HALT技术在变频器中的应用初探

HALT技术可在产品设计阶段快速消除设计缺陷,缩短研发时间和成本,迅速提高产品的质量和固有可靠性。本文从HALT试验的背景出发,介绍了HALT试验的基本原理和意义。在对HALT箱各方面性能验证的基础上,针对我司11kW变频器,详细讲述了HALT试验的具体操作过程。     

低密度、高强度DG型高变催化剂的研制

本文叙述了一种适合大型氨厂使用的、堆密度低到1.25 kg·L^-1、还原态侧压强度高达350 N·cm^-1以上、本体含硫＜500 ppm(wt)、低温活性好的高温变换催化剂的研制开发过程 还介绍了催化剂制备工艺特点和工业试用效果。     

低压长袋脉冲袋式除尘器设计与应用

以工业原料尤里卡沥青(EP)为对象，详细论述了低压长袋脉冲袋式除尘器的主要设计环节，着重分析了新型脉冲阀技术。指出了该技术在化肥行业原料干燥、风扫制备等方面的推广应用和发展趋势。     

双曲线冷却塔风筒几何缺陷分析

由于施工放样原因,双曲线冷却塔风筒发生移位变形,筒壁出现初始几何缺陷,偏差超出规范允许值,造成冷却塔应力状态改变.利用冷却塔专用计算软件对冷却塔结构进行静力计算,根据计算的内力对强度进行验算,分析初始几何缺陷对冷却塔应力状态的影响,评价冷却塔结构安全性及是否需要进行加固处理,并对冷却塔后期维护提出建议.     

Modeling deterministic echo state network with loop reservoir

Echo state network (ESN),which efficiently models nonlinear dynamic systems,has been proposed as a special form of recurrent neural network.However,most of the proposed ESNs consist of complex reservoi...     

基于增广矩阵束方法的平面天线阵列综合

针对平面阵列的稀布优化问题,提出了一种基于增广矩阵束方法的减少阵元数目、求解阵元位置和设计幅度激励的优化方法。首先对期望平面阵的方向图进行采样并由采样点数据构造增广矩阵,对此矩阵进行奇异值(SVD)分解,确定在误差允许范围内所需的最小阵元数目;然后基于广义特征值分解分别计算两组特征值,并根据类ESPRIT算法对特征值进行配对;最后在最小二乘准则条件下根据正确的特征值对求解平面阵列的阵元位置和激励。仿真结果表明该算法具有较高的计算效率和数值精度。     

Physiological responses to simulated firefighter exercise protocols in varying environments

For decades, research to quantify the effects of firefighting activities and personal protective equipment on physiology and biomechanics has been conducted in a variety of testing environments. It is unknown if these different environments provide similar information and comparable responses. A novel Firefighting Activities Station, which simulates four common fireground tasks, is presented for use with an environmental chamber in a controlled laboratory setting. Nineteen firefighters completed three different exercise protocols following common research practices. Simulated firefighting activities conducted in an environmental chamber or live-fire structures elicited similar physiological responses (max heart rate: 190.1 vs 188.0 bpm, core temperature response: 0.047°C/min vs 0.043°C/min) and accelerometry counts. However, the response to a treadmill protocol commonly used in laboratory settings resulted in significantly lower heart rate (178.4 vs 188.0 bpm), core temperature response (0.037°C/min vs 0.043°C/min) and physical activity counts compared with firefighting activities in the burn building.

Practitioner Summary: We introduce a new approach for simulating realistic firefighting activities in a controlled laboratory environment for ergonomics assessment of fire service equipment and personnel. Physiological responses to this proposed protocol more closely replicate those from live-fire activities than a traditional treadmill protocol and are simple to replicate and standardise.     

凝析气藏相态参数实验研究

油气藏流体主要有烃类成分组成,在油藏及地面条件下,这种烃类混合物的物理性质取决于其化学成分及给定的温度和压力。对于烃类的相态特征及流体组分研究在油气田开发中具有重要的意义,尤其是凝析气藏田。对海榆和10井的研究,归纳总结其流体PVT性质,为其开发提供科学依据。     

A method for observing the three-dimensional morphologies of inclusions in steel

A method for observing the three-dimensional morphologies of inclusions by deeply eroding a steel sample with a kind of organic solution composed of bromine water,acetone,and HC1 (volume ratio,45∶45∶10...     

Effects of road surface appearance and low friction warning systems on driver behaviour and confidence in the warning system

Warning systems for slippery road conditions are a potential newcomer among driver support systems. A total of 75 participants drove in a high-fidelity driving simulator on roads with both visible and invisible ice, to investigate to which extent drivers rely on a low friction warning system. Three experimental groups with different versions of a low friction warning system and a control group without warning system were compared. All drivers ranked the systems according to trust. A system displaying recommended speed received the best ratings. Driving speed was analysed for three particular segments of the route. Generally, lowest speeds were achieved with the recommended speed system. The participants drove more slowly on a slippery segment that looked icy than on the segments that looked dry when they did not receive a low friction warning. When they received a warning for low friction they also lowered their speed for the segment looking like asphalt. The results provide guidelines for how to present low friction warnings to drivers. The design has substantial effects on the resulting behaviour and therefore it can have a high impact on traffic safety. So far, not much research on low friction warning systems has been reported.