编译 | 冯维维
Nature, 3 September 2020, Volume 585 Issue 7823
《自然》2020年9月3日，第585卷7823期
物理学Physics
Universal structure of dark matter haloes over a mass range of 20 orders of magnitude
详解暗物质晕的质量范围
▲ 作者：J. Wang, S. Bose, C. S. Frenk, L. Gao, A. Jenkins, V. Springel & S. D. M. White
▲ 链接：
https://www.nature.com/articles/s41586-020-2642-9
▲ 摘要
暗物质由冷基本粒子组成的宇宙学模型预测，暗物质晕的质量应该比星系形成时的质量低许多个数量级。
假设暗物质以弱相互作用的大质量粒子的形式存在时，其质量约为100千兆电子伏，在所有观测到的晕质量范围内（20个数量级），作者报告了形成今天的晕的宇宙学模拟。
该模拟具有30个数量级的全动态范围的质量，并像对待数百个丰富的星系团那样，详细地解析了数百个地球质量晕的内部结构。
▲ Abstract
Cosmological models in which dark matter consists of cold elementary particles predict that the dark halo population should extend to masses many orders of magnitude below those at which galaxies can form. Here we report a cosmological simulation of the formation of present-day haloes over the full range of observed halo masses (20 orders of magnitude) when dark matter is assumed to be in the form of weakly interacting massive particles of mass approximately 100 gigaelectronvolts. The simulation has a full dynamic range of 30 orders of magnitude in mass and resolves the internal structure of hundreds of Earth-mass haloes in as much detail as it does for hundreds of rich galaxy clusters.
Floating under a levitating liquid
船浮悬液下
▲ 作者：Benjamin Apffel, Filip Novkoski, Antonin Eddi & Emmanuel Fort
▲ 链接：
https://www.nature.com/articles/s41586-020-2643-8
▲ 摘要
液体层如果超过一定规模，当被置于较低密度的介质上时，通常会向下坍塌，因为重力会作用在较低的液体界面上，会触发一种称为“瑞利—泰勒不稳定性”的不稳定效应。
作者利用共振支持体积高达半升，宽度高达20厘米的大型悬浮液层。作者理论和实验上预测，垂直振动也会在液体的下界面产生稳定的浮力位置，仿佛重力倒置。因此，物体可以倒挂在悬浮液层的下界面上。
▲ Abstract
When placed over a less dense medium, a liquid layer will typically collapse downwards if it exceeds a certain size, as gravity acting on the lower liquid interface triggers a destabilizing effect called a Rayleigh–Taylor instability. Here we take advantage of the excitation resonance of the supporting air layer to perform experiments with large levitating liquid layers of up to half a litre in volume and up to 20 centimetres in width. Moreover, we predict theoretically and show experimentally that vertical shaking also creates stable buoyancy positions on the lower interface of the liquid, which behave as though the gravitational force were inverted. Bodies can thus float upside down on the lower interface of levitating liquid layers.
物理化学Physical chemistry
Stable room-temperature continuous-wave lasing in quasi-2D perovskite films
室温下稳定的绿色准二维钙钛矿激光
▲ 作者：Chuanjiang Qin, Atula S. D. Sandanayaka, Chenyang Zhao, Toshinori Matsushima, Dezhong Zhang, Takashi Fujihara & Chihaya Adachi
▲ 链接：
https://www.nature.com/articles/s41586-020-2621-1
▲ 摘要
有机-无机卤化铅准二维钙钛矿由于其成本低、颜色可调、稳定性好和在溶液中可加工性好，是一种很有前途的激光应用材料。
作者采用高质量因数的分布反馈腔，采用三联态管理策略，在室温条件下实现了稳定的绿色准二维钙钛矿激光。他们期望这一发现为实现未来电流注入钙钛矿激光器铺平道路。
▲ Abstract
Organic–inorganic lead halide quasi-two-dimensional (2D) perovskites are promising gain media for lasing applications because of their low cost, tunable colour, excellent stability and solution processability. By using a distributed-feedback cavity with a high quality factor and applying triplet management strategies, we achieve stable green quasi-2D perovskite lasers under CW optical pumping in air at room temperature. We expect that our findings will pave the way to the realization of future current-injection perovskite lasers.
A disordered rock salt anode for fast-charging lithium-ion batteries
快速充电锂离子电池
▲ 作者：Haodong Liu, Zhuoying Zhu, Ping Liu
▲ 链接：
https://www.nature.com/articles/s41586-020-2637-6
▲ 摘要
可充电的高能量密度锂离子电池是理想的电力运输和其他应用。作者报道了无序岩盐Li3+xV2O5可以作为快速充电阳极，与Li/Li+参考电极相比，它可以在平均0.6伏特电压下可逆地循环两个锂离子。
如果使用适当的充电控制，与石墨相比增加的电势降低了金属锂电镀的可能性，减轻了主要的安全问题（与锂枝晶生长有关的短路）。
此外，无序岩盐Li3V2O5阳极的锂离子电池产生的电池电压远远高于使用商业快速充电的钛酸锂阳极或其他插层阳极(Li3VO4和LiV0.5Ti0.5S2)的电池。
▲ Abstract
Rechargeable lithium-ion batteries with high energy density that can be safely charged and discharged at high rates are desirable for electrified transportation and other applications. Here we report that disordered rock salt Li3+xV2O5 can be used as a fast-charging anode that can reversibly cycle two lithium ions at an average voltage of about 0.6 volts versus a Li/Li+ reference electrode. The increased potential compared to graphite reduces the likelihood of lithium metal plating if proper charging controls are used, alleviating a major safety concern (short-circuiting related to Li dendrite growth).In addition, a lithium-ion battery with a disordered rock salt Li3V2O5 anode yields a cell voltage much higher than does a battery using a commercial fast-charging lithium titanate anode or other intercalation anode candidates (Li3VO4 and LiV0.5Ti0.5S2)
气候学Climatology
Butterfly effect and a self-modulating El Ni?o response to global warming
蝴蝶效应和厄尔尼诺对全球变暖的自我调节反应
▲ 作者：Wenju Cai, Benjamin Ng, Tao Geng, Lixin Wu, Agus Santoso & Michael J. McPhaden
▲ 链接：
https://www.nature.com/articles/s41586-020-2641-x
▲ 摘要
厄尔尼诺和拉尼娜，统称为厄尔尼诺-南方涛动（ENSO），不仅具有高度的后果性，而且具有很强的非线性。
研究表明，就像蝴蝶效应一样，一个无穷小的随机扰动在相同的初始条件下导致了巨大的不同的初始ENSO变异性，这将系统地影响一个世纪后它对温室效应的反应。
如果温室变暖引起的ENSO变异性的增加最初被内部变异性抑制，未来ENSO变异性可能会增强，反之亦然。这种连接ENSO随时间变化的自调节为理解气候变化中多个时间尺度上的ENSO变化动力学提供了一个不同的视角。
▲ Abstract
El Ni?o and La Ni?a, collectively referred to as the El Ni?o–Southern Oscillation (ENSO), are not only highly consequential but also strongly nonlinear. Here we show that like a butterfly effect, an infinitesimal random perturbation to identical initial conditions induces vastly different initial ENSO variability, which systematically affects its response to greenhouse warming a century later. If the greenhouse-warming-induced increase in ENSO variability is initially suppressed by internal variability, future ENSO variability is likely to be enhanced, and vice versa. This self-modulation linking ENSO variability across time presents a different perspective for understanding the dynamics of ENSO variability on multiple timescales in a changing climate.
生态学Ecology
Accelerating homogenization of the global plant–frugivore meta-network
警惕物种引入带来的同质化
▲ 作者：Evan C. Fricke & Jens-Christian Svenning
▲ 链接：
https://www.nature.com/articles/s41586-020-2640-y
▲ 摘要
人类引入的物种正在跨越生物地理屏障，导致物种组成的同质化。引入物种的生态和进化后果源于它们对物种相互作用网络的影响，但目前缺乏对引入物种对生态网络及其全球生物地理格局的影响的定量了解。
作者通过分析410个本地网络的互惠性的种子传播相互作用，包括1631种动物和3208种植物之间的24455种独特的成对相互作用，来解决这个数据缺口。
研究表明，物种引入减少了全球元网络的生物地理划分，其中节点是物种，链接是在任何局部网络中观察到的相互作用。研究强调了管理日益增长的生态复杂性同质化的重要性。
▲ Abstract
Introductions of species by humans are causing the homogenization of species composition across biogeographic barriers. The ecological and evolutionary consequences of introduced species derive from their effects on networks of species interactions4,5, but we lack a quantitative understanding of the impacts of introduced species on ecological networks and their biogeographic patterns globally. Here we address this data gap by analysing mutualistic seed-dispersal interactions from 410 local networks, encompassing 24,455 unique pairwise interactions between 1,631 animal and 3,208 plant species. We show that species introductions reduce biogeographic compartmentalization of the global meta-network, in which nodes are species and links are interactions observed within any local network. Our results highlight the importance of managing the increasing homogenization of ecological complexity.