Cation effects in electrocatalytic reduction reactions:Recent advances

Electrocatalytic reduction reactions,powered by clean energy sources such as solar energy and wind,offer a sustainable method for converting inexpensive feedstocks(e.g.,CO_(2),N_(2)/NO_(x),organics,and O_(2))into high-value-added chemicals or fuels.The design and modification of electrocatalysts have been widely implemented to improve their performance in these reactions.However,bottle-necks are encountered,making it challenging to further improve performance through catalyst development alone.Recently,cations in the electrolyte have emerged as critical factors for tuning both the activity and product selectivity of reduction reactions.This review summarizes recent advances in understanding the role of cation effects in electrocatalytic reduction reactions.First,we introduce the mechanisms underlying cation effects.We then provide a comprehensive overview of their application in electroreduction reactions.Characterization techniques and theoretical calcula-tion methods for studying cation effects are also discussed.Finally,we address remaining challeng-es and future perspectives in this field.We hope that this review offers fundamental insights and design guidance for utilizing cation effects,thereby advancing their development.

Enhancing selectivity in acidic CO_(2) electrolysis:Cation effects and catalyst innovation

The electrochemical reduction of CO_(2)(eCO_(2)R)under ambient conditions is crucial for reducing carbon emissions and achieving carbon neutrality.Despite progress with alkaline and neutral electrolytes,their efficiency is limited by(bi)carbonates formation.Acidic media have emerged as a solution,addressing the(bi)carbonates challenge but introducing the issue of the hydrogen evolu-tion reaction(HER),which reduces CO_(2) conversion efficiency in acidic environments.This review focuses on enhancing the selectivity of acidic CO_(2) electrolysis.It commences with an overview of the latest advancements in acidic CO_(2) electrolysis,focusing on product selectivity and electrocatalytic activity enhancements.It then delves into the critical factors shaping selectivity in acidic CO_(2) electrolysis,with a special emphasis on the influence of cations and catalyst design.Finally,the research challenges and personal perspectives of acidic CO_(2) electrolysis are suggested.

Change Color Effect and Spectral Properties of Gold Nanoparticle-cationic Surfactants System

The change color effect of gold nanoparticle solutions was studied by means of resonance scattering and absorption spectrometry and scan electron microscopy. The red Au nanoparticles with a size of 10 nm exhibit a resonance absorption peak and a resonance scattering peak all at 525 nm. After some inorganic electrolyte was added to a red Au nanoparticles solution, the color of the solution became blue and the absorbance at (600_700) nm was significantly increased. The ratio of the concentration of monovalent cations, at which the resonance scattering of the system at 525 nm is maximal to that of divalent cations, is in the range of 100∶1_100∶1.8. It is in good agreement with the Schulze-Hardy rule of the coagulation value of electrolyte. After adding some cationic surfactants to the above solution, the color of the solution is in deep blue, with two resonance absorption peaks at 550 and 680 nm, and a greatly enhanced resonance scattering peak at 525 nm. The experiments demonstrate that the stronger the hydrophobicity of the cationic surfactant is, the stronger the change color effect of the Au nanoparticle solution promoted by cationic surfactant is. The change color effect of Au nanoparticle solution is resulted from the increased diameter of Au nanoparticles, and the changes of resonance absorption peak and resonance scattering.

Interactions of Cations with Electrodialyzed Clay Fraction of Soils as Inferred from Wien Effect in Soil Suspensions

The electrical conductivities (ECs) of suspensions containing 25 and 30 gkg^(-1) solids prepared from the electrodialyzed clay fraction (< 2μm in diameter) of latosol,yellow-brown soil, and black soil, dispersed in various nitrate solutions having concentrations of 1X 10^(-4)/z mol L^(-1), where z is the valence, and in distilled water, were measured at fieldstrengths ranging from 14 kV cm^(-1) to 210 kV cm^(-1). On the basis of analyses of the chargedensity and exchangeable ion composition on the surfaces of soil particles in the suspensions, andof the characters of the EC-field strength curves of the various suspensions, it was inferred thatthe increment of EC (ΔEC) and/or relative electrical conductivity (REC) can indicate the bondingstrength between cations and soil particles. The bonding strengths of various cations with the soilsdiminished in the order: K^+ > Zn^(2+) > Mg^(2+) = Ca^(2+) > Na^+ for latosol, Ca^(2+) > Zn^(2+) >Mg^(2+) = K^+ > Na^+ for yellow-brown soil, and Zn^(2+) ≥ Ca^(2+) ≥ Mg^(2+) > K^+ > Na^+ for blacksoil.

Cooperative structure-directing effect of choline cation and *BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolite

In this contribution,we report the cooperative structure-directing effect of choline hydroxide and aluminosilicate*BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolites for the first time.*BEA zeolites,at variance with any other aluminosilicate zeolites,can serve as heterogeneous seeds for the growth of IWR zeolites and play a cooperative structure-directing role.The crystallization process was investigated using multiple techniques to characterize a series of solid products obtained with various crystallization times.The experiments clearly showed the dissolution of the*BEA zeolite and of an intermediate CDO-type structure.A plausible mechanism for the novel cooperative synthesis has been proposed.The crystallization of the IWR zeolite involves several steps,among which the crucial one is believed to be the reassembly of the building units produced from the decomposition of*BEA zeolite seeds,induced by choline molecules.Having similar structure and common building units(four-,five-,and six-membered rings)with the IWR zeolite,the*BEA zeolite is capable of promoting the reassembly of the building units and can thus play a cooperative structure-directing role.By highlighting the cooperative structure-directing effect of organic molecules and heterogeneous seeds,this study opens up new perspectives for the synthesis of target zeolites that are difficult to prepare by traditional methods.This new synthetic route is also expected to shed light on the discovery of novel zeolites.

Alkali metal cation effects on electrocatalytic CO_(2)reduction with iron porphyrins

The electrocatalytic CO_(2)reduction reaction(CO_(2)RR)has attracted increasing attention in recentyears.Practical electrocatalysis of CO_(2)RR must be carried out in aqueous solutions containing electrolytesof alkali metal cations such as sodium and potassium.Although considerable efforts havebeen made to design efficient electrocatalysts for CO_(2)RR and to investigate the structure–activityrelationships using molecular model complexes,only a few studies have been investigated the effectof alkali metal cations on electrocatalytic CO_(2)RR.In this study,we report the effect of alkali metalcations(Na^(+)and K^(+))on electrocatalytic CO_(2)RR with Fe porphyrins.By running CO_(2)RR electrocatalysisin dimethylformamide(DMF),we found that the addition of Na^(+)or K^(+)considerably improves thecatalytic activity of Fe chloride tetrakis(3,4,5‐trimethoxyphenyl)porphyrin(FeP).Based on thisresult,we synthesized an Fe porphyrin^(N)18C6‐FeP bearing a tethered 1‐aza‐18‐crown‐6‐ether(^(N)18C6)group at the second coordination sphere of the Fe site.We showed that with the tethered^(N)18C6 to bind Na^(+)or K^(+),^(N)18C6‐FeP is more active than FeP for electrocatalytic CO_(2)RR.This workdemonstrates the positive effect of alkali metal cations to improve CO_(2)RR electrocatalysis,which isvaluable for the rational design of new efficient catalysts.

A Precise Description of the Electronic Structures and Spin-Allowed Transition Properties of PF and Its Cation:All-Electron Configuration-Interaction Investigations Including Relativistic Effect

The electronic structures of PF and PF＋ are calculated with the high-level configuration interaction method. To improve the precision of calculations, the spin-orbit coupling effect, the scalar relativistic effect, and the Davidson correction（q-Q） are also considered. The spectroscopic parameters of bound states are derived by the electronic structures of PF and PF＋, which are in good accordance with the measurements. The transition dipole moments of spin-allowed transitions are evaluated, and the radiative lifetimes of several A S states of PF and PF＋ are obtained.

Synergistic effect of salts on inducingobvious viscoelastic behavior of cationic trimeric surfactant solutions

A viscoelastic system formed by the solutions of di（2-hydroxyl-dimethylene ether）-α,ω, y-triple （ dimethyloctadecylammonium chlorine ） （ 18-4 （ OH ） -18-4 （ OH ） -18 ） is proposed to solve the problems of poor temperature and shear resistances of clean fracturing fluid. The apparent viscosity of 18-4（ OH）-18-4（ OH）-18 solution affected by inorganic salt, hydrotropic salt and their mixtures is investigated using steady state measurements. Meanwhile, the temperature and shear resistances of systems of 18-4（ OH）-18-4（ OH）-18 and several common single-chain surfactants are compared. The rheological experiments show that, the coexistence of NaSal and NaC1 makes it easier for the system to promote micellar growth yielding wormlike micelles than single NaSal or NaC1. The apparent vis- cosity of 18-4（OH） -18-4（OH） -18 solution maintains over 87. 5 mPa-s above 100 22. The results indi- cate that there exists a synergistic effect in solutions of 18-4 （ OH ） -18-4 （ OH ） -18 trimeric surfactant

Styrene epoxidation catalyzed by polyoxometalate/quaternary ammonium phase transfer catalysts: The effect of cation size and catalyst deactivation mechanism

Catalytic epoxidation of alkenes is an important type of organic reaction in chemical industry,and the deep insight into catalyst deactivation will help to develop new epoxidation process.In this work,series of quaternary ammoniums bearing different cationic sizes,i.e.MTOA+(methyltrioctylammonium,[(C_(8)H_(17))_(3)CH_(3)N]+),HTMA+(hexadecyltrimethylammonium,[(C_(16)H_(33))(CH_(3))_(3)N]+) and DMDOA+(dimethyldioctadecylammonium,[(C_(18)H_(37))_(2)(CH_(3))_(2)N]+) were incorporated with polyoxometalate (POM) anions to prepare phase transfer catalysts (PTCs),which were used in the styrene epoxidations.Among them,(MTOA)_(3)PW_(4)O_(24)exhibits the best catalytic performance judged from the highest styrene conversion rate(52%) and styrene oxide selectivity (93%),during which the styrene epoxidation conditions were optimized.Meanwhile,the deactivation mechanism of this kind of PTCs was proposed firstly,i.e.in the case of low H_(2)O_(2) content,the oxidant can only be used in the styrene epoxidation,in which the catalyst can transform into stable Keggin-type POM.But when the content of H_(2)O_(2) is higher,the excess H_(2)O_(2) can reactivate the Keggin-type POM into active (PW_(4)O_(24))_(3)-anions,which can trigger the ring-opening polymerization of styrene oxide.Consequently,the catalyst is deactivated by adhered poly(styrene oxide)irreversibly,which was determined by NMR spectra.In this situation,the active moiety{PO_(4)[WO(O_(2))_(2)]_(4)}_(3)-in phase-transfer catalytic system can break into some unidentified species with low W/P ratio with the presence of epoxides.This work will be beneficial for the design of new PTCs in alkene epoxidation in fine chemical industry.

MECHANISM FOR THE EFFECTS OF MONO-VALENT CATIONS ON ^(23)Na NMR

The effects of mono-valent cations, Li^+, K^+, Rb^+, Cs^+ and NH_4^+, on ^(23)Na NMR were investigated. It was found that the chemical shifts for Na^+ signal shifted downfield with the increase in the relative amounts of monovalent cations. It was suggested that mono-valent cations had competition coordination with Na^+ for Dy(PPP)_2^(7-).

Effects of Hyperfine and Dopant Cation Interactions on theDC-Electrical Conductivity of MnZn Ferrites

Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spinel cubic structure. The Mossbauer spectrum of the base sample indicates line broadening and overlapping due to relaxation of magnetic dipoles. The temperature dependence of DC-electrical conductivity has been discussed on the basis of electronic conduction (electron hopping) and ionic conduction mechanism.

A new boundary element solution to evaluate the geometric effects of the canyon site on the displacement response spectrum

This paper presents a step-by-step procedure using the three-dimensional boundary element approach to study the behavior of semi-circular canyons under seismic shear waves. The boundary element code TDASC allows utilization for various canyon geometries, evaluation of concurrent seismic waves and calculation of the ground motions on canyons due to an excitation at any arbitrary point of the incident field. Considering the widening ratio of the canyon(including prismatic, semi-prismatic and non-prismatic canyons), wave characteristics(wavelength, dimensionless period, direction) and maximum amplification pattern, the solution was applied to carry out a series of parametric studies. It was shown that canyon form can significantly affect the displacement amplification, especially at the points located on its edges. By increasing the wave dimensionless frequency(η > 1), the amplification pattern becomes more complex. On the basis of the results from a variety of considered cases, a new expression has been presented for the limiting wavelength beyond which the widening of the canyon will not have a major effect on the displacement amplification. To verify the reliability of the proposed approach, the obtained results, expressed in terms of displacement amplitude, were compared with those from the available published literature and a reasonably good agreement was observed.

An experimental study of electroreduction of CO2 to HCOOH on SnO2/C in presence of alkali metal cations(Li^+,Na^+,K^+,Rb^+and Cs^+)and anions(HCO3^-,Cl^-,Br^-and I^-)

It is well-known that the electrolytes can influence the electrochemical reduction of carbon dioxide(ERCO2)in aqueous media.In this work,we explore the effects of alkali metal cations and anions(Li^+,Na^+,K^+,Rb^+,Cs^+,HCO3^-,Cl^-,Br^-,I^-)on the current density and product selectivity for the ERCO2 into formic acid(HCOOH)on the SnO2/carbon paper(Sn O2/C)electrode.Results of the ERCO2 experiments show that for the cations,the promotion effects on current density and faradaic efficiencies(FEs)are in the order of Li^+b Na^+b K^+b Cs^+b Rb^+.For the anions,the current density values are in the order of Na HCO3 b NaClb Na Br b Na I and KHCO3 b KCl≈KI b KBr,respectively,and that on the FEs for the formation of the HCOOH(FEHCOOH)is HCO3-b Cl-b Br-b I-.Based on this result,the effects of alkali metal cations and anions on ERCO2 are discussed.

Coastal afforestation effects on soil properties at Hatiya in Bangladesh

An exploratory study was conducted in the coastal plantation （12- and 17-year-old Sonneratia apetala） of Char Alim and Char Piya and on their adjacent barren lands at Char Rehania and Char Nurul Islam in Hatiya of Noakhali district, in Bangladesh to determine afforestation effects on soil properties. At soil depths of 0-10, 10-30 and 30-40 cm across three different land strips viz. inland, middle and sea side in 12- and 17-year-old keora （Sonneratia apetala） plantations, soil moisture, particle density, organic matter and C, total N, pH, available P, K, Na, Ca and Mg were significantly （p≤0.05, p≤0.01, p≤0.001） higher, and soil salinity significantly （p〈0.001） lower than that in their adjacent barren lands. Soil moisture, particle density, organic matter and C, total N, pH, soil salinity, available P, K, Na, Ca and Mg of surface soil in Char Alim plantation at inland were 31.09%, 2.24 g.cm^-3, 2.41%, 4.14%, 0.58%, 7.07, 0.09 dS＇cm^-1, 28.06 mg.L^-1, 0.50 mg-L^- 1 11.5 mg-L^-1, 3.30 mg·L^-1 and 2.7 mmol.kg^-1, respectively. Their corresponding values for the same depth and land position at adjacent Char Rehania barren land were 16.69%, 1.25g.cm^-3, 0.43%, 0.74%, 0.25%, 6.57, 0.13 dS.cm^-1, 13.07mg-L^-1, 0.30 mg.L^-1, 1.4 mg.L^-1, 0.30 mmol·kg^-1 and 0.50 mg.L^-1, respectively. Soil moisture, particle density, organic matter and C, total N, pH, available P, K and Ca decreased, and soil salinity, available Na and Mg increased from inland towards sea side in the plantations. Although soil texture did not differ in most soil depths between plantation and adjacent barren land, proportion of sand particle was significantly （p≤0.01） lower and silt particle significantly （p〈0.001） in the plantations higher than that in their adjacent barren lands. In the study, evaluation of all the parameters was also done for the other pair of lands.

Coastal afforestation effects on soil properties at Hatiya in Bangladesh

An exploratory study was conducted in the coastal plantation (12-and 17-year-old Sonneratia apetala) of Char Alim and Char Piya and on their adjacent barren lands at Char Rehania and Char Nurul Islam in Hatiya of Noakhali district, in Bangladesh to determine afforestation effects on soil properties. At soil depths of 0-10, 10-30 and 30-40 cm across three different land strips viz. inland, middle and sea side in 12-and 17-year-old keora (Sonneratia apetala) plantations, soil moisture, particle density, organic matter and C, total N, pH, available P, K, Na, Ca and Mg were significantly (p≤0.05, p≤0.01, p≤0.001) higher, and soil salinity significantly (p≤0.001) lower than that in their adjacent barren lands. Soil moisture, particle density, organic matter and C, total N, pH, soil salinity, available P, K, Na, Ca and Mg of surface soil in Char Alim plantation at inland were 31.09%, 2.24 g·cm-3, 2.41%, 4.14%, 0.58%, 7.07, 0.09 dS·cm-1, 28.06 mg·L-1, 0.50 mg·L-1 11.5 mg·L-1, 3.30 mg·L-1 and 2.7 mmol·kg-1, respectively. Their corresponding values for the same depth and land position at adjacent Char Rehania barren land were 16.69%, 1.25g·cm-3, 0.43%, 0.74%, 0.25%, 6.57, 0.13 dS·cm-1, 13.07mg·L-1, 0.30 mg·L-1, 1.4 mg·L-1, 0.30 mmol·kg-1 and 0.50 mg·L-1, respectively. Soil moisture, particle density, organic matter and C, total N, pH, available P, K and Ca decreased, and soil salinity, available Na and Mg increased from inland towards sea side in the plantations. Although soil texture did not differ in most soil depths between plantation and adjacent barren land, proportion of sand particle was significantly (p≤0.01) lower and silt particle significantly (p≤0.001) in the plantations higher than that in their adjacent barren lands. In the study, evaluation of all the parameters was also done for the other pair of lands.

考虑弯曲空间效应影响的箱梁强迫振动分析

选取附加挠度为剪力滞广义位移,箱梁体系总动能中计入剪力滞附加变形的影响,综合运用薄壁结构弹性理论和Hamilton原理,建立考虑弯曲空间效应影响的箱梁强迫振动控制微分方程及边界条件,并给出任意简谐荷载作用下简支和连续箱梁的强迫振动解析解。引入振动频率影响的应力和挠度放大系数,详细分析简支、连续箱梁剪切剪力滞效应在初等梁结果中的占比及放大系数分布规律。算例分析表明:考虑弯曲空间效应影响的箱梁截面纵向动应力与有限元结果吻合良好;振动频率越大,应力和挠度放大系数、剪切效应占比越大,剪力滞效应占比越小;同频率振动时,简支箱梁放大系数远大于两跨连续箱梁(单跨长等于简支跨长),且频率越高,差值比越大;基频内振动时,箱梁纵向应力计算可忽略剪力滞效应,挠度计算需考虑剪切变形的影响。

人工智能赋能大学治理:多重效应与治理效能转化

当人工智能与大学治理相遇后,数字化不仅成为提升大学治理能力和治理水平现代化的客观要求,还成为推进大学治理创新和制度变迁的重要途径。根据大学制度的层级结构、治理结构的复杂性程度以及治理事项的数字化程度,建构制度嵌入下人工智能技术赋能大学治理的解释模型,并借此模型着重分析人工智能技术对大学治理影响的多重效应及其治理效能转化机制/过程。研究发现,在制度嵌入和人工智能技术的共同影响下,现代大学治理随着大学制度外显性的不断加强而愈显复杂,在此渐进过程中,人工智能技术的影响力和渗透力也就愈加微弱,由此产生了人工智能技术对大学治理影响的多重效应及其治理效能的不同转化和提升机制:大学治理结构的复杂性程度越低,大学制度的层级结构越低,治理领域可数字化的程度就越高,人工智能技术对大学治理的积极效应越显著,大学具体制度得以更迭的可能性越大,也就愈容易借助“技术—制度”协同机制将中国特色现代大学的制度优势转化为治理效能;大学治理结构的复杂化程度越高,大学制度的层级结构越高,治理领域可数字化的程度越低,人工智能技术对大学治理的抑制效应越明显,其所依靠的(部分)基本制度和基础制度被替代/更迭的速度越慢,而被同化的可能性越大,也就越容易走上模仿西方大学制度建设的路径依赖。为此,一方面,要注重人工智能技术对大学治理的积极效应,充分发挥人工智能技术对于大学常规性治理、(部分)决策性治理的积极作用,通过大学具体制度和基本制度的不断健全和完善,推动现代大学制度的标准化建设和精细化发展;另一方面,要警惕人工智能技术对大学治理带来的潜在危险,充分考虑现代大学的组织特性,避免过度技术化而导致大学治理中技术应用的无限拓展和无序泛化。

外科护理学实践课程思政教学设计与实践

目的:探讨外科护理学实践课程思政教学设计及其应用效果。方法:系统设计以“三条挖掘路径、六种目标精神”为主线的外科护理学实践课程教学方案,在2020级185名护理本科生中展开实施,通过问卷调查评价教学效果,并将2020级护生的理论、实践考核成绩与2019级护生进行比较。结果:2020级护生理论考核、实践考核成绩显著高于2019级护生(P<0.01);70%以上的护生认可该教学设计,并表示六种目标精神有所提升。结论:在外科护理学实践课程中开展思政教学,有利于提高护生理论知识、实践能力及思政素养,同时有利于提升教师的思政育人能力。

即穿型人工血管在血管通路中的应用效果及并发症分析

目的 研究即穿型人工血管在血管通路中的应用效果及并发症。方法 选取从2019年2月—2022年2月于资阳市人民医院接受人工血管内瘘手术的83例患者为研究对象。将流出道静脉直径>4mm分为即穿型人工血管组(n=41),流出道静脉直径3~4 mm分为膨体聚四氟乙烯(expanded polytetrafluoroethylen,ePTFE)人工血管组(n=42),分别选用即穿型人工血管、ePTFE人工血管进行造瘘手术。对所有患者均实施为期18个月的随访,比较2组手术后通畅率,治疗效果,手术后并发症,手术后生存率。结果 即穿型人工血管组与e PTFE人工血管组手术后6、12、18个月初级通畅率(t=1.437、0.609、0.595,P=0.231、0.435、0.441)及次级通畅率(t=2.108、0.149、0.310,P=0.147、0.699、0.578)对比无统计学差异。即穿型人工血管组首次穿刺时间、手术后透析导管移除时间均短于ePTFE人工血管组(t=78.386、21.491,均P<0.001);2组手术后透析血流量及人工血管使用率对比均不明显(t/χ^(2)=0.214、0.988,P=0.831、0.320)。即穿型人工血管组手术后肿胀、血栓形成发生率均低于ePTFE人工血管组(χ^(2)=24.418、7.540,P<0.001、0.006)。2组手术后6、12、18个月患者生存率对比均不明显(χ^(2)=1.037、0.239、0.183,P=0.309、0.625、0.668)。结论 即穿型人工血管应用于血管通路中可实现早期穿刺,通畅率高,且并发症发生风险较低,值得推广应用。

高效聚磷酸镁肥料的研制及应用

研究高效聚磷酸镁制备,对合成反应所需的基本要求进行了探讨,筛选出符合要求的采用聚磷技术并在农业生产中应用。研究方法采用磷酸溶液放入装有电动搅拌器的聚合反应釜中,聚合5~6h,反应结束产物降至常温,控制物料的pH值为1.5~3.0;然后加入碱性含镁化合物粉末进行混合,在常温常压下进行搅拌混合反应,混合后物料的化学计量摩尔比为n(MgO):n(P_(2)O_(5))=0.7~1.0:1.0,混合后物料的pH值控制在6.0~7.0之间;加入丁二酸双二乙氨基乙醇酯柠檬酸盐混匀,即为所需的高效聚磷酸镁肥料。农田蔬菜的应用结果指出:高效聚磷酸镁的有效性提高一倍以上,肥料质量稳定、控释性能好。