降温技术在温室领域的应用

回顾了降温技术在农用温室领域的应用,讨论了每项技术代表性的方法;根据现有温室的系统特征、使用方法以及表现形式等相关信息,着重阐述了几种主要温室降温方法,即通风降温(自然通风和机械通风)、遮阳降温、蒸发降温(湿帘-风机降温、喷雾降温和喷淋降温)及创新型降温技术(机械制冷技术、空气-土壤热交换技术和地下水降温技术);综合所收集的信息,并分析每种降温方法存在的不足和局限性.     

粮堆通风阻力的研究方法及阻力模型研究进展

粮食储存过程中,干燥和通风是重要的单元操作。对粮堆进行强制通风,可以干燥或冷却粮堆,调节粮堆的温度和水分。探究气流通过粮堆的流动和压力分布规律、计算粮堆通风阻力是科学设计通风系统的关键之一。本文简要地介绍了国内外研究储粮通风流动和阻力的方法,重点综述了国内外通风阻力的理论、半理论和经验模型,分析了各种模型的优缺点,探讨了影响通风阻力的各种因素,可以为储粮通风阻力的研究、通风系统的设计和优化提供借鉴。     

温室开窗机构研究

本文对温室中常用的电动开窗机构、手动开窗机构、气动开窗机构的工作原理、优缺点、使用性能和注意事项做了详细的分析。结果发现,传统的电动齿轮齿条开窗机构存在响应慢、使用寿命短等缺点;气动开窗机构响应快,能够在环境比较恶劣的条件下正常使用。将气动技术应用到温室开窗系统中具有潜在的优越性。气动开窗初步研究存在不足,在温室内实现气动开窗有待于进一步研究。     

上海地区荷兰玻璃温室内温、湿控制分析

采用线性回归分析方法分析冬、春、秋季温室内温、湿度与界温、湿度,管道温度,通风窗开窗幅度之间的关系,得出冬、春、秋季温,湿控制的基本规律。     

教学实验室通风柜排风系统设计的思考

针对设计教学实验室通风柜排风系统中遇到的问题进行了探讨,并提出了设计中应注意的事项。     

Successful management of severe generalized tetanus in two dogs

Objective: To describe the clinical course and successful outcome of severe generalized tetanus in 2 dogs. Case series summary: Two dogs presenting with severe muscle rigidity, opisthotonus, and trismus were diagnosed with tetanus. In both cases, generalized convulsions, respiratory compromise, and autonomic dysfunction necessitated emergent interventions followed by intensive treatment and monitoring. In the second case, transient mechanical ventilation was required. Both dogs survived and were discharged after 19 days (first case) and 18 days (second case) of hospitalization. Although costly and time‐consuming, treatment for severe generalized tetanus was successful in these 2 dogs. New information provided: Severe generalized tetanus with convulsions, respiratory compromise, and autonomic dysfunction can have a successful outcome with intensive care and appropriate treatment.     

柑桔控温通风贮藏库——Ⅱ.贮藏效果及经济效益

锦橙在控温通风库贮藏,贮藏期可达180天以上。果实贮后仍新鲜饱满,风味好;3月份以后果实贮藏后期腐烂率比用改良通风库贮藏减少30％～60％;因果实销售的季节差价和腐烂减少,每贮藏1万公斤果实纯收益可达6800多元,比用改良通风库贮藏增值3600元以上,经济效益和社会效益显著。     

The effects of spontaneous and mechanical ventilation on central cardiovascular function and peripheral perfusion during isoflurane anaesthesia in horses

OBJECTIVE: To compare the effects of spontaneous breathing and mechanical ventilation on haemodynamic variables, including muscle and skin perfusion measured with laser Doppler flowmetery, in horses anaesthetized with isoflurane. STUDY DESIGN: Prospective controlled study. ANIMALS: Ten warm-blood trotter horses (five males, five females). Mean mass was 492 kg (range 420-584 kg) and mean age was 5 years (range 4-8 years). MATERIALS AND METHODS: After pre-anaesthetic medication with detomidine (10 microg kg(-1)) anaesthesia was induced with intravenous (IV) guaifenesin and thiopental (4-5 mg kg(-1) IV) and maintained using isoflurane in oxygen. The horses were positioned in dorsal recumbency. In five animals breathing was initially spontaneous (SB) while the lungs of the other five were ventilated mechanically using intermittent positive pressure ventilation (IPPV). Total anaesthesia time was 4 hours with the ventilatory mode changed after 2 hours. During anaesthesia, heart rate (HR) cardiac output (Qt) stroke volume (SV) systemic arterial blood pressures (sAP), and pulmonary arterial pressure (pAP) were recorded. Peripheral perfusion was measured in the semimembranosus and gluteal muscles and on the tail skin using laser Doppler flowmetry. Arterial (a) and mixed venous (v) blood gases, pH, haemoglobin concentration [Hb], haematocrit (Hct), plasma lactate concentration and muscle temperature were measured. Oxygen content, venous admixture (s/Qt) oxygen delivery (DO(2)) and oxygen consumption (VO(2)) were calculated. RESULTS: During mechanical ventilation, HR, sAP, pAP, Qt, SV, Qs/Qt and PaCO(2) were lower and PaO(2) was higher compared with spontaneous breathing. There were no differences between the modes of ventilation in the level of perfusion, DO(2), VO(2), [Hb], (Hct), or plasma lactate concentration. After the change from IPPV to SB, left semimembranosus muscle and skin perfusion improved, while muscle perfusion tended to decrease when SB was changed to IPPV. Low-frequency flow motion was seen twice as frequently during IPPV compared with SB. CONCLUSIONS: Mechanical ventilation impaired cardiovascular function compared with SB in horses during isoflurane anaesthesia. Muscle and skin perfusion changes occurred with ventilation, although further studies are needed to elucidate the underlying mechanisms.     

Unstable endobronchial intubation in a cat undergoing tracheal laceration repair

A peri-carinal tracheal laceration was produced in a 11-year-old cat during tracheal intubation. Before reconstructive surgery began, the leak was bypassed with an endobronchial tube positioned using endoscopy and direct vision. However, single-lung ventilation could not be sustained because the tube became dislodged and could not be repositioned. Consequently, surgery was completed with periods of intermittent apnoea interspersed with manually controlled hyperventilation. Cardiovascular variables were stable during anaesthesia and no signs of hypoxia were detected. The difficulties in maintaining endobronchial tube position resulted from the animal's small size relative to the dimensions of the endotracheal tube.     

西北夏季双孢蘑菇培养料简易通气发酵方法研究

以培养料常规一次发酵为对照,研究了双孢蘑菇料堆中半埋入直径12 cm PVC管强制通风和直径30cm铁圈自然通风的方法及其栽培效果。结果表明,料堆中半埋入直径12 cm PVC管强制通风发酵或直径30 cm铁圈自然通风发酵时,培养料料堆厌氧区减小,放线菌层厚度和放线菌在料堆中所占比例增加,发酵料质量提高,出菇期间病害减轻,产量较高。半埋入直径12 cm PVC管发酵法产量达到10.29 kg/m2,半埋入直径30 cm铁圈发酵法产量达9.66 kg/m2。