电极/碱性聚电解质界面的微分电容曲线和零电荷电位测定

碱性聚合物电解质作为现代碱性氢氧燃料电池的核心组成部分,其单离子导体的特性使得“电极/碱性聚电解质”界面的性质与“电极/溶液”界面有所不同。本文使用微电极,运用循环伏安、电化学交流阻抗以及浸入法等方法,测定了电极/碱性聚电解质界面的微分电容曲线和零电荷电位。该界面的微分电容曲线呈“U”状,且存在局域极小值,该极小值所对应的电位与浸入法测得的零电荷电位数值一致。单离子导体的特性使得“电极/碱性聚电解质”界面在零电荷电位两侧表现出不同的电化学极化行为。

Eff ects of continuous renal replacement therapy on infl ammation-related anemia, iron metabolism and prognosis in sepsis patients with acute kidney injury

BACKGROUND:This study aims to evaluate the eff ect of continuous renal replacement therapy(CRRT)on inflammation-related anemia,iron metabolism,and the prognosis in sepsis patients with acute kidney injury(AKI).METHODS:Sepsis patients with AKI were prospectively enrolled and randomized into the CRRT and control groups.The clinical and laboratory data on days 1,3 and 7 after intensive care unit(ICU)admission were collected.The serum interleukin(IL)-6,hepcidin,erythropoietin,ferritin,and soluble transferrin receptor(sTfR)were determined by enzyme-linked immunosorbent assay.The Sequential Organ Failure Assessment(SOFA)score and 28-day mortality were recorded.Data were analyzed using Pearson’s Chi-square test or Fisher’s exact test(categorical variables),and Mann-Whitney U-test or t-test(continuous variables).RESULTS:The hemoglobin and serum erythropoietin levels did not signifi cantly diff er between the CRRT and control groups though gradually decreased within the first week of ICU admission.On days 3 and 7,the serum IL-6,hepcidin,ferritin,and red blood cell distribution width significantly decreased in the CRRT group compared to the control group(all P<0.05).On day 7,the serum iron was significantly elevated in the CRRT group compared to the control group(P<0.05).However,the serum sTfR did not signifi cantly diff er between the groups over time.In addition,the SOFA scores were signifi cantly lower in the CRRT group compared to the control group on day 7.The 28-day mortality did not signifi cantly diff er between the control and CRRT groups(38.0%vs.28.2%,P=0.332).CONCLUSION:CRRT might have beneficial effects on the improvement in inflammationrelated iron metabolism and disease severity during the fi rst week of ICU admission but not anemia and 28-day mortality in sepsis patients with AKI.

Worldwide research trends on chloroquine:a bibliometric analysis from 2012 to 2021

Background:Chloroquine(CQ)is an antimalarial drug that was first synthesized by Hans Andersag,a German scientist,in 1934.Chloroquine has been widely researched and used over the years.The rapid development in the fields of modern science and technology has also contributed to the increase in interest in chloroquine.Hence,it is necessary to comprehensively summarize the research trends to understand the breakthroughs made in the field.Methods:The required data was compiled by analyzing the Web of Science Core Collection(WoSCC)database.The search period for studying global research trends in chloroquine research was set from 2012 to 2021 to ensure a comprehensive analysis over an extended timeframe.Data retrieval was performed on April 4,2022,focusing on articles and reviews published in English.The retrieval words were:(TS=(chloroquine))OR(TS=(aralen)).A total of 1,091 reviews and 7,259 articles were retrieved and analyzed.The data obtained from WoSCC was captured and analyzed using VOS viewer(version 1.6.16)and Citesspace(version 5.8.R5).Results:The number of literature reports on chloroquine published in the past 10 years has shown an annual increase.Among the countries,the United States has contributed the highest number of papers and ranks first in terms of both H-index and citation count.The League of European Research Universities is one of the largest research-focused university networks,and Malaria Journal stands out as a prominent journal publishing articles relevant to the field of study.A paper authored by Gautret and Philippe in 2020 achieved the highest citation score globally.The biosynthesis of chloroquine,mechanisms of drug resistance,and drug combinations are receiving growing attention.Conclusion:The research area of chloroquine has been significantly influenced by the American and China.The progress of chloroquine research is further propelled by fruitful collaborations among various countries.Researchers have extensively studied the anti-malarial effect,drug resistance mechanism,and autophagy of chloroquine for the development of a treatment method for COVID-19 based on chloroquine.Bibliometric analysis can be employed to identify hotspots,new directions,and frontiers in the field of chloroquine research.

热处理过程对Ti-6Al-4V-10Nb合金显微组织和拉伸性能的影响（英文）

研究热处理过程对Ti-6Al-4V-10Nb合金显微组织和力学性能的影响。采用扫描电镜、透射电镜和X射线衍射仪对合金显微组织进行研究,并通过拉伸试验对其室温和高温力学性能进行评估。结果表明,锻造和热处理后的主要组织为板条和球状初生α相、次生α相和β相。次生α相的尺寸明显小于初生α相的尺寸。热处理后,初生α相的体积分数减少,次生α相的体积分数增加。随着固溶温度的升高,初生α相的体积分数明显减少,次生α相的体积分数明显增加。随着固溶温度的升高,Ti-6Al-4V-10Nb合金的屈服强度和抗拉强度明显提高。

Coarsening behavior of MX carbonitrides in type 347H heat-resistant austenitic steel during thermal aging

In this work, the growth kinetics of MX （M - metal, X - C/N） nanoprecipitates in type 347H austenitic steel was systematically studied. To investigate the coarsening behavior and the growth mechanism of MX carbonitrides during long-term aging, experiments were performed at 700, 800, 850, and 900℃ for different periods （1, 24, 70, and 100 h）. The precipitation behavior of carbonitrides in specimens subjected to various aging conditions was explored using carbon replicas and transmission electron microscopy （TEM） observations. The corresponding sizes ofMX carbonitrides were measured. The results demonstrates that MX carbonitrides precipitate in type 347H austenitic steel as Nb（C,N）. The coarsening rate constant is time-independent; however, an increase in aging temperature results in an increase in coarsening rate of Nb（C,N）. The coarsening process was analyzed according to the calculated diffusion activation energy of Nb（C,N）. When the aging temperature was 800-900℃, the mean activation energy was 294 kJ·mol -1, and the coarsening behavior was controlled primarily by the diffusion of Nb atoms.

Comparison of acute pneumonia caused by SARS-CoV-2 and other respiratory viruses in children:a retrospective multi-center cohort study during COVID-19 outbreak

Background:Until January 18,2021,coronavirus disease-2019(COVID-19)has infected more than 93 million individuals and has caused a certain degree of panic.Viral pneumonia caused by common viruses such as respiratory syncytial virus,rhinovirus,human metapneumovirus,human bocavirus,and parainfluenza viruses have been more common in children.However,the incidence of COVID-19 in children was significantly lower than that in adults.The purpose of this study was to describe the clinical manifestations,treatment and outcomes of COVID-19 in children compared with those of other sources of viral pneumonia diagnosed during the COVID-19 outbreak.Methods:Children with COVID-19 and viral pneumonia admitted to 20 hospitals were enrolled in this retrospective multi-center cohort study.A total of 64 children with COVID-19 were defined as the COVID-19 cohort,of which 40 children who developed pneumonia were defined as the COVID-19 pneumonia cohort.Another 284 children with pneumonia caused by other viruses were defined as the viral pneumonia cohort.The epidemiologic,clinical,and laboratory findings were compared by Kolmogorov-Smirnov test,t-test,Mann-Whitney U test and Contingency table method.Drug usage,immunotherapy,blood transfusion,and need for oxygen support were collected as the treatment indexes.Mortality,intensive care needs and symptomatic duration were collected as the outcome indicators.Results:Compared with the viral pneumonia cohort,children in the COVID-19 cohort were mostly exposed to family members confirmed to have COVID-19(53/64 vs.23/284),were of older median age(6.3 years vs.3.2 years),and had a higher proportion of ground-glass opacity(GGO)on computed tomography(18/40 vs.0/38,P<0.001).Children in the COVID-19 pneumonia cohort had a lower proportion of severe cases(1/40 vs.38/284,P=0.048),and lower cases with high fever(3/40 vs.167/284,P<0.001),requiring intensive care(1/40 vs.32/284,P<0.047)and with shorter symptomatic duration(median 5d vs.8d,P<0.001).The proportion of cases with evaluated inflammatory indicators,biochemical indicators related to organ or tissue damage,D-dimer and secondary bacterial infection were lower in the COVID-19 pneumonia cohort than those in the viral pneumonia cohort(P<0.05).No statistical differences were found in the duration of positive PCR results from pharyngeal swabs in 25 children with COVID-19 who received antiviral drugs(lopinavir-ritonavir,ribavirin,and arbidol)as compared with duration in 39 children without antiviral therapy(median 10d vs.9d,P=0.885).Conclusions:The symptoms and severity of COVID-19 pneumonia in children were no more severe than those in children with other viral pneumonia.Lopinavir-ritonavir,ribavirin and arbidol do not shorten the duration of positive PCR results from pharyngeal swabs in children with COVID-19.During the COVID-19 outbreak,attention also must be given to children with infection by other pathogens infection.

Effect of microstructure variation on the corrosion behavior of high-strength low-alloy steel in 3.5wt% NaCl solution

The effect of microstructure variation on the corrosion behavior of high-strength low-alloy（HSLA） steel was investigated. The protective property of the corrosion product layer was also explored. Experimental results reveal that the type of microstructure has significant effect on the corrosion resistance of HSLA steel. The measurement results of weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy indicate that the steel with acicular ferrite microstructure exhibits the lowest corrosion rate. Martensite exhibits a reduced corrosion resistance compared with polygonal ferrite. It is found that the surface of the acicular ferrite specimen uniformly covered by corrosion products is seemingly denser and more compact than those of the other two microstructures, and can provide some amount of protection to the steel; thus, the charge transfer resistance and modulus values of the acicular ferrite specimen are the largest. However, corrosion products on martensite and polygonal ferrite are generally loose, porous, and defective, and can provide minor protectiveness; thus, the charge transfer resistance values for polygonal ferrite and martensite are lower.

Asparaginase-associated pancreatitis in chemotherapytreated pediatric patients:a five-year retrospective study

Asparaginase(Asp)represents a key agent in induction remission for acute lymphoblastic leukemia(ALL)and certain subtypes of non-Hodgkin lymphoma(NHL).By catalyzing the hydrolysis of extracellular asparagine,thus depleting the level of plasma asparagine necessary for the growth of leukemic lymphoblasts,Asp can inhibit leukemic lymphoblast protein synthesis and lead to subsequent apoptosis with little myelosuppression.[1]This will achieve anti-leukemia efficacy,and promote the remission of leukemia.[2]A previous study showed that an Asp-containing regimen could significantly increase the event-free survival rate(71%vs.31%).[3]A previous study showed that those who completed the Asp regimen had a higher 5-year event-free survival rate(90%)than those who were unable to tolerate toxicity and quitted the treatment(73%).[4]

Predicting Quantum Many-Body Dynamics with Transferable Neural Net works

Advanced machine learning(ML)approaches such as transfer learning have seldom been applied to approximate quantum many-body systems.Here we demonstrate that a simple recurrent unit(SRU)based efficient and transferable sequence learning framework is capable of learning and accurately predicting the time evolution of the one-dimensional(ID)Ising model with simultaneous transverse and parallel magnetic fields,as quantitatively corroborated by relative entropy measurements between the predicted and exact state distributions.At a cost of constant computational complexity,a larger many-body state evolution is predicted in an autoregressive way from just one initial state,without any guidance or knowledge of any Hamiltonian.Our work paves the way for future applications of advanced ML methods in quantum many-body dynamics with knowledge only from a smaller system.

Effect of pH and applied stress on hydrogen sulfide stress corrosion behavior of HSLA steel based on electrochemical noise analysis

The influence mechanism of pH and the externally applied stress on sulfide stress corrosion cracking behavior based on the joint analysis of the in situ electrochemical noise and microstructure was studied.The results showed that{\mathrm{H}}^{+}in solution changes the composition and structure of corrosion product film by affecting the concentration of{\mathrm{S}}^{2-}and{\mathrm{Fe}}^{2+}near the anode surface.When the pH increased from 2.6 to 3.6 and 4.6,the corrosion product film changed from porous Mackinawite to dense and stable FeS.The change in corrosion product type delayed the crack initiation time by 10.5 and 45.5 h,while the uniform corrosion time was prolonged by 6.1 and 46 h,respectively,delaying SSC behavior.After increasing the applied stress,the local plastic deformation on the material surface increases the porosity and crack rate of the corrosion product film and becomes a fast propagation channel for SSC cracks.When the applied stress is 110%of the actual yield strength of the material,the initiation time of stress corrosion cracking is 6 and 18.1 h earlier than that of 90%and 100%,respectively.The local corrosion time was extended by 23.5 and 8.2 h,respectively,accelerating SSC behavior.

Microstructure and Mechanical Properties of RAFM-316L Dissimilar Joints by Friction Stir Welding with Different Butt Joining Modes

Dissimilar welded joints of reduced activation ferritic/martensitic(RAFM)steel and 316 L austenitic stainless steel were prepared by friction stir welding with different butt joining modes and welding parameters.The weld quality of the joint was improved by placing the 316 L steel on the advancing side and the RAFM steel on the retreating side,and using a relatively high rotational speed of 400 rpm.The microstructure of the stir zone on the 316 L steel side consisted of single-phase austenite,and the microstructure of the stir zone on the RAFM steel side mainly consisted of lath martensite and equiaxed ferrite.A mechanical mixture of the two steels and diffusion of Cr and Ni could be detected near the bonding interface.Diffusion of Ni from the 316 L steel to the RAFM steel resulted in the formation of a dual-phase structure consisting of austenite and ferrite.The as-welded joints showed good strength and ductility at room temperature and 550°C,which were nearly equal to those of the 316 L base material.The heat-affected zone on the RAFM side had the lowest impact toughness throughout the weld with a value of 13.2 J at-40°C,~52%that of the RAFM base material.

Analysis of cracks origin behaviors during sulfide stress corrosion (SSC) in HSLA steel at different temperatures by electrochemical noise

The sulfide stress corrosion(SSC)behaviors of the high strength low alloy steel at the different temperatures were investigated by the microstructural observation and electrochemical noise(EN)analysis.With the corrosion temperature increasing from 20 to 40℃,SSC ruptured time is prolonged.The increase in corrosion temperature results in the decrease of the saturation solubility of H_(2)S in the solution and thus increases pH value of solution.The increase in corrosion temperature decreases the size of the holes and cracks in the corrosion product film on the surface of the sample,which is due to the formation of the dense FeS corrosion product film.The current kurtosis results indicate that the time for the first occurrence of crack initiation is postponed by the increase in the corrosion temperature.The standard deviation of current noise signals,current kurtosis,power spectral density and energy distribution plot results shows a great consistency,which suggests that EN analysis method can reflect SSC behaviors in real time.

Effects of Isothermal Aging on Microstructure and Mechanical Property of Low-Carbon RAFM Steel

In order to investigate the microstructure and mechanical property evolution of low-carbon reduced activation ferritic/martensitic(RAFM)steel during isothermal aging,the normalized and tempered specimens were aged at 600℃for 500,1000,and 3000 h,respectively.The microstructural evolution with aging time was analyzed,including the precipitation and growth of M23C6 and MX-type carbides as well as the formation of Laves phase.The results indicate that the coarsening of M23C6 is more obvious than that of MX with increase in aging time.During the long-term thermal exposure,the Fe2 W Laves phase precipitates adjacent to M23C6 along the prior austenite grain boundaries and packet boundaries.Lower carbon content can delay the precipitation of Laves phase compared to the steel containing higher carbon.In addition,the Laves phase precipitated along boundaries can provide the precipitation strengthening,slightly increasing the tensile strength of low-carbon RAFM steel after aging for 3000 h.

Effects of tantalum on austenitic transformation kinetics of RAFM steel

The RAFM（reduced activation ferritic/martensitic）steels containing different tantalum contents（0wt.%,0.027wt.%,0.073wt.%）were designed and cast.Differential scanning calorimetry and optical microscopy were employed to explore the influence of tantalum content on the austenitic transformation of RAFM steels.The austenitic transformation kinetics was described by aphase-transformation model.The model,involving site saturation nucleation,diffusion-controlled growth and impingement correction,was established based on the classical Johnson-Mehl-Avrami-Kolmogorov model.The phase-transformation kinetics parameters,including D_0（pre-exponential factor for diffusion）and Q_d（activation energy for diffusion）,were calculated by fitting the experimental data and the kinetic model.The results indicated that the average grain size is decreased with the increase of tantalum.The values of A_（c1） and A_（c3） （onset and finish temperature of austenitic transformation,respectively）are increased by increasing the tantalum content.The increase of tantalum caused the decrease of D_0.However,Q_d is increased with the increase of tantalum.In addition,as a carbides forming element,tantalum would reduce the carbon diffusion coefficient and slow down the austenitic transformation rate.

Effect of deformation twinning on high-temperature performance of cold-rolled S31042 steel

Influence of deformation twinning on high-temperature instantaneous performance of cold-rolled S31042 steel was investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy, and high-temperature tensile test. An increasing number of deformation twins have formed as the cold rolling reduction degree increases during the cold rolling process. During the tensile process at 700 ℃, M23C6 particles generated along the deformation twin boundaries, and NbCrN nanoparticles dispersedly precipitated throughout the austenite grains. For the high-temperature tensile sample subjected to cold reduction for 80%, it is observed from the fractured cross section that numerous defor-mation twin boundaries were decorated by discontinuous M23C6 particles. Therefore, austenite grains were divided into several independent zones by the deformation twins, and the grains were refined. Due to the grain refinement strengthening and precipitation strengthening, the high-temperature temporal strength of the 80% cold-rolled sample was significantly improved, and simultaneously, this sample exhibited favorable high-temperature elongation.

Microstructural evolution and constitutive models of 9CrMoCoB heatresistant steel during high-temperature deformation

In order to research the hot deformation behavior of 9CrMoCoB heat-resistant steel,hot compression tests were performed over a wide range of temperatures from 850 to 1150℃ and strain rates from 0.01 to 10.00 s^-1.The flow stress appears to increase with the decrease in deformation temperature and the increase in strain rate.The relationship between microstructural evolution and deformation parameters was studied,indicating that both low strain rate and high deformation temperature appear to promote the dynamic recrystallization,while excessively high temperature with low strain rate would result in the high non-uniformity of grain size.The experimental stress-strain data was applied to calculate the material constants involved in the Arrhenius-type constitutive model and the modified Zerilli-Armstrong(MZA)model,and feasibility of these two models was evaluated.The results show that the MZA model is more accurate to predict the high-temperature flow behavior of the experimental steel than the Arrhenius-type constitutive equation.

Correction to:Microstructure and Mechanical Properties of RAFM-316L Dissimilar Joints by Friction Stir Welding with Different Butt Joining Modes

The authors regret that we misused the dimensions of the ten-sile samples when drawing the stress--strain curves as shown in Fig.13(a)in the original paper.This leads to the mis-calculated values of the Fig.13(a)stress-strain curves.The original data of the tensile experiments have been checked,and the correct figure is provided in this correction as below.