Exchange Competition Research Articles

An evaluation of the consistency of data and models for performance assessment: Divalent metal sorption on montmorillonite

A detailed analysis of literature data on the retention of divalent metal by purified montmorillonite or montmorillonite-rich material (e.g. bentonite) was conducted. Data for which sufficient experimental conditions were available were modeled with the 2SPNE SC/CE model available in the literature, and with a “minimalist” model, which uses a minimum number of parameters to reproduce the data.A successful data modeling could only be achieved if considering (i) cation exchange competition with aqueous Ca2+ and Mg2+, originating from the dissolution of the clay mineral itself or accessory minerals and (ii) precipitation, at high pH, of phases incorporating the divalent metal of interest. However, in many studies, the concentration of aqueous Ca2+ and Mg2+ and, more generally, a full characterization of solution composition (e.g., Si, Al, dissolved organic carbon, alkalinity) is not provided, thus impeding accurate data modeling. Further difficulties stem from uncertainties related to the nature of the solids precipitating at high pH and missing or inaccurate thermodynamic data related to mineral solubility.Log KD values cannot be predicted from available literature data with an accuracy better than ±1 log unit, without sorption data obtained on a material representative of in situ conditions. In addition, the most reactive sites, commonly referred to as strong sites, which have been characterized only on some, but not all, reference clay materials, should not be considered in blind predictions based on the mineralogical composition of clay materials.

The (geo)politics of controlling shareholders

Abstract In this Article, I extend the analysis of controlling shareholders typically reflected in corporate governance scholarship—which is fundamentally framed in terms of shareholder wealth creation and diversion at the behest of the controller—to the increasing (geo)political significance of firms with controlling shareholders. This effort requires shifting the unit of analysis to the fusion of political-economic power inherent in corporate control and examining the implications of this fusion beyond the boundaries of the firm itself. I illustrate the approach by analyzing examples from a variety of new and old corporate capitalist systems operating globally today, and by surveying numerous policy domains in which firms with controlling shareholders are key protagonists: national security and economic sanctions, stock exchange competition, corporate influence on domestic political systems, and ESG. Expanding the lens through which controlling shareholders are viewed sheds light on their considerable influence in largely unexplored realms of wideranging geostrategic and political importance.

A Theory of Stock Exchange Competition and Innovation: Will the Market Fix the Market?

A Theory of Stock Exchange Competition and Innovation: Will the Market Fix the Market?

Spectroscopic study of cooperative states of Nd3+ pair centers in fluorite-type crystals: A competition of dipole-dipole and quadrupole-quadrupole energy exchange

Pair centers of Nd3+ ions in the CdF2, CaF2, and SrF2 doped crystals at T=6.5K were studied under tunable narrow-linewidth laser excitation. It has been established that the exchange of electronic excitation leads to the splitting of the one-exciton cooperative 4G5/2(1) x 4I9/2(1) state by 2–3 cm−1 with a non-monotonic dependence on the distance between the ions in the pairs in these crystals. This dependence is explained by the competition of forced dipole-dipole and quadrupole-quadrupole interactions with spin flip. The high rate of such exchange mechanisms is due to strong spin–orbit interaction and small energy difference between the 4f levels of Nd3+ ions. It is shown that the pair centers in all one-exciton cooperative states, in contrast to the ground and two-exciton excited states, have nonzero static dipole moments. This makes it possible to use the latter states as ultrafast qubits, and one-exciton states as control qubit to implement a CNOT quantum gate.

Analysis of Terms of Trade of Agricultural Commodities in Afghanistan

The agricultural sector plays a leading role in the national exports of Afghanistan. Still, prolonged war and political instability in the country have weakened internal food security, intensified the dependence on imports of food items, and made the country suffer a chronic agricultural trade deficit.This engulfing agricultural trade deficit is attributed to a relative growth in agricultural exports and imports and a relative change in export prices.The present study attempted to examine the exchange competitiveness of traded commodities by estimating a ratio of export prices to import prices.The results showed that the commodity terms of trade of agricultural exports versus agricultural imports of Afghanistan with the rest of the world had increased during the study period. It was suggested that the country focus on producing quality products with a higher market value at a low-costto gain from international trade.

Spin Wave Spectra in Pseudoperovskite Manganites with Superexchange Interaction Competition

In compounds La1/3Ca2/3MnO3 and BiMnO3, a calculation of spin-wave dispersion dependences along pseudoperovskite directions of reciprocal space is made. The model includes orbitally dependent superexchange interaction and single-ion anisotropy. Considered compounds present competing exchange interactions within magnetic unit cell because of orbital or charge-orbital ordering. The nearest neighbor superexchange interaction is taken into account. The magnetic structure and dispersion dependences of spin waves frequencies are calculated within the framework of regular multi-sublattice model. The peculiarities of frustrated magnetic spin-wave spectra are found. It is shown, that crossing and splitting of spin-waves branches in non-symmetric points of magnetic Brillouin zone is a common feature of the spectra due to exchange competition. The band structure of Г-point spectra for both compounds are predicted.

Density Functional Theory Studies on Magnetic Manipulation in NiI2 Layers

Effective manipulation of magnetic states is fundamentally important to modern data storage and electronic devices that underpin the information age. Controlling magnetism via electric fields instead of magnetic fields has long been envisioned as a revolutionary technology to achieve higher energy efficiency and ultimate device miniaturization. The electric field paradigms, however, face major challenges of volatility, high energy cost, and low storage density. In this work, from density functional theory simulations, we developed effective approaches to achieve magnetic control in bilayer NiI2 via electrostatic doping and polarization field of the ferroelectric heterostructure. The interlayer antiferromagnetic (AFM) to ferromagnetic (FM) transition has been observed in bilayer NiI2 when the critical electron doping concentration reaches 0.625% due to the magnetic exchange competition between antiferromagnetic and ferromagnetic couplings. The critical concentration of magnetic transition can be reduced or increased depending on the polarization direction when it is placed on the ferroelectric substrate of Sc2CO2 as a result of polarization-induced interfacial electron transfer. Owing to the antiferromagnetic-to-ferromagnetic (AFM–FM) transition, the reversal of ferroelectric polarization modulates the electronic properties dramatically due to the strong interfacial magnetoelectric effect. The magnetic and electronic manipulation from electrostatic doping and polarization provides feasible approaches for next-generation electronics and spintronics.

The Demise of the NYSE and Nasdaq: Market Quality in the Age of Market Fragmentation

AbstractU.S. equity exchanges have experienced a dramatic increase in competition from new entrants, resulting in the fragmentation of trading across venues. While market quality has generally improved over this period, we show most of the improvements have accrued to the largest stocks. We then show this bifurcation in market quality is related to the fragmentation of trading. Theoretically, more exchange competition should reduce trading costs, yet it may also increase adverse selection for liquidity providers, leading to higher spreads. We document evidence of both effects (fragmentation improves market quality for large stocks while small stocks experience relatively worse quality).

Correlation vs. exchange competition drives the singlet-triplet excited-state inversion in non-alternant hydrocarbons.

In this work, we focus on the understanding of the driving force behind the S1-T1 excited-state energy inversion (which would thus violate Hund's rule, making the S1 state lower in energy than the T1 state) of two non-benzenoid non-alternant hydrocarbons, composed of odd-membered rings. The molecules considered here have identical chemical composition but different atomic configuration in space. The delicate interplay between structural and electronic factors that might induce inversion and its energy extension, only by a few meV, is systematically investigated here by state-of-the-art calculations. Qualitative and quantitative accurate predictions are obtained employing post-HF methods, thanks to the balanced and careful inclusion of electron correlation effects. The obtained results might guide and rationalize new searches for molecules violating Hund's rule, concomitantly demonstrating the importance of key contributions from the theoretical method of choice.

Exchange introduction and market competition: The entrance of MEMX and MIAX

In September of 2020, two new equity exchanges, Members Exchange and Miami International Holdings Pearl Equities Exchange, were introduced further fragmenting an already vast array of venues that trade equities in the United States. In this paper we examine several aspects exchange competition following the introduction of these exchanges. We find that NASDAQ appears to lose market share and IEX appears to gain market share in the post-introduction period. This is interesting as IEX is a fee-based model, where order routers will not receive a rebate, and also introduces a speed bump, which could result in slower executions. Using Rule 605 data we document that IEX exhibits faster execution following the introduction. Finally, we examine clientele effects and find that known proxies for algorithmic trading and retail trading increase in the post introduction period.

Impact of maker-taker fees on stock exchange competition from an agent-based simulation

Impact of maker-taker fees on stock exchange competition from an agent-based simulation

Thermal and magnetic properties of chalcogenide CZFTS nanoparticles for solar cell application

An attempt is made to resolve the controversy related to the reconstruction mechanism of magneto-optical stannite/kieserite crystal structure with a random mixture of two quaternary compounds of Cu2ZnSnS4-Cu2FeSnS4 while the identification of phase formation by XRD is difficult. Since the Fe is surprisingly emerged on the Cu position while Fe is replaced by Zn. The induced dynamical sliding by Cu-ionic-host could be existed which is strongly consequence of magnetic exchange competition (F.M and AFM) through the thermos remanent magnetic reflected on DTA thermal loop. Towards the distortion of intra-plane “a-b”, the volume unit cell and c/a are decreased to minimize Gibbs free energy where the band gap energy is also decreased. The broad maximum of Raman spectroscopy is almost decreased linearly. A strong competition between F.M and AF.M due to the distribution of exchange interaction are evident in x≤0.5 which is dominated by AF.M on x=1.

Magnetic and lattice excitations in the quasi-2D quantum spin compound (CuCl)LaNb2O7

Raman scattering phonon data of the quasi-two-dimensional quantum spin system (CuCl)LaNb2O7 are used to derive an effective structural model that may serve as a basis for its unconventional magnetic properties. Furthermore, a rich spectrum of magnetic excitations is observed, including quasielastic energy density fluctuations and finite energy bound states. These modes are the key to understand (CuCl)LaNb2O7 as a system with strong interactions between well-localized triplet excitations based on a pronounced competition of magnetic exchange.

Exchange Competition, Entry, and Welfare

Abstract We assess the consequences for market quality and welfare of different entry regimes and exchange pricing policies. To do so, we integrate a microstructure model with a free-entry, exchange competition model where exchanges have market power in technological services. Free-entry delivers superior liquidity and welfare outcomes vis-á-vis an unregulated monopoly, but entry can be excessive or insufficient. Depending on the extent of the monopolist’s technological services undersupply compared to the first best, a planner can achieve a higher welfare controlling entry or platform fees. Review of Financial Studies, forthcoming

The diffusion mechanism of the application of intelligent manufacturing in SMEs model based on cellular automata

Abstract Based on the characteristics of intelligent manufacturing and the theory of technology diffusion, this paper constructs a cellular automata model with government support policy, information exchange, technology maturity, diffusion intermediary, and market competition as the influencing factors and analyzes the influence mechanism of the first three main factors on the diffusion of intelligent manufacturing technology in industrial clusters using MATLAB. This paper also makes an empirical analysis of the diffusion of intelligent manufacturing technology in the bearing industry cluster in Xinchang County and finds that the results are basically consistent by comparing the simulation data with the fit degree of the real data. In this paper, the diffusion intermediary and government support policy have the greatest influence on the application of intelligent manufacturing in small- and medium-sized enterprises, and the model proposed in this paper is effective.

Time complexity evaluation of cover song identification algorithms

Cover Song Identification (CSI) is a task in Music Information Retrieval (MIR) that attempts to identify other versions of a song containing different structures, tonalities, and tempos, what brings several challenges to this task. Some of frameworks proposed to identify cover songs were evaluated through the Music Information Retrieval Evaluation eXchange (MIREX) competition that aims to assess algorithms for MIR tasks. Among the problems faced by researchers is the time complexity of the algorithms considered in the context of CSI, what limits or makes unfeasible their application in real-world scenarios. Considering this challenge, we present a time complexity evaluation of the two most popular frameworks presented and ranked at the MIREX competition. This assessment confirms both algorithms have the same worst-case scenario of O(n2), besides a significant difference in terms of their constants, which impact in overall processing time. Finally, this analysis can support researchers to improve algorithms for the CSI task, thus leading to more suitable frameworks for real-world scenarios.

Lattice Solutions in a Ginzburg\u2013Landau Model for a Chiral Magnet

We examine micromagnetic pattern formation in chiral magnets, driven by the competition of Heisenberg exchange, Dzyaloshinskii–Moriya interaction, easy-plane anisotropy and thermodynamic Landau potentials. Based on equivariant bifurcation theory, we prove existence of lattice solutions branching off the zero magnetization state and investigate their stability. We observe in particular the stabilization of quadratic vortex–antivortex lattice configurations and instability of hexagonal skyrmion lattice configurations, and we illustrate our findings by numerical studies.

The electric and magnetic properties of novel two-dimensional MnBr2 and MnI2 from first-principles calculations

The structural, electronic, and magnetic properties of two-dimensional (2D) manganese dibromide (MnBr2) and manganese diiodide (MnI2) are investigated using first principles calculations. The dynamical and thermal stabilities of 2D MnBr2 and MnI2 have been illustrated from the phonon dispersion and molecular dynamic calculations. From the phonon dispersion, three Raman-active and three infrared-active vibration modes are found. The calculated formation energies and cleavage energies indicate that 2D MnBr2 and MnI2 are energetically stable and could be potentially obtained by exfoliation. The hybrid functional theory is employed to discover that 2D MnBr2 and MnI2 are wide gap semiconductors. The magnetic frustration is revealed by the calculation of magnetic exchange interaction and magnetocrystalline anisotropy interaction. By analyzing different magnetic orders, the relatively weak magnetic exchange is attributed to the competition of the direct exchange and the superexchange interaction.

Will the Market Fix the Market? A Theory of Stock Exchange Competition and Innovation

This paper builds a new model of financial exchange competition, tailored to the institutional details of the modern US stock market. In equilibrium, exchange trading fees are competitive but exchanges are able to earn economic profits from the sale of speed technology. We document stylized facts consistent with these results. We then use the model to analyze incentives for market design innovation. The novel tension between private and social innovation incentives is incumbents’ rents from speed technology in the status quo. This creates a disincentive to adopt new market designs that eliminate latency arbitrage and the high-frequency trading arms race.

C−H Functionalization—Prediction of Selectivity in Iridium(I)‐Catalyzed Hydrogen Isotope Exchange Competition Reactions

AbstractAn assessment of the C−H activation catalyst [(COD)Ir(IMes)(PPh3)]PF6 (COD=1,5‐cyclooctadiene, IMes=1,3‐bis(2,4,6‐trimethylphenyl)imidazol‐2‐ylidene) in the deuteration of phenyl rings containing different functional directing groups is divulged. Competition experiments have revealed a clear order of the directing groups in the hydrogen isotope exchange (HIE) with an iridium (I) catalyst. Through DFT calculations the iridium–substrate coordination complex has been identified to be the main trigger for reactivity and selectivity in the competition situation with two or more directing groups. We postulate that the competition concept found in this HIE reaction can be used to explain regioselectivities in other transition‐metal‐catalyzed functionalization reactions of complex drug‐type molecules as long as a C−H activation mechanism is involved.