茅莓无性扦插繁殖技术的优化试验

采用正交试验研究方法,以生根率、平均根长和平均生根数3个因子为生根质量的指标,对茅莓进行无性扦插繁殖技术的优化试验。结果表明:NAA浓度、扦插基质、插穗类型和处理时间对茅莓扦插繁殖的生根质量有明显影响。其中,扦插基质对茅莓无性扦插繁殖生根质量的影响最大,插穗类型次之,NAA浓度第3,处理时间影响最小。当NAA浓度为100 mg/L,扦插基质为菜园土,插穗为带顶芽茎段,处理时间为2 h时,茅莓扦插的生根质量最佳。     

圆柱腔体搭接部对UWB脉冲的屏蔽效能及耦合规律

采用时域有限差分(FDTD)法对超宽带(UWB)脉冲和圆柱腔体连接缝隙的耦合过程进行研究,通过不同脉宽UWB脉冲对腔体耦合电场的时域和频域分析,观察共振效应和增强效应等现象,讨论了圆柱腔体连接缝隙的耦合电场特性和带有连接缝隙腔体的谐振特性.     

Relationship between persistent HPV infection and cervical carcinoma

Human papillomavirus (HPV) genital infection is a very common sexual transmitted disease. Mostly, the infection is transient and asymptomatic. The induction of effective immune responses usually allows the infection to be spontaneously cured. However, the infection sometimes can be responsible for an intraepithelial lesion, which may progress to be cervical cancer. Cervical cancer is one of the most common neoplastic diseases affecting women. It is clear that carcinogenic HPV infection is the necessary process for the development of cervical cancer. HPV infection is very frequent in young women aged less than 25 years and viral clearance lasts for 8 months in average. This clearance is the consequence of host immunity intervention, which leads to spontaneous regression of infection and the overwhelming majority of low-grade squamous intraepithelial lesions (more than 80% within a period of 2 years). The major factor, which permits the progression to high grade squamous intraepithelial lesions and invasive cervical cancer, is the persistent feature of HPV infection. HPV infection is usually transient, but several factors were identified as host factors (genetic, immunodepression, oral contraception and smoking) and viral factors (genotype, variants, viral load and integration) to increase the persistence. Cervical cancer is clearly the first virus-induced solid tumor discovered in human. Furthermore, it represents a woman death cause that can be avoided.     

玉米杂交制种关键技术探讨

在杂交种生产利用过程中,长期以来在一定程度上存在种子整齐度差、纯度差、发芽率低等问题,针对这种情况,本文从基地选择、安全隔离、精细播种、田间管理、去杂去雄、人工辅助授粉、适时收获等方面作了详细的介绍.以期为玉米杂交制种的推广提供参考.     

海南中部生态功能保护区生物多样性研究

海南中部国家级生态功能保护区生物多样性丰富,经调查,保护区内的尖峰岭、五指山陆栖脊椎动物分别占全国的16.3%和12.7%;尖峰岭有国家I级和Ⅱ级珍稀濒危保护植物种41种,占全国的16.0%;保护区热带原始林的生物多样性指标达到5.19-6.28,即便40年天然更新山地雨林物种多样性指标也达到了4.77.     

桉属不同遗传水平材料在贵州南部冻害调查与区划研究

对贵州桉树遭受2008年1~2月期间特大雨雪凝冻灾害后的冻害情况进行较全面调查。调查结果结合气候、树种/种源、环境、经营措施等对桉树冻害形成的因子进行综合分析。在此基础上,根据所处的气候带类型、地理环境、年平均温度以及凝冻发生的程度,初步提出了桉树在贵州适宜发展的区域、栽培树种和经营技术措施等,为今后贵州桉树的发展提供科学依据和技术参考。