基站围护结构的保温控制策略

基站是一种特殊的公共建筑,它具有单位面积发热量大、耗电量大及一般面积较小的特点。选取全国不同的温度带,利用能耗模拟软件,分别模拟计算在加保温和不加保温两种不同策略下的基站制冷能耗,得到基站围护结构外墙保温做法的指导公式。     

Implementing single-scale wavelet transform processor with magnetostatic surface wave device

When the envelope of the conducting strips for the input transducer of magnetostatic surface wave(MSSW) device is designed according to the wavelet-function envelope,the impulse-response function of the input transducer for MSSW device is equal to the wavelet function,so that single-scale wavelet-transform processor of MSSW type is fabricated.First,according to the envelope function of the wavelet,the length function of the conducting strips is defined,then,the lengths of the conducting strips can be calcul...     

A computerized potentiometric system for structural and functional anthropometric measurements

A prototype computerized potentiometric system was developed for structural and functional anthropometric measurements. The system uses four potentiometric units, a power supply unit, and a computer with analogue/digital (A/D) converter to measure the position of a movable stylus in three (X, Y, Z) dimensions. The system is easy to use, more accurate, and more cost effective than other existing systems. It has been found to be accurate for the intended application, faster than the manual methods available, and much less expensive than the photographic and opto-electronic systems currently available. For use in the industrial setting, a portable version of the system is envisaged in the future.     

Preliminary investigation of a vapor-open envelope tailored for subtropical climate

Concerning global warming and resource depletion, the impact of buildings in subtropical regions is becoming even greater due to a high growth rate of urbanized areas. From the viewpoint of building physics, the main problem concerning subtropical climate is the high level of humidity in combination with high temperature. In this study, a flexible building envelope consisting of wood and clay components was developed so that the materials and the assemblies can be easily tailored to comply with local climatic conditions. The movement and accumulation of moisture in the wall was of prime concern. This has been investigated by means of testing full scale walls in a climate chamber and the corresponding one dimensional transient heat and transfer simulation. In order to achieve a consistency between calculation and measurement, the individual materials were tested for their hygric and thermal properties. Based on these findings attempts were made to calculate the behavior of an optimized wall assembly under real climatic conditions of central Japan. As a result, it was shown that the hygrothermal behavior of the envelope is predictable by means of the models and the simulation program used, and that no risk of interstitial condensation and mold growth was predicted under the real climatic conditions of Kyoto.     

In-cavity evaporation allowance—A drying capacity indicator for wood-frame wall system

Although moisture significantly affects the performance and durability of building envelope systems, effective methods to quantify the relative drying capacity of these systems are yet to be developed. A new testing method and an evaluation approach for comparing the drying capacity of wood-frame wall systems in evacuating water due to rain penetration in the stud cavities are presented in this paper. A controllable and consistent moisture loading is created by placing a water tray on a load cell at the bottom of the stud cavity of the wall assembly which is then subjected to lab generated indoor/outdoor conditions. The data on water evaporation from water trays and the monitored moisture accumulations in the materials surrounding the stud cavities are used to establish load–response relations. Using these relations the relative performance of various building envelope systems in preventing biodeterioration caused by rainwater penetration into the stud cavities can be compared. The concept of in-cavity evaporation allowance (ICEA) has been proposed and it is based on the limit of 20% moisture content (MC) being reached at any location of the building envelope.     

一种新型齿轮廓线形成的径向包络方法

提出一种新方法加工的齿轮廓线，可有效克服渐开线齿轮廓曲线的不足，不用VB语言编制了相应的计算机仿真程序，对其进行了检验、证明。     

基于无瞬心包络的微细铣刀螺旋槽刃磨分析*

螺旋沟槽属于复杂的空间螺旋面,砂轮与刀具的相对运动复杂,在微细立铣刀的制造过程中耗时最长、难度最大,精确、高效加工螺旋沟槽成为微细铣刀制造过程亟须解决的关键问题之一。基于无瞬心包络原理研究了微细铣刀螺旋沟槽的刃磨过程,提出一种微细螺旋铣刀轴向型线的计算模型,该模型避免了利用接触公法线求解时,因砂轮截形上的奇点和圆滑二次曲线导致无法求解的情况,计算过程与求解简单,适用于对砂轮廓形复杂时刃磨求解。在所建模型基础上分析了砂轮形状和加工参数对螺旋槽型形状的影响,以及砂轮摆角和前刀面宽度对径向前角的影响。通过刃磨验证了模型与分析的正确性,试验证明实际加工的微细铣刀沟槽截形与包络计算的沟槽型线几何形状参数吻合良好。     

采用Gabor滤波器的轴承状态监控方法

针对滚动轴承状态监控中最优共振频带难确定的问题,提出一种新的寻优方法和目标函数,可快速准确地定位共振频带,提取状态信息.通过两步网格搜索法,以包络稀疏性为目标函数,对Gabor滤波器参数寻优;然后对振动信号进行滤波并得到信号包络;最后运用包络自相关谱抑制噪声,突出运行状态信息.用仿真信号和实际信号对该方法进行了验证,结果表明,该方法能准确判明轴承运行状态.     

Impact of the Relationship between Phase Change Temperature and Boundary Temperature on the Thermal Performance of a PCM Wall and the Presentation of PCM Thermal Performance Indexes

In the composite phase change material (PCM) building envelope, the matching relationship between the phase change temperature of the PCM and the wall's boundary temperature significantly affects the energy storage performance of the PCM building envelope. In this paper, a type of concrete hollow block with a typical structure and a common PCM were adopted to produce multiform composite PCM hollow blocks, and the temperature changing hot chamber method was performed to test the thermal performance of the hollow block walls under different temperature conditions. New indexes were proposed for the thermal performance evaluation of the PCM wall. Meanwhile, combined with experimental data, the effective heat capacity model and the enthalpy model were used to analyze the effect of correlations concerning how the relationship between phase change temperature and wall's boundary temperature influenced the thermal performance of PCM wall. Three main impact factors related to temperature were obtained through the analysis. In addition, approaches for improving the thermal performance of a composite PCM wall were put forward. This paper provides the theoretical basis, data reference and practical instruction for the proper use of a PCM wall and ways for improving the thermal performance of a composite PCM wall.     

发酵乳杆菌细胞壁蛋白酶的分离纯化及酶学性质研究

研究分离纯化发酵乳杆菌细胞壁蛋白酶(cell envelope proteinase,CEP)的方法及其酶学性质。用50mmol/L Tris-HCl缓冲液(pH7.8)悬浮菌体,进行超声波破碎,细胞质量浓度为0.06g/mL,破碎功率330W,工作220次(工作时间3s,间隔时间5s),离心取上清液即为粗酶液。60%硫酸铵沉淀,Sephacryl S-300 HR凝胶层析,Native-PAGE割胶回收纯化发酵乳杆菌的CEP。用纯化的CEP 酶解脱脂乳,酶解液ACE(angiotensin I-converting enzyme)抑制率为50%。SDS-PAGE检测CEP分子质量为32.5kD,最适酶反应温度为41℃,最适酶反应pH值为8.0。Mg2+、Co2+、Ca2+对CEP活性有激活作用;Zn2+、Ni2+、PMSF、EDTA对CEP活性有抑制作用,说明CEP为丝氨酸蛋白酶且酶的活性中心结构的维持与金属离子有关。