Impact of the 6 February 2023 Earthquake in Turkey on Borjomi Mineral Water Wells

The study of Borjomi mineral water deposit starts from the 30 s of XIX century. Chemical composition of Borjomi deposit mineral water is of great importance for study of issues of mineral water formation, creation of geodynamic model of the deposit and increasing of useful resources. The impact of several strong earthquakes in the region on the wells of the deposit is described. Stability of chemical composition of Borjomi deposit mineral water is proved.

Geochemical characteristics and their significances of rare-earth elements in deep-water well core at the Lingnan Low Uplift Area of the Qiongdongnan Basin

A geochemical analysis of rare-earth elements （REEs） in 97 samples collected from the core of deep-water Well LS-A located at the Lingnan Low Uplift Area of the Qiongdongnan Basin is conducted, with the pur-pose of revealing the changes of sedimentary source and environment in the study region since Oligocene and evaluating the response of geochemical characteristics of REEs to the tectonic evolution. In the core samples, both∑REE and∑LREE （LREE is short for light-group REEs） fluctuate in a relatively wide range, while∑HREE （HREE is short for heavy-group REEs） maintains a relatively stable level. With the stratigraphic chronology becoming newer, both∑REE and∑LREE show a gradually rising trend overall. The∑REE of the core is relatively high from the bottom of Yacheng Formation （at a well depth of 4 207 m） to the top of Ledong Formation, and the REEs show partitioning characteristics of the enrichment of LREE, the stable content of HREE, and the negative anomaly of Eu to varying degrees. Overall the geochemical characteristics of REEs are relatively approximate to those of China＇s neritic sediments and loess, with significant ＂continental ori-entation＂. The∑REE of the core is relatively low in the lower part of Yacheng Formation （at a well depth of 4 207-4 330 m）, as shown by the REEs partitioning characteristics of the depletion of LREE, the relative enrich-ment of HREE, and the positive anomaly of Eu; the geochemical characteristics of REEs are approximate to those of oceanic crust and basalt overall, indicating that the provenance is primarily composed of volcanic eruption matters. As shown by the analyses based on sequence stratigraphy and mineralogy, the provenance in study region in the early Oligocene mainly resulted from the volcanic materials of the peripheral uplift ar-eas; the continental margin materials from the north contributed only insignificantly; the provenance devel-oped to a certain extent in the late Oligocene. Since the Miocene, the provenance has ceaselessly expanded from proximal to distal realm, embodying a characteristic of multi-source sedimentation. In the core strata with 31.5, 28.4, 25.5, 23, and 16 Ma from today, the geochemical parameters of REEs and Th/Sc ratio have significant saltation, embodying the tectonic movement events in the evolution of the Qiongdongnan Basin. In the tectonic evolution history of the South China Sea, the South China Sea Movement （34-25 Ma BP, early expansion of the South China Sea）, Baiyun Movement （23 Ma BP）, late expansion movement （23.5-16.5 Ma BP）, expansion-settlement transition, and other important events are all clearly recorded by the geochemi-cal characteristics of REEs in the core.

Determining water well sites based on electrical structure in Taobei District of Baicheng

Drilling a well randomly would lead to high uncertainties and could not meet the demand of water supply from the increasing population.It is in dire need to improve success rate of well drilling.The high-density resistivity method offers us a good choice.In this study,high-density resistivity method is used for groundwater survey in five villages in the Taobei District of Baicheng.The data obtained by high-density resistivity method is inverted through Res2dinv software.It is found that the electrical structure is characterized by a horizontal layer distribution,and the resistivity shows a"high-medium low-low"feature from shallow to deep.Moreover,obvious electrical gradient zones are identified in the strata below each section,which are interpreted as tectonic weak zones,i.e.,the faults.The low-resistance anomaly areas are inferred to be favorable aquifers.The results show that high-density resistivity exploration is an efficient and practical method for determining water well sites in rural areas and can provide a guide for finding water resources in the area.

Accessibility to Safe Drinking Water and Diarrheal Diseases: A Quasi-Experiment on a Case of Water Well Drilling in the Village of Kassouala, Municipality of Tchaourou, Benin, January 2018-July 2019

Background: In 2017, 900 million people in the world did not have sustainable access to safe drinking water (SDW). In addition, between 2016 and 2020, the global population with safely managed drinking water at home increased from 70 percent to 74 percent. Drinking water insecurity is the daily situation of people in developing countries. The lack of SDW supply is at the root of many diseases, including diarrheal diseases. Kassouala is a village in the municipality of Tchaourou without access to SDW, but having benefited from the drilling of a well in September 2018. The objective of this study was to study the effect of access to safe drinking water on the frequency of diarrheal diseases in Kassouala between January 2018 and July 2019. Methods: We conducted a quasi-experimental study in Kassouala using the natural experiments of the village of Bérétou as a control group for estimating the effect of a causal nature. There were double temporal (January 2018-July 2019) and geographical (Kassouala-Bérétou) comparisons based on data collected from health care registers. A population-based comparability survey of the two villages was conducted among 170 households in each village (experimental village, control village). A two-stage cluster sampling procedure was used to select the survey participants. Data were collected from heads of household by semi-structured questionnaire. We used Pearson or Mantel-Haenszel chi-square tests, as appropriate, and the “difference-in-difference” method to assess the effect. Results: In Kassouala, the proportion of households with access to safe drinking water had increased to 78.88%, whereas it was nil in 2018 before the well drilling, and the frequency of diarrheal diseases decreased significantly from January 2018 before drilling to July 2019 after drilling (57.11% to 44.64%;p Conclusion: Access to safe drinking water in Kassouala has a causal effect on the reduction of diarrheal diseases. However, for the supply of drinking water to be integrated into the community development plan of Tchaourou, it is necessary to support the scaling up of this intervention, which would be considered as a pilot, of a community participation program.

Zoning of Nitrite and Nitrate Concentration in Groundwater Using Geografic Information System (GIS), Case Study: Drinking Water Wells in Yazd City

Studies have demonstrated that the presence of nitrate and nitrite in drinking water can cause some disease such as cancer and blu baby in the infant. The Environmental Protection Agency (EPA) has since adopted the 10 mg/L standard as the maximum contaminant level (MCL) for nitrate-nitrogen and 1 mg/L for nitrite-nitrogen for regulated public water systems. Given the importance of nitrate and nitrite in drinking water as well as GIS ability in spatial analysis of various factors in the groundwater, this study aimed to evaluate concentration of nitrate and nitrite in the drinking water wells of Yazd using two IDW (Inverse Distance Weighting) and Kriging models. In this descriptive study, the applied data on the water quality of underground water of Yazd Environmental Health Office and the average annual nitrate and nitrite in 2015 were related to 24 wells in the studied area. The nitrate and nitrite rate in groundwater in wells was compared to the standard amount of Institute of Standard and Industrial Researches and then was analyzed via Arc GIS software using IDW and Kriging interpolation methods. The mean concentration of nitrate was 17.62 ± 3.08 mg/l and for nitrite was 0.011 ± 0.003 mg/l in the wells. In the all studied zone, the nitrate and nitrite rate was in the standard range according to the National Standard of Iran (No. 1053). In this study, Kriging interpolation method was more efficient than IDW method.

Study on Optimal Water ControlMethods for Horizontal Wells in Bottom Water Clastic Rock Reservoirs

The segmented water control technology for bottom water reservoirs can effectively delay the entry of bottom water and adjust the production profile.To clarify the impact of different methods on horizontal well production with different reservoir conditions and to provide theoretical support for the scientific selection of methods for bottom water reservoirs,a numerical simulation method is presented in this study,which is able to deal with wellbore reservoir coupling under screen tube,perforation,and ICD(Inflow Control Device)completion.Assuming the geological characteristics of the bottom-water conglomerate reservoir in the Triassic Formation of the Tahe Block 9 as a test case,the three aforementioned completion methods are tested to predict the transient production characteristics.The impact of completion parameters,reservoir permeability,bottom-water energy,and individual well control on the time to encounter water in horizontal wells(during a water-free production period)is discussed.A boundary chart for the selection of completion methods is introduced accordingly.The results show that the optimized ICD completion development effect for heterogeneous reservoirs is the best,followed by optimized perforation completion.Permeability is the main factor affecting the performances of completion methods,while bottom water energy and single well controlled reserves have a scarce impact.The average permeability of the reservoir is less than 500 mD,and ICD has the best water control effect.If the permeability is greater than 500 mD,the water control effect of perforation completion becomes a better option.

Well water contaminants and colorectal cancer in North Dakota

This study aims to identify common contaminants in well water linked to an increase in colorectal cancer(CRC)incidence rates in North Dakota(ND)counties.County-specific incidence rates for CRC were obtained from the ND Statewide Cancer Registry.Corresponding demographic,agricultural,and geophysical data were obtained from population-based sources.Associations between well water contaminants and CRC incidence were examined for 16 counties in ND with complete well water profiles between 1997-2019.Data were analyzed by multiple linear regression.Iron in well water exhibited a significant positive association with CRC incidence(4.75,P=0.001),and barium exhibited a small,but significant negative association(-0.06907,P=0.01).Residents in counties in ND with prevalent well water usage contaminated with iron may be at higher risk for CRC.

Rate transient analysis methods for water-producing gas wells in tight reservoirs with mobile water

Tight gas reservoirs with mobile water exhibit multi-phase flow and high stress sensitivity.Accurately analyzing the reservoir and well parameters using conventional single-phase rate transient analysis methods proves challenging.This study introduces novel rate transient analysis methods incorporating evaluation processes based on the conventional flowing material balance method and the Blasingame type-curve method to examine fractured gas wells producing water.By positing a gas-water two-phase equivalent homogenous phase that considers characteristics of mobile water,gas,and high stress sensitivity,the conventional single-phase rate transient analysis methods can be applied by integrating the phase's characteristics and defining the phase's normalized parameters and material balance pseudotime.The rate transient analysis methods based on the equivalent homogenous phase can be used to quantitatively assess the parameters of wells and gas reservoirs,such as original gas-in-place,fracture half-length,reservoir permeability,and well drainage radius.This facilitates the analysis of production dynamics of fractured wells and well-controlled areas,subsequently aiding in locating residual gas and guiding the configuration of well patterns.The specific evaluation processes are detailed.Additionally,a numerical simulation mechanism model was constructed to verify the reliability of the developed methods.The methods introduced have been successfully implemented in field water-producing gas wells within tight gas reservoirs containing mobile water.

Dynamics of Potable Well Water Quality in Key Mining Chiefdoms in Kono District, Eastern Sierra Leone

Groundwater is increasingly being used due to its universal availability and generally good quality. However, the risk of contamination of groundwater due to various human activities such as mining is equally increasing across the globe. In this study, the physical parameters of potable well waters in the key mining areas in Nimikoro and Tankoro Chiefdoms in Kono District were analyzed for compliance with drinking water quality standard. To do this, both unpurged and purged well water samples were collected once every month for a period of one year. Some of the well water properties like temperature, Total Dissolved Solids (TDS) and Electrical Conductivity (EC) were measured on site and others determined in the laboratory. The data collected from the laboratory analyses were statistically analyzed in MS Excel, SPSS and ArcGIS environments for quality trends in time-space fabric. The results showed that well water quality in the study area generally fell short of drinking water quality standards of Sierra Leone and WHO. There were high temperature and turbidity during the dry season and then high TDS and EC during the rainy season. Temperature and turbidity also significantly influenced well water quality in the study area, much more than TDS and EC. The implications for drinking water of lower quality than the standard could be huge for the local population and therefore needs the attention of stakeholders in the study area and decision makers in the country.

Permeability evolution and gas flow in wet coal under non-equilibrium state:Considering both water swelling and process-based gas swelling

Accurate knowledge of gas flow within the reservoir and related controlling factors will be important for enhancing the production of coal bed methane.At present,most studies focused on the permeability evolution of dry coal under gas adsorption equilibrium,gas flow and gas diffusion within wet coal under the generally non-equilibrium state are often ignored in the process of gas recovery.In this study,an improved apparent permeability model is proposed which accommodates the water and gas adsorption,stress dependence,water film thickness and gas flow regimes.In the process of modeling,the water adsorption is only affected by water content while the gas adsorption is time and water content dependent;based on poroelastic mechanics,the effective fracture aperture and effective pore radius are derived;and then the variation in water film thickness for different pore types under the effect of water content,stress and adsorption swelling are modeled;the flow regimes are considered based on Beskok’s model.Further,after validation with experimental data,the proposed model was applied to numerical simulations to investigate the evolution of permeability-related factors under the effect of different water contents.The gas flow in wet coal under the non-equilibrium state is explicitly revealed.

Inter-layer interference for multi-layered tight gas reservoir in the absence and presence of movable water

Due to the dissimilarity among different producing layers,the influences of inter-layer interference on the production performance of a multi-layer gas reservoir are possible.However,systematic studies of inter-layer interference for tight gas reservoirs are really limited,especially for those reservoirs in the presence of water.In this work,five types of possible inter-layer interferences,including both absence and presence of water,are identified for commingled production of tight gas reservoirs.Subsequently,a series of reservoir-scale and pore-scale numerical simulations are conducted to quantify the degree of influence of each type of interference.Consistent field evidence from the Yan'an tight gas reservoir(Ordos Basin,China)is found to support the simulation results.Additionally,suggestions are proposed to mitigate the potential inter-layer interferences.The results indicate that,in the absence of water,commingled production is favorable in two situations:when there is a difference in physical properties and when there is a difference in the pressure system of each layer.For reservoirs with a multi-pressure system,the backflow phenomenon,which significantly influences the production performance,only occurs under extreme conditions(such as very low production rates or well shut-in periods).When water is introduced into the multi-layer system,inter-layer interference becomes nearly inevitable.Perforating both the gas-rich layer and water-rich layer for commingled production is not desirable,as it can trigger water invasion from the water-rich layer into the gas-rich layer.The gas-rich layer might also be interfered with by water from the neighboring unperforated water-rich layer,where the water might break the barrier(eg weak joint surface,cement in fractures)between the two layers and migrate into the gas-rich layer.Additionally,the gas-rich layer could possibly be interfered with by water that accumulates at the bottom of the wellbore due to gravitational differentiation during shut-in operations.

Development of advanced anion exchange membrane from the view of the performance of water electrolysis cell

Green hydrogen produced by water electrolysis combined with renewable energy is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.Among water electrolysis technologies,the anion exchange membrane(AEM) water electrolysis has gained intensive attention and is considered as the next-generation emerging technology due to its potential advantages,such as the use of low-cost non-noble metal catalysts,the relatively mature stack assembly process,etc.However,the AEM water electrolyzer is still in the early development stage of the kW-level stack,which is mainly attributed to severe performance decay caused by the core component,i.e.,AEM.Here,the review comprehensively presents the recent progress of advanced AEM from the view of the performance of water electrolysis cells.Herein,fundamental principles and critical components of AEM water electrolyzers are introduced,and work conditions of AEM water electrolyzers and AEM performance improvement strategies are discussed.The challenges and perspectives are also analyzed.

Grain yield and N uptake of maize in response to increased plant density under reduced water and nitrogen supply conditions

The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.However,whether an increased maize density can compensate for the negative effects of reduced water and N supply on grain yield and N uptake in the arid irrigated areas remains unknown.This study is part of a long-term positioning trial that started in 2016.A split-split plot field experiment of maize was implemented in the arid irrigated area of northwestern China in 2020 to 2021.The treatments included two irrigation levels:local conventional irrigation reduced by 20%(W1,3,240 m^(3)ha^(-1))and local conventional irrigation(W2,4,050 m^(3)ha^(-1));two N application rates:local conventional N reduced by 25%(N1,270 kg ha^(-1))and local conventional N(360 kg ha^(-1));and three planting densities:local conventional density(D1,75,000 plants ha^(-1)),density increased by 30%(D2,97,500 plants ha-1),and density increased by 60%(D3,120,000 plants ha^(-1)).Our results showed that the grain yield and aboveground N accumulation of maize were lower under the reduced water and N inputs,but increasing the maize density by 30% can compensate for the reductions of grain yield and aboveground N accumulation caused by the reduced water and N supply.When water was reduced while the N application rate remained unchanged,increasing the planting density by 30% enhanced grain yield by 13.9% and aboveground N accumulation by 15.3%.Under reduced water and N inputs,increasing the maize density by 30% enhanced N uptake efficiency and N partial factor productivity,and it also compensated for the N harvest index and N metabolic related enzyme activities.Compared with W2N2D1,the N uptake efficiency and N partial factor productivity increased by 28.6 and 17.6%under W1N1D2.W1N2D2 had 8.4% higher N uptake efficiency and 13.9% higher N partial factor productivity than W2N2D1.W1N2D2 improved urease activity and nitrate reductase activity by 5.4% at the R2(blister)stage and 19.6% at the V6(6th leaf)stage,and increased net income and the benefit:cost ratio by 22.1 and 16.7%,respectively.W1N1D2 and W1N2D2 reduced the nitrate nitrogen and ammoniacal nitrogen contents at the R6 stage in the 40-100 cm soil layer,compared with W2N2D1.In summary,increasing the planting density by 30% can compensate for the loss of grain yield and aboveground N accumulation under reduced water and N inputs.Meanwhile,increasing the maize density by 30% improved grain yield and aboveground N accumulation when water was reduced by 20% while the N application rate remained constant in arid irrigation areas.

Insights on advanced substrates for controllable fabrication of photoanodes toward efficient and stable photoelectrochemical water splitting

Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of photoanodes is crucial to guarantee the high efficiency and stability of PEC reactions,which fundamentally rely on rationally designed semiconductors(as the active materials)and substrates(as the current collectors).In this review work,we start with a brief introduction of the roles of substrates in the PEC process.Then,we provide a systematic overview of representative strategies for the controlled fabrication of photoanodes on rationally designed substrates,including conductive glass,metal,sapphire,silicon,silicon carbide,and flexible substrates.Finally,some prospects concerning the challenges and research directions in this area are proposed.

A study on the simulation of carbon and water fluxes of Dangxiong alpine meadow and its response to climate change

The alpine meadow ecosystem accounts for 27%of the total area of the Tibetan Plateau and is also one of the most important vegetation types.The Dangxiong alpine meadow ecosystem,located in the south-central part of the Tibetan Plateau,is a typical example.To understand the carbon and water fluxes,water use efficiency(WUE),and their responses to future climate change for the alpine meadow ecosystem in the Dangxiong area,two parameter estimation methods,the Model-independent Parameter Estimation(PEST)and the Dynamic Dimensions Search(DDS),were used to optimize the Biome-BGC model.Then,the gross primary productivity(GPP)and evapotranspiration(ET)were simulated.The results show that the DDS parameter calibration method has a better performance.The annual GPP and ET show an increasing trend,while the WUE shows a decreasing trend.Meanwhile,ET and GPP reach their peaks in July and August,respectively,and WUE shows a“dual-peak”pattern,reaching peaks in May and November.Furthermore,according to the simulation results for the next nearly 100 years,the ensemble average GPP and ET exhibit a significant increasing trend,and the growth rate under the SSP5–8.5 scenario is greater than that under the SSP2–4.5 scenario.WUE shows an increasing trend under the SSP2–4.5 scenario and a significant increasing trend under the SSP5–8.5 scenario.This study has important scientific significance for carbon and water cycle prediction and vegetation ecological protection on the Tibetan Plateau.

Experimental study on the effect of water absorption level on rockburst occurrence of sandstone

To investigate the mechanism of rockburst prevention by spraying water onto the surrounding rocks,15 experiments are performed considering different water absorption levels on a single face.High-speed photography and acoustic emission(AE)system are used to monitor the rockburst process.The effect of water on sandstone rockburst and the prevention mechanism of water on sandstone rockburst are analyzed from the perspective of energy and failure mode.The results show that the higher the ab-sorption degree,the lower the intensity of the rockburst after absorbing water on single side of sand-stone.This is reflected in the fact that with the increase in the water absorption level,the ejection velocity of rockburst fragments is smaller,the depth of the rockburst pit is shallower,and the AE energy is smaller.Under the water absorption level of 100%,the magnitude of rockburst intensity changes from medium to slight.The prevention mechanism of water on sandstone rockburst is that water reduces the capacity of sandstone to store strain energy and accelerates the expansion of shear cracks,which is not conducive to the occurrence of plate cracking before rockburst,and destroys the conditions for rockburst incubation.

CsABF3-activated CsSUT1 pathway is implicated in pre-harvest water deficit inducing sucrose accumulation in citrus fruit

Pre-harvest water deficit(PHWD)plays an important role in sugar accumulation of citrus fruit.However,the mechanism is not known well.Here,it was confirmed that PHWD promoted sucrose accumulation of citrus fruit,but had limited effect on fructose,glucose and total acid.A sucrose transporter,Cs SUT1,which localizes to the plasma membrane,was demonstrated to function in sucrose transport induced by PHWD.Compared to wild-type,Cs SUT1 overexpression in citrus calli stimulated sucrose,fructose and glucose accumulation,while its silencing in juice sacs reduced sucrose accumulation.Increased sugar accumulation in transgenic lines enhanced plant drought tolerance,and resulted in decreased electrolyte leakage,malondialdehyde and hydrogen peroxide contents,as well as increased superoxide dismutase activity and proline contents.An abscisic acid(ABA)-responsive transcription factor,Cs ABF3,was found with a same expression pattern with Cs SUT1 under PHWD.Yeast one-hybrid,electrophoretic mobility shift assay and dual-luciferase assays all revealed that Cs ABF3 directly bound with the Cs SUT1 promoter by ABA responsive elements.When Cs ABF3 was overexpressed in citrus calli,the sucrose,fructose and glucose concentration increased correspondingly.Further,transgenic studies demonstrated that Cs ABF3 could affect sucrose accumulation by regulating Cs SUT1.Overall,this study revealed a regulation of Cs ABF3 promoting Cs SUT1 expression and sucrose accumulation in response to PHWD.Our results provide a detail insight into the quality formation of citrus fruit.

Mechanical properties and acoustic emission characteristics of soft rock with different water contents under dynamic disturbance

Uniaxial compression tests and cyclic loading acoustic emission tests were conducted on 20%,40%,60%,80%,dry and saturated muddy sandstone by using a creep impact loading system to investigate the mechanical properties and acoustic emission characteristics of soft rocks with different water contents under dynamic disturbance.The mechanical properties and acoustic emission characteristics of muddy sandstones at different water contents were analysed.Results of experimental studies show that water is a key factor in the mechanical properties of rocks,softening them,increasing their porosity,reducing their brittleness and increasing their plasticity.Under uniaxial compression,the macroscopic damage characteristics of the muddy sandstone change from mono-bevel shear damage and‘X’type conjugate bevel shear damage to a roadway bottom-drum type damage as the water content increases.Dynamic perturbation has a strengthening effect on the mechanical properties of samples with 60%and less water content,and a weakening effect on samples with 80%and more water content,but the weakening effect is not obvious.Macroscopic damage characteristics of dry samples remain unchanged,water samples from shear damage and tensile–shear composite damage gradually transformed into cleavage damage,until saturation transformation monoclinic shear damage.The evolution of acoustic emission energy and event number is mainly divided into four stages:loading stage(Ⅰ),dynamic loading stage(Ⅱ),yield failure stage(Ⅲ),and post-peak stage(Ⅳ),the acoustic emission characteristics of the stages were different for different water contents.The characteristic value of acoustic emission key point frequency gradually decreases,and the damage degree of the specimen increases,corresponding to low water content—high main frequency—low damage and high water content—low main frequency—high damage.

Influence of water coupling coefficient on the blasting effect of red sandstone specimens

This study investigates the impact of different water coupling coefficients on the blasting effect of red sandstone.The analysis is based on the theories of detonation wave and elastic wave,focusing on the variation in wall pressure of the blasting holes.Using DDNP explosive as the explosive load,blasting tests were conducted on red sandstone specimens with four different water coupling coefficients:1.20,1.33,1.50,and 2.00.The study examines the morphologies of the rock specimens after blasting under these different water coupling coefficients.Additionally,the fractal dimensions of the surface cracks resulting from the blasting were calculated to provide a quantitative evaluation of the extent of rock damage.CT scanning and 3D reconstruction were performed on the post-blasting specimens to visually depict the extent of damage and fractures within the rock.Additionally,the volume fractal dimension and damage degree of the post-blasting specimens are calculated.The findings are then combined with numerical simulation to facilitate auxiliary analysis.The results demonstrate that an increase in the water coupling coefficient leads to a reduction in the peak pressure on the hole wall and the crushing zone,enabling more of the explosion energy to be utilized for crack propagation following the explosion.The specimens exhibited distinct failure patterns,resulting in corresponding changes in fractal dimensions.The simulated pore wall pressure–time curve validated the derived theoretical results,whereas the stress cloud map and explosion energy-time curve demonstrated the buffering effect of the water medium.As the water coupling coefficient increases,the buffering effect of the water medium becomes increasingly prominent.

Recent advances in cobalt phosphide-based materials for electrocatalytic water splitting:From catalytic mechanism and synthesis method to optimization design

Electrochemical water splitting has long been considered an effective energy conversion technology for trans-ferring intermittent renewable electricity into hydrogen fuel,and the exploration of cost-effective and high-performance electrocatalysts is crucial in making electrolyzed water technology commercially viable.Cobalt phosphide(Co-P)has emerged as a catalyst of high potential owing to its high catalytic activity and durability in water splitting.This paper systematically reviews the latest advances in the development of Co-P-based materials for use in water splitting.The essential effects of P in enhancing the catalytic performance of the hydrogen evolution reaction and oxygen evolution reaction are first outlined.Then,versatile synthesis techniques for Co-P electrocatalysts are summarized,followed by advanced strategies to enhance the electrocatalytic performance of Co-P materials,including heteroatom doping,composite construction,integration with well-conductive sub-strates,and structure control from the viewpoint of experiment.Along with these optimization strategies,the understanding of the inherent mechanism of enhanced catalytic performance is also discussed.Finally,some existing challenges in the development of highly active and stable Co-P-based materials are clarified,and pro-spective directions for prompting the wide commercialization of water electrolysis technology are proposed.