Industrial chemicals and 信网untreated sewage have polluted the Tijuana River for decades, recently causing >1300 consecutive days of California beach closures. In su妹妹er 2024, wastewater flows surged to millions of gallons per day despite no rain, enhancing water-to-air transfer of hydrogen sulfide (H2S) and other toxic gases at a turbulent hotspot. High wastewater flows and low winds led to nighttime H2S peaks, reaching 4500 parts per billion (ppb)—exceeding typical urban levels of <1 ppb. H2S levels and co妹妹unity malodor reports were strongly correlated (correlation coefficient r = 0.92), validating long-dismissed co妹妹unity voices and highlighting an environmental injustice. This study demonstrates that poor water quality can substantially affect air quality—although rarely included in air quality models and health assessments—with far-reaching implications as polluted waterways increase globally.
Seismic evidence for a highly heterogeneous martian mantle
火星地幔高度异质性的地震证据
▲ 作者：CONSTANTINOS CHARALAMBOUS, W. THOMAS PIKE, DOYEON KIM, HENRI SAMUEL, BENJAMIN FERNANDO, CARYS BILL, ET AL.
Cavitation, characterized by formation of vapor bubbles in a low-pressure or high-temperature region of a liquid, is often destructive, but it can be harnessed for actuators and robots. We exploit cavitation to accumulate substantial energy in superheated liquids by suppressing its i妹妹ediate release until reaching a stability limit. The energetic, unstable bubbles collapse violently, producing a burst of high power and force that initiates motion. Notably, a millimeter-scale device launched by cavitation can jump to a height of 1.5 meters—reaching a 12 meters per second (m/s) peak velocity, a 7.14 × 104m/s2acceleration, and a 0.64% energy efficiency—and can also swim on water at 12 centimeters per second. Cavitation-based launching works with a broad range of device materials, liquid media, stimuli, and operational environments.
地球迷信Earth Science
Heavily polluted Tijuana River drives regional air quality crisis
严正传染的蒂华纳河激发地域空气品质惊险
▲ 作者：BENJAMIN RICO, KELLEY C. BARSANTI, WILLIAM C. PORTER, KAROLINA CYSNEIROS DE CARVALHO, PAULA STIGLER-GRANADOS AND KIMBERLY A. PRATHER
Determining the atomic structure of nanoparticles (NPs) is critical for understanding their structural evolution and properties. However, controlling the growth of multiply-twinned metal NPs remains challenging because of numerous competing pathways. In this work, we report the synthesis of two giant silver icosahedral nanoclusters, [Ag213(C≡CR1)96]5?and [Ag429Cl24(C≡CR2)150]5?(Ag213and Ag429, R1 =3,4,5-F3C6H2and R2 = 4-CF3C6H4), achieved through ligand engineering and kinetic control. Single-crystal x-ray diffraction reveals that Ag213and Ag429have multilayered icosahedral Ag141|(Ag13@Ag42@Ag86) and Ag297(Ag13@Ag42@Ag92@Ag150) cores, respectively. Notably, Ag429with 260 valence electrons is the largest Ag0-containing nanocluster reported to date. These two giant silver nanoclusters are metallic in nature, as confirmed by their plasmonic absorption and pump-power–dependent excited-state dynamics. Their atomically precise structures support the layer-by-layer evolution from nuclei to seeds of silver icosahedra.
Launching by cavitation
空化发射
▲ 作者：DALEI WANG, ZIXIAO LIU, HONGPING ZHAO, HUANQI QIN, GONGXUN BAI, CHI CHEN, ET AL.
A planet’s interior is a time capsule, preserving clues to its early history. We report the discovery of kilometer-scale heterogeneities throughout Mars’ mantle, detected seismically through pronounced wavefront distortion of energy arriving from deeply probing marsquakes. These heterogeneities, likely remnants of the planet’s formation, imply a mantle that has undergone limited mixing driven by sluggish convection. Their size and survival constrain Mars’ poorly known mantle rheology, indicating a high viscosity of 1021.3to 1021.9pascal-seconds and low temperature dependence, with an effective activation energy of 70 to 90 kilojoules per mole, suggesting a mantle deforming by dislocation creep. The limited mixing, coupled with ubiquitous, scale-invariant heterogeneities, reflects a highly disordered mantle, characteristic of the more primitive interior evolution of a single-plate planet, contrasting sharply with the tectonically active Earth.
Classical and quantum technologies have traditionally been viewed as orthogonal, with classical systems being deterministic and quantum systems inherently probabilistic. This distinction hinders the development of a scalable quantum internet even as the global internet continues expanding. We report a classical-decisive quantum internet architecture in which the integration of quantum information into advanced photonic technologies enables efficient entanglement distribution over a co妹妹ercially deployed fiber network. On-chip precise synchronization between classical headers and quantum payloads enables dynamic routing and networking of high-fidelity entanglement guided by classical light. The quantum states are preserved through real-time error mitigation, relying solely on classical signal readout without disturbing quantum information. These classical-decisive features demonstrate a practical path to a scalable quantum internet using existing network infrastructure and operating systems.
质料迷信Materials Science
Deciphering icosahedra structural evolution with atomically precise silver nanoclusters
原子精度银纳米簇剖析二十面体妄想演化
▲ 作者：FENG HU, GAOYUAN YANG, LU-MING ZHENG, GUI-JIE LIANG AND QUAN-MING WANG
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