离心泵用作液力透平叶轮出口滑移系数的计算方法

为了通过理论的方法预测液力透平的性能,并针对国内外对液力透平滑移系数计算公式研究的空白,借助于离心泵滑移系数计算公式的研究方法和相关理论,结合流体力学中的相关原理研究液力透平叶轮流道中流体的流动形式,推导叶轮出口的滑移系数计算公式以及在考虑叶轮进出口滑移时液力透平的基本能量方程,最后选取模型对滑移系数计算公式进行验证,并与已有试验值进行比较分析。研究结果发现:随着比转数的增加,液力透平叶轮出口的滑移量逐渐减小,且对于大部分低比转数液力透平叶轮进口的滑移量小于叶轮出口的滑移量,而对于中、高比转数的液力透平叶轮进口的滑移量大于叶轮出口的滑移量。叶轮出口滑移量随着叶轮进口直径和出口安放角的增加而增大;随着叶片数的增加而减小;随着进口安放角的增加先增大后减小;而叶轮出口直径和叶轮进口宽度对液力透平叶轮出口滑移系数的影响较小,在研究液力透平叶轮出口滑移时可不考虑二者对液力透平叶轮出口滑移系数的影响。研究结果为采用理论的方法预测液力透平的性能提供参考。     

Effects of bio-organic fertilizer plus soil amendment on the control of tobacco bacterial wilt and composition of soil bacterial communities

Tobacco bacterial wilt (TBW) is caused by Ralstonia solanacearum (R. solanacearum), a severe pathogenic agent with a wide host range. In this study, lime?+?ammonium bicarbonate (L?+?AB), organic fertilizer (OF), bio-organic fertilizer (BOF), and integrated treatment (L?+?AB?+?BOF) were assessed for the ability to control TBW and to influence the composition of native soil bacterial communities. The results showed that disease incidence of L?+?AB?+?BOF for two growth seasons in pot experiment was the lowest, with only 15.56 and 11.11 % at seasons 1 and 2, respectively. The integrated treatment could also significantly suppress TBW in the field, with a disease incidence of only 14.27 % compared with 35.41, 50.03, and 31.32 % in L?+?AB, OF, and BOF treatments, respectively. With application of the integrated treatment in pot and field experiments, the abundances of R. solanacearum were both significantly lower than those with other treatments. Denaturing gradient gel electrophoresis (DGGE) patterns showed that application of BOF significantly affected composition of bacterial communities of rhizosphere. The analysis of 454 sequencing data showed that application of integrated treatment recruited more beneficial bacteria than other treatments, such as Bacillus, Paenibacillus, Arthrobacter, and Streptomyces, while the abundance of Ralstonia with the integrated treatment was decreased. Overall, these results suggested that application of integrated agricultural management could effectively suppress bacterial wilt by affecting the composition of bacterial community and reducing the population of R. solanacearum.     

RAPID DIAGNOSIS OF NUTRIENT ELEMENTS IN FINGERED CITRON LEAF USING NEAR INFRARED REFLECTANCE SPECTROSCOPY

In order to provide references for leaf nutrition diagnosis of fingered citron, the technique of near infrared reflectance spectroscopy (NIRS) was introduced to analyze nitrogen (N), phosphorus (P), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in the dry-leaf samples of fingered citron. The best calibration model for N was developed with high RSQ_CAL (0.90), SD/SECV (2.73) and low SEC (1.06 mg g^?1), good calibration models were obtained for P, K, Fe and Mn, and no significant correlations were found between the spectra and the individual amounts of Zn and Cu. When tested using a validation set (n = 38), N was well predicted with low values of SEP (1.21 mg g^?1) and high RPD (2.5). The values of SEP and RPD were also acceptable for the external validation of P, Fe and Mn. Near-infrared spectroscopy analysis technique shows potential of diagnosing minerals in fingered citron, particularly for N, P, Fe and Mn.     

螺旋输送与筛筒组合式分离装置性能试验

大中型谷物联合收割机分离装置存在体积庞大、振动强等问题,小型谷物联合收割机分离装置缺乏对断茎秆的处理能力且分离能力较弱。为此,提出了一种螺旋输送与筛筒组合式分离装置。通过室内试验,研究了搅龙转速、装置倾角和分离筛孔尺寸对分离性能的影响,得出了最优结构和运动参数组合,实现了籽粒、颖糠及茎秆在输送过程中的有效分离,为清选装置在谷物联合收割机上的应用提供了依据。     

河南鸡公山白粉菌寄主植物调查

2005—2006年在河南省鸡公山国家级自然保护区调查白粉菌寄主植物,发现白粉菌寄主植物23科43属52种植物,其中7种为中国新记录寄主植物,27种为河南省新记录寄主植物;使鸡公山国家级自然保护区有记录的白粉菌寄主植物达25科47属57种。     

不同氮肥水平下杂交粳稻滇杂35产量分析

 在不同施氮（0,150,300,450kg/hm2）条件下,对滇杂35及其亲本（母本合系42-5A, 父本南34）以及全国超级稻品种楚粳27的产量进行分析。结果表明：在土壤供氮水平较高条件下（土壤碱解氮154mg/kg）,随施氮量的增加,滇杂35及合系42-5B的产量明显下降（P＜005）,南34的产量显著增加（P＜005）,楚粳27的产量差异不明显。在不施氮和施氮量150kg/hm2的条件下,滇杂35的产量表现均优于其余供试材料,特别是不施氮条件下产量差异尤为明显,较合系42-5B,南34和楚粳27分别高3144%, 3856%, 2477%。此结果与滇杂35多年的推广生产结果一致,表明滇杂35特别在适合土壤氮肥较低的地区推广种植。     

中国北部高原地区谷子(粟)品种高产稳产性的评价

 利用回归系数法、稳定性参数法和高稳系数法 ,对我国北部高原地区新育成的 18个新品种 (系 )的高产稳产性进行了研究。结果表明 ,参试品种多数产量较高 ,占 5 5 .5 % ,但其中产量稳定性较差的占多数 ,高产稳产的品种较少 ,仅有铁 93- 115、95汾选 3和承谷 8号 ,占 16 .7% ,其余的均为低产稳产和低而不稳的类型 ,各占 2 2 .2 %。这可能与品种性状的适应性有关     

中间锦鸡儿fad2基因克隆与序列分析

油酸去饱和酶FAD2(fatty acid desaturase 2)在油酸中引第二个双键生成亚油酸,是负责植物体内产生多不饱和脂肪酸的第一步关键酶.本研究采用RT-PCR和RACE(rapid amplification of cDNA ends)技术,以中间锦鸡儿未成熟种子为材料,克隆了三个fad2基因(分别命名为fad2-2A、fad2-1A和fad2-1B).将这三个基因与汪阳东从中间锦鸡儿枝叶中克隆的fad2-2B(CaFAD2基因,GenBank登录号AY957394)一起进行了序列比对和分析.序列同源性比较结果表明,fad2-1A与fad2-1B同源性很高,fad2-1A编码的前283个氨基酸与fad2-1B的同源性高达98.9%,fad2-2B与fad2-1A的氨基酸序列同源性最低,只有64.7%.这四个基因的成功克隆,为进一步研究基因分工、调控方式打下了基础,为实现对锦鸡儿属植物脂肪酸成分直接、精确调控提供了保证,也是从一个物种中克隆四个fad2基因的第一次报道.     

银川市几种针叶绿化树种的春季滞尘能力比较

对银川市西夏区的四个针叶树种在三个不同粉尘污染区的春季滞尘能力进行测定与分析,结果表明:各树种在不同的粉尘污染区均表现出明显的滞尘效应;不同树种的滞尘能力存在明显差异;树种的滞尘能力与降尘环境、滞尘时间等因素有关;随着时间的延长,四树种在不同的粉尘污染区的滞尘能力呈增大趋势;几种针叶树种的滞尘能力由强到弱的顺序为:侧柏>白皮松>桧柏>云杉。       

Development of an immunochromatographic lateral-flow test strip for rapid detection of sulfonamides in eggs and chicken muscles

A rapid immunochromatographic lateral-flow test strip was developed in the competitive reaction format for the detection of sulfonamides in eggs and chicken muscle. A monoclonal antibody against the common structure of sulfonamides was conjugated to colloidal gold particles as the detection reagent and an N-sulfanilyl-4-aminobenzoic acid (SUL)-bovine serum albumin (BSA) conjugate was immobilized to a nitrocellulose membrane as the capture reagent to prepare the test strip. With this method, it required only 15 min to accomplish the semiquantitative or quantitative detection of sulfonamides. The sensitivity to sulfonamides (sulfamonomethoxine, sulfamethoxydiazine, sulfadimethoxine, and sulfadiazine) was at least 10 ng/mL, as determined with an optical density scanner. By eye measurement, the sensitivity was 20 ng/mL for sulfamonomethoxine, sulfamethoxydiazine, and sulfadimethoxine and 40 ng/mL for sulfadiazine. On the basis of a sulfamonomethoxine standard curve, recoveries were from 89.5 to 95.6% for sulfamonomethoxine, from 89.5 to 95.1% for sulfamethoxydiazine, from 85.0 to 95.6% for sulfadimethoxine, and from 44.8 to 60.9% for sulfadiazine in egg and chicken muscle samples. A parallel analysis of 27 egg samples and 28 chicken muscle samples from the animal experiment showed that the differences between test strips and high-performance liquid chromatography (HPLC) were from 0.8 to 11.2% for egg samples and from 2.2 to 34% for chicken muscle samples for the quantitative detection, and the agreement rates between test strips and HPLC were 100%, based on the maximum allowed residue level of sulfadiazine (100 ng/g) established by the European Union and China. In conclusion, the method is rapid and accurate for the detection of sulfonamides in eggs and chicken muscles.