Genetic Variation and Geographical Differentiation of \u3cem\u3eElymus nutans\u3c/em\u3e (Poaceae: Triticeae) from West China

Elymus nutans Griseb. is not only an important alpine forage grass, but also as a crucial gene pool for improving cereal crops. Understanding and maintaining the genetic diversity of the species are essential for both conservation strategy and breeding programs. However, little is known about its genetic and geographical differentiation patterns. E. nutans is a perennial, caespitose and allohexaploid (2n=6x=42) species that contains the St, H and Y genomes. It is native to temperate and tropical Asia, ranging from western and central Asia in the west to China and Mongolia in the east, from Russia in the north to India and the Himalayas areas in the south (Clayton et al. 2006). It is distributed in the north, northwest and southwest China, particularly in the Qinghai-Tibet Plateau. E. nutans is a valuable forage grass in the alpine regions that is resistant to cold, drought and pests, which can be used to improve cereal crops. In addition, it can play an important role in the restoration of disturbed grasslands and the establishment of artificial grasslands, especially at altitudes from 3,000 to 4,500 m (Chen and Jia 2000). During recent decades, its distribution has contracted because of over-exploitation, habitat destruction and fragmentation. Therefore, it is urgent to understand and monitor the genetic and geographical differentiation of wild germplams of E. nutans

SAR-to-Optical Image Translation via Thermodynamics-inspired Network

Synthetic aperture radar (SAR) is prevalent in the remote sensing field but is difficult to interpret in human visual perception. Recently, SAR-to-optical (S2O) image conversion methods have provided a prospective solution for interpretation. However, since there is a huge domain difference between optical and SAR images, they suffer from low image quality and geometric distortion in the produced optical images. Motivated by the analogy between pixels during the S2O image translation and molecules in a heat field, Thermodynamics-inspired Network for SAR-to-Optical Image Translation (S2O-TDN) is proposed in this paper. Specifically, we design a Third-order Finite Difference (TFD) residual structure in light of the TFD equation of thermodynamics, which allows us to efficiently extract inter-domain invariant features and facilitate the learning of the nonlinear translation mapping. In addition, we exploit the first law of thermodynamics (FLT) to devise an FLT-guided branch that promotes the state transition of the feature values from the unstable diffusion state to the stable one, aiming to regularize the feature diffusion and preserve image structures during S2O image translation. S2O-TDN follows an explicit design principle derived from thermodynamic theory and enjoys the advantage of explainability. Experiments on the public SEN1-2 dataset show the advantages of the proposed S2O-TDN over the current methods with more delicate textures and higher quantitative results

Effect of Microstructure on Electromigration-Induced Stress

In this paper, a finite element based simulation approach for predicting the effect of microstructure on the stresses resulting from electromigration-induced diffusion is described. The electromigration and stress-driven diffusion equation is solved coupled to the mechanical equilibrium and elastic constitutive equation, where a diffusional inelastic strain is introduced. Here, the focus is on the steady state, infinite life case, when the current-driven diffusion is balanced by the resulting stress gradient. The effect of the crystal orientation in Sn-based solder joints on the limiting current density for an infinite life is investigated and compared to experimental observations in the literature. The effect of the grain structure for Al interconnect lines on the dominant diffusion path and estimates for the effective charge number for two different diffusion paths in Al interconnects determined by matching simulations to experimental measurements of elastic strain components in the literature are also presented