Hydrogen-bonded organic framework modified separator for simultaneously enhancing the safety and electrochemical performance of Ni-rich lithium-ion battery

Nickel-rich layered oxide cathode(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x>0.5,NCM)shows substantial potential for applications in longer-range electrical vehicles.However,the rapid capacity decay and serious safety concerns impede its practical viability.This work provides a hydrogen-bonded organic framework(HOF)modification strategy to simultaneously improve the electrochemical performance,thermal stability and incombustibility of separator.Melamine cyanurate(MCA),as a low-cost and reliable flame-retardant HOF,was implemented in the separator modification layer,which can prevent the battery short circuit even at a high temperature.In addition,the supermolecule properties of MCA provide unique physical and chemical microenvironment for regulating ion-transport behavior in electrolyte.The MCA coating layer enabled the nickel-rich layered oxide cathode with a high-capacity retention of 90.3%after 300 cycles at 1.0 C.Collectively,the usage of MCA in lithium-ion batteries(LIBs)affords a simple,low-cost and efficient strategy to improve the security and service life of nickel-rich layered cathodes.

STUDY ON ENRICHMENT AND SEPARATION OF TRACE ELEMENTS WITH SILICA GELS MODIFIED BY HETEROCYCLIC AZO DYES

Two types of modified silica gels were prepared by adsorption method and bonding method respectively. Enrichment and separation of trace metal ions have been done by using the column packed with modified silica gels.

Fe3C-N-doped carbon modified separator for high performance lithium-sulfur batteries

A new Fe3C-N-doped reduced graphene oxide(Fe3C-N-rGO)prepared by a facile method is used as a separator for high performance lithium-sulfur(Li-S)batteries.The Fe3C-N-rGO is coated on the surface of commercial polypropylene separator(Celgard 2400)close to the sulfur cathode.The special nanotubes are in-situ catalyzed by Fe3C nanoparticles.They could entrap lithium polysulfides(Li PSs)to restrain the shuttle effect and reduce the loss of active material.The battery with the modified separator and sulfur cathode shows an excellent cycle performance.It has a high rate performance,580.5 mAh/g at the high current rate of 4 C relative to 1075 mAh/g at 0.1 C.It also has an initial discharge capacity of 774.8 m Ah/g measured at 0.5 C and remains 721.8 mAh/g after 100 cycles with a high capacity retention of 93.2%.The outstanding performances are notable in recently reports with modified separator.

Solving mKdV-sinh-Gordon equation by a modified variable separated ordinary differential equation method

By introducing a more general auxiliary ordinary differential equation （ODE）, a modified variable separated ODE method is developed for solving the mKdV-sinh-Gordon equation. As a result, many explicit and exact solutions including some new formal solutions are successfully picked up for the mKdV-sinh-Gordon equation by this approach.

Solving (2+1)-dimensional sine-Poisson equation by a modified variable separated ordinary differential equation method

By introducing a more general auxiliary ordinary differential equation （ODE）, a modified variable separated ordinary differential equation method is presented for solving the （2 ＋ 1）-dimensional sine-Poisson equation. As a result, many explicit and exact solutions of the （2 ＋ 1）-dimensional sine-Poisson equation are derived in a simple manner by this technique.

A COF-modified Polyimide Ion Track-etched Separator for Lithium-ion Batteries

Enhancing the thermal stability of separator is the main strategy for improving the safety of lithium-ion batteries(LIBs)against thermal runaway.We successfully developed a roll-to-roll process to fabricate a COF(covalent organic framework)-modi ed polyimide(PI)ion track-etched separator by combining heavy ion track etching and doctor blade coating to achieve highly safe LIBs(Fig.1).

Synthesis of Chiral Polyaniline Induced by Modified Hemoglobin

The synthesis of chiral polyaniline （PANI） induced by modified hemoglobin （Hb） was pro- foundly explored for the first time. Results revealed that after being separated, inactivated or immobilized, Hb can still induce the formation of chiral PANI successfully, suggesting that Hb can be used as the chiral inducers regardless of harsh reaction conditions. By examining the properties of PANI induced by modified Hb, it was found that Hb（inactivated）-PANI possessed excellent chirality, stability, and crystalline structure. The globin separated from Hb was demonstrated to have the ability of inducing the production of chiral PANI whereas the hematin from Hb had no capacity to direct enantio specificity for the PANI chains. Results indicated that Hb（immobilized）-PANI exhibited poor yield, doping state, and crys- talline structure, indicating that the immobilization of Hb by entrapment was not beneficial to the polymerization reaction. Results also showed that the structure of Hb may have significant effects on the morphologies of chiral PANI.

COMPETITIVE FACILITATED TRANSPORT OF ACID GASES IN MODIFIED CARRIER MEMBRANES

1 INTRODUCTIONMany attempts to develop semipermeable membranes for gas separation have beendone over the past twenty years [1,2].However,it is still difficult to prepare apolymer film which makes certain gas separation processed within range of being econ-omically and technically feasible,since most polymeric materials are relativelyimpermeable to gases.Facilitated transport concept which was first proposed

Molecular insights on Ca^(2+)/Na+separation via graphene-based nanopores:The role of electrostatic interactions to ionic dehydration

Ca^(2+)/Na+separation is a common problem in industrial applications,biological and medical fields.However,Ca^(2+)and Na+have similar ionic radii and hydration radii,thus Ca^(2+)/Na+separation is challenging.Inspired by biological channels,group modification is one of the effective methods to improve the separation performance.In this work,molecular dynamics simulations were performed to investigate the effects of different functional groups(COO,NH3+)on the separation performance of Ca^(2+)and Na+through graphene nanopores under an electric field.The pristine graphene nanopore was used for comparison.Results showed that three types of nanopores preferred Ca^(2+)to Na+,and Ca^(2+)/Na+selectivity followed the order of GE-COO(4.06)>GE(1.85)>GE-NH3+(1.63).Detailed analysis of ionic hydration microstructure shows that different nanopores result in different hydration factors for the second hydration layer of Ca^(2+)and the first layer of Na+.Such different hydration factors corresponding to the dehydration ability can effectively evaluate the separation performance.In addition,the breaking of hydrogen bonds between water molecules due to electrostatic effects can directly affect the dehydration ability.Therefore,the electrostatic effect generated by group modification will affect the ionic hydration microstructure,thus reflecting the differences in dehydration ability.This in turn affects the permeable and separation performance of cations.The results of this work provide perceptive guidelines for the application of graphene-based membranes in ion separation.

Quasi-Periodic Structures Based on Symmetrical Lucas Function of (2+1)-Dimensional Modified Dispersive Water-Wave System

By introducing the Lucas-Riccati method and a linear variable separation method, new variable separation solutions with arbitrary functions are derived for a （2＋1）-dimensional modified dispersive water-wave system. The main idea of this method is to express the solutions of this system as polynomials in the solution of the Riecati equation that the symmetrical Lucas functions satisfy. From the variable separation sohition and by selecting appropriate functions, some novel Jacobian elliptic wave structure with variable modulus and their interactions with dromions and peakons are investigated.

Design, Synthesis and Application of SiO₂-RATP Nanoparticles for Preconcentration and Separation of Trace Copper Ions: A Green Analytical Method

A new analytical method using Resacetophenone (RATP) modified SiO2 nanoparticles as solidphase extractant has been developed for the preconcentration of trace amounts of Cu(II) in different water samples. Conditions of the analysis such as preconcentration factor, effect of pH, sample volume, shaking time, elution conditions and effects of interfering ions for the recovery of analyte were investigated. The adsorption capacity of nanometer SiO2-RATP was found to be 61.50 μmol·g-1 at optimum pH and the detection limit (3σ) was 0.36 μg·L-1. The extractant showed rapid kinetic sorption. The adsorption equilibrium of Cu(II) on nanometer SiO2-RATP was achieved in 15 mins. Adsorbed Cu(II) was easily eluted with 5 mL of 4 M hydrochloric acid. The maximum preconcentration factor was 60. The method was applied for the determination of trace amounts of Cu(II) in various water and food samples.

Interaction between two folded solitary waves for a modified Broer-Kaup system

By means of a Painlevé-Baicklund transformation and a multi-linear separation-of-variable approach, abundant localized coherent excitations of a modified Broer-Kaup system are derived. There appear possible phase shifts for the interactions of the （2＋1）-dimensional novel localized structures, which are discussed in this paper.

隧道超挖超耗管控措施研究

隧道的超挖超耗管控是绿色低碳时代背景下工程界最关心的难题,对施工企业的成本控制和效益提升具有重要意义。以武两高速XFS隧道为背景,系统总结了隧道超挖超耗的10类影响因素和常见对策,包括围岩条件、施工参数、测量放样、爆破方案、钻孔质量、喷射混凝土回弹率、预留变形量、物资设备性能、作业人员水平和现场施工管控。分析了XFS隧道超挖超耗的原因,并制定了加强地质预报和超前支护施作,减小开挖进尺;动态调整爆破方案,严格炮孔质量检查;引入超细改性硅微粉优化配合比,提高喷射工艺水平;加强现场施工管控,制定超挖超耗管控办法,落实作业人员的激励奖惩等措施。措施执行后,XFS隧道平均超挖由30.1 cm降低至16.6 cm,综合超耗由173.7%降低至100.7%。

Recovery of iron from copper slag via modified roasting in CO-CO2 mixed gas and magnetic separation

A novel technology,modified roasting in CO-CO2 mixed gas and magnetic separation,was presented to recover iron from copper slag.The effects of various parameters such as dosage of flux(CaO),gas flowrate of CO and CO2,roasting temperature,roasting time,particle size of modified slag and magnetic flux density on the oxidized modification and magnetic separation were investigated by comparison of the X-ray diffraction patterns and iron recovery ratio.The optimum conditions for recovering iron by oxidizing roasting and magnetic separation are as follows:calcium oxide content of 25 wt.%,mixed gas flow rates of CO2 and CO of 180 and 20 mL/min,oxidizing roasting at 1323 K for 2 h,grinding the modified slag to 38.5-25.0μm and magnetic separation at 170 mT.The mineralogical and microstructural characteristics of modified slag revealed that the iron-bearing minerals in the copper slag were oxidized,the generated magnetite grew into large particles,and the silicate in copper slag was combined with calcium oxide to form calcium silicate.Finally,the iron-bearing concentrate with an iron grade of 54.79%and iron recovery ratio of 80.14%was effectively obtained.

Preparation of SGO-modified nanofiltration membrane and its application in SO_4^(2-) and Cl^- separation in salt treatment

The lack of fresh water in the world makes the search for an effective method to decontaminate water an urgent priority.An important step is to remove different multivalent ions in salt treatment.Nanofiltration(NF)has been used for treating water containing different kinds of salts.In this work,sulfonate group-modified graphene oxide(SGO)was prepared,and added during the interfacial polymerization(IP)reaction to prepare SGO-modifiedNF membranes(PA-SGO).The chemical composition,structure and surface properties of PA and PA-SGO membranes were characterized by FT-IR,XPS,SEM,AFM,contact angle and zeta potential measurements.Their water flux,salt rejection and antifouling abilities were investigated systematically.The testing results showed that the water flux of PA-SGO(0.03%SGO)was 45.85 LMH under a pressure of 0.2 MPa,and the salt rejection varied in the order of Na_2SO_4(98.99%)>MgSO_4(91.25%)>MgCl_2(42.27%)>NaCl(21.96%).An anti-fouling experiment indicated that the PA-SGO membrane had good anti-fouling properties because of its decreased roughness and increased hydrophilicity and electronegativity.The PA-SGO membrane has good potential for use in removing salt ions from water.

Results of Fontan in Patients with Apicocaval Juxtaposition or/and Separated Hepatic Venous Drainage

Objective:Modifications of the Fontan operation,which are also known as total cavopulmonary connection(TCPC),are widely applied for patients with functionally univentricular hearts(FUH).Herein,we summed up the different surgical pathways and clinical outcomes in FUH patients with apicocaval juxtaposition(ACJ)or/and separated hepatic venous(SHV)drainage.Methods:Between January 2009 and December 2019,123 patients who undergone TCPC in our institute were included in this retrospective study.We have included 70 patients with ACJ(Group 1)and 53 patients with SHV(Group 2).Moreover,Group 2 included 17 cases combing with ACJ(32.1%).In Group 1,three different TCPC methods were conducted.While 45 cases were conducted with the extracardiac conduit-TCPC(EC-TCPC)method,24 cases used the intracardiac conduit-TCPC(IC-TCPC)method,and only one case used the lateral tunnel-TCPC(LT-TCPC).In Group 2,four TCPC methods were conducted on patients.Forty cases used the EC-TCPC-common open technique,6 cases with IC-TCPC technique,4 cases with LT-TCPC,and 3 cases with intra-extracardiac conduit-TCPC(IEC-TCPC).Results:There were 7 patients in Group 1 and 14 patients in Group 2 who required early re-operation during hospitalization(p<0.05).Postoperative mean pulmonary artery pressure(mPAP)greater than 15 mmHg emerged as a predictor for early re-operation(p<0.01)and early death(p<0.001)in univariate analysis.Conclusions:TCPC can be performed in these patients and shows beneficial results.Under the Fontan principle of connecting systemic venous to the pulmonary vasculature unimpededly,surgeons should carefully evaluate three components when choosing for the surgical technique:The distance between inferior vena cava(IVC)and the apex;the site of the vertebrae relative to the ACJ;the distance between ACJ and SHV if coexisting.However,the technique should be altered when the postoperative mPAP was greater than 15 mmHg.

聚苯胺/二氧化钛改性膜的制备及其印染废水处理性能

采用原位氧化聚合法,以二氧化钛为填料、苯胺为单体、聚四氟乙烯膜为基底膜制成聚苯胺/二氧化钛/聚四氟乙烯改性膜;采用傅里叶红外光谱(FTIR)、扫描电子显微镜(SEM)、接触角测试等对改性膜的结构和形貌进行表征,并考察改性前后膜对甲基橙的处理效率。结果表明:聚苯胺和二氧化钛成功固载到基底膜表面,二氧化钛分散均匀且无明显的相分离,改性膜的亲水性提高,纯水通量增加到380 L/(m^(2)·h),对甲基橙的处理效率达到83%,且经过5次再生循环后,处理效率仍然大于70%。

基于改性逆向热致相分离法聚砜微孔膜的制备与性能

针对逆向热致相分离法(RTIPS)制备聚砜(PSF)微孔膜成膜体系稳定性较差的问题,首先对亲水性的端羟基型超支化聚酯(HBPE)进行封端,然后以PSF为膜材料,通过添加亲水剂封端HBPE构建四元低临界共溶温度(LCST)成膜体系PSF/HBPE/N,N-二甲基乙酰胺/聚乙二醇400,采用改性逆向热致相分离法(m-RTIPS)一步制备了亲水性PSF微孔膜。对封端HBPE进行了结构分析和分子量测试,分析了HBPE的封端率对四元成膜体系浊点和黏度的影响,研究了HBPE的封端率对PSF微孔膜的形貌、渗透性、亲水性、抗污染性和力学性能的影响。结果表明,成功对HBPE进行了封端,封端后HBPE的分子量增加;成膜体系的浊点和黏度随HBPE封端率的升高而增大,但黏度上升的幅度较小;3种添加不同封端率HBPE的PSF微孔膜的纯水通量、截留率、亲水性和力学性能都优于纯PSF微孔膜;随HBPE封端率的增加,膜的纯水通量下降,但截留率差别很小。当HBPE封端率为30%时,PSF膜纯水通量恢复率达88%,抗污染性最佳。添加不同封端率HBPE都可制得表面多孔的膜,当HBPE封端率为50%时,PSF膜具有全双连续结构的形貌,其拉伸强度、拉伸弹性模量和断裂伸长率分别为4.86,143.92 MPa和22.68%,综合力学性能优异。

汽车组合仪表有意电磁干扰空时域联合分离系统设计

有意电磁波与汽车仪器电磁传输波产生的混合干扰,降低了汽车组合仪表的稳定运行能力,造成仪表设备失灵;为避免上述情况的发生,设计汽车组合仪表有意电磁干扰空时域联合分离系统;在步进电机驱动电路中,设置汽车组合仪表控制器、分离电源与PCB电路板、有意电磁干扰数字传感器;分配有意电磁波空时域源地址,通过计算干扰信号平坦度的方式,确定脉冲参数的取值范围,实现汽车组合仪表有意电磁的空时域干扰效应分析;估算有意电磁波干扰信号的数目,按照信号分解的处理原则,求解联合分离修正函数,实现电磁干扰的联合分离;在设置频率范围在100 MHz~1 GHz之间、幅度范围为0.5~5 V、脉冲宽度范围为10~100 ns区间后,通过实验结果表明,设计系统应用后可以在混合信号中,按照空域、时域标准的不同分离有意电磁波,且分离后的信号波长、信号频率依然在1.0μm、300 Hz左右,不会因混合干扰降低汽车组合仪表的稳定运行能力。

膜技术处理高浓度有机废水及资源化利用研究进展

随着工业化进程的推进,高浓度有机废水的产生量与日俱增,环境威胁日益严重。因此,如何有效处理高浓度有机废水已成为一个重要的科学问题。膜分离技术以其分离效率高、能耗低、无相变、应用范围广等优势,受到了广泛关注和应用。为此,利用Citespace对相关文章进行可视化分析,综述了膜生物反应器、超滤、纳滤、反渗透、膜组合工艺以及改性膜材料在高浓度有机废水处理中的研究进展。同时,分析了高浓度有机废水及污泥处理过程中的资源化现状。最后,总结了膜分离技术用于高浓度有机废水处理的难点和存在问题,在此基础上,对如何加强污水资源化管理和优化废水排放技术进行了展望。