bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of A/B‐Site Non‐stoichiometry on the Structure and Properties of La0.9Sr0.1Ga0.9Mg0.1O3−δ Solid Electrolyte in Intermediate‐Temperature Solid Oxide Fuel Cells
Authors: Wang Jian Qiu , Zhou De Feng , Gao Jin Quan , Sun Hao Ran , Zhu Xiao Fei , Meng Jian 
Published: December 2017

Abstract(La0.9Sr0.1)x(Ga0.9Mg0.1)yO3‐δ [(LS)x(GM)y] (x=0.97, 1.00, 1.03; y=1.00 and x=1.00; y=0.97, 1.00, 1.03) electrolyte is prepared through a sol‐gel method followed by sintering at 1300 °C for 10 h. The microstructures of the samples are characterized by using X‐ray diffraction (XRD) and field‐emission scanning electron microscopy (FE‐SEM). The electrical and thermal stability properties are measured by means of electrochemical impedance spectroscopy (EIS) and thermal expansion coefficient (TEC), respectively. It is shown that phase purity could improve by adjusting the non‐stoichiometry of A/B‐site. This, in turn, affects the conductivity and thermal expansion of the solid electrolyte. The samples with B‐site defects [LS(GM)0.97] are found to exhibit the best phase purity and density with minimal grain boundary/total resistances, and superior thermal stability. The conductivity of LS(GM)0.97 is 1.56 time higher than that of LSGM. The average thermal expansion coefficient of LS(GM)0.97 at 50–850 °C is 4.13 % lower than that of LSGM. The maximum power density of single cells containing LS(GM)0.97 electrolyte could reach 0.54 W cm−1 at 800 °C, which is 16.7 % higher than that of cells containing LSGM electrolyte. The stability test for over 120 h at 800 °C indicates a slight decrease in performances during the first 10 h, but no significant differences in electrode polarization are observed even after long‐term operation. These findings suggest the potential applications of LS(GM)0.97 as a novel electrolyte for intermediate‐temperature solid oxide fuel cells.
Analytical Understanding of the Materials Design with Well‐Described Shrinkages on Multiscale
Authors: Ma Qiang , Dutta Saikat , Wu Kevin C.‐W. , Kimura Tatsuo 
Published: December 2017

AbstractShrinkages derived from condensation of frameworks are one of the significant steps for fabricating demanded materials having unique morphologies and properties. Enormous efforts have been dedicated to understanding their mechanisms that are quite useful for the materials design. In this context, diversified measuring and observing tools have been facilitated to evaluate structural contractions and corresponding driving forces. All of the investigations are crucial to encourage the utilization of such shrinkages for the precise design of nanomaterials. In this review, we summarize significant works how to analyze shrinkages in multiscale during the synthesis of materials, which will be useful as a follow‐up review to our latest contribution. Well‐defined porous materials are also selected as a good candidate for understanding well‐described shrinkages. This review aims to provide a detailed glimpse of the development of analyses on shrinking behaviors in multiscale for the materials design. Shrinking degree and direction in multiscale, which are driven by condensation of frameworks, are predominant for understanding and/or predicting final nanostructures of materials after shrinkages.
Johnson Solids: Anion‐Templated Silver Thiolate Clusters Capped by Sulfonate
Authors: Wang Zhi , Su Hai‐Feng , Wang Xing‐Po , Zhao Quan‐Qin , Tung Chen‐Ho , Sun Di , Zheng Lan‐Sun 
Published: December 2017

AbstractSulfonates were incorporated into six novel high‐nuclearity silver(I) thiolate clusters under the guidance of anion templates varied from S2−, SO42−, α‐[Mo5O18]6−, β‐[Mo5O18]6−, [Mo2O8]4−, to [Mo4O14(SO4)]6−. Single crystal X‐ray analysis revealed that SD/Ag1, SD/Ag3, SD/Ag5, and SD/Ag6 are discrete [S@Ag60], [α‐Mo5O18@Ag36], [Mo2O8@Ag30]2, and [Mo4O14(SO4)@Ag73] clusters, respectively, whereas SD/Ag2 and SD/Ag4 are one‐dimensional (1D) chains based on the [SO4@Ag20] and [β‐Mo5O18@Ag36] cluster subunits, respectively. Their silver skeletons are protected exteriorly by thiolates and sulfonates and interiorly supported by diverse anions as templates. Structurally, cluster SD/Ag1 is a typical core–shell structure comprised of an inner Ag12 cuboctahedron and an outer Ag48 shell. The sulfate‐templated drum‐like Ag20 cluster subunits are bridged by PhSO3− to give a 1D chain of SD/Ag2. Complex SD/Ag3 and SD/Ag4 are spindle‐like Ag36 clusters with isomeric [Mo5O18]6− inside, and the latter is further extended to a 1D chain through PhSO3− bridges. A pair of [Mo2O8]4− templated gourd‐like Ag30 clusters are dimerized in a head‐to‐head fashion to form SD/Ag5. Complex SD/Ag6 is the largest cluster in this family and doubly templated by unprecedented [Mo4O14(SO4)]6− anions. Geometrically, the silver shells of SD/Ag1–SD/Ag5 show the polyhedral features of Johnson solids, instead of the usual Platonic or Archimedean solids. Solution behaviors and luminescent properties were also investigated in detail.
Efficient Reduction of CO2 to CO Using Cobalt–Cobalt Oxide Core–Shell Catalysts
Authors: Yin Guoheng , Yuan Xiaotao , Du Xianlong , Zhao Wei , Bi Qingyuan , Huang Fuqiang 
Published: December 2017

AbstractThe route of converting CO2 to CO by reverse water‐gas shift (RWGS) reaction is of particular interest due to the direct use of CO as feedstock in many significant industrial processes. Here, an engineered cobalt–cobalt oxide core–shell catalyst (Co@CoO) with nanochains structure has been made for the efficient reduction of CO2 to useful CO. Owing to the excellent performance for H2 activation of metal nanoparticles and the enhanced absorption and activation for CO2 molecule of defective metal oxides, the unique synergistic effect of metallic Co and encapsulating coordinatively unsaturated CoO species shows high performance for clean generation of CO under moderate and practical conditions. Furthermore, with N‐dopant into the defective CoO shell, the Co@CoO‐N achieves the highest conversion of 19.2 % and an exceptional CO evolution rate of 96 mL min−1 gcat−1 at 523 K with a gas hourly space velocity (GHSV) of 42,000 mL gcat−1 h−1, which is comparable with the previously reported materials under identical conditions.
Selective Transformation of Well‐Defined Alkenyllithiums to Alkenylmagnesiums via Transmetalation
Authors: Zhu Miaomiao , Liu Liang , Zhang Yongliang , Yu Hai‐Tao , Zhang Wen‐Xiong , Xi Zhenfeng 
Published: December 2017

AbstractA series of butadienyl organomagnesium complexes, including 1‐Li‐4‐(MgR)‐butadienes, 1,4‐bis(MgR)‐butadienes, and 1‐Mg‐4‐(MgR)‐butadiene were synthesized starting with 1,4‐dilithio butadienes via the transmetalation reaction between alkenyllithium bond and alkenylmagnesium bond. Single‐crystal X‐ray structural analysis of these butadienyl organomagnesiates revealed unique bonding modes. Study on their structural transformation demonstrated that 1‐Li‐4‐(MgR)‐butadiene is the key intermediate in the reaction process leading to the formation of 1,4‐bis(MgR)‐butadiene and 1‐Mg‐4‐(MgR)‐butadiene.
Bandgap Optimization of Perovskite Semiconductors for Photovoltaic Applications
Authors: Xiao Zewen , Zhou Yuanyuan , Hosono Hideo , Kamiya Toshio , Padture Nitin P. 
Published: December 2017

AbstractThe bandgap is the most important physical property that determines the potential of semiconductors for photovoltaic (PV) applications. This Minireview discusses the parameters affecting the bandgap of perovskite semiconductors that are being widely studied for PV applications, and the recent progress in the optimization of the bandgaps of these materials. Perspectives are also provided for guiding future research in this area.
A Direct Proof of the Resonance‐Impaired Hydrogen Bond (RIHB) Concept
Authors: Lin Xuhui , Wu Wei , Mo Yirong 
Published: December 2017

AbstractThe concept of resonance‐enhanced hydrogen bond (RAHB) has been widely accepted and applied as it highlights the positive impact of π‐conjugation on intramolecular H‐bonds. However, electron delocalization is directional and there is a possibility that π‐resonance goes from the H‐bond acceptor to the H‐bond donor, leading to a negative impact on H‐bonds. Here we used the block‐localized wavefunction (BLW) method which is a variant of ab initio valence bond (VB) theory and able to derive strictly electron‐localized structures self‐consistently, to quantify the interplay between H‐bond and π‐resonance in the terms of geometry, energetics and spectral properties. The comparison of geometrical optimizations with and without π‐resonance shows that conjugation can indeed either enhance or weaken intramolecular H‐bonds. We further experimented with various substituents attached to either the H‐bond acceptor and/or H‐bond donor side(s) to tune the H‐bonding strength in both directions.
An Exfoliated 2D Egyptian Blue Nanosheet for Highly Selective Enrichment of Multi‐Phosphorylated Peptides in Mass Spectrometric Analysis
Authors: Yang Shi‐Shu , Yu Hai‐Xia , Wang Zi‐Zhen , Liu Hai‐Long , Zhang Hao , Yu Xizhong , Shang Wenbin , Chen Gui‐Quan , Gu Zhi‐Yuan 
Published: December 2017

AbstractInvited for the cover of this issue are the group of Zhi‐Yuan Gu at Nanjing Normal University, and co‐workers at Nanjing University of Chinese Medicine and Nanjing University. The image depicts a 2D CaCuSi4O10 nanosheet as an intriguing adsorbent towards highly selective enrichment of multi‐phosphopeptides Read the full text of the article at 10.1002/chem.201704138.
Real‐time feedback control of SAGD wells using model predictive control to optimize steam chamber development under uncertainty
Authors: Vembadi Shiv S. , Patel Rajan G. , Trivedi Japan J. , Prasad Vinay 
Published: December 2017

ABSTRACTThe efficiency of steam assisted gravity drainage (SAGD) operation depends on developing a uniform steam chamber by maintaining an optimal subcool temperature along the length of the well pair. Implementing operational parameters obtained from model‐based optimization directly in the field may not lead to the desired subcool temperature. Based on the real‐time measurements from surface and downhole sensors, along with other well and surface constraint information, a real‐time feedback control of SAGD well pairs can be implemented to optimize subcool and steam chamber development. Model predictive control (MPC), which is a multivariable constrained controller, provides a framework for such control. To evaluate the use of MPC for real‐time control of SAGD wells, a case study is performed using a 3D heterogeneous reservoir model. Porosity and permeability realizations are created and ranked based on net present value (NPV). One of the realizations is considered as the ‘true’ reservoir, and two other realizations are selected to represent different cases of uncertain reservoir models. For each model, a reservoir simulator is used to find the optimum rates and subcool temperature, which become the set‐points for MPC to operate the wells. We compare the steam chamber growth and NPV calculated using MPC with the base case where no MPC is used and discuss the implementation advantages. Since MPC led to expedited and accurate tracking of optimized operating targets obtained using reservoir models, ∼18 % improvement in NPV is achieved compared to manual open‐loop application of optimum rates, a practice used commonly in the field.
Modelling of water transport through mixed‐ion conducting dense ceramics
Authors: Al Selgin , Song Feng , Zhang Guangru 
Published: December 2017

AbstractThis study develops and demonstrates a model that characterizes defect transports, responsible for water transport within dense ceramics, and calculates the diffusion coefficients for those defects. The multi‐species mass transfer processes within yttrium doped barium cerates are modelled by applying the Nernst‐Planck equation to the system. The Nernst‐Planck equation with suitable boundary conditions is adopted to compute defect diffusion coefficients in COMSOL Multiphysics. All related equations, based on charge and defect conservation, are solved numerically and validated experimentally. The model also predicts the concentration distribution of the defects and potential profiles throughout the membranes. The results provided convenient insights about the water transport and charge distribution as a function of membrane thickness.
Analysis of the multi‐echo spin‐echo pulse sequence
Authors: Zur Yuval 
Published: December 2017

AbstractThe multi‐echo spin‐echo sequence is a series of operators, referred to as periodic operators. Each periodic operator consists of a free rotation (no RF), a refocusing RF pulse, and another free rotation, identical to the first one. A preparation operator that precedes the periodic operators converts the equilibrium magnetization Mz into an initial magnetization Mi. It is shown that a multi‐echo sequence is equivalent to a simple rotation of the magnetization about a tilted axis. The component of Mi along the rotation axis is stationary and provides a stable signal, denoted pseudo steady‐state. The perpendicular component rotates and eventually de‐phases. Using this model, we derive analytic expressions to the signal for different preparation operators, and show how to align Mi with the rotation axis such that the signal is maximized. A simple and efficient algorithm is presented to calculate the Fourier coefficients of the magnetization during the sequence using the discrete Fourier transform. Finally, formulas of the echo signal when unavoidable phase errors are generated are derived. We show how to eliminate artifacts caused by these errors and restore the original image.
Photoinduced Intermolecular Electron Transfer Mediated by the Colloidal Tyrosyl Bolaamphiphile Assembly
Authors: Cho Junghyun , Kwak Jinyoung , Oh Juwon , Kim Dongho , Lee Sang‐Yup 
Published: December 2017

AbstractThe self‐assembly of tyrosyl bolaamphiphiles is exploited to create a colloidal protein‐like host matrix, upon which sacrificial electron‐donor molecules associate to create a photosystem II (PSII) mimetic electron‐relay system. This system harnesses the tyrosine phenol groups abundant on the surface of the assemblies to mediate photoinduced intermolecular electron transfer. Compared with the l‐tyrosine molecules, the tyrosyl bolaamphiphile assembly facilitates electron transfer from the sacrificial electron donor to the oxidized photosensitizer. The enhanced electron relay is likely to be driven by the host function of the assembly associated with the sacrificial electron donor and by the suppression of the oxidative cross‐linking of phenoxyl radicals. The tyrosyl bolaamphiphile assembly is advantageous in the construction of a PSII mimetic system with a protein‐like nature and displaying biochemical functions.
A Chemical View on X‐ray Photoelectron Spectroscopy: the ESCA Molecule and Surface‐to‐Bulk XPS Shifts
Authors: Delesma Francisco A. , Van den Bossche Maxime , Grönbeck Henrik , Calaminici Patrizia , Köster Andreas M. , Pettersson Lars G. M. 
Published: December 2017

AbstractIn this paper we remind the reader of a simple, intuitive picture of chemical shifts in X‐ray photoelectron spectroscopy (XPS) as the difference in chemical bonding between the probed atom and its neighbor to the right in the periodic table, the so called Z+1 approximation. We use the classical ESCA molecule, ethyl trifluoroacetate, and 4d‐transition metals to explicitly demonstrate agreement between core‐level shifts computed as differences between final core‐hole states and the approach where each core‐ionized atom is replaced by a Z+1 atom. In this final state, or total energy picture, the XPS shift arises due to the more or less unfavorable chemical bonding of the effective nitrogen in the carbon geometry for the ESCA molecule. Surface core level shifts in metals are determined by whether the Z+1 atom as an alloy segregates to the surface or is more soluble in the bulk. As further illustration of this more chemical picture, we compare the geometry of C 1s and O 1s core‐ionized CO with that of, respectively, NO+ and CF+. The scope is not to propose a new method to compute XPS shifts but rather to stress the validity of this simple interpretation.
Unprecedented Ionization Processes in Mass Spectrometry Provide Missing Link between ESI and MALDI
Authors: Trimpin Sarah , Lee Chuping , Weidner Steffen M. , El‐Baba Tarick J. , Lutomski Corinne A. , Inutan Ellen D. , Foley Casey D. , Ni Chi‐Kung , McEwen Charles N. 
Published: December 2017

AbstractIn the field of mass spectrometry, producing intact, highly‐charged protein ions from surfaces is a conundrum with significant potential payoff in application areas ranging from biomedical to clinical research. Here, we report on the ability to form intact, highly‐charged protein ions on high vacuum time‐of‐flight mass spectrometers in the linear and reflectron modes achievable using experimental conditions that allow effective matrix removal from both the sample surfaces and from the charged clusters formed by the laser ablation event. The charge states are the highest reported on high vacuum mass spectrometers, yet they remain at only around a third of the highest charge obtained using laser ablation with a suitable matrix at atmospheric pressure. Other than physical instrument modifications, the key to forming abundant and stable highly‐charged ions appears to be the volatility of the matrix used. Cumulative results suggest mechanistic links between the ionization process reported here and traditional ionization methods of electrospray ionization and matrix‐assisted laser desorption/ionization.
Kinematic Modeling of Mechanocatalytic Depolymerization of α‐Cellulose and Beechwood
Authors: Kessler Martin , Woodward Robert T. , Wong Narumi , Rinaldi Roberto 
Published: December 2017

AbstractMechanocatalytic depolymerization of lignocellulose presents a promising method for the solid‐state transformation of acidified raw biomass into water‐soluble products (WSPs). However, the mechanisms underlining the utilization of mechanical forces in the depolymerization are poorly understood. A kinematic model of the milling process is applied to assess the energy dose transferred to cellulose during its mechanocatalytic depolymerization under varied conditions (rotational speed, milling time, ball size, and substrate loading). The data set is compared to the apparent energy dose calculated from the kinematic model and reveals key features of the mechanocatalytic process. At low energy doses, a rapid rise in the WSP yield associated with the apparent energy dose is observed. However, at a higher energy dose obtained by extended milling duration or high milling speeds, the formation of a substrate cake layer on the mill vials appear to buffer the mechanical forces, preventing full cellulose conversion into WSPs. By contrast, for beechwood, there exists a good linear dependence between the WSP yield and the energy dose provided to the substrate over the entire range of WSP yields. As the formation of a substrate cake in depolymerization of beechwood is less severe than that for the cellulose experiments, the current results verify the hypothesis regarding the negative effect of a substrate layer formed on the mill vials upon the depolymerization process. Overall, the current findings provide valuable insight into relationships between the energy dose and the extent of cellulose depolymerization effected by the mechanocatalytic process.
An integrative mating system assessment of a nonmodel, economically important Pacific rockfish (Sebastes melanops) reveals nonterritorial polygamy and conservation implications for a large species flock
Authors: Karageorge Kurt W. , Wilson Raymond R. 
Published: December 2017

AbstractCharacterizing the mating systems of long‐lived, economically important Pacific rockfishes comprising the viviparousSebastesspecies flock is crucial for their conservation. However, direct assignment of mating success to sires is precluded by open, offshore populations and high female fecundity. We addressed this challenge by integrating paternity‐assigned mating success of females with the adult sex ratio (ASR) of the population, male evolutionary responses to receptive females, and reproductive life history traits—in the framework of sexual selection theory—to assess the mating system ofSebastes melanops. Microsatellite parentage analysis of 17 pregnant females, 1,256 of their progeny, and 106 adults from the population yielded one to four sires per brood, a mean of two sires, and a female mate frequency distribution with a truncated normal (random) pattern. The 11 multiple paternity broods all contained higher median allele richness than the six single paternity broods (Wilcoxon test:W = 0,p < .001), despite similar levels of average heterozygosity. By sampling sperm and alleles from different males, polyandrous females gain opportunities to enhance their sperm supply and to lower the cost of mating with genetically incompatible males through reproductive compensation. A mean of two mates per mated female with a variance of one, anASR = 1.2 females per male, and the expected population mean of 2.4 mates for mated males (and the estimated 35 unavailable sires), fits polygamous male mate frequency distributions that distinguish polygynandry and polyandrogyny mating systems, that is, variations of polygamy, but not polyandry. Inference for polygamy is consistent with weak premating sexual selection on males, expected in mid‐water, schoolingS. melanops, owing to polyandrous mating, moderately aggregated receptive females, an evenASR, and no territories and nests used for reproduction. Each of these characteristics facilitates more mating males and erodes conspicuous sexual dimorphism. Evaluation of male evolutionary responses of demersal congeners that express reproductively territorial behavior revealed they have more potential mechanisms for producing premating sexual selection, greater variation in reproductive success, and a reduced breeding effective population size of adults and annual effective size of a cohort, compared toS. melanopsmodeled with two mates per adult. Such divergence in behavior and mating system by territorial species may differentially lower their per capita birth rates, subsequent population growth, and slow their recovery from exploitation.