bluuebunny/crossref_metadata_2025_split huggingface dataset:
Keto‐Enol Tautomerization Controls the Acid‐Catalyzed Robinson Annulation ‐ A DFT Study
Authors: Yamabe Shinichi , Tsuchida Noriko , Yamazaki Shoko 
Published: May 2019

AbstractThree Robinson annulation reactions (A), (B) and (C) were investigated by DFT calculations. (A) is a base catalyzed one, where cyclohexanone, methyl vinyl ketone (MVK) and OH−(H2O)7 were employed as reactants. Eight elementary steps were obtained. The second transition state, TS2(A), is of the Michael addition prompted by the secondary orbital interaction, and TS5(A) is of the aldol condensation. The second TS of E1cB, TS8(A), has an appreciable activation energy, which would make the diketone A‐4 and ketol A‐7 detectable species. (B) is an acid catalyzed reaction, where 2‐methylcyclohexanone, MVK and H3O+(H2O)7 were adopted as reactants. Seven elementary steps were obtained. All the intermediates in B‐2 to B‐7 are neutral species (not protonated). The keto‐enol tautomerization assisted by the proton transfer is involved in all TSs. (C) is a neutral reaction, where 2‐methylcyclopentane‐1,3‐dione, 1‐chloro‐3‐pentanone and (H2O)8 were reactants. The first C−C bond formation is brought about by the nucleophilic substitution (SN2) where the leaving group is the chloride ion. The concomitantly generated H3O+ works as the acid catalyst to promote the subsequent processes. Again, the keto‐enol tautomerization is involved in all TSs.
Synthesis of Highly Active Pd Nanoparticles Supported Iron Oxide Catalyst for Selective Hydrogenation and Cross‐Coupling Reactions in Aqueous Medium
Authors: Shukla Astha , Singha Rajib K. , Sasaki Takehiko , Prasad Vemulapalli V. D. N. , Bal Rajaram 
Published: May 2019

AbstractPost synthetic approach was successfully employed for the synthesis of Pd supported iron oxide (Pd‐Fe2O3TA) catalyst using polyvinylpyrrolidone as capping agent and triethanolamine as reducing agent. Performance of Pd‐Fe2O3TA catalyst was investigated for selective hydrogenation of nitro compounds and Suzuki coupling reactions. Prepared catalyst exhibited excellent yield of corresponding substituted amines and biphenyls, under optimized reaction conditions. Different analytical techniques such as BET‐surface area measurements, XRD, ICP‐AES, SEM, TEM, XPS, TPR, FT‐IR, RAMAN, UV‐Vis and EXAFS analysis were employed to characterize the catalyst. Average particle size of palladium nanoparticles (NPs) was found to be ∼5.2 nm supported on 60–120 nm size of iron oxide nanocrystals. Various reaction parameters such as time, temperature, solvents, active metal loading, base and different substituent were investigated in detail. Different catalysts were also prepared and compared their activity with that of Pd‐Fe2O3TA catalyst. Experimental observations revealed that size of palladium NPs and metal‐support interaction favoured the superior activity of Pd‐Fe2O3TA catalyst compared to other catalysts. Stability of Pd‐Fe2O3TA catalyst was confirmed by its recyclability tests indicated true heterogeneous nature of catalyst.
Synthesis of Novel 3 a‐Substituted Tetrahydro‐1H‐1λ6‐pyrrolo[1,2‐b]isothiazole‐1,1,3(2H)‐triones through the CSIC Reaction
Authors: Omelian Taras V. , Dobrydnev Alexey V. , Ostapchuk Eugeniy N. , Volovenko Yulian M. 
Published: May 2019

AbstractWe report a strategy for the construction of tetrahydro‐1H‐1λ6‐pyrrolo[1,2‐b]isothiazole‐1,1,3(2H)‐triones bearing the substituents at the 5‐ and/or 3a‐positions. To this purpose, a range of 2‐substituted and 2,4‐disubstituted methyl 2‐pyrrolidinecarboxylates were sulfonylated with methanesulfonyl chloride and the resulting sulfonamides were subjected to sulfa‐Dieckmann condensation through the CSIC (Carbanion mediated Sulfonate (Sulfonamido) Intramolecular Cyclization) reaction to give the desired 1λ6‐isothiazolidine‐1,1,4‐triones. All the precursors, as well as target compounds, could be synthesized in a multigram scale following the general protocols.
One‐Step Interfacial Functionalization and Synthesis of Mo–Modified TiO2 Nanocrystalline as Composite PtRu Anode Catalyst Support for DMFCs
Authors: Li Jia‐Long , Zhao Lei , Li Xi‐Fei , Hao Su‐E , Wang Zhen‐Bo 
Published: May 2019

AbstractA one‐step approach of synthesis and interfacial functionalization of Mo to modify TiO2 nanocrystallines (iMTNCs) derived from tetrabutyl orthotitanate is proposed through mild alkaline and reductive hydrothermal reaction. Ultrafine crystallite sized TiO2 nanocrystallines (TNCs) with functionalized interface are obtained from the interfered synthesis process by hydrothermal etching and liquid phase infiltration of Mo dopants. The composite iMTNCs−C (incorporated with carbon black) is employed as the functionalized support for PtRu binary catalyst towards methanol electrooxidation. The resultant PtRu/iMTNCs−C catalyst manifests 1.68 times higher mass activity comparing to that of the un‐functionalized catalyst (PtRu/TNCs−C) and 1.44 times enhanced mass activity to PtRu/C catalyst with improved durability. These improvements in catalytic performance are attributed to the electronic donation from Mo functionalized interface of iMTNCs to PtRu nanoparticles (NPs) and ultrafine crystallite sized architecture of composite support. This work suggests a potential application of the functionalized nanocrystalline support material in fuel cell.
In Situ Synthesis of 3D Pt/CdS/ Hydrogenated BiOBr Microspheres with Enhanced Visible Light Photocatalytic Activity
Authors: Ye Jin , Fu Congcong , He Jiahui , Zhou Xuejian , Sun Yangyang , Liu Jiahui , Zhang Yue , Xu Lidong , Wang Juan , Yang Yongfang 
Published: May 2019

AbstractThe construction of heterojunction, the loading of noble metals and introduction of oxygen vacancies are an effective technology to enhance catalyst photocatalytic activity using solar energy. In this paper, 3D Pt/CdS/h‐BiOBr microspheres were successfully synthesized by the method of solvothermal and multiple depositions. Photocatalytic activity of all samples was investigated by degrading methylene blue (MB) under visible light. Among the catalysts, 3D Pt/CdS/h‐BiOBr sample has excellent photocatalytic activity due to improving its light harvesting and charge separation by establishment of heterostructure, which is 1.17, 1.67 and 3.39 times of h‐BiOBr/CdS, h‐BiOBr and BiOBr, respectively
Preparation and Characterization of Porous Carbon@ZnO‐NPs for Organic Compounds Removal: Classical Adsorption Versus Ultrasound Assisted Adsorption
Authors: Anfar Zakaria , Zbair Mohamed , Ahsaine Hassan Ait , Abdellaoui Youness , El Fakir Abdellah Ait , Amaterz El Hassan , Jada Amane , El Alem Noureddine 
Published: May 2019

AbstractIn this paper, the synthesis and characterization of porous carbon (PC) and porous carbon loaded ZnO nanoparticles (PC@ZnO) were investigated. The removal efficiency of Methylene Blue (MB) under ultrasound waves (UAA) and without ultrasound waves (SA) was studied considering the adsorbents dose, contact time, solution pH, temperature and initial dye concentration. Ultrasound irradiation have a positive effect on the removal efficiency of MB whereas ZnO nanoparticles incorporate in the surface of PC improve the regeneration efficiency of PC. PC@ZnO NPs shows high performance of MB removal using UAA, which was used for simultaneous removal of Crystal Violet (CV) and Congo Red (CR). The ultrasonic adsorption of CV/CR on PC@ZnO was found to be dependent on different parameters such as contact time, solution pH and initial dye concentration. The experimental results were found to follow the pseudo‐second‐order and Langmuir models. The adsorbed amount was found to be 64 mg g−1 (for CR) and 109 mg g−1 (for CV). Further, the effects of various parameters such as contact time, pH, initial dye concentration, and CV:CR ratio, were studied using central composite design coupled with response surface methodology. The data showed that the PC@ZnO has strong selective adsorption of CV dye in comparison to CR, and optimum conditions were found to be natural pH, 11.19 mg, (55:45%) of CV:CR ratio, 25 min and 30 mg L−1 at adsorption temperature T=25 °C ± 1. In these conditions, both dyes (CV and CR) are easily regenerated using HCl (0.1 M).
Vacancy‐Induced Synaptic Behavior in 2D WS2 Nanosheet–Based Memristor for Low‐Power Neuromorphic Computing
Authors: Yan Xiaobing , Zhao Qianlong , Chen Andy Paul , Zhao Jianhui , Zhou Zhenyu , Wang Jingjuan , Wang Hong , Zhang Lei , Li Xiaoyan , Xiao Zuoao , Wang Kaiyang , Qin Cuiya , Wang Gong , Pei Yifei , Li Hui , Ren Deliang , Chen Jingsheng , Liu Qi 
Published: May 2019

AbstractMemristors with nonvolatile memory characteristics have been expected to open a new era for neuromorphic computing and digital logic. However, existing memristor devices based on oxygen vacancy or metal‐ion conductive filament mechanisms generally have large operating currents, which are difficult to meet low‐power consumption requirements. Therefore, it is very necessary to develop new materials to realize memristor devices that are different from the mechanisms of oxygen vacancy or metal‐ion conductive filaments to realize low‐power operation. Herein, high‐performance and low‐power consumption memristors based on 2D WS2 with 2H phase are demonstrated, which show fast ON (OFF) switching times of 13 ns (14 ns), low program current of 1 µA in the ON state, and SET (RESET) energy reaching the level of femtojoules. Moreover, the memristor can mimic basic biological synaptic functions. Importantly, it is proposed that the generation of sulfur and tungsten vacancies and electron hopping between vacancies are dominantly responsible for the resistance switching performance. Density functional theory calculations show that the defect states formed by sulfur and tungsten vacancies are at deep levels, which prevent charge leakage and facilitate the realization of low‐power consumption for neuromorphic computing application.
Nachweis der Ermüdungsfestigkeit mittels Kerbdehnungskonzept
Authors: Ladinek Markus , Niederwanger Alexander , Timmers Ralph , Lang Robert , Osterhuber Dominik 
Published: May 2019

AbstractDer Nachweis der Ermüdungsfestigkeit wird im Stahlbau hauptsächlich mithilfe des Nennspannungskonzepts geführt, was nicht zuletzt auf die aktuelle Normenlage zurückzuführen ist. Ist die Definition von Nennspannungen aufgrund der Bauteilkomplexität nicht mehr möglich, kann im Rahmen der EN 1993‐1‐9 der Nachweis mittels der Methode der korrigierten Nennspannungen oder mit dem Strukturspannungskonzept geführt werden. Eine Aussage über das örtliche Plastifizieren ist damit nicht möglich, jedoch ist dieses Verhalten implizit erfasst. Das Kerbdehnungskonzept ermöglicht eine Nachweisführung basierend auf lokalen Dehnungen im gekerbten Bereich unter Berücksichtigung plastischer Effekte. Neuere Forschungs‐ und Normungsbemühungen scheinen diesem Bemessungsansatz mehr Aufmerksamkeit zu schenken. Es darf vermutet werden, dass dadurch das Kerbdehnungskonzept auch im deutschsprachigen Raum in Zukunft mehr Akzeptanz und eine breitere Anwendung in der Bemessungspraxis erfahren wird. Da dieses Konzept einige Besonderheiten aufweist, soll der vorliegende Beitrag eine erste Einführung für in der Praxis tätige Ingenieure darstellen.
Entwicklung einer praxisnahen Analyse zur Dämpfungsbestimmung von vorgespannten Seilen und Kabeln
Authors: Mack Thomas , Geier Roman , Strauss Alfred 
Published: May 2019

AbstractDie Erfassung der Dämpfung von vorgespannten Seilen und Kabeln führte aufgrund von Schwebungen und Superpositionen aller Schwingungsformen immer wieder zu kaum abgesicherten Ergebnissen. Über die letzten Jahrzehnte wurden die Methoden zur Dämpfungsermittlung verfeinert und mittels neuer Softwarepakete beschleunigt, aber die Reproduzierbarkeit der Ergebnisse für das jeweilige Bauteil oder das Gesamtsystem bei neuerlichen Messungen und Auswertungen wurde bisher nicht verfolgt. Im Zuge von Laborversuchen und zugehörigen Verifikationen wurde eine kombinierte Anwendung der bekannten Methoden mit der Nachweisführung durch die neue Reproduktionsmethode erarbeitet. Unabhängig von Messzeitpunkt, Ausschwingvorgang, Auswertepersonal etc. wird als Ergebnis ein Dämpfungskorridor anstatt einer einzelnen Dämpfungszahl bestimmt, in welchem sich je nach aktivierten Dämpfungsparametern im Zuge einer Anregung das Ausschwingen des Bauteils oder Gesamtsystems befindet. Mittels dieser neuen Methode können Dämpfungswerte verlässlich, nachvollziehbar, reproduzierbar und abgesichert für den Betreiber des Ingenieurbauwerks ermittelt werden. Im Zuge der Ermittlung der Eigenfrequenzen ist auch eine Erfassung der Kraft im jeweiligen Seil oder Kabel schnell und einfach kombinierbar.
Warum BIM (noch) nicht die erwartete Produktivitätssteigerung bringt
Authors: Zwielehner Thomas , Spreitzer Peter 
Published: May 2019

AbstractIn letzter Zeit werden Bauprojekte vermehrt mit Methoden des BIM (building information modeling) abgewickelt. Das Marketing der Softwarehersteller einerseits sowie die Initiativen zahlreicher Länder und sonstiger öffentlicher Institutionen andererseits führen dazu, dass bei neuen Projekten fast standardmäßig die Frage im Raum steht, ob diese mittels BIM abgewickelt werden sollen. Mancherorts wird BIM bei öffentlichen Aufträgen schon vorgeschrieben oder eine solche Verpflichtung steht unmittelbar bevor. Viele Pilotprojekte wurden bereits abgeschlossen, und auf die anfängliche Euphorie folgte die Ernüchterung. Oftmals brachte BIM nicht die gewünschten – fast schon versprochenen – Einsparungen oder Verbesserungen. Dieser Bericht zeigt, welche falschen Hoffnungen bei der Einführung von BIM eine Rolle spielen und warum diese nicht erfüllt werden können. BIM als Methode mit transparenten Prozessen, einer offenen Kommunikation und einer neuen Fehlerkultur steht im Gegensatz zur derzeitigen Arbeitsweise in der Baubranche. Es wird dargelegt, wie BIM auf technologischer Ebene grundsätzliche soziale und kulturelle Probleme in Bauprojekten lösen sollte und welche Grundvoraussetzungen für ein Gelingen zu schaffen sind.
An experimental study on the local buckling strength of an SBHS700 stub column with cruciform section
Authors: Nie Jing , Sugimoto Hikaru , Ono Kiyoshi , Miyashita Takeshi , Matsumura Masahide , Okada Seiji 
Published: May 2019

AbstractKurita‐Albrecht Young Engineers Award 2018 – SteelRecently, SBHS (Steels for Bridge High‐Performance Structure) has been introduced in Japan because of its remarkable mechanical properties. The main features of SBHS are high yield strength, improved toughness and weldability, which are superior to conventional steel materials at the corresponding tensile strength grades. In this study, these material properties of SBHS were compared with conventional steel materials through experimental studies as well as the Japanese design specifications. The main focus of this paper is the evaluation of the local buckling strength of two SBHS700 stub columns, each with cruciform section through compression tests. The load‐displacement relationship, strain bifurcation related to plate buckling and out‐of‐plane deformation are discussed. Two test specimens with different width‐to‐thickness ratio parameters RR are compared. As the results indicate, for the specimen having a larger RR, an abrupt decrease in load was observed after the peak load, whereas the decrease in load for the specimen with a smaller RR proceeded gradually after the peak load with a much larger vertical displacement. In terms of local buckling strength, it was found to be possible to evaluate the SBHS700 stub column with cruciform section based on the existing ultimate strength curves.
Failure analysis of a transmission tower subjected to combined wind and rainfall excitations
Authors: Fu Xing , Li Hong‐Nan , Wang Jia 
Published: May 2019

SummaryMany transmission towers have collapsed during severe gales and thunderstorms, and these failures have traditionally been attributed simply to wind loading. This study attempts to reveal the full failure mechanism of tower structures under strong wind excitation considering the rainfall effect. First, the calculation of rain load for a tower‐line system is provided. Then, an uncertainty analytical method for estimating the strength capacity and predicting the failure pattern of transmission towers induced by wind and rain loads is presented. Next, a real collapsed transmission line is considered to establish the finite element model, followed by the determination of the most vulnerable tower, which is then used to perform the uncertainty analysis. The results illustrate that the collapse basic wind speed considering the rainfall effect is smaller than the pure wind condition. In addition, the failure probability of the tower body is the largest, which is consistent with the deterministic method, whereas the most vulnerable tower began to fail from the tower leg in reality, indicating that the initial broken position of the transmission tower may not occur in the location with the largest probability and that the deterministic method is invalid in some cases. Finally, the influence of the wind attack angle and bundle number of transmission conductor is investigated. The most unfavorable wind attack angle is 90°, and the rainfall effect becomes increasingly significant with increases in the bundle number; this relationship should be given particular attention.
Fisetin activates Hippo pathway and JNK/ERK/AP‐1 signaling to inhibit proliferation and induce apoptosis of human osteosarcoma cells via ZAK overexpression
Authors: Fu Chien‐Yao , Chen Mei‐Chih , Tseng Yan‐Shen , Chen Ming‐Cheng , Zhou Zhengtao , Yang Jaw‐Ji , Lin Yueh‐Min , Viswanadha Vijaya P. , Wang Guiqing , Huang Chih‐Yang 
Published: May 2019

AbstractOsteosarcoma (OS) is a tumor entity that can cause a large number of cancer‐related deaths. Although chemotherapy can decrease proliferation and increase apoptosis of human OS cells, the clinical prognosis remains poor. Fisetin is a flavonol found in fruits and vegetables and is reported to inhibit cell growth in numerous cancers. But the molecular mechanism underlying fisetin in human OS cells is not clear. It is known that sterile‐alpha motif and leucine zipper containing kinase (ZAK), a kinase in the MAP3K family, is involved in various cell processes, including proliferation and apoptosis. In our lab, we have demonstrated that overexpression of ZAK can induce apoptosis in human OS cells. In the previous studies, MAP4K, the upstream of MAP3K, can act in parallel to MST1/2 to activate LATS1/2 in the Hippo pathway. Turning on the Hippo pathway can decrease proliferation and otherwise cause cell apoptosis in cancer cells. In this study, we found that fisetin can upregulate ZAK expression to induce the Hippo pathway and mediate the activation of JNK/ERK, the downstream of ZAK, to trigger cell apoptosis via AP‐1 dependent manner in human OS cells. These findings reveal a novel molecular mechanism underlying fisetin effect on human OS cells.
Evaluation of full‐field energy dispersive X‐ray fluorescence imaging apparatus and super resolution analysis with compressed sensing technique
Authors: Yamauchi Aoi , Iwasaki Masanori , Hayashi Kazunori , Tsuji Kouichi 
Published: May 2019

A full‐field energy dispersive X‐ray fluorescence (FF‐EDXRF) imaging spectrometer that utilizes single‐photon counting analysis with a charge‐coupled device was developed in our laboratory.We evaluated the developed spectrometer with respect to its energy resolution, spatial resolution, quantitative performance, and elemental imaging and compared it with the corresponding characteristics of scanning‐type EDXRF spectrometers. In addition, we demonstrate that the limit of detection and sensitivity deteriorate as the analytical area decreases. Finally, compressed sensing, which is a widely used information‐processing technique, was applied for clearing XRF images.
Residual contagion in emerging markets: ‘herd’ and ‘alarm’ effects in informatization
Authors: Fang Min , Yang Shenggang , Lei Yuliang 
Published: May 2019

AbstractThe present study investigates residual contagion of the recent two international crises under the dual functions of “herd effect” and “alarm effects in informatization, focusing on emerging markets. Both the impulse response method and dynamic conditional correlation MGARCH model are used to capture residual contagion from developed markets to emerging markets during the period 2000–2016. The results show that the level of volatility in emerging stock markets was greater than that of developed markets, such as the US and the EU, although they are less integrated with the world. Emerging stock markets are significantly subjected to residual contagion during the US subprime mortgage crisis and Europe’s protracted debt crisis. Moreover, the residual contagion effects of these two crises are noticeably heterogeneous in emerging markets.
Associations between rare microglia‐linked Alzheimer's disease risk variants and subcortical brain volumes in young individuals
Authors: Lancaster Thomas M. 
Published: May 2019

AbstractIntroductionRecent exome sequencing studies have identified three novel risk variants associated with Alzheimer's disease (AD). However, the mechanisms by which these variants confer risk are largely unknown.MethodsIn the present study, the impact of these rare coding variants (in ABI3, PLCG2, and TREM2) on all subcortical volumes is determined in a large sample of young healthy individuals (N = 756–765; aged 22–35 years).ResultsAfter multiple testing correction (PCORRECTED < .05), rare variants were associated with basal ganglia volumes (TREM2 and PLCG2 effects within the putamen and pallidum, respectively). Nominal associations between TREM2 and reduced hippocampal and thalamic volumes were also observed.DiscussionOur observations suggest that rare variants in microglia‐mediated immunity pathway may contribute to the subcortical alterations observed in AD cases. These observations provide further evidence that genetic risk for AD may influence the volume of subcortical volumes and increase AD risk in early life processes.
Living with decade-old vulnerabilities in datacentre software
Authors: Goldberg Daniel 
Published: May 2019

The underlying assumption that system software is secure by design has proven wrong many times over the past few years. A modern approach to network design requires a new basis – ‘assume vulnerable’. As all defence is inherently a risk management process this assumption requires different methods of quantifying network security, performing changes and monitoring. The assumption that system software is secure by design has been proven wrong many times and a better approach to network design is – ‘assume vulnerable’. As all defence is inherently a risk management process, this assumption requires different methods of quantifying network security, performing changes and monitoring. It is reasonable to assume that there are numerous vulnerabilities across different core system programs and libraries, explains Daniel Goldberg of Guardicore.