Delocalized, asynchronous, closed-loop discovery of organic laser emitters
非定域、非同步、閉環有機激光發射器的發現
▲ 作者:FELIX STRIETH-KALTHOFF, HAN HAO, VANDANA RATHORE, JOSHUA DERASP, THéOPHILE GAUDIN, NICHOLAS H. ANGELLO, MARTIN SEIFRID, EKATERINA TRUSHINA, MASON GUY, AND ALáN ASPURU-GUZIK
Recent advances in experimental automation and integration with artificial intelligence (AI) have laid the foundation for so-called “self-driving labs,” but they remained limited to simple proof-of-concept experiments. Strieth-Kalthoff et al. introduced the concept of asynchronous cloud-based delocalized closed-loop (ACDC) discovery to drive multiple geographically distributed platforms in a single discovery campaign in which each unit operates as an independent, asynchronous worker executing experiments planned by a central AI entity. The ACDC concept has been successfully applied in the search for organic solid-state laser gain materials with state-of-the-art lasing performance, a challenging scientific problem with slow progress, thereby demonstrating the power of this closed-loop campaign.
Bandgap-universal passivation enables stable perovskite solar cells with low photovoltage loss
帶隙通用鈍化使穩定的鈣鈦礦太陽能電池具有低光電壓損失
▲ 作者:YEN-HUNG LIN, VIKRAM, FENGNING YANG, XUE-LI CAO, AKASH DASGUPTA, ROBERT D. J. OLIVER, ALEKSANDER M. ULATOWSKI, MELISSA M. MCCARTHY, XINYI SHEN, AND HENRY J. SNAITH
The efficiency and longevity of metal-halide perovskite solar cells are typically dictated by nonradiative defect-mediated charge recombination. In this work, we demonstrate a vapor-based amino-silane passivation that reduces photovoltage deficits to around 100 millivolts (>90% of the thermodynamic limit) in perovskite solar cells of bandgaps between 1.6 and 1.8 electron volts, which is crucial for tandem applications. A primary-, secondary-, or tertiary-amino–silane alone negatively or barely affected perovskite crystallinity and charge transport, but amino-silanes that incorporate primary and secondary amines yield up to a 60-fold increase in photoluminescence quantum yield and preserve long-range conduction. Amino-silane–treated devices retained 95% power conversion efficiency for more than 1500 hours under full-spectrum sunlight at 85°C and open-circuit conditions in ambient air with a relative humidity of 50 to 60%.
物理學Physics
Global band convergence design for high-performance thermoelectric power generation in Zintls
Zintls高性能熱電發電的全球波段收斂設計
作者:XIN SHI, SHAOWEI SONG, GUANHUI GAO, AND ZHIFENG REN
Zintl materials can be attractive for thermoelectric applications because of their wide range of compositions and tunable properties. Shi et al. devised a method to quickly find which materials from four parent compounds have electronic band structures that improve thermoelectric performance. After identifying several compositions, the authors showed that the best of these has good long-term and high temperature stability. This compound can be paired with another zintl material to make a device that has attractive thermoelectric performance at midrange temperatures.
Diamond-lattice photonic crystals assembled from DNA origami
由DNA折紙組裝的鉆石晶格光子晶體
▲ 作者:GREGOR POSNJAK, XIN YIN, PAUL BUTLER, OLIVER BIENEK, MIHIR DASS, SEUNGWOO LEE, IAN D. SHARP, AND TIM LIEDL
Colloidal self-assembly allows rational design of structures on the micrometer and submicrometer scale. One architecture that can generate complete three-dimensional photonic bandgaps is the diamond cubic lattice, which has remained difficult to realize at length scales comparable with the wavelength of visible or ultraviolet light. In this work, we demonstrate three-dimensional photonic crystals self-assembled from DNA origami that act as precisely programmable patchy colloids. Our DNA-based nanoscale tetrapods crystallize into a rod-connected diamond cubic lattice with a periodicity of 170 nanometers. This structure serves as a scaffold for atomic-layer deposition of high–refractive index materials such as titanium dioxide, yielding a tunable photonic bandgap in the near-ultraviolet.
行為學Ethology
Tool use increases mechanical foraging success and tooth health in southern sea otters (Enhydra lutris nereis)
工具的使用增加了南方海獺的機械覓食成功率和牙齒健康
▲ 作者:CHRIS J. LAW , M. TIM TINKER, JESSICA A. FUJII, TERI NICHOLSON, MICHELLE STAEDLER, JOSEPH A. TOMOLEONI, COLLEEN YOUNG AND RITA S. MEHTA
Although tool use may enhance resource utilization, its fitness benefits are difficult to measure. By examining longitudinal data from 196 radio-tagged southern sea otters, we found that tool-using individuals, particularly females, gained access to larger and/or harder-shelled prey. These mechanical advantages translated to reduced tooth damage during food processing. We also found that tool use diminishes trade-offs between access to different prey, tooth condition, and energy intake, all of which are dependent on the relative prey availability in the environment. Tool use allowed individuals to maintain energetic requirements through the processing of alternative prey that are typically inaccessible with biting alone, suggesting that this behavior is a necessity for the survival of some otters in environments where preferred prey are depleted.
How power shapes behavior: Evidence from physicians
Power—the asymmetric control of valued resources—affects most human interactions. Although power is challenging to study with real-world data, a distinctive dataset allowed us to do so within the critical context of doctor-patient relationships. Using 1.5 million quasi-random assignments in US military emergency departments, we examined how power differentials between doctor and patient (measured by using differences in military ranks) affect physician behavior. Our findings indicate that power confers nontrivial advantages: “High-power” patients (who outrank their physician) receive more resources and have better outcomes than equivalently ranked “low-power” patients. Patient promotions even increase physician effort. Furthermore, low-power patients suffer if their physician concurrently cares for a high-power patient. Doctor-patient concordance on race and sex also matters. Overall, power-driven variation in behavior can harm the most vulnerable populations in health care settings.