Preparation and properties of asphalt binders modified by THFS extracted from direct coal liquefaction residue

This paper aims to study the preparation and viscoelastic properties of asphalt binder modified by tetrahydrofuran soluble fraction (THFS) extracted from direct coal liquefaction residue. The modified asphalt binders, which blended with SK-90 (control asphalt binder) and 4%, 6%, 8% and 10% THFS (by weight of SK-90), were fabricated. The preparation process for asphalt binder was optimized in terms of the orthogonal array test strategy and gray correlation analysis results. The properties of asphalt binder were measured by applying Penetration performance grade and Superpave performance grade specifications. In addition, the temperature step and frequency sweep test in Dynamic Shear Rheometer were conducted to predict the rheological behavior, temperature and frequency susceptibility of asphalt binder. The test results suggested the optimal preparation process, such as 150 °C shearing temperature, 45 min shearing time and 4000 rpm shearing rate. Subsequently, the addition of THFS was beneficial in increasing the high-temperature properties but decreased the low-temperature properties and resistance to fatigue. The content analysis of THFS showed the percentage of 4~6% achieved a balance in the high-and-low temperature properties of asphalt binder. The asphalt binder with higher THFS content exhibited higher resistance to rutting and less sensitivity to frequency and temperature

Baiji genomes reveal low genetic variability and new insights into secondary aquatic adaptations

The baiji, or Yangtze River dolphin (Lipotes vexillifer), is a flagship species for the conservation of aquatic animals and ecosystems in the Yangtze River of China; however, this species has now been recognized as functionally extinct. Here we report a high-quality draft genome and three re-sequenced genomes of L. vexillifer using Illumina short-read sequencing technology. Comparative genomic analyses reveal that cetaceans have a slow molecular clock and molecular adaptations to their aquatic lifestyle. We also find a significantly lower number of heterozygous single nucleotide polymorphisms in the baiji compared to all other mammalian genomes reported thus far. A reconstruction of the demographic history of the baiji indicates that a bottleneck occurred near the end of the last deglaciation, a time coinciding with a rapid decrease in temperature and the rise of eustatic sea level

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

Online classroom engagement: A Mixed-Method Exploration of Effective Engagement Strategies of Online Classrooms in the College of Education During COVID-19

Thesis (Master's)--University of Washington, 2023The COVID-19 pandemic has influenced the idea of classroom teaching in many ways, and the notion of online learning becomes more popular as teachers and students both find themselves benefiting from this learning experience. Since 2020, studies about self-efficacy, digital literacy, and online learning curricula development have promoted the quality of online learning. However, the popularity of online learning came with a multitude of issues about recreating “the classroom engagement” between students and instructors, resulting in a general decrease in student learning enthusiasm for attending schools (Elshareif & Mohamed, 2021). In this paper, I aimed to address the problem of forming a more engaging and effective online learning environment in the higher education setting, and I used the online learning experience at the University of Washington (UW) as the reference. I conducted mixed-method research to collect, analyze, and discuss the online learning engagement at UW’s COVID-19 remote instruction through students and faculty’s experiences. Data gathered from a multitude of sources revealed that both students and faculty at UW had positive experiences and attitudes about their online learning engagement during their online instruction, but they also agreed upon needing more robust improvement over the differentiated online engagement strategy in both synchronous and asynchronous environments, supports for students and faculty’s online learning effectiveness, and general increase over the digital literacy. This paper provides an authentic record of online learning during the COVID-19 pandemic for future research. It also urges higher education faculty to embrace the opportunity for improving, establishing, and researching effective online engagement methods in promoting a more inclusive and less intimidating environment that could benefit students in their future online learning endeavors

Cause and prevention of pleural effusion after liver resection

Liver resection is the main method of treatment of hepatic space-occupying lesion, and pleural effusion is one of the common complications. With the technological development in recent years, this paper analyzes the pleural effusion after liver resection from the aspects of hypoproteinemia, diaphragm defects, inflammatory response, portopulmonary shunt, and hepatitis B immune complex deposition, summarizes the causes of pleural effusion after liver resection and its preventive measures, and explores the effective ways to reduce the incidence of pleural effusion after liver resection, with the purpose of providing guidance for future clinical practice

mRMR-Tri-ConcaveHull Detector for Floating Small Targets in Sea Clutter

For the feature-based detector of small targets in sea clutter, on the one hand, the three-dimensional convex hull-based detector deviates from the distribution of sea clutter vectors in the feature space and only combines the information of low-dimensional features. On the other hand, the redundancy and correlation between high-dimensional features are high. Consequently, we propose a detector for detecting small floating targets in sea clutter in high-dimensional feature space (HDFS) in this article. First, the maximum relevance-minimum redundancy (mRMR) algorithm to choose the low-relatedness features from the HDFS is proposed. For the mRMR algorithm, we choose the target features and sea clutter features from the eight-dimensional feature space (8-DFS), where the target features and sea clutter features have the highest degree of discrimination in the 3-DFS. Second, the distribution of sea clutter in the 3-DFS is concave or convex, which depends on the selection of features. In most cases, the distribution is concave. Using the traditional convex hull to match the concave distribution of sea clutter inevitably enlarges the judgment area and considerably decreases the detection probability. Due to the concave distribution of sea clutter in the 3-DFS, we propose a new false alarm controllable three-dimensional concave hull detector based on the mRMR (mRMR-Tri-ConcaveHull detector). In the mRMR-Tri-ConcaveHull detector, the feature vectors in the 3-DFS, which are selected by mRMR, form a concave area that is more suitable for the Concave Hull detector. Through the experimental analysis of the measured data, we find that the proposed mRMR-Tri-ConcaveHull in this article can significantly enhance the detection performance compared with the three-feature convex hull detector

An efficient layer node attack strategy to dismantle large multiplex networks

Network dismantling aims to identify the minimum set of nodes whose removal breaks the network into components of sub-extensive size. The solution to this problem is significant for designing optimal strategies for immunization policies, information spreading, and network attack. Modern systems, such as social networks and critical infrastructure networks, which consist of nodes connected by links of multiple types can be encapsulated into the framework of multiplex networks. Here we focus on the dismantling problem in multiplex networks under layer node-based attack, and propose an efficient dismantling algorithm based on network decycling. Experiments on synthetic and real-world networks show that the proposed algorithm outperforms existing algorithms by a considerable margin. We also show how the robustness of a multiplex network is affected by the interlayer degree correlation. Our results shed light on the design of more resilient network systems and the effective destruction of harmful networks

Design of the Nonlinear Pin Rubber Forming Equipment Integrating the Functions of Extruding, Dewatering, Drying & Expanding

The top priority of car-tire suppliers is to improve wetland grip force of the using tires, reduce the rolling resistance and the rolling noise of tires. It is urgent for the tire industry to research and develop high-performance tires to solve the above problems. They must use the high- performance synthetic rubber and auxiliary rubber to develop the most advanced manufacturing technologies and equipment. Silica, a kind of important tire auxiliary rubber, can significantly reduce the rolling resistance of tires, improve the grip force and properties resistant to ice, wetness or slippery of tires. In this paper, based on the conventional tire rubber forming technologies of extrusion, dewatering, drying and expanding, a study is made on the conical screw, the dewatering barrel, the drying barrel, the pin layout scheme, the expanding die head, cutter and the control system. The nonlinear pin rubber forming equipment integrating the functions of extrusion, dewatering, drying and expanding is designed and applied to tire auxiliary rubber forming. The experiment shows that the forming device can realize the one-step forming, with high forming efficiency, low cost and less labor