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Search Results: 1 - 10 of 291991 matches for " 李进东 "
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关于分担一个值的亚纯函数的唯一性的一个注记
A Note on Uniqueness of Meromorphic Functions Sharing One Value
 [PDF]


Pure Mathematics (PM) , 2012, DOI: 10.12677/PM.2012.24040
Abstract: 本文研究了分担一个值的亚纯函数的唯一性,得到两个结果,这改进了张同对、吕魏然的一个结果。
 In this paper, we study the uniqueness of meromorphic functions sharing one value, prove two main theorems which generalize and improve some results earlier given by M. L. Fang and W. Hong, T. D. Zhang and W. R. Lv in [6]
涉及重值的亚纯函数的唯一性象集

重庆大学学报 , 2003, DOI: 10.11835/j.issn.1000-582X.2003.04.019
Abstract: 应用值分布理论,在涉及重值情况下进一步研究了亚纯函数唯一性理论中Gross.F提出的一个问题,获得如下结果:设集合S={ω∈C|P(ω)=aω7-42ω2+70bω-30b2=0},其中a,b为不等于零的常数,ab5≠2。若f与g为满足Ek)(S,f)=Ek)(S,g)的非常数的亚纯函数,则当下列条件之一成立时有f≡g。①k≥3,Θ(∞,f)>34,Θ(∞,g)>34,②k=2,Θ(∞,f)>89,Θ(∞,g)>89结论改进推广了仪洪勋,方明亮和华歆厚等人的一些已知结果。
Np-237在AP1000首循环堆芯中的嬗变研究
Transmutation of Np-237 in the First Cycle of AP1000 Core
 [PDF]

贾仁, 刘滨,,
Nuclear Science and Technology (NST) , 2015, DOI: 10.12677/NST.2015.33012
Abstract:
核电站所产生的乏燃料中含有大量的放射性核素,主要包括长寿命裂变产物(LLFP)和少量锕系元素(MA),这些核素要通过上万年的衰变才能消除放射性危害。分离嬗变技术(P&T)是将这些放射性核素从乏燃料中分离出来,放入特定装置中,对其进行中子照射,使其转变成低放射性核素或稳定核素。镎(Np)作为一种最主要的MA核素,其含量高,半衰期长。本文利用MCNP程序搭建AP1000反应堆堆芯模型,以二氧化镎(NpO2)嬗变棒为引入方式,设计出在首循环堆芯中添加嬗变材料的10种方案。通过计算比较各种方案中有效增殖因子(keff)、二氧化镎的添加质量和使堆芯重新达到临界所需要改变堆芯的程度,结果显示在堆芯燃料富集度为4.45%区域添加二氧化镎涂层的方案具有优势,本文对该方案进行了分析并进行了优化。
The spent fuel generated by nuclear power plants contains large quantities of radionuclides, in-cluding long-lived fission products (LLFP) and minor actinides (MA). These nuclides decay to no harm through thousands of years. Partitioning and transmutation technology (P&T) is to separate these nuclides from the spent fuel into specific device for neutron irradiation, making it into a low-level radioactive nuclides or stable nuclides. As a major MA nuclide, neptunium (Np) has a high productivity and long half-time. In this paper, MCNP code is used to build the AP1000 reactor core model, and neptunium dioxide (NpO2) transmutation rod is introduced to design 10 schemes where transmutation material is putted into the first cycle core. By calculation and comparing the effective multiplication factor (keff), the added quality of neptunium dioxide and the changing extent to make the core reach the critical again, the result shows that the scheme where neptunium dioxide coating is putted in the fuel enrichment 4.45% of the core has advantages. This paper analyzes the scheme and optimized.
DRAGON用于嬗变MA的计算研究
Computational Study of DRAGON for Minor Actinide Transmutation
 [PDF]

, 刘滨, 贾仁,
Nuclear Science and Technology (NST) , 2015, DOI: 10.12677/NST.2015.33015
Abstract: 长寿命高放废物MA作为核电站乏燃料中的重要组成部分,由于其特殊的物理化学性质,对生态有很强的危害性,一直是各国研究的重要课题之一。目前处理MA最安全有效的方法,是中子嬗变技术,而压水堆又是我国目前投入商业运行的主要的堆型,因此开展压水堆嬗变MA的研究在我国具有重要的意义。本文利用DRAGON程序建立了简化的AP1000燃料组件模型,模拟计算了在可燃毒物内均匀混合MA、在可燃毒物外镀层引入MA两种方式对燃料组件有效增殖因子(keff)、堆芯燃耗、燃料周期以及堆芯寿期的影响。结果表明:MA以上述两种方式添加到可燃毒物中后,燃料组件的燃耗深度会减少,从而延长了堆芯的燃料周期,同时也会对燃料组件的keff值产生影响,燃料组件维持在临界以上的时间也会延长,在一定程度上也会对整个堆芯的寿期产生有利影响。
The Minor Actinides (MA), a sort of long-lived and high-level radioactive nuclides is one of the most important part in the nuclear spent fuel. The MA is harmful to the ecological system because of its peculiar physical and chemical property. How to handle the MA in the spent fuel has always been one of the most important issues in nuclear waste management all over the world. The MA can be transmuted into stable or short-lived nuclides by neutron irradiation, and this is the most effective way to manage those high-level wastes. The PWR is the main reactor type at commercial operation in China, and the MA has a larger capture and fission cross section in the thermal reactor, therefore the study on the transmutation of the MA in the PWR has an important significance in China. This paper has used the DRAGON to build a simplified model of the AP1000 PWR fuel assembly and calculated the impacts on the k-effective of the fuel assembly, the fuel burnup, the fuel cycle and core lifetime when the MA uniformly mixed with the burnable poison or cladded on the burnable poison. The results show that: when the MA is added to the burnable poison in the above two methods, burnup level of the fuel assembly decreases and the fuel cycle of the core lengthens. It also has an impact on the k-effective of the fuel assembly, extending the time of the fuel assembly maintaining above the critical and has a favorable impact on core lifetime.
纵向数据下线性指数分布参数的经验Bayes双边检验
The Empirical Bayes Two-Sided Tests for the Parameter of Linear Exponential Distribution under Longitudinal Data
 [PDF]

罗修辉, 韦程,
Statistics and Applications (SA) , 2016, DOI: 10.12677/SA.2016.53022
Abstract: 基于纵向数据下,本文讨论了在平方损失函数下线性指数分布参数的双边检验问题,利用Markov不等式证明了构造的经验贝叶斯双边检验函数具有渐近最优性,并获得了其收敛速度。
In the case of longitudinal data, this paper studies two-side test problem of linear exponential dis-tribution parameters under square loss function. By applying Markov inequality, the EB test rules for parameter of the linear exponential distribution are constructed and the asymptotically optimal property is obtained. Finally, we obtain the convergence rate of the proposed EB test under suitable conditions.
Pfu酶基因的克隆、表达、纯化及长距离PCR的研究
,谷成,
科学通报 , 1998,
Abstract: 用PCR方法从Pyrococcus furiosus的总NDA扩增出了含有Pfu DNA polA基因的2.3kb片段,并将该基因克隆入pGEM-T载体。用NcoI和XhoI对重组质粒pT-pfu进行了酶切。并将pfu polA基因捶 入表达载体pET-3d-X。
体外预应力加固桥梁正截面强度的计算
王晓,
公路交通科技 , 2006,
Abstract: 针对体外预应力加固梁时的受力机理和破坏形式,推导出了采用体外预应力加固设计的计算公式和应满足的条件,并应用于川藏公路某大桥的加固实践。该大桥根据本文所论述的原理进行加固后,一直维持了正常的通车和承载力,取得了良好的使用效果。该加固方法施工简单易行,加固效果明显。本文中所建立的体外预应力加固设计计算公式可供同类加固设计参考使用。
Pfu酶基因的克隆、表达、纯化及长距离PCR的研究
,谷成,
科学通报 , 1998,
Abstract: 用PCR方法从Pyrococcusfuriosus的总DNA扩增出了含有PfuDNApolA基因的2.3kb片段,并将该基因克隆入pGEMT载体.用NcoⅠ和XhoⅠ对重组质粒pTpfu进行酶切,并将pfupolA基因插入表达载体pET3dX.在大肠杆菌BL21(DE3)中将pfupolA基因进行表达,然后用热变性、聚乙二胺(PEI)沉淀和Biorex70离子交换法对其基因产物(Pfu酶)进行纯化.用蛋白质N末端测序法证实了确为重组Pfu酶.利用重组Pfu酶,成功地用长距离PCR法扩增出大于10kb的λDNA片段.
基于密度的划分式聚类过程参数选择算法
吴杨,王韬,
- , 2016, DOI: 10.13195/j.kzyjc.2014.1592
Abstract: 为确定??-means 等聚类算法的初始聚类中心, 首先由样本总量及其取值区间长度确定对应维上的样本密度统计区间数, 并将满足筛选条件的密度峰值所在区间内的样本均值作为候选初始聚类中心; 然后, 根据密度峰值区间在各维上的映射关系建立候选初始聚类中心关系树, 进一步采用最大最小距离算法获得初始聚类中心; 最后为确定最佳聚类数, 基于类内样本密度及类密度建立聚类有效性评估函数. 针对人工数据集及UCI 数据集的实验结果表明了所提出算法的有效性.
追施氮肥对苏丹草光合特性及种子产量的影响
庞立,卫军,
草业科学 , 2014, DOI: 10.11829\j.issn.1001-0629.2014-0371
Abstract: ?以新苏2号苏丹草(Sorghumsudanense‘XinsuNo.2’)为试材,采用单因素完全随机区组设计,在拔节、孕穗和灌浆期追施氮肥,以揭示施氮对苏丹草叶片光合生理特性及种子产量性状的影响。结果表明,追施氮肥可显著提高苏丹草叶片光合速率、气孔导度和水分利用效率,当追肥超过600kg·hm-2时,在拔节期和抽穗期对光合速率产生抑制作用。随追肥量增加SPAD值随之增大,追肥量超过450kg·hm-2后,SPAD值增幅较小或不增加。追施氮肥可有效增加种子千粒重、穗粒数,从而使苏丹草种子产量明显增加,然而,追施氮量增加,落粒率升高,产量增幅明显减小,追氮150与300kg·hm-2时,产量增幅分别达23.7%和32.2%,而追氮750kg·hm-2时,产量增幅仅为3.9%,追施氮肥600kg·hm-2时,可获最大种子产量3815kg·hm-2。综合苏丹草光合生理指标及产量性状的变化认为,追肥量为600kg·hm-2为最佳,此时光合速率最大,并可获得最大种子产量。
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