沈阳故宫院落声场的测试及分析

针对目前学界对中国传统建筑院落声场特征研究不足的情况,选择沈阳故宫博物院的三个室外院落声场作为研究对象,首先在所选院落内放置12面体作为连续声源,对其相邻各进院落的声压级进行测量,目的是分析故宫院落内声环境的私密程度,然后采用声音切断法对故宫院落的重要声学指标混响时间T10进行系统测试。研究成果将有利于了解古代宫殿院落的声场特征,并为后续的研究奠定扎实的基础。     

采用周线积分法计算人体与辐射板的辐射角系数

辐射角系数是计算人体与辐射板间辐射换热量的一个重要参数,针对人体与辐射板之间辐射角系数问题求解的复杂性,使用长方体模型代替站立姿态时的人体形状,进行辐射角系数的计算。以辐射顶板为例,运用周线积分法和代数法建立了任意位置下人体与辐射板之间辐射角系数的数学表达式,并对结论的合理性进行了验证。     

辐射板供冷性能影响因素与计算方法

通过对现有计算方法的分析,提出了以室内等效辐射温度作为辐射换热计算参数的方法。通过实例计算定量地分析了室内热源环境对辐射板供冷能力的影响。提出将辐射板热阻作为衡量辐射板供冷性能优劣的参数。     

辐射板安装角度的探讨

倾斜安装的辐射板按目前资料一般只有安装角度和安装高度的关系表,全国通用采暖通风标准图CN501-1中只列有5种安装角度。我们认为辐射板倾斜安装角度(辐射板与水平面的角度)α除与安装高度有关外,还与车间跨度有关,车间跨度越大,α应该越大。传热学中兰贝特定律指出:圆表面积dF沿各个方向所放射的能量是不同的,随该方向和表面法线间所构成的φ角而变。在法线方向上(φ=0)辐射能量最多,当φ角增大时,则辐射能量渐趋减少,直到φ=π/2时减少到零。根据该定律E_φ=E_ncos_φ千卡/米~2·小时·弧度。式中E_hE_φ是指圆表面沿法线方向及φ方向每单位表面积在单位时间、单位立体角内所辐射的能量(见图1)。     

导热油辐射采暖的特点及水力计算

分析了高温导热油辐射采暖特性 ,对导热油带形辐射板设计和安装提出了注意事项。     

辐射采暖的设计计算

辐射采暖在集中采暖工程实践中因其施工安装设计计算较为复杂,影响了它的发展和应用,但辐射采暖的优点也是较为明显的,诸如; (1)能给人体造成良好的舒适条件; (2)室内温度波动小; (3)可以防止墙内表面产生凝结水; (4)由于墙面温度较高,有毒性溶胶对墙面的沾结力差,有利于污染后的清洗; (5)可以利用多种热媒,达到采暖的目的,如蒸汽,热水、电能,低温废气、低温热水等。     

改进的半空间频率均方声压法计算结构频带振动声辐射

为计算中高频半空间结构频带振动下声辐射问题,推导了基于能量源的半空间频率均方声压法(Frequency Averaged Quadratic Pressure, FAQP),并提出了改进的半空间FAQP法,克服了半空间FAQP法在失效频率下解不唯一的问题。频率带宽为4 Hz的刚性壁面作用下的脉动球和与自由表面相接触的脉动半球的声辐射数值计算,验证了改进的半空间FAQP法对解决失效频率下解不唯一问题的有效性。同时,刚性壁面作用下的脉动球和与自由表面相接触的脉动半球声辐射数值计算结果均表明,在1/3倍频程下,改进的半空间FAQP法与常规边界元方法相比,具有更高的计算精度,更适用于中高频计算。     

塑料管地板辐射采暖的测试

地板辐射采暖方式早在二十世纪初就已被人们所采用。实践证明它比普通散热器采暖更舒适,但是,由于地板辐射采暖的费用比普通散热器采暖高,以及钢管埋设在混凝土中腐蚀、损坏后无法更换等问题,致使地板辐射采暖未能得到广泛的应用。本世纪七十年代,由于塑料工业的发展,出现了耐温、耐压的塑料管。一些工业比较发达的国家用这种塑料管代替了地板辐射采暖中的钢管。1979年我国由旅大塑料研究所研制成功了这种耐温、耐压的塑料管——交联聚乙烯     

变厚度筏板的应用及计算

介绍了采用PKPM软件板元法计算柱下局部加厚筏板的内力和配筋的方法,并通过工程实例分析对比柱下独立基础方案,给出了一些经验性结论。     

钢制采暖散热器的发展浅析

对钢制散热器的特点和优势进行了分析，从国家产业政策，国内外市场和城镇住宅方面论述了发展散热器的要求和广阔前景，指出了钢制散热器的发展方向。     

国外散热器技术进步的启示

国际交流活动的加强,为全面提升我国采暖散热器行业的水平,为采暖散热器企业的技术进步,以至我国散热器产品走向世界,都发挥了具有重要意义的推动作用.     

金属板轻质隔墙隔声性能的探究

结合目前轻质隔墙的使用现状,对金属板轻质隔墙进行实验研究,从隔声量与墙体厚度两方面,对比分析其与传统轻质隔墙的差异性,指出金属板轻质隔墙具有较高隔声量的特点,在建筑材料隔声领域应用前景十分广阔。     

从城市广场说开去

该文从出现在中国城市广场的种种美化现象谈起,阐明在有“历史为鉴”的情况下．反而“重蹈”发生在一百年前美国城市美化运动“覆辙”的种种客观原因,进而揭示其本质根源在于因缺乏自信而导致的思维追随以至全盘吸收西方经验的心理状态。     

Development of limiting-state regions in the bed soil of a square plate

Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, pp. 15–17, March–April, 1991.     

Effects of geometry on the sound field in atria

The atria in commercial buildings are widespread. However, the sound environment has not been given sufficient consideration. Geometry affects the acoustics in the atria. The concept of geometry in this paper includes five parameters, namely, length (l), height (h), aspect ratio of length to width (l/w), skylight form and slope, to provide suggestions for the acoustic environment design in atria. A series of computer models are simulated to analyse the effects of the form parameters on the acoustic environment, such as sound pressure level (SPL) and reverberation time (T₃₀ in this paper). The results indicate that with an increase in the length or height, the values of the average SPL decrease, and the trends of the curves are logarithmic. For an increasing length, the T₃₀ increases first sharply and then slowly. With the scattering increasing, the increment of the T₃₀ is smaller. For an increasing height, the changes of T₃₀ are determined by the absorption and scattering. In terms of the aspect ratio of l/w increasing for a given volume and area, the average SPL values approximately decrease linearly; furthermore, the T₃₀ decreases unless the atrium is extremely high. The T₃₀ is the longest for a flat skylight compared to that of other forms, and it is shorter when the skylight has a slope, including either a single or a double-pitch skylight. It can decrease nearly by 40% when the angle of the lean-to skylight is 7°. The T₃₀ is lower and the amount of decrease is considerably smaller for an increasing slope. When the absorption is evenly distributed in the atria, the skylight has minimal effect on the average SPL or T₃₀ values. Additionally, the classical formula can approximately calculate the SPL distribution unless the atrium is in a form of long space. The Arau-Purchades formula is generally appropriate to predict T₃₀ with uneven absorption distributions unless the absorption or scattering coefficient is low.     

采暖散热器面积换算的分析

在采暖工程系统不变、热媒供应方式不变、系统安装方式不变、散热器连接方式不变的情况下,对原设计的散热器更换其他种类或形式散热器的问题进行分析,得出上述情况下用公式F′=K/K′F进行面积换算可行的结论。     

场板结构对AlGaN/GaN HFET电场分布的影响

场板结构可以有效抑制横向型HFET器件栅极边缘的电场集边效应,降低尖峰电场峰值,从而大幅提高器件的耐压特性。利用Sentaurus TCAD工具,构建具有场板结构的HFET器件,研究了场板长度和钝化层的厚度对器件沟道电场分布的影响,归纳出场板结构设计的基本规律和一般方法。     

Assessment of the sound field in an open plan office

The calculated attenuation curve for an open office using a multi-image model has been shown to agree well with the attenuation curves measured in that office. The measured attenuation curves for no furniture in the office undulate out to distances of approximately 10m from the source and tend to stay close to the 6dB per distance doubling attenuation line beyond 10m from the source. The introduction of furniture and screens was found to have little influence on the attenuation curve.     

Assessment of the sound field in an open plan office

The calculated attenuation curve for an open office using a multi-image model has been shown to agree well with the attenuation curves measured in that office. The measured attenuation curves for no furniture in the office undulate out to distances of approximately 10m from the source and tend to stay close to the 6dB per distance doubling attenuation line beyond 10m from the source. The introduction of furniture and screens was found to have little influence on the attenuation curve.