Thin polymer electrolyte with MXene functional layer for uniform Li^(+) deposition in all-solid-state lithium battery

Solid polymer electrolyte(SPE) shows great potential for all-solid-state batteries because of the inherent safety and flexibility;however, the unfavourable Li+deposition and large thickness hamper its development and application. Herein, a laminar MXene functional layer-thin SPE layer-cathode integration(MXene-PEO-LFP) is designed and fabricated. The MXene functional layer formed by stacking rigid MXene nanosheets imparts higher compressive strength relative to PEO electrolyte layer. And the abundant negatively-charged groups on MXene functional layer effectively repel anions and attract cations to adjust the charge distribution behavior at electrolyte–anode interface. Furthermore,the functional layer with rich lithiophilic groups and outstanding electronic conductivity results in low Li nucleation overpotential and nucleation energy barrier. In consequence, the cell assembled with MXene-PEO-LFP, where the PEO electrolyte layer is only 12 μm, much thinner than most solid electrolytes, exhibits uniform, dendrite-free Li+deposition and excellent cycling stability. High capacity(142.8 mAh g-1), stable operation of 140 cycles(capacity decay per cycle, 0.065%), and low polarization potential(0.5 C) are obtained in this Li|MXene-PEO-LFP cell,which is superior to most PEO-based electrolytes under identical condition. This integrated design may provide a strategy for the large-scale application of thin polymer electrolytes in all-solid-state battery.

Laminar Composite Solid Electrolyte with Poly(Ethylene Oxide)-Threaded Metal-Organic Framework Nanosheets for High-Performance All-Solid-State Lithium Battery

Developing laminar composite solid electrolyte with ultrathin thickness and continuous conduction channels in vertical direction holds great promise for all-solid-state lithium batteries.Herein,a thin,laminar solid electrolyte is synthesized by filtrating–NH 2 functionalized metal-organic framework nanosheets and then being threaded with poly(ethylene oxide)chains induced by the hydrogen-bonding interaction from–NH_(2) groups.It is demonstrated that the threaded poly(ethylene oxide)chains lock the adjacent metal-organic framework nanosheets,giving highly enhanced structural stability(Young’s modulus,1.3 GPa)to 7.5-μm-thick laminar composite solid electrolyte.Importantly,these poly(ethylene oxide)chains with stretching structure serve as continuous conduction pathways along the chains in pores.It makes the non-conduction laminar metal-organic framework electrolyte highly conductive:3.97×10^(−5) S cm^(−1) at 25℃,which is even over 25 times higher than that of pure poly(ethylene oxide)electrolyte.The assembled lithium cell,thus,acquires superior cycling stability,initial discharge capacity(148 mAh g^(−1) at 0.5 C and 60℃),and retention(94% after 150 cycles).Besides,the pore size of nanosheet is tailored(24.5–40.9˚A)to evaluate the mechanisms of chain conformation and ion transport in confined space.It shows that the confined pore only with proper size could facilitate the stretching of poly(ethylene oxide)chains,and meanwhile inhibit their disorder degree.Specifically,the pore size of 33.8˚A shows optimized confinement effect with trans-poly(ethylene oxide)and cis-poly(ethylene oxide)conformation,which offers great significance in ion conduction.Our design of poly(ethylene oxide)-threaded architecture provides a platform and paves a way to the rational design of next-generation high-performance porous electrolytes.

Simulation of Tert-Butyl Alcohol Forming Process by Slurry Catalytic Distillation with Custom Kinetic Program

Producing tert-butyl alcohol (TBA) by slurry catalytic distillation is a green new technology. In order to provide reference data for this production process, this paper applied advanced simulation software Aspen to simulate and optimize the slurry catalytic distillation process of producing TBA. And the kinetics equation of isobutylene hydration which is catalyzed by cation exchange resin in continuous stirred tank reactor (CSTR) is used to display the reaction process. Appropriate theoretical plate number of rectifying section, reaction section and stripping section, reflux ratio and liquid hold-up are obtained by the analog computation. Under this process condition, the conversion rate of isobutylene is 82.53%;the mole fraction of TBA in the bottom discharging is 82.5%.

Isolated mixing regions and mixing enhancement in a high-viscosity laminar stirred tank

Laminar mixing in the stirred tank is widely encountered in chemical and biological industries.Isolated mixing regions(IMRs)usually exist when the fluid medium has high viscosity,which are not conducive to mixing.In this work,the researches on IMRs,enhancement of laminar mixing and the phenomenon of particle clustering within IMRs are reviewed.For most studies,the aim is to destroy IMRs and improve the chaotic mixing.To this end,the mechanism of chaotic mixing and the structure of IMRs were well investigated.The methods developed to destroy IMRs include off-centered agitation,dynamic mixing protocol,special designs of impellers,baffles,etc.In addition,the methods to characterize the shape and size of IMRs as well as mixing effect by experiments and simulations are summarized.However,IMRs are not always nuisance,and it may be necessary in some situations.Finally,the present engineering applications are summarized,and the prospect of the future application is predicted.For example,particle clustering will form in the co-existing system of chaotic mixing and IMRs,which can be used for solid–liquid separation and recovery of particles from high viscosity fluid.

Breeding of New Processing Apricot Cultivar ‘Jinxiu'

‘Jinxiu' is a processing apricot(Armeniaca vulgaris L.) cultivar derived from the cross of ‘Chuanzhihong'בJintaiyang'.The fruit is oval-shaped with the ground color of orange and 1/4-1/2 sheet red in the surface. The average fruit weight is65.5 g, and the maximum value is 106 g. The flesh is orange, fine with very less fiber, toughness, less juice and freestone, and tastes sour and sweet. The soluble solid content is 12.5%. The edible rate is 95.8%. The fruit skin hardness is 12.9 kg/cm2 and storable. The preserved apricots have orange color and are tasty. The preserved yield is 40%. The fruit development period is 72 d. The fruit has high yield, and the fruit yield in full fruit period can reach 37 000 kg/hm2. ‘Jinxiu' was examined and approved by Hebei Examination and Approval Committee of Forest Tree Variety in 2013.

Effect of Postharvest Heat Treatment on Pear Browning during Storage

The effect of postharvest heat treatment on browning of Huangguan pear was investigated. The results showed that heat treatment improved hardness and soluble solid content of stored pear fruit, postponed the improvement of MDA content and PPO activity in stored pear fruit and alleviated the reduction of SOD activity and the lowering of PG activity. To sum up, heat treatment reduces the occurrence of browning of stored pear fruit through the regulation of the changes in a series of physiological and biochemical indexes of fruit.

Effect of Calcium Treatment During Production on Quality of Stored Huangguan Pear Fruit

The effect of calcium treatment during production on the quality(soluble solids, fruit firmness, soluble sugar content, titratable acid content, etc.) of Huangguan pear was studied. The results showed that the calcium treatment during production improved the comprehensive quality of Huangguan pear fruit, delayed and reduced the occurrence of browning of fruit core, and enhanced its storage effect in the cold storage. Therefore, the calcium treatment improved the quality of stored pear fruit.

Impacts of Exogenous Calcium and Calcium Inhibitor on Fruit Cracking of Apricot

Calcium nitrate and EGTA（ calcium inhibitor） were sprayed on Dafeng Apricot during young fruit period. The results showed that calcium（ Ca） spraying during young fruit period increased Ca and VCcontents in the fruit,improved SOD and POD activities,and declined K content,K/Ca and the occurrence of fruit cracking. When spraying calcium inhibitor during young fruit period,it aggravated fruit cracking.

Asymmetric breakup of a droplet in an axisymmetric extensional flow

The asymmetric breakups of a droplet in an axisymmetric cross-like microfluidic device are investigated by using a three-dimensional volume of fluid(VOF) multiphase numerical model. Two kinds of asymmetries(droplet location deviation from the symmetric geometry center and different flow rates at two symmetric outlets) generate asymmetric flow fields near the droplet, which results in the asymmetric breakup of the latter. Four typical breakup regimes(no breakup, one-side breakup, retraction breakup and direct breakup) have been observed.Two regime maps are plotted to describe the transition from one regime to another for the two types of different asymmetries, respectively. A power law model, which is based on the three critical factors(the capillary number,the asymmetry of flow fields and the initial volume ratio), is employed to predict the volume ratio of the two unequal daughter droplets generated in the direct breakup. The influences of capillary numbers and the asymmetries have been studied systematically in this paper. The larger the asymmetry is, the bigger the oneside breakup zone is. The larger the capillary number is, the more possible the breakup is in the direct breakup zone. When the radius of the initial droplet is 20 μm, the critical capillary numbers are 0.122, 0.128, 0.145,0.165, 0.192 and 0.226 for flow asymmetry factor AS= 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5, respectively, in the flow system whose asymmetry is generated by location deviations. In the flow system whose asymmetry is generated by two different flow rates at two outlets, the critical capillary numbers are 0.121, 0.133, 0.145, 0.156 and 0.167 for AS= 1/21, 3/23, 1/5, 7/27 and 9/29, respectively.

Effect of heat flux and inlet temperature on the fouling characteristics of nanoparticles

In order to study the effect of heat flux and inlet temperature on the fouling characteristics of nanoparticles, and to further reveal the fouling mechanism for insights into proper operating conditions, γ-Al_2O_3/water suspensions were chosen as the subject of this research. The particulate fouling characteristics of γ-Al_2O_3/water suspensions on the surface of stainless steel have been experimentally studied by varying the heat flux and the inlet temperature under single-phase flow and subcooled-flow boiling conditions. The results show that in the condition of single-phase flow, the asymptotic value of fouling resistance decreases with increasing of heat flux and inlet temperature. The asymptotic value of fouling resistance under single-phase flow is much higher than for the subcooled-flow boiling condition. The effect of heat flux on the fouling resistance under the two flow states has an inverse relationship, and there exists a minimum value of fouling resistance between these two states. For subcooled-flow boiling, the asymptotic value of fouling resistance increases with increasing heat flux, whereas the effect on fouling resistance by the inlet temperature is negligible.

Design method and experimental study of a cathode tool with an extremely high leveling ratio for electrochemical machining of blisk

To obtain final parts with the desired dimensional accuracy and repeatability via electrochemical machining(ECM), the machining process must enter an ECM balanced state. However,for the ECM processing of blisk, a key component of aerospace engines, the surface of the blade blank often has an uneven allowance distribution due to the narrow passage of the cascade. It is difficult to remedy this issue in subsequent processing steps, which is necessary to ensure the dimensional accuracy and repeatability of the final blade profile. To solve this problem, electrolytic machining must be preceded by electrolytic shaping, which requires cathode tools with large leveling ratios to quickly homogenize the blank surface of the blade. In this study, to obtain a cathode tool with an extremely high leveling ratio, a design method based on the variation in the electrode gap in the non-equilibrium electrolytic state is proposed, and a dissolution model based on the nonequilibrium state is established. In this design method, the allowance on the blank to be machined is first divided into many discrete allowances with the normal direction. The initial machining clearance, feed rate, and total machining time are then calculated using classical ECM equilibrium state theory based on the maximum allowance. Meanwhile, the point coordinates of the cathode tool at maximum allowance can be determined. The non-equilibrium model can then be used to calculate the relative coordinate positions corresponding to the remaining discrete allowances. Finally, the entire cathode tool profile is designed. Simulations, fundamental experiments, and blisk unit workpiece experiments were carried out to validate the design approach. In the simulated processing of the plane workpiece, the leveling ratio of the cathode tool designed by the proposed method(0.77)was 83% higher than that of the cathode tool designed using the traditional method. The simulation results were confirmed by processing experiments. In the machining of blisk unit workpieces with complex curved surfaces, the leveling ratios of the convex and concave parts of the blade machined using the proposed cathode tool respectively reached 0.75 and 0.54, which are 75% and 38% higher than those obtained using the traditional method. This new cathode design method and machining technology can significantly improve the surface allowance distribution of blank before electrolytic finishing. It is helpful for finishing machine to enter electrolytic equilibrium state. Finally, the final blade profile accuracy can be guaranteed and repeated errors can be reduced.

Formatted PVDF in lamellar composite solid electrolyte for solidstate lithium metal battery

Solid polymer electrolytes(SPEs)hold great application potential for solid-state lithium metal battery because of the excellent interfacial contact and processibility,but being hampered by the poor room-temperature conductivity(~10^(−7)S·cm^(−1))and low lithium-ion transference number(tLi+).Here,a lamellar composite solid electrolyte(Vr-NH_(2)@polyvinylidene fluoride(PVDF)LCSE)withβ-conformation PVDF is fabricated by confining PVDF in the interlayer channel of-NH_(2)modified vermiculite lamellar framework.We demonstrate that the conformation of PVDF can be manipulated by the nanoconfinement effect and the interaction from channel wall.The presence of-NH_(2)groups could induce the formation ofβ-conformation PVDF through electrostatic interaction,which serves as continuous and rapid lithium-ion transfer pathway.As a result,a high room-temperature ionic conductivity of 1.77×10^(−4)S·cm^(−1)is achieved,1-2 orders of magnitude higher than most SPEs.Furthermore,Vr-NH_(2)@PVDF LCSE shows a high tLi+of 0.68 because of the high dielectric constant,~3 times of that of PVDF SPE,and surpassing most of reported SPEs.The LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)||Li cell assembled by Vr-NH_(2)@PVDF LCSE obtains a discharge specific capacity of 137.1 mAh·g^(−1)after 150 cycles with a capacity retention rate of 93%at 1 C and 25℃.This study may pave a new avenue for high-performance SPEs.

Lamellar quasi-solid electrolyte with nanoconfined deep eutectic solvent for high-performance lithium battery

Electrolytes with high-efficiency lithium-ion transfer and reliable safety are of great importance for lithium battery.Although having superior ionic conductivity(10^(−3)–10^(−2) S·cm^(−1)),traditional liquid-state electrolytes always suffer from low lithium-ion transference number(tLi+<0.4)and thus undesirable battery performances.Herein,the deep eutectic solvent(DES)is vacuum-filtered into the~1 nm interlayer channel of vermiculite(Vr)lamellar framework to fabricate a quasi-solid electrolyte(Vr-DES QSE).We demonstrate that the nanoconfinement effect of interlayer channel could facilitate the opening of solvation shell around lithiumion.Meanwhile,the interaction from channel wall could inhibit the movement of anion.These enable high-efficiency lithium-ion transfer:2.61×10^(−4)S·cm^(−1)at 25℃.Importantly,the tLi+value reaches 0.63,which is 4.5 times of that of bulk DES,and much higher than most present liquid/quasi-solid electrolytes.In addition,Vr-DES QSE shows significantly improved interfacial stability with Li anode as compared with DES.The assembled Li symmetric cell can operate stably for 1000 h at 0.1 mA·cm^(−2).The lithium iron phosphate(LFP)|Vr-DES QSE|Li cell exhibits high capacity of 142.1 mAh·g^(−1)after 200 cycles at 25℃ and 0.5 C,with a capacity retention of 94.5%.The strategy of open solvation shell through nanoconfinement effect of lamellar framework may shed light on the development of advanced electrolytes.

Improving profile accuracy and surface quality of blisk by electrochemical machining with a micro inter-electrode gap

Electrochemical machining(ECM)has emerged as an important option for manufacturing the blisk.The inter-electrode gap(IEG)distribution is an essential parameter for the blisk precise shap-ing process in ECM,as it affects the process stability,profile accuracy and surface quality.Larger IEG leads to a poor localization effect and has an adverse influence on the machining accuracy and surface quality of blisk.To achieve micro-IEG(<50 lm)blisk finishing machining,this work puts forward a novel variable-parameters blisk ECM strategy based on the synchronous coupling mode of micro-vibration amplitude and small pulse duration.The modelling and simulation of the blisk micro-IEG machining have been carried out.Exploratory experiments of variable-parameters blisk ECM were car-ried out.The results illustrated that the IEG width reduced with the progress of variable parameter pro-cess.The IEG width of the blade’s concave part and convex part could be successfully controlled to within 30 lm and 21 lm,respectively.The profile deviation for the blade’s concave surface and convex surface are 49 lm and 35 lm,while the surface roughness reaches R_(a)=0.149 lm and R_(a)=0.196 lm,respectively.The profile accuracy of the blisk leading/trailing edges was limited to within 91 lm.Com-pared with the currently-established process,the profile accuracy of the blade’s concave and convex profiles was improved by 50.5%and 53.3%,respectively.The surface quality was improved by 53.2%and 50.9%,respectively.Additionally,the machined surface was covered with small corrosion pits and weak attacks of the grain boundary due to selective dissolution.Some electrolytic products were dispersed on the machined surface,and their components were mainly composed of the carbide and oxide products of Ti and Nb elements.The results indicate that the variable-parameters strategy is effective for achieving a tiny IEG in blisk ECM,which can be used in engineering practice.

单孔腹腔镜子宫肌瘤旋切隔离保护技术的应用

目的:比较袋内一体化电动旋切与袋内手动冷刀旋切在经脐单孔腹腔镜子宫肌瘤剔除术中的应用效果。方法:回顾性分析2021年7月至2023年6月期间在武汉大学中南医院妇科行经脐单孔腹腔镜子宫肌瘤剔除术患者的病历信息,包括袋内一体化电动旋切组52例,袋内手动冷刀旋切组61例。分析比较两组患者住院时长、手术时间、术中出血量、术中输血率、术后并发症发生率、术后24 h视觉模拟评分法(visual analogue scale,VAS)疼痛评分、取物袋破损率、术后引流管拔除时间、术后尿管拔除时间、术后肠道通气时间、术前与术后(1 d和3 d)血红蛋白差值及术后病理。结果:与袋内手动冷刀旋切组相比,袋内一体化电动旋切组手术时间更短[(152.88±43.37)min vs. (176.23±59.45)min,P=0.021]、取物袋破损率更低[0(0.0%) vs. 8(13.1%),P=0.019]差异存在统计学意义(P<0.05)。住院时长、术中出血量、术中输血率、术后并发症发生率、术后24 h VAS疼痛评分、术后引流管拔除时间、术后尿管拔除时间、术后肠道通气时间、术前与术后(1 d和3 d)血红蛋白差值及术后病理,两组差异无统计学意义(P>0.05)。结论:在经脐单孔腹腔镜子宫肌瘤剔除术中,袋内一体化电动旋切是一种安全可行的方案,可与单孔腹腔镜及电动旋切器配套使用,与袋内手动冷刀旋切相比手术时长更短、取物袋破损率更低,但仍需大样本前瞻性研究进一步验证。

Free-standing polymer-metal-organic framework membrane with high proton conductivity and water stability

As a new class of porous material,polymer-metal-organic framework(polyMOF)has attracted tremendous interests owing to their combined advantages of polymer and crystalline MOF.However,the poor film-forming ability of polyMOF limits its widespread application,especially in membrane separation area.Herein,for the first time,we demonstrate the fabrication of freestanding polyMOF membrane.The polyMOF nanosheets are synthesized by a polymer-assisted self-inhibition crystal growth strategy.Followed by self-assembly through vacuum filtration,a 20μm-thick free-standing polyMOF membrane is constructed.Benefiting from the inclusion of polymer with hydrophobic backbone and the continuously distributed non-coordinated hydrophilic groups along polymer chain,the polyMOF membrane attains excellent structure stability against water,as well as superior proton transfer property.Proton conductivity as high as 112 and 25.6 mS·cm^(–1)is obtained by this polyMOF membrane at 100%and 20%relative humidity(RH),respectively,which are two orders of magnitude higher than those of pristine MOF.The conductivity under low humidity(20%RH)is even over 8 times higher than that of commercial Nafion membrane(3 mS·cm^(–1)).This study may provide some guidance on the development of polyMOF membranes.

Preoperative diagnosis of malignant pulmonary nodules in lung cancer screening with a radiomics nomogram

Background:Lung cancer is the most commonly diagnosed cancer worldwide.Its survival rate can be significantly improved by early screening.Biomarkers based on radiomics features have been found to provide important physiological information on tumors and considered as having the potential to be used in the early screening of lung cancer.In this study,we aim to establish a radiomics model and develop a tool to improve the discrimination between benign and malignant pulmonary nodules.Methods:A retrospective study was conducted on 875 patients with benign or malignant pulmonary nodules who underwent computed tomography(CT)examinations between June 2013 and June 2018.We assigned 612 patients to a training cohort and 263 patients to a validation cohort.Radiomics features were extracted from the CT images of each patient.Least absolute shrinkage and selection operator(LASSO)was used for radiomics feature selection and radiomics score calculation.Multivariate logistic regression analysis was used to develop a classification model and radiomics nomogram.Radiomics score and clinical variables were used to distinguish benign and malignant pulmonary nodules in logistic model.The performance of the radiomics nomogram was evaluated by the area under the curve(AUC),calibration curve and Hosmer-Lemeshow test in both the training and validation cohorts.Results:A radiomics score was built and consisted of 20 features selected by LASSO from 1288 radiomics features in the training cohort.The multivariate logistic model and radiomics nomogram were constructed using the radiomics score and patients’age.Good discrimination of benign and malignant pulmonary nodules was obtained from the training cohort(AUC,0.836;95%confidence interval[CI]:0.793-0.879)and validation cohort(AUC,0.809;95%CI:0.745-0.872).The Hosmer-Lemeshow test also showed good performance for the logistic regression model in the training cohort(P=0.765)and validation cohort(P=0.064).Good alignment with the calibration curve indicated the good performance of the nomogram.Conclusions:The established radiomics nomogram is a noninvasive preoperative prediction tool for malignant pulmonary nodule diagnosis.Validation revealed that this nomogram exhibited excellent discrimination and calibration capacities,suggesting its clinical utility in the early screening of lung cancer.

Electrochemical machining on blisk channels with a variable feed rate mode

Electrochemical machining(ECM)is an economical and effective method for blisk manufacturing and includes two steps:channel machining and profile machining.The allowance distribution after the channel machining will directly affect the profile machining.Therefore,to improve the uniformity of allowance distribution in the machining of channels,a method that incorporates a variable feed rate mode is developed.During the machining process,the feed rates are dynamically changed according to the needs of the side gap at the different feed depths.As a result,the side gaps at the different feed depths vary,contributing to a decrease in the allowance difference.In this study,the dissolution processes of a blisk channel are simulated using different feed rates,and prediction profiles are obtained.Based on the prediction profiles,the relationship among the feed rate,feed depth,and side gap is established.Then,the feed rates at different feed depths are adjusted according to the relationship.In addition,contrast experiments are conducted.Compared with blisk channel ECM using a constant feed rate of 1 mm/min,using the variable feed rate decreases the allowance differences in the convex and concave parts by 62.2%and 67.4%,respectively.This indicates that using the variable feed rate in the ECM process for a blisk channel is feasible and efficient.

Activated carbon-hybridized and amine-modified polyacrylonitrile nanofibers toward ultrahigh and recyclable metal ion and dye adsorption from wastewater

Nanofibers with high specific surface area and chemical stability have broad prospects in the applications of adsorption.However,the adsorption capacity is limited by the scarcity of adsorption groups and storage space.Herein,the activated carbon-hybridized and amine-modified nanofibers are prepared by integrating activated carbon(AC)and polyacrylonitrile(PAN)via electrospinning method and the subsequent amination,which could provide additional storage space and adsorption groups for ultrahigh adsorption capability.Thus,the obtained amine-rich porous PAN nanofibers(APAN/AC)readily realized the ultrahigh adsorption capacity for metal ions and dyes in wastewater.Specifically,the adsorption capacity of APAN/AC nanofibers were 284 mg·g^(-1) for Cr(VI)and 248 mg·g^(-1) for methyl orange,which were almost 2 and 4 times than that of amine-modified nanofibers(APAN)and carbon-hybridized nanofibers(PAN/AC),respectively.Moreover,the AC inhibited the chain mobility of polymer matrix and thereby endowing APAN/AC nanofibers with excellent recyclability.The adsorption capability retained 80%after nine adsorption-desorption cycles.The adsorption kinetics and corresponding mechanism were further explored.This strategy combines the advantages of polymer nanofibers and AC,opening a new avenue for developing next-generation absorbent materials.

Sponge-based materials for oil spill cleanups: A review

Elimination of leaked oil from aquatic environs has recently gained importance owing to the disasters associated with leakages into marine environments.The need for an environmentally friendly and viable line of action concerning the environs has brought forward numerous affordable,non-toxic,and decomposable materials;further,diverse biomasses for fabricating nano-to micro-scale materials,membranes,and sponges/aerogels have also been incorporated for the elimination and retrieval of oils from water.Moreover,selectivity,sorption capacity,and reusability of these materials after the retrieval of oils are also desired from the viewpoint of sustainability.This review encompasses the recent progress in the field of elimination and retrieval of oil spills using various sponge-based materials.