从马尾松毛虫中制备高脱乙酰度壳聚糖的初步研究

采用酸碱法从马尾松毛虫蛹中制备壳聚糖,结果表明:马尾松毛虫蛹依次经盐酸脱矿物质、氢氧化钠脱有机物质、双氧水脱色处理后获得白色片状固体物甲壳素,其水分含量为3.32%,灰分为0.99%,脱乙酰度为92.54%,粘度为18.3MPa·s;由甲壳素制备壳聚糖的条件为NaOH浓度50%,处理时间5h,处理温度80℃;由甲壳素获得壳聚糖产品的产率为79.21%。     

耕作方式对黑土有机碳及有机无机复合状况的影响

[目的]研究耕作方式对黑土有机碳数量的变化、有机无机复合度及腐殖质结合形态的影响。[方法]采用设置休闲、玉米连作和玉米—大豆轮作3种耕作方式进行长期定位试验。[结果]不同耕作方式对黑土有机无机复合状况有明显的影响。休闲、连作及轮作均能增加土壤有机碳及其各组分、重组有机碳含量以及原土复合量,提高土壤活性有机碳含量,降低土壤有机碳的氧化稳定性及原土复合度。连作和轮作增加黑土土壤追加复合量和追加复合度,以轮作效果最好。不同耕作方式中各种结合形态的腐殖质在绝对含量上均有明显提高,以松结合态腐殖质增加较多。[结论]轮作更有利于提高土壤HA/FA比值、HA的E4/E6比值、土壤松结合态腐殖质含量及土壤重组腐殖质碳的松/稳和松/紧比值。     

澳门民间遛狗文化与城市遛狗公园建设匹配度研究

民间遛狗文化是澳门的民俗特色之一。如何科学合理地规划建设城市遛狗公园（遛狗区）以满足市民日益增长的生活需求已成为专业部门面临的重要挑战。通过对文献实证研究、遥感测绘和实地调研,梳理了近代以来澳门遛狗、赛狗的民俗文化活动特点,分析了澳门高密度城市环境中的民间遛狗文化与城市遛狗公园建设的供需匹配度,得出澳门半岛与离岛城市遛狗公园建设均有较大的匹配度失衡,针对性提出未来澳门城市遛狗公园建设的规划策略思路。     

近50年菏泽地区雷暴日数的气候分布特征

以观测雷暴日资料为基础,采取线性倾向分析法、Mann-Kendall检验法、morlet小波分析法,对菏泽地区雷暴日数的气候分布特征进行详细分析。发现1964～2013年间,菏泽各区县雷暴日数分布均匀。从20世纪60年代中期开始,年雷暴日数以2.9 d /10a的线性趋势显著减少。雷暴日数减少是一种突变现象,开始时间是1981年。在7年层次里,菏泽市雷暴日序列存在准15年周期的振荡,在20年层次里,菏泽市雷暴日序列存在准40年周期的振荡,20世纪80年代后期是一个转折点。雷暴日空间分布均匀。     

Quantitative trait loci mapping of seed colour,hairy leaf,seedling anthocyanin,leaf chlorosis and days to flowering in F2 population of Brassica rapa L.

A diversity arrays technology (DArT) map was constructed to identify quantitative trait loci (QTL) affecting seed colour, hairy leaf, seedling anthocyanin, leaf chlorosis and days to flowering in Brassica rapa using a F₂ population from a cross between two parents with contrasting traits. Two genes with dominant epistatic interaction were responsible for seed colour. One major dominant gene controls the hairy leaf trait. Seedling anthocyanin was controlled by a major single dominant gene. The parents did not exhibit leaf chlorosis; however, 32% F₂ plants showed leaf chlorosis in the population. A distorted segregation was observed for days to flowering in the F₂ population. A linkage map was constructed with 376 DArT markers distributed over 12 linkage groups covering 579.7 cM. The DArT markers were assigned on different chromosomes of B. rapa using B. rapa genome sequences and DArT consensus map of B. napus. Two QTL (RSC1‐2 and RSC12‐56) located on chromosome A8 and chromosome A9 were identified for seed colour, which explained 19.4% and 18.2% of the phenotypic variation, respectively. The seed colour marker located in the ortholog to Arabidopsis thaliana Transparent Testa2 (AtTT2). Two QTL RLH6‐0 and RLH9‐16 were identified for hairy leaf, which explained 31.6% and 20.7% phenotypic variation, respectively. A single QTL (RSAn‐12‐157) on chromosome A7, which explained 12.8% of phenotypic variation was detected for seedling anthocyanin. The seedling anthocyanin marker is found within the A. thaliana Transparent Testa12 (AtTT12) ortholog. A QTL (RLC6‐04) for leaf chlorosis was identified, which explained 55.3% of phenotypic variation. QTL for hairy leaf and leaf chlorosis were located 0–4 cM apart on the same chromosome A1. A single QTL (RDF‐10‐0) for days to flowering was identified, which explained 21.4% phenotypic variation.     

晴阴天对不同结构日光温室温度的影响

[目的]研究不同天气条件下不同结构类型日光温室的温度变化规律。[方法]建立2个不同结构的日光温室,在典型的阴晴天观测并记录室外天气情况和室内温度变化。[结果]晴天时,1号温室比2号温室升降温快,17:00后1号温室a点温度比2号温室低;2号温室的升温时间更长;11:00～17:00,1号温室c点温度比2号温室低,其他时间2个温室温度较接近;11:00～16:00,1号温室d点升温较快,其最高温度比2号温室高3.0℃。阴天时,整天内2个温室的温度均呈波动下降趋势;23:00,1号温室a、b点的温度分别降至10.5和7.8℃,2号温室的分别降至8.2和10.5℃;1号温室c点温度一直比2号温室低;1号温室d点温度变化较为平缓。[结论]2号温室的保温效果较好,温度变化较平缓,应作为山东省的重点推广温室类型。     

论鲜活农产品直配模式的形成机理及交易效率——以河北省为例

随着我国农业产业化程度的提高和农产品流通体制的健全,鲜活农产品在其生产和流通领域正在发生一些变化。通过对河北各地的实地考察,文章对河北省鲜活农产品配送模式中两种典型的直配模式进行了分析和比较,认为"合作经济组织+超市"模式具有较高的组织化程度和交易效率,但由于其市场目标一般为高端市场,其规模不宜太大;"生产基地+终端消费市场"模式计划性很强,是目前组织化程度最高的配送模式之一,但其外生交易费用较高。     

Protein Hydrolysates from Shrimp (Metapenaeus dobsoni) Head Waste: Optimization of Extraction Conditions by Response Surface Methodology

Utilization of shrimp head waste from the processing industry offers a solution to environmental pollution and also produces valuable bioactive peptides. The present study was aimed to optimize the alcalase assisted extraction conditions by response surface methodology (RSM) to obtain protein hydrolysates from shrimp (Metapenaeus dobsoni) head waste with maximum antioxidant activity. Based on the models derived by RSM, the optimized conditions for maximum degree of hydrolysis (DH) were pH 8.2, temperature of 45.4°C, and enzyme/substrate (E/S) of 1.8%. Meanwhile, the optimized conditions for maximum antioxidant activity of protein hydrolysates as measured by 2, 2-diphenyl-1-picrylhydrozyl (DPPH) and ferric reducing antioxidant power (FRAP) assays were pH 8.2 and 8.1, temperatures of 49.7 and 59.4°C, and E/S of 2.1 and 2.7%, respectively. The maximum predicted values for DH, DPPH, and FRAP were 42.44%, 39.64% inhibition, and 8.3 μM Fe (II)/g wet wt. of sample, respectively. The extraction of protein hydrolysates at optimal conditions derived by these models resulted in DH, DPPH, and FRAPs of 40.31%, 38.93%, and 8.21 μM Fe (II)/g of sample, respectively, demonstrating the fitness of the models. The present study demonstrates the potential of Metapenaeus dobsoni head waste as a source of protein hydrolysates with prospective antioxidant activity.     

乙草胺对昆明小鼠肝脏病理性变化的研究

通过设定不同浓度低剂量的乙草胺,对昆明小鼠进行90 d灌胃试验,来确定乙草胺的亚慢性毒性。结果表明,与空白对照组相比,受试物组的动物体重有明显下降(P＜0.05)。浓度越高,体重下降越快。通过HE染色镜检观察,发现受试物组动物肝脏出现不同程度的脂肪粒增加、肝细胞纤维化。浓度越高,肝内脂肪含量越多,肝细胞纤维化程度越严重...     

水稻根系果胶去甲酯化促进细胞壁磷再利用的机制探究

在缺磷条件下,水稻根系细胞壁中的果胶组分能促进细胞壁磷的再利用,而其中的潜在机制仍有待进一步的研究。选取粳稻品种Nipponbare(Nip)和籼稻品种Kasalath(Kas)作为试验材料,研究了在缺磷条件下,水稻内源磷可利用水平的变化及其差异,并探究了产生这种差异的原因。结果表明:在缺磷处理后,水稻体内的可溶性磷含量迅速降低,而Nip根系和地上部的可溶性磷含量均一直高于Kas。同时Nip根系中释放出了更多的细胞壁磷,说明相对于Kas而言,Nip的内源磷再利用能力更强。缺磷胁迫时,与Kas相比,Nip可通过提高根系中的果胶甲酯酶活性,维持较低的果胶甲酯化度。体外试验又表明,甲酯化度越低的果胶,活化难溶态磷的能力越强。综上,缺磷胁迫下,水稻可通过提高根系果胶甲酯酶活性,将细胞壁的果胶甲酯化度维持在较低水平,从而促进细胞壁磷的释放来增加体内的可溶性磷含量,以供其他部位再利用。