解磷根瘤菌液体培养基类型,浓度及透气条件的比较

以解磷根瘤菌SL01为供试菌株,采用液体培养研究了培养基类型和浓度以及透气状况对其生长的影响。结果表明:供试的培养基中,最适的液体种子培养基为LB和1/2 LB液体培养基,菌株的繁殖速度不仅与培养基的类型有关,更受到营养条件的限制;培养基接入解磷根瘤菌SL01并充分发酵之后,发酵液的pH值都相当程度的偏离了初始的酸碱度;根瘤菌作为好气菌,YMA液体培养基中培养12 h后,透气条件下发酵液内的活菌数达12.2×109cfu/mL,为密闭培养条件下的10.51倍,在解磷根瘤菌的发酵培养中,透气状况应作为重要的环节进行考虑。     

Continuous positive airway pressure administered via face mask in tranquilized dogs

Objective – To evaluate the tolerance of a continuous positive airway pressure (CPAP) mask in tranquilized dogs and compare PaO₂ in arterial blood in dogs receiving oxygen with a regular face mask or CPAP mask set to maintain a pressure of 2.5 or 5 cm H₂O. Design – Prospective, randomized clinical study. Setting – University teaching hospital. Animals – Sixteen client‐owned dogs without evidence of cardiopulmonary disease were studied. Interventions – Eight animals were randomly assigned to each of 2 treatment groups: group A received 2.5 cm H₂O CPAP and group B received 5 cm H₂O CPAP after first receiving oxygen (5 L/min) by a regular face mask. Animals were tranquilized with acepromazine 0.05 mg/kg, IV and morphine 0.2 mg/kg, IM. An arterial catheter was then placed to facilitate blood sampling for pHa, PaO₂, and PaCO₂ determinations before and after treatments. Direct mean arterial pressure, heart rate, respiratory rate, and temperature were also recorded after each treatment. Measurements and Main Results – CPAP administration was well tolerated by all animals. The mean arterial pressure, heart rate, respiratory rate, temperature, PaCO₂, and pHa, did not differ at any time point between groups. Differences were seen in oxygenation; in group A, PaO₂ significantly increased from a mean of 288.3±47.5 mm Hg with a standard mask to a mean of 390.3±65.5 mm Hg with the CPAP mask and in group B, PaO₂ increased similarly from 325.0±70.5 to 425.2±63.4 mm Hg (P<0.05); no differences were detected between the 2 CPAP treatments. Conclusions – In healthy tranquilized dogs noninvasive CPAP is well tolerated and increases PaO₂ above values obtained when using a regular face mask.     

根际通气量对盆栽番茄生长、蒸腾量及果实产量的影响

为确定作物生长的最优根际通气量,采用空气压缩机控制供气,设置了0.4（T1）、0.8（T2）和1.2（T3）3个通气系数,研究根际通气量对盆栽番茄生长、蒸腾量及相关生理指标的影响。结果表明：通气处理可显著提高番茄植株的茎粗、叶面积指数、叶片叶绿素含量及干物质积累,且均在T2处理下达最高值;在试验不同时期,盆栽番茄的累积蒸腾量受通气量影响的表现不同,盆栽番茄的累积蒸腾量最终表现为：T2>T3>T1>CK;通气处理对盆栽番茄的产量和作物水分生产率均有显著影响。在T2处理下的产量、干物质积累量最高,该处理最有利于盆栽番茄生长。     

平房仓调质通风试验技术研究

采用保水调质机对所储小麦进行调质通风试验,结果表明调质作业能有效减少粮食的重量损失,保持粮食的良好品质,增加经济效益。     

Simulation for the Effect of Building Plan andOrientation on Natural Ventilation

Indoor thermal comfort can be significantly improved by natural ventilation with reasonable architectural design. In order to compare natural ventilation effect, the distribution of velocity field, temperature field and the PMV in different architecture layout and orientation design were analyzed with house types in Best House Type Competition. It was found that indoor natural ventilation effect was obviously improved by means of altering the layout and orientation, where the maximum velocity varied from 0.24m/s to 0.82m/s. And the temperature decreased 0.9℃ and the value of PMV was more approximate to comfort.     

逆流糙米通风加湿调质的加湿特性研究

稻谷（糙米）在储存过程中,因其本身呼吸作用及生化变化,水分逐渐降低,低水分值对稻谷的安全保管是有益的,但对稻谷的加工来说却降低了其品质,使大米精度下降,碎米率增加,出米率降低,口感变差。为此,对逆流糙米通风加湿调质进行了试验,研究了逆流糙米通风加湿调质的加湿特性。研究结果表明：随着风温的增加,单位热耗减小,加湿速率增大,出机粮温线性增加;随着风速的增加,单位热耗增大,加湿速率增大。     

自然通风条件下塑料大棚温度和湿度模拟

为了深入研究大棚通风对大棚内温、湿度影响,基于能量与物质平衡原理建立了大棚内部温、湿度预测模型,对大棚内部温、湿度进行预测模拟,并以试验观测数据对模型进行了检验。结果表明,模拟晴天天窗开度50%(处理1)与100%(处理2)时,大棚温度预测值和实测值决定系数分别为0.98、0.99,相对湿度预测值和实测值决定系数为0.9,模型能较好的预测棚内温、湿度;大通风面积对大棚内温、湿度影响大于小通风面积,通风面积对大棚内温度影响比相对湿度影响明显。研究结果可为通风条件下塑料大棚温、湿度环境控制研究及南方塑料大棚生产管理提供参考依据。     

牛舍冷风机-风管上置置换通风系统设计及降温效果

为了探索一种高效且运行成本低的牛舍降温方式,该试验通过设计合理的风管布置和开口,采取上置置换通风的模式对肉牛舍降温。该设计方案用计算流体力学(computational fluid dynamics,CFD)的方法验证其可行性,并通过实际测试设定风机开启和关闭的适宜时间,试验表明:处理舍系统产生的冷风大量流向牛活动区域,温湿度梯度比对照舍明显,达到了局部降温的节能目的。该系统开启后,10:00-18:00期间,处理舍牛的平均热负荷指数(heat load index,HLI)比对照舍降低7.4(P0.01),平均呼吸频率降低12次/min(P0.01),平均日增质量提高0.37 kg/d(P0.01),缓解了肉牛的热应激,提高了肉牛的养殖效益。处理舍由于相对封闭,故牛活动区域平均相对湿度、CO2和NH3浓度分别比对照舍高26.8%、252 mg/m3、0.54 mg/m3(P0.01),但牛舍环境空气质量符合相关行业标准的要求。该试验为冷风机-风管通风降温系统设计提供了一些参考参数,有利于该系统的优化,并发挥更好的降温效果。     

青藏高原高寒牧区家畜粪便堆肥化处理技术研究

堆肥化处理是有效利用青藏高原高寒牧区牲畜粪便、减轻环境影响的可行途径。本文针对高寒牧区低温和劳动力资源缺乏的问题,研究了一种静态通气方式和保温措施对堆腐效果的影响。静态通气通过埋植于堆体中的通气管实现,而保温通过堆体外的双层塑料膜的温室效应实现。实验结果表明,埋入通气管与翻堆相比可以显著提高堆体内部和堆体外层的温度,有效加快腐熟速度,减少堆腐过程中养分的损失,降低劳动力投入,可以作为高寒牧区替代翻堆的更好通气手段。双层保温膜与单层膜相比能够有效辅助通气管维持堆体高温。堆肥原料中添加磷肥虽然可提高堆腐温度,但同时也增加了堆腐过程中有机质和氮素的损失,需要根据当地实际情况选用。