催化器OBD诊断监测频率功能的研究与验证

介绍了利用储氧量(OSC)法对催化器进行OBD故障诊断的原理,并介绍了法规新增的监测频率(IUPR)功能。通过转鼓试验,验证了在NEDC,FTP75和JC08循环中催化器诊断的完成情况和相应的IUPR率的增长情况。通过实际道路试验,观察IUPR率的变化规律,我们得出:经过一定里程后,同一OBD系族车型催化器诊断的IUPR率趋于稳定一致,可以作为该车型在用符合性检查的数据指标。     

Ethyl acetate fraction of flavonoids from Polygonum hydropiper L. modulates pseudorabies virus-induced inflammation in RAW264.7 cells via the nuclear factor-kappa B and mitogen-activated protein kinase pathways

Pseudorabies virus (PRV) infection leads to severe inflammatory responses and tissue damage, and many natural herbs exhibit protective effects against viral infection by modulating the inflammatory response. An ethyl acetate fraction of flavonoids from Polygonum hydropiper L. (FEA) was prepared through ethanol extraction and ethyl acetate fractional extraction. An inflammatory model was established in RAW264.7 cells with PRV infection to evaluate the anti-inflammatory activity of FEA by measuring cell viability, nitric oxide (NO) production, reactive oxygen species (ROS) release, and mRNA expression of inflammatory factors, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Its functional mechanism was investigated by analyzing the phosphorylation and nuclear translocation of key proteins in the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Our findings indicate that PRV induced inflammatory responses in RAW264.7 cells, and the responses were similar to that in lipopolysaccharide (LPS)-stimulated cells. FEA significantly suppressed NO synthesis and down-regulated both expression and secretion of COX-2, iNOS, and inflammatory cytokines (P<0.05 or P<0.01). FEA also reduced NF-κB p65 translocation into the nucleus and decreased MAPK phosphorylation, indicating that the NF-κB/MAPK signaling pathway may be closely related to the inflammatory response during viral infection. The findings suggested the potential pharmaceutical application of FEA as a natural product that can treat viral infections due to its ability to mitigate inflammatory responses.     

太阳能制冷低温储粮应用效果初探

从降低机械压缩式制冷低温储粮能耗及运行成本的角度出发,设计、建造了一台太阳能吸附式制冷系统,并将该系统在高温季节进行了低温储粮的实仓实验。测试结果表明:在夏秋高温季节,采用太阳能制冷系统冷却粮仓上部空气隔离层,可有效降低仓温,抑制粮温回升,实现准低温储粮。经济性分析表明太阳能制冷系统用于低温储粮的运行成本明显低于压缩式制冷谷物冷却机。     

Atomic force microscopy study of the ultrastructural changes of chelate-soluble pectin in peaches under controlled atmosphere storage

The influences of controlled atmosphere (CA) and storage time on ultrastructural degradation of chelate-soluble pectin (CSP) in yellow peaches (Prunus persica L. Batsch.) were investigated. Freshly harvested peaches were stored at 2 °C under CA (CA1, 2% O₂ + 10% CO₂; CA2, 5% O₂ + 5% CO₂) or regular atmosphere conditions. Qualitative and quantitative aspects of CSP polymers were studied by atomic force microscopy (AFM) on the initial, the 15th and the 45th days. The frequency of small width CSP observations increased with time in both groups, but was greater in the regular atmosphere group, indicating CA conditions inhibited the degradation of CSP molecules. Widths of CSP chains were composed of four basic units with widths of 17.578, 19.531, 23.438 and 29.297 nm from the AFM determination. These results indicate that parallel linkages or intertwists between the basic units are fundamental structural conformations for CSP molecules.     

平行梁冲量式谷物质量流量传感器弹性元件设计

冲量式传感器具有结构简单、使用方便等优点，但容易受到基础振动的干扰。为此设计了平行梁结构冲量式谷物质量流量传感器弹性元件，对弹性元件安装端部采用了削弱设计。有限元分析表明该设计方案不仅符合应力集中原则，而且可以提高传感器抵抗振动干扰的能力。给出了传感器电桥电路，以及后续放大、电压电流变换等调理电路，使得传感器输出零点可以方便调节，降低了传感器在联合收割机上的安装要求。试验结果表明，传感器线性度误差小于0.1%，输出不受外力作用点的影响，同时具备了合适的工作频带宽度。     

高压共轨喷油系统多次喷射油量精确测量与规律分析

该文采用先进的EFS瞬时喷油量测量仪对高压共轨喷油系统多次喷射的预喷和主喷油量同时进行精确的测量，通过大量试验数据分析，文章总结了主、预喷油量跟随喷油间隔的变化规律。另外，发现了主喷油量在小喷油间隔时明显的波动性，通过试验分析确定了喷油器的电液力延迟和喷油间隔时高压燃油的波动是主要原因，为喷油参数的标定和多次喷射控制策略的设计提供了可靠的试验依据。     

中国生物质燃料乙醇项目能量生产效率评估

为了对玉米和木薯乙醇的能量和可再生能量生产效率进行评估，该文统计了玉米和木薯乙醇生命周期能耗，并用市场价值量法按照主副产品的能耗进行了分配。计算出玉米和木薯燃料乙醇的净能量和净可再生能量。并计算了单产和化肥用量变化时的净能量和净可再生能量的变化。计算结果显示，玉米、木薯乙醇的净能量分别为1.472 MJ/L和2.417 MJ/L，净可再生能量分别为1.474 MJ/L和2.459 MJ/L。使用玉米、木薯生产燃料乙醇在能量生产和再生能量生产上都是可行的，木薯乙醇比玉米乙醇可行性更高，单产和化肥用量是提高能源利用和再生能源的关键因素，加强副产品的开发和使用有机肥代替化肥有利于提高系统的能效，提高系统的可再生性。     

基于多方位视觉的果实形状特征的提取研究

针对传统瓜果分级中捕捉单幅果实图像来分析果实特征时信息较少的缺陷，提出了一种基于多方位视觉系统的果实形状特征提取算法。同步采集3个方向的果实图像信息，经OHTA空间上的图像分割和改进的BLOB算法去噪声等处理后，分别给出果实的多方位的图像特征信息。运用统计学原理，设计了线性分类器，对3个方向的图像特征信息进行了互补性融合，得出分级判别准则。利用开发的智能瓜果精选分级试验样机，验证了该算法的有效性, 试验结果证明识别成功率达到97％，达到了实用的要求。     

基于决策树和图层叠置的精准农业产量图分析方法

作物产量限制因子的提取是精准农业变量施肥的重要环节之一。决策树和GIS图层叠置方法研究结果表明，土壤有机质始终占据决策树全部知识规则的第一次分支，起着重要的决定性作用，其次为速效磷和碱解氮；产量空间分布与有机质、碱解氮、速效磷高度吻合，平均吻合度分别达到91%、83%和49%。土壤有机质、速效磷和碱解氮含量是宁夏暖泉农场小麦产量主要限制因子，提高土壤有机质含量是提高单产的重要措施。结论得到生产实际验证，说明运用决策树和GIS图层叠置分析方法挖掘产量限制因子在技术上可行。     

自控温室气象条件对甜椒产量的影响

根据上海东海蔬菜示范基地1996～1997年2茬甜椒产量资料及同期温室内的气象资料,运用数理统计方法分析气象条件对甜椒产量的影响,初步得出温室中甜椒生长关键期的适宜气象指标为播种约30d日最低温度为1.5～15.0℃,日最高温度25.0～25.5℃,CO2浓度400～450mg／kg;播种后加热管温度50℃;而播种后10d左右相对湿度维持在75％,80d左右光照强度为6～6.5万lx。