天文學(xué) Astronomy

▲  作者：CHRYSA AVDELLIDOU, MARCO DELBO’, DAVID NESVORNY, KEVIN J. WALSH & ALESSANDRO MORBIDELLI

▲ 鏈接：

https://www.science.org/doi/10.1126/science.adg8092

▲ 摘要：

太陽(yáng)系的巨行星最初在緊湊軌道上形成，由于軌道不穩(wěn)定過(guò)渡至目前更寬的結(jié)構(gòu)。這種不穩(wěn)定發(fā)生的時(shí)機(jī)很難確定。

研究組使用動(dòng)力學(xué)模擬來(lái)證明軌道不穩(wěn)定將類地行星區(qū)域的星子碎片植入小行星主帶。使用隕石數(shù)據(jù)表明，植入發(fā)生在太陽(yáng)系誕生后超6000萬(wàn)年。

將這一約束條件與先前從木星特洛伊小行星中得出的上限相結(jié)合，研究組得出結(jié)論，軌道不穩(wěn)定發(fā)生在太陽(yáng)系誕生后6000萬(wàn)年至1億年。形成月球的巨大撞擊發(fā)生在該時(shí)期，因此其可能與巨行星不穩(wěn)定有關(guān)。

▲ Abstract：

The giant planets of the Solar System formed on initially compact orbits, which transitioned to the current wider configuration by means of an orbital instability. The timing of that instability is poorly constrained. In this work, we use dynamical simulations to demonstrate that the instability implanted planetesimal fragments from the terrestrial planet region into the asteroid main belt. We use meteorite data to show that the implantation occurred >60 million years (Myr) after the Solar System began to form. Combining this constraint with a previous upper limit derived from Jupiter’s trojan asteroids, we conclude that the orbital instability occurred 60 to 100 Myr after the beginning of Solar System formation. The giant impact that formed the Moon occurred within this range, so it might be related to the giant planet instability.

材料科學(xué) Materials Science

▲  作者：XINYU LIU, DONGXUN LYU, CéLINE MERLET, MATTHEW J. A. LEESMITH, XIAO HUA, ZHEN XU, ET AL.

▲ 鏈接：

https://www.science.org/doi/10.1126/science.adn6242

▲ 摘要：

納米多孔碳電極復(fù)雜結(jié)構(gòu)的表征困難導(dǎo)致缺乏明確的設(shè)計(jì)原則來(lái)改進(jìn)超級(jí)電容器?？讖匠叽缫恢北徽J(rèn)為是提高電容的主要杠桿。

然而，研究組對(duì)大量商業(yè)納米多孔碳的評(píng)估發(fā)現(xiàn)孔徑和電容之間缺乏相關(guān)性。相反，核磁共振波譜測(cè)量和模擬揭示了電極結(jié)構(gòu)無(wú)序和電容之間的強(qiáng)烈相關(guān)性。

具有更小的類石墨烯結(jié)構(gòu)域的無(wú)序碳因在其納米孔中更有效地存儲(chǔ)離子，從而表現(xiàn)出更高的電容。該發(fā)現(xiàn)提出了理解和利用無(wú)序來(lái)實(shí)現(xiàn)高能量密度超級(jí)電容器的方法。

▲ Abstract：

The difficulty in characterizing the complex structures of nanoporous carbon electrodes has led to a lack of clear design principles with which to improve supercapacitors. Pore size has long been considered the main lever to improve capacitance. However, our evaluation of a large series of commercial nanoporous carbons finds a lack of correlation between pore size and capacitance. Instead, nuclear magnetic resonance spectroscopy measurements and simulations reveal a strong correlation between structural disorder in the electrodes and capacitance. More disordered carbons with smaller graphene-like domains show higher capacitances owing to the more efficient storage of ions in their nanopores. Our findings suggest ways to understand and exploit disorder to achieve highly energy-dense supercapacitors.

▲  作者：SANGMOON HAN, JUSTIN S. KIM, EUGENE PARK, YUAN MENG, ZHIHAO XU, ALEXANDRE C. FOUCHER, ET AL.

▲ 鏈接：

https://www.science.org/doi/10.1126/science.adl2835

▲ 摘要：

靜電電容器因其超快的充放電能力成為先進(jìn)電子器件和大功率電氣系統(tǒng)的基礎(chǔ)元件。鐵電材料具有較高的最大極化，但高殘余極化阻礙了其在儲(chǔ)能應(yīng)用中的有效部署。先前方法由于鐵電材料結(jié)晶度退化而遭遇瓶頸。

研究組介紹了一種利用二維（2D）材料控制弛豫時(shí)間的方法，同時(shí)通過(guò)使用2D/3D/2D異質(zhì)結(jié)構(gòu)來(lái)最小化能量損失，并保持鐵電3D材料的結(jié)晶度。使用該方法可實(shí)現(xiàn)191.7 J/c m ³ 的能量密度，效率超過(guò)90%。

這種對(duì)弛豫時(shí)間的精確控制有望促進(jìn)廣泛應(yīng)用，并有潛力加速高效儲(chǔ)能系統(tǒng)的發(fā)展。

▲ Abstract：

Electrostatic capacitors are foundational components of advanced electronics and high-power electrical systems owing to their ultrafast charging-discharging capability. Ferroelectric materials offer high maximum polarization, but high remnant polarization has hindered their effective deployment in energy storage applications. Previous methodologies have encountered problems because of the deteriorated crystallinity of the ferroelectric materials. We introduce an approach to control the relaxation time using two-dimensional (2D) materials while minimizing energy loss by using 2D/3D/2D heterostructures and preserving the crystallinity of ferroelectric 3D materials. Using this approach, we were able to achieve an energy density of 191.7 joules per cubic centimeter with an efficiency greater than 90%. This precise control over relaxation time holds promise for a wide array of applications and has the potential to accelerate the development of highly efficient energy storage systems.

▲  作者：YUJIAN YAO, PINGXIA ZHANG, FEI SUN, WEN ZHANG, MENG LI, GANG SHA, ET AL.

▲ 鏈接：

https://www.science.org/doi/10.1126/science.adk0632

▲ 摘要：

近半個(gè)世紀(jì)以來(lái)，薄膜復(fù)合反滲透膜一直是海水淡化和水凈化的黃金標(biāo)準(zhǔn)技術(shù)。聚酰胺膜具有優(yōu)異的透水性和拒鹽性，但也有耐氯性差、結(jié)垢傾向高和拒硼率低的缺點(diǎn)。

研究組通過(guò)分子設(shè)計(jì)聚酯膜復(fù)合反滲透膜來(lái)解決這些問(wèn)題，使用共溶劑輔助界面聚合法使3,5-二羥基-4-甲基苯甲酸與均苯三甲酰氯反應(yīng)。這種聚酯膜具有優(yōu)異的透水性，對(duì)氯化鈉和硼高截留，以及完全耐氯。

與聚酰胺膜相比，該膜的超光滑、低能量表面還可防止污垢和礦物結(jié)垢。通過(guò)進(jìn)一步優(yōu)化水鹽選擇性，該膜有望超越聚酰胺膜，為大大減少海水淡化的預(yù)處理步驟提供新途徑。

▲ Abstract：

Thin-film composite reverse osmosis membranes have remained the gold standard technology for desalination and water purification for nearly half a century. Polyamide films offer excellent water permeability and salt rejection but also suffer from poor chlorine resistance, high fouling propensity, and low boron rejection. We addressed these issues by molecularly designing a polyester thin-film composite reverse osmosis membrane using co-solvent–assisted interfacial polymerization to react 3,5-dihydroxy-4-methylbenzoic acid with trimesoyl chloride. This polyester membrane exhibits substantial water permeability, high rejection for sodium chloride and boron, and complete resistance toward chlorine. The ultrasmooth, low-energy surface of the membrane also prevents fouling and mineral scaling compared with polyamide membranes. These membranes could increasingly challenge polyamide membranes by further optimizing water-salt selectivity, offering a path to considerably reducing pretreatment steps in desalination. 

人工智能 Artificial Intelligence

▲  作者：TAI-HAO WEN, JE-MIN HUNG, WEI-HSING HUANG, CHUAN-JIA JHANG, YUN-CHEN LO, HUNG-HSI HSU, ET AL.

▲ 鏈接：

https://www.science.org/doi/10.1126/science.adf5538

▲ 摘要：

人工智能（AI）邊緣設(shè)備更傾向于采用高容量非易失性內(nèi)存計(jì)算（CIM）來(lái)實(shí)現(xiàn)高能效和足夠準(zhǔn)確的快速喚醒響應(yīng)。大多數(shù)先前的工作要么依據(jù)基于憶阻器的CIM，但因其耐用性有限而遭受精度損失且不支持訓(xùn)練；要么依據(jù)數(shù)字靜態(tài)隨機(jī)存取存儲(chǔ)器（SRAM）的CIM，但受限于大面積制造需求和易失性存儲(chǔ)。

研究組報(bào)道了一種使用憶阻器-SRAM CIM融合方案的AI邊緣處理器，可同時(shí)利用數(shù)字SRAM CIM的高精度和電阻式隨機(jī)存取存儲(chǔ)器憶阻器CIM的高能效和存儲(chǔ)密度。這也使自適應(yīng)本地訓(xùn)練能夠適應(yīng)個(gè)性化特征和用戶環(huán)境。

該融合處理器實(shí)現(xiàn)了高CIM容量、短喚醒-響應(yīng)延遲（392微秒）、高峰值能效（77.64 TOPS/W）和穩(wěn)健的精度（精度損失<0.5%）。這項(xiàng)工作表明，憶阻器技術(shù)已經(jīng)超越了實(shí)驗(yàn)室開(kāi)發(fā)階段，現(xiàn)已具備用于AI邊緣處理器的可制造性。

▲ Abstract：

Artificial intelligence (AI) edge devices prefer employing high-capacity nonvolatile compute-in-memory (CIM) to achieve high energy efficiency and rapid wakeup-to-response with sufficient accuracy. Most previous works are based on either memristor-based CIMs, which suffer from accuracy loss and do not support training as a result of limited endurance, or digital static random-access memory (SRAM)–based CIMs, which suffer from large area requirements and volatile storage. We report an AI edge processor that uses a memristor-SRAM CIM-fusion scheme to simultaneously exploit the high accuracy of the digital SRAM CIM and the high energy-efficiency and storage density of the resistive random-access memory memristor CIM. This also enables adaptive local training to accommodate personalized characterization and user environment. The fusion processor achieved high CIM capacity, short wakeup-to-response latency (392 microseconds), high peak energy efficiency (77.64 teraoperations per second per watt), and robust accuracy (<0.5% accuracy loss). This work demonstrates that memristor technology has moved beyond in-lab development stages and now has manufacturability for AI edge processors.

地球科學(xué) Earth Science

▲  作者：ZURUI AO, XIAOMEI HU, SHENGLI TAO, XIE HU, GUOQUAN WANG, MINGJIA LI, ET AL.

▲ 鏈接：

https://www.science.org/doi/10.1126/science.adl4366

▲ 摘要：

中國(guó)大規(guī)模的城市化浪潮可能會(huì)受到地面沉降的威脅。

利用星載干涉合成孔徑雷達(dá)測(cè)量技術(shù)，研究組對(duì)2015—2022年中國(guó)主要城市的地面沉降進(jìn)行了系統(tǒng)評(píng)估。在被調(diào)查的城市土地中，45%的土地每年沉降速度超過(guò)3毫米，16%的土地每年沉降速度超過(guò)10毫米，分別影響了29%和7%的城市人口。

沉降似乎與地下水抽取和建筑物重量等一系列因素有關(guān)。到2120年，由于城市沉降和海平面上升的綜合影響，22%~26%中國(guó)沿海土地的相對(duì)海拔將低于海平面，占沿海人口的9%~11%。

該研究結(jié)果強(qiáng)調(diào)了加強(qiáng)保護(hù)措施以減輕沉降造成潛在損害的必要性。

▲ Abstract：

China’s massive wave of urbanization may be threatened by land subsidence. Using a spaceborne synthetic aperture radar interferometry technique, we provided a systematic assessment of land subsidence in all of China’s major cities from 2015 to 2022. Of the examined urban lands, 45% are subsiding faster than 3 millimeters per year, and 16% are subsiding faster than 10 millimeters per year, affecting 29 and 7% of the urban population, respectively. The subsidence appears to be associated with a range of factors such as groundwater withdrawal and the weight of buildings. By 2120, 22 to 26% of China’s coastal lands will have a relative elevation lower than sea level, hosting 9 to 11% of the coastal population, because of the combined effect of city subsidence and sea-level rise. Our results underscore the necessity of enhancing protective measures to mitigate potential damages from subsidence.