微波杀灭霉变玉米中寄生曲霉动力学模型

为描述微波对霉菌的杀菌过程和预测杀菌效果,建立了微波对霉变玉米中寄生曲霉孢子的杀菌动力学模型.在50～75C的微波加热条件下获得了寄生曲霉孢子的致死曲线.选取线性模型、Weibull模型和Weibull 简化模型来拟合微波杀菌的动力学过程,以决定系数、均方误差、精确因子和偏差因子作为模型拟合度优劣的评判指标.结果表明,Weibull模型较线性模型能更好地拟合微波处理下寄生曲霉孢子失活动力学变化;Weibull模型简化后与原模型具有相似的拟合性,可有效预测特定温度-时间组合下的微波灭菌效果;通过Weibull模型预测微波杀菌时间可避免线性模型导致的杀菌不彻底或者过度杀菌的现象.     

不同径向间隙对离心泵动静干涉作用影响的数值模拟

通过改变蜗壳基圆直径改变叶轮与隔舌之间的间隙,采用SST模型对3个蜗壳基圆直径的离心泵全流道进行非定常数值模拟.3个蜗壳基圆直径分别为184、198和214 mm,其对应的间隙率为5.74％、13.79％和22.99％.通过非定常数值模拟获得了不同基圆直径离心泵的压力脉动特性、作用在叶轮上的径向力和扭矩特性,并对其进行比较分析.结果表明:不同测点的压力脉动、作用在叶轮上的径向力和扭矩呈周期波动,均以叶片通过频率为主;不同基圆直径泵叶轮上的径向力矢量图基本呈圆形分布;随着蜗壳基圆直径的增大,叶轮上的径向力先减小后增大,各测点压力脉动幅值逐渐减小,高频脉动也逐渐减少.同时针对蜗壳基圆直径为184 mm的泵进行数值模拟,并对该泵进行了性能试验,对比分析结果表明:数值模拟的结果是可信的.     

我国东北4种常见阔叶乔木物候对气候变化的响应

物候现象是指示气候及自然环境变化的重要指标(Peuelas et al.,2001;Moresette et al.,2009)。自然物候记录可以提供全球环境变化最直接和最有效的证据。已有研究结果表明,受全球气候变化影响,1952—2000年地中海地区(Peuelasetal.,2001)、1851—1994年匈牙利(Walkovszky,1998)、1936—     

Identification and mapping of a novel Turnip mosaic virus resistance gene TuRBCS01 in Chinese cabbage (Brassica rapa L.)

We aimed to identify Turnip mosaic virus (TuMV) resistance genes in Chinese cabbage by analysing the TuMV resistance of 43 P₁ (resistant), 88 P₂ (susceptible), 26 F₁, 104 B₁ (F₁ × P₁), 108 B₂ (F₁ × P₂) and 509 F₂ individuals. All parents and progeny populations were mechanically inoculated with TuMV‐C4. Both F₁ and B₁ populations showed TuMV resistance. Resistant: susceptible ratios in the B₂ and F₂ populations were 1 : 1 and 3 : 1, respectively. TuMV resistance in P₁ was controlled by a dominant gene, TuRBCS01. Bulked segregation analysis was performed to identify simple sequence repeat or insertion or deletion markers linked to TuRBCS01. Data from 108 B₂ individuals with resistant or susceptible phenotypes were analysed using mapmake r/exp 3.0. Polymorphic marker sequences were blast searched on http://brassicadb.org/brad/ . TuRBCS01 was found to be linked to eight markers: SAAS_mDN192117a_159 (3.3 cM), SAAS_mDN192117b_196 (4.0 cM), SAAS_mDN192403_148 (13.0 cM), SAAS_mGT084561_233 (6.8 cM), BrID10723 (3.3 cM), mBr4041 (3.3 cM), SAAS_mBr4055_194 (2.6 cM) and mBr4068 (4.0 cM). Further, TuRBCS01 was mapped to a 1.98‐Mb region on chromosome A04 between markers BrID10723 and SAAS_mBr4055_194.     

RAMP与REMAP分子标记技术及其应用

引物设计是RAMP和REMAP标记分析的关键，二者都使用锚定的微卫星序列引物。目前已开发出多个RAMP锚定微卫星序列引物，与不同的RAPD引物进行扩增，得到更多的引物组合。REMAP使用反转录转座子的外向LTR引物和锚定微卫星序列引物。而RAMP分析采用不对称PCR循环，在PCR扩增的后15个循环中，退火温度设为2个；REMAP则采用常规PCR循环。扩增产物可在聚丙烯酰胺凝胶、变性聚丙烯酰胺凝胶、琼脂糖凝胶上进行电泳分离，检测时可使用同位素、银染或溴化乙锭染色等技术。目前，这两种标记技术已在作物和动物种质资源的遗传多样性分析、遗传连锁图谱构建、转基因植株基因稳定性分析等方面都有成功的应用。     

加强质量管理促进种子经营

随着种子市场全面开放，市场竞争日益激烈，各种坑农害农事件也相应增加。要搞好种子经营工作，更好地服务农业生产，就必须确保种子质量，因为种子质量是种子企业的生命，抓住了质量就抓住了市场，抓住了发展。因此，要建立一个全方位全过程的质量保证体系，就必须从繁殖制种、种子收购、加工、包装储运、入库、销售以及售后跟踪服务等各个环节严格把关。     

棉花黄萎病菌VdSge1基因的敲除与功能分析

为了明确棉花黄萎病菌大丽轮枝菌(Verticillium dahliae Kleb.)的VdSge1基因功能,本研究利用基因同源重组原理,通过构建敲除载体,对棉花黄萎病菌落叶型强致病力菌株V592的VdSge1基因进行了敲除,获得了4个目标基因敲除的突变体;以野生型菌株V592为对照,通过对敲除突变体生物学性状和致病性测定,结果表明,突变体的菌落生长速度、产孢量明显高于野生型,并且丧失对棉花的致病性。利用q RT-PCR对其他基因在突变体中的表达情况进行分析,结果表明,VdSge1基因敲除后,VMK1、VGB和VdGARP1的表达量随之下降,而VDH1和PevD1的表达却明显上升。由此说明,VdSge1基因与大丽轮枝菌的菌落生长速度、产孢量及致病性密切相关,并且可以影响其他一些基因的表达。     

浙能海发电厂循环冷却水系统水锤

对浙能海发电厂循环冷却水系统水泵事故停泵的水力过渡过程进行了计算机模拟，根据该系统水力过渡过程的特点提出了有效的水锤防护措施和循环冷却水系统安全运行的措施。抑制了循环冷却水系统管线由于液柱分离及再弥合而导致的压力升高。     

PGR在百合上的应用研究进展

PGR是指施用在植物上，在植物体内很少量就能调控植物生长的非营养有机物。百合相关产品的保鲜技术欠缺，繁殖缓慢等问题是影响百合经济效益的瓶颈之一。本文介绍百合切花衰老机理；对PGR应用于百合切花、鳞茎保鲜，组织培养，栽培技术等方进行概述，并提出了需要进一步研究的问题     

Effect of the Silicic Acid Polymerization Degree on the Coagulating Property of Polyalumium Silicate Chloride

Polyaluminum silicate is a new type of inorganic macromolecular flocculants, which is developed as a complex product in recent years on the base of polyalumium flocculant and polysilicic acid flocculant. Sodium silicate is diluted to the concentration of 3.0% SiO 2 with distilled water. The solution was adjusted to pH 4.5 with sulphate acid and kept at quiescency for different time to get polysilicic acid with different polymerization degrees. Using polysilicic acid prepared and aluminium chloride as materials, a series of polyaluminium silicate chlorides(PASC) with different basicities(B), Al/Si molar ratios and polymerization degree of silicic acid are prepared by copolymerization technique. The Al-Ferron timed complex colorimetric method is applied to characterize species distribution of PASC and to study its influence factors. The interaction between hydrolyzed aluminum species and polysilicic acid with different polymerization degrees in PASC is discussed.The flocculant prepared is applied to the treatment of commercial concrete wastewater. The turbidity removal of commercial concrete wastewater is up to 97% when a PASC, prepared with polysilicic acid of 145 min polymerization degree.