bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic carbon and short-range order minerals responsible for cementation of the spodic horizon (ortstein): a new proposal of chemical extractions in undisturbed samples
Authors: Pilar Mateus Roveda , Melo Vander Freitas , Roveda Luis Fernando , Lima Marcelo Ricardo , de Oliveira Junior Jairo Calderari 
Published: June 2024

Context The cementation of spodic horizons (ortstein) has long been studied through chemical analysis in disturbed soil samples of <2 mm (soil structure destructuring). Aims Use of the undisturbed samples and selective chemical extractions to study the soil organic matter (SOM) and short-range order phase (SROP) cementing the spodic horizon. Methods The study was carried out in a Spodosol (ortstein) from southern Brazil in undisturbed cubes (1.5 cm × 1.5 cm × 1.5 cm). The undisturbed cubes were separated in two visual colour standards (yellow colour (YC – 10YR 6/8) and yellow dark colour (YDC – 10YR 4/3)) and were submitted to four SROP chemical extractions (pyrophosphate (PYR), ammonium oxalate (AO), NaOH 0.5 mol L−1, and water). Key results The choice of selective SROP extraction in two colour standards of undisturbed samples enabled the identification of cementation details of the ortstein : (1) SOM illuviation also increases Fe, Al, Mn, Si, Ca, and Mg contents; (2) the SRO-Fe and Al oxides cover the SOM and/or there is a larger proportion of mineral in relation to OC in the organo/mineral association; (3) SRO-Al oxides were the main compounds responsible for cementation; and (4) the illuvial SOM associated with SRO-Fe oxides did not contribute to ortstein physical stability. Conclusions and implications The best extractions to study the samples were AO for YC colour and NaOH for YDC colour. We recommend the use of undisturbed samples and the inclusion of NaOH 0.5 mol L−1 in the chemical protocol for analysis to better understand which organic and mineral phases clog the ortstein pores in different pedogenetic conditions around the world.
Mental representation of words and concepts in late multilingualism
Authors: Sperl Laura , Schroeger Anna , Kaufmann Jürgen M. , Kreysa Helene 
Published: June 2024

Abstract
Speakers of multiple languages must store the respective lexical items efficiently to enable correct access.
Importantly, all items must be linked to semantic information and world knowledge. One prominent model of the mental lexicon of
late bilinguals is the Revised Hierarchical Model (Kroll & Stewart, 1994), which
postulates bidirectional but asymmetrical connections between separate stores for L1 (native language) and L2 (second/foreign
language), and a shared conceptual store. Using German native speakers with advanced English proficiency, Experiment 1 largely
confirmed model predictions regarding different preferred mental routes and processing times depending on translation direction.
Moreover, the original design was extended by including abstract stimuli and picture naming in L2. A series of additional
measures, such as proficiency and age of acquisition, served to specify the language experience of the participants and made it
possible to compare the results with a group of non-native speakers of German (Experiment 2). Interestingly, the results suggest
that the model also applies to two or more non-native languages, potentially influenced by the experimental and environmental
language context.
Ultrasensitive Mechanical Sensor Using Tunable Ordered Array of Metallic and Insulating States in Vanadium Dioxide
Authors: Ma 马 Zecheng 泽成 , Yan 闫 Shengnan 胜楠 , Chen 陈 Fanqiang 繁强 , Dai 戴 Yudi 玉頔 , Liu 刘 Zenglin 增霖 , Xu 徐 Kang 康 , Xu 徐 Tao 涛 , Tong 童 Zhanqin 湛钦 , Chen 陈 Moyu 墨雨 , Wang 王 Lizheng 利铮 , Wang 王 Pengfei 鹏飞 , Sun 孙 Litao 立涛 , Cheng 程 Bin 斌 , Liang 梁 Shi-Jun 世军 , Miao 缪 Feng 峰 
Published: June 2024

Abstract
Detecting tiny deformations or vibrations, particularly those associated with strains below 1%, is essential in various technological applications. Traditional intrinsic materials, including metals and semiconductors, face challenges in simultaneously achieving initial metallic state and strain-induced insulating state, hindering the development of highly sensitive mechanical sensors. Here we report an ultrasensitive mechanical sensor based on a strain-induced tunable ordered array of metallic and insulating states in the single-crystal bronze-phase vanadium dioxide [VO2(B)] quantum material. It is shown that the initial metallic state in the VO2(B) flake can be tuned to the insulating state by applying a weak uniaxial tensile strain. Such a unique property gives rise to a record-high gauge factor of above 607970, surpassing previous values by an order of magnitude, with excellent linearity and mechanical resilience as well as durability. As a proof-of-concept application, we use our proposed mechanical sensor to demonstrate precise sensing of the micro piece, gentle airflows and water droplets. We attribute the superior performance of the sensor to the strain-induced continuous metal-insulator transition in the single-crystal VO2(B) flake, evidenced by experimental and simulation results. Our findings highlight the potential of exploiting correlated quantum materials for next-generation ultrasensitive flexible mechanical sensors, addressing critical limitations in traditional materials.
On approximations of the redshift-space bispectrum and power spectrum multipoles covariance matrix
Authors: Novell-Masot Sergi , Gil-Marín Héctor , Verde Licia 
Published: June 2024

Abstract
We investigate, in dark matter and galaxy mocks, the effects of approximating the galaxy power spectrum-bispectrum estimated covariance as a diagonal matrix, for an analysis that aligns with the specifications of recent and upcoming galaxy surveys. We find that, for a joint power spectrum and bispectrum data-vector, with corresponding k-ranges of 0.02 < k[hMpc-1] < 0.15 and 0.02 < k[hMpc-1] < 0.12 each, the diagonal covariance approximation recovers ∼ 10% larger error-bars on the parameters {σ
8,f,α
∥,α
⊥} with respect to the full covariance case, while still underestimating the corresponding true errors on the recovered parameters by ∼ 10%. This is caused by the diagonal approximations weighting the elements of the data-vector in a sub-optimal way, resulting in a less efficient estimator, with poor coverage properties, than the maximum likelihood estimator featuring the full covariance matrix. We further investigate intermediate approximations to the full covariance matrix, with up to ∼ 80% of the matrix elements being zero, which could be advantageous for theoretical and hybrid approaches. We expect these results to be qualitatively insensitive to variations of the total cosmological volume, depending primarily on the bin size and shot-noise, thus making them particularly significant
for present and future galaxy surveys.
Study on pervaporation performance of hydrophobically modified carbon-based membrane materials
Authors: Han Liqiong , He Xing , Shen Shaopeng 
Published: June 2024

Abstract
Based on the appropriate pore size, the surface of the carbon membrane was hydrophobically modified to preferentially adsorb alcohols, so as to achieve the purpose of enriching alcohols in the penetrant. This operation is significant for expanding the application of carbon membranes for gas separation. In this work, a hydrophobic silica sol was synthesized using tetraethyl orthosilicate (TEOS) and methyltriethoxysilane (MTES) as mixed silicon sources, and it was impregnated and coated on a rolled carbon membrane. The material was then dried and thermally treated to obtain the hydrophobic carbon membrane. The preparation procedure of silica sol was also investigated, and the surface chemical structure and morphology of the hydrophobic carbon membrane were characterized by contact angle (CA), Fourier Transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). The pervaporation performance of the hydrophobic carbon membrane was inspected with both ethanol/water and isopropanol/water mixed solution. The results showed that the hydrophobic carbon membrane has favorable pervaporation performance. With the elevation of temperature, the total flux significantly increased while the selectivity slightly decreased. The increase of alcohol (ethanol and isopropanol) content also enhanced total flux, but the selectivity reduced prominently. The phenomena indicated that a relatively ideal effect had been achieved.
Effects of high-intensity ultraviolet irradiation on the structure and mechanical properties of Sisal fibers
Authors: Wang Fei , Zhu Jing , Liu Jiawei. , Jiang Xin , Zhang Weiguang , Lang Fengchao 
Published: June 2024

Abstract
To explore the impact of high-intensity ultraviolet light on the structure and mechanical properties of sisal fibers, the article uses chemical methods in the sisal fiber surface silver-plated, untreated, and alkali-treated sisal fibers as a comparison, with the help of scanning electron microscopy, infrared spectroscopy on the fiber surface topography, the molecular structure of the research, determination of high-intensity ultraviolet irradiation under the mechanical tensile properties of the fiber. Exposure to high-intensity ultraviolet radiation for a brief period results in a reduction in the tensile strength, fracture elongation, and elastic modulus of untreated, alkali-treated, and chemically silver-plated sisal fibers by 95.2%, 77.7%, 55.9%, 92.8%, 76.9%, 42.1%, and 89.4%, 70.2%, 34.2%, respectively.
Preparation and interface modification of Si3N4f/SiO2 ceramic matrix composites
Authors: Zhang Shuwei , Men Weiwei , Zhu Siyu , Wu Xiao , Xu Hui 
Published: June 2024

Abstract
In order to meet the overall performance of high temperature resistant and transmitted materials for electromagnetic windows of hypersonic aircraft. In this study, Si3N4f/SiO2 ceramic matrix composites were prepared by sol-gel process. After 5 process cycles, the materials were prepared with the best comprehensive performance, with a density of 1.79 g/cm3, a bending strength of 149 MPa, a tensile strength of 82.1 MPa, a dielectric constant of 3.52, and a tangent of the dielectric loss of 0.004. The effects of Al2O3 and LaPO4 interface coatings on the mechanical properties of composites were studied. At room temperature, the interface coating has little effect on the bending properties of the material, and the bending strength of the Al2O3 interface coating composite at 1200°C remains basically unchanged. Compared with the sample without interface coating, the strength retention rate is increased by about 16%. LaPO4 coating had no obvious influence on the bending property of the material at 1200°C.
NiMoO4/MnCo2O4 for high-performance positive electrodes of supercapacitors
Authors: Yan Dinkun 
Published: June 2024

Abstract
To discover more effective energy storage materials, it is crucial to investigate the impact of composite properties. The composite material NiMoO4/MnCo2O4 was synthesized on a nickel foam substrate through hydrothermal and annealing methods. Physical and electrochemical performance tests were subsequently performed on the product. The X-ray diffraction analysis revealed a blend of NiMoO4 and MnCo2O4 peaks. The microscopic morphology of the composites yielded both nanosheet arrays and nanoflowers. Furthermore, the EDS patterns demonstrated inconsistent elemental distributions, which confirm a composite material nature. The material exhibits promising electrochemical properties, offering a viable solution for incorporating composites into the anode of supercapacitors.
Study on the tensile properties of 3D printing cell structure based on fractal theory
Authors: Lin Shiyun , Peng Chenyun , Deng Fanghang , Yin Dagang 
Published: June 2024

Abstract
Using lightweight technology involves optimizing materials, structures, and manufacturing processes to reduce structural weight while meeting performance standards. This technology has emerged as pivotal in advancing the next generation of aerospace equipment. This study employed the 3D printing method using PLA material to produce tensile test specimens of three structures: the concave hexagonal, bionic feather, and standard structures. Tensile and finite element simulation tests were conducted to assess their tensile properties. By comparing crack propagation paths under tensile load, the impact of these paths on structure fracture toughness was analyzed using fractal theory. The findings reveal that distinct structures exhibit varied fracture toughness due to differing crack propagation paths during tensile fracture. Fractal dimensions were calculated for each structure: 1.491 for the concave hexagonal structure, 1.488 for the bionic feather structure, and 1.465 for the standard structure. These dimensions suggest that the concave hexagonal structure possesses the highest fracture toughness among the three structures.
Influence of humid and thermal environment on flexural properties of CFRP reinforced foam sandwich structures
Authors: Yang Shiyu , Gai Di , Xu Hai , Yu Shengjie , Yao Zhipeng , Zhao Zheng 
Published: June 2024

Abstract
The influence of the moisture and heat environment on the bending properties of CFRP laminates and CFRP reinforced foam sandwich structures was studied by mass change and three-point bending test. The results show that the saturation moisture absorption rate of CFRP laminates is low, only 0.62%. The CFRP reinforced foam sandwich structure exhibits a saturation moisture absorption rate of 1.48%. Humidity and heat have little effect on the bending modulus of CFRP laminates but have some effect on the bending strength, which decreases by 13.23% compared with normal temperature and dry conditions. The flexural strength and average energy absorption of CFRP reinforced foam sandwich structure decreased by 11.5% and 5.56% under hot and humid environments. The flexural fracture of the CFRP foam sandwich structure is smooth under normal temperatures and dry conditions. Many fibers are pulled out, and the resin falls off, obviously under hot and humid environments. The stratification of CFRP panels and foam cores in hot and humid environments is more obvious than in dry conditions at normal temperatures.
Polyether-functionalized ionic liquid-assisted Rh-AMPP-catalyzed asymmetric hydrogenation of ketopantoyl lactone to D-(−)-pantolactone
Authors: Yin Yingchun , Jin Xin 
Published: June 2024

Abstract
In this paper, the reaction of chiral Rh-AMPP catalysts for the asymmetric hydrogenation of ketopantoyl lactone to D-(-)pantolactone under a polyether guanidinium salt ionic liquid ([Me(EO)16TMG][OMs])/toluene homogeneous catalytic system was investigated. The impact of polyether ionic liquid doping on the catalytic activity and enantioselectivity was investigated. To separate and recycle chiral Rh-AMPP catalysts, a “homogeneous catalytic-liquid/solid separation” system on the basis of [Me(EO)16TMG][OMs] was constructed. The catalytic system exhibited high catalytic activity, enantioselectivity, and long-term stability, and no obvious reduction in enantioselectivity was found after four cycles.
Preparation of shrimp shell powder-PVDF filtration membrane and its application in oil-water separation
Authors: Fang Xia , Xia Mengsheng , Chen Yan 
Published: June 2024

Abstract
In recent years, the problem of ship-related oily wastewater discharge has escalated due to the growing ship trade. Consequently, the hydrophobic modification of polyvinylidene fluoride (PVDF) membranes has gained significant traction within the oil-water separation technology domain as a potential solution. This study presents a new membrane composed of shrimp shell powder, tannic acid (TA), polyvinyl alcohol (PVA), and PVDF with excellent hydrophilicity and micro-nano porosity. The preparation method is simple, non-toxic, and environmentally friendly. Shrimp shell powder is beneficial to modify the hydrophobic PVDF membrane. The strongly adhesive TA-PVA complex helps to improve the durability of shrimp shell powder in TA-PVA-PVDF membranes. Shrimp shell powder was evenly coated on the PVDF (polyvinylidene difluoride) membrane by vacuum filtration to prepare the TA-PVA-PVDF filter membrane with superhydrophilic-underwater hydrophobicity. The initial efficiency of the emulsified oil-water mixture in the separation experiments reached 99.5%. Furthermore, even after conducting 10 repeated experiments, the separation efficiency remained consistently high at 96.1%.
Study on the optimal hydrogen production rate for the preparation of Mo-Co bimetallic catalysts
Authors: Liu Lidong , Wei Yongsheng 
Published: June 2024

Abstract
In the process of preparing Mo-Co bimetallic catalysts, the parameters involved in the experimental process all affect the experimental performance to varying degrees. Since the laws of the influence of these parameter variables on the experimental performance interact with each other, it is difficult to theoretically find a suitable functional relationship to describe them, and thus the optimization strategy of the experimental performance varies from person to person, which is a difficult problem that needs to be solved urgently. Therefore, by taking the hydrogen production rate as the optimization objective, obtaining the relationship between each experimental parameter factor and the experimental performance index, and finding out the law and trend of the influence of each factor on the experimental index, the optimal combination of each factor level can be obtained. In this paper, during the preparation of Mo-Co bimetallic catalysts, several sets of orthogonal experiments were carried out to determine the hydrogen production rate under a variety of reaction parameters, and the correlation between each experimental parameter and the hydrogen production rate was investigated by various methods. Finally, the experimental parameters affecting the hydrogen production rate and their significant influence degree were obtained, and the optimal hydrogen production rate was further found.
Fabrication and characterization of UTSA-16 metal-organic frameworks with excellent adsorption performances on CO2
Authors: Zhang Xiangmei , Wang Chunlai , Li Xinbo , Sun Yuan , Lv Li 
Published: June 2024

Abstract
In this research, two distinct UTSA-16 metal-organic frameworks were synthesized using the solvothermal method. These frameworks were characterized by XRD, FTIR, SEM, BET, and TGA. Both materials had complete structures, regular morphologies, and superior specific surface areas. At 25°C and 1 bar, UTSA-16 (Co) demonstrated a maximum CO2 adsorption ability of 183 mg/g, while UTSA-16 (Zn) demonstrated a maximum CO2 adsorption ability of 161 mg/g. These findings present a development of MOFs with excellent adsorption performances on CO2 and simplified preparation processes.
Significantly improved electrical conductivity and cycling stability of manganese dioxide by poly (3,4-ethylene-dioxythiophene) coating
Authors: Chai Penghao , Nie Yuelin , Bao Lixia , Peng Jiong , Li Xin 
Published: June 2024

Abstract
Manganese dioxide (MnO2) is widely acknowledged as a prospective pseudocapacitive material aimed at alleviating the issue of low energy density in supercapacitors. Nevertheless, hampered by its intrinsic low conductivity and poor structural stability, MnO2-based energy storage materials often exhibit lower practical capacity in practical applications. During this investigation, the synthesis of MnO2@PEDOT (poly(3,4-ethylenedioxythiophene)) composite materials involved an in-situ oxidative polymerization approach, whereby PEDOT nanowires were integrated onto the MnO2 nanoparticle surface. Notably, the internal configuration of the MnO2@PEDOT composite material demonstrated a high surface area morphology, while the externally entwined PEDOT nanowire layer further expanded the material’s specific surface area. As a result, the MnO2@PEDOT composite material demonstrated a specific capacitance reaching 214 F g-1, a 91% improvement compared to unmodified MnO2. Furthermore, the winding of PEDOT nanowires effectively suppressed the structural disintegration of MnO2. The MnO2@PEDOT composite material exhibited a remarkable improvement in cycling stability, maintaining 81% of its initial capacity after 5000 cycles. The electron-rich PEDOT not only improved the conductivity of the inner MnO2 through electron migration but also prevented MnO2 structural degradation by tightly enveloping it. The outcomes of our study propose a method for constructing MnO2 featuring a structurally stable configuration and a prolonged cycling lifespan, offering valuable insights for designing electrode materials with high cycling stability in supercapacitors.
Effect of cell sintering temperature on the performance of non-noble metal loaded cerium oxide SOEC anodes
Authors: Li Ziyong , Huang Qingdan , Wang Tingyan , Huang Huihong , Song Haoyong 
Published: June 2024

Abstract
Introducing methane oxidation reaction into the anode of the high-temperature solid oxide electrolysis cell (SOEC) can reduce the power consumption for water electrolysis. Compared to the traditional conditions of methane oxidation, the methane oxidation catalyst sintered at the SOEC anode, which is closely related to the cell sintering process. This study uses non-noble metals as active sites for methane oxidation, zirconia, and samarium oxides doped ceria as catalyst support and oxygen ion conductors. The effects of anode sintering temperature on the electrochemical performance of SOEC assisted by methane oxidation were investigated. The results indicate that the high-temperature sintering process promotes the performance of the SOEC anode with Ni as the active site, while high temperature harms the performance of the Co-loaded anode. The sintering temperature exhibits a poor effect on the Fe-loaded anode. The Ni exhibits good enhancement of methane oxidation on reducing the electrolysis voltage of SOEC, while Co only exhibits methane oxidation assistance at low-temperature sintering. Differently, Fe has almost no obvious methane oxidation assistance for SOEC, which mainly represents good oxygen evolution performance.
Simulation of tensile fatigue crack propagation in carbon fiber unidirectional laminates under progressive fatigue damage model
Authors: Yu Shengjie , Gai Di , Zhang Lei , Zhao Zheng , Yao Zhipeng , Yang Shiyu 
Published: June 2024

Abstract
This paper predicts and analyzes the tensile fatigue crack propagation of carbon fiber reinforced unidirectional laminates at high-stress levels using the carbon fiber stiffness strength degradation formula. The results show that different paving modes significantly affect crack propagation and stress distribution. Under the 45° layup, two cracks appeared. The upper crack expanded along the fiber direction, and the lower crack first appeared as a horizontal crack at the constrained end and then along the fiber direction. Under 0° layering, vertical cracks appear at the prefabricated crack tip, and the crack direction is the same as the loading direction. At a -45° layup, two cracks appeared at the prefabricated crack tip, and then the lower crack extended to the integral separation of the test piece. In addition, the strain characteristic analysis shows that the strain increases and decreases rapidly during crack propagation. This study has a certain reference value for further understanding of fatigue crack propagation characteristics of carbon fiber-reinforced composites.