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Purpose: Natural disasters profoundly influence agricultural trade sustainability. This study investigates the effects of natural disasters on agricultural production imports in China within 2002 and 2018. This exploration estimates the mediating role of transportation infrastructure and agriculture value-added and the moderating role of government effectiveness and diplomatic relations. Design/methodology/approach: This investigation uses Probit, Logit, Cloglog and Ordinary Least Squares (OLS) models. Findings: The results confirm the mediating role of transportation infrastructure and agriculture value-added and the moderating role of government effectiveness and diplomatic relations in China. According to the findings, natural disasters in trading partners heighten the risk to the agricultural imports. This risk raises, if disasters damage overall agricultural yield or transportation infrastructure. Moreover, governments' effective response or diplomatic ties with China mitigate the risk. Finally, the effect of disasters varies by the developmental status of the country involved, with events in developed nations posing a greater risk to China's imports than those in developing nations. Originality/value: China should devise an early warning system to protect its agricultural imports by using advanced technologies such as data analytics, remote sensing and artificial intelligence. In addition, it can leverage this system by improving its collaboration with trading partners, involvement in international forums and agreement for mutual support in crisis. [ABSTRACT FROM AUTHOR]

Although the literature has assessed the impact of Intellectual property protection on urban innovation, there is still a gap in the assessment of the impact of green innovation at the firm level. This study constructs a multi-period differences-in-differences (DID) model using China's Intellectual Property Demonstration Cities (IPDC) as a quasi-natural experiment to investigate the impact of IPDC on corporate green innovation. The findings indicate that (1) the IPDC program significantly stimulates corporate green innovation and has long-term effects. This finding still holds after using PSM-DID as well as robust IW estimators. (2) Mechanism analysis suggests that IPDC can promote firms' green innovation by reducing R&D spillover losses and alleviating financing constraints. (3) Heterogeneity tests show that the IPDC program has a more significant promotion effect on small, state-owned, growth-stage firms. Based on the above findings, this study provides policy implications for enhancing intellectual property protection to stimulate corporate green innovation. [ABSTRACT FROM AUTHOR]

Background: This study aimed to elucidate the characteristics of symptom network of childhood trauma (CT) and sleep disorder (SD) in Chinese adolescents, with the influence of depressive symptoms taken into account. Method: A total of 1301 adolescent students were included, and their CT, SD and depressive symptoms were measured using the Pittsburgh sleep quality index (PSQI), the Childhood Trauma Questionnaire-Short Form (CTQ-SF), and The Patient Health Questionnaire-9 (PHQ-9), respectively. Central symptoms and bridge symptoms were identified based on centrality indices and bridge centrality indices, respectively. Network stability was examined using the case-dropping procedure. Results: In CT and SD symptom network, emotional abuse and sleep quality symptoms had the highest centrality values, and two bridge symptoms, i.e., emotional abuse and sleep disturbance symptoms, were also identified. In symptom network for CT, SD, and depressive symptoms, sleeping difficulty symptoms, daily dysfunction symptoms, and emotional abuse appeared to be potential bridge symptoms. In symptom network of CT, SD, and depressive symptoms (excluding the symptom of sleeping difficulty), daily dysfunction symptoms, emotional abuse, and sleep disturbance symptoms appeared to be bridge symptoms. Conclusions: In this study, emotional abuse and poor sleep quality were found to be central symptoms in the CT-SD network structure among Chinese adolescent students, with daytime dysfunction as the bridge symptom in the CT-SD-depression network structure. Systemic multi-level interventions targeting the central symptoms and bridge symptoms may be effective in alleviating the co-occurrence of CT, SD and depression in this population. [ABSTRACT FROM AUTHOR]

Coalbed methane (CBM) development requires dewatering until the reservoir pressure is less than the critical desorption pressure. Significant quantities of CBM in China are buried >1000 m deep. Therefore, the desorption characteristics of deep CBM reservoirs must be investigated for the further development of deep CBM. In this study, the variation laws of adsorbed and free CH4 during adsorption in dry samples and during desorption via dewatering are investigated using nuclear magnetic resonance. During CH4 adsorption in dry samples by increasing CH4 pressure and during CH4 desorption in water-injected samples by dewatering, a Langmuir relationship exists between the volume of adsorbed CH4 and the pressure in deep and shallow coals, and the volume of free CH4 and the pressure are linearly related. When the pressure is the same, the volume of adsorbed CH4 in the dry coal samples during adsorption is larger than that in the water-injected samples during desorption by dewatering. When the pressure is the same, for the difference in the adsorbed CH4 volume between adsorption and desorption isotherms, shallow coal is less significant than deep coal. The slopes of free CH4 in deep coal are lower than those in shallow coal during adsorption and desorption. [ABSTRACT FROM AUTHOR]

Staged multicluster fracturing (SMCF) is crucial for the low‐permeability coalbed methane (CBM) reservoirs development. To reveal the fracture propagation mechanism and characteristics in SMCF and select appropriate hydraulic fracturing parameters, this study considers CBM exploitation in the Shizhuang block, Qinshui Basin in China as the engineering background. Then, XSite hydraulic fracturing software based on the discrete lattice theory and synthetic rock mass method is used to construct a three‐dimensional model. The influence mechanisms of the cluster spacing (CS) and lateral pressure coefficient (LPC) on the fractures propagation characteristics were investigated. With an increase in the CS, the stress interference between fractures gradually weakens, and the fracture deflection also decreases. Both the stimulated reservoir area (SRA) and fracture aperture of a single cluster increase with an increase in CS, but the SRA and fracturing efficiency exhibit limited growth when the CS is greater than 15 m. The SRA decreases exponentially with an increase in LPC. When the LPC increases from 0.4 to 1.4, the SRA decreases by 74.2%. The LPC plays a decisive role in the fracture propagation direction. When the LPC reaches 1.4, the fractures propagate along the horizontal direction. With an increase in LPC, the fracturing fluid pressure increases linearly, and the fracturing efficiency decreases exponentially. The results of this study reveal the fracture propagation law of SMCF and can provide a reference for engineering applications. In the SMCF at the 3# coal seam of the Shizhuang block, the CS can be set to approximately 15 m, and the CS can be appropriately reduced when the LPC is large. [ABSTRACT FROM AUTHOR]

The mechanical behavior of coal is significantly influenced by the loading rate and bedding plane. In this paper, the uniaxial compression tests at different loading rates were conducted on coal specimens with vertical bedding (CSVB) and coal specimens with parallel bedding (CSPB), which were prepared by the coal with bursting liability from the Ordos deep mining areas, China. The results show that the uniaxial compressive strengths of CSVB and CSPB are positively correlated with the loading rate. The peak values of acoustic emission (AE) counts and accumulated absolute AE energy of CSVB and CSPB increase with the loading rate, and the AE parameters of CSVB are larger than those of CSPB. The variation rules of input energy density and elastic energy density are similar for CSVB and CSPB, but the variation rules of dissipated energy density in stage IV are different. As the axial load increases, the energy storage rate and energy dissipation rate of both coal specimen types increase and decrease, respectively. The bedding planes of coal and the loading conditions in the field should be fully considered when identifying the bursting liability of coal and forecasting coal burst. This study can provide a reference for coal burst warning and prevention under similar geological conditions in Ordos deep mining areas. [ABSTRACT FROM AUTHOR]

This study investigated the development and formation of ground fissures at panel 12,401 of the Shangwan Colliery in the Shendong mining area, characterized by the current largest mining height and an aeolian sand surface in China. An integrated monitoring method was employed to examine the ground subsidence, distribution and development pattern of ground fissures, and the relationship between fissure width and depth, including an unmanned aerial vehicle, ground penetrating radar, and real-time kinematic and manual measurements. Then, the development and formation mechanisms of ground fissures were elucidated through theoretical analysis and physical simulation. The results indicate that ultra large mining height longwall panel extraction causes a greater ground subsidence and horizontal deformation than those of the conventions, resulting in more severe damage in the permanent margin area. The ratio of burial depth to mining height (H/M) decreases to less than 30 due to the ultra large mining height, and deep-burial panel displays the characteristics of shallow coal seam mining, such as "step subsidence". The sliding instability of the primary key stratum causes the simultaneous cutting-off of the aeolian sand layer to form step-like ground fissures. The cause of the tensile fissures is the horizontal surface deformation exceeding the deformation threshold of the aeolian sand layer, and the dynamic tensile fissures were self-restored in 2 weeks as the panel advanced. Step-like fissures connected the working face with the ground, but the depth of the tensile fissures was less than 5.0 m and increased linearly with the fissure width. [ABSTRACT FROM AUTHOR]

High-intensity coal mining activities in China's western mining area are damaging fragile ecological environments. The key to coordinating ecological protection and coal mining is to understand the law of overlying strata migration in high-intensity mining. However, it is difficult for conventional monitoring methods to efficiently monitor overburden movement in high-intensity mining areas in real time. In this paper, a space-sky-surface (3S) integrated system is proposed to conquer this challenge. This monitoring system consists of three parts: a space monitoring component (a combination of a global navigation satellite system (GNSS) and interferometric synthetic aperture radar (InSAR)), a sky observation component (an unmanned aerial vehicle (UAV) equipped with a measuring camera (MC)), and a surface exploration component (ground-penetrating radar (GPR) and high-density electricity method (HDEM)). This system was successfully applied to the 12,401 longwall face in the Shangwan coal mine (the maximum mining height is 8.8 m). The deformation cloud map of the entire mining area was obtained through InSAR monitoring technology accompanying the 3D laser scanning to improve the accuracy in the local region of 12,401 longwall face. The distribution characteristics and dynamic evolution of surface fractures were obtained using UAV and MC (visible light camera + infrared camera). Using the HDEM and GPR technologies, the fracture development was well detected. Based on the strata movement theory, combined with the monitoring results, a three-dimensional model of overburden rock fracture after 12,401 longwall face mining was constructed. Monitoring results and the fracture model provide a basis for controlling air leakage in the goaf and remediation of surface fracture. [ABSTRACT FROM AUTHOR]

Accurate prediction of the height of the water-conducting fracture zone (WCFZ) is very important for safe coal mining, water resource storage, and protecting the environment. The proportion coefficient of hard rock and the actual height of the top caving coal were defined to predict the height of the WCFZ more accurately. A multivariate regression analysis method was adopted to establish a nonlinear model for predicting the height of the WCFZ based on various factors, including mining height, panel width, proportion of hard rock, mining depth, and extraction rate. Investigations conducted using data from western China show that the ratio of the height of the WCFZ to the mining height obtained using the actual height of the top caving coal is ≈ 20, which is consistent with the distribution of the longwall full-seam mining technology. The values predicted by the multiple regression model in this study are closer to the measured values than those derived using traditional empirical equations, with a relative error < 10%. The ratio of the height of the WCFZ to mining height was generally higher in the western mining area than in the eastern mining area, due to the increase in panel dimensions and harder lithology. However, the influences of extraction rate and mining depth on the development of the WCFZ were found to be relatively weak. Finally, the model accurately predicted the height of the WCFZ in panel 12,511 of the Bulianta coal mine. [ABSTRACT FROM AUTHOR]

Coal mining-induced ground subsidence often causes buried oil-gas pipeline failure. Insight the evolution of pipeline failure length and inflection points under the influence of adjustable factors (the distance between the panel pipe, panel width, internal pressure, and burial depth) has become increasingly essential for pipeline maintenance and operation. At present, the pipeline's failure length, failure time series, and inflection point distribution in subsidence areas are vague, which is not perfect in terms of specificity and clarity. Thus, a novel method to distinguish local failure and inflection points of pipelines is proposed by combining its moment and volume strain. Taking Panel 22102 of Ordos in western China as an example, the pipeline failure length and time series characteristics, as well as the inflection point spacing (IPS) are analyzed under the influence of adjustable factors by numerical simulation. The results show that (ⅰ) By increasing the distance between the panel pipe, and reducing the panel width, burial depth, and internal pressure, we can effectively mitigate or prevent pipe failures. For Panel 22102, the distance between the panel pipe should be less than 120 m to prevent failure. When it is unavoidable for the panel to pass underneath the pipeline, the width of the panel needs to be reduced to less than 120 m. (ⅱ) The pipeline failure length decreases by 2.9% for every 10 m reduction in the panel-to-pipeline distance. For every 10 m reduction in panel width, the pipeline failure length decreases by 5.7%. For every 0.1 m decrease in the burial depth, the pipeline failure length decreases by 2.16%. For each 1 MPa increase in internal pressure, the pipeline failure length increased by 0.48%. (ⅲ) The IPS is proportional to the panel width, burial depth, and internal pressure while exhibiting an exponential relationship with the distance between the panel and pipe. (ⅳ) The failure first spreads from the pipeline's subsidence center towards both ends, followed by spreading from both ends and the center towards inflection points simultaneously. (ⅴ) A multi-level and multi-faceted resilient management and collaborative operating pattern is established for the gas-coal integrated mining field. The research results provide scenario guidance and decision support for managers to develop adjusting measures to maintain pipelines, and also promote the coordinated mining of gas and coal resources. • The method was established to judge pipeline local failure and inflection points. • The length, proportion, and time series of pipeline failures were elucidated. • The inflection point and bending moment of the pipeline were clarified. • Multi-level and multi-faceted pipeline management schemes were proposed. [ABSTRACT FROM AUTHOR]

The effect of mining-induced stress–fracture–seepage field coupling (SFSC) is critical to the safety and productivity of the underground mining. This study investigated the spatiotemporal effect of SFSC at the Bulianta Colliery panel #31401 of the Shendong coalfield in China, characterized by ladder key stratum and composite aquifer. An integrated method including borehole and working face observation, in-site water leakage, and real-time video imaging was adopted to examine the behavior of overburden movement, water level change, and groundwater inrush. Simultaneously, the evolution of the SFSC was visualized by the FLAC3D–CFD (fluent) simulator with a developed non-Darcy model, and the dynamic characteristics of the SFSC were analyzed. The results indicated that the macro-stress shell, fractured field distributed beneath the macro-stress shell with a 48 m height difference in the lower and higher key stratum zone, and seepage field including initiation zone, acceleration zone, deceleration zone, and drainage zone were identified. The confined aquifer was affected by the fracture field with a height of 140–154 m, and groundwater invasion was triggered and developed beneath the lower key stratum. The confined aquifer was kept stable by protection of the higher key stratum by controlling the propagation of the fracture field at the height of 90–100 m. Highly permeable channels were distributed beneath the micro-stress shell as a result of the release of in-site stress, especially at the rupture region of the micro-stress shell between the lower and higher key stratum, with the maximum fluid discharge. Furthermore, the SFSC response resulted in large and medium groundwater invasion and strong variation of abutment stress peak, when creating rupture at the micro-stress shell and main roof. Finally, based on the mechanism of the SFSC, the developed optimization strategy could efficiently mediate the effect of the SFSC by lowering the mining height, increasing the advance rate, and enhancing the support resistance of the longwall mining face. [ABSTRACT FROM AUTHOR]

The effect of mining-induced multi-physics coupling, characterized by stress–fracture–seepage field coupling (SFCC), is critical to safe mining and environmental protection. We investigated the spatiotemporal characteristics of the SFCC at the #31401 panel of the Bulianta Colliery. Changes in overburden movement, groundwater level, and groundwater inrush were monitored by means of borehole and working face observations, water leakage, and real-time video imaging. The results indicate that the distribution of mining-induced fractures was dominated by the key stratum, distributed as a "ladder shape" 30–75 m above the coal seam. The fracture penetrated into the lower key stratum and developed into the confined aquifer with a height of 140.5–154.0 m, while being truncated by the higher key stratum. Horizontal and vertical fractures developed sequentially in the confined aquifer-disturbed zone. Initiation, propagation, and interconnection of the seepage channel occurred in the fracture field, mediated by the redistributed stress. An abnormal discharge of 120–300 m3/h along the direction of mining commenced at the transition of the lower key stratum to the higher key stratum, and concentrated below the Bulian Gully. A fracture height model was developed based on the vertical fracture propagation, and mining parameters were modified, including reducing the mining height and increasing the advance rate and support resistance of the longwall mining face to effectively reduce the SFCC effect. [ABSTRACT FROM AUTHOR]

Thick hard rock strata (THRS) are widely distributed among coal-bearing strata in China. The dynamic THRS failure may induce the coal-rock dynamic hazards during underground coal mining. In this study, the size, stress and energy characteristics of dynamic THRS failure were analyzed; the Yangliu coal mine, Huaibei coal basin, China, was taken as a case study. Then the apparent-depth effects of the dynamic THRS failure on the underlying coal mining were researched. The results revealed that the rock roof would be caved, fractured and deformed and even develop the bed separation during underlying coal mining. A large quantity of elastic energy is stored in the bent and compressed THRS, the amount and scope of the vertical stress concentration in front of the working face increases significantly before THRS breaking. THRS generally exhibit the square-form structure failure (SSF), after which the elastic and kinetic energy is attenuated in power form with the energy spreading distance. The shock force and energy effects of the dynamic THRS failure on the underlying coal mass were greater than those observed for the common lithological rock strata. Thus the mining coal mass below THRS bears similar mechanical conditions as the deeper coal mass and is of greater apparent depth, which is called the apparent-depth effects of the dynamic THRS failure. The apparent-depth effects of the dynamic THRS failure significantly influenced the coal-rock dynamic hazards according to in situ measurements of the mine earthquake energy, in situ stress, roof pressure and gas emission parameters. As a result, reasonable measures should be taken to avoid stress concentration and energy accumulation and to reduce the apparent depth of the mining-disturbed coal mass for preventing coal-rock dynamic hazards. The research results provide significant value for the control of coal-rock dynamic hazards below THRS. [ABSTRACT FROM AUTHOR]

• Pore structure of bentonite were quantitatively investigated by SAXS and LTNAD methods. • The two PSD methods (lognormal distribution and maximum entropy) in SAXS were compared with the PSD obtained by LTNAD. • The pore size calculated by the maximum entropy method was larger than that calculated by the Guinier methods. Quantitative characterization of the pore structure of typical bentonite in China is beneficial to nuclear waste treatment and sludge solidification modeling. A new small angle X-ray scattering (SAXS) method and conventional method low-temperature nitrogen adsorption and desorption (LTNAD) were combined to investigate the pore structure of four Chinese typical bentonites. The pore size and pore size distribution measured by the novel SAXS and conventional LTNAD methods were compared. The results suggested that Gaomiaozi bentonite exhibited Porod positive deviation effect. The GMZ01 had better sortability than GMZ07, and the pore size was concentrated. The average pore size of GMZ01 and GMZ07 calculated by the maximum entropy method were close. LTNAD experiment indicated that the specific surface area (SSA) of bentonite depended on the pore volume of mesopores and micropores and the types of exchangeable cations between layers. The SSA was positively correlated with the adsorption capacity. SAXS revealed that pore size estimated by maximum entropy method was larger than that evaluated by Guinier method. The log-normal distribution method in SAXS model was more suitable for characterizing small pores than maximum entropy method. Compared with maximum entropy method, The LTNAD method was more compatible with the SAXS lognormal distribution method. Compared with LTNAD, the SAXS has a wider detection range. These findings fill a gap in SAXS research on Gaomiaozi bentonite (GMZ01, GMZ07, CaGMZ). [ABSTRACT FROM AUTHOR]

Background: Adolescence is a critical period for the onset of mental health issues. In China, high school students face significant academic and social pressures, leading to high rates of mental health challenges. Gender differences in the manifestation of these symptoms have been observed, with boys and girls exhibiting distinct psychological profiles., Objective: This study aims to explore the structure of psychological symptoms among Chinese high school students using network analysis, focusing on identifying core symptoms and gender differences in symptom networks. The key objectives are to: 1) identify the central psychological symptoms for boys and girls, and 2) uncover the interactions between symptoms to inform targeted interventions., Methods: A cluster sampling method was used to recruit 3,769 high school students (2,206 males and 1,563 females) in Shanghai. The Middle School Students Mental Health Scale (MSSMHS) was administered, and network analysis was conducted using the R packages bootnet and qgraph to assess symptom network edges, centrality, and network strength. Comparisons between male and female networks were made., Results: Network analysis showed tightly connected symptom networks for both genders, with 43 non-zero edges for boys (sparsity 0.04) and 39 for girls (sparsity 0.13). Depression was the core symptom for boys (centrality 1.20), while anxiety was central for girls (centrality 1.46). Boys showed a stronger link between interpersonal sensitivity and depression (edge value 0.20), while girls exhibited a stronger connection between anxiety and obsessive-compulsive symptoms (edge value 0.16). Network comparison tests revealed no significant differences in overall network strength between boys (4.625) and girls (4.660), with P-values greater than 0.05 across all comparisons., Conclusion: This study highlights significant gender differences in the psychological symptom networks of Chinese high school students. Depression and anxiety emerged as core symptoms for boys and girls, respectively. These findings provide a foundation for developing gender-sensitive mental health interventions, emphasizing the need for tailored approaches based on gender-specific symptom profiles., (© 2024. The Author(s).)

Numerous historical buildings exist in Shanxi Province, a major coal producing area in China, so there exist many overlapping areas between ancient wooden buildings and coal mining. Coal mining in overlapping areas will lead to surface subsidence, which will have an impact on historical buildings. Based on the distribution of historical buildings and the distribution and mining of coal resources in Shanxi Province, this paper concludes that the overlapping areas of coal mining and ancient wooden buildings in Shanxi Province are mainly concentrated in Changzhi City, and the Lu'an mining area in Changzhi City is selected as the research object. In addition, using the gray correlation analysis method, the surface subsidence coefficient, which characterizes the intensity of mining subsidence, is used as the reference sequence. Seven factors selected from the geological conditions and mining conditions of the Lu'an mining area are used as the comparison sequence to calculate the gray correlation between each influencing factor and the surface subsidence coefficient, and to obtain that geological factors such as the nature of the overlying rock layer, bedrock thickness and dip angle of the coal seam, and mining factors such as mining height, average mining depth and working face size largely determine the surface subsidence coefficient. The surface subsidence in the overlap area could largely be influenced by geological factors such as the nature of the overlying rock layer, bedrock thickness and coal seam inclination, and mining factors such as mining height, average mining depth and working face size. Finally, we investigate the possible effects of surface subsidence on ancient wooden buildings in the overlapping area with the surface subsidence and formation mechanism and propose technical measures to reduce the effects of surface subsidence due to coal mining on historical buildings in the overlapping area.

Background & Aims: The current criteria for defining sarcopenic obesity (SOB) combines the threshold criteria for sarcopenia and obesity, but no consensus has been reached on the criteria. Given the variations among ethnic groups and in the prevalence of sarcopenia, the study aim was to establish sex-specific cutoff points for Chinese cancer patients and investigate the effect of SOB on clinical consequences., Methods: A prospective study of 2480 cancer patients was conducted. Clinical materials, bioelectrical impedance analysis measurements, and follow-up data were analyzed. The survival receiver operating characteristic curve was used to determine threshold values. The odds ratios for nutrition risk, severe malnutrition, and quality of life were calculated. The global and sex-specific survival statistics were extracted from the Kaplan-Meier curve and Cox proportional hazard regression models., Results: The cutoff points of visceral fat area to best classify patients regarding time to death were >75.6 cm 2 for males and >61.2 cm 2 for females. And the cutoff points of percent of body fat were 15% in males and 25% in females. Among all participants, the prevalence of SOB was 3.03% in males and 4.46% in females. SOB significantly increased the nutrition risk and severe malnutrition probability and worsened quality of life. Finally, SOB was significantly associated with overall cancer mortality [hazard ratio 2.772, 95% confidence interval 2.080-3.694, P < 0.001]., Conclusions: On the basis of sex-specific cutoff values, SOB was strongly associated with unfavorable clinical consequences and mortality in cancer patients. These results indicate the importance of SOB detection in routine clinical practice for improving patient assessments, cancer prognosis, and intervention., Competing Interests: Conflict of Interest The authors declare no conflict of interest., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)