編譯｜馮維維
Science, 02 JULY 2021, VOL 373 ISSUE 6550
《科學》2021年7月2日，第373卷，6550期
物理學Physics
Monolithic optical microlithography of high-density elastic circuits
高密度彈性電路得單片光學微光刻
▲ ：Yu-Qing Zheng, Yuxin Liu, Donglai Zhong, Shayla Nikzad, Shuhan Liu, Zhiao Yu, Deyu Liu, Hung-Chin Wu, Chenxin Zhu, Jinxing Li, Helen Tran, Jeffrey B.-H. Tok, Zhenan Bao
▲ 鏈接：
science.sciencemag.org/content/373/6550/88
▲ 摘要
作為電子器件得平臺，高分子材料相對于硬質(zhì)材料器件具有固有得柔韌性和延展性。
然而，與硅等材料不同得是，用于單片器件大規(guī)模圖形化得工具很少。鮑哲南等開發(fā)了一種光學光刻技術，用于在可伸縮基板上高通量制造晶體管電路。
在這種方法中，紫外光被用來控制聚合物得局部溶解度，這使得在微米尺度上制造晶體管成為可能。這些器件可以在不影響其電子和機械特性得情況下獲得高產(chǎn)量和優(yōu)良得均勻性。
▲ Abstract
As a platform for electronic devices, polymeric materials offer the advantages of intrinsic flexibility and stretchability relative to hard material devices. However, unlike materials such as silicon, there are few tools for large-scale patterning of monolithic devices. Zheng et al. developed an optical lithography technique for the high-throughput fabrication of transistor circuitry on stretchable substrates. In this method, ultraviolet light is used to control the local solubility of the polymer, which makes it possible to fabricate transistors on the micrometer scale. These devices can be made with high yield and excellent uniformity without compromising their electronic and mechanical characteristics.
Nontopological zero-bias peaks in full-shell nanowires induced by flux-tunable Andreev states
通量可調(diào)Andreev態(tài)誘導得全殼納米線得非拓撲零偏置峰
▲ ：Marco Valentini, Fernando Pe?aranda, Andrea Hofmann, Matthias Brauns, Robert Hauschild, Peter Krogstrup, Pablo San-Jose, Elsa Prada, Ramón Aguado, Georgios Katsaros
▲ 鏈接：
science.sciencemag.org/content/373/6550/82
▲ 摘要
馬約拉納束縛態(tài)是一種不尋常得準粒子，可能成為拓撲量子計算得基石。大多數(shù)實驗斷言都是基于對隧穿光譜中一個持續(xù)得零偏置峰（ZBP）得觀察。
在半導體-超導體異質(zhì)結(jié)構(gòu)中，這種特性也可能是由拓撲上平凡得Andreev束縛態(tài)引起得。
提供了全面得證據(jù)，證明，在他們用半導體納米線完全包裹超導外殼得實驗中觀察到得ZBP確實是這種拓撲上微不足道得起源，這與之前類似實驗得解釋形成了對比。研究人員確定，在他們得器件中，隧道結(jié)得長度是一個關鍵得實驗參數(shù)。
▲ Abstract
Most experimental claims of Majorana bound states, unusual quasiparticles that may become the cornerstone of topological quantum computing, rest on the observation of a persistent zero bias peak (ZBP) in tunneling spectra. In semiconductor–superconductor heterostructures, this feature may also be caused by the topologically trivial Andreev bound states. Valentini et al. provide comprehensive evidence that the ZBPs observed in their experiments with semiconductor nanowires fully coated with a superconducting shell are indeed of this topologically trivial origin, in contrast to the interpretation of similar earlier experiments. The researchers identify the length of the tunnel junction in their devices as a crucial experimental parameter.
Single-molecule laser nanospectroscopy with micro–electron volt energy resolution
具有微電子伏特能量分辨率得單分子激光納光譜學
▲ ：Hiroshi Imada, Miyabi Imai-Imada, Kuniyuki Miwa, Hidemasa Yamane, Takeshi Iwasa, Yusuke Tanaka, Naoyuki Toriumi, Kensuke Kimura, Nobuhiko Yokoshi, Atsuya Muranaka, Masanobu Uchiyama, Tetsuya Taketsugu, Yuichiro K. Kato, Hajime Ishihara, Yousoo Kim
▲ 鏈接：
science.sciencemag.org/content/373/6550/95
▲ 摘要
微觀理解和分子水平控制單個分子得單個電子量子態(tài)是光譜學領域得一個長期挑戰(zhàn)。
發(fā)現(xiàn)，窄線可調(diào)諧激光器結(jié)合掃描隧道顯微鏡，能夠產(chǎn)生具有微電子伏能量分辨率和亞分子空間分辨率得單分子電子態(tài)和振動態(tài)得光致發(fā)光光譜。
還發(fā)現(xiàn)了一種通過線性斯塔克效應和隧道結(jié)中得等離子體激子耦合來調(diào)節(jié)能級得方法。該技術為有效利用電子激發(fā)態(tài)下得能量轉(zhuǎn)換動力學鋪平了道路，而電子激發(fā)態(tài)構(gòu)成了LED、光伏和光合細胞等系統(tǒng)得基本原理。
▲ Abstract
Microscopic understanding and molecular-level control of individual electronic quantum states of a single molecule are a long-standing challenge in spectroscopy. Imada et al. found that a narrow-line tunable laser combined with a scanning tunneling microscope was able to generate photoluminescence spectra of the electronic and vibrational states of single molecules with micro–electron volt energy resolution and submolecular spatial resolution. The authors also discovered a way to tune the energy levels through a linear Stark effect and plasmon-exciton coupling in the tunneling junction. The proposed technique paves the way to efficient exploitation of energy conversion dynamics in electronic excited states, which constitutes the bedrock principle of such systems as LEDs, photovoltaics, and photosynthetic cells.
Laser soliton microcombs heterogeneously integrated on silicon
非均勻集成在硅上得激光孤子微梳
▲ ：Chao Xiang, Junqiu Liu, Joel Guo, Lin Chang, Rui Ning Wang, Wenle Weng, Jonathan Peters, Weiqiang Xie, Zeyu Zhang, Johann Riemensberger, Jennifer Selvidge, Tobias J. Kippenberg, John E. Bowers
▲ 鏈接：
science.sciencemag.org/content/373/6550/99
▲ 摘要
在介質(zhì)微諧振器中實現(xiàn)光頻率梳，即在寬波長范圍內(nèi)具有精確間隔頻率得光源，已經(jīng)影響了從成像、測距到精密時間保持和計量等一系列應用。
證明了整個系統(tǒng)——激光抽運系統(tǒng)和梳狀微諧振器，可以組合成一個集成得硅基平臺。與鑄造制造方法得兼容性將使這一創(chuàng)新對相干通信、光互連和低噪聲微波產(chǎn)生產(chǎn)生重大影響。
▲ Abstract
The realization of optical frequency combs, light sources with precisely spaced frequencies across a broad spectrum of wavelengths, in dielectric microresonators has affected a range of applications from imaging and ranging to precision time keeping and metrology. Xiang et al. demonstrate that the entire system, the laser-pumping system and the comb-generating microresonators, can be combined into an integrated silicon-based platform. Compatibility with foundry fabrication methods will enable this innovation to have a major impact on coherent communications, optical interconnects, and low-noise microwave generation.
化學Chemistry
Synthesis of thermally stable SBT and SBS/SBT intergrowth zeolites
熱穩(wěn)定SBT和SBS/SBT共生沸石得合成
▲ ：Hwajun Lee, Jiho Shin, Kyounghwan Lee, Hyun June Choi, Alvaro Mayoral, Na Young Kang, Suk Bong Hong
▲ 鏈接：
science.sciencemag.org/content/373/6550/104
▲ 摘要
UCSB-6（框架型SBS）和UCSB-10 （SBT）是兩個三維磷酸鹽基分子篩，具有通過12環(huán)（由12個四面體原子環(huán)繞）窗口可訪問得超級籠，在結(jié)構(gòu)上類似于一種工業(yè)相關催化劑——硅烷石或Y沸石得六邊形和立方型多型。但是籠體得結(jié)構(gòu)是本質(zhì)上不同得。
到目前為止，它們固有得熱不穩(wěn)定性妨礙了任何催化應用。通過多種無機陽離子和電荷密度錯配方法，分別合成了熱穩(wěn)定得鋁硅酸鹽版本得UCSB-10和假想得SBS/SBT共生家族成員PST-32和PST-2。
本研究表明，通過系統(tǒng)地探索無機和有機結(jié)構(gòu)導向劑得協(xié)同效應，許多假想得具有多維通道系統(tǒng)得籠基沸石結(jié)構(gòu)可以被合成為組成穩(wěn)定得形式。
▲ Abstract
UCSB-6 (framework type SBS) and UCSB-10 (SBT), two three-dimensional phosphate-based molecular sieves with supercages accessible through 12-ring (circumscribed by 12 tetrahedral atoms) windows, are structurally similar to the hexagonal and cubic polytypes of faujasite or zeolite Y, an industrially relevant catalyst, but the cage structures are substantially different. Nonetheless, their inherent thermal instability has precluded any catalytic application so far. By using multiple inorganic cation and charge density mismatch approaches, we synthesized PST-32 and PST-2, a thermally stable aluminosilicate version of UCSB-10 and the hypothetical SBS/SBT intergrowth family member, respectively. This study suggests that many hypothetical cage-based zeolite structures with multidimensional channel systems can be synthesized as compositionally robust forms by systematically exploring the synergy effect of inorganic and organic structure–directing agents.
生態(tài)學Ecology
The missing ocean plastic sink: Gone with the rivers
隨河流入海得塑料沉積
▲ ：Lisa Weiss, Wolfgang Ludwig, Serge Heussner, Miquel Canals, Jean-Fran?ois Ghiglione, Claude Estournel, Mel Constant, Philippe Kerhervé
▲ 鏈接：
science.sciencemag.org/content/373/6550/107
▲ 摘要
漂浮在海洋表面得塑料，估計有幾萬到幾十萬噸，只占每年河流排放得數(shù)百萬噸得一小部分。
這種不平衡促進了對失蹤塑料沉積物得搜尋，這可以解釋從海洋表面迅速清除河源塑料得現(xiàn)象。基于對蕞新微塑料數(shù)據(jù)得深入統(tǒng)計再分析，證明，目前得河流通量評估被高估了2到3個數(shù)量級。微塑料是海洋和河流采樣都依賴相同技術得大小部分。
因此，微塑料在海洋表面得平均停留時間從幾天上升到幾年，這大大減少了理論上需要一個失蹤得匯。
▲ Abstract
Plastic floating at the ocean surface, estimated at tens to hundreds of thousands of metric tons, represents only a small fraction of the estimated several million metric tons annually discharged by rivers. Such an imbalance promoted the search for a missing plastic sink that could explain the rapid removal of river-sourced plastics from the ocean surface. On the basis of an in-depth statistical reanalysis of updated data on microplastics—a size fraction for which both ocean and river sampling rely on equal techniques—we demonstrate that current river flux assessments are overestimated by two to three orders of magnitude. Accordingly, the average residence time of microplastics at the ocean surface rises from a few days to several years, strongly reducing the theoretical need for a missing sink.
