Influencing factors analysis of hard limestone reformation and strength weakening under acidic effect

Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way to control the hard limestone roof.In this study,the effects of various factors on the reaction characteristics and mechanical properties of limestone were analyzed.The results show that the acid with stronger hydrogen production capacity after ionization(pK_(a)<0)has more prominent damage to the mineral grains of limestone.When pKa increases from−8.00 to 15.70,uniaxial compressive strength and elastic modulus of limestone increase by 117.22%and 75.98%.The influence of acid concentration is manifested in the dissolution behavior of mineral crystals,the crystal defects caused by large-scale acid action will lead to the deterioration of limestone strength,and the strength after 15%concentration reformation can be reduced by 59.42%.The effect of acidification time on limestone has stages and is the most obvious in the initial metathesis reaction stage(within 60 min).The key to the strength damage of acidified limestone is the participation of hydrogen ions in the reaction system.Based on the analytic hierarchy process method,the influence weights of acid type,acid concentration and acidification time on strength are 24.30%,59.54% and 16.16%,respectively.The research results provide theoretical support for the acidification control of hard limestone roofs in coal mines.

Revisiting the mitigation of coke formation:Synergism between support&promoters'role toward robust yield in the CO_(2)reformation of methane

CO_(2)reformation of methane(CRM)and CO_(2)methanation are two interconnected processes with significant implications for greenhouse gas reduction and sustainable energy production for industrial purposes.While Nibased catalysis suffers from poor stability due to coke formation or sintering,we report a super stable remedy.The active sites of mesoporous MgO were loaded using wet impregnation.The incorporation of Ni and promoters altered the physical features of the catalysts.Sm–Ni/MgO showed the smallest crystallite size,specific surface area,and pore volume.The Sm–Ni/MgO catalyst was selected as the most suitable candidate for CRM,with 82%CH4 and H2/CO ratio of approximately 100%and also for CO_(2)methanation with the conversion of carbon dioxide(82%)and the selectivity toward methane reaches 100%at temperatures above 300ᵒC.Furthermore,the Sm–Ni/MgO catalyst was stable for 900 min of continuous reaction,without significant carbon deposition.This stability was largely due to the high oxygen mobility on the catalyst surface in the presence of Sm.Overall,we demonstrated the efficacy of using promoted Ni catalysts supported by mesoporous magnesia for the improved reformation of greenhouse gases.

Research on the Joint Reformation for Public Health Services, Medical Insurance and Medical Production Circulation from the Perspective of System Science

Objective To study the linkage points in the reform of public health services,medical insurance and medical production circulation and provide countermeasures for optimizing the reform.Methods The theory of system science was used to analyze the new emergent property of key linkage points in the main reform departments.Results and Conclusion The research found that four linkage points were not active,and all departments of the reform should strengthen their linkage in the following aspects.The departmental linkage in the decision-making mechanism should be strengthened,which requires to revise the assessment indicators of essential drugs in time,and carry out relevant policies.Besides,the linkage of various departments to supervise the use of medical insurance fund should be strengthened.Therefore,the National Health Commission(NHC)and National Medical Products Administration(NMPA)should play their supervisory roles.Lastly,the construction of adverse reaction data sharing platform should be improved.

Steam Methane Reforming(SMR)Combined with Ship Based Carbon Capture(SBCC)for an Efficient Blue Hydrogen Production on Board Liquefied Natural Gas(LNG)Carriers

The objective of this study is to propose an optimal plant design for blue hydrogen production aboard a liquefiednatural gas(LNG)carrier.This investigation focuses on integrating two distinct processes—steam methanereforming(SMR)and ship-based carbon capture(SBCC).The first refers to the common practice used to obtainhydrogen from methane(often derived from natural gas),where steam reacts with methane to produce hydrogenand carbon dioxide(CO_(2)).The second refers to capturing the CO_(2) generated during the SMR process on boardships.By capturing and storing the carbon emissions,the process significantly reduces its environmental impact,making the hydrogen production“blue,”as opposed to“grey”(which involves CO_(2) emissions without capture).For the SMR process,the analysis reveals that increasing the reformer temperature enhances both the processperformance and CO_(2) emissions.Conversely,a higher steam-to-carbon(s/c)ratio reduces hydrogen yield,therebydecreasing thermal efficiency.The study also shows that preheating the air and boil-off gas(BOG)before theyenter the combustion chamber boosts overall efficiency and curtails CO_(2) emissions.In the SBCC process,puremonoethanolamine(MEA)is employed to capture the CO_(2) generated by the exhaust gases from the SMR process.The results indicate that with a 90%CO_(2) capture rate,the associated heat consumption amounts to 4.6 MJ perkilogram of CO_(2) captured.This combined approach offers a viable pathway to produce blue hydrogen on LNGcarriers while significantly reducing the carbon footprint.

Accumulation and Reformation of Silurian Reservoir in the Northern Tarim Basin

Silurian sandstone in Tarim Basin has good reservoir properties and active oil and gas shows, especially thick widely-distributed bituminous sandstone. Currently, the Silurian was found containing both bitumen and conventional reservoirs, with petroleum originating from terrestrial and marine source rocks. The diversity of their distribution was the result of ＂three sources, three stages＂ accumulation and adjustment processes. ＂Three sources＂ refers to two sets of marine rocks in Cambrian and Middle-Upper Ordovician, and a set of terrestrial rock formed in Triassic in the Kuqa depression. ＂Three stages＂ represents three stages of accumulation, adjustment and reformation occurring in Late Caledonian, Late Hercynian and Late Himalayan, respectively. The study suggests that the Silurian bitumen is remnants of oil generated from Cambrian and Ordovician source rocks and accumulated in the sandstone reservoir during Late Caledonian-Early Hercynian and Late Hercynian stages, and then damaged by the subsequent two stages of tectonic uplift movements in Early Hercynian and Pre-Triassic. The authors presumed that the primary paleo-reservoirs formed during these two stages might he preserved in the Silurian in the southern deep part of the Tabei area. Except for the Yingmaili area where the Triassic terrestrial oil was from the Kuqa Depression during Late Himalayan Stage, all movable oil reservoirs originated from marine sources. They were secondary accumulations from underlying Ordovician after structure reverse during the Yanshan- Himalayan stage. Oil/gas shows mixed-source characteristics, and was mainly from Middle-Upper Ordovician. The complexity and diversity of the Silurian marine primary properties were just defined by these three stages of oil-gas charging and tectonic movements in the Tabei area.

Bursting oscillations in a hydro-turbine governing system with two time scales

A fast-slow coupled model of the hydro-turbine governing system （HTGS） is established by introducing frequency disturbance in this paper. Based on the proposed model, the performances of two time scales for bursting oscillations in the HTGS are investigated and the effect of periodic excitation of frequency disturbance is analyzed by using the bifurcation diagrams, time waveforms and phase portraits. We find that stability and operational characteristics of the HTGS change with the value of system parameter kd. Furthermore, the comparative analyses for the effect of the bursting oscillations on the system with different amplitudes of the periodic excitation a are carried out. Meanwhile, we obtain that the relative deviation of the mechanical torque mt rises with the increase of a. These methods and results of the study, combined with the performance of two time scales and the fast-slow coupled engineering model, provide some theoretical bases for investigating interesting physical phenomena of the engineering system.

Experimental investigation on the reformation and strength weakening of hard limestone by acidizing

Several derivative disasters such as ground pressure disasters and methane explosions can be caused by the hard roof in coal mines.For limestone roofs with fine integrity and extreme hardness,collapse is difficult and the effect of conventional roof control methods is limited.Acidizing reformation is an effective way to weaken the strength of roof strata based on acid-rock reaction.In this study,the rock strength damage law and acid reaction characteristics were tested by the limestone acidification experiment.Besides,the strength degradation mechanism of limestone under the acidity effect was analyzed.The results show that the acid corrosion characteristics of limestone are obvious,as numerous mineral grains generate voids under the effects of acid corrosion,and more defects are formed inside.The acid-rock reaction is the most intense at the early stage and then gradually reaches dynamic equilibrium,and the acid corrosion rate of limestone is 4.24%(10%HCl,360 min).The hard limestone is damaged after acidification.Furthermore,the internal cracks can be induced to rapid initiation and unstable propagation under load,which reduces the strain required for rock failure by 33.33%.The failure morphology is more complicated,and the uniaxial compressive strength and elastic modulus decrease by 52.42%and 34.44%respectively.The strength weakening of hard roof after acidification is due to the defects such as intergranular cracking caused by the corrosion of rock crystals under acidity effect,which accelerate the initiation and propagation of internal cracks with external force.Macroscopically,acidification induced the deterioration of rock mechanical properties by reforming the roof structure.The feasibility of acidizing reformation method to control hard roof is confirmed in this study.

On Reformation and the Development of Capitalism

Due to Reformation movement in the 16th century,Protestantism came into being.Lutheranism,Calvinism and Puritanism rationalized and justified worldly economic activity.The Protestant asceticism was considered favorable to the development of capitalistic economy.Religious reform was in a certain degree beneficial to the development of capitalism.This thesis mainly discusses the influence of Reformation upon the development of capitalism.

Expanding telemedicine to reduce the burden on the healthcare systems and poverty in Africa for a post-coronavirus disease 2019 (COVID-19) pandemic reformation

The coronavirus disease 2019(COVID-19)global public health emergency,has exposed the fragility of health systems.Access to healthcare became a scarce commodity as healthcare providers and resource-poor popula­tions became victims of the novel corona virus.Therefore,this study focuses on Africa’s readiness to integrate telemedicine into the weak health systems and its adoption may help alleviate poor healthcare and poverty after COVID-19.We conducted a narrative review through different search strategies in Scopus on January 20,2021,to identify available literature reporting implementation of various telemedicine modes in Africa from January 1,2011 to December 31,2020.We summarized 54 studies according to geographies,field,and implementation methods.The results show a willingness to adopt telemedicine in the resource-poor settings and hard-to-reach populations,which will bring relief to the inadequate healthcare systems and alleviate poverty of those who feel the burden of healthcare cost the most.With adequate government financing,telemedicine promises to enhance the treating of communicable and non-communicable diseases as well as support health infrastructure.It can also alleviate poverty among vulnerable groups and hard-to-reach communities in Africa with adequate government financing.However,given the lack of funding in Africa,the challenges in implementing telemedicine require global and national strategies before it can yield promising results.This is especially true in regards to alleviating the multidimensionality of poverty in post-COVID-19 Africa.

Fractional-Order Modeling and Dynamical Analysis of a Francis Hydro-Turbine Governing System with Complex Penstocks

This paper investigates the stability of the Francis hydro-turbine governing system with complex penstocks in the grid-connected mode. Firstly, a novel fractional-order nonlinear mathematical model of a Francis hydro-turbine governing system with complex penstocks is built from an engineering application perspective. This model is described by state-space equations and is composed of the Francis hydro-turbine model, the fractional-order complex penstocks model, the third-order generator model, and the hydraulic speed governing system model. Based on stability theory for a fractional-order nonlinear system, this study discovers a basic law of the bifurcation points of the above system with a change in the fractional-order a. Secondly, the stable region of the governing system is investigated in detail,and nonlinear dynamical behaviors of the system are identified and studied exhaustively via bifurcation diagrams, time waveforms, phase orbits, Poincare maps, power spectrums and spectrograms. Results of these numerical experiments provide a theoretical reference for further studies of the stability of hydropower stations.

Experiments on Development of Channel Pattern in the Process of River Reformation

The changing of flow conditions caused by construction of hydro-projects will result in river's refor- mation and development of channel pattern.In this paper,the development of channel pattern in the process of reformation is studied by means of flume experiments.Influence of slope,grain size,angle-of-inflow,dis- charge and discharge process are comprehensively analyzed according to the experimental data.It was found that the channel would be widened as the river slope or discharge increased and grain s...

Stability analysis of hydro-turbine governing system based on machine learning

Hydro-turbine governing system is a time-varying complex system with strong non-linearity,and its dynamic characteristics are jointly affected by hydraulic,mechanical,electrical,and other factors.Aiming at the stability of the hydroturbine governing system,this paper first builds a dynamic model of the hydro-turbine governing system through mechanism modeling,and introduces the transfer coefficient characteristics under different load conditions to obtain the stability category of the system.BP neural network is used to perform the machine study and the predictive analysis of the stability of the system under different working conditions is carried out by using the additional momentum method to optimize the algorithm.The test set results show that the method can accurately distinguish the stability category of the hydro-turbine governing system(HTGS),and the research results can provide a theoretical reference for the operation and management of smart hydropower stations in the future.

Existence of hidden attractors in nonlinear hydro-turbine governing systems and its stability analysis

This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link,and propose a new six-dimensional system,which exhibits some hidden attractors.The parameter switching algorithm is used to numerically study the dynamic behaviors of the system.Moreover,it is investigated that for some parameters the system with a stable equilibrium point can generate strange hidden attractors.A self-excited attractor with the change of its parameters is also recognized.In addition,numerical simulations are carried out to analyze the dynamic behaviors of the proposed system by using the Lyapunov exponent spectra,Lyapunov dimensions,bifurcation diagrams,phase space orbits,and basins of attraction.Consequently,the findings in this work show that the basins of hidden attractors are tiny for which the standard computational procedure for localization is unavailable.These simulation results are conducive to better understanding of hidden chaotic attractors in higher-dimensional dynamical systems,and are also of great significance in revealing chaotic oscillations such as uncontrolled speed adjustment in the operation of hydropower station due to small changes of initial values.

Cost-Utility Analysis of Liraglutide in Type 2 Diabetes Patients in China after Chinese Reformation of Medical Care System

Objectives: The cost-utility analysis of Liraglutide is aimed at evaluating whether Liraglutide is cost-effective or not after Chinese reformation on medical insurance. The analysis is based on the results of clinical trial conducted in Asia. Methods: We applied a Markov model to estimate the quality-adjusted life years, medical cost and incidence of diabetes-related complications for patients receiving the Liraglutide as an add-on to the metformin treatment. Baseline characteristics were taken from a China’s study while the treatment effect is from an Asian study. The related medical cost and utility score were obtained from a local study in China. Having set 30 years’ simulations, the incremental cost-effectiveness ratio was calculated comparing with glimepiride treatment. The ratio would be compared with the willingness to pay for a quality-adjusted-life-year (QALY) which is three times of the GDP per capita in Beijing. Sensitivity analysis was also performed. Result: During a period of 30 years, the base-case analysis which takes discount rate at 3% shows that Liraglutide 1.8 mg results in an average incremental cost of CNY 82,671.49, an improvement in 0.12 QALYs and a reduction of incidence of diabetes-related complications comparing to glimepiride. The associated incremental cost-effectiveness ratio is CNY 688,929.08. Conclusion: Long-term project shows that taking Liraglutide as an add-on to the metformin treatment will lead to increasing quality-adjusted life years and reduction of incidence of diabetes-related complications. When the price of Liraglutide is reduced by 43 percent in China’s yuan, Liraglutide will be cost-effective in China from the healthcare system perspective taking three times of GDP per capita as our WTP threshold.

Researches on an expert decision-making system of technology reformation schemes of a colliery

In this paper, an expert decision-making system of technology reformation schemes of a colliery (for short EDSTRC) is researched by comprehensively using ES and DSS principles and computer technique. The functional and logical structures of EDSTRC as well as its sub-systems are mainly designed, and its development and application environment are simply introduced. EDSTRC is consisted of eight main parts, i.e. data base (DB), knowledge base (KB), model base (MB), approach base (AB), graph base (GB), result base (RB), man-compute system (MCS), and problem-solved system (PSS). Through application of practical examples, it is proved that the EDSTRC’s prototype design is correct, its man-computer interface is amicable, and its applicable prospect is wider.

Fluid interaction mechanism and diagenetic reformation of basement reservoirs in Beier Sag, Hailar Basin, China

Based on analysis of core observation, thin sections, cathodoluminescence, scanning electron microscope(SEM), etc., and geochemical testing of stable carbon and oxygen isotopes composition, element content, fluid inclusions, and formation water, the fluid interaction mechanism and diagenetic reformation of fracture-pore basement reservoirs of epimetamorphic pyroclastic rock in the Beier Sag, Hailar Basin were studied. The results show that:(1) Two suites of reservoirs were developed in the basement, the weathering section and interior section, the interior section has a good reservoir zone reaching the standard of type I reservoir.(2) The secondary pores are formed by dissolution of carbonate minerals, feldspar, and tuff etc.(3) The diagenetic fluids include atmospheric freshwater, deep magmatic hydrothermal fluid, organic acids and hydrocarbon-bearing fluids.(4) The reservoir diagenetic reformation can be divided into four stages: initial consolidation, early supergene weathering-leaching, middle structural fracture-cementation-dissolution, and late organic acid-magmatic hydrothermal superimposed dissolution. Among them, the second and fourth stages are the stages for the formation of weathering crust and interior dissolution pore-cave reservoirs, respectively.

Overview of the Reports on the Reformation of Personal Income Taxation

Presentation of the reports on the reformation of personal income taxation that have been prepared with a development plan for the Greek economy,that discuss the issue of taxation and point out its important features.The goal is the complete modernization of the tax system,so that it responds more fully to the principles of social justice,contributes to the economic development of the country and is governed by simple and modern procedures,which apply to all tax objects.The purpose of the study is to deepen the proposals for tax reform based on the peculiarities of the Greek economy,the international trends in this field and the weaknesses of the tax system.The effects of a tax reformation are analyzed and how it should take the form of the reform,which,however,requires a new legislation,which will bring about radical and deep cuts,which respond to the new conditions and the internationalization of the economy.Proposals for a set of structural measures,which are necessary for the country’s adaptation to the wider European environment and the elimination of the weaknesses that increase its distance from the other member countries.Citation of the common points of the reports on the reformation of personal income taxation and their adoption by the tax leadership.

Review on The Teaching of Building Materials in Higher Vocational Colleges Based on the“Three Educations”Reformation

Building materials is not only a basic course content of architectural specialization,but also a practical course content taught in higher vocational institutions.It has a large number of knowledge points,a large number of principled and operational contents,and weak logic,all of which have an impact on the teaching effect.It is necessary to strengthen research on higher vocational building materials curriculum against the background of“three educations”reformation,as well as explore curriculum teaching reform strategy in conjunction with the current situation of higher vocational building materials curriculum teaching,in order to cultivate talents of high quality and professional ability.

Upcycling municipal solid waste to sustainable hydrogen via two-stage gasification-reforming

As global municipal solid waste(MSW)quantities continue to escalate,serious socio-environmental challenges arise,necessitating innovative solutions.Waste-to-hydrogen(WTH)via two-stage gasification-reforming(TSGR)presents an emergent technology for MSW upcycling,offering to ease waste management burdens and bolster the burgeoning hydrogen economy.Despite early initiatives to advance TSGR technology,a cohesive and critical analysis of cutting-edge knowledge and strategies to enhance hydrogen production remains lacking.This review aggregates literature on MSW upcycling to hydrogen via TSGR,with a focus on optimizing process control and catalytic efficiency.It underscores technological avenues to augment hydrogen output,curtail catalyst costs,and refine system performance.Particularly,the review illuminates the potential for integrating chemical and calcium looping into TSGR processes,identifying opportunities,and pinpointing challenges.The review concludes with a summary of the current state of techno-economic analysis for this technology,presenting outstanding challenges and future research directions,with the ultimate goal of transitioning WTH from theoretical to practical application.

Methanol steam reforming for hydrogen production driven by an atomically precise Cu catalyst

Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can be used as light-harvesting materials in solar energy utilization such as photocatalytic methanol steam reforming.In this work,we report an atomically precise Cu_(13)cluster protected by dual ligands of thiolate and phosphine that can be viewed as the assembly of one top Cu atom and three Cu_(4)tetrahedra.The Cu_(13)H_(10)(SR)_(3)(PR’_(3))_(7)(SR=2,4-dichlorobenzenethiol,PR’_(3)=P(4-FC_(6)H_(4))_(3))cluster can give rise to highly efficient light-driven activity for methanol steam reforming toward H_(2)production.