双歧杆菌发酵胡萝卜汁酸乳贮藏稳定性研究

从健康人体中选育出2株发酵活力高、耐氧性和抗逆性强的双歧杆菌优良发酵菌株两歧双歧杆菌Bbm和长双歧杆菌Blm作为试验菌株,制备了双歧杆菌纯种及双歧杆菌与乳酸菌混种发酵胡萝卜汁酸乳,考察了发酵产品在室温(20~30℃)和冷藏(0~4℃)条件下的贮藏稳定性。试验结果表明:0~4℃冷藏21d,活菌含量仍可达1×109cfu/mL以上,pH值降至4.2~4.3,酸甜适宜。因此,确定发酵产品0~4℃下贮藏期为21d。     

Novel Components of the Sex Pheromones Produced by Emerald Moths: Identification,Synthesis, and Field Evaluation

The subfamily Geometrinae (Lepidoptera: Geometridae) includes many species called emerald moths. Based on our recent finding of novel polyenyl compounds, including a double bond at the 12-position from two geometrine species, Hemithea tritonaria and Thalassodes immissaria intaminata, (6Z,9Z,12Z)-6,9,12-trienes and (3Z,6Z,9Z,12Z)-3,6,9,12-tetraenes with a C₁₇–C₂₀ straight chain were synthesized and analyzed by GC-MS. The 6,9,12-trienes, which were prepared by a double Wittig reaction between two alkanals and an ylide derived from (Z)-1,6-diiodo-3-hexene, characteristically produced fragment ions at m/z 79, 150, and M–98. The 3,6,9,12-tetraenes, which were prepared by a coupling between (Z)-3-alkenal and an ylide derived from (3Z,6Z)-1-iodo-3,6-nonadiene, showed fragment ions at m/z 79, 148, and M–96. These diagnostic ions were useful to distinguish these compounds from other known polyenyl pheromones, such as 4,6,9- and 6,9,11-trienes and 1,3,6,9-tetraenes. With reference to the GC-MS data, pheromone extracts of other species in Geometrinae inhabiting the Iriomote Islands were analyzed, and the 6,9,12-trienes were identified in the pheromone gland extracts of Pamphlebia rubrolimbraria rubrolimbraria and Maxates versicauda microptera. Furthermore, a field evaluation of the synthetic polyenes in a mixed forest of Tokyo revealed the following new male attractants for emerald moths: Idiochlora ussuriaria by a C₁₇ 6,9,12-triene and Jodis lactearia by a C₂₀ 3,6,9,12-tetraene, indicating the characteristic chemical structures of Geometrinae pheromones. On the other hand, through reexamination of the pheromone extract of H. tritonaria, (3E,6E)-α-farnesene was identified as an electrophysiologically active component in addition to the C₁₇ 6,9,12-triene. The binary mixture attracted more males than the single component lure baited with the triene in the Iriomote Islands.     

20钢管坯表面裂纹研究

详细分析了新钢公司20钢管坯表面裂纹的类型、产生原因、形成机理,针对原管坯生产中的工艺问题提出了改进措施,按新工艺进行了工业性生产试验.试验结果及一年来的生产实践证明,按新工艺生产的20钢管坯表面质量明显改善,表面裂纹明显减少,风铲报废率显著降低.     

Untersuchung des Reflexions- und Transmissionsverhaltens an einem verlustbehafteten Halbraum im Zeitbereich

Übersicht Das Reflexions- und Transmissionsverhalten einer ebenen Grenzfläche zwischen einem Isolator und einem verlustbehafteten Halbraum wird für senkrecht einfallende ebene TEM-Wellen mit beliebiger Wellenformfunktion analytisch im Zeitbereich untersucht. Die reflektierten und durchgehenden Teilwellen werden danach für eine impulsförmige Wellenformfunktion der einfallenden Welle spezialisiert. Aufgrund der Verluste entstehen kontinuierliche Feldanteile. Für die Aufteilung und Ausbreitung der impulsförmigen Feldanteile gelten ganz elementare Zusammenhänge. Durch geeignete Normierungen lassen sich die Feldlösungen sehr allgemein verwenden und auch auf leitungsgebundene Wellen anwenden.

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Investigation of the reflection and transmission properties of a lossy half space in time domain

Contents The reflection and transmission of a plane TEM-wave with arbitrary wave shape which is perpendicular incident on a planar interface between a perfect dielectric and a lossy semi-infinite medium is analytically investigated in the time domain. In addition the reflected and transmitted waves are calculated for incident impulse waves. Due to the losses, continuous terms evolve. The distribution and the propagation of the impulse-shaped parts can easily be described. Because of appropriate normalisation, the field solutions are very flexible and can also be used for transmission lines.

     

Mycotoxins in foodstuffs VI. Formation of sterigmatocystin in bread by Aspergillus versicolor

Sterigmatocystin was formed on different kinds of bread (whole wheat bread, whole rye bread, whole rye bread with shredded wheat, whole wheat bread with wheat germs and whole wheat bread with linseed) by two strains ofAspergillus versicolor. The highest yields were in the range of 0,1–0,4 rg/g. The growth of the moulds and the toxin production were influenced by the total acid content (Säuregrad; must be less than approximately 9) and by the temperature (optimal growth temperature: 20–30° C, optimal temperature for toxin synthesis: 20° C). After 10 days of incubation most of the toxin was already formed.     

硫转移剂在催化裂化装置中的运用

通过分析催化裂化装置中硫分布的影响因素和SOx的转移机理，介绍了国内外硫转移剂的应用和研究情况。最后结合我厂的实际情况提出了一些建议。     

字幕翻译中的功能对等运用——Friends中文化语汇翻译赏析

截取美国情境喜剧《六人行》中部分片段,试用尤金.耐达＂功能对等＂理论来对其字幕中文化语汇的翻译进行赏析,并分析功能对等在字幕翻译中的作用和局限,以期对字幕翻译及翻译教学有所启发。     

Experimental and Numerical Study of the Effect of Gas-Shrouded Plasma Spraying on Cathode Coating of Alkaline Electrolysis Cells

The aim of this work is to improve the performance of electrodes prepared via atmospheric plasma spray by means of gas shrouding which is expected to apparently reduce the oxygen content of the plasma plume and subsequently improve the coating quality. Electrodes with dual-layer coating for alkaline water electrolysis were deposited on Ni-coated perforated substrates. Microstructure and morphology were studied by SEM. Element content was measured by EDS. Enthalpy probe was employed for measuring plasma temperature and velocity as well as the gas composition. For verifying and better understanding the shrouding effect numerical calculation was carried out according to the experimental settings. Electrochemical test was carried out to validate the shrouding effect. The results showed slight protecting effect of gas shrouding on plasma plume and the final coating. Over the dual-layer section, the measured oxygen fraction was 3.46 and 3.15% for the case without gas shrouding and with gas shrouding, respectively. With gas shrouding the coating exhibited similar element contents as the coating sprayed by VPS, while no obvious improvement was observed in the microstructure or the morphology. Evident electrochemical improvement was nevertheless achieved that with gas shrouding the electrode exhibited similar performance as that of the VPS-sprayed electrode.