米兰-《科学》（20241025出版）一周论文导读—新闻—科学网

Science, 25 OCT 2024, VOL 386, ISSUE 6720

《科学》2024年10月25日，第386卷，6720期

材料科学Materials Science

Reductive pathways in molten inorganic salts enable colloidal synthesis of III-V semiconductor nanocrystals

熔融无机盐还原路子实现III-V族半导体纳米晶的胶体合成

▲ 作者：JUSTIN C. ONDRY, ZIRUI ZHOU, KAILAI LIN, ARITRAJIT GUPTA, JUN HYUK CHANG, HAOQI WU, ET AL.

▲链接：

https://www.science.org/doi/10.1126/science.ado7088

▲摘要：

胶体量子点具有尺寸可调的光电特征和可扩大的合成，实现了便宜高机能半导体的利用。合成科学的冲破是实现量子点手艺的要害，但主要的III-V族半导体，包罗胶体砷化镓（GaAs），依然没法用现有方式合成。

研究组介绍的高温熔融盐胶体合成手艺可用在制备此前难以处置的胶体材料。操纵熔融盐氧化还原化学和利用概况活性剂添加剂来节制纳米晶外形，研究组在熔融无机盐中直接成核和发展胶体量子点。

425℃以上的合成温度是实现光致发光GaAs量子点的要害，这强调了熔融盐溶剂实现高温的主要性。研究组推行了该方式，并展现了近十几种此前没有报导过的III-V族固溶体纳米晶成份。

▲ Abstract：

Colloidal quantum dots, with their size-tunable optoelectronic properties and scalable synthesis, enable applications in which inexpensive high-performance semiconductors are needed. Synthesis science breakthroughs have been key to the realization of quantum dot technologies, but important group III–group V semiconductors, including colloidal gallium arsenide (GaAs), still cannot be synthesized with existing approaches. The high-temperature molten salt colloidal synthesis introduced in this work enables the preparation of previously intractable colloidal materials. We directly nucleated and grew colloidal quantum dots in molten inorganic salts by harnessing molten salt redox chemistry and using surfactant additives for nanocrystal shape control. Synthesis temperatures above 425°C are critical for realizing photoluminescent GaAs quantum dots, which emphasizes the importance of high temperatures enabled by molten salt solvents. We generalize the methodology and demonstrate nearly a dozen III-V solid-solution nanocrystal compositions that have not been previously reported.

Topological grain boundary segregation transitions

拓扑晶界偏析相变

▲ 作者：VIVEK DEVULAPALLI, ENZE CHEN, TOBIAS BRINK, TIMOFEY FROLOV AND CHRISTIAN H. LIEBSCHER

▲链接：

https://www.science.org/doi/10.1126/science.adq4147

▲摘要：

操纵溶质偏析手艺设计晶界（GBs）布局是一种定制多晶材料机能的颇具前景的方式。从理论上讲，溶质偏析触发GB相变可为设计界面供给分歧的路子，但缺少对其本征原子性质的理解。

研究组连系了原子分辩率电子显微镜和原子摹拟，发现钛中铁向GB的偏析不变了二十面体单位（“笼”），构成了分歧GB相的稳健构建块。因为其五重对称性，铁“笼”堆积并组装成具有分歧数目和分歧摆列的二十面体单位构建块的分层GB相。

这类进步前辈的GB布局猜测算法和原子摹拟验证了这些不雅察到的各相不变性，和相变所顺应GB处铁的高过量。

▲ Abstract：

Engineering the structure of grain boundaries (GBs) by solute segregation is a promising strategy to tailor the properties of polycrystalline materials. Solute segregation triggering phase transitions at GBs has been suggested theoretically to offer different pathways to design interfaces, but an understanding of their intrinsic atomistic nature is missing. We combined atomic resolution electron microscopy and atomistic simulations to discover that iron segregation to GBs in titanium stabilizes icosahedral units (“cages”) that form robust building blocks of distinct GB phases. Owing to their five-fold symmetry, the iron cages cluster and assemble into hierarchical GB phases characterized by a different number and arrangement of the constituent icosahedral units. Our advanced GB structure prediction algorithms and atomistic simulations validate the stability of these observed phases and the high excess of iron at the GB that is accommodated by the phase transitions.

Soft hydrogel semiconductors with augmented biointeractive functions

软水凝胶半导体可加强生物交互功能

▲ 作者：YAHAO DAI, SHINYA WAI, PENGJU LI, NAISONG SHAN, ZHIQIANG CAO, YANG LI, ET AL.

▲链接：

https://www.science.org/doi/10.1126/science.adp9314

▲摘要：

水凝胶因其与生物组织的机械和化学类似性而著名，普遍利用在生物手艺，而半导体则供给进步前辈的电子和光电功能，如旌旗灯号放年夜、传感和光调制。将半导体特征与水凝胶设计相连系可以加强生物界面处的生物交互功能和密切性，但因为聚合物半导体的亲水性较低，这很难实现。

研究组开辟了一种溶剂亲和引诱组装方式，将不溶在水的聚合物半导体连系到双收集水凝胶中。这些半导体表示出软至81千帕的组织级模量、150%应变的拉伸率、高达1.4平方厘米/伏/秒的载流子迁徙率。当其与生物组织连系时，该组织级模量可减轻免疫反映。

水凝胶的高孔隙度加强了半导体-生物流体界面的份子彼此感化，从而实现了具有更高响应的光调制和具有更高活络度的体积生物传感。

▲ Abstract：

Hydrogels, known for their mechanical and chemical similarity to biological tissues, are widely used in biotechnologies, whereas semiconductors provide advanced electronic and optoelectronic functionalities such as signal amplification, sensing, and photomodulation. Combining semiconducting properties with hydrogel designs can enhance biointeractive functions and intimacy at biointerfaces, but this is challenging owing to the low hydrophilicity of polymer semiconductors. We developed a solvent affinity–induced assembly method that incorporates water-insoluble polymer semiconductors into double-network hydrogels. These semiconductors exhibited tissue-level moduli as soft as 81 kilopascals, stretchability of 150% strain, and charge-carrier mobility up to 1.4 square centimeters per volt per second. When they are interfaced with biological tissues, their tissue-level modulus enables alleviated immune reactions. The hydrogel’s high porosity enhances molecular interactions at semiconductor-biofluid interfaces, resulting in photomodulation with higher response and volumetric biosensing with higher sensitivity.

能源科学Energy Science

Unification of insertion and supercapacitive storage concepts: Storage profiles in titania

插入式储能和超等电容储能概念的同一：二氧化钛中的储能概况

▲ 作者：CHUANLIAN XIAO, HONGGUANG WANG, ROBERT USISKIN, PETER A. VAN AKEN AND JOACHIM MAIER

▲链接：

https://www.science.org/doi/10.1126/science.adi5700

▲摘要：

电池电极中的插入式储能和超等电容储能凡是被认为是两个自力的现象，是以由分歧的科学界进行研究。

经由过程对分歧厚度的氧化钛薄膜进行定制尝试，研究组证实了这两个进程可同时产生。为领会释包括这两种进献的全部存储散布，夹杂导体和临近相中电荷载流子的（自由）能是独一需要的材料参数。

尝试成果实现了插入式储能和超等电容储能的同一，前者在厚膜中占主导地位，后者在薄膜或可疏忽电子导电性的膜中占主导地位。是以，存储介质的尺寸和电流搜集相的性质可用来调剂功率密度与能量密度。

▲ Abstract：

Insertion storage in battery electrodes and supercapacitive storage are typically considered to be independent phenomena and thus are dealt with in separate scientific communities. Using tailored experiments on titanium oxide thin films of various thicknesses, we demonstrate the simultaneous occurrence of both processes. For the interpretation of the entire storage profile encompassing both contributions, the (free) energies of the charge carriers in the mixed conductor and the neighboring phase are the only materials parameters required. The experimental results enable no less than a unification of insertion and supercapacitive storage, the first being dominant for thick films, the latter for thin films or negligible electronic conductivity. Therefore, the size of the storage medium and the nature of the current collecting phases can be used to tune power density versus energy density.

地球科学Earth Science

The fastest-growing and most destructive fires in the US (2001 to 2020)

美国增加最快、最具粉碎性的火警（2001~2020年）

▲ 作者：JENNIFER K. BALCH, VIRGINIA IGLESIAS, ADAM L. MAHOOD, MAXWELL C. COOK, CIBELE AMARAL, AMY DECASTRO, ET AL.

▲链接：

https://www.science.org/doi/10.1126/science.adk5737

▲摘要：

美国汗青上最具粉碎性、最致命的野火来势汹汹。

操纵卫星数据，研究组阐发了2001年至2020年美国本土6万多起火警的日增加率。近一半的生态区履历了粉碎性的快速火警，年夜火在一天内舒展了1620多公顷。这些火警造成78%的建筑物被毁，占灭火费用的61%（189亿美元）。

从2001年到2020年，美国西部这些火警的平均峰值日增加率翻了一倍多（相对2001年增加249%）。在此时代，美国有近300万栋建筑物距离一场快速火警不到4千米。鉴在比来扑灭性的野火，领会快速火警对改良消防策略和社区预备相当主要。

▲ Abstract：

The most destructive and deadly wildfires in US history were also fast. Using satellite data, we analyzed the daily growth rates of more than 60,000 fires from 2001 to 2020 across the contiguous US. Nearly half of the ecoregions experienced destructive fast fires that grew more than 1620 hectares in 1 day. These fires accounted for 78% of structures destroyed and 61% of suppression costs (美金18.9 billion). From 2001 to 2020, the average peak daily growth rate for these fires more than doubled (+249% relative to 2001) in the Western US. Nearly 3 million structures were within 4 kilometers of a fast fire during this period across the US. Given recent devastating wildfires, understanding fast fires is crucial for improving firefighting strategies and community preparedness.

Twenty years of microplastic pollution research—what have we learned?

二十年的微塑料污染研究——我们学到了甚么？

▲ 作者：RICHARD C. THOMPSON, WINNIE COURTENE-JONES, JULIEN BOUCHER, SABINE PAHL, KAREN RAUBENHEIMER AND ALBERT A. KOELMANS

▲链接：

https://www.science.org/doi/10.1126/science.adl2746

▲摘要：

在初次利用“微塑料”一词的出书物颁发20年后，研究组回首了当前的理解，完美了界说，并斟酌了将来的前景。微塑料有多种来历，包罗轮胎、纺织品、化装品、油漆和年夜件物品的碎片，其普遍散布在全部天然情况中，有证据注解在生物组织的多个层面上都有风险。

微塑料在食品和饮猜中遍及存在，已在人体中被检测到，并呈现了负面影响的新证据。到2040年，情况污染可能会翻一番，估计会造成年夜范围的风险。公家的存眷日趋增添，国际构和正在斟酌解决微塑料污染的各类办法。

当前需要明白证据证实潜伏解决法子的效率，以解决微塑料污染并尽可能削减不测后果的风险。

▲ Abstract：

Twenty years after the first publication that used the term microplastic, we review current understanding, refine definitions, and consider future prospects. Microplastics arise from multiple sources, including tires, textiles, cosmetics, paint, and the fragmentation of larger items. They are widely distributed throughout the natural environment, with evidence of harm at multiple levels of biological organization. They are pervasive in food and drink and have been detected throughout the human body, with emerging evidence of negative effects. Environmental contamination could double by 2040, and wide-scale harm has been predicted. Public concern is increasing, and diverse measures to address microplastic pollution are being considered in international negotiations. Clear evidence on the efficacy of potential solutions is now needed to address the issue and to minimize the risks of unintended consequences.

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