Influence of Low Light Irradiance on Grain Filling in Rice (Oryza saliva L.) cultivars

Time course of grain filling pattern in two rice (Oryza sativa L.) cultivars, grown under normal and low light intensities, was studied. The number of spikelets, partially filled grains and high density grains were monitored at a 5 day interval during grain filling period from uniform panicles tagged at anthesis. The low light tolerant cultivar Swarnaprabha had more high density grains and less partially filled grains throughout the grain filling period and at harvest compared to cultivar Ratna under both normal and low light intensities. Further, the opening of spikelets in two flushes in Swarnaprabha seemed to result in a more efficient resource allocation and hence better yield as compared to Ratna, in which the opening of spikelets was in a single flush on day 10.     

朝阳东大桥承台砼施工技术

叙述了朝阳东大桥主桥两个承台大体积砼的施工经过。总结了施工方案优选过程和大体积低水化热砼的配合比试验情况,并在实际施工中,证明,该技术措施可行,方案经济合理,取得了比较成功的经验。     

自由曲面前照灯近光配光的防眩目研究

从驾驶员心理学和生理学角度探讨了汽车夜间会车时眩目的机理．由于传统的前照灯配光设计停留在二维的层面上，设计周期长，且配光效果差，很难达到防眩目的要求．本文通过Reflector CAD软件反求出了符合ECE法规配光要求的自由曲面前照灯反射镜的三维模型，该模型可以直接用于数控程序的编制，减小了前照灯的设计成本和设计周期，利用TracePro软件对模型进行近光配光的仿真实验，通过光线追踪的方法避免了实际配光实验时调整反射镜配光所需的反复制造过程，同时又保证了前照灯防眩目的效果。     

Synergistic and antagonistic effects of atrazine on the toxicity of organophosphorodithioate and organophosphorothioate insecticides to Chironomus tentans (Diptera: Chironomidae)

The acute toxicities of two organophosphorodithioate (dimethoate and disulfoton) and two organophosphorothioate (omethoate and demeton-S-methyl) insecticides were evaluated individually and in binary combination with the herbicide atrazine using fourth-instar larvae of the aquatic midge, Chironomus tentans. Atrazine alone up to 1000 μg/L did not show significant toxicity to the midges in a 48-h bioassay. However, atrazine concentrations as low as 1 μg/L in combination with dimethoate at EC₂₅ (concentration to affect 25% of tested midges), 100 μg/L in combination with disulfoton (EC₂₅), and 10 μg/L in combination with demeton-S-methyl (EC₂₅) significantly enhanced the toxicity of each organophosphate insecticide. In contrast, atrazine concentrations of 10 μg/L and above in combination with omethoate (EC₂₅) significantly decreased the toxicity of the insecticide. Biochemical analysis indicated that increased toxicity of dimethoate, disulfoton, and demeton-S-methyl in binary combination with atrazine correlated to the increased inhibition of acetylcholinesterase. Furthermore, cytochrome P450-dependent O-deethylation activity in the midges exposed to atrazine at 1000 μg/L was 1.5-fold higher than that in the control midges. Thus, atrazine appeared to induce cytochrome P450 monooxygenases in the midges. Elevated cytochrome P450 monooxygenase activity may increase the toxicities of dimethoate, disulfoton, and demeton-S-methyl by enhancing the oxidative activation of dimethoate into omethoate, and disulfoton and demeton-S-methyl into their sulfoxide analogs with increased anticholinesterase activity. In contrast, atrazine reduced the toxicity of omethoate possibly by enhancing the oxidative metabolic detoxification since omethoate does not require oxidative activation.     

马尾松毛虫多功能氧化酶测定正交试验优化研究

应用L16(43)正交试验设计对影响马尾松毛虫多功能氧化酶细胞色素P450测定的因素PMSF浓度、酶原稀释比和离心速度进行优化研究。结果表明供试的16组复配组合中,组合A1B1D1(选用0.2 mol/L PMSF浓度、酶原稀释比为2∶1,离心速度1为5 000 r/min)最优,按照该组合的条件进行马尾松毛虫MFO酶细胞色素P450测定,效果最佳。     

甘肃桃(Prunus kansuensis)雌雄配子体发育规律及遗传特性的研究

为了了解甘肃桃的早花性与其花芽分化的关系及早花性的遗传能力,以甘肃桃1号(甘肃桃)(Prunus kan-suensis)、96-7(普通桃)(P.persica)、甘肃桃1号×96-7的杂种一代群体(20株)为试材,对材料的生物学特性和花芽分化解剖结构进行了研究。结果表明,1)通过对叶、花、果形态特征观察发现,甘肃桃1号×96-7杂种群体的表现性状趋向甘肃桃1号。2)甘肃桃1号在落叶前形成雄配子体,具有花粉的早熟性。3)杂种群体花芽分化始期及花芽分化特性也趋向于母本甘肃桃1号。     

三种内生真菌与大花蕙兰共生对矿质营养吸收的影响

以从兰科植物出的内生真菌与大花蕙兰接种,均能形成菌根,其中ＧＣ９４１和ＧＣ９４５两种菌只侵染根的表皮细胞,在细胞内呈菌丝结结构,而ＧＣ９３４菌在侵染前期同前两和种真菌,后期菌丝可部分侵染皮层细胞,并呈疏松的分枝状结构。３种内生真菌可使幼苗茎叶干重比增施矿质营养但不接种真菌的处理（ＣＫ２）提高１７３．２％－２５０．１％,并对植株吸收Ｎ,Ｐ,Ｋ养分有促进作用,其中ＧＣ９４５菌使幼苗吸收Ｎ和Ｋ的量比ＣＫ     

2009/2010年内蒙古冬季低温特征及成因分析

利用常规观测资料,分析2009/2010年内蒙古冬季低温的特征。并通过对欧亚地区大气环流、影响我国的冷空气活动、北极涛动指数和EI Nino年内蒙古冬季气温的分析,探讨此次低温的气候成因。结果表明：此次冬季低温是内蒙古自1986年以来范围最广、时间最长、强度最大的一次冬季低温。强降温的同时,还伴随着强降雪和大风沙尘天气。地面西伯利亚高压偏强、850 hPa内蒙古北侧偏北气流偏强、500 hPa位势高度场偏低、东亚大槽位置偏西偏强以及强冷空气活动频繁是造成此次低温的主要原因。此次低温还与北极涛动指数负异常和EI Nino事件有关。     

西花蓟马对高低温胁迫响应的转录组分析

为揭示西花蓟马Frankliniella occidentalis对温度的适应机制,采用高通量测序技术对低温（-13℃）、常温（26℃）和高温（40℃）胁迫1 h后西花蓟马进行转录组测序分析,筛选差异表达的unigenes,并对其进行功能注释与相关代谢通路富集分析,同时随机选择8个西花蓟马耐热性相关unigenes进行实时荧光定量（real-time fluorescence quantification PCR,qRT-PCR）测定,以验证转录组测序数据的正确性。结果显示,转录组测序、组装后共获得79 516个unigenes,在NR和KEGG数据库中分别注释到28 675个和47 285个unigenes。40℃与26℃温度胁迫后差异表达的unigenes数量最多,为333个;-13℃与26℃温度胁迫后差异表达的unigenes最少,只有134个;40℃与-13℃温度胁迫后差异表达的unigenes为230个。差异表达的unigenes主要参与内质网蛋白合成和代谢通路等途径,其中有许多热激蛋白基因和细胞色素P450基因受到高低温胁迫后上调表达,表明这些unigenes可能参与西花蓟马应对极端温度的耐受性作用。随机筛选的8个差异表达unigenes的qRT-PCR结果与转录组测序结果一致,表明转录组数据可靠。