bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytochemical Screening, Anti-nutritional and Mineral Composition of Telfairia occidetallis (Fluted Pumpkin) and Cleome rutidosperma (Fringe Spider Flower)
Authors: Alexander Priscilla , Bwatanglang I. B. , Buba Adamu
Published: September 2019

The study was conducted to investigate phytochemicals, anti-nutrients and mineral compostions of Telfeira occidentalis and Cleome rutidospermas leaves. The High Performance Chromatography (HPLC) was used in the Quantitative analysis of Phytochemicals as well as the anti-nutrient contents while the Elemental Compositions was analysed using Atomic Absorption Spectrophotometer (AAS) (Buck Scientific). The antinutrients content analysed were as follows hydrocyanic acid (31.0±0.001 and 25.0±0.001), oxalate (570±0.004 and 740±0.003), phytic acid (7.50±0.002 and 9.20±0.005 mg/100 g), for T. occidentallis and C. rutidosperma respectively and  the values were all within the NAFADAC/WHO tolerable limit. The Minerals Compositions was found to be, Mn (1.684±0.40 and 0.718±0.31 mg/100 g), Zn (1.740±0.10 and 1.570±0.31 mg/100 g), Fe (3.823±0.03 and 4.329±0.01 mg/100 g), Na (2.572±0.42 and 2.659±0.80 mg/100 g), Ca (74.405±13.60 and 29.677±13.50 mg/100 g), Mg (35.277±10.05 and 12.438±10.4 mg/100 g), Cu (0.049±0.03 and 0.044±0.01 mg/100 g) for T.  occidentallis and C. rutidosperma respectively. The presences of some secondary metabolites like alkaloids, flavonoids, terpenoids, tannins, cardiac glycosides and some essential minerals shows that the plants can be alternative sources of medicine. The results of the antinutrients indicated that the samples are free of toxic substances which might cause ill health to the body. Though, the anti-nutrient contents found in both T. occidentallis and C. rutidosperma were low, it will still be safer if these leaves were boiled for about 5 to 15 minutes to reduce the anti-nutritional factors significantly.
A Review on Principles and Applications of Scanning Thermal Microscopy (SThM)
Authors: Zhang Yun , Zhu Wenkai , Hui Fei , Lanza Mario , Borca‐Tasciuc Theodorian , Muñoz Rojo Miguel
Published: September 2019

As the size of materials, particles, and devices shrinks to nanometer, atomic, or even quantum scale, it is more challenging to characterize their thermal properties reliably. Scanning thermal microscopy (SThM) is an emerging method to obtain local thermal information by controlling and monitoring probe–sample thermal exchange processes. In this review, key experimental and theoretical components of the SThM system are discussed, including thermal probes and experimental methods, heat transfer mechanisms, calibration strategies, thermal exchange resistance, and effective heat transfer coefficients. Additionally, recent applications of SThM to novel materials and devices are reviewed, with emphasis on thermoelectric, biological, phase change, and 2D materials.
Solution‐Processed Laminated Perovskite Layers for High‐Performance Solar Cells
Authors: Wang Yangyang , Li Tianhao , Li Zengrong , Wang Sen , Deng Xianyu
Published: September 2019

Laminated multilayers of perovskite films with different optical and electronic characteristics will easily realize high‐performance optoelectronic devices because it is widely demonstrated that differential distribution of film properties in the vertical direction of devices plays particularly important roles in device performance. However, the existing laminated perovskite films are hardly prepared by a solution process because there is no solvent with sufficient selectivity of solubility for different perovskite materials. Here, it is demonstrated that aniline (AN) has a largely different solubility toward the perovskite MAPbI3 and the MAPbI3 blend with an additive of hydrochloride diethylammonium chloride. By using AN as the solvent in the perovskite precursor solution, two laminated perovskite layers with different crystal size and optical and electrical characteristics are achieved. Inverted perovskite solar cells with the laminated films as active layers achieve an averaged power conversion efficiency of 20.65% originating from the high VOC 1.112 V and fill factor of 80.8%. The devices maintain 98% efficiency after 400 h under 65% RH. This work provides a very simple and feasible method for production of laminated perovskite films to achieve high‐performance perovskite solar cells.
Heterojunction Architecture of N‐Doped WO3 Nanobundles with Ce2S3 Nanodots Hybridized on a Carbon Textile Enables a Highly Efficient Flexible Photocatalyst
Authors: Huang Yongchao , Guo Zhongjie , Liu Hong , Zhang Shanqing , Wang Pingshan , Lu Jun , Tong Yexiang
Published: September 2019

The availability of robust, versatile, and efficient photocatalysts is the main bottleneck in practical applications of photocatalytic degradation of organic pollutants. Herein, N‐WO3/Ce2S3 nanotube bundles (NBs) are synthesized and successfully immobilized on a carbon textile, resulting in a flexible and conducting photocatalyst. Due to the large interfacial area between N‐WO3 and Ce2S3, the interwoven 3D carbon architecture and, more importantly, the establishment of a heterojunction between N‐WO3 and Ce2S3, the resultant photocatalyst exhibits excellent light absorption capacity and superior ability to separate photoinduced electron–hole pairs for the photocatalytic degradation of organic compounds in air and water media. Theoretical calculations confirm that the strong electronic interaction between N‐WO3 and Ce2S3 can be beneficial to the enhancement of the charge carrier transfer dynamics of the as‐prepared photocatalyst. This work provides a new protocol for constructing efficient flexible photocatalysts for application in environmental remediation.
A Molecular Dynamics Study on Self‐Assembly of Single‐Walled Carbon Nanotubes: From Molecular Morphology and Binding Energy
Authors: Zhang Jianwei , Cui Jianlei , Cheng Yang , Wang Wenjun , He Xiaoqiao , Mei Xuesong
Published: September 2019

Molecular dynamics simulations are used to reveal the adsorption behavior of modified single‐walled carbon nanotubes (M‐SWNTs) on the functionalized surfaces (F‐surfaces) bound to a silicon dioxide substrate, in order to illustrate the mechanism of patterned self‐assembly of SWNTs on the atomic scale. Noncovalent modification strategy with surfactants is adopted to investigate the structural transition of the surfactant on SWNTs in aqueous solution. Core/shell hybrid structures are formed ultimately by the surfactant scrolling onto SWNTs periphery. Two different kinds of silanes are used to control the wettability of the F‐surfaces from hydrophobic to hydrophilic. An excluded‐volume constraints algorithm is employed to calculate the global energy minimum to rationalize the driving force controlling the behavior evolution. The mechanisms for self‐assembly are illustrated in two segments in detail that the electrostatic attraction starts the self‐assembly program on the hydrophilic surface, while van der Waals interaction plays an important role in the behavior of nonassembly to the hydrophobic surface. The results are not only helpful to understand many phenomena in the self‐assembly process on the atomic scale but also will provide meaningful guidance in fabrication of SWNTs patterns to keep fidelity.
Carbon Black from Diesel Soot for High‐Performance Wearable Pressure Sensors
Authors: Liu Kangning , Yu Junsheng , Li Ying , Yan Xingwu , Bai Dongyu , Liao Xiaoqing , Zhou Ziqiang , Gao Yuanyuan , Yang Xin , Li Lu
Published: September 2019

The rational design of high‐performance flexible pressure sensors with both high sensitivity and large workable range attracts great attentions due to the potential applications in wearable electronics and human–machine interfaces. Here, carbon black (CB) from diesel soot, an air pollutant produced during incomplete combustion of hydrocarbon fuels, is used as the active material to construct high‐performance flexible all‐textile pressure sensors. Due to the unique hierarchical structures and large surface roughness of the CB‐coated fabric, the pressure sensor exhibits outstanding performances, such as high sensitivity (81.61 kPa−1 within the range of 0–10 kPa), extrawide workable pressure regime (0–100 kPa), and rapid response and relaxation time (6 and 30 ms, respectively). Based on these superior sensing properties, its practical applications are demonstrated in detecting the signals of musical sound and of human physiology, showing its potential for health monitoring as wearable electronics.
Enhanced Tunable Light Absorption in Nanostructured Si Arrays Based on Double‐Quarter‐Wavelength Resonance
Authors: Li Zhigang , Feng Shangshen , Liu Yanping , Hu Jinlian , Wang Caifen , Wei Bingqing
Published: September 2019

Simultaneously tuning light absorption wavelength and absorbance is a critical challenge in photoelectric detection, mimic of photosynthesis, and simulation of photoreceptors in some animals' retinas. Here, highly ordered hexagonal nanostructured Si arrays are fabricated using monolayer colloid crystal templates. A quantitative relationship between geometric size and light absorption is unveiled in the Si arrays, namely double‐quarter‐wavelength resonance (DQWR). Based on the DQWR model, the absorption wavelength can be readily tuned from 200 to 2400 nm, and the absorbance can be enhanced from ≈80% to above 99% in the full spectrum. Due to the hemisphere‐shell structural feature of the Si arrays, excellent omnidirectional antireflective performance can also be realized. Most importantly, the outstanding antireflection performance of the nanostructures is independent of the substrate. The results not only have important implications for understanding the antireflective mechanism of the nanostructured arrays, but also endow the approach promising in diverse applications, including biomimicry, antireflective film, infrared imagery, and other optoelectronic devices.
Ultrafast Terahertz Frequency and Phase Tuning by All‐Optical Molecularization of Metasurfaces
Authors: Hu Yuze , Jiang Tian , Zhou Junhu , Hao Hao , Sun Hao , Ouyang Hao , Tong Mingyu , Tang Yuxiang , Li Han , You Jie , Zheng Xin , Xu Zhongjie , Cheng Xiangai
Published: September 2019

The integration of photoactive semiconductors exhibiting strong light–matter interactions into functional unit meta‐atoms facilitates effective approaches to dynamically manipulate terahertz (THz) waves. Here, a new metaphotonic modulator is proposed and comprehensively studied, which demonstrates extensive tunability of the resonant frequency and phase with the merit of ultrafast photoswitching. Specifically, parallel silicon (Si) bridges are embedded in metasurfaces to reinforce the connection ability, achieving ultrafast optical molecularization from a magnetic quadrupole into an electric dipole. Under femtosecond pulse excitation, the demonstrated resonant frequency tuning range is as high as 40% (from 1.16 to 0.7 THz) and can be further promoted up to 48% (from 1.56 to 0.81 THz) by varying the Si bridge length. Meanwhile, the phase delay at given frequencies can be controlled up to 53.3° without significantly changing the high transmission. Furthermore, the transient frequency switching and phase shifting dynamics are systematically investigated for the first time, showing a full recovery time within 2 ns. By optically molecularizing metasurfaces, extended tuning ranges with regard to the resonant frequency and phase, as well as an ultrafast switching speed, are simultaneously acquired in the proposed metamodulator, which provides deeper insight into the multifunctional active‐tuning systems.
Iron(III) Chloride/Phenylsilane‐Mediated Cascade Reaction of Allyl Alcohols with Maleimides: Synthesis of Poly‐Substituted γ‐Butyrolactones
Authors: Zhang Hua , Zhan Xiao‐Yu , Chen Xu‐Ling , Tang Lei , He Shuai , Shi Zhi‐Chuan , Wang Yu , Wang Ji‐Yu
Published: September 2019

A iron‐catalyzed free radical cascade reaction of allyl alcohols with N‐substituted maleimides for accessing poly‐substituted γ‐butyrolactones has been developed. In this protocol, various allyl alcohols can open N‐substituted maleimide rings to form allyl ester intermediates, and the allyl ester intermediates can be converted into an allyl ester alkyl radicals and undergo intramolecular free radical addition cyclization to form a polysubstituted γ‐butyrolactones. In this protocol, spiro γ‐butyrolactone compounds can be also synthesized. Meanwhile, the strategy could be applied to further construct a fully substituted tetrahydrofuran. The reaction is not sensitive to oxygen or moisture and has been performed on gram‐scale.

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Symmetry Reductions, Group‐Invariant Solutions, and Conservation Laws of a (2+1)‐Dimensional Nonlinear Schrödinger Equation in a Heisenberg Ferromagnetic Spin Chain
Authors: Du Xia‐Xia , Tian Bo , Yuan Yu‐Qiang , Du Zhong
Published: September 2019

Nonlinear spin excitations in ferromagnetic spin chains are studied for spintronic and magnetic devices including magnetic‐field sensors and for high‐density data storage. Here, (2+1)‐dimensional nonlinear Schrödinger equation is investigated, which describes the nonlinear spin dynamics for a Heisenberg ferromagnetic spin chain. Lie point symmetry generators and Lie symmetry groups of that equation are derived. Lie symmetry groups are related to the time, space, scale, rotation transformations, and Galilean boosts of that equation. Certain solutions, which are associated with the known solutions, are constructed. Based on the Lie symmetry generators, the reduced systems of such an equation are obtained. Based on the polynomial expansion and through one of the reduced systems, group‐invariant solutions are constructed. Soliton‐type group‐invariant solutions are graphically investigated and effects of the magnetic coupling coefficients, that is, α1, α2, α3, and α4, on the soliton's amplitude, width, and velocity are discussed. It is seen that α1, α2, α3, and α4 have no influence on the soliton's amplitude, but can affect the soliton's velocity and width. Lax pair and conservation laws of such an equation are derived.
Room‐Temperature Insulating Ferromagnetic (Ni,Co)1+2xTi1−xO3 Thin Films
Authors: Fujioka Yukari , Frantti Johannes , Rouleau Christopher , Puretzky Alexander , Gai Zheng , Lavrik Nickolay , Herklotz Andreas , Ivanov Ilia , Meyer Harry
Published: September 2019

Insulating uniaxial room‐temperature ferromagnets are a prerequisite for commonplace spin wave‐based devices, the obstacle in contemporary ferromagnets being the coupling of ferromagnetism with large conductivity. It is shown that the uniaxial A1 + 2xTi4+1 − xO3 (ATO), A = Ni2+,Co2+, and 0.6 < x ≤ 1, thin films are electrically insulating ferromagnets already at room temperature. The octahedra network of the ATO and the corundum and ilmenite structures are the same yet different octahedra‐filling proved to be a route to switch from the antiferromagnetic to ferromagnetic regime. Octahedra can continuously be filled up to x = 1, or vacated (−0.24 < x < 0) in the ATO structure. TiO‐layers, which separate the ferromagnetic (Ni,Co)O‐layers and intermediate the antiferromagnetic coupling between the ferromagnetic layers in the NiTiO3 and CoTiO3 ilmenites, can continuously be replaced by (Ni,Co)O‐layers to convert the ATO‐films to ferromagnetic insulator with abundant direct cation interactions.
Synthesis of Imines via Reactions of Benzyl Alcohol with Amines Using Half‐Sandwich (η6‐p‐cymene) Ruthenium(II) Complexes Stabilised by 2‐aminofluorene Derivatives
Authors: Vinoth Govindasamy , Indira Sekar , Bharathi Madheswaran , Durgadevi Anandhan , Abinaya Ravikumar , Alves Luis G. , Martins Ana Margarida , Bharathi Kuppannan Shanmuga
Published: September 2019

A new class of half‐sandwich (η6‐p‐cymene) ruthenium(II) complexes supported by 2‐aminofluorene derivatives [Ru(η6‐p‐cymene)(Cl)(L)] (L = 2‐(((9H‐fluoren‐2‐yl)imino)methyl)phenol (L1), 2‐(((9H‐fluoren‐2‐yl)imino)methyl)‐3‐methoxyphenol (L2), 1‐(((9H‐fluoren‐2‐yl)imino)methyl)naphthalene‐2‐ol (L3) and N‐((1H‐pyrrol‐2‐yl)methylene)‐9H‐fluorene‐2‐amine (L4)) were synthesized. All compounds were fully characterized by analytical and spectroscopic techniques (IR, UV–Vis, NMR) and also by mass spectrometry. The solid state molecular structures of the complexes [Ru(η6‐p‐cymene)(Cl)(L2)], [Ru(η6‐p‐cymene)(Cl)(L3)] and [Ru(η6‐p‐cymene)(Cl)(L4)] revealed that the 2‐aminofluorene and p‐cymene moieties coordinate to ruthenium(II) in a three‐legged piano‐stool geometry. The synthesized complexes were used as catalysts for the dehydrogenative coupling of benzyl alcohol with a range of amines (aliphatic, aromatic and heterocyclic). The reactions were carried out under thermal heating, ultrasound and microwave assistance, using solvent or solvent free conditions, and the catalytic performance was optimized regarding the solvent, the type of base, the catalyst loading and the temperature. Moderately high to very high isolated yields were obtained using [Ru(η6‐p‐cymene)(Cl)(L4)] at 1 mol%. In general, microwave irradiation produced better yields than the other two techniques irrespective of the nature of the substituents.
Durchstanztragverhalten von Flachdecken mit variierenden Durchstanzbewehrungsgraden
Authors: Schmidt Philipp , Kueres Dominik , Claßen Martin , Hegger Josef
Published: September 2019

Mit der bauaufsichtlichen Einführung des Eurocode 2 in Deutschland wurde die Durchstanzbemessung von Flachdecken neu geregelt. Seitdem ergibt sich die Durchstanztragfähigkeit mit Durchstanzbewehrung aus der Summe eines konstanten Betontraganteils und eines Stahltraganteils, der unabhängig vom Bauteil aus einem 33°‐Fachwerk resultiert. Für die Berechnung des Stahltraganteils wird gemäß Eurocode 2 eine reduzierte Stahlfestigkeit in Abhängigkeit von der statischen Nutzhöhe angesetzt, wodurch die Verankerungsqualität der Durchstanzbewehrung berücksichtigt wird. Auf Basis einer Datenbankauswertung und eines Vergleichs des Sicherheitsniveaus mit der damaligen DIN 1045‐1 wurden im Deutschen Anhang zum Eurocode 2 (EC2+NA(D)) zusätzliche Erhöhungsfaktoren für die ersten beiden Durchstanzbewehrungsreihen ergänzt, die nahezu zu einer Verdopplung der Durchstanzbewehrungsmenge führen. Während zur Bewertung der Bemessungsgleichungen für die Ermittlung der Durchstanztragfähigkeit ohne Durchstanzbewehrung und auf dem Niveau der maximalen Durchstanztragfähigkeit zahlreiche Versuchsergebnisse vorliegen, sind bislang nur sehr wenige Versuchsreihen an Flachdeckenausschnitten mit einem Durchstanzversagen innerhalb des durchstanzbewehrten Bereichs vorhanden.

Zur systematischen Untersuchung des Durchstanztragverhaltens von Flachdecken mit Bügeln als Durchstanzbewehrung wurden daher insgesamt drei Versuchsserien mit variierenden Durchstanzbewehrungsgraden durchgeführt. Das Versuchsprogramm umfasste drei Referenzversuche ohne Durchstanzbewehrung und acht Versuchskörper mit geringen und mittleren Durchstanzbewehrungsgraden. Dabei erfolgte die Variation der Durchstanzbewehrungsmenge jeweils ausschließlich über den Bügeldurchmesser. Weitere untersuchte Einflussparameter waren die Schubschlankheit und die statische Nutzhöhe. Im vorliegenden Beitrag werden die durchgeführten Versuche vorgestellt und die Versuchsergebnisse diskutiert. Durch den Vergleich der experimentell ermittelten Bruchlasten mit den rechnerischen Durchstanztragfähigkeiten nach Eurocode 2 und EC2+NA(D) können die bestehenden normativen Regeln bewertet werden. Darüber hinaus werden die Bemessungsregeln nach Model Code 2010 in die Bewertung mit einbezogen.
Querkrafttragverhalten von großformatigen Spannbetonbalkenelementen mit Plattenbalkenquerschnitt
Authors: Schramm Nicholas , Gehrlein Sebastian , Fischer Oliver
Published: September 2019

Die Beschreibung des Querkrafttragverhaltens von Betonbauteilen im Bruchzustand gestaltet sich äußerst komplex, sodass diese Thematik auch heute noch Gegenstand aktueller Forschung ist. Insbesondere zur Erfassung der für Bestandsbrücken charakteristischen Parameter sowie generell für große, baupraktisch relevante Querschnittsabmessungen besteht nach wie vor Forschungsbedarf. Der vorliegende Beitrag geht in diesem Zusammenhang auf die Ergebnisse von großformatigen Querkraftversuchen an Spannbetonbalkenelementen mit plattenbalkenförmigem Querschnitt ein, die als Ergänzung und in Anlehnung an in‐situ‐Querkraftversuche an einer realen, durchlaufenden Spannbetonbrücke durchgeführt wurden. Die Laborversuche an 1,10 m hohen Spannbetonträgerausschnitten wurden dabei unter Anwendung eines innovativen Versuchskonzepts, der sogenannten „Substrukturtechnik“, durchgeführt. Neben der Wirksamkeit von nicht normenkonformer Querkraftbewehrung geht der Fachaufsatz speziell auf den Einfluss der Querschnittsform auf das Querkrafttragverhalten ein und vergleicht die Versuchsergebnisse mit rechnerischen Tragwiderständen aus aktuellen Modellvorstellungen.
TargeTron Technology Applicable in Solventogenic Clostridia: Revisiting 12 Years’ Advances
Authors: Wen Zhiqiang , Lu Minrui , Ledesma‐Amaro Rodrigo , Li Qi , Jin Mingjie , Yang Sheng
Published: September 2019

Clostridium has great potential in industrial application and medical research. But low DNA repair capacity and plasmids transformation efficiency severely delay development and application of genetic tools based on homologous recombination (HR). TargeTron is a gene editing technique dependent on the mobility of group II introns, rather than homologous recombination, which makes it very suitable for gene disruption of Clostridium. The application of TargeTron technology in solventogenic Clostridium is academically reported in 2007 and this tool has been introduced in various clostridia as it is easy to operate, time saving, and reliable. TargeTron has made great progress in solventogenic Clostridium in the aspects of acetone–butanol–ethanol (ABE) fermentation pathway modification, important functional genes identification, and xylose metabolic pathway analysis and reconstruction. In the review, 12 years’ advances of TargeTron technology applicable in solventogenic Clostridium, including its principle, technical characteristics, application, and efforts to expand its capabilities, or to avoid potential drawbacks, are revisisted. Some other technologies as putative competitors or collaborators are also discussed. It is believed that TargeTron combined with CRISPR/Cas‐assisted gene/base editing and gene‐expression regulation system will make a better future for clostridial genetic modification.
A Family of Related Fungal and Bacterial Di‐ and Sesterterpenes: Studies on Fusaterpenol and Variediene
Authors: Rinkel Jan , Steiner Simon T. , Bian Guangkai , Chen Rong , Liu Tiangang , Dickschat Jeroen S.
Published: September 2019

The absolute configuration of fusaterpenol (GJ1012E) has been revised by an enantioselective deuteration strategy. A bifunctional enzyme with a terpene synthase and a prenyltransferase domain from Aspergillus brasiliensis was characterised as variediene synthase, and the absolute configuration of its product was elucidated. The uniform absolute configurations of these and structurally related di‐ and sesterterpenes together with a common stereochemical course for the geminal methyl groups of GGPP unravel a similar conformational fold of the substrate in the active sites of the terpene synthases. For variediene, a thermal reaction observed during GC/MS analysis was studied in detail for which a surprising mechanism was uncovered.
Rational Construction of Z‐Scheme CuInS2/Au/g‐C3N4 Heterostructure: Experimental Results and Theoretical Calculation
Authors: Ye Wenhua , Hu Jisong , Hu Xiaofeng , Zhang Wenhua , Ma Xinguo , Wang Huihu
Published: September 2019

Two dimensional (2D) heterojunction based on g‐C3N4 and CuInS2(CIS) nanosheets has been successfully constructed with the assistance of biomolecules L‐cysteine. We demonstrated that a typical p–n junction charges transfer mode of CIS/PCN (protonated g‐C3N4) can be switched to Z‐scheme transfer mode through the integration of Au by weakening the role of built‐in electric field. The morphology of CIS/Au/PCN can be well adjusted through the formation of Au−S covalent bond and the electrostatic adsorption between Au and PCN during the hydrothermal process. Furthermore, the intimate interface contact inside CIS/Au/PCN heterojunction was indeed constructed, which may promote the charges separation and transfer process at the interface as evidenced by ESR spectra and time‐resolved PL spectra. Under visible light illumination, the CIS/Au/PCN exhibited an enhanced CO (19.46 μmol/g) and CH4 (1.18 μmol/g) yield in CO2 reduction, which was about 5.04 times and 2.03 times higher than pure PCN. The composite heterojunction also showed excellent photocatalytic activity for tetracycline degradation with a 87 % degradation efficiency in 1 hour, which was 2.07 times higher than pure PCN. The experimental and theoretical calculation results demonstrated that an all‐solid‐state Z‐scheme heterojunction was formed in the CIS/Au/PCN system, which was different from the typical p–n junction charges transfer mechanism in CIS/PCN.
Condensation of Supramolecular Assemblies at Low Temperatures as a Tool for the Preparation of Photoactive C3N3O Materials
Authors: Barrio Jesús , Karjule Neeta , Qin Jiani , Shalom Menny
Published: September 2019

We report the synthesis of new photoactive carbon nitride polymers with high oxygen content (CNO) at low calcination temperatures (300–400 °C). To do so, we designed new carbon‐ and oxygen‐rich supramolecular assemblies as reactants. The starting monomers’ composition allows the formation of photoactive CNO semiconductors with extended absorption and ordered morphologies. Interestingly, at these reaction temperatures, the chemical structure of the starting monomers is partially retained, opening a path for the transfer of properties from the molecular level to the final CN materials after condensation. The new CNO polymers exhibit good photoactivity for the hydrogen evolution reaction, CO2 reduction and rhodamine B dye degradation.
In Situ Evaluation of Anticancer Monoclonal Antibody Nivolumab‐DNA Interaction Using a DNA‐Electrochemical Biosensor
Authors: Machini Wesley B. S. , Marques Nuno V. , Oliveira‐Brett Ana Maria
Published: September 2019

The cancer treatment based on monoclonal antibodies has become one of the most successful therapeutic strategies. Among the monoclonal antibodies, nivolumab (NIVO) stands out as being a relatively new anticancer drug. The NIVO‐dsDNA interaction was evaluated, in incubated solutions, by differential pulse voltammetry, UV‐Visible spectrophotometry and gel electrophoresis, and in situ with dsDNA‐, poly[G]‐ or poly[A]‐electrochemical biosensors, by differential pulse voltammetry, electrochemical impedance spectroscopy, and quartz crystal microbalance. The interfacial behaviour of the dsDNA‐electrochemical biosensor was also investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The NIVO‐dsDNA interaction mechanism caused, for shorter times, the binding of the NIVO to DNA, resulting in a NIVO‐dsDNA complex, and for longer times, the relaxation/unwinding of this complex structure. The monoclonal antibody NIVO did not promote oxidative damage to DNA.
Zn–Co Sulfide Microflowers Anchored on Three‐Dimensional Graphene: A High‐Capacitance and Long‐Cycle‐Life Electrode for Asymmetric Supercapacitors
Authors: Deng Qianwen , Tian Zhen , Wang Xiaomin , Yang Zhewei , Wu Yucheng
Published: September 2019

Zinc–cobalt double‐metal sulfides (ZCS) as Faradic electrode materials with high energy density have great potential for supercapacitors, but their poor transfer efficiency for electrons and ions hinders their electrochemical response. Herein, ZnCo2(CO3)1.5(OH)3@ZCS microflower hybrid arrays consisting of thin nanolayer petals were anchored on three‐dimensional graphene (ZnCo2(CO3)1.5(OH)3@ZCS/3DG) by a simple hydrothermal method and additional ion‐exchange process. A ZnCo2(CO3)1.5(OH)3@ZCS/3DG electrode delivered high capacitance (2228 F g−1 at 1 A g−1) and long cycling life (85.7 % retention after 17 000 cycles), which are ascribed to the multicomponent structural design. The 3DG conductive substrate improves the electron‐transfer dynamics of the electrode material. Meanwhile, the microflowers consisting of thin nanolayer petals could not only provide many active sites for ions to improve the capacitance, but also alleviate the volume expansion to ensure the structural stability. Furthermore, an all‐solid‐state asymmetric supercapacitor based on a ZnCo2(CO3)1.5(OH)3@ZCS/3DG electrode achieved a high energy density of 27 W h kg−1 at 528.3 W kg−1 and exhibits exceptional cyclic stability for 23 000 cycles. Its ability to light a blue LED for 9 min verified the feasibility of its application for energy storage devices.
In Situ Growth of Hierarchical Ni‐Mn‐O Solid Solution on a Flexible and Porous Ni Electrode for High‐Performance All‐Solid‐State Asymmetric Supercapacitors
Authors: Yu Huan , Li Xiaofeng , Yang Jing , Deng Zhiming , Yu Zhong‐Zhen
Published: September 2019

To endow all‐solid‐state asymmetric supercapacitors with high energy density, cycling stability, and flexibility, we design a binder‐free supercapacitor electrode by in situ growth of well‐distributed broccoli‐like Ni0.75Mn0.25O/C solid solution arrays on a flexible and three‐dimensional Ni current collector (3D‐Ni). The electrode consists of a bottom layer of compressed but still porous Ni foam with excellent flexibility and high electrical conductivity, an intermediate layer of interconnected Ni nanoparticles providing a large specific surface area for loading of active substances, and a top layer of vertically aligned mesoporous nanosheets of a Ni0.75Mn0.25O/C solid solution. The resultant 3D‐Ni/Ni0.75Mn0.25O/C cathode exhibits a specific capacitance of 1657.6 mF cm−2 at 1 mA cm−2 and shows no degradation of the capacitance after 10 000 cycles at 3 mA cm−2. The assembled 3D‐Ni/Ni0.75Mn0.25O/C//activated carbon asymmetric supercapacitor has a high specific capacitance of 797.7 mF cm−2 at 2 mA cm−2 and an excellent cycling stability with 85.3 % of capacitance retention after 10 000 cycles at a current density of 3 mA cm−2. The energy density and power density of the asymmetric supercapacitor are up to 6.6 mW h cm−3 and 40.8 mW cm−3, respectively, indicating a fairly promising future of the flexible 3D‐Ni/Ni0.75Mn0.25O/C electrode for efficient energy storage applications.
Photophysics and Inverted Solvatochromism of 7,7,8,8‐Tetracyanoquinodimethane (TCNQ)
Authors: Tamaya Honami , Torii Yuto , Ishikawa Takumi , Nakano Hideyuki , Iimori Toshifumi
Published: September 2019

We report absorption, fluorescence, and Raman spectroscopy of 7,7,8,8‐tetracyanoquinodimethane (TCNQ) in a variety of solvents. The fluorescence quantum yields (QYs) of linear alkane solutions are similar to one another, but QY is shown to acutely decrease in other solvents with increasing polarities. The slope of the solvatochromic plot of absorption maxima is inverted from negative to positive with an increase in solvent polarity. A significant change in the frequency of carbon‐carbon double bond stretching modes is not observed in Raman spectra of TCNQ in different solvents. The molar absorption coefficient is determined to calculate the oscillator strength of the absorption band. The radiative decay rate constant calculated from the oscillator strength is approximately ten times larger than that elucidated from the fluorescence lifetime and QY. These spectroscopic parameters reveal that the relaxation occurs from a Franck‐Condon excited state to a distinct fluorescence emissive state with a smaller transition dipole moment.
Fully Recyclable Bio‐Based Thermoplastic Materials from Liquefied Wood
Authors: Ruiz M. Pilar , Mijnders Janine , Tweehuysen Rogier , Warnet Laurent , van Drongelen Martin , Kersten Sascha R. A. , Lange Jean‐Paul
Published: September 2019

A novel, low‐cost, and fully recyclable thermoplastic material is produced from liquefied lignocellulosic biomass and natural fibers. The matrix, which is the heavy fraction of the liquefaction product, is characterized in terms of molecular weight distribution, density, viscosity, softening point and tensile strength. It is possible to increase the mechanical strength of the matrix by a factor of up to 100 by reinforcing it with flax fibers. Specifically, the tensile strength increased from 0.4 MPa for the non‐reinforced matrix, to 55 MPa for the matrix/flax composite with a fiber content of 20 wt %. These values are comparable to conventional thermoplastics, such as poly(methyl methacrylate), polyvinyl chloride, or polystyrene.
A parasitic insensitive passive switched‐capacitor interpolation finite impulse response filter
Authors: Nakhi Amirreza , Jannesari Abumoslem
Published: September 2019

This paper proposes a passive switched‐capacitor (SC) interpolation finite impulse response (IFIR) filter designed with complementary metal‐oxide semiconductor (CMOS) 0.18‐μm technology. Comparing with previous works in analog and digital domain, this filter consumes less power and takes advantage of passive SC circuits, providing high bandwidth and linearity. In addition, offset variation, which is distinctly observed in preceding works, and alteration in the pole, caused by output parasitic capacitance, are no longer present in the proposed filters. Also, a 15‐tap IFIR filter with interpolation factor of 5 has been introduced in the paper, which is able to fully remove the effect of output parasitic capacitance. This filter, which is differentially designed, increases the sampling rate from 25 to 125 MHz and features P1dB and noise figure (NF) of −5 dBm and 20 dB, respectively. The result of process and temperature variation tests as well as Monte Carlo simulation performed for the circuit truly confirms the excellent performance of the filter. The highest image tone observed in the spectrum is below −57 dB, and the fixed pattern noise tone generated by charge injection, offset voltage, and its variation has been decreased to −65 dB. Moreover, the effect of clock feed through, capacitor mismatch, and clock phase mismatch as well as thorough and informative noise analysis has been presented for giving a better insight into nonidealities. This paper also analyzes the sensitivity of the position of notches to coefficient variation and enables optimization for reduced sensitivity.
Non‐paraxial theory of self‐focusing/defocusing of Hermite cosh Gaussian laser beam in rippled density plasmas
Authors: Pathak Nidhi , Kaur Manpreet , Kaur Sukhdeep , Gill T. S.
Published: September 2019

Present research work focuses on study of self‐focusing and self‐trapping of Hermite cosh Gaussian (HchG) laser beams in rippled density plasma by considering relativistic non‐linearity. The coupled non‐linear differential equations for the beam width parameters (for modes m = 0, 1, and 2) were derived by employing higher‐order correction in comparison to paraxial ray theory by expanding dielectric function and eikonal up to r4 terms. It is observed that the inclusion of higher‐order terms significantly influence the off‐axial properties for m ≥ 1 mode indices. Furthermore, the effect of parameters including beam intensity, ripple factor, depth of density modulation, and decentred parameter on self‐focusing and self‐trapping is analysed and discussed both analytically and numerically.
Self‐gravito‐acoustic waves and their instabilities in a self‐gravitating degenerate quantum plasma system
Authors: Mamun A. A.
Published: September 2019

A self‐gravitating degenerate quantum plasma (SGDQP) system containing degenerate electron and light nucleus species along with extremely low‐dense heavy‐nucleus species is considered. The existence of new degenerate pressure‐driven self‐gravito‐acoustic (DPDSGA) waves in this SGDQP system is found, and their dispersion properties along with stable and unstable parametric regimes are identified. The DPDSGA waves emit from this SGDQP system due to the compression and rarefaction (and vice‐versa) of the perturbed state of it. Its compression is due to the inward poll of degenerate electron and light nucleus species by the self‐gravitational attractive pressures, whereas its rarefaction is due to the outward degenerate pressures exerted by the degenerate electron and light nucleus species. The DPDSGA waves are new because they completely disappear if the electron and light nucleus degeneracies are neglected. The DPDSGA waves exist in the SGDQP system that occurs in astrophysical compact objects like white dwarfs [H. M. Van Horn, Science 252, 384 (1991); D. Koester, Astron. Astrophys. Rev. 11, 33 (2002)].
Odd clipping optical orthogonal frequency division multiplexing for VLC system
Authors: Ibrahim Asmaa , Ismail Tawfik , Elsayed Khaled , Darweesh M. Saeed
Published: September 2019

The Orthogonal Frequency Division Multiplexing (OFDM) has emerged as one of the promising techniques because of its robustness to multipath fading with high‐speed data transmission. Classical bipolar OFDM cannot be used in intensity modulated with direct detection (IM/DD) optical communication systems, as visible light communication (VLC), so many optical modulation techniques as asymmetrical clipped optical OFDM (ACO‐OFDM) and DC‐Clipped OFDM (DCO‐OFDM) have been investigated. In this paper, we introduce a novel optical modulation scheme that meets the optical communications requirements. The proposed odd clipping optical OFDM technique (OCO‐OFDM) is based on the Fourier transform symmetry properties in which the imaginary and odd signal is converted to odd and real valued signal. As a result of this work, the proposed OCO‐OFDM and its modified version have several benefits over ACO‐OFDM and DCO‐OFDM. By introducing a better bit error rate, with the same spectral efficiency as DCO‐OFDM and the same power efficiency as ACO‐OFDM for real valued modulation technique as Binary Phase‐Shift Keying (BPSK), and with the same spectral efficiency and power efficiency as ACO‐OFDM for complex valued modulation technique as Quadrature Phase‐Shift Keying (QPSK) and Eight Phase‐Shift Keying (8PSK).
Microfluidic capillary zone electrophoresis mass spectrometry analysis of alkaloids in Lobelia cardinalis transgenic and mutant plant cell cultures
Authors: Kelley Zachary D. , Rogers D. Trent , Littleton John M. , Lynn Bert C.
Published: September 2019

Application of a microfluidic CE* device for CZE‐MS allows for fast, rapid, and in‐depth analysis of large sample sets. This microfluidic CZE‐MS device, the 908 Devices ZipChip, involves minimal sample preparation and is ideal for small cation analytes, such as alkaloids. Here, we evaluated the microfluidic device for the analysis of alkaloids from Lobelia cardinalis hairy root cultures. Extracts from wild‐type, transgenic, and selected mutant plant cultures were analyzed and data batch processed using the mass spectral processing software MZmine2 and the statistical software Prism 8. In total 139 features were detected as baseline resolved peaks via the MZmine2 software optimized for the electrophoretic separations. Statistically significant differences in the relative abundance of the primary alkaloid lobinaline (C27H34N2), along with several putative “lobinaline‐like” molecules were observed utilizing this approach. Additionally, a method for performing both targeted and untargeted MS/MS experiments using the microfluidic device was developed and evaluated. Coupling data‐processing software with CZE‐MS data acquisition has enabled comprehensive metabolomic profiles from plant cell cultures to be constructed within a single working day.
Zeta potentials of PDMS surfaces modified with poly(ethylene glycol) by physisorption
Authors: Song Yongxin , Feng Angran , Liu Zhijian , Li Dongqing
Published: September 2019

Controlling zeta potential of PDMS surface coated with a layer of PEG is important for electroosmosis and electrophoresis in PDMS made microfluidic chips. Here, zeta potentials of PDMS surfaces modified by simple physisorption of PEG of different concentrations in phosphate buffer solutions, pure water, and PEG solution were reported. Coating PEG on PDMS surfaces was achieved by immersing a PDMS layer into the PEG solution for 10 min and then taking it out and placing it in an oven at 80℃ for 10 h. To avoid damaging the PEG layer on the PDMS surface, an induction current method was employed for zeta potential measurement. Zeta potentials of PEG modified PDMS in electrolyte solutions were measured. The results show that 2.5% PEG can effectively modify PDMS surface with positive zeta potential value in phosphate buffer solutions, pure water and 10% PEG solution. Further increase in PEG solution beyond 5% for surface modification has no obvious effect on zeta potential change.
An efficient approach to improving fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene composites via incorporating organo‐modified sepiolite
Authors: de Juan Sergio , Zhang Junhao , Acuña Pablo , Nie Shibin , Liu Zhiqi , Zhang Wen , Luisa Puertas María , Esteban‐Cubillo Antonio , Santarén Julio , Wang De‐Yi
Published: September 2019

In this work, an efficient approach to improving the fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene (PP) composites is developed via incorporating functionalized sepiolite (organo‐modified sepiolite [ONSep]). The PP composites with different amounts of intumescent flame retardants and ONSep were prepared by melt compounding. The morphology, thermal behavior, fire retardancy, smoke suppression, and mechanical property of flame‐retardant PP composites were studied. The results indicate an appropriate amount of ONSep in the flame‐retardant PP composites can increase thermal degradation temperature and char formation as well as a reduction of the peak heat release rate and total heat release; moreover, the addition of ONSep significantly decreases the CO production, total smoke production, smoke production rate, and smoke temperature. Simultaneously, the impact strength of intumescent flame‐retardant PP composite is also maintained by introducing an appropriate amount of ONSep as compared with that without ONSep.
Antimicrobial activity of flavonoids from Sedum aizoon L. against Aeromonas in culture medium and in frozen pork
Authors: Xu Feng , Cao Shifeng , Wang Chunxing , Wang Kaikai , Wei Yingying , Shao Xingfeng , Wang Hongfei
Published: September 2019

The chemical composition and antimicrobial activity of flavonoids from Sedum aizoon L. against Aeromonas in vitro were investigated, and the effect of flavonoid treatment on the quality of fresh pork during frozen storage for 6 months was also explored. The results showed that kaempferol, quercetin dihydrate, and catechin were the most predominant flavonoids from S. aizoon L. Flavonoids exhibited antibacterial activity to Aeromonas in vitro, which caused membrane damage, disruption of the bacterial surface, and internal ultrastructure, and resulted in the leakage of reducing sugars and proteins. Meanwhile, flavonoid treatment retarded the microbial growth and deteriorates of pork characteristics, including pH value, total volatile basic nitrogen (TVB‐N), texture, and sensory evaluation during frozen storage, thereby prolonged the shelf life. Their results suggested that flavonoids from S. aizoon L. offer a promising choice for food safety and preservation.
Effect of conditioner and moisture content on flowability of yellow cornmeal
Authors: Chinwan Dipanshu , Castell‐Perez M. Elena
Published: September 2019

Flow characterization of ground materials based on standard physical properties is not always accurate and must be complemented with other properties that help characterize their flowability. The flow properties of yellow cornmeal as a function of moisture content (10.0%, 13.5% 17.0%, and 20.0% wet basis) and concentrations of added conditioner (calcium stearate, a caking agent classified at GRAS, at 0.50%, 0.75%, and 1.00% wt/wt) were measured. The optimum flow behavior characteristics of the cornmeal were achieved at 0.50% wt/wt calcium stearate and 10.0% (w.b.) moisture content based on the flow function test. Overall, the material's flowability decreased with increased moisture content based on very high values for Hausner's ratio, Carr's Index, and angle of repose. The flow index (ffc) obtained by the flow function test decreased from 6.47 to 3.82 as moisture increased, indicating increased cohesivity. Calcium stearate increased the flowability of the material at 0.50% wt/wt, beyond which the flowability was not affected (p > .05). Samples were very hygroscopic and classified as Class IV. The Hausner's ratio, Carr's Index, and angle of repose showed a strong linear relationship with the flow index with correlation values of 0.91, 0.88, and 0.88, respectively. Isotherms together with physical properties should be used to determine the flow characteristics of granulated materials such as yellow cornmeal to establish the best storage and processing conditions.
Carbon capture induced changes in Deccan basalt: a mass‐balance approach
Authors: Kumar Amit , Shrivastava J. P.
Published: September 2019

Previous studies on the Deccan basalt–water–CO2 interaction were focused on numerical simulations and experimental validation that revealed carbonate formation, but restricted to low temperatures and for a shorter period. However, during prolonged interactions, silicates restricted carbonates from forming, and thus necessitated for comparative mass‐balance calculations of parent basalt, neo‐formed mineral and dissolution products to understand apposite parameters that control the reaction extent and optimal geochemical conditions. To examine these interactions, mass‐balance calculations have been attempted. A gradual increase in HCO3− concentration and basalt dissolution is concomitant with the increase in experimental run time; thus, the pH of the solution is affected. X‐ray diffraction and scanning electron microscope–energy dispersive X‐ray spectrometer analyses revealed the presence of carbonates in the post‐experiment residue (run for a shorter period). Owing to gradual carbonate decrease in the residue, Ca2+, Fe2+ and Mg2+ released from basalt gradually increased in the leachate at 100°C. But with the progression of time at 200°C, more secondary silicates were formed and incorporated Mg2+ and Si4+, which led to a decrease in Mg2+ and Si4+ concentrations in the leachate. Mass‐balance calculations revealed that the maximum amount of CO2 is mineralized (22.88 mol%) from the ions derived from the parent basalt at 100°C under 5 bar CO2 and 70 h of experiment running time. But, for longer periods of experiments, the rate of ionic interactions as well as CO2 mineralization is almost ceased. Thus, the rate of dissolution is affected by temperature, but the amount of CO2 mineralization is directly a function of the basalt–water–CO2 interaction time. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.
The effect of the Affordable Care Act preexisting conditions provision on marriage
Authors: Hampton Matt , Lenhart Otto
Published: September 2019

This paper investigates the effect of the Affordable Care Act preexisting conditions provision on marriage. The policy was implemented to prevent insurers from denying insurance coverage to individuals with preexisting health conditions. We test whether the implementation of the provision led to decreases in marriage among affected adults. We add to earlier work on how marital behavior is influenced by spousal health insurance and examine for the presence of “marriage lock,” a situation in which individuals remain married primarily for insurance. Using longitudinal data from the Panel Study of Income Dynamics from 2009 to 2017 and estimating difference‐in‐differences models, we find that male household heads with preexisting conditions are 7.12 percentage points (8.9 percent) less likely to be married after the policy. Using information on insurance status prior to the policy change, we find significant reductions in marriage among individuals with preexisting conditions who were previously insured by spousal health insurance plans. The findings suggest that the inability to attain individual coverage and reliance on spousal insurance provided incentives to remain married before 2014.