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In order to study the influence of box subgrade haunching on structural static characteristics of high-speed railway, a more reasonable box subgrade haunching method is found. In this paper, the box subgrade is divided into independent components, and the reinforcement mode of each independent component is calculated through static analysis. ABAQUS software is used for numerical simulation. In view of the stress concentration phenomenon at the connection node between the top plate and the vertical plate of the box subgrade structure, the influence of different haunching heights and angles of the triangular haunch on the stress concentration at the node is studied by using the control variable method, and the optimal haunching mode is proposed to optimize the static characteristics of the box subgrade structure. The analysis results show that when the fixed axillary height is 400 mm and the axillary angle is between 15° ~ 60°, the stress mutation reduction ratio Sr value decreases with the increase of axillary angle; When the axillary angle is between 60° ~ 75°, the Sr value increases with the increase of the axillary angle, and the optimal axillary angle is between 45° ~ 60°. When the axillary angle is fixed at 60°, the Sr value decreases as the axillary length increases, and the optimal axillary length is between 300 ~ 400 mm. The determination of the reinforcement mode and the optimal haunching mode of the box type subgrade is innovative to a certain extent, and provides valuable technical experience for the research of structural optimization of box type Subgrade of high-speed railway in China. [ABSTRACT FROM AUTHOR]

Conduction between the unique geological formation karst collapse pillar (KCP) and the fractures caused by mining in the coal seam floor can lead to catastrophic water inrush disasters in many coalmines in Northern China. It is widely recognized that seepage mutation induced by the migration/loss of KCP fillings (highly broken rocks filling the fractured rocks) happens during occurrence of the KCP-related water inrush. However, roles of fluid path (mining-induced fracture) scale and KCP filling porosity in seepage mutation evolution remain unclear. Here, we conducted seepage tests on natural KCP fillings containing rock particles of different sizes. The filling specimens were deformed to different porosities from 14 to 26% through axial compression, and small to large fluid paths were simulated by seepage plates with distinct pore sizes from 2.5 to 12.5 mm. We found that seepage mutation occurs with significant permeability enhancement by 2 orders of magnitude under a pore diameter of 12.5 mm and a specimen porosity of 26%. There is a strong linear relationship between specimen permeability and Reynolds number (Re) over seepage mutation. The mutation is caused by the sudden collapse of the specimen skeleton and subsequent quick outflow of the particles. Therefore, it is inferred that the KCP-related water inrush is more likely to happen when highly porous KCP fillings are present and mining-induced fractures are well developed. [ABSTRACT FROM AUTHOR]

China is estimated to have 70 million lesbian, gay, bisexual, and transgender (LGBT) people, and in recent decades, the LGBT movement has seen rapid growth. However, because of the unavailability of data, a comprehensive understanding of the degree of regional development of the Chinese LGBT movement has been unavailable. By analyzing keyword search volumes for LGBT-related terms on Baidu (the largest internet search engine in China) from 2009 through 2015, we have produced the first representative and longitudinal portrait of LGBT orientation across the country. Our data revealed that the level of LGBT orientation search index in a province is significantly correlated with modernization and cultural capital stock factors, such as GDP per capita, resident income level, openness to foreign culture, and local cultural infrastructure. [ABSTRACT FROM AUTHOR]

In recent years, research has begun to touch upon the associations between the natural environment and individuals' subjective wellbeing; however, whether such associations would vary among different groups of people remains under‐studied. Using four waves (2010–2013) of data from the Chinese General Social Survey, we investigate the group‐specific correlation between environment—specifically, greenspace exposure—and individuals' happiness in contemporary urban China. For this study, the normalized difference vegetation index at the county level is a proxy for greenspace exposure. The results from the ordered logit model indicate that county‐level green vegetation is associated with individuals' happiness level, but such effects vary with a household's relative deprivation. While greenspace exposure is positively associated with happiness among individuals from less deprived families, it is negatively associated with happiness among those from deprived households. These findings contribute to the body of knowledge of the heterogeneous effect of greenspace on residents' subjective well‐being. [ABSTRACT FROM AUTHOR]

The increasing use of high-voltage transmission wires requires more and more high-voltage pylons, and sometimes, constructing pylons in mining areas is very urgent. To ensure the safe operation of pylons, coal pillars with large side lengths are usually used to provide sufficient support; however, this results in a huge waste of coal. Eight high-voltage pylons are arranged on the ground surface corresponding to the location of working face 1110 of Sima Coal Mine in Shanxi Province, China, which cannot be mined by traditional methods. Taking this as the engineering background, the failure mode of high-voltage pylon is first analyzed. Using FLAC3D numerical simulations, the influence of five different mining plans on ground surface deformation in working face 1110 is evaluated, and the vertical settlement and horizontal deformation in different areas of the ground surface, as well as the variation law of horizontal strain and slope are analyzed. According to the numerical simulation results, the range of thickness-limiting mining or backfill mining in working face 1110 is shown in scheme 3, and the key regions in the mining process are determined. Secondly, the strengthening scheme of high-voltage pylons is designed, that is, the four foundations of high-voltage pylons are connected as a whole with steel supports and steel connectors so as to improve the structural strength of the high-voltage pylon. Finally, the position change in the foundation of high-voltage pylons was monitored for 22 consecutive months. The results show that the maximum settlement of the high-voltage tower foundation is 3.1 m, which is consistent with the actual mining thickness; The high-voltage pylon was stably moved, and the change in transmission line tension and total length was usually less than 1.0%. The combined mining scheme and foundation strengthening scheme can ensure the safe operation of high-voltage pylons and provide a new method for the stability control of ground buildings in coal mining subsidence area. [ABSTRACT FROM AUTHOR]

Abstract Cements and shales play a vital role in the construction and energy sectors. Here, we use a set of advanced NMR methods to characterize the porous networks and dynamics of fluids in hydrated cement and shale samples. We compare the properties of cements from two different manufacturers, BASF and Portland, as well as shales brought from USA and China. 129Xe NMR spectra of xenon gas adsorbed in the samples indicate that the capillary mesopores are smaller and the exchange between free and confined gas is slower in the Portland than in the BASF cement samples. The pores probed by xenon in the shale samples from USA are significantly smaller than in the cement samples, partially in the micropore region. There is a substantial difference in between the 129Xe spectra of shales from USA and China. Whereas the latter show a clear signature of paramagnetic impurities by exhibiting large negative 129Xe chemical shifts (referenced to the free gas), the samples from USA lack the negative chemical shifts but feature large positive shift values, which may indicate the presence of micropores and/or paramagnetic defects. 1H NMR cryoporometry measurements using acetonitrile as probe liquid allowed the observation of mesopores in the shale samples as well, and T 2 - T 2 relaxation exchange experiment enabled the quantification of the exchange rates between free and confined acetonitrile. Graphical abstract Image 1 Highlights • Porous structure of shales and cements was studied by 1H and 129Xe NMR spectroscopy. • Xenon highlights capillary pores in cements and micropores in shales. • NMR cryoporometry reflects mesopore size distribution in shales. • Chemical composition of shales affects the paramagnetic effects. [ABSTRACT FROM AUTHOR]

The inhomogeneity, discontinuity, and elastoplasticity of the rock mass affect the deformation and failure of rock, and it is difficult to describe the stress–strain relationship of the rock mass by traditional constitutive models with a certain mathematical models. In order to address the complex problems caused by multiple variables, firstly, 77 rock specimens were collected from overburden of the working face 1012001 in Yuanzigou coal mine, China. Triaxial compression tests were carried out on these samples, and 673,632 data samples were output. Secondly, based on deep convolutional neural networks (CNN), a CNN-based rock constitutive model (CNNCM) was proposed. The structure and hyperparameters of deep CNN include M , ρ , E d , υ d , σ z , and σ y , as the input features, ɛ z as the output features;Conv2D layers ×4; Max pooling2D layers×4; Dense layers ×4; learning rate_0.001; Epoch_ 200; Batch size_1024; Total params: 160801. Comparing the test results of eleven rock samples with the predicted results of CNNCM, the scope of MAPE and R 2 from 0.52–1.94% and 0.999870–0.999988, which indicates the proposed CNNCM has good performance. The sensibility and correlation of physical parameters were analyzed, and the results show that the correlation of stress, E d , υ d , and ɛ z is strong. Finally, considering the availability and simplicity of CNNCM, a new CNNCM is proposed though replacing the E d and υ d with E and υ , and different input features. The predictive performance of the trained CNNCMs(#6 and #2) is also performs well although the predicted results are worse than CNNCM #0. The different CNNCMs show that E has a great influence on the results and the rank of importance of other five features is E > σ y > υ > M > ρ. This study proposes a machine learning method to describe the stress–strain relationship in the process of the rock failure. [Display omitted] • A CNN was built for machine learning of rock constitutive model. • The CNNCMs reveal the σ – ɛ relationship well in inelastic stages. • Elasticity modulus has the most critical influence on the predicted performance of CNNCM. [ABSTRACT FROM AUTHOR]

Based on a panel of 30 provinces and a timeframe from January 2009 to December 2013, we estimate the association between monthly human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) incidence and the relevant Internet search query volumes in Baidu, the most widely used search engine among the Chinese. The pooled mean group (PMG) model show that the Baidu search index (BSI) positively predicts the increase in HIV/AIDS incidence, with a 1% increase in BSI associated with a 2.1% increase in HIV/AIDS incidence on average. This study proposes a promising method to estimate and forecast the incidence of HIV/AIDS, a type of infectious disease that is culturally sensitive and highly unevenly distributed in China; the method can be taken as a complement to a traditional HIV/AIDS surveillance system.