不同处理对芹菜种子萌发过程中抗氧化系统及激素水平的影响

为研究芹菜种子的萌发机制,采用不同试剂组合（5 g/L NaOH+10% PEG、10% PEG+500 mg/L壳聚糖、5 g/L NaOH+500 mg/L壳聚糖）和不同温度(18、24、30℃)对芹菜种子进行处理,观察芹菜种子的萌发指标,并探究种子萌发过程中的抗氧化系统及内源激素水平的变化。结果表明,30℃对种子发芽率、发芽势及发芽指数提高具有促进作用,加快种子萌发进程。与蒸馏水对照组相比,试剂组合处理在18、24℃时种子发芽率、发芽势和发芽指数升高,促进种子萌发,18℃时5 g/L NaOH+500 mg/L壳聚糖处理下的发芽势最高,24℃时5 g/L NaOH+10% PEG处理下发芽势达到最大值;30℃时不同试剂组合处理间发芽率、发芽势和发芽指数无明显差异。18、30℃对种子具有一定程度的胁迫作用,种子SOD和CAT活性较24℃条件下有所增加;18℃时MDA含量和脯氨酸含量显著增加;5 g/L NaOH+10% PEG处理能显著降低MDA含量。萌发过程中,芹菜种子内部ABA含量下降,GA₃、ZA含量增加。试剂组合及适当高温有利于提高芹菜种子的发芽率、发芽势和发芽指数,促进种子萌发,提高种子萌发整齐度;芹菜种子萌发过程中抗氧化系统和激素水平会积极响应不同的处理条件。     

Effect of dietary Moringa stem meal level on growth performance,slaughter performance and serum biochemical parameters in geese

Moringa stem meal (MSM) with a high level of crude fibre (CF) might be developed and utilized in herbivorous geese as an unconventional feedstuff. The aim of this study was to investigate the effect of the MSM level in the diet on the growth performance, slaughter performance, breast meat quality and serum biochemical parameters in geese from 22 to 70 days of age. A one-factor completely randomized design was adopted in our study. A total of one thousand eight 21-day-old geese were randomly divided into six groups, with six replicates per group and 28 birds per replicate. The geese were fed diets containing MSM levels of 0, 20, 40, 60, 80 or 100 g/kg during day 22–70. The dietary MSM level had no effect (p > .05) on the final body weight (BW), average daily gain (ADG) or average daily feed intake (ADFI). The feed/gain ratio (F/G) increased linearly (p < .001) as the dietary MSM level increased. No differences (p > .05) were observed in the slaughter performance, meat quality and the relative organ weight (except for thymus) of the geese (p > .05). The relative weight of the thymus in the geese fed diets with supplementation of MSM was higher than that in the non-supplemented MSM control group (p < .05). In addition, 100 g MSM/kg of diet decreased the serum glucose (GLU) level (p < .05) and increased the alanine transaminase (ALT) enzyme activity (p = .03). Dietary MSM levels of no more than 60 g/kg had no effects on the growth performance and slaughter performance, whereas diets with 100 g MSM/kg increased the F/G and serum ALT enzyme activity, as well as decreasing the serum GLU level. Therefore, MSM provided at a reasonable level could be developed as an unconventional feedstuff for geese at the finisher period.     

样条权函数神经网络在机械手逆运动学中的应用

针对传统神经网络算法中存在的缺陷,提出了一种样条权函数神经网络,并将其应用于机械手的逆运动学求解中。该类型的神经网络结构简单,训练得到的权值是由三次样条函数组成,而非传统神经网络的常数,通过求解线性方程组得到三次样条函数的表达式。所以本算法不存在局部极小、收敛慢等缺点,仿真证明该算法具有较高的精度。     

基于逆周期的主权信用评级指标体系研究

现行国际主权信用评级呈现出明显的顺周期特征而广受诟病。在对评级指标体系优化的基础上，采用90个主权国家2005~2012年经济数据进行面板随机效应和门限效应回归，对主权信用评级决定模型进行估计，运用欧债危机发生前后的数据进行模拟评级，结果表明：优化后的指标体系显示出较好的逆周期特征。     

浅析黑龙江省林业产业结构优化调整对策

合理的产业结构会带动经济的快速发展,促进自然资源的合理利用,对于保持生态平衡有非常大的推动作用。文章在我省现有林业产业结构分析的基础上,通过建立林业产业园区,发展林下经济以及大力发展旅游及其相关产业的林业产业结构调整对策。     

新疆南疆棉花品种试验分析

本研究收集新疆南疆大面积种植的56个棉花品种,对非抗虫棉、常规转基因抗虫棉、杂交抗虫棉F1及F2共4类品种的产量及纤维品质进行了比较分析。结果表明,转基因抗虫棉比非抗虫棉增产29.8%,差异达显著水平;杂交棉比常规棉平均增产4.6%,铃重增加0.38g,衣分提高0.91百分点,均未达到显著水平;杂交抗虫棉F1明显优于F2,主要表现在单株结铃性的显著提高导致产量显著提高,而且断裂比强度和纤维整齐度指数等主要品质指标显著提高。由于在河南安阳试验的密度与新疆有明显差异,其准确性需要在新疆高密度条件下继续验证。     

谷子杂交种与常规种光合和叶绿素荧光特性的比较

为了明确杂交谷的光合优势是否是其产量高于常规谷的一大主因,本研究于2013年对常规谷晋谷21号和杂交谷张杂谷5号的光合和叶绿素荧光特性进行比较。采用完全随机设计,每个品种种植5个小区,在拔节期和灌浆期分别测定各项光合指标。结果表明,在拔节期,张杂谷5号的净光合速率、PSⅡ实际光化学量子产量显著高于晋谷21号;但在灌浆期,张杂谷5号和晋谷21号之间的总叶绿素含量、净光合速率、蒸腾速率、气孔导度、胞间CO2浓度、PSⅡ实际光化学量子产量、光化学淬灭参数和非光化学淬灭参数都存在显著差异。总体杂交谷在拔节期和灌浆期的光合性能高于常规谷。     

Advances on Detection Methods for Residues of Nitrofurans in Food

Nitrofurans are broad-spectrum antibiotics which have been widely used in food animals to the prevention and treatment of gastrointestinal infections.Due to abuse of drugs by criminals,animals could produce drug-resistant strains,which reduces the role of antibiotics.Meanwhile,excessive drugs residues in food has carcinogenic,teratogenic and mutagenic effects to the human body.In this paper,the damage and the detection methods of the residues of the nitrofurans in food are surveyed.The main detection methods include high performance liquid chromatography,liquid chromatography-mass spectrometry,liquid chromatography tandem mass spectrometry,enzyme-linked immunoassay,colloidal gold immunoassay and fluorescence immunity analysis method.The research status of various detection methods are summarized and the suggestions for further research are put forward.It is expected to provide reference for future research.     

香港人工林改造对林下植物自然更新 和物种多样性的早期影响

以嘉氏羊蹄甲（Bauhinia galpinii）种子为材料，开展了不同浸种催芽处理对比试验。结果表 明，相比不浸种处理，3 个浸种处理明显提高嘉氏羊蹄甲的种子发芽势和发芽率，平均苗高也明显高于不 浸种组，其中，温水(60 ℃ ) 浸种6 h 组嘉氏羊蹄甲种子发芽率最高，达74.7%，苗高生长最快。