金银花中主要内含物最佳浸提条件研究

[目的]为了确定金银花的最适浸提条件,为加工金银花饮料提供参考。[方法]通过花水比、温度、时间三因素二水平正交试验,测定水浸出物、氨基酸、黄酮和绿原酸含量并分析其变化情况。[结果]金银花中水浸出物的最适浸提条件为:花水比1∶40,温度80℃,时间20 min,水浸出物含量为45.96%;金银花中绿原酸的最适浸提条件为:花水比1∶40,温度80℃,时间15 min,绿原酸含量为4.09%;金银花中氨基酸的最适浸提条件为:花水比1∶30,温度70℃,时间10 min,氨基酸含量为2.02%;金银花中黄酮的最适浸提条件为:花水比1∶40,温度80℃,时间15 min,黄酮含量为0.826 2%。[结论]金银花的最适浸提条件是花水比1∶30~1∶40,温度70~80℃,时间10~15min。     

不同耕作施肥条件下玉米连作对黑土有机无机复合体性状的影响

本文研究了不同耕作、施肥条件下玉米连作对黑土有机无机复合体组成、土壤有机碳及氮、磷在各级复合体中分配的影响。结果表明,经常施用有机肥料条件下的玉米连作可使土壤中粉粒复合体含量、土壤及各级复合体的有机碳、氮、磷的含量有不同程度的提高,并可使粉粒复合体的有机碳贮量也相应增加;玉米连作时如果连年秋翻,可促进土壤有机质的分解,各级复合体的有机碳含量及粉粒复合体的数量均相对减少,很少秋翻的土壤的情况则与之相反;玉米连作年限的长短,对有机无机复合体组成、有机碳含量及其在各级复台体中的分配的影响,主要取决于土壤的耕作、施肥及管理水平,经常施用有机肥并很少秋翻条件下的玉米连作,有利于土壤有机质的保持与积累,并促进土壤肥力的提高。     

重庆南岸区山地景观生态复合体的景观组成特点分析

选择山地城市中具有典型景观生态复合体特色的重庆主城区南滨路到南山风景区山脊范围为研究对象,主要采用景观生态学的理论和研究方法,分析了山地城市景观生态复合体的景观组成特点,以及海拔梯度变化与人为干扰对景观组成特点的影响,旨在研究人为干扰对景观格局的影响.     

小鼠腔前卵泡卵母细胞的采集和体外成熟

酶消化配合机械分离，采集１０日龄小鼠腔前卵泡中的卵母细胞一颗粒细胞复合作（ＯＧＣｓ），以自制的胶原膜为底物，在 ＭＥＭ培养液中培养 １０ ｄ．卵母细胞－颗粒细胞复合体由 １１０． ５±１８． ６ μｍ增长到 １８４．４±６０． ６ μｍ，卵母细胞由 ５６． ２５±２． ０ μｍ增长到 ８２． ０±１０． ５μｍ．３６．７％的ＯＧＣ．具有５层以上颗粒细胞，其中９．１％放出第一极体。     

枳壳挥发油包合工艺的优化

[目的]研究枳壳挥发油的β-环糊精包合工艺,并建立可靠的测定包合率的方法.[方法]挥发油包合采用研磨法,检测方法为高效液相色谱法,色谱柱为ACE-C18(4.6 mm×50 mm,1.8μm),以甲醇-水(75∶25)为流动相,检测波长210 nm,柱温25℃,流速1ml/min.[结果]枳壳挥发油最佳包合工艺为10倍量β-环糊精,挥发油与无水乙醇1∶1混匀,研磨30 min,60℃烘干.[结论]包合工艺稳定,质量可控.HPLC法测定枳壳挥发油中柠檬烯含量、计算包合率的方法快速准确、可靠,可作为枳壳挥发油包合率的测定方法.     

若干钕-钼杂多配合物的合成和表征

本文报导了以稀土元素钕为杂原子和铝形成的杂多配合物（NH4）12。H10[Nd4MO29O104（H2O）12）· 22H2O及 Na4（NH4）10[Nd4 MO29 O100（H2O）16]· 34H2O的合成方法．通过元素分析、热分析、红外吸收光谱、XPS对所合成的杂多配合物进行了表征．     

土壤有机和无机组分对多环芳烃环境行为影响的研究进展

土壤中多环芳烃(PAHs)的环境行为取决于它们与土壤不同组分之间的相互作用。本文综述了土壤有机质、黏土矿物以及有机矿质复合体对PAHs土壤环境行为影响的研究进展,期望从土壤基本组成和性质上对PAHs的土壤环境行为有一个本质的了解。     

Adsorption of pure and dirty bacterial DNA on clay minerals and their transformation frequency

Several studies have investigated the adsorption of pure DNA on soil particles and its transformation ability. However, the presence of not purified (dirty) rather than pure DNA is more common in the extracellular soil environment. For this reason, we have investigated the adsorption and binding of dirty DNA on montmorillonite (M) and kaolinite (K) and their transforming ability in comparison to pure DNA. After lysis of Bacillus subtilis cells, induced by KCl, dirty DNA was characterized by the presence of cellular wall debris (cwd) and other constitutional organic components (coc). The dirty DNA was then divided into two fractions, one with cellular wall debris (DNA +cwd) and the other without cellular wall debris (DNA −cwd). B. subtilis BD 1512 (Cm^r) and BD 170 (Cm^s) were selected as donor and recipient bacteria, respectively, for adsorption and transformation studies. Both cwd and coc seem to facilitate the adsorption of DNA to clay minerals, whereas only cwd promote the DNA binding on clays, protecting also the DNA fragments below 400 bp against nucleases. Both dirty DNA fractions adsorbed and bound on clay minerals were able to transform competent cells.     

山姜素-环糊精新型包合物的性能研究

[目的]研究山姜素分子与环糊精(α-CD,β-CD和γ-CD)形成的配位包合物的制备方法和性能。[方法]采用紫外光谱滴定、粉末X-射线衍射和热量分析等方法对山姜素分子与环糊精形成的包合物进行性能研究。[结果]山姜素和环糊精的(α-CD,β-CD和γ-CD)形成配位包合物,且形成包合物后,山姜素的水溶性和热稳定均性明显提高。[结论]山姜素作为医药分子具有潜在的应用价值。     

Effect of repeated heating and cooling cycles on the pasting properties of starch

The properties of starch and starch–lipid pastes have been explored using a novel extended Rapid Visco Analyser (RVA) profile, in which the heating and cooling cycles are repeated five times. Starches from four wheat varieties with amylose content ranging from 23 to 27%, and waxy starches of wheat, rice and maize were tested, alone and in mixtures with lauric acid and monopalmitin (glyceryl-1-monopalmitin). Gels of all of the starches formed and melted reproducibly during repeated heating and cooling in the RVA. The addition of lauric acid to the waxy starches had no effect on the multiple RVA profile. Monopalmitin caused an increase in viscosity during the heating stage of the second to the fifth cycles with the waxy starches, which was attributed to the presence of monopalmitin aggregates. Changes in the multiple cycle viscosity traces observed when monopalmitin or lauric acid was added to the amylose-containing starches were complex. It was concluded that RVA paste viscosities were determined by starch–lipid interactions, as well as by free lipid in the starch mixtures. The water solubility of the lipid and association of proteins with starch granules influence these interactions.