间歇性低压低氧对大鼠肺动脉高压的预防作用及血管保护机制

目的采用野百合碱(MCT)诱导雄性SD大鼠肺动脉高压(PAH)模型,观察间歇性低压低氧(IHH)对动物模型PAH的预防作用及其对肺血管的保护机制。方法大鼠随机分为正常对照组(CON组)、肺动脉高压组(PAH组)、间歇性低压低氧组(IHH组)和IHH+MCT组。CON组不进行任何处理,28 d后直接行右心室收缩压(RVSP)和肺动脉平均压(m PAP)的测定,计算右心室肥厚指数(RVHI)并行血管环灌流实验观察血管反应性改变。PAH组经腹腔注射MCT 14 d后进行实验。IHH组接受模拟5 km海拔高度,6 h/d的IHH处理28 d后实验。IHH+MCT组先经受28 d的IHH后,腹腔注射MCT 14 d后实验。结果PAH组大鼠从注射MCT后1周体重较CON组减轻,倦卧,喘促,活动量、进食量减少。IHH+MCT组大鼠一般情况较同期的PAH组有所改善,但较CON组差。实验过程中PAH组死亡2只,其余各组均全部存活。PAH组的m PAP、RVSP、RV、LV+S、RVHI与其他组比较,差异有统计学意义(P<0.05),PAH组高于其他组,IHH+MCT组的指标较PAH组显著降低。PAH组大鼠肺动脉的内皮依赖性血管收缩及舒张反应与CON组比较,差异有统计学意义(P<0.05),PAH组受损,而IHH干预后,可改善其受损的内皮依赖性的血管收缩及舒张反应。结论 IHH能够有效降低MCT诱导的PAH大鼠升高的m PAP、RVSP、RV、LV+S、RVHI,且对PAH大鼠肺血管的内皮依赖性血管收缩及舒张反应具有保护作用。

Recovery and separation of rare earth elements by molten salt electrolysis

With the increasing demand of rare earth metals in functional materials,recovery of rare earth elements(REEs)from secondary resources has become important for the green economy transition.Molten salt electrolysis has the advantages of low water consumption and low hazardous waste during REE recovery.This review systematically summarizes the separation and electroextraction of REEs on various reactive electrodes in different molten salts.It also highlights the relationship between the formed alloy phases and electrodeposition parameters,including applied potential,current,and ion concentration.Moreover,the feasibility of using LiF–NaF–KF electrolyte to recover REEs is evaluated through thermodynamic analysis.Problems related to REE separation/recovery the choice of electrolyte are discussed in detail to realize the low-energy and high current efficiency of practical applications.

Electrochemical behavior and underpotential deposition of Sm on reactive electrodes(Al,Ni,Cu and Zn)in a LiCl-KCl melt

Sm extraction from a LiCl-KCl melt was carried out by forming alloys on various electrodes,including Al,Ni,Cu,and liquid Zn,and the electrochemical behaviors of the resultant metal products were investigated using different electrochemical techniques.While Sm metal deposition via the conventional two-step reaction process was not noted on the inert electrode,underpotential deposition was observed on the reactive electrodes because of the latter's depolarization effect.The depolarization effects of the reactive electrodes on Sm showed the order Zn>Al>Ni>Cu.Sm-M(M=Al,Ni,Cu,Zn)alloys were deposited by galvanostatic and potentiostatic electrolysis.The products were fully characterized by X-ray diffractometry(XRD)and scanning electron microscopy(SEM)-energy dispersive spectrometry(EDS),and the stability of the obtained M-rich compounds was determined.Finally,the relationship between the electrode potential and type of Sm-M intermetallic compounds formed was assessed on the basis of the observed electrochemical properties and electrodeposits.

Molten salt synthesis and supercapacitor properties of oxygen-vacancy LaMnO3-δ

Due to the unique structure of perovskite materials,their capacitance can be improved by introducing oxygen vacancy.In this paper,the LaMnO3-δ material containing oxygen vacancy was synthesized by molten salt method in KNO3-NaNO3-NaNO2 melt.The La-Mn-O crystal grows gradually in molten salt with the increase of temperature.It was confirmed that LaMnO3-δ with perovskite structure and incomplete oxygen content were synthesized by molten salt method and presented a three-dimensional shape.LaMnO3-δ stores energy by redox reaction and adsorption of OH-in electrolyte simultaneously.In comparison with the stoichiometric LaMnO3 prepared by the sol-gel method,LaMnO3-δ prepared by molten salt method proffered higher capacitance and better performance.The galvanostatic charge-discharge curve showed specific capacitance of 973.5 F/g under current density of 1 A/g in 6 M KOH.The capacitance of LaMn03-δ was 82.7%under condition of 5 A/g compared with the capacitance at the current of 1A/g,and the specific capacitances of 648.0 and 310.0 F/g were obtained after 2000 and 5000 cycles of galvanostatic charging-discharging,respectively.Molten salt synthesis method is relatively simple and suitable for industrial scale,presenting a promising prospect in the synthesis of perovskite oxide materials.

Progress in preparation of rare earth metals and alloys by electrodeposition in molten salts

Rare earth（RE） metals and their alloys have attracted considerable practical interests due to their functional properties. Because of their negative deposition potentials, RE metals cannot be electrochemically deposited from aqueous media. Using molten salt as medium provides a unique opportunity for the electrowinning and electrorefining of high-purity RE metals, as well as for the electrochemical formation of their alloys and intermetallic compounds. Certainly, the electrochemical behaviors of RE metals and their alloys have been investigated in a number of different molten salts comprising all-fiuorides,all-chlorides and mixed chloride-fiuoride media. Based on the results, RE and their alloys were produced by molten salt electrolysis. In this paper, the developments of preparation of RE metals and their alloys by electrolysis in molten salts in recent years were systematically summarized on both the local and international levels. Attention was paid mainly to the electrodeposition of RE metals and their alloys, including RE-Mg, RE-Al, RE-Ni, RE-Co,RE-Cu, RE-Fe and RE-Zn alloys.

Fabrication of Al-Coated Mg-Li Alloy Sheet and Investigation of Its Properties

An Al-coated Mg-8 mass% Li alloy rectangular bar was fabricated by hot extrusion, and then, it was hot-rolled into a thin sheet. The Al coating was uniform in thickness and had good bonding with the substrate during all the processing. This Alcoated Mg–Li alloy exhibited a good corrosion resistance in a 0.5 mass% HCl aqueous solution. No intermetallic compound was observed at the Al/Mg–Li interface after the extrusion and the rolling. The Al-coated Mg–Li alloy sheet exhibited an elongation to fracture of 35% at room temperature at a strain rate of 0.001 s(-1)without any debonding between the coating and the substrate. When tensile tested at 573 K at 0.001 s(-1)in the air, the Al coating remained undamaged even until an elongation of about 150%. Further elongation generated cracks on the coating and the specimen fractured at an elongation of about 200%. In an Ar atmosphere, the specimen exhibited a fracture elongation of over 400% under the same conditions at 573 K at 0.001 s(-1), although a large number of cracks generated on the Al coating.

Electrochemical co-reduction of holmium and magnesium ions in eutectic LiCl-KCl salts

The electrochemical co-reduction of Ho(Ⅲ)and Mg(Ⅱ)ions was investigated on Mo electrode in eutectic LiCl–KCl salts at temperature of 773 K using various electrochemical techniques.Cyclic voltammogram(CV)and square wave voltammogram exhibit three reduction peaks corresponding to the reduction of Ho(Ⅲ)on pre-deposited Mg electrode,whose potentials are more positive than that of Ho on Mo electrode because of the formation of Mg-Ho intermetallic compounds by co-reduction of Ho(Ⅲ)and Mg(Ⅱ)ions.Meanwhile,chronopotentiometry and open-circuit chronopotentiometry were used to explore the electrochemical formation of Mg–Ho intermetallics.Mg–Ho alloys were produced by galvanostatic electrolysis at the current of 1.5 A for different electrolysis durations.Ho_(5)Mg_(24),HoMg_(2) and HoMg intermetallic compounds were acquired and characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM)coupled with energy-dispersive spectroscopy(EDS).The results indicate that Mg–Ho intermetallic compounds,Ho_(5)Mg_(24),HoMg_(2) and HoMg,could be prepared by molten salts electrolysis.