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发布日期：2024-12-20 作者：开云
Nature, 31 October 2024, Volume 634 Issue 8036
《天然》, 2024年10月31日，第634卷，8036期
天文学Astronomy
Selection bias obfuscates the discovery of fast radio burst sources
选择性误差恍惚了快速射电暴源的发现
▲ 作者：Mohit Bhardwaj, Jimin Lee Kevin Ji▲ 链接：https://www.nature.com/articles/s41586-024-08065-w
▲摘要：在此，我们供给实证证据，操纵非定向巡天发现的快速射电暴的宿主星系样本，证实在具有年夜倾角的星系中探测快速射电暴存在显著的选择误差。这类与偏向性相干的误差可能致使论文研究中陈述的快速射电爆发生率被严重低估（约低估一半），且不撑持此前球状星团作为快速射电暴首要来历的猜测。这些结论对快速射电暴祖模子和有针对性的快速射电暴随访策略具有主要意义。
我们进一步研究了这类误差对分歧宿主情况下快速射电暴相对产生率的影响。我们的阐发注解，快速射电暴宿主星系中的散射多是不雅测误差的缘由。但是，需要更年夜的局部快速射电暴样本，以正确量化散射对倾斜相干选择误差的进献。
▲ Abstract：Here we present empirical evidence for a substantial selection bias against detecting FRBs in galaxies with large inclination angles (edge-on) using a sample of hosts identified for FRBs discovered by untargeted surveys. This inclination-related bias probably leads to a significant underestimation (by about a factor of two) of the FRB rates reported in the literature and disfavours globular clusters as the dominant origin of FRB sources, as previously speculated. These conclusions have important implications for FRB progenitor models and targeted FRB follow-up strategies. We further investigate the impact of this bias on the relative rate of FRBs in different host environments. Our analysis suggests that scattering in FRB hosts is probably responsible for the observed bias. However, a larger sample of localized FRBs is required to robustly quantify the contribution of scattering to the inclination-related selection bias.
化学Chemistry
Smooth trends in fermium charge radii and the impact of shell effects镄电荷半径的光滑趋向和壳层效应的影响▲ 作者：Jessica Warbinek, Elisabeth Rickert et al.▲ 链接：https://www.nature.com/articles/s41586-024-08062-z
▲摘要：在此，我们展现了镄（Z=100）同位素链的激光光谱丈量和一个要害区域扩大的中子同位素链（Z=102）数据。采取多种出产方案和分歧的进步前辈手艺来肯定原子跃迁中的同位素位移，从中提取核均方电荷半径的转变。
一系列基在能量密度泛函的核模子很好地再现了不雅察到的核尺寸的光滑演化。模子猜测的显著一致性和分歧同位素猜测的类似性都注解，与较轻的原子核比拟，壳层效应对原子核巨细的影响较小。
▲ Abstract：Here we present laser spectroscopy measurements along the fermium (Z = 100) isotopic chain and an extension of data in the nobelium isotopic chain (Z = 102) across a key region. Multiple production schemes and different advanced techniques were applied to determine the isotope shifts in atomic transitions, from which changes in the nuclear mean-square charge radii were extracted. A range of nuclear models based on energy density functionals reproduce well the observed smooth evolution of the nuclear size. Both the remarkable consistency of model prediction and the similarity of predictions for different isotopes suggest a transition to a regime in which shell effects have a diminished effect on the size compared with lighter nuclei.
材料科学Material Sciences
A graphite thermal Tesla valve driven by hydrodynamic phonon transport一种流体动力声子输运驱动的石墨热特斯拉阀▲ 作者：Xin Huang, Roman Anufriev et al.▲ 链接：https://www.nature.com/articles/s41586-024-08052-1
▲摘要：在此，我们利用声子流体力学方式，在同位素富集的石墨晶体中实现热传导整流。我们在90纳米厚的石墨中设计了一个微米级的特斯拉阀，在45K时，不雅测到相反标的目的的热导率差别可辨认为15.2%。
这项研究标记着在微标准和纳米标准电子器件中利用集体声子行动进行热治理的主要一步，为固体中的热整流斥地道路。
▲ Abstract：Here we demonstrate a phonon hydrodynamics approach to realize the rectification of heat conduction in isotopically enriched graphite crystals. We design a micrometre-scale Tesla valve within 90-nm-thick graphite and experimentally observe a discernible 15.2% difference in thermal conductivity between opposite directions at 45 K. This work marks an important step towards using collective phonon behaviour for thermal management in microscale and nanoscale electronic devices, paving the way for thermal rectification in solids.
地球科学Earth Science
Common occurrences of subsurface heatwaves and cold spells in ocean eddies
海洋涡旋中常见的次表层热浪和冷浪
▲ 作者：Qingyou He, Weikang Zhan et al.
▲ 链接：https://www.nature.com/articles/s41586-024-08051-2
▲摘要：在此，我们供给了全球不雅测证据，证实中标准涡旋在次表层热浪和冷浪的产生和加强中阐扬了主要感化。我们发现，在深度100米以下丈量到的80%的热浪和冷浪与表层环境纷歧致。与表层冷浪和海洋涡旋之间的弱联系相反，全球海洋中近三分之一的次表层热浪/冷浪、和亚热带环流和中纬度主流系统中一半以上的此类事务产生在反气旋（气旋）涡旋中。
在曩昔的几十年里，这些与涡旋相干的极端温度以高在布景程度的速度加重，这注解跟着全球延续变暖，海洋涡旋对次表层热浪和冷浪的影响愈来愈年夜。
▲ Abstract：Here we present global observational evidence for the important role of mesoscale eddies in the occurrence and intensification of subsurface MHWs and MCSs. We found that 80% of measured MHWs and MCSs below a depth of 100 m do not concur with surface events. In contrast to the weak link between surface MHWs (MCSs) and ocean eddies, nearly one-third of subsurface MHWs (MCSs) in the global ocean, and more than half of such events in subtropical gyres and mid-latitude main current systems, occur within anticyclonic (cyclonic) eddies. These eddy-associated temperature extremes have intensified at rates greater than background level in past decades, suggesting a growing impact of ocean eddies on subsurface MHWs and MCSs with ongoing global warming.
考古学Archaeology
Large-scale medieval urbanism traced by UAV–lidar in highland Central Asia在中亚高原经由过程无人机激光雷达追踪的年夜范围中世纪城市化遗址
▲ 作者：Michael D. Frachetti, Jack Berner, Xiaoyi Liu, Edward R. Henry, Farhod Maksudov Tao Ju
▲ 链接：https://www.nature.com/articles/s41586-024-08086-5
▲摘要：在此，我们展现了在中亚进行的无人驾驶飞翔器激光雷达查询拜访的成果，这些查询拜访是在乌兹别克斯坦东南部比来发现的两个考古遗址——塔什布拉克和图贡布拉克——进行的。这些遗址位在海拔约2000—2200米的处所，是最新被记实下来的、位在亚洲中世纪丝绸之路（公元6—11世纪）的山区十字路口的年夜型高海拔城市中间。
虽然埋没在几个世纪的地表下，我们将高分辩率的概况建模与半主动特点检测相连系，在图贡布拉克描画了120公顷的记念碑防御工事和建筑的具体平面图，从而展现了前现代中亚最年夜的高原城市群之一。
中亚山区是丝绸之路的主要纽带，对中亚山区中世纪社区普遍的城市根本举措措施和手艺出产的记实为研究中世纪欧亚年夜陆的经济、政治和社会构成中高原生齿的介入供给了新视角。
▲ Abstract：Here we present the results of uncrewed aerial vehicle–lidar surveys in Central Asia, conducted at two recently discovered archaeological sites in southeastern Uzbekistan: Tashbulak and Tugunbulak. Situated at around 2,000–2,200 m above sea level, these sites illustrate a newly documented geography of large, high-altitude urban centres positioned along the mountainous crossroads of Asia’s medieval Silk Routes (6th–11th century CE (Common Era). Although hidden by centuries of surface processes, our pairing of very-high-resolution surface modelling with semiautomated feature detection produces a detailed plan of monumental fortifications and architecture spanning 120 ha at Tugunbulak, thereby demonstrating one of the largest highland urban constellations in premodern Central Asia. Documentation of extensive urban infrastructure and technological production among medieval communities in Central Asia’s mountains—a crucial nexus for Silk Road trade networks6—provides a new perspective on the participation of highland populations in the economic, political and social formation of medieval Eurasia.
公共卫生Public Health
Bureaucrat incentives reduce crop burning and child mortality in South Asia
权要鼓励削减了南亚的农作物燃烧和儿童灭亡率
▲ 作者：Gemma Dipoppa Saad Gulzar
▲ 链接：https://www.nature.com/articles/s41586-024-08046-z
▲摘要：南亚的空气污染每一年造成200万人灭亡，是一个很是迫切的卫闹事件。在冬季收成月份，农作物秸秆燃烧酿成的污染占峰值污染的40—60%。虽然这长短法的，但这类做法依然很遍及。任何遏制这一问题的解决方案都需要当局采纳年夜范围步履。
在此，我们对负责节制燃烧的官员进行鼓励是不是可以减缓这一现象进行了研究。操纵十年来来自卫星的风、火和健康数据和生齿与健康查询拜访项目标查询拜访，我们注解了权要鼓励对农作物燃烧发生了影响：当风最有可能将污染引向临近管辖区时，火警产生率增添15%；当风污染本身的管辖区时，火警产生率削减14.5%。这些影响跟着权要鼓励和能力的加强而扩年夜。我们还发现，制止燃烧的权要行动禁止了潜伏的报酬燃烧行动，进一步削减了13%的火警。
最后，操纵年夜气模子，我们估量子宫内表露在燃烧污染的每增添一个对数，就会使儿童灭亡率增添30—36‰，从而强调了官方步履的主要性。与愈来愈多的人认为燃烧农作物的问题难以解决的不雅点相反，这些发现强调了现有官员在恰当鼓励下可以改良情况治理和公共卫生成果的具体方式。
▲ Abstract：Air pollution in South Asia is a health emergency, responsible for 2 million deaths every year. Crop residue burning accounts for 40–60% of peak pollution during the winter harvest months. Despite being illegal, this practice remains widespread. Any solution to curb the problem necessitates government action at scale. Here we study whether leveraging the incentives of bureaucrats tasked with controlling burning can mitigate this phenomenon. Using a decade of wind, fire and health data from satellites and surveys from the Demographic and Health Surveys Program, we show that crop burning responds to bureaucrat incentives: fires increase by 15% when wind is most likely to direct pollution to neighbouring jurisdictions, and decrease by 14.5% when it pollutes their own. These effects intensify with stronger bureaucratic incentives and capacity. We also find that bureaucrat action against burning deters future polluters, further reducing fires by 13%. Finally, using an atmospheric model, we estimate that one log increase in in utero exposure to pollution from burning raises child mortality by 30–36 deaths per 1,000 births, underscoring the importance of bureaucrat action. Contrary to the growing beliefs that the problem of crop burning is intractable, these findings highlight specific ways in which existing bureaucrats, when properly incentivized, can improve environmental management and public health outcomes.
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