bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of 3-Halo-7-azaindoles through a 5-endo-dig Electrophilic Cyclization Reaction
Authors: Philips Aimee , Cunningham Christopher , Naran Kajal , Kesharwani Tanay
Published: May 2019

Biologically useful 7-azaindoles were synthesized by electrophilic cyclization of 3-alkynyl-N,N-dimethylpyridine-2-amines with molecular iodine. By this simple atom-economical approach under ambient reaction conditions, a library of interesting 3-iodo-7-azaindoles were synthesized in high yields. To synthesize the corresponding 3-bromo- and 3-chloro-7-azaindoles, an environmentally benign copper-mediated cyclization was employed, with inexpensive, nontoxic, and noncorrosive sodium chloride and sodium bromide as the sources of chlorine and bromine, respectively.
Concise Seven-Membered Oxepene/Oxepane Synthesis – Structural Motifs in Natural and Synthetic Products
Authors: Osei Akoto Clement , Rainier Jon D.
Published: May 2019

This work outlines a suitable method for the synthesis of oxepane skeleton using iterative C-glycoside technology on the oxepene intermediate, which was synthesized utilizing Wilkinson’s catalyst [Rh(PPh3)3Cl] to generate the isomerized product in a linear synthetic manner. The central core of the oxepene motif was achieved via an olefin metathesis reaction using the Grubbs second-generation and Schrock catalysts. The synthesis of the functionalized oxepane having the desired adriatoxin E-ring relative stereochemistry was achieved starting from commercially available homopropargylic alcohol.
Incidence of Femoral Component Malrotation Using Posterior Condylar Referencing in Total Knee Arthroplasty
Authors: Lee Diana K. , Grosso Matthew J. , Trofa David P. , Sonnenfeld Julian J. , Cooper H. John , Shah Roshan P. , Geller Jeffrey A.
Published: May 2019

Proper femoral component rotation in total knee arthroplasty (TKA) is important, given the prognostic impact of a poorly positioned component. The purpose of this observational study was to determine the incidence of femoral component malrotation using posterior condylar axis (PCA) referencing. A total of 100 knees in 92 patients with varus gonarthritis of the knee undergoing primary TKA using a standard medial parapatellar approach were evaluated intraoperatively. After distal femoral resection, the standard femoral sizing guide referencing the posterior condylar axis was used to set femoral component rotation. This was then compared with both the transepicondylar (TEA) and trochlear anteroposterior axes (TRAx). Disparites were recorded and corrected in line with the epicondylar axis. Rotational adjustment for addition of further external rotation was made in 13 (13.0%) cases. In seven cases, the medial pin sites were raised between 1 and 3 mm, and in six cases, the lateral pin site was lowered between 1 and 3 mm (based on risk of notching the femoral cortex). It is critical to not rely exclusively on the PCA to confirm rotational positioning of the femoral component as predicted by posterior condylar referencing guides. Intraoperative adjustment and confirmation using the TEA and TRAx occurred in 13% of primary TKA cases, which might have, otherwise, had a significant effect on the clinical outcome.
Direct measurement of electron numbers created at near-infrared laser-induced ionization of various gases
Authors: Sharma A. , Slipchenko M. N. , Rahman K. A. , Shneider M. N. , Shashurin A.
Published: May 2019

In this work, we present temporally resolved measurements of electron numbers created at photoionization of various gases by a femtosecond-laser pulse at 800 nm wavelength. The experiments were conducted in O2, Xe, Ar, N2, Kr, and CO at room temperature and atmospheric pressure. Elastic microwave scattering was used to directly measure the electron numbers. Numbers of electrons in the range 3 × 108–3 × 1012 were produced by the laser pulse energies 100–700 μJ. After the laser pulse, plasma decayed on the time scale from 1 to 40 ns depending on the gas type and governed by two competing processes, namely, the creation of new electrons from ionization of the metastable atoms and loss of the electrons due to dissociative recombination and attachment to oxygen.
An efficient algorithm for Cholesky decomposition of electron repulsion integrals
Authors: Folkestad Sarai D. , Kjønstad Eirik F. , Koch Henrik
Published: May 2019

Approximating the electron repulsion integrals using inner projections is a well-established approach to reduce the computational demands of electronic structure calculations. Here, we present a two-step Cholesky decomposition algorithm where only the elements of the Cholesky basis (the pivots) are determined in the pivoting procedure. This allows for improved screening, significantly reducing memory usage and computational cost. After the pivots have been determined, the Cholesky vectors are constructed using the inner projection formulation. We also propose a partitioned decomposition approach where the Cholesky basis is chosen from a reduced set generated by decomposing diagonal blocks of the matrix. The algorithm extends the application range of the methodology and is well suited for multilevel methods. We apply the algorithm to systems with up to 80 000 atomic orbitals. The accuracy of the integral approximations is demonstrated for a formaldehyde-water system using a new Cholesky-based CCSD implementation.
A graphical approach to estimate the critical coupling strength for Kuramoto networks
Authors: Gilg Brady , Armbruster Dieter
Published: May 2019

The Kuramoto model is an archetypal model for studying synchronization in groups of nonidentical oscillators. Each oscillator is imbued with its own personal inherent driving frequency and experiences attractive coupling forces toward all the other oscillators in the system. As the coupling increases, there exists a minimal coupling strength called the critical coupling beyond which the system moves in a collective rhythm. A unified approach for creating approximations of the critical coupling is created. It is based on an interpretation of a measurement of phase synchronization among the oscillators (the order parameter) as a function of the coupling strength. The approach allows a graphical way to develop new approximations that are provably, strict lower bounds. It is shown that several of the critical coupling bounds that have been previously studied can be interpreted in this unified framework. In addition, a process based on fixed point sampling is introduced that converts upper bounds for the critical coupling into associated lower bounds.
Toward understanding the anomalous Li diffusion in inorganic solid electrolytes by studying a single-crystal garnet of LLZO–Ta by pulsed-gradient spin-echo nuclear magnetic resonance spectroscopy
Authors: Hayamizu Kikuko , Terada Yasuhiko , Kataoka Kunimitsu , Akimoto Junji
Published: May 2019

Li diffusion was observed by 7Li nuclear magnetic resonance (NMR) spectroscopy in three single-crystal samples of LLZO–Ta (Li6.5La3Zr1.5Ta0.5O12) grown by the floating zone melting method as well as a crushed sample in this study. Previously, the pulsed-gradient spin-echo 7Li NMR method was applied to Li+ diffusion measurements in inorganic solid electrolyte powder samples. Anomalous Li+ diffusion behaviors were observed such as dependence of the observing time (Δ) and pulsed-field-gradient strength (g), and the diffusive-diffraction patterns in short Δ in the echo-attenuation plots. In the powder samples, it is uncertain that the Li ions diffuse in the bulk within grain, across grains, or both. To date, the origins of the anomalous Li+ diffusion have not yet been clearly understood. From models of atomic-level lithium pathways, the micrometer-space diffusion channels are assumed to be narrow with curvatures. In contrast to the powder samples, a single crystal is supposed to be uniform without grain boundaries and the Li ions in single-crystal samples can diffuse in the bulk with negligible effects from the surface. The single-crystal samples are expected to give us proper answers. We found that the 7Li echo-attenuation plots of the single-crystal samples showed anomalous phenomena in dependence on Δ and g with much reduced manners. We found that the phenomena are inherent characteristics of Li+ diffusion in inorganic solid electrolytes. From the aspects of Li+ carrier numbers, the fast divergent Li+ diffusion constants, observed at short Δ with small g, contribute importantly to the electrochemical high ionic conduction measured by impedance spectroscopy.
Weakly charged round micro-plasma jet flows into vacuum
Authors: Cai S. , Cai C. , Li J.
Published: May 2019

This paper presents a model for highly dilute microplasma jet flows expanding into a vacuum from a round exit, with given number density, bulk velocity, temperature, and potential at the exit. The Debye length at the exit is assumed to be large, the quasi-neutral condition is adopted to treat charges, and the potential field is computed with the Boltzmann relation. At farfield, the exit degenerates as a point source, and simplified analytical formulas for the density, velocity, temperatures, potential, and electric field components are obtained. From the crucial centerline properties, exact but more compact solutions are further developed. The treatment is based on the gas kinetic theory, and the results are analytical and generic. The results include rich physics and offer insights into better understanding of many existing models in the literature, for example, the cosine law plume model shall be used with caution. The current results can be widely applicable to estimate the whole flow and potential fields, with reduced simulation and measurement costs. Farfield property estimations can be performed without numerical simulations and measurements. Based on these results from this work, more advanced models may be further developed.
Absolute cross sections for chemoradiation therapy: Damages to cisplatin-DNA complexes induced by 10 eV electrons
Authors: Zhou Limei , Liu Wenhui , Brodeur Nicolas , Cloutier Pierre , Zheng Yi , Sanche Léon
Published: May 2019

In chemoradiation therapy, the synergy between the radiation and the chemotherapeutic agent (CA) can result in a super-additive treatment. A priori, this increased effectiveness could be estimated from model calculations, if absolute cross sections (ACSs) involved in cellular damage are substantially higher, when the CA binds to DNA. We measure ACSs for damages induced by 10 eV electrons, when DNA binds to the CA cisplatin as in chemotherapy. At this energy, DNA is damaged essentially by the decay of core-excited transient anions into bond-breaking channels. Films of cisplatin-DNA complexes of ratio 5:1 with thicknesses 10, 15, and 20 nm were irradiated in vacuum during 5–30 s. Conformation changes were quantified by electrophoresis and yields extrapolated from exposure-response curves. Base damages (BDs) were revealed and quantified by enzymatic treatment. The ACSs were generated from these yields by two mathematical models. For 3197 base-pair plasmid DNA, ACS for single strand breaks, double strand breaks (DSBs), crosslinks, non-DSB cluster damages, and total BDs is 71 ± 2, 9.3 ± 0.4, 10.1 ± 0.3, 8.2 ± 0.3, and 115 ± 2 ×10−15 cm2, respectively. These ACSs are higher than those of nonmodified DNA by factors of 1.6 ± 0.1, 2.2 ± 0.1, 1.3 ± 0.1, 1.3 ± 0.3, and 2.1 ± 0.4, respectively. Since LEEs are produced in large quantities by radiolysis and strongly interact with biomolecules, we expect such enhancements to produce substantial additional damages in the DNA of the nucleus of cancer cells during concomitant chemoradiation therapy. The increase damage appears sufficiently large to justify more elaborate simulations, which could provide a quantitative evaluation of molecular sensitization by Pt-CAs.
Softening effects due to reorientations of Cu precipitates in α-iron: Atomistic simulations of dislocations-obstacles interactions
Authors: Wu Xiaoyu , Wang Xiaoyang , Wang Yinan , Liu Wei , Shu Guogang , Li Chengliang , Li Qiulin , Xu Ben
Published: May 2019

Radiation-induced hardening by precipitates, which essentially has a dislocation pinning effect, is a major issue in nuclear reactor pressure vessels research. In this study, simulations of interactions between edge dislocations and copper precipitates are conducted as an example to investigate size-dependent pinning effects. Using molecular dynamics simulations, we discover a new two-stage mechanism that includes the processes of reorientations and atomistic collective migrations during the interactions. Both of these result in a weakening of the pinning effect on dislocations when the phase transition occurs in copper precipitates, which can be reflected in the decrease of the critical shear stress in stress and strain curves. Our studies considered the atomistic arrangement of the obstacle during the interaction, which constructively provide a new perspective for research studies of dislocation–obstacle pinning interaction and offer a more comprehensive estimation on the pinning strength of dislocations.
Piezoelectricity and electrostriction in ferroelastic materials with polar twin boundaries and domain junctions
Authors: Lu Guangming , Li Suzhi , Ding Xiangdong , Salje Ekhard K. H.
Published: May 2019

Weak piezoelectricity, compared with electrostriction, occurs in twinned ferroelastic materials even when the uniform bulk material is centro-symmetric. In a simple computer simulation, polarity is exclusively generated by the flexoelectric effect. Simple twinned structures (parallel twin walls) are electrostrictive and show no piezoelectricity. Complex twinned structures break inversion symmetry by the simultaneous appearance of junctions, kinks, needle domains, etc. Such structures show weak piezoelectricity (d ∼ 10−4 pm/V) under periodic boundary conditions together with significant electrostriction. The macroscopic piezoelectric response is stronger (d ∼ 10−3 pm/V) under free boundary conditions due to the effect of relaxing surfaces.
Utilization of O-X-B mode conversion of 28 GHz microwaves to heat core electrons in the upgraded Proto-MPEX
Authors: Biewer T. M. , Lau C. , Bigelow T. S. , Caneses J. F. , Caughman J. B. O. , Goulding R. H. , Kafle N. , Kaufman M. C. , Rapp J. ,   Proto-MPEX Team
Published: May 2019

The magnetic geometry of the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) was recently modified to enable more effective utilization of 28 GHz microwave auxiliary power, specifically: (1) to heat plasma electrons in the radial core of the device and (2) to deliver the heated plasma to the target plate of the device. To achieve this goal, the microwave launcher geometry and placement were significantly re-engineered, guided by previous experimental results and computational modeling. The core electron temperature in the launcher region is observed to increase from 3 eV to 11 eV with 30 kW of auxiliary power after the improvements, and an increase from 3 eV to 6 eV is concurrently measured in the target region (∼1 m from the launcher) at electron density above O-mode cutoff. Radially resolved measurements in the launcher region exhibit a strong dependence on the magnetic geometry. The results of a magnetic field scan reinforce the effectiveness of the intended O-X-B mode conversion scenario that is currently planned for microwave heating of the Material Plasma Exposure eXperiment (MPEX).
Ultrafast intramolecular vibrational energy transfer in carbon nitride hydrocolloid examined by femtosecond two-dimensional infrared spectroscopy
Authors: Zheng Xuan , Yu Pengyun , Wang Jianping
Published: May 2019

In this work, ultrafast vibrational and structural processes in a graphitic carbon nitride hydrocolloid system were studied using a combination of linear infrared and nonlinear two-dimensional infrared (2D IR) spectroscopies. The experimentally observed three IR line shapes in the C=N stretching vibration frequency region were analyzed and attributed to the rigid and conjugated molecular frame of the prepared g-CN molecular species, which is believed to be a dimeric tris-s-triazine, as well as attributed to insignificant solvent influence on the delocalized C=N vibrations. Vibrational transition density cubes were also computed for the proposed g-CN dimer, confirming the heterocyclic C=N stretching nature of the three IR absorption peaks. Intramolecular vibrational energy transfer dynamics and spectral diffusion of the g-CN system were characterized by examining a series of time-dependent 2D IR spectra. A picosecond intramolecular vibrational energy redistribution process was found to occur among these delocalized C=N stretching modes, acting as an efficient vibrational energy transfer channel. This work reasonably connects the experimentally observed IR signature to a specific g-CN structure and also provides the first report on the ultrafast intramolecular processes of such carbon nitride systems. The obtained results are fundamentally important for understanding the molecular mechanisms of such carbon-nitride based functional materials.
Low-frequency noise and defects in copper and ruthenium resistors
Authors: Fleetwood D. M. , Beyne S. , Jiang R. , Zhao S. E. , Wang P. , Bonaldo S. , McCurdy M. W. , Tőkei Zs. , DeWolf I. , Croes Kristof , Zhang E. X. , Alles M. L. , Schrimpf R. D. , Reed R. A. , Linten D.
Published: May 2019

1.8-MeV proton irradiation to a fluence of 1014/cm2 does not significantly affect the resistance or low-frequency noise of copper or ruthenium resistors fabricated via modern microelectronic fabrication techniques used to form metal lines. The room-temperature noise of these Cu and Ru resistors is surprisingly similar to that of Cu and Pt metal lines and wires fabricated using late-1970s nanofabrication techniques; however, measurements of the temperature dependence of the noise show that the defect kinetics are quite different among the various materials. A large increase in the noise magnitude observed above 200 K in Cu but not in Ru is consistent with the superior resistance to electromigration that Ru lines have shown, relative to Cu.
Micromechanically motivated constitutive model embedded in two-dimensional polygonal finite element framework for magnetostrictive actuators
Authors: Sathish Kumar R. , Jayabal K.
Published: May 2019

A two-dimensional constitutive model based on micromechanical domain rotation events is presented in this work to demonstrate the nonlinear actuator behavior of magnetostrictive materials, in particular, Galfenol. The model constructed upon thermodynamic principles accounts back fields which resist or aid the domain rotation events inside a grain due to external magnetomechanical loading. The developed model is then incorporated into the polygonal finite element technique that combines Voronoi-based discretization with the hybrid finite element method. In this approach, the stress and magnetic flux density are treated as approximate functions inside the element, but the mechanical displacement and magnetic potential, which act as degrees of freedom, are defined only along the element boundary. This approach allows each randomly generated Voronoi polygon in the plane discretization to act as a single finite element mimicking an individual magnetomechanical grain in a polycrystalline Galfenol, eliminating the need for further subdiscretization of the Voronoi polygon. This coupled framework simulates the nonlinear actuator characteristics of the magnetostrictive material under complex magnetomechanical loading conditions in line with the experimental observations reported in the literature.
Intercalation of transition metals in aluminene bi-layers: An ab initio study
Authors: Pandey Dhanshree , Kamal C. , Chakrabarti Aparna
Published: May 2019

Using first principles calculations based on density functional theory (DFT), we probe various possible stacking arrangements of bilayer aluminene and intercalate six transition metal (TM) atoms (Ti, Cr, Mn, Fe, Co, and Ni) in unique bilayer aluminene systems. Further, we calculate valence charge density and electron localization function to ascertain the nature of bonding present in both the pristine and TM-intercalated composite systems. Intercalation of Cr, Mn, and Fe is found to result in the magnetic ground state. For Ti, Co, and Ni-intercalated systems, the starting trigonal symmetry has changed to a tetragonal symmetry. Co and Ni intercalated systems exhibit much higher (negative) formation energies compared to the other composite systems. In addition, nesting of the Fermi surface has been probed for the Co and Ni intercalated systems and observations indicate the possibility of the presence of charge density wave in the systems. A dispersion-corrected DFT study suggests that the van der Waals interaction is not likely to play a crucial role in determining the properties of both the pristine and TM-intercalated systems.
Local and global dynamics of the viscous ion conductors 2Ca(NO3)2-3KNO3 and 2Ca(NO3)2-3RbNO3 probed by 87Rb nuclear magnetic resonance and shear rheology
Authors: Beerwerth Joachim , Bierwirth S. Peter , Adam Jens , Gainaru Catalin , Böhmer Roland
Published: May 2019

The microscopic and macroscopic dynamics of calcium alkali nitrate melts are studied in their supercooled regime by means of shear rheology and nuclear magnetic resonance (NMR). The structural relaxation is probed using shear rheology to access the viscoelastic flow as well as using physical aging experiments. By exploiting the strongly quadrupole-perturbed 87Rb nucleus, the local dynamics is probed on the milliseconds to nanoseconds range using various NMR methods involving central-transition stimulated-echo techniques, line shape analyses, spin relaxations, and second-order dynamic shift effects. The time scales monitored via the local Rb probe are in harmony with the electrical conductivity relaxation times. The low-temperature NMR line shapes agree excellently with those predicted by the Czjzek model. The temperature dependent second-order dynamic frequency shift is described using the imaginary part of the spectral density. It is demonstrated how the latter quantity can be generalized to include effects of correlation time distributions.
Trajectory-adjusted electronic zero point energy in classical Meyer-Miller vibronic dynamics: Symmetrical quasiclassical application to photodissociation
Authors: Cotton Stephen J. , Miller William H.
Published: May 2019

An electronic zero-point energy (ZPE) adjustment protocol is presented within the context of the symmetrical quasiclassical (SQC) quantization of the electronic oscillator degrees of freedom (DOF) in classical Meyer-Miller (MM) vibronic dynamics for the molecular dynamics treatment of electronically nonadiabatic processes. The “adjustment” procedure maintains the same initial and final distributions of coordinates and momenta in the electronic oscillator DOF as previously given by the SQC windowing protocol but modifies the ZPE parameter in the MM Hamiltonian, on a per trajectory basis, so that the initial nuclear forces are precisely those corresponding to the initial electronic quantum state. Examples demonstrate that this slight modification to the standard SQC/MM approach significantly improves treatment of the multistate nonadiabatic dynamics following a Franck-Condon type vertical excitation onto a highly repulsive potential energy surface as is typical in the photodissociation context.
Linear and quadratic internally contracted multireference coupled-cluster approximations
Authors: Black Joshua A. , Köhn Andreas
Published: May 2019

Linear and quadratic approximations to the internally contracted multireference coupled-cluster (icMRCC) method are implemented and analyzed by using the linked and unlinked coupled-cluster formalisms. This includes methods based on perturbation theory as well as the coupled-electron pair approximation, CEPA(0). The similarities and differences between all the approximations serve to highlight and provoke discussion about methodological peculiarities of the icMRCC ansatz. When calculating potential energy curves (PECs), discontinuities are observed for the linear icMRCC energies. Using a diagrammatic representation, the terms that cause but also reduce these discontinuities are identified. For benchmarking test cases such as calculating PECs, singlet-triplet splittings, and barrier heights, the multireference CEPA(0) approximation performs well; however, it suffers from a lack of size consistency and so cannot represent a step forward to the goal of developing a computationally cheap and accurate icMRCC method.
Electron scattering from 1-butanol at intermediate impact energies: Total cross sections
Authors: Gomes M. , da Silva D. G. M. , Fernandes A. C. P. , Ghosh S. , Pires W. A. D. , Jones D. B. , Blanco F. , García G. , Brunger M. J. , Lopes M. C. A.
Published: May 2019

We report experimental measurements of the absolute total cross sections (TCSs) for electron scattering from 1-butanol at impact energies in the range 80–400 eV. Those measurements were conducted by considering the attenuation of a collimated electron beam, at a given energy, through a gas cell containing 1-butanol, at a given pressure, and through application of the Beer-Lambert law to derive the required TCS. We also report theoretical results using the Independent-Atom Model with Screening Corrected Additivity Rule and Interference approach. Those results include the TCS, the elastic integral cross section (ICS), the ionization total ICS, and the sum over all excitation process ICSs with agreement at the TCS level between our measured and calculated results being encouraging.
Revealing magnetic ground state of a layered cathode material by muon spin relaxation and neutron scattering experiments
Authors: Miao Ping , Wang Rui , Zhu Weiming , Liu Jiajie , Liu Tongchao , Hu Jiangtao , Li Shuankui , Tan Zhijian , Koda Akihiro , Zhu Fengfeng , Feng Erxi , Su Yixi , Kamiyama Takashi , Xiao Yinguo , Pan Feng
Published: May 2019

Although the majority of studies on battery materials have focused on enhancing their electrochemical performance, the understanding of their magnetic and atomic structures as well as the intimate connections between these structures and properties is significant. Muon spin relaxation (μSR) spectroscopy and neutron scattering techniques at low temperature have been used to explore the nature of the magnetic state of Li(Ni0.4Mn0.4Co0.2)O2 cathode materials. Interestingly, the μSR experiment reveals that the spins of Ni/Mn/Co ions turn glassy at a low temperature of 19 K, while the unprecedented spin dynamics survives until the base temperature of 5.6 K. Moreover, the complementary neutron scattering measurements show magnetic diffuse scattering signals in the form of a broad peak at Q = 1.6 Å−1 attributed to short-range spin correlation which establishes below ∼120 K. Upon cooling to as low as 480 mK, long-range magnetic order still could not be established. The inelastic neutron scattering intensities demonstrate clearly the existence of dynamic spin fluctuations. In contrast to the conventional spin glass system, the coexistence of both dynamic and static components in the ground state suggests an unconventional spin glass state in magnetically frustrated Li(Ni0.4Mn0.4Co0.2)O2 cathode materials for Li-ion batteries.
Global gyrokinetic simulation of microturbulence with kinetic electrons in the presence of magnetic island in tokamak
Authors: Fang K. S. , Lin Z.
Published: May 2019

An electrostatic model has been formulated and implemented in the gyrokinetic toroidal code to study the nonlinear ion temperature gradient (ITG) turbulence in the presence of an n = 1, m = 2 magnetic island. The ions are described by the gyrokinetic equation while the electrons are treated with the drift-kinetic equation. In our simulation, an n = 1, m = 2 electrostatic mode is formed with the same vortex structure of the magnetic island. When the magnetic island flattening effect is turned on, the island vortex mode is well preserved and couples to the n = 0, m = 0 geodesic acoustic mode. Simulation shows that the magnetic island can suppress the ITG turbulence at the island O-point and strengthen it near the X-point. We show that the vortex mode can generate a substantial helical shear flow around the island. We also find that the turbulence and transport are suppressed inside the island and enhanced at the island X-point.
Photoionization and dissociation study of 2-methyl-2-propen-1-ol: Experimental and theoretical insights
Authors: Yu Ye-peng , Li Zhao-hui , Lin Xuan , Chen Jun , Zhang Hang , Li Yan-bo , Wang Huang-huang , Sun Rui-rui , Meng Qing-hui , Shan Xiao-bin , Liu Fu-yi , Sheng Liu-si
Published: May 2019

The photoionization and dissociation of 2-methyl-2-propen-1-ol (MPO) have been investigated by using molecular beam experimental apparatus with tunable vacuum ultraviolet synchrotron radiation in the photon energy region of 8.0–15.5 eV. The photoionization efficiency (PIE) curves for molecule ion and fragment ions: C4H8O+, C4H7O+, C3H5O+, C4H7+, C4H6+, C4H5+, C2H4O+, C2H3O+, C3H6+, C3H5+, C3H3+, CH3O+, CHO+ have been measured, and the ionization energy (IE) and the appearance energies (AEs) of the fragment ions have been obtained. The stable species and the first order saddle points have been calculated on the CCSD(T)/cc-pvTZ//B3LYP/6-31+G(d,p) level. With com-bination of theoretical and experimental results, the dissociative photoionization pathways of 2-methyl-2-propen-1-ol are proposed. Hydrogen migrations within the molecule are the dominant processes in most of the fragmentation pathways of MPO.
Channel-resolved ultrafast dissociation dynamics of NO2 molecules studied via femtosecond time-resolved ion imaging
Authors: Wang Qin-xin , Shi Dan-dan , Zhang Jun-feng , Wang Xue , Si Yu , Gao Chun-bin , Fang Jian , Luo Si-zuo
Published: May 2019

The ultrafast dissociation dynamics of NO2 molecules was investigated by femtosecond laser pump-probe mass spectra and ion images. The results show that the kinetic energy release of NO+ ions has two components, 0.05 eV and 0.25 eV, and the possible dissociation channels have been assigned. The channel resolved transient measurement of NO+ provides a method to disentangle the contribution of ultrafast dissociation pathways, and the transient curves of NO+ ions at different kinetic energy release are fitted by a biexponential function. The fast component with a decay time of 0.25 ps is generated from the evolution of Rydberg states. The slow component is generated from two competitive channels, one of the channel is absorbing one 400 nm photon to the excited state A2B2, which has a decay time of 30.0 ps, and the other slow channel is absorbing three 400 nm photons to valence type Rydberg states which have a decay time less than 7.2 ps. The channel and time resolved experiment present the potential of sorting out the complex ultrafast dissociation dynamics of molecules.
Two-dimensional VDW crystal SnP3 with high carrier mobility and extraordinary sunlight absorbance
Authors: Wang Chen , Hu Ting , Kan Erjun
Published: May 2019

Although bulk SnP3 has been fabricated by experiments in the 1970’s, its electronic and optical properties within several layers have not been reported. Here, based on first-principles calculations, we have predicted two-dimensional SnP3 layers as new semiconducting materials that possess indirect band gaps of 0.71 eV (monolayer) and 1.03 eV (bilayer), which are different from the metallic character of bulk structure. Remarkably, 2D SnP3 possesses high hole mobility of 9.171 × 104 cm2·V−1·s−1 and high light absorption (~106 cm−1) in the whole visible spectrum, which predicts 2D SnP3 layers as prospective candidates for nanoelectronics and photovoltaics. Interestingly, we found that 2D SnP3 bilayer shows similar electronic and optical characters of silicon.
Chinese L2 users as active social agents: Sentence final particles variation and identities
Authors: Han Yiting
Published: May 2019

This study investigated the sociolinguistic pragmatic
performance of eight advanced Chinese learners from a variationist
sociolinguistic perspective, focusing on the variable appearance versus absence
of Mandarin sentence final particles (SFPs) in non-interrogative sentences.
These learners participated in a Chinese TV talk show and have become popular on
social media platforms. The speech data from the talk show (400 tokens) and
online data from Chinese social media platform Weibo (400 tokens) were collected
and analyzed. These Chinese L2 users productively demonstrated variation in
their use of SFPs in non-interrogative sentences, in that they added SFPs to a
sentence in around 20% of variable contexts. Rbrul (logistic regression)
analyses revealed that the variable presence of SFPs was conditioned by their
duration of time spent in China and gender-related personalities. Follow-up case
analyses explored how they made use of SFPs in different situations and how they
were received by other participants. The study found that these Chinese L2 users
became active social agents who made decisions to shift styles in different
contexts or to strengthen their identities. The results are discussed within a
broader context of identity, language socialization, and L2 social agency. This
study also attempts to offer pedagogical implications for the acquisition of
Chinese SFPs.
The rivalry between far from being + predicative item and its counterpart omitting the copula in Modern English
Authors: Vosberg Uwe , Rohdenburg Günter
Published: May 2019

Distinguishing between several subtypes of the frame far from + optional and recessive being + predicative phrase, this paper charts the evolution of the rivalling variants in British and American English over the last few centuries. The paper reports on two major findings. First, in line with the Complexity Principle, there is a tendency for more complex predicatives to help preserve the more explicit being variant better than simpler ones. In particular, morphologically complex adjectives and syntactically complex noun phrases in the predicative slot are shown to retain the being variant longer than less complex ones. Second, as regards the establishment of the less explicit zero variant, the relation between British and American English corresponds to the so-called lag and overtake scenario. While initially trailing behind British English, American English has - in more recent times - adopted the zero variant much faster than British English.
The relevance of specific semantic categories in investigating the neural bases of abstract and concrete semantics
Authors: Dreyer Felix R. , Pulvermüller Friedemann
Published: May 2019

Previous research has shown that modality-preferential sensorimotor areas are relevant for processing of words referring to concrete objects or actions. However, whether modality preferential areas also play a role for abstract words is still under debate. In this chapter we will argue that the apparent lack of empirical evidence for a grounding of abstract words stems, at least in part, from the treatment of abstract words as one monolithic semantic category, rather than taking into account specific abstract word types and sub-categories. We will review classical and recent empirical evidence from neuropsychological, neuroimaging and behavioral approaches and demonstrate the necessity of considering specific semantic meaning types when investigating a possible grounding of concrete and abstract concepts, for both theoretical and methodological reasons.
Acceptability properties of abstract senses in copredication
Authors: Murphy Elliot
Published: May 2019

This chapter explores the acceptability properties of copredication and how they can inform debates about the representation of abstract concepts. Across a series of acceptability judgment experiments, it was tested whether copredication in book-, lunch- and city-type nominals is difficult across-the-board or depends on adjective ordering in sentences like “John said that the folded and educational newspaper was on the shelf”. The results revealed no acceptability difference between copredication and non-copredication, however there was a strong preference for concrete adjectives to be placed before abstract ones. It is suggested for the first time that the parser is sensitive to semantic complexity, and that it is more optimal to access abstract concepts after associated concrete concepts than the reverse.
Different degrees of abstraction from visual cues in processing concrete nouns
Authors: Franzon Francesca , Zanini Chiara
Published: May 2019

Concreteness has been defined as a semantic property related to physical perception. In this paper we tackle the concreteness issue from the viewpoint of countability by arguing that uncountable expressions (e.g., some cake), although concrete, are more abstract than countable ones (e.g., one cake) since the former entail the suppression of the reference to shape, which is a salient property in the representation of entities.

We report empirical data collected with preschool children in which we show that the uncountable reference is dispreferred. We discuss possible reasons for this phenomenon, which involve the roles played by shape and by language (and in particular grammar) in early perceptual processing, and we suggest how these factors may relate to our ability to abstract from perceptual experience.
The development of the abstract scientific concept of heat energy in a naturalistic classroom setting
Authors: Zacharias Sally
Published: May 2019

Science aims to understand the physical and living world around us. To do this, it requires us to develop abstract ways of thinking. The aim of this chapter is to describe and explain how the abstract concepts of heat energy and heat transfer emerge and evolve during two secondary (high) school science lessons, by providing an account of how they are linguistically represented in discourse using a cognitive discursive framework. The analysis of a teacher-led demonstration, a group writing task, and an interview, during which pupils externalize their mental images in speech, writing, and in visual representations, shows how the discourse as well as the social and concrete here-and-now physical contexts, affect the development of these abstract concepts.
An outline of some future research issues for internet pragmatics
Authors: Yus Francisco
Published: May 2019

Internet communication has evolved a lot since it first became popular in the early nineties of the last century. Pragmatics has also evolved and has tried to come to terms with the non-stop changes that internet is constantly producing in our lives and especially in how we communicate and interact. We are probably now at a stage of internet development in which we can make some sound predictions regarding certain challenges that a pragmatics of internet communication will have to face in the next few years to deal with the radical changes that are taking place in today’s internet use. This article will be devoted to listing some of these research issues and to discussing what pragmatics can do to address them accurately, ranging from those issues centred upon the interpretation of online discourses to those involving interfaces and their options for contextualisation.
The pragmatic use of vocatives in private one-to-one digital communication
Authors: Asprey Esther , Tagg Caroline
Published: May 2019

This article examines a corpus of private text messages collected in Birmingham and surrounding towns in 2015. We look specifically at pragmatic roles played by the vocatives we find in the corpus. Since text messages are sent to targeted recipients, vocatives are structurally redundant, and we review literature concerning vocatives in spoken and written data to first see what categories others have proposed for these functions. We then challenge some of these categorisations, identifying a new category of ‘focuser’ which we argue is akin to a summons in spoken language. We also examine the pragmatic value of vocatives in performing identity work for both sender and receiver. We finish by looking at gendered performance of identity as a case study in our corpus of how text producers construct themselves and others.
Discursive metaphorical frames in newspaper texts on language change
Authors: Bogetić Ksenija
Published: May 2019

The concept of ‘metaphorical framing’ is currently witnessing renewed interest in metaphor research, but for discourse-oriented work it remains a problematic analytical tool given the variety of senses it has been employed with. The present paper considers an approach to metaphorical frames in discourse, by proposing the notion ofdiscursive metaphorical framesto capture the complex, systematic metaphorical representations prominent across discourse. The perspective follows the direction of recent integrated approaches to metaphor, frames and discourse (e.g.,Burgers et al., 2016;Cameron et al., 2009;Semino et al., 2016) and is proposed as particularly suited to studying public discourses, as ideologically laden, multi-textual and multi-voiced. The approach is illustrated through an analysis of metaphorical representations of language in Serbian and British newspapers. The analysis reveals the deeper social ideologies underlying the newspaper discussions on language in Serbia and Great Britain, including similarities as well as notable differences, pointing to the diverse ideological processes shaping contemporary media metadiscourses. The results are also discussed in relation to the adopted approach, to frames of presentation, (sub)domain representations and the dynamics of metaphor use in public discourse.
The effectiveness of the Conceptual Metaphor Approach to English idiom acquisition by young Chinese learners
Authors: Pan Molly Xie
Published: May 2019

Although the Conceptual Metaphor Approach (CMA) has been claimed to be effective with respect to English idiom acquisition for EFL/ESL learners at elementary level, the claim awaits further investigation with empirical evidence (Beréndi, Csábi, & Kövecses, 2008;Boers, 2004). How CMA benefits these learners’ idiom acquisition and in what way it can best be implemented in their classrooms remain unknown. This study addresses these issues and sheds light on the effectiveness of CMA through a quasi-experiment, in which metaphor is exploited as an intervention that explicitly introduces the connection between idioms and the underlying Conceptual Metaphor theme. Quantitative and qualitative data were collected from 43 participants through questionnaires, tests and a semi-structured interview with the instructor. Results from an immediate post-test showed that participants under CMA scored higher than their counterparts who were undergoing a Memorizing Translation Approach, though the difference was statistically insignificant (p = 0.08). A one-week delayed post-test found that CMA facilitated idiom acquisition at a statistically significant level (p < .05). Findings from participants’ drawings and the semi-structured interview showed that CMA had contributed to an engaging and active learning experience. Pedagogical implications of this study are discussed further.
Elicited imitation as a diagnostic tool of morpho-syntactic processing
Authors: Saturno Jacopo
Published: May 2019

This chapter evaluates the Elicited Imitation (EI) test as a tool to assess learners’ morpho-syntactic processing abilities. Within the VILLA project, the treatment of the nominative/accusative opposition by 17 Italian L1 initial learners of Polish L2 is observed on the one hand in an EI test paired with a comprehension test and on the other hand in free production. The EI test regularly elicits more accurate output than free production. We argue that this is not because learners simply repeat strings of sounds with no underlying processing but because of the lower communicative pressure exerted by the structured task. Although EI is not equivalent to spontaneous production, it may well represent a good compromise between ecological validity and practicality.
The acquisition of Turkish (genitive-)possessive structures by adult Norwegian learners
Authors: Heiden Emel Türker-van der , Mercan Gözde
Published: May 2019

This study investigates the development of phrasal and clausal (Genitive)-Possessive structures in L2 Turkish. The phrasal structures under scrutiny are possessive noun phrases and nominal phrases/compounds consisting of a bare noun and a following possessive noun. The clausal structures are subordinated noun clauses with verbal predicates nominalized through the -mA and -DIK1 suffixes. The data comprise translations and exam essays of Norwegian university students who received Turkish instruction at the University of Oslo across four semesters over two years. We provide a descriptive analysis of the target and non-target structures produced by these learners. This study may pave the way for a future Processability Theory analysis of these structures in the data from this particular group of L2 learners.
Heritage language development and the promise of Processability Theory
Authors: Montrul Silvina
Published: May 2019

Heritage language acquisition is a type of early bilingual acquisition that takes place in a specific sociolinguistic environment. The heritage language is a societal minority language, acquired as a first language, either by itself or simultaneously with the majority language. Very often the heritage language is not supported at school, and it is common for heritage speakers to eventually achieve greater fluency and proficiency in the majority language than in the heritage language. As a result the heritage language shows many of the linguistic characteristics of a second language. The acquisition of heritage languages has been approached from different perspectives within linguistics, bilingualism and language acquisition. This chapter considers the applicability of Processability Theory, primarily conceived to explain second language acquisition and processing, to the acquisition of heritage languages.
The dynamics of ethnocentrism in Europe. A comparison of enduring and emerging determinants of solidarity towards immigrants
Authors: Aschauer Wolfgang , Mayerl Jochen
Published: May 2019

This article examines cross-national differences in solidarity towards immigrants in the EU. This concept of solidarity is operationalized through perceived ethnic threat vs. a positive view of multicultural society. The main argument of this article is that ‘classical’ enduring determinants (sociodemographic factors, subjective values and structural factors) are still able to explain ethnocentrism, but these factors are enriched and mediated by a cluster of five emerging explanatory factors which reflect societal malaise. These factors include dissatisfaction with society, political distrust, fear of social decline, lack of recognition, and social distrust. The thesis of societal malaise as a powerful concept to explain contemporary restrictions of macro-solidarity is tested with a Multiple-Group Structural Equation Model using data from 21 countries of the European Social Survey (wave 6 2012). A theory-guided approach is used to categorize European nations into six heterogeneous European areas. Statistical analyses reveal that new emerging factors of societal malaise indeed act as a mediator of classical explanations of ethnocentrism. From a comparative perspective, the determinants of macro-solidarity are strongly heterogeneous throughout the six European areas particularly between the East and West of the European Union.