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Background Study: Technology‐supported learning environments, act as significant observational and enabling indicators for evaluating and encouraging the digital revolution of education, are of vital importance in current educational research. Keeping track of the dynamics of technology‐supported learning environment research allows for the enrichment of theoretical studies and a prompt innovation of talent‐training environments. Objectives: The present study carried out a bibliometric analysis of the core collection of WoS database over the last two decades. Method: This study is a bibliometric research. We applied CiteSpace and VOSviewer for co‐occurrence and evolution analysis. In addition, we extracted the fundamental ideas and thoughts through reading and analysis. Results: First, the study found that technology‐supported learning environment research is in a growth phase, with core journals such as Interactive Learning Environments or Computers & Education. The findings show that a core research team comprised of such scholars as Hwang Gwo‐Jen, Lester James C. and Wong Lung‐Hsiang. Key nations of publishing and research strength are from China, the United States, the United Kingdom and the Netherlands. Second, the hot topics in research on technology‐supported learning environments were virtual learning environments, technology‐enabled learning environments and interactive learning environments. Nine study specifics were derived from these three topics such as moulding function, generating scenario, stimulating sensation, effect verification, design idea, research reflection, inquiry and research, virtual community, and mixed environment. Lastly, the frontier evolution offers a pattern of development from enhancing performance to changing mode to incorporating experience. Conclusion: Looking ahead, our research recommendations for the field of technology‐supported learning environments include a multifaceted approach. We should aim to enhance research designs and methodologies, develop contemporary guiding theories and strive for a balanced representation across various educational domains, expanding our scope to encompass all academic disciplines. In terms of practical application, it is imperative to focus on the design and implementation of technology‐supported learning environments from three critical perspectives: "change‐demand," "student‐learning" and "online‐offline." These approaches will collectively ensure that technology‐supported learning environments are both innovative and responsive to the diverse needs of the educational landscape. Lay Description: What is already known about this topic: Technology‐supported learning environments are currently a focal and hot research topic in the field of education.Although numerous studies have been conducted on the learning environment of technical support, there has yet to be a systematic and comprehensive review of the related research. What this paper adds: This study provides a comprehensive review of research on the technology‐supported learning environments over the past two decades.This study primarily presents an overview of research on the technology‐supported learning environments over the past two decades, focusing on main literature, research strength, hot topics and frontier evolution. Implications for practice and/or policy: Researchers need to further advance research on technology‐supported learning environments by enriching research designs and methods, constructing up‐to‐date guiding theories and achieving a balance across different educational domains while extending the reach to all disciplines.Educational practitioners need to pay attention to the design and implementation of technology‐supported learning environments from the three viewpoints of "change‐demand," "student‐learning" and "online‐offline." [ABSTRACT FROM AUTHOR]

With the rising demand for hydropower energy, China has built numerous concrete‐faced rockfill dams (CFRDs) with considerable heights. The potential failure pattern of the concrete face slab is the key to the safety of the anti‐seepage system. However, engineers commonly employ an elastic relationship to model the concrete face slab for simplicity, which induces inaccurate estimation of the face slab's stresses, especially under seismic conditions. On the other hand, the existing elastoplastic models for concrete often require complex derivation of the necessary formula and thus are difficult to apply to finite element (FE) analysis. Under the comprehensive action of the upstream water, supporting rockfill, and surrounding mountains, the damage mode of the quasibrittle concrete slab is not a tensile mode but a compressive shearing mode. Therefore, it is urgent to establish an elastoplastic model that is adapted to the actual working environment of the slab and easy to apply. To this end, a generalized plasticity model is developed within the phenomenology modeling concept, which is validated at both the experimental level and application level. The results indicate that three‐dimensional stress‒strain behaviors, such as the strength nonlinearity, prepeak dilatancy, and postpeak softening, can be effectively captured. In addition, the seismic characteristics of a 200‐m high CFRD are numerically investigated. The findings show that the slab's stress accumulation can be reflected during the earthquake and that the final stress distribution conforms to the field observations. The conclusions of this paper provide a reliable reference for the seismic resistance design of CFRDs. [ABSTRACT FROM AUTHOR]

A calamitous landslide happened at 22:00 on September 1, 2014 in the Yunyang area of Chongqing City, southwest China, enforcing the evacuation of 508 people and damaging 23 buildings. The landslide volume comprised 1.44 million m3 of material in the source area and 0.4 million m3 of shoveled material. The debris flow runout extended 400 m vertically and 1600 m horizontally. The Xianchi reservoir landslide event has been investigated as follows: (1) samples collected from the main body of landslide were carried out using GCTS ring shear apparatus; (2) the parameters of shear and pore water pressure have been measured; and (3) the post‐failure characteristics of landslide have been analyzed using the numerical simulation method. The excess pore‐water pressure and erosion in the motion path are considered to be the key reasons for the long‐runout motion and the scale‐up of landslides, such as that at Xianchi, were caused by the heavy rainfall. The aim of this paper is to acquired numerical parameters and the basic resistance model, which is beneficial to improve simulation accuracy for hazard assessment for similar to potentially dangerous hillslopes in China and elsewhere. [ABSTRACT FROM AUTHOR]

The coal production exploited from extra‐thick coal seams accounts for 45% of China's total coal production. With large coal output, the extra‐thick coal seams require that the chamber section be more than 100 m2. In case of parting (the noncoal rock, usually mudstone, sandwiched in the coal seam) in the extra‐thick coal seams, the integrity of the coal seams will be damaged and the large‐section chamber is extremely easy to occur rib spalling and roof leakage, which will increase the chamber's supporting difficulty. To solve such problems, this paper took the electromechanical chamber in Tashan Coal Mine as the engineering background and analyzed the deformation and failure characteristics of this chamber surrounding rocks by the numerical simulation method during the excavation process. The results indicated that the failure areas of surrounding rocks were mainly in partings, chamber ribs, and chamber dome with the failure depths of 15 m, 10 m, and 5 m, respectively. Based on the obtained deformation and failure characteristics, the supporting method of grouting integrated with high‐strength bolts and anchor cables was put forward. The grouting method was firstly used to improve the integrity of the chamber surrounding rocks, and the high‐strength bolts and anchor cables were used for supporting. Then, the supporting parameters of the bolts and anchor cables and the grouting parameters were optimized by the numerical simulation method. The optimized parameters were applied in the electromechanical chamber in Tashan Coal Mine, and the on‐site chamber ribs lateral displacement and roof separation amounts were only 0.018 m and 0.012 m, respectively, indicating that the surrounding rocks were controlled effectively. [ABSTRACT FROM AUTHOR]

Spatio-temporal modeling is an active research problem with broad applications. In this problem, proper description and estimation of the data covariance structure plays an important role. In the literature, most available methods assume that the data covariance is stationary and follows a specific parametric form. In practice, however, such assumptions are hardly valid or difficult to verify. In this paper, we propose a new and flexible method for estimating the underlying covariance structure. Our proposed method does not require the covariance to be stationary or follow a parametric form. It can accommodate nonparametric space-time-varying mean structure of the observed data. Under some mild regularity conditions, it is shown that our estimated covariance structure converges to the true covariance structure. The proposed method is also justified numerically by a simulation study and an application to a hand, foot, and mouth disease data. [ABSTRACT FROM AUTHOR]

In recent years, the availability of infectious disease counts in time and space has increased, and consequently, there has been renewed interest in model formulation for such data. In this paper, we describe a model that was motivated by the need to analyze hand, foot, and mouth disease surveillance data in China. The data are aggregated by geographical areas and by week, with the aims of the analysis being to gain insight into the space-time dynamics and to make short-term predictions, which will aid in the implementation of public health campaigns in those areas with a large predicted disease burden. The model we develop decomposes disease-risk into marginal spatial and temporal components and a space-time interaction piece. The latter is the crucial element, and we use a tensor product spline model with a Markov random field prior on the coefficients of the basis functions. The model can be formulated as a Gaussian Markov random field and so fast computation can be carried out using the integrated nested Laplace approximation approach. A simulation study shows that the model can pick up complex space-time structure and our analysis of hand, foot, and mouth disease data in the central north region of China provides new insights into the dynamics of the disease. [ABSTRACT FROM AUTHOR]

The increase in extraction height will increase the mining‐induced overlying strata failure height. In this scenario, the strata pressure behavior is strong in a fully mechanized face with large mining height (FMFLMH), which frequently causes coal wall falls, roof falls, and hydraulic support failure accidents (e.g., support closure and hydraulic column damage). The key to solving these issues is to determine support's working resistance of the FMFLMH. In this paper, comprehensive theoretical analysis, numerical simulation, and field observation were applied to determine the support's working resistance in the FMFLMH based on movement type of the first subordinate key stratum (SKS 1). First, six kinds of movement types of SKS 1 in the FMFLMH are found and defined by theoretical analysis and numerical simulation, which are the direct caving movement type of cantilever structure (direct caving), the double‐sided rotation movement type of cantilever structure (double‐side rotation), the quadratic rotation movement type of cantilever structure (quadratic rotation), the alternative movement type of cantilever structure hinged structure (alternate hinged), the voussoir beam structure movement type (voussoir), and the short voussoir beam structure movement type (short voussoir), respectively. Besides, based on this, the support load calculation model of each movement type was established, and a formula for the support working resistance of each movement type was obtained. Finally, the correctness of the formulae for the support working resistance under six types of movement of SKS 1 were verified using measurement data from four FMFLMHs in China. These research results have important guiding significance for reasonable selection of support and ensuring safe mining of the FMFLMH. [ABSTRACT FROM AUTHOR]

This paper is mainly concerned with the development and design of a reduced order model in numerical simulation of the unsteady temperature field of the stadium building foundation in frozen areas, based the finite element (FE) method and proper orthogonal decomposition (POD) with the snapshot technique. We first derive the standard FE formulation of the unsteady temperature field and compute its FE full solutions, from which we choose a few spatio‐temporal solutions as snapshots. Based on POD technique, we then build a set of optimal POD bases maximizing the energy content in the original ensemble data, and in the new space spanned by the POD basis, we establish a low‐order numerical model of reduced‐order finite element (ROFE) formulation of the unsteady temperature field. And we prove the error estimates of the ROFE solutions of the unsteady temperature field. Finally, numerical tests are provided to simulate the temperature field of crushed stone clay under the natural pavement near the foundation of a stadium building in a frozen soil area of the northwest of Sichuan province in China. [ABSTRACT FROM AUTHOR]

The water body is just like a quasi-static fluid after the impoundment of the Three Gorges Reservoir in China to 175 m water level in late 2010. In this paper, fluid dynamic model and numerical method were presented to analyse its dynamic characteristic. Then, based on an oil spill model coupled with the hydrodynamic model, the oil fractions evolvement with time as well as the recovery process with emergency actions under oil spills were numerically simulated and illustrated in the Three Gorges Reservoir. Emergency actions were accordingly analysed based on the simulated pollution area and density, by which a decay parameter was additionally brought into the simulation to understand the recovery of polluted area. The simulated results could be an aid for better emergency response strategy in case of oil spill accidents in the Three Gorges Reservoir in China. [ABSTRACT FROM AUTHOR]

The Trans-Pacific Partnership ( TPP) is a new negotiation on cross-border liberalisation of goods and service flows going beyond WTO disciplines and focused on issues such as regulation and border controls. This paper uses numerical simulation methods to assess the potential effects of a TPP agreement on China and also China's inclusion or exclusion on other countries. We use a numerical 11-country global general equilibrium model with trade costs and inside money. Trade costs are calculated using a method based on gravity equations. TPP barriers potentially removable are trade costs less tariffs. Simulation results reveal that China will be slightly hurt by TPP initiatives in welfare when China is out, but the total production and export will be increased. Other non- TPP countries will be mostly hurt in welfare, but member countries will mostly gain. If China takes part in TPP, she will significantly gain and increase other TPP countries' gain as well. The comparison of TPP effects and global free trade effects show that the positive effects of global free trade are stronger than TPP effects. Japan's joining TPP would be beneficial to both herself and most of other TPP countries, but which negative effects on China's welfare when out of TPP will increase further. [ABSTRACT FROM AUTHOR]

A software maintenance process is important for reducing maintenance effort and for improving software quality. In recent years, the Lean-Kanban approach has been widely applied in software practice including software maintenance. This approach minimizes Work-in-Progress (WIP), which is the number of items that are worked on by the team at any given time, thus improving the maintenance process. In this paper, we describe our simulation studies, which show that the Lean-Kanban approach can indeed help reduce the average time needed to complete maintenance requests. We develop a process simulator that can simulate both existing maintenance processes that do not use a WIP limit and that adopt it. We perform two case studies using real maintenance data collected from a Microsoft project and from a Chinese software firm. The main results of our study are twofold. First, we demonstrate that it is possible to effectively model and simulate, using actors and events, a maintenance process where a flow of issues is processed through a sequence of activities, correctly reproducing key statistics of real data. Second, our results confirm that the WIP-limited process could be useful to increase the efficiency of software maintenance, as reported in previous industrial practices. [ABSTRACT FROM AUTHOR]

Planning for the long-term management of flooding should be underpinned by credible evidence of current and future flood risk. Simulation of flood extents and depths is a key component of the evidence base of flood risk analysis, but flood modelling can be a time-consuming activity. For scenario analysis studies, such as that undertaken on the Taihu Basin in China, the potentially extensive computational and staff time demands of standard flood modelling are compounded by the need for simulations of multiple futures over large areas. In this paper, we describe how a credible flood simulation method was selected and implemented for the Taihu Basin within the challenging data, resource and programme constraints. The lessons learned from the study are described and generalised to help inform modelling components of other studies, particularly broad scale analysis for flood risk management planning. [ABSTRACT FROM AUTHOR]

In the evening of 11 April 2011, vortex/wave shedding from a mountain to the south of the Hong Kong International Airport (HKIA) appeared to occur following the establishment of fresh to strong easterly airflow in Hong Kong. This paper documents the observations by the various meteorological instruments of the event and discusses the possibility of forecasting the vortex/wave shedding using a high resolution numerical weather prediction (NWP) model. The vortex/wave shedding was well observed by the Light Detection and Ranging (LIDAR) system at HKIA. The vortex/wave appeared as an area of reversed flow against the background east to southeasterly airflow in the airport area. It was detached from the mountain and moved to the northwest with the background southeasterly flow, with a gradual decrease of the spatial extent in the area of reversed flow. The vortex/wave brought about significant wind shear to both arrival flight paths to the west of HKIA, as evidenced from the headwind profile data measured by the LIDARs and the aircraft data. It had rather large vertical extent, reaching the top of the boundary layer, but did not extend downward to the surface, as shown from the vertical scans of the LIDAR and the surface wind observations. The shedding event is successfully captured by high-resolution NWP model with a spatial resolution of 50 m. The model output has a lead time of 6-7 h ahead of the event, indicating the possible occurrence of terrain-induced wind shear in the form of vortex/wave shedding from a mountain. As a result, the numerical simulation could be useful in giving an early alert to the aviation weather forecaster about the significant wind shear event, which could be hazardous to the landing aircraft. Copyright © 2011 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

In modern power systems, the impact of random power sources and loads on power systems is increasing, resulting in threatened system frequency security. However, traditional methods are often not comprehensive in modelling randomness, and there is no analytical method to assess the frequency response of power systems under uncertain power fluctuations. Here, the power fluctuation in a power system is regarded as an interval random quantity. An analytical prediction method of the power system frequency deviation under uncertain power fluctuation is proposed. Through further deduction, the allowable range of power fluctuation under the premise of secure frequency deviation can also be defined, which provides a reference for frequency security and accident prevention in power systems. Numerical simulations with the model of the East China Power Grid demonstrate that the proposed analytical method can delimit the response interval of system frequency deviation well, and the backstepping calculation can also delimit the allowable range of power fluctuation to ensure the secure operation of the system. [ABSTRACT FROM AUTHOR]

To accelerate the groundwater flow simulation process, this paper reports our work on developing an efficient parallel simulator through rebuilding the well-known software MODFLOW on JASMIN (J Adaptive Structured Meshes applications Infrastructure). The rebuilding process is achieved by designing patch-based data structure and parallel algorithms as well as adding slight modifications to the compute flow and subroutines in MODFLOW. Both the memory requirements and computing efforts are distributed among all processors; and to reduce communication cost, data transfers are batched and conveniently handled by adding ghost nodes to each patch. To further improve performance, constant-head/inactive cells are tagged and neglected during the linear solving process and an efficient load balancing strategy is presented. The accuracy and efficiency are demonstrated through modeling three scenarios: The first application is a field flow problem located at Yanming Lake in China to help design reasonable quantity of groundwater exploitation. Desirable numerical accuracy and significant performance enhancement are obtained. Typically, the tagged program with load balancing strategy running on 40 cores is six times faster than the fastest MICCG-based MODFLOW program. The second test is simulating flow in a highly heterogeneous aquifer. The AMG-based JASMIN program running on 40 cores is nine times faster than the GMG-based MODFLOW program. The third test is a simplified transient flow problem with the order of tens of millions of cells to examine the scalability. Compared to 32 cores, parallel efficiency of 77 and 68% are obtained on 512 and 1024 cores, respectively, which indicates impressive scalability. [ABSTRACT FROM AUTHOR]

A tornado/waterspout associated with a supercell thunderstorm was observed in the adjacent waters of southern China on the evening of 18 April 2019. The case was documented using surface weather observations and Doppler radar data. A weather station near the tornado/waterspout, recorded wind gusts corresponding to hurricane intensity for a few seconds, never observed before in the region. The Doppler velocity associated with the tornado/waterspout was analysed and the vertical profile of the velocity could be very useful for wind engineering applications in the region. Dual‐polarization observations also were analysed and exhibited some similar signatures documented in supercell tornadoes in other parts of the world. Predictability of the tornado/waterspout was studied using a numerical weather prediction model. It showed that the location and timing of the waterspout/tornado could be roughly reproduced, and the model might be used to give earlier alerting to the vessels operating in the south China coastal waters. [ABSTRACT FROM AUTHOR]

Northeast China is a major agricultural production base in East Asia, and spring is the agricultural ploughing season throughout the region. The precipitation in spring is therefore significant to agricultural activity and production in the region. In this study, the interdecadal variation in spring precipitation across northeast China is investigated. In the past four decades, there has been a significant increase in spring precipitation in northeast China, and the increase in May precipitation made a dominant contribution to that increase. Further analysis indicates that the increase in May precipitation is concurrent with the decline in Arctic sea ice concentration (SIC) over the Barents Sea; both variables show an interdecadal shift around the early 2000s. Physical analysis based on observations and numerical simulations demonstrates that a decline in the Barents Sea SIC could excite a Rossby wave train propagating southeastward across the Mongolia‐Baikal region and reaching northeast China, thereby inducing a zonal anticyclone–cyclone–anticyclone teleconnection pattern over mid‐ to high‐latitude Eurasia. Under the influence of such a teleconnection pattern, significant southerlies prevail over northeast China, bringing warm and wet air to the region; in addition, the local atmospheric instability and upward motion are also increased. The changes in the moisture and dynamic conditions favour the increase in May precipitation over northeast China. Furthermore, SIC anomalies in the Barents Sea persist from late winter to spring; therefore, the SIC signal could provide signals for predictions of the interdecadal changes in May precipitation over northeast China. [ABSTRACT FROM AUTHOR]

The dry‐wet abrupt alternation (DWAA) event, which is defined as the phenomenon of dry (or wet) spells abruptly following wet (or dry) spells, magnifies the influence of individual wet and dry events. The dynamic evolution of DWAA events has not been studied for different climate zones of China that is particularly susceptible to dry and wet extremes. This study explores the future changes in the abrupt alternations between dry and wet extremes across 10 climate divisions of China, with a thorough assessment of dry and wet conditions using the Standardized Precipitation Evapotranspiration Index (SPEI). We take advantage of an ensemble of regional climate model simulations including the Providing Regional Climate Impacts for Studies (PRECIS) experiment and five CORDEX East Asia experiments to produce high‐resolution climate information for a baseline period of 1975–2004 and a future period of 2069–2098. Our findings disclose that a total of 70% of China's land area suffered from the DWAA events at least once during 1975–2004. The wet‐dry alternation event is projected to become more frequent in summer, and a prominent increase in the number of dry‐wet alternation events is expected to occur in spring over most parts of China. Moreover, an increasing number of DWAA events with intensified magnitude is projected to strike the North China Plain dominated by warm temperature and humid zone, which is the most densely populated region of the country and is also the largest agriculture production area. Our findings also reveal a strong positive correlation between DWAA and heavy rainfall. The 95th percentile rainfall event contributes most to the wet‐dry alternation event for most climate divisions of China. Plain Language Summary: The emerging disaster of dry‐wet abrupt alternation (DWAA) has been receiving increasing attention due to its compound effects on agricultural production and socioeconomic development. Since China is exposed to dry and wet hydrological extremes as well as their interconnections, a first attempt is made in this study to explore the historical evolution and the future change in the abrupt shifts between dry and wet extremes for different climate divisions of China. Our findings reveal that a total of 70% of China's land area suffered from DWAA events at least once from 1975 to 2004. More importantly, the DWAA is expected to occur more frequently and intense by the end of the 21st century, especially for the North China Plain which is the most densely populated region of the country and is also the largest agricultural production area. Moreover, the summertime wet‐dry alternation is expected to become more frequent for most climate divisions of China, while the dry‐wet alternation event is projected to occur more frequently in spring over East China. These findings provide meaningful insights into the development of adaptation strategies for enhancing society's resilience to compound extremes in a changing climate. Key Points: A total of 70% of China's land area suffered from the dry‐wet abrupt alternation events at least once during 1975–2004The dry‐wet abrupt alternation events are projected to occur more frequently with greater intensity in the North China PlainThe 95th percentile rainfall event contributes most to the wet‐dry alternation event for most climate divisions of China [ABSTRACT FROM AUTHOR]

We use a hydrodynamic model applied to an idealized fan‐shaped basin to explore the morphology and dynamics of radial sand ridges in a convergent coastal system. A positive morphological feedback between channel incision and flow redistribution is responsible for the formation of the channel‐ridge pattern. The selection mechanism of bottom wavelength is associated with flow concentration in the deeper part of the channels. Our results are compared to sediment and hydraulic dynamics in the radial sand ridges (RSRs) in China. In a convergent, sloping basin the tangentially averaged tidal velocity peaks at 47 km from the apex. This distance is similar to the arc distance, 62 km, where the RSRs are most incised. An offshore shift in tidal phase results in stronger flows near the north coastline, explaining the presence of asymmetric channel patterns. A numerical stability analysis indicates that small radial oscillations with a wavelength of 10° to 15° maximize the velocity in the troughs. This oscillation wavelength also emerges in the RSRs, which display a peak in spectral energy at a radial wavelength between 25° to 37.5°. High‐resolution numerical simulations in the RSRs confirm that flow concentration occurs in the deeper part of the channels, keeping them flushed. We therefore conclude that the RSRs display morphometric characteristics similar to other tidal incisions, like tidal inlets and intertidal channels. This result further supports the dominant role of tidal prism and related peak velocities in incising coastal landscapes. © 2020 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

For increasing the regulation accuracy and efficiency, commercial computational fluid dynamics (CFD) software Fluidyn‐PANACHE was induced to assist in the analysis of typical radionuclides atmospheric diffusion for the Chinese nuclear safety regulation. The atmospheric dispersion simulation system that used three‐dimensional CFD methods, combined three‐dimensional GIS, and multiple technical methods, such as boundary values calculation, body‐fitting mesh generation, and refinement, was established to simulate and discuss the local wind field characteristics, pollutant transportation, and spatial distribution patterns under spot or constant meteorological conditions following unsteady (real time) or steady methods, respectively. This method can be used to reasonably simulate the turbulent and circumferential flow around large cooling towers in the inland nuclear power plant, compensating the shortage in subtleness of the standard Gaussian model, as well as shortage in realizing multiwind direction simulation in the calculation by the traditional CFD model. The calculation results of annual average atmospheric dispersion factor under normal operation indicated the seasonal differences, with maximum average dispersion factor in autumn, which were consistent with those suggested by Gaussian mixture model. Consequently, it is reasonable to avoid refueling overhauling in autumn to diminish pollution. The CFD numerical simulation method, which has a high agreement with the results of physical tests such as wind tunnel test, provides a new reference for the nuclear safety review of inland nuclear facilities in China. [ABSTRACT FROM AUTHOR]

Based on the analysis of the monitoring data of surface displacement and internal multipoint displacement of coal pillars near three inclined strata roadways, which have similar burial depth and different surrounding rock conditions in a coal mine in the east China, the coal pillars' stress change was combined with discontinuous numerical simulation software to simulate the deformation process of one of the roadways. Field monitoring data and numerical simulation results show that when this working face roadway is dug, the coal pillar enters plastic state after being affected by multiple mining influence, but it can still maintain the basic stability of the roadway and control coal pillar deformation under the current widely used supporting method. With the shortening of the distance between the monitoring area and the working face, the vertical and horizontal stress in the coal pillar increase gradually, but the maximum value of the vertical stress decreases by 1.4 MPa, and deformation amount and velocity of the coal pillar show the characteristics of nonlinear rapid increase. The shape of the vertical stress core area in the coal pillar changed from oval to rectangle, and the width of the core area increased, and it moved 1 m to the goaf side. In the process of coal pillar deformation, there is no zero displacement surface within the monitoring range of 6 m. [ABSTRACT FROM AUTHOR]

Typhoon Mujigae was the strongest typhoon in 2015, and underwent an extreme rapid intensification (RI). The RI of Mujigae was reasonably reproduced by a 72‐hr control simulation. By enhancing two updrafts in the eye wall, connective bursts (CBs) were found to have played an important role in the formation of the two warming cores in the middle and upper troposphere, respectively, which triggered and maintained the RI of Typhoon Mujigae. Meanwhile, CBs induced the upper‐tropospheric potential vorticity anomaly and caused the downward transfer of momentum from the upper to the middle troposphere which was also conducive to the RI of the typhoon. Sensitivity tests confirmed our conclusion. [ABSTRACT FROM AUTHOR]

This study reports the magnitude, spatial pattern and temporal trend of near-surface wind speed (NWS) by comparing 20th century simulations in Coupled Model Intercomparison Project phase 5 (CMIP5) and 3 (CMIP3) and the climate reanalyses with measurements at 563 weather stations in China over 1961-2005. Both CMIP5 and CMIP3 agree quite well with observations in reproducing the spatial pattern of annual mean NWS. CMIP5 models are superior to CMIP3 models in hindcasting the magnitude and spatial pattern of seasonal mean NWS, the temporal trend in annual and seasonal mean NWS. Although both CMIP3 and CMIP5 reproduced the decline trend in the annual and seasonal mean NWS, the hindcasted decline rate is smaller than observed decline trend by the magnitude of one order. The ensemble of optimal models that are better correlated to observations in both NWS and temporal trend possesses advantages over individual model hindcast and reanalyses. The reanalyzed data are not able to represent the observed either the spatial pattern or the decline trend of NWS. The analyses presented here reveal the uncertainties in the current wind field products including reanalyses and model outputs and highlight the benefits of parameterization development and increased horizontal resolution in the new-generation CMIP models. [ABSTRACT FROM AUTHOR]

An opposed multi-burner (OMB) entrained-flow gasifier with coal water slurry feeding is developed by the East China University of Science and Technology. A 3D model is employed to numerically simulate the gas flow field, motion of char particles, and distributions of temperature and gaseous components in an OMB gasifier and in a conceptual two-stage gasifier modified from the OMB gasifier (TS-OMB gasifier). Results show that the TS-OMB gasifier produces higher concentration and productivity of the effective gases (CO+H2) with a slightly higher carbon conversion than the OMB gasifier. The reasons for the differences between these two types of gasifier are discussed by means of numerical simulation. This information is valuable for guiding the design of an advanced OMB gasifier. [ABSTRACT FROM AUTHOR]

Soil organic carbon ( SOC) modelling is a useful approach to assess the impact of nutrient management on carbon sequestration. Roth C was parameterized and evaluated with two long-term experiments comparing different fertilizer treatments in north ( Zhengzhou) and northeast ( Gongzhuling) China. Four nutrient application treatments were used: no fertilizer ( Control), mineral nitrogen-phosphorus-potassium fertilizers ( NPK), NPK mineral fertilizer plus manure ( NPKM), and NPK mineral fertilizer plus straw return ( NPKS). The comparison between simulated and observed data showed that the model can adequately simulate SOC contents in the Control, NPK and NPKM treatments but overestimated in the NPKS treatment at both sites. By changing the value of decomposable plant material:resistant plant material (DPM:RPM) ratio from the default value to 3.35 for the NPKS treatment at the Zhengzhou site, dynamics of simulated SOC agreed with measured values. A pseudo-parameter, straw retention factor was introduced to adjust the amount of straw incorporated into soils. Using the inverse simulation method and the modified value of the ratio, the best-fitted value was 0.24 for the NPKS treatment at the Gongzhuling site. This result indicated that retaining straw on the soil surface makes less contribution to carbon sequestration than if it is incorporated. With this modification for straw, the model produced reasonable predictions for the two sites. The model was run for another 30 years with the modified parameter values and current average climatic conditions for different fertilizer treatments at both sites. The results suggested that the NPK application plus the addition of manure or straw would be better management practices for carbon sequestration. [ABSTRACT FROM AUTHOR]

Based on 43 Harvard CMT solutions in Yunnan region, GPS observations from 1999 to 2004 by China Crustal Movement Observatory Network, and results from SKS splitting and Pn fast wave anisotropy, we obtained the average directions of principle stress fields at different depths by average angle method. Then we further analyzed the coupling difference between geodynamic parameters in different tectonic blocks. Then we built five three-dimensional finite element models to simulate the crustal velocity field in Sichuan-Yunnan region and stratified stress–strain fields in different tectonic blocks. In order to implement the numerical simulation, we constrained the FEA model boundaries with GPS observations, and determined the possible flow patterns at the top of upper mantle by SKS anisotropic splitting data. Based on the simulated kinematic pattern and stress–strain fields, we analyzed the geodynamic environment in the deep part of the area, and found that the difference between lateral stress fields in different tectonic blocks is the main reason why the boundaries of tectonic blocks and their neighborhood are so active areas and capable of generating strong earthquakes. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A tornado that occurred in eastern China on June 23, 2016 was simulated with the Weather Research and Forecasting (WRF) model (version 3.9) using three different microphysical schemes (WRF single‐moment 6‐class [WSM6] scheme, Morrison double‐moment scheme, and Milbrandt–Yau [MY] scheme). The results showed that the Morrison scheme's simulation result was the best among the three schemes. The Morrison scheme simulated a better structure of three layers, including a cold pool near the ground, thick heating layer in the middle levels, and cooling again above 14 km. From the microphysical processes, the possible formation mechanism was that the convective activity was first evoked by the near‐ground cold pool, and then the horizontal vortex tube was raised and vertically stretched before turning in the vertical direction by the release of latent heat caused by the water vapor condensation. Thereafter, the vortex tube was cut off by the downward movement caused by the cloud water evaporation and the snow melting in the front of the convection system, causing the violent vertical lift of the rear vortex tube, forming the tornado. The radar reflectivity (units: dBZ) from (a) observation, (b) the Morrison scheme, (c) the MY scheme, and (d) the WSM6 scheme at 0600 UTC; and the 1‐hr total rainfall (units: mm) from (e) observation, (f) the Morrison scheme, (g) the MY scheme, and (h) the WSM6 scheme during 0600–0700 UTC June 23, 2016. [ABSTRACT FROM AUTHOR]