Changes In Rules Research Articles

Study on Pyrolysis and Oxidation Characteristics of Coal Gangue Based on TGA-DSC.

Coal gangue spontaneous combustion has caused serious environmental and ecological problems. To investigate the reaction kinetic parameters of the gangue and the exothermic characteristics of the spontaneous combustion of the influence of the law, this study employs the thermogravimetric method to explore the characteristic parameters of the pyrolysis and oxidative combustion process of the gangue from the perspective of thermodynamics, and, at the same time, using the differential scanning calorimetry (DSC) on the exothermic effect of the gangue to explore the gangue to obtain the gangue and the original coal TG/DTG/DSC curves to be compared and from the perspective of thermodynamics. The change rule and potential parameters in the pyrolysis and oxidative combustion process of coal gangue (CG) were analyzed, the oxidation kinetic properties of CG were studied, and the reaction mechanism of oxidative spontaneous combustion of CG was further explained. The results show that the TG/DTG/DSC curves of CG in different gas atmospheres will have significant differences in all stages, and in the process of pyrolysis and oxidative combustion, the thermogravimetric curves of CG and those of the original coal show a consistent trend, except for the large difference in peak amplitude in different stages; in different gas atmospheres, as the rate of warming increases, the TG/DTG/DSC curves of the gangue are tilted toward the high-temperature region, they are inclined to the high-temperature region with the increase of the heating rate, and the phenomenon of "hysteresis" of characteristic temperature occurs. The research results provide a theoretical basis for the construction of a spontaneous combustion early warning system based on the fine division of gangue pyrolysis and oxidation combustion stages.

Study on mechanical properties and failure mechanism of hard rock with stiff discontinuities based on 3D printing

To examine the influence of stiff discontinuities with different angles and roughness on the stability of deep hard rock engineering, RLSD is created through the integration of 3D scanning, digital modeling, and 3D printing. The specimen's composition truly reflects the mineral components of the original rock. The impact of angle and roughness on the strength, deformation, and failure characteristics of RLSD is explored by uniaxial tests. The failure process and mechanism of specimens under the influence of stiff discontinuity feature are investigated through the integration of DIC, AE, and SEM test. The study results demonstrate that achieving highly similar specimen of hard rock containing stiff discontinuities with different angles and roughness is attainable by utilizing rock-like materials based on original rock mineral components and employing a combination of 3D scanning and 3D printing techniques. The peak strength, peak strain and elastic modulus of RLSD increase with the increase of JRC, and there is a V-shaped trend of“decrease first and then increase” with the increase of angle. The failure mode of RLSD shows the change rule of tension failure - tension-shear composite failure - shear failure - tension-shear composite failure - tension failure with the increase of angle. At angles of 60° and 75°, a sudden increase in hit and energy of AE feature is observed in RLSD, resulting in brittle failure. The cumulative energy exhibits a positive correlation with JRC. Based on the test results, an empirical estimation formula is established for the uniaxial compressive strength of RLSD, considering the influence of angle and JRC. The research results can provide reference for estimating the strength of surrounding rock in deep underground engineering as well as disaster prevention and control.

Evolutionary patterns and influencing factors of relationships among ecosystem services in the hilly red soil region of Southern China.

As a crucial ecological protection area in China, the Southern hilly red soil region is characterized by uneven spatial and temporal distribution of ecological landscape elements, unpredictable and changeable interrelationships between them, diversified driving factors, and lack of comprehensive consideration of ecosystem services. In order to better understand the interaction between ecosystem services, restore regional ecology, and promote sustainable development, the evolution law and influencing mechanism of ecosystem services and their driving factors are quantitatively analyzed in the study. Based on simulations of different ecosystem services from 2000 to 2020, their spatial and temporal changes and the contributions of main drivers are quantified, their trade-offs and synergies are analyzed, and the changing rules under the influence of natural factors and socioeconomic factors are explored. The results show that (1) the crop production significantly increases in the southwest and north regions, the habitat quality decreases in urban and coastal areas, and the soil retention and water yield show an increasing trend from west to east. (2) Land use/cover is the main driver of carbon storage and habitat quality variation, and precipitation is an important driver of water yield spatial variation. (3) The crop production and the other four ecosystem services show a trade-offs relationship, and the relationship between supporting services and regulating services is the synergetic. (4) The altitude weakens the synergistic relationship between soil retention and habitat quality/carbon storage, while it enhances the synergistic relationship between soil retention and water yield. Driven by precipitation factors, ecosystem services related to water yield have significant differences in the change. The population density enhances the trade-offs of crop production and soil retention, as well as the synergistic relationship between soil retention and habitat quality/carbon storage. In different land use/cover (LULC), the influence of urban land on ecosystem services relationship change is more obvious. Overall, this study can provide scientific bases and policy suggestions for ecosystem protection/restoration in the red soil region of Southern China, which has an important theoretical and practical significance.

Microstructure and chloride transport of aeolian sand concrete under long-term natural immersion

Abstract River sand was consumed in large quantities, and alternatives to river sand were urgently needed. There are a large number of natural resources of aeolian sand in western China. Aeolian sand was prepared into aeolian sand concrete (ASC). It can greatly reduce the consumption of river sand and inhibit the process of desertification to protect the environment. ASC is a new type of concrete material prepared by using aeolian sand as fine aggregate. To clarify the chloride ion transport behaviour in the ASC under long-term natural immersion, the aeolian sand was 100% substituted for the river sand to prepare the full ASC with three water–binder ratios. The ASC was naturally immersed in 3 and 6% NaCl solutions for a long time, and nuclear magnetic resonance and microscopic scanning electron microscopy techniques were used. The change rule of chloride ion content at different depths of the ASC was studied, and its microstructure characteristics under different erosion times were analysed. The results showed that the free chloride ion concentration at different depths of the ASC increased with increasing water–binder ratio, immersion time, and chloride concentration. After soaking in the salt solution, the hydration products in the ASC reacted with chloride ions to form Friedel salt, which filled the internal pores and microcracks of the ASC, improved its interface transition zone structure, and increased the compactness of the test piece. The porosity of the three groups of ASC with different water–binder ratios decreased by 0.95, 1.03, and 1.15% after soaking in 6% salt solution for 12 m. To study the diffusion law of chloride ions in ASC, combined with influencing factors such as temperature, humidity, D value, deterioration effect and chloride ion combination, Fick’s second law was modified, and a chloride ion diffusion model of ASC with high accuracy was established, with a fitting correlation number above 0.93, which provided a reference for the research and application of ASC in saline areas.

A Fractal-Based Quantitative Method for the Study of Fracture Evolution of Coal under Different Confining Pressures

To study the dynamic crack evolution process of loaded coal from the perspective of fractals, we carried out in situ industrial CT scanning tests of loaded coal under different confining pressures, visualizing loaded coal fracturing. Combined with fractal theory, the temporal and spatial evolution law of coal cracks is described quantitatively. The results provide two findings: (1) from the perspective of two-dimensional images and three-dimensional space, the evolution characteristics of cracks in coal under different confining pressures were basically the same in each loading stage. During the loading stages, the cracks exhibited a change rule of a slow reduction, initiation/development, rapid increase, expansion, and penetration. (2) The fractal dimension of coal was calculated by introducing fractal theory, and its change law was in good agreement with the dynamic changes of the cracks, which can explain the influence of the confining pressure on the loaded coal. The fractal dimension showed three stages: a slight decrease, a stable increase, and then a significant increase. The larger the confining pressure, the more obvious the limiting effect. Thus, our approach provides a more accurate method for evaluating the spatial and temporal evolution of cracks in loaded coal. This study can be used to predict the instability failure of loaded coal samples.

Study on the Rule of Change of Reservoir Rocks under Subcritical Steam Effect

This paper examines the lithology, pore throat, and fluid characteristics of the reservoir in Liaohe Oilfield Block 3624, using group V rocks as an example, combining a high-temperature and high-pressure reaction still with other equipment such as a rock mechanics tester and a scanning electron microscope. This study also designs and develops three controlled variable experiments, including the subcritical steam reservoir rock dissolution experiment, the subcritical steam reservoir rock mineral composition transformation experiment, and the subcritical steam reservoir rock mineral mechanical property experiment, also making clear the rule of change on the part of the rocks in the deep and heavy oil reservoirs after the injection of subcritical steam. Experimental results reveal the following: (1) Steam causes the dissolution of rocks, and when the steam temperature is in the subcritical region, dissolution is visible. After a 350 °C subcritical steam treatment, the relative melting temperatures of the components of rock materials are substantially greater than the melting point of the cement holding them together, causing the cement to significantly dissolve and a secondary crack network to emerge. (2) The mineral composition of the rocks changes as a result of elevated temperatures, with various mineral transformation trajectories being recorded after various steam treatments. Montmorillonite in reservoir rocks is converted into minerals like illite and chlorite in the subcritical steam temperature range. Another element influencing the creation of secondary cracks on rock surfaces is the reciprocal transformation of minerals, which alters the cohesiveness among mineral components. (3) Rocks suffer thermal damage and changes to their mechanical characteristics as a result of high-temperature steam dissolution and mineral transformations; the severity of these changes increases with the steam temperature.

Modeling and Optimization of Interior Ballistics within Pneumatic Underwater Launchers

A new area of underwater equipment research focus is the use of underwater unmanned vehicles (UUVs) with launch mechanisms to deploy lightweight and small-sized robots for functions including communication, exploration, and detection. The internal ballistic mathematical model of the underwater launch system for small robots is established in this paper. The internal ballistic parameters and the robot displacement and velocity change rule over time are obtained. The optimization calculation of the crucial parameters to be determined by the particle swarm algorithm is completed. Following optimization, the gas cylinder’s initial pressure is 2 MPa, its capacity is 30 L, its opening area is 9.683 × 10−5 m2, and its opening time is 0.02 s. A numerical simulation is performed for the small robot’s underwater launch process, based on the mathematical and physical model supplied by Fluent 2020 software. The results yield the robot’s motion law and the properties of the flow field during the launch process. The purpose of the underwater launcher experiment is to determine the robot’s motion characteristics. The accuracy of the theoretical model is confirmed by comparing and analyzing the numerical simulation results with the actual data.

Formation of electromagnetic pulses with nonzero electrical area by media with ferromagnetism

The known rule of conservation of the electrical area of pulses, which plays a decisive role in the effectiveness of the action of extremely short pulses on microobjects, is valid for a wide class of media, including all non-magnetic ones. We show how this rule changes in magnetically ordered media, where pulses can induce magnetization variation. We found that such variations serve as another source of pulse electrical area, in addition to the movement of charges.

Numerical investigation of flow patterns in cuttings transport for extended-reach horizontal wells with rotation drillpipe

During the drilling process of extended-reach horizontal wells, the formation of the cuttings bed at the bottom of the wellbore is prone to cause drilling sticking and pump accidents. A coupled method of Computational Fluid Dynamics and Discrete Element Method (CFD-DEM) is used here to study the flow patterns and transition of cuttings transport. Firstly, the model is validated with experimental results, which shows a good agreement. Then, the impact of the rotation speed, eccentricity, and conveying velocity on cuttings flow pattern are analyze. The total Reynolds number is introduced here to established a curve with dimensionless pressure drop, which divides the parameter interval of each flow pattern, and the change rule of cuttings flow pattern is also revealed. This study will establish a theoretical foundation for enhancing borehole cleaning efficiency and hold practical significance in guiding the drilling field construction of extended-reach wells.

Study on the change rule of low-temperature properties of asphalt binder with aging time

ABSTRACT Low-temperature cracking is common distress in asphalt pavements. Understanding the change rule of its low-temperature properties is helpful in investigating the optimal maintenance timing of asphalt pavement. In this paper, the change rule of low-temperature properties of asphalt binders with aging time is investigated by various indexes. Four asphalt binders and four anti-aging modified asphalt binders were subjected to the rolling thin film oven (RTFO) test and pressure aging vessel (PAV) test. Dynamic Shear Rheometer (DSR) with the 4 mm parallel plates was used to determine the low-temperature properties of asphalt binders. The results show that aging and low temperature have a negative impact on the low-temperature properties of asphalt binders. The anti-aging agent improves the low-temperature properties and aging resistance of asphalt binders. Compared with other indexes, the critical cracking temperature Tc and the critical temperature difference ΔTc are more suitable for analysing the effect of aging on the low-temperature properties of asphalt binders. Also, the ΔTc shows the three-stage decreasing rule of ‘fast-slow-fast’, with the inflection points. It meant that the low-temperature properties of asphalt binders had been altered at the inflection points, which provided a favourable reference to research on the optimal maintenance timing of asphalt pavement.

Behavioral Responses to Sporting Contest Design: A Review of the Literature

Sporting contests are designed to elicit an effort from contestants. Well-designed contests have beneficial behavioral responses of competitors such as increased effort which results in higher quality of competition. However, poorly designed contests may not reward the best competitor or may elicit unethical behaviors. This article reviews the literature on sporting contest design, paying particular attention to empirical studies over the last 20 years. Topic areas include different contest designs in a single sport, scheduling of contests and individual games, contest rule changes and game rule changes, and unintended behavioral consequences of sporting contest design.

From Temple to Theatre: The Making of Commercial Grassroots Performance Spaces in Republican China

Abstract: This article analyzes the transformation of xiqu (traditional Chinese theatre) performance space in Republican China (1912–1949), focusing on the performances in Wenzhou, Zhejiang Province. It investigates the institutional and habitus differences compared to larger urban areas, and changes in admission rules, particularly the implementation of ticketed admission, which transformed temples into commercial theatres. Disputes over ticketed admission, involving local officials, residents, and Japanese, emerged due to the new admission rules, which differentiated between audience and non-audience members and regulated entry into the performance space. This monetization strategy contributed to the reorganization of the local entertainment market and was followed by the conversion of temples into commercial theatres during the 1930s. This article argues that an alternative “modernization” process and spatial politics rooted in the aspiration to build a modern state was nurtured by cultural interactions but also emerged from the local context, which profoundly influenced the local spatial understanding and local society. This process was closely linked to, yet distinct from, colonial modernization. The development of cities modernized by colonization had become one of the main driving forces behind the development of the cities within their radius .

Study on condensation of oily particles under the influence of water vapor phase transition

To address the problem that oily fine particles are too small to be easily captured by traditional dust removal equipment, which hinders improving the purification efficiency, this paper proposes using the technical principle of water vapor phase transition to conduct experiments and simulations. A set of water vapor experimental devices for fine particles of oil mist is designed, and the data are analyzed by a Grimm spectrometer. The experimental results show the phase change of water vapor has a remarkable effect on the agglomeration of oily fine particles. Phase change condensation makes the particle size of fine particles increase by 5–10 times in a truly brief time, and the polymerization and removal efficiency are greatly improved. To analyze the changes of the coalescence characteristics in a larger range of parameter changes, the Euler multiphase flow model is adopted, the particle condensation growth rate function is introduced by a user-defined function to establish a coalescence model and the heterogeneous condensation growth characteristics of oily particles are analyzed in a supersaturated water vapor environment. The simulation results show that the condensing chamber temperature of the condensing chamber is 283 K, and the lower the air flow rate of the condensing chamber, the more favorable the heterogeneous condensation growth of oil particles. The change rule of agglomeration characteristics of oily particles obtained by experiment and simulation proves the feasibility of improving the removal efficiency of oily fine particles.

Seasonal variations and water chemical control mechanism of water quality in a suburban river near a coal city: a case study in the Xinbian River of Suzhou City, Anhui Province, China

Abstract To study the seasonal change rules of water quality indicators and water chemical control mechanisms in the nearby city river Xinbian River, in Suzhou City, Anhui Province, China, nine points were selected and periodically sampled for 12 months. Totally 108 water samples were collected, and basic physical–chemical indicators and routine ions (e.g., Ca2+, Mg2+, Na+, K+, SO42−, Cl−, F−, NO3−, CO32−, and HCO3−) were measured. Piper diagram, Gibbs diagram, and ion ratio method were used. The result shows that the seasonal and upstream-to-downstream variations in pH were less varied, whereas the fluctuation in dissolved oxygen was large. Four ions, namely, SO42-, F−, Cl−, and Na+ generally first decreased overall and then changed from spring to winter. The maximum contents of SO42- (406.03 mg/L), Cl− (250.22 mg/L), and Na+ (269.99 mg/L) in single water samples appeared at the S9 sampling point (Suzhou control gate) in March 2020. The dominant hydrochemical types in summer were Na–Ca–HCO3 and Na–Mg–SO4, while Na–Mg–SO4 and Na–Mg–HCO3 were the main hydrochemical types in the other seasons. The control factors of water chemical composition vary according to the season. However, rock weathering (e.g., silicate dissolution) is the dominant control factor of water chemistry in the studied river section.

Calculation and Analysis of Key Parameters of Underwater Optical Imaging System.

When photographing objects underwater, it is important to utilize an optical window to isolate the imaging device from the water. The properties of the entire imaging system will change, and the imaging quality will decrease due to the refraction impact of the water and the window. The theoretical calculation method for air imaging is no longer relevant in this context. To analyze the unique rule, this research derives the formulas for key parameters of underwater imaging systems under paraxial circumstances. First, the optical window is modeled, then the formula for the optical window's focal length in the underwater environment is derived, and the change rule for the focal length of various window forms underwater is condensed. For the ideal imaging system using a domed optical window, the equivalent two-optical group model of the imaging system is established, and the formula for calculating the focal length, working distance, and depth of field of the underwater imaging system is derived through paraxial ray tracing. The accuracy of the formula is verified through the comparative analysis of the formula calculation results and the Zemax modeling simulation results. It provides an important theoretical basis for the in-depth study of underwater imaging technology.

Sosialisasi Peraturan Permainan Bola Basket Bagi Siswa Sekolah Menengah Pertama

The socialization of basketball game rules in junior high schools throughout Gorontalo City was carried out to overcome the main problem of the need for more understanding by students who are active in basketball extracurriculars regarding the latest rule changes. This service aims to convey the latest regulations to junior high school students in Gorontalo City, predominantly male and female students who are active in basketball extracurriculars. The socialization activity lasted for 7 days, from 4 to 10 January 2024, at SMPN 2 Gorontalo City, involving 50 junior high school students throughout Gorontalo City as respondents. Measuring students' understanding of the rules of the basketball game was carried out using a questionnaire, and the results of data analysis showed that 80% of students really understood, 16% understood, and 4% quite understood the rules of the game. Therefore, the participants have a good understanding of aspects such as how to play, the basics of the game, and the rules of the basketball game.

DeforestVis: Behaviour Analysis of Machine Learning Models with Surrogate Decision Stumps

AbstractAs the complexity of machine learning (ML) models increases and their application in different (and critical) domains grows, there is a strong demand for more interpretable and trustworthy ML. A direct, model‐agnostic, way to interpret such models is to train surrogate models—such as rule sets and decision trees—that sufficiently approximate the original ones while being simpler and easier‐to‐explain. Yet, rule sets can become very lengthy, with many if–else statements, and decision tree depth grows rapidly when accurately emulating complex ML models. In such cases, both approaches can fail to meet their core goal—providing users with model interpretability. To tackle this, we propose DeforestVis, a visual analytics tool that offers summarization of the behaviour of complex ML models by providing surrogate decision stumps (one‐level decision trees) generated with the Adaptive Boosting (AdaBoost) technique. DeforestVis helps users to explore the complexity versus fidelity trade‐off by incrementally generating more stumps, creating attribute‐based explanations with weighted stumps to justify decision making, and analysing the impact of rule overriding on training instance allocation between one or more stumps. An independent test set allows users to monitor the effectiveness of manual rule changes and form hypotheses based on case‐by‐case analyses. We show the applicability and usefulness of DeforestVis with two use cases and expert interviews with data analysts and model developers.

Research on Google’s Latest Algorithm Rules and Application Strategies

With the booming development of the Internet digital economy, the number of corporate websites has increased sharply. In order to ensure the accuracy and relevance of search results to meet the personalized needs of users, search engines must constantly iterate and optimize their algorithms and rules. At the same time, developers are also actively exploring the working mechanism of search engines and the factors that affect search rankings. These studies form the cornerstone of search engine optimization. Therefore, it is crucial for SEO practitioners to deeply analyze the latest algorithm and rule changes of search engines such as Google. This article will review and analyze the algorithm and rule changes officially announced by Google in the past four years, extract the core elements that play a key role in improving search rankings, and form an optimization application strategy.

Research on inspection route of hanging environmental robot based on computational fluid dynamics

The environment of a closed piggery is commonly characterized by spatial unevenness, and there are currently no specific standards for installation points of various environmental monitoring sensors. Therefore, the project team used the hanging track inspection robot (HTIR) as an environmental mon-itoring platform to seek the environmental monitoring points and ensure the scientific layout of moni-toring points. Ansys-CFD software was used to study the change rules of environmental parameters at 1.6 m (α plane), 0.7 m (β plane), and 0.4 m (γ plane) above the ground. The 300 monitoring points ((x1~x30) ×(y1~y10)) in each plane were analyzed to determine the most suitable monitoring points and inspection routes for HTIR. The results showed that: (1) All monitoring points could be arranged directly below the y3 track. (2) Monitoring points (x1, y3), (x10, y3) and (x30, y3) were environmental feature points. At (x1, y3), the maximum relative humidity and NH3 concentration on the α plane could be detected, and the maximum wind speed, maximum temperature, and maximum NH3 concentration on other planes could also be detected; At (x10, y3), the minimum temperature and maximum relative humidity of the β and γ planes could be detected; At (x30, y3), the maximum NH3 concentration in the α plane and the minimum relative humidity in all planes could be detected. This study scientifically arranged the inspection track and monitoring points for HTIR, improved the accuracy of environmental monitoring, and put forward suggestions for reducing NH3 concentration in closed piggeries, laying the foundation for the next step.

Wrong Kind of Transparency? Mutual Funds’ Higher Reporting Frequency, Window Dressing, and Performance

ABSTRACTThis study examines whether mandatory increase in reporting frequency exacerbates agency problems. Utilizing the setting of the 2004 SEC mandate on increased reporting frequency of mutual fund holdings, we show that increased reporting frequency elevates window dressing (buying winners or selling losers shortly before the end of the reporting period). This effect is driven by low‐skill fund managers’ incentives to generate mixed signals. Funds managed by low‐skill managers experience lower returns, more outflows, and a higher collapse rate when their window dressing is elevated after the 2004 rule change. These results suggest that, although higher reporting frequency on agents’ actions can exacerbate signal manipulations, the related manipulation costs improve sorting among agents in the longer term.