近55 a内蒙古极端降水指数时空变化特征

基于内蒙古100个气象站点1960-2014年日降水数据,选取气候变化监测与指数专家组(ETCCDI)推荐的9个极端降水指数,采用Sen’s斜率法和Mann-Kendall非参数统计检验方法以及空间地统计方法,研究了极端降水指数时空演变特征。结果表明:研究区区域平均的全部极端降水指数均呈不同程度的下降趋势,且年际波动显著;分区的年际趋势有所差异,即东部地区潮湿日数(NW)呈增加趋势,其余极端降水指数均呈减少趋势,其中持续干燥指数(CDD)呈显著下降趋势(P<0.05);中部地区所有极端降水指数均呈减少趋势,其中年总降水量(PRCPTOT)减少趋势较明显;西部地区持续湿润指数(CWD)、强降水量(R95)、单日最大降水量(Rx1day)、5日最大降水量(Rx5day)呈减少趋势,其余指数均呈增加趋势。从极端降水指数变化趋势的空间分布特征来看,区域差异显著,总体上呈下降趋势的站点主要分布于内蒙古东部和中部地区,而呈上升趋势的站点主要分布于内蒙古东北部和西部地区。     

近43年黄河上游来水来沙变化特点

选取黄河头道拐站实测水沙序列(1960-2002年)资料,对水沙序列进行了多时间尺度和趋势识别的小波分析。结果表明:①黄河上游来水来沙量汛期所占比例减少,而非汛期所占比例增加;在年际变化上,水沙量逐年减少;同时,水沙相关关系具有一定的变化;②黄河上游水沙序列具有相同的多时间尺度(准周期)变化,但同一尺度下,水沙所处的丰枯变化并不一致;③年水沙序列趋势变化基本一致,20世纪80年代以来,两者存在明显减少趋势;但在非汛期,两者的趋势变化有较大区别。     

黄花菜胚囊受精前后的超微结构观察

 应用透射电镜技术研究黄花菜（Hemerocallis citrine Baroni）助细胞、卵细胞、中央细胞、 合子与初生胚乳核的超微结构特征。结果如下：助细胞有高度发达的丝状器;一个助细胞在花粉管进入 后退化;宿存助细胞在合子期退化。受精前,卵细胞、助细胞合点端无壁,细胞膜完整;受精后,合子 被完整的细胞壁包围。受精前超微结构特征显示卵细胞代谢活动低,合子期的代谢活性被激活;中央细 胞、初生胚乳核代谢活性较高。卵细胞质中的精核由双层核膜包被,染色质高度凝聚,核孔数少。助细 胞、卵细胞、中央细胞缺乏中央大液泡是黄花菜成熟胚囊的显著特征。     

河南省花生收获机械应用现状与发展分析

介绍了国内外花生收获机械应用的现状及主要机型,重点分析了河南省花生收获机械研制和推广方面取得的成效及存在问题,讨论了我国花生收获机械发展缓慢的原因并提出了具体措施,同时展望了未来花生收获机械的发展前景。     

Molecular cloning and expression of kidney‐type glutaminase from common carp (Cyprinus carpio) and its up‐regulation by glutamine in primary culture enterocyte

Glutaminase (GLS) is the key enzyme of glutamine (Gln) metabolism and utilization. In this study, a cDNA encoding GLS protein was identified from common carp Cyprinus carpio intestine. The open reading frame of GLS cDNA encodes a polypeptide of 595 amino acids, which shows a high similarity with its zebrafish Danio rerio counterpart. Bioinformatic analysis showed the protein belongs to kidney‐type GLS. The putative protein has glutaminase domain and ankyrin repeats domain, which are highly conserved among vertebrate orthologues. Real‐time quantitative PCR analysis revealed that the abundance of GLS mRNA was the highest in the white muscle, followed by the brain, eyeball and pituitary. Glutaminase was ubiquitously expressed in all intestinal segments of common carp. The activity of GLS did not distribute uniformly along the entire length of the intestine. In primary culture enterocyte, and the expression of GLS mRNA is up‐regulated quickly and effectively by Gln.     

德系安哥拉兔的生长特性

德系安哥拉兔不仅以产毛量高、毛质好而著称,而且有生长迅速、体成熟早、体型大的特点。六月龄时已达成年体重的87.37％。母兔的初配可在此时进行,公兔可延迟一个月配种。四月龄与六月龄体重和成年体重的相关系数分别为0.505与0.508,这为德系安哥拉兔体重的早期选择提供了有利时机。     

Decomposition Dynamics and Nutrient Release Pattern from Leaf Litters of Five Commonly Occurring Homegarden Tree Species in Mizoram,India

Leaf litter decomposition and nutrient release patterns from five common multipurpose tree species—viz., Artocarpus heterophyllus, Mangifera indica, Areca catechu, Citrus sp., and Tamarindus indica, found in homegardens of Mizoram—were evaluated using a litter bag technique. The result of the study indicates a varying pattern of decomposition and nutrient release (N&P) among the species. Citrus sp. and T. indica were found to be the most labile species with comparatively much higher decay constant and faster nutrient release. Initial nitrogen concentration, lignin content, and lignin/N ratio of foliage litter showed significantly higher (p < .01) correlation with the decay coefficient and were found to be the important determinants in the decay process. The initial slow release and immobilization of N in A. heterophyllus and M. indica leaf litter reflect their potential as a source of nitrogen storage and effective mulching material. While litter from T. indica and Citrus sp. can provide the short-term nutrient need, foliage for the other three species may supply the long-term nutrient requirement for the understory crops in such agroforestry systems.     

南方优质米加工的降碎措施

南方优质米加工易碎,成本高,不利企业竞争。针对优质米生产加工中易产生碎米的原因,可从稻谷的品种、栽培、收购、储存、加工工艺和设备优化等方面入手,采取有效措施降低碎米率。     

云南省水电开发中森林资源的保护与恢复对策

简要地介绍了云南省水能资源及开发的现状,从林业发展的角度分析了水电站开发对森林资源产生的正、负面影响,并提出水电开发中森林资源的恢复和保护对策.     

田面微地形对滴灌灌水均匀性的影响

首先分析了田面微地形对滴头实际工作压力的影响,田面越不平整,滴头实际工作压力与设计工作压力的差值越大,当田面局部高差大于滴头设计工作压力时,滴头流量等于零;然后提出了田面微地形产生的流量偏差率公式,并用泰勒级数展开;最后利用描述统计方法和独立样本T-检验的方法对余项进行分析,置信度为99%的余项取值区间为0.001￣0.002,说明余项能够被忽略,田面微地形产生的流量偏差率公式可以用简单的形式来表示。