《科学》(20230707出版)一周论文导读

发布时间:2023-08-10    来源:admin

Science, 7 JUL 2023, Volume 381 Issue 6653

《科学》2023年7月7日,第381卷,6653期

物理Physics

An improved bound on the electron’s electric dipole moment

电子电偶极矩的改进测量

▲ 作者:TANYA S. ROUSSY, LUKE CALDWELL et al.

▲ 链接:

https://www.science.org/doi/10.1126/science.adg4084

▲ 摘要:

宇宙中物质和反物质的不平衡为寻找未被发现的、违反电荷宇称对称的粒子提供了强烈的动力。与这些新粒子相关的场的真空波动的相互作用将诱发电子的电偶极矩(eEDM)。我们利用分子离子内部的电子,经受巨大的分子内电场,并相干演化长达3秒,提出了迄今为止最精确的eEDM测量方法。

我们的结果比此前的最佳上限提升了约2.4倍。我们的结果为新物理学的广泛类别提供了1013电子伏特以上的限制,超出了当前或未来几十年可能可用的粒子对撞机的直接范围。

▲ Abstract:

The imbalance of matter and antimatter in our Universe provides compelling motivation to search for undiscovered particles that violate charge-parity symmetry. Interactions with vacuum fluctuations of the fields associated with these new particles will induce an electric dipole moment of the electron (eEDM). We present the most precise measurement yet of the eEDM using electrons confined inside molecular ions, subjected to a huge intramolecular electric field, and evolving coherently for up to 3 seconds. Our result is consistent with zero and improves on the previous best upper bound by a factor of ~2.4. Our results provide constraints on broad classes of new physics above 1013 electron volts, beyond the direct reach of the current particle colliders or those likely to be available in the coming decades.

Direct observation of nonlocal fermion pairing in an attractive Fermi-Hubbard gas

吸引费米-哈伯德气体中非局域费米子配对的直接观测

▲ 作者:THOMAS HARTKE, BOTOND OREG et al.

▲ 链接:

https://www.science.org/doi/10.1126/science.ade4245

▲ 摘要:

我们直接观察了哈伯德晶格气体中费米子配对的非局域性质,在双层显微镜下使用约 1000个费米子钾-40原子进行自旋和密度分辨成像。完整的费米子对揭示了随着引力增加而消失的全局自旋涨落。

在强相关状态下,我们发现费米子对的大小与粒子间的平均间距相同。我们的研究为强相关费米子系统的赝隙行为提供了理论依据。

▲ Abstract:

We directly observe the nonlocal nature of fermion pairing in a Hubbard lattice gas, using spin- and density-resolved imaging of 1000 fermionic potassium-40 atoms under a bilayer microscope. Complete fermion pairing is revealed by the vanishing of global spin fluctuations with increasing attraction. In the strongly correlated regime, the fermion pair size is found to be on the order of the average interparticle spacing. Our study informs theories of pseudo-gap behavior in strongly correlated fermion systems.

材料科学Materials Science

A lithium superionic conductor for millimeter-thick battery electrode

一种用于毫米厚电池电极的锂超离子导体

▲ 作者:YUXIANG LI, SUBIN SONG, HANSEUL KIM et al.

▲ 链接:

https://www.science.org/doi/10.1126/science.add7138

▲ 摘要:

利用高熵材料的特性,我们通过增加已知锂超离子导体的成分复杂性,设计了一种高离子导电固体电解质,可以消除离子迁移障碍,同时保持超离子传导的结构框架。

其组成复杂的合成相,显示出离子电导率的提高。我们展示了高导电性固体电解质能够在室温下对厚锂离子电池阴极进行充电和放电,从而有潜力改变传统的电池配置。

▲ Abstract:

Taking advantage of the properties of high-entropy materials, we have designed a highly ion-conductive solid electrolyte by increasing the compositional complexity of a known lithium superionic conductor to eliminate ion migration barriers while maintaining the structural framework for superionic conduction. The synthesized phase with a compositional complexity showed an improved ion conductivity. We showed that the highly conductive solid electrolyte enables charge and discharge of a thick lithium-ion battery cathode at room temperature and thus has potential to change conventional battery configurations.

Interface engineering for high-performance, triple-halide perovskite–silicon tandem solar cells

高性能的三卤化物钙钛矿—硅串联太阳能电池 

▲ 作者:SILVIA MARIOTTI, EIKE K?HNEN et al.

▲ 链接:

https://www.science.org/doi/10.1126/science.adf5872

▲ 摘要:

提高双端单片钙钛矿—硅串联太阳能电池的稳定性和效率需要减少重组损失。通过将三卤化物钙钛矿(带隙为1.68电子伏)与碘化哌嗪相结合,我们改善了能带排列,减少了非辐射重组损失,并增强了电子选择接触处的电子提取。这样,太阳能电池显示,p-i-n单结的开路电压高达1.28伏,钙钛矿—硅串联太阳能电池的开路电压高达2伏。串联电池的认证功率转换效率高达32.5%。

▲ Abstract:

Improved stability and efficiency of two-terminal monolithic perovskite-silicon tandem solar cells will require reductions in recombination losses. By combining a triple-halide perovskite (1.68 electron volt bandgap) with a piperazinium iodide interfacial modification, we improved the band alignment, reduced nonradiative recombination losses, and enhanced charge extraction at the electron-selective contact. Solar cells showed open-circuit voltages of up to 1.28 volts in p-i-n single junctions and 2.00 volts in perovskite-silicon tandem solar cells. The tandem cells achieve certified power conversion efficiencies of up to 32.5%.

地球科学Geoscience

Effect of climate warming on the timing of autumn leaf senescence reverses after the summer solstice

气候变暖对秋天叶片衰老时间的影响在夏至后逆转

▲ 作者:CONSTANTIN M. ZOHNER, LEILA MIRZAGHOLI et al.

▲ 链接:

https://www.science.org/doi/10.1126/science.adf5098

▲ 摘要:

通过利用卫星、地面、碳通量和实验的数据,我们发现季初变暖和季末变暖对叶片衰老有相反的影响,逆转通常在一年中最长的一天(夏至)之后发生。

在84%的北方森林地区,冬至前温度和植被活动的升高导致叶片衰老的发生时间平均提前1.9±0.1天每摄氏度,而冬至后温度的升高使叶片衰老持续时间延长2.6±0.1天每摄氏度。目前叶片衰老开始时间早和进展慢的变化轨迹,影响了整个北半球生长季节时间和森林生产力的趋势。

▲ Abstract:

Using satellite, ground, carbon flux, and experimental data, we show that early-season and late-season warming have opposite effects on leaf senescence, with a reversal occurring after the year’s longest day (the summer solstice). Across 84% of the northern forest area, increased temperature and vegetation activity before the solstice led to an earlier senescence onset of, on average, 1.9 ± 0.1 days per °C, whereas warmer post-solstice temperatures extended senescence duration by 2.6 ± 0.1 days per °C. The current trajectories toward an earlier onset and slowed progression of senescence affect Northern Hemisphere–wide trends in growing-season length and forest productivity.

古生物学Paleobiology

Paleoenvironments shaped the exchange of terrestrial vertebrates across Wallace’s Line

古环境决定了陆生脊椎动物跨越华莱士线的变化情况

▲ 作者:A. SKEELS, L. M. BOSCHMAN et al.

▲ 链接:

《科学》(20230707出版)一周论文导读

https://www.science.org/doi/10.1126/science.adf7122

▲ 摘要:

在此,利用地理气候和生物多样性模型对20000多种脊椎动物的分析显示,广泛的降水耐受性和扩散能力是跨越该地区深时降水梯度交换的关键。Sundanian(东南亚)谱系在类似于华莱士区潮湿的“垫脚石”的气候中进化,促进了Sahulian(澳大利亚)大陆架的殖民化。

相反,Sahulian谱系主要是在干燥的条件下进化的,这阻碍了在巽他的形成,并塑造了动物的独特性。我们展示了过去环境条件的适应历史如何塑造不对称的殖民化和全球生物地理结构。

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▲ Abstract:

Here, analysis of more than 20,000 vertebrate species with a model of geoclimate and biological diversification shows that broad precipitation tolerance and dispersal ability were key for exchange across the deep-time precipitation gradient spanning the region. Sundanian (Southeast Asian) lineages evolved in a climate similar to the humid “stepping stones” of Wallacea, facilitating colonization of the Sahulian (Australian) continental shelf. By contrast, Sahulian lineages predominantly evolved in drier conditions, hampering establishment in Sunda and shaping faunal distinctiveness. We demonstrate how the history of adaptation to past environmental conditions shapes asymmetrical colonization and global biogeographic structure.

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