bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D Transformable Modular Kirigami Based Programmable Metamaterials
Authors: Li Yanbin , Zhang Qiuting , Hong Yaoye , Yin Jie 
Published: July 2021

AbstractKirigami, the ancient paper art of cutting, has recently emerged as a new approach to construct metamaterials with novel properties imparted by cuts. However, most studies are limited to thin sheets‐based 2D kirigami metamaterials with specific forms and limited reconfigurability due to planar connection constraints of cut units. Here, 3D modular kirigami is introduced by cutting bulk materials into spatially closed‐loop connected cut cubes to construct a new class of 3D kirigami metamaterials. The module is transformable with multiple degrees of freedom that can transform into versatile distinct daughter building blocks. Their conformable assembly creates a wealth of reconfigurable and disassemblable metamaterials with diverse structures and unique properties, including reconfigurable 1D column‐like materials, 2D lattice‐like metamaterials with phase transition of chirality, as well as 3D frustration‐free multilayered metamaterials with 3D auxetic behaviors and programmable deformation modes. This study largely expands the design space of kirigami metamaterials from 2D to 3D.
Spin‐Orbit Torque in Van der Waals‐Layered Materials and Heterostructures
Authors: Tang Wei , Liu Haoliang , Li Zhe , Pan Anlian , Zeng Yu‐Jia 
Published: July 2021

AbstractSpin‐orbit torque (SOT) opens an efficient and versatile avenue for the electrical manipulation of magnetization in spintronic devices. The enhancement of SOT efficiency and reduction of power consumption are key points for the implementation of high‐performance SOT devices, which strongly rely on the spin‐orbit coupling (SOC) strength and magnetic properties of ferromagnetic/non‐magnetic heterostructures. Recently, van der Waals‐layered materials have shown appealing properties for use in efficient SOT applications. On the one hand, transition‐metal dichalcogenides, topological insulators, and graphene‐based heterostructures possess appreciable SOC strength. This feature can efficiently converse the charge current into spin current and result in large SOT. On the other hand, the newly discovered layered magnetic materials provide ultra‐thin and gate‐tunable ferromagnetic candidates for high‐performance SOT devices. In this review, the latest advancements of SOT research in various layered materials are summarized. First, a brief introduction of SOT is given. Second, SOT studies of various layered materials and heterostructures are summarized. Subsequently, progresses on SOT‐induced magnetization switching are presented. Finally, current challenges and prospects for future development are suggested.
Mechanisms behind pH changes during electrocoagulation
Authors: Weiss Søren Fredberg , Christensen Morten Lykkegaard , Jørgensen Mads Koustrup 
Published: July 2021

AbstractElectrocoagulation is a promising method for removing pollutants from surface water and industrial wastewater. The coagulation efficiency is dependent on pH but it is not fully understood how electrocoagulation affects pH of the treated water. Three series of experiments have been conducted to study how (1) chloride and sulfate anions, (2) negatively charged organic macromolecules, and (3) carbonate influence pH during electrocoagulation. It is found that dissolved carbonate has a significant influence on the pH change as CO2 is stripped off during electrocoagulation due to formation of H2 microbubbles at the cathode. The pH increased by 1 pH unit, which may significantly affect coagulation efficiency of iron. The pH increase depended strongly on the initial pH and the concentration of carbonate in the water. A secondary contribution to pH change was found to be ion exchange by sulfate and chloride ions into Fe(OH)3 flocs, whereby OH− was released into solution but only minor pH change was observed, not enough to affect the coagulation. The presence of charged organic macromolecules did not have any significant effect on pH.
The modulation of ethane‐selective adsorption performance in series of bimetal PCN‐250 metal–organic frameworks: Impact of metal composition
Authors: Wu Houxiao , Chen Yongwei , Yuan Yinuo , Lv Daofei , Tu Shi , Liu Zewei , Li Zhong , Xia Qibin 
Published: July 2021

AbstractThe developments of high‐performance adsorbents have attracted ever‐increasing attention in the separation of ethane/ethylene (C2H6/C2H4) mixtures. In this work, a series of ultra‐stable C2H6‐selective metal–organic frameworks (MOFs), PCN‐250, and its bimetal version PCN‐250(Fe2M2+, M2+ = Ni2+, Co2+, Zn2+, Mn2+), were synthesized to investigate the influence of metal compositions on the C2H6‐selective performance. Among the five materials, at 298 K and 100 kPa, PCN‐250(Fe2Co) showed the largest C2H6 uptake (6.21 mmol/g) while PCN‐250(Fe2Zn) exhibited the highest C2H6/C2H4 ideal adsorption solution theory (IAST) selectivity (1.70). The molecular simulation revealed that the introduced metal ions have different influences on the atomic partial charge within the framework which varied the framework adsorption affinities toward C2H6/C2H4 molecules. Moreover, the research on PCN‐250(Fe2Zn) suggested that the increased positive partial charge of metal sites together with a decreased charge density of benzene ring (BR) sites from the organic ligands will be beneficial to improve the desired C2H6 selectivity.
ThermosensitivePMMAcore/oligo(ethylene glycol)‐based shell microgels as drug carriers in detoxification treatment
Authors: Meng Yuting , Shen Jing , Fu Ting , Feng Xiyun , Wang Siping , Wang Tongwen , Zhang Xufeng 
Published: July 2021

AbstractThe core‐shell structured polymer microgels were synthesized by coating the hydrophobic poly(methyl methacrylate) (PMMA) sphere cores with hydrophilic nonlinear poly(ethylene glycol)‐based gel shell layer. The uniqueness of these core‐shell microgels lies in the integration of the PMMA core microsphere with strong hydrophobicity and the novel oligo(ethylene glycol)‐based gel layer with well‐defined thermosensitivity for improving loading/release efficacy of two detoxification drugs (chlorpromazine and diltiazem). The hydrophilic shell is composed of hydrophilic copolymer of 2‐(2‐methoxyethoxy)ethyl methacrylate (MEO2MA) with oligo(ethylene glycol) methyl ether methacrylates (MEO5MA). It was found that the molar ratio of two shell monomersn(MEO2MA)/n(MEO5MA) of 1:6 was an ideal matching value for production of the P(MEO2MA)/P(MEO2MA‐co‐MEO5MA) core‐shell microgels with tunable volume phase transition temperature and excellent colloidal stability across the physiologically important temperature range. Moreover, chlorpromazine‐ and diltiazem‐loaded microgels can show an obvious thermosensitive release and in vitro sustained‐release characteristic up to 80 h.
Vulcanization, static mechanical properties, and thermal stability of activated calcium silicate/styrene‐butadiene rubber composites prepared via a latex compounding method
Authors: Wang Weijiang , Zhang Yinmin , Zhang Yongfeng , Sun Junmin 
Published: July 2021

AbstractHerein, we describe the latex compounding preparation of activated calcium silicate (ACS)/styrene‐butadiene rubber (SBR) composites aiming to improve filler dispersibility. The effects of ACS particle size and filler content on the vulcanization, static mechanical properties, and thermal stability of composite materials were evaluated. FT‐IR analyses showed that the rubber macromolecules were chemically adsorbed on the surface of the ACS particles, while SEM and TEM indicated that the ACS particles were uniformly distributed in the composites, and agglomeration occurred only at high filler content levels. ACS particle size reductions accelerated composite vulcanization, whereas increasing filler content had the opposite effect. ACS particles strengthened the mechanical properties of prepared composites, with marked increases in tensile strength and tear strength as ACS particle size decreased and filler content rose, reaching maximal values of 15.37 MPa (increased by 932%) and 45.91 kN/m (increased by 425%), respectively, at an ACS average particle size of 1 μm and 90 phr loading. ACS particle integration also enhanced composite thermal stability. These data indicate that ACS enhances rubber composites owing to the incorporation of well‐dispersed ACS particles into the rubber matrix, strong interactions between ACS particles and rubber molecules, and the thermal barrier effects of these particles.
High‐Temperature and Large‐Polarization Ferroelectric with Second Harmonic Generation Response in a Novel Crown Ether Clathrate
Authors: Han Ding Chong , Tan Yu Hui , Li Yu Kong , Wen Jia Hui , Tang Yun Zhi , Wei Wen Juan , Du Peng Kang , Zhang Hao 
Published: July 2021

AbstractMolecular ferroelectrics of high‐temperature reversible phase transitions are very rare and have attracted increasing attention in recent years. In this paper is described the successful synthesis of a novel high‐temperature host‐guest inclusion ferroelectric: [(C6H5NF3)(18‐crown‐6)][BF4] (1) that shows a pair of reversible peaks at 348 K (heating) and 331 K (cooling) with a heat hysteresis about 17 K by differential scanning calorimetry measurements, thus indicating that 1 undergoes a reversible structural phase transition. Variable‐temperature PXRD and temperature‐dependent dielectric measurements further prove the phase‐transition behavior of 1. The second harmonic response demonstrates that 1 belongs to a non‐centrosymmetric space group at room temperature and is a good nonlinear optical material. In its semiconducting properties, 1 shows a wide optical band gap of about 4.43 eV that comes chiefly from the C, H and O atoms of the crystals. In particular, the ferroelectric measurements of 1 exhibit a typical polarization‐electric hysteresis loop with a large spontaneous polarization (Ps) of about 4.06 μC/cm2. This finding offers an alternative pathway for designing new ferroelectric‐dielectric and nonlinear optical materials and related physical properties in organic‐inorganic and other hybrid crystals.
Continuous Flow Synthesis of [Au(NHC)(Aryl)] (NHC=N‐Heterocyclic Carbene) Complexes
Authors: Cauwenbergh Thibault , Tzouras Nikolaos V. , Scattolin Thomas , Bhandary Subhrajyoti , Simoens Andreas , Van Hecke Kristof , Stevens Christian V. , Nolan Steven P. 
Published: July 2021

AbstractThe use of weak and inexpensive bases has recently opened promising perspectives towards the simpler and more sustainable synthesis of Au(I)‐aryl complexes with valuable applications in catalysis, medicinal chemistry, and materials science. In recent years, continuous manufacturing has shown to be a reliable partner in establishing sustainable and controlled process scalability. Herein, the first continuous flow synthesis of a range of Au(I)‐aryl starting from widely available boronic acids and various [Au(NHC)Cl] (NHC=N‐heterocyclic carbene) complexes in unprecedentedly short reaction times and high yields is reported. Successful synthesis of previously non‐ or poorly accessible complexes exposed fascinating reactivity patterns. Via a gram‐scale synthesis, convenient process scalability of the developed protocol was showcased.
Unveiling the Role of Hydrogen Bonds in Luminescent N‐Annulated Perylene Liquid Crystals
Authors: Bujosa Sergi , Greciano Elisa E. , Martínez Manuel A. , Sánchez Luis , Soberats Bartolome 
Published: July 2021

AbstractWe report the liquid‐crystalline (LC) and luminescent properties of a series of N‐annulated perylenes (1–4) in whose molecular structures amide and ester groups alternate. We found that the LC properties of these compounds not only depend on the number of hydrogen‐bonding units, but also on the relative position of the amide linkers in the molecule. The absence of amide groups in compound 1 leads to no LC properties, whereas four amide groups induce the formation of a wide temperature range columnar hexagonal phase in compound 4. Remarkably, compound 3, with two amide groups in the inner part of the structure, stabilizes the columnar LC phases better than its structural isomer 2, with the amide groups in the outer part of the molecule. Similarly, we found that only compounds 1 and 2, which have no hydrogen bonding units in the inner part of the molecule, exhibit luminescence vapochromism upon exposure to organic solvent vapors.
Life‐history responses of a freshwater rotifer to copper pollution
Authors: Schanz Federica R. , Sommer Stefan , Lami Andrea , Fontaneto Diego , Ozgul Arpat 
Published: July 2021

AbstractIn organisms with dormant stages, life‐history responses to past pollution can be studied retrospectively. Here, we study such responses in a rotifer (Brachionus calyciflorus) from the once heavily copper‐polluted Lake Orta (Italy). We extracted resting eggs from sediments, established clonal lineages from hatchlings, and exposed newborns of these lineages to one of three copper concentrations that each mimicked a specific period in the lake's pollution history. For each rotifer, we daily collected life‐table data. We then estimated treatment‐specific vital rates and used a stage‐structured population model to project population growth rate λ. We also estimated elasticities of λ to vital rates and contributions of vital rates to observed Δλ between copper treatments. As expected, λ decreased with increasing copper concentration. This decrease resulted mostly from a decline in juvenile survival rate (SJ) and partly from a decline in the survival rate of asexually reproducing females (SA). Maturation rate, and with one exception fecundity, also declined but did not contribute consistently to Δλ. λ was most elastic to SJ and SA, indicating that survival rates were under stronger selection than maturation rate and fecundity. Together, our results indicate that variation in juvenile survival is a key component in the rotifers’ copper response. The consistent decrease in SJ with increasing copper stress and the sensitivity of λ to that decrease also suggest that juvenile survival is a useful indicator of population performance under environmental pollution.
Spatio‐temporal heterogeneities in water quality and their potential drivers in Lake Chaohu (China) from 2001 to 2017
Authors: Zhang Lei , Fang Yong , Cai Hua , Zhang Siqing 
Published: July 2021

AbstractDamage to the water ecosystems and the deterioration of lake water resources may negatively affect the surface water resources, particularly, which of the daily drinking water supply of residents. Therefore, it is particularly important to study the spatio‐temporal heterogeneity of water quality in large lakes. We analysed the data from six sampling sites in Lake Chaohu from 2001 to 2017 and eight sampling sites of the inflow rivers in 2001, 2009 and 2017. The six sampling sites were divided into SG I and SG II through cluster analysis, and the spatio‐temporal changes of the water quality in the Lake Chaohu Basin were studied. The results indicated the following: All nutrient variables had relatively high concentrations in SG II except DO, while SG I had relatively high concentrations of only TN. Besides, the value of Chl a in each group is generally high. On the temporal scale, the changes in the water quality of the lake showed strong seasonality; the nutrient variable (TN, TP, NH4‐N and CODMn) except DO in the inflow rivers is generally higher than that of the lake; the water quality of Lake Chaohu has improved during the study period, and it has also improved to a certain extent compared with that of the late 1980s. Fortunately, parts water quality parameters of Lake Chaohu have improved faster than that of the other four largest freshwater lakes in China. This research result has a certain guiding significance for the prevention and control of large lake water pollution.
Synthesis of 10H‐Indolo[1,2‐a]indole Derivatives via Intramolecular Cycloaddition and H‐Migration
Authors: Zhao Yulei , Li Shuai , Fan Yuhang , Guo Xuqiang , Jiao Xin , Tian Laijin , Sun Xuejun 
Published: July 2021

AbstractA novel method for synthesizing 10H‐indolo[1,2‐a]indole derivatives is reported here. All products are prepared by applying the intramolecular cyclization strategy at room temperature. The reaction was realized through I2/ZnI2 catalyzed intramolecular nucleophilic addition, hydrogen migration, and rearrangement procedures. The electronic effect and steric hindrance have a significant influence on the reactivity. Moreover, the synthetic value of 10H‐indolo[1,2‐a]indole was also exemplified by the selective decarboxylation and aromatization.
Fracturing and production analysis of the efficacy of hydraulic fracture stage reduction in the improvement of cost‐effectiveness in shale oil development: A case study of Jimsar shale oil, China
Authors: Zhi Dongming , Guo Xuyang , Wang Wei , Jin Yan , Liu Caiguang , Chen Gang , Wang Zhenlin 
Published: July 2021

AbstractThe effective production of shale oil is important for the cost‐effectiveness in the oil and gas industry. Oil price volatility and uncertainty require suitable hydraulic fracturing schemes to maximize production and to minimize fracturing costs. Since the reduction of fracture stage saves bridge plugs and fracturing costs, it is considered as a possible method to improve the cost‐effectiveness. To maintain the stimulated reservoir volume, cluster numbers per stage are consequently increased, which may induce nonuniform fracture propagation and interference which affects the stimulation efficiency. This study conducts a comparative study for single‐stage (reduced) and two‐stage (not reduced) fracturing schemes with the same fracturing fluid volume. Reservoir geomechanics and rock mechanics analyses are conducted for Jimsar shale oil in north‐western China with a single‐stage multicluster fracturing model established. Fracture geometries and key factors are investigated followed by the evaluation of the fractured well production. The relationship between multicluster parameters and production is quantified. Meanwhile, two‐stage fracturing modeling is also set up to compare with single‐stage fracturing modeling. Fracturing results show that although single‐stage fracturing results in nonuniform fracture propagation, the overall stimulation is satisfactory. Production results show that the nonuniform growth of fracture clusters leads to different contributions to the production from individual clusters and the production from inner fractures is significantly inhibited. Compared with two‐stage fracturing with the same pumping volume, it is found out that single‐stage fracturing can lead to cost‐effective horizontal well production in Jimsar shale oil given certain values of hydraulic fracturing costs, and the reduced stage scheme is preferable in low oil price and high uncertainty scenarios.
Feeding containing the aerial part of Scutellaria baicalensis promotes the growth and nutritive value of rabbit fish Siganus fuscescens
Authors: Xia Yi‐Teng , Cheng Edwin Hok‐Chi , Zheng Brody Zhong‐Yu , Wu Qi‐Yun , Dong Tina Ting‐Xia , Duan Ran , Qin Qi‐Wei , Wang Wen‐Xiong , Tsim Karl Wah‐Keung 
Published: July 2021

AbstractThe root of Scutellaria baicalensis (Scutellaria Radix) has been used as herbal medicine for years, while its stem and leaf (aerial part) are considered as waste. The water extract from the aerial part of S. baicalensis (named as SBA) being included in the feeding of Siganus fuscescens (grey rabbit fish) has been shown to replace antibiotics in aquaculture with excellent outcome. To strengthen the usage of SBA in fish feeding, the total fish output and its nutritive value were determined here. Feeding the fishes with different doses of SBA for a month, the body length and weight were significantly increased after intake of standard feed containing 1% SBA. In parallel, the expressions of alkaline phosphatase and growth‐related factors in bone, liver, and muscle of 1% SBA‐fed fishes were markedly increased, suggesting the beneficial effects of SBA. The composition of amino acid and fatty acid in fish muscle, after intaking 1% SBA‐containing feed, was altered. In SBA‐fed fish muscle, the amounts of threonine and methionine were increased, while the amount of leucine was decreased, as compared with control group. The amounts of fatty acids, including docosahexaenoic acid, phosphatidylcholine, and phosphatidylethanolamine, were increased in the 1% SBA‐fed fish, while the amounts of triglycerides were decreased. The results indicated the growth‐promoting activity of SBA in an in vivo culture of S. fuscescens, as well as to increase the nutritive values of the muscle. Thus, the re‐cycle of waste products during the farming of S. baicalensis herb in serving as fish feeding should be encouraged.
The opportunity cost of hedging under incomplete information: Evidence from ETF/Ns
Authors: Cui Zhenyu , Simaan Majeed 
Published: July 2021

AbstractThis paper considers the optimal hedge ratio problem under estimation risk. Due to incomplete information, the decision‐maker evaluates the opportunity cost of hedging using exchange‐traded funds or notes (ETF/Ns). Using a backtesting procedure over the last 5 years and 13 different hedging instruments—both inverse‐equity ETFs and volatility ETNs—we quantify the proposed opportunity cost using different out‐of‐sample performance metrics. Given the greater accessibility of commission‐free brokers for small investors along with the popularity of ETF/Ns, our paper appeals to retail investors and provides guidance in terms of choosing the optimal hedge ratio under estimation risk.
Overlapping and specific neural correlates for empathizing, affective mentalizing, and cognitive mentalizing: A coordinate‐based meta‐analytic study
Authors: Arioli Maria , Cattaneo Zaira , Ricciardi Emiliano , Canessa Nicola 
Published: July 2021

AbstractWhile the discussion on the foundations of social understanding mainly revolves around the notions of empathy, affective mentalizing, and cognitive mentalizing, their degree of overlap versus specificity is still unclear. We took a meta‐analytic approach to unveil the neural bases of cognitive mentalizing, affective mentalizing, and empathy, both in healthy individuals and pathological conditions characterized by social deficits such as schizophrenia and autism. We observed partially overlapping networks for cognitive and affective mentalizing in the medial prefrontal, posterior cingulate, and lateral temporal cortex, while empathy mainly engaged fronto‐insular, somatosensory, and anterior cingulate cortex. Adjacent process‐specific regions in the posterior lateral temporal, ventrolateral, and dorsomedial prefrontal cortex might underpin a transition from abstract representations of cognitive mental states detached from sensory facets to emotionally‐charged representations of affective mental states. Altered mentalizing‐related activity involved distinct sectors of the posterior lateral temporal cortex in schizophrenia and autism, while only the latter group displayed abnormal empathy related activity in the amygdala. These data might inform the design of rehabilitative treatments for social cognitive deficits.