汽车发电机电动势3次谐波分量的估算

分析了Y联接和Y0联接整流电路在畸变电动势作用时的中性点电压,给出了畸变电动势3次谐波分量的估算方法,并估算了Y0联接汽车交流发电机在中性点二极管导通时电动势中3次谐波分量的大小.     

Identification and Gene Mapping of Completely Dominant Earliness in Rice

The completely dominant earliness was identified in a genic male-sterile and early maturing indica line 6442S-7. F1 progenies from 6442S-7 crossed with thirteen various types of medium- or latematuring varieties, shared the same heading date as 6442S-7. The segregation of heading date in the F2 and B1F1 populations showed that the earliness of 6442S-7 is mainly controlled by two dominant major genes. The local linkage map of one dominant earliness gene harbored in 6442S-7 was constructed with F2 population and four kinds of molecular marker techniques. The results showed that the gene was located between a RFLPmarker C515 and a RAPD marker OPI 11. 557 on the terminal region of short arm of rice chromosome 3,10.9cM and 1.5 cM from C515 and OPI11. 557, respectively. The genetic distances from the target gene to twoSSR markers, RM22 and RM231, and one AFLP marker, PT671, were 3.0, 6.7 and 12.4 cM, respectively. This gene, being identified and mapped first, is designated tentatively as Ef-cd (t). As a new genetic resource of completely dominant earliness, 6442S-7 has splendid future in rice improvement.     

Development and Application of a GeXP-multiplex PCR Assay for Detection of Seven Foodborne Pathogenic Bacterias

This experiment was developed to simultaneously detect the seven common foodborne pathogenic bacterias include E. coli O157:H7, Salmonella, V. cholera, L. monocytogenes, C. jejuni, V. Parahemolyticus and S. aureus. Seven pairs of specific primers were designed according to the conserved sequences of the genes from each pathogen available in the GenBank database. Single and mixed pathogen DNA templates were used to evaluate the specificity of the GeXP-multiplex assay. Control group was set up, recombinant plasmids were constructed, and samples of different DNA concentrations were randomly combined to verify the sensitivity, specificity, accuracy and anti-interference of the established GeXP method. To certify the accuracy and reliability of the GeXP assay, it was evaluated using 120 clinical specimens that were compared with the single PCR. The obtained results showed that the corresponding specific fragments of genes were amplified by the single and the multiplex GeXP PCR assay. The detection limit of GeXP was 10³ copies·μL^-1 when all of seven bacterial pathogens were detected. The results of the interference assay showed the presence of specific amplification peaks when different templates. The detection rate of the GeXP multiplex PCR method was 2.50% (3/120)-15.83% (19/120) while the conventional PCR was 2.50% (3/120)-15.00% (18/120), and GeXP multiple PCR detected 8 more positive cases, which means that, the GeXP was more sensitive and accurate in the detection of the clinical samples. In conclusion, this GeXP-based multiplex PCR is a high-throughput, specific and sensitive test to detect seven common foodborne pathogenic bacterias. This assay provides a method in rapid molecular diagnosis for mix clinical seven common foodborne pathogenic bacterias.     

氮磷钾肥配施对火龙果产量及品质的影响

为火龙果生产上的合理施肥提供科学依据,采用3414试验设计,研究了氮、磷、钾肥配施对火龙果产量及品质的影响。结果表明:不同氮、磷、钾肥的配施水平均可显著提高火龙果的产量,但处理15(常规施肥区)与处理9(3414试验的最高产量)的产量无显著差异;不同施肥处理对火龙果果实的可溶性固形物、总糖、总酸及矿质营养元素的影响程度各不相同,果实中的N、P、K元素含量并不随氮、磷、钾肥用量的增加而提高,可能与火龙果的生长特性和植株对养分的分配需求密切相关。     

石蛃目昆虫的研究进展

石蛃是已知现存的最原始的无翅昆虫,处于昆虫起源的基部,保留了很多原始古昆虫的特征,是昆虫纲的活化石,对其进行研究,对了解昆虫的起源、揭示无翅类昆虫的进化以及探讨陆生的无翅昆虫如何进化到水生的古翅类群等均具有一定的实际意义。旧的分类体系把石蛃和衣鱼合为缨尾目,随着人类科学文化的发展,现已独立为石蛃目。综述了石蛃目昆虫的分类地位、形态特征、生活习性及研究现状。     

薰衣草精气与精油化学成分的比较

对薰衣草精气与精油化学成分进行比较.结果表明,薰衣草精油共鉴定出39种化合物,其主要成分为芳樟醇(37.03％)、乙酸芳樟酯(22.34％)、乙酸薰衣草酯(14.55％)、α-松油醇(4.03％)、乙酸香叶酯(2.05％).薰衣草精气共鉴定出13种化合物,其主要成分为对异丙基甲苯(23.17％)、柠檬烯(20.76％)、1-甲基-4-(1-甲基乙烯基)苯(17.58％).薰衣革精气和精油在化学成分和相对含量上有很大不同,不能以精油的成分作为精气医用诊疗或保健养生的依据.     

宜宾竹叶水提液的抑菌作用研究

[目的]比较宜宾毛竹与慈竹的叶水提液对常见食品污染菌的抑菌作用,研究了温度、紫外光和pH对其抑菌效果的影响。[方法]采用滤纸片法,测定2种竹叶的抑菌效力。[结果]毛竹叶与慈竹叶都有较强的抑菌作用,且对不同供试菌的抑菌效果有差异,其中毛竹叶对枯草芽孢杆菌的抑制最强,而慈竹叶对大肠杆菌的抑制效果最好。慈竹叶的抑菌效力强于毛竹叶。2种竹叶水提液具有较好的热稳定性和pH稳定性,但紫外光稳定性较差。[结论]宜宾毛竹与慈竹的叶提取物有望被开发成新型天然食品防腐剂。     

Preliminary research on flowering habit and quality of Rosa chinensis in summer

[目的]对不同月季品种夏季开花习性及开花品质进行观察,并研究赤霉素对月季外观品质的影响,为夏季月季生产提供科学依据.[方法]2010年6～8月,对22个月季品种的现蕾期、露瓣期、初花期、盛花期、盛花末期及植株长势和花朵外观品质进行田间观察,筛选出综合表现较好的品种;在月季现蕾期分别以浓度为100、150、200 mg/L的赤霉素,采用叶面喷施法对筛选出的月季品种进行赤霉素对花朵外观品质的影响试验.[结果]地平线、粉佳人、蓝精灵、玛利亚和影星等5个品种在夏季开花的综合表现较好,表现为单朵花期较长、长势较好;以浓度为100 mg/L赤霉素叶面喷施处理的月季花朵外观品质最佳,可使花枝增长约10％、花茎增粗56％～65％、最大花径增大11％～14％、花梗长度增加10％～12％,且子房变大,花朵大小和颜色正常.[结论]地平线、粉佳人、影星、玛利亚、蓝精灵等5个品种夏季开花表现较 好,可在桂南地区推广种植;在现蕾期使用浓度为100 mg/L的赤霉素叶面喷施月季,能改善月季外观品质,可在夏季月季生产中推广应用.     

微透析探针对杨树嫩茎细胞损伤的显微观察

利用微透析技术研究植物汁液成分时,所遇到的首要问题是其透析液来自质外体还是共质体。以冬季水培的吴屯杨和荷兰杨幼苗为材料,采用石蜡切片法,制作微透析探针插入杨树嫩茎后,对嫩茎受损部分横切面组织切片进行显微观察并加以探讨。结果表明,微透析探针的粗度约为杨树细胞直径20倍,探针对周围细胞造成一定程度的破坏,因此,探针插入杨树嫩茎后开始一段时间内收集的透析液将受到破损细胞液的污染,随着微透析时间的推移,逐渐地趋近于质外体汁液。对微透析技术可以获得植物质外体汁液从细胞显微结构变化方面予以解释,为微透析技术在植物质外体研究中的应用奠定细胞学基础。     

山白兰树皮率、心材率及木材密度研究

采用排水法、体积法及质量法测定了山白兰树的密度、树皮率、生材体积和树皮率。结果表明:山白兰生材密度从髓心向外呈先减少,随后略增加的趋势,随着树高的增加,生材密度减小,生材密度的平均值为0.864g.cm-3;基本密度自髓心向外呈增大趋势,随着树高增加,基本密度减小,基本密度的平均值为0.462g.cm-3;生材含水率从髓心向外呈减小的趋势,随着树高的增加,生材含水率先增加后减小,生材含水率的平均值为89.0%;树皮体积百分率及质量百分率均随着树高的增加而增加,树皮体积百分率及质量百分率平均值分别为16.2%、20.4%;心材率随着树高的增加而减少,心材百分率平均值为16.3%。