冲泡时间对酸枣叶茶有效成分及抗氧化活性的影响

研究了不同冲泡时间(5～9 min)对酸枣叶茶中总多酚、总黄酮和芦丁等有效成分含量,以及其对DPPH自由基清除率、ABTS自由基清除率及还原能力等抗氧化活性的影响。结果表明,随着冲泡时间的延长,酸枣叶茶的有效成分含量及其抗氧化活性均呈逐渐增加的趋势,冲泡时间超过7 min后,有效成分及其抗氧化活性达到动态平衡,处于相对稳定状态。因此,从有效成分含量和抗氧化活性的角度分析,酸枣叶茶的最佳冲泡时间为7 min。     

丁香对卤制鸡肉风味物质形成的影响

采用道口烧鸡工艺中丁香与鸡肉的配比制作卤鸡腿,运用SPME和GC-MS测定鸡肉中的挥发性风味成分,研究了丁香对卤制鸡肉挥发性风味物质形成的影响。结果表明,丁香组与空白组鸡肉中分别鉴定出59种和72种成分,其中59种为共有成分。与空白组相比,丁香组鸡肉中的挥发性成分新增了13种物质,其中丁香油酚、乙酸丁香酚酯、芳樟醇、连四甲苯、2-丁酮、6-甲基-1-辛烯和1-癸烯等7种物质差异显著,2-辛烯醛的含量减少,而苯甲醛、正辛醛、十六醛、己醇、庚醇、十三烷、(+)-柠檬烯、2-庚酮、2-戊基呋喃、乙酰苯、萘等11种风味物质含量显著增加。     

The Calculation of Section of Al2O3-CaO-SiO2 System and Its Verification

The basic phase is selected according to the measured phase diagram, two isothermal sections and two vertical sections of the Al 2O 3-CaO-SiO 2 ternary system are calculated using FACT software. The sections in the same conditions are described through the measured phase diagram. Because of the complexity of this ternary system, there is a large difference between the measured and the calculated phase diagram. It is necessary for FACT to ameliorate the calculation model and perfect the database in calculating oxide system which the interaction is strong. For this kind system, the isothermal section and vertical section should be founded through the experiment result and referencing the calculated phase diagram at the same time.     

Parametric Bispectrum Estimation and Slice Analysis for Pulse Signals

Higher-order statistics method is an overhead subject in the fields of signal processing in the world in recent years. The pulse signals are analyzed by applying parametric bispectrum estimation. Non-Gaussian AR model is for calculating the bispectrum of pulse signals for 15 heroin addicts and 15 healthy persons. Characteristic parameters of magnitude bispectrum of the pulse signals are obtained by using horizontal slices of magnitude bispectrum. Characteristic parameters of bispectrum phase of the pulse signals are obtained by using horizontal slices of bispeetrum phase. Moreover,two primary criterions are also obtained by using the characteristic parameters. Exactness ratios of two pnmary criterions reach 93.3% and 90%, respectively. The research result shows that parametric bispectmm estimation for analyzing pulse signals of heroin addicts is really an effective method.     

Influence of the Fluctuation on the Property of the Interface in Molecular Dynamics Simulation

The paper advances a new calculation method improved by using(2~5)/1.2rm rule which concerns the influence of the fluctuation of molecules on the results of molecular dynamics simulation of the interface.The densities of saturated vapor and liquid of homogeneous phase and the surface tension of inhomogeneous phase of CH4 are obtained by applying this new calculation method.Compared with the traditional molecular dynamics simulation,this method has less error in calculating the surface tension of inhomogeneous phase and takes less calculating time.     

Intergenotypic competition in mixed stands of spring wheat genotypes

Summary Grain yield and yield components were studied in the three spring wheat genotypes HD 2160 (dwarf), Kalyansona (semi-dwarf) and C 306 (tall) in pure stands as well as in their binary mixed stands during two years. The grain yields of the three genotypes in pure stands ranked as follows: HD 2160 > Kalyansona > C 306. Four mixed stands, 3:1 HD:K, 1:1 HD:C in the first year and 1:1 K:C, 1:3 K:C in the second year out-yielded the pure stand of the better component genotype by 4.4, 2.7, 3.3 and 0.8 percent, respectively. Out of the nine mixed stands four in the first year and seven in the second year out-yielded the midmonoculture yields and the increases ranged from 1 to 7.6 percent. Mixed stands were more stable than pure stands.The yield and yield components of the dwarf genotype HD 2160 scored less and those of the taller genotype C 306 scored higher in mixed stands. The semi-dwarf genotype Kalyansona yielded more with HD 2160 and less with C 306. Plant height but not high yielding ability conferred high competitive ability. With respect to competitive ability the three genotypes ranked as follows: C 306 > Kalyansona > HD 2160.The results illustrate the importance of intergenotypic competition in increasing crop production and reducing genotype-environment interactions. Such studies are important to agronomists as genotypes with high competitive ability can be useful to combat the weed problem. They are also important to plant breeders for predicting the fate of genotypes with low competitive ability in heterogeneous populations.     

SEPARATION OF THE SECOND PHASE IN STEEL AND DETERMINATION OF SOLIDIFIED VANDIUM

In this paper, the dissolving condition of iron and vandium solidified in iron and the collecting method of the second phase vandium compounds in alloy steel are studied, the existing possibility of spreading phase vandium compounds in steel is discussed, which provide the possible conditions for concentration and electrochemical separation of the second phase vandium compounds. Using this method, quite reliable results in measuring vandium solidified in iron can be obtained.     

含喜树碱植物水培根系化感化合物的分离分析

本研究旨在探明喜树碱植物水培体系中化感物质的种类及其长期积累对植物生产的作用。建立了喜树幼苗和野生型蛇根草水培体系根系分泌物的新分离富集方法:首先以硅胶填充固相萃取柱萃取水培液根系分泌物,然后取出填充硅胶加到硅胶层析柱上层进行柱层析分离,再经洗脱后,用GC-MS技术分析不同组分的洗脱液。从喜树水培根系分泌物中检测到1,1,2,2-四氯乙烷、N,N-二甲基苯胺、二苯铬等11种化感物质;在广州蛇根草水培根系分泌物中检测到邻苯二甲酸二丁酯、苯硒酚、二苯铬等14种化感物质。2种含喜树碱植物水培根系分泌物中化感物质的大量分离富集和分析,为清除水培体系的生长抑制物、优化水培体系、实现喜树碱的高效生物合成奠定基础。     

大兴安岭北方森林凋落物真菌及其抗菌化合物

为了研究大兴安岭森林凋落物真菌的抗菌活性,首先利用颗粒涂布平板法分离真菌,通过扩增与比对内部转录间隔区序列初步鉴定分离到的真菌。采用双平板打孔药剂扩散法检测抗菌活性,使用层析法分离目标菌株单体化合物。通过波谱学分析确定其化学结构,使用96孔板液体稀释法检测单体化合物的最低抑菌浓度。共分离得到88株真菌,其隶属于57个属、74个分类单元,其中18株真菌内部转录间隔区序列相似性≤97%。其中6株真菌的乙酸乙酯提取物具有抗菌活性,2株真菌KNFL008和KNFL040抗菌活性较强。经活性追踪分离,共得到4个单体化合物,分别为化合物A（1,3-2-羟基-5-十五烷基苯）、化合物B（麦角固醇）、化合物C（2-氨基-3H-苯氧嗪-3-酮）和化合物D（2-乙酰氨基-3H-苯氧嗪-3-酮）。对化合物A、B、C进行了最低抑菌浓度的测定,为3.13~200 μg/mL。化合物A和D为首次在真菌提取物中分离。本研究为进一步开发利用大兴安岭凋落物真菌资源打下了基础。     

海绵共附生放线菌Streptomyces sp. A01059抗稻瘟病活性物质的分离研究

摘要：目的 对海绵共附生放线菌Streptomyces sp. A01059的发酵液进行研究,以获得有抗稻瘟病活性的化合物;方法 用乙酸乙酯对发酵液进行萃取,然后用活性追踪的方法对乙酸乙酯萃取物进行分析,最后使用制备液相获得相应的活性部位;结果 获得分子量为508和522的两个活性化合物;结论 本实验首次对放线菌Streptomyces sp. A01059的代谢产物进行分离研究,为稻瘟病的防治提供了新的途径。     

葡萄果实中酚类物质研究进展

葡萄果实酚类物质是葡萄生长发育过程中重要的次生代谢产物,可以彰显葡萄果实品质,并且具有一定的抗氧化活性,已成为近年来的研究热点。综述了葡萄果实中酚类物质的组成、含量、生物合成、提取及应用方面的国内外研究进展,并展望了葡萄果实酚类物质在未来研究的方向及难点问题,以期为葡萄果实酚类物质的研究与综合应用提供借鉴。     

奶酪酶解方法及风味成分分析

研究了用蛋白酶和脂肪酶酶解奶酪,以增加其风味的酶解工艺,并对风味成分进行分析。结果表明,奶酪经蛋白酶和脂肪酶的酶解,可有效提高其风味。正交试验优化后的酶解工艺是:原料选择美兰黄波奶酪,0.5%的风味酶与0.6%的万力脂肪酶或脂肪酶AY,酶解时间18~24 h。经GC-MS分析,酶解物中含有癸酸、辛酸、己酸、丁酸等脂肪酸,以及甲基酮和内酯类等多种风味成分。     

梨果实中酚类物质的研究进展

酚类物质是梨果实中主要的化学成分,不仅参与果实的生长发育,而且对人体健康有多方面的生理功能。综述了梨果实中酚类物质组分及含量、梨果实生长发育及贮藏期间酚类物质动态变化以及酚类物质测定方法的国内外研究进展,并展望了今后梨果酚类物质的研究方向,以期为酚类物质的进一步研究提供参考。     

刺梨挥发油香味成份毛细管气相色谱法定量分析

采用超临界流体萃取得到刺梨挥发油,平均出油率为2.46%。利用毛细管气相色谱仪对刺梨挥发油的21种化学成分进行了定量分析,其主要成分为：亚油酸(34.80%)、亚麻酸(21.25%)、棕榈酸(12.31%)、油酸(9.20%)、亚油酸甲酯(2.24%)、月桂酸(1.85%)、亚麻酸乙酯(1.62%)、丁香酚(1.22%)等。该方法的回归方程的相关系数为：0.9937~0.9998;回收率在84.02%~96.58%之间,RSD在1.82%~4.87%之间。该方法快速简便、准确,适于刺梨挥发油中主要化学成分分析。     

彩色樱桃番茄果实挥发性风味物质分析

为了研究不同彩色樱桃番茄品种果实挥发性风味物质种类及相对含量差异,利用顶空固相微萃取-气相色谱-质谱联用技术测定了2个彩色樱桃番茄品种果实的挥发性物质成分和相对含量。结果表明,海棠黑彩和彩星分别含有72种和58种挥发性物质。海棠黑彩和彩星具有53种相同成分,其中醇类14种、酮类4种、酯类2种、醛类20种、烃类4种、其他类9种;包括18种主要风味成分,分别为3-甲基-1-丁醇、2-甲基-1-丁醇、1-戊醇、6-甲基-5-庚烯-2-醇、苯乙醇、1-戊烯-3-酮、6-甲基-5-庚烯-2-酮、β-紫罗兰酮、E-2-戊烯醛、E-2-己烯醛、E-2-庚烯醛、苯甲醛、苯乙醛、正壬醛、Z-4-癸烯醛、1-硝基-3-甲基丁烷、2-异丁基噻唑、1-硝基-2-苯乙烷,这些共有的挥发性物质构成了彩色樱桃番茄的主体风味。另外,海棠黑彩和彩星挥发性风味物质种类和相对含量存在显著性差异。海棠黑彩含有19种特有成分,其中E,E-2,4-癸二烯醛、愈创木酚、苯乙腈为主要风味物质。彩星含有5种特有成分,其中乙酸己酯为主要风味物质,为彩色樱桃番茄品种的高效利用提供了科学依据。     

Correction of Fe-rich Solidus in the Fe-based Binary Equilibrim Diagram According fo the Fe Melting Heat

According to the dada of the iron melting hcat,correction was made to thesolidus of iron and alloy element binary phase diagram in the rich iron end,and according to the ra-tio of slope of corrected solidus and slopo of liquidus,evaluation was given to the corrected distribu-tion rate of allov element in the solid and liquid phase, This rate was close to that got by chipman.     

大葱粉中挥发性风味物质的分析

新鲜大葱经40℃加热干燥后粉碎,利用顶空固相微萃取法萃取大葱粉中的挥发性风味物质,然后用气质联用法对不同处理中的挥发性成分进行分离鉴定。结果表明,大葱粉中风味性成分主要是含硫化合物和醛类,其中二甲基硫醚和3-甲基丁醛的含量最高,葱白粉中的含硫化合物含量高于葱叶中的含量。     

Dynamic signatures method for analysis of vehicle bridge resonance

The dynamic behavior of railway bridges (dynamic deflection and acceleration) is one of the running safety control indices for high speed trains. Therefore, the dynamic behavior of railway bridges is studied based on the concept of the dynamic signatures of the train and the bridge. By simplifying the train excitation as a series of moving concentrated forces, the mathematical expressions of the dynamic signatures of the train are obtained through theoretical derivations, and then a method is presented for calculating the resonance speed of trains and the maximum vertical acceleration of the bridge. With this method, the dynamic responses of the simple supported bridge can be calculated quickly. The feasibility of this method is validated through some examples, in which the resonance mechanism of train bridge system and the influencing factors are investigated. In addition, the effect of high frequency components to the bridge acceleration is also analyzed.     

大兴安岭森林凋落物的活性真菌及其代谢产物研究

本研究旨在分离鉴定大兴安岭森林凋落物中的真菌,并发现具有抗菌活性与纤维素降解活性的菌株及抗菌代谢物。以凋落物为材料,用颗粒涂布平板法分离真菌,用打孔药剂扩散法与刚果红染色法检测抗菌活性与纤维素降解活性。分离培养了76株真菌,其隶属于9个纲,15个目,25个科,59个分类单元,其中21株真菌ITS序列相似性≤98.5%。7株真菌具有抗菌活性。经代谢物分离,得到2个单体化合物,它们是FLF409A（6,9-表氧基-7,22-烯-3-麦角甾醇）和FLF449A（4,6,8-三羟基-7-甲氧基-3-甲基二氢异香豆素）。首次发现了Parapyrenochaeta属真菌具有纤维素降解活性。本研究说明大兴安岭凋落物中尚有大量具有活性的真菌资源,值得进一步被开发利用。     

小麦沼渣中挥发性物质分析及其应用

运用顶空固相微萃取结合气相色谱质谱联用( HS-SPME/GC-MS)技术,比较处理前后小麦沼渣中挥发性物质的变化,分析小麦沼渣臭味的主要成分。结果表明：固相微萃取的最佳萃取条件为65 μm PDMS/DVB 萃取头,60 ℃下萃取30 min。未处理的小麦沼渣中共检测出49种挥发性化合物,其中醇类3种、酸类3种、酯类7种、烃类18种、酮类5种和其它杂环类物质13种,未处理沼渣具有腐败沼泽气味的主要原因是含有2-苯基-1-丙烯、二甲基三硫、二甲基四硫和吲哚等臭味物质;小麦沼渣添加麦麸等营养物质经微生物发酵后,加工制成沼渣饲料,相同分析条件下检测沼渣饲料中的挥发性化合物有40种,其中醇类2种、酸类8种、醛类5种、酯类9种、烃类10种、酮类3种和其它杂环化合物3种。沼渣中含有少量挥发性有害物质,而处理后的沼渣饲料中有害物质种类和含量均明显降低;沼渣和沼渣饲料中的含氮物质不易挥发,有利于饲料的保存与利用。