Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Development of Underwater Wireless Communication Equipment Technology

Underwater wireless communication (UWC) equipment facilitates information transmission and data exchange in underwater environments, playing vital roles in marine scientific research, underwater network monitoring, underwater collaborative operation, and marine safety maintenance. This study explores four primary UWC equipment categories: underwater acoustic communication, underwater optical communication, underwater electromagnetic communication, and underwater magnetic induction communication. It conducts in-depth analyses of the technical challenges associated with each category, comprehensively reviews their development status in China and abroad, and forecasts future trends. Focusing on the UWC industry of China, we summarize the development challenges in terms of overarching gaps, common issues, and top-level system, and propose the following development suggestions: (1) improving fundamental mechanisms and addressing common issues, (2) prioritizing breakthroughs in industry core areas, (3) elucidating the top-level system structure of the UWC equipment, and (4) enhancing safeguard measures and support policies. This study is expected to provide references for understanding the developmental trend and promoting the research and application of the UWC equipment

Buckling Behavior of Stainless Wave-Shaped Pressure Hulls

This study primarily focuses on the buckling behavior of wave-shaped pressure hulls subjected to uniform external pressure. The effect of slant angle on the buckling behavior of hulls was examined. The tested slant angles ranged from 0° to 30° and were increased at 1° increments. The buckling of smooth cylindrical pressure hulls and wave-shaped pressure hulls was investigated using numerical methods. A wave-shaped pressure hull was produced for experimental verification. The nonlinear numerical results aligned with the collected experimental data. The buckling load of the tested wave-shaped pressure hull was approximately 1.87 times that of the equivalent cylindrical pressure hull. Furthermore, a formula was developed to estimate the load-bearing capacity of the wave-shaped pressure hull. This formula, which has been experimentally validated, comprises a correction coefficient (obtained through numerical evaluation and regression analysis) and a classic semi-analytical formula for cylindrical pressure hulls

Vision-Based Target Detection and Positioning Approach for Underwater Robots

The accurate target detection under different environmental conditions and the real-time target positioning are vital for the successful accomplishment of underwater missions of Remotely operated vehicles (ROVs). In this paper, we propose a vision-based underwater target detection and positioning approach to detect and estimate the position and attitude of artificial underwater targets. The proposed approach is composed of an underwater target detection algorithm YOLO-T and a target positioning algorithm. Firstly, we modify the structure of YOLOv5 algorithm using Ghost module and SE attention module to improve the calculation time of target detection. Secondly, a series of image processing operations are performed on the improved YOLOv5 detection results to increase the detection accuracy. Thirdly, a cooperative marker is designed as the artificial underwater target, and the corresponding positioning algorithm is presented to calculated the position and attitude of the target according to the geometric information of the designed marker. We validate our approach through experimental tests respectively in a water tank, an anechoic tank, and the sea trial in Huanghai Sea in China. The results demonstrate the accurate performance of the proposed detection and positioning method

Development Strategy of Deep-Sea Exploration and Residence Equipment

Deep-sea exploration and residence equipment is an important basis for the development of marine science. In recent years, China’s independent research and development of related equipment has made good progress; however, some technical problems still exist in the process of localization. It is urgent to overcome these problems and promote China’s capabilities for constructing a “transparent ocean”. This study analyzes the development demand for deep-sea exploration and residence equipment and summarizes the development status and problems of the equipment by focusing on six key areas: general equipment for deepsea perception and detection; general platforms for deep-sea carrier detection; deep-sea multi-functional operation platforms; deepsea communication, navigation, and positioning equipment; general tools for deep-sea operation; and intelligent control systems for deep-sea manned and unmanned equipment. Moreover, the study proposes the key development direction of the deep-sea exploration and residence equipment in China, covering nine key technologies: exploration equipment energy supply, design and optimization of equipment systems, power systems with a high power density, in-situ experimental research and development, livability and emergency rescue of manned equipment, underwater dynamic networked positioning, underwater acoustic–optical multi-mode hybrid communication networks, human–machine hybrid decision-making and collaborative control, and evaluation and optimization of human–computer interaction effectiveness. On this basis, it is necessary to accelerate the construction of key marine areas while adhering to scientific development, promote infrastructure co-construction and information sharing through overall planning and intensive development, and encourage the innovation-driven and sustainable development of new technologies and equipment, thus to promote the high-quality development of the deep-sea exploration and residence equipment in China

Internal Hydroforming of Large Stainless-Steel Eggshells from Stepped Preforms

The internal hydroforming of large stainless-steel eggshells from a stepped preform is investigated in this paper. The nominal major and minor axes of the eggshell were 1537 and 1070 mm, respectively. The stepped preform was fabricated from thin-walled (1.9 mm thick) stainless-steel sheets and comprised twelve conical segments inscribed inside the target eggshell. The preform was then hydroformed, and its wall thickness and shape were measured. The yield load distribution and material hardening of the hydroforming process were investigated analytically. Nonlinear finite-element analyses were employed to further investigate hydroforming behaviors and the effect of weld lines on hydroforming. The experimental, numerical, and analytical results were consistent. The results confirm that, during the hydroforming process, considerable springback occurs for large eggshells, which greatly affects forming precision. However, this effect can be reduced by accounting for the strengthening effect of weld lines