Global existence and blow-up of solutions to reaction-diffusion system with a weighted nonlocal source     

蒋良军  王悦生 《上海大学学报(英文版)》2011,15(6):501-505

In this paper, we study a semi-linear reaction-diffusion system with a weighted nonlocal source, subject to the null Dirichlet boundary condition. Under certain conditions, we prove that the classical solution exists globally and blows up in finite time respectively, and then obtain the uniform blow-up rate in the interior.  相似文献   

模糊综合评判的神经网络方法在损害分析中的应用   总被引：4，自引：0，他引：4  

隋伟莹  王明明  邹开其 《大连大学学报》2004,25(6):16-18

本文针对反倾销中损害案件的调查,在满足法律条文规定的基础上,采用模糊综合评判的神经网络方法,优化损害和损害程度的综合评判模型中企业经营指标的评判指标权重,进而采用优化后的权重进行损害和损害程度的综合评判.使评判过程和结果更加具有科学性,也使反倾销损害调查的裁决更加具有公共性和透明度.此方法对政府有关部门裁决倾销和反倾销案件有一定的辅助决策.  相似文献   

个性化英语培训系统的设计与实现     

钟美华  万江平 《广东轻工职业技术学院学报》2004,3(1):23-26

从个性化教育出发，研究将个性化技术应用于英语培训教学上。首先，介绍了培训资源的本体特征和特征描述的表示，接着阐明了基于聚类事务的用户特征聚合的个性化技术。最后，建立一个个性化英语培训系统，描述了系统的信息流程，资料控制器功能结构和系统实现的软件构架。  相似文献   

基于模糊变权法的《动车组结构及原理》教学模式改革评价     

李永华  王剑  宫琦 《教育教学论坛》2020,(7):119-120

文章以《动车组结构及原理》课程为例,结合模糊层次分析法和变权综合法提出一种基于模糊变权法的教学模式改革评价方法。该方法有效降低各评价因素权重的主观性,更好地反映改革的整体评价结果,对同类课程的教学模式改革具有一定的借鉴意义。  相似文献   

用改进的试探函数法求解广义KdV方程     

谢元喜 《娄底师专学报》2006,(3):13-15

试探函数法求解非线性数学物理中一个非常著名的非线性偏微分方程-广义KdV方程，求得其一般形式的指数函数解，据此不但求得了广义KdV方程的sech^2型钟状正则孤波解，而且求得了其csch^2型奇异行波解，最后，利用一些熟知的数学关系式，又求得其若干其它显式精确解，包括三角函数型周期波解等。  相似文献   

Mathematical　Model　of　Weight　in　Evaluation　System     

孙璐  邓学钧 《东南大学学报》1996,(2)

ＭａｔｈｅｍａｔｉｃａｌＭｏｄｅｌｏｆＷｅｉｇｈｔｉｎＥｖａｌｕａｔｉｏｎＳｙｓｔｅｍＳｕｎＬｕ（孙璐）ＤｅｎｇＸｕｅｊｕｎ（邓学钧）（ＴｒａｎｓｐｏｒｔａｔｉｏｎＣｏｌｅｇｅ，ＳｏｕｔｈｅａｓｔＵｎｉｖｅｒｓｉｔｙ，Ｎａｎｊｉｎｇ２１００１８）Ａ...  相似文献   

肝细胞生成素等人胎肝来源新基因的系列研究     

贺福初  张成岗  李勇  陆承荣  张令强 《中国科学基金》2006,20(6):337-341

拥有正常、稳定的造血功能是机体生理活动正常发挥的物质基础，同时，尽快恢复机体造血功能也是临床上放射病和辐射损伤治疗，以及肿瘤放化疗后机体恢复的关键环节，因此，具有造血功能的组织器官对机体的重要性不言而喻。大量研究发现，12—26周孕龄的人胎肝是造血、免疫系统干／祖细胞的主要来源，整个造血系统必须首先从卵黄囊迁入胎肝、经其“培育”发育成熟后再行迁出并进入骨髓。其中，22周孕龄是胎肝造血兴／衰、造血系统迁入／迁出的转折点，提示其对于机体造血功能的维持和发挥非常重要。上世纪70—80年代，我国曾广泛应用胎肝治疗多种疾病（如放化疗病人造血衰竭、再生障碍性贫血、重症肝炎等）并取得显著疗效，提示其中可能存在大量有待发掘的具有重要医学价值（如造血调控、肝脏代谢、组织发育）的活性成分，但其分子基础长期不明，迫切需要深入研究。  相似文献   

用户画像视域下档案馆精准服务:内涵、机理及实现策略   总被引：1，自引：0，他引：1  

苏君华  牟胜男 《档案学通讯》2020,(2):58-66

充分挖掘档案用户数据价值有助于档案馆开展精准服务,而嵌入用户画像则进一步满足了档案用户需求,为优化档案服务提供新方法。通过梳理当前档案馆精准服务研究成果,探究用户画像服务内涵及功能,从而探析用户画像视域下档案馆精准服务的运行机理及应用前景。结合档案馆应用用户画像的进展,就用户画像视域下的精准服务核心难点提出了相应策略:增强档案用户数据扩展与融合、强化用户画像实时变化中的隐私保护、完善精准服务反馈评价体系,以实现精准化档案信息检索、信息推荐及知识服务。  相似文献   

Genetic analysis for brix weight per stool and its component traits in sugarcane （Saccharum officinarum）     

Liu GF  Zhou HK  Hu H  Zhu ZH  Hayat Y  Xu HM  Yang J 《Journal of Zhejiang University. Science. B》2007,8(12):860-866

Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five component traits, including stalk diameter (SD), stalk length (SL), stalk number (SN), stalk weight (SW), and brix scale (BS) of sugarcane. Phenotypic data of all the six traits were analyzed by mixed linear model and their phenotype variances were portioned into additive (A),dominance (D), additive×environment interaction (AE) and dominance×environment interaction (DE) effects, and the correlations of A, D, AE and DE effects between BW and its components were estimated. Conditional analysis was employed to investigate the contribution of the components traits to the variances of A, D, AE and DE effects of BW. It was observed that the heritabilities of BW were significantly attributed to A, D and DE by 23.9%, 30.9% and 28.5%, respectively. The variance of A effect for BW was significantly affected by SL, SN and BS by 25.3%, 93.7% and 17.4%, respectively. The variances of D and DE effects for BW were also significantly influenced by all the five components by 5.1%～85.5%. These determinants might be helpful in sugarcane breeding and provide valuable information for multiple-trait improvement of BW.  相似文献   

QTL analysis for some quantitative traits in bread wheat     

Pushpendra KG  Harindra SB  Pawan LK  Neeraj K  Ajay K  Reyazul RM  Amita M  Jitendra K 《Journal of Zhejiang University. Science. B》2007,8(11):807-814

Quantitative trait loci (QTL) analysis was conducted in bread wheat for 14 important traits utilizing data from four different mapping populations involving different approaches of QTL analysis. Analysis for grain protein content (GPC) sug- gested that the major part of genetic variation for this trait is due to environmental interactions. In contrast, pre-harvest sprouting tolerance (PHST) was controlled mainly by main effect QTL (M-QTL) with very little genetic variation due to environmental interactions; a major QTL for PHST was detected on chromosome arm 3AL. For grain weight, one QTL each was detected on chromosome arms 1AS, 2BS and 7AS. QTL for 4 growth related traits taken together detected by different methods ranged from 37 to 40; nine QTL that were detected by single-locus as well as two-locus analyses were all M-QTL. Similarly, single-locus and two-locus QTL analyses for seven yield and yield contributing traits in two populations respectively allowed detection of 25 and 50 QTL by composite interval mapping (CIM), 16 and 25 QTL by multiple-trait composite interval mapping (MCIM) and 38 and 37 QTL by two-locus analyses. These studies should prove useful in QTL cloning and wheat improvement through marker aided selection.  相似文献