First record of the genus Leptodactylus (Anura: Leptodactylidae) in Cuba: Leptodactylus fragilis,a biological invasion?

The Neotropical genus Leptodactylus is currently represented by three species in the West Indies (Leptodactylus albilabris, Leptodactylus fallax and Leptodactylus validus). Based on morphological, acoustic and molecular evidence, we document the presence of a fourth species in the Caribbean region, Leptodactylus fragilis (Brocchi, 1877). The species was found at two localities in western Cuba, and molecular data suggest a northern South American origin, possibly Venezuela, for these populations. We discuss the potential invasive status of L. fragilis, based on its known distribution, relative abundance, behaviour and possible impacts on native species of Cuban amphibians.     

PCR—SSCP研究肝癌原发灶和转移灶中P16^INK4exon2的突变

用两步ＰＣＲ法,成功地从石蜡包埋组织ＤＮＡ中扩增了Ｐ＾１６ＩＮＸＫ４ｅｘｏｎ２片段;并用单链构象多态分析ＰＣＲ产物的差异。     

PIC16F877单片机在密码锁中的应用

PIC16F877是一款新型高性能单片机 ,将其应用在密码锁中具有高可靠性、高安全度、结构简单及性价比高等优点 .详细介绍了锁的硬件设计方案和软件设计方法 ,并给出了部分电路图和程序主要流程图 .     

Axillary 5α-androst-16-en-3-one in men and women: Relationships with olfactory acuity to odorous 16-androstenes

Summary Axillary 5-androst-16-en-3-one (5-androstenone) levels were found to be significantly higher in men than in women but do not vary between left and right axillae, are not related to age, handedness or degree of hirsutism (in women) nor to anosmia to this steroid. In men (but not in women), levels are related linearly to axillary cholesterol concentrations but not to squalene. Olfactory thresholds for 5-androstenone varied widely, the lowest recorded being 0.2 ppb, but there was no difference in thresholds between men and women. Women (70%) found the smell repellant but anosmia did not differ greatly between men and women (9–20%). Anosmia to the smell of 5-androst-16-en-3-ol was most marked in women (90%) rather than in men (45%). Axillary 5-androstenone values were generally consistent with the musky or strong smells of male axillary extracts, compared with the sweet smell of those from female subjects.Supported by the Herbert Dunhill Trust.     

辽王朝在燕云地区民族政策之研究

在封建时代,民族平等是相对的,而民族歧视是绝对的。尤其是在北方少数民族进入中原后所建立的政权之下,民族歧视和民族压迫现象一般都显得较为突出。辽王朝在拥有了燕云十六州后,自然也不例外,但辽统治者在遭遇汉人抵抗后,很快采取了一系列宽松的民族政策来减缓燕云汉人的抵抗情绪。最后,辽王朝不仅赢得汉人的民心,稳定了自己在燕云地区的统治秩序,而且促进了汉族与契丹等民族间的相互融合,为我国统一多民族国家的发展做出了贡献。     

多音干扰下Nakagami-m信道传输Link16数据链的性能分析

Link16数据链的应用综合广泛,由于运用了跳扩频和编码技术使其具有强大的抗干扰能力。为了探究Link16数据链在衰落信道下的响应,在加性高斯白噪信道的基础之上,研究了Link16数据链经过Nakagami-m衰落信道的系统性能。着重推导了Link16数据链单脉冲结构在多音干扰下经过Nakagami-m衰落信道的误码率(bit error rate, BER)表达式,并给出了双脉冲结构BER公式。仿真实验结果验证了Link16数据链单脉冲结构在多音干扰下经过Nakagami-m衰落信道的BER公式的准确性,分析了多径参数对Link16数据链抗干扰性能的影响,得出增加衰落参数m和可分辨路径可以提升Link16数据链的系统性能,且当信干比一定、被干扰频点个数在25个及以上时系统BER达到10^-1。     

对向靶溅射α″-Fe16N2薄膜的结构与磁性

用对向靶反向溅射法制备了α″－Fe16N2薄膜,用X射线衍射（XRD）和振动样品磁强计（VSM）对其结构、磁性进行了分析讨论,对磁性的分析表明造成饱和磁化强度存在较大差异的原因与其晶胞的大小有很大的关系。     

甲烷二氧化碳转化制合成气的研究--部分失活CN-16催化剂再生条件的选择

本文采用一种新型的再生剂对部分失活ＣＮ－１６催化剂进行再生,并对部分失活ＣＮ－１６催化剂再生条件进行了选择。其最佳再生条件为：再生剂中Ａ的摩尔百分含量为５ｍｏｌ％～１０ｍｏｌ％,再生温度为８５０℃或９００℃。部分失活ＣＮ－１６催化剂再生后,其催化性明显高于再生前,并且接近新ＣＮ－１６催化剂活性。     

西沙野生诺尼内生细菌群落多样性初步研究

采用构建16S rDNA克隆文库方法,首次对我国海南永兴岛西沙野生诺尼果内生细菌的群落结构和多样性进行初步研究.首次采用Mothur软件对诺尼果内生细菌克隆文库数据进行分析,构建Mothur软件数据分析平台.构建的西沙野生诺尼果内生细菌16S rDNA克隆文库中,93个克隆分属于12个不同可操作分类单元(operational taxonomic units,OTU),序列比对结果表明大部分克隆与已知细菌16S rDNA序列相似性较高.分别属于变形菌门(Proteobacteria)的Alpha、Beta、Gamma亚群,放线菌门(Actinobacteria)和厚壁菌门(Firmicutes).水库杆菌属(Piscinibacter sp.)细菌为野生诺尼果内生细菌优势菌群.优势菌属分别为水库杆菌属(Piscinibacter sp.)为80.65%,蛋白胨菌属(Peptoniphilus sp.)和链球菌属(Streptococcus sp.)均为3.23%,甲基杆菌属(Methylobacterium sp.)为2.15%.研究结果表明西沙野生诺尼果中存在较为丰富的内生细菌资源,将为进一步研究奠定理论基础.     

基于nRF24L01的无线通信系统设计

介绍了一种以nRF24L01无线收发芯片,以ATmega16单片机为控制核心的半双工无线通信系统,并对系统进行了传输速率和传输距离的测试,详细阐述了硬件和软件的设计要点。