科研
科研
编译｜李言
Science, 26 JUL 2024, Volume 385 Issue 6707
《科学》2024年7月26日，第385卷，6707期
量子计算Quantum Computing
Operating semiconductor quantum processors with hopping spins
通过跳频自旋操控半导体量子处理器
▲ 作者：CHIEN-AN WANG, VALENTIN JOHN et al.
▲链接：
https://www.science.org/doi/10.1126/science.ado5915
▲摘要：
在此，我们展示了通过设计具有位点依赖自旋量子化轴的量子点之间的自旋跳，可以用离散信号建立量子控制。我们展示了基于跳跃的量子逻辑，并获得了99.97%的单量子位门保真度，每跳99.992%的相干穿梭保真度和99.3%的双量子位门保真度，对应已经预测的允许量子纠错的错误率。
我们还通过统计映射10量子点系统的相干性，证明跳变自旋构成了一种调谐方法。我们的研究结果表明，分散布置的密集量子点阵列可以用于高效和高连接的量子比特寄存器。
▲ Abstract：
Here, we show that by engineering the hopping of spins between quantum dots with a site-dependent spin quantization axis, quantum control can be established with discrete signals. We demonstrate hopping-based quantum logic and obtain single-qubit gate fidelities of 99.97%, coherent shuttling fidelities of 99.992% per hop, and a two-qubit gate fidelity of 99.3%, corresponding to error rates that have been predicted to allow for quantum error correction. We also show that hopping spins constitute a tuning method by statistically mapping the coherence of a 10–quantum dot system. Our results show that dense quantum dot arrays with sparse occupation could be developed for efficient and high-connectivity qubit registers.
化学Chemistry
The sugar cube: Network control and emergence in stereoediting reactions
己糖立方：立体编辑反应中的网络控制和涌现
▲ 作者：HAYDEN M. CARDER, GINO OCCHIALINI et al.
▲链接：
https://www.science.org/doi/10.1126/science.adp2447
▲摘要：
在此我们提出“网络控制”，这是一种对比范例，可以利用速率常数之间隐藏的相互作用放大适度的内在偏差，并实现精确的多站点编辑。
当网络控制应用于己糖的光化学异构化时，可以选择性地获得八种可能的非对映体中的六种。放大效应可以看作是介于简单化学系统的动力学控制和复杂生物系统的代谢调节之间的一种中尺度现象。
▲ Abstract：
We propose “network control,” a contrasting paradigm that exploits hidden interactions between rate constants to greatly amplify modest intrinsic biases and enable precise multisite editing. When network control is applied to the photochemical isomerization of hexoses, six of the eight possible diastereomers can be selectively obtained. The amplification effect can be viewed as a mesoscale phenomenon between the limiting regimes of kinetic control in simple chemical systems and metabolic regulation in complex biological systems.
材料科学Material Sciences
Borrowed dislocations for ductility in ceramics
借位错实现陶瓷拉伸塑性变形
▲ 作者：L. R. DONG, J. ZHANG et al.
▲链接：
https://www.science.org/doi/10.1126/science.adp0559
▲摘要：
在此，我们提出了一种“借位错”的策略，该策略使用具有有序化学键的共格界面。这种方法使陶瓷通过界面调动大量来自金属的位错，大大提高了陶瓷的拉伸延展性，从而克服了陶瓷内部直接位错成核的挑战。这种策略为提高陶瓷的拉伸延展性提供了新方法。
▲ Abstract：
Here, we propose a “borrowing-dislocations” strategy that uses a tailored interfacial structure with well-ordered bonds. Such an approach enables ceramics to have greatly improved tensile ductility by mobilizing a considerable number of dislocations in ceramic borrowed from metal through the interface, thereby overcoming the challenge associated with direct dislocation nucleation within ceramics. This strategy provides a way to enhance tensile ductility in ceramics.
地球科学Earth Science
Fault size–dependent fracture energy explains multiscale seismicity and cascading earthquakes
断层大小相关的断裂能解释多尺度地震活动性和级联地震
▲ 作者：ALICE-AGNES GABRIEL, DMITRY I. GARAGASH et al.
▲链接：
https://www.science.org/doi/10.1126/science.adj9587
▲摘要：
我们认为，小地震和大地震的断裂过程是完全不同的。我们将地震观测与基于物理的地震模型相结合，发现在小地震的能量收支中，动力减弱和再强化效应都是不可忽视的。
我们建立了断裂能与断层大小的线性标度关系，以及断裂标度与滑动的线性标度关系。通过超级计算，我们应用这种尺度揭示了断层损伤区内涉及超过700个多尺度裂缝的大型动态破裂地震级联。我们为地震活动性提供了一个简单的解释，这对理解地震成因和多断层破裂级联具有重要意义。
▲ Abstract：
We propose that fundamentally different fracture processes govern small and large earthquakes. We combined seismological observations with physics-based earthquake models, finding that both dynamic weakening and restrengthening effects are non-negligible in the energy budget of small earthquakes. We established a linear scaling relationship between fracture energy and fault size and a break in scaling with slip. We applied this scaling using supercomputing and unveiled large dynamic rupture earthquake cascades involving >700 multiscale fractures within a fault damage zone. We provide a simple explanation for seismicity across all scales with implications for comprehending earthquake genesis and multifault rupture cascades.
Anthropogenic amplification of precipitation variability over the past century
人类活动导致过去百年来全球降水变率增强
▲ 作者：WENXIA ZHANG, TIANJUN ZHOU, AND PEILI WU
▲链接：
https://www.science.org/doi/10.1126/science.adp0212
▲摘要：
在此，我们表明在过去的一个世纪里，由于人为变暖累积，全球（超75%的陆地面积）降水变率已经增长。从每日到季节的时间尺度范围都可以看到变率的增加，全球日变率每10年增加1.2%，在欧洲、澳大利亚和北美东部尤为突出。
降水变率的增加主要是由与大气湿润有关的热力学驱动的，在年代际尺度上受环流变化的调节。这对天气和气候预测以及社会和生态系统的复原力和适应能力提出了新的挑战。
▲ Abstract：
Here we show that precipitation variability has already grown globally (over 75% of land area) over the past century, as a result of accumulated anthropogenic warming. The increased variability is seen across daily to intraseasonal timescales, with daily variability increased by 1.2% per 10 years globally, and is particularly prominent over Europe, Australia, and eastern North America. Increased precipitation variability is driven mainly by thermodynamics linked to atmospheric moistening, modulated at decadal timescales by circulation changes. Amplified precipitation variability poses new challenges for weather and climate predictions, as well as for resilience and adaptation by societies and ecosystems.
生物学Biology
Neurons for infant social behaviors in the mouse zona incerta
小鼠未定带中负责幼儿社会行为的神经元
幼鼠无动带社会行为的神经元
▲ 作者：YUEXUAN LI, ZHONG-WU LIU et al.
▲链接：
https://www.science.org/doi/10.1126/science.adk7411
▲摘要：
了解婴儿社会行为的神经基础对于阐明早期社会和情感发展的机制至关重要。在这项研究中，我们报告在断奶前小鼠的未定带（ZISST）中表达生长抑素的特定神经元群，这些神经元对社会互动做出动态反应，特别是与母亲的互动。
在幼鼠中进行的双向神经活动操作表明，断奶前的ZISST神经元与感觉、情绪和认知脑中心的广泛连接介导了与母亲存在相关的两个关键适应功能:减少行为困扰和促进学习。这些发现揭示了幼鼠大脑中的协调与母亲的关系对幼鼠行为和生理的积极影响的神经元。
▲ Abstract：
Understanding the neural basis of infant social behaviors is crucial for elucidating the mechanisms of early social and emotional development. In this work, we report a specific population of somatostatin-expressing neurons in the zona incerta (ZISST) of preweaning mice that responds dynamically to social interactions, particularly those with their mother. Bidirectional neural activity manipulations in pups revealed that widespread connectivity of preweaning ZISST neurons to sensory, emotional, and cognitive brain centers mediates two key adaptive functions associated with maternal presence: the reduction of behavior distress and the facilitation of learning. These findings reveal a population of neurons in the infant mouse brain that coordinate the positive effects of the relationship with the mother on an infant’s behavior and physiology.
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