Fundamental Properties Of Nature Research Articles

Chiral Quantum Materials: When Chemistry Meets Physics.

Chirality is a fundamental property of nature with relevance in biochemistry and physics, particularly in the field of catalysis. Understanding the mechanisms underlying chirality transfer is crucial for advancing the knowledge of chiral-related catalysis. Chiral quantum materials with intriguing chirality-dependent electronic properties, such as spin-orbital coupling (SOC) and exotic spin/orbital angular momentum (SAM/OAM), open novel avenues for linking solid-state topologies with chiral catalysis. In this review, the growth of topological homochiral crystals (THCs) is described, and their applications in heterogeneous catalysis, including hydrogen evolution reaction (HER), oxygen electrocatalysis, and asymmetric catalysis are summarized. A possible link between chirality-dependent electronic properties and heterogeneous catalysis is discussed. Finally, existing challenges in this field are highlighted, and a brief outlook on the impact of THCs on the overarching chemical-physical research is presented.

"Point-Line-Plane-Helix" Binuclear Platinum(II) Complexes: Metal-Induced Chirality, Chirality Self-Sorting, and Chiroptical Properties.

Chirality is a fundamental property of nature, and thus, building novel chiral molecules plays a crucial role in multidisciplinary fields. Herein, we have developed a straightforward approach to effectively incorporate all four types of point, axial, planar, and helical chiralities into a single molecule for the first time. The resultant "point-line-plane-helix" binuclear Pt(II) complexes exhibit multiple chiralities, including not only point and axial chiralities from the bridging ligands but also planar and helical chiralities from metal coordination. The intramolecular π-π and Pt-Pt interactions will restrict intramolecular rotations, thereby stabilizing the metal-induced planar and helical chiralities. Furthermore, enantiopure (R,R,R,Rp,M) or (S,S,S,Sp,P) molecules could be obtained by chirality self-sorting without the use of chiral high-performance liquid chromatography. Their single-crystal, circular dichroism, and circularly polarized luminescence properties are comprehensively investigated, providing unequivocal insights into the design of multiple-chirality materials for related applications.

Tailoring the Recognition Property of a 19F-Labeled Gallium-Based NMR Probe: The Influence of the Metal Center.

Chirality is a fundamental property of nature and an essential element of the life process. As the biological activities, metabolic pathways, and toxicity of individual enantiomers are often varied, methods to rapidly and accurately discriminate chiral analytes are in great demand. Here, we report a 19F-labeled gallium-based probe for the enantiodifferentiation of chiral monoamines, diamines, amino alcohols, amino acids, and N-heterocycles. A comparison between the new gallium-based probe and the previously developed aluminum aminotrisphenolate complex was performed. It was revealed that the gallium metal center displays a much stronger affinity toward the amino group compared to the hydroxy group, thereby producing simplified 19F NMR signals for analytes with multiple Lewis basic sites. For sterically bulky analyte, the replacement of the aluminum with gallium is envisioned to expand the binding pocket of the probe to allow different binding models to interconvert rapidly. This feature is important to the creation of easily interpretable 19F signals corresponding to each enantiomer. It is further demonstrated that the gallium-based probe is suitable for the assessment of the enantiomeric excess values of the crude products obtained in asymmetric reactions without the need for purification.

Perspectives and opportunities: a molecular toolkit for fundamental physics and matter-wave interferometry in microgravity * *A portion of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

The study of molecular physics using ultracold gases has provided a unique probe into the fundamental properties of nature and offers new tools for quantum technologies. In this article we outline how ultracold molecular physics in a space environment opens opportunities for (a) exploring ultra-low energy regimes of molecular physics with high efficiency, (b) providing a toolbox of capabilities for fundamental physics, and (c) enabling new classes of matter-wave interferometers with applications in precision measurement for fundamental and many-body physics.

Electrochemical Bottom-Up Synthesis of Chiral Carbon Dots from L-Proline and Their Application as Nano-Organocatalysts in a Stereoselective Aldol Reaction.

Chirality is undoubtedly a fundamental property of nature since the different interactions of optically active molecules in a chiral environment are essential for numerous applications. Thus, in the field of asymmetric synthesis, the search for efficient, sustainable, cost-effective and recyclable chiral catalysts is still the main challenge in organic chemistry. The field of carbon dots (CDs) has experienced tremendous development in the last 15 years, including their applications as achiral catalysts. Thus, understanding the implications of chirality in CDs chemistry could be of utmost importance to achieving sustainable and biocompatible chiral nanocatalysts. An efficient and cost-effective electrochemical synthetic methodology for the synthesis of L-Proline-based chiral carbon dots (CCDs) and EtOH-derived L-Proline-based chiral carbon dots (CCDs) is herein reported. The electrochemical set-up and reaction conditions have been thoroughly optimised and their effects on CCDs size, photoluminescence, as well as catalytic activity have been investigated. The obtained CCDs have been successfully employed to catalyze an asymmetric aldol reaction, showing excellent results in terms of yield, diastereo- and enantioselectivity. Moreover, the sustainable nature of the CCDs was demonstrated by recycling the catalysts for up to 3 cycles without any loss of reactivity or stereoselectivity.

Formal Modeling and Performance Evaluation for Hybrid Systems: A Probabilistic Hybrid Process Algebra-Based Approach

Probabilistic behavior is omnipresent in computer-controlled systems, in particular, so-called safety-critical hybrid systems, due to various reasons, like uncertain environments or fundamental properties of nature. In this paper, we extend the existing hybrid process algebra ACP[Formula: see text] with probability without sacrificing the nondeterministic choice operator. The existing approximate probabilistic bisimulation relation is fragile and not robust in the sense of being dependent on the deviation range of the transition probability. To overcome this defect, a novel approximate probabilistic bisimulation is proposed which is inspired by the idea of Probably Approximately Correct (PAC) by relaxing the constraints of transition probability deviation range. Traditional temporal logics, even probabilistic temporal logics, are expressive enough, but they are limited to producing only true or false responses, as they are still logics and not suitable for performance evaluation. To settle this problem, we present a new performance evaluation language that expands quantitative analysis from the value range of [Formula: see text] to real number to reason over probabilistic systems. After that, the corresponding algorithms for performance evaluation are given. Finally, an industrial example is given to demonstrate the effectiveness of our method.

Wave and particle properties can be spatially separated in a quantum entity

Wave and particle are two fundamental properties of nature. The wave–particle duality has indicated that a quantum object may exhibit the behaviors of both wave and particle, depending upon the circumstances of the experiment. The major significance of wave–particle duality has led to a fundamental equation in quantum mechanics: the Schrödinger equation. At present, the principle of wave–particle duality has been deeply rooted in people’s hearts. This leads to a common-sense perception that wave property and particle property coexist simultaneously in a quantum entity, and these two physical attributes cannot be completely separated from each other. In classical physics, a similar common-sense thought is that a physical system is inseparable from its physical properties. However, this has been recently challenged and beaten by a quantum phenomenon called the “quantum Cheshire cat,” in which a cat and its grin can be spatially separated. In this work, we propose a thought experiment based on the technology similar to the quantum Cheshire cat. We find that wave and particle attributes of a quantum entity can be completely separated, thus successfully dismantling the wave–particle duality for a quantum entity. Our result is still consistent with the complementarity principle and deepens the understanding of quantum foundations.

Quantum-Based Photonic Sensors for Pressure, Vacuum, and Temperature Measurements: A Vison of the Future with NIST on a Chip.

The NIST on a Chip (NOAC) program's central idea is the idea that measurement technology can be developed to enable metrology to be performed "outside the National Metrology Institute" by the creation of deployed and often miniaturized standards. These standards, when based on fundamental properties of nature, are directly tracible to the international system of units known as the SI. NIST is also developing quantum-based standards for SI traceability known as QSI, or Quantum based International System of units. Specifically, this paper will cover NIST efforts in the area of thermodynamic metrology to develop NOAC standards for pressure, vacuum and temperature measurements.

One-loop corrections to η/s in AdS4/CFT3

We study quantum corrections at one-loop order to the shear viscosity to entropy ratio by implementing the Vilkovisky-Barvinsky effective action in asymptotically Anti-de Sitter spacetimes. The shear viscosity is shown to receive no corrections at this order, but the entropy acquires a logarithmic correction. The coefficient of this logarithm turns out to depend on the spin of the particles running in the loop and it can be either positive or negative. On the basis of this result, we argue that the Kovtun–Son–Starinets bound cannot be seen as a fundamental property of nature beyond the classical regime.

On vague chemistry

Generally, an object is vague when its properties cannot precisely defined. The ontic view of vagueness is the idea that vagueness is a fundamental property of Nature. This simply means that everything is vague: animals, plants, molecules, atoms, etc. Furthermore, if atoms and molecules are vague, then the subject matter of chemistry is vague. However, we first need to understand why molecules and atoms are vague.

Chiral <italic>N</italic>,<italic>N</italic>ʹ-dioxide and their metal complexes in asymmetric catalysis

Chirality is a fundamental property of nature. Chiral compounds are closely related to life science, human health, material science, and so on. Asymmetric catalysis is one of the most efficient and important synthetic methodologies to obtain chiral compounds, which meets the requirement of green chemistry. Metal-catalyzed asymmetric reactions attract much attention in the past few years, and thousands of chiral ligands have been synthesized, however, widely applicable, so-called privileged chiral ligands are still very limited. Therefore, the design and synthesis of highly efficient and selective chiral ligands becomes the most important and challenging goal. Our group is committed to asymmetric catalysis and develope a novel type of C 2-symmetric chiral ligand of N , N ʹ-dioxide amide compounds which is easily synthesized from cheap chiral amino acids and amines. Such conformationally flexible privileged ligands break through the notion of the rigid feature of previously privileged ligands. Naturally, it would guide the creation of new ideal chiral ligands and catalysts. N , N ʹ-dioxides are not only used as bifunctional organocatalysts, but also provide an arsenal of chiral metal complexes upon coordination with a variety of metal salts, such as alkaline-earth metal salts, transition metal salts and rare-earth metal salts. This powerful catalyst system has been proved to be highly effective for more than fifty types of asymmetric reactions with wide substrate generality under mild conditions, including carbon-carbon bond formation, and carbon-heteroatom bond formation reactions. The concerns of controlling chemo-, regio-, and stereoselectivity of involved reactions are well addressed. Some new and challengling asymmetric reactions are realized, for intances, the first asymmetric Roskamp reaction is achieved with a N , N ʹ-dioxide/Sc(III) complex at low catalyst loading, which updates the comment about β-keto esters in text of Organic Chemistry , Oxford, and the reaction is amended as “Roskamp-Feng reaction” in Elsevier’s Organic Synthesis Based on Name Reactions . The asymmetric amination of ketones with α-diazoesters shed light on the diversity of diazo chemistry. N , N ʹ-dioxide/La(III) complex catalyzed sulfa-Michael reaction exhibits very strong chiral amplification effect. N , N ʹ-dioxide/Ni(II) complex acts as both chiral Lewis catalyst and metal-carbene promotor in Doyle-Kirmse reaction, [ 2 , 3 ] -Stevens rearrangement and Sommelet-Hauser rearrangement of a new type of designed α-diazo pyrazoleamides. Such the creation of catalytic systems and catalytic asymmetric methods provide simple, efficient, precise, green access to several biologically active drug molecules and natural products, such as Paroxetine, Pregabalin, Thiazesim, KAE609 and so on. Now, N , N ʹ-dioxides have become commercially available chiral ligands and have been successfully applied by many research groups and companies. The above original and systematic research achievements make important contribution to the chirality science.

Modeling Hall viscosity in magnetic-skyrmion systems

Magnetic skyrmions are topologically stable objects that are made with a bunch of spins tightly arranged in a smooth fashion. Their topological nature provides unusual and complex transport properties, such as the skyrmion Hall effect. Extensive Hall data have further revealed asymmetry between skyrmion and antiskyrmion Hall angles, which cannot be accounted by known mechanisms. Here, we explain this asymmetry by utilizing another universal transport coefficient called `Hall viscosity,' extensively studied in quantum Hall systems. Hall viscosity is modeled in steady-state skyrmions motion by generalizing the Thiele equation with a transverse velocity component and is independent of the skyrmion charge. Our analyses, based on available asymmetric Hall angle data, reveal this transverse force amounts 3\% - 5.4\% of the force due to the skyrmion Hall effect. Further clarification of Hall viscosity will be essential for designing next generation storage devices properly, not to mention for our deeper understanding of fundamental properties of nature.

Ion-Based Cellular Signal Transmission, Principles of Minimum Information Loss, and Evolution by Natural Selection

The Extreme Physical Information EPI principle states that maximum information transmission or, equivalently, a minimum information loss is a fundamental property of nature. Prior work has demonstrated the universal EPI principle allows derivation of nearly all physical laws. Here, we investigate whether EPI can similarly give rise to the fundamental law of life: Evolution. Living systems require information to survive and proliferate. Heritable information in the genome encodes the structure and function of cellular macromolecules but this information remains fixed over time. In contrast, a cell must rapidly and continuously access, analyze, and respond to a wide range of continuously changing spatial and temporal information in the environment. We propose these two information dynamics are linked because the genes encode the structure of the macromolecules that form information conduits necessary for the dynamical interactions with the external environment. However, because the genome does not have the capacity to precisely locate the time and location of external signals, we propose the cell membrane is the site at which most external information is received and processed. In our model, an external signal is detected by gates on transmembrane ion channel and transmitted into the cytoplasm through ions that flow along pre-existing concentration gradients when the gate opens. The resulting cytoplasmic ion “puff” is localized in both time and space, thus producing spatial and temporal information. Small, localized signals in the cytoplasm are “processed” through alterations in the function and location of peripheral membrane proteins. Larger perturbations produce prolonged or spatially extensive changes in cytoplasmic ion concentrations that can be transmitted to other organelles via ion flows along elements of the cytoskeleton. An evolutionary constraint to the ever-increasing acquisition of environmental information is the cost of doing so. One solution to this trade-off is the evolution of information conduits that minimize signal loss during transmission. Since the structures of these conduits are encoded in the genome, evolution of macromolecular conduits that minimize signal loss is linked to and, in fact, governed by a universal principle, termed extreme physical information (EPI). Mathematical analysis of information dynamics based on the flow of ions through membrane channels and along wire-like cytoskeleton macromolecules fulfills the EPI principle. Thus, the empirically derived model of evolution by natural selection, although uniquely applicable to living systems, is theoretically grounded in a universal principle that can also be used to derive the laws of physics. Finally, if minimization of signal loss is a mechanism to overcome energy constraints, the model predicts increasing information and associated complexity are closely linked to increased efficiency of energy production or improved substrate acquisition.

Do Categorical Properties Confer Dispositions on Their Bearers?

Abstract Categorical Monism (that is, the view that all fundamental natural properties are purely categorical) has recently been challenged by a number of philosophers. In this paper, I examine a challenge which can be based on Gabriele Contessa's [10] defence of the view that only powers can confer dispositions. In his paper Contessa argues against what he calls the Nomic Theory of Disposition Conferral (NTDC). According to NTDC, in each world in which they exist, (categorical) properties confer specific dispositions on their bearers; yet, which disposition a (categorical) property confers on its bearers depends on what the (contingent) laws of nature happen to be. Contessa, inter alia, rests his case on an intuitive analogy between cases of mimicking (in which objects do not actually possess the dispositions associated with their displayed behaviour) and cases of disposition conferral through the action of laws. In this paper, I criticize various aspects of Contessa's argumentation and show that the conclusion he arrives at (that is, only powers can confer dispositions) is controversial.

Overpowering: How the Powers Ontology Has Overreached Itself

Many authors have argued in favour of an ontology of properties as powers, and it has been widely argued that this ontology allows us to address certain philosophical problems in novel and illuminating ways, for example, causation, representation, intentionality, free will and liberty. I argue that the ontology of powers, even if successful as an account of fundamental natural properties, does not provide the insight claimed as regards the aforementioned non-fundamental phenomena. I illustrate this argument by criticizing the powers theory of causation presented by Mumford and Anjum (2011) and showing that related criticisms can be directed at other abuses of (the ontology of) powers.

Application of the Principle of Analytic Continuation to Interpolate/Extrapolate System Responses Resulting in Reduced Computations—Part B: Nonparametric Methods

This review paper is a sequel to our earlier paper entitled “Application of the principle of analytic continuation to interpolate/extrapolate system responses resulting in reduced computations-Part A: Parametric methods” dealing with parametric methods in the context of the principle of analytic continu-ation and providing its relationship to reduced rank modeling using the total least-squares-based singular value decomposition methodology. The problem with a parametric method is that the quality of the solution is determined by the choice of the basis functions, and the use of bad basis functions generates bad solutions. A priori, it is quite difficult to recognize what are good basis functions and what are bad basis functions, even though methodologies exist in theory on how to choose good ones. The advantage of the nonparametric methods is that no such choices of the basis functions need to be made, as the solution procedure itself develops the nature of the solution and no a priori information is necessary. This is accomplished through the use of the Hilbert transform, which exploits one of the fundamental properties of nature, i.e., causality. The Hilbert transform illustrates that the real and imaginary parts of any nonminimum-phase transfer function from a causal system satisfy this relationship. In addition, some parameterization can also be made of this procedure, which can enable one to generate a nonminimum-phase function from its amplitude response and from that generate the phase response and, thereby, can compute the time-domain data for the amplitude-only case except for a delay in the response. This uncertainty is removed in holography, as in such a procedure, amplitude and phase information is measured for a specific look angle, thus eliminating the phase ambiguity. An overview of the technique along with examples is presented to illustrate this methodology.

Application of the Principle of Analytic Continuation to Interpolate/Extrapolate System Responses Resulting in Reduced Computations—Part A: Parametric Methods

This review paper is a sequel to our earlier paper entitled “Application of the principle of analytic continuation to interpolate/extrapolate system responses resulting in reduced computations—Part A: Parametric methods” dealing with parametric methods in the context of the principle of analytic continu-ation and providing its relationship to reduced rank modeling using the total least-squares-based singular value decomposition methodology. The problem with a parametric method is that the quality of the solution is determined by the choice of the basis functions, and the use of bad basis functions generates bad solutions. A priori, it is quite difficult to recognize what are good basis functions and what are bad basis functions, even though methodologies exist in theory on how to choose good ones. The advantage of the nonparametric methods is that no such choices of the basis functions need to be made, as the solution procedure itself develops the nature of the solution and no a priori information is necessary. This is accomplished through the use of the Hilbert transform, which exploits one of the fundamental properties of nature, i.e., causality. The Hilbert transform illustrates that the real and imaginary parts of any nonminimum-phase transfer function from a causal system satisfy this relationship. In addition, some parameterization can also be made of this procedure, which can enable one to generate a nonminimum-phase function from its amplitude response and from that generate the phase response and, thereby, can compute the time-domain data for the amplitude-only case except for a delay in the response. This uncertainty is removed in holography, as in such a procedure, amplitude and phase information is measured for a specific look angle, thus eliminating the phase ambiguity. An overview of the technique along with examples is presented to illustrate this methodology.

Continuous symmetry measures for complex symmetry group

Symmetry is a fundamental property of nature, used extensively in physics, chemistry, and biology. The Continuous symmetry measures (CSM) is a method for estimating the deviation of a given system from having a certain perfect symmetry, which enables us to formulate quantitative relation between symmetry and other physical properties. Analytical procedures for calculating the CSM of all simple cyclic point groups are available for several years. Here, we present a methodology for calculating the CSM of any complex point group, including the dihedral, tetrahedral, octahedral, and icosahedral symmetry groups. We present the method and analyze its performances and errors. We also introduce an analytical method for calculating the CSM of the linear symmetry groups. As an example, we apply these methods for examining the symmetry of water, the symmetry maps of AB4 complexes, and the symmetry of several Lennard-Jones clusters.

The “Constant” Threat to the Dispositional Essentialist Conception of Laws

Abstract According to the dispositional essentialist account of laws of nature, the latter express the dispositional nature of fundamental natural properties. In this paper I discuss the difficulty that the existence of fundamental constants of nature raises for that account. To this end, I examine a relevant argument against the account and describe how an advocate of the dispositionalist conception may try to undermine it by raising objections to its premises. Then I discuss those objections and show that eventually all fail. I finally conclude that the existence of the fundamental constants remains a “constant” threat to the dispositional essentialist conception of laws.

Simple Hardy-Like Proof of Quantum Contextuality

Contextuality and nonlocality are two fundamental properties of nature. Hardy's proof is considered the simplest proof of nonlocality and can also be seen as a particular violation of the simplest Bell inequality. A fundamental question is: Which is the simplest proof of contextuality? We show that there is a Hardy-like proof of contextuality that can also be seen as a particular violation of the simplest noncontextuality inequality. Interestingly, this new proof connects this inequality with the proof of the Kochen-Specker theorem, providing the missing link between these two fundamental results, and can be extended to an arbitrary odd number n of settings, an extension that can be seen as a particular violation of the n-cycle inequality.