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1.
图G的全色数XT(G)是使得V(G)U∪E(G)中相邻或相关联的元素均染不同颜色的最少颜色数目.如果XT(G)=△(G)+1,则记如果XT(G)=△(G)+2,则记G∈.两个图G和H的联图G∨H是一个简单图,使得V(G∨H)=V(G)∪V(H),E(G∨H)=E(G)∪E(H)∪{uv(G),v∈(H)}.本文证明了对任意的两个正整数m和n,Pm∨Pn∈当且仅当m=n=2或m=n=1,从而完全确定了两个路的联图的全色数.  相似文献   

2.
研究了分布于甘肃省临泽地区的沙拐枣、珍珠、霸王、泡泡刺、胡杨等5种沙生植物的光合酶:果糖-1.6-双磷酸酯酶(FDPase)、1.5-二磷酸核酮糖羧化酶(RUBPcase)、磷酸烯醇式丙酮酸羧化酶(PEPcase)、NAD-苹果酸脱氢酶(NAD-MDH)活性的季节变化。结果表明,珍珠和沙拐枣的FDPase酶活性远低于其它几种材料;珍珠、霸王、沙拐枣的PEPcase活性明显高于其它两种材料;珍珠、沙拐枣的NAD-MDH活性明显高于其它三种材料。可见,珍珠、霸王是CAM植物,沙拐枣是C4植物,胡杨是C3植物,泡泡刺有可能在干旱协迫下由C3向C4或CAM途径转化。  相似文献   

3.
报道了AβMxHy[MW9Mn3(H2O)3O37]·nH2O(M=Si,Ge,Ga;M=Bu4N+,K+)的合成方法并对IR、UV、磁化率以及催化活性等进行研究。  相似文献   

4.
图G=(V,E)的一个同构因子分解是边集E的一个划分:{E1,E2,…,Et},使得生成子图(V, E1),…,(V,Et)都彼此同构。若 H≌(V,E1),记为 H[G或 t]G.若对每个t≥2.当   时.均有:tG,则称G为有理图.文章证明了超立方图(hypercube)和超立方有向图都是有理图.  相似文献   

5.
合成了通式为(C15H15N2O3)xRE(NO3)y(H2O)z(当RE=La~Pr时,x=3,y=6,z=0;RE=Nd时,x=2,y=5,z=1;RE=Sm~Lu,Y时,x=2,y=5,z=0)的一系列15种标题配合物.通过元素分析,IR,UV,1HNMR,TG-DTA,摩尔电导和X射线粉末衍射分析等对配合物的性质进行了表征.认为可能生成包含一分子水的11配位钕配合物的原因在于抗衡阳离子的空间效应,使其与络阴离子间的vanderWaals力增强的结果  相似文献   

6.
玉米锈病的研究初报马桂珍,暴增海(河北农业技术师范学院农学系昌黎,066600)PRIMARYREPORTONTNESTUDYOFCORNRUSTMaGuizhenBaoZenghai(Department,ofAgronorny,HATC,Chan...  相似文献   

7.
文中证明了类似于Wielandt定理的结果:设G为有限群,H是G的n-幂零Π-Hall子群,若M是G的Π-子群,(|M|,n(1-n))=1,则存在a∈G使M ̄a≤H。  相似文献   

8.
研究了以甲基丙烯酸酯端基不饱和取酯树脂为主链,用甲基丙烯酸甲酯取代苯乙烯作为交联剂制成的甲基丙烯酸酯树脂(MAER)与通用型不饱和聚酯树脂(GUPR)的热裂解机理、燃烧现象。结果表明:MAER的裂角产物中苯环化合物含量(14.9%)少于GUPR(74.5%)。MAER燃烧时的发烟量和毒性也远低于GUPR。在MAER中加入三水合氧化铝(ATH)后,裂解产物中有毒物质的各类和数量更少,在燃烧时只有少量  相似文献   

9.
软质UHMWPVC/LMWPVC共混体系的力学性能和流变性能研究   总被引:3,自引:0,他引:3  
采用增塑UHMWPVC与LMWPVC共混的新方法,在UHMWPVC树脂力学性能下降较少的前提下,大大改善其加工流动性能.同时,在UHMWPVC中加入LMWPVC,又可减少增塑剂用量,降低制品成本.系统地研究了LMWPVC及增塑剂用量对UHMWPVC/LMWPVC共混体系力学性能的影响规律,研究了剪切速率、温度、LMWPVC及增塑剂用量对体系流变性能的影响规律.发现了不少新现象,得出的一些结论具有一定理论和实用价值.  相似文献   

10.
通过极谱和循环伏安全,结合紫外光谱和X射线光电子能谱研究了过渡元素Kn「MW11O39Ni(H2O)」.xH2O(M=Si、Ti、Ga、Zr)在溶液中的氧化还原性质,提出了它们的还原机理,杂多阴离子的极谱半波电位顺序为Zr〉Ti〉Ga〉Si,发现杂多阴离子的E1/2与M元素的电负性有线性关系。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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