材料科学Materials Science

▲ 作者：GEORGII BOGDANOV, ALEKSANDRA ANNA STRZELECKA, NIKHIL KAIMAL, STEPHEN L. SENFT, SANGHOON LEE, ROGER T. HANLON, ET AL.

▲ 链接：

https://www.science.org/doi/10.1126/science.adn1570

▲ 摘要：

利用具有不同折射率分布的材料来操纵光在自然系统和现代技术中很普遍。然而，理解动物如何利用折射率差异实现动态变色，并将其转化为可调光学设备仍颇具挑战性。

研究组通过实验和计算证明，含有正弦波折射率分布的布拉格反射体的虹彩细胞使鱿鱼背侧套膜组织能够在接近透明和彩色状态之间可逆转换。然后，他们从这些发现中汲取灵感，设计和开发了具有可调可见光和红外功能的虹彩细胞启发的多光谱复合材料。

该研究为鱿鱼的动态结构调色机制提供了新见解，并为伪装、热管理、显示和传感应用等提供了一种技术。

▲ Abstract：

▲ 作者：CHAO MA, ZHENGHAN ZHANG, MENGDI ZHANG, XUDONG TIAN, CONG LIN, LEI HAN, ET AL.

▲ 链接：

https://www.science.org/doi/10.1126/science.adv5073

▲ 摘要：

具有超大孔隙和纳米尺寸的稳定沸石能够处理大分子，需求量很大，但很难生产。其复杂的结构和纳米级晶体尺寸为传统X射线衍射结构分析带来了挑战，导致材料开发效率低下。

研究组报道了两种稳健、全连接的硅酸铝纳米沸石NJU120-1和NJU120-2，具有超大22元环孔的互联通道系统。NJU120-1是一种厚度仅为8纳米左右的纳米片，相当于1.5个晶胞，NJU120-2是一种尺寸为50′250纳米的纳米棒。

通过MicroED的快速结构测定，大大加快了两者的合成优化，并揭示了其多维孔隙结构。这两种沸石的最大自由球直径约为1.2纳米，再加上纳米形态，实现了大分子的催化裂解。

▲ Abstract：

Stable zeolites with extra-large pores and nano dimensions that are capable of processing large molecules are in high demand but have been difficult to produce. Their complex structures and nanoscale crystal sizes present challenges for analysis using conventional x-ray diffraction techniques, leading to inefficiencies in material development. We report NJU120-1 and NJU120-2, two robust and fully connected aluminosilicate nano zeolites featuring interconnected channel systems with extra-large 22-ring pores. NJU120-1 is a nanosheet with only about 8-nanometer thickness, corresponding to 1.5 unit cells, and NJU120-2 is a nanorod with 50 by 250 nanometer dimensions. Their synthesis optimization was greatly accelerated through rapid structure determination with MicroED, revealing their multidimensional pore structures. Their very large largest-free-sphere diameters of approximately 1.2 nanometers coupled with nano morphologies enabled catalytic cracking of large molecules.

化学Chemistry

▲ 作者：MERCEDE AZIZBAIG MOHAJER, PALLAB BASURI, ANDREI EVDOKIMOV, GROGORY DAVID, DANIEL ZINDEL, EVANGELOS MILIORDOS, ET AL.

▲ 链接：

https://www.science.org/doi/10.1126/science.adv2362

▲ 摘要：

尿素是寻找生命起源的关键分子，也是工业大量生产的基础化学品。由氨和二氧化碳形成尿素通常需要高压和高温，或在较温和的条件依赖催化剂或额外的试剂来形成。

研究组观察到在环境条件下，氨和二氧化碳在水滴表层自发形成尿素。他们利用拉曼光谱带作为标记探测了单个光学捕获的液滴。结果发现液滴表层就像一个微型流动反应器，化学梯度提供了一种非常规反应途径。

该观测揭示了独特液滴化学的通用机理方案。界面化学是前生命时期尿素生成的一种潜在的非耗能途径。

▲ Abstract：

▲ 作者：ZINING ZHANG AND GUANGBIN DONG

▲ 链接：

https://www.science.org/doi/10.1126/science.adx2723

▲ 摘要：

在药物开发中，用硫原子取代骨架碳原子可产生具有优异性能的生物活性化合物类似物。目前，硫类似物几乎都是通过从头合成制备；现有的碳硫交换方法效率低下，且涉及化学计量汞试剂。

研究组报道了一种两步羰基到硫原子（CO-to-S）交换方法，通过合理设计的N’-烷基-肼酰胺（NAHA）试剂，经由不同机制连续两次形成预芳香中间体，从而实现酮底物两个α-C-C键的均裂。

Ts-S-Ts（Ts，对甲苯磺酰基）试剂通过中心硫原子连续捕获分子间和分子内烷基自由基来介导这一过程。该方法显示出广泛的底物范围和良好的化学选择性，为从易得的酮类化合物构建含硫支架提供了一条简化途径。

▲ Abstract：

In drug development, replacement of a skeletal carbon with a sulfur atom can result in analogs of bioactive compounds with improved properties. Currently, the sulfur analogs are almost exclusively prepared by de novo synthesis; the existing approach to swap carbon with sulfur is inefficient and involves stoichiometric mercury reagents. In this study, we report a two-step carbonyl-to-sulfur (CO-to-S) atom swap approach, enabled by a rationally designed N′-alkyl-hydrazonamide (NAHA) reagent that promotes forming pre-aromatic intermediates twice sequentially by different mechanisms, thereby achieving homolytic cleavage of both α-C-C bonds of the ketone substrates. A Ts-S-Ts (Ts, p-toluenesulfonyl) reagent mediates this process through successive intermolecular and intramolecular alkyl radical trapping by the central sulfur. This method shows a broad substrate scope and excellent chemoselectivity, providing a streamlined route to sulfur-containing scaffolds from readily available ketones.

地球科学Earth Science

▲ 作者：JOSHUA R. EDGINGTON, DEMIAN M. SAFFER AND CHARLES A. WILLIAMS

▲ 链接：

https://www.science.org/doi/10.1126/science.ads9715

▲ 摘要：

近海俯冲带应变积累和释放模式与浅层同震滑移和海啸发生的可能性直接相关，但这些模式仍然难以捉摸。

研究组分析了日本本州岛南海俯冲带三个海上钻孔观测站的地层孔隙压力记录，以捕获沿板块边界最外缘的两次慢滑事件（SSE）的详细滑移时间史。滑移起始于海沟向陆一侧约30千米处；以每天1至2千米的速度向海迁移，到达距离海沟几千米以内，并可能突破海沟边界；且与震颤和/或极低频地震的发生和迁移相吻合。

SSE震源区处于高孔隙流体压力和低应力带，为将这些因素与浅层慢地震联系起来提供了明确的观测证据。

▲ Abstract：

Patterns of strain accumulation and release offshore in subduction zones are directly linked to the potential for shallow coseismic slip and tsunamigenesis, but these patterns remain elusive. In this work, we analyze formation pore pressure records from three offshore borehole observatories at the Nankai subduction zone, Honshu, Japan, to capture detailed slip-time histories of two slow slip events (SSEs) along the outermost reaches of the plate boundary. Slip initiates ~30 kilometers landward of the trench; migrates seaward at 1 to 2 kilometers per day to within a few kilometers of, and possibly breaching, the trench; and coincides with the onset and migration of tremor and/or very-low-frequency earthquakes. The SSE source region lies in a zone of high pore fluid pressure and low stress, which provides clear observational evidence linking these factors to shallow slow earthquakes.

▲ 作者：SHINZABURO OZAWA, HIROSHI MUNEKANE, HISASHI SUITO AND HIROSHI YARAI

▲ 链接：

https://www.science.org/doi/10.1126/science.adu7076

▲ 摘要：

利用全球导航卫星系统数据，研究组分析了2024年日本日向滩地震前、中、后期的板块间滑移特征。

地震前，从2023年底开始，在主震的下倾延伸区观测到一次矩震级（Mw）6.0的慢滑事件（SSE）。同震滑移与1996年日向滩震源相邻。余震在震源区附近和主震的下倾延伸区消退，在2024年9月16日达到累积6.7级。

在地震发生前，滑裂前区SSE的重现周期从过去30年观测估计的平均2年缩短到1年，这与南海大型逆冲区构造减弱的归因模拟结果一致。

▲ Abstract：

Using Global Navigation Satellite System data, we investigated the interplate slip before, during, and after the 2024 Hyuga-nada earthquake in Japan. Before the earthquake, a moment magnitude (Mw) 6.0 slow-slip event (SSE) was observed from late 2023 in a downdip extension of the mainshock. The coseismic slip was adjacent to the 1996 Hyuga-nada earthquake source. The afterslip resolved near the hypocenter area and in the downdip extension of the mainshock, reaching Mw 6.7 on 16 September 2024. Leading up to the earthquake, the recurrence interval for SSEs in the preslip area shortened from an average of 2 years, estimated from observations over the past 30 years, to 1 year, consistent with simulations in which the weakening of the Nankai megathrust was attributed to the cause.