The Physiological Importance of Glucosinolates on Plant Response to Abiotic Stress in Brassica

Glucosinolates, a class of secondary metabolites, mainly found in Brassicaceae, are affected by the changing environment. This review is focusing on the physiological significance of glucosinolates and their hydrolysis products in the plant response to different abiotic stresses. Special attention is paid to the crosstalk between some of the physiological processes involved in stress response and glucosinolate metabolism, with the resulting connection between both pathways in which signaling mechanisms glucosinolate may act as signals themselves. The function of glucosinolates, further than in defense switching, is discussed in terms of alleviating pathogen attack under abiotic stress. The fact that the exogenous addition of glucosinolate hydrolysis products may alleviate certain stress conditions through its effect on specific proteins is described in light of the recent reports, but the molecular mechanisms involved in this response merit further research. Finally, the transient allocation and re-distribution of glucosinolates as a response to environmental changes is summarized.     

反相乳液聚合法制备P（AA-AMPS）高吸水树脂的合成及其性能结构研究

文章以2-丙烯酰胺基-2-甲基丙磺酸（AMPS）、丙烯酸（从）为共聚功能单体,过硫酸钾（KPS）,过氧化苯甲酰（BPO）为引发剂,聚乙二醇双丙烯酸酯（PEGDA）（Mw=700）为交联剂,以Span-60,Triton X-100为复配乳化剂,通过反相乳液聚合法制备两性离子型高吸水树脂,研究了SAP的合成条件,详细探讨了聚合过程中各种因素对SAP性能的影响,SAP结构与性能的关系等.     

一种基于VME总线双余度容错处理系统的设计与实现

VME总线是具有高可靠性的并行总线,在机载嵌入式系统领域受到广泛应用。文章首先对VME总线结构进行了分析,然后描述了用双机数据处理系统的组成与工作原理,最后重点说明了双机数据处理系统VME总线接口逻辑与系统容错设计方法。     

含锌硝酸铵钙中锌、镁含量测定方法探讨

含锌硝酸铵钙为四川泸天化股份有限公司硝酸铵的改性产品,即硝酸铵中添加了钙、镁、锌元素。通过试验建立了含锌硝酸铵钙产品中锌、镁含量的测定方法,确定了锌含量测定的实验室允许差。本方法精密度、准确度都比较高,锌、镁含量测定的标准偏差分别为0．01和0．10,加标回收率分别为96．00％-106．18％、95．48％-101．72％。     

敏感系数对微波毫米波器件性能指标影响分析

从数学分析的角度给出了一种确定微波毫米波器件敏感系数的方法.可以较为准确地求出器件对某一尺寸变异所引起的工作特性的变化.并以同轴线为例具体讨论了敏感系数的求解方法,给出了根据同轴线特性阻抗所确定的敏感系数表达式,并计算了其各项结构尺寸变异量值的大小.以此证明了该方法在器件设计上的所具有的理论指导意义.     

变倍光学系统的公差分析

为了保证可见光变倍光学系统加工和装配后的成像质量,提出一种基于传递函数灵敏度的公差设计方法,该方法通过标准公差等级模拟实际情况,采用蒙特卡罗模拟和曲线拟合确定公差参数的灵敏度,并利用满足成像要求的基本公差等级,合理分配光机公差。结果表明,在满足像质的要求下,通过这个方法可以放宽对公差的要求,降低加工和装调难度。     

食物成分对胡萝卜中滴滴涕生物有效性的影响

采用基于生理学的体外实验,通过模拟人体的胃肠环境,研究不同食品及食用豆油对胡萝卜中滴滴涕(DDTs)生物有效性的影响。结果表明：0.12g 胡萝卜中添加0.12g 菠菜、0.12g 白菜及0.12g 猪肉作为混合食品时,DDTs 的生物有效性明显下降;其中菠菜和白菜使其降幅较大且相近,分别为78.3%～86.1% 和69.8%～78.6%,猪肉使其降幅相对较小,为46.8%～72.7%。而添加0.12g 大米会导致DDTs 的生物有效性增大37.2%～40.0%。添加0.6g 菠菜、白菜、猪肉和大米后,DDTs 的生物有效性较添加0.12g 有不同程度的降低。DDTs 的生物有效性与食品中蛋白质及纤维素的含量呈负相关,与碳水化合物的含量和热量呈正相关。此外,DDTs 的生物有效性随着添加食用豆油量的增大而增大,在油量为50μl 时增长趋势最为明显。     

SOFC anodes for direct oxidation of hydrogen and methane fuels containing H2S

Single cell solid oxide fuel cells using Ni-YSZ and Co-YSZ anodes were tested in H₂, CH₄, H₂S/H₂ and H₂S/CH₄ fuel mixtures. Their performance was found to quickly degrade in dry CH₄ due to carbon deposition and lifting of the anode from the electrolyte. In contrast, hydrogen or methane containing H₂S showed an increase in exchange current densities when compared to H₂,M/YSZ/LSM,air systems (M = Ni or Co) despite having less optimal anode microstructure. Conversion from metal to metal-sulfide in the presence of H₂S produced large, dense metal-sulfide particles surrounded by YSZ, thus decreasing the triple-phase boundary. Furthermore, CoS-based anodes showed phase segregation and densification toward the electrolyte. Despite this, long-term testing at η_a = 0.5 V of the H₂S/CH₄,CoS-YSZ/YSZ/LSM,air system showed no signs of degradation of the anode over a 6-day period. Only after removal of H₂S from the H₂S/CH₄ stream did the CoS-anode reduce back to Co, signifying H₂S is required to maintain the metal-sulfide active anode.     

Experimental factors that influence carbon monoxide tolerance of high-temperature proton-exchange membrane fuel cells

The poisoning effect of carbon monoxide (CO) on high-temperature proton-exchange membrane fuel cells (PEMFCs) is investigated with respect to CO concentration, operating temperature, fuel feed mode, and anode Pt loading. The loss in cell voltage when CO is added to pure hydrogen anode gas is a function of fuel utilization and anode Pt loading as well as obvious factors such as CO concentration, temperature and current density. The tolerance to CO can be varied significantly using a different experimental design of fuel utilization and anode Pt loading. A difference in cell performance with CO-containing hydrogen is observed when two cells with different flow channel geometries are used, although the two cells show similar cell performance with pure hydrogen. A different combination of fuel utilization, anode Pt loading and flow channel design can cause an order of magnitude difference in CO tolerance under identical experimental conditions of temperature and current density.