你不必追

<正>你不必追,天空的鸟儿。在宁静的清晨,你只需慵懒地躺在床上,就可以听见鸟儿在窗外枝头上天籁般地清唱;你也可以光着脚丫,走在挂满露珠的草尖旁,看鸟儿轻盈地在霞光里扇动翅膀,低低飞,低低飞……你不必追,调皮的春风。在白云朵朵低垂的田野上,你只需带上一只风筝放飞在天空,风会调皮地带着风筝去远方流浪;你也可以站在嫩草青青的山坡上,风会悄悄回到你的身旁,轻轻揉乱你的秀发,让你很美,很美……你不必追,流淌的溪水。在一个温暖的黄昏,你只需坐在河边的石块上,伸出脚     

胫骨骨外露治疗体会

重点介绍了胫骨开放骨折内固定术后胫骨外露患者,通过应用邻近皮（肌）瓣转移术及小隐静脉腓肠神经蒂皮瓣移位术治疗,取得了满意效果。     

小议瓣形穹顶建筑的特征与功能

肋环形球面网壳、施威德勒型球面网壳、联方型球面网壳、凯威特型球面网壳、短程线球面网壳等是目前大跨度空间穹顶网格结构的常用结构形式。球壳的结构拓扑不同,故结构的受力特点也不相同。而它们在形态上的共同特征是圆球面,曲面上任何一点的曲率相等且为正高斯曲率,球面上任何一个节点均满足方程：x2＋y2＋z2=r2。这些经典的球面穹顶网格结构形式经过了国内外近百年数以万计大大小小的工程实践,证明这些结构形式是可靠的、合理的。然而,无论是哪一种类型的球面网壳,从建筑外部形态上看,它们都无法摆脱圆球面特征。本文在总结了传统的穹顶结构特点的基础上,提出并用CAD技术建构了一种新型的空间网格穹顶结构———瓣形穹顶,同样是圆形平面,瓣形穹顶却可变化出各种造型极为丰富的空间形态。文章对瓣形穹顶的几何特征、建筑形态与构成、结构的受力特点和结构布置方案作了系统的研究,这种穹顶结构既可以用于中小跨度结构,也可应用于大跨度的空间穹顶结构。     

瓣结鱼的外部形态特征及性状变动

利用320尾标本进行了可量性状、可数性状的研究，发现各龄组雌鱼的可量性状及头长／眼径的平均值比雄鱼大．且头长／眼径随龄组值增大而增大．弥补了前人对外部形态特征描述的不足．扩大了前人研究的性状范围．     

健康问与答

为什么会出现粉红色尿?Q我的宝宝4个月了。在宝宝3个多月的时候,我们搬到了新家。这之后,我发现宝宝的尿布开始出现粉红色的尿液,刚开始很淡,不注意看不出来,后来粉红色越来越明显     

麻栗坡兜兰——兜兰属与杓兰属的一个中间类型，兼论兜兰属的地理起源问题

Paphiopedilum malipoense S. C. Chen et Tsi is a very interesting new species with its flower similar to that of Cypripedium, especially section Cypripedium.  It belongs to subgenus Brachypetalum, the most primitive group of Paphiopedilum, but differs from its allied species in hgniva elliptic-lanceolate sepal with cuspidately acuminate apex, rather narrow petals and horizontal lip, which are of common occurrence in many cypripediums, but very rare in paphiopedilums.  Apparently, this is an intermediate form, or a link, between Paphiopedilum and Cypripedium, but it does not seem to arise from hybridization between them, because no Cypripedium has been found wherever Paphiopedilum occurs.       The new species is distributed in southeastern Yunnan of China. In this area, as well as in river valleys of western Yunnan or the Hengduan Mountains, there have been four species of the same genus reported before. As we know, the Hengduan Mountains and their adjacent areas are rich in Cypripedium.  The differentiation of the genus there is remarka- ble.  All five sections it contains occur there and three of them are quite distinctive.  For example, the general appearance of the section Bracleosa is dissimilar to that of any other cypripediums, but closely resembles that of Listera.  It appears that the difference between sect.  Bracteosa of Cypripedium and sect.  Brachypetalum of Paphiopedilum is not neces- sarily wider than that between sect. Bracteosa and sect. Cypripedium of the same genus. Apparently, it is reasonable to consider Paphiopedilum to be an evolutional branch of Cy- pripedium extending into tropical area, with its primitive group (subgenus Brachypetalum) still remaining in its northern fringe area.  This primitive subgenus has eight species, dis- tributed from western Yunnan to the Malay Peninsula.  Five of them, including the inter- mediate and primitive form published here, are found in the hilly land of southeastern Yun- nan and the river valleys of western Yunnan.  All these facts suggest its area of origin: the river valleys of the Hengduan Mountains and the lower hilly land contiguous to the southof them.     

红树植物无瓣海桑北移种植的生长适应研究

分析了北移种植在福建省霞浦、连江、泉港、集美、漳浦5个样地无瓣海桑（Sonneratiaapetala）的存活率、株高、根长、冠幅、生物量及生物量分配,结果表明：无瓣海桑人工引种北界在26°47′N～26°16′N之间,且存活率随着纬度的增高而降低;各样地无瓣海桑营养器官的含水量为：叶〉根〉茎,其含水量均值分别为86．4％、71．0％、63．0％,植株有机质在根茎叶器官分配为茎〉根〉叶;根部的长度和重量随着纬度的升高而下降;株高、冠幅随着纬度的升高有所变化,但没有显著性差异．