菜籽油脱臭馏出物中甾醇分离的甲酯化过程优化研究

运用中心组合设计，以甾醇得率与纯度为考察指标，对菜籽油脱臭馏出物的甲酯化过程工艺进行了优化研究。通过甾醇回收率的响应曲面分析，考察了甲酯化时间、催化剂浓硫酸量与甲醇/物料比及其交互作用的影响，并建立了其数学回归模型，利用Matlab绘制出响应曲面图，揭示了内在关系。结果表明：甲酯化温度60℃，甲醇/物料比100 mL/(100 g)，甲酯化时间1.65 h，催化剂浓硫酸加量4.4%，将甲酯化产物通过结晶与冷冻高速离心，甾醇得到较高纯度与得率，维生素E也得到较好保留。二次重结晶甾醇纯度可以达到95％以上，总得率达到45％以上。     

粮田土壤磷、钾养分的垂直分布特征

本文研究了粮田土壤磷、钾养分垂直分布特征。结果表明 ,0～ 2 0 cm土层 N( NH4 - N)、P、K、Mn、Zn、Fe、Cu等主要养分速效含量明显高于 2 0～ 4 0和 4 0～ 60 cm土层 ,其中 0～ 2 0 cm土层 P含量数倍高于 2 0～ 4 0和 4 0～ 60 cm土层 ,显示磷肥应尽可能深施 ,以提高下部土层 P素肥力 ,2 0～ 4 0和 4 0～ 60 cm土层养分含量差异不大。不同施肥措施对上部土层 ( 0～ 2 0 cm) P、K等养分含量有较明显影响 ,而对下部土层 ( 2 0～ 4 0和 4 0～ 60 cm) P、K等养分含量影响较小     

Molecular genetic and chemical assessment of Rhizoma Curcumae in China

Rhizoma Curcumae (Ezhu) is a traditional Chinese medicine that has been used in removing blood stasis and alleviating pain for over a thousand years. Three species of Curcuma rhizomes are being used, which include Curcuma wenyujin, Curcuma phaeocaulis, and Curcuma kwangsiensis. In China, the production of Rhizoma Curcumae largely depends on agricultural farming. The essential oils are considered as active constituents in Rhizoma Curcumae, which include curdione, curcumol, and germacrone. On the basis of the yield of curdione, curcumol, and germacrone in an orthogonal array design, the optimized extraction condition was developed. The amounts of these compounds within essential oils in Rhizoma Curcumae varied according to different species and their regions of cultivation. Chemical fingerprints were generated from different species of Curcuma, which therefore could serve as identification markers. In molecular genetic identification of Rhizoma Curcumae, the 5S-rRNA spacer domains of 5 Curcuma species, including the common adulterants of this herb, were amplified, and their nucleotide sequences were determined. Diversity in DNA sequences among various species was found in their 5S-rRNA spacer domains. Thus, the chemical fingerprint together with the genetic distinction could serve as markers for quality control of Curcuma species.     

基于BP神经网络的脂肪酶酯化菜籽油脱臭馏出物的仿真研究

该文采用BP神经网络对脂肪酶催化酯化菜籽油脱臭馏出物的工艺条件进行了仿真研究。将中心组合试验和神经网络相结合，采用动量梯度下降法对网络进行训练仿真，并利用训练好的网络对催化酯化工艺条件进行预测。结果表明：经过训练的网络可以很好的模拟反应条件，得到了脂肪酶催化反应的最佳工艺参数，此时脂肪酸甲酯的含量为55.2%，维生素E保留率达到90%,为脱臭馏出物的酯化催化效果的预测提供了一条可行的途径。     

磁化水对黄瓜叶片氮磷钾钙镁含量的影响

以当地冬春茬保护地品种寒秀、鲁圣顶峰1号为试材，研究了磁化水对黄瓜叶片氮、磷、钾、钙、镁含量的影响。结果表明：叶片生长发育期间，黄瓜叶片氮、磷含量呈单峰曲线变化；钾、钙、镁含量呈双峰曲线变化。磁化水处理后，寒秀叶片内磷、镁含量极显著高于对照，钙含量显著高于对照，氮、钾含量差异不显著；鲁圣顶峰1号磷、镁含量极显著高于对照，氮、钾、钙含量差异不显著。     

非饱水冻融作用下的古砖动弹性模量

在对我国北方销售的冻梨品种、产地来源、制作方式及存在问题进行实地调查的基础上,对冻梨的生产历史、文化、品种特性及研究现状进行综述与分析,并提出我国冻梨产业需要解决的问题及今后的研究方向。     

Preprocessor of Reinforced Concrete FEM Analysis

Reinforcing element and concrete element have effects on the order of the stiff-matrix of the reinforce-concrete FEM. The program divided the elements is programmed by FORTRAN language in current analysis, and the data of the elements are stored by the array. The stiff-matrix of the reinforce-concrete FEM is extended by the large residual between the serial numbers of the nodes of cohering element. This paper establishes the graph class, path class and point class via objectoriented programming. The storage of the points and the paths by the chain structure realization of copying graph, moving graph, adding graph, continuously numbering the cohering elements are built. This paper presents the example of the dividing domain with the crack.     

高产优质西瓜对氮,磷,钾的吸收及分配规律

研究表明，西瓜苗期对氮、磷、钾的吸收很少。随着植株的生长逐渐增多，抽蔓到一棚瓜成熟期间对氮的吸收有明显的线性关系，回归方程为ｙ＝０．１４１９ｘ－５．３８７８，ｒ＝０．９９７１＊＊。座果后对磷的吸收逐渐增多；开花结果后对钾的吸收逐渐增多。西瓜植株对、氮、磷、钾的分配在结果前主要用于叶的发育和建成，其次是茎、根的生长；座果后，逐渐转向果实的发育     

光敏核不育水稻存在BT型等位不育基因及其遗传关系的研究

农垦58s及其转育于不同遗传背景的光敏核不育水稻与BT型不育水稻六千辛A和寒丰A杂交,得到的F_1植株完全不育,证明农垦58s不育的2对隐性基因中有1对来源于农垦58,即为与BT型水稻等位的不育基因.由此推论农垦58s源于农垦581个基因位点的突变,而它的光敏不育性则为此突变基因和原有不育基因重叠作用的结果.当用作光敏不育的恢复亲本原已存在或不存在BT型水稻不育基因,决定了它们杂种F_2代的可育株和不育株呈3:1或15:1不同的比率分离.     

Movement of mud snails affects population dynamics,primary production and landscape heterogeneity in tidal flat ecosystems

Landscape Ecology - Animal movements influence the spatial heterogeneity of variously ecosystem processes. However, our understand of how movement in heterogeneous landscapes shapes ecological...