非齐次粗糙核参数型Marcinkiewicz算子的H~p有界性

设Ω是球面上函数,b是径向函数,ρ是实部正的复数;设Ψ为C~2([0,∞))的递增凸函数,Ψ(0)=0.本文研究非齐次粗糙核参数型Marcinkiewicz算子μ_(Ω,b)~ρ,以及旋转曲面上的非齐次粗糙核参数型Marcinkiewicz算子μ_(Ω,Ψ,b)~ρ,给出非齐次粗糙核Ω和b的最小光滑性条件,建立算子μ_(Ω,b)~ρ和μ_(Ω,Ψ,b)~ρ在Hardy空间和弱Hardy空间上的有界性.本文结果推进了先前b≡1情形的已有工作.     

关于FLP问题一种新的单纯形算法的推广

指出FLP问题的一种新的单纯形算法[1]中主要结论成立的适用条件,并给出了该适用条件不成立时,一般条件下的推广.     

Lipschitzian stability of parametric variational inequalities over generalized polyhedra in Banach spaces

This paper concerns the study of solution maps to parameterized variational inequalities over generalized polyhedra in reflexive Banach spaces. It has been recognized that generalized polyhedral sets are significantly different from the usual convex polyhedra in infinite dimensions and play an important role in various applications to optimization, particularly to generalized linear programming. Our main goal is to fully characterize robust Lipschitzian stability of the aforementioned solution maps entirely via their initial data. This is done on the basis of the coderivative criterion in variational analysis via efficient calculations of the coderivative and related objects for the systems under consideration. The case of generalized polyhedra is essentially more involved in comparison with usual convex polyhedral sets and requires developing elaborated techniques and new proofs of variational analysis.     

Robinson metric regularity of parametric variational systems

In this paper, the Robinson metric regularity of a parametric variational system is investigated. Some applications to the contingent derivative of parametric variational system and to the Robinson metric regularity of a parametric vector optimization problem are then studied.     

Sonolysis of per- and poly fluoroalkyl substances (PFAS): A meta-analysis

Human ingestion of per- and polyfluoroalkyl substances (PFAS) from contaminated food and water is linked to the development of several cancers, birth defects and other illnesses. The complete mineralisation of aqueous PFAS by ultrasound (sonolysis) into harmless inorganics has been demonstrated in many studies. However, the range and interconnected nature of reaction parameters (frequency, power, temperature etc.), and variety of reaction metrics used, limits understanding of degradation mechanisms and parametric trends. This work summarises the state-of-the-art for PFAS sonolysis, considering reaction mechanisms, kinetics, intermediates, products, rate limiting steps, reactant and product measurement techniques, and effects of co-contaminants. The meta-analysis showed that mid-high frequency (100 – 1,000 kHz) sonolysis mechanisms are similar, regardless of reaction conditions, while the low frequency (20 – 100 kHz) mechanisms are specific to oxidative species added, less well understood, and generally slower than mid-high frequency mechanisms. Arguments suggest that PFAS degradation occurs via adsorption (not absorption) at the bubble interface, followed by headgroup cleavage. Further mechanistic steps toward mineralisation remain to be proven. For the first time, complete stoichiometric reaction equations are derived for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) sonolysis, which add H₂ as a reaction product and consider CO an intermediate. Fluorinated intermediate products are derived for common, and more novel PFAS, and a naming system proposed for novel perfluoroether carboxylates. The meta-analysis also revealed the transition between pseudo first and zero order PFOA/S kinetics commonly occurs at 15 – 40 µM. Optimum values of; ultrasonic frequency (300 – 500 kHz), concentration (>15 – 40 μM), temperature (≈20 °C), and pH range (3.2 – 4) for rapid PFOX degradation are derived by evaluation of prior works, while optimum values for the dilution factor applied to PFAS containing firefighting foams and applied power require further work. Rate limiting steps are debated and F⁻ is shown to be rate enhancing, while SO₄²⁻ and CO₂ by products are theorised to be rate limiting. Sonolysis was compared to other PFAS destructive technologies and shown to be the only treatment which fully mineralises PFAS, degrades different PFAS in order of decreasing hydrophobicity, is parametrically well studied, and has low-moderate energy requirements (several kWh g⁻¹ PFAS). It is concluded that sonolysis of PFAS in environmental samples would be well incorporated within a treatment train for improved efficiency.     

材料吸声系数双传声器测量的参数识别方法

本文提出了在普通房间中利用双传声器对多孔性和纤维性吸声材料吸声系数测量时的参数识别方法。利用Delany&Bazley经验模型对测量数据进行了参数识别,建立了材料的阻抗模型,并计算出材料全频带的吸声系数。与驻波管方法得到的吸声系数相比,在0～3000Hz范围内,二者都能较好地吻合。通过在不同的环境中进行对比测试,说明该方法具有较好的重复性和准确性。     

Broadly tunable parametric line emission from β-barium borate on pumping with picosecond pulses

Tunable line emission (LE) over a large wavelength region (340–980 nm) is obtained by pumping thick crystals of β-barium borate (BBO) with picosecond pulses at 532 nm. Phenomena of group velocity dispersion, diffraction and phase matching take place simultaneously such that the radiation shows specific features that are characteristic of (i) strongly coupled fundamental and harmonic fields, (ii) amplified phase matched superfluorescence, (iii) conical emission and (iv) four wave mixing.     

Parametric oscillatory instability in a Fabry–Perot cavity of the Einstein Telescope with different mirror's materials

We discuss the parametric oscillatory instability in a Fabry–Perot cavity of the Einstein Telescope. Unstable combinations of elastic and optical modes for two possible configurations of gravitational wave third-generation detector are deduced. The results are compared with the results for gravitational wave interferometers LIGO and LIGO Voyager.