八角叶多糖提取及含量测定

采用水溶醇析法和硫酸-苯酚法进行八角叶多糖提取及含量测定,粗多糖得率为6．13％,多糖含量为9．83％;加标回收率检测试验显示,平均回收率为101．66％,RSD为4．45％（n=5）。表明利用该方法进行八角叶多糖提取及含量测定是可行的。研究结果为多糖生物活性研究及天然药物开发应用提供了依据。     

氨苄西林混悬液在鸡体内的药物动力学及其生物利用度研究

作者对10%氨苄西林混悬液在靶动物-鸡体内的药物动力学及生物利用度进行了研究,结果表明,10%氨苄西林混悬液吸收迅速,达峰时间快,约0.89h即达峰值;消除半衰期较短,约2.5h;绝对生物利用度为35.27%,略高于氨苄西林溶液剂的绝对生物利用度(34.30%);氨苄西林混悬液在鸡口服给药后的生物等效性为109.8%。     

柳州市主城区滨水绿地植物景观效益数量化研究

园林植物景观效益的数量化是今后园林绿化的一个发展趋势。在抽样调查的基础上,借鉴唐东芹等人的AHP模型与方法,采用定量与定性指标相结合的方法对柳州市主城区滨水绿地植物景观效益进行数量化分析。结果表明,绿化树种丰富,以乡土树种为主,植物群落多样化,观花和其他观赏特征并存,季相变化明显,植物配置将美观与实用结合起来,真正实践了“以人为本”的植物景观设计理念。但地方文化树种、特色树种有待进一步的挖掘和应用,滨水绿地的养护管理与生态建设有待进一步的加强。     

湿度与棉铃虫发生的关系研究

利用同在半径5 km区域内连续10年的湿度和棉铃虫(Helicoverpa armigera Hübner)百株卵量的调查资料,分析研究了湿度与棉铃虫发生的关系。结果表明,2月平均绝对湿度和最小绝对湿度均与二代棉铃虫百株卵量呈极显著正相关,11月的定时最小相对湿度与次年二代棉铃虫百株卵量呈显著负相关,11月的月平均绝对湿度和月平均相对湿度与次年二代棉铃虫百株卵量呈极显著负相关,10~12月的5种湿度资料均与次年二代棉铃虫百株卵量呈负相关。建立了5个棉铃虫百株卵量与湿度因子呈显著或极显著相关的回归方程。     

基于数量化理论和BP神经网络的滑坡体积预测

[目的]探讨数量化理论Ⅲ和BP神经网络在滑坡中综合应用的效果,为滑坡体积的预测提供一种新的思路。[方法]采用数量化理论Ⅲ分析滑坡体积的影响因素及其耦合作用强度,并结合其分析结果,将次要因素和强耦合程度样本进行剔除,再依据其剔除的不同阶段构建3种滑坡体积的BP神经网络预测模型。[结果]滑坡体积的主要影响因素是坡角、坡向、植被覆盖率和坡高,次要影响因素是岩层倾角、斜坡高程和岩层倾向因素,且在不同样本中,体积影响因素之间的耦合程度具有一定的差异。[结论]该预测方法可行,对次要因素和强耦合程度样本的剔除,提高了预测精度。     

绝对收入、务工成本、社会保障权益对农民工城镇就业的影响———基于新疆605份维族农民工样本的实证分析

从绝对收入、务工成本、社会保障权益3个方面探究维吾尔族农民工有序进城就业问题,以实地调研的605份问卷资料为依据,运用Logistic模型回归分析发现：新疆农村维族外出务工者进城非农就业的意愿强烈,对务工收入非常看重,尽管进城务工成本费用会产生明显的负面影响,但并不会改变他们进城长期务工的意愿,他们最担忧的是进城务工面临的"劳动保险"和"人身安全保障冶问题。     

冷激黄瓜贮藏品质及冷激过程传热特性分析

为研究冷激处理对黄瓜保鲜效果的影响及冷激过程中黄瓜内部组织传热机理,建立了黄瓜冷激过程的传热数学模型,并以0℃的冰水混合物为冷激介质,对处理时间分别为20、40、60 min黄瓜的保鲜效果进行了对比试验研究。结果表明,黄瓜保鲜效果差异不仅与冷激处理时组织的最低温度有关,还与最低温度持续的时间有关。冷激处理40 min能够有效抑制黄瓜硬度、可溶性固形物含量的下降,减缓失重率的上升,保持较高的过氧化物酶活性。所建的传热模型能够准确预测冷激处理过程中黄瓜不同深度位置处的组织温度变化。冷激传热模型及相关结论可为黄瓜采后冷激处理工艺提供理论及实践指导。     

评价回归模型拟合效果的数量化方法

回归模型模拟的效果直接影响其预测结果的精确性，针对残差分析法检验模型似合效果的局限性，采用数量化方法进行检验，不仅综合分析的模拟效果，而且可以直接比较模型间的拟合效果，并为建立拟合效果好的新模型提供了充分的依据。     

A New,Quick, and Simple Protocol to Evaluate Microalgae Polysaccharide Composition

In this work, a new methodological approach, relying on the high specificity of enzymes in a complex mixture, was developed to estimate the composition of bioactive polysaccharides produced by microalgae, directly in algal cultures. The objective was to set up a protocol to target oligomers commonly known to be associated with exopolysaccharides’ (EPS) nutraceutical and pharmaceutical activities (i.e., rhamnose, fucose, acidic sugars, etc.) without the constraints classically associated with chromatographic methods, while maintaining a resolution sufficiently high to enable their monitoring in the culture system. Determination of the monosaccharide content required the application of acid hydrolysis (2 M trifluoroacetic acid) followed by NaOH (2 M) neutralization. Quantification was then carried out directly on the fresh hydrolysate using enzyme kits corresponding to the main monosaccharides in a pre-determined composition of the polysaccharides under analysis. Initial results showed that the enzymes were not sensitive to the presence of TFA and NaOH, so the methodology could be carried out on fresh hydrolysate. The limits of quantification of the method were estimated as being in the order of the log of nanograms of monosaccharides per well, thus positioning it among the chromatographic methods in terms of analytical performance. A comparative analysis of the results obtained by the enzymatic method with a reference method (high-performance anion-exchange chromatography) confirmed good recovery rates, thus validating the closeness of the protocol. Finally, analyses of raw culture media were carried out and compared to the results obtained in miliQ water; no differences were observed. The new approach is a quick, functional analysis method allowing routine monitoring of the quality of bioactive polysaccharides in algal cultures grown in photobioreactors.     

Interactive Effects of Nitrogen Source and Salinity on Growth Indices and Ion Content of Indian Mustard

ABSTRACT

The interactions between salinity and different nitrogen (N) sources nitrate (NO₃ ^?), ammonium (NH₄ ⁺), and NO₃ ^? + NH₄ ⁺ were investigated on Indian mustard (Brassica juncea cv. RH30). Treatments were added to observe the combined effect of two salinity levels (8 and 12 ds m^{? 1}) and three nitrogen sources (NO₃ ^?, NH₄ ⁺, and NO₃ ^? + NH₄ ⁺) on different growth parameters and mineral composition in different plant parts, i.e., leaves, stem, and root. Salinity has been known to affect the uptake and assimilation of various essential nutrients required for normal growth and development. Different growth parameters, i.e., leaf area, dry weight of different plant parts, absolute growth rate (AGR), relative growth rate (RGR), and net assimilation rate (NAR) declined markedly by salinity at pre-flowering and flowering stages. All growth indices were less sensitive to salinity (12 d s m^{? 1}) with the nitrate form of nitrogen. It is pertinent mention that a high dose (120 kg ha^{? 1}) of nitrogen in ammonium form NH₄ ⁺, acted synergistically with salinity in inhibiting growth. Plants fed with combined nitrogen (NO₃ ^? + NH₄ ⁺) had an edge over individual forms in ameliorating the adverse effects of salinity on growth and yield. Under salt stress, different nutrient elements such as N, phosphorus (P), potassium (K⁺), and magnesium (Mg^{2 +}) were decreased in different plant parts (leaves, stem, and root). The maximum and minimum reduction was observed with ammoniacal and combined form of nitrogen, respectively, while the reverse was true of calcium (Ca^{2 +}), sodium (Na⁺), chloride (Cl^?), and sulfate (SO₄ ^2?) at harvest. Nitrogen application (120 Kg ha^{? 1}) in combined form had been found to maintain highest concentrations of N, P, Mg^{2 +}, and Ca^{2 +} along with reduced concentrations of Na⁺, Cl^?, and SO₄ ^{2 ?}. However, reverse was true with ammoniacal form of nitrogen.