基于人机工程学的头戴式耳机舒适性设计

目的 为了有效提升头戴式耳机的舒适性,提高用户使用头戴式耳机产品的满意度,保证头戴式耳机设计的合理性。方法 面向头戴式耳机设计对象,系统分析耳机用户头部关键尺寸和头部受力情况,测量耳机夹紧力范围及耳机质量,研究影响头戴式耳机舒适性的各设计要素。 结论 以人机工程学原理和方法为依据,探讨了耳机关键设计要素对用户佩戴舒适性的影响,提出了基于人机工程学的头戴式耳机设计原则,为耳机设计的功能尺寸、结构形式以及材料选择提供了相应的理论和实践依据,为耳机的人机工程学设计提供有效建议。     

头戴助视仪

头戴助视仪产品主要针对高度弱势群体推出,头戴式产品设计的最大挑战在于人机工程设计。头戴助视仪产品主要针对高度弱势群体推出,通过一体化设计手法,塑造产品简洁独特的形态特征,舒适的人机工程设计是本产品设计的最大挑战。通过多次的人机数据模拟,手板打样,不断调整人机配合度,得到最舒适的头戴效果。     

基于暖体假人的汽车空调热舒适性评价

目的 汽车空调是车内环境热舒适性营造的主要部件,探讨空调运行策略分析人体的主观感受.方法 基于暖体假人对车内非均匀环境热舒适性进行研究,汽车在环境实验室实际运行的情况下,通过暖体假人测试了某个制冷工况下车内副驾驶座位的假人局部和全身的等效空间温度,在相同运行工况下又通过被试者主观体验测试了局部和全身的热感觉及舒适性,并...     

AKG新品USB供电降噪耳机

全球四大耳机生产商之一奥地利AKG公司最新推出两款头戴式耳机，全称分别为K490NC和K495NC，均延续了AKG自适应头戴耳机使用方便、佩戴舒适的特点，同时做工非常精美，以沉稳的黑色为主色调，高贵而典雅，简洁而统一。     

儿童乘坐安全座椅压力—舒适性探究

目的 探究儿童在乘坐安全座椅时背部与臀部接触区域的舒适性差异,得出背部和臀部的压力舒适区域,为今后的设计提供一定理论基础.方法 招募8名4～8岁的健康儿童作为被试,让被试先后坐在三款儿童安全座椅上,提取压力数据并做舒适性主观测试;计算标准差检验座椅的稳定性,进行配对样本t检验比较座椅间的差异性;绘制压力—舒适性图像验证舒适与不适的区域.结果 在"瞬时"压力测试中C座椅界面压力分配方案最优,与主观测试结果一致(C>B>A).在"10 min"的压力测试中,B座椅的峰值压力更稳定,A、C座椅无显著差异,与主观测试结果不一致,推测儿童对安全座椅的舒适性判断取决于入座时的第一印象.结论 实验结果表明4～8岁儿童在乘坐不同安全座椅时,材质偏硬、坐面造型平坦的安全座椅对人体的压迫性更强;材质偏软、包裹性强的安全座椅更贴合人机形态,舒适性更高.     

昆明火车站过渡季节热舒适性分析

在过渡季节,如何评价火车站候车室内的人体热舒适性是研究的内容。针对昆明火车站的过渡季节的候车室内的热舒适性进行分析探讨。评价该自然通风方式能否达到人体舒适性指标以及调研乘客对候车室内热环境的主观感受。利用热舒适仪器测试和使用问卷调查相结合的方式对候车室内的热环境进行综合评价,并提出建设性意见。     

房间空调器恒温暖房技术实验研究

针对普通热泵空调在制热除霜过程房间温度波动约6℃~10℃,用户使用过程感到忽冷忽热的问题,设计了一款在低温环境下制热除霜过程中持续制热、恒温暖房的空调器;通过实验验证,实现制热除霜过程房间温度波动约0.6℃~1.6℃,解决了用户使用过程中忽冷忽热的感受,提高了热泵空调系统在低温环境下使用的舒适性。     

面向电影化虚拟现实的用户注意力机制研究

电影化虚拟现实是一种面向全景电影制作的视听技术.不同于传统电影固定视域的观影方式,用户可以借助头戴式显示设备环顾虚拟空间,产生沉浸式观影体验.面向上述观影场景,本文通过分析不同摄影机运动和景别引导下的用户反馈,提出了一种基于时间—空间—视点的注意力机制研究范式,探讨适用于电影化虚拟现实内容制作的视听语言及叙事技巧.本文...     

基于PMV指标的驾驶舱热舒适性研究

针对某型机驾驶舱热舒适性的问题,在CFD软件建立仿真计算模型,模拟了送风温度为30℃和40℃时舱室的温度场和速度场,并由试验数据验证仿真模拟的正确性,进而由速度和温度结果推导出舱室热舒适性评价参数PMV和PPD的值。结果表明,驾驶舱空气分配形成的气流组织满足HB7489的要求;送风温度40℃时机组人员脚部周围空气温度可满足GJB1129"足趾温度舒适区为24℃～30℃"的要求,PMV和PPD值反映机组人员周围的大部分区域舒适性较好,但脚部区域PMV值小于-1,需通过增加辅助的加热设备改善脚部舒适性。     

工位空调热舒适指标PMV人工神经网络模型研究

建立了预测工位空调微环境热舒适指标PMV的人工神经网络模型。模型的7938组输入向量数据选自ISO7730中推荐的PMV及其参数范围,并考虑工作位形成的微环境的参数区间,以及ASHRAE标准舒适区域。编制程序计算出输入向量对应的PMV值作为模型的输出量。对网络进行训练和测试的结果表明,用人工神经网络建立的模型能够迅速准确地预测工位空调微环境的热舒适指标PMV。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from