<i>Relationship between stress relaxation characteristics and quality of Chinese cabbage (Brassica pekinensis L.)</i>

2020 ◽  
Author(s):  
Yuting Dai ◽  
Jun Wang ◽  
Dongdong Du
Alloy Digest ◽  
1981 ◽  
Vol 30 (5) ◽  

Abstract ULTRONZE is a copper alloy also known as Olin Alloy 654. It bridges the gap between standard high-performance copper alloys and beryllium-copper alloys, thus enabling the design of parts with properties previously only attainable with more expensive materials. The alloy has superior stress-relaxation characteristics, good bend performance and excellent corrosion resistance. Among its typical uses are electrical connectors, fuse clips and relay springs. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Cu-417. Producer or source: Olin Brass.


2012 ◽  
Vol 8 (1) ◽  
pp. 47-49
Author(s):  
Jinghe Wang ◽  
Miao Yu ◽  
Zhichao Wu ◽  
Yingchun Liang ◽  
Shen Dong

Author(s):  
Е.В. ЛИСОВАЯ ◽  
М.Р. ЖАНЕ ◽  
Е.В. ВЕЛИКАНОВА ◽  
Е.П. ВИКТОРОВА

Жидкие соевые лецитины вырабатывают в больших объемах, чем лецитины из других растительных масел. Поэтому актуален поиск инструментального способа определения качества жидких соевых лецитинов – кислотного числа (КЧ). Для разработки способа определения КЧ жидких соевых лецитинов на основе импульсного метода ядерного магнитного резонанса (ЯМР) исследовали содержание и влияние на ядерно-магнитные релаксационные характеристики (ЯМ-релаксационные характеристики) жидких соевых лецитинов липидов, проявляющих кислотные свойства. Объектом исследования были две пары образцов жидких соевых лецитинов. Образцы в каждой паре имели одинаковое содержание фосфолипидов и масла при различных значениях КЧ. Исследование ЯМ-релаксационных характеристик протонов жидких соевых лецитинов проводили на ЯМР-анализаторе АМВ-1006М при температуре 23°С. Установлено, что значение КЧ жидких соевых лецитинов не влияет на время релаксации и амплитуду сигналов ЯМР протонов компонент жидких соевых лецитинов, которая изменяется только в зависимости от содержания в лецитине масла и фосфолипидов. Таким образом, необходимо продолжить поиск аналитического параметра, который бы с высокой точностью характеризовал содержание липидов, проявляющих кислотные свойства, в жидких соевых лецитинах и, следовательно, значение их КЧ. Liquid soy lecithins are produced in larger volumes than lecithins from other vegetable oils. Therefore, the search for an instrumental method for determining the quality of liquid soy lecithins – the acid number (AN) is relevant. To develop a method for determining the AN of liquid soy lecithins based on the pulse method of nuclear magnetic resonance (NMR), the content and effect on the nuclear magnetic relaxation characteristics (NM-relaxation characteristics) of liquid soy lecithins of lipids that exhibit acidic properties were studied. The object of the study was two pairs of samples of liquid soy lecithins. The samples in each pair had the same content of phospholipids and oil at different values of AN. The study of the NM-relaxation characteristics of protons of liquid soy lecithins was performed on an AMV-1006M NMR-analyzer at a temperature of 23°C. It was found that the value AN of liquid soy lecithins does not affect the relaxation time and the amplitude of NMR signals of proton components of liquid soy lecithins, which changes only depending on the content of oil and phospholipids in lecithin. Thus, it is necessary to continue searching for an analytical parameter that would accurately characterize the content of lipids that exhibit acidic properties in liquid soy lecithins and, consequently, the value of their AN.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
He-He Cao ◽  
Hui-Ru Liu ◽  
Zhan-Feng Zhang ◽  
Tong-Xian Liu

Abstract The green peach aphid, Myzus persicae Sulzer, is a notorious pest on vegetables, which often aggregates in high densities on crop leaves. In this study, we investigated whether M. persicae could suppress the resistance level of Chinese cabbage Brassica pekinensis. M. persicae performed better in terms of weight gain (~33% increase) and population growth (~110% increase) when feeding on previously infested (pre-infested) Chinese cabbage compared with those on non-infested plants. However, when given a choice, 64% of the aphids preferred to settle on non-infested leaves, while 29% of aphids chose pre-infested leaves that had a 2.9 times higher concentration of glucosinolates. Aphid feeding significantly enhanced the amino acid:sugar ratio of phloem sap and the absolute amino acid concentration in plant leaves. Aphid infestation significantly increased the expression levels of salicylic acid (SA) marker genes, while it had marginal effects on the expression of jasmonate marker genes. Exogenously applied SA or methyl jasmonate had no significant effects on M. persicae performance, although these chemicals increased glucosinolates concentration in plant leaves. M. persicae infestation increase amino acid:sugar ratio and activate plant defenses, but aphid performed better on pre-infested plants, suggesting that both nutrition and toxics should be considered in insect-plant interaction.


1973 ◽  
Vol 62 (4) ◽  
pp. 549-556 ◽  
Author(s):  
H. J. B. Lowe

Apterous adult Myzus persicae (Sulz.) of a glasshouse strain differed greatly in their ability to colonise sugar-beet according to the plant on which they and their forebears were cultured. Those from Chinese cabbage (Brassica pekinensis) settled least readily on beet, whilst aphids from broad beans (Vicia faba) produced larger populations than those cultured on sugar-beet. When reared wholly on groundsel (Senecio vulgaris) young adults differed in their ability to colonise Chinese cabbage, sugar-beet and broad bean according to their parents' culture host species, and these differences were detected in a second generation reared wholly on groundsel. The responses of clones isolated from cultures maintained continuously on Chinese cabbage and broad bean were similar, showing that the effect was caused by the aphids' host-plant experience, and was not due to fixed, heritable characters of the sub-cultures. Some, but not all clones of M. persicae collected from the field showed enhanced colonising ability after culture on broad bean as compared with Chinese cabbage. This was apparent on sugar-beet and lettuce (Lactuca sativa). These effects of former hosts on the ability of M. persicae to colonise plants may be important both in work on resistance to aphids and in the epidemiology of aphid-borne diseases.


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