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The absence of intrinsic p-type 2D layered semiconductors has hampered the development of 2D devices, particularly in complementary metal–oxide–semiconductor (CMOS) devices and integrated circuits. Developing practical p-type semiconductors and advanced modulation techniques for precise carrier control is paramount to advancing electronic devices and systems. Here, by applying pressure to continuously tune the Peierls distortion in NbOI2, we effectively control the polarity and concentration of carriers and significantly enhance its photoelectric properties. The results demonstrate that by suppressing the off-center displacement of Nb atoms along the in-plane bdirection under pressure, NbOI2undergoes a semiconductor-to-semiconductor phase transition from C2 to C2/m, leading to a significant transition from n-type to p-type carrier behavior. Additionally, the gradual inhibition of internal interactions within Nb–Nb dimers along the in-plane cdirection under high pressure facilitates electron delocalization, substantially enhancing the photoelectric properties. The photocurrent is increased by more than 3 orders of magnitude under xenon irradiation, and the spectral response range is continuously red-shifted and extended to 1450 nm. These findings highlight the potential of pressure engineering to adjust photoelectric properties effectively and flexibly, offering valuable insights for designing high-performance p-type two-dimensional semiconductors.

The trust management and the identity authentication in the Vehicular Edge Computing (VEC) is the critical part of data security. However, most of the existing authentication schemes fail to fully address the data trust issue among edge computing nodes in cross-regional communications, and lack anonymous security features. In this paper, a lightweight Multi-entity Authenticated Group Key Agreement (MAGKA) protocol is proposed for blockchain-based VEC networks. The proposed blockchain network built from the roadside units is to ensure the un-deniability of any data exchanged among the edge networks to provide data trust management. The MAGKA protocol substantiates the lightweight authentication between the vehicles, the roadside unit, and the trusted authority anonymously, allowing the vehicles to join or leave the edge network dynamically on the premise of ensured security. The security analysis shows that MAGKA protocol can resist common attacks effectively. In addition, the performance evaluation shows that the MAGKA reduces the computational cost for the low-power node and powerful node by 75% and 50%, respectively, over the existing authentication protocols.

Polynitrogen has been widely studied recently as a rising star of high energy density materials. Here, we performed a systematic study of the Zr-N compounds in the N-rich region by the first-principles method. The high-pressure phase diagram of the Zr-N system is enriched by proposing five new compounds. ZrN10with the infinitely extended band shaped structure is first reported. The band-like polynitrogen of ZrN10decomposes into a more stable chain-like polynitrogen structure under the influence of temperature. Additionally, the novel honeycomb-like band-shaped N10structure hcb-N10has been discovered by removing the Zr atoms. The absence of the −4 oxidation state in the N10unit prompts its further polymerization, which makes hcb-N10possess dynamical and thermal stability in ambient conditions. hcb-N10is a semiconductor with a bandgap of 2.97 eV due to highly localized electrons. Both chain-ZrN10and hcb-N10represent potential candidates for HEDMs with outstanding energy and explosive performance.

[Display omitted] Zinc electrolytic anode slime (ZEAS) contains high contents of Mn, Zn, Sr and Pb, showing a great economic value and potential threats to environment. During the formation of ZEAS, Pb and Sr in the electrolyte were simultaneously crystallization crystallized to form a mixcrystal structure, which dramatically impedes the dissolution of Sr with a small conventional Sr leaching efficiency of 26.06%. In this study, a high-efficiency leaching method of Sr from refractory ZEAS by mechanochemical ball milling-soda converting-acid leaching-purifying-carbonating was proposed. Mechanochemical ball milling enhances the leaching efficiency of Sr by destroying the Pb and Sr cocrystallization structure and greatly improved the reaction rate of the subsequent process. The leaching efficiency of Sr is increased to 83.03%. Moreover, the Sr leaching efficiency reaches 96.81% under the optimum mechanochemical ball milling, soda conversion and acid leaching conditions. In the purification process, the optimum pH value of 13.2 and the recovery of Sr is 94.57%. The comprehensive recovery rate of Sr is above 90%, and SrCO 3 product with purity above 96% was prepared. In addition, the separation and recovery mechanism of Sr was studied, and the enrichment direction of Pb, Mn, Zn, and Ca elements were also evaluated. [ABSTRACT FROM AUTHOR]

[Display omitted] • The vulcanization step-by-step and the vulcanized trajectory of which were proposed. • The thiomolybdate method is still suitable to separate Mo (Mo/WO 3 > 2 wt%). • The efficient separation of macro-molybdenum was realized by floating extraction. • The WO 3 with a purity of 99.99% was prepared from purified solutions. • Microbubble floating-extraction mechanisms were comprehensively interpreted. The gradually increasing demand for high-purity tungsten products has become a key challenge and attracted considerable attention in chemical industry, the premise of which is to achieve the deep separation of molybdenum impurities from tungstate solutions. An innovative separation of molybdenum impurity from tungstate solutions were systematically investigated in this work. On the foundation of the theoretical analysis, a novel strategy named vulcanization step-by-step and the vulcanized trajectory of which were proposed. It was found that the thiomolybdate method is still suitable to separate molybdenum from tungstate solutions (Mo/WO 3 > 2 wt%) based on the vulcanization step-by-step, and satisfactory separation results were obtained by microbubble floating-extraction. Under optimized conditions, the separation efficiency of molybdenum can reach over 99 %, and the loss of tungsten is approximately 2 %. As a results, the tungstate solutions with Mo/WO 3 less than 2 × 10−6 was obtained. Subsequently, the tungsten products (WO 3) with a purity greater than 99.99 % was prepared from purified tungstate solutions. Ultimately, the microbubble floating-extraction mechanisms including the mineralization behaviors of target component, the attachment behaviors of hydrophobic complexes on the surface of rising microbubbles and the mass transfer process at the oil–water phase were comprehensively interpreted at the molecular level. This work can provide an important technical support for the preparation of high-purity tungsten products from tungstate solutions containing macro amount of molybdenum. [ABSTRACT FROM AUTHOR]

National Integrated Circuit Industry Investment Fund (NICIIF) is an important policy tool to support the innovation and development of enterprises. This paper establishes the first phase of the National Integrated Circuit Industry Investment Fund as a quasi-natural experiment. It uses Shanghai and Shenzhen A-share listed companies from 2010 to 2020 to examine the influence and mechanism of NICIIF on enterprise innovation. The empirical results show that the NICIIF can significantly improve the innovation quality of enterprises, which causes a 20.37% increase in innovation quality. The NICIIF lays the financial foundation for enterprises’ technological innovation by alleviating enterprises’ financing constraints. Moreover, the NICIIF significantly promotes innovation for young, small-scale, and integrated circuit enterprises in the Bohai Rim and midwestern regions. This paper provides empirical evidence for the NICIIF to promote enterprise innovation, which is conducive to achieving breakthrough technological innovation and improving the security of the integrated circuit industry chain.

Simultaneous study of magnetic and electrocatalytic properties of cobaltites under extreme conditions expands the understanding of physical and chemical processes proceeding in them with the possibility of their further practical application. Therefore, La0.6Sr0.4CoO3(LSCO) nanopowders were synthesized at different annealing temperatures tann= 850–900 °C, and their multifunctional properties were studied comprehensively. As tannincreases, the rhombohedral perovskite structure of the LSCO becomes more single-phase, whereas the average particle size and dispersion grow. Co3+and Co4+are the major components. It has been found that LSCO-900 shows two main Curie temperatures, TC1and TC2, associated with a particle size distribution. As pressure Pincreases, average ⟨TC1⟩ and ⟨TC2⟩ increase from 253 and 175 K under ambient pressure to 268 and 180 K under P= 0.8 GPa, respectively. The increment of ⟨dTC/dP⟩ for the smaller and bigger particles is sufficiently high and equals 10 and 13 K/GPa, respectively. The magnetocaloric effect in the LSCO-900 nanopowder demonstrates an extremely wide peak δTfwhm> 50 K that can be used as one of the composite components, expanding its working temperature window. Moreover, all LSCO samples showed excellent electrocatalytic performance for the oxygen evolution reaction (OER) process (overpotentials of only 265–285 mV at a current density of 10 mA cm–2) with minimal η10for LSCO-900. Based on the experimental data, it was concluded that the formation of a dense amorphous layer on the surface of the particles ensures high stability as a catalyst (at least 24 h) during electrolysis in 1 M KOH electrolyte.

As a commercial chalcopyrite, the ternary Zn-based semiconductor ZnGeP2is a promising material because of its economical and practical applications in photocatalytic, nonlinear optic, and photoelectric applications. Nevertheless, there is still an urgent need to explore an effective approach to further optimize the photoelectric-related properties of ZnGeP2. Herein, the superior photoelectric properties of ZnGeP2with high photocurrent density (Jph) of 1467 μA/cm2, and photoresponsivity (R) of 780.3 mA/W were obtained at 21.4 GPa, which enhanced 3 orders of magnitude higher compared with initial values. Intriguingly, the photoresponse range of ZnGeP2was extended to 1650 nm. Extensive high-pressure spectral analysis and theoretical simulation revealed that the metal phase (Fm3̅m) started at 14.3 GPa, followed by a successive metallization process dominated by a mixed-phase state up to 23.3 GPa, which contributed to the significant pressure-enhanced photoelectric properties of ZnGeP2. These findings demonstrate significant improvement of the photoelectric properties in ZnGeP2via external pressure, which also provides methods to modify the photoelectric properties of other chalcopyrites.

Autonomous driving demands robust and precise vehicle localization in complex environments with limited on-board computational resources. Incorporating reliable semantic information with localization algorithms can increase accuracy remarkably, however, the process of extracting semantic information from LiDAR point clouds and matching it to semantic maps is computationally intensive. Moreover, pure semantic localization cannot achieve the robustness requirements for safe self-driving as the necessary quantity of semantic landmarks cannot be guaranteed under extreme conditions. In this paper, we present a lightweight semantic-aided localization method that improves upon traditional techniques in two ways. First, we propose a highly efficient pipeline to extract three semantic classes from a LiDAR scan. Second, instead of semantic 3D point cloud registration, map matching is performed through 2D key point matching. We then integrate these two functions into a dynamic semantic aided localization framework. Our on-road experiments demonstrate that the proposed method achieves both the high accuracy of semantic localization and the robustness of non-semantic localization. With our algorithm consuming under 10% of CPU resources, we observe reduced positioning error, especially peak error, when comparing to non-semantic counterparts.

The domestication and artificial selection of wild boars have led to dramatic morphological and behavioral changes, especially in East Chinese (ECN) pigs. Here, we provide insights into the population structure and current genetic diversity of representative ECN pig breeds. We identify a 500-kb region containing six tooth development-relevant genes with almost completely different haplotypes between ECN pigs and Chinese wild boars or European domestic pigs. Notably, the c.195A>G missense mutation in exon 2 of AMBNmay cause alterations in its protein structure associated with tusk degradation in ECN pigs. In addition, ESR1may play an important role in the reproductive performance of ECN pigs. A major haplotype of the large lop ear-related MSRB3gene and eight alleles in the deafness-related GRM7gene may affect ear morphology and hearing in ECN pigs. Interestingly, we find that the two-end black (TEB) coat color in Jinhua pigs is most likely caused by EDNRBwith genetic mechanisms different from other Chinese TEB pigs. This study identifies key loci that may be artificially selected in Chinese native pigs related to the tusk, coat color, and ear morphology, thus providing new insights into the genetic mechanisms of domesticated pigs.

The emergence of superconductivity in two-dimensional (2D) materials has attracted tremendous research efforts because the origins and mechanisms behind the unexpected and fascinating superconducting phenomena remain unclear. In particular, the superconductivity can survive in 2D systems even with weakened disorder and broken spatial inversion symmetry. Here, structural and superconducting transitions of 2D van der Waals (vdW) hydrogenated germanene (GeH) are observed under compression and decompression processes. GeH possesses a superconducting transition with a critical temperature (Tc) of 5.41 K at 8.39 GPa. A crystalline to amorphous transition occurs at 16.80 GPa, while superconductivity remains. An abnormal increase of Tcup to 6.11 K was observed during the decompression process, while the GeH remained in the 2D amorphous phase. A combination study of in situhigh-pressure synchrotron X-ray diffraction, in situhigh-pressure Raman spectroscopy, transition electron microscopy, and density functional theory simulations suggests that the superconductivity in 2D vdW GeH is attributed to the increased density of states at the Fermi level as well as the enhanced electron–phonon coupling effect under high pressure even in the form of an amorphous phase. The unique pressure-induced phase transition of GeH from 2D crystalline to 2D amorphous metal hydride provides a promising platform to study the mechanisms of amorphous hydride superconductivity.

Microelectrolysis (ME) is an efficient method for treating organic wastewater. The utilization of copper slag for high-performance microelectrolysis material preparation for pollutant degradation is meaningful for environmental conservation. Herein, a Fe-Cu-C microelectrolysis material (MEM) was prepared by carbothermal reduction with copper slag, copper powder and anthracite as the raw materials for phenol degradation in wastewater. The phase and structural transformations that occur in the reduction process of copper slag during MEM preparation were investigated via X-ray diffraction (XRD) and an electroprobe microanalyzer (EPMA). The prepared Fe-Cu-C MEMs were characterized by XRD, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The anchored structure of the iron droplets on the SiO2bulk surface is beneficial for the microelectrolysis reaction as well as for the stability of the microstructure. The Fe-Cu-C MEM displayed wide pH and temperature application ranges for phenol degradation. Interestingly, 1O2was found to play a critical role in phenol degradation in the ME system. Under the optimal conditions, the phenol degradation efficiency of Fe-Cu-C MEM reached 96.48% after 60 min, with chemical oxygen demand and total organic carbon removal rates of 82.65% and 67.34%, respectively. This research provides a feasible method for the production of Fe-Cu-C MEM and the degradation of phenol in wastewater.

Recently, the possibility of exploiting the phenomenon of spin transition (ST) has been intensively investigated; therefore, it is particularly important to study the behavior of ST under various stimuli. Here, the shape and content of the intermediate phase of ST in Hoffmann-like compounds [Fe(Fpz)2M(CN)4] (M = Pt, Pd) under external stimuli are studied. For this purpose, magnetic and Raman spectroscopy studies were carried out. In pressure-induced spin transition (PIST), a mixture of high-spin and low-spin states appears, while in temperature-induced spin transition (TIST), a homogeneous state occurs. The first-order ST induced by pressure has a hysteresis but is not abrupt. However, the temperature-induced spin transition at ambient pressure is hysteretic and abrupt. To investigate this difference, we discuss using a thermodynamic model that considers elastic interactions, showing that the slope of the hysteresis loop is related to the appearance of internal pressure, which is related to the difference in sample compressibility under high-spin and low-spin states.

Lead-free halide double perovskites (DPs) have been proposed as stable and promising alternatives to lead halide perovskites. Understanding the structural–optical properties of halide DPs is important for their applications. In this study, Cs2AgInCl6DP nanocrystals, with a direct band gap, were synthesized and studied. Because of a strong electron–phonon coupling leading to exciton self-trapping, a broad emission with a large Stokes shift of Cs2AgInCl6DP nanocrystals is observed. We observed an abnormal blue-shifted emission accompanied by a red-shifted direct absorption edge because of the reduced electron–phonon coupling under compression in the cubic phase Cs2AgInCl6DP nanocrystals. Our study clarified the basic structural–optical correlation of halide DPs and may promote their application in related fields.

AbstractThe identification of oleaginous yeast species capable of simultaneously utilizing xylose and glucose as substrates to generate value-added biological products is an area of key economic interest. We have previously demonstrated that the Cutaneotrichosporon dermatisNICC30027 yeast strain is capable of simultaneously assimilating both xylose and glucose, resulting in considerable lipid accumulation. However, as no high-quality genome sequencing data or associated annotations for this strain are available at present, it remains challenging to study the metabolic mechanisms underlying this phenotype. Herein, we report a 39,305,439 bp draft genome assembly for C. dermatisNICC30027 comprised of 37 scaffolds, with 60.15% GC content. Within this genome, we identified 524 tRNAs, 142 sRNAs, 53 miRNAs, 28 snRNAs, and eight rRNA clusters. Moreover, repeat sequences totaling 1,032,129 bp in length were identified (2.63% of the genome), as were 14,238 unigenes that were 1,789.35 bp in length on average (64.82% of the genome). The NCBI non-redundant protein sequences (NR) database was employed to successfully annotate 11,795 of these unigenes, while 3,621 and 11,902 were annotated with the Swiss-Prot and TrEMBL databases, respectively. Unigenes were additionally subjected to pathway enrichment analyses using the Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Cluster of Orthologous Groups of proteins (COG), Clusters of orthologous groups for eukaryotic complete genomes (KOG), and Non-supervised Orthologous Groups (eggNOG) databases. Together, these results provide a foundation for future studies aimed at clarifying the mechanistic basis for the ability of C. dermatisNICC30027 to simultaneously utilize glucose and xylose to synthesize lipids.

Amorphous materials inherit short- and medium-range order from the corresponding crystal and thus preserve some of its properties while still exhibiting novel properties1,2. Due to its important applications in technology, amorphous carbon with sp2or mixed sp2–sp3hybridization has been explored and prepared3,4, but synthesis of bulk amorphous carbon with sp3concentration close to 100% remains a challenge. Such materials inherit the short-/medium-range order of diamond and should also inherit its superior properties5. Here, we successfully synthesized millimetre-sized samples—with volumes 103–104times as large as produced in earlier studies—of transparent, nearly pure sp3amorphous carbon by heating fullerenes at pressures close to the cage collapse boundary. The material synthesized consists of many randomly oriented clusters with diamond-like short-/medium-range order and possesses the highest hardness (101.9 ± 2.3 GPa), elastic modulus (1,182 ± 40 GPa) and thermal conductivity (26.0 ± 1.3 W m−1K−1) observed in any known amorphous material. It also exhibits optical bandgaps tunable from 1.85 eV to 2.79 eV. These discoveries contribute to our knowledge about advanced amorphous materials and the synthesis of bulk amorphous materials by high-pressure and high-temperature techniques and may enable new applications for amorphous solids.

A comprehensive experimental and theoretical study of both thermal-induced spin transition (TIST) as a function of pressure and pressure-induced spin transition (PIST) at room temperature for the two-dimensional Hofmann-like SCO polymer [Fe(Fpz)2Pt(CN)4] is reported. The TIST studies at different fixed pressures have been carried out by magnetic susceptibility measurements, while PIST studies have been performed by means of powder X-ray diffraction, Raman, and visible spectroscopies. A combination of the theory of elastic interactions and numerical Monte Carlo simulations has been used for the analysis of the cooperative interactions in TIST and PIST studies. A complete (T, P) phase diagram for the compound [Fe(Fpz)2Pt(CN)4] has been constructed. The critical temperature of the spin transition follows a lineal dependence with pressure, meanwhile the hysteresis width shows a nonmonotonic behavior contrary to theoretical predictions. The analysis shows the exceptional role of the total entropy and phonon contribution in setting the temperature of the spin transition and the width of the hysteresis. The anomalous behavior of the thermal hysteresis width under pressure in [Fe(Fpz)2Pt(CN)4] is a direct consequence of a local distortion of the octahedral geometry of the Fe(II) centers for pressures higher than 0.4 GPa. Interestingly, there is not a coexistence of the high- and low-spin (HS and LS, respectively) phases in TIST experiments, while in PIST experiments, the coexistence of the HS and LS phases in the metastable region of the phase transition induced by pressure is observed for a first time in a first-order gradual spin transition with hysteresis.

The purpose of this paper is to explore the co-creation experience of virtual tourist community members based on value co-creation and social capital theory, which can help us determine the antecedents of co-creation experiences, as well as the internal mechanism of members' behaviors that are beneficial to the community. After collecting 453 valid questionnaires, the results of structural equation model analysis have shown that the social capital obtained by the members of a virtual tourist community has a positive effect on the co-creation experience. That experience also positively influences the intention of future participation and recommendation behaviors. In theory, this paper makes an effort to enrich the research content of the value co-creation and social capital theory. In practice, it is helpful for community managers to do a great job on constructing soft environments, encouraging members to play their roles, and improving the enterprise's competitiveness.

The polymerization of three typical aromatic solvent-doped fullerene materials with similar hexagonal closest packed (hcp) structures (mesitylene/C60, m-dichlorobenzene/C60and m-xylene/C60solvates) is studied under high pressure and high temperature (HPHT, 1.5 GPa, 573 K and 2 GPa, 700 K, respectively). Raman and photoluminescence spectroscopies reveal that the intercalated aromatic solvents play a crucial role in tailoring the extent of polymerization of C60molecules. In the solvates, the solvents confine formation of covalent bonds between C60molecules to the 001 direction and the (001) plane of the hcp lattices, leading to the formation of mixed polymeric phases of monomers, dimers, one-dimensional (1D) chainlike oligomers, and two-dimensional (2D) tetragonal phase polymers under suitable HPHT conditions. The type and number of substituent groups of the aromatic solvents are found to have significant influence, determining the amounts and types of polymeric phases formed. Our studies enrich the understanding of the formation mechanisms for controllably fabricating polymeric fullerenes and facilitate targeted design and synthesis of unique fullerene-based carbon materials.

As a prominent platform possessing the properties of superconductivity (SC) and charge density wave (CDW), transition-metal dichalcogenides (TMDCs) have attracted considerable attention for a long time. Moreover, extensive efforts have been devoted for exploring the SC and/or the interplay between SC and CDW in TMDCs in the past few decades. Here, we systematically investigate the electronic properties and structural evolution of 1T-TaSe2under pressure. With increasing pressure, pressure-induced superconductivity is observed at ∼2.6 GPa. The superconductive transition temperature (Tc) increases with the suppression of the CDW state to the maximum value of ∼5.1 K at 21.8 GPa and then decreases monotonously up to the highest pressure of 57.8 GPa. 1T-TaSe2transforms into a monoclinic C2/mstructure above 19 GPa. The monoclinic phase coexists with the original phase as the pressure is released under ambient conditions and the retainable superconductivity with Tc= 2.9 K is observed in the released sample. We suggest that the retained superconductivity can be ascribed to the retention of the superconductive high-pressure monoclinic phase in the released sample. Our findings demonstrate that both the structure and CDW order are related to the superconductivity of TaSe2.

In the current era of global climate change, environmental stresses, especially drought and salt, have impaired the growth and productivity of crops, e.g., cotton. Understanding the mechanisms of plants’ adaptation to these abiotic stresses is crucial to breed stress-tolerant crop species. In the present study, integrated metabolomics, lipidomics, and mass spectrometry imaging (MSI) were used to discover the spatial distribution of differential metabolites and lipids in two cottonseed cultivars with contrasting drought and salt tolerance properties. Seventeen differential metabolites and 125 differential lipids were identified. Their possible roles in augmenting stress tolerance were illustrated, which were involved in reactive oxygen species scavenging, osmotic adjustment, and cell membrane structure reconstruction. MSI analysis provided a visualization of nine differential lipids and four differential metabolites in cottonseeds with varied abundances and distributions. The results may help understand cottonseeds’ convictive metabolic and lipidomic regulatory networks in coping with salinity and drought stresses and give new insights into the stress-tolerance traits relevant to other crops.

As a newly emerging approach for surface-enhanced Raman spectroscopy (SERS), pressure-induced SERS (PI-SERS) has been attracting increasing interest for its applications in Raman signal enhancement at extreme conditions. However, how to efficiently realize the PI-SERS enhancement and elucidate the corresponding mechanism remain open questions. Herein, we demonstrate the PI-SERS enhancement up to 8.04 GPa using monolayer molybdenum disulfide (ML-MoS2) as a SERS substrate and three organic molecules with similar energy levels but different symmetries as probes. The combined theory and experiment results show that a pressure-induced increase in the Fermi level of the ML-MoS2substrate and a decrease in the highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) energy gap of probe molecules lead to a transition from the multiple resonance-related SERS enhancement to charge transfer (CT)-dominated PI-SERS selective enhancement, depending on the incident laser energy and the pressure applied. Such PI-SERS selective enhancement has been discussed in the framework of CT-induced strengthening of electron–phonon coupling, as well as a possible match of the structural symmetries between probe molecules and the substrate. This study provides deep insights into our understanding of PI-SERS enhancement, and the revealed mechanism can be extended to other molecules for SERS at extreme conditions.

A systematic high-pressure study of the CdNx(x= 2, 3, 4, 5, and 6) system is performed by using the first-principles calculation method in combination with the particle swarm optimization algorithm. We proposed four stable high-pressure phases (P4mbm-CdN2, Cmmm-CdN4, I4̅2d-CdN4, and C2/c-CdN5) and one metastable high-pressure phase (C2/m-CdN6), for which the structural frames are composed of a diatomic quasi-molecule N2, standard armchair N-chain, S-type bent armchair N-chain, zigzag–antizigzag N-chain, and N14network structure. Among them, the novel zigzag–antizigzag N-chain and N14network structure are reported for the first time. More importantly, Cmmm-CdN4and C2/m-CdN6possess high stability under ambient conditions, which may be quenched to ambient conditions once they are synthesized at high-pressure conditions. The high decomposition energy barrier (1.14 eV) results in a high decomposition temperature (2500 K) of Cmmm-CdN4, while a low decomposition energy barrier (0.19 eV) results in a mild decomposition temperature (500 K) of C2/m-CdN6. The high energy density and outstanding explosive performance make Cmmm-CdN4, I4̅2d-CdN4, C2/c-CdN5, and C2/m-CdN6potential high-energy materials. The electronic structure analyses show that these predicted high-pressure structures are all metallic phases, and the N–N and Cd–N bonds are the strong covalent and ionic bond interactions, respectively. The charge transfer from the Cd atom plays an important role in the stability of the proposed structures.

Ultrahigh pressure generation at high temperatures is technologically challenging for large sample volumes. In this study, we successfully generated pressures of 37.3–40.4 GPa at 1900–2100 K in a Walker-type large-volume press (LVP). Expansion of the pressure range at high temperatures was achieved by adapting newly designed ZK01F tungsten carbide (WC) anvils with tapered surfaces and using cell assemblies with an ∼1 mm3sample volume and hard materials, as well as by applying certain adjustments to the apparatus. The pressure efficiencies of the different types of WC anvils and cell assemblies were also studied. Using the above-mentioned techniques, we successfully synthesized and characterized bulk samples of nearly pure sp3-hybridized ultrahard amorphous carbon, core–shell nanocrystals with high Néel temperatures, as well as large-sized single crystals of lower-mantle minerals. The developed LVP techniques presented here could enable the exploration of the chemical and physical properties of novel materials and Earth’s interior.

Exploring new physical properties of nanomaterials with special morphology have been important topics in nanoscience and nanotechnology. Here we report a morphology-tuned structural phase transition under high pressure in the horseshoe shaped BaTiO3nanomaterials with an average diameter of 26 ± 4 nm. A direct structural phase transition from the tetragonal to the cubic phase without local rhombohedral distortion was observed at about 7.7 GPa by in situ high-pressure X-ray diffraction and Raman spectroscopy, which is clearly different from the phase transition processes of the BaTiO3bulks and nanoparticles. Additionally, bulk modulus of the tetragonal and cubic phases were determined to be 125.0 and 211.7 GPa, respectively, obviously smaller than the estimated values for BaTiO3nanoparticles with the same grain size. Further analysis shows that the unique phase transition process and the enhanced structural stability of the tetragonal horseshoe shaped BaTiO3nanomaterials, may be attributed to the similar axes compressibility. Comparing with the high-pressure study on BaTiO3nanoparticles, this study suggests that the morphology plays an important role in the pressure-induced phase transition of BaTiO3nanomaterials.

The high-pressure phase transformation of Er3+-doped Gd2O3nanorods was studied by synchrotron radiation X-ray diffraction (XRD) and Raman scattering spectra. The starting cubic phase is stable up to about 9 GPa, and the Gd2O3/Er3+nanorods start to transform into an amorphous phase related to monoclinic structure at 9.4 GPa. The phase transition is different from that direct crystal–crystal transformation observed in the bulk Gd2O3and Gd2O3nanomaterials. The bulk modulus for cubic Gd2O3/Er3+nanorods is determined to be K0= 196 ± 13.4 GPa by fitting to the second-order Birch–Murnaghan equation of state, which is larger than that of 164 ± 3 GPa of the bulk Gd2O3/Er3+. In addition, the quenched samples almost maintain their pristine nanorod shape but with amorphous form. It is proposed that the special rodike morphology and particle size probably play important roles in the high-pressure behavior of Er3+-doped Gd2O3nanorods.

The high-pressure behavior of SnBr4has been explored by angle-dispersive X-ray diffraction, Raman spectroscopy, optical absorption/transmission measurements, and ab initio calculations. The joint of experimental and theoretical results shows that there is a crystal–crystal transition induced by molecular dimerization, which begins at ∼10.8 GPa and completes at 21.5 GPa. Above 21.5 GPa, the gradual crystal–amorphous transition induced by the molecular dissociation appears, and the sample remains in partial amorphous state up to 43.8 GPa. At ∼40.3 GPa, the possible insulator–metal transformation is discovered by in situ optical transmission measurements. It is proposed that the observed amorphous phase is a nonmolecular phase by theoretical calculations.

Single crystalline C70nanotubes having a face-centered-cubic (fcc) structure with diameters on a nanometer scale were synthesized by a facile solution method. In situ high pressure Raman spectroscopy and X-ray diffraction have been employed to study the structural stability and phase transitions of the pristine sample. We show that the molecular orientation-related phase transition from the fcc structure to a rhombohedral structure occurs at about 1.5 GPa, which is ∼1 GPa higher than in bulk C70. Also, the C70molecules themselves are more stable in the nanotubes than in bulk crystals, manifested by a partial amorphization at ∼20 GPa. The crystal structure of C70nanotubes could partially return to the initial structure after a pressure cycle above 30.8 GPa, and the C70molecules were intact up to 43 GPa. The bulk modulus of C70nanotubes is measured to be ∼50 GPa, which is twice larger than that of bulk C70.

Animals often acquire ritual and symbolic significance when incorporated into mortuary contexts in human society. In Bronze Age China, horses and chariots were frequently interred together as teams in separate pits associated with burials, forming integral components of the mortuary rituals among elites in settled states. Although examples are scarce, the mortuary use of horses and chariots was also observed in pastoral societies during the first millennium BCE. The examination of complete horse skeletons from an elite tomb at Majiayuan, a large burial site in northwestern China dating back to the 4th-3rd centuries BCE, indicates the integration of four adult, male, tall horses with an elaborate wooden chariot. Alongside the combination of four horse skulls and one chariot, which likely represents an alternative form of the team, these practices were exclusive to a select group of high-ranking individuals at Majiayuan. The selection, arrangement, and interment of horses and chariots followed the examples of four-horse-one-chariot sets in contemporary settled states, while also retaining pastoral society's practice of interring animal skulls and hooves in burials. This blend of emulation from settled states and retention of pastoral mortuary traditions reflects part of a ritualized set of mortuary practices at Majiayuan, highlighting the social importance attributed to horses in pastoral societies and their symbolic connections to centers of political power.