Probability-Distribution-Configurable True Random Number Generators Based on Spin-Orbit Torque Magnetic Tunnel Junctions

The incorporation of randomness into stochastic computing can provide ample opportunities for applications such as simulated annealing, non-polynomial hard problem solving, and Bayesian neuron networks. In these cases, a considerable number of random numbers with an accurate and configurable probability distribution function (PDF) are indispensable. Preferably, these random numbers are provided at the hardware level to improve speed, efficiency, and parallelism. In this paper, how spin-orbit torque magnetic tunnel junctions (SOT-MTJs) with high barriers are suitable candidates for the desired true random number generators is demonstrated. Not only do these SOT-MTJs perform excellently in speed and endurance, but their randomness can also be conveniently and precisely controlled by a writing voltage, which makes them a well-performed Bernoulli bit. By utilizing these SOT-MTJ-based Bernoulli bits, any PDF, including Gaussian, uniform, exponential, Chi-square, and even arbitrarily defined distributions can be realized. These PDF-configurable true random number generators can then promise to advance the development of stochastic computing and broaden the applications of the SOT-MTJs.

In Situ Transmission Electron Microscopy Methods for Lithium-Ion Batteries

In situ Transmission Electron Microscopy (TEM) stands as an invaluable instrument for the real-time examination of the structural changes in materials. It features ultrahigh spatial resolution and powerful analytical capability, making it significantly versatile across diverse fields. Particularly in the realm of Lithium-Ion Batteries (LIBs), in situ TEM is extensively utilized for real-time analysis of phase transitions, degradation mechanisms, and the lithiation process during charging and discharging. This review aims to provide an overview of the latest advancements in in situ TEM applications for LIBs. Additionally, it compares the suitability and effectiveness of two techniques: the open cell technique and the liquid cell technique. The technical aspects of both the open cell and liquid cell techniques are introduced, followed by a comparison of their applications in cathodes, anodes, solid electrolyte interphase (SEI) formation, and lithium dendrite growth in LIBs. Lastly, the review concludes by stimulating discussions on possible future research trajectories that hold potential to expedite the progression of battery technology.

A new toothless pterosaur from the Early Cretaceous Jehol Biota with comments on the Chaoyangopteridae

The Chaoyangopteridae is a clade of azhdarchoid pterosaurs that stands out in China, particularly in the Jehol Biota, as a Cretaceous group of medium-sized and high-crested pterosaurs. Herein, we describe a new species, Meilifeilong youhao gen. et sp. nov., based on two specimens, one tentatively referred to this taxon. This new species represents the most complete and well-preserved chaoyangopterid recorded to date. Along with a set of characters (low premaxillary crest above the nasoantorbital fenestra extending posteriorly, posterior premaxillary process arched and curving posteriorly, a slightly convex sternal articulation surface of coracoid, and a fibular shaft close to proximal articulation strongly arched posteriorly), this species also provides new information both on the unknown palatal region of this clade, and on the rarely preserved (in place) ear portion with stapes. Moreover, M. youhao sheds light on paleoecological aspects, while also giving new information about the taxonomic diversity of this peculiar group of Jiufotang pterosaurs.

Si-Based High-Entropy Anode for Lithium-Ion Batteries

Up to now, only a small portion of Si has been utilized in the anode for commercial lithium-ion batteries (LIBs) despite its high energy density. The main challenge of using micron-sized Si anode is the particle crack and pulverization due to the volume expansion during cycling. This work proposes a type of Si-based high-entropy alloy (HEA) materials with high structural stability for the LIB anode. Micron-sized HEA-Si anode can deliver a capacity of 971 mAhg-1 and retains 93.5% of its capacity after 100 cycles. In contrast, the silicon-germanium anode only retains 15% of its capacity after 20 cycles. This study has discovered that including HEA elements in Si-based anode can decrease its anisotropic stress and consequently enhance ductility at discharged state. By utilizing in situ X-ray diffraction and transmission electron microscopy analyses, a high-entropy transition metal doped Lix (Si/Ge) phase is found at lithiated anode, which returns to the pristine HEA phase after delithiation. The reversible lithiation and delithiation process between the HEA phases leads to intrinsic stability during cycling. These findings suggest that incorporating high-entropy modification is a promising approach in designing anode materials toward high-energy density LIBs.

Stem Anatomy Confirms Tingia unita Is a Progymnosperm

Tingia Halle, a representative genus of the Cathaysia Flora, has been studied for nearly 100 years, being a small heterosporous tree based on the gross morphology of Tingia unita. However, the systematic affinity of Tingia is uncertain. Now, a number of well-preserved fossils of T. unita from the Taiyuan Formation of Lower Permian in Wuda Coalfield, Wuhai City, Inner Mongolia facilitates an examination of wood anatomy. The stem anatomy of T. unita shows parenchymatous pith, endarch primary xylem, pycnoxylic secondary xylem, and cortex, typically a type of gymnosperm wood, which taken together with pteridophytic reproduction, certainly evidences that Tingia Halle is a progymnosperm. In addition, Tingia together with Paratingia provide strong evidence to link the Noeggerathiales with progymnosperms.

Plant developmental stage drives the differentiation in ecological role of the maize microbiome

BACKGROUND

Plants live with diverse microbial communities which profoundly affect multiple facets of host performance, but if and how host development impacts the assembly, functions and microbial interactions of crop microbiomes are poorly understood. Here we examined both bacterial and fungal communities across soils, epiphytic and endophytic niches of leaf and root, and plastic leaf of fake plant (representing environment-originating microbes) at three developmental stages of maize at two contrasting sites, and further explored the potential function of phylloplane microbiomes based on metagenomics.

RESULTS

Our results suggested that plant developmental stage had a much stronger influence on the microbial diversity, composition and interkingdom networks in plant compartments than in soils, with the strongest effect in the phylloplane. Phylloplane microbiomes were co-shaped by both plant growth and seasonal environmental factors, with the air (represented by fake plants) as its important source. Further, we found that bacterial communities in plant compartments were more strongly driven by deterministic processes at the early stage but a similar pattern was for fungal communities at the late stage. Moreover, bacterial taxa played a more important role in microbial interkingdom network and crop yield prediction at the early stage, while fungal taxa did so at the late stage. Metagenomic analyses further indicated that phylloplane microbiomes possessed higher functional diversity at the early stage than the late stage, with functional genes related to nutrient provision enriched at the early stage and N assimilation and C degradation enriched at the late stage. Coincidently, more abundant beneficial bacterial taxa like Actinobacteria, Burkholderiaceae and Rhizobiaceae in plant microbiomes were observed at the early stage, but more saprophytic fungi at the late stage.

CONCLUSIONS

Our results suggest that host developmental stage profoundly influences plant microbiome assembly and functions, and the bacterial and fungal microbiomes take a differentiated ecological role at different stages of plant development. This study provides empirical evidence for host exerting strong effect on plant microbiomes by deterministic selection during plant growth and development. These findings have implications for the development of future tools to manipulate microbiome for sustainable increase in primary productivity. Video Abstract.

How the ovules get enclosed in magnoliaceous carpels

Angiosperms distinguish themselves from gymnosperms by their ovules that are enclosed before pollination. However, how the ovules get enclosed in angiosperms remains a mystery, especially for Magnoliaceae. The only key to this mystery is finding a series of carpels transitional from fully closed with enclosed ovules to open with naked ovules. We use routine paraffin section technology, LM, SEM to document the morphology and anatomy of carpel variation in Michelia figo (Magnoliaceae). A series of carpel variations within a single flower of Michelia figo (Magnoliaceae) are documented, in which the ovules are exposed in atypical carpels. These atypical and typical carpels for the first time demonstrate clearly how the naked ovule get enclosed. Each atypical carpel, with naked ovules, clearly comprises two parts, namely, subtending foliar part and branches bearing ovules, suggesting that a typical carpel is actually an end-product of the fusion between the ovuliferous branches and subtending foliar parts. The only difference among these carpels is the extent of fusion between these two parts. This generalization is in full agreement with the molecular genetic studies on angiosperm flowers.