RELATIVE REACTIVITIES OF THE EXCITED STATES OF FUROCOUMARINS FOR [2+2] PHOTOCYCLOADDITION REACTION WITH TETRAMETHYLETHYLENE

Abstract— The Stern-Volmer constants for fluorescence quenching by tetramethylethylene decrease in the order DMC ≫ DHP > F-2 > 8-MOP. The same order was observed for the quantum yields of [2+2] cycloaddition reaction with tetramethylethylene on direct irradiation. In [2+2] photocycloaddition of F-2 with tetramethylethylene in ethanol, the ratio of quantum yields deduced from singlet and triplet states of F-2; φ₃⁰/φ₁⁰, is about 5. The excited triplet state is the reactive state for the [2+2] photocycloaddition of F-2 with tetramethylethylene in solution but the excited singlet state of F-2 becomes very important in biological conditions.     

A GENERALIZATION OF BOYD'S INTERPOLATION THEOREM

Boyd's interpolation theorem for quasilinear operators is generalized in this pa-per,which gives a generalization for both the Marcinkiewicz interpolation theor...     

Development of an RPLC-based Method for Measurement of Indoprofen Stability and Validation of the Method

A method for quantitative measurement of the photochemical decomposition of the anti-inflammatory agent, indoprofen （INP） is descriped. An RPLC-based assay that could determine the extent of degradation of INP in a rapid, sensitive, and accurate manner was developed. The method was validated under photoirradiation. Quantitation was monitored with an Inertsil ODS-3V column using a mobile phase of acetonitril and 1% HOAc solution in deionized H2O. Statistics relevant to the system criteria, peak integrity and resolution among the parent drug and its degradation products were performed. From the intra- and inter-day tests, the coefficients of variation were found to range from 0.59% to 4.25% for the former and from 0.71% to 4.86% for the latter. The good selectivity and specificity of this RPLC-based procedure render it suitable for measurements of INP stability.     

银袋内酯乙的乙酰化物的晶体结构和分子结构

本文报道从变色马兜铃(Aristolochia versicolar)的块根中提取的一种新倍半萜内酯-银袋内酯乙的乙酰化物的晶体结构和分子结构.分子式为C~17H~22O~4,分子量290.4,晶体属单斜晶系,空间群为P2~1,a=0.9594(5),b=0.6626(6),c=1.2924(12)um,β=94.48(6)`,V=0.819(1)nm^3,Z=2,Dx=1,18g.cm^-^3,F(000)=266e,μ=0.77cm^-^1(MoKa).结构用直接法解出,经最小二乘法修正后1280个衍射点偏离因子为R=5.5%,Rw=5.2%.分子由椅型.椅型的1,5二烯十员环([2323]矩形)和共用两个相邻DunitzIII型碳C(4),C(5),一个Dunitz II型碳C(6)的五员内酯环组成.十员环与五员内酯环之间夹角为99.该分子骨架拓扑在迄今已知的倍半萜内酯中只与银袋内酯丙相似.所有非氢原子的键长和键角均在实验误差范围内接近理论值。     

ON THE NEUTRINO MASS,THE ABUNDANCE OF RIGHT-HANDED NEUTRINO AND THE CLOSENESS OF THE UNIVERSE

We point out that although the neutrino mass is finite,the left-handed neutrino density still dominates over the righthanded one in the universe unless there exists one or more elementary fernions (quark or lepton) whose mass is larger than 10⁶ GeV. or M_WR/M_WL≤10². (M_WLand M_WR are the left and right handed intermediate boson respectively.If there exists neutrino the mass of which is about 34 ev. as indicated in some experiments, then one can conclude that the total neutrino mass of the universe s,bvld contribute abput 99%. to the whole masses and lead to the closeness of the universe.This conclusion can be brought to the agreement of all observation datd which have been-obtained so far. A mass limit of all species of neutrinos obtained by reexamining all data is ≤ 200 eV.     

The maximum balanced subgraph of a signed graph: Applications and solution approaches

The Maximum Balanced Subgraph Problem (MBSP) is the problem of finding a subgraph of a signed graph that is balanced and maximizes the cardinality of its vertex set. This paper is the first one to discuss applications of the MBSP arising in three different research areas: the detection of embedded structures, portfolio analysis in risk management and community structure. The efficient solution of the MBSP is also in the focus of this paper. We discuss pre-processing routines and heuristic solution approaches to the problem. a GRASP metaheuristic is developed and improved versions of a greedy heuristic are discussed. Extensive computational experiments are carried out on a set of instances from the applications previously mentioned as well as on a set of random instances.     

ON THE REACTION MECHANISM AND THE SELECTION RULE IN THE DOUBLE CHARGE EXCHANGE REACTION OF PIONS ON NUCLEI (DCX)-A STUDY OF THE CONNECTION BETWEEN THE 2β-DECAY AND DCX ON jP=O+ NUCLEI

It is shown that in the pion induced double charge exchange reaction on J^p=O⁺→O⁺ nuclei,there exists a possible new reaction mechanism π⁺(Δ⁰,Δ⁺⁺)π^- or π⁺(Δ^-,Δ⁺)π^- in so-called single step process,while that old speculative mechanism π⁺(N,Δ)π^- or π⁺(N,Δ)π^- is firbidden by a well-known selection rule which has been indicated in the theory of the nuclear 2β-decay.     

INFORMATION ABOUT SUBQUARK FROM EXPERIMENTS ON SUPERNIGH ENERGY COSMIC RAY

In this paper a kind of fireball model for subquark stratum is proposed, which can be used to explain the cosmic ray experiments for superhigh energy range, e. g., the mean multiplicity of secondary particles increases as S increases average transversal momentum ⊥> increases as S increases …etc. It can also give predictions which can be verified experimentally. This means that the information of the existence of subquark can be probed in the experiments on superhigh energy cosmic ray. Furthermore, this also means that some new phenomena observed in the experiments. on superhigh energy cosmiq ray provide. probably this kind of information.