Science,12 JUL 2024, VOL 385, ISSUE 6705

《科学》2024年7月12日，第385卷，6705期

物理学Physics

Structured electrons with chiral mass and charge

具备手性子量以及电荷的布局电子

▲ 作者：YIQI FANG, JOEL KUTTRUFF, DAVID NABBEN, AND PETER BAUM

▲链接：

https://www.science.org/doi/10.1126/science.adp9143

▲择要：

手性是一种于根蒂根基物理学、质料科学、化学、光学以及光谱学中具备广泛联系关系的征象。

这项事情中，研究组证实了自由电子可经由过程激光场周期转化为品质以及电荷的右旋或者左旋。与相位涡旋光束比拟，该电子连结了平展的德布罗意波，但从当时空指望值的外形得到了响应的手性。

经由过程阿秒门控丈量波函数密度，展现了具备左旋或者右旋螺距的线圈以及双线圈的三维外形。具备此类或者相干手性几何布局的项目基本粒子可运用在手性传感、自由电子量子光学、粒子物理学或者电子显微镜等范畴。

▲ Abstract：

Chirality is a phenomenon with widespread relevance in fundamental physics, material science, chemistry, optics, and spectroscopy. In this work, we show that a free electron can be converted by the field cycles of laser light into a right-handed or left-handed coil of mass and charge. In contrast to phase-vortex beams, our electrons maintained a flat de Broglie wave but obtained their chirality from the shape of their expectation value in space and time. Measurements of wave function densities by attosecond gating revealed the three-dimensional shape of coils and double coils with left-handed or right-handed pitch. Engineered elementary particles with such or related chiral geometries should be useful for applications in chiral sensing, free-electron quantum optics, particle physics or electron microscopy.

质料科学Materials Science

A crystal capping layer for formation of black-phase FAPbI3 perovskite in humid air

于湿润空气中造成黑相FAPbI3钙钛矿的晶体笼罩层

▲ 作者：YU ZOU, WENJIN YU, HAOQING GUO, QIZHI LI, XIANGDONG LI, LIANG LI, ET AL.

▲链接：

https://www.science.org/doi/10.1126/science.adn9646

▲择要：

黑相甲脒碘化铅（α-FAPbI3）钙钛矿是光伏运用的抱负相，但水会激发诸如δ-FAPbI3光惰性杂质相的造成。

研究组注解，钙钛矿打造的经典溶剂体系加重了这类可反复性应战。传统配位溶剂二甲亚砜（DMSO）因其吸湿性，于高相对于湿度（RH）前提下促成了δ-FAPbI3的造成。

研究组引入含氯无机份子来造成笼罩层，制止水份渗入，同时保留基在DMSO的共同物来调治晶体生长。所患上钙钛矿太阳能电池于20%至60% RH下的能量转换效率 24.5%，于80% RH下为23.4%。于最年夜功率点运转500小时后，未封装装备于空气中（40至60% RH）仍保留96%的初始机能。

▲ Abstract：

Black-phase formamidinium lead iodide (α-FAPbI3) perovskites are the desired phase for photovoltaic applications, but water can trigger formation of photoinactive impurity phases such as δ-FAPbI3. We show that the classic solvent system for perovskite fabrication exacerbates this reproducibility challenge. The conventional coordinative solvent dimethyl sulfoxide (DMSO) promoted δ-FAPbI3 formation under high relative humidity (RH) conditions because of its hygroscopic nature. We introduced chlorine-containing organic molecules to form a capping layer that blocked moisture penetration while preserving DMSO-based complexes to regulate crystal growth. We report power conversion efficiencies of 24.5% for perovskite solar cells fabricated across an RH range of 20 to 60%, and 23.4% at 80% RH. The unencapsulated device retained 96% of its initial performance in air (with 40 to 60% RH) after 500-hour maximum power point operation.

Partitioning polar-slush strategy in relaxors leads to large energy-storage capability

弛豫器的极性雪泥态区块化计谋可实现年夜储能容量

▲ 作者：LIANG SHU, XIAOMING SHI, XIN ZHANG, ZIQI YANG, WEI LI, YUNPENG MA, ET AL.

▲链接：

https://www.science.org/doi/10.1126/science.adn8721

▲择要：

弛豫铁电（RFE）薄膜因其高能量密度（Ue）以及高效率而成为小型化高功率电子体系很有远景的储能候选质料。然而，将其Ue提高到200 J/cm3焦耳以上颇具应战性，这限定了RFE鄙人一代储能装备中的运用潜力。

研究组于RFE中实行了一种极性雪泥态区块化计谋来冲破Ue的边界。于相场模仿的引导下，经由过程按捺非极性立方矩阵以及引入高绝缘收集，设计并制备了具备断绝极性雪泥态团簇的Bi(Mg0.5Ti0.5)O3-SrTiO3基高机能RFE薄膜。

可逆极化以及击穿强度的同时加强致使Ue到达202 J/cm3，效率高达79%。该计谋为下一代高机能电介质提供了设计自由度。

▲ Abstract：

Relaxor ferroelectric (RFE) films are promising energy-storage candidates for miniaturizing high-power electronic systems, which is credited to their high energy density (Ue) and efficiency. However, advancing their Ue beyond 200 joules per cubic centimeter is challenging, limiting their potential for next-generation energy-storage devices. We implemented a partitioning polar-slush strategy in RFEs to push the boundary of Ue. Guided by phase-field simulations, we designed and fabricated high-performance Bi(Mg0.5Ti0.5)O3-SrTiO3–based RFE films with isolated slush-like polar clusters, which were realized through suppression of the nonpolar cubic matrix and introduction of highly insulating networks. The simultaneous enhancement of the reversible polarization and breakdown strength leads to a Ue of 202 joules per cubic centimeter with a high efficiency of ~79%. The proposed strategy provides a design freedom for next-generation high-performance dielectrics.

化学Chemistry

Resetting tropospheric OH and CH4 lifetime with ultraviolet H2O absorption

哄骗紫外水接收重设对于流层OH以及CH4寿命

▲ 作者：MICHAEL J. PRATHER AND LEI ZHU

▲链接：

https://www.science.org/doi/10.1126/science.adn0415

▲择要：

甲基氯仿（一种禁用的耗损臭氧物资）的衰变提供了对于流层羟基自由基（OH）平均品貌的明确不雅测指标。险些所有当前的全世界化学模子都计较出约15%的OH过多，从而致使甲烷丧失过快。甲烷是一种短暂的天气因子，对于实现全世界变暖方针至关主要，这一过错影响了人们对于天气变迁的模子猜测。

研究组对于紫外线区（290至350纳米）水汽接收的新不雅测注解，近地表热带年夜气中的要害光解速度降落了8%至12%，致使阳光削减。化学输运模子中纳入这一新机制仅能削减4%的OH以及甲烷丧失，但联合其他提出的机制，如对于流层卤素化学（7%），研究组无望解决这一难题。

▲ Abstract：

The decay of methyl chloroform, a banned ozone-depleting substance, has provided a clear observational metric of mean tropospheric hydroxyl radical (OH) abundance. Almost all current global chemistry models calculate about 15% too much OH and thus too rapid methane loss. Methane is a short-lived climate forcer, critical to achieving global warming targets, and this error affects our model projections of climate change. New observations of water vapor absorption in the ultraviolet region (290 to 350 nanometers) imply reductions in sunlight with key photolysis rates decreasing by 8 to 12% in the near-surface tropical atmosphere. Incorporation of this new mechanism in a chemistry-transport model reduces OH and methane loss by only 4%, but combined with other proposed mechanisms, such as tropospheric halogen chemistry (7%), we may be able to resolve this conundrum.

Progra妹妹ed alternating current optimization of Cu-catalyzed C-H bond transformations

铜催化C-H键转化的可编程交流电优化

▲ 作者：LI ZENG, QINGHONG YANG, JIANXING WANG, XIN WANG, PENGJIE WANG, SHENGCHUN WANG, ET AL.

▲链接：

https://www.science.org/doi/10.1126/science.ado0875

▲择要：

直流（DC）电合成技能于已往一个世纪里履历了不停的优化，于各类工业工艺中起着举足轻重的作用。交流（AC）电合成具备极性反转以及周期性颠簸的特性，或者有益在多种化学反映，但装备、道理以及运用场景进展较慢。

于这项事情中，研究组先容了一种可编程交流（pAC）电合成和谈，可体系地调解电流、频次以及占空比。代表性pAC波形的运用促成了于DC以及化学氧化前提下体现欠安的交织偶联以及双官能化反映中的铜催化碳-氢键裂解。

此外，不雅察差别波形运用下的催化剂动态变迁为人们提供了机理见解。

▲ Abstract：

Direct current (DC) electrosynthesis, which has undergone optimization over the past century, plays a pivotal role in a variety of industrial processes. Alternating current (AC) electrosynthesis, characterized by polarity reversal and periodic fluctuations, may be advantageous for multiple chemical reactions, but apparatus, principles, and application scenarios remain underdeveloped. In this work, we introduce a protocol for progra妹妹ed AC (pAC) electrosynthesis that systematically adjusts currents, frequencies, and duty ratios. The application of representative pAC waveforms facilitates copper-catalyzed carbon-hydrogen bond cleavage in cross-coupling and difunctionalization reactions that exhibit suboptimal performance under DC and chemical oxidation conditions. Moreover, observing catalyst dynamic variation under diverse waveform applications provides mechanistic insight.

地球科学Earth Science

Stratospheric air intrusions promote global-scale new particle formation

平流层空气流入促成全世界标准新粒子的造成

▲ 作者：JIAOSHI ZHANG, XIANDA GONG, EWAN CROSBIE, GLENN DISKIN, KARL FROYD, SAMUEL HALL, ET AL.

▲链接：

https://www.science.org/doi/10.1126/science.adn2961

▲择要：

自由对于流层中新粒子的造成是全世界云凝聚核的重要来历。支流不雅点以为，于自由对于流层中，新粒子重要于对于流云外流中造成。

研究组哄骗全世界不雅测提出了另外一种机制。成果发明，于平流层空气流入事务中，降落且富含臭氧的平流层空气与更潮湿的自由对于流层配景混淆致使羟基自由基（OH）浓度升高。

这类混淆于对于流层顶四周最为遍及，那里二氧化硫（SO2）的混淆比率较高。SO2以及OH程度配合升高致使硫酸浓度升高，促成颗粒造成。这类新粒子的造成频次高，地舆漫衍规模广，是中纬度自由对于流层的主要粒子来历。

▲ Abstract：

New particle formation in the free troposphere is a major source of cloud condensation nuclei globally. The prevailing view is that in the free troposphere, new particles are formed predominantly in convective cloud outflows. We present another mechanism using global observations. We find that during stratospheric air intrusion events, the mixing of descending ozone-rich stratospheric air with more moist free tropospheric background results in elevated hydroxyl radical (OH) concentrations. Such mixing is most prevalent near the tropopause where the sulfur dioxide (SO2) mixing ratios are high. The combination of elevated SO2 and OH levels leads to enhanced sulfuric acid concentrations, promoting particle formation. Such new particle formation occurs frequently and over large geographic regions, representing an important particle source in the midlatitude free troposphere.