Achieving a superior Na storage performance of Fe-based Prussian blue cathode by coating perylene tetracarboxylic dianhydride amine

Fe-based Prussian blue(Fe-PB)cathode material shows great application potential in sodium(Na)-ion batteries due to its high theoretical capacity,long cycle life,low cost,and simple preparation process.However,the crystalline water and vacancies of Fe-PB lattice,the low electrical conductivity,and the dissolution of metal ions lead to limited capacity and poor cycling stability.In this work,a perylene tetracarboxylic dianhydride amine(PTCDA)coating layer is successfully fabricated on the surface of Fe-PB by a liquid-phase method.The aminated PTCDA(PTCA)coating not only increases the specific surface area and electronic conductivity but also effectively reduces the crystalline water and vacancies,which avoids the erosion of Fe-PB by electrolyte.Consequently,the PTCA layer reduces the charge transfer resistance,enhances the Na-ion diffusion coefficient,and improves the structure stability.The PTCA-coated Fe-PB exhibits superior Na storage performance with a first discharge capacity of 145.2 mAh g^(−1) at 100 mA g^(−1).Long cycling tests exhibit minimal capacity decay of 0.027%per cycle over 1000 cycles at 1 A g^(−1).Therefore,this PTCA coating strategy has shown promising competence in enhancing the electrochemical performance of Fe-PB,which can potentially serve as a universal electrode coating strategy for Na-ion batteries.

采用原位无序工程提高Bi_(5)O_(7)Br的可见光光催化药物降解和析氢性能

为了同时解决光吸收能力弱和光生载流子复合率高的问题,本文作者通过简单的原位无序工程合成具有丰富有序/无序结构的Bi_(5)O_(7)Br(O/D-Bi_(5)O_(7)Br)光催化剂。采用XRD、TEM、HRTEM、SAED、XPS和UV-Vis DRS对所制备的样品进行表征,并通过可见光催化降解盐酸四环素(TC)和光解水析氢评价其光催化活性。结果表明,有序/无序结构不仅增强了Bi_(5)O_(7)Br的光吸收能力,提高了其导带位置,促进了光生载流子的转移和分离,而且为光催化过程提供了丰富的不饱和原子作为反应活性位点。因此,O/D-Bi_(5)O_(7)Br表现出38.12μmol/(g·h)的高析氢率和在135 min内86%的TC降解率。

酸性和碱性溶液中金属氮碳材料氧还原和氢析出反应的理论研究

单原子催化剂(SAC)由于其低成本和在各种电催化反应中潜在的高催化活性而被认为是铂族金属的有前景的替代材料,但仍然缺乏对不同金属氮碳材料催化剂之间活性差异的原子机理的理解。在此,通过实验和理论研究相结合,研究了非贵金属氮碳材料(Me-N-C,Me=Fe和Co)作为模型催化剂,以探索在普遍的p H值下氧还原反应(ORR)和氢析出反应(HER)的催化活性以及相对应的反应机理。原子理论模拟表明,Fe-N-C具有比Co-N-C高的ORR活性,这是因为其速率决定步骤的反应势垒较低,而HER的活性趋势却相反。我们的模拟结果与实验观察结果一致。

Ternary Ni-based Prussian blue analogue with superior sodium storage performance induced by synergistic effect of Co and Fe

Prussian blue analogue Na2Ni[Fe(CN)6](Ni-PB)has been widely studied as a cathode material for sodium-ion battery due to its excellent cycling performance.However,Ni-PB has a low theoretical capacity of 85 mAh g^(−1) because of the electrochemical inertness of Ni.Herein,ternary Ni-PB is successfully synthesized by double doping with Co and Fe at Ni-site,and the effect of doping with Co and Fe on the electrochemical performance of Ni-PB is systematically investigated through theoretical calculations and electrochemical tests.The first principles calculations confirm that double doping with Co and Fe can significantly reduce the energy barrier and bandgap of Ni-PB.X-ray diffraction and composition analysis results indicate that ternary NiCoFe-PB composite not only has good crystallinity and high Na content but also has low defects and crystal water.Electrochemical tests reveal that,besides the capacity contribution of high-spin Co/Fe and low-spin Fe,Co-doping enhances the electrochemical activity of low-spin Fe and Fe-doping improves the activity of high-spin Co;moreover,double doping can decrease the diffusion resistance of Na+ions through solid electrolyte interface film,accelerate the kinetics for both ion diffusion process and Faradic reaction,and increase active sites.Under the synergistic effect of Co and Fe,this ternary NiCoFe-PB exhibits outstanding electrochemical performance with a high initial discharge capacity of 120.4 mAh g^(−1) at 20mA g^(−1) and an extremely low capacity fading rate of 0.0044%per cycle at a high current density of 2 A g^(−1) even after 10,000 cycles,showing great application potential of ternary NiCoFe-PB in the field of large-scale energy storage.

Effect of isotope on state-to-state dynamics for reactive collision reactions O(3P)+H2^+→OH^++H and O(3P)+H2^+→OH+H^+ in ground state 1^2A" and first excited 1^2A' potential energy surfaces

We carry out quantum scattering dynamics and quasi-classical trajectory（QCT） calculations for the O+H2+ reactive collision in the ground（12 A"）.nd first excited（12 A’） potential energy surface.We calculate the reaction probabilities of O+H2+（v=0,j=0）→OH++H and O+H2+（v=0,j=0）→OH+H+reaction for total angular momentum J=0.The results calculated by QCT are consistent with those from quantum mechanical wave packet.Using the QCT method,we generate in the center-of-mass frame the product state-resolved integral cross-sections（ICSs）;two commonly used generalized polarization-dependent differential cross-sections（PDDCS s）,（2π/σ）(dσ00/dωt),（2π/σ）(dσ20/dωt));and three angular distributions of the product rotational vectors,p（θr）,P（φr）,and p（θr,φr）.We discuss the influence on the scalar and vector properties of the potential energy surface,the collision energy,and the isotope mass.Since there are deep potential wells in these two potential energy surfaces,their kinetic characteristics are similar to each other and the isotopic effect is not obvious.However,the well depths and configurations of the two potential energy surfaces are different,so the effects of isotopic substitution on the integral cross-section and the rotational polarization of product are different.

平衡、非平衡、交流状态下电化学双电层建模的初学者指南

本文定位在一篇电化学双电层(EDL)理论建模方面入门级文章。我们首先简要介绍了EDL的基本特征,简述了EDL理论建模的发展历史,特别是D.C.Grahame之后近几十年的发展历史。然后,我们依次介绍了平衡状态和动态下不同复杂度的EDL模型。作为一篇入门级文章,我们尽可能详细地阐释理论模型的物理图像、假设、数学推导、形式分析、数值分析,并附上Matlab仿真代码。平衡状态下的模型包括Gouy-Chapman-Stern(GCS)模型,Bikerman-Poisson-Boltzmann(BPB)模型,和非对称离子尺寸模型。我们强调GCS模型和BPB模型在处理离子有限尺寸上存在一个微妙的不同。GCS模型通过人为引入Helmholtz平面来考虑离子有限尺寸,但在Helmholtz平面内及弥散层内却依然采用没有考虑离子尺寸效应的Poisson-Boltzmann理论,因而此处的离子浓度可以无限大。与之不同,BPB模型通过格子气体方法,能够自洽描述离子有限尺寸效应。不同以往直接采用Poisson-Nernst-Planck方程描述EDL动态行为,我们从EDL的巨势出发,运用基本的泛函分析方法,推导了一个考虑离子有限尺寸的EDL动态模型。这一理论方法拓展性好。读者可以根据研究对象的需要,建立不同复杂度的EDL动态模型。最后,我们基于EDL动态模型,推导了EDL的电化学阻抗谱理论模型,以试图向读者展示如何从一个时域物理模型出发,推导相应的阻抗谱物理模型。读者若想要踏进理论电化学这个美丽的花园,根据我们自己学习和研究的经验,一个可行的方式是拿起纸和笔来开始推导本文所介绍的这些模型。

State-to-state dynamics of reactions H+DH'(v=0,j=0)→HH'(v',j')+D/HD(v',j')+H'with time-dependent quantum wave packet method

State-to-state time-dependent quantum dynamics calculations have been carried out to study H+DH'→HH'+D/HD+H'reactions on BKMP2 surface.The total integral cross sections of both reactions are in good agreement with earlier theoretical and experimental results,moreover the rotational state-resolved reaction cross sections of H+DH'→HH‘+D at collision energy Ec=0.5 eV are closer to the experimental values than the ones calculated by Chao et al[J.Chem.Phys.1178341(2002)],which proves the higher precision of the quantum calculation in this work.In addition,the state-to-state dynamics of H+DH'→HD'+H reaction channel have been discussed in detail,and the differences of the micro-mechanism of the two reaction channels have been revealed and analyzed clearly.

Novel potential energy surface-based quantum dynamics of ion–molecule reaction O^++ D_2→OD^++ D

According to a novel electronic ground-state potential energy surface of H2O^＋（X^4 A″）,we calculate the reaction probabilities and the integral cross section for the titled reaction O^＋＋ D2→OD^＋＋ D by the Chebyshev wave packet propagation method.The reaction probabilities in a collision-energy range of 0.0 e V–1.0 e V show an oscillatory structure for the O^＋＋ D2 reaction due to the existence of the potential well.Compared with the results of Martinez et al.,the present integral cross section is large,which is in line with experimental data.

Inhibitory Effects of Sulfur Dioxide on Rat Myocardial Fibroblast Proliferation and Migration

Background： Myocardial fibrosis is an important pathological change has not yet been fully elucidated. The study was designed to examine fibroblast proliferation and migration inhibitor. in many heart diseases, but its pathogenesis is very complex and whether endogenous sulfur dioxide （SO2） is a novel myocardial Methods： Primary rat myocardial fibroblasts were isolated and transfected with aspartate aminotransferase （AAT1 and AAT2） knockdown lentivirus or empty lentivirus. SO2 content in the supematant was determined with high-performance liquid chromatography, and the expressions of AATI, AAT2, proliferating cell nuclear antigen （PCNA）, phosphorylated extracellular signal-regulated protein kinase （p-ERK）, and total ERK （T-ERK） in the cells were detected. Cell migration was detected by wound healing test. Independent sample t-test （for two groups） and one-way analysis of variance （three or more groups） were used to analyze the results. Results： Both AATI and AAT2 knockdown significantly reduced SO2 levels （F = 31.46, P 〈 0.01） and AATI/2 protein expression （AAT1, t = 12.67, P 〈 0.01 ; AAT2, t = 9.61, P 〈 0.01 ）, but increased PCNA expression and Cell Counting Kit-8 （CCK-8） activity as well as the migration in rat primary myocardial fibroblasts （P 〈 0.01）. Supplementation of SO： rather than pyruvate significantly inhibited the increase in proliferation and migration caused by AAT knockdown （P 〈 0.01）. Mechanistically, the ratio of p-ERK to T-ERK was significantly increased in the AAT1/2 knockdown groups compared with that in the empty lentivirus group （AATI, t = -7.36, P 〈 0.01; AAT2, t = 10.97, P 〈 0.01 ）. Whereas PD98059, an inhibitor of ERK activation, successfully blocked AAT knockdown-induced PCNA upregulation （F = 74.01, P 〉 0.05）, CCK-8 activation （F = 50.14, P 〉 0.05）, and migration augmentation in myocardial fibroblasts （24 h,F= 37.08, P〉 0.05; 48 h, F= 58.60, P〉 0.05）. Conclusion： Endogenous SO2 might be a novel myocardial fibrob/ast proliferation and migration inhibitor via inhibiting the ERK signaling pathway.

A differential control method for the proportional directional valve

For the proportional directional valve controlled by two proportional solenoids, the normal control method(NCM) energizes only one solenoid at a time. The performance of the valve is greatly influenced by the nonlinearity of the proportional solenoid, such as dead zone and low force gain with a small current, and this effect cannot be eliminated by a simple dead-zone current compensation. To avoid this disadvantage, we propose the differential control method(DCM). By employing DCM, the controller outputs differential signals to simultaneously energize both solenoids of the proportional valve, and the operating point is found by analyzing the force output of the two solenoids to make a minimum variation of the current force gain. The comparisons of the valve response characteristics are made between NCM and DCM by nonlinear dynamic simulation and experiments. Simulation and experimental results show that by using DCM, the frequency response of the valve is greatly enhanced, especially when the input is small, which means that the dynamic characteristics of the proportional valve are improved.

N,S-codoped porous carbon nanosheets decorated with Fe_(3)C nanoparticles as high-performance anode materials for lithium ion hybrid supercapacitors

The practical applications of carbon anode for lithium-ion batteries(LIBs)are largely obstructed by their moderate rate capability and cyclic stability.Herein,we report a N,S-codoped porous carbon nanosheet(NSC)decorated with Fe_(3)C nanoparticles(Fe_(3)C/NSC)by a one-pot pyrolysis process.The high surface area and abundant defects of NSC can not only promote electrons and ions transfer,but also induce high pseudocapacitive contribution.More importantly,the synergistic catalysis effect of Fe-Nx and Fe_(3)C can catalyze the reversible conversion of some solid electrolyte interface(SEI)components to offer excess capacity during cycling.As expected,the Fe_(3)C-NSC anode delivers a discharge capacity of750 mAh·g^(-1)under a current density of 0.5 A·g^(-1)through 500 cycles and retains a dis-charge capacity of 366 mAh·g^(-1)at 4 A·g^(-1)after 1600 cycles,respectively.Most importantly,the lithium-ion capacitors based on Fe_(3)C/NSC anode demonstrate a high energy density of 249.5 Wh·kg^(-1)at 560 W·kg^(-1).

Characterization of spatial variability with observed responses:application of displacement back estimation

Soil spatial variability is difficult to evaluate due to insufficient test data.An alternative option is estimation by indirect methods such as inverse analysis.In this paper,two examples are presented to demonstrate the capability and accuracy of the probabilistic estimation method to characterize soil spatial variability with displacement responses.The first example is a soil slope subject to a surcharge load,in which the spatially varied field of the elastic modulus is estimated with displacements.The results show that estimations based on horizontal displacements were more accurate than those based on vertical displacements.The accuracy of the estimated field was substantially reduced by increasing variance of elastic modulus.However,the estimation was generally acceptable as the error was not more than 10%,even for the high variance case(COV^l.5).The accuracy of estimation was also affected by the type of covariance function and the correlation length.When the correlation length decreased,the accuracy of estimation was reduced.The second example is a validation of laboratory model tests where a horizontal load was applied on a layered ground.The estimated thicknesses of soil layers were close to those in the real situation,which demonstrates the capacity of the estimation method.

Relationship between Prognosis and Time Interval from Cholecystectomy to Reoperation in Postoperative Incidental Gallbladder Carcinoma

To the Editor： Gallbladder cancer （GBC）, a rare entity with poor prognosis, is often discovered incidentally during or after cholecystectomy.It tends to disseminate early through lymphatic, peritoneal, endobiliary, and hematogenous pathways. Patients usually present with metastatic diseases. If GBC is suspected during cholecystectomy, conversion to open surgery to perform radical resection after confirmation of cancer by intraoperative frozen biopsy is considered. When GBC is diagnosed after cholecystectomy, reoperation for radical resection according to depth of invasion of cancer （T stage） is inevitable. However, reoperation with radical surgery is not performed in all patients for several reasons including refusal to undergo radical surgery, poor medical condition, or cancer progression suggesting unresectability.

Mo-V-Nb-O-based catalysts for low-temperature selective oxidation of Cα-OH lignin model compounds

Mo-V-Nb tri-component oxide catalysts were prepared and firstly used for the selective oxidation of Cα-OH lignin compounds.The catalytic performance of the composite oxides was obviously enhanced due to the synergistic effects of Mo and V elements.Mo5-xVxO14 phase with a variable Mo/V ratio provided suitable active sites for the oxidative dehydrogenation(ODH)of Cα-OH lignin model compound.The optimized Mo-V-Nb molar composition was confirmed as Mo0.61V0.31Nb0.08Ox/TiO2,which exhibited the prominent catalytic activity with the turnover frequency of 1.04×10-3 mmol·g(cat)-1·s-1.Even at room temperature,the catalysts showed highly-efficient ODH reaction activities.The active phase for selective oxidation reaction and the inhibiting effect ofα-MoO3 phase were also discussed in the study.

Identification of novel PKD1 mutations in two Chinese families with autosomal dominant polycystic kidney disease by targeted next generation sequencing

To the Editor:Autosomal dominant polycystic kidney disease(ADPKD)is a common inherited kidney disease with an estimated incidence of 1 in 400 to 1 in 1000.[1] It is a late-onset systemic disorder characterized by the development and progressive enlargement of cysts in the kidney,eventually leading to end-stage renal disease.[2] Previous studies have shown that ADPKD is a heterogeneous monogenic disorder resulting from mutations in two genes:PKD1 and PKD2.Clinical data showed that PKD1 and PKD2 mutations account for 85% and 15% of ADPKD cases,respectively.[3]