Relationship between cation–π and anion–π interactions: individual binding energies in the π–Mz+–π–X−–π system

The mutual influence of cation–π and anion–π interactions in the π–M^z+–π–X^?–π system (M^z+ = Li⁺, Na⁺, K⁺, Be²⁺, Mg²⁺, Ca²⁺ and X^? = F^?, Cl^?) has been studied by quantum mechanical calculations. Both geometric parameters and energy data reveal that cation–π and anion–π interactions enhance each other in the π–M^z+–π–X^?–π system. Individual binding energies (E_ion···π) have been estimated in the quintuplet system using a simple new method from electron charge densities calculated at the bond critical points (BCPs) of the ion···π interaction by the atoms in molecules (AIM) method at the M062X/6-31+G(d) level of theory. With respect to the obtained individual binding energies, the strength of an ion···π interaction depends on the cooperative effects of other components.     

Occupational doses of medical staff and their relation to patient exposure incurred in coronary angiography and intervention

Patient kerma–area product P_KA, cumulative kerma in the air K_IRP, fluoroscopic time t, personal dose equivalent (in terms of Hp(10), Hp(0.07) and Hp(3)) for most common interventional cardiology procedures were measured. P_KA and K_IRP measurements were used for patients and thermoluminescent dosimetry for the personnel. Dosemeters for personal doses measurements containing MCP-N (LiF: Mg, Cu, P) type thermoluminescence detectors (TLDs), were read out at the Institute of Nuclear Physics Polish Academy of Science (IFJ PAN) dosimetry service.The patient and personal doses were similar to those reported by other authors. The mean values of total kerma–area product (P_KA) were 22.7 (7.3–50.9) Gy·cm² for coronary angiography (CA) and 43.1 (3.2–86.4) Gy·cm² for percutaneous coronary intervention (PCI). In general, doses received by the staff performing PCI procedures were found to be systematically higher than those after CA procedures, by some 30% or more. Within the medical team, operators always received the highest doses, followed by nurses and technicians. Maximum eye lens doses, skin doses and whole body doses were 165 μSv, 962 μSv and 30 μSv per procedure, respectively. Annual eye lens doses received by the operators, especially in PCI procedures, may well exceed the value of the recently recommended annual dose limit of 20 mSv and should be monitored.No meaningful correlation could be established between occupational doses and patient exposure, however some degree of correlation was observed between values of dose to the eye lens and whole body dose.     

考虑随机扰动的群体决策理性演化模型

在群体决策过程中,随机噪音对个体理性和群体理性的变化具有不可忽视的影响.针对存在随机扰动条件下群体决策理性的演化行为,在假设个体和群体理性之间存在作用叠加效果的基础上,建立了刻画个体和群体理性受随机噪声影响的个体和群体理性演化动力学模型,利用随机微分方程理论,论证了模型解的存在性和唯一性,在给定群体决策的随机扰动为白噪声的假设条件下得到了模型的解析解,讨论了群体决策中两个重要参数:理性作用强度和随机干扰作用强度对于群体理性演化的影响.理论分析结果表明:群体决策理性的演化行为取决于这两个参数的相对大小,存在着三条不同的演化路径,数值算例验证了模型的合理性和有效性,并对群体理性的演化行为进行了直观说明,对于深入认识群体决策规律和提高决策质量具有积极的理论和实际意义.     

Bogomolov multipliers for some <Emphasis Type="Italic">p</Emphasis>-groups of nilpotency class 2

The Bogomolov multiplier B ₀(G) of a finite group G is defined as the subgroup of the Schur multiplier consisting of the cohomology classes vanishing after restriction to all abelian subgroups of G. The triviality of the Bogomolov multiplier is an obstruction to Noether’s problem. We show that if G is a central product of G ₁ and G ₂, regarding K _i ≤ Z(G _i ), i = 1, 2, and θ: G ₁ → G ₂ is a group homomorphism such that its restriction \(\theta {|_{{K_1}}}:{K_1} \to {K_2}\) is an isomorphism, then the triviality of B ₀(G ₁/K ₁),B ₀(G ₁) and B ₀(G ₂) implies the triviality of B ₀(G). We give a positive answer to Noether’s problem for all 2-generator p-groups of nilpotency class 2, and for one series of 4-generator p-groups of nilpotency class 2 (with the usual requirement for the roots of unity).     

Individual irrationality,network structure,and collective intelligence: An agent‐based simulation approach

An agent‐based model is constructed to study the effects of individual irrationality and network structure on collective performance. We find that individual irrationality and network density are the most influential factors. Moderate degree of irrationality results in moderate knowledge unity and superior quality of knowledge; increasing network connections or decreasing average path length (APL) can promote quality of knowledge integration and knowledge unity. Furthermore, APL is more influential than clustering coefficient and centralization (CE). Less clustering may contribute to higher quality of knowledge integration, while higher CE may contribute to higher knowledge unity. © 2015 Wiley Periodicals, Inc. Complexity 21: 44–54, 2016     

Ionic components of the real and chemical Gibbs energy of transport of potassium and chloride ions from water to water-methanol mixtures

With the method of volta-potential differences at 298.15 K the ionic components of the standard real and chemical thermodynamic properties of the resolvation of potassium and chloride ions were determined in mixtures of water and methanol (MeOH). The value of the surface potential at the methanol/gas phase boundary (Δχ^MeOH = ?0.18 V) is obtained. The characteristics of the solvation of these ions in a water-methanol medium are identified, and a comparison with literature data for other nonaqueous mixtures is carried out.     

基于Ekeland变分原理的一类平衡问题解集的稳定性研究及应用

基于Ekeland变分原理建立的平衡问题,减弱了函数和定义域的凸性要求,减弱了三角不等式条件,函数只有循环反单调性,但其具有良好的性质.一方面,利用非线性分析方法,对非凸紧和非凸非紧的平衡问题研究解的唯一性,在Baire分类意义下,得到基于Ekeland变分原理建立的平衡问题的解具有通有唯一性.另一方面,利用有限理性模...     

几类考虑有限理性平衡问题解的稳定性

对Ky Fan点问题定义了理性函数,证明了大多数的KyFan点问题(在Baire分类意义上)都是结构稳定的,对$\varepsilon$-平衡也都是鲁棒的.作为应用,还给出了Nash平衡问题和变分不等式问题的稳定性结论.     

An epistemic model of an agent who does not reflect on reasoning processes

This paper introduces an epistemic model of a boundedly rational agent under the two assumptions that (i) the agent’s reasoning process is in accordance with the model but (ii) the agent does not reflect on these reasoning processes. For such a concept of bounded rationality a semantic interpretation by the possible world semantics of the Kripke (1963) type is no longer available because the definition of knowledge in these possible world semantics implies that the agent knows all valid statements of the model. The key to my alternative semantic approach is the extension of the method of truth tables, first introduced for the propositional logic by Wittgenstein (1922), to an epistemic logic so that I can determine the truth value of epistemic statements for all relevant truth conditions. In my syntactic approach I define an epistemic logic–consisting of the classical calculus of propositional logic plus two knowledge axioms–that does not include the inference rule of necessitation, which claims that an agent knows all theorems of the logic. As my main formal result I derive a determination theorem linking my semantic with my syntactic approach. The difference between my approach and existing knowledge models is illustrated in a game-theoretic application concerning the epistemic justification of iterative solution concepts.     

Stability analysis of a cobweb model with market interactions

This paper explores the steady-state properties and the dynamic behavior of a generalization of the classical cobweb model. Under fairly general demand and cost functions, producers form naïve expectations about future prices and select their output so as to maximize expected profits. Unlike the traditional setup, producers have the choice between two markets, and tend to enter that which was more profitable in the recent past. Such a switching process implies time-varying aggregated supply schedules, thus representing a further source of nonlinearity for the dynamics of prices. Analytical investigations and the numerical simulation of a particular case with linear demand and supply indicate that such interactions may destabilize otherwise stable markets and generate complex dynamics.