. Therefore, it is important to use a model to simulate differences in N 2 O emissions and identify farmland management methods that limit N 2 O emissions. During the July–August 2012 and July–September 2013 growing seasons, the denitrification and decomposition (DNDC) model was tested against experimental N 2 O emissions data from vineyards in Yuquanying, Yongning, Yinchuan, Ningxia. After model validation, the simulated differences in emissions between furrow irrigation and drip irrigation were 9.86 ± 0.845 and 0.966 ± 0.464 kg ha −1 a −1 in 2012 and 2013, respectively. Thus, the emissions were reduced by approximately 72.5% and 52.4% in 2012 and 2013. In the regional simulation, the Global Warming Potential (GWP) of the annual N 2 O emission reductions reached 27,749,760 ± 5,489,160 kg CO 2 -equivalents after the vineyards in the Ningxia Autonomous Region were converted from furrow irrigation to drip irrigation. In conclusion, the DNDC model, which proved to be a powerful tool for addressing the efficacy of alternative management practices in vineyards, revealed that N 2 O emissions can be reduced by adopting drip irrigation systems rather than traditional furrow irrigation systems. [ABSTRACT FROM AUTHOR]

• A framework for analyzing the tropical-cyclone-induced flutter failure reliability of long-span bridges is developed. • Uncertainties of bridge dynamic characteristics and aerodynamic parameters are quantified. • The tropical-cyclone-induced wind hazard curve of at the height of the bridge deck is achieved. • The tropical-cyclone-induced flutter failure reliability of a suspension bridge is investigated. Continuously growing number and span length of long-span bridges in coastal region of China require a robust aeroelastic design to against the tropical-cyclone (TC) -induced flutter instability. Instead of using the deterministic approach, this study presents a Monte-Carlo-technique-based framework to analyze the flutter reliability of a long-span suspension bridge subjected to TC winds. A limit state function formulated as the difference between the flutter capacity and the extreme gust wind, termed as the product of a random gust factor and the TC mean wind hazard is employed. The flutter fragility curve in terms of the critical wind speed is derived using 2D and 3D flutter analysis models accounting for the structural modal and damping randomness as well as experiment-induced errors of aeroelastic flutter derivatives. The TC wind hazard curves at the height of the bridge deck described as the probability of exceedance at any given years of interest versus the extreme 10-min mean wind speed are estimated through generating a large quantity of synthetic tracks around the bridge site. The probabilistic solutions of the gust factor associated with any gust duration of interest are determined utilizing the statistics of observed TCs coupled with a theoretical model. The TC-induced flutter failure probabilities of present bridge are then predicted in different combinations of gust duration, surface roughness length and flutter analysis models, which enables the assessment of flutter risk subjected to TC winds as compared to code-suggested target reliability indices. The present reliability analysis provides some basic information to assist and enhance the flutter-resistant design of long-span bridges due to TC winds during the preliminary stage. [ABSTRACT FROM AUTHOR]

Based on Quick Bird satellite image data, the present study examined small-scale herbaceous community patches in the marsh of the Sanjiang Plain and measured patch characteristics such as the area, perimeter and shape by GPS. The coenological characteristics of the patches were investigated using quadrat method, and the vascular plant species were recorded using transect method. A total of 219 plant species were recorded, which represents 12.2% of the vascular flora in Heilongjiang Province. Our results showed that species number S correlated with patch area and perimeter; richness index (R) correlated with patch perimeter; Simpson index (D) correlated with patch area and perimeter/area; Shannon-Wiener index (H′) correlated with patch area, perimeter and perimeter/area; Evenness index (Jsw) correlated with perimeter/area. Both S and R have significant difference between different size of patches. Plant diversity in the small-scale herbaceous communities tended to increase with the patch area and perimeter. We concluded that edge effects and the habitat heterogeneity of the patches are important in determining the number of species. The relative smoothness of the patch edges also affects the plant diversity of the patches. The richness of plant species in the marsh in the Sanjiang Plain is highly sensitive to the small-scale patches, which continues to play an important role in preserving plant diversity in the local area. [ABSTRACT FROM AUTHOR]