Exploration of engine characteristics in a CRDI diesel engine enriched with hydrogen in dual fuel mode using toroidal combustion chamber

The impact of dual fuel (diesel/hydrogen) on different performance aspects of CRDI diesel engines is investigated in this study. Amongst the fuel alternatives for IC (internal combustion) engines, the research described in this study recommended hydrogen as the least polluting and renewable in the long term. A CNG-LPG injector feeds hydrogen into the intake manifold, while diesel injectors pump pilot diesel to a DI engine adapted to hydrogen and diesel (dual-fuel mode). By maintaining 5.2 KW of consistent IP (Indicated Power) and engine speed at 1500 ± 10 rotations per minute (RPM), the hydrogen energy was varied in the dual fuel at 0% (100% diesel), 6%, 12%, 18% and 24%. With the increase in H₂ energy proportion, a decrease (5.2% decrease at 24% HES) in the BSEC (brake specific energy consumption) and the engine's BTE (brake thermal efficiency) is improved (7.85% increase at 24% HES). When emissions are considered, indicated NO_x increased (3.42%) while indicated CO₂ (3.61%), CO (2.84%), and smoke (4.85%) decreased with an increase in the proportion of hydrogen. Along with this, it was noted that the peak HRR (heat release rate) of 69.8 J/deg and in-cylinder pressure of 80.8 bar which increased significantly with the increase in hydrogen rate.     

Comparative analysis on similarities and differences of hydrogen energy development in the World's top 4 largest economies: A novel framework

A low-carbon energy transition is permeating many industrialized countries due to the overuse of fossil fuels and the climate change. Some countries stress the hydrogen energy in optimizing their energy structures. This article examines both the markets and the policies of the hydrogen industry in the World's Top 4 largest economies. To make the comparative analysis more logical, a novel conceptual model for energy transition -- the institution-economics-technology-behavior framework -- has been adopted to make a multi-dimensional discussion. The results show that: (1) From the perspective of strategic intention, developing hydrogen energy is conductive to the energy transition. (2) From the horizontal comparison, each country has its own advantages, however, the main driving factors are different. (3) From the vertical comparison, the hydrogen energy development in each country is still in the stage of quantitative change, and the inflection point of qualitative change has not been reached yet.     

Neural Emotion Detection via Personal Attributes

There has been a recent line of work to automatically detect the emotions of posts in social media. In literature, studies treat posts independently and detect their emotions separately. Different from previous studies, we explore the dependence among relevant posts via authors' backgrounds, since the authors with similar backgrounds, e.g., "gender", "location", tend to express similar emotions. However, personal attributes are not easy to obtain in most social media websites. Accordingly, we propose two approaches to determine personal attributes and capture personal attributes between different posts for emotion detection: the Joint Model with Personal Attention Mechanism (JPA) model is used to detect emotion and personal attributes jointly, and capture the attributes-aware words to connect similar people; the Neural Personal Discrimination (NPD) model is employed to determine the personal attributes from posts and connect the relevant posts with similar attributes for emotion detection. Experimental results show the usefulness of personal attributes in emotion detection, and the effectiveness of the proposed JPA and NPD approaches in capturing personal attributes over the state-of-the-art statistic and neural models.     

基于微生物灭活芽孢的矿冶粉尘清洁皂的制备及性能研究

矿冶粉尘给一线工人皮肤健康带来严重威胁。通过添加微生物灭活芽孢于清洁皂中,研究了不同芽孢添加量对清洁皂去污能力的影响,对比了硅藻土、活性炭和芽孢添加皂在粉尘去污和重金属去除方面的异同,并通过感官评价测试了三种皂在皮肤清洁方面的效果。结果表明,添加硅藻土可以达到80%的粉尘去除率。而活性炭尽管比表面积高,但微粒细小同样易于吸附于手掌纹理中,造成二次污染,故去除率最低。在基础皂中添加1%(w/w)灭活芽孢对粉尘污染的去污率达到了95%,二次洗涤可将重金属去除率从90%提高到95%以上。感官评价中,黑色活性炭的吸附作用造成了清洗后的手掌依然不够干净,观感最差;硅藻土皂的清洁效果接近日常家用皂,观感居中;而芽孢皂的清洁效果最明显,观感最佳。     

Preparation and investigation of pulse co-deposited duplex nanoparticles reinforced Ni-Mo coatings under different electrodeposition parameters

In this work, Ni–Mo–SiC–TiN nanocomposite coatings were deposited on aluminium alloy by pulse electrodeposition with various electrodeposition parameters. The influences of the pulse frequency and duty cycle on the phase structure, morphology, mechanical and corrosion performance of the coatings were systematically investigated. The results showed that with increasing pulse frequency and decreasing duty cycle, the content of embedded duplex nanoparticles increased, and the grains refined gradually. The nanocomposite coating that was prepared at 20% duty cycle and 1000 Hz pulse frequency exhibited compact, uniform, and fine microstructures with the maximum incorporation of nanoparticles (6.81 wt% TiN and 1.72 wt% SiC). The wear rate and average friction coefficient then declined to 4.812 × 10^?4 mm³/N·m and 0.13, respectively, with a maximum microhardness of 519 HV. Simultaneously, the corrosion current density was reduced to 3.11 μA/cm², and a maximum impedance of 34888 Ω cm² was exhibited. The uniformly distributed duplex nanoparticles acted as a hindrance, which consequently supported the enhancement of corrosion and wear resistance. By investigating the variation of the pulse diffusion layer with electrical parameters, it was discovered that when the crystallite size is equivalent to or smaller than the diffusion layer thickness, it would be easier to cross the diffusion layer to incorporate in the coating. Additionally, the effects of various duty cycles and pulse frequencies on the nucleation process of the grains were discussed.     

Realizing enhanced thermoelectric properties in Cu2GeSe3 via a synergistic effect of In and Ag dual-doping

In this work, we propose a modulation doping strategy for simultaneous achievement of low lattice thermal conductivity and high Seebeck coefficient in the Cu₂GeSe₃ compound. The Ag and In dual-doping can optimize the hole carrier concentration to balance electrical conductivity and Seebeck coefficient, achieving a high power factor of ～6.4 μW cm^?1 K^?2 for the Cu₂GeSe₃ compound. The Ag point defect makes a great contribution to blocking the propagation of phonons besides the phonon-phonon Umklapp process, yielding a minimum lattice thermal conductivity of ～0.38 W m^–1 K^–1. Remarkably, a maximum ZT value of ～0.97 at 723 K is achieved for Cu_1.8Ag_0.2Ge_0.95In_0.05Se₃ compound, which is the highest value for the Cu₂GeSe₃-based systems in the temperature range of 323–723 K.     

“方变圆”变径筒状结构滑模施工技术

为解决塔式光热的核心构筑物吸热塔"方变圆"变径超高筒体结构施工难题,选用一套可变形的滑模平台系统,通过操作系统上可调千斤顶支座、门架横向液压千斤顶装置、多处可调节模板角度和收缩模板的丝杆等,使得滑模根据施工需求可在一定的范围内调节模板倾角、间距,并逐步完成收缩变形,其理论滑模允许偏角20°,最终高效完成异形结构施工。该滑模系统刚度大、承载及堆料能力强、空间大、机械化程度高,施工操作简单,安全性高,适应沙漠极端环境。全过程仅需使用一套滑模体系,就能完成方形段、方变圆的变形段及圆形段施工,大大提高了施工效率,为类似环境下相似结构的施工提供了一定的参考。     

Development of an injury prevention model for playing-related musculoskeletal disorders in orchestra musicians based on predisposing risk factors

IntroductionPlaying an instrument could lead to various disorders and several musicians report problems during their career. As there is no existing one, the aim of this study was to build a comprehensive model of injury prevention and risk factors in musicians by combining literature with interviews of musicians and experts.MethodsThe initial model has been based on literature. This model identified nine categories of risk factors. Then, interviews were conducted with 15 Royal Liverpool Philharmonic Orchestra musicians and 9 experts in musicians’ health to develop the final version.ResultsEighty percent of the RLPO instrumentalists experienced at least once PRMDs in their career. Postural and workload issues were mentioned most frequently. Experts agreed broadly with the initial model and added interesting items that should be taken into account in assessing musicians’ health.DiscussionThis theoretical framework provides perspectives in terms of assessment, treatment and prevention in musicians, whether they are currently suffering from PRMDs or not.