Science,迷信  11 AUG 2023, VOL 381, ISSUE 6658

《迷信》2023年8月11日，第381卷，出书6658期

生态Ecology

Global water use efficiency saturation due to increased vapor pressure deficit

由于蒸汽压差削减，周论全天上水利勤勉用趋于饱以及

▲ 作者 ：FEI LI,文导 JINGFENG XIAO, JIQUAN CHEN, ASHLEY BALLANTYNE, KE JIN, BING LI, MICHAEL ABRAHA, AND RANJEET JOHN

▲ 链接：

https://www.science.org/doi/full/10.1126/science.adf5041

▲ 摘要 ：

在一个大气中二氧化碳浓度不断削减、气温不断回升的迷信天下里，植物若何在碳的出书削减以及水的损失之间妨碍失调的。作者钻研表明 ，周论植物水份利勤勉用，文导即光协熏染净罗致碳与蒸腾气孔导度之比 ，迷信在1982~2000年间呈回升趋向  ，出书但在2001~ 2016年间坚持巩固。周论

钻研者批注说，文导这是迷信由于蒸气压削减以及蒸发蒸腾减轻的服从
。钻研服从从另一个方面剖析了天气变暖的出书倒霉影响使实现碳中以及变患上愈加难题。

▲ Abstract：

How have plants managed the trade‐off between carbon gain and water loss in a world of increasing atmospheric carbon dioxide concentrations and rising temperatures. Li et al. showed that plant water use efficiency,周论 the ratio between the net assimilation of carbon through photosynthesis and the stomatal conductance of transpiration, increased from 1982 to 2000, but then remained constant from 2001 to 2016. The authors interpret this as being the result of increases in the vapor pressure and intensifying evapotranspiration. Their results illustrate one more way in which the adverse effects of climate warming make it more difficult to achieve carbon neutrality.

Declining cost of renewables and climate change curb the need for African hydropower expansion

可再沉闷力老本着落以及善象变更或者抑制非洲水电扩展需要

▲ 作者：ANGELO CARLINO, MATTHIAS WILDEMEERSCH, CELRAY JAMES CHAWANDA, MATTEO GIULIANI, SEBASTIAN STERL, WIM THIERY, ANN VAN GRIENSVEN, AND ANDREA CASTELLETTI

▲ 链接：

hhttps://www.science.org/doi/full/10.1126/science.adf5848

▲ 摘要：

在生齿削减以及后退生涯水平目的的增长下，特意是在最不发达地域 ，良多非洲国家妄想扩展其发电能耐，以知足未来能源需要 。到2050年
，非洲总电力需要估量将以每一年5%到6%的速率削减，次若是在撒哈拉以南非洲地域 。

可是 ，非洲能源零星的未来不光受到格外能源需要的驱动，还将受到减紧迫顺应答谢天气变更的需要的驱动 。水电黑白洲电力零星的紧张组成部份，特意是在撒哈拉以南国家
。

它提供了总发电量的20%摆布 ，但其全副后劲尚未被开拓进去 。传统上被以为是低碳电力的重价源头 ，全部非洲大陆正在思考兴修300多座水电站，至关于格外的100吉瓦发电能耐。

▲ Abstract：

Driven by population growth and the goal of improving living standards, especially in the least-developed regions, many African countries plan to expand their power generation capacities to meet future energy demand. Indeed, total electricity demand is expected to grow by 5 to 6% per year until 2050, mainly in sub-Saharan Africa. Yet the future of African energy systems will not only be driven by the additional energy demand but also by the need to mitigate and adapt to anthropogenic climate change. Hydropower is an important component of African power systems, especially in sub-Saharan countries. It provides around 20% of total electricity generation, but its full potential has not been exploited yet. Traditionally considered a cheap source of low-carbon electricity, more than 300 hydropower plants, corresponding to an additional 100-GW power capacity, are under consideration across the continent.

物理学以及生物物理学Physics & Biophysics

Wafer-scale δ waveguides for integrated two-dimensional photonics

集成二维光子学的晶圆尺度δ波导

▲ 作者
：MYUNGJAE LEE, HANYU HONG, JAEHYUNG YU, FAUZIA MUJID, ANDREW YE, CE LIANG, AND JIWOONG PARK

▲ 链接 ：

https://www.science.org/doi/full/10.1126/science.adi2322

▲ 摘要 ：

芯片级光学电路需要在不断减小的长度尺度以及差距元件之间限度、操作以及转达光的能耐。处置组件之间的光学不立室个别会导致实际配置装备部署的尺寸以及功能调以及。

作者钻研表明，可能在超薄的二维质料（厚度<1纳米）中限度以及向导光
。运用二硫化钼单层 ，他们捉拿了一束激光，并发生了沿薄膜转达厘米距离的二维光子波 。经由集成微加工薄膜光学元件 ，钻研者揭示了种种光学功能，从而为二维纳米光子学提供了一个通用平台 。

▲ Abstract ：

Chip-scale optical circuits require the ability to confine, control, and propagate light over ever-decreasing length scales and across different components. Addressing the optical mismatch between components typically results in compromises in size and performance for practical devices. Lee et al. showed that they could confine and guide light in an ultrathin two-dimensional (2D) material (<1 nanometer thick). Using molybdenium disulfide monolayers, they trapped a laser beam and generated a 2D photonic wave propagating along the film over centimeter distances. By integrating microfabricated thin-film optical components, the authors demonstrated various optical functionalities, thereby providing a general platform for 2D nanophotonics.

Bioadhesive polymer semiconductors and transistors for intimate biointerfaces

用于亲密生物界面的生物粘合剂聚合物半导体以及晶体管

▲ 作者
：NAN LI, YANG LI, ZHE CHENG, YOUDI LIU, YAHAO DAI, SEOUNGHUN KANG, SONGSONG LI, NAISONG SHAN, SHINYA WAI, AND SIHONG WANG

▲ 链接：

https://www.science.org/doi/full/10.1126/science.adg8758

▲ 摘要 ：

生物电子配置装备部署可用于监测或者修复体内的紧张机关，但这个别需要直接衔接以及粘附 ，当概况湿润时 ，这是一个特意的挑战。钻研者妄想了一种散漫了生物粘合剂以及半导体的双收集共聚物。

特意是刷子组件搜罗一个可能吸水的侧组 ，在与机关概况的初始打仗时，它有助于干燥以增强附着力。钻研者经由在离体大鼠心脏以及活体大鼠肌肉上建树一个电心理记实传感器来证实新质料的能耐 
。

▲ Abstract ：

Bioelectronic devices can be used to monitor or repair vital tissues in the body, but this often requires direct interfacing and adhesion, which is a particular challenge when the surface is wet. Li et al. designed a double-network copolymer that combines a bioadhesive with a semiconductor. In particular, the brush component included a side group that could absorb water so that on initial contact with the tissue surface, it helps to dry it to enhance adhesion. The authors demonstrate the capabilities of their material by building a sensor for electrophysiological recording on an isolated rat heart and on in vivo rat muscles. —Marc S. Lavine

化学Chemistry

Chemical upcycling of polyethylene, polypropylene, and mixtures to high-value surfactants

聚乙烯 、聚丙烯及混合物的接管 
，以取患上高价钱概况活性剂

▲ 作者：ZHEN XU, NUWAYO ERIC MUNYANEZA, QIKUN ZHANG, MENGQI SUN, CARLOS POSADA, PAUL VENTURO, NICHOLAS A. RORRER, JOEL MISCALL, BOBBY G. SUMPTER , AND GUOLIANG LIU

▲ 链接：

https://www.science.org/doi/full/10.1126/science.adh0993

▲ 摘要
 ：

将塑料废物转化为脂肪酸是填补这些高价钱
 、大批量化学品源头的一种有排汇力的本领 。钻研者报道了将聚乙烯（PE）以及聚丙烯（PP）以80%的转化率转化为脂肪酸的措施，其数平均摩尔品质分说高达~700以及670道尔顿。该工艺适用于都市PE以及PP废物及其混合物。

温度梯度热解是PE以及PP可控降解成蜡以及抑制小份子天生的关键
。蜡经由氧化硬脂酸锰以及随后的加工降级为脂肪酸。PP裂解比PE裂解可发生更多的烯烃蜡以及更高的酸数脂肪酸  。钻研进一步将脂肪酸转化为高价钱 、大市场容量的概况活性剂。工业规模的技术经济合成表明 ，在不需要津贴的情景下  ，这一措施在经济上是可行的 。

▲ Abstract：

Conversion of plastic wastes to fatty acids is an attractive means to supplement the sourcing of these high-value, high-volume chemicals. We report a method for transforming polyethylene (PE) and polypropylene (PP) at ~80% conversion to fatty acids with number-average molar masses of up to ~700 and 670 daltons, respectively. The process is applicable to municipal PE and PP wastes and their mixtures. Temperature-gradient thermolysis is the key to controllably degrading PE and PP into waxes and inhibiting the production of small molecules. The waxes are upcycled to fatty acids by oxidation over manganese stearate and subsequent processing. PP?-scission produces more olefin wax and yields higher acid-number fatty acids than does PE?-scission. We further convert the fatty acids to high-value, large–market-volume surfactants. Industrial-scale technoeconomic analysis suggests economic viability without the need for subsidies.

Progra妹妹ing twist angle and strain profiles in 2D materials

二维质料的修正角以及应变曲线编程

▲ 作者：MA?LLE KAPFER, BJARKE S. JESSEN, MEGAN E. EISELE, MATTHEW FU, DORTE R. DANIELSEN, THOMAS P. DARLINGTON, SAMUEL L. MOORE, NATHAN R. FINNEY, ARIANE MARCHESE, AND CORY R. DEAN

▲ 链接 ：

https://www.science.org/doi/full/10.1126/science.ade9995

▲ 摘要 ：

由单层质料在扭曲构型中重叠而组成的莫尔维尔超晶格可能承载良多配合态
 。可是 ，这种妄想被发现是无序的
，在单个样品中扭曲角以及应变的变更不可预料。钻研者发现了一种操作修正角度以及削减凌乱的措施。

他们在六方氮化硼的顶部部署了带状石墨烯层，并运用原子力显微镜的尖端笔直了带的一端
。由此发生的妄想具备从缎带开始笔直到其收尾不断削减的扭曲角度
，这种操作有望后退这种质料的可一再性以及对于其的清晰 。

▲ Abstract ：

Moiré superlattices formed by stacking single-layer materials in a twisted configuration can host many exotic states. However, such structures have been found to be disordered, with the twist angle and strain varying unpredictably within a single sample. Kapfer et al. found an elegant method for controlling the twist angle and decreasing the disorder. The researchers placed a ribbon-shaped graphene layer on top of hexagonal boron nitride and bent one end of the ribbon using the tip of an atomic force microscope. The resulting structure had a twist angle that increased continuously from the point at which the ribbon started bending to its end. Such control is expected to improve reproducibility and understanding of this class of materials.