Purification and characterisation of the 7S globulin storage protein from sesame (Sesamum indicum L.)

The 7S globulin from sesame seeds was purified by means of selective precipitation and anion-exchange chromatography on Q Sepharose Fast Flow. The 7S globulin migrated as a single band on native PAGE, which suggested homogeneity of the sample. The isolated protein was composed of at least eight polypeptide chains, ranging from 12.4 to 65.5 kDa, judged by SDS–PAGE analysis, and did not contain disulphide bonds. Furthermore, comparison of the polypeptide bands of the 7S and 11S globulins by SDS–PAGE indicated that the purified 7S globulin was free of legumin-like contaminant polypeptides and of 2S albumin. The identity of the purified polypeptides was verified by comparing the N-terminal amino acid sequences of the main polypeptide bands with the amino acid sequence deduced from a cDNA clone, which encoded the sesame 7S globulin precursor. Purification of the 7S globulin from sesame has not previously been reported.     

硬限幅函数神经元的精确实现

本文提出了一种新的利用跨导运放ＯＴＡ精确实现电压－电流型硬限幅函数神经元方法，它的主要特点是容易实现、且神经元的输幅可调。     

Local observability of invariant dynamics on compact Lie groups with square integrable output map functions

In this work, we give a sufficient algebraic condition for the local observability problem of invariant control systems on compact Lie groups such that the output map is not differentiable. In particular, the usual techniques involving Lie derivatives do not work. Our approach comes from the representation theory. We use the regular representation to construct a bilinear system on the Hilbert space of the square integrable function defined on the group to a finite-dimensional vector space. If this bilinear system is observable, then we prove that the invariant control system is locally observable.     

基于One Wire Bus的CRC校验软件实现

利用OneWireBus串行传输iButton器件数据，CRC校验是必不可少的。有二种CRC校验实现方案：硬件实现和软件实现方案。软件方案中，又有几种不同的方法，软件实现节省了专门的硬件校验电路。DOWCRC用查表法速度更快，CRC16用公式法更优越，既节省存储空间又提高校验速度。     

黑龙江产芫荽籽香气成分研究

研究了黑龙江产芫荽籽的香气成分。采用两种固相微萃取柱萃取芫荽籽香气成分，并用GC—MS分析，还与水蒸气蒸馏法获取的芫荽籽精油的成分进行了比较。用DVB／CAR on PDMS萃取柱时，检出24个成分，解析出占总成分的85．391％的17种物质，主要成分芳樟醇相对含量44．666％；用CAR on PDMS萃取柱时，检测出19种成分，解析出占总成分98．443％的18种成分，主要成分芳樟醇相对含量为32．578％；水蒸气蒸馏法获取的芫荽籽精油得油率为0．50％，检测出31个成分，解析出占精油总成分的99．727％的29种成分，芳樟醇相对含量为73．614％。     

Effects of loading mode and water chemistry on stress corrosion crack growth behavior of 316L HAZ and weld metal materials in high temperature pure water

The stress corrosion cracking (SCC) growth rates of 316L weld heat-affected zone (HAZ) and weld metal materials in high temperature pure water at 288 °C were measured using contoured double cantilever beam (CDCB) specimens and an alternating current potential drop (ACPD) in situ crack-length monitoring system. The effects of loading mode and dissolved oxygen and hydrogen on crack growth rate (CGR) were experimentally quantified. Typical intergranular SCC was found in the HAZ specimen and interdendritic SCC was identified in the weld metal specimen. The HAZ specimen and the weld metal specimen showed quite a similar response to the applied loading modes and the water chemistry, even though their absolute CGR values were different. The crack growth rates under trapezoidal loading were moderately higher than those under constant loading by several tenths percent. Switching the water chemistry from the oxygen-bearing water to the hydrogen-bearing water drastically decreased the electrochemical potential and the crack growth rate, and vice versa. A time-lag period for crack growth was observed after switching the water chemistry back to the oxygen-bearing water, where the crack growth rate was low even the dissolved oxygen concentration and the electrochemical potential had become high. Strain hardening and the resultant uneven distribution of deformation contribute to the enhanced intergranular SCC growth behavior in the HAZ area. The crack growth kinetics is analyzed based on the deformation/oxidation interaction at the crack tip, considering the importance of the electric-charge transfer, mass transport kinetics and the crack tip strain rate.     

Effect of Salt Stress on the Expression and Promoter Methylation of the Genes Encoding the Mitochondrial and Cytosolic Forms of Aconitase and Fumarase in Maize

The influence of salt stress on gene expression, promoter methylation, and enzymatic activity of the mitochondrial and cytosolic forms of aconitase and fumarase has been investigated in maize (Zea mays L.) seedlings. The incubation of maize seedlings in 150-mM NaCl solution resulted in a several-fold increase of the mitochondrial activities of aconitase and fumarase that peaked at 6 h of NaCl treatment, while the cytosolic activity of aconitase and fumarase decreased. This corresponded to the decrease in promoter methylation of the genes Aco1 and Fum1 encoding the mitochondrial forms of these enzymes and the increase in promoter methylation of the genes Aco2 and Fum2 encoding the cytosolic forms. The pattern of expression of the genes encoding the mitochondrial forms of aconitase and fumarase corresponded to the profile of the increase of the stress marker gene ZmCOI6.1. It is concluded that the mitochondrial and cytosolic forms of aconitase and fumarase are regulated via the epigenetic mechanism of promoter methylation of their genes in the opposite ways in response to salt stress. The role of the mitochondrial isoforms of aconitase and fumarase in the elevation of respiration under salt stress is discussed.     

Volatile compounds in table olives (Olea Europaea L., Nocellara del Belice cultivar)

Table olive quality depends on a number of factors, including fruit characteristics, ripening and processing technologies. Volatile and semi-volatile organic compounds, present both in the sample matrix and in the headspace aroma, are responsible for the olive fruit flavour influencing the consumer’s preference.     

IP接入网

文章给出了IP接入网的定义、功能体系,介绍了IP用户终端和ISP链路层协议,重点讨论了适于支持IP接入的几种方式。