新型智能宠物喂养系统的设计与实现

本设计突破目前国外同类产品采用的机械模式,而以触摸显示屏,作为显示和输入设备,在简化操作界面的同时,不但提高了用户交互界面的美观性,也为系统实现智能化提供了可能。传感器件选择目前技术已经非常成熟的悬臂梁式称重传感器,大大节省了成本。微型电磁阀可快速控制水流的通断。微型电动推杆,则通过两个固态继电器,实现伸缩控制。     

船舶柴油机供油提前角云控制模型研究

船舶柴油机作为船舶动力装置,对航运经济有非常重要的支持作用.但是,由其产生的排放污染不容忽视,而且越来越为严重.云是语言值表示的某个定性概念与其定量表示之间的不确定性转换模型.基于云模型的定性知识推理,以概念为基本表示,从数据库中挖掘出定性知识,构造规则发生器.多条定性规则构成规则库,当输入一个特定的条件激活多条定性规则时,通过推理引擎,实现带有不确定性的推理和控制.通过将云控制技术应用于船舶柴油机供油提前角的控制,从而达到控制NOx排放量的目的.并经仿真验证了该方法的正确性.     

基于三次多项式变速算法的中药粉剂下药系统

中药粉剂配方下药系统是一个精度高、反应大滞后的系统,难以使用传统的方法进行下药控制.为有效实现中药粉剂快速、稳定、高精确度的下药问题,本文提出一种利用三次多项式加减速控制算法来实现在线分析医生处方上的中药粉剂配量,并通过Profibus光纤模块控制远程变频电机以计算所得运动曲线进行下药控制.实验结果验证了此方法的有效性.     

随动式动态混合器掺稀混合性能研究

针对稠油掺稀过程中原混合器混合效果不佳的问题,选择满面式螺旋叶片作为混合元件,增加动力叶轮,以增强叶片对流体的剪切能力和转动频率.基于CFD仿真软件,对影响动态混合器混合效果的叶片螺距和动力叶轮两参数进行数值模拟分析,并以管内稀油体积分布情况作为评价标准,研究混合过程中混合元件几何结构的变化对混合器性能的影响规律.结果...     

济钢2^#1750m^3高炉喂线护炉实践

针对济钢2#1750m3高炉炉缸侧壁G1和E1点温度上升的情况,采取了风口喂入含钛包芯线护炉措施,E1点温度从801℃下降到522℃,但G1点温度下降不明显。对喂线期间高炉操作参数的分析表明,喂线促进了炉缸的均匀,对高炉操作影响不大,为解决炉缸局部区域侵蚀提供了一种技术手段,但需要对喂线部位加强冷却。     

Evaluating part designs for automatic feeding in robotic assembly systems: A geometric analysis of the nesting of polyhedral objects

One of the problems encountered by automatic feeding devices, such as vibratory bowl feeders, in robotic assembly systems is nesting which leads to inseparability of parts and jamming. In this paper, we describe a design evaluation procedure to determine whether a part is prone to nesting and to quantify the degree of nesting. The proposed methodology reduces the 3-D protrusion-hole polyhedral containment problem of nesting to a 2-D polygon containment problem by employing a loop-based feature recognition scheme. Subsequently, the 3-D containment configuration is reconstructed from that of the 2-D by using a strategy calleddrop, pull and push. In this context, we introduce the notion of axis as a characteristic direction of a feature that facilitates the analysis of generalized 3-D polyhedral containment. The algorithms are applicable to generic B-Rep CAD data, and their time and space complexities are polynomial.     

筋板自动进料焊接装置的研制

针对大直径冲击钻头和锥形管与法兰的筋板焊接进行了研究,研制了一种筋板自动上料焊接装置,提高了焊接效率。介绍了该装置的自动化上料装置以及其电控系统的设计。该装置主要由机架、上料机构、夹持测距机构、焊枪运动机构、焊机及控制柜等组成。电控系统包括检测与控制两部分,检测部分的检测锥形管的旋转位置,以确定筋板的焊接位置;控制部分控制焊枪的运动,实现对筋板的焊接。该装置可提高肋板焊接的自动化程度,降低焊工的劳动强度,提高工作效率。     

金属线宽与间距渐变的片上螺旋电感设计规则研究

在分析片上螺旋电感的磁场分布及射频损耗机制的基础上,研究了电感的金属线宽及线圈间距的变化对电感性能的影响,在大量数值分析基础上提出了金属线宽与间距之和不变,而金属线宽与间距之比从外圈到内圈逐渐减小的渐变型片上螺旋电感,并得到了实验验证,多组样品的测试结果与数值分析结果相吻合,以2.4 GHz频段处为例,在高阻硅衬底上制备的5 nH渐变结构电感的品质因子Q为11,比具有相同外径和电感值的固定金属线宽及间距的传统电感高19.6%.     

Effects of conjugated linoleic acid supplementation and feeding level on dairy performance,milk fatty acid composition,and body fat changes in mid-lactation goats

The objective of this trial was to study the interaction between the supplementation of lipid-encapsulated conjugated linoleic acid (CLA; 4.5 g of cis-9,trans-11 C18:2 and 4.5 g of trans-10,cis-12 C18:2) and feeding level to test if milk performance or milk fatty acid (FA) profile are affected by the interaction between CLA and feeding level. Twenty-four dairy goats were used in an 8-wk trial with a 3-wk adaptation to the experimental ration that contained corn silage, beet pulp, barley, and a commercial concentrate. During the third week, goats were assigned into blocks of 2 goats according to their dry matter intake (DMI), raw milk yield, and fat yield. Each block was randomly allocated to control (45 g of Ca salt of palm oil/d) or CLA treatment. Within each block, one goat was fed to cover 100% (FL100) of the calculated energy requirements and the other was fed 85% of the DMI of the first goat (FL85). Individual milk production and composition were recorded weekly, and milk FA composition was analyzed in wk 3, 5, and 7. Conjugated linoleic acid supplementation reduced milk fat content and fat yield by 17 and 19%, respectively, independent of the feeding level. It reduced both the secretion of milk FA synthesized de novo, and those taken up from the blood. No interaction between CLA and feeding level was observed on milk secretion of any group of FA. The CLA supplementation had no effect on DMI, milk yield, protein, and lactose yields but it improved calculated net energy for lactation balance. Goats fed the FL100 × CLA diet tended to have the highest DMI and protein yield. The interaction between CLA and feeding level was not significant for any other variables. Compared with the goats fed FL100, those fed FL85 had lower DMI, lower net energy for lactation balance, and lower digestible protein in the intestine balance. The body weight; milk yield; milk fat, protein, and lactose yields; and fat, protein, lactose, and urea contents in milk were not affected by feeding level. In conclusion, reduction in energy spared via fat yield reduction after CLA supplementation was not partitioned toward milk lactose or protein in goats at a low feeding level, possibly because of a simultaneous shortage of energy and amino acids. In goats on the high feeding level, energy spared tended to be partitioned toward milk protein yield, and at the same time to the prevention of excessive lipid mobilization.     

Migration of bisphenol A from polycarbonate baby bottles under real use conditions

Migration of the potential endocrine disrupter, bisphenol A (BPA), from 31 polycarbonate (PC) baby bottles into aqueous food simulants was studied under real repetitive use, using a sensitive and fully validated liquid chromatographic method with fluorescence detection. Confirmation of the presence of BPA was performed by liquid chromatography–mass spectrometry (LC–MS). The effects of cleaning in a dishwasher or with a brush, sterilization with boiling water and the temperature of migration were examined. It was shown that temperature was the crucial factor for the migration of BPA from the plastic bottles to water. All samples released BPA in the concentration range 2.4–14.3 µg kg^?1 when filled with boiled water and left at ambient temperature for 45 min. The decrease of BPA release in the sterilization water and in the food simulant over 12 cycles of use indicated that the hypothesis of polymer degradation in water is dubious. Estimated infantile dietary exposure, regarding the use of PC baby bottles, ranged between 0.2 and 2.2 µg kg^?1 bw day^?1, which is below the Tolerable Daily Intake of 50 µg kg^?1 bw recently established by EFSA.