排序方式: 共有44条查询结果,搜索用时 15 毫秒
1.
SC_9-4是以植物油为原料研制成功的一种高速冷轧工艺润滑油。经武钢高速冷轧机轧制性能鉴定,它的高速轧制性能优于棕榈油。我们使用高效液相色谱比较分析鉴定了SC_9-4和棕榈油的甘油三酯组成。分析结果:SC_9-4:的主要甘油三酯是POP(42.8%)和PPP(14.6%),而棕榈油的主要甘油三酯是POP(31.3%)、POO(20.1%)、PLP(12.2%)和PLO(11.6%)。我们初步探讨甘油三酯组成与轧制性能关系认为,SC_9-4的高速轧制性能优于棕榈油,可能是和SC_9-4含PPP、PPS和PSS的含量(18.8%)高于棕榈油(9.9%)有关。 相似文献
2.
修剪强度对乌桕产量的影响 总被引:5,自引:0,他引:5
对乌桕Sapium sebiferum(L.)Roxb.林进行四种不同强度的修剪试验,结果表明,以中度修剪产量最高,结实性状最好。 相似文献
3.
4.
5.
The introduced tree Sapium sebiferum (Euphorbiaceae) is considered a serious threat to the preservation of the coastal prairie region of Louisiana and Texas, although it is currently uncommon in the western part of the region. The objective of this study was to evaluate the potential effects of location, soils, and available moisture on the growth and survival of S. sebiferum in coastal prairie. In a field experiment, S. sebiferum mortality was significantly greater at a western site than at central and eastern sites. The greatest mortality and least growth of surviving plants occurred on a soil from the western region, regardless of site. A greenhouse study also found that S. sebiferum growth was lowest on the western soil. Watering frequency significantly affected S. sebiferum growth, except on the western soil. Sapium sebiferum growth responded to both nitrogen and phosphorus additions for all soils. Soil analyses revealed the highest sand, sodium, and phosphorus contents, and much higher electrical conductivity in the western soil. It is concluded that the soil examined from the western region is unfavorable for S. sebiferum growth, though not to the extent to preclude S. sebiferum completely. Evidence suggests that soil salinity may be the primary cause of the poor S. sebiferum growth at the western site. 相似文献
6.
James Kirby J. Genevieve Park Farnaz Nowroozi Dominik Behrendt Jeffrey L. Fortman Holly E. Johnson Jay D. Keasling 《Phytochemistry》2010,71(13):1466-1025
A large number of diterpenes have been isolated from Euphorbiaceae plants, many of which are of interest due to toxicity or potential therapeutic activity. Specific Euphorbiaceae diterpenes of medical interest include the latent HIV-1 activator prostratin (and related 12-deoxyphorbol esters), the analgesic resiniferatoxin, and the anticancer drug candidate ingenol 3-angelate. In spite of the large number of diterpenes isolated from these plants and the similarity of their core structures, there is little known about their biosynthetic pathways. Other than the enzymes involved in gibberellin biosynthesis, the only diterpene synthase isolated to date from the Euphorbiaceae has been casbene synthase, responsible for biosynthesis of a macrocyclic diterpene in the castor bean (Ricinus communis). Here, we have selected five Euphorbiaceae species in which to investigate terpene biosynthesis and report on the distribution of diterpene synthases within this family. We have discovered genes encoding putative casbene synthases in all of our selected Euphorbiaceae species and have demonstrated high-level casbene production through expression of four of these genes in a metabolically engineered strain of Saccharomyces cerevisiae. The only other diterpene synthase found among the five plants was a neocembrene synthase from R. communis (this being the first report of a neocembrene synthase gene). Based on the prevalence of casbene synthases, the lack of other candidates, and the structure of the casbene skeleton, we consider it likely that casbene is the precursor to a large number of Euphorbiaceae diterpenes. Casbene production levels of 31 mg/L were achieved in S. cerevisiae and we discuss strategies to further increase production by maximizing flux through the mevalonate pathway. 相似文献
7.
8.
An in vitro propagation technique based on axillary bud proliferation has been developed for matureSapium sebiferum trees. Nodal segments cultured on Murashige and Skoog (MS) medium supplemented with benzyl adenine (1–10 m and -naphthaleneacetic acid (0–0.5 m showed axillary bud proliferation. Shoots proliferated in vitro were multiplied on Murashige and Skoog medium containing 2.5 m benzyl adenine and 0.25 m
-naphthaleneacetic acid. Seasonal changes affected the shoot proliferation potential of the initial explant. Shoots were rooted on a half-strength, growth-regulator-free, agar-gelled, MS medium after a 48-h treatment on half-strength MS liquid medium with 10 m indole-3-butyric acid. Rooted plantlets were potted and acclimatized in a growth chamber and then moved to the greenhouse. Four-month-old plants were transplanted to the field.Abbreviations
BA
Benzyl adenine
-
IBA
Indole-3-butyric acid
- 2-ip
N6-(-dimethylallylamino)purine
-
MS
Murashige and Skoog (1962) medium
-
NAA
-Naphthaleneacetic acid 相似文献
9.
Soil fertility and precipitation are major factors regulating transitions from grasslands to forests. Biotic regulation may influence the effects of these abiotic drivers. In this study, we examined the effects of extreme rainfall events, anthropogenic nutrient loading and insect herbivory on the ability of Chinese tallow tree ( Sapium sebiferum ) to invade coastal prairie to determine how these factors may influence woody invasion of a grassland. We manipulated soil fertility (NPK addition) and simulated variation in frequency of extreme rainfall events in a three growing season, full factorial field experiment. Adding water to or pumping water out of plots simulated increased and decreased rainfall frequencies. We added Sapium seeds and seedlings to each plot and manipulated insect herbivory on transplanted Sapium seedlings with insecticide. We measured soil moisture, Sapium performance, vegetation mass, and carbon and nitrogen in vegetation and soils (0–10 cm deep, 10–20 cm deep). Fertilization increased Sapium invasion intensity by increasing seedling survival, height growth and biomass. Insect damage was low and insect suppression had little effect in all conditions. Recruitment of Sapium from seed was very low and independent of treatments. Vegetation mass was increased by fertilization in both rainfall treatments but not in the ambient moisture treatment. The amount of carbon and nitrogen in plants was increased by fertilization, especially in modified moisture plots. Soil carbon and nitrogen were independent of all treatments. These results suggest that coastal tallgrass prairies are more likely to be impacted by nutrient loading, in terms of invasion severity and nutrient cycling, than by changes in the frequency of extreme rainfall events. 相似文献
10.
The triglycerides of fats from several varieties of Sapium sebiferum (L.) Roxb. were determined by means of pancreatic lipase hydrolysis technigue. Triglycerides of the fats. are composed of 9–14 kinds of triglycerides. They are similar to Cocoa butter. Fatty acid composition in 2-position of glycerides is oleic acid in more than 82%. The disaturated glycerides account for 81-88%, in which POP is in the majority (74–81%); the proportion of monosaturated glycerides is 1.8–6.0%; the trisaturated glycerides hold 9.6–15.6%, in which the main one is PPP (8.5–14.0%). The fats can be used for making Cocoa butter substitute by proper processing. Fat contents of the four varieties (“Da Li Ji Zhao”, “Wu Gong”, “Tong Chui” and “Xiao Li Ji Zhao”) cultivated in Guangxi province are richer (32.0–34.3%) than that of the wild species of the same plant. The proportion of disaturated glycerides is the highest (88.0%) and that of trisaturated glycerides is the lowest (9.6%) in fat from "Da Li Ji Zhao". 相似文献