浅议结构后浇带在寒冷地区施工中的应用     

王积香  于同元 《黑龙江科技信息》2001,(1):F010-F010

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改善实验尝试创新     

宋建陵  魏学元 《中学生数理化》2003,(11):9-10

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遍地英雄遍地歌     

王俊  张林  陈里连  仓爱民  武伟政  各县市电视台 《视听界》1993,(Z2)

1991年7月间,江苏省重灾区扬州里下河。洪水的魔爪四处虏掠着,死亡的阴影八面埋伏着,所有的人都面临着一场生与死、英勇与懦弱、伟大与渺小的大考验。  相似文献   

谈人力资源与经济持续发展     

潘日鸣  张若元 《科技．人才．市场》2000,(6):34-35

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商业银行贷款风险综合评价     

张讳凯王秋红  李紫玥 《黑龙江科技信息》2007,(6S):69-69

研究了主成分和改进神经网络混合算法在商业银行贷款风险评价中的应用，分析了商业银行贷款风险的影响因素，建立了基于主成分-改进神经网络的预测模型，并用实例验证了模型的有效性。  相似文献   

铃兰族(广义)花粉形态与叶表皮特征的研究     

马黎明  洪德元 《中国科学院研究生院学报》1990,28(3):228-236

对铃兰族(广义)7个属分别作了花粉(17种)扫描电镜观察和叶表皮(12种)的光学显微镜和 扫描电镜观察。花粉可分为8个类型。在狭义的铃兰族的4个属内，花粉全为远极单槽，舟状。它们 的外壁除夏须草属外，都具细孔。夏须草属的花粉外壁则为细皱。  Hutchinson(1934)的蜘蛛抱蛋族 花粉形态变异很大，其中开口箭属和万年青属的花粉为远极单槽，舟形，外壁具穿孔或网纹，而蜘蛛抱 蛋属的花粉则为球状，无萌发孔。其间的显著差异支持Nakai为前两个属建立万年青族(Rohdeae)。 表1归纳了7个属的花粉形态；图1是我们对铃兰族(广义)花粉形态演化的见解。叶表皮观察表明，气 孔器为无规则型，上表皮角质层主要为条纹加厚，或均匀加厚，而铃兰属的角质层秕糠状加厚。7个属的叶表皮特征归纳于表2。  相似文献   

芍药属的研究(1)——国产几个野生种核型的报道   总被引：1，自引：0，他引：1  

洪德元  张志宪  朱相云 《中国科学院研究生院学报》1988,26(1):33-43

In the present paper 8 species with 15 populations of the genus Paeonia L. (if P. papaveracea and P. japonica are recognised as species) were collected from Sichuan, Shaanxi and Hebei provinces (see the Appendix for detail of the materials).  The micrographs of their somatic metaphase (also Mii in the case of P.veitchii) are shown in Plates 1-4, the karyo- type formulae, ranges of chromosome length and classification of karyotypes according to Steb- bins (1971) are shown in Table 5: the idiograms in Figs. 1-2, and the parameters of chromo- somes in Table 1-4.  The essential points are mentioned as follows:        (1)   Chromosomes of the various species in the section Modan have so far been examined and they are all diploid, the two species in the section Onaepia are also diploid, and thus tetraploids exist only in the section Paeonia.        (2)  Chromosomes in the genus Paeonia are relatively stable except for the differentiation of ploidy.  The karyotypes (Table 1-4) show no differences among different taxa in Sect. Modan and the same can also be said about the taxa in Sect. Paeonia (Table 1).  Not only are the karyotypes very similar, but also among the members within  either section have the same parameters of chromosomes, and, differences, if occur, are not statistically significant. Between the two sections, however, the situation is different. The arm ratios of the first pairs of chromosomes in Sect. Modan are 1.53, 1.52 and 1.48 (Table 1), but those in Sect. Paeonia are 1.12-1.28 (Table 2-4), 95% confidence limits are 1.46-1.60 for the section Modan and 1.07-1.28 (1.21-1.35 only for PB85078) for the section Paeonia, not overlapping, which indi- cates that the two sections have differentiated in respect of the first pairs of chromosomes.        (3)The population PB85024, which belongs to the P. obovata complex, has a karyotype of 2B (stebbins, 1971), which is a new one in the genus Paeonia. This karyotype is a stable one, for several individuals in the population are uniform in this respect, which shows that Steb- bins’ (1971) generalization that all the species in Paeonia have 2A does not hold true.        (4)  Three populations of P. obovata complex studied in this work from Sichuan and Shaanxi are all tetraploids, and one from Hebei is a diploid.  From the present work and the previcus reports, the materials from Japan and Korea, no matter whether flowers are pink or white, are diploids, those from Heilongjiang Province (with both pink and white flowers) (Liu Ming-yuan, personal communication) and from Heibei Province (with pink flowers) in China are also diploids, the one from Sakhalin (pink flowers) is tetraploid, those from Priamur of the Soviet Union are a tetraploid (with white flowers) and a diploid (with pink flowers), and those from Shaanxi (the Qinling Range) and western Sichuan (with both pink and white flowers) are all tetraploids.  As far as we have now known, ploidy in this parti- cular complex is correlated with the geographical distribution: diploids are found in the cen- tral part, tetraploids occur in the northern limits, and in the south  letraploids are the only cytotype.      (5)  The materials of P. mairei from western Sichuan and Shaanxi (the Qinling Range) are found all to be tetraploids, which shows that two cytotypes, diploid and tetraploid, exist in this  species,  but the geographical distribution pattern of these two cytotypes is to be revealed in the future investigation.  相似文献   

关于政府部门网站建设的几点思考   总被引：1，自引：0，他引：1  

凯茵 《中国科技信息》2006,(2):226

本文介绍了政府网站发展的现状,分析了存在的主要问题,就政府部门网站建设提出了具体的构想,并对网站的运行维护提出制度落实、人员落实和经费落实等建议。  相似文献   

人类到底能飞多远?     

士元 《华夏星火》2002,(9)

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高原隧道通过风积、沙积地层施工技术     

金邦元 《西藏科技》2006,(7):28-31

高原地区由于风沙天气较多，常在山坡的受风面形成风积沙地层。高原隧道的洞口段常遇该类不良地质地层，风积沙围岩白稳能力极差，开挖时极易坍塌。施工防坍塌、沉降是影响安全和进度的重要因素，解决这一因素的有效方法成为高原隧道施工的课题。  相似文献