On a class of generalised Schmidt groups

Annali di Matematica Pura ed Applicata (1923 -) - In this paper families of non-nilpotent subgroups covering the non-nilpotent part of a finite group are considered. An $$A_5$$ -free group...     

Investigation of the Evolution Behavior of Light Tar During Bituminous Coal Pyrolysis in a Fluidized Bed Reactor

The evolution behavior of the light tar fraction of tar during large bituminous coal particle pyrolysis in a fluidized bed reactor at 500-900℃ was investigated to optimize the industrial process. The coal residence time was varied from 30 s to 150 s. The crude tar obtained was distilled and separated into the light fraction and the heavy fraction through an evaporator under conditions of 280℃ and 10⁴ Pa. The light tar was subjected to GC-MS analysis, and the 300 main species in each spectrum were determined and analyzed. The experimental results showed that the evolution behavior of the light tar fraction and the heavy tar fraction presented spectacularly different variation trends with pyrolysis temperature and coal residence time. The molecular weight and number of rings per aromatic compound molecule contained in the light tar fraction increased with increasing pyrolysis temperature because of polymerization. It was also observed that the amount of methyl substituents decreased with an increasing number of rings per molecule of poly-aromatic ring compounds. The chain aliphatic compound evolution was suppressed and underwent heterocyclization with increasing temperature.     

Characterization of simple K 4-groups

In this paper, we prove that a group G is isomorphic to M, where M is a simple K ₄-group, if and only if the following hold: (1) |G| = |M|, (2) nse(G) = nse(M).      

过渡金属氧化物催化剂上NH3 分解Claus反应机理研究

运用浸渍法制备了七种过渡金属氧化物催化剂 .对于NH3 分解反应均可获得很高的NH3 转化率 ;对于NH3 分解Claus反应则可以获得较高的SO2 转化率和单质硫选择性 .通过比较发现Co3 O4 TiO2 和Fe2 O3 TiO2 催化剂的低温活性比较高 .经过XRD表征发现 ,在NH3 分解Claus反应中 ,催化剂的活性相可能是过渡金属硫化物 .结合活性评价和XRD表征结果提出了NH3 分解Claus反应的机理 .     

素数幂、双素数幂阶元的共轭类长的个数为4的 有限群的结构

设群G为一个有限群.如果群G中素数幂、双素幂阶元的共轭类长的集合为{1,p~a,m,p~bm},那么群G是可解的,其中ab为正整数,p为素数且与m互素.进一步,给出了群G/Z(G)的结构,这是对文"Chen R F,Zhao X H.A criterion for a group to have nilpotent p-complements[J].Monatsh Math,2016,179(2):221-225"中定理A主要结论的一个推广.     

Cr3+的水解聚合作用的研究 Ⅺ.在顺丁烯二酸存在下的水解和聚合

在60℃和恒定离子强度下,用平衡法研究了0.004mol dm^-3Cr(NO₃)₃在三种不同浓度顺丁烯二酸H₂A(0.008,0.010,0.014mol dm^-3的水溶液中的状态,用计算机拟合和p.q.r分析方法得到了[Cr(OH)A₂]^2-,[Cr₂(OH)A₂]⁺[Cr₃(OH)₂A₂]⁺和CrA₃^3-四种水解产物,并计算了其平衡常数,在我们系列工作中研究了在宽广的Cr³⁺和顺丁烯二酸浓度下Cr³⁺的状态,共生成11种配合物,本文对其形成规律进行了讨论.     

冠醚配合物的研究XV.若干席夫碱及仲胺型双冠醚和碱金属离子的配位反应

本文运用微量电导滴定及计算机拟合技术，研究了若干席夫碱及仲胺型双冠醚和碱金属离子的配位反应，测定了配合物的组成及稳定常数，并对实验结果进行了讨论。     

[(dien)Cu(imH)](ClO4)2、[(tren)Cu(imH)](ClO4)2中配位咪唑的离解

本文用紫外可见光谱、pH滴定等方法研究了配合物[(dien)Cu(imH)](ClO₄)₂、[(tren)Cu(imH))(ClO₄)₂中Cu-imH的配位和离解作用,得到了它们的稳定常数,并探索了共存配体的影响。     

An extension of a theorem of Alan Camina on conjugacy class sizes

Let G be a finite group. Let n be a positive integer and p a prime coprime to n. In this paper we prove that if the set of conjugacy class sizes of primary and biprimary elements of group G is {1,p ^a , p ^a n}, then G ≌ G ₀ × H, where H is abelian and G ₀ contains a normal subgroup M × P ₀ of index p. Moreover, M × P ₀ is the set of all elements of G ₀ of conjugacy class sizes p ^a or 1, where M is an abelian π(n)-subgroup of G ₀ and P ₀ is an abelian p-subgroup of G ₀, neither being central in G. Finally, p ^a = p and P/P ₀ acts fixed-point-freely on M and ?(P) ≤ Z(P). This is an extension of Alan Camina’s theorems on the structure of groups whose set of conjugacy class size is {1,p ^a , p ^a q ^b }, where p and q are two distinct primes.