Some inequalities for partial orders

We establish some inequalities connecting natural parameters of a partial order P. For example, if every interval [a,b] contains at most maximal chains, if some antichain has cardinality v, and if there are ₁ chains whose union is cofinal and coinitial in P, then the chain decomposition number for P is ₁v (Theorem 2.2), and the inequality is sharp in a certain sense (Section 3).This paper was written while the authors were visitors at the Laboratoire d'algèbre ordinale, Département de Mathématiques, Université Claude Bernard, Lyon 1, France.Research supported by NSERC grant # A5198.     

An introduction to covariant superstring field theories

A pedagogical account is given of the recent developments in covariant (super)string field theories. After reviewing the construction of the free open bosonic string field theory, the super-symmetric case is treated and the space-time supersymmetry transformations are explained. The present status and some future problems are also summarized.Invited talk presented at the International Conference Selected Topics in Quantum Field Theory and Mathematical Physics, Bechyn, Czechoslovakia, June 23–27, 1986.On leave of absence fromNational Laboratory for High Energy Physics (KEK), Tsukuba, Ibaraki, Japan.I would like to thank A. Neveu, H. Nicolai and P. West for many discussions, and the CERN Theoretical Physics Division for hospitality and generous support.     

Effects of surface nonlinear interactions on the local critical behavior

The energy spectrum and the wave functions of quantum wells in strong magnetic fields parallel to the potential walls are calculated analytically by means of a new, graph supported method. This Arrow Train Method allows to solve the recurrence relations which originate in the evaluation of eigenvalue determinants of infinite order. The energy eigenvalues for infinite barrier height are computed as a power series in the magnetic fieldB and the center of orbit coordinatez ₀. The power series is evaluated up to the 18th order inB ² for the first four levels and for cyclotron radii comparable to or considerable less than the well width. The corresponding wave functions and the field dependent center of mass shifts are obtained.Work supported in part by the Deutsche Forschungsgemeinschaft     

Cluster model study of lightp-shell Λ-hypernuclei with OBE-based effective ΛN interaction

The structures of the lightp-shell hypernuclei \({}_\Lambda ^6 He,{}_\Lambda ^7 Li,{}_\Lambda ^9 Liand{}_\Lambda ^9 Be\) are studied by using a realistic effectiveΛN interaction (YNG), and compared to those with the use of the simple one-range Gaussian (ORG) interaction. The YNG interaction, which simulates theΛNG-matrix for the Nijmegen OBE modelD, is characterized by the inner repulsive core and the density-dependence along with the space-exchange and spin-spin components. The framework we adopt is the microscopic α +x + Λ (x=n, d, t or α) three-cluster model, where nucleon antisymmetrization is exactly treated. The characteristic behaviors ofΛ?x andΛ?(αx) interactions derived from the YNG are displayed and discussed. In spite of the remarkable characteristic of YNG, the calculated energy levels of the four hypernuclei are very similar to those previous obtained by using the simple ORG interaction. The stabilization and contraction of the hypernuclear system due to the glue-like role ofΛ-particle persists in the present calculation, though the repulsive core of theΛN interaction tends to prevent from too much contraction.     

A new C21-steroidal glycoside from Cynanchum stauntonii

A new C21-steroidal glycoside with two known compounds were isolated from the root of Cynanchum Stauntonii.Based on thespectral analysis,including MS,1H NMR,13C NMR,DEPT,1H-1H COSY,13C-1H COSY,HMQC and HMBC,their chemicalstructures were determinated as glaucogenin-C 3-O-a-L-cymaropyranosyl-(1→4)-b-D-digitoxopyranosyl-(1→4)-β-D-canaropyranoside(1),stigmasterol(2)and ursolic acid(3).     

Alkylation of benzene with 1-hexene in acidic ionic liquid systems: Et3NHCl-FeCl3and Et3NHCl-AlCl3ionic liquids

Summary The alkylation of benzene with 1-hexene has been investigated in different triethylamine hydrochloride-ferric chloride (Et₃NHCl-FeCl₃) and triethylamine hydrochloride-aluminium chloride (Et₃NHCl-AlCl₃) ionic liquids. Both high catalyst activity and monoalkylation selectivity were observed for these two type of ionic liquids. Systems prepared by modification with HCl in Et₃NHCl-FeCl₃ionic liquids prove to be very suitable solvents and catalysts for the reaction. When employing Et₃NHCl-AlCl₃ionic liquids as catalysts, the reaction takes place in biphasic mode with facile catalyst separation and catalyst recycling.     

Inclusive ϕ production inK − p interactions at 110 GeV/c and search for structure in φ π−

Results on inclusive ? production inK ^? p interactions at 110 GeV/c are presented. The production cross section is found to be larger than in πp andpp interactions at similar energies, suggesting OZI allowed \(s\bar s\) fusion to be the dominant mechanism in ? production. Thex distributions of ? and \(\bar K^{*0} \) are found to be similar to each other over the entirex range suggesting an overall strangeness suppression factor of 0.20±0.04 in the sea to be the dominant source of the difference in the cross section for ? and \(\bar K^{*0} \) . There is no evidence of a narrowφπ ^? state around 2.1 GeV/c² as suggested byK ⁺ experiments, but there is some excess of events in the region 1.94?1.98 GeV/c² consistent with theF-meson mass as observed ine ⁺ e ^? experiments.     

喹喔啉—2,3—二甲酰胺与3d过渡金属配合物的合成及性质研究

首次合成了喹喔啉－２，３－二甲酰胺（Ｑｘｄａ）与３ｄ过渡金属的三种固体配合物：Ｍ（Ｑｘｄａ）２ｃｌ２（Ｍ＝Ｃｏ（Ｉ），Ｎｉ（Ｉ），Ｃｕ（Ⅱ）。通过元素分析，摩尔电导，红外光谱，电子光谱，磁化率，热分析等手段对配合物的组成和性质进行了研究。