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141.
Two new species of the Liliaceae are described from Anhui Province, China. i. e.
Fritillaria qimenensis D. C. Zhang et J. Z. Shao and Lilium anhuiense D. C. Zhang et J. Z.Shao. 相似文献
142.
One of the theoretically important factors for incubator firm performance is the strength of their linkages to the research university sponsoring the technology incubator. Herein, we focus on two types of university linkages to the sponsoring institution: a license obtained from the university and a link to university faculty, while controlling for incubator firm linkages to non-sponsoring research universities, among other factors. We propose that a university link to the sponsoring institution reduces the probability of new venture failure and, at the same time, retards timely graduation. Further, we suggest that these effects are more pronounced the stronger the university link. Due to the difficulty of obtaining fine-grained longitudinal data, the incubation literature is characterized by a dearth of studies focusing on incubator firm differential performance. We attempt to take a first step towards closing this gap by testing these hypotheses through following 79 start-up firms incubated in the Advanced Technology Development Center at the Georgia Institute of Technology over the 6-year period between 1998 and 2003. We find broad support for the hypotheses advanced. 相似文献
143.
镉在不同品种小白菜中的亚细胞分布 总被引:4,自引:0,他引:4
以差速离心法,研究了Cd在苏州青和沪青一号两小白菜品种不同器官的亚细胞分布.结果表明,不同器官Cd分布量依次为根系>叶片>叶柄,品种间略有差异.在植株各器官中,Cd主要分布在细胞可溶性成分、细胞壁和质体(或叶绿体)中,而在细胞核、线粒体和核糖体中分布较少.根系四种重要细胞器(质体、细胞核、线粒体和核糖体)中Cd分配率随Cd处理浓度增加而增加,沪青一号Cd分配率上升更明显;叶片中叶绿体、线粒体和核糖体中的Cd随Cd处理量增加而增加,沪青一号表现更为明显;叶柄中,沪青一号四种细胞器Cd分配率高于苏州青,增加Cd浓度两品种线粒体和核糖体Cd分配率上升但叶绿体和细胞核Cd分配率下降.高Cd处理对沪青一号重要细胞器中Cd增加更明显,推测Cd浓度增加对沪青一号细胞生命活动的危害有可能比苏州青更为严重. 相似文献
144.
The chromosome number of thirteen species of Tamarix L. in China is re-
ported in this paper. All of them have the same number (2n=24) and most of them
are reported for the first time except T. hispida, whose chromosome number is the same
as previously reported. 相似文献
145.
Uwe Cantner 《Research Policy》2006,35(4):463-480
We apply social network analysis methods to describe the evolution of the innovator network of Jena, Germany in the period from 1995 to 2001. We find this evolution to be directed towards an increasing focus on core competencies of the network. Further we analyse the network resulting from R&D cooperations and explain - by means of network regression techniques - that the job mobility of scientists and the technological overlap between the actors, rather than past cooperations, can best predict the resulting structure. 相似文献
146.
M. Swarna M. Sujatha P. Usha Rani P. P. Reddy 《Indian journal of clinical biochemistry : IJCB》2004,19(2):163-167
Recent studies have presented evidence for the involvement of L1CAM gene mutations in various X-linked mental retardation
syndromes. The neural cell adhesion molecule, L1CAM is a transmembrane protein belonging to the super family of the immunoglobulins
that play a key role in embryonic development of the nervous system and is involved in memory and learning. No studies were
carried out from India on L1 CAM gene in X-linked mental retardation syndromes. Hence, an investigation was taken up to delineate
the role of L1CAM gene in mental retardation.
Two families (Family I and Family II) having only two members affected with mental retardation in each family were studied
for mutations in L1CAM gene. In family II, the younger sibling showed deletion involving region between the nucleotide 13,773
(intron 25) and 14,158 (intron 27) region. The mutation what we observed in younger sibling of the family II is a novel mutation
which was not hitherto reported in the world literature. 相似文献
147.
用不同浓度(100—500m g/1)的硝酸锌溶液处理蒜小鳞茎,发现随着培养时间的延长和浓度的增加,毒害加重,外观表现为根尖生长受阻,内部表现为细胞有丝分裂指数下降,而分裂细胞异常率增高。分裂细胞异常主要表现为染色体粘连,染色体解体,微核及核解体等,但锌对蒜的毒害作用明显低于镉和铅 相似文献
148.
银杏叶愈伤组织增殖过程中生理生化特性的研究 总被引:2,自引:0,他引:2
本文系统研究了银杏叶愈伤组织培养细胞的生长周期,并对培养过程中细胞内的可溶性蛋白的含量,过氧化物酶、苯丙氨酸解氨酶活性的变化以及银杏总黄酮的含量进行了测定,以期为银杏细胞的大规模培养积累数据。 相似文献
149.
There are a lot of factors affecting Second Language Acquisition or Learning(SLA/L). It is very important and beneficial to be clear about these factors in SLA/L.This paper only focuses on one of these important factors—Motivation. The author elaborates the importance of motivation in SIA/ L, analyzes the different types of motivation in SLA/L as well as the function of motivation, also puts forward some suggestions on how to culti-vate and stimulate learners motivation in SLA/ L. 相似文献
150.
应用正交试验法研究六种非激素因素(氮源、琼脂、碳源、有机添加物.p H及光照)对茉莉愈伤组织生长的综合影响.结果表明,其主要影响因素是蔗糖、光照及有机添加物 相似文献