Reversible solid-liquid conversion enabled by self-capture effect for stable non-flow zinc-bromine batteries

Non-flow aqueous zinc-bromine batteries without auxiliary components(e.g.,pumps,pipes,storage tanks)and ion-selective membranes represent a cost-effective and promising technology for large-scale energy storage.Unfortunately,they generally suffer from serious diffusion and shuttle of polybromide(Br^(-),Br^(3-))due to the weak physical adsorption between soluble polybromide and host carbon materials,which results in low energy efficiency and poor cycling stability.Here,we develop a novel self-capture organic bromine material(1,10-bis[3-(trimethylammonio)propyl]-4,4'-bipyridinium bromine,NVBr4)to successfully realize reversible solid complexation of bromide components for stable non-flow zinc-bromine battery applications.The quaternary ammonium groups(NV^(4+)ions)can effectively capture the soluble polybromide species based on strong chemical interaction and realize reversible solid complexation confined within the porous electrodes,which transforms the conventional“liquid-liquid”conversion of soluble bromide components into“liquid-solid”model and effectively suppresses the shuttle effect.Thereby,the developed non-flow zinc-bromide battery provides an outstanding voltage platform at 1.7 V with a notable specific capacity of 325 mAh g^(-1)NVBr4(1 A g^(-1)),excellent rate capability(200 mAh g^(-1)NVBr4 at 20 A g^(-1)),outstanding energy density of 469.6 Wh kg^(-1)and super-stable cycle life(20,000 cycles with 100%Coulombic efficiency),which outperforms most of reported zinc-halogen batteries.Further mechanism analysis and DFT calculations demonstrate that the chemical interaction of quaternary ammonium groups and bromide species is the main reason for suppressing the shuttle effect.The developed strategy can be extended to other halogen batteries to obtain stable charge storage.

Influences of oscillation on the physical stability and explosion characteristics of solid-liquid mixed fuel

The stratification phenomenon resulting from differences in the physical properties of solid-liquid components seriously affect the final combustion and explosion characteristics of mixed fuel under the action of oscillation.The effects of oscillation on the physical stability of mixed fuel with two solid-liquid ratios and three liquid component distribution ratios have been investigated using a self-designed experimental system at oscillation frequencies of 60-300 r/min.The explosion characteristics of mixed fuel before and after oscillation are gained from a 20 L spherical explosion container system.When the mass ratio of liquid components is controlled at 66.9%,64.7%,62.6%the final explosion characteristics are stable,with a maximum difference of only 0.71%.The volume of liquid fuel precipitation increases with increasing oscillation frequency when the mass ratio of liquid components reaches 71.7%,69.6%,67.7%.The fuel explosion overpressure after oscillation decreases with increasing liquid precipitation volume,and the repeatability is poor,with a maximum standard deviation of 82.736,which is much higher than the ratio without stratification.Properly controlling the mass ratio of liquid components of the mixed fuel can effectively combat the impact of oscillation on the physical state and maintain the stability of the final explosion characteristics.

Experimental Investigation of Particles Dynamics and Solid-Liquid Mixing Uniformity in a Stirred Tank

Particle suspension and deposition dynamics are significant factors affecting the level of mixing quality in solidliquid two-phase stirring processes. In general, the ability to increase the suspension rate and minimize depositioneffects is instrumental in improving the uniformity of particle mixing, accelerating the reaction of involved solidliquid two-phase, and improving the efficiency of production operations. In this work, suspension and depositionindicator based on the Betti number and a uniformity indicator are introduced and obtained by means of imageanalysis. The influence of the blade type, rotation speed, blade diameter and blade bottom height on the particlesuspension/deposition characteristics and mixing uniformity are carefully investigated. The experimental resultsshow that the two-phase motion region can be divided into three local regions, including a bottom motion alongthe wall, a low-degree suspension region under the blade and a high suspension region above the blade. The bestdegree of particle suspension is attained by the double-inclined blade paddle at a speed of 270 r/min, a paddlediameter ratio of 0.414, and a height-diameter ratio of 0.086. The double-inclined blade paddle has a better effecton promoting particle suspension and solid-liquid two-phase mixing uniformity.

Experimental study of solid-liquid origami composite structures with improved impact resistance

In this paper,a liquid-solid origami composite design is proposed for the improvement of impact resistance.Employing this design strategy,Kresling origami composite structures with different fillings were designed and fabricated,namely air,water,and shear thickening fluid(STF).Quasi-static compression and drop-weight impact experiments were carried out to compare and reveal the static and dynamic mechanical behavior of these structures.The results from drop-weight impact experiments demonstrated that the solid-liquid Kresling origami composite structures exhibited superior yield strength and reduced peak force when compared to their empty counterparts.Notably,the Kresling origami structures filled with STF exhibited significantly heightened yield strength and reduced peak force.For example,at an impact velocity of 3 m/s,the yield strength of single-layer STF-filled Kresling origami structures increased by 772.7%and the peak force decreased by 68.6%.This liquid-solid origami composite design holds the potential to advance the application of origami structures in critical areas such as aerospace,intelligent protection and other important fields.The demonstrated improvements in impact resistance underscore the practical viability of this approach in enhancing structural performance for a range of applications.

Rapid prediction of flow and concentration fields in solid-liquid suspensions of slurry electrolysis tanks

Slurry electrolysis(SE),as a hydrometallurgical process,has the characteristic of a multitank series connection,which leads to various stirring conditions and a complex solid suspension state.The computational fluid dynamics(CFD),which requires high computing resources,and a combination with machine learning was proposed to construct a rapid prediction model for the liquid flow and solid concentration fields in a SE tank.Through scientific selection of calculation samples via orthogonal experiments,a comprehensive dataset covering a wide range of conditions was established while effectively reducing the number of simulations and providing reasonable weights for each factor.Then,a prediction model of the SE tank was constructed using the K-nearest neighbor algorithm.The results show that with the increase in levels of orthogonal experiments,the prediction accuracy of the model improved remarkably.The model established with four factors and nine levels can accurately predict the flow and concentration fields,and the regression coefficients of average velocity and solid concentration were 0.926 and 0.937,respectively.Compared with traditional CFD,the response time of field information prediction in this model was reduced from 75 h to 20 s,which solves the problem of serious lag in CFD applied alone to actual production and meets real-time production control requirements.

Extraction Behavior of Rare Earths with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 Using Solid-liquid Extraction Technique

The extraction behavior of rare earths was studied by using paraffin with ceresin as a diluent containing 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5.In solid phase,the composition of complexes is REP_3.The equilib- rium extraction constants and pH_(1/2) values of solid-liquid extraction are higher than those of normal liquid-liquid extraction.The extraction efficiency tends to maximum when the ratio of phases is 1:1.When the extraction temperature is higher than the melting point of paraffin and the extraction time is over 10 min,the extraction efficiency keeps constant.Moreover,the relationship among separation factor,equilibrium extrac- tion constant,pH_(1/2) value and atomic number was obtained.The mechanism of solid-liquid extraction is analogous to that of liquid-liquid extraction.

How to Behave Well

In order to build a healthy and civilized city,we students should try our best to behave well in many ways.First of all,we must respect old people and polite1 to others.Second,we should make our city clean every day.Don’t throw litter here and there.Third,it’s polite to say'Thank you','Please'and so on.We should never speak2 dirty words.Be friendly to others and always be ready to help others.

Integration of uniform design and quantum-behaved particle swarm optimization to the robust design for a railway vehicle suspension system under different wheel conicities and wheel rolling radii

This paper proposes a systematic method, integrating the uniform design (UD) of experiments and quantum-behaved particle swarm optimization (QPSO), to solve the problem of a robust design for a railway vehicle suspension system. Based on the new nonlinear creep model derived from combining Hertz contact theory, Kalker's linear theory and a heuristic nonlinear creep model, the modeling and dynamic analysis of a 24 degree-of-freedom railway vehicle system were investigated. The Lyapunov indirect method was used to examine the effects of suspension parameters, wheel conicities and wheel rolling radii on critical hunting speeds. Generally, the critical hunting speeds of a vehicle system resulting from worn wheels with different wheel rolling radii are lower than those of a vehicle system having original wheels without different wheel rolling radii. Because of worn wheels, the critical hunting speed of a running railway vehicle substantially declines over the long term. For safety reasons, it is necessary to design the suspension system parameters to increase the robustness of the system and decrease the sensitive of wheel noises. By applying UD and QPSO, the nominal-the-best signal-to-noise ratio of the system was increased from -48.17 to -34.05 dB. The rate of improvement was 29.31%. This study has demonstrated that the integration of UD and QPSO can successfully reveal the optimal solution of suspension parameters for solving the robust design problem of a railway vehicle suspension system.

Effect of HEA/Al composite interlayer on microstructure and mechanical property of Ti/Mg bimetal composite by solid-liquid compound casting

In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.

Data-driven optimization study of the multi-relaxation-time lattice Boltzmann method for solid-liquid phase change

Sharp phase interfaces and accurate temperature distributions are important criteria in the simulation of solid-liquid phase changes.The multi-relaxation-time lattice Boltzmann method(MRT-LBM)shows great numerical performance during simulation;however,the value method of the relaxation parameters needs to be specified.Therefore,in this study,a random forest(RF)model is used to discriminate the importance of different relaxation parameters to the convergence,and a support vector machine(SVM)is used to explore the decision boundary of the convergent samples in each dimensional model.The results show that the convergence of the samples is consistent with the sign of the decision number,and two types of the numerical deviations appear,i.e.,the phase mushy zone and the non-physical heat transfer.The relaxation parameters chosen on the decision boundary can further suppress the numerical bias and improve numerical accuracy.

美国BEHAVE系统中的BURN子系统分析

BEHA VE系统是一组对话式计算机程序,是美国当今用于各种林火管理活动的计算机辅助系统,它包括火行为估计子系统(BURN子系统)和可燃物模拟子系统(FUEL子系统)。FUEL子系统提供了建立可燃物模型的系统方法,它有NEWMDL和TSTMDL两个程序模块。

父母心理控制与青少年外化问题行为的关系:意志控制和越轨同伴交往的链式中介作用

本研究以生态系统理论和选择理论为基础,考察意志控制、越轨同伴交往在父母心理控制和外化问题行为关系中的链式中介效应。研究使用父母心理控制问卷、意志控制问卷、越轨同伴交往问卷和外化问题行为问卷对1053名中学生进行了调查。结果显示:在控制了人口学变量(性别、年龄以及家庭经济社会地位)后,(1)越轨同伴交往在父母心理控制与青少年外化问题行为之间的中介作用显著;(2)意志控制在父母心理控制与青少年外化问题行为间的中介作用不显著;(3)意志控制和越轨同伴交往在父母心理控制与青少年问题行为之间的链式中介作用显著;(4)中介效应在男女生中呈现相似的显著性模式、在不同学段中不存在显著差异。这些结果对于青少年外化问题的预防与干预提供了一定的启示。

多场景下基于AHP-EWM的人体健康状态评估模型研究

为解决人体健康评估方法个性化监测不足的问题以及在满足不同场景下健康状态精细化评估的需求,需要一种基于多场景的人体健康状态评估方法来实现长期自动化监测。提出一种基于层次分析法(AHP)和熵权法(EWM)组合的多场景人体健康状态评估模型。首先采集人体在运动、休息、工作/学习和娱乐等4种不同场景下的健康监测指标数据,构建相应的评估指标体系。然后分别根据评估指标计算出AHP和EWM权重,再采用量子粒子群优化(QPSO)算法对AHP和EWM中的主客观权重进行分配,以确保评价指标占比的客观性。最后通过模糊综合评价法对人体健康状态进行评估和量化,并利用实际监测数据对方法的可靠性和稳定性进行验证。实验结果表明,在4种场景下所提方法的综合得分分别为63.78、59.83、58.71和59.21,表明在不同场景下该模型都具有较好的准确性和稳定性。根据评估结果,对测试者的身体状态评价结果进行分析,并给出一些健康建议。所提模型可全面了解人体在不同场景下的健康状况,并为人们提供科学的健康指导,从而为健康管理和疾病预防提供科学依据。

Application of fluid modulus inversion to complex lithology reservoirs in deep-water areas

It has been a challenge to distinguish between seismic anomalies caused by complex lithology and hydrocarbon reservoirs using conventional fluid identification techniques,leading to difficulties in accurately predicting hydrocarbon-bearing properties and determining oil-water contacts in reservoirs.In this study,we built a petrophysical model tailored to the deep-water area of the Baiyun Sag in the eastern South China Sea based on seismic data and explored the feasibility of the tri-parameter direct inversion method in the fluid identification of complex lithology reservoirs,offering a more precise alternative to conventional techniques.Our research found that the fluid modulus can successfully eliminate seismic amplitude anomalies caused by lithological variations.Furthermore,the seismic databased direct inversion for fluid modulus can remove the cumulative errors caused by indirect inversion and the influence of porosity.We discovered that traditional methods using seismic amplitude anomalies were ineffective in detecting fluids,determining gas-water contacts,or delineating high-quality reservoirs.However,the fluid factor Kf,derived from solid-liquid decoupling,proved to be sensitive to the identification of hydrocarbon-bearing properties,distinguishing between high-quality and poor-quality gas zones.Our findings confirm the value of the fluid modulus in fluid identification and demonstrate that the tri-parameter direct inversion method can significantly enhance hydrocarbon exploration in deep-water areas,reducing associated risks.

基于量子行为粒子群算法的舱室噪声监测点优化布置

针对舱室噪声在线监测及声场预报问题,本文提出了一种基于量子行为粒子群算法的舱室内部声监测点优化布置方法。根据研究频段范围确定所需声腔模态阶数,计算全部备选监测点位置处各阶声腔模态的声场分布,采用模态置信矩阵作为目标函数,基于量子行为粒子群算法对监测点位置进行优化,获得优化布置方案。从声腔模态采样的正交性及内外声场响应的角度与其他测点布置方案进行了性能比较。研究表明:本文方法优化得到的测点布置方案采集声腔模态信息更全面,可有效提升舱室内声场的重建精度和基于舱室内声场监测的水下辐射噪声预报精度。

Mechanism of slag pellets sticking on the wall of reduction pot in magnesium production by Pidgeon process

In the preparation of magnesium by Pidgeon process,the phenomenon slag pellets sticking on the wall of reduction pot always appear,and the glaze sticking on the inner wall of the reduction pot is difficult to remove.The mechanism of this phenomenon is studied in this work by X-ray fluorescence spectrometer(XRF)measurement,electron probe microanalyzer scanning(EPMA)analysis,differential scanning calorimetry(DSC)analysis,and thermodynamic calculations.The main components of the glaze are MgO,Ca_(12)Al_(14)F_(2)O_(32),CaF_(2),CaO,and a small amount of Ca_(4)Si_(2)O_(7)F_(2).The solid-liquid transition temperature of Ca_(12)Al_(14)F_(2)O_(32)and CaF_(2)is close to the production temperature of Pidgeon process,which leads to the bonding between the slag pellets and the pot wall.The loss of CaF_(2)in glaze layer will reduce the total amount of liquid phase and increase the temperature at which Ca_(12)Al_(14)F_(2)O_(32)is completely transformed into liquid phase,which causes glaze layer sticking on the inner wall of the reduction pot.

高分子量PE-HD的添加对双峰聚乙烯抗熔垂性能的影响

针对管材用双峰聚乙烯抗熔垂性能不足,导致大口径厚壁管材壁厚尺寸不均的现象,首先应用高温凝胶渗透色谱仪表征了双峰聚乙烯的平均分子量、分子量分布以及短支链分布,对表征结果进行分析发现低分子量部分占比较大是影响双峰聚乙烯抗熔垂性能的重要原因。然后,应用熔体流动速率(MFR)仪、微量混合流变仪、旋转流变仪等研究了高分子量高密度聚乙烯(PE-HD)添加量对双峰聚乙烯抗熔垂性能的影响,同时研究了高分子量PE-HD的添加对双峰聚乙烯结晶熔融行为的影响。结果表明,平均分子量为80万的PE-HD的少量添加就能够明显降低双峰聚乙烯的MFR,提高其挤出加工过程的扭矩和熔体黏度,同时提高体系的零剪切黏度(η0)和松弛时间(λ),而MFR越低、η0和λ越高说明双峰聚乙烯的抗熔垂性能越好,因此实验结果表明高分子量PE-HD的添加能够有效改善双峰聚乙烯的抗熔垂性能。添加少量的平均分子量为80万的PE-HD会降低PE-HD100S的结晶峰值温度并提高其熔融峰值温度。上述研究结果能够对双峰聚乙烯的抗熔垂改性和管材应用起到一定的指导作用。

行权与死义:董仲舒“国灭君死”说考辨——以齐顷公和纪侯为例

“国灭君死之,正也”最早见于《公羊传》,董仲舒对其进行了重新建构。与《公羊传》“君获”而“绝之”的阐释不同,董仲舒认为,“君获”等同于“国灭”,“佚获”较“君获”罪更甚之,“国灭”则君应死之。《公羊传》对逢丑父代君而斮本无褒贬,意在批评齐顷公“佚获”,董仲舒则以齐顷公无耻和纪侯死国阐发“贤死义”之义理,且将其纳入经权讨论,认为只有臣子在危亡之际可行权,国君则不能。董仲舒将纪季在纪国灭亡之际以酅入于齐的行为,解读为纪侯命其弟所为,纪侯的存社稷是以纪季代为行权实现的,变《公羊传》的“贤纪季”为“贤纪侯”。董仲舒“国灭君死”说虽与《公羊传》有所差异,但其与公羊义理一脉相承,因而可以说是对公羊义理的完善和发展。

利用可穿戴设备监测学龄儿童量化用眼行为并定量分析近视发生相关因素

目的:探索一种无创的、智能可穿戴设备监测学龄儿童量化的用眼行为,并定量分析近视发生的相关因素。方法:招募佛山市禅城区石湾第二小学三年级及狮城中学小学部五年级的年龄为7~11岁部分学生共171例。所有受试者均按照非睫状肌麻痹主觉验光结果分为近视组108例和非近视组63例,所有受试者均佩戴智能可穿戴设备“云夹”,进行为期10 d(2022年9月21日—2022年10月2日)的用眼行为数据(近距离用眼距离、近距离用眼时间、近距离环境光照、有效户外时间)采集。采用t检验比较近视组与非近视组儿童在用眼行为数据之间的差异,并应用Logistic回归分析用眼行为与近视发生的相关性。绘制受试者操作特征(receiver operating characteristic curve,ROC)曲线,并计算曲线下面积(area under curve,AUC)分析用眼行为习惯对近视发生的预测价值。结果:学龄期儿童近视患病率为63.2%。近视组与非近视组在每天用眼时间、单次用眼时间、用眼距离、白天用眼光照、晚上用眼光照、每天户外活动时间及每天有效户外活动暴露次数比较差异均有统计学意义(均P<0.05)。Logistic回归分析显示,单次用眼时间、每天用眼时间是近视发生的危险因素。Spearman相关性分析显示,单次用眼时间及每天用眼时间均与近视发生呈正相关(均P<0.05)。单次用眼时间预测近视发生的ROC曲线下面积为0.939。结论:可穿戴设备“云夹”可量化学龄期儿童用眼行为;学龄期儿童近视发生可能与近距离用眼时间有一定相关性;预测模型可结合儿童屈光发育档案,量化近视发生风险,对儿童实现分类管理,及时采取个性化干预。

Numerical Simulation and Analysis of Solid-liquid Two-phase Flow in Centrifugal Pump

The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far. There exist two main problems in the operation of the two-phase flow pumps, i.e., low overall efficiency and severe abrasion. In this study, the three-dimensional, steady, incompressible, and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics （CFD） code based on the mixture model of the two-phase flow and the RNG k-~ two-equation turbulence model, in which the influences of rotation and curvature are fully taken into account. The coupling between impeller and volute is implemented by means of the frozen rotor method. The simulation results predicted indicate that the solid phase properties in two-phase flow, especially the concentration, the particle diameter and the density, have strong effects on the hydraulic performance of the pump. Both the pump head and the efficiency are reduced with increasing particle diameter or concentration. However, the effect of particle density on the performance is relatively minor. An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration. The suction side of the blade is subject to much more severe abrasion than the pressure side. The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump, and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps.