This study was conducted during 2004 utilizing selected sectors of River Tigris and the This study was conducted during 2004 utilizing selected sectors of River Tigris and the Lower Al-Zab River among Kirkuk and Salah...This study was conducted during 2004 utilizing selected sectors of River Tigris and the This study was conducted during 2004 utilizing selected sectors of River Tigris and the Lower Al-Zab River among Kirkuk and Salahaldeen Governerates of Iraq. Water samples from eight stations were analyzed for total coliforms, fecal coliforms, total viable counts of bacteria, Oxygen biological demand (BOD), water turbidity, electrical conductivity and temperature. The mean total viable counts (TVC,s) of bacteria isolated was almost 800 cells/ml. The means of total coliforms (TC) and faecal coliforms (FC) were almost 708 and 436 per 100 ml of water samples tested respectively.The oxygen biological demand was more than 8 mg/l. The mean of water tubidity was more than 35 ntu. The assessment of water electrical conductivity revealed almost 354 us/cm. The present study revealed a wide variation in the water quality due to different pollution pressures affected the different sites of River Tigris and Al-Zab River waters. These water sources are used for drinking and other human activities. The Lower Al-Zab River was less affected by the mentioned factors compared to River Tigris The analysis of variance showed a significant difference between BOD values re- corded at different months and the P value was less than 0.5. The overall mean of BOD was 2.4 mg/l which is suitable for human consumption after drinking water purification process with reference to European characterizations 74/ 464/EEC of waters used as sources for drinking waters.展开更多
Greater Zab is the largest tributary of the Tigris River in lraq where the catchment area is currently being plagued by water scarcity and pollution problems.Contemporary studies have revealed that blue and green wate...Greater Zab is the largest tributary of the Tigris River in lraq where the catchment area is currently being plagued by water scarcity and pollution problems.Contemporary studies have revealed that blue and green waters of the basin have been manifesting increasing variability contributing to more severe droughts and floods apparently due to climate change.In order to gain greater appreciation of the impacts of climate change on water resources in the study area in near and distant future,SWAT(Soil and Water Assessment Tool)has been used.The model is first tested for its suitability in capturing the basin characteristics,and then,forecasts from six GCMs(general circulation models)with about half-a-century lead time to 2046-2064 and one-century lead time to 2080-2100 are incorporated to evaluate the impacts of climate change on water resources under three emission scenarios:A 1 B,A2 and BI.The results showed worsening water resources regime into the future.展开更多
Heavy metals (i.e. Cr, Co, Ni, Cu, Zn, Rb, Sr, Ba, Pb, V and Ga) distribution and their correlation with clay fraction were investigated. Fifteen samples of stream sediments were collected from the Lesser Zab River (L...Heavy metals (i.e. Cr, Co, Ni, Cu, Zn, Rb, Sr, Ba, Pb, V and Ga) distribution and their correlation with clay fraction were investigated. Fifteen samples of stream sediments were collected from the Lesser Zab River (LZR), which represent one of three major tributaries of the Tigris River at north-eastern Iraq. Grain size distributions and textural composition indicate that these sediments are mainly characterized as clayey silt and silty sand. This indicates that the fluctuation in the relative variation of the grain size distribution in the studied sediments is due local contrast in the hydrological conditions, such as stream speed, energy of transportation and geological, geomorphological and climatic characterizations that influenced sediments properties. On the other hand, clay mineral assemblages consist of palygorskite, kaolinite, illite, chlorite and smectite, which in turn reveals that these sediments were derived from rocks of similar mineralogical and chemical composition as it is coincided with other published works. The clay mineral assemblages demonstrate that major phase transformations were not observed except for the palygorskite formation from smectite, since the minerals pair exhibit good negative correlation (-0.598) within the Lesser Zab River (LZR) sediments. To determine interrelation between the heavy metals and the clay fractions in the studied samples, correlation coefficients and factor analysis were performed. Heavy metals provide significant positive correlation with themselves and with Al2O3, Fe2O3 and MnO. In addition, the results of factor analysis extracted two major factors;the first factor loading with the highest percent of variation (60%) from the major (Fe2O3, Al2O3 and MnO in weight %), heavy metals and clay fraction. While the second factor with the (14%) of variance includes Cr and silt fraction, which indicate the affinity of the heavy metals being adsorbed onto solid phase like clay particles. These observations suggest that a common mechanism regulates the heavy metal abundance, and that their concentrations are significantly controlled by fine clay fractions, clay mineral abundance and ferro manganese oxides-hydroxides.展开更多
The M’zab region is subject to an arid Saharan climate where surface and sub-surface waters are of little importance. The <span style="font-family:Verdana;">Albian Aquifer</span><span style=&...The M’zab region is subject to an arid Saharan climate where surface and sub-surface waters are of little importance. The <span style="font-family:Verdana;">Albian Aquifer</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> commonly called Continental Intercalary (CI)</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> main component</span><span style="font-family:Verdana;"> of North Western Sahara Aquifer System (NWSAS/SASS)</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> constitutes the most extensive aquifer formation of the region. In our study area</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">the CI is identified</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> as a regional subset</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> as the Albian Aquifer of M</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">zab Region (AAMR). Its groundwater resources are considered the only source available to meet the growing needs of drinking water supply</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> agriculture and industry. This aquifer is heavily exploited by a very large number of wells (more than 750). Its supply is very low</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> so it is a very low renewable layer. This requires periodic monitoring and control of its piezometric level and its physico-</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">chemical quality. The objective of our study is to know the current state of this aquifer</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">while studying the variation of its piezometry for the period 2010</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">2018</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and also the chemical quality of its groundwater by analyzing </span><span style="font-family:Verdana;">more than 90 samples over the entire study area. The application of geostatistics</span> <span style="font-family:Verdana;">by kriging and the steps of analysis</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> modelling and calculation of semivariogram</span><span style="font-family:Verdana;"> have enabled us to draw up maps of the various hydrogeological and hydrochemical parameters. As a result</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> twelve thematic maps were gridded using Geostatistical tools of ArcGIS software. The water-level-change map showed a significant drop in the groundwater level over the entire M</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">zab region and especially around the major cities (Gharda<span style="white-space:nowrap;">ï</span>a</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">Berriane</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> Metlili and Zelfana) with more than 8 meters. Chemical analyses of the Albian groundwater in the study area show the dominance of evaporite facies (Cl</span><sup><span style="font-family:Verdana;">-</span></sup><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">Na</span><sup><span style="font-family:Verdana;">+</span></sup></span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">Ca</span><sup><span style="font-family:Verdana;">2+</span></sup><span style="font-family:Verdana;">) with low concentrations than the Algerian Standards for Drinking (ASD). All the water quality indices (WQI) that have been mapped reveal that the groundwater samples were suitable for drinking and irrigation with a high quality of water located in the south of the study area.</span></span>展开更多
Kurdistan in northern Iraq, a semi-arid region, predominantly a pastureland, is nourished by Lesser Zab, which is the second major tributary of Tigris River. The discharge in the tributary, in recent times, has been e...Kurdistan in northern Iraq, a semi-arid region, predominantly a pastureland, is nourished by Lesser Zab, which is the second major tributary of Tigris River. The discharge in the tributary, in recent times, has been experiencing increasing variability contributing to more severe droughts and floods supposedly due to climate change. For a proper appreciation, SWAT model has been used to assess the impact of climate change on its hydrological components for a half-centennial lead time to 2046-2064 and a centennial lead time to 2080-2100. The suitability of the model was first evaluated, and then, outputs from six GCMs were incorporated to evaluate the impacts of climate change on water resources under three emission scenarios: A1B, A2 and B1. The results showed worsening water resources regime.展开更多
ZooKeeper Atomic Broadcast (Zab) is an atomic broadcast protocol specially designed for ZooKeeper, which supports additional crash recovery. This protocol actually has been widely adopted by famous Internet companies,...ZooKeeper Atomic Broadcast (Zab) is an atomic broadcast protocol specially designed for ZooKeeper, which supports additional crash recovery. This protocol actually has been widely adopted by famous Internet companies, but there are few studies on the correctness and credibility of the Zab protocol, and thus we utilize formal methods to study the correctness. In this paper, Zab, Paxos and Raft are all analyzed and compared to help better understand the Zab protocol. Then we model the Zab protocol with TLA+ and verify three properties abstracted from the specification by the model checker TLC, including two liveness properties and one safety property. The final experimental results can prove that the design of the protocol conforms to the original requirements. This paper makes up for the analysis of formal methods in the Zab protocol.展开更多
Rechargeable neutral aqueous zinc-air batteries(ZABs)are a promising type of energy storage device with longer operating life and less corrosiveness compared with conventional alkaline ZABs.However,the neutral ZABs no...Rechargeable neutral aqueous zinc-air batteries(ZABs)are a promising type of energy storage device with longer operating life and less corrosiveness compared with conventional alkaline ZABs.However,the neutral ZABs normally possess poor oxygen evolution reactions(OERs)and oxygen reduction reactions performance,resulting in a large charge–discharge voltage gap and low round-trip efficiency.Herein,we demonstrate a sunlight-assisted strategy for achieving an ultralow voltage gap of 0.05 V in neutral ZABs by using the FeOOH-decorated BiVO4(Fe-BiVO_(4))as an oxygen catalyst.Under sunlight,the electrons move from the valence band(VB)of Fe-BiVO_(4) to the conduction band producing holes in VB to promote the OER process and hence reduce the overpotential.Meanwhile,the photopotential generated by the Fe-BiVO_(4) compensates a part of the charging potential of neutral ZABs.Accordingly,the energy loss of the battery could be compensated via solar energy,leading to a record-low gap of 0.05 V between the charge and discharge voltage with a high round-trip efficiency of 94%.This work offers a simple but efficient pathway for solar-energy utilization in storage devices,further guiding the design of high energy efficiency of neutral aqueous ZABs.展开更多
Electrocatalysts play a crucial role in the performance of rechargeable Zn-air batteries(ZABs),but it is still difficult to produce nonprecious materials with excellent bifunctional oxygen reduction reactions(ORR)and ...Electrocatalysts play a crucial role in the performance of rechargeable Zn-air batteries(ZABs),but it is still difficult to produce nonprecious materials with excellent bifunctional oxygen reduction reactions(ORR)and oxygen evolution reactions(OER).Herein,conjugated polyaniline-phytic acid polymer(pANI-PA)was directly calcined to fabricate Co_(2)P nanoparticles embedded in N,P-doped carbon network composites(Co_(2)P@pDC-PA)for metal-air cathodes.The resulting pANI-PA derived Co_(2)Pbased carbon composite exhibits exceptional bifunctional ORR/OER activities with a half-wave potential of 0.79 V for ORR and 1.62 V of over-potential for OER at 10mA·cm^(-2).Owing to the synergistic effect of its unique three-dimensional(3D)structure,N,P-doped carbon framework,and encapsulated Co_(2)P nanoparticles,as-fabricated composite can be used as a highly efficient air cathode in the rechargeable metal-air battery.The assembled rechargeable ZAB demonstrates a high-power density of 190.0 mW·cm^(-2)and remarkable cycling stability over1000 h.This study introduced a novel approach that paves the way for the efficient,cost-effective,and scalable production of bifunctional electrocatalysts for rechargeable ZABs.展开更多
For zinc air batteries,a non-noble metal-based electrocatalyst with a high performance and stability in oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is imperative in application.Herein,a catalyst ba...For zinc air batteries,a non-noble metal-based electrocatalyst with a high performance and stability in oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is imperative in application.Herein,a catalyst based on FeCo-N encapsuled in nitrogen-doped carbon nanotubes has been prepared,which provides an implementable method to design controlled structures with excellent bifunction al electrocatalytic activities.By adjusting the molar ratio of two metals,the synthesized FeCo-N-C catalyst delivers a competitive ORR and OER performance compared with commercial Pt/C and IrO_(2),performing a low overvoltage gap between ORR(E_(1/2))and OER(E_(j=10))of 0.8 V.Moreover,as a promising cathode in zinc air battery,the FeCo-N-C catalyst possesses an affirmative stability of over 100 h and large power density(129 mW·cm^(-2)).This work demonstrates that FeCo-N-C is one of the most promising catalysts for zinc air batteries and provides a possibility for exploration of batteries with high stability by adjusting the molar ratio of metals in the catalysts.展开更多
Rechargeable zinc-air batteries(ZABs)are currently receiving extensive attention because of their extremely high theoretical specific energy density,low manufacturing costs,and environmental friendliness.Exploring bif...Rechargeable zinc-air batteries(ZABs)are currently receiving extensive attention because of their extremely high theoretical specific energy density,low manufacturing costs,and environmental friendliness.Exploring bifunctional catalysts with high activity and stability to overcome sluggish kinetics of oxygen reduction reaction and oxygen evolution reaction is critical for the development of rechargeable ZABs.Atomically dispersed metal-nitrogen-carbon(M-N-C)catalysts possessing prominent advantages of high metal atom utilization and electrocatalytic activity are promising candidates to promote oxygen electrocatalysis.In this work,general principles for designing atomically dispersed M-N-C are reviewed.Then,strategies aiming at enhancing the bifunctional catalytic activity and stability are presented.Finally,the challenges and perspectives of M-N-C bifunctional oxygen catalysts for ZABs are outlined.It is expected that this review will provide insights into the targeted optimization of atomically dispersed M-N-C catalysts in rechargeable ZABs.展开更多
Lesser Zab is one of the most important tributaries of Tigris River. During the last few decades, the streamflow significantly decreased for long periods followed by extensive flood in short periods. This study aimed ...Lesser Zab is one of the most important tributaries of Tigris River. During the last few decades, the streamflow significantly decreased for long periods followed by extensive flood in short periods. This study aimed to quantify the impact of climate change on streamflow at Dokan Dam until year 2050 using SWAT model based on the scenario of medium emission (A1B) and five climate projection models. SWAT run using Climate Forecasting System Reanalysis (CFSR) was used as weather input data then calibrated and validated on monthly time step for the period from 1980 to 2013 with Nash-Sutcliff Efficiency (NSE) of 0.73 and determination coefficient (R2) 0.73 for calibration processes. The data of this period is more reliable. The result indicated to a significant decrease on the projected streamflow until year 2050 with average streamflow for the six climate models of 167 m3/sec in past compared with the observed streamflow of 176.5 m3/sec for the base period (1980-2013). In addition, the study shows that most runoffs come from Iranian part of the Dokan Dam Watershed with 65% of total simulated runoff. It is highly recommended to improve the efficiency of water using for current and future water projects to meet the expected water shortage.展开更多
Strengthening the operational durability of oxygen reduction reaction(ORR)catalysts is essential for advancing both fuel cells and metal-air batteries.However,developing highly active and durable catalysts remains a s...Strengthening the operational durability of oxygen reduction reaction(ORR)catalysts is essential for advancing both fuel cells and metal-air batteries.However,developing highly active and durable catalysts remains a significant challenge.In this study,a catalyst(Co/Cu-N-C)featuring uniformly distributed Co nanoparticles(NPs)and Co/Cu sites has been synthesized via a facile complex-assisted pyrolysis strategy.We observed that Cu-N-C support effectively confines the growth and leaching of Co NPs during both synthesis and ORR catalysis,thereby boosting the stability of the catalyst.Meanwhile,the presence of Co NPs and Cu sites slightly contributes to the ORR activity by optimizing the ^(*)OH desorption.The assembled zinc-air battery(ZAB)demonstrates a superhigh power density of 256.1 mW·cm^(−2)and a long-term operational stability exceeding 500 h.This work not only underscores the potential of bimetallic systems and NPs in enhancing catalyst stability but also provides valuable insights for the synthesis of high-performance ORR electrocatalysts.展开更多
Novel and highly durable air cathode electrocatalyst with three dimensional （3D）-clam-shaped structure, MnO2 nanotubes-supported Fe2O3 （Fe2O3/MnO2） composited by carbon nanotubes （CNTs） （（Fe2O3/ MnO2）3/4-（C...Novel and highly durable air cathode electrocatalyst with three dimensional （3D）-clam-shaped structure, MnO2 nanotubes-supported Fe2O3 （Fe2O3/MnO2） composited by carbon nanotubes （CNTs） （（Fe2O3/ MnO2）3/4-（CNTs）1/4） is synthesized using a facile hydrothermal process and a following direct heat- treatment in the air. The morphology and composition of this catalyst are analyzed using scanning elec- tronic microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and energy dispersive X-ray spectroscopy （EDX）. The morphology characteristics reveal that flower-like Fe2O3 parti- cles are highly dispersed on both MnO2 nanotubes and CNT surfaces, coupling all three components firmly. Electrochemical measurements indicate that the synergy of catalyst exhibit superior bi- functional catalytic activity for both oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） as well as stability than Pt/C and lrO2 catalysts. Using these catalysts for air-cathodes, both primary and rechargeable zinc-air batteries （ZABs） are assembled for performance validation. In a primary ZAB, this 3D-clamed catalyst shows a decent open circuit voltage （OCV, -1.48 V） and a high discharge peak power density （349 mW cm 2）, corresponding to a coulomhic efficiency of 92%. In a rechargeahle ZABs with this bifunctional catalyst, high OCV （〉1.3 V） and small charge-discharge voltage gap （〈1.1 V） are achieved along with high specific capacity （780 mAh g 1 at 30 mA cm-2） and robust cycle-life （1,390 cycles at cycle profile of 20 mA/10 min）.展开更多
文摘This study was conducted during 2004 utilizing selected sectors of River Tigris and the This study was conducted during 2004 utilizing selected sectors of River Tigris and the Lower Al-Zab River among Kirkuk and Salahaldeen Governerates of Iraq. Water samples from eight stations were analyzed for total coliforms, fecal coliforms, total viable counts of bacteria, Oxygen biological demand (BOD), water turbidity, electrical conductivity and temperature. The mean total viable counts (TVC,s) of bacteria isolated was almost 800 cells/ml. The means of total coliforms (TC) and faecal coliforms (FC) were almost 708 and 436 per 100 ml of water samples tested respectively.The oxygen biological demand was more than 8 mg/l. The mean of water tubidity was more than 35 ntu. The assessment of water electrical conductivity revealed almost 354 us/cm. The present study revealed a wide variation in the water quality due to different pollution pressures affected the different sites of River Tigris and Al-Zab River waters. These water sources are used for drinking and other human activities. The Lower Al-Zab River was less affected by the mentioned factors compared to River Tigris The analysis of variance showed a significant difference between BOD values re- corded at different months and the P value was less than 0.5. The overall mean of BOD was 2.4 mg/l which is suitable for human consumption after drinking water purification process with reference to European characterizations 74/ 464/EEC of waters used as sources for drinking waters.
文摘Greater Zab is the largest tributary of the Tigris River in lraq where the catchment area is currently being plagued by water scarcity and pollution problems.Contemporary studies have revealed that blue and green waters of the basin have been manifesting increasing variability contributing to more severe droughts and floods apparently due to climate change.In order to gain greater appreciation of the impacts of climate change on water resources in the study area in near and distant future,SWAT(Soil and Water Assessment Tool)has been used.The model is first tested for its suitability in capturing the basin characteristics,and then,forecasts from six GCMs(general circulation models)with about half-a-century lead time to 2046-2064 and one-century lead time to 2080-2100 are incorporated to evaluate the impacts of climate change on water resources under three emission scenarios:A 1 B,A2 and BI.The results showed worsening water resources regime into the future.
文摘Heavy metals (i.e. Cr, Co, Ni, Cu, Zn, Rb, Sr, Ba, Pb, V and Ga) distribution and their correlation with clay fraction were investigated. Fifteen samples of stream sediments were collected from the Lesser Zab River (LZR), which represent one of three major tributaries of the Tigris River at north-eastern Iraq. Grain size distributions and textural composition indicate that these sediments are mainly characterized as clayey silt and silty sand. This indicates that the fluctuation in the relative variation of the grain size distribution in the studied sediments is due local contrast in the hydrological conditions, such as stream speed, energy of transportation and geological, geomorphological and climatic characterizations that influenced sediments properties. On the other hand, clay mineral assemblages consist of palygorskite, kaolinite, illite, chlorite and smectite, which in turn reveals that these sediments were derived from rocks of similar mineralogical and chemical composition as it is coincided with other published works. The clay mineral assemblages demonstrate that major phase transformations were not observed except for the palygorskite formation from smectite, since the minerals pair exhibit good negative correlation (-0.598) within the Lesser Zab River (LZR) sediments. To determine interrelation between the heavy metals and the clay fractions in the studied samples, correlation coefficients and factor analysis were performed. Heavy metals provide significant positive correlation with themselves and with Al2O3, Fe2O3 and MnO. In addition, the results of factor analysis extracted two major factors;the first factor loading with the highest percent of variation (60%) from the major (Fe2O3, Al2O3 and MnO in weight %), heavy metals and clay fraction. While the second factor with the (14%) of variance includes Cr and silt fraction, which indicate the affinity of the heavy metals being adsorbed onto solid phase like clay particles. These observations suggest that a common mechanism regulates the heavy metal abundance, and that their concentrations are significantly controlled by fine clay fractions, clay mineral abundance and ferro manganese oxides-hydroxides.
文摘The M’zab region is subject to an arid Saharan climate where surface and sub-surface waters are of little importance. The <span style="font-family:Verdana;">Albian Aquifer</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> commonly called Continental Intercalary (CI)</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> main component</span><span style="font-family:Verdana;"> of North Western Sahara Aquifer System (NWSAS/SASS)</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> constitutes the most extensive aquifer formation of the region. In our study area</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">the CI is identified</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> as a regional subset</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> as the Albian Aquifer of M</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">zab Region (AAMR). Its groundwater resources are considered the only source available to meet the growing needs of drinking water supply</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> agriculture and industry. This aquifer is heavily exploited by a very large number of wells (more than 750). Its supply is very low</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> so it is a very low renewable layer. This requires periodic monitoring and control of its piezometric level and its physico-</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">chemical quality. The objective of our study is to know the current state of this aquifer</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">while studying the variation of its piezometry for the period 2010</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">2018</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and also the chemical quality of its groundwater by analyzing </span><span style="font-family:Verdana;">more than 90 samples over the entire study area. The application of geostatistics</span> <span style="font-family:Verdana;">by kriging and the steps of analysis</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> modelling and calculation of semivariogram</span><span style="font-family:Verdana;"> have enabled us to draw up maps of the various hydrogeological and hydrochemical parameters. As a result</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> twelve thematic maps were gridded using Geostatistical tools of ArcGIS software. The water-level-change map showed a significant drop in the groundwater level over the entire M</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">zab region and especially around the major cities (Gharda<span style="white-space:nowrap;">ï</span>a</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">Berriane</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> Metlili and Zelfana) with more than 8 meters. Chemical analyses of the Albian groundwater in the study area show the dominance of evaporite facies (Cl</span><sup><span style="font-family:Verdana;">-</span></sup><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">Na</span><sup><span style="font-family:Verdana;">+</span></sup></span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">Ca</span><sup><span style="font-family:Verdana;">2+</span></sup><span style="font-family:Verdana;">) with low concentrations than the Algerian Standards for Drinking (ASD). All the water quality indices (WQI) that have been mapped reveal that the groundwater samples were suitable for drinking and irrigation with a high quality of water located in the south of the study area.</span></span>
文摘Kurdistan in northern Iraq, a semi-arid region, predominantly a pastureland, is nourished by Lesser Zab, which is the second major tributary of Tigris River. The discharge in the tributary, in recent times, has been experiencing increasing variability contributing to more severe droughts and floods supposedly due to climate change. For a proper appreciation, SWAT model has been used to assess the impact of climate change on its hydrological components for a half-centennial lead time to 2046-2064 and a centennial lead time to 2080-2100. The suitability of the model was first evaluated, and then, outputs from six GCMs were incorporated to evaluate the impacts of climate change on water resources under three emission scenarios: A1B, A2 and B1. The results showed worsening water resources regime.
基金This work was partly supported by the National Key Research and Development Program of China under Grant No.2018YFB2101300the National Natural Science Foundation of China under Grant No.61872145+1 种基金Shanghai Collaborative Innovation Center of Trustworthy Software for Internet of Things under Grant No.ZF1213the Fundamental Research Funds for the Central Universities of China.
文摘ZooKeeper Atomic Broadcast (Zab) is an atomic broadcast protocol specially designed for ZooKeeper, which supports additional crash recovery. This protocol actually has been widely adopted by famous Internet companies, but there are few studies on the correctness and credibility of the Zab protocol, and thus we utilize formal methods to study the correctness. In this paper, Zab, Paxos and Raft are all analyzed and compared to help better understand the Zab protocol. Then we model the Zab protocol with TLA+ and verify three properties abstracted from the specification by the model checker TLC, including two liveness properties and one safety property. The final experimental results can prove that the design of the protocol conforms to the original requirements. This paper makes up for the analysis of formal methods in the Zab protocol.
基金This work was supported by the National Natural Science Foundation of China(Grant No.22278349)Natural Science Foundation of Hebei Province(Grant No.B2023203026)+2 种基金Youth Foundation of Hebei Educational Committee(Grant No.QN2020137)Cultivation Project for Basic Research and Innovation of Yanshan University(Grant No.2021LGZD015)Subsidy for Hebei Key Laboratory of Applied Chemistry after Operation Performance(Grant No.22567616H).
文摘Rechargeable neutral aqueous zinc-air batteries(ZABs)are a promising type of energy storage device with longer operating life and less corrosiveness compared with conventional alkaline ZABs.However,the neutral ZABs normally possess poor oxygen evolution reactions(OERs)and oxygen reduction reactions performance,resulting in a large charge–discharge voltage gap and low round-trip efficiency.Herein,we demonstrate a sunlight-assisted strategy for achieving an ultralow voltage gap of 0.05 V in neutral ZABs by using the FeOOH-decorated BiVO4(Fe-BiVO_(4))as an oxygen catalyst.Under sunlight,the electrons move from the valence band(VB)of Fe-BiVO_(4) to the conduction band producing holes in VB to promote the OER process and hence reduce the overpotential.Meanwhile,the photopotential generated by the Fe-BiVO_(4) compensates a part of the charging potential of neutral ZABs.Accordingly,the energy loss of the battery could be compensated via solar energy,leading to a record-low gap of 0.05 V between the charge and discharge voltage with a high round-trip efficiency of 94%.This work offers a simple but efficient pathway for solar-energy utilization in storage devices,further guiding the design of high energy efficiency of neutral aqueous ZABs.
基金financially supported by Hubei Provincial Natural Science Foundation and Huangshi of China(No.2022CFD039)the National Natural Science Foundation of China(Nos.22075072,52202284 and 52301272)+6 种基金the College Students Innovation and Entrepreneurship Training Program of China(Nos.D202305271035223001,D202305271407085899 and D202305272109110950)Zhejiang Provincial Natural Science Foundation(No.LQ23E020002)Wenzhou Key Scientific and Technological Innovation Research Projects(No.ZG2023053)Wenzhou Natural Science Foundation(Nos.ZG2022032,G20220019 and G20220021)the Cooperation between Industry and Education Project of Ministry of Education(No.220601318235513)the State Key Laboratory of Electrical Insulation and Power Equipment,Xi'an Jiaotong University(No.EIPE22208)the Doctoral Innovation Foundation of Wenzhou University(No.3162023001001)。
文摘Electrocatalysts play a crucial role in the performance of rechargeable Zn-air batteries(ZABs),but it is still difficult to produce nonprecious materials with excellent bifunctional oxygen reduction reactions(ORR)and oxygen evolution reactions(OER).Herein,conjugated polyaniline-phytic acid polymer(pANI-PA)was directly calcined to fabricate Co_(2)P nanoparticles embedded in N,P-doped carbon network composites(Co_(2)P@pDC-PA)for metal-air cathodes.The resulting pANI-PA derived Co_(2)Pbased carbon composite exhibits exceptional bifunctional ORR/OER activities with a half-wave potential of 0.79 V for ORR and 1.62 V of over-potential for OER at 10mA·cm^(-2).Owing to the synergistic effect of its unique three-dimensional(3D)structure,N,P-doped carbon framework,and encapsulated Co_(2)P nanoparticles,as-fabricated composite can be used as a highly efficient air cathode in the rechargeable metal-air battery.The assembled rechargeable ZAB demonstrates a high-power density of 190.0 mW·cm^(-2)and remarkable cycling stability over1000 h.This study introduced a novel approach that paves the way for the efficient,cost-effective,and scalable production of bifunctional electrocatalysts for rechargeable ZABs.
基金financially supported by Gansu Provincial Natural Science Foundation of China(Nos.17JR5RA198,2020HZ-2)the Cooperation project of Gansu Academy of Sciences(No.2020HZ-2)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.lzujbky-2018-119,lzujbky-2018-ct08,lzujbky-2019-it23)the Key Areas Scientific and Technological Research Projects in Xinjiang Production and Construction Corps(No.2018AB004)。
文摘For zinc air batteries,a non-noble metal-based electrocatalyst with a high performance and stability in oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is imperative in application.Herein,a catalyst based on FeCo-N encapsuled in nitrogen-doped carbon nanotubes has been prepared,which provides an implementable method to design controlled structures with excellent bifunction al electrocatalytic activities.By adjusting the molar ratio of two metals,the synthesized FeCo-N-C catalyst delivers a competitive ORR and OER performance compared with commercial Pt/C and IrO_(2),performing a low overvoltage gap between ORR(E_(1/2))and OER(E_(j=10))of 0.8 V.Moreover,as a promising cathode in zinc air battery,the FeCo-N-C catalyst possesses an affirmative stability of over 100 h and large power density(129 mW·cm^(-2)).This work demonstrates that FeCo-N-C is one of the most promising catalysts for zinc air batteries and provides a possibility for exploration of batteries with high stability by adjusting the molar ratio of metals in the catalysts.
基金This work is supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)Centre Québéco is sur les Materiaux Fonctionnels(CQMF),Fonds de Recherche du Québec-Nature et Technologies(FRQNT)+2 种基金Institut National de la Recherche Scientifique(INRS)This work is also supported by the National Natural Science Foundation of China(21972017)the“Scientific and Technical Innovation Action Plan”Hong Kong,Macao and Taiwan Science&Technology Cooperation Project of Shanghai Science and Technology Committee(19160760600).F.Dong gratefully acknowledges scholarships from the China Scholarship Council(CSC).
文摘Rechargeable zinc-air batteries(ZABs)are currently receiving extensive attention because of their extremely high theoretical specific energy density,low manufacturing costs,and environmental friendliness.Exploring bifunctional catalysts with high activity and stability to overcome sluggish kinetics of oxygen reduction reaction and oxygen evolution reaction is critical for the development of rechargeable ZABs.Atomically dispersed metal-nitrogen-carbon(M-N-C)catalysts possessing prominent advantages of high metal atom utilization and electrocatalytic activity are promising candidates to promote oxygen electrocatalysis.In this work,general principles for designing atomically dispersed M-N-C are reviewed.Then,strategies aiming at enhancing the bifunctional catalytic activity and stability are presented.Finally,the challenges and perspectives of M-N-C bifunctional oxygen catalysts for ZABs are outlined.It is expected that this review will provide insights into the targeted optimization of atomically dispersed M-N-C catalysts in rechargeable ZABs.
文摘Lesser Zab is one of the most important tributaries of Tigris River. During the last few decades, the streamflow significantly decreased for long periods followed by extensive flood in short periods. This study aimed to quantify the impact of climate change on streamflow at Dokan Dam until year 2050 using SWAT model based on the scenario of medium emission (A1B) and five climate projection models. SWAT run using Climate Forecasting System Reanalysis (CFSR) was used as weather input data then calibrated and validated on monthly time step for the period from 1980 to 2013 with Nash-Sutcliff Efficiency (NSE) of 0.73 and determination coefficient (R2) 0.73 for calibration processes. The data of this period is more reliable. The result indicated to a significant decrease on the projected streamflow until year 2050 with average streamflow for the six climate models of 167 m3/sec in past compared with the observed streamflow of 176.5 m3/sec for the base period (1980-2013). In addition, the study shows that most runoffs come from Iranian part of the Dokan Dam Watershed with 65% of total simulated runoff. It is highly recommended to improve the efficiency of water using for current and future water projects to meet the expected water shortage.
基金support of the Fundamental Research Funds for the Central Universities(No.40120631)National Natural Science Foundation of China(No.52202291)for the support+2 种基金C.C.acknowledges the financial support of the Natural Science Foundation of Hubei Province(No.2022CFB388)the Natural Science Foundation of Hainan Province of China(No.623MS068)the Innovation Studio Project of the Jing men Center for Technology Transfer at Wuhan University of Technology(No.WHUTJMZX-2024CX-06).
文摘Strengthening the operational durability of oxygen reduction reaction(ORR)catalysts is essential for advancing both fuel cells and metal-air batteries.However,developing highly active and durable catalysts remains a significant challenge.In this study,a catalyst(Co/Cu-N-C)featuring uniformly distributed Co nanoparticles(NPs)and Co/Cu sites has been synthesized via a facile complex-assisted pyrolysis strategy.We observed that Cu-N-C support effectively confines the growth and leaching of Co NPs during both synthesis and ORR catalysis,thereby boosting the stability of the catalyst.Meanwhile,the presence of Co NPs and Cu sites slightly contributes to the ORR activity by optimizing the ^(*)OH desorption.The assembled zinc-air battery(ZAB)demonstrates a superhigh power density of 256.1 mW·cm^(−2)and a long-term operational stability exceeding 500 h.This work not only underscores the potential of bimetallic systems and NPs in enhancing catalyst stability but also provides valuable insights for the synthesis of high-performance ORR electrocatalysts.
基金supported by the National Natural Science Foundation of China(U1510120)Natural Science Foundation of Shanghai(14ZR1400700)+2 种基金the Project of Introducing Overseas Intelligence High Education of China(2017-2018)the Graduate Thesis Innovation Foundation of Donghua University(EG2017031,EG2016034)the College of Environmental Science and Engineering,State Environmental Protection Engineering Centre for Pollution Treatment and Control in Textile Industry,Donghua University
文摘Novel and highly durable air cathode electrocatalyst with three dimensional （3D）-clam-shaped structure, MnO2 nanotubes-supported Fe2O3 （Fe2O3/MnO2） composited by carbon nanotubes （CNTs） （（Fe2O3/ MnO2）3/4-（CNTs）1/4） is synthesized using a facile hydrothermal process and a following direct heat- treatment in the air. The morphology and composition of this catalyst are analyzed using scanning elec- tronic microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and energy dispersive X-ray spectroscopy （EDX）. The morphology characteristics reveal that flower-like Fe2O3 parti- cles are highly dispersed on both MnO2 nanotubes and CNT surfaces, coupling all three components firmly. Electrochemical measurements indicate that the synergy of catalyst exhibit superior bi- functional catalytic activity for both oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） as well as stability than Pt/C and lrO2 catalysts. Using these catalysts for air-cathodes, both primary and rechargeable zinc-air batteries （ZABs） are assembled for performance validation. In a primary ZAB, this 3D-clamed catalyst shows a decent open circuit voltage （OCV, -1.48 V） and a high discharge peak power density （349 mW cm 2）, corresponding to a coulomhic efficiency of 92%. In a rechargeahle ZABs with this bifunctional catalyst, high OCV （〉1.3 V） and small charge-discharge voltage gap （〈1.1 V） are achieved along with high specific capacity （780 mAh g 1 at 30 mA cm-2） and robust cycle-life （1,390 cycles at cycle profile of 20 mA/10 min）.
