论香烟小包包装高速机械化和包装材料性质的关系

本文简要介绍了我国香烟小包包装生产的发展方向是淘汰竖包、发展横包；与此同时香烟小包包装机也正在向高速机械化和自动化方向发展。为此，必须加强对香烟小包包装材料的物理、机械等特性的研究，使之适应香烟小包包装机高速化、自动化的要求。     

硼砂型固体渗硼剂渗硼机理探讨

本文应用吉布斯函数法．对化学反应自由焓变化进行计算，通过热力学分析．探讨了以硼砂为供硼源的固体渗硼机理。作者认为．选择合适的还原剂和增加渗剂活性．是提高硼砂型团体渗硼剂渗硼速度的关键。     

谈白云铁矿主采场预裂爆破使用自制预裂药柱的效果

本文介绍了白云鄂博铁矿主采场预裂爆破使用自制预裂药柱的施工要求和效果，并针对采场不同岩性计算出基本的预裂爆破参数。     

重力式三相分离器内流场泥砂沉积规律研究

重力式油气水三相分离器是油田集输系统中的关键设备。通过理论和现场工业性试验研究 ,得出结论 :(1)混合液进入设备后 ,流速突然减慢造成泥砂迅速沉积 ,沉积主要集中在聚结填料尾部 ,最大沉积量在斜板轴向尺寸中部 ;(2 )斜板对泥砂去除率最高 ,特别是对大粒度泥砂去除效果最好 ,粒度 2 5 0 μm以上的砂粒去除率占总堆积量的 83%以上。波纹板填料对泥砂的去除率次之 ,蛇形板填料最差 ;(3)根据分离器内泥砂沉降规律及泥砂粒度分布规律 ,除砂装置应设置在聚结填料尾部 ,尤应考虑设置在斜板下方 ,且冲砂强度要大     

Animal welfare in cross-ventilated, compost-bedded pack, and naturally ventilated dairy barns in the upper Midwest

The objective of this cohort study was to investigate animal welfare in 2 newer dairy housing options in the upper Midwest, cross-ventilated freestall barns (CV) and compost-bedded-pack barns (CB), compared with conventional, naturally ventilated freestall barns (NV). The study was conducted on 18 commercial dairy farms, 6 of each housing type, in Minnesota and eastern South Dakota. The primary breed in all farms was Holstein; 1 CV and 1 NV herd had approximately 30% Jersey-Holstein crossbreds. All freestall herds used sand for bedding. Farms were visited 4 times (once in each season) between January and November 2008, and approximately 93% of all animals in each pen were visually scored on each visit. Outcome-based measurements of welfare (locomotion, hock lesions, body condition score, hygiene, respiration rates, mortality, and mastitis prevalence) were collected on each farm. Lameness prevalence (proportion of cows with locomotion score ≥3 on a 1 to 5 scale, where 1 = normal and 5 = severely lame) in CB barns (4.4%) was lower than that in NV (15.9%) and CV (13.1%) barns. Lameness prevalence was similar between CV and NV barns. Hock lesion prevalence (proportion of cows with a lesion score ≥2 on a 1 to 3 scale, where 1 = normal, 2 = hair loss, and 3 = swelling) was lower in CB barns (3.8%) than in CV (31.2%) and NV barns (23.9%). Hygiene scores (1 to 5 scale, where 1 = clean and 5 = very dirty) were higher for CB (3.18) than CV (2.83) and NV (2.77) barns, with no differences between CV and NV barns. Body condition scores, respiration rates, mastitis prevalence, culling, and mortality rates did not differ among housing systems. The CV and NV barns were evaluated using the cow comfort index (proportion of cows lying down in a stall divided by all animals touching a stall) and the stall usage index (proportion of cows lying divided by all animals in the pen not eating). The CV barns tended to have greater cow comfort index (85.9%) than the NV barns (81.4%) and had greater stall usage index (76.8% and 71.5%, respectively). Dairy cattle housed in CB barns had reduced lameness and hock lesions compared with those housed in freestall barns and had no adverse associations with body condition, respiration rates, mastitis prevalence, culling, or mortality. When comparing the 2 freestall housing options, CV barns had improved cow comfort indices compared with NV barns. Although cows in CB barns had better feet and leg health, as indicated by the reduced lameness and hock lesion prevalence, acquiring bedding and managing the bedded pack could limit their use.     

北皂煤矿海域扩采区地应力测量与分析

基于北皂煤矿海域扩采区为三软地层,为了合理布置巷道,解决巷道支护较困难问题,采用地应力解除法,使用空芯包体应力计对海域扩采区进行了地应力测量,通过对所测数据进行分析得到了北皂煤矿海域扩采区水平构造应力与垂向应力的比值平均为1.56,地应力场以水平构造应力为主,最大主应力方向为北偏东约45,°因此建议巷道轴线方向应尽可能沿北东方向布置。     

大斜度长隔层套管射孔井砾石充填完井设计与应用

大斜度长隔层套管射孔井砾石充填完井对完井作业方案及管柱设计提出了更高的要求,需要对各种完井方案进行分析对比,合理选择井下工具和工艺,优化完井管柱设计及作业程序,减少作业风险并保证作业顺利进行。渤海油田多层套管射孔砾石充填完井,通常采用一次管柱多层充填工艺,该工艺充填的层段总长受到限制并存在作业风险,需考虑作业的时效性。针对多层防砂、有效层间隔离及完井工具要求高等技术难点,采取了先砾石充填后实现层间隔离的思路,采用带管外封隔器的一趟管柱合层砾石充填的方案。该井砾石充填作业顺利完成,既节省了逐层充填的时间,又满足各油层有效开发的要求。现场的成功应用验证了该完井方案的有效性,并为以后类似大斜度长隔层套管井的砾石充填完井提供了参考。     

HEV动力电池组数据采集系统设计

数据采集电路主要完成电池组总电压、各单体电池电压、充放电电流、电池表面温度等信号的实时采集.电池组电压检测主要通过精密电阻进行分压处理;电流检测是通过霍尔电流传感器LTS6-NP将电流信号转换成电压信号;温度检测主要采用LM35温度传感器将温度信号转换成电压信号.将此采集方案和卡尔曼滤波修正算法结合计算得到的SOC值平...     

冰淇淋硬化工艺

主要讨论了几种硬化方法:直接硬化、隧道式硬化、冷藏式硬化和低温硬化,重点分析膨胀率、冰淇淋挤出温度和包装尺寸与硬化时间(冰淇淋中心温度达到-15℃所需时间)的关系。     

电动汽车电池仓内温度场数值模拟

利用FLUENT软件建立相应的数学模型,对不同尺寸的电动汽车电池仓内温度场进行模拟计算,得到了电池仓的最佳尺寸。在此条件下改变电池仓的送风温度,对比电池的温度场变化,获得了最佳送风温度,为电动汽车用锂离子电池仓的温度优化提供理论依据。