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Thin film bulk acoustic wave resonators (FBARs) leveraging sputtered aluminum nitride (AlN) and scandium aluminum nitride (ScAlN) films, are a leading commercial solution for compact radio frequency (RF) filters in mobile devices. However, as 5G/6G bands extend beyond 6 GHz, achieving the required thinner piezoelectric film thicknesses below 500 nm presents a significant challenge to high-quality sputtering, resulting in a moderate quality factor (Q). Additionally, AlN/ScAlN platforms are limited by moderate electromechanical coupling (k2), restricting bandwidth. More recently, ultra-thin transferred single-crystal piezoelectric lithium niobate (LN) has enabled lateral field excited resonators (XBAR) at 10-30 GHz. While these devices boast a high Q and k2, they face challenges with low capacitance density, large footprint, and significant electromagnetic (EM) effects. On the other hand, thickness-field excited LN FBARs face challenges with bottom electrode integration. In this work, we implement a transferred LN on aluminum FBAR platform on sapphire wafers with an intermediate amorphous silicon layer without the need for a patterned bottom electrode. The resonators show first order symmetric mode (S1) at 10.5 GHz with a 3-dB series resonance Q of 38 and k2 of 14.1%, alongside third order symmetric mode (S3) at 27 GHz with a 3-dB series resonance Q of 22 and a high k2 of 11.3%. Further analysis shows that higher Q could be achieved by adjusting the low-loss piezoelectric to lossy metal volume ratio. 

This letter presents a versatile design method for achieving precise frequency and bandwidth control of compact acoustic filters monolithically at millimeter wave (mmWave) in transferred thin-film lithium niobate (LiNbO3). Prototypes are implemented with lateral field excited first-order antisymmetric (A1) mode bulk acoustic resonators (XBARs). The design leverages the in-plane anisotropy of the e15 piezoelectric coefficient in 128° Y-cut LiNbO3, enabling monolithic control of electromechanical coupling ( k2 ) by simply rotating the resonator layout. This allows for filters with customizable fractional bandwidths (FBWs). Additionally, fine-tuning of the center frequency ( fc ) is achieved through selective trimming of the film for series and shunt resonators, enabling a single design to be scaled across frequencies with enhanced fabrication tolerance. To validate the approach, we designed and fabricated a filter centered at 18.6GHz, achieving a low insertion loss (IL) of 1.84 dB, and a precise designed FBW of 9.5%. This platform shows a significant promise for enabling a monolithic filter bank with precise band selection, paving the way for the next generation of mmWave acoustic filters. 

The importance of phosphorus (P) in regulating ecosystem responses to climate change has fostered P-cycle implementation in land surface models, but their CO₂effects predictions have not been evaluated against measurements. Here, we perform a data-driven model evaluation where simulations of eight widely used P-enabled models were confronted with observations from a long-term free-air CO₂enrichment experiment in a mature, P-limitedEucalyptusforest. We show that most models predicted the correct sign and magnitude of the CO₂effect on ecosystem carbon (C) sequestration, but they generally overestimated the effects on plant C uptake and growth. We identify leaf-to-canopy scaling of photosynthesis, plant tissue stoichiometry, plant belowground C allocation, and the subsequent consequences for plant-microbial interaction as key areas in which models of ecosystem C-P interaction can be improved. Together, this data-model intercomparison reveals data-driven insights into the performance and functionality of P-enabled models and adds to the existing evidence that the global CO₂-driven carbon sink is overestimated by models. 

The synthesis and characterization of an Au 20 (PET) 15 (DG) 2 (PET = phenylethane thiol; DG = diglyme) cluster is reported. Mass spectrometry reveals this as the first diglyme ligated cluster where diglyme ligands survive ionization into the gas phase. Thermal analysis shows the cluster degrades at 156 °C, whereas the similar Au 20 (PET) 16 cluster degrades at 125 °C, representing markedly increased thermal stability. A combination of NMR spectroscopy and computational modeling suggests that the diglyme molecules bind in a tridentate manner for this cluster, resulting in a binding energy of 35.2 kcal mol −1 for diglyme, which is comparable to the value of ∼40 kcal mol −1 for thiolates. IR and optical spectroscopies show no evidence of assembly of this cluster, in contrast to Au 20 (PET) 15 (DG), which readily assembles into dimeric species, which is consistent with a tridentate binding motif. Evidence for stacking among Au-bound and non-bound diglyme molecules is inferred from thermal and mass analysis. 

Online radicalization is among the most vexing challenges the world faces today. Here, we demonstrate that homogeneity in moral concerns results in increased levels of radical intentions. In Study 1, we find that in Gab—a right-wing extremist network—the degree of moral convergence within a cluster predicts the number of hate-speech messages members post. In Study 2, we replicate this observation in another extremist network, Incels. In Studies 3 to 5 ( N = 1,431), we demonstrate that experimentally leading people to believe that others in their hypothetical or real group share their moral views increases their radical intentions as well as willingness to fight and die for the group. Our findings highlight the role of moral convergence in radicalization, emphasizing the need for diversity of moral worldviews within social networks.