bluuebunny/crossref_metadata_2025_split huggingface dataset:
Semiconductor Nanocrystal Engineering by Applying Thiol‐ and Solvent‐Coordinated Cation Exchange Kinetics
Authors: Bai Bing , Xu Meng , Li Nan , Chen Wenxing , Liu Jiajia , Liu Jia , Rong Hongpan , Fenske Dieter , Zhang Jiatao 
Published: September 2018

AbstractThiol‐ and solvent‐coordinated cation exchange kinetics have been applied to engineer the composition and crystallinity of novel nanocrystals. The detailed thermodynamics and kinetics of the reactions were explored by NMR spectroscopy, time‐dependent photoluminescence (PL) characterizations and theoretical simulations. The fine structure of the colloidal semiconductor nanocrystals (CSNCs) was investigated by X‐ray absorption near‐edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS). In this way, high‐quality p‐type Ag‐doped ZnS quantum dots (QDs) and Au@ZnS hetero‐nanocrystals with a cubic phase ZnS shell were synthesized successfully.The unprecedented dominant Ag+‐dopant‐induced fluorescence and p‐type conductivity in the zinc‐blende ZnS are reported.
Ultrastabilisierung von Zeolith Y wandelt Brønsted‐Brønsted‐Säurepaare in Brønsted‐Lewis‐Säurepaare um
Authors: Schroeder Christian , Hansen Michael Ryan , Koller Hubert 
Published: September 2018

AbstractIn den Super‐ und den Sodalith‐Käfigen von Zeolith H,Na‐Y wurde jeweils ein Paar von Brønsted‐Säurezentren identifiziert, die durch Ultrastabilisierung (Dealuminierung) in Paare von Brønsted‐ und Lewis‐Säurezentren umgewandelt wurden. Diese milde postsynthetische Behandlung ist ein wichtiger Prozess, um den Katalysator für industrielle Anwendungen zu optimieren. Die Paare wurden mithilfe von 1H‐Doppelquanten‐NMR‐Experimenten am dehydratisierten Zeolithen H,Na‐Y und dessen ultrastabilisierter Form H,Na‐USY untersucht. Diese Methode ermöglicht den Nachweis von Brønsted‐ und Lewis‐Säurepaaren und deren Unterscheidung von isolierten Säurezentren mit bisher unerreichter Auflösung. Die Dealuminierung wurde außerdem durch statische 27Al‐Festkörper‐NMR‐Experimente beobachtet.
Structural Elucidation of Trace Components Combining GC/MS, GC/IR, DFT‐Calculation and Synthesis—Salinilactones, Unprecedented Bicyclic Lactones from Salinispora Bacteria
Authors: Schlawis Christian , Kern Simone , Kudo Yuta , Grunenberg Jörg , Moore Bradley S. , Schulz Stefan 
Published: September 2018

AbstractThe analysis of volatiles released by marine Salinispora bacteria uncovered a new class of natural compounds displaying an unusual bicyclic [3.1.0]‐lactone skeleton. Although only sub‐μg quantities of the compounds were available, the combination of analytical methods, computational spectroscopy, and synthesis allowed unambiguous structural identification of the compounds, called salinilactones, without the need for isolation. Orthogonal hyphenated methods, GC/MS and solid‐phase GC/IR allowed to propose a small set of structures consistent with the data. A candidate structure was selected by comparison of DFT‐calculated IR spectra and the experimental IR‐spectrum. Synthesis confirmed the structure and absolute configuration of three bicyclic lactones, salinilactones A–C. The salinilactones are structurally closely related to the A‐factor class of compounds, autoregulators from streptomycete bacteria. They exhibited inhibitory activity against Salinispora and Streptomyces strains.
Photoinduced Palladium‐Catalyzed Negishi Cross‐Couplings Enabled by the Visible‐Light Absorption of Palladium–Zinc Complexes
Authors: Abdiaj Irini , Huck Lena , Mateo José Miguel , de la Hoz Antonio , Gomez M. Victoria , Díaz‐Ortiz Angel , Alcázar Jesús 
Published: September 2018

AbstractA visible‐light‐induced Negishi cross‐coupling is enabled by the activation of a Pd0–Zn complex. With this photocatalytic method, the scope of deactivated aryl halides that can be employed in the Negishi coupling was significantly expanded. NMR experiments conducted in the presence and absence of light confirmed that the formation of the palladium–zinc complex is key for accelerating the oxidative addition step.
Physiochemical characterization and support interaction of alumina‐supported heteropolyacid catalyst for biodiesel production
Authors: Kurhade Ankeeta , Dalai Ajay K. 
Published: September 2018

Abstract12‐Tungstophosphoric acid (TPA)‐supported γ‐Al2O3 catalysts were synthesized with varying TPA loadings. Catalysts characteristics were determined using Brunauer–Emmett–Teller surface area analysis, thermogravimetric analyses, X‐ray diffraction, Raman, pyridine‐adsorbed Fourier‐transform infrared spectroscopy, and 13C hpdec (high‐power 1H decoupling) nuclear magnetic resonance, whereas surface morphology was studied using scanning electron microscope and transmission electron microscopy analyses. Surface defects were found in the catalyst with higher TPA loadings (55–65 wt.%). The presence of WOx was observed at higher loadings and later agglomerated into tungsten oxide crystals. The TPA impregnated catalysts were investigated for biodiesel synthesis from canola oil. The reaction was found to be independent of mass transfer limitation. The activation energy was 33.6 kJ mol−1, and pre‐exponential factor was 7.3*10−2 min−1. The turnover frequency for the supported catalysts was found in the range of 9.7*10−4–8.8*10−2 min−1. A conversion of 94.9 ± 2.3% was obtained under the optimized conditions, that is, 10 wt.% of the catalyst loading, 17.5 methanol to oil molar ratio, 4 MPa, and at 200°C in 10 hr.
A simple one‐step drop‐coating approach on fabrication of supported carbon molecular sieve membranes with high gas separation performance
Authors: Wu Yonghong , Wang Fei , Zhang Bing , Zhao Dandan , Wang Tonghua , Qiu Jieshan 
Published: September 2018

AbstractSupported carbon molecular sieve membranes (CMSMs) were fabricated from polyimide, via coating, drying, and pyrolysis. Thermogravimetric analysis, X‐ray diffraction, and scanning electron microscope were used to characterize the thermal stability of precursor, microstructure, and morphology of CMSMs, respectively. The influences of coating droplets, pyrolysis temperature, permeation temperature, and pressure on the gas permeation of CMSMs were investigated. Results show that high‐performance CMSMs can be easily obtained by one‐step drop‐coating. Coating with more droplets brings about more amorphous microstructure and higher gas permeability of CMSMs. The gas permeability of CMSMs increases with elevating permeation temperature or reducing pyrolysis temperature. The as‐prepared CMSMs can enrich the molar composition of oxygen to 66% from the compressed air by single one time.
A novel approach for synthesis of poly(norbornene)‐co‐poly(styrene) block copolymers via metathesis polymerization and free‐radical polymerization
Authors: Miao Pengcheng , Lin Shaohui , Rempel Garry L. , Pan Qinmin 
Published: September 2018

AbstractIt is successfully realized that block copolymers are synthesized via metathesis polymerization followed by free‐radical polymerization. This method is performed using styrene (St) and norbornene, one block is synthesized using the Grubbs second generation catalyst in the presence of chain transfer agents, and the subsequent polymerization of St is initiated by azo compounds to complete the additional blocks in the copolymers. The use of free‐radical polymerization instead of controlled radical polymerization or ionic polymerization can be potentially superior for industrialization. As a result, the molecular weights of the block copolymers ranging from 10.4 to 54.3 kDa and polydispersity indices ranging from 1.30 to 1.91 are obtained. In principle, this new method can be potentially useful to prepare a broad range of block copolymers with cyclic olefin groups in the main chains, which may be used in some particular applications.
Curcumin incorporated PVA‐borax dual delivery hydrogels as potential wound dressing materials—Correlation between viscoelastic properties and curcumin release rate
Authors: Rezvan Gelareh , Pircheraghi Gholamreza , Bagheri Reza 
Published: September 2018

ABSTRACTPoly(vinyl alcohol) (PVA) is a biocompatible polymer which can be physically crosslinked by Borax to form hydrogel. PVA‐Borax (PB) hydrogel is a promising candidate for drug delivery system. Therefore, it is necessary to find the quantitative relationship between drug release rate and network structure of PB hydrogels to predict and control drug release rate. In this work, at first step the optimum ratio of Borax: PVA was determined by studying the interactions between PVA chains and Borax molecules by means of Fourier transform infrared spectroscopy, while viscoelastic properties of prepared PB hydrogels were measured in the oscillatory shear flow field. In the following, curcumin as a hydrophobic drug was encapsulated in Pluronic F127 micelles and then these nano carriers (Cur‐P) were loaded into prepared hydrogels. The curcumin release rate in PBS solution was investigated by UV–vis spectroscopy measurements. The strong power law correlation between curcumin release rate and viscoelastic properties of PB hydrogel was confirmed. This drug delivery vehicle can be used as a competent wound dress. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46734.
Bromomethylated poly(phenylene oxide) (BPPO)‐assisted fabrication of UiO‐66‐NH2/BPPO/polyethersulfone mixed matrix membrane for enhanced gas separation
Authors: Jia Mingmin , Feng Yi , Qiu Jianhao , Lin Xiaocheng , Yao Jianfeng 
Published: September 2018

ABSTRACTUiO‐66‐NH2nanocrystals were synthesized and embedded into bromomethylated poly(phenylene oxide)/polyethersulfone (BPPO/PES) polymer matrix to form UiO‐66‐NH2/BPPO/PES mixed matrix membranes (MMMs). The crystalline structure, interaction between UiO‐66‐NH2and BPPO, and dispersion of UiO‐66‐NH2were characterized by FTIR, XRD, and SEM. Nanoparticle dispersion was drastically enhanced with the assistance of BPPO, giving an improved adhesion between the polymer and filler particles. Owing to the intrinsic adsorption property of UiO‐66‐NH2and BPPO to CO2, the CO2permeability was significantly increased. As a result, the UiO‐66‐NH2/BPPO/PES membrane exhibited enhanced gas separation performance, where CO2/N2and H2/N2ideal selectivities were increased to 50.2 and 302.4 with a CO2permeability of 125.6 Barrer. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46759.
Preparation and characterization of shape memory composite foams based on solid foaming method
Authors: Yao Y. , Zhou T. , Xu Y. , Liu Y. , Leng J. 
Published: September 2018

ABSTRACTAs we know, shape‐memory foams with porous feature are better suited for a certain application compared with their solid counterparts, especially in tissue engineering, drug delivery, filtration, etc. In this study, a type of biocompatible composite foam with shape‐memory property has been developed on the basis of biocompatible materials cross‐linked poly(ε‐caprolactone) (PCL) and silk fibrin (SF). Solid‐state foaming method was used to fabricate the composite shape‐memory foam. Hierarchical cellular foam with micropore on the cellular wall was observed. To optimize pore morphology, the relationship between cross‐linking agent content/reinforcement filler content and PCL matrix was investigated. Excellent shape‐recovery property (>97.6%) and shape‐fixing property (>98%) have been achieved for PCL foam. For composite foams, SF addition is not too much effective on their shape‐memory property by varying SF content. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46767.
Comparison of ethyl cellulose–gelatin composite films fabricated by electrospinning versus solvent casting
Authors: Liu Yuyu , Deng Lingli , Zhang Cen , Chen Kailun , Feng Fengqin , Zhang Hui 
Published: September 2018

ABSTRACTIn this study, we fabricated ethyl cellulose (EC)–gelatin (G) composite films by solvent casting and electrospinning. The characterization of the cast and electrospun films was performed by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, X‐ray diffraction, Fourier transform infrared spectroscopy, X‐ray photoelectron spectrometry, and water contact angle measurements. The results showed that the blending of EC with G improved the spinnability of the composite films with higher thermal stability. Compared with solvent casting, electrospinning induced a helix‐to‐coil transition of G and provided more hydrogen‐forming sites for EC to form a compatible network. Interestingly, the electrospun composite film had a hydrophobic surface with a water contact angle of 113.8°, whereas the cast composite film showed a hydrophilic surface at 67.5°. The confocal laser scanning microscopy observations suggested that after water immersion, the cast composite film collapsed into aggregates, whereas the electrospun composite film maintained the nanofibrous structures well; this indicated an improved water resistance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46824.
Dynamic relaxations in a bio‐based polyamide with enhanced mechanical modulus
Authors: Haddou G. , Roggero A. , Dandurand J. , Dantras E. , Ponteins P. , Lacabanne C. 
Published: September 2018

ABSTRACTA new grade of bio‐based polyamide (PA)—PA meta‐xylylene diamine 10 (PA mXD 10)—was investigated. Its first interest is that it permits mild processing conditions at about 200 °C. The calorimetric study shows the existence of two cold crystallizations indicative of slow crystallization rate. The glass transition stabilizes at 55 °C. By combining calorimetry with dynamic mechanical analysis and dynamic dielectric spectroscopy, we found a perfect consistency between the set of data giving the molecular mobility. The localized relaxations follow Arrhenius equations while the viscoelastic transition follows a Vogel–Fulcher–Tammann law. The compilation of all the relaxation times determined by means of the different analyses highlights a good correlation. This result is perfectly explained by the polarity of the macromolecular chain. The dynamic mechanical behavior showed a storage modulus higher than for the corresponding aliphatic PA and nearly constant until room temperature. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46846.
Controlled‐release fertilizer based on poly(butylene succinate)/urea/clay and its effect on lettuce growth
Authors: Baldanza V. A. R. , Souza F. G. , Filho S. T. , Franco H. A. , Oliveira G. E. , Caetano R. M. J. , Hernandez J. A. R. , Ferreira Leite S. G. , Furtado Sousa A. M. , Nazareth Silva A. L. 
Published: September 2018

ABSTRACTControlled‐release fertilizer is one of the most critical tools in agribusiness for decreasing environmental impacts. Thus, the development of bio‐based systems able to induce the slow release of fertilizers has become the focus of numerous researchers. In this sense, this work presents a slow‐release fertilizer prepared by melt mixing of poly(butylene succinate) filled with 30 wt % urea and 5 wt % montmorillonite clay. The obtained materials were characterized using FTIR, XRD, and SAXS. Also, the release of urea was investigated using gravimetric and spectrophotometric tests. Finally, a vegetable growth analysis was performed to evaluate the development of lettuce (Lactuca sativa L.). The best composite material can increase the diameter of the lettuce by 67%, whereas the conventional use of urea increased this diameter by 48%. Therefore, the presented materials are useful as fertilizer systems.
Sodium humate modified superabsorbent resin with higher salt‐tolerating and moisture‐resisting capacities
Authors: Guan H.L. , Yong D.L. , Fan M.X. , Yu X.L. , Wang Z. , Liu J.J. , Li J.B. 
Published: September 2018

ABSTRACTThe superabsorbent resin (SAR) containing sodium humate (SH) has been synthesized by free‐radical graft copolymerization with acrylic acid, 2‐acrylamido‐2‐methylpropane sulfonic acid, and SH as monomers in aqueous solution, using N,N′‐methylenebisacrylamide as crosslinking reagent and potassium persulfate as initiator. The structure and morphology of the as‐prepared SARs were fully characterized by Fourier transform infrared , scanning electron microscopy and thermogravimetric analysis, respectively. Meanwhile, the effects of crosslinking reagent, initiator, SH, and neutralization degree on the water absorbency of SAR were studied. The results showed that the adding of SH in the SAR enhanced the salt‐tolerating and moisture‐resisting capacities obviously. The SAR without SH [poly(acrylic acid) (PAA)/2‐acrylamido‐2‐methyl‐1‐propanesulfonic (AMPS)] showed a maximum water absorbency of 600 g g−1 in distilled water and 60 g g−1 in 0.9 wt % NaCl solution, while SAR modified by SH (PAA/AMPS/SH) exhibited the maximum water absorbency of 1380 g g−1 in distilled water and 117 g g−1 in 0.9 wt % NaCl solution. Furthermore, the moisture‐resisting capacity of PAA/AMPS/SH decreases to 8 wt % compared with PAA/AMPS. PAA/AMPS/SH also has better water absorbency in different cation solutions. The results indicated that the introduction of SH could enhance the performance of SAR obviously. The possible reasons with this enhancement were also investigated. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46892.
Relationship between the passivation of TiO2particles and LLDPE photodegradation: a comparison between bulk and surface impacts
Authors: Castillo‐Reyes Blanca E. , Quiñones‐Jurado Zoe V. , Catarino‐Centeno R. , López‐Jiménez J. Roberto , Pérez Elías 
Published: September 2018

ABSTRACTThe effect of the concentration of alumina (Al2O3) and silica (SiO2) used to passivate titanium dioxide (TiO2) particles on the photodegradation of plastic films containing these particles was investigated. The films were made of linear low‐density polyethylene (LLDPE) containing four different types of passivated TiO2particles. The UV degradation of the films was evaluated for the surface and the bulk by measuring the physical and chemical changes as a function of time. The surface chemical and physical degradation effects were measured by ATR‐FTIR and AFM, respectively. A statistical Gaussian adjustment was proposed to correlate the AFM depth profiles of the eroded surfaces of the films after the photodegradation process. The bulk physical effect was evidenced by the loss of mechanical properties in the films. The results showed that the higher the concentrations of Al2O3are, the better the inhibition of the photodegradation of the LLDPE films. In this study, it was confirmed that the observed UV degradation effect correlated at both the surface and bulk levels. The results showed not only the reduction of the photodegradative effect as the passivation of the TiO2particles increased but also the possibility of using these particles as UV stabilizers of LLDPE films. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47026.
Searching for (data on) Cracow astroplates
Authors: Kundera T. , Kuligowska E. , Stachowski G. , Bajan K. 
Published: September 2018

We briefly describe the issues and problems related to gathering our astronomical plates in one place – and preserving them. For a variety of reasons, they have not been properly preserved or stored in the past, which led to significant damages and losses. The general condition of the plates is discussed here, together with our most recent findings and future plans to use them for science.
Toe Walking Assessment in Autism Spectrum Disorder Subjects: A Systematic Review
Authors: Valagussa Giulio , Trentin Luca , Signori Alessio , Grossi Enzo 
Published: September 2018

There is increasing evidence that autism spectrum disorder (ASD) subjects have also motor impairments. Toe walking (TW) is a phenomenon that can be found in ASD subjects during gait, even if this condition was found not to be necessarily related only to walking, since these children often also stand and run on their tiptoes. Since persistent TW in ASD subjects may contribute to secondary shortening of the Achilles's tendon, it becomes important to have an assessment tool and/or outcome measure for both the clinical and rehabilitative settings. The aim of this systematic review is to critically evaluate and describe the methods employed to assess toe walking in ASD subjects. The systematic review protocol was previously registered on PROSPERO. We conducted an extensive literature search in PubMed, CINAHL, PsycINFO, The Cochrane Library, and Scopus databases. There were no restrictions on the types of study design eligible for inclusion. Ten studies were included in the systematic review. Risk of bias of the included studies was conducted using the following instruments depending on the study types: STROBE Statement, Cochrane risk of bias tool, and CARE checklist. Almost all the included studies (8/10) proposed a tip‐toe behavior (TTB) assessment only during walking. Nine out of ten of the included studies assessed TTB using a qualitative methodology. The results evidenced the heterogeneity of qualitative methods and a lack of a structured quantitative test to assess toe walking in ASD subjects. Autism Res 2018, 11: 1404–1415. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.Lay AbstractToe walking (TW) is a phenomenon that can be found during ASD subject's gait. The persistence of this behavior may contribute to secondary Achilles's tendon shortening. In this perspective it becomes important to have an assessment tool and/or outcome measure for both the clinical and rehabilitative settings. The current systematic review aimed to describe the methods employed to assess TW. The results evidenced the lack and the need of a structured quantitative test to assess TW in ASD subjects.
Statische und dynamische Reibwertermittlung an geschliffenen Segmentfugen
Authors: Hartwig Steffen , Marx Steffen , Betz Thorsten 
Published: September 2018

AbstractDie Entwicklung der Türme von Windenergieanlagen (WEA) hat eine Vielzahl von Konstruktionen hervorgebracht und bereits bestehende Konstruktionsarten wurden stetig weiterentwickelt. Eine dieser Konstruktionen ist die Segmentbauweise, welche sich aufgrund der großen Anzahl an vorgefertigten Bauteilen für den Turmbau besonders gut eignet. Von besonderer Bedeutung bei dieser Konstruktion sind die entstehenden Segmentfugen, welche bereits im Brückenbau vielfach untersucht wurden. Als großer Unterschied zum Brückenbau werden die Segmente jedoch nicht mit Schubverzahnungen ausgeführt, sondern größtenteils als geschliffene Trockenfugen ausgebildet. Bei einer Vorspannung der Türme mit einer externen Vorspannung erfolgt die Kraftübertragung in den Segmentfugen somit ausschließlich über Reibung. Die in der Vergangenheit durchgeführten Untersuchungen von solchen „sehr glatten“ Fugen wurden i. d. R. an glatt geschalten Oberflächen und nicht an geschliffenen Proben durchgeführt. Es ist daher fraglich, inwieweit die derzeitigen Normenwerte zu der Konstruktionsart der geschliffenen Segmentfugen passen. Weiter handelt es sich bei den Türmen von WEA um hochdynamisch beanspruchte Konstruktionen. Somit gilt es zu klären, ob der i. d. R. statisch ermittelte Reibbeiwert über die Dauer der dynamischen Lasten Bestand hat. Die Ergebnisse der durchgeführten statischen als auch dynamischen Versuche zur Ermittlung des Reibbeiwerts werden ausgewertet und diskutiert.