Research on charge ordering and magnetic properties in La_(0.3)Ca_(0.7)Mn_(1-x)W_xO_3 system

The perovskite manganite sample La0.3Ca0.7Mn1-xWxO3 （x = 0.08, 0.12） was prepared by the solid-state reaction method. The effect of W doping on the Mn site to La0.3Ca0.7MnO3 charge ordering phase and the changing process of magnetic properties were studied through the measurement of the M-T curve, M-H curves, and ESR curves of the sample. The results showed that when x = 0.08, the charge ordering （CO） phase exists in the system, the transition temperature Tco= 275 K, and the system exhibits PM when T 〉 275 K. The system transforms from spin-disordering paramagnetism to spin-ordering antiferromagnetism in the charge ordering state with the temperature decreasing from 275 K to 230 K. The long-range antiferromagnetism forms and AFM/CO states coexist between 230 K and 5 K. There is a little ferromagnetic component in the AFM/CO background in a low temperature range. When x = 0.12, the CO phase in the system has almost melted completely. There is a little remnant of the CO phase below 150 K. The system exhibits paramagnetism when T 〉 150 K and transforms from paramagnetism to ferromagnetism when T〈 150 K.

Optimization on transport of charge carriers in cathode of sulfide electrolyte-based solid-state lithium-sulfur batteries

Lithium-sulfur(Li-S)batteries are considered as promising candidates for novel energy storage technology that achieves energy density of 500 Wh·kg^(−1).However,poor cycle stability resulting from notorious shuttle effect and the safety concerns deriving from flammability of ether-based electrolyte hinder the practical application of Li-S batteries.Because of low solubility to polysulfide,high ionic conductivity,and safety property,sulfide-based electrolytes can fundamentally address above issues.It is widely known that the effective transports of both electrons and ions are basic requirement for redox reaction of active materials in cathode.Thereby,construction of fast and stable ionic and electronic transport paths in cathode is especially pivotal for cycle stability of solid-state Li-S batteries(SSLSBs).In this review,we provide research progresses on facilitating transport of charge carriers in composite cathode of SSLSBs.From perspective of materials,intrinsically conductivity of electrolyte and carbon shows dramatic effect on migration of charge carriers in cathode of SSLSBs,thereby the conductive additives are summarized in the manuscript.Additionally,the charge transport in cathode of SSLSBs fully depends on the physical contact between active materials and conductive additives,therefore we summarized the strategies optimizing interfacial contact and reducing interfacial resistance.Finally,potential future research directions and prospects for SSLSBs with improved energy density and cycle performance are also proposed.

固液装药结构的FAE爆炸抛撒试验研究

针对一种 FAE装药结构 ,对燃料进行了爆炸抛撒的试验研究 ,得到了装药结构参数对固液混合燃料抛撒和分散的影响规律。试验结果表明 FAE装药结构可行 ,满足设计要求 ,为高威力FAE战斗部设计提供了依据。

一次起爆FAE中心装药的实验研究

为了探讨不同组分的中心装药对不同FAE燃料可能的一次起爆情况,采用物理方法对中心装药的配方进行设计,并对不同的FAE燃料进行了一次起爆实验研究,结果表明含有诱发剂的中心装药可以实现FAE燃料的一次起爆。为了进一步弄清中心装药中诱发剂含量对FAE燃料一次起爆过程的影响,利用不同诱发剂含量的中心装药对自行研制的新型复合燃料进行了一次起爆实验研究,CCD像机现场拍摄记录及压力测试结果表明,中心装药中的诱发剂含量会直接影响FAE燃料抛撒、延迟点火时间、爆炸波超压大小以及爆炸作用效果,诱发剂含量存在一个最优值,中心装药中加入适量诱发剂会增强FAE的一次起爆效果。

一次起爆型FAE装药发射安全性实验研究

为了一次起爆型FAE药剂在高过载条件下的应用,文中采用落锤撞击模拟实验装置,利用炸药感度实验中的"上下法"模拟弹丸发射时FAE装药所受的轴向应力,对不同的装药工艺、装药密度、药剂配方进行了模拟实验。通过对一次起爆型FAE装药发射安全性的实验结果分析,得出影响FAE装药发射安全性的主要因素是其药剂配方和装药密度。因此,一定要严格遵照药剂配方进行战斗部装药,并保持适当的装药压力和一定的装药量。

Lighting up aggregate emission of perylene diimide by leveraging polymerization-mediated through-space charge transfer and π-π stacking

The molecular engineering of fluorescent organic/polymeric materials,specifically those emitting in the deep red to near-infrared spectrum,is vital for advancements in optoelectronics and biomedicine.Perylene diimide(PDI),a well-known fluorescent scaffold,offers high thermal and photophysical stability but suffers from fluorescence quenching in solid or aggregate states due to intenseπ-πinteractions.To mitigate this,simple and versatile methods for strong PDI aggregate emission without extensive synthetic demands are highly desirable but still lacking.Here,we report a straightforward strategy to enhance the solid-state emission of PDI by introducing certain degree of through-space charge transfer(TSCT)via controlled radical polymerization,which can efficiently distort the typical face-to-face PDI stacking,enabling greatly enhanced deep red emission.This is achieved by growing electron-donating star-shape styrenic(co)polymers from a multidirectional electron-accepting PDI initiator.The incorporation of polycyclic aromatic monomers further shifted the emission into the near-infrared region,albeit with a reduced intensity.Overall,the emission of the PDI-based TSCT polymers can be systematically manipulated by leveraging the balance between PDI stacking and the TSCT degree,as confirmed by both experimental study and theoretical calculations.Our approach circumvents complex synthetic procedures,offering highly emissive materials with large Stokes shifts and showing broad potential for optoelectronic technology.

冲击载荷条件下FAE装药的应力计算

文中主要是针对一次起爆型FAE装药结构,对其进行合理简化,建立了FAE装药结构的简化模型。并对其简化模型进行受力分析,得出了冲击载荷作用下FAE装药的内部应力值大小及其变化过程;利用ANSYS-LS/DYNA对FAE装药的内部应力进行数值模拟,通过比较FAE装药底部应力的理论计算值与数值模拟值,得出了理论计算和数值模拟具有较好的一致性;从而验证简化模型的合理性以及FAE装药内部应力的理论计算值的确切性。

Interfacial compatibility issues in rechargeable solid-state lithium metal batteries:a review

Solid-state lithium metal batteries(SSLBs)contain various kinds of interfaces,among which the solid electrode|solid electrolyte(ED|SE)interface plays a decisive role in the battery's power density and cycling stability.However,it is still lack of comprehensive knowledge and understanding about various interfacial physical/chemical processes so far.Although tremendous efforts have been dedicated to investigate the origin of large interfacial resistance and sluggish charge(electron/ion)transfer process,many scientific and technological challenges still remain to be clarified.In this review,we detach and discuss the critical individual challenge,including charge transfer process,chemical and electrochemical instability,space charge layers,physical contact and mechanical instability.The fundamental concepts,individual effects on the charge transfer and potential solutions are summarized based on material's thermodynamics,electrode kinetics and mechanical effects.It is anticipated that future research should focus on quantitative analysis,modeling analysis and in-situ microstructure characterizations in order to obtain an efficient manipulation about the complex interfacial behaviors in all solid-state Li batteries.

分散药T型装药控制二次引爆型FAE云雾研究

为了控制新型FAE弹体云雾的窜火、形状、直径与高度等,设计出直径不同的两种药柱间隔装填的分散药T型装药结构,着重对两种药柱的半径、高度、爆速、密度、分散药燃料比进行了设计。在假设小药柱以平面爆轰波引爆大药柱的前提下,对大药柱爆轰波正常传播条件进行了理论推导。选择宏观固态燃料,对Φ330mm×430mm的新型FAE炸弹进行静爆实验;运用柯达高速运动系统观测云雾形成及爆轰过程,并对FAE云雾的直径、高度和体积进行了处理和分析。结果表明,分散药T型装药能有效地控制FAE云雾的形状、直径、高度以及云雾体积,特别是对遏制云雾窜火有很好的效果。

Functional LiTaO_(3)filler with tandem conductivity and ferroelectricity for PVDF-based composite solid-state electrolyte

Composite solid-state electrolytes have received significant attention due to their combined advantages as inorganic and polymer electrolytes.However,conventional ceramic fillers offer limited ion conductivity enhancement for composite solid-state electrolytes due to the space-charge layer between the polymer matrix and ceramic phase.In this study,we develop a ferroelectric ceramic ion conductor(LiTaO_(3))as a func-tional filler to simultaneously alleviate the space-charge layer and provide an extra Li+transport pathway.The obtained composite solid-state electrolyte comprising LiTaO_(3)filler and poly(vinylidene difluoride)matrix(P-LTO15)achieves an ionic conductivity of 4.90×10^(−4)S cm−1 and a Li+transference number of 0.45.The polar-ized ferroelectric LiTaO_(3)creates a uniform electric field and promotes homogenous Li plating/stripping,providing the Li symmetrical batteries with an ultrastable cycle life for 4000 h at 0.1 mA cm^(−2)and a low polar-ization overpotential(~50 mV).Furthermore,the solid-state NCM811/P-LTO15/Li full batteries achieve an ultralong cycling performance(1400 cycles)at 1 C and a high discharge capacity of 102.1 mAh g^(−1)at 5 C.This work sheds light on the design of functional ceramic fillers for composite solid-state electrolytes to effec-tively enhance ion conductivity and battery performance.

Iontronic components: From liquid- to solid-states

In modern electronics,the ionic charges have not occupied the same role as the electrons mainly because of their relatively low mobilities.However,these“slow”charge carriers contribute to brain computing with high efficiency and extremely low power consumption.Inspired by the“ionic”life,iontronic components have recently attracted considerable attention.In this review,we first introduce the progress of iontronic devices operating with the involvement of water,specifically,two types of systems—nanofluidic and hydrogels.Next,the issues and challenges within these liquid-state ionic devices are summarized.To avoid the negative impact of water,we also propose two solid-state materials—ionogels and charged metal nanoparticles—to construct several basic ionic devices such as diodes and transistors.Finally,we summarize this review and outlook the promising directions for the further developments of iontronic devices.

环境温度对云爆剂装药性能的影响研究

为掌握环境温度对云爆剂装药性能的影响,针对液固态云爆剂装药,开展了高低温环境试验,采用CT检测、DR扫描方法,获取了云爆剂装药特性数据。结果表明:高温条件下,云爆剂装药轴向发生膨胀,线膨胀率达2.99%,同时云爆剂装药内部孔隙发生膨胀,较常温下孔隙截面积扩大8倍;低温条件下,云爆剂装药发生轴向收缩,线收缩率达1.43%,云爆剂装药内部孔隙发生收缩。需优化装药工艺,以提高云爆战斗部高低温作用可靠性和环境适应性。

某云爆弹装药金属接触腐蚀性研究

为了探索某新型云爆弹装药对接触金属产生腐蚀的原因,对3种典型的新型云爆弹装药进行了与金属接触腐蚀性实验,并对装药各组分进行了内相容性分析。实验结果表明,在标准实验条件下,含有AP(高氯酸铵)成分的云爆弹装药对接触金属试片产生明显的腐蚀性穿孔现象。这主要是AP分解产生HClO4溶于水形成的高氯酸溶液与金属发生了强烈的氧化还原反应的缘故。对金属表面进行防腐处理以及对药柱进行密封都能有效地降低装药对金属的腐蚀作用。其中,对药柱密封,使之与外界的水分充分隔离具有较强的可操作性,是行之有效的一种方法。

新型扫雷装药爆炸场特性分析及应用

基于爆破法扫雷爆破筒扫雷作用原理,设计了8.2 kg一次引爆型固态FAE扫雷装置。通过改变起爆位置和设置方式,多次野外近地面爆炸试验,采用反射压力传感器在装药正向与侧向离爆点不同位置进行压力测试,同时在正向测线压力传感器的对应位置设置某型防步兵地雷,得到爆炸场不同位置处的爆炸参数以及防步兵雷扫雷范围。结果表明:水平设置扫雷装药的扫雷范围明显大于垂直设置的装药,最佳炸高约为0.60 m;且其爆炸场正压区作用时间曲线呈“V”形,产物作用范围达63倍装药半径,与等当量的TNT的作用时间有明显的优势;本装置的扫雷范围约为目前扫雷爆破筒爆破扫雷范围的1.8~3.85倍,正向可靠扫雷范围可达其装药半径的77倍,侧向达69倍。由于该装药爆炸作用区域正压作用时间明显加长,因此有利于各种地雷的清除,是一种潜在高效的爆破法扫雷装药。

二次起爆条件对小型燃料空气炸药爆轰参数的影响

对装药主要由铝粉和环氧丙烷组成的3 kg级液固燃料空气炸药(FAE)进行静爆场试验,研究了不同二次起爆药(钝化黑索今)质量及多点起爆方式下FAE的爆炸情况,探讨了爆炸超压的变化规律。结果表明,在一定范围内增加二次起爆药质量能提高FAE爆炸超压,二次起爆方式的改变对FAE爆炸超压的影响较小。在二次起爆药质量较小的情况下,FAE抛散形成的云雾中,部分燃料在较低起爆能的激发下无法充分燃烧,甚至不能被点燃,存在爆炸不良效应。二次起爆药质量为120 g时,FAE的爆炸空中超压峰值是二次起爆药质量为60 g时的2.80~6.41倍,此时爆炸场超压趋于稳定。建议采用质量为120 g的起爆药柱作为二次起爆药来进行3 kg级液固型FAE的爆炸试验。研究结果有助于小型FAE试验中二次起爆药质量的选择,促进燃料的高效反应。

Surface Passivation and Energetic Modification Suppress Nonradiative Recombination in Perovskite Solar Cells

Surface passivation via post-treatment is an important strategy for improving power conversion efficiency and operational stability of perovskite solar cells.However,so far the interaction mechanisms between passivating additive and perovskite are not well understood.Here,we report the atomic-scale interaction of surface passivating additive 2,2-difluoroethylammonium bromine(2FEABr)on the MAPbI_(3).It is found that the bulky 2FEA+cations tend to distribute at film surface,while the Br−anions diffuse from surface into bulk.A combination of 19F,207Pb,and 2H solid-state NMR further reveal the Br−anions’partial substitution for the I−sites,the restricted motion of partial MA+cations,and the firmed perovskite lattices,which would improve charge transport and stability of the perovskite films.Optical spectroscopy and ultraviolet photoelectron spectroscopy demonstrate that the 2FEABr induced surface passivation and energetic modification suppress the nonradiative recombination loss.These findings enable the efficiency of the p-i-n structured PSC significantly increasing from 19.44 to 21.06%,accompanied by excellent stability.Our work further establishes more knowledge link between passivating additive and PSC performance.

Multiscale understanding of high-energy cathodes in solid-state batteries: from atomic scale to macroscopic scale

In the crucial area of sustainable energy storage,solid-state batteries(SSBs)with nonflammable solid electrolytes stand out due to their potential benefits of enhanced safety,energy density,and cycle life.However,the complexity within the composite cathode determines that fabricating an ideal electrode needs to link chemistry(atomic scale),materials(microscopic/mesoscopic scale),and electrode system(macroscopic scale).Therefore,understanding solid-state composite cathodes covering multiple scales is of vital importance for the development of practical SSBs.In this review,the challenges and basic knowledge of composite cathodes from the atomic scale to the macroscopic scale in SSBs are outlined with a special focus on the interfacial structure,charge transport,and mechanical degradation.Based on these dilemmas,emerging strategies to design a high-performance composite cathode and advanced characterization techniques are summarized.Moreover,future perspectives toward composite cathodes are discussed,aiming to facilitate the develop energy-dense SSBs.

Plasma Model of Generation and Slip of Linear Defects in Crystalline Materials

In dielectrics and semiconductors, a plasma model of the generation and slip of dislocations is considered, where under shock loads in a generalized space of rectangular pulses an alternating field forms a distribution of pairs of photoelectrons and cations;these electrons with velocities Ve create δ-collisions with cold plasma from free electrons and holes with masses me and mh (mh ≫ me), they emit and absorb longitudinal electron plasma waves whose phase velocities wpw / kpw are close to or are equal to the velocities Ve, while the frequencies wpw and wave numbers kpw of the wave packet of plasma waves are complex, the short-wave components of this wave packet at kpw ⋅ ae ≫ 1 (ae -Debye screening radius) decay in the core linear defect, and its long-wavelength components propagate in the region of the medium surrounding the core of the defect at kpw ⋅ ae <≅ 1. When a defect is generated, the distribution of cations under the influence of the internal Coulomb field shifts to the region of the first peak (protrusion) of the electron plasma wave, thereby forming a vacancy valley. When sliding under the influence of an external electric field, a cationic plasma wave consisting of a vacancy valley and two cationic protrusions moves against the background of an additional potential relief created by an electron plasma wave near the core of the defect. It has been shown that δ-collisions create flows of dynamic large-scale correlations of plasma fluctuations in the form of asymptotics of different-time correlators of density and potential fluctuations as t → +∞.

Research progress on electrolytes for fast-charging lithium-ion batteries

Fast-charging is considered to be a key factor in the successful expansion and use of electric vehicles.Current lithium-ion batteries(LIBs)exhibit high energy density,enabling them to be used in electric vehicles(EVs)over long distances,but they take too long to charge.In addition to modifying the electrode and battery structure,the composition of the electrolyte also affects the fast-charging capability of LIBs.This review provides a comprehensive and in-depth overview of the research progress,basic mechanism,scientific challenges and design strategies of the new fast-charging solution system,focusing on the influences that the compositions of liquid and solid electrolytes have on the fast-charging performance of LIBs.Finally,new insights,promising directions and potential solutions for the electrolytes of fast-charging systems are proposed to stimulate further research on revolutionary next-generation fastcharging LIB chemistry.

Unraveling the evolution of Cathode-Solid electrolyte interface using operando X-ray Photoelectron spectroscopy

Understanding the evolution of the solid electrolyte-electrode interface is currently one of the most challenging obstacles in the development of solid-state batteries(SSBs).Here,we develop an X-ray Photoelectron Spectroscopy(XPS)that allows for operando measurement during cycling.Based on theoretical analysis and the modulated electrode and detector co-grounding mode,the displacement of binding energy can be correlated with the surface electrostatic potential of the material,revealing the charge distribution and composition evolution of the space charge layer between the cathode and the electrolyte.In the investigation of typical LiCoO_(2)(LCO)/Li6PS5Cl(LPSC)/Li-In batteries,we observed the static potential difference and oxidative decomposition between LPSC and LCO,and the effectiveness of the LiNbO3 coating in reducing potential difference and inhibiting the diffusion of Co and oxidation of S species.Furthermore,our study also revealed that the potential drop between LiNi0⋅8Co0⋅1Mn0⋅1O_(2) and LPSC is smaller than that of LCO,whilst that between Li3InCl6 and LCO remains near zero.The proposed operando XPS method offers a novel approach for real-time monitoring of interface potential and species formation,providing rational guidance for the interface engineering in SSBs.