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71.
本文讨论了范畴RMSM中的复形与同调模,证明了下列结果:设OMM′→LL′→KK′→O是一个短正合列,则对任何RS一模AA′有长正合列O→HR(A,M)Hs(A′,M′)→HR(A,L)Hs(A′,L′)→H_R(A,K)Hs(A′,K′)→Ext′(AA′,LL′)→…→Ext~n(AA′,MM′),Ext~n(AA′,L)L′)→Ext~n(AA′,KK′)→…同时给出了AA′是投射RS-模的几个等价命题。  相似文献   
72.
微型滴定法测定饮品中的总酸度   总被引:2,自引:0,他引:2  
本文利用微型滴定法测定饮品中的总酸度,并对微型滴定法与常量滴定法的平行测定结果进行了比较,结果无显著性差异,F检T检结果均在允许范围内,相对偏差均小于0.5%,微型滴定法的精度达到常量滴定法测定水平,能满足化学分析要求.  相似文献   
73.
可视化是研究复杂网络的重要方法,目前2D平面可视化研究十分成熟,而3D可视化研究相对较少.为解决目前3D可视化布局结果不能真实展示复杂网络结构特征的问题,提出了一种两级力导引3D可视化算法.该算法基于复杂网络的特征分析,通过对网络聚类得到多个子网络及建立抽象网络,然后分两步依次对抽象网络和子网络进行力导引布局,从而得到最终布局.真实数据的实验分析表明,该算法的可视化布局结果能够真实展示复杂网络结构特征,同时具有较低的时间复杂度和较好美观度、清晰度.  相似文献   
74.
In order to describe collaborative decision-making process, the command and control model is put forward based on complex information relation integrtion and OODA. The characteristics of individual decision-making are analyzed, the complex information relation is considered as the cause of OODA difficulty to describe collaborative decision-making exactly. From the perspective of armament system of systems combat, the information, data, intelligence and knowledge is defined based on knowledge management and Shannon's entropy theory. The basic element is confirmed and the information flow way is analyzed which in the physical, information, cognitive and social domains. From the perspective of information, the armament system of systems complex networks model framework is put forward based on the idea of using OODA to guide armament system of systems complex networks model design. The data, information, intelligence and knowledge flow is analyzed and the describing meta-model is put forward. Using the reticular structure of OODA to describe collaborative decision-making idea is proposed, the command and control model is put forward based on the idea, the simulating tool ExtendSim is used for simulation analysis and results show that our work offer a reference for innovate command and control thory. ©, 2015, The Journal Agency of Complex Systems and Complexity Science. All right reserved.  相似文献   
75.
To better explore the universal robustness against cascading failures on complex networks, closely focusing on the load which is the most important physical quantity that can affect the spread of cascading failure, and dynamic process after a node fails, a cascading failure model with tunable parameters is proposed based on the local characteristic of node. With this model we study the cascading failure condition of ER and BA networks, and obtain the formula of phase transition point theoretically. The relationship between the robustness against cascading failures on complex networks and parameters in the model, including the topology parameters, the initial load coefficient, and the redistribution coefficient, is discussed numerically. In addition, theoretical results also are verified by the simulation results of the ER and BA networks. ©, 2015, The Journal Agency of Complex Systems and Complexity Science. All right reserved.  相似文献   
76.
本文探讨了自然科学复杂问题研究中的解析法、实验法和仿真法各自不同的内涵和思维活动特征,论述了三种研究方法的特点、作用、地位和相互之间的关系。以风力机气动设计为例,重点论述了解析法的研究步骤,对研究过程中出现的本质与现象、对立与统一、主要矛盾与次要矛盾、复杂与简化、局部与整体等辩证法范畴的问题进行了分析。  相似文献   
77.
Bacterial nonspecific acid phosphohydrolases (NSAPs) are secreted enzymes, produced as soluble periplasmic proteins or as membrane-bound lipoproteins, that are usually able to dephosphorylate a broad array of structurally unrelated substrates and exhibit optimal catalytic activity at acidic to neutral pH values. Bacterial NSAPs are monomeric or oligomeric proteins containing polypeptide components with an M r of 25 – 30 kDa. On the basis of amino acid sequence relatedness, three different molecular families of NSAPs can be distinguished, indicated as molecular class A, B and C, respectively. Members of each class share some common biophysical and functional features, but may also exhibit functional differences. NSAPs have been detected in several microbial taxa, and enzymes of different classes can be produced by the same bacterial species. Structural and phyletic relationships exist among the various bacterial NSAPs and some other bacterial and eucaryotic phosphohydrolases. Current knowledge on bacterial NSAPs is reviewed, together with analytical tools that may be useful for their characterization. An overview is also presented concerning the use of bacterial NSAPs in biotechnology. Received 21 November 1997; received after revision 10 March 1998; accepted 10 March 1998  相似文献   
78.
Many trinary lanthanide complexes have been studied. However, few mixed anion complexes with bidentate heterocyclic amines were synthesized. We synthesized mixed anion complexes Ln ( CHi CICO0 )2 (NO3) (phen) which was determined by elemental analyses. The IR spectra analyses indicate that NO3 ,CH2 C1CO0- and phen are coordinated with Ln. The molar conductances of the complexes at 10-3 mol. L-1 were founded to be between 32.4 and 35.8 S. cma@mol- 1 , suggesting the nonelectrolytes in N Dimethylformamide. And we determined the fluorescent spectra Eu(CH2C1COO)2(NO3) ( phen ) and ESR spectra of Gd( CH2 ClC00 )2 ( NOs ) ( phen ) .  相似文献   
79.
岳展  史波珍 《科技信息》2013,(11):402-402
提出一种适用于复杂能源系统研究的半物理模拟方法,分析了单纯实验和单纯模拟研究的不足,而利用半物理模拟研究方法则更快捷,结果更为准确,预测的范围更为宽广。  相似文献   
80.
1.INTRODUCTIONThealgorithmforconstrainedoptimizationincomplexsystemscanbedividedintotwoclasses:exactandheuristicmethods.Theexactmethods,whicharepartlysummarizedbyTitanetal.[1],havecomputationalrequiremeatsthatgrowexponentiajlywiththesizeoftheproblem.AlthoughheuristicmethodshavemodestcomputationalrequirementsandareeasytoAnplemellt,theyaregenerallyforredundancyallocation[2-4].2.S~EMENTOFProBLEM2.1NotationN:nUmberofcomponents;M:numberofconstraints;Rs:systemreliability;Rj:thereliabili…  相似文献   
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