Detecting One-Hundred-Year Environmental Changes in Western China Using Seven-Year Repeat Photography

Due to its diverse, wondrous plants and unique topography, Western China has drawn great attention from explorers and naturalists from the Western World. Among them, Ernest Henry Wilson (1876 –1930), known as ‘Chinese’ Wilson, travelled to Western China five times from 1899 to 1918. He took more than 1,000 photos during his travels. These valuable photos illustrated the natural and social environment of Western China a century ago. Since 1997, we had collected E.H. Wilson's old pictures, and then since 2004, along the expedition route of E.H. Wilson, we took 7 years to repeat photographing 250 of these old pictures. Comparing Wilson's photos with ours, we found an obvious warming trend over the 100 years, not only in specific areas but throughout the entire Western China. Such warming trend manifested in phenology changes, community shifts and melting snow in alpine mountains. In this study, we also noted remarkable vegetation changes. Out of 62 picture pairs were related to vegetation change, 39 indicated vegetation has changed to the better condition, 17 for degraded vegetation and six for no obvious change. Also in these photos at a century interval, we found not only rapid urbanization in Western China, but also the disappearance of traditional cultures. Through such comparisons, we should not only be amazed about the significant environmental changes through time in Western China, but also consider its implications for protecting environment while meeting the economic development beyond such changes

An Attractor-Guided Neural Networks for Skeleton-Based Human Motion Prediction

Joint relation modeling is a curial component in human motion prediction. Most existing methods tend to design skeletal-based graphs to build the relations among joints, where local interactions between joint pairs are well learned. However, the global coordination of all joints, which reflects human motion's balance property, is usually weakened because it is learned from part to whole progressively and asynchronously. Thus, the final predicted motions are sometimes unnatural. To tackle this issue, we learn a medium, called balance attractor (BA), from the spatiotemporal features of motion to characterize the global motion features, which is subsequently used to build new joint relations. Through the BA, all joints are related synchronously, and thus the global coordination of all joints can be better learned. Based on the BA, we propose our framework, referred to Attractor-Guided Neural Network, mainly including Attractor-Based Joint Relation Extractor (AJRE) and Multi-timescale Dynamics Extractor (MTDE). The AJRE mainly includes Global Coordination Extractor (GCE) and Local Interaction Extractor (LIE). The former presents the global coordination of all joints, and the latter encodes local interactions between joint pairs. The MTDE is designed to extract dynamic information from raw position information for effective prediction. Extensive experiments show that the proposed framework outperforms state-of-the-art methods in both short and long-term predictions in H3.6M, CMU-Mocap, and 3DPW

Cracking mechanism analysis and experimental verification of encapsulated module under high low temperature cycle considering residual stress

Aiming at the cracking failure of the modified epoxy resin encapsulated module as a result of interface failure under high low temperature cycles, numerical simulation and experimental studies were carried out. Firstly, the residual stress field in the encapsulated module was reconstructed after measuring the curing residual stresses in epoxy resin using the hole-drilling method. Temperature-dependent material models were developed after testing the mechanical and thermal characteristic parameters of encapsulated module components, such as modified epoxy resin, in high and low temperature conditions. Then, a finite element model of a high-reduction encapsulated module with multiple components, multiple interfaces, and complicated contacts was established considering residual stress and temperature effects. To simulate the failure behaviour of the resin-embedded part interfaces, the cohesive zone model was utilized. Finally, the stress and strain of the encapsulated module under high and low temperature cycles were simulated, and their distribution features and cracking failure mechanism were analyzed. The results indicate that regardless of the heating/cooling process, significant due to a mismatch in thermal expansion coefficients between the resin and the embedded parts. As the temperature approaches the glass transition temperature Tg, the difference grows dramatically. The resulting thermal stress, together with the residual stress, led to the interface failure in encapsulated module. The numerical results were in good agreement with the high and low temperature cycle test results of the encapsulated module, which verified the effectiveness of the analysis method and the established finite element model. The investigation provides an important reference for the high-reliability design of the encapsulation module

Characterization of the complete mitochondrial genome of Chrysochir aureus and phylogenetic studies of Sciaenidae

The complete mitochondrial genome of Chrysochir aureus was sequenced. The full length of the mitochondrial genome was 16,501 bp, including 13 protein-coding genes (PCGs), two ribosomal RNAs, 22 transfer RNA genes, a non-coding control region (CR) and one origin of replication on the light-strand (OL). The total nucleotide composition of mitochondrial DNA was 26.95% A, 29.99% C, 26.29% T, and 16.77% G. Twelve PCGs used the canonical ATG as their initiation codon, whereas COI gene started with an alternative start codon GTG. The mitochondrial genome of C. aureus described in this study could be a useful basis for management of this species and laid a foundation for further research involved with phylogenetic relationship within Sciaenidae

Widely tunable and monochromatic terahertz difference frequency generation with organic crystal DSTMS

Widely tunable and monochromatic terahertz (THz) difference frequency generation with organic crystal DSTMS was investigated experimentally. A double-pass KTiOPO4 optical parametric oscillator, pumped by a frequency-doubled Nd:YAG laser, was employed as the source of 1.3-1.6 µm dual wavelength. The THz tuning spectrum covered a range of 0.88−19.27 THz. The dependence of the THz output on the crystal thickness and pump wavelength was studied. The results were well explained based on theoretical calculations. With a pump energy of 2.47 mJ, the output energy reached 85.3 nJ/pulse at 3.80 THz, which corresponded to a peak power of 17.9 W and photon conversion efficiency of 3.6‰

Copper-Catalyzed Direct Oxidative C–H Functionalization of Unactivated Cycloalkanes into Cycloalkyl Benzo[<i>b</i>]phosphole Oxides

The first simple and efficient Cu-catalyzed radical addition/cyclization of various unactivated cycloalkanes with diaryl­(arylethynyl)-phosphine oxides has been developed, providing a general, one-step approach to construct a new class of important benzo­[<i>b</i>]­phosphole oxides via sequential C–H functionalization along with two new C–C bond formations

Characterization of the complete mitochondrial genome of Hyphessobrycon herbertaxelrodi (Characiformes, Characidae) and phylogenetic studies of Characiformes

In this study, the complete mitochondrial genome of Hyphessobrycon herbertaxelrodi is presented, and we also discussed its mitochondrial characteristics. The full length of the mitochondrial genome was 17,417 bp, including 13 protein coding genes (PCGs), 2 ribosomal RNAs (12S and 16S), 22 transfer RNA genes, 1 non-coding control region (D-loop), and 1 origin of replication on the light-strand. The total nucleotide composition of mitochondrial DNA was 29.76%A, 29.88%T, 25.35%C, 15.01%G, and AT was 59.64%. The phylogenetic tree suggested that H. herbertaxelrodi shared the most recent common ancestor with Astyanax giton, Grundulus bogotensis, Astyanax paranae, and Oligosarcus argenteus