编译｜未玖

Science, 19 Feb 2026, VOL 391, ISSUE 6787

《科学》2026年2月19日，第391卷，6787期

天文学Astronomy

Carbonated ultramafic igneous rocks in Jezero crater, Mars

火星杰泽罗陨石坑中的碳酸盐化超镁铁质火成岩

▲ 作者：Kenneth H. Williford, Kenneth A. Farley, Briony H. N. Horgan, Brad Garczynski, Allan H. Treiman, Sanjeev Gupta, et al.

▲链接：

https://www.science.org/doi/10.1126/science.adu8264

▲摘要：

“毅力号”火星车在火星杰泽罗陨石坑成功着陆，该陨石坑曾有一个液态水湖。

研究组报道了“毅力号”在从杰泽罗陨石坑西边沉积扇底部到陨石坑上缘的10公里穿越行程中，探测的垂直跨度超过400米的岩石特性。这些岩石由粗粒橄榄石、镁铁碳酸盐、硅石和页硅酸盐组成，包括杰泽罗陨石坑内一些最古老的暴露物质。

研究组推断这些岩石是在一个层状侵入岩的火成系统中由橄榄石堆积而成，随后暴露于水和二氧化碳中，导致硅酸盐矿物广泛碳酸化。在较低海拔处，水蚀作用更为明显。陨石坑边缘较高海拔处的暴露岩石与广泛分布于尼利福萨地区的富橄榄石岩石类似。

▲ Abstract：

The Perseverance rover landed in Jezero crater on Mars, which once contained a lake of liquid water. We report the rock properties encountered by Perseverance during a 10-kilometer traverse extending over 400 meters in elevation, from beneath Jezero’s western sedimentary fan to the upper crater rim. These rocks consist of coarse-grained olivine, magnesium and iron carbonates, silica, and phyllosilicates, including some of the oldest materials exposed within Jezero. We infer that these rocks formed by olivine accumulation in an igneous system of layered intrusions, followed by exposure to water and carbon dioxide, which caused extensive carbonation of the silicate minerals. Aqueous alteration was more pronounced at lower elevations. Higher-elevation exposures on the crater rim appear similar to olivine-rich rocks distributed over the wider Nili Fossae region.

人工智能Artificial Intelligence

Toward universal steering and monitoring of AI models

迈向AI模型的全面控制和监测

▲ 作者：Daniel Beaglehole, Adityanarayanan Radhakrishnan, Enric Boix-Adserà and Mikhail Belkin

▲链接：

https://www.science.org/doi/10.1126/science.aea6792

▲摘要：

人工智能（AI）模型蕴含着大量人类知识。理解这种知识的表征方式将有助于提升模型性能并提供安全保障。

基于特征学习领域的进展，研究组开发了一种从AI模型中提取语义概念或观念的线性表征方法。并展示了这些概念表征如何实现模型调控，从而发现模型缺陷并提升其性能。该研究证明了概念表征具有跨语言可迁移性，并实现了多概念引导。

在数百个概念中，研究组发现规模较大的模型更具可操控性，且模型控制与单纯提示工程相比更能提升模型功能。结果发现，概念表征在监测异常内容方面比使用评判模型更为有效。该研究表明，内部表征对于提升AI安全性和模型能力方面具有重要作用。

▲ Abstract：

Artificial intelligence (AI) models contain much of human knowledge. Understanding the representation of this knowledge will lead to improvements in model capabilities and safeguards. Building on advances in feature learning, we developed an approach for extracting linear representations of semantic notions or concepts in AI models. We showed how these representations enabled model steering, through which we exposed vulnerabilities and improved model capabilities. We demonstrated that concept representations were transferable across languages and enabled multiconcept steering. Across hundreds of concepts, we found that larger models were more steerable and that steering improved model capabilities beyond prompting. We showed that concept representations were more effective for monitoring misaligned content than for using judge models. Our results illustrate the power of internal representations for advancing AI safety and model capabilities.

Who is using AI to code? Global diffusion and impact of generative AI

谁在使用AI进行编码？生成式AI的全球扩散与影响

▲ 作者：Simone Daniotti, Johannes Wachs, Xiangnan Feng and Frank Neffke

▲链接：

https://www.science.org/doi/10.1126/science.adz9311

▲摘要：

生成式编码工具有望大幅提高工作效率，但其应用不均衡可能会加剧技能和收入的差距。

研究组训练了一个神经分类器，用于识别来自160097名软件开发者所提交的超过3000万个GitHub代码段中人工智能（AI）生成的Python函数，并追踪这些工具的普及速度及其普及范围。目前美国约29%的Python函数由AI生成，虽领先其他国家但优势正逐渐缩小。据此估算，以在线代码贡献为衡量标准，季度产出相应增长了3.6%。

AI似乎对经验丰富的高级开发人员更有益：他们提高了工作效率，并且更积极拓展至软件开发新领域。相比之下，初入职场的开发人员并未从采用AI技术中显著获益。这可能会加大技能差距，并重塑软件开发领域的未来职业发展路径。

▲ Abstract：

Generative coding tools promise big productivity gains, but uneven uptake could widen skill and income gaps. We train a neural classifier to spot artificial intelligence (AI)–generated Python functions in more than 30 million GitHub commits by 160,097 software developers, tracking how fast, and where, these tools take hold. Currently, AI writes an estimated 29% of Python functions in the US—a shrinking lead over other countries. We estimate that quarterly output, measured in online code contributions, consequently increased by 3.6%. AI seems to benefit experienced, senior-level developers: They increased productivity and more readily expanded into new domains of software development. By contrast, early-career developers showed no significant benefits from AI adoption. This may widen skill gaps and reshape future career ladders in software development.

古生物学Paleontology

Scimitar-crested Spinosaurus species from the Sahara caps stepwise spinosaurid radiation

撒哈拉沙漠中的弯刀棘龙物种是棘龙科逐步辐射演化的结果

▲ 作者：Paul C. Sereno, Daniel Vidal, Nathan P. Myhrvold, Evan Johnson-Ransom, María Ciudad Real, Stephanie L. Baumgart, et al.

▲链接：

https://www.science.org/doi/10.1126/science.adx5486

▲摘要：

研究组描述了一种埃及棘龙的近亲，它背部具有高耸帆状结构，以鱼类为食，是来自北非近岸沉积物中的巨型恐龙。新发现的“弯刀棘龙”化石是在撒哈拉沙漠中部河岸地带与长颈恐龙一同被发现的。其显著特征是头顶上方有一个呈弯刀形状的骨质突起，远远高出头骨表面。

研究组确认了棘龙科演化的三个独立阶段：第一阶段起源于侏罗纪，出现了一种细长的捕鱼头骨，随后分化为不同的演化路径；第二阶段为早白垩世时期，棘龙科成为了环特提斯海域栖息地中的主要掠食者；最终阶段始于大西洋开始形成的晚白垩纪初期，此时棘龙科动物达到了最大体型，它们擅长在浅水区域伏击猎物，其活动范围仅限于非洲北部和南美洲。

▲ Abstract：

We describe a close relative of Spinosaurus aegyptiacus, the sail-backed, fish-eating giant from nearshore deposits of northern Africa. Spinosaurus mirabilis sp. nov., discovered in the central Sahara alongside long-necked dinosaurs in a riparian habitat, is distinguished by a scimitar-shaped bony crest projecting far above its skull roof. We discern three discrete phases in spinosaurid evolution. During the first phase with roots in the Jurassic, an elongate fish-snaring skull emerged that soon was modified along divergent paths. During a second Early Cretaceous phase, spinosaurids became the dominant predators in circum-Tethyan habitats. The final phase began just before the Late Cretaceous during the opening of the Atlantic Ocean, when spinosaurines attained maximum body size as shallow water ambush specialists limited geographically to northern Africa and South America.

化学Chemistry

Single-molecule infrared spectroscopy with scanning tunneling microscopy

结合扫描隧道显微镜的单分子红外光谱技术

▲ 作者：Kangkai Liang, Zihao Wang, Weike Quan, Yueqing Shi, Hao Zhou, Liya Bi, et al.

▲链接：

https://www.science.org/doi/10.1126/science.adz6643

▲摘要：

在单分子层面上探测振动对于在真实复杂环境中实现特定键的精准化学控制至关重要。

研究组介绍了一种新的测量方案，将可调频率的红外激发与扫描隧道显微镜相结合，用于表征单分子振动引起的核运动。首先通过监测乙炔基自由基在红外光诱导下的旋转来验证该技术的可行性，然后将其应用于绘制吡咯烷的构象动力学图谱。所得宽谱带光谱捕捉到了基本振动模式和通过常规方法无法获得的丰富泛频和组合谱带，这一点通过同位素替代实验得到了验证。

密度泛函理论计算表明，与吡咯烷环扭曲相耦合的离域模式推动了结构的转变，这与传统红外光谱分析所显示的规则有所不同。这个新型实验平台能够以原子级的精度来探究分子振动和变化情况。

▲ Abstract：

Probing vibrations at the single-molecule level is essential for achieving bond-specific chemical control in realistic heterogeneous environments. Here, we introduce a new measurement scheme that integrates frequency-tunable infrared excitation with scanning tunneling microscopy to characterize vibration-mediated nuclear motions of single molecules. We first validated the technique by monitoring the infrared-induced rotation of the ethynyl radical and then applied it to mapping pyrrolidine’s conformational dynamics. The resulting broadband spectra captured fundamental vibrational modes together with rich overtone and combination bands inaccessible by conventional methods, which we confirmed with isotopic substitutions. Density functional theory calculations showed that delocalized modes coupled with pyrrolidine ring puckering drive the structural transition, revealing altered selection rules compared with traditional infrared spectroscopy. This new experimental platform enables molecular vibrations and transformations to be probed with atomic precision.

地球科学Earth Science

Simple unilateral rupture of the great Mw 8.8 2025 Kamchatka earthquake

2025年堪察加半岛发生的8.8级单侧破裂型大地震

▲ 作者：Chengli Liu, Yefei Bai, Thorne Lay, Ping He, Yangmao Wen, Xiong Xiong and Tuncay Taymaz

▲链接：

https://www.science.org/doi/10.1126/science.aeb8232

▲摘要：

2025年7月29日，堪察加半岛南部近海发生了一次矩震级（Mw）8.8级的大地震，其余震区域与1952年那场8.8至9.0级的地震区域重叠。与1952年情况相似，2025年地震也始于断层的东北端，此前还伴随着强烈的前震活动。

通过对远震数据和干涉合成孔径雷达（InSAR）数据的联合反演，研究组得出了该区域时空滑动分布的结果，并通过深水海啸记录的正演模型进行了验证，结果显示在弯曲板块边界上存在一个向西南延伸的大型滑动区域。在堪察加半岛南部和帕拉穆希尔岛附近海域，研究组发现了一处长达14米的最大滑移量。

1952年的那场地震在夏威夷引发了更强烈的海啸信号，这表明两次地震的滑动分布情况有所不同。2025年的地震峰值滑移量超过了自1952年以来累积的最大滑移亏缺量。对堪察加半岛多次强烈地震后火山喷发的观测数据为地震与火山之间的相互作用提供了有力证据。

▲ Abstract：

On 29 July 2025, a moment magnitude (Mw) 8.8 great earthquake ruptured along offshore southern Kamchatka, with the aftershock region overlapping that of a 1952 Mw 8.8 to 9.0 event. Like 1952, the 2025 event nucleated at the northeastern end of the rupture, preceded by intense foreshock activity. Joint inversion of teleseismic and InSAR (Interferometric Synthetic Aperture Radar) data for the space-time slip distribution, with validation by means of forward modeling of deep-water tsunami recordings, revealed a southwestward elongated large-slip patch on the curved plate boundary. A slip of up to 14 meters was located offshore southern Kamchatka and Paramushir Island. The 1952 earthquake generated stronger tsunami signals in Hawaii, indicating a different slip distribution. Peak slip in 2025 exceeded the maximum slip deficit accumulated since 1952. Observations of volcanic eruptions after multiple great earthquakes in Kamchatka provide compelling evidence of earthquake-volcano interactions.