基于非线性PID的串联锂离子电池组的均衡控制

针对串联锂离子电池组充放电过程中的均衡问题,设计了一种新型的非线性PID均衡控算法。利用非线性函数,构造了误差与PID参数的非线性映射关系,使得PID调节器中的增益参数随控制误差而变化,比常规的线性PID调节器具有更强的鲁棒性和更好的动态响应。仿真结果表明,该算法控制精度高,速度快,能够无超调地实现锂离子电池的能量均衡。     

包埋法制备SiC涂层内残留Si的高温抗氧化作用机制

采用包埋法在C/C基体上制备了SiC涂层, 借助X射线衍射仪(XRD)和扫描电镜(SEM)对涂层的相组成及微观形貌进行了观察和分析, 研究了涂层在1500℃静态空气中的氧化行为, 并进一步阐述了涂层的抗氧化机制。结果显示: 包埋法制备的涂层由α-SiC、 β-SiC及游离Si组成, 经XRD半定量分析得到不同工艺制备的涂层中游离Si含量不同; 游离Si含量越高涂层越致密; 氧化性能显示涂层中适量的游离Si有利于涂层的抗氧化, 当涂层中游离Si质量分数为1.3%和2.9%时其抗氧化性能均较好, 在1500℃静态空气中氧化7 h失重率分别为0.19%和0.16%。      

煤粉对裂缝导流能力的伤害机理

应用FCES-100裂缝导流仪和平流泵模拟了煤层气排采过程中煤粉颗粒侵入压裂裂缝支撑剂充填层的过程,研究了煤粉在支撑剂充填层内的运移规律及其对导流能力的伤害机理、影响程度。实验表明：煤粉易侵入支撑剂充填层,不易随水排出,对导流能力伤害严重,并且随着煤粉浓度增加伤害程度急剧增大。煤粉的聚集附着、桥堵孔喉是支撑剂充填层导流能力伤害的主要原因。粒径较小的煤粉更易运移聚集伤害裂缝导流能力,使用小粒径支撑剂可以有效地俘获煤粉颗粒,有利于提高主裂缝的导流能力;压裂后快速返排有助于煤粉迅速排出,减少其在裂缝内的滞留,并保持排采稳定有利于煤粉顺利排出,避免聚集堵塞。     

自组装颗粒调驱体系注入方式优选实验研究

针对渤海油田储层渗透率高、水驱窜流严重的问题,采用新型自组装颗粒调驱体系,进行室内封堵以及驱油实验研究,并对颗粒注入方式进行对比。静态实验表明,自组装颗粒具有良好的耐温耐盐性能,耐温100 ℃, 耐盐35 000 mg/L;封堵实验表明,对于渗透率为10 000×10^-3 μm² 左右的砂管模型,采用胍胶或聚合物溶液悬浮颗粒封堵后,砂管渗透率降至3000×10^-3 μm² 左右,砂管有效封堵率达70%;驱油实验表明,对于渗透率为20000× 10^-3 μm2 和4 000×10^-3 μm² 的并联砂管模型,在水驱采出程度为27.34%~28.17%的基础上,注入0.4PV 自组装颗粒调驱体系,其采出程度可提高28.57%~38.76%,最终达55.91%~66.80%,且采用胍胶或聚合物悬浮颗粒的注入方式效果较好。实验揭示了自组装颗粒的封堵机理主要是填充封堵、架桥封堵、黏接封堵。     

Dairy cow preference for different types of outdoor access

Dairy cows display a partial preference for being outside, but little is known about what aspects of the outdoor environment are important to cows. The primary aim of this study was to test the preference of lactating dairy cattle for pasture versus an outdoor sand pack during the night. A secondary aim was to determine whether feeding and perching behavior changed when cows were provided outdoor access. A third objective was to investigate how the lying behavior of cows changed when given access to different outdoor areas. Ninety-six lactating pregnant cows were assigned to 8 groups of 12 animals each. After a baseline phase of 2 d in which cows were kept inside the freestall barn, cows were habituated to the outdoor areas by providing them access to each of the 2 options for 24 h. Cows were then given access, in random order by group, to either the pasture (pasture phase) or the sand pack (sand phase). As we tested the 2 outdoor options using space allowances consistent with what would be practical on commercial dairy farms, the space provided on pasture was larger (21,000 m²) than that provided on the sand pack (144 m²). Cows were tested at night (for 2 nights in each condition), from 2000 h until morning milking at approximately 0800 h, as preference to be outdoors is strongest at this time. During the next 3 nights cows were given access to both outside options simultaneously (choice phase). Feeding and perching behaviors were recorded when cows were indoors during the day and night periods. Lying behavior was automatically recorded by HOBO data loggers (Onset, Bourne, MA). Cows spent more time outside in the pasture phase (90.0 ± 5.9%) compared with the sand phase (44.4 ± 6.3%). When provided simultaneous access to both options, cows spent more time on pasture than on the sand pack (90.5 ± 2.6% vs. 0.8 ± 0.5%, respectively). Time spent feeding indoors during the day did not change regardless of what type of outdoor access was provided, but there was a decline in perching during the day when cows were provided access to either outdoor option at night. Lying time in the pasture phase was lower than in the baseline or sand phase. During the nighttime, lying time outside was not different between the sand (55.4 ± 7.9%) and pasture (52.0 ± 7.4%) phases. In summary, cows spent a considerable amount of time outside during the night when given the opportunity and showed a preference for a large pasture versus a small sand pack as an outdoor area.     

Application of lithium ion phosphate battery in 110 kV substation DC power system

本项目选用了两种不同的电池管理模式对磷酸铁锂电池组进行管理,并将组装好的两套电池组应用于110 kV变电站直流系统的日常运行.运行结果表明,磷酸铁锂电池可以在变电站替代铅酸蓄电池使用,并且可以浮充运行;运行过程中,单体电池的电压会由于电池充电态的变化下降或上升;单体电池的内阻呈现先下降再上升的变化;电池组的放电容量随着运行时间的延长出现每年3%左右的衰减(浮充电压为3.6 V);合适的电池管理模式能将电池组内单体电池的电压差保持在较小的范围,有利于电池组长寿命的运行.     

双组分水性聚氨酯涂料的研究

通过使用交联固化剂氮丙啶与丙烯酸聚氨酯复合乳液（PUA）组成双组分体系,进行配漆和性能测试。最终通过提高体系交联密度进一步改善涂膜的各项性能;借助傅里叶变换红外光谱和力学实验技术等研究了聚氨酯胶膜的结构及力学性能的影响。     

浅谈化工与食品安全

化工制剂对食品行业的发展起到了重要的推动作用,然而其不合理的使用导致的食品安全问题频发,也令化工制剂成为了食品安全问题的"替罪羊"。文章介绍了化工制剂在食品生产、加工及包装等环节中可能存在的安全问题,并分析了其主要原因,提出了预防措施,以期引发人们对化工制剂正确使用的关注,更好的解决日益严峻的食品安全问题。     

海上疏松砂岩稠油油藏压裂充填优化设计

建立了考虑疏松砂岩稠油油藏启动压力梯度、压力敏感性,以及裂缝导流能力失效性的压裂井数学模型,实现了该模型的数值求解。在防止地层出砂的前提下,对渤海湾某油田进行了压裂充填参数设计。研究表明,与不压裂相比,在该区块实施压裂充填改造在经济上是可行的,参数优化结果为该区开发方案设计提供了技术支撑。     

一起通信基站蓄电池组火灾事故的调查

介绍了金华兰溪市某通信基站的蓄电池组火灾事故,调查组通过现场勘查、物证鉴定、询问调查,并调取基站后台的电流、电压、人员进入告警、断电警报、烟雾探测器等设备运行数据,对此次起火事故进行了综合分析认定,并总结了调查此类火灾的经验。