Optimized reinforcement of granite residual soil using a cement and alkaline solution: A coupling effect

Granite residual soil (GRS) is a type of weathering soil that can decompose upon contact with water, potentially causing geological hazards. In this study, cement, an alkaline solution, and glass fiber were used to reinforce GRS. The effects of cement content and SiO_(2)/Na2O ratio of the alkaline solution on the static and dynamic strengths of GRS were discussed. Microscopically, the reinforcement mechanism and coupling effect were examined using X-ray diffraction (XRD), micro-computed tomography (micro-CT), and scanning electron microscopy (SEM). The results indicated that the addition of 2% cement and an alkaline solution with an SiO_(2)/Na2O ratio of 0.5 led to the densest matrix, lowest porosity, and highest static compressive strength, which was 4994 kPa with a dynamic impact resistance of 75.4 kN after adding glass fiber. The compressive strength and dynamic impact resistance were a result of the coupling effect of cement hydration, a pozzolanic reaction of clay minerals in the GRS, and the alkali activation of clay minerals. Excessive cement addition or an excessively high SiO_(2)/Na2O ratio in the alkaline solution can have negative effects, such as the destruction of C-(A)-S-H gels by the alkaline solution and hindering the production of N-A-S-H gels. This can result in damage to the matrix of reinforced GRS, leading to a decrease in both static and dynamic strengths. This study suggests that further research is required to gain a more precise understanding of the effects of this mixture in terms of reducing our carbon footprint and optimizing its properties. The findings indicate that cement and alkaline solution are appropriate for GRS and that the reinforced GRS can be used for high-strength foundation and embankment construction. The study provides an analysis of strategies for mitigating and managing GRS slope failures, as well as enhancing roadbed performance.

Residual alkali-evoked cross-linked polymer layer for anti-air-sensitivity LiNi_(0.89)Co_(0.06)Mn_(0.05)O_(2)cathode

High-energy density lithium-ion batteries(LIBs)with layered high-nickel oxide cathodes(LiNi_(x)Co_(y)Mn_(1-x-y)O_(2),x≥0.8)show great promise in consumer electronics and vehicular applications.However,LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)faces challenges related to capacity decay caused by residual alkalis owing to high sensitivity to air.To address this issue,we propose a hazardous substances upcycling method that fundamentally mitigates alkali content and concurrently induces the emergence of an anti-air-sensitive layer on the cathode surface.Through the neutralization of polyacrylic acid(PAA)with residual alkalis and then coupling it with 3-aminopropyl triethoxysilane(KH550),a stable and ion-conductive cross-linked polymer layer is in situ integrated into the LiNi_(0.89)Co_(0.06)Mn_(0.05)O_(2)(NCM)cathode.Our characterization and measurements demonstrate its effectiveness.The NCM material exhibits impressive cycling performance,retaining 88.4%of its capacity after 200 cycles at 5 C and achieving an extraordinary specific capacity of 170.0 mA h g^(-1) at 10 C.Importantly,this layer on the NCM efficiently suppresses unfavorable phase transitions,severe electrolyte degradation,and CO_(2)gas evolution,while maintaining commendable resistance to air exposure.This surface modification strategy shows widespread potential for creating air-stable LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)cathodes,thereby advancing high-performance LIBs.

Response of Rice Growth and Nutrient Absorption in a SalineAlkali Paddy to Different Nitrogen Fertilizer Applications

Nitrogen(N),phosphorus(P)and carbon(C)are essential nutrients for rice growth and development,but the response of nutrient absorption by rice plants to different types of nitrogen fertilizer(N-fertilizer)under saline-alkali conditions is unclear.This study conducted a 147-day field-scale experiment to evaluate rice biomass and nutrient absorption capacity with five N-fertilizer applications.The results showed that the biomass.

The Decarbonization of Construction—How Can Alkali-Activated Materials Contribute?

1.Introduction and context Enormous emphasis is currently being paid to the decarbonization of the global built environment as a leading priority for the engineering community and related industrial sectors[1].One of the main contributors to the overall emissions footprint of the built environment-and thus a cornerstone of efforts to achieve decarbonization-is the emissions profile of construction materials during their production and utilization.The cement and concrete sector is the largest-volume contributor to the emissions incurred in meeting the world’s construction material needs and is therefore targeted in the discussion of the deep,rapid decarbonization that must be achieved in order to minimize irreversible damage to the Earth and its ecosystems.

Calcium carbonate-associated milk-alkali syndrome as a cause of altered mental status in the emergency department:a case report

Hypercalcemic crises as a result of milk-alkali syndrome(MAS)are an uncommon cause of altered mental status and acute renal failure in the emergency department.Although it is uncommonly reported in the emergency medicine literature,emergency physicians should be aware of this syndrome due to significant morbidity and mortality if left undiagnosed.

Highly dispersed Pd nanoparticles in situ reduced and stabilized by nitrogen-alkali lignin-doped phenolic nanospheres and their application in vanillin hydrodeoxygenation

Herein,we introduced a nitrogen-alkali lignin-doped phenolic resin(N@AL_(n)PR)to produce palladium nanoparticles through an in situ reduction of palladium in an aqueous phase,without the need for additional reagents or a reducing atmosphere.The phenolic resin nanospheres and the resulting palladium nanoparticles were extensively characterized.Alkali lignin created a highly conducive environment for nitrogen incorporation,dispersion,reduction,and stabilization of palladium,leading to a distinct catalytic performance of palladium nanoparticles in vanillin hydrodeoxygenation.Under specific conditions of 1 mmol of vanillin,40 mg of catalyst,1 MPa H_(2),90°C,and 3 h,the optimized Pd/N@AL_(30)PR catalyst exhibited a nearly complete conversion of vanillin,98.9%selectivity toward p-creosol,and good stability for multiple reuses.Consequently,an environmentally friendly lignin-based catalyst was developed and used for the efficient hydrodeoxygenation conversion of lignin-based platform compounds.

Steric hindrance shielding viologen against alkali attack in realizing ultrastable aqueous flow batteries

Viologens known as a kind of promising negolyte materials for aqueous organic redox flow batteries,face a critical stability challenge due to the S_N2 nucleophilic attack by hydroxide ions(OH-)during the battery cycling.In this work,a N-cyclic quaternary ammonium-grafted viologen molecule,viz.1,1'-bis(4,4'-dime thylpiperidiniumyl)-4,4'-bipyridinium tetrachloride((DBPPy)Cl_(4)),is developed by the molecular engineering strategy.The obtained(DBPPy)Cl_(4) molecule shows a decent solubility of 1.84 M and a redox potential of-0.52 V vs.Ag/AgCl,Experimental and theoretical results reveal that the grafted N-cyclic quaternary ammonium groups act as the steric hindrance to prevent nucleophilic attack by OH~-,increasing the alkali resistance of the electroactive molecule.The symmetrical battery with 0.50 M(DBPPy)Cl4shows negligible decay during the 13-day cycling test.As demonstration,the flow battery utilizing 1.0 M(DBPPy)Cl_(4) as the negolyte and 1-(1-oxyl-2,2',6,6'-tetramethylpiperidin-4-yl)-1'-(3-(trimethylammonio)propyl)-4,4'-bipyridinium trichloride as the posolyte exhibits a high capacity retention rate of 99.99%per cycle at 60 mA cm^(-2).

Insight into the Alkali Resistance Mechanism of CoMnHPMo Catalyst for NH_(3) Selective Catalytic Reduction of NO

The existence of alkali metals in fl ue gases originating from stationary sources can result in catalyst deactivation in the low-temperature selective catalytic reduction(SCR)of nitrogen oxides(NO_(x)).It is widely accepted that alkali metal poisoning causes damage to the acidic sites of catalysts.Therefore,in this study,a series of CoMn catalysts doped with heteropolyacids(HPAs)were prepared using the coprecipitation method.Among these,CoMnHPMo exhibited superior catalytic performance for SCR and over 95%NO_(x) conversion at 150-300.Moreover,it exhibited excellent catalytic activity and stability after alkali poisoning,demonstrating outstanding alkali metal resistance.The characterization indicated that HPMo increased the specifi c surface area of the catalyst,which provided abundant adsorption sites for NO_(x) and NH_(3).Comparing catalysts before and after poisoning,CoMnHPMo enhanced its alkali metal resistance by sacrifi cing Brønsted acid sites to protect its Lewis acid sites.In situ DRIFTS was used to study the reaction pathways of the catalysts.The results showed that CoMnHPMo maintained high NH_(3) adsorption capacity after K poisoning and then reacted rapidly with NO intermediates to ensure that the active sites were not covered.Consequently,SCR performance was ensured even after alkali metal poisoning.In sum-mary,this research proposed a simple method for the design of an alkali-resistant NH_(3)-SCR catalyst with high activity at low temperatures.

Intensifying recovery of metallic aluminum in secondary aluminum dross by alkali roasting−water leaching

An innovative process was proposed to recover metallic aluminum from secondary aluminum dross(SAD)by alkali roasting−water leaching.Thermodynamic calculations and experimental results were used to illustrate the phase transformation and reaction mechanism of the alkali roasting process.The leaching behaviors of roasted residue were also analyzed.Under optimal conditions,the aluminum extraction rate reached 93.08%.In addition,the kinetics of the water leaching of roasted products was studied through shrinking core model,and it was revealed that the leaching process of aluminum was in accord with diffusion control.The apparent activation energy of the leaching process was calculated to be 3.44 kJ/mol.Based on the above study,the underlying mechanism of the alkali roasting−water leaching was clarified.

Alkali Tolerance of Concrete Internal Curing Agent Based on Sodium Carboxymethyl Starch

Internal curing agents (ICA) based on super absorbent polymer have poor alkali tolerance and reduce the early strength of concrete.An alkali tolerate internal curing agent (CAA-ICA) was designed and prepared by using sodium carboxymethyl starch (CMS) with high hydrophilicity,acrylic acid (AA) containing anionic carboxylic group and acrylamide (AM) containing non-ionic amide group as the main raw materials.The results show that the ratio of CAA-ICA alkali absorption solution is higher than that existing ICA,which solves the low water absorption ratio of the ICA in alkali environment.The water absorption ratio of CAA-ICA in saturated Ca(OH)_(2) solution is 95.8 g·g^(-1),and the alkali tolerance coefficient is 3.4.The application of CAA-ICA in cement-based materials can increase the internal relative humidity and miniaturize the pore structure.The compressive strength of mortar increases up to 12.95%at 28 d,which provids a solution to overcome the reduction of the early strength.

Alkali burn injury model of meibomian gland dysfunction in mice

AIM:To establish a stable,short-time,low-cost and reliable murine model of meibomian gland dysfunction(MGD).METHODS:A filter paper sheet soaked in 1.0 mol/L sodium hydroxide(NaOH)solution was used to touch the eyelid margin of C57BL/6J mice for 10s to establish the model.The other eye was left untreated as a control group.Eyelid margin morphological changes and the meibomian glands(MGs)were observed by slit lamp microscopy on days 5 and 10 post-burn.Hematoxylin-eosin(HE)staining and Oil red O staining were adopted in detecting the changes in MGs morphology and lipid deposition.Real-time polymerase chain reaction,Western blot,immunofluorescence staining and immunohistochemical staining were used to detect interleukin(IL)-6,IL-1β,IL-18,tumor necroses factor(TNF)-α,interferon(IFN)-γ,nicotinamide adenine dinucleotide phosphate(NADPH)oxidase 4(NOX4),3-nitroturosine(3-NT),4-hydroxynonenal(4-HNE)and cytokeratin 10(K10)expression changes in MGs.RESULTS:MGs showed plugging of orifice,glandular deficiency,abnormal acinar morphology,ductal dilatation,and lipid deposition after alkali burn.The expressions of IL-6,IL-18,IL-1β,IFN-γ,and TNF-αindicators of inflammation and oxidative stress in MGs tissues were significantly increased.Abnormal keratinization increased in the MG duct.CONCLUSION:A murine model of MGD is established by alkali burn of the eyelid margin that matches the clinical presentation of MGD providing a stable,short-time,lowcost,and reliable MGD model.The new method suggests efficient avenues for future research.

Alkali and Plasma-Treated Guadua angustifolia Bamboo Fibers:A Study on Reinforcement Potential for Polymeric Matrices

This study focuses on treating Guadua angustifolia bamboo fibers to enhance their properties for reinforcement applications in composite materials.Chemical(alkali)and physical(dry etching plasma)treatments were used separately to augment compatibility of Guadua angustifolia fibers with various composite matrices.The influence of these treatments on the fibers’performance,chemical composition,and surface morphology were analyzed.Statistical analysis indicated that alkali treatments reduced the tensile modulus of elasticity and strength of fibers by up to 40%and 20%,respectively,whereas plasma treatments maintain the fibers’mechanical performance.FTIR spectroscopy revealed significant alterations in chemical composition due to alkali treatments,while plasma-treated fibers showed minimal changes.Surface examination through Scanning Electron Microscopy(SEM)revealed post-treatment modifications in both cases;alkali treatments served as a cleanser,eliminating lignin and hemicellulose from the fiber surface,whereas plasma treatments also produce rough surfaces.These results validate the impact of the treatments on the fiber mechanical performance,which opens up possibilities for using Guadua angustifolia fibers as an alternative reinforcement in composite manufacturing.

Defect Engineering in Earth-Abundant Cu_(2)ZnSnSe_(4) Absorber Using Efficient Alkali Doping for Flexible and Tandem Solar Cell Applications

To demonstrate flexible and tandem device applications,a low-temperature Cu_(2)ZnSnSe_(4)(CZTSe)deposition process,combined with efficient alkali doping,was developed.First,high-quality CZTSe films were grown at 480℃by a single co-evaporation,which is applicable to polyimide(PI)substrate.Because of the alkali-free substrate,Na and K alkali doping were systematically studied and optimized to precisely control the alkali distribution in CZTSe.The bulk defect density was significantly reduced by suppression of deep acceptor states after the(NaF+KF)PDTs.Through the low-temperature deposition with(NaF+KF)PDTs,the CZTSe device on glass yields the best efficiency of 8.1%with an improved Voc deficit of 646 mV.The developed deposition technologies have been applied to PI.For the first time,we report the highest efficiency of 6.92%for flexible CZTSe solar cells on PI.Additionally,CZTSe devices were utilized as bottom cells to fabricate four-terminal CZTSe/perovskite tandem cells because of a low bandgap of CZTSe(~1.0 eV)so that the tandem cell yielded an efficiency of 20%.The obtained results show that CZTSe solar cells prepared by a low-temperature process with in-situ alkali doping can be utilized for flexible thin-film solar cells as well as tandem device applications.

Recovery of Solid Oxide Fuel CellWaste Heat by Thermoelectric Generators and AlkaliMetal Thermoelectric Converters

A Solid Oxide Fuel Cell(SOFC)is an electrochemical device that converts the chemical energy of a substance into electrical energy through an oxidation-reduction mechanism.The electrochemical reaction of a solid oxide fuel cell(SOFC)generates heat,and this heat can be recovered and put to use in a waste heat recovery system.In addition to preheating the fuel and oxidant,producing steam for industrial use,and heating and cooling enclosed rooms,this waste heat can be used for many more productive uses.The large waste heat produced by SOFCs is a worry that must be managed if they are to be adopted as a viable option in the power generation business.In light of these findings,a novel approach to SOFC waste heat recovery is proposed.The SOFC is combined with a“Thermoelectric Generator and an Alkali Metal Thermoelectric Converter(TG-AMTC)”to transform the excess heat generated by both the SOFC and the TG-AMTC.The proposed TG-AMTC is evaluated using a number of performance indicators including power density,operating temperature,heat recovery rate,exergetic efficiency,energy efficiency,and recovery time.The experimental results state that TG-AMTC has provided an exergetic efficiency,energetic efficiency,and recovery time of 97%,98%,and 23%,respectively.The study proves that the proposed TG-AMTC for SOFC is an efficient method of recovering waste heat.

Coordination and Supramolecular Assemblies from Alkali+-Cucurbit[5]uril-[CdCl_(4)]^(2-)Systems

Thispaper has investigated the coordination and supramolecular assemblies of alkali metal ions,cucurbit[5]uril(Q[5]),and[CdCl_(4)]^(2-)to confirm whether[CdCl_(4)]^(2-)can produce the“honeycomb effect”,induce coordination of alkali metal ions to Q[5],and form linear coordination polymers.In this work,the effect of alkali metal ions on the construction of Q[5]-Cd^(2+)ion system under acidic conditions was investigated.Five complexes were successfully obtained by solvent evaporation method.Among the five crystal structures obtained,it can be observed that the presence of[CdCl_(4)]^(2-)did not result in the complexation of alkali metal ions by the Q[5]molecule.Instead,a bowl-like Cd^(2+)@Q[5]complex was formed.Indeed,[CdCl_(4)]^(2-)did not produce the honeycomb effect but led to the formation of Q[5]-based honeycomb frameworks with hexagonal cellsoccupied by[CdCl_(4)]^(2-).The experimental results show that cadmium ion showed stronger ability to coordinate to Q[5]in HCl solution.

Fundamental Study on Alkali-Activated Slag System with Sodium Carbonate or Calcium Hydroxide

Cement as a building material, has high fluidity, compressive strength, and durability, but carbon dioxide emissions during cement production are a major problem. As one of the countermeasures, alkali-activated cement using blast furnace slag powder with alkaline stimulants is considered to be a very promising solution for reducing carbon dioxide emissions, but there is a lack of information about the fundamental properties of alkali-activated materials. This study presents an experimental investigation of the fundamental properties of an alkali-activated slag system with sodium carbonate (NC) and calcium hydroxide (CH). The effects of calcium sulfo-aluminate (CSA) and shrinkage reducing agent (SRA) on the properties of blast furnace slag (BFS) based alkali-activated mixture were also investigated. In the experiments, fundamental characteristics including compressive strength, drying shrinkage, and water penetration tests of mortar were evaluated. Porosity, pH, and ignition loss were measured to verify the effectiveness of the materials. The experimental investigation revealed that the compressive strength was increased with the increasing replacement rates of NC in the BFS mortar, and in the case of water to BFS ratio of 0.45 with sodium carbonation addition contents 10 wt.%, the compressive strength for 28 days of curing reaches more than 50 MPa. Low water to BFS ratio and higher addition ratio of NC had a positive effect on the compressive strength development of mortar. Incorporating NC into BFS would affect the decrease in porosity and increase in ignition loss, leading to higher compressive strength. There was a negligible change to the compressive strength, porosity, pH, and ignition loss of BFS samples made with CH, thus, the addition rates of CH to BFS have no or little significant effect on the fundamental properties of alkali-activated cement. From the results of drying shrinkage and water penetration tests, the addition of NC and CH only to BFS exhibited poor drying shrinkage and water penetration characteristics. However, these problems may be overcome due to the use of CSA or SRA in the alkali-activated system made with NC or CH.

我国盐碱地治理:现状、问题与展望

随着社会经济快速发展,我国人口、资源、环境的矛盾与日俱增,可持续发展的压力越来越大。与耕地一样,盐碱地作为以盐类集积为主要特征的土地资源,不仅承载着污染净化、生物资源、生物多样性、全球碳库、自然文化遗产、景观旅游等重要功能,也是人类赖以生存的重要农业生产资料。盐碱地治理是以减少作物逆境胁迫、作物健康及其高产优质为主要目标,对于国家粮食安全、生态环境安全、人类健康具有十分重要的意义。近几十年来,历经几代人的努力,我国科技工作者已基本厘清了盐碱地治理理论体系,并建立了符合我国国情的盐碱地治理技术模式。但是,由于盐碱地类型复杂多样,盐碱化程度不同、治理措施多元化等原因,我国尚未建立起分类分区,精准治理,兼顾高水平与低成本的高效治理方法,更没有建立起盐碱地治理及其长效管理的技术与服务体系框架。本文在论述盐碱地概念的基础上,重点介绍盐碱地主要障碍因子、盐碱地治理基本理论与技术方法、盐碱地治理效果判别标准以及盐碱地农业生产的主要模式,阐述盐碱地治理主要问题及展望,以期启发人们对盐碱地的科学认识,强化盐碱地治理技术的应用与实践,结合现代农业新成果,更好地推动盐碱地农业的发展。

树脂对竹纤维耐碱性和界面黏结性能的影响

为提升竹纤维耐碱性及其在水泥基复合材料中的界面性能,研究了树脂类型对竹纤维在碱性环境中长期力学性能和界面性能的影响.结果表明:经过环氧树脂、乙烯基树脂和呋喃树脂浸渍后,竹纤维的抗拉强度分别增长了132.42%、36.96%和30.60%;在Ca(OH2)溶液中浸泡60 d后,3种竹纤维的抗拉强度保有率分别为55.91%、59.71%和29.49%;与未浸渍树脂竹纤维相比,浸渍树脂竹纤维与基体的黏结强度分别提升了4.62、3.47、1.87倍,乙烯基树脂对竹纤维耐碱性的提升效果最为显著.

Performance characterization, of rigid polyurethane foam with refined alkali lignin and modified alkali lignin

The two kinds of rigid polyurethane （PU） foams were prepared with respectively adding the refined alkali lignin and alkali lignin modified by 3-chloro-1,2-epoxypropane to be instead of 15% of the polyether glycol in weight. The indexes of mechanical performance, apparent density, thermal stability and aging resistance were separately tested for the prepared PU foams. The results show that the mechanical property, thermal insulation and thermal stability for PU foam with modified alkali lignin are excellent among two kinds of PU foams and control samples. The additions of the refined alkali lignin and modified alkali lignin to PU foam have little effect on the natural aging or heat aging resistance except for decreasing hot alkali resistance apparently. Additionally, the thermal conductivity of modified alkali lignin PU foam is lowest among two kinds of PU foams and control samples. The alkali lignin PU foam modified by 3-chloro-1,2-epoxypropane could be applied in the heat preservation field.

高铝粉煤灰中锂元素碱溶浸出及协同萃取回收研究

研究采用碱溶脱硅联用对苯甲酰三氟丙酮(Benzoyltrifluoroacetone,HBTA)-三辛基氧膦(Trioctylphosphine Oxide,TOPO)协同萃取的方法回收高铝粉煤灰(High Alumina Fly Ash,HAFA)中的Li,同时获得了具有高经济价值的富铝渣。研究结果显示,约有92.62%的Li富集在HAFA玻璃相中。碱溶脱硅工艺可以在温和条件[NaOH质量浓度200 g/L,95℃,2 h,液固比(mL∶g)20∶1]下高效地选择性溶解HAFA中玻璃相和玻璃相中所含的Li,并同时得到富铝渣(Al_(2)O_(3)质量分数≥49.00%)。之后,采用HBTA-TOPO协同萃取体系高效地萃取并回收碱性浸出液中的Li+。在室温最优萃取条件[c(HBTA)∶c(TOPO)=1∶1、协同萃取剂浓度为0.03 mol/L、O/A比(mL∶mL)为1∶1、萃取时间为2 min]下,Li的三级萃取率达到99.68%。研究对实现HAFA中锂、铝资源绿色和高附加值回收利用具有重要意义。