一种新型摩托车耐久试验台的研制

介绍了摩托车耐久试验系统的硬件、软件实现方法，并阐述了用改进的PID算法控制摩托车车速的过程。     

700℃等级超超临界汽轮机用材探讨

综合国内外先进超超临界汽轮机材料方面的研究资料,给出我国700℃等级汽轮机用候选材料及材料技术的研发重点。     

日本桥规中的抗震性能

桥梁抗震设计首先需要设定抗震设防标准。抗震性能就是抗震设计中由设防标准决定的在地震时和地震后需要达到的结构性能和目标。文章系统介绍日本桥规中有关桥梁抗震性能的定义、抗震性能标准以及在不同抗震性能标准时对桥梁桥墩、桩基、上部结构等构件的极限状态设定。介绍检验抗震性能指标的工程评估指标和抗震设计方法。     

干式空心电抗器的安全运行及检修

干式空心电抗器作为电力系统中的关键元件,其安全运行对输电可靠性至关重要。本文介绍了干式空心电抗器的结构特点及绝缘材料的耐热特性,分析了影响电抗器使用寿命的材料因素和结构因素,热负荷和机械负荷对电抗器结构及绝缘配合的影响。介绍了国家标准对不同电抗器的温升限值的规定,介绍了制造电抗器的工艺方法及设计方案对空心电抗器的安全运行的影响,并提出了保障电抗器安全所需的运行检修和日常维护建议。     

Development of a friction energy capacity approach to predict the surface coating endurance under complex oscillating sliding conditions

In the case of surface coatings application it is crucial to establish when the substrate is reached to prevent catastrophic consequences. In this study, a model based on local dissipated energy is developed and related to the friction process. Indeed, the friction dissipated energy is a unique parameter that takes into account the major loading variables which are the pressure, sliding distance and the friction coefficient. To illustrate the approach a sphere/plane (Alumina/TiC) contact is studied under gross slip fretting regime. Considering the contact area extension, the wear depth evolution can be predicted from the cumulated dissipated energy density. Nevertheless, some difference is observed between the predicted and detected surface coating endurance. This has been explained by a coating spalling phenomenon observed below a critical residual coating thickness. Introducing an effective wear coating parameter, the coating endurance is better quantified and finally an effective energy density threshold, associated to a friction energy capacity approach, is introduced to rationalize the coating endurance prediction. The surface treatment lifetime is then simply deduced from an energy ratio between this specific energy capacity and a mean energy density dissipated per fretting cycle. The stability of this approach has been validated under constant and variable sliding conditions and illustrated through an Energy Density–Coating Endurance chart.     

Subject‐specific hand grip fatigability indicator determined using parameter identification technique

During hand grip operations, the fatigability of the local muscle determines the antifatigue capacity and influences the risk of injury of the workers. This study proposes a new hand grip subject‐specific fatigability indicator using a parameter identification technique from a physiologically based muscle fatigue model. Experimental measurements were conducted in a laboratorial fatiguing operation with a fixed external load (5 kg) under a static posture. Sixty participants (30 males and 30 females) participated in the experiment. Subject‐specific hand muscle fatigue rates (k) were identified by performing regressions of the muscle strength during time intervals using the muscle fatigue model. The majority (46/60) of the goodness of fit statistics (R²) was over 0.70, which indicates the validity of using the fatigue rate (k) as a hand grip fatigability indicator. Individual differences in the hand grip fatigue rate (k) were substantial, ranging from 0.14 to 2.57 min^?1 with a coefficient of variation of 59.0%. The gender effect and body mass index did not exhibit significant influences on the hand grip muscle fatigue rates (k).     

High Performance β-Ga2O3 Schottky Barrier Transistors with Large Work Function TMD Gate of NbS2 and TaS2

Gallium trioxide, β-Ga₂O₃, has been recently studied due to its promising semiconducting properties as active material in transistors or Schottky diodes. Transistors with β-Ga₂O₃ channels are mostly metal oxide field effect transistors (MOSFET), and they show very negative threshold voltages (V_th) in general. Metal semiconductor field effect transistors (MESFETs) with top gate are also reported with less negative V_th. Still, β-Ga₂O₃ MESFETs are only a few. Here, bottom gate architecture β-Ga₂O₃ MESFETs using transition metal dichalcogenide (TMD) NbS₂ and TaS₂ are reported. Due to the large work functions of those metallic TMDs, the MESFETs display minimum subthreshold swing of 61 mV dec⁻¹, small V_th of −1.2 V, minimum OFF I_D of ≈100 fA, and maximum ON/OFF current ratio of ≈10⁸. Both β-Ga₂O₃ Schottky diodes with TaS₂ and NbS₂ display good junction stability even after 300 °C measurements in 10 mTorr vacuum. When the β-Ga₂O₃ MESFET with TaS₂ gate is integrated as a switching FET into an organic light emitting diode (OLED) circuit, it demonstrates long-term leakage endurance performance, maintaining an OLED brightness higher than 58% of the initial intensity after 100 s passes since the ON-switching point, which is even superior to the performance of conventional a-IGZO MOSFET switch.     

Combination of bifunctional aldehydes and poly(vinyl alcohol) as the crosslinking systems to improve paper wet strength

Two bifunctional aldehydes (i.e., glyoxal and glutaraldehyde) are used as the crosslinking agents to improve paper wet strength in the presence of fully hydrolyzed poly(vinyl alcohol) (PVA) as a co‐reactant. These bifunctional aldehydes alone improve paper wet strength but diminish its folding endurance. The use of PVA as a co‐reactant not only improves paper wet strength but also increases its dry strength and folding endurance. Glutaraldehyde is able to impart much higher levels of wet strength to the treated paper than glyoxal when a catalyst is present. The wet strength of the treated paper increases as the amount of PVA added is increased, and it also increases as the molecular weight (M_w) of the PVA increases. The data suggest that the reaction between glutaraldehyde and PVA promotes the formation of interfiber crosslinking, thus improving the wet strength without diminishing the flexibility of the treated paper. The use of a catalyst is critical to achieve high levels of durable wet strength of the treated paper. We studied the effects of different Lewis acids as the catalysts for crosslinking of pulp cellulose by glutaraldehyde and found that Zn(NO₃)₂ is the most effective one. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1673–1680, 2004     

Predicting protected steel member fire endurance using spread-sheet programs

The simple method of computing the time-temperature response of protected steel members that has been recommended by the European Convention for Constructional Steelwork (ECCS) is presented in this paper. The method is a one-dimensional heat flow approach that explicitly accounts for the thickness and thermal properties of the insulation as well as the area and perimeter of the steel section.Two different cases are recognized. In the simpler, the heat required to increase the temperature of the insulation is small and can be ignored. This will be the case for sprayed mineral fiber fire protection. In other cases, a large amount of heat is absorbed by the insulation and it must explicitly be taken into account. This will be true for gypsum plaster, concrete, or masonry fire protection.A time-step approach is used, in which thermal equilibrium is considered during each of several short time intervals. This leads to repetitive calculations in a format ideally suited to use in a spreadsheet program in a microcomputer. The time-temperature course of the fire is explicitly taken into account, and the fire may follow the ASTM E-119 curve or any other curve.Three examples are presented, and comparisons of measured and computed fire endurances are made, with reasonably good agreement found.     

AAA住宅小区深圳振业城的建筑设计

对振业城的概况进行了介绍,以适用性能、环境性能、经济性能、安全性能、耐久性能几个方面详细地介绍了AAA住宅小区深圳振业城的建筑设计,可供建筑设计人员参考借鉴。