带扰动的流体排队模型

考虑了一类带扰动的无限容量的流体排队模型.假设系统的服务速率是线性的,扰动由布朗运动和与过程有关的函数模拟,从而模型的容量过程满足一个随机微分方程.作为衡量排队模型的重要指标,得到了此流体模型容量过程的期望值,以及首中时的拉普拉斯变换和期望.     

Sea surface temperature and terrestrial biomarker records of the last 260 ka of core MD05-2904 from the northern South China Sea

This paper reports high-resolution biomarker records of the last 260 ka for core MD05-2904 from the northern South China Sea （SCS）. The sea surface temperature （SST） record using the U37^k＇, index reveals a minimum of 21.5℃（MIS 2） and a maximum of 28.3℃（MIS 5.5）, for a temperature difference of almost 7℃, and provides the longest high-resolution U37^k＇ SST record in northern SCS. The content of odd-number long chain n-alkanes and several n-alkanes indexes such as the CPI, ACL and the C31/C27 ratio, all reveal generally higher values during the glacials and lower values during the interglaclals. Terrestrial input as Indicated by n-alkane content was mostly controlled by sea-level changes： During the glacials, lower sea-level exposed the continental shelf to enable rivers to transport more terrestrial materials to the slope; and the situation reverses during the interglacials. The n-alkane indexes changes reveal more n-alkanes from contemporary vegetation during glacials as a result of the proximity of the core site to the source region, while the increases in ACL and C81/C27 ratio during glaclals indicate a change to more grassy vegetation. However, the highest values for CPI, ACL and the C81/C27 ratio all occurred during late MIS 3, and it was suggested that this period was characterized by a strong summer monsoon-dominated humid climate which resulted in a denser vegetation for the exposed continental shelf region.     

数字式温度传感器在冰箱检测系统中的应用

本文介绍了数字式温度传感器的工作原理、性能特征以及如何在冰箱检测系统中引入单总线技术,使用数字式温度传感器更好的实现温度的采集。     

泵送混凝土温度收缩裂缝的产生机理及对策

对泵送混凝土温度收缩产生裂缝的机理及影响因素进行了研究,从原料的选择、配合比的设计、施工及养护等几方面阐述了裂缝控制措施。     

不同方法检测荷兰豆中苯甲酸的结果比较及研究

使用不同的方法检测荷兰豆中的苯甲酸得到截然不同的结果。研究表明,荷兰豆本身不含有苯甲酸,但在酸和高温加热条件的影响下,某些物质会转化产生苯甲酸。且随着温度的升高和酸加入量的增多,苯甲酸检出量呈上升趋势,达到一定浓度后渐趋稳定。     

基于LonWorks现场总线技术的变风量空调系统温度PID控制

采用LonWorks现场总线技术和PID控制算法,对变风量空调系统的送风温度和回风温度进行了控制方法的研究.以某一空调房间为控制区域,运用该方法进行了实时控制,测量了送风温度和回风温度随时间变化的趋势曲线.试验结果表明,该方法可行有效,控制效果良好.     

托卡马克上软x射线能谱测量电子温度的修正

HT-7托卡马克上通常采用软x射线能谱诊断测量等离子体的电子温度.由于该测量的弦积分效应,测量的不是局域的值.数值分析结果表明该测量误差取决于电子温度剖面、等离子体密剖面,以及拟合的能区.这个效应在等离子体电子温度测量中会低估电子温度.     

基于气候环境的浙江建筑设计措施分析

基于建筑所在地区的气候环境,在不借助机械设备条件下通过采用建筑气候设计措施,延长建筑室内环境的舒适时间、减少不利环境的出现几率,是当前建筑研究领域中一个重要课题.在广泛调查的基础上,得到浙江地区的中性温度,并以杭州为例,利用气候分析法对其气候环境进行分析,得到了杭州地区建筑最适宜采用的设计措施,以及可以实施建筑气候设计措施的日数,以供设计人员在以后的建筑设计中作为参考.     

各种添加剂对低温陶瓷结合剂性能的影响

实验主要研究6种添加剂对陶瓷结合剂性能影响。实验证明,随着α-Al2O3加入量的增多,结合剂的熔点逐渐升高,在加入量为15%时流动度最好;CuO、Cr2O3和Zn对结合剂熔点有明显的提高作用;Sn和Cu可以降低结合剂的熔点;加入8%Cr2O3或加入6%Sn时其流动度值最佳。     

In Situ Measurement of the Undisturbed Ground Temperature for Ground Source Heat Pump System

The undisturbed ground temperatures are important for design of the ground heat exchangers in ground source heat pump （GSHP） systems. In this paper, the undisturbed ground temperatures measured in two different methods are presented. The investigation was carried out in two cases. The temperature measured with the direct method is assumed to give the correct undisturbed ground temperature profile. The temperature measured with indirect method overestimates the undisturbed ground temperature by 2.1℃ and 1.7~C. This difference is mainly caused by the circulation pump and ambient air to the fluid. Therefore, the results that are decreased about 2℃ as compared with the indirect measured are recommended to estimate the undisturbed ground temperature in situ measuring. A smaller pump or deeper borehole or mild weather would result in a more correct temperature. Because the undisturbed ground temperature is affected by many factors. Whether or not these conclusions are correct to other areas, this would need further investigation.