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51.
Finite-time performance of genetic algorithm with elitist operator in finite solution space is studied, and the relationship between evolution generation and the quality of the solution found best so far is analyzed. The estimating formulations of the expectation value as well as upper bound and lower bound for the evolution generation earliest achieving specific performance are provided.  相似文献   
52.
凉山岩鹰鸡三周龄脱温配套技术是凉山岩鹰鸡生态养殖中的重要环节。本文从脱温室的修建、雏鸡运输和防疫、饮水和开食、合理的密度、养殖环境的调控等方面对岩鹰鸡脱温鸡苗生产技术进行了总结。  相似文献   
53.
Isotopic compositions of Mn-carbonate and organic carbon from the same individual samples and sulfur isotopic compositions of pyrites in the basal Datangpo Formation were analyzed. Highly 34S-enriched pyrites (δ3434Spyrite =31.7‰—59.4‰) were precipitated in relatively occlusive pore water under anoxic condition in sediments, which is consistent with the observation of large and scattered pyrite framboids. The sulfidic deep ocean was not “oxidized” in the early Datangpo interglacial interval, thus the level of seawater sulfate remained low and marine δ3434Ssulphate remained high. Low δ13Ccar (average -7.4‰) and abnormal relationship between δ1313Ccar and fractionation (?car-org) imply that the negative δ13Ccar excursion may have resulted from oxidation of part of a large organic carbon reservoir. High ? car-org (average 25.1‰) implicates high CO2 level in the atmosphere. Small standard deviation (1.0‰) of ??sup>??Ccar values indicates the Mn-carbonate was precipitated near the water-sediment interface rather than in occlusive pore water in sediments under dysoxic conditions.  相似文献   
54.
The androgenetic embyronic stem (aES) cells are useful models in studying the effects of imprinted genes on pluripotency maintaining and embryo development. The expression patterns of imprinted genes are significantly different between uniparental derived aES cells and zygote-derived embryonic stem (ES) cells, therefore, the imprinting related cell pluripotency needs further exploitation. Several approaches have been applied in generation of androgenetic embryos and derivation of aES cell lines. Here, we describe a method to generate androgenetic embryos by injecting two mature sperms into one enucleated oocyte. Then these androgenetic embryos were treated with a histone deacetylase inhibitor: m-carboxycinnamic acid bishydroxamide (CBHA). Further, aES cell lines were successfully derived from these treated androgenetic embryos at blastocyst stage. The CBHA could improve not only the quality of androgenetic embryos, but also the efficiencies of aES (CaES) cells derivation and chimeric mice generation. The imprinted gene expression pattern in the CBHA treated embryo-derived aES (CaES) cells was also highly similar to that of zygote-derived ES cells.  相似文献   
55.
The forest musk deer(Moschus berezovskii) is one of the most endangered species in China.Over the past decades,extensive hunting and poaching have pushed the forest musk deer to the edge of extinction,and conservation biologists are presently pursuing scientific management plans to rescue this species.The major histocompatibility complex(MHC),a cluster of genes responsible for antigen presentation,is a highly polymorphic genomic region in vertebrates that has become a popular functional marker system for studying adaptive variation.In this study,we developed locus-specific genotyping primers for exon 2 fragments of one DRA gene and one DRB locus of the forest musk deer using a suite of comprehensive methods that included universal primer amplification,genome walking,single-strand conformation polymorphism(SSCP),heteroduplex(HD) profiling,and sequence analysis.Each forest musk deer showed no more than two sequences per locus,confirming the specificity of our primers.Genotyping with these primers allowed us to identify two DRA alleles and six DRB alleles in a captive breeding population of the Sichuan Musk Deer Breeding Institution.For the DRA locus,we found a slightly higher observed heterozygosity(N O =0.154) than expected(N E =0.143).In contrast,the DRB locus showed a significant heterozygote deficiency(N O =0.508;N E =0.761;P<0.05),which was probably due to inbreeding in the captive population.An obvious excess of nonsynonymous substitutions over synonymous was observed at the antigen-binding positions of the DRA and DRB loci,showing the presence of positive selection in the forest musk deer DR genes.Finally,generation of phylogenetic trees for the DRA and DRB sequences of the forest musk deer and other ruminants revealed that the DRA and DRB loci identified in this study had homologous relationships with the known ruminant DRA and DRB genes.Based on this analysis,and to facilitate future studies,we named these novel loci Mobe-DRA and Mobe-DRB3.  相似文献   
56.
Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) were used to study the microstructure, microsegregation, and fluid flow tendency of the superalloy Waspaloy in the mushy zone, which had been solidified at different cooling rates. The investigation was accompanied with the calculation of Rayleigh numbers. It is found that Ti is the main segregating element and the content of Ti is the highest in the final liquid at the cooling rates of 3–6℃/min. The eta phase (η) precipitate presented in the residual liquid at the cooling rates higher than 6 ℃/min is responsible for the fluctuations in the curves of Ti content. The dendrite arm spacing is found to markedly decrease with the increase of cooling rate. The maximum relative Rayleigh number occurs at 10–20℃ below the liquidus temperature at a cooling rate of 1℃/min, where the mushy zone is most unstable and fluid flow is most prone to occur.  相似文献   
57.
The defective information of substation equipment is usually recorded in the form of text. Due to the irregular spoken expressions of equipment inspectors, the defect information lacks sufficient contextual information and becomes more ambiguous.To solve the problem of sparse data deficient of semantic features in classification process, a short text classification model for defects in electrical equipment that fuses contextual features is proposed. The model uses bi-directional long-short term ...  相似文献   
58.
贾春强  Yu  Ling  Tian  Shujun  Gao  Yanming 《高技术通讯(英文版)》2007,13(4):363-368
To solve the combinatorial optimization problem of outer layout and inner connection integrated schemes in the design of hydraulic manifold blocks(HMB),a hybrid genetic simulated annealing algorithm based on niche technology is presented.This hybrid algorithm,which combines genetic algorithm,simulated annealing algorithm and niche technology,has a strong capability in global and local search,and all extrema can be found in a short time without strict requests for preferences.For the complex restricted solid spatial layout problems in HMB,the optimizing mathematical model is presented.The key technologies in the integrated layout and connection design of HMB,including the realization of coding,annealing operation and genetic operation,are discussed.The framework of HMB optimal design system based on hybrid optimization strategy is proposed.An example is given to testify the effectiveness and feasibility of the algorithm.  相似文献   
59.
Wireless sensor networks can be used to monitor the interested region by deploying dense sensor nodes. Coverage is a primary metric to evaluate the capacity of monitoring. In this paper, we focus on the coverage problem under border effects, where the sensor nodes are distributed in a circle-shaped region randomly. Under this scenario, we derive the expected coverage of the sensor node and the total network coverage provided by n sensor nodes accurately by probability. These findings are useful to determine the related parameters (sensing range, number of sensor nodes and radius of monitored region) for a specific network coverage ratio. Simulation results demonstrate that our analysis is correct and effective.  相似文献   
60.
允许缺货和转包的受限批量模型的多项式算法   总被引:1,自引:1,他引:0  
有效组织带转包的采购计划对企业提高竞争力和参与全球产业分工有重要意义.研究了一个新的非减库存能力约束下的允许缺货和转包的企业采购计划模型,提出了一个基于动态规划的多项式算法.引入子计划概念,将问题归结为有效计算子计划;依据最优解的性质设计了求解子计划的多项式算法;再通过动态规划算法以多项式时间枚举所有可能子计划组合,得到问题的最优解.数值试验显示了该算法的有效性及高效性.  相似文献   
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