Covalently Bonded Ni Sites in Black Phosphorene with Electron Redistribution for Efficient Metal‑Lightweighted Water Electrolysis

The metal-lightweighted electrocatalysts for water splitting are highly desired for sustainable and economic hydrogen energy deployments,but challengeable.In this work,a low-content Ni-functionalized approach triggers the high capability of black phosphorene(BP)with hydrogen and oxygen evolution reaction(HER/OER)bifunctionality.Through a facile in situ electro-exfoliation route,the ionized Ni sites are covalently functionalized in BP nanosheets with electron redistribution and controllable metal contents.It is found that the as-fabricated Ni-BP electrocatalysts can drive the water splitting with much enhanced HER and OER activities.In 1.0 M KOH electrolyte,the optimized 1.5 wt%Nifunctionalized BP nanosheets have readily achieved low overpotentials of 136 mV for HER and 230 mV for OER at 10 mA cm^(−2).Moreover,the covalently bonding between Ni and P has also strengthened the catalytic stability of the Ni-functionalized BP electrocatalyst,stably delivering the overall water splitting for 50 h at 20 mA cm^(−2).Theoretical calculations have revealed that Ni–P covalent binding can regulate the electronic structure and optimize the reaction energy barrier to improve the catalytic activity effectively.This work confirms that Ni-functionalized BP is a suitable candidate for electrocatalytic overall water splitting,and provides effective strategies for constructing metal-lightweighted economic electrocatalysts.

Effects of nitrogen fertilization strategies on nitrogen use efficiency in physiology, recovery, and agronomy and redistribution of dry matter accumulation and nitrogen accumulation in two typical rice cultivars in Zhejiang, China

Field experiments were conducted in farmers’ rice fields in 2001 and 2002 to study the effects of nitrogen (N) man-agement strategies on N use efficiency in recovery (RE), agronomy (AE) and physiology (PE) and redistribution of dry matter accumulation (DMA) and nitrogen accumulation (NA) in two typical rice cultivars in Jinhua, Zhejiang Province. This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency (NUE) of rice in Zhejiang by comparing farmers’ fertilizer practice (FFP) with advanced site-specific nutrient management (SSNM) and real-time N management (RTNM). The results showed that compared to FFP, SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering. There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution (post-DMR) and post-flowering nitrogen redistribution (post-NR). These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer’s routine practice of Zhejiang. With SSNM, about 15% of the current total N input in direct-seeding early rice and 45% in single rice could be reduced without yield loss in Zhejiang, China.

Variation of nutrient fluxes by rainfall redistribution processes in the forest canopy of an urban larch plantation in northeast China

Atmospheric deposition(dry and wet deposition)is one of the primary sources of chemical inputs to terrestrial ecosystems and replenishes the nutrient pool in forest ecosystems.Precipitation often acts as a primary transporting agent and solvent;thus,nutrient cycles in forests are closely linked to hydrological processes.We collected precipitation data during a growing season to explore variations in nutrient cycling and nutrient balances in the rainfall redistribution process(wet deposition)in a larch plantation in northeast China.We measured nutrient(NO_(3)^(-),PO_(4)^(3−),Cl^(−),K,Ca,Na,and Mg)inputs via bulk precipitation,throughfall and stemfl ow,and used a canopy budget model to estimate nutrient fl uxes via canopy exchange.Our results suggest that the average concentrations of the base cation(K,Ca,Na,and Mg)showed the following order:stemfl ow>throughfall>bulk precipitation.Throughfall and stemfl ow chemistry dramatically fl uctuated over the growing season when net fl uxes(throughfall+stemfl ow—bulk precipitation)of NO−3,PO3−4,SO2−4,Cl−,K,Ca,Na,and Mg were−6.676 kg·ha^(-1),−1.094 kg·ha^(-1),−2.371 kg·ha^(-1),1.975 kg·ha^(-1),0.470 kg·ha^(-1),−5.202 kg·ha^(-1),−0.336 kg·ha^(-1),and 1.397 kg·ha^(-1),respectively.These results suggest that NO−3,PO3−4,SO2−4,Ca,and Na were retained,while Cl−,K,and Mg were washed off by throughfall and stemfl ow.

Exercise induces tissue hypoxia and HIF-1α redistribution in the small intestine

Background'. Exercise induces blood flow redistribution among tissues, leading to splanchnic hypoperfusion. Intestinal epithelial cells are positionedbetween the anaerobic lumen and the highly metabolic lamina propria with an oxygen gradient. Hypoxia-inducible factor (HIF)-la is piv・otal in the transcriptional response to the oxygen flux.Methods: In this study, the pimonidazole hydrochloride staining was applied to observe the tissue hypoxia in different organs, which might beaffected by the blood flow redistribution. The HIF-la luciferase reporter ROSA26 oxygen-dependent degradation domain (ODD)-Luc/+ mousemodel (ODD domain-Luc;female, n = 3—6/group) was used to detect the HIF-la expression in the intestine. We used 3 swimming models: mod・erate exercise for 30 min, heavy-intensity exercise bearing 5% bodyweight for 1.5 h, and long-time exercise for 3 h.Results'. We found that 1 session of swimming at different intensities could induce tissue hypoxia redistribution in the small intestine, colon, liverand kidney, but not in the spleen, heart, and skeletal muscle. Our data showed that exercise exacerbated the extent of physiological hypoxia in thesmall intestine. Next, using ODD-Luc mice, we found that moderate exercise increased the in vivo HIF-la level in the small intestine. The post・exercise HIF-la level was gradually decreased in a time-dependent manner. Interestingly, the redistribution of tissue hypoxia and the increase ofHIF-la expression were not related to the exercise intensity and duration.Conclusion'. This study provided evidence that the small intestine is the primary target organ for exercise-induced tissue hypoxia and HIF-laredistribution, suggesting that HIF-la may be a potential target for the regulation of gastrointestinal functions after exercise.

POSTMORTEM REDISTRIBUTION KINETICS OF ACONITINE IN RABBITS

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Solute Redistribution Model for Multicomponent AHoys during Rapid Solidification

1.IntroductionThe solute redistribution models for binary alloys during the rapid solidification havebeen extensively studied in recent years[1-10],but up to now the solute redistribution modelfor multicomponent alloys has not been reported.In this paper the solute redistribution mod-el for the multicomponent alloys based on the Aziz model is established theoretically.

REDISTRIBUTION OF IMPURITY ATOMS AI, Si, Mn AND Cu IN Ni DURING LASER MELTING

An explanation of the redistribution of impurity atoms such as Al, Si, Mn and Cu in purenickel during low speed laser melting is made by one-dimensional analysis model for heattransfer. The solid-liquid interface solute redistribution seems to be the principal cause thatmakes the impurity atoms redistribute in the depth direction. The diffusion of impurity atomsfrom low to high temperature zones and their surface selective evaporation are believed to benoticeably contributed to the redistribution.

Impacts of oak deforestation and rainfed cultivation on soil redistribution processes across hillslopes using ^(137)Cs techniques

Background:As one of the main components of land-use change,deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences.Specifically,one example could be the impacts of land-use changes from oak forests into agricultural ecosystems,which may have detrimental impacts on soil mobilization across hillslopes.However,to date,scarce studies are assessing these impacts at different slope positions and soil depths,shedding light on key geomorphological processes.Methods:In this research,the Caesium-137(^(137)Cs)technique was applied to evaluate soil redistribution and soil erosion rates due to the effects of these above-mentioned land-use changes.To achieve this goal,we select a representative area in the Lordegan district,central Iran.^(137)Cs depth distribution profiles were established in four different hillslope positions after converting natural oak forests to rainfed farming.In each hillslope,soil samples from three depths(0–10,10–20,and 20–50 cm)and in four different slope positions(summit,shoulder,backslope,and footslope)were taken in three transects of about 20m away from each other.The activity of ^(137)Cs was determined in all the soil samples(72 soil samples)by a gamma spectrometer.In addition,some physicochemical properties and the magnetic susceptibility(MS)of soil samples were measured.Results:Erosion rates reached 51.1 t·ha^(−1)·yr^(−1) in rainfed farming,whereas in the natural forest,the erosion rate was 9.3 t·ha^(−1)·yr^(−1).Magnetic susceptibility was considerably lower in the cultivated land(χhf=43.5×10^(−8)m^(3)·kg^(−1))than in the natural forest(χhf=55.1×10^(−8)m^(3)·kg^(−1)).The lower soil erosion rate in the natural forest land indicated significantly higher MS in all landform positions except at the summit one,compared to that in the rainfed farming land.The shoulder and summit positions were the most erodible hillslope positions in the natural forest and rainfed farming,respectively.Conclusions:We concluded that land-use change and hillslope positions played a key role in eroding the surface soils in this area.Moreover,land management can influence soil erosion intensity and may both mitigate and amplify soil loss.

Charge redistribution caused by sulfur doping of bimetal FeCo phosphides supported on heteroatoms-doped graphene for Zn-air batteries with stable cycling

Exploring feasible synthesis approaches to highly efficient and robust bifunctional electrocatalysts toward both oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is triggering researcher’s even-increasing interest in rechargeable Zn-air batteries.Herein,sulfur-doped bimetal FeCo phosphide nanoparticles dispersed on N,P,S-tri-doped graphene(donated as S-FeCo3P/NPSG)are rationally prepared through a controllable one-step carbothermal-phosphorization strategy.The modified charge distribution and electron-donor properties of S-FeCo3P/NPSG caused by S decoration render a significantly beneficial effect on the electrocatalytic activities.Consequently,the S-FeCo3P/NPSG electrode exhibits extraordinary bifunctional activities toward oxygen electrochemistry of the OER overpotential of 290 m V at 10 m A cm^(-2) and the ORR half-wave potential of 0.83 V,approaching to that of noblemetal IrO_(2)(289 m V)and Pt/C(0.84 V),respectively,but with more stronger operation stability in alkaline media.When S-FeCo3P/NPSG serves as the air cathode for liquid-state Zn-air battery,the large peak power density and energy density,as well as superb discharge-charge durability(cycling life>600 h)of this device are obtained.Furthermore,all-solid-state Zn-air battery with S-FeCo3P/NPSG as air electrode also displays excellent mechanical flexibility,high power density and stable cycling stability.The self-reconstruction behavior of the S-FeCo3P/NPSG cathode catalysts is also investigated during the electrocatalytic Zn-air battery operation.This work would provide some novel inspiration from aspects of bonding and charge distribution for the rational construction of active and cost-efficient bifucntional oxygen electrocatalysts for energy storage and conversion devices.

Experimental Observation of Electrie Field Induced C_(60) Redistribution in Benzene Solution

We report the experimental observation of electric field induced Gso redistribution,in benzene solution by thermal blooming change of transmitted light.The pol&riz&tion of C_(60) molecules in external field is analyzed.

Change and Redistribution of Immature Fiber Number during Cotton Carding Based on Different Taker-in Speeds

The change and redistribution of immature fiber number after cotton carding were investigated under different taker-in speeds.The immature fiber contents (IFCs) of card sliver,flat strips,takerin droppings and cylinder screen droppings (including droppings under cylinder screen and cylinder-doffer triangle section) produced under different taker-in speeds were tested by using USTER advanced fiber information system (AFIS). Based on these results and relevant data,immature fiber number was calculated. Results show that the carding process makes the immature fiber number increase. After carding, immature fibers are distributed mainly in card sliver,accounting for approximately 90% in their total number. All of the cylinder screen,taker-in and flat have the functions of excluding immature fibers; furthermore,IFC in cylinder screen droppings is the highest,followed successively by those in taker-in droppings,flat strips and card sliver. The IFC of card sliver is the lowest when the taker-in speeds are 1000 and 1400 r/min.

Tailoring interfacial electron redistribution of Ni/Fe_(3)O_(4) electrocatalysts for superior overall water splitting

Exploring highly active earth-abundant bifu nctional electrocatalysts for water splitting at a high output is essential for the forthcoming hydrogen economy.Non-noble Fe_(3)O_(4) catalyst owns outstanding conductivity and its octahedral Fe sites can markedly promote water dissociation.However,it lacks active centers on the surface,resulting in its poor activity when used as a catalyst for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Herein,an electron redistribution strategy is proposed by introducing Ni sites onto the surface of Fe_(3)O_(4)(Ni/Fe_(3)O_(4)).The abundant delocalized electrons,derived from the electronic interaction of Ni and Fe_(3)O_(4) species,significantly optimize the electronic structure of the Ni/Fe_(3)O_(4) catalyst,leading to its improved adsorption behavior.This Ni/Fe_(3)O_(4) catalyst exhibits remarkable bifunctional activity,steadily outputting 1000 mA cm^(-2)at the low overpotential of 387 mV for HER and 338 mV for OER,respectively.Using Ni/Fe_(3)O_(4) as a bifunctional catalyst for overall water splitting reaction exhibits the optimal performance with outstanding stability,obtaining a current density of1000 mA cm^(-2)at 1.98 V,much superior to a Pt/C‖IrO_(2)cell.Experimental analysis and theoretical calculations collectively corroborate that the electron redistribution of Fe_(3)O_(4) is activated by coupling Ni species,leading to the promoted HER and OER kinetics.This electron redistribution strategy provides an effective method to activate transition metal-based catalysts which are promising to be utilized as superior electrocatalysts for the industrial overall water splitting reaction.

Solute redistribution and macrosegregation in continuous casting slab of carbon steel during solidification process

Based on the modified Scheil model of solute redistribution,the effects of solidification rate,molten steel flow,and alloy composition on solute macrosegregation during the solidification of carbon steel continuous casting billet are calculated and analyzed. The formation mechanism of "white band "segregation under the condition of electromagnetic stirring is also involved,and some practical countermeasures to restrain the central segregation are suggested. The results show that the modified Scheil model can be applied to predict and analyze the macrosegregation of casting slab effectively. The ratio vx/R of the flow velocity of molten steel to solidification rate has decisive formations of segregation such as linear,V,and "white band"types. It is an effective way to select sufficient terminal cooling and reasonable electromagnetic stirring in order to decrease macrosegregation in the slab. The concept of the characteristic distance of solute enrichment layer can drastically simplify the calculation of solute redistribution at the solid/liquid interface of various elements in carbon steel.

Who Are Hakka People?A Discussion of the Redistribution and Reco of the Hakka People in the Hakka Policies During Shui-Bian Chen’s Term as President

This study discusses the contents and methods of the implementation of Hakka policies during Shui-Bian Chen’s term as president from the viewpoint of redistribution and recognition proposed by Nancy Fraser, and finds that the Hakka people mostly feel inferior and are not willing to identify themselves as Hakkas. The issue of “‘who’ are Hakka people” thus emerged during the implementation of the Hakka policies.

Solute Redistribution in Directional Melting Process

The solute redistribution in directional melting process is theoretically studied. Based on quantitative evaluations, uniform solute distribution in liquid and a quasi-steady solute distribution in solid are supposed. The discussion on the solute balance comes to a simple model for the solute redistribution in directional melting process. As an example, the variation of liquid composition during melting process of carbon steel is quantitatively evaluated using the model. Results show that the melting of an alloy starts at solidus temperature, but approaches the liquidus temperature after a very short transient process.

Dynamic coupling of ferrihydrite transformation and associated arsenic desorption/redistribution mediated by sulfate-reducing bacteria

Sulfate-reducing bacteria play an important role in the geochemistry of iron(oxyhydr)oxide and arsenic(As)in natural environments;however,the associated reaction processes are yet to be fully understood.In this study,batch experiments coupled with geochemical,spectroscopic,microscopic,and thermodynamic analyses were conducted to investigate the dynamic coupling of ferrihydrite transformation and the associated As desorption/redistribution mediated by Desulfovibrio vulgaris(D.vulgaris).The results indicated that D.vulgaris could induce ferrihydrite transformation via S^(2-)-driven and direct reduction processes.In the absence of SO_(4)^(2-),D.vulgaris directly reduced ferrihydrite,and As desorption and re-sorption occurred simultaneously during the partial transformation of ferrihydrite to magnetite.The increase in SO_(4)^(2-)loading promoted the S^(2-)-driven reduction of ferrihydrite and accelerated the subsequent mineralogical transformation.In the low and medium SO_(4)^(2-)treatments,ferrihydrite was completely transformed to a mixture of magnetite and mackinawite,which increased the fraction of As in the residual phase and stabilized As.In the high SO_(4)^(2-)treatment,although the replacement of ferrihydrite by only mackinawite also increased the fraction of As in the residual phase,22.1%of the total As was released into the solution due to the poor adsorption affinity of As to mackinawite and the conversion of As^(5+)to As^(3+).The mechanisms of ferrihydrite reduction,mineralogy transformation,and As mobilization and redistribution mediated by sulfate-reducing bacteria are closely related to the surrounding SO_(4)^(2-)loadings.These results advance our understanding of the biogeochemical behavior of Fe,S,and As,and are helpful for the risk assessment and remediation of As contamination.

Nutrient enrichment driven by canopy rainfall redistribution:Mechanism,quantification,and pattern

Vegetation canopies intercept and redistribute rainfall into throughfall and stemflow,which transfer substantial amounts of elements into the soil,influencing soil microbial community,plant survival,and plant community succession.Despite advancements in ecohydrological research,the implication of nutrient enrichment resulting from this redistribution of rainfall by canopies remains largely unexplored.To address this gap,we conducted a systematic review of 1020 papers published between 2000 and 2022,gathering data on nutrient concentration and enrichment for critical ions(including K^(+),Na^(+),Ca^(2+),Mg^(2+),NH_(4)^(+),Cl^(-),NO_(3)^(-)and SO_(4)^(2-))from the Web of Science and Chinese Knowledge Infrastructure databases.We aimed to synthesize the mechanisms,quantify the enrichments,and identify global patterns of nutrient enrichment in stemflow and throughfall across climate zones,and vegetation types and ecosystems.The results of this study indicate that stemflow exhibits,on average,2.1times greater ion concentration(6.13 mg L^(-1))compared to throughfall.In particular,among the investigated ions,SO_(4)^(2-)(12.45and 6.32 mg L^(-1))for stemflow and throughfall,respectively,and Cl^(-)(9.21 and 4.81 mg L^(-1))exhibit the highest concentrations in both rainfall redistribution components,while K^(+)(13.7 and 5.8)and Mg^(2+)(5.6 and 2.8)have the highest enrichment factors.Across climate zones,throughfall and stemflow show the lowest ion concentrations but the highest enrichment factors in extremely humid regions.Along the temperature gradient,ion concentrations are the highest in cold climates with no clear patterns observed for enrichment factors with increasing temperature.In addition,shrubs,conifers,mixed forests,and artificial ecosystems demonstrate enrichment factors 1.1 to 3.0 times greater than those of trees,broad-leaved plants,pure forests,and natural ecosystems.These findings emphasize the need for increased attentions to artificial ecosystems,such as urban and agricultural ecosystems,which often received limited research focus,especially regarding shrubs and conifers exhibiting stronger nutrients enrichment capabilities.Future investigations should integrate soil moisture analysis to better understand the impact of rainfall redistribution on the nutrient enrichment processes,patterns,and nutrient balance in global terrestrial ecosystems.

Interfacial charge redistribution to promote the catalytic activity of Vs-CoP-CoS_(2)/C n-n heterojunction for oxygen evolution

Modulating surface charge redistribution based on interface and defect engineering has been considered as a resultful means to boost electrocatalytic activity.However,the mechanism of synergistic regulation of heterojunction and vacancy defects remains unclear.Herein,a Vs-CoP-CoS_(2)/C n-n heterojunction with sulfur vacancies is successfully constructed,which manifests superior electrocatalytic activity for oxygen evolution,as demonstrated by a low overpotential of 170 mV to reach 10 mA/cm^(2).The experimental results and density functional theory calculations testify that the outstanding OER performance of Vs-CoP-CoS_(2)/C heterojunction is owed to the synergistic effect of sulfur vacancies and built-in electric field at n-n heterogeneous interface,which accelerates the electron transfer,induces the charge redistribution,and regulates the adsorption energy of active intermediates during the reaction.This study affords a promising means to regulate the electrocatalytic performance by the construction of heterogeneous interfaces and defects,and in-depth explores the synergistic mechanisms of n-n heterojunction and vacancies.

Synergistic Effect of Nitrogen/Phosphorus Co-Doping and Molybdenum Carbide Induced Electron Redistribution of Carbon Layer to Boost Hydrogen Evolution Reaction

The development of highly efficient non-precious-metal-based electrocatalysts for the hydrogen evolution reaction is imperative for promoting the large-scale application of electrochemical water splitting.Herein,nitrogen/phosphorus co-doped carbon nanorods encapsulated Mo_(2)C nanoparticles(Mo_(2)C@PNc)have been prepared by pre-phosphating treatment in combination of the coordination with polydopamine and the subsequent pyrolysis.The phosphating temperature has a significant effect on the content of phosphorus within the resultant Mo_(2)C@PNC,and the optimal catalyst delivers superior HER activity with the low overpotential of 104 mV at a current density of 10 mAcm^(-2) and good stability for 8 h,which has been theoretically demonstrated to originate from the synergistic effect between P doping and Mo_(2)C induced electron redistribution of nitrogen-doped carbon layer.

Interfacial coupling of sea urchin-like(Mo4O11-MoS2-VO_(2)) promoted electron redistributions for significantly boosted hydrogen evolution reaction

Developing efficient electrocatalysts for hydrogen evolution reaction(HER) is of great importance in contemporary water electrolysis technology. Here, a novel hierarchically sea urchin-like electrocatalyst(Mo_(4)O_(11)-MoS_(2)-VO_(2)) is synthesized by hydrothermal deposition and post-annealing strategy. The optimized electrocatalyst behaves as a high active hydrogen evolution electrode in 0.5 mol/L H_(2)SO_(4). This electrode needs overpotential of only 43 m V to achieve 10 m A/cm^(2)with a Tafel slope of 37 m V/dec and maintains its catalytic activity for at least 36 h. Better than most previously reported non-noble metal electrocatalysts anchored on carbon cloth. It is worth mentioning that the hierarchical sea urchin-like structure promotes the redistribution of electrons and provides more catalytic active sites. This strategy shows a way for the construction of inexpensive non-noble metal electrocatalysts in the future.