基于压电效应的简易型细胞力学测试仪

针对传统的细胞力学研究方法的非无损性,不能对细胞力学参数连续、长期监测的特点,研制出一种基于石英晶体压电效应的简易型细胞力学测试仪。该测试仪以STM32 103C8 为核心,设计有石英晶体在液相环境下的起振电路、稳定振荡电路,采用了频率/电压转换电路。系统实现了对石英晶体频率变化的高精度采集,对与传感器耦合的界面层（细胞）的质量、粘弹性和表面应力多参数敏感,能对细胞黏附过程和细胞力学性能进行动态监测。通过整机在细胞培养液环境下的实验,验证了测试仪系统的可行性与稳定性。     

发电机原动系统仿真器程序设计

研制了一种新型的基于80C196KC单片机的原动机仿真系统的软件．对系统中的调速器，利用灵活的单片机的软件去实现其功能，不仅使硬件线路大为简化，并且克服了模拟电路结构复杂、电子元器件容易老化、易受环境温度影响和抗干扰能力差等缺点，提高了整个系统的控制精度、可靠性和稳定性．此外还设置了液晶显示器和人机通讯接口，可将原动机仿真系统的运行参数以数字信号的形式传输到监控系统或者PC机，操作直观、便于监视．微机软件编写采用了模块化，使软件的编写更方便、简单，软件已完全通过调试，达到了预期的效果。     

夏季猪舍屋顶遮阳降温效果研究

本文通过理论分析与试验研究了屋顶遮阳系统在猪舍夏季降温中的应用效果,应用红外热图像摄取及分析系统获取猪舍屋顶内表面和猪体表面的热图像,结果表明屋顶上架设铝箔遮阳网对减少太阳辐射进入猪舍进而降低猪舍环境温度和减轻猪热应激的效果显著。     

Effect of floor cooling on performance of lactating sows during summer

Forty Landrace × Large White lactating sows were used to evaluate the effects of cooling of the floor when maintained under high temperature conditions during summer on their productive and reproductive performance. The sows were allocated in a completely randomized design with two treatments with 20 replicates according to parity number and body weight, with each animal being considered an experimental unit. The treatments consisted of cooling of the floor under the sow with water circulation at about 17 °C and no cooling. The resulting temperatures of the floor were 27.6 and 35.8 °C for the cooled and the control treatments, respectively. The sows from both treatments were exposed to average maximum and minimum environmental temperatures of 26.9 and 20.8 °C, respectively. Sows maintained on a cooled floor had a higher feed intake (6.47 vs. 5.61 kg/day; P < 0.01). Despite this higher intake, sows maintained on a cooled floor had higher body weight and body protein losses during the lactation period (P < 0.01) in connection with a higher milk yield and subsequent growth of the litter (2280 vs. 1798 g/day; P < 0.01). There was an effect of treatment on rectal temperature, surface temperatures and respiratory rate (P < 0.01) with lower values in sows submitted to floor cooling. It is concluded that floor cooling under the lactating sow improves its productive and reproductive performance, as well as the performance of its litter.     

THE WAYS FOR IMPROVING INDOOR ENVIRONMENT AND AIR-CONDITIONING SYSTEMS IN DANCLING HALLS

Since 1988, air temperature, humidity, air quality, noise level and intensity of illumination in lots of dancing halls in China have been investigated and tested. This paper introduces the present situation of indoor environment and air conditioning systems in dancing halls of China. The design indexes of cooling load for room and ontside air are recommended. The reasons for indoor environment deterioration have been found out. From the actual situation of China, the ways for imoroving indoor environment and approach of energy conservation in air conditioning systems are explored.     

Initial cooling time before freezing affects post‐thaw quality and reproductive performance of rabbit semen

The aim of this study was to investigate the effect of initial cooling time at 5°C during semen cryopreservation on post‐thaw quality and reproductive performance of rabbit semen. Pooled semen samples (n = 6) were divided into two subsamples and cooled at 5°C for 45 or 90 min. After cooling, the semen samples were diluted to a ratio of 1:1 (v:v) with a freezing extender composed of Tris‐citrate‐glucose (TCG) containing 16% of dimethylsulfoxide and 0.1 mol/L sucrose. The semen was subsequently loaded in 0.25 ml straws, equilibrated at 5°C and frozen in liquid nitrogen vapor. After thawing, sperm motility, viability, osmotic resistance, acrosome and DNA integrity were assessed. Our results indicate that the longer cooling time, that is, 90 min before cryopreservation significantly improves sperm post‐thaw viability, motility and fertility. In fact, reproductive performances obtained with semen frozen after a 90 min cooling time were similar to those produced by fresh semen insemination. Hence, the present research provides an effective freezing protocol for rabbit semen that will allow for the creation of a sperm cryobank for the conservation of Italian rabbit genetic resources, as well as the use of frozen semen doses in commercial farms.     

Quantification of reservoir bags as airway pressure-limiting devices in a nonrebreathing system

ObjectiveTo evaluate the influence of reservoir bag types, volumes and previous use on the peak pressures (Pmax) and the times to develop 30 cmH₂O pressure (P30) within a nonrebreathing system with a closed adjustable pressure-limiting (APL) valve.Study designIn vitro study using three-way factorial design with repeated measure on one factor.SubjectsA total of 75 new anesthesia reservoir bags (five types, three volumes, five bags from each type × volume). The bag types were reusable latex (RL), disposable latex (DL) and three disposable neoprene (DN-1, DN-2 and DN-3).MethodsEach bag was tested three times (treatments): new, after prestretching and 1 week later. The bags were attached to a Bain system and anesthesia machine with closed APL valve and patient port with O₂ flow 2 L minute^–1 until Pmax was reached. The Pmax and time to reach P30 values were determined from recorded pressure traces. General linear mixed model analysis was used to examine the effects of bag type, volume and treatment. One-sided 95% upper prediction limits of Pmax were calculated to test the null hypothesis that predicted Pmax of new bags would be ≥ 50 cmH₂O for each factor combination.ResultsRL bags were the least and DN-3 bags were the most compliant. Prestretching increased compliance in all bag types. Smaller bags of RL, DL and DN-1 were less compliant than larger ones. The predicted Pmax values were < 50 cmH₂O only for DN-3 bags after prestretching. The time to reach P30 was critically low when using 0.5 L bags (median 17 seconds).Conclusions and clinical relevanceTo minimize the risk of barotrauma, highly compliant reservoir bags (e.g. DN-3) are recommended and reusable bags should be avoided. Bags should be prestretched before first use, 0.5 L bags should be avoided and fresh gas flow minimized.     

连栋塑料温室喷雾降温及外遮荫降温试验研究

为解决夏季温室高温、高湿问题,在温室喷雾水膜降温的基础上,直接在内遮荫幕上做喷雾降温试验,并与外遮荫降温系统进行比较。试验结果表明:单独采用内遮荫幕系统可使室内气温比外界低1℃左右;采用在内遮荫幕上喷雾降温,室内气温比室外可低2°～3℃;采用外遮荫降温系统可使室内温度比室外低3°～4℃。     

除湿降温系统用于温室降温的可行性探索

结合我国温室降温的现状，指出了高温高湿气候条件下直接蒸发降温方法的局限性；提出了利用除湿降温系统来解决高温高湿地区温室降温难的问题；分析了该系统的构成以及实现降温的可行性。     

草地螟滞育和非滞育幼虫抗寒能力的研究

对草地螟幼虫过冷却点和冰点测定的结果表明,光照、温度、幼虫滞育的深度以及虫体含水量均可以影响草地螟幼虫的抗寒能力。长光照(16 h)条件下发育成的非滞育幼虫过冷却点、冰点均显著低于短光照(10 h)发育而成的滞育幼虫;无论是非滞育幼虫还是滞育幼虫,经低温处理后抗寒能力都会上升。经4℃处理1 d的非滞育幼虫冰点为-2.28℃,而处理25 d的则降低到-4.76℃,过冷却点可从-13.97℃降低到-21.47℃;经4℃处理25、35 d的滞育幼虫,其过冷却点分别为-25.82、-26.79℃,冰点分别为-5.59-、9.13℃。滞育幼虫的过冷却点、冰点与其体重不相关,但与其体内的含水量显著相关。