花椒麻味素含量两种检测方法之比较

为确定花椒麻味素含量快速测定方法,利用华州黄盖、韩城大红袍、华州大红袍花椒及其无水乙醇提取的花椒麻味素,对甲醛滴定法(A)和凯氏定氮法(B)检测法进行了实验比较研究。结果表明,花椒麻味素含量(y)华州黄盖>韩城大红袍>华州大红袍;花椒乙醇提取物A法麻味素含量平均值()是B法麻味素含量平均值()的19.56倍,用19.56将x校正为麻味素含量y′后,t测验说明y′与差异显著,用模型y′=2.3839+8.8147将x校正为麻味素含量y′,则y′与间无差异;用B法测定花椒粉末样N含量x′,用模型y″=0.0151x′2-1.0216 x′+26.8190将x′校正为麻味素含量y″,t测验说明y与y″无显著差异。研究结果表明,定氮仪法测定花椒N含量,并建立麻味素含量与N含量关联模型,再将N含量转换为麻味素含量,可实现用凯氏定氮法间接检测花椒麻味素含量。

制备工艺对亚麻增强热塑性复合材料拉伸力学性能的影响

将增强体亚麻纱线和基体丙纶复丝制成pp/亚麻包覆纱后,进行织造,织物用层合热压法制成复合材料。制备工艺中,包覆纱法对复合材料的拉伸强度最好;麻含量50%的复合材料的拉伸强度达到最佳;当纬纱密度相同时,随着经纱密度的增大经向的拉伸强力和拉伸弹性模量也随之增大,而纬向的却随之减小,当经纱密度相同时,随着纬纱密度的增大,经向的拉伸强力和拉伸弹性模量随之减小,纬向的随之增大。

Regression Relationship between WI and FMC at Different Growth Periods of Sawtooth Oaks Leaf

[Objective] The aim was to study the regression relationship between water index （WI） and fuel moisture content （FMC） of different growth periods of sawtooth oaks leaf.[Method] Taking sawtooth oaks in Huaguo Mountain,Lianyungang City as research object,the sensitivity of WI to leaf FMC was studied at leaf level,and statistical characteristics were analyzed.[Result] The WI of sawtooth oaks leaves was sensitive to the changes of FMC,and the line regression level between them was significant.A fitting curve between leaf FMC and WI was obtained.[Conclusion] The research provides reference for acquisition methods of vegetation water remote sensing within the range of study area.

Composition and Thermal Behavior of Oils from Native Seeds and Fruits of Argentina and Uruguay

The purpose of this work was to study the thermal characterization of oils extracted from native seeds and fruits of the Argentina, Uruguayan region. This is important because it＇s necessary to find new applications for food industry. Uruguayan wild cardoon seed, Argentinian wild papaya seeds, Argentinian avocado pulp, Argentinian cherimoya seeds, Argentinian grapeseeds and four commercial brands of chia oils were studied. The thermal behaviors of the oils were analyzed on a differential scanning calorimetry （DSC）, TA Instrument, Q20 model equipped with an intercooler. These oils＇ thermal profiles presented differences, which are related to the compositions of fatty acids and triacylglycerols. The thermogram for the chia oil, with a high content of linolenic acid, presented a very important peak at about -40 ℃; whereas, the papaya oil with an oleic acid content of 74%, showed a peak at about -3 ℃. When comparing the thermal behaviors of these oils to commercial brand oils, it was found that the chia oil is similar to the flaxseed oil, the papaya similar to the olive oil and the avocado similar to the rice bran oil. The avocado oil, in particular, presents high solid content at cold store or winter temperatures, which would make its use in those conditions difficult （for example, a cosmetic cream or gourmet oil）. In conclusion, the thermal behavior of one oil sample as determined by DSC provides valuable information with regards to the possible use of new oils of American origin as replacement of usual commercial others.

Effects of Aluminum Toxicity on Physiological Indices of Jatropha curcas L.Seedling

Jatropha curcas was taken as the test material,6 concentrations including 0,25,50,100,200 and 400μmol/L AlCl3,plus 3 time gradients including 7,14 and 21 d,were set to study the effects of Al^(3+)stress on the antioxidant system of Jatropha curcas L.seedling.The results showed that with the Al^(3+)treatment being applied,protein content increased first,then decreased and finally increased with the increase of Al^(3+)concentration;the soluble sugar content increased first and then decreased with the increase of Al^(3+)concentration.Under low concentration of Al^(3+)treatment,Pro content,MDA content and POD activity of Jatropha curcas L.seedling leaves changed a little,while under high concentration of Al^(3+)treatment,Pro and MDA content of Jatropha curcas L.seedling leaves rapidly accumulated,POD activity increased and they showed a trend of increase with the increase of Al^(3+)concentration;From the perspective of Al^(3+)stress time,protein content,soluble sugar content,MDA content and POD activity increased with stress time being prolonged,while Pro content decreased with stress time being prolonged.These results indicated that the leaves of Jatropha curcas L.seedlings had certain self-protection and remediation abilities under Al^(3+)stress.

Effect of Microclimatic Modification on Growth and Yield of Sesame （Sesamum indicum L.） in a Semi-Desert Region of Northern Sudan

An investigation was carried out in the semi- desert region of northern Sudan, during 2000, to study the influence of different micrometeorological parameters on growth and yield of sesame under alley cropping system. Sesame, cv. Kenana-2, was grown in 6-m wide alleys formed by 3 year old Acacia ampliceps and Acacia stenophylla. Air temperature, relative humidity, wind speed, solar energy and shade behaviour were measured throughout the growing season. Irrigation was measured by water meter and soil moisture by gravimetric sampling at depths of 15, 30, 45 and 60 cm, in alley cropping and control plots. Sesame was evaluated for growth and yield performance in southern, central and northern parts of each alley. The results showed substantial reduction in wind runs, solar radiation and air temperature, while relative humidity was increased under alley conditions. Soil moisture content, especially in the upper 045 cm soil depth, was much higher in alley cropped plots than in the control plots. A. stenophylla resulted in the highest saving of irrigation water and considerably increased （40%） sesame seed yield. In contrast, sesame seed yield was reduced by 46% under A. ampliceps-alley cropping. Competition for light and water were highly responsible for variation in sesame seed yield in the different zones of the alley. A. stenophylla tree is, therefore, recommended in an alley cropping system in the semi-desert region of northern Sudan for its superiority in optimizing radiation and saving of irrigation water.

Study on chemical constituents of Apocynum venetum L. leaves by LC/MS and determination of the best harvest season

The dried leaves of Apocynum venetum L. （AVL） is a traditional Chinese medicine widely used as antihypertensive medicine in China. Accurate determination of its best harvest season is important for its effective and safe use. In the present study, we developed a reliable method based on high-performance liquid chromatography-diode array detector-electro spray ionization-ion trap-time of flight （HPLC-DAD-ESI-IT-TOF） mass spectrometry and HPLC-DAD for the identification and quantification of major components in AVL leaves. Quantitative analysis of 24 samples collected weekly helped monitor the changes of compounds dynamically in AVL leaves to determine the best harvest season. A total of 30 compounds were identified, including quinic acid, five phenolic acids and 24 flavonoids. For the first time, 16 compounds were selected as marker compounds and simultaneously monitored weekly instead of monthly during the growth of the plant. The results showed that in May the leaves had the highest amount of phenolic acids, flavonoids and total compounds. Therefore, May should be the best harvest season for AVL leaves, which was distinct from previous studies. The established method was validated to be simple, accurate and precise, and thus it was of great importance for determination of the best harvest season.

Seasonal changes in tannin and nitrogen contents of Casuarina equisetifolia branchlets

Seasonal dynamics of total phenolics (TP), extractable condensed tannins (ECT), protein-bound condensed tannins (PBCT), fiber-bound condensed tannins (FBCT), total condensed tannins (TCT), and protein precipitation capacity (PPC) in young, mature and senescent branchlets of Casuarina equisetifolia were studied at Chishan Forestry Center of Dongshan County, Fujian Province, China. In addition, nitrogen contents of branchlets at the different developmental stages were also determined. The contents of TP and ECT, and PPC in young branchlets were significantly higher than those in mature and senescent branchlets through the season. However, PBCT contents were significantly higher in senescent branchlets than those in young and mature branchlets; FBCT fluctuated with season. Young branchlets had the highest N content, which decreased during branch maturity and senescence. The highest contents of TP and the lowest contents of TCT and N in young and mature branchlets were observed in summer. There was a significant negative correlation between TP and N contents. In contrast, TCT contents were positively correlated to N contents. Nutrient resorption during senescence and high TCT:N ratios in senescent branchlets are the important nutrient conservation strategies for C. equisetifolia.

Water-enhanced plastic deformation in felsic rocks

Using Fourier transform infrared spectroscopy(FTIR),we measured water contents in quartz and feldspar for four kinds of felsic rocks,i.e.,undeformed granite,banded granitic gneiss,fine-grained felsic mylonite,and fine-grained quartz-mica schist,collected from Pengguan Complex and Kangding Complex in the Longmenshan tectonic zone,Sichuan,China.The absorbance spectra suggest that water in coarse-grained quartz and feldspar of undeformed granite and banded granitic gneiss occurs mainly as hydroxyl in crystal defects,and water in most of fine-grained quartz and feldspar of felsic mylonite is molecular water in inclusions and liquid-type water in grain boundaries,but in some cases it still occurs as hydroxyl in crystal defects.Water content of quartz in undeformed granite is 0.001 wt%-0.009 wt %,and that of feldspar 0.005 wt%-0.02 wt%.The banded granitic gneiss shows water contents of 0.002 wt%-0.011 wt% in quartz and 0.012 wt%-0.036 wt% in feldspar.Quartz ribbon and feldspar ribbon in fine-grained felsic mylonite show that their water contents are similar to those of coarse-grained quartz and feldspar in granite,0.002 wt%-0.011 wt%,and 0.004 wt%-0.02 wt%,respectively.Water contents of fine-grained quartz and feldspar are respectively 0.004 wt%-0.02 wt% and 0.012 wt%-0.06 wt%.Water content of quartz in fine-grained quartz-mica schist is 0.007 wt%-0.15 wt%.Water-bearing minerals display much higher water contents than those of nominally anhydrous minerals,and the percentage of water-bearing minerals in felsic rocks increases with the strain of rocks.These new data indicate that hydroxyl in crystal defects has basically not been released during the shear deformation,and on the contrary,the increase in molecular water in inclusions and liquid-type water in grain boundaries as well as water-bearing minerals after shear deformation leads to a significant increase of the water content in deformed rocks.Based on data of creep tests,it is inferred here that the fine-grained mylonites with more water have much lower strength than that of the weakly deformed coarse-grained rocks in the middle crust,and this indicates that trace amount of water significantly helped develop the ductile shear zone.