高产施肥条件下水稻穗粒数与茎粗关系

在三个高产水稻课题的研究和推广过程中，研究了水稻的穗粒数与茎粗之间的关系，其关系符合直线方程Y=a＋bX。因此认为在水稻栽培中．必须培育茎秆粗壮的高产群体。     

水稻基因组全图绘制完成

科学家们已完成了水稻基因组序列全图图谱的绘制，其覆盖率和精确度均远远高于此前发表的草图，这是迄今在高等生物中最精确、最完整的测序工作之一。科学家希望这一重大突破能帮助人类解决粮食生产问题，而且全世界研究人员均可免费从计算机数据库中获取这一图谱。这一成就公布在近期出版的英国《自然》上。     

粉煤灰磁化肥在南阳黄褐土上的增产效果

根据两年的研究结果,粉煤灰磁化肥在南阳黄褐土上有一定的增产作用,与等量氮、磷、钾肥料相比,大豆、花生的增产幅度为5.3%～9.9％,对大豆的增产作用表现在分枝数,每株荚数、百粒重及根瘤的提高、改善和增加。     

钒镉复合污染对水稻吸收积累镉、钒和磷的影响

采用溶液培养法研究钒与镉复合污染对水稻生长及其吸收积累镉的影响,以便弄清在钒与镉复合污染条件下水稻的生长情况.试验结果表明,钒镉复合污染可影响水稻的生长发育.在培养液镉浓度(1 0mg·L-1)不变的情况下,随着溶液中钒浓度的增加,水稻根长、根系和茎叶的干重不断减少.当溶液中钒浓度达到1 6mg·L-1和3 2mg·L-1时,水稻茎叶和根系干重减少分别达到显著水平(p<0 05).钒镉复合污染也影响水稻植株对磷、钒和镉的吸收与积累.当培养液中镉浓度不变时,随着溶液中钒浓度的增加,水稻根系和茎叶中的磷浓度不断降低,而钒含量却不断提高,根系比茎叶积累更多的钒.此外,钒可抑制水稻植株对镉的吸收与积累.     

浅谈土锅炉的危害及治理

本文分析了近几年土锅炉的存在原因及爆炸事故,阐述了土锅炉的危害及以预防措施。     

土-结构相互作用对铅芯橡胶支座隔震结构的影响

利用有限元方法,将隔震结构、基础和土体作为一个整体系统进行分析,研究了不同土性土-结构相互作用对基底地震动输入和隔震体系动力特性与地震响应的影响.分析结果表明,土-结构相互作用对基础隔震结构存在影响,因而在工程设计中,隔震结构不应忽略土-结构相互作用效应的影响.     

模拟酸雨对水稻叶片质膜H~+-ATPase与质膜过氧化的影响

在水培条件下研究酸雨(pH值为2.5~5.5)对水稻叶片质膜过氧化与H+-ATPase活性的影响。结果表明,与对照相比,pH≥3.5酸雨处理下的水稻叶片质膜H+-ATPase活性、质膜透性、丙二醛(MDA)含量、过氧化氢(H2O2)含量和过氧化氢酶(CAT)活性(pH=3.5下CAT活性除外)无显著变化(p0.05);pH≤3.0处理组质膜H+-ATPase活性随酸雨pH值降低呈先升后降趋势,其余指标随pH值降低而增大,表明质膜H+-ATPase活性受抑使质膜过氧化加剧。在恢复期,pH≥3.5处理组各指标仍无显著变化(p0.05);pH=3.0组各指标变幅减小,H+-ATPase与CAT活性恢复至CK(对照),表明植物自修复使质膜过氧化减轻;pH=2.5组H+-ATPase活性仍低于CK,质膜透性和MDA含量不仅高于CK且高于胁迫期,表明质膜H+-ATPase活性受抑使质膜过氧化持续。在高强度酸雨(pH≤3.0)的胁迫下,水稻叶片质膜H+-ATPase活性的变化与质膜过氧化程度密切相关。     

人工冻结法调控多年冻土区桩基础地温场的效果分析*

为了解决青藏铁路运营过程中,由于多年冻土地基的升温退化,部分多年冻土区桥梁桩基础承载性能下降,产生有害沉降变形,进而造成桥梁上部结构移位破坏,甚至部分桥梁桩基础在短时间内产生较大的沉降变形这一严重问题。基于当前多年冻土区桥梁桩基础沉降病害快速抢修技术空缺,提出人工冻结技术处置多年冻土区桥梁桩基础沉降病害的新设想,利用数值软件建立冻结管-桩基础三维模型分析该技术的可行性与调控效果,分析冻结参数、场地冻土条件等对冻结效果的影响。研究结果表明:人工冻结法可以快速降低桩周多年冻土温度;同时,冻结96 h可以对桩基地温场起到较好的冷却效果;冻结管至桩的距离对冻结效果的影响最为显著,冻土的含冰量越大,则降温速率越慢。     

Response of the grain yield and quality of hybrid rice to weak light stress北大核心CSCD

In this study, three rice varieties, Byou268 (low light-sensitive type), Nei5you768 (intermediate type), and Yixiangyou1108 (low light-tolerant), were used as experimental materials to investigate the yield and quality responses of different rice varieties to low light stress under normal light (CK) and low light (SH). The results showed the following: (1) Compared with normal light, the decrease in Yixiangyou1108’s 1 000-grain weight, grain number per spike, and seed setting rate under low light treatment were much lower than those of Nei5you768 and Byou268. The yield decline of Yixiangyou1108 (46.5%) was significantly lower than that of Nei5you768 (56.5%) and Byou268 (69.8%). Yixiangyou1108 showed strong tolerance to low light stress in terms of 1 000-grain weight, seed setting rate, grain number per panicle, and yield. (2) Compared with normal light, the reduction in grain length and width of Yixiangyou1108 under low-light treatment was significantly greater than that of Byou268; however, the reduction in the length-width ratio did not reach a significant level. The amylose content and gel consistency of the rice were significantly reduced. The reduction in amylose content of Yixiangyou1108 (24.5%) was significantly lower than that of Nei5you768 (28.1%) and Byou268 (30.6%); however, the decrease in gel consistency of Yixiangyou1108 (14.7%) was significantly higher than that of Nei5you768 (9.8%) and Byou268 (8.1%). After low light treatment, the characteristic values of the RVA curve of rice changed. The peak viscosity and breakdown viscosity of Yixiangyou1108, Nei5you768, and Byou268 were significantly decreased, but the cold glue viscosity and setback viscosity were significantly increased, while there was no significant difference in the peak time and peak temperature. The response of 1 000-grain weight, grain number per spike, and seed setting rate under low light stress can be used as a yield index of rice breeding with low light tolerance; rice grain type, amylose, and gel consistency; and peak viscosity and hot paset viscosity in RVA characteristic values can be used as quality indexes of low-light-tolerant rice material breeding. © 2022 Science Press. All rights reserved.