甘肃省藓类植物新纪录

报道了分布于白龙江流域的甘肃省藓类植物的1个新纪录科,8个新纪录属和66个新纪录种．新纪录科是四齿藓科（Tetraphidaceae）,新纪录属是白氏藓属（Brothera）,圆口藓属（Cyroweisia）,异蒴藓属（Lyellia）,拟白发藓属（Paraleucobryum）,平珠藓属（Plagiopus）,锯齿藓属（Prionidium）,扭毛藓属（Streblotrichum）和四齿藓属（Tetraphis）,新纪录种为白氏藓（Brotheraleana）,短颈圆口藓（Gyroweisia brevicoulis）,宽果异蒴藓（Lyellia platycarpa）,拟白发藓（Paraleucobryum enerve）和长叶拟白发藓（P．longifolium）等．     

Analysis of DNA methylation variation in wheat genetic background after alien chromatin introduction based on methylation-sensitive amplification polymorphism

During the process of alien germplasm introduced into wheat genome by chromosome engineering, extensive genetic variations of genome structure and gene expression in recipient could be induced. In this study, we performed GISH （genome in situ hybridization） and AFLP （amplified fragment length polymorphism） on wheat-rye chromosome translocation lines and their parents to detect the identity in genomic structure of different translocation lines. The results showed that the genome primary structure variations were not obviously detected in different translocation lines except the same 1RS chromosome translocation. Methylation sensitive amplification polymorphism （MSAP） analyses on genomic DNA showed that the ratios of fully-methylated sites were significantly increased in translocation lines （CN12, 20.15%; CN17, 20.91%; CN18, 22.42%）, but the ratios of hemimethylated sites were significantly lowered （CN12, 21.41%; CN17, 23.43%; CN18, 22.42%）, whereas 16.37% were fully-methylated and 25.44% were hemimethylated in case of their wheat parent. Twenty-nine classes of methylation patterns were identified in a comparative assay of cytosine methylation patterns between wheat-rye translocation lines and their wheat parent, including 13 hypermethylation patterns （33.74%）, 9 demethylation patterns （22.76%） and 7 uncertain patterns （4.07%）. In further sequence analysis, the alterations of methylation pattern affected both repetitive DNA sequences, such as retrotransposons and tandem repetitive sequences, and low-copy DNA.     

New dragonflies （Insecta： Odonata： Gomphaeschnidae） from the Yixian Formation in Inner Mongolia,China

Two fossil dragonflies from the Upper Jurassic to Lower Cretaceous Yixian Formation in Liutiaogou Village, Ningcheng County, Inner Mongolia, China are described and illustrated. They are assigned to two new genera and species, i.e., Sophoaeschna frigida gen. et sp. nov. and Falsisophoaeschna generalis gen. et sp. nov. within the family Gomphaeschnidae Tillyard ＆ Fraser, 1940. This is the first report of Odonata from Yixian Formation in Inner Mongolia and the second record of fossil Gomphaeschnidae from China.     

“依然”与“仍然”的比较分析

本文在大规模语料的基础上,比较分析现代汉语副词"依然"与"仍然"在句法特征、句式语义和固定格式上的差异。通过分析认为:在句法上,两者都能做状语,而"依然"还可以做谓语;做状语时在大多数情况下两者可以替换。在语义和格式上,"依然"侧重于对静态持续态的修饰,有成词的固定格式;"仍然"可以表动作的间隔重复,并具有更重的转折意味。     

Nurse plant theory and its application in ecological restoration in lower subtropics of China

urse plants are those that facilitate the growth and development of other plant species (target species) beneath their canopy because they offer benign microhabitats that are more favorable for seed germination and/or seedling recruitment than their surrounding environment. Nurse plants have been mainly used to restore vegetation in arid and sub-arid zones in recent years. Based on summarizing the definition of nurse plant and target plant, we review the nursing effect mechanisms, ecological factors that influence nursing effect, relationships between nurse plant and ecological restoration. This review also brings forward possible pairs of nurse and target species at lower subtropical areas. Furthermore, we provide the potential tendency in nurse plant research and application.     

New dragonflies (Insecta: Odonata: Gomphaeschnidae) from the Yixian Formation in Inner Mongolia, China

Two fossil dragonflies from the Upper Jurassic to Lower Cretaceous Yixian Formation in Liutiaogou Village, Ningcheng County, Inner Mongolia, China are described and illustrated. They are assigned to two new genera and species, i.e., Sophoaeschna frigida gen. et sp. nov. and Falsisophoaeschna generalis gen. et sp. nov. within the family Gomphaeschnidae Tillyard & Fraser, 1940. This is the first report of Odonata from Yixian Formation in Inner Mongolia and the second record of fossil Gomphaeschnidae from China.     

企业组织间关系:结构与战略选择

在经济全球化、管理信息化和产品模块化的时代条件下,任何企业都不可避免地卷入企业网络空间中生存。如何摆脱激烈竞争,开拓新的价值空间已经成为企业迫切需要解决的问题,组织间关系研究为解决这些问题提供了新的理论视角,成为理论界研究的热点。为深入、系统的分析和构建组织间关系,在相关理论研究基础上,运用系统论和关系治理框架探究了企业组织间关系结构和战略选择。     

硫酸软骨素提取方法研究

系统介绍了采用降解法提取硫酸软骨素的方法——中性盐法、碱提取法、酶提取法、超声波法和乙酸抽提法的工艺路线及其优缺点.     

HHT方法分析冠心病患者支架置入手术对其脉搏波的影响

采用HHT(Hilbert-Huang Transformation)时间序列分析方法分析冠心病患者支架置入手术对其脉搏波信号的影响.通过经验模态分解(EMD)技术将一非线性、非稳态过程的原始离散数据序列分解为一组内在模态函数(IMFs),每一内在模态函数对应一种物理激励机制.通过对临床采集冠心病患者支架置入手术前后的脉搏波信号分别进行分解,可得到两者的特定模态改变信息.把冠心痛患者支架置入手术前后脉搏波信号的模态分解数据和正常人脉搏波的分解数据比较可以发现,C3模态和冠心病血管堵塞与否的相关性最大.     

有机—无机纳米复合材料研究进展

有机-无机纳米复合材料兼有无机和有机物的特点。溶胶-凝胶法、插层复合法、辐射合成法等无机纳米复合材料的制备方法均具有广泛的应用前景,今后的研究重点应着眼于提高其技术工艺的成熟性,利于工业化生产。