烤烟房温湿度自动测控系统设计

介绍了基于89C51单片机的烤烟房温湿度测控系统软硬件的设计,整个系统由数据采集、数据调理、单片机和控制部分组成.引入了温度传感器AD590和湿度传感器HS1101在烤烟方面的运用,采用该测控系统准确地检测烤烟房内的温湿度数据,有效地自动控制烤烟房内的温湿度,提高了烤烟房内的控制水平和烟叶的烘烤质量,从而增加了烟农的收入.     

玉米黄色素的稳定性研究

主要研究了玉米黄色素的稳定性.该色素耐光性、耐热性较差,对氧化剂极不稳定,对Al3 、Fe3 等离子稳定性较差,而对酸、碱、还原剂、食品添加剂及Na 、K 等离子较稳定.     

TECHNICO-ECONOMICAL FEASIBILITY OF SOLAR-ASSISTED VIRGINIA TOBACCO CURING

The technical and economical feasibility of using solar energy for curing Virginia tobacco in the bulk barn is investigated. The results illustrate that the energy saving obtained by each type of the system studied is limited because of the nature of the tobacco curing energy requirement. From the technical point of view, the system using water as a heat transfer fluid with an evacuated solar collector shows the best performance. To be economically competitive, the systems need to be multi-purpose: for example, they can be used for space and water heating or for drying other crops during the off-season for tobacco.     

密集烤房陶火管散热系统研究

为有效解决密集烤房散热系统的耐用性和设备的更新换代问题,降低密集烤房建造成本,提高散热设备使用寿命,我们通过改进散热系统的使用材质和设计结构,采用成本低廉、取材方便、经久耐用的陶火管散热系统来代替钢质材料散热系统。对比试验结果表明,陶火管散热系统比钢质材料散热系统成本低2 400元/座,使用寿命增加6～10年,烤房烘烤性能、烘烤运行成本及烤后烟叶外观质量较理想,陶火管散热系统具有很好的推广应用前景。     

半堆积式烤房的试验、研究和应用

结合安徽实际对半堆积式烤房的结构进行了改造,初步探讨了适合的烘烤工艺,并与普通烤房和烤霸进行了比较试验.实践证明,半堆积式烤房具有安全、省工、节能、高效的特点,建造成本、烘烤成本和投入产出比等多项指标优于普通烤房和烤霸.     

Effects of flooring and restricted freestall access on behavior and claw health of dairy heifers

Claw health, locomotion, feed intake, milk yield, body weight, activity, and lying and standing behavior of dairy heifers were monitored in a single dairy herd during the first 3 mo after calving. During the first 8 wk after calving, 2 treatments were applied: restricted freestall access by closing the stalls between 2300 h and 0500 h (yes or no) and alley flooring (concrete or rubber topped slatted floors). Apart from treatments, housing was identical. The animals were kept in small groups (n = 4 to 6) in adjacent barn pens. Thereafter, the animals were kept in 1 group in a freestall section with concrete slatted floor and unrestricted access to the stalls for 5 wk. All animals were fed the same partial mixed ration. We hypothesized that (1) hard flooring causes high mechanical load of the claws and (2) restricted freestall access causes prolonged standing bouts and reinforced effects of hard flooring on claws. The heifers had only minor claw lesions before first calving, and the prevalence and severity of sole hemorrhages increased during the first 3 mo after calving (from 0.24 ± 0.08 to 1.18 ± 0.14 and from 0.04 ± 0.01 to 0.24 ± 0.02, respectively), particularly in the outer hind claws. Animals kept on rubber alley flooring had lower average hemorrhage scores in wk 9 (0.13 ± 0.03 vs. 0.21 ± 0.03) and wk 14 (0.20 ± 0.03 vs. 0.27 ± 0.03) after calving, had a slower feed intake (3.05 ± 0.14 vs. 3.46 ± 0.14 g/s) and spent more time feeding (7.3 ± 0.3 vs. 6.6 ± 0.3 min/h) than animals kept on hard concrete alley floors. Restricted freestall access resulted in fewer standing bouts per day (14.4 ± 1.0 vs. 17.9 ± 1.0) and more strides per hour (99.8 ± 5.4 vs. 87.2 ± 5.4) without changing overall standing time (15.0 ± 0.3 vs. 14.7 ± 0.3 h/d) and did not affect the occurrence of sole hemorrhages. The animals with no overnight freestall access spent more time standing (55.9 ± 0.9 vs. 35.8 ± 0.9 min/h) and feeding (7.8 ± 0.3 vs. 4.3 ± 0.3 min/h) between 2300 and 0500 h and less during the rest of the 24-h period (31.3 ± 0.8 vs. 37.0 ± 0.8 min/h and 6.8 ± 0.3 vs. 7.6 ± 0.3 min/h). Thus, the animals adapted to restricted freestall access, that caused increased overnight standing, by additional lying down during the day and used part of the extra standing time at night for feeding. The restrictions probably had only a minor effect on the mechanical load of their claws. Therefore, the first part of the hypothesis was confirmed and the second part was rejected.     

粮仓电磁探测环境的FDTD仿真分析

粮仓的电磁探测技术是储粮检测领域的研究热点问题。本研究针对粮仓电磁探测技术中,回波图像解释困难这一瓶颈问题展开研究,选取我国最常见浅圆形粮仓,采用时域有限差分(FDTD)法进行仓内电磁波回波图像仿真。针对探仓雷达常采取的2种探测路径,分析了仓顶、仓壁、仓底在二维回波图像中的位置和形态,并通过对实际探仓数据的分析,证实了粮仓电磁探测环境的FDTD仿真分析能够为探仓雷达回波图像的解释提供依据,为提高探仓雷达回波预处理精度及有效目标回波的合理提取提供技术支持。     

群体高耸粮仓筒壁顶盖一体化施工技术

指出中粮(郑州)产业园项目立筒仓工程和浅圆仓工程采用筒壁顶盖一体化施工技术,详细介绍了该施工技术的工艺原理、操作要点、质量保证措施,并通过在工程中实践证明,采用筒壁顶盖一体化施工技术工艺合理,节时节工,操作方便,有效控制了施工质量。     

射孔-防砂联作防砂效果室内模拟与测试

通过测试，岩心靶防砂填充层的孔隙度达39．15％、油测渗透率为46．55μm^2，说明防砂填充层的渗透性很好，能够满足油井高产要求。采用地面模拟装置、选择不同粒径的砂样进行防砂实验得出，140～200m砂样最大出砂浓度为0．07278％，更细的砂粒不出砂。此结果表明，对大粒径的防砂效果好。     

Prevalence of lameness in high-producing holstein cows housed in freestall barns in Minnesota

A cross-sectional study was conducted to estimate the prevalence of clinical lameness in high-producing Holstein cows housed in 50 freestall barns in Minnesota during summer. Locomotion and body condition scoring were performed on a total of 5,626 cows in 53 high-production groups. Cow records were collected from the nearest Dairy Herd Improvement Association test date, and herd characteristics were collected at the time of the visit. The mean prevalence of clinical lameness (proportion of cows with locomotion score ≥3 on a 1-to-5 scale, where 1 = normal and 5 = severely lame), and its association with lactation number, month of lactation, body condition score, and type of stall surface were evaluated. The mean prevalence of clinical lameness was 24.6%, which was 3.1 times greater, on average, than the prevalence estimated by the herd managers on each farm. The prevalence of lameness in first-lactation cows was 12.8% and prevalence increased on average at a rate of 8 percentage units per lactation. There was no association between the mean prevalence of clinical lameness and month of lactation (for months 1 to 10). Underconditioned cows had a higher prevalence of clinical lameness than normal or overconditioned cows. The prevalence of lameness was lower in freestall herds with sand stalls (17.1%) than in freestall herds with mattress stall surfaces (27.9%). Data indicate that the best 10th percentile of dairy farms had a mean prevalence of lameness of 5.4% with only 1.47% of cows with locomotion score = 4 and no cows with locomotion score = 5.