小型低温制冷机上的低温密封型式浅析

随着小型低温制冷机在工业、高科技等尖端产业得到越来越广泛的应用，用于其上的低温密封也愈来愈引起人们的重视，低温密封比起普通的密封具有自己独特的要求，该文主要针对小型低温制冷机中的低温密封型式进行简要的说明，并具体给出一些低温制冷机上采用的低温密封实例。     

热声理论的研究进展及其应用

回顾了热声理论研究的发展起源.详细介绍了热声理论的研究内容,对各理论的特点进行了比较.给出热声应用实例,指出微型热声制冷机的应用前景.     

线性(自由活塞)压缩机在冰箱上的应用

在提高传统压缩机COP的基础上,许多公司提出使用线性压缩机,通过线性电动机以电磁共振方式驱动,而不由旋转电动机通过机械连接方式驱动压缩机.这种压缩机的特点是结构简单,没有曲柄连杆机构,因而摩擦可大大减少,噪音也能大大降低;可以少用润滑油或不用润滑油,故能与多种类型的制冷剂相匹配;在整个可变容量范围内效率都非常高.     

The effect of blowing agent choice on energy use and global warming impact of a refrigerator

A study, comparing the effect of blowing agent selection on energy consumption and the life cycle climate performance (LCCP) of a typical European refrigerator is discussed. Energy consumption of prototype European-style refrigerators made with a foam formulation with HFC-245fa as the blowing agent was measured and compared with energy consumption of the same model as currently produced (using a foam with a pentane blend for the blowing agent). Results were used in a LCCP study, considering both direct and indirect climate impacts due to blowing agent emissions and energy consumption in manufacturing processes and over the life cycle of the refrigerator. An assumption is made that the refrigerator is built and used in the European market.     

The Relationship Between Witnessing Parental Conflict During Childhood and Later Psychological Adjustment Among University Students: Disentangling Confounding Risk Factors.

The purpose of the current study was to examine in detail the association between witnessing domestic violence (DV) and long-term psychological adjustment. Important limitations of past research were addressed, including controlling for several associated risk factors. Special attention was paid to whether the perpetrator of the violence was the maternal or paternal figure, as well as to whether the witness to the violence was male or female. Participants completed measures examining DV witnessed, direct child abuse experienced, and current psychopathology. Following screening for physical and sexual abuse, a sample of 351 individuals was selected. Four groups of participants were compared. Results indicated that individuals who had witnessed either physical DV or major psychological DV had higher levels of psychopathology than individuals who reported witnessing minor psychological DV or controls. After controlling for direct psychological abuse experienced, witnessing DV remained a significant predictor of psychopathology for males but not for females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do Dogs (Canis familiaris) Understand Invisible Displacement?

Domestic dogs (Canis familiaris) perform above chance on invisible displacement tasks despite showing few other signs of possessing the necessary representational abilities. Four experiments investigated how dogs find an object that has been hidden in 1 of 3 opaque boxes. Dogs passed the task under a variety of control conditions, but only if the device used to displace the object ended up adjacent to the target box after the displacement. These results suggest that the search behavior of dogs was guided by simple associative rules rather than mental representation of the object's past trajectory. In contrast, Experiment 5 found that on the same task, 18- and 24-month-old children showed no disparity between trials in which the displacement device was adjacent or nonadjacent to the target box. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

国产碳纤维上浆剂的比较

探索了不同类型国产上浆剂对碳纤维接触角、表面能、耐磨性、表面微观形态等物理特性的影响。结果表明:使用YJ上浆剂的碳纤维的硬挺度、耐磨性比使用FD、HIT的好,使用HIT上浆剂的碳纤维的外观、丝束幅宽比YJ的好。     

家政O2O发展现状分析

随着国内家政行业进阶为万亿级市场,家政业务交易额每年增幅都超过20％.家政O2O作为大众期望的一种运营模式,刚好能迎合这样快速发展的家政市场.首先介绍了国内家政服务市场的现状,然后分析了家政O2O的发展基础,最后以95081的家政O2O模式为例,分析了国内家政O2O的出路.     

SAFARI engineering model 50 mK cooler

SAFARI is an infrared instrument developed by a European based consortium to be flown in SPICA, a Japanese led mission. The SAFARI detectors are transition edge sensors (TES) and require temperatures down to 50 mK for their operation. For that purpose we have developed a hybrid architecture based on the combination of a 300 mK sorption stage and a small adiabatic demagnetization stage. An engineering model has been designed to provide net heat lifts of 0.4 and 14 μW respectively at 50 and 300 mK, with an overall cycle duration of 48 h and a duty cycle objective of over 75%. The cooler is self-contained, fits in a volume of 156 × 312 × 182 mm and is expected to weigh 5.1 kg. It has been designed to withstand static loads of 120 g and a random vibration level of 21 g RMS.     

Levels of microbial contamination of domestic refrigerators in Italy

AimAccording to the EFSA Report 2013, 32.7% of outbreaks of foodborne illness registered in Europe occurs within the home, due to inadequate hygienic behaviour of consumers when preparing foods in the kitchen. The efficacy of proper cleaning of cutting boards, dishes and cutlery in limiting microbial cross-contaminations in the kitchen has been documented many times, whereas few researches have been performed to determine the microbial load of the internal walls of domestic refrigerators, in Italy. The aim of this investigation is to ascertain the role played by internal surfaces of home refrigerators as possible sources of microbial contamination of foods.Material and methodsWe analyzed 293 domestic refrigerators of students or workers at the university campus of Agripolis (Legnaro, Italy). For each refrigerator, 2 internal surfaces were sampled using sponge-bags. The amounts of total viable count (TVC), Gram-negative spoiling bacteria, moulds and yeasts and the main pathogenic bacterial species were determined.ResultsTVCs greater than 1 log CFU cm⁻² are in a little over 50% of the samples analyzed and are found mainly on the bottom of the refrigerator (61%) compared to the walls (39%) (P < 0.001). Even for other microbial counts the risk ratio of finding them on the bottom of the refrigerator is significantly higher than on the walls; the possibility of there being a finding on the bottom with respect to the walls varies from 2.5 to 8.5 times respectively for moulds and Aeromonas spp. Salmonella spp. was found in 1.7% of the samples, Bacillus cereus in 5.6%, Coagulase-positive staphylococci (CPS) in 4%, the prevalence of which is always higher on the bottom of the refrigerator. Listeria monocytogenes and Yersinia enterocolitica were never found.ConclusionsIt is necessary to better educate consumers to clean their appliances more frequently.