摘要：试验通过在断奶仔猪日粮中添加经嗜酸乳杆菌或乳酸片球菌发酵的高水分玉米,研究其对断奶仔猪生长性能和肠道菌群的影响。试验采用完全随机分组设计,选用体重和窝次没有显著差异并刚断奶的仔猪270头(去势公猪和母猪各半),随机分配到3个饲粮处理组(每组5个重复,每个重复18头猪)。各组日粮包括基础饲粮与以下各组补充饲粮:未添加任何微生物菌剂但自然发酵的高水分玉米(对照组);乳酸杆菌(LA)发酵的高水分玉米;乳酸片球菌(PA)发酵的高水分玉米。日粮以液体形式饲喂仔猪5周。采用定量聚合酶链式反应(定量PCR)和PCR特异性引物对嗜酸乳杆菌或乳酸片球菌进行分析,结果表明,每个在高水分玉米中接种发酵的细菌群体都发育良好,其中短链脂肪酸(SCfA)的主要发酵产物是乳酸。从3组中抽样进行检测发现,LA-发酵玉米含乳酸浓度最高。在5周的饲养期间不同日粮处理对猪的生长性能无显著影响(P&gt;0.05)。但试验的后3周,LA处理组的体增重显著高于PA处理组(P<0.05)。饲喂LA-发酵高水分玉米组的粪便样本中大肠杆菌显著低于饲喂PA-发酵高水分玉米组(P<0.05)。PCR和变性梯度凝胶电泳(DggE)技术联合分析结肠菌群的细菌型显示,3个菌群和PA处理组的微生物形成1个群集。此外,饲喂LA-或PA-发酵玉米可显著减少结肠细菌微生物复制的多样性和丰富性(P<0.05),说明嗜酸乳杆菌和乳酸片球菌对猪的小肠没有不良的影响。研究结果表明,日粮中添加由益生菌发酵的高水分玉米,可调节肠道菌群,且LA有影响断奶仔猪生长性能的潜能。

摘要：基于青藏铁路楚玛尔河试验段10年（2003～2013）的地温监测资料，对青藏铁路4种典型路基结构的长期热状况进行了对比分析．结果表明，不同路基结构的长期热状况表现出较大的差异．普通路基与块石基底路基地温场存在明显的不对称分布，表明以上两种路基结构不利于路基的长期热稳定．但块石护坡路基与u型块石路基的地温场分布则表现出了较好的对称性．尽管块石护坡路基下浅层冻土地温存在一定的降温过程，但深层多年冻土却呈现出缓慢升温趋势，显示u型块石路基的热稳定性要优于块石护坡路基．被监测的4种路基结构中，u型块石路基在降低多年冻土温度与提高路基地温场对称性方面表现出了最佳的长期效应．基于青藏铁路10年的监测结果，充分肯定了主动冷却路基设计思路在保护冻土路基长期热稳定性方面的有效性，同时采用冷却路基技术的青藏铁路也达到了时速100kmh-1的设计要求．尽管如此，由于坡向效应所导致的路基左右路肩下的热差异存在于所有监测的路基结构中，但不同结构的热差异幅度不同，并将可能导致路基发生潜在的非均匀性沉降变形，因此需要在后续的维护工程中进行调整．

摘要：Theoretically,aeroponic cultivation is easy to make plant roots in a better growth *** order to give better play to the theoretical advantages of aeroponic cultivation,further optimize the structure of the aeroponic cultivation system,and make the aeroponic cultivation system more scientific and reasonable,a barrel-shaped aeroponic cultivation system is *** aeroponic cultivation system is composed of a monitoring and control system,power equipment,nutrient solution storage,and treatment facility,nutrient solution supply pipelines,aeroponic cultivation barrels,and nutrient solution return *** cultivation system working principle and its technical requirements were analyzed,and its structure for meeting the requirements of large-scale production was determined.A performance test of the barrel-shaped aeroponic cultivation system using cultivated narrow leaved Chinese chives was *** Chinese chives were cultivated to 6 beds of the cultivation *** system supplied nutrient solution every 30 min for 2 min each *** 5 weeks growth,the length,leaf width,and single weight of Chinese chive ranged from 293-362 mm,4.1-6.7 mm,and 3.48-5.47 g,respectively,the average length,leaf width,and single weight of Chinese chive were 327 mm,5.1 mm,and 4.24 g,respectively,and there were no significant differences in the length,leaf width,and single weight of Chinese chive on 6 beds by One-way *** test results showed that all the Chinese chive in each bed of the cultivation barrel grew well and uniform,which indicated that the circulation process of nutrient solution supply and return in the system was normal,the process of nutrient solution atomization in the system was uniform,and the aeroponic cultivation system operated normally and stable and could be applied in production.