bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Inherently Chiral Au24 Framework with Double‐Helical Hexagold Strands
Authors: Sugiuchi Mizuho , Shichibu Yukatsu , Konishi Katsuaki 
Published: May 2018

Abstract2,3‐bis(diphenylphosphino)butane enantiomers (chiraphos, L) used as chiral auxiliaries results in the preferential formation of an unprecedented Au24 framework with inherent chirality. The crystal structure of [Au24L6Cl4]2+ (1) has a square antiprism‐like octagold core twinned by two helicene‐like hexagold motifs, where the inherent chirality is associated with the helical arrangement. The clusters carrying (R,R)‐ and (S,S)‐ diphosphines had right‐ and left‐handed strands, respectively. Circular dichroism spectra showed peaks in the visible to near‐IR region, some of which did not coincide with absorption bands, suggesting the enantiomeric Au24 frameworks possess unique chiroptical properties. The Au24 frameworks were thermally robust, which could be attributed to the superatomic concept (18 e− system) and the steric constraint effects of the bridging ligand units.
MOF‐Derived Hollow CoS Decorated with CeOx Nanoparticles for Boosting Oxygen Evolution Reaction Electrocatalysis
Authors: Xu Huajie , Cao Jing , Shan Changfu , Wang Bingkai , Xi Pinxian , Liu Weisheng , Tang Yu 
Published: May 2018

AbstractTransition‐metal sulfides (TMSs) have emerged as important candidates for oxygen evolution reaction (OER) electrocatalysts. Now a hybrid nanostructure has been decorated with CeOx nanoparticles on the surface of ZIF‐67‐derived hollow CoS through in situ generation. Proper control of the amount of CeOx on the surface of CoS can achieve precise tuning of Co2+/Co3+ ratio, especially for the induced defects, further boosting the OER activity. Meanwhile, the formation of protective CeOx thin layer effectively inhibits the corrosion by losing cobalt ion species from the active surface into the solution. It is thus a rare example of a hybrid hetero‐structural electrocatalyst with CeOx NPs to improve the performance of the hollow TMS nanocage.
Controlled Expansion of a Strong‐Field Iron Nitride Cluster: Multi‐Site Ligand Substitution as a Strategy for Activating Interstitial Nitride Nucleophilicity
Authors: Drance Myles J. , Mokhtarzadeh Charles C. , Melaimi Mohand , Agnew Douglas W. , Moore Curtis E. , Rheingold Arnold L. , Figueroa Joshua S. 
Published: May 2018

AbstractMultimetallic clusters have long been investigated as molecular surrogates for reactive sites on metal surfaces. In the case of the μ4‐nitrido cluster [Fe4(μ4‐N)(CO)12]−, this analogy is limited owing to the electron‐withdrawing effect of carbonyl ligands on the iron nitride core. Described here is the synthesis and reactivity of [Fe4(μ4‐N)(CO)8(CNArMes2)4]−, an electron‐rich analogue of [Fe4(μ4‐N)(CO)12]−, where the interstitial nitride displays significant nucleophilicity. This characteristic enables rational expansion with main‐group and transition‐metal centers to yield unsaturated sites. The resulting clusters display surface‐like reactivity through coordination‐sphere‐dependent atom rearrangement and metal–metal cooperativity.
Controlling the Self‐Metalation Rate of Tetraphenylporphyrins on Cu(111) via Cyano Functionalization
Authors: Lepper Michael , Köbl Julia , Zhang Liang , Meusel Manuel , Hölzel Helen , Lungerich Dominik , Jux Norbert , de Siervo Abner , Meyer Bernd , Steinrück Hans‐Peter , Marbach Hubertus 
Published: May 2018

AbstractThe reaction rate of the self‐metalation of free‐base tetraphenylporphyrins (TPPs) on Cu(111) increases with the number of cyano groups (n=0, 1, 2, 4) attached at the para positions of the phenyl rings. The findings are based on isothermal scanning tunneling microscopy (STM) measurements. At room temperature, all investigated free‐base TPP derivatives adsorb as individual molecules and are aligned with respect to densely packed Cu substrate rows. Annealing at 400 K leads to the formation of linear dimers and/or multimers via CN‐Cu‐CN bonds, accompanied by self‐metalation of the free‐base porphyrins following a first‐order rate equation. When comparing the non‐cyano‐functionalized and the tetracyano‐functionalized molecules, we find a decrease of the reaction rate by a factor of more than 20, corresponding to an increase of the activation energy from 1.48 to 1.59 eV. Density functional theory (DFT) calculations give insights into the influence of the peripheral electron‐withdrawing cyano groups and explain the experimentally observed effects.
Preparation of poly (N,N‐dimethylaminoethyl methacrylate) (PDAEM) membranes: Application for water purification
Authors: Abdellaoui Naima , Laoui Fouad Mouloud , Cerbah Hamza , Arous Omar 
Published: May 2018

ABSTRACTThe present work concerns a development of new membranes for performing ions separation. These membranes were prepared by solution casting followed by solvent evaporation, using a commercial cellulose triacetate (CTA), synthesized poly (N,N‐dimethylaminoethyl methacrylate), macrocylic polyethers (15‐crown‐5 and Dibenzo‐24‐crown‐8) as carrier and dioctylphtalate as plasticizer. Different Polymer Inclusion Membranes were characterized using physical and chemical techniques as well as Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. Transport of lead and cadmium in aqueous solution has been studied using these systems. The selective separation of these membranes is accomplished by the presence of specific compounds, called carriers, in the membrane phase. The carriers are responsible to facilitate the transport of the target component across selective membranes. The influence of the membrane nature has been studied using some supports of different physical characteristics. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46592.
Copper/Diboron‐Mediated Intramolecular Oxygenation and Allylation/Benzylation of Nitroalkynes for the Synthesis of C2‐Quaternary Indolin‐3‐ones
Authors: Fu Wenqiang , Zhou Yao , Song Qiuling 
Published: May 2018

AbstractA direct strategy for intramolecular transfer oxygenation of alkynes and cycloisomerization of 2‐nitroalkynes to synthesize a wide range of C2‐quaternary indolin‐3‐ones was developed by a copper/diboron system. The desired allylation, benzylation and propargylation products were obtained in moderate to excellent yields with good functional group tolerance. The mechanism study indicated that this protocol involved a radical process.
The development of the production cost of oxymethylene ethers as diesel additives from biomass
Authors: Oyedun Adetoyese O , Kumar Amit , Oestreich Dorian , Arnold Ulrich , Sauer Jörg 
Published: May 2018

AbstractOxymethylene ethers (OMEs) are important diesel additives because of their ability to reduce soot loading, particulate matter (PM) emissions, and NOx emissions. Some research has been undertaken on the feasibility of producing OMEs from biomass but there is no techno‐economic assessment of OME production from biomass. In this study, we estimate the unit cost to produce OMEn (n = 1–8) from three different biomass types common to western Canada: whole‐tree woodchips, forest residues, and wheat straw. The techno‐economic model uses the OME production simulation results for 500 MT day−1 of dry biomass. The simulation results show that 97.70, 98.86, and 99.80 MT day−1 of OME1–8 can be produced from whole‐tree woodchips, forest residues, and wheat straw, respectively. The costs of producing OME per liter over 20 years of production are $1.93 ±0.15/L, $1.68 ±0.14/L, and $1.66 ±0.13/L, respectively, at a 95% confidence level for whole‐tree woodchips, forest residues, and wheat straw biomass. The sensitivity analysis results show that the internal rate of return, OME yield, capital cost, and biomass delivery cost significantly influence OME unit price. The production price versus capacity profile reveals that the optimum minimum price can be obtained at a plant capacity of 4000 MT day−1 of biomass; beyond this, the increase in capacity does not result in any appreciable decrease in production price. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.
A survey on modeling and simulation practices for teaching power harmonics
Authors: Igual Raúl , Plaza Inmaculada , Marcuello Juan José , Arcega Francisco 
Published: May 2018

AbstractIn recent years the undergraduate engineering curriculum of several areas has started to incorporate the study of harmonic distortion on electrical systems. Several education simulation tools have been developed and investigated, most of them a short time ago. However, to the best of our knowledge, there is not any literature review on this topic. In this work, we present for the first time a systematic survey on educational tools to model and simulate the effect of power harmonics on industrial electrical networks. As a result, several improvement aspects have been identified and recommendations and implications for future research have been provided. For that, a retrospective study has been accomplished, showing a growing trend toward simulation and modeling. The key instructors’ perceptions to incorporate these practices are the ease of the teaching‐learning process and the importance of modeling and simulation in the industry. The main research challenge is the conduction of integral assessments that comprise both tools’ quality and use experience, and their contribution to achieve learning outcomes. Statistical tests should be used to validate the academic results obtained. This is a major challenge, since only a few of the existing studies incorporate such tests. Other implications for future research refer to the involvement of a higher number of students in the evaluations and the use of free software in the development of the applications.
Modeling real world software engineering using cryptography
Authors: Çulha Davut 
Published: May 2018

AbstractIn software engineering, real world projects are very important for software engineering students. Real world projects help software engineering students to be prepared for real world development. However, directly involving in real world projects is difficult and its benefits are questionable. Therefore, simulation of real world projects can be a solution for this situation. In this paper, the power of cryptography is used to simulate real world projects. Simulation of a project is designed and applied, and its results are discussed.
Emotional virtual crowd on task completion in virtual markets
Authors: Huang Po‐Han , Wong Sai‐Keung 
Published: May 2018

AbstractThis paper studies the effects of a virtual crowd with emotion on task completion in a virtual market. The users have to interact with the virtual agents so that the virtual agents are willing to lead the users to specific vendors. Then, the users can buy the required items. The users communicate with the virtual agents via a conversation dialog. The emotional agents' moods are affected by their own interaction (e.g., collision) while they are walking. Furthermore, their moods are also affected by the conversational responses of the users. We adopt a simple 2D mood model and use icons to represent the mood states of the agents. The mood model supports four mood states, which are “Excitement”, “Anger”, “Sadness”, and “Neutral”. We conducted a user study to evaluate the effects of the emotional virtual agents in different aspects, including task completion, time spent in conversation, following distance, and realism of the emotional virtual crowd.
Transporting objects by multiagent cooperation in crowd simulation
Authors: Chen Hsuan , Wong Sai‐Keung 
Published: May 2018

AbstractThis paper focuses on simulating agents transporting passive objects in a virtual environment with pedestrians. The agents adopt the pushing manipulation patterns to transport the passive objects. We propose techniques to achieve two kinds of cooperation. First, the agents transport the passive objects to the goal positions. During the transportation process, the agents may adjust their formation to transport the passive objects effectively. Second, the agents avoid collision with each other and passive objects in an unfreezing manner. Experiment results show that our technique avoids the freezing problem while the agents are transporting multiple objects.
A novel refocusing distance measurement method using super‐resolved light field images
Authors: Zhao Mandan , Hao Xiangyang 
Published: May 2018

AbstractThis paper proposes a novel distance measurement method using superresolved light‐field images. We first superresolve the light field using the hybrid cross‐resolution input based on PatchMatch and convolutional neural network method, which combines and takes advantage of these two methods. In this way, we can explore the similarity between images and deal with challenging scenes effectively. The scaling factor is up to eight times, which is much larger than the ordinary superresolution scaling factor, and our superresolution method can also maintain a satisfactory accuracy. With the traditional idea of focus ranging, the light‐field 3D measurement method is established. A proper definition evaluation function suitable for light‐field data is selected to evaluate the imaging quality, and the triangle barycenter interpolation method is proposed to measure 3D scenes. Experimental results demonstrate that the proposed method not only improves the quality of the reconstructed high‐resolution light field but also has the ability of the distance measurement. It indicates that the light‐field imaging is a promising 3D measurement technique.
Empowerment and embodiment for collaborative mixed reality systems
Authors: Pan Ye , Sinclair David , Mitchell Kenny 
Published: May 2018

AbstractWe present several mixed‐reality‐based remote collaboration settings by using consumer head‐mounted displays. We investigated how two people are able to work together in these settings. We found that the person in the AR system will be regarded as the “leader” (i.e., they provide a greater contribution to the collaboration), whereas no similar “leader” emerges in augmented reality (AR)‐to‐AR and AR‐to‐VRBody settings. We also found that these special patterns of leadership only emerged for 3D interactions and not for 2D interactions. Results about the participants' experience of leadership, collaboration, embodiment, presence, and copresence shed further light on these findings.
Preparation of Cyclic Prodiginines by Mutasynthesis in Pseudomonas putida KT2440
Authors: Klein Andreas Sebastian , Brass Hannah Ursula Clara , Klebl David Paul , Classen Thomas , Loeschcke Anita , Drepper Thomas , Sievers Sonja , Jaeger Karl‐Erich , Pietruszka Jörg 
Published: May 2018

AbstractProdiginines are a group of naturally occurring pyrrole alkaloids produced by various microorganisms and known for their broad biological activities. The production of nature‐inspired cyclic prodiginines was enabled by combining organic synthesis with a mutasynthesis approach based on the GRAS (generally recognized as safe) certified host strain Pseudomonas putida KT2440. The newly prepared prodiginines exerted antimicrobial effects against relevant alternative biotechnological microbial hosts whereas P. putida itself exhibited remarkable tolerance against all tested prodiginines, thus corroborating the bacterium's exceptional suitability as a mutasynthesis host for the production of these cytotoxic secondary metabolites. Moreover, the produced cyclic prodiginines proved to be autophagy modulators in human breast cancer cells. One promising cyclic prodiginine derivative stood out, being twice as potent as prodigiosin, the most prominent member of the prodiginine family, and its synthetic derivative obatoclax mesylate.
Regulation of inward rectifier potassium current ionic channel remodeling by AT1‐Calcineurin‐NFAT signaling pathway in stretch‐induced hypertrophic atrial myocytes
Authors: He Jionghong , Xu Yanan , Yang Long , Xia Guiling , Deng Na , Yang Yongyao , Tian Ye , Fu Zenan , Huang Yongqi 
Published: May 2018

AbstractPrevious studies have shown that the activation of angiotensin II receptor type I (AT1) is attributed to cardiac remodeling stimulated by increased heart load, and that it is followed by the activation of the calcineurin‐nuclear factor of activated T‐cells (NFAT) signaling pathway. Additionally, AT1 has been found to be a regulator of cardiocyte ionic channel remodeling, and calcineurin‐NFAT signals participate in the regulation of cardiocyte ionic channel expression. A hypothesis therefore follows that stretch stimulation may regulate cardiocyte ionic channel remodeling by activating the AT1‐calcineurin‐NFAT pathway. Here, we investigated the role of the AT1‐calcineurin‐NFAT pathway in the remodeling of inward rectifier potassium (Ik1) channel, in addition to its role in changing action potential, in stretch‐induced hypertrophic atrial myocytes of neonatal rats. Our results showed that increased stretch significantly led to atrial myocytes hypertrophy; it also increased the activity of calcineurin enzymatic activity, which was subsequently attenuated by telmisartan or cyclosporine‐A. The level of NFAT3 protein in nuclear extracts, the mRNA and protein expression of Kir2.1 in whole cell extracts, and the density of Ik1 were noticeably increased in stretched samples. Stretch stimulation significantly shortened the action potential duration (APD) of repolarization at the 50% and 90% level. Telmisartan, cyclosporine‐A, and 11R‐VIVIT attenuated stretch‐induced alterations in the levels of NFAT3, mRNA and protein expression of Kir2.1, the density of Ik1, and the APD. Our findings suggest that the AT1‐calcineurin‐NFAT signaling pathway played an important role in regulating Ik1 channel remodeling and APD change in stretch‐induced hypertrophic atrial myocytes of neonatal rats.
Peraryl Arsoles: Practical Synthesis, Electronic Structures, and Solid‐State Emission Behaviors
Authors: Imoto Hiroaki , Urushizaki Aya , Kawashima Ikuo , Naka Kensuke 
Published: May 2018

Abstract2,3,4,5‐Tetraaryl‐1‐phenylarsoles were synthesized by utilizing safely generated diiodophenylarsine and zirconacyclopentadienes. The obtained peraryl arsoles showed aggregation‐induced emission (AIE), where intense emission was observed in the solid states (quantum yields up to 0.61), whereas the corresponding solutions were very weakly emissive. The optical and electronic properties were examined by experimental and computational methods. It was elucidated that the aryl groups at the 2,5‐positions affected the frontier orbitals and the aromaticity of the arsole core. On the other hand, those at the 1,3,5‐positions were perpendicular to the luminophore and effective for a restriction of aggregation‐caused quenching. Because the lone pair of the arsenic atom has a sufficient coordination ability due to the low aromaticity of the arsole moiety, a gold(I) chloride complex of 1,2,3,4,5‐pentaphenylarsole was synthesized. The complex formation caused a blue shift of the emission from the bare ligand. Interestingly, the complex showed luminescent mechanochromism; grinding the crystals with a blue emission (λem=445 nm) gave amorphous samples with a greenish–blue emission (λem=496 nm).
B‐Heterocyclic Carbene Arising from Charge Shift: A Computational Verification
Authors: Zhang Congjie , Fan Fan , Wang Zhimin , Song Jinshuai , Li Chunsen , Mo Yirong 
Published: May 2018

Abstract1‐Borabicyclo[1.1.0]but‐2(3)‐ene (1BB) is a singlet biradical with two single electrons that can form an ionic resonance structure through a charge shift. The ionic resonance structure is a B‐heterocyclic carbene (BHC), which can act as a carbene, Lewis base, or L‐ and Z‐type ligand, to give adducts and complexes. Through a range of quantum methods, four types of stable compounds (A–D) derived from 1BB have been designed. These compounds retain the unique features of 1BB. As a consequence, the structures, stability, and Wiberg bond indices of the Lewis adducts of A–D with Lewis acids (BePh2, BH3, AlH3, AlCl3, C5BH5, and C13BH9) and CuI, AgI, and AuI complexes have been investigated. Results show that A–D can indeed react as carbenes. Interestingly, compounds A–D, as L‐type ligands, can attach to BePh2, BH3, AlH3, AlCl3, C5BH5, C13BH9, and CuCl and form compounds with planar tetracoordinate carbon (ptC), whereas Z‐type ligands A–D can bind to AgCl and AuCl to provide complexes with planar tetracoordinate boron (ptB). In addition, the binuclear complexes of ClX(1BB)CuCl (X=Ag, Au) have been studied and A–D behave as both L‐ and Z‐type ligands, in which these complexes contain both ptC and ptB. Thus, a novel method for designing compounds with ptC and ptB is presented. These rationally designed compounds involve the elements of carbene, ptC, ptB, and L‐ and Z‐type ligands, and are expected to be unique and useful in experimental chemistry once they are synthesized.
Online learning with sparse labels
Authors: He Wenwu , Zou Fumin , Liang Quan 
Published: May 2018

SummaryIn this paper, we consider an online learning scenario where the instances arrive sequentially with partly revealed labels. We assume that the labels of instances are revealed randomly according to some distribution, eg, Bernoulli distribution. Three specific algorithms based on different inspirations are developed. The first one performs the idea of Estimated gradient for which a strict high‐probability regret guarantee in scale of
can be derived, when the distributing parameter p is revealed. An empirical version is also developed for cases where the learner has to learn the parameter p when it is not revealed. Experiments on several benchmark data sets show the feasibility of the proposed method. To further improve the performance, two kinds of aggressive algorithms are presented. The first one is based on the idea of instances recalling, which tries to get the full use of the labeled instances. The second one is based on the idea of labels learning, and it tries to learn the labels for unlabeled instances. In particular, it includes the step of online co‐learning, which aims to learn the labels, and the step of weighted voting, which aims to make the final decision. Empirical results confirm the positive effects of the two aggressive algorithms.