互叶白千层油化学成分的研究

采用水蒸汽蒸馏收集互叶白千层芳香油,对该油进行ＧＣ／ＭＳ／ＤＳ定性分析及其总离于流图的面积归一化定量分析,鉴定出２５种化合物,其中含氧化合物６种,碳氢化合物１９种。直接影响该油商品价值的化学成分４－萜品醇含量约为１７％,桧樟脑含量约为２．４％。     

Biochemical effects of chlorpyrifos organophosphorous insecticide,camphor plant oil and their mixture on Spodoptera littoralis (Boisd.)

The biochemical effects of the chlorpyrifos organophosphate insecticide and camphor plant oil in addition to their combination were studied and compared against the fourth larval instars of the cotton leaf worm Spodoptera littoralis under laboratory condition. Biochemical analysis showed that the total protein content of the cotton leaf worm larval instars was decreased at 31, 26 and 13.5% by using a camphor extract, chlorpyrifos and combination, respectively. In addition, the activity of acid phosphatase, α-esterase was significantly declined. Biochemical analysis also showed that the alkaline phosphatase activity was increased comparing with control in another side. Acetylcholinesterase enzyme amount and activity were increased with the treatment of camphor extract followed by chlorpyrifos, even though the mixture of them nearly showed the same amount in control trail. In contrast, chitinase enzyme showed a negative effect of both camphor and chlorpyrifos with nearly about the same lowering in the amount and activity of chitinase, while the mixture of them revealed a high positive increasing in the amount and activity of chitinase. On the opposite trend, phenoloxidase enzyme of treated larvae increased by action of chlorpyrifos, followed by camphor, while the mixture of them showed a negative decrease when comparing with the control.     

油樟叶中黄酮类物质抑菌效果研究

探究从油樟（Cinnamomum longipaniculatum）叶中提取出的不同极性黄酮样品对大肠杆菌（Escherichia coli）、志贺杆菌（Shigella）、金黄色葡萄球菌（Staphylococcus aureus）、稻瘟病菌（Magnaporthe grisea）和黄曲霉菌（Aspergillus flavus）五种病原菌的抑制作用。以五种病原菌为指示菌,将不同的黄酮样品滴加在滤纸片上,观察抑菌圈的大小。结果显示,样品Fr1、Fr2、Fr3、Fr4和Fr7对大肠杆菌有抑菌作用;样品Fr2、Fr3、Fr4、Fr5、Fr7和Fr8对志贺杆菌有抑菌作用;样品Fr4和Fr8对金黄色葡萄球菌有抑菌作用;样品过孔和Fr4对黄曲霉菌有抑菌作用;样品过孔对稻瘟病菌有抑菌作用。故不同极性的黄酮样品有良好的抑菌性。     

Available nitrogen: A time-based study of manipulated resource islands

Spatial and temporal heterogeneity of available nitrogen are critical determinants of the distribution and abundance of plants and animals in ecosystems. Evidence for the resource island theory suggests that soils below tree and shrub canopies contain higher amounts of resources, including available nitrogen, than are present in interspace areas. Disturbances, such as prescribed fire and tree removal, are common management practices in shrub-woodland ecosystems, but it is not known if these practices affect resource islands. We examined temporal variation in resource islands of available nitrogen and their retention after fire and woody plant removal. From August 1997 to October 1998, soil nitrate (NO₃^–) and ammonium (NH₄⁺) were measured monthly from canopy and interspace plots within four juniper-sagebrush sites along a precipitation gradient in central Oregon, USA. At each site, soil samples were collected from untreated plots, plots in which woody plants were removed, and those treated with prescribed fire in fall 1997. In burned treatments, canopy concentrations were significantly higher than interspace concentrations throughout the measurement period. Canopy NO₃^– and NH₄⁺ concentrations were significantly higher on burned vs. unburned treatments for four months after fire. After woody plant removal, NO₃^– and NH₄⁺ concentrations did not differ from the controls. Untreated control areas had higher NO₃^– and NH₄⁺ concentrations under juniper canopies for nearly all months. Wetter sites had smaller differences between canopy and interspace concentrations through time than did the two drier sites. In relation to NO₃^– and NH₄⁺ in this ecosystem, resource islands appear to be more ephemeral in wetter sites, and more pronounced following fire disturbances than in controls or those treated by woody plant removal.     

Difference in tree growth responses to climate at the upper treeline: Qilian Juniper in the Anyemaqen Mountains

Three ring-width chronologies were developed from Qilian Juniper (Sabina przewalskii Kom.) at the upper treeline along a west-east gradient in the Anyemaqen Mountains.Most chronological statistics,except for mean sensitivity (MS),decreased from west to east.The first principal component (PC1) Ioadings indicated that stands in a similar climate condition were most important to the variability of radial growth.PC2 Ioadings decreased from west to east,suggesting the difference of tree-growth between eastern and western Anyemaqen Mountains.Correlations between standard chronologies and climatic factors revealed different climatic influences on radial growth along a west-east gradient in the study area.Temperature of warm season (July-August) was important to the radial growth at the upper treeline in the whole study area.Precipitation of current May was an important limiting factor of tree growth only in the western (drier) upper treeline,whereas precipitation of current September limited tree growth in the eastern (wetter) upper treeline.Response function analysis results showed that there were regional differences between tree growth and climatic factors in various sampling sites of the whole study area.Temperature and precipitation were the important factors influencing tree growth in western (drier) upper treeline.However,tree growth was greatly limited by temperature at the upper treeline in the middle area,and was more limited by precipitation than temperature in the eastern (wetter) upper treeline.     

Synthesis of new pryridyl alcohols and their use as catalysts in the asymmetric addition of diethylzinc to aldehydes.

Optically active new pyridyl alcohols 1-4, which can be easily synthesized by the reaction of (+)-camphor or (-)-menthone with lithiated pyridine derivatives, were applied as chiral ligands in the asymmetric addition of diethylzinc to aldehydes. Good yields with up to 94.0% enantiomeric excesses were observed in these reactions.     

10-nonacosanol,sitosterol and nonacosanediols in Juniperus pinchotii

GC of juniper leaf non-saponifiables gave three peaks of sterol-triterpenes which were identified as 10-nonacosanol, sitosterol and a mixture of nonacosanediols.     

Establishment of a 4650-year-long eigenvalue chronology based on tree-ring cores from Qilian junipers (Juniperus przewalskii Kom.) in Western China

This paper describes a tree-ring width chronology that spans the past 4650 years, established using the recently developed eigenanalysis technique. The aim is to show whether this eigenanalysis method enables the extraction of long-term tree-growth variations that are due to climatic changes, from a large dataset comprising 1263 tree-ring width records sampled from the highlands of Western China. In order to exclude the so-called growth rate/life span association effect, tree-ring width records were sorted into six subsets, based on the life spans of the trees sampled: 200–400, 400–600, 600–800, 800–1000, 1000–1500 years old, and trees older than 1500 years. Some partial chronologies were created, by pairing the set of all tree samples (living, dead, archaeological remains) with the living trees belonging to each subset. We computed the contours of tree-growth variations (on both 100-year and longer time scales) for each subset, ending with six pairs of these partial subset chronologies. Two sums of all these partial chronologies thus yielded a record of precipitation variations over a period ranging from 2627 BCE up to 2012 CE. It was found that this record shows a high degree of similarity to the existing chronology produced using the regional curve standardization (RCS) method applied to the same dataset, indicating that the eigenvalue chronology is capable of faithfully extracting long-term climatic variations. This also confirms that the first eigenvector represents the growth pattern that is characteristic of each biologically unique tree as well as the micro-environment of each tree stand. The variations observed over the last millennium seem to be connected to a cycle of solar activity with a period of ∼200 years. However, a clear lack of correspondence between solar activity and tree growth prior to 1000 CE indicates that the recent consistency may be coincidental. We believe that the eigenanalysis technique is readily applicable to other kinds of tree-ring datasets from different parts of the world.