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1. An arrayed optofluidic system for three-dimensional (3D) focal control via electrowetting

   https://doi.org/10.1364/OE.489508  

   Lee, Yeonwoo; Lee, Cheng-Hsun; Park, Sung-Yong (January 2023, Optics Express)

   A new lens capability for three-dimensional (3D) focal control is presented using an optofluidic system consisting ofn × narrayed liquid prisms. Each prism module contains two immiscible liquids in a rectangular cuvette. Using the electrowetting effect, the shape of the fluidic interface can be rapidly adjusted to create its straight profile with the prism’s apex angle. Consequently, an incoming ray is steered at the tilted interface due to the refractive index difference between two liquids. To achieve 3D focal control, individual prisms in the arrayed system are simultaneously modulated, allowing incoming light rays to be spatially manipulated and converged on a focal point located atP_focal(f_x,f_y,f_z) in 3D space. Analytical studies were conducted to precisely predict the prism operation required for 3D focal control. Using three liquid prisms positioned on thex-,y-, and 45°-diagonal axes, we experimentally demonstrated 3D focal tunability of the arrayed optofluidic system, achieving focal tuning along lateral, longitudinal, and axial directions as wide as 0 ≤ f_x ≤ 30 mm, 0 ≤ f_y ≤ 30 mm, and 500 mm ≤ f_z ≤ ∞. This focal tunability of the arrayed system allows for 3D control of the lens’s focusing power, which could not be attained by solid-type optics without the use of bulky and complex mechanical moving components. This innovative lens capability for 3D focal control has potential applications in eye-movement tracking for smart displays, autofocusing of smartphone cameras, or solar tracking for smart photovoltaic systems. 

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2. Frequency Moments in Noisy Streaming and Distributed Data under Mismatch Ambiguity

   https://doi.org/10.1145/3801901  

   Liu, Kaiwen; Zhang, Qin (May 2026, Proceedings of the ACM on Management of Data)

   We propose a novel framework for statistical estimation on noisy datasets. Within this framework, we focus on the frequency moments (F_p) problem and demonstrate that it is possible to approximateF_pof the unknown ground-truth dataset using sublinear space in the data stream model and sublinear communication in the coordinator model, provided that the approximation ratio is parameterized by a data-dependent quantity, which we call theF_p-mismatch-ambiguity. We also establish a set of lower bounds, which are tight in terms of the input size. Our results yield several interesting insights:-In the data stream model, theF_pproblem is inherently more difficult in the noisy setting than in the noiseless one. In particular, whileF₂can be approximated in logarithmic space in terms of the input size in the noiseless setting, any algorithm forF₂in the noisy setting requires polynomial space. -In the coordinator model, in sharp contrast to the noiseless case, achieving polylogarithmic communication in the input size is generally impossible forF_punder noise. However, when theF_pmismatch ambiguity falls below a certain threshold, it becomes possible to achieve communication that is entirely independent of the input size. 

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3. Polygon: Symbolic Reasoning for SQL using Conflict-Driven Under-Approximation Search

   https://doi.org/10.1145/3729303  

   Zhao, Pinhan; Wang, Yuepeng; Wang, Xinyu (June 2025, Proceedings of the ACM on Programming Languages)

   We present a novel symbolic reasoning engine for SQL which can efficiently generate an inputIfornqueriesP₁, ⋯,P_n, such that their outputs onIsatisfy a given property (expressed in SMT). This is useful in different contexts, such as disproving equivalence of two SQL queries and disambiguating a set of queries. Our first idea is to reason about an under-approximation of eachP_i— that is, a subset ofP_i’s input-output behaviors. While it makes our approach both semantics-aware and lightweight, this idea alone is incomplete (as a fixed under-approximation might miss some behaviors of interest). Therefore, our second idea is to perform search over an expressive family of under-approximations (which collectively cover all program behaviors of interest), thereby making our approach complete. We have implemented these ideas in a tool, Polygon, and evaluated it on over 30,000 benchmarks across two tasks (namely, SQL equivalence refutation and query disambiguation). Our evaluation results show that Polygon significantly outperforms all prior techniques. 

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4. Chain ends excite polymer cooperative motion

   https://doi.org/10.1126/sciadv.aea0786  

   Xu, Quanyin; Wu, Zhenghao; Randazzo, Katelyn; Xu, Wen-Sheng; Zhang, Bokai; Priestley, Rodney D; Zuo, Biao (November 2025, Science Advances)

   Among glasses, polymers stand out as the chain connectivity endows them with distinct properties in glass formation, among them the transition temperature (T_g) and dynamic fragility (m) varying with chain length. Here, we resolve the nature of the chain length–dependent behaviors, revealing the strong correlation between the number of chain ends within the cooperatively rearranging region and glassy properties includingT_gandm. The correlations suggest a simple yet common mechanism of glass formation for the chain molecules, i.e., fast-relaxing chain ends alleviate the requirements of cooperativity for structural rearrangement, thus facilitating the cooperative motion that reducesT_gandmas chain length is shortened. We categorize the role of end groups between soft and rigid by proposing a physical quantifier—index of rigidity. Our results provide a unifying picture of polymer glass formation, regarding the role of chain end, length, and topology, a foundational phenomenon with implications across fields of chemistry, soft-condensed matters, and material science. 

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5. High-magnetic-field phases in U _1-x Th _x Te ₂

   https://doi.org/10.1073/pnas.2521261122  

   Moir, Camilla M; Singleton, John; Blawat, Joanna; Lee-Wong, Eric; Deng, Yuhang; Feng, Keke; Wannamaker, Tyler; Baumbach, Ryan E; Maple, M Brian (October 2025, Proceedings of the National Academy of Sciences)

   At temperaturesTmuch lower than its superconducting critical temperatureT_c= 2.1 K, the heavy fermion superconductor UTe₂has a unique phase diagram of magnetic fieldHvs. φ and θ, anglesHis tilted from theb-axis toward thea- andc-axes, respectively, of its orthorhombic unit cell. The phase diagram contains three distinct superconducting phases: SC₁in which φ and θ extend from 0 to 90° andH≤ ~15 T; SC₂for φ ≤ ~7°, θ ≤ ~4° and ~15 T ≤H≤H_m= ~35 T, the onset of the magnetic field polarized (FP) phase, and SC_FPwhich resides entirely within the FP phase in a pocket of superconductivity extending from θ ≈ 20° to 40° and from ~40 T to above 60 T. We studied the evolution of theHvs. θ phase diagram for Th concentrations 0.005 ≤x≤ 0.047 in the U_1-xTh_xTe₂system at ~0.6 K. Within this range ofxvalues, SC₁extends over 0 ≤ θ ≤ 90° andH≤ ~10 T forx= 0.047, while SC₂is suppressed. The SC_FPand FP phases are unaffected tox= 0.02 but are completely suppressed in the regionx= 0.025 to 0.047 where the residual resistance ratioRRR~3 indicates a significant amount of disorder. These results complement recent studies of nonsuperconducting disordered UTe₂single crystals in which the SC₁and SC₂phases are absent, but the FP and so-called “orphan” SC_FPphases are retained. 

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