Since researchers first observed the optical anisotropy phenomenon, i.e., birefringence, in a natural crystal, more than three centuries have passed. Known crystals either exhibit relatively small birefringence (e.g., commercial crystals with birefringence <0.3) or do not allow for transmittance of visible light, which limits their significant applications in diverse photonics fields. Herein, by the solution method, we obtained a new crystal K2HC9N133H(2)O, which is not only transparent in the whole visible spectral region because of its wide bandgap of 3.52 eV, but also exhibits giant birefringence as large as 0.87. To the best of our knowledge, this birefringence is the largest among transparent crystals. First-principles calculations reveal that this giant birefringence mainly arises from the anisotropy of pi-electron clouds in (H2C9N13)(-) with parallel spacing arrangement. We believe that this work would be insightful for the design and synthesis of birefringent crystals for transparent compact polarized optics.

Birefringent crystals can manipulate the phase and polarization of light, so they are widely used as essential components in various optical devices. Common strategies to construct birefringent crystals are introducing metal cations that are either able to realize favorable coordination with functional anionic units or are susceptible to polarizability anisotropy. Herein, we report a metal-free crystal, NH4(H2C6N7O3)2H2O, synthesized using the facile solution method. In the crystal structure of NH4(H2C6N7O3)2H2O, (H2C6N7O3)- functional units are assembled in an optimal manner by cooperative non-covalent interactions, i.e., hydrogen bonding and pi-pi interactions. As a result, this metal-free crystal possesses exceptional birefringence up to 0.54@550 nm, which is larger than those of most metal-containing birefringent crystals. In addition, the interference color of this crystal does not change obviously from 243 K to 313 K, indicating that the birefringence is robust at different temperatures. This work will inspire useful insights into the role of non-covalent interactions in designing outstanding birefringent crystals for efficient polarized optical devices. By the cooperation of non-covalent interactions, we designed a metal-free birefringent crystal, NH4(H2C6N7O3)2H2O, which possesses high birefringence Delta n(exp) = 0.54@550 nm for effective modulation of polarized light.

Manufacturing metals using additive manufacturing is of great interest for industries applications. Here, the mechanical and microstructural responses of a 316L stainless steel (316LSS) built by selective laser melting (SLM) with XOY and XOZ directions were revealed by performing in situ neutron diffraction tensile tests. For the XOY sample, the changes in diffraction peaks along the loading direction (LD) mainly are (111), (200), (220), (311), (222), and (331), while the changes in diffraction peaks perpendicular to the loading direction (ND) mainly are (220), (311), and (331). For the XOZ sample, the changes in diffraction peaks along the LD and ND mainly are (111), (200), (220), (311), (222), and (331). As the stress increased from 0 to ~700 MPa, the lattice constants of the XOY-sample in the LD increased from ~3.59571 Å to ~3.60635 Å, while the lattice constants in the ND decreased from ~3.60025 Å to ~3.59535 Å. As the stress increased from 0 to ~570 MPa, the lattice constants of the XOZ-sample in the LD increased from ~3.59518 Å to ~3.61269 Å, while the lattice constants in the ND decreased from ~3.60026 Å to ~3.59535 Å. It is indicated that no matter how the difference of neutron diffraction peaks, the lattice constants was almost identical from ND during tensile tests. As a result, deformation anisotropy mechanism of additive manufactured 316LSS based on in situ neutron diffraction were the differences of diffraction peaks and lattice constants during tensile tests at room temperature.

The effect of rare earth addition on the microstructure and mechanical performances of as-cast and wrought Al alloys has been attracting increasing attention recently. Rare earth addition has great potential in modifying the structure and improving the properties of materials. However, there are currently few reports about the effect of rare earth addition on the microstructure and performances of Al alloys prepared via selective laser melting. Here, AlSi10Mg alloys were manufactured using selective laser melting, and the effect of Er addition was investigated. The results indicate that Er addition leads to α-Al refinement and modifies the minority Si phase. The formation of the Al3Er phase induced by Er addition enhances the strength of the material. Modification of the Si phase also increases ductility. This strategy can help improve the mechanical performance of aluminum alloys prepared via selective laser melting.

The paper presents a new liquid metal putty strain sensor that can measure strains from 0.05% to 300%. A wireless motion monitoring system is developed based on this sensor, which is expected to be used for health and motion tracking.

Despite the rapid progression of organic semiconductors, developing high-air-stability n-type organic semiconductors are still challenging. Herein, novel strong acceptors based on benzothiadiazoloimidazole units are reported. The results reveal that the strong acceptor BTI-NDI-BTI-a has good solubility and high electron affinity (3.94 eV), accompanied by 1D slipped-stacking crystals. Notably, the material presents promising potential for developing into air-stable n-type organic semiconductor materials.

A novel high-entropy AlFeCrCoNi2.1 alloy particle (5 wt.%)-reinforced Al matrix composite ( HEA/AMC) was successfully prepared by selective laser melting. In comparison to the AlSi10Mg sample, the mean grain size of the HEA/AMC decreased from 4.17 to 3.24 μm. Moreover, the inner cell width of the HEA/AMC decreased to less than 0.3 μm. Unmelted HEA particles consisting of a pure B2 phase structure were well retained in the Al matrix with good wettability and interfacial bonding. Newly generated spherical HEA nanoparticles precipitated in Si phases due to the rapid solidification of the locally formed metallic liquid enriched with Al, Si, Fe, Co, Cr, and Ni. The HEA/AMC exhibited higher tensile strength (478 MPa), compressive strength (719 MPa), tensile elongation (5.4%), Vickers hardness (173 HV0.5), and wear resistance (coefficient of friction £ 0.4) than the AlSi10Mg sample. The findings of this work can provide guidance for the selective laser melting of HEA/AMCs with excellent comprehensive mechanical properties.

Liquid-liquid phase separation was used to design phase-separated metallic glasses with special properties. In this work, Zr60Cu40-xFex phase-separated metallic glasses were designed by partial substitution of Cu by Fe in Zr60Cu40 metallic glass. The liquid-liquid phase separation behavior of Zr60Cu40-xFex alloy was investigated. The results show that the miscibility gap of the binary Cu-Fe system can be extended into the Zr60Cu40-xFex system and that liquid-liquid phase separation into Cu-rich and Fe-rich liquids occurred during rapid cooling. On the basis of the behavior of liquid-liquid phase separation of the Zr60Cu40-xFex system, the effect of partial substitution of Cu by Fe on the microstructure and phase formation of the Zr60Cu40-xFex alloys was investigated. The microstructure evolution and the competitive mechanism of phase formation in the as-quenched Zr60Cu40-xFex alloy were discussed. For the Zr60Cu20Fe20 alloy, liquid-liquid phase separation into Cu-rich and Fe-rich liquids and then liquid-glass transition occurred during rapid cooling and resulted in a heterogeneous structure with glassy Fe-rich matrix embedded with glassy Cu-rich nanoparticles. Considering this structure, the electrical properties and nanoindentation behavior of the as-quenched Zr60Cu20Fe20 alloy were examined. The abnormal change in electrical resistivity during crystallization and the effect of nanoscale phase separation on the shear transformation zone of the Zr60Cu20Fe20 alloy were analyzed.

废旧电路板是一种物理结构和化学组成复杂的固体废物,蕴藏丰富的有价金属资源.本文以废旧电路板中处理难度较大的内存条为对象,开展废旧内存条(WMM)低温熔融混碱(MH)处理回收研究,考察温度、时间、物料比等工艺参数对内存条非金属与金属解离的影响,探讨了熔融碱处理过程中内存条非金属(溴化环氧树脂、玻璃纤维等)的降解机理.研究发现,当温度为400℃、碱与内存条物料比mMH/mWMM为5时,在反应釜中持续反应60 min后,内存条中非金属物料的降解率可达95.45％,最终获得由Cu、Fe、Ni及贵金属Au、Ag等组成的混合多金属产物.

燃料电池是一种把化学能直接连续转化为电能的高效、环保的发电系统.固体氧化物燃料电池(SOFC)作为第四代燃料电池,其结构为全固态结构,在中高温条件下工作.SOFC具备燃料范围广、材料成本低、使用寿命长、发电效率高、余热利用价值高等优点.SOFC阳极为从外界输运过来的燃料与从阴极传递过来的氧离子发生电化学反应提供场所.开发高性价比的阳极是提高SOFC性能、降低其制造成本的关键.SOFC阳极材料包括贵金属、Ni基材料、Cu基材料、钙钛矿等.然而,贵金属阳极受成本制约较为严重,Ni基阳极在使用碳氢燃料时易产生积碳而降低其使用寿命,Cu基阳极的电化学活性较低.钙钛矿阳极因其稳定的结构、较高的抗积碳和耐硫毒化能力而得到广泛关注,近年来各类钙钛矿阳极的报道层出不穷.钛基钙钛矿因其较好的催化活性、电化学稳定性、抗硫中毒及抗积碳性能成为近年来SOFC阳极研究的热点.但相较传统Ni基阳极,钛基钙钛矿仍存在催化活性和电导率较低等问题.因此,若将钛基钙钛矿阳极直接应用于SOFC中则无法满足大功率放电需求.近年来,研究者们发现可以采用掺杂、复合改性等方法来提高钛基钙钛矿阳极的电化学活性.本文以目前研究较为广泛的La掺杂钛酸锶、Y掺杂钛酸锶和其他体系的钛基钙钛矿作为对象,重点讨论了钛基钙钛矿的改性方法(如掺杂和复合)和研究进展,并给出钛基钙钛矿的发展方向.本文将为高活性、高稳定性SOFC钙钛矿阳极的研究开发提供参考依据.

The immiscible Cu-Fe alloy was characterized by a metastable miscibility gap. With the addition element Zr, the miscibility gap can be extended into the Cu-Fe-Zr ternary system. The effect of the atomic ratio of Cu to Fe and Zr content on the behavior of liquid-liquid phase separation was studied. The results show that liquid-liquid phase separation into Cu-rich and Fe-rich liquids took place in the as-quenched Cu-Fe-Zr alloy. A glassy structure with nanoscale phase separation was obtained in the as-quenched (Cu0.5Fe0.5)40Zr60 alloy sample, exhibiting a homogeneous distribution of glassy Cu-rich nanoparticles in glassy Fe-rich matrix. The microstructural evolution and the competitive mechanism of phase formation in the rapidly solidified Cu-Fe-Zr system were discussed in detail. Moreover, the electrical property of the as-quenched Cu-Fe-Zr alloy samples was examined. It displays an abnormal change of electrical resistivity upon temperature in the nanoscale-phase-separation metallic glass. The crystallization behavior of such metallic glass has been discussed.

The topological distance is to measure the structural difference between two graphs in a metric space. Graphs are ubiquitous, and topological measurements over graphs arise in diverse areas, including, e.g. COVID-19 structural analysis, DNA/RNA alignment, discovering the Isomers, checking the code plagiarism. Unfortunately, popular distance scores used in these applications, that scale over large graphs, are not metrics, and the computation usually becomes NP-hard. While, fuzzy measurement is an uncertain representation to apply for a polynomial-time solution for undirected multigraph isomorphism. But the graph isomorphism problem is to determine two finite graphs that are isomorphic, which is not known with a polynomial-time solution. This paper solves the undirected multigraph isomorphism problem with an algorithmic approach as NP=P and proposes a polynomial-time solution to check if two undirected multigraphs are isomorphic or not. Based on the solution, we define a new fuzzy measurement based on graph isomorphism for topological distance/structural similarity between two graphs. Thus, this paper proposed a fuzzy measure of the topological distance between two undirected multigraphs. If two graphs are isomorphic, the topological distance is 0; if not, we will calculate the Euclidean distance among eight extracted features and provide the fuzzy distance. The fuzzy measurement executes more efficiently and accurately than the current methods.

Recycling of waste electrical and electronic equipment has become an urgent global issue in recent years from the prospectives of resources recycling and environmental protection. In the present work, the recycling of waste memory modules (WMMs) through low-temperature alkali melts was investigated, based on the thermodynamic analysis of the nonmetallic reactions of brominated epoxy resin, glass fiber and memory chip with the molten mixed alkali. The effects of the reaction temperature and the ratio of alkali mixture on the removal rate of nonmetallic parts in WMMs were discussed under the condition of air atmosphere. The optimum process parameters were further confirmed by in-situ monitoring of the temperature during the whole reaction process. The mixtures with Cu, Fe and Ni as the main components were obtained after the treatment of WMMs in the molten alkali. These mixed metals were further separated into copper-rich and ferronickel-rich metals by physical magnetic separation. Moreover, the precious metals Au and Ag were enriched in Cu-rich alloys. This work provided an efficient and environment-friendly method for metal recycling from WMMs.

The pyrolysis experiment was carried out on the waste printed circuit boards (WPCBs) of mobile phones to obtain the mixed metals which contains more than ten valuable metals. The main components in the mixed metals are elements Fe, Cu, Pb, Sn. The liquid-liquid phase separation behavior of (Fe0.4Cu0.6)100-xPbx ternary alloy has been studied. The introduction of Pb into the metastable immiscible Fe-Cu alloy can result in a stable liquid-liquid phase separation into L(Fe) and L(Cu,Pb) liquids. With the increasing of Pb content, the second phase separation in the residual L(Cu,Pb) liquid was detected, resulting in the formation of three-zone-separation structure. On this basis, a hierarchical separation system was designed to recycle mixed metals in super gravity field. The results show that the metals Cr, Co, Ni, Si are mainly enriched in the Fe-rich zone, the precious metals Au, Ag and a small amount of Zn are concentrated in the Cu-rich zone, while the low-melting-point metals Sn, Bi, Cd, and In are collected in the Pb-rich zone.

The pyrolysis processing was carried out on the waste printed circuit boards (WPCBs) of mobile phones to dissociate metals from non-metals and obtain mixed metals with Fe, Cu and Pb as main components. Based on the main compositions of Fe, Cu and Pb, the liquid-liquid phase separation behavior of (Fe0.4Cu0.6)(100-x)Pb-x ternary alloy has been studied experimentally. The results show that the liquid-liquid phase separation of L -> L(Fe)+L(Cu, Pb) may occur during the ternary Fe-Cu-Pb alloy melt cooling in the miscibility gap. After the liquid L(Fe) solidified, the secondary liquid-liquid phase separation L(Cu, Pb)-> L(Cu)+L(Pb) takes place in the residual L(Cu, Pb) liquid phase, finally resulting in a three-zone separation structure. On the basis of the behavior of the liquid-liquid phase separation, a self-organized hierarchical separation system has been designed to separate and recycle these mixed metals from WPCBs. The enrichment behavior of the minor components like Cr, Au and Cd in the separation system was explored. The effect of super-gravity level on the metal separation and recycling rates has been discussed. As a result, a new harmless route has been established to recycle metal resources in WPCBs.

Waste electrical and electronic equipment is rapidly increasing worldwide, resulting in a large quantity of waste printed circuit boards (WPCBs). There is a great challenge on how to efficiently separate mixed metals in WPCBs, which consists of more than 10 elements including hazardous Cr, Pb and Cd. In this work, based on atomic interactions, a method of liquid-liquid hierarchical separation is developed to separate the mixed metals dissociated from the pyrolyzed WPCBs of mobile phones. The hierarchical separation of L→LFe-rich + LCu,Pb-rich, LCu,Pb-rich→LCu-rich + LPb-rich and LPb-rich→SCu-dendritical + L'Pb-rich produces four immiscible Fe-rich, Cu-rich, Cu-dendritical and Pb-rich substances. The separation rate between these substances can reach more than 96% in a super-gravity field of G = 1000g. Other metals selectively distribute in the four substances. The Fe-rich substance collects Cr, Co, Ni and Si. Almost all of Au and Ag are trapped in the Cu-rich and Cu-dendritical substances. The low-melting-point metals, i.e. Bi, Cd, In and Sn, are located in the Pb-rich substance. This work provides a green shortcut for efficiently separating and recycling overall metals in WPCBs.

Resistive random access memory (RRAM) with inherent logic-in-memory capability exhibits great potential to construct beyond von-Neumann computers. Particularly, unipolar RRAM is more promising because its single polarity operation enables large-scale crossbar logic-in-memory circuits with the highest integration density and simpler peripheral control circuits. However, unipolar RRAM usually exhibits poor switching uniformity because of random activation of conducting filaments and consequently cannot meet the strict uniformity requirement for logic-in-memory application. In this contribution, a new methodology that constructs cone-shaped conducting filaments by using chemically a active metal cathode is proposed to improve unipolar switching uniformity. Such a peculiar metal cathode will react spontaneously with the oxide switching layer to form an interfacial layer, which together with the metal cathode itself can act as a load resistor to prevent the overgrowth of conducting filaments and thus make them more cone-like. In this way, the rupture of conducting filaments can be strictly limited to the tip region, making their residual parts favorable locations for subsequent filament growth and thus suppressing their random regeneration. As such, a novel "one switch + one unipolar RRAM cell" hybrid structure is capable to realize all 16 Boolean logic functions for large-scale logic-in-memory circuits.

Structural regular polyaniline was synthesized via a modified-chemical oxidative polymerization reaction. Highly hydrophilic polyaniline (PANi) and polyaniline-poly(vinylidene fluoride) blend (PANi-PVDF) membranes were prepared by solution casting and phase inversion techniques. Both of the mechanical and filtration properties of the membranes depend on the polymer composition and doping level of the blends. The elasticity of the membrane is greatly improved upon introducing poly(vinylidene fluoride) into the blend. The water permeability of the blend membranes is further enhanced when the membranes are doped with hydrochloric acid. The PANi-PVDF blend membranes are capable of recovering metallic gold from the acid/halide leaching streams spontaneous and sustainably, and are promising candidates for wastewater treatments in electronic industries.

The high-voltage spinel LiNi0.5Mn1.5O4 cathode material suffers from the rapid degradation of electrochemical cycling performance at elevated temperatures, which prevents its successful commercialization. Herein, we show that coating the surface of this material with Ta2O5, which has high resistance against hydrofluoric acid (HF) attack, is an effective way to improve its electrochemical cycling performance. A Ta2O5-coated LiNi0.5Mn1.5O4 half-cell shows a capacity retention of,-93% and a Coulombic efficiency of similar to 98% after 100 cycles at 55 degrees C, compared to the corresponding values of similar to 76% and, similar to 95% measured for the bare LiNi0.5Mn1.5O4 half-cell. The detailed structural analysis of the Ta2O5-coated LiNi0.5Mn1.5O4 shows that a small amount of Ta54 ions diffuse into the 16c site on the cathode surface during the coating process, as directly observed by Cs corrected scanning transmission electron microscopy. The modification of the LiNi0.5Mn1.5O4 surface with Ta5+, together with the residual Ta2O5 coating, stabilizes the surface structure during cycling, leading to reduced Ni and Mn dissolution as well as formation of the solid electrolyte interface (SEI). In contrast, LiNi0.5Mn1.5O4 coated with HF scavengers, such as Al2O3, shows only limited improvement in cycling performance after prolonged cycling at 55 degrees C, due to the consumption of the surface coating by reaction with HF, which leaves LiNio,Mni,MnO, unprotected against HF attack.