bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Energetic Complexes as Catalysts for Ammonium Perchlorate Thermal Decomposition
Authors: Lei Guorong , Zhong Ye , Xu Yiqiang , Yang Fan , Bai Jiandong , Li Zhimin , Zhang Jianguo , Zhang Tonglai 
Published: January 2021

Main observation and conclusionIn this study, four new energetic complexes (1) [Cu(vimi)4]DCA2, (2) [Co(vimi)4]DCA2, (3) [Ni(vimi)4]DCA2, and (4) [Cu(vimi)4]CBH2 (vimi: 1‐vinylimidazole, DCA: dicyanamide anion, CBH: cyanoborohydride anion) were prepared, and their structures were characterized via single‐crystal X‐ray diffraction, elemental analysis, and Fourier‐transform infrared spectroscopy. The catalytic effects of the complexes on ammonium perchlorate thermal decomposition were studied via thermal analysis methods, including differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Among the complexes, complex 2 showed the best catalytic performance. The two decomposition peaks in the DSC curve of the pure ammonium perchlorate—low‐temperature decomposition (LTD) peak: 295 °C and high‐temperature decomposition (HTD) peak: 418 °C—were merged into a lower decomposition peak (325 °C) in the curve of AP with complex 2. Moreover, the heat released by ammonium perchlorate with complex 2 (1661.7 J g−1) was significantly higher than that released by the pure ammonium perchlorate (814.5 J g−1). The kinetic parameters calculated using Kissinger's method revealed that the complexes had a significant effect on the activation energy of ammonium perchlorate decomposition (223.5 kJ mol−1), and complex 2 lowered the activation energy to 115.6 kJ mol−1. The results indicate that complex 2 is a potential energetic additive for ammonium perchlorate‐based solid propellants.
Evaluation of Guangxi common wild rice for resistance to brown planthopper using a new stem evaluation method
Authors: Luo Liang , Wang Xuan , Guo Xinying , Lu Taian , Yuan Ruizhi , Liao Shanyue , Huang Suosheng , Han Yue , Usman Babar , Qin Baoxiang , Luo Jijing , Liu Fang , Huang Fengkuang , Li Rongbai 
Published: January 2021

AbstractBrown planthopper [BPH,Nilaparvata lugens(Stål)] is considered one of the most important pests of rice (Oryza sativaL.), which poses a serious threat to rice production. Identifying resistantOryzagermplasm can provide reliable accessions for breeding BPH resistant rice cultivars. In this study, the stem evaluation method (SEM) was first applied to identify the BPH resistance of 1,221 accessions of common wild rice (O. rufipogonGriff.) collected from three different regions of Guangxi Province, China. From this screening, 58 BPH resistant accessions were screened a second time, with 33 accessions ultimately identified as stable, highly resistant germplasm as confirmed by a third identification at the adult‐plant stage. The distribution of the 58 BPH‐resistant common wild rice accessions varies significantly from region to region. Genotypic analyses based on 42 simple sequence repeat (SSR) markers revealed that these 58 BPH‐resistant accessions were genetically diverse, reflecting the rich genetic diversity reported in Guangxi common wild rice. Furthermore, results verified that the SEM is efficient for rapid and accurate screening of BPH‐resistant germplasm, especially when a limited number of seeds are available or elite breeding lines need to be screened immediately. Also, SEM is the best method for evaluating BPH resistance at the adult stage because fewer insects are needed, and it is possible to repeat the evaluation in the same crop season. The 33 resistant rice accessions are a potential source of novel BPH resistance genes for developing cultivars with improved BPH resistance.
Experimental study on high‐energy surface arc plasma excitation control of cylindrical detached shock wave
Authors: Tang Bingliang , Guo Shanguang , Hua Liang 
Published: January 2021

AbstractIn this study, an electrical parameter test system and a high‐speed Schlieren system are used to study the control of a cylindrical detached shock wave through high‐energy surface arc plasma excitation. The results show that, when plasma excitation is not applied, the bow shockwave angle around the cylinder is 52°. After the plasma excitation is applied, the arc discharge releases a large amount of heat within a short time, generating a shockwave and a control gas bulb (CGB). As a result, the bow shockwave angle first decreases and then increases, the pressure ratio before and after the shockwave decreases, and the intensity of the bow shockwave weakens. At t = 280 μs, the bow shockwave angle is reduced to a minimum of 46°. The effective interference time of high‐energy surface arc plasma excitation on a cylindrical detached shockwave is 820 μs. A high temperature is used to control the heating effect of the bubbles, which will increase the local sound velocity near the wall, reduce the local Mach number, cause the sound velocity to move online, and eventually push the bow shockwave away from the cylinder. Concurrently, heating will accelerate the gas flow, reduce the pressure, and cause the mass flow in the unit flow area of the heated area to decrease, resulting in a strong compression effect, which deforms the bow shockwave. The high‐energy surface arc plasma excitation will provide a potential technical means for high‐speed aircraft detached shockwave control.
Electrostatic dust‐acoustic envelope solitons in an electron‐depleted plasma
Authors: Shikha R.K. , Chowdhury N.A. , Mannan A. , Mamun A.A. 
Published: January 2021

AbstractA standard nonlinear Schrödinger equation has been established by using the reductive perturbation method to investigate the propagation of electrostatic dust‐acoustic waves, and their modulational instability as well as the formation of localized electrostatic envelope solitons in an electron‐depleted unmagnetized dusty plasma system comprising opposite polarity dust grains and super‐thermal positive ions. The relevant physical plasma parameters (viz., charge, mass, number density of positive and negative dust grains, and super‐thermality of the positive ions, etc.) have rigorous impact to recognize the stability conditions of dust‐acoustic waves. The present study is useful for understanding the mechanism of the formation of dust‐acoustic envelope solitons associated with dust‐acoustic waves in the laboratory and space environments.
Earlier than previously thought: Yawn contagion in preschool children
Authors: Cordoni Giada , Favilli Eleonora , Palagi Elisabetta 
Published: January 2021

AbstractYawning is a primitive and stereotyped motor action involving orofacial, laryngeal, pharyngeal, thoracic and abdominal muscles. Contagious yawning, an involuntarily action induced by viewing or listening to others' yawns, has been demonstrated in human and several non‐human species. Previous studies with humans showed that infants and preschool children, socially separated during video experiments, were not infected by others' yawns. Here, we tested the occurrence of yawn contagion in 129 preschool children (ranging from 2.5 to 5.5 years) belonging to five different classes by video recording them in their classrooms during the ordinary school activities. As it occurs in adult humans, children of all ages were infected by others' yawns within the 2 min after the perception of the stimulus. The yawn contagion occurred earlier than previously thought. For children, it appears that the natural social setting is more conducive to yawn contagion than the inherently artificial experimental approach. Moreover, children's gender did not affect the level of contagious yawning. The neural, emotional and behavioural traits of preschool children are probably not sufficiently mature to express variability between boys and girls; nevertheless, children appeared to be already well equipped with the 'neural toolkit' necessary for expressing yawn contagion.
The role of changes in environmental quality in multitrait plastic responses to environmental and social change in the model microalga Chlamydomonas reinhardtii
Authors: Melero‐Jiménez Ignacio J. , Flores‐Moya Antonio , Collins Sinéad 
Published: January 2021

AbstractIntraspecific variation plays a key role in species' responses to environmental change; however, little is known about the role of changes in environmental quality (the population growth rate an environment supports) on intraspecific trait variation. Here, we hypothesize that intraspecific trait variation will be higher in ameliorated environments than in degraded ones. We first measure the range of multitrait phenotypes over a range of environmental qualities for three strains and two evolutionary histories of Chlamydomonas reinhardtii in laboratory conditions. We then explore how environmental quality and trait variation affect the predictability of lineage frequencies when lineage pairs are grown in indirect co‐culture. Our results show that environmental quality has the potential to affect intraspecific variability both in terms of the variation in expressed trait values, and in terms of the genotype composition of rapidly growing populations. We found low phenotypic variability in degraded or same‐quality environments and high phenotypic variability in ameliorated conditions. This variation can affect population composition, as monoculture growth rate is a less reliable predictor of lineage frequencies in ameliorated environments. Our study highlights that understanding whether populations experience environmental change as an increase or a decrease in quality relative to their recent history affects the changes in trait variation during plastic responses, including growth responses to the presence of conspecifics. This points toward a fundamental role for changes in overall environmental quality in driving phenotypic variation within closely related populations, with implications for microevolution.
Disturbance and predation risk influence vigilance synchrony of black‐necked cranes Grus nigricollis, but not as strongly as expected
Authors: Kong Dejun , Møller Anders Pape , Zhang Yanyun 
Published: January 2021

AbstractAnimals monitor surrounding dangers independently or cooperatively (synchronized and coordinated vigilance), with independent and synchronized scanning being prevalent. Coordinated vigilance, including unique sentinel behavior, is rare in nature, since it is time‐consuming and limited in terms of benefits. No evidence showed animals adopt alternative vigilance strategies during antipredation scanning yet. Considering the nonindependent nature of both synchronization and coordination, we assessed whether group members could keep alert synchronously or in a coordinated fashion under different circumstance. We studied how human behavior and species‐specific variables impacted individual and collective vigilance of globally threatened black‐necked cranes (Grus nigricollis) and explored behavior‐based wildlife management. We tested both predation risk (number of juveniles in group) and human disturbance (level and distance) effects on individual and collective antipredation vigilance of black‐necked crane families. Adults spent significantly more time (proportion and duration) on scanning than juveniles, and parents with juveniles behaved more vigilant. Both adults and juveniles increased time allocation and duration on vigilance with observer proximity. Deviation between observed and expected collective vigilance varied with disturbance and predation risk from zero, but not significantly so, indicating that an independent vigilance strategy was adopted by black‐necked crane couples. The birds showed synchronized vigilance in low disturbance areas, with fewer juveniles and far from observers; otherwise, they scanned in coordinated fashion. The collective vigilance, from synchronized to coordinated pattern, varied as a function of observer distance that helped us determine a safe distance of 403.75 m for the most vulnerable family groups with two juveniles. We argue that vigilance could constitute a prime indicator in behavior‐based species conservation, and we suggesting a safe distance of at least 400 m should be considered in future tourist management.
Visible‐Light‐Responsive TiO2/NiFe Mixed Metal Oxide‐Carbon Photocatalytic Fuel Cell with Synchronous Hydrogen Peroxide Production
Authors: Tao Sheng , Wang Fengming , Zhang Junzheng , Shi Jingjing , Guo Wenqing , Lu Jun 
Published: January 2021

AbstractThe photocatalytic fuel cell (PFC) synergistically utilizes the photocatalytic oxidation of biomass and the electrochemical reaction of the fuel cell to selectively reduce oxygen to produce hydrogen peroxide (H2O2) at room temperature. Herein, we report a PEC system that NiFe‐layered double oxide (LDO)/TiO2 as photoanode, carbon black as cathode for utilizing biomass and oxygen to simultaneously convert solar energy into electricity and produce hydrogen peroxide without applied electric bias. The photoanode catalyst was fabricated with TiO2‐supported NiFe mixed metal oxides (MMO) which obtained by layered double hydroxides (LDHs) pyrolysis. The research results indicate that under solar irradiation, the photocurrent density and faraday efficiency have a significantly improved compared with pure NiO/TiO2. With methanol as the feeding fuel at the photoanode, the optimal device yields an excellent open circuit voltage (Voc), short circuit current (Jsc) and a maximum power density (Pmax) of 0.78 V, 1093 μA/cm2 and 169 μW/cm2, respectively. This performance improvement is attributed to the Fe3+ doped in NiFe‐MMO and use TiO2 as an electron transport layer. Simultaneously, the hydrogen peroxide concentration reached 0.443 mM after 180 min illumination at the cathode, the generation rate was optimized to 0.126 μmol/min/cm2 at neutral aqueous solution. The PEC system exhibited an excellent higher rate of production for H2O2, and faraday efficiency (FE) reached 31.7 %. This PFC is a green technology for photocatalytically oxidize biomass at the photoanode and convert solar energy into electricity as well as supply it to the cathode to reduce O2 to produce H2O2 efficiently.
Arsenic‐Bridged Silafluorene and Germafluorene as a Novel Class of Mixed‐Heteroatom‐Bridged Heterofluorenes
Authors: Sasaki Hiroshi , Akioka Ippei , Imoto Hiroaki , Naka Kensuke 
Published: January 2021

AbstractArsenic‐bridged silafluorene and germafluorene were synthesized as a novel class of mixed‐heteroatom‐bridged heterofluorenes. Their structures, photophysical properties, and electronic natures were studied by experimental and computational means. The doubly‐bridged biphenyl moieties were distorted from the reported singly‐bridged ones. The intersystem crossing from the singlet excitation states to the triplet ones was enhanced by the arsenic‐bridging structures, implying that bridging through an arsenic atom is favorable for phosphorescence.
Gold Nanowires – Assisted Prussian Blue Enhancing Peroxidase – Like Activity for the Non‐enzymatic Electrochemically Sensing H2O2 Released From Living Cells
Authors: Zhang Keying , Zhang Ziqing , Zhou Xiaolong , Zhang Na 
Published: January 2021

AbstractPrussian blue nanoparticles (PBNPs) have peroxidase‐like activity for H2O2. However, PB alone have poor electrochemical performances. Herein, a strategy was proposed by direct in‐situ growth PBNPs onto gold nanowires (AuNWs) surface to obtain the peroxidase‐like activity with about 4.05 times higher than that of PBNPs alone. PBNPs@AuNWs was employed to construct a non ‐ enzymatic electrochemical H2O2 sensor with the detection limit of 5.3×10−9 mol/L (S/N=3). The sensor was successfully used to detect H2O2 in human serum samples or secreted from living HeLa cells. It may be a competitive candidate for H2O2 assaying in biological samples or cellular investigation.
Integrated dielectrophoretic and impedimetric biosensor provides a template for universal biomarker sensing in clinical samples
Authors: Velmanickam Logeeshan , Jayasooriya Vidura , Nawarathna Dharmakeerthi 
Published: January 2021

AbstractThe detection and quantification of nucleic acid and proteomic biomarkers in bodily fluids is a critical part of many medical screening and diagnoses. However, majority of the current detection platforms are not ideal for routine, rapid, and low‐cost testing in point‐of‐care settings. To address this issue, we developed a concept for a disposable universal point‐of‐care biosensor that can detect and quantify nucleic acid and proteomic biomarkers in diluted serum samples. The central tenet of sensing is the use of dielectrophoresis, electrothermal effects, and thermophoresis to selectively and rapidly isolate the biomarkers of interest in electrodes and then quantify using electrical impedance. When the sensor was applied to quantify microRNA and antigen biomarker molecules directly in diluted serum samples, it produced a LOD values in the fM range and sensitivity values from 1012 to 1015 Ω/M with a 30 min assay time and assay cost of less than $50 per assay.
Modeling nonstationary extremes of storm severity: Comparing parametric and semiparametric inference
Authors: Konzen Evandro , Neves Cláudia , Jonathan Philip 
Published: January 2021

AbstractThis article compares the modeling of nonstationary extreme events using parametric models with local parametric and semiparametric approaches also motivated by extreme value theory. Specifically, three estimators are compared based on (a) (local) semiparametric moment estimation, (b) (local) maximum likelihood estimation, and (c) spline‐based maximum likelihood estimation. Inference is performed in a sequential manner, highlighting the synergies between the different approaches to estimating extreme quantiles, including the T‐year level and right endpoint when finite. We present a novel heuristic to estimate nonstationary extreme value threshold with exceedances varying on a circular domain, and hypothesis‐testing procedures for identifying max‐domain of attraction in the nonstationary setting. Bootstrapping is used to estimate nonstationary confidence bounds throughout. We provide step‐by‐step guides for estimation, and explore the different inference strategies in application to directional modeling of hindcast storm peak significant wave heights recorded in the North Sea.
Natural dye‐sensitized solar cells: Case study with tropical organic pigments
Authors: Pereira José Waltrudes Castanheira , Cataldi Marcio , Salcedo Ivanovich Lache 
Published: January 2021

AbstractIn recent years, the increase in evolution of new photovoltaic technologies demonstrates the global importance given to solar energy. New photovoltaic technologies are in the third generation. The article presents a third‐generation technology of solar cells called dye‐sensitized solar cell (DSSC), enhancing cell efficiency through material improvements. DSSC is a solar technology with minimal environmental impact and low cost in manufacturing. The dyes used in the study were natural dyes of açaí and chlorophyll. For better electrical comprehension of natural dye‐sensitized solar cells, the cells were tested with varying temperature and irradiance. The main objectives were to introduce and improve sensitized solar cells with the combination of a Brazilian dye (açaí) with a global dye (chlorophyll), indicating a potential renewable source to South America.
Adsorption of reduced chromium(VI) ions by vitamin C tablets onto a tellurato‐functionalized cellulose derivative and its composite with Cyanobacteria green algae in aqueous media
Authors: Saad Eman M. , Butler Ian S. , Mostafa Sahar I. 
Published: January 2021

AbstractThe removal of toxic chromium(VI) ions from wastewaters in the environment are of considerable importance throughout the world as these ions are known to cause severe medical problems in living organisms. This article describes a novel reduction process for Cr(VI) ions to the less toxic Cr(III) ions in typical wastewaters by using ecofriendly vitamin C tablets as a source of ascorbic acid, which completely reduces Cr(VI) to Cr(III) ions. The efficient adsorption of reduced Cr(VI) ions onto cellulose functionalized with sodium‐tellurate, Cell‐TeO(OH)4(ONa)/Cell‐Cl {Cell‐Te}, both in the absence and the presence of Cyanobacteria green algae (CBGA), has been accomplished. This green algae has polysaccharide binding groups that enhance the adsorption of heavy metal ions. The uptake of reduced Cr(VI) ions by the two sorbents are dependent on the initial pH, contact time, temperature, presence of foreign ions, sorbent dose, and initial Cr(VI) ion concentration. The maximum uptakes of reduced Cr(VI) ions by {Cell‐Te} and Cell‐TeO(OH)4(ONa)/Cell‐Cl:CBGA; 3:2 w/w {Cell‐Te‐CBGA} are 56.5 and 88.7 mg g−1, respectively. The hydroxyl and amide groups on the surface of the CBGA most probably play a significant role in facilitating the adsorption capacities of the two sorbents toward Cr(VI) ions.
Non‐competitive and competitive adsorption of Zn(II), Cu(II), and Cd(II) by a granular Fe‐Mn binary oxide in aqueous solution
Authors: Du Xiaoli , Cui Shenshen , Wang Qian , Han Qiang , Liu Guizhong 
Published: January 2021

AbstractThis work assessed the non‐competitive and competitive adsorption of Zn(II), Cu(II), and Cd(II) by a granular Fe‐Mn binary oxide (GFMO). Kinetic data for Zn(II), Cu(II), and Cd(II) adsorption followed with the pseudo‐second‐order model. Equilibrium data were well fitted using the Langmuir isotherm model both in single‐metal and in multi‐metal systems. The maximum adsorption capacities were determined to be 0.115, 0.124, and 0.055 mmol/g for Zn(II), Cu(II), and Cd(II) in the single‐metal solutions, respectively, while the maximum adsorption capacities were estimated to be 0.088, 0.112, and 0.041 mmol/g in multi‐metal systems. The adsorption of each metal ion was both nonspontaneous and endothermic demonstrated by thermodynamic assessments. The adsorption process was also greatly affected by pH, with the maximum adsorption at pH 6.0 for Cu(II) and 5.0 for Zn(II) and Cd(II). Metal ion adsorption was suppressed as coexisting metal ions competed for adsorption sites on the GFMO surface, suggesting an antagonistic effect. Adsorption data suggested that Cu(II) was preferentially adsorbed by GFMO in the multi‐component solutions. The adsorption of these metals by GFMO evidently proceeded on the basis of hydroxyl replacement, electrostatic attraction, and surface complexation.Novelty or SignificanceA granular Fe‐Mn binary oxide (GFMO) was synthesized in conjunction with polyvinyl alcohol to overcome the nano‐particles dispersion state of Fe‐Mn binary oxides. Because Zn(II), Cu(II), and Cd(II) with higher concentration and risk coexisted in road runoff, the performance of GFMO for Cd(II), Cu(II), and Zn(II) non‐competitive and competitive adsorption was investigated to identify their engineering application potential when GFMO applies as the filler in some green infrastructures, such as constructed wetlands, bioretentions, and rain gardens.