孪生组合恒等式(十二)--第2类Stirling数类型

叙述2组第2类Stirling数类型的孪生恒等式,第1组含有Bernoulli数与第2类Stirling数,第2组含有Euler数与第2类Stirling数,运用形式幂级数运算给出证明.     

煤燃烧过程中痕量元素的分类研究

采用原子吸收分光光度计(带测汞装置)、石墨炉原子吸收光谱仪和X射线荧光光谱仪，测定了一台220t／h煤粉炉中原煤、底渣和飞灰中9种痕量元素的质量分数．除As因质量分数低不能归类外，其他痕量元素按照在飞灰中相对富集系数不同，可分成3类：第1类是Pb，Zn；第2类是Mn，Cr，Se，Hg；第3类是Ba，Cd．按照飞灰相对于底渣痕量元素富集程度不同，可分成两类：第1类是Mn，Cr；第2类是Pb，Bd，Se，Zn，Cd，Hg．按照痕量元素挥发性和在燃烧产物中的分布规律，可分成3类：第1类是Hg；第2类是Pb，Ba，Zn，Cd；第3类是Mn．Se介于第1类元素和第2类元素之间．Cr同时表现出第1类和第3类元素性质．研究还发现除Mn外，其他元素在飞灰中的富集程度随粒径减小而增加；Pb比Cd更容易挥发．     

正、负顾客依状态到达的M/M/m/（k-m）优先权排队系统

研究了具有2类顾客的多服务台排队系统,2类顾客共用一个容量为（k-m）的等待空间.其中第1类顾客具有强占优先权,第2类顾客分正顾客和负顾客2种,正、负顾客依状态到达,且负顾客不接受服务,负顾客到达系统后一对一抵消排在队尾的第2类正顾客.利用矩阵分析理论得到2类顾客的平均队长和溢出率.     

单向耦合下两个不同Chen系统的广义同步

利用辅助系统方法,基于稳定性理论和响应系统的有界性,得到了单向耦合下两个不同Chen系统达到广义同步时的充分条件;并根据响应系统的修正系统具有零渐近稳定平衡点、非零渐近稳定平衡点和轨道渐近稳定周期解的情况,将广义同步分为第1类、第2类和第3类;利用Routh-Hurwitz定理,对修正系统平衡点的稳定性进行分析,给出了单向耦合下两个不同Chen系统具有第1类、第2类广义同步的充分条件。数值仿真表明了该方法的有效性与可行性。     

应用聚类分析法划分重庆玉米种植区研究

应用聚类分析法,根据重庆市2006年和2007年2年共19个点次试验、13个玉米单交种的产量和株高性状表现,将重庆市的玉米种植区划分为6类.第1类包括丰都、涪陵、长寿、南川、潼南;第2类为合川;第3类为江津;第4类为万州,第5类为酉阳;第6类为黔江.其分类结果与按地理位置分类结果基本一致,说明根据玉米自身的重要性状表现,应用聚类分析法进行种植区划是一种经济、实用、准确的方法,可为玉米生产,引种和区域试验提供科学依据.     

第Ⅱ类超导体及其电磁性质

第Ⅱ类超导体发现过程的简要回顾 ,2个重要参数λ ,ξ与第Ⅱ类超导体的关系 ,磁通量子、涡旋及相关的物理性质 ,低端和高端临界磁场Hc1和Hc2 的估算等     

关于两类Lucas序列的一些恒等式

研究了两类Lucas序列的乘积和问题．利用解析方法给出了第1类Lucas序列和第2类Lucas序列的恒等式．作为应用,给出了几个关于Fibonacci数和Lucas数的恒等式．     

模糊聚类分析法在广西区域经济中的应用

运用模糊聚类分析法对广西14个市、地区的综合实力进行模糊聚类分析。结果广西分为5类地区，第1类为南宁市、柳州市和桂林市；第2类为玉林市和南宁地区；第3类为梧州市、北海市、钦州市、贵港市、百色市和河池市；第4类为贺州市和来宾市；第5类为防城港市，分析结果与广西的实际情况比较吻合。     

关于斐波纳奇数和鲁卡数的一组恒等式

用初等方法给出了第1类和第2类契贝谢夫多项式的一些非常有趣的恒等式,在此基础上利用文献[1]的结果得到了关于斐波纳奇数和鲁卡数的一组恒等式.     

3种蝈螽鸣声结构的比较研究

研究了优雅蝈螽Gampsocleis gratiosa、暗褐蝈螽Gampsocleis sedakovii及秃毛蝈螽Gampsocleis glabra 3种螽斯雄性的鸣声。优雅蝈螽鸣声是由振幅高低不同的2类脉冲组构成的脉冲序列,一系列的脉冲组间隔重复出现,其中,第1类脉冲组有9～10个脉冲,第2类脉冲组有10～11个脉冲,鸣声的主能峰频率约7.75 kHz,次能峰频率约4 kHz;暗褐蝈螽鸣声由一系列振幅高低不同的2类脉冲组构成,第1类脉冲组有2个脉冲,第2类脉冲组也有2个脉冲,鸣声的主能峰频率为10.50 kHz,次能峰频率为5.75 kHz;秃毛蝈螽鸣声由2类振幅高低不同的脉冲组构成,第1类脉冲组振幅较大,有1个脉冲,第2类振幅较小,有4～5个脉冲,鸣声的主能峰频率约9.1 kHz,次能峰频率不明显。     

4-Formyl-2-（2H-benzotriazol-2-yl）-phenol： an ESIPT chromophore

In the present work, excited state intramolecular proton transfer （ESIPT） emission properties of a new benzotriazole derivative 4-formyl-2-（2H-benzotriazol-2-yl）- phenol （C1） were studied. 4-Formyl-2-（2H-benzotriazol-2- yl）-methoxy-benzene （C2）, 4-formyl-2-（2H-benzotriazol-2- yl）-phenyl acetate （C3） and 4-methyl-2-（2H-benzotriazol- 2-yl）-phenol （C4） were used as the reference molecules. ^1H NMR chemical shift of hydroxy group in C1 was located at more down field than that of C4 or p-hydroxy-benzaldehyde （C5）, respectively. C1 showed two absorption bands in the range of 260-400 nm zones in various solvents, while C2 and C3 exhibited single absorption band. The equal molar mixtures of C2/C5 or C3/C5 showed single absorption band. C2 and C3 displayed single fluorescence emission band in various solvents, while C1 exhibited dual emission bands in some strong polar solvents. Furthermore, the second emission band in these strong polar solvents showed the large Stokes shift. The results show that the second emission band of C1 was produced by ESIPT. C2 and C3 could not undergo ESIPT due to no hydroxy group. The geometry optimization calculation of enol and keto forms in the ground and excited states of C1 provided tough theoretical evidences of ESIPT.     

Research on a Class of Equations over Finite Fields

Let F_q stand for the finite field of odd characteristic p with q elements(q=p~n,n∈N)and F_q~* denote the set of all the nonzero elements of F_q.In this paper,by using the augmented degree matrix and the result given by Cao,we obtain a formula for the number of rational points of the following equation over F_q:f(x _1,x _2,...,x _n)=(a_1 x_1 x_2~d+a_2 x_2 x_3~d...+a_(n-1)x_(n-1)x_n~d+a_n x_n x_1~d)~λ-bx_1~(d1)x_2~d2...x_n~(dn),with a_i,b∈F_q~*,n≥2,λ0 being positive integers,and d,d_i being nonnegative integers for 1≤i n.This technique can be applied to the polynomials of the form h_1~λ=h_2 with λ being positive integer and h_1,h_2∈F_q[x _1,x _2,...,x _n].It extends the results of the Markoff-Hurwitz-type equations.     

最大度是4的可平面图的边染色

对于最大度是Δ的可平面图G,如果χ′（G）=Δ称G为第一类图,如果χ′（G）=Δ＋1称G为第二类图,χ′（G）表示G的边染色数.1965年,Vizing举例说明,最大度是4的平面图中不仅有第一类图,也有第二类图.论文运用Discharge方法及临界图的重要性质证明：最大度是4,不含5圈和6圈,且任意两个相交面的度不相同的可平面图是第一类图.     

最大度是5的可平面图的边染色

对于最大度是Δ的可平面图G,如果χ′(G)=Δ,称G为第一类图;如果χ′(G)=Δ+1,称G为第二类图.χ′(G)表示G的边染色数.1965年,Vizing举例说明Δ=5的可平面图中既有第一类图,也有第二类图.作者运用Discharge方法证明最大度是5且不包含有弦的4-圈和有弦的5-圈,或不包含有弦的4-圈和有弦的6-圈的可平面图是第一类图.     

Domain interactions of H-2 class I antigens alter cytotoxic T-cell recognition sites

H-2 class I antigens appear to direct the recognition of virus-infected and neoplastic transformed cells by cytotoxic T lymphocytes (CTLs). Here, to identify the regions of class I antigens involved in CTL recognition, four hybrid class I genes were constructed in which exons were exchanged between the H-2Kb and H-2Db genes. These class I genes were expressed in mouse L cells and recognition of the hybrid Kb/Db antigens by CTLs and monoclonal antibodies specific for either Kb or Db was investigated. The pattern of CTL and monoclonal antibody recognition obtained indicates three correlations between structure and function of class I antigens. First, most CTL recognition sites and alloantigenic determinants are located on domains 1 and 2 of the antigen molecule. Second, these CTL recognition sites and alloantigenic determinants are not influenced by interaction of domains 1 and 2 with polymorphic regions of domain 3. Third, in contrast, interaction between domains 1 and 2 alters these CTL recognition sites and alloantigenic determinants. The alteration of CTL recognition sites by interaction between domains 1 and 2 suggests that a CTL site may be formed by amino acids from both domains 1 and 2, or that the conformation of amino acids at a CTL site may be altered by interactions between domains 1 and 2. Through these two features, the conformation of CTL recognition sites on H-2 class I antigens may be sensitive to alteration by interaction of either domain 1 or 2 with viral antigens.     

Gracefulness of several unconnected graphs with wheel

In the paper, we study the gracefulness of several unconnected graphs related to wheel. For natural number p ≥1,t ≥1, let n =2t +3, 2t +4, which proved W_n∪K_(p,t)~(1)∪K_(p,t)~(2) is graceful; for p ≥1, t ≥1,let n=2t+3,2t+4, then W_(n,2n+1)∪K_(p,t)~(1)∪K_(p,t)~(2) is graceful and for m≥1,r ≥1, let n =2m +5, W_(n,2n+1) ∪( C_3∨K m) U St( r)is graceful.     

Ham-2 corrects the class I antigen-processing defect in RMA-S cells.

The murine major histocompatibility complex (MHC) contains two genes (Ham-1 and Ham-2) that encode members of a super-family of ATP-dependent transport proteins. These genes are believed to mediate the transport of peptide antigen from the cytoplasm into the lumen of the endoplasmic reticulum for binding by MHC class I molecules. Evidence for such a function has come from the rescue of class I surface expression by a cloned copy of the human homologue of Ham-1, PSF-1, in a human cell line that is defective in antigen processing. A mutant murine cell line, RMA-S, has an identical antigen-processing-defective phenotype. Here we show that expression of a cloned copy of the Ham-2 gene in RMA-S cells results in recovery of the ability to process and present class I-restricted antigens to cytotoxic T lymphocytes, and in partial recovery of class I surface expression. Processing defects for classical (H-2 K and D) and non-classical (Qa1 and HMT) class I molecules are corrected by Ham-2. These data indicate that both MHC-linked transporter genes are probably required for class I antigen processing, and that the functional transporter in this pathway may consist of a Ham-1/Ham-2 heterodimer.     

New terpenoids from the roots of Jatropha curcas

Two new sesquiterpenoids,(1S,2R)-dihydroxycycloax-4(15)-ene(1),14-dehydroxyl daucucarotol(2),and one new rhamnofalane diterpenoid,2-hydroxy-3-dehydroxycaniojane(3),together with two known compounds,curcusone D(4) and curcusone C(5),were isolated from the roots of Jatropha curcas.The chemical structures of these compounds were established by chemical methods and extensive 1D-and 2D-NMR spectroscopic data analyses.     

Critical Chords of Convex Bodies of Constant Width

In this paper, we show that when Minkowski measure of asymmetry of convex body K of constant width is bigger than α (n-1), K has at least n+1 critical chords, where \(\alpha (n) = \frac{{n + \sqrt {2n(n + 1)} }}{{n + 2}}\).     

Ranks of repeated-root constacyclic code

By the discussion of division in \(F_{^{^{^{_2 m} } } } \left[ u \right]/\left\langle {u^4 } \right\rangle \), the minimal spanning set and the rank of a (1 + u + u ²) - constacyclic code with an arbitrary length N = 2 ^e n over \(\Phi \) are determined based on the factorization of (x ⁿ - 1) over \({F_{{2^m}}}\).