来源:科学网微信公众号 发布时间:2024/2/25 20:17:54
选择字号:
《科学》(20240223出版)一周论文导读

 

编译 | 冯维维

Science, Volume 383, Issue 6685, 23 February 2024

《科学》,第383卷,6685期,2024年2月23日

图片


物理学Physics


Emission lines due to ionizing radiation from a compact object in the remnant of Supernova 1987A

超新星1987A残骸中致密天体电离辐射的发射线

▲ 作者:C. FRANSSON, M. J. BARLOW, P. J. KAVANAGH, J. LARSSON, O. C. JONES, B. SARGENT, M. MEIXNER, P. BOUCHET, T. TEMIM, AND B. VANDENBUSSCHE

▲ 链接:

https://www.science.org/doi/10.1126/science.adj5796

▲ 摘要:

地球附近的超新星SN 1987A肉眼可见,其演变在最近几十年里一直被观察到。此次爆炸被认为产生了一个中子星或黑洞,但并未被直接探测到。

研究者利用近红外和中红外积分场光谱观测到了SN 1987A的残余物,发现电离氩的发射线只出现在残骸的中心附近。光电离模型表明,线比和速度可以用中子星的电离辐射来解释,这些辐射照亮了爆炸恒星内部的气体。

▲ Abstract:

The nearby supernova SN 1987A was visible to the naked eye, and its evolution has been observed over the ensuing decades. The explosion is thought to have produced a neutron star or black hole, but none has been directly detected. Fransson et al. observed a remnant of SN 1987A using near- and mid-infrared integral field spectroscopy. They identified emission lines of ionized argon that appear only near the center of the remnant. Photoionization models show that the line ratios and velocities can be explained by ionizing radiation from a neutron star illuminating gas from the inner parts of the exploded star.

Achieving sub-0.5-angstrom–resolution ptychography in an uncorrected electron microscope

电子显微镜实现低于0.5埃分辨率触觉成像

▲ 作者:KAYLA X. NGUYEN, YI JIANG, CHIA-HAO LEE, PRITI KHAREL, YUE ZHANG, AREND M. VAN DER ZANDE, AND PINSHANE Y. HUANG

▲ 链接:

https://www.science.org/doi/10.1126/science.adl2029

▲ 摘要:

电子显微镜中的像差校正通常是用复杂和昂贵的透镜光学来完成的,但平面摄影提供了一种替代方法,在不同的探针位置收集会聚光束衍射图,并用于确定图像的部分计算。

研究者发现,通过将数据收集扩展到具有大动量散射的电子,并考虑探针的部分相干性,可以实现更高的分辨率。他们展示了在未校正的显微镜下扭曲二硒化钨双分子层样品的分辨率高达0.44埃。

▲ Abstract:

Aberration correction in electron microscopy is usually performed with complex and expensive lens optics, but ptychography offers an alternative method in which convergent-beam diffraction patterns are collected at different probe positions and used to determine the image partial computationally. Nguyen et al. show that higher resolution can be achieved by extending data collection to electrons with large momentum scattering and by accounting for the partial coherence of the probe. They demonstrated resolution up to 0.44 angstrom in an uncorrected microscope for twisted tungsten diselenide bilayer samples.

生态Ecology

Arctic sea ice retreat fuels boreal forest advance

北极海冰退缩助长北方森林扩张

▲ 作者:ROMAN J. DIAL, COLIN T. MAHER, REBECCA E. HEWITT, AMY M. WOCKENFUSS, RUSSELL E. WONG, DANIEL J. CRAWFORD, MADELINE G. ZIETLOW, AND PATRICK F. SULLIVAN

▲ 链接:

https://www.science.org/doi/10.1126/science.adh2339

▲ 摘要:

北极变暖速度比全球平均速度快数倍,而冰融化和树木覆盖增加导致的反照率下降进一步加剧了全球气候变化。据预测,随着气候变暖,北方森林将转移到冻土带,但到目前为止,树木线向北移动缓慢或尚未移动。

研究者将林木线的推进与北冰洋海冰的减少联系起来,将阿拉斯加北部的野外和遥感测量结果与其他60个北极地区公布的数据相结合,发现与海冰的距离可以预测树木的生长和补充,以及森林发展的可能性。

▲ Abstract:

The arctic is warming multiple times faster than the global average, and the resulting loss of albedo from melting ice and increasing tree cover is further increasing global climate change. Boreal forest is predicted to shift into the tundra zone as the climate warms, but thus far tree lines have moved northward slowly or not at all. Dial et al. linked tree line advance to declines in Arctic Ocean sea ice. Combining field and remotely sensed measurements from northern Alaska with published data from 60 other Arctic sites, the authors found that distance to sea ice predicted tree growth and recruitment, as well as the probability of forest advance.

Global and regional temperature change over the past 4.5 million years

过去450万年全球和区域温度变化

▲ 作者:PETER U. CLARK, JEREMY D. SHAKUN, YAIR ROSENTHAL, PETER K?HLER, AND PATRICK J. BARTLEIN

▲ 链接:

https://www.science.org/doi/10.1126/science.adi1908

▲ 摘要:

过去450万年里,全球气候已经大幅降温,但由于通常用于测量温度的替代方法存在不确定性,很难确定具体的降温幅度和具体的降温轨迹。

研究者提出了该时期的温度重建,避免了一些不确定性,并提供了更可靠的温度曲线。该发现或有助于更好地理解导致全球温度变化的气候系统的相互作用和反馈。

▲ Abstract:

Global climate has cooled considerably over the past 4.5 million years, but by exactly how much and following exactly what trajectory is difficult to specify because of uncertainties in the proxy methods commonly used to measure temperatures. Clark et al. present a temperature reconstruction for that period that avoids some of those uncertainties and provides a more reliable temperature curve. Their findings should help to provide a better understanding of the interactions and feedbacks of the climate system that caused the global temperature changes.

Chemistry-albedo feedbacks offset up to a third of forestation’s CO2 removal benefits

化学反照率反馈或抵消造林去除二氧化碳效益的1/3

▲ 作者:JAMES WEBER, JAMES A. KING, NATHAN LUKE ABRAHAM, DANIEL P. GROSVENOR, CHRISTOPHER J. SMITH, YOUNGSUB MATTHEW SHIN, PETER LAWRENCE, STEPHANIE ROE, DAVID J. BEERLING, AND MARIA VAL MARTIN

▲ 链接:

https://www.science.org/doi/10.1126/science.adg6196

▲ 摘要:

植树造林被认为是隔绝大气二氧化碳和凉爽气候的好方法,但它对气候的影响比碳捕获的影响要复杂得多。

研究者通过量化造林对地表反照率和大气成分的影响,探讨了造林对气候的影响。他们发现,反射的减少和气溶胶散射的增加抵消了造林产生的二氧化碳去除所带来的大约三分之一的冷却效果。

▲ Abstract:

Forestation is considered a good way to sequester atmospheric carbon dioxide and cool climate, but its impact on climate is more complex than just its effects through carbon capture. Weber et al. explored the impacts of forestation on climate by quantifying its influence on surface albedo and atmospheric composition (see the Perspective by Hayman). They found that the combination of decreased reflection and increased aerosol scattering of incident sunlight offsets about one-third of the cooling by carbon dioxide removal that forestation produces.

化学Chemistry

Homogeneous crystallization and buried interface passivation for perovskite tandem solar modules

钙钛矿串联太阳能组件的均匀结晶和埋藏界面钝化

▲ 作者:HAN GAO, KE XIAO, RENXING LIN, SIYANG ZHAO, WENLIANG WANG, SERGEY DAYNEKO, CHENYANG DUAN, CHENGLONG JI, HONGFEI SUN, AND HAIREN TAN

▲ 链接:

https://www.science.org/doi/10.1126/science.adj6088

▲ 摘要:

在全钙钛矿串联太阳能电池中,采用铅锡钙钛矿代替硅作为窄带隙电池,但成核不均匀和结晶速度快限制了薄膜质量和器件效率。新研究表明,氨基乙酰胺盐酸盐能在溶液中强配位前驱体组分,使结晶过程均质化,也钝化了埋藏的钙钛矿界面。

研究者在一个20平方厘米的模块上实现了经认证的24.5%的功率转换效率,该模块由叶片涂层制成。

▲ Abstract:

In all-perovskite tandem solar cells, a lead-tin perovskite is used instead of silicon as the narrow band gap cell, but nonuniform nucleation and fast crystallization has limited film quality and device efficiency. Gao et al. now show that aminoacetamide hydrochloride can strongly coordinate the precursor components in solution, which homogenizes the crystallization process and also passivates the buried perovskite interface. The authors achieved a certified power conversion efficiency of 24.5% for a 20-square-centimeter module made by blade-coating the layers. 



 
特别声明:本文转载仅仅是出于传播信息的需要,并不意味着代表本网站观点或证实其内容的真实性;如其他媒体、网站或个人从本网站转载使用,须保留本网站注明的“来源”,并自负版权等法律责任;作者如果不希望被转载或者联系转载稿费等事宜,请与我们接洽。
 
 打印  发E-mail给: 
    
 
相关新闻 相关论文

图片新闻
中国天眼揭秘宇宙“随机烟花” 导师:年年审毕业论文,总有这些问题!
科学家发现第一颗拥有永久黑暗面的行星 中国超重元素研究加速器装置刷新纪录
>>更多
 
一周新闻排行
 
编辑部推荐博文