编译｜冯维维
science, 15 december 2023, volume 382, issue 6676
《科学》，2023年12月15日，第382卷，6676期
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物理学physics
emission and coherent control of levitons in graphene
石墨烯中列维子的发射和相干控制
▲ 作者：a. assouline, l. pugliese, h. chakraborti, seunghun lee, l. bernabeu, m. jo, k. watanabe, t. taniguchi, d. c. glattli, and p. roulleau
▲ 链接：
https://www.science.org/doi/10.1126/science.adf9887
▲ 摘要：
量子比特是量子计算机的组成部分，通常在固定的实体中实现，如捕获离子或量子点。传播量子信息的工作通常交给光子。然而，光子不会相互作用，使用电子实现传播“飞行”而量子比特是有利的。
研究者通过在单层石墨烯中制备和控制单电子飞行量子比特态实现了这一目标。
▲ abstract：
qubits, the building blocks of quantum computers, are usually implemented in stationary entities such as trapped ions or quantum dots. the job of propagating quantum information is usually given to photons. however, photons do not interact with each other, and it would be advantageous to implement a propagating (“flying”) qubit using electrons. assouline et al. achieved this goal by preparing and controlling single-electron flying qubit states in monolayer graphene.
low voltage–driven high-performance thermal switching in antiferroelectric pbzro3 thin films
反铁电pbzro3 薄膜中低压驱动的高性能热开关
▲ 作者：chenhan liu, yangyang si, hua zhang, chao wu, shiqing deng, yongqi dong, meng zhuo, ningbo fan, and zuhuang chen
▲ 链接：
https://www.science.org/doi/10.1126/science.adj9669
▲ 摘要：
通过开关器件控制热传输具有挑战性，因为快速改变材料的热特性具有难度。研究者证明了用小电压控制氧化锆铅可以制成热敏开关。
在电场的作用下，材料可以从反铁电性转变为铁电性，极大地改变了材料的热性能。这个开关在一个方向上改变了两倍的热传输，创造了一个有用的热开关。
▲ abstract：
controlling thermal transport by switching devices is challenging because rapidly changing a material’s thermal properties is difficult. liu et al. demonstrate that a thermal switch can be made from lead zirconium oxide controlled with a small voltage. the material can be changed from antiferroelectric to ferroelectric with an electric field that also dramatically changes the thermal properties. this switch changes the thermal transport by a factor of two in one direction, creating a useful thermal switch.
an observed population of intermediate-mass helium stars that have been stripped in binaries
在双星中被剥离的中等质量氦恒星的观测群
▲ 作者：m. r. drout , y. g?tberg , b. a. ludwig, j. h. groh, s. e. de mink, a. j. g. o’grady, and n. smith
▲ 链接：
https://www.science.org/doi/10.1126/science.ade4970
▲ 摘要：
大质量恒星富含氢的外层可以通过与双星伴星的相互作用而被移除。理论模型预测这种剥离会产生2到8个太阳质量的热氦恒星，然而，到目前为止，只有一个这样的系统被确定。
研究者使用紫外光度法来识别潜在的剥离氦星，然后使用光谱学对其中的25颗进行了研究。他们发现了温度高（~6万到10万开尔文）、表面重力大、表面氢耗尽的恒星；16颗恒星也表现出双星运动。这些性质符合对初始质量为8到25个太阳质量的恒星的期望，这些恒星被双星相互作用剥离。
它们的质量落在亚矮星氦星和沃尔夫—拉叶星之间。研究者提出这些恒星可能是剥离包层超新星的祖先。
▲ abstract：
the hydrogen-rich outer layers of massive stars can be removed by interactions with a binary companion. theoretical models predict that this stripping produces a population of hot helium stars of ~2 to 8 solar masses (m☉), however, only one such system has been identified thus far. we used ultraviolet photometry to identify potential stripped helium stars then investigated 25 of them using optical spectroscopy. we identified stars with high temperatures (~60,000 to 100,000 kelvin), high surface gravities, and hydrogen-depleted surfaces; 16 stars also showed binary motion. these properties match expectations for stars with initial masses of 8 to 25 m☉ that were stripped by binary interaction. their masses fall in the gap between subdwarf helium stars and wolf-rayet stars. we propose that these stars could be progenitors of stripped-envelope supernovae.
self-sustaining personal all-day thermoregulatory clothing using only sunlight
只使用阳光的全天候体温调节服装
▲ 作者：ziyuan wang, yiwen bo, peijia bai, shuchao zhang, guanghui li, xiangjian wan, yongsheng liu , rujun ma , and yongsheng chen
▲ 链接：
https://www.science.org/doi/10.1126/science.adj3654
▲ 摘要：
为了舒适和安全，人体必须保持在一定的温度范围内。然而，温度调节服的挑战存在于恶劣的应用场景，如全昼夜循环，寒冷的极地地区和太空旅行。
研究者通过集成柔性有机光伏（opv）模块直接从阳光和双向电热（ec）设备中获取能量，开发了一种灵活且可持续的个人体温调节服装系统。柔性opv—ec热调节服（oetc）可将人体热舒适区从22℃~28℃扩展到12.5℃~37.6℃，温度调节速率快。
ec装置的低能耗和高效率允许24小时可控和双模式温度调节，12小时的阳光能量输入。该自供电可穿戴式体温调节平台结构简单、设计紧凑、效率高、自适应性强，以太阳光为唯一能源。
▲ abstract：
the human body must stay within a certain temperature range for comfort and safety. however, challenges for thermoregulatory clothing exist for harsh application scenarios, such as full day/night cycles, frigid polar regions, and space travel. we developed a flexible and sustainable personal thermoregulatory clothing system by integrating a flexible organic photovoltaic (opv) module to directly acquire energy from sunlight and bidirectional electrocaloric (ec) devices. the flexible opv-ec thermoregulatory clothing (oetc) can extend the human thermal comfort zone from 22°–28°c to 12.5°–37.6°c with a fast thermoregulation rate. the low energy consumption and high efficiency of the ec device allows for 24 hours of controllable and dual-mode thermoregulation with 12 hours of sunlight energy input. this self-powered wearable thermoregulatory platform has a simple structure, compact design, high efficiency, and strong self-adaptability with sunlight as the sole energy source.
化学chemistry
iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere
碘氧酸促进大气中硫酸颗粒的成核
▲ 作者：xu-cheng he, mario simon, siddharth iyer, hong-bin xie, birte r?rup, jiali shen, henning finkenzeller, dominik stolzenburg, rongjie zhang, and markku kulmala
▲ 链接：
https://www.science.org/doi/10.1126/science.adh2526
▲ 摘要：
海洋上空的空气中，氨是形成过程中重要的一种物质，但含量并不丰富，新粒子是如何形成的？研究者报告说，在海洋环境中丰富的碘氧酸，可以大幅增加在原始海洋和极地地区常见的低氨条件下新颗粒形成的速度。
这种效应在低空海洋层积云中可能特别重要，因为层积云将入射太阳辐射的很大一部分反射回空间，对全球辐射平衡和气候具有重要影响。
▲ abstract：
how are new particles formed in the air above the oceans, where ammonia, an important species in the process, is not very abundant? he et al. report that iodine oxoacids, which are plentiful in marine environments, can substantially increase the rate of new particle formation in the low-ammonia conditions commonly found in pristine marine and polar regions. this effect could be particularly important in low-level marine stratocumulus clouds, which reflect a large fraction of incident solar radiation back into space and have an important influence on global radiation balance and climate.
生物化学biochemistry
light-gated channelrhodopsin sparks proton-induced calcium release in guard cells
光门控通道视紫红质激发保护细胞中质子诱导的钙释放
▲ 作者：shouguang huang, like shen, m. rob g. roelfsema, dirk becker, and rainer hedrich
▲ 链接：
https://www.science.org/doi/10.1126/science.adj9696
▲ 摘要：
质子（h ）和钙离子（ca2 ）经常穿梭于细胞膜并作为信号。在植物中，质子高度积聚在细胞外空间，而ca2 储存可以在内质网和其他细胞室中发现。胞质中的h 和ca2 浓度在信号事件中经常密切相关。
研究者将原生生物衍生的光门控离子通道引入植物细胞，允许h 而不是ca2 的选择性运输。他们发现，诱导h 转运到细胞质中导致随后的ca2 释放。这项研究建立了细胞内ph值和保护细胞中ca2 信号之间的因果关系，并为在其他情况下操纵离子运动提供了新的工具。
▲ abstract：
protons (h ) and calcium ions (ca2 ) are often shuttled across cellular membranes and act as signals. in plants, protons accumulate highly in the extracellular space, whereas ca2 stores can be found in the endoplasmic reticulum and other cellular compartments. h and ca2 concentrations in the cytoplasm are often closely correlated during signaling events. huang et al. introduced a light-gated protist-derived ion channel into plant cells, allowing selective transport of h but not ca2 . they found that induction of h transport into the cytoplasm led to subsequent ca2 release. this work establishes a causal relationship between intracellular ph and ca2 signaling in guard cells and offers a new tool for manipulating ion movement in other contexts.
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