In the context of ultrafast spectroscopy, the availability of few-femtosecond UV pulses is key to disclose the role of electron dynamics in photo-activated biochemically relevant processes. Here, we present an optical setup for the generation of UV pulses spectrally tunable between 270 and 350 nm with transform limited durations of 3.0 and 2.9 fs, respectively, and repetition rates up to 50 kHz, using resonant dispersive wave (RDW) emission in an argon-filled hollow-core fiber. The RDW emission is driven by 1030 nm sub-20 fs pulses produced by post-compressing an Yb-based laser with a dispersion-engineered multi-pass cell (MPC). The combination of an MPC with a capillary constitutes a compact source to deliver few-femtosecond UV pulses at high-repetition rates, which is ideal for statistically demanding experiments in molecular physics.

ABSTRACT Purpose This study explores the implications of low journal self-citation rate (LJSCR). While some interpret LJSCR as a sign that a journal’s authors do not cite each other’s work, others see it as a mark of prestige, reflecting greater recognition from outside the journal. We argue that these perspectives are not contradictory: low self-citation can be prestigious precisely because it reflects low self-readership. Design/methodology/approach We analyze the physics and mathematics of journal self-citation. Our findings show that the self-citation rate (i) increases with journal market share, (ii) approaches a well-defined upper bound, (iii) this upper bound remains significantly below unity, and (iv) without a minimum level of market share, self-citation is virtually absent. Here, market share refers to the proportion of a journal’s publications relative to its Web of Science (WOS) subject category. To test our analysis, we examine 61 journal-years of data from three major hybrid fluid dynamics journals: Journal of Fluid Mechanics, Physical Review Fluids, and Physics of Fluids. Findings We identify a consistent relationship between journal self-citation and market share. A striking result is the mathematical analogy we establish between journal self-citation behavior and the concentration of intermediates in consecutive irreversible unimolecular chemical reactions. We also observe that creating specialized subdisciplinary journals (“twigging”) can reduce self-citation rates by narrowing scope. Research limitations The study is limited to fluid dynamics journals. Broader validation across disciplines is needed. Practical implications Editors and publishers can apply these insights to interpret citation metrics and assess the visibility and readership of their journals. Originality/value This work redefines LJSCR as a counterintuitive metric—one that may reflect both low author engagement and high external impact. It introduces a novel physics-based model to understand citation behavior across journals.

The Fourier series has been used widely to model various physical phenomena. It becomes a core concept taught in mathematical physics courses. To help students understanding the concept and interpretation of the Fourier series, we propose the utilization of the Desmos application in the classroom. Desmos has a feature of a graphing calculator that can be used for visualizing a function without programming. With an appropriate teaching approach, the Fourier series can be understood more easily.

In mathematical physics, the nonlinear dispersive modified Benjamin-Bono-Mahony equation is an essential nonlinear evolution equation. This paper employs the Sardar sub-equation approach to derive the analytic solutions of the space-time fractional nonlinear dispersive modified Benjamin-Bona-Mahony equation with a conformable derivative. These solutions, obtained using the proposed approach, are presented in specialized generalized hyperbolic and trigonometric forms. The soliton solutions are also obtained using the presented approach. Additionally, some of these solutions are illustrated in both two- and three-dimensional graphs for visualization. Finally, the suggested approach is novel, easy, and productive for obtaining analytic solutions and is applicable to numerous nonlinear fractional partial differential equations.

Abstract This paper examines a (2 + 1)-dimensional generalized Konopelchenko-Dubrovsky-Kaup-Kupersh-midt(gKDKK) system, with applications in fluid mechanics and plasma physics. Painlevé analysis, a powerful method that employs the Laurent series to explore singularity structures and evaluate the integrability of nonlinear partial differential equations(NLPDEs), is used to demonstrate that the considered equation is completely integrable. By applying the Painlevé analysis method, the Laurent series is truncated to derive an auto-Bäcklund transformation (ABT). Using ABT, three distinct families of analytical solutions are derived for the considered system. Additionally, multi-soliton solutions are obtained using the simplified Hirota method. All the obtained results are depicted in 3D graphs through numerous functions and parameter settings. These graphs provide a clear understanding of wave structures and soliton interactions of the system being studied.

William Happer, born in Vellore (1939), Tamil Nadu, India is an American icon on Climate Physics. He is currently the Cyrus Fogg Brackett Professor Emeritus in the Department of Physics at Princeton University, New Jersey, USA. Amid numerous brilliant Climate Researchers, William Happer has distinguished himself as “The Consequential Climate Physicist” for the following reasons. 1. He has over 300 publications, which include (a) 18 Premier Climate Physics Articles, (b) 32 Articles, Commentaries, Interviews, Lectures, Testimonies, and Podcasts, and (c) 157 Atomic, Molecular, and Optical Physics Publications. 2. He is not only an eminent Climate Physicist, but also a great communicator, inventor, educator, motivator, historian, humorist, and public servant under two American Presidents (George H. W. Bush and Donald J. Trump). 3. His seminal climate message is simply the following. Because of the heavy saturation of the CO2 absorption-emission bands of Earth’s atmosphere, additional CO2 can only have a very small effect on climate. Even doubling of CO2 will only amount to an increase of <1○C in Temperature. 4. Importantly, William Happer’s single greatest gift to the world is his brilliant and uncanny ability to convert complex Climate-Physics knowledge into simple, easy-to-understand, narratives and communicate them to the masses via a plethora of print and digital media relentlessly. Consequently, Climate Researchers, with alternative viewpoints to Anthropogenic Global Warming (AGW), have been successful not only in exposing the Climate Scam but also in rescuing humanity from a near extinction due to the insane Net-Zero nonsense.

Abstract This paper presents a laboratory experiment designed for college and undergraduate students to measure thermocapillary force (Marangoni effect) and demonstrate the trapping of microbubbles, a phenomenon arising from temperature-induced surface tension gradients along fluid interfaces that causes fluid motion towards the regions of lower surface tension. Despite its significance in microfluidic systems, bioengineering, and precision manufacturing, the thermocapillary effect is often overlooked in standard curricula. The suggested experimental setup allows students to manipulate microbubbles in a liquid using temperature gradients induced by a low power laser, helping them explore fluid dynamics, surface tension, and temperature gradients in a controlled environment. The experiment not only reinforces fundamental physics principles but also highlights real-world applications such as drug delivery, micro-manufacturing, and tissue engineering. By providing hands-on experience, the experiment bridges the gap between theoretical knowledge and practical applications, offering a cost-effective tool for fostering a deeper understanding of fluid mechanics and thermodynamics in the classroom.

Physical or chemical phase changes in ablation, such as sublimation, melting or dissolution, are studied in physics for their many engineering applications. At solid/fluid interfaces, the interaction between a phase change and a flow can lead to pattern formation. In this case, the fluid mechanics associated with such phase changes play a key role in the evolution of terrestrial and planetary landscapes, observed by probes orbiting planets and moons. On Earth, sea ice, glaciers and karst plateaus extend over meters or kilometers. The scale of these landscapes contrasts with the scale of the physical mechanisms that govern their evolutionary dynamics. Indeed, it is the typical size of atmospheric boundary layers or meltwater/vapor/solute films that constrain the heat/concentration transfer at the phase change/dissolution interface, and hence the rate of solid ablation. In many situations, these layers are controlled by fluid flow, either natural or forced convection. In the former case, the flow may be buoyancy driven by the melting/dissolution/sublimation itself, resulting in density stratification caused by, for example, temperature/concentration gradients. This stratification may be stable or unstable. In the second case, the flow forced by winds or slopes can be considered as a flow of an infinite height or of a finite height, such as shallow water flow. In all cases, the mass flux modifies topography, which in turn affects the boundary layer flows and thus the ablation rate in a retroactive way. In nature, the positive feedback between geometry and mass transfer drives the spontaneous formation of characteristic patterns at different scales. These patterns are not just geological curiosities, such as Zen stones or dirt cones but markers of the hydrodynamic processes at work. Many landscapes are shaped by regular, repeated patterns, whether sharp-edged, scalloped, parallel-crested, or stepped. By experimentally investigating different modes of flow transport on solid substrates undergoing physical or chemical phase change, this review aims to highlight the role of the flow transport mode in the diversity of patterns observed on analogous materials. Understanding the diversity of these patterns is key to assessing the environmental conditions under which they form on planets such as Mars or Pluto, where phase changes play a very important geomorphological role.

Abstract Cold molecular physics has been the frontier of atomic, molecular and optical physics for over two decades due to the unique and unprecedented applications. We simulate the evaporative cooling of 87Rb133Cs molecules in a modified electric-assisted magnetic trap by decreasing the electric field. When 10-time loading the experimentally available cold RbCs molecules, we would achieve a number N = 811, a temperature T = 21.34 nK, a phase-space density PSD = 2.67 and a number density n = 5.01 × 1012 cm-3 of Bose–Einstein condensation RbCs molecules in 480 ms.