994 resultados para 7140-213
Resumo:
采用外周血淋巴细胞培养方法,以及C-带、G-带和银染技术,对云南地方猪种撒坝猪、大河猪进行显带染色体研究。测量了各号染色体的相对长度、着丝点指数及臂比,Ag-NORs定位于7号和10号染色体。撒坝猪、大河猪的G-带带型与其它家猪相似,C-带和Ag-NORs具有多态性。撒坝猪和大河猪的C-带和Ag-NORs存在一定差异。
Resumo:
The optimal control of problems that are constrained by partial differential equations with uncertainties and with uncertain controls is addressed. The Lagrangian that defines the problem is postulated in terms of stochastic functions, with the control function possibly decomposed into an unknown deterministic component and a known zero-mean stochastic component. The extra freedom provided by the stochastic dimension in defining cost functionals is explored, demonstrating the scope for controlling statistical aspects of the system response. One-shot stochastic finite element methods are used to find approximate solutions to control problems. It is shown that applying the stochastic collocation finite element method to the formulated problem leads to a coupling between stochastic collocation points when a deterministic optimal control is considered or when moments are included in the cost functional, thereby forgoing the primary advantage of the collocation method over the stochastic Galerkin method for the considered problem. The application of the presented methods is demonstrated through a number of numerical examples. The presented framework is sufficiently general to also consider a class of inverse problems, and numerical examples of this type are also presented. © 2011 Elsevier B.V.
Resumo:
Ranid frogs of the genus Amolops occur in Southeast Asia and are typically found near waterfalls. Their phylogenetic relationships have not been resolved. We include 2,213 aligned nucleotide sites of the 12S, 16S and tRNA(val) gene regions of the mitochondrial DNA genome from 43 individuals of Chinese and Vietnamese Amotops, Huia, Hylarana, Meristogenys, Odorrana and Rana. The outgroup species were from the genera Chaparana, Limnonectes, Nanorana, and Paa. The data were analyzed within the framework of a refutationist philosophy using maximum parsimony. Four clades of waterfall frogs were resolved. Meristogenys was not resolved as the sister group to either Huia nor Amolops. The hypothesis Of evolutionary relationships placed Amolops chapaensis and Huia nasica in the genus Odorrana.
Resumo:
分别研究了室内和露天条件下在鹅卵石上着生的刚毛藻Cladophora oligoclona对富营养化湖水中氮(N)和磷(P)的净化效果及其对水华藻类生长的抑制能力,同时对处理后湖水的藻类生长潜力进行了测试.结果显示,刚毛藻在原始浓度总氮(TN)10.512 mg/L和总磷(TP)0.856 mg/L的富营养化湖水中能维持正常的生长代谢,并能有效去除水体中的N、P养分.在室内12 d培养期间,刚毛藻对TN、氨氮(NH4-N)、TP和无机磷(PO4-P)的平均去除率分别达53.13%,44.40%,35.71