不同灌溉和施肥方式对杂交稻生长和根际环境的影响

对杂交稻中优218不同灌溉方式和氮肥管理下水稻生长和根际环境的变化进行研究,结果表明,水稻好气灌溉条件下各施肥处理产量均高于传统灌溉处理,产量比淹水灌溉增产10.5%~11.3%,主要表现在每穗粒数增加而提高产量。好气灌溉与淹水灌溉比较各生育期地上部干物重和叶面积指数均增加,土壤氧化还原电位提高,放线菌数量显著增加。增加有机肥降低土壤氧化还原电位和提高放线菌数量,在好气灌溉条件下施相同氮素有机肥放线菌数多于化肥。     

Effects of formalin on total haemocytes count and histopathological changes in the shrimp Litopenaeus schmitti (Pérez‐Farfante & Kensley 1997)

Formalin is used in shrimp industry to eliminate ectoparasites and as a disinfectant. However, the effect of formalin on shrimp's defense mechanism is unknown. Several biomarkers were used to assess the immune response of juveniles of the shrimp Litopenaeus schmitti exposed to different concentrations of formalin (10, 25 and 50 mg L^?1) during 24 and 48 h. Formalin concentrations of 25 and 50 mg L^?1 produced a significant reduction in the total haemocyte count at both 24 and 48 h. Peroxidase and phenoloxidase activity did not show variations. The total protein concentration in haemolymph of shrimps was not significantly different between experimental groups. Histological analysis showed hyperplasia in the gills of animals exposed at 10 mg L^?1 for 24 h; however, the exposure at 25 and 50 mg L^?1 caused necrosis in gills, hepathopancreas and the antennal gland.     

半解析数值法分析四边自由中厚板的受力特性

根据Reissner中厚板理论,结合胡海昌的解耦函数法,本文构造出一种能满足全部自由边界条件的试函数,并以此建立两个广义位移,用该位移求得双参数地基上四边自由矩形中厚板弯曲问题的解析解.利用最小平方误差法并结合数值算例,重点探讨了板弯剪刚度比、地基刚度以及地基剪切模量对弹性地基上四边自由中厚板受力特性影响规律.结果显示:(1)Vlazov地基模型优于Winkle地基模型,因为它考虑了地基剪切刚度的影响,使得板的内力和挠度均有减小,发挥了地基的潜力;(2)当地基刚度较小时,地基的剪切模量对板的挠度和内力的影响显著;当地基的刚度较大时,剪切模量对板的内力和挠度的影响不明显.本文计算精度高,计算工作量小且便于对参数进行分析,以及提供数值分析法判据等多项特点.     

国产X65卷板在库鄯管道的应用

上海宝钢首次生产的Ｘ６５卷板，作为库鄯输油管道用钢哮，经制管和试验检查，钢材稳定、质量合格，完全符合ＡＰＩ５Ｌ标准，在力学性能和化学成分等方面邓国际水平，为我国高强度、高韧性的管 道用钢填补了空白。     

Progress and Yield Bottleneck of Aerobic Rice in the North China Plain: A Case Study of Varieties Handao 297 and Handao 502

Aerobic rice has been considered a promising rice cultivation system as water scarcity is increasing in the world. This article summarizes the advances in aerobic rice management researches in the North China Plain, focusing on yield formation and its bottleneck. High-yielding and good-quality aerobic rice varieties adapted to aerobic soil conditions have been released officially and adopted by farmers in North China. The varieties Handao 502 and Handao 297 have been recognized as the most promising varieties reaching a yield level ranging 3.5-5.0 t ha-1 with 450-650 mm water input. Compared with lowland rice, water input in aerobic rice was more than 50% lower, and water productivity was 60% higher. Researches on responses of rice cultivars to nitrate nitrogen （N） and ammonium N supplied at early growth stages provided the first evidence for a preference of aerobic rice HD297 for nitrate N supply, compared with the lowland rice variety. Zinc uptake studies demonstrated that introduction of aerobic rice system on calcareous soils may increase zinc deficiency problems. Sink size was identified as the limitation of aerobic rice yield, because its spikelet number m-2 was too low （20000-24 000） compared with the lowland rice. For future research, more attention is suggested to be paid to yield formation focusing on effects of water regimes on tiller dynamics. Understanding of nutrient uptake and response to fertilization effects are also urgently required to establish optimized crop management technology. Additionally, alternative cropping systems based on aerobic rice should be established, and key sustainability and environmental impact issues in the systems need to be identified.     

阿拉尔片区部分豆制品卫生学评价

本实验是以阿拉尔片区部分豆制品卫生质量进行感观和细菌学评价,为消费者的健康饮食做以指导。结果显示:阿拉尔片区所售的部分豆制品存在着卫生质量问题,菌落总数不合格的为44%;大肠菌群数不合格的为25%;九团检样豆腐中检出一例蜡样芽胞杆菌,阿拉尔片区部分豆制品总体合格率占检样的56%。     

山楂枝皮过氧化物酶同功酶及嫁接亲和力初探

应用聚丙烯酰胺凝胶电泳法检测了山楂属植物5个种11个品种枝皮的过氧化物酶同功酶,结果得知:山楂属植物枝皮过氧化物酶同功酶分2大酶区,有4条特征性谱带,种间差异较大,品种间差异较小。嫁接后不同砧,穗组合的过氧化物酶同功酶酶谱基本稳定,但随组合不同而有一定的变化。砧,穗过氧化物酶同功酶相同值越大,嫁接亲和力越强。同时对4个种,11个品种的44个组合进行了嫁接亲和力预测。     

好氧颗粒污泥实现同步除磷脱氮的试验研究

在厌氧反应1h，好氧反应4h，缺氧反应2h的运行条件下，研究了序批式反应器中好氧颗粒污泥同步除磷脱氮的情况，并对好氧颗粒污泥除磷脱氮的机理进行了探讨．试验结果表明，该系统对氮、磷和有机物具有良好的去除效果，对氨氮、总无机氮、磷、COD的去除率分别达到89．2％～98．9％，81．3％～89．4％，86．8％～90．0％和82．7％～96．6％。     

鸡羽毛氮素释放规律及肥效研究

本文通过室内好气培养试验和盆栽试验,研究了不同细度、不同用量鸡羽毛在不同土壤上的无机氮释放规律及肥效。试验结果表明,好气培养2～3周内,羽毛无机氮释放速率和释放量均较高,羽毛中有15%～70%的氮以无机氮的形式释入出来。2～3周以后,羽毛无机氮的释放速率和释放量则显著下降。羽毛的细度、用量及土壤类型对羽毛无机氮的释放有显著的影响。在施氮量相同的情况下,施用羽毛和施用化肥对盆栽油菜可以起到相同的增产效果。     

甘薯磨锉机中筛板作用分析

甘薯磨锉机具有淀粉提取率高、结构简单和功耗低等优点、其结构上主要特点之一是增加了筛板。本文通过对甘薯力学特性试验和筛面压力测试试验结果的分析,研究了甘薯磨锉过程。结果表明,筛板的主要功能为;限制过筛物料粒径和增加对物料的破碎作用。