广西近海区棘皮动物的调查报告

本文根据1983月4月至1985年1月,在广西近海区(东经108°12′30″～109°41′、北纬20°53′45″～21°46′)进行底栖生物调查所获得的资料,主要阐述棘皮动物在广西近海区的组成、分布及季节变化: 1.本次调查共获棘皮动物标本10734个,共67种,分隶于5纲,11目,25科、44属。海参纲出现的种数最多。 2.棘皮动物的种数在平面分布上比较有规律,出现深水区高于浅水区的趋势。但其数量、生物量及栖息密度的分布很不规则,这主要与个别种出现量巨大有关。 3.棘皮动物在各季度总生物量平均值波动于2.83～6.35克/米~2之间,总平均为4.38克/米~2。总栖息密度平均值波动于26～145个/米~2之间,总平均为98个/米~2。 4.洼颚倍棘蛇尾(depressus)出现量最大,共获5976个,占棘皮动物总采获量的55.7％。     

Groundwater Mass Transport and Heterogenous Equilibrium Chemical Reaction-----A Kind of Free Boundary Problem

This paper considers another kind of chemical reaction different from [1]. The difference is that the chemical reactions under consideration are assumed to be heterogeneous,, fast, reversible.and classical. As a typical example, the author reduces this problem to an one phase Stefan problem with nohcommon data, and investigates the classical solution as well as the weak solution.     

AN OSCILLATION CRITERION FOR A DISCRETE ELLIPTIC EQUATION

ＡＮＯＳＣＩＬＬＡＴＩＯＮＣＲＩＴＥＲＩＯＮＦＯＲＡＤＩＳＣＲＥＴＥＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮ￥ＳｕｉＳｕｎＣｈｅｎｇ（ＴｓｉｎｇＨｕａＵｎｉｖｅｒｓｉｔｙ，ＴＡＩＷＡＮ，３００４３）Ａｂｓｔｒａｃｔ：Ａｎｏｓｃｉｌｌａｔｉｏｎｃｒｔｅｒｉｏｎ...     

体积全息图中光子禁带结构性质的分析

利用光子晶体的概念和方法，从理论上分析了一维全息图在再现光以不同角度入射情况下禁带结构的性质。分析表明，当再现光非正入射时，体积全息图的禁带结构是倾斜的，正入射时的非倾斜结构是倾斜结构的一个特例。     

A study on the nonstoichiometry of tin oxides by coulometric titration

In this investigation, nonstoichiometries and defect structures of tin oxides were studied between 694 and 990 K by coulometric titration using solid state electrolyte (YSZ) cells. The relationship between nonstoichiometry of the oxide (x) and equilibrium oxygen partial pressure (P_o2) was expressed by the proportionality: xP_O2^−1/6. An intermediate oxide phase, Sn₃O₄ between Sn and SnO₂ was observed in the temperature range of 696–732 K. The standard Gibbs energy of formation of Sn₃O₄ via the reaction; was found to be ΔG^o_Sn3O4 = −1163960+417.36 T (J/mol). The standard Gibbs energy change for the defect formation reaction in SnO_2−x was calculated to be ΔG^o_SnO2−x = 3.05×10⁵−38.97 T (J/mol)).     

OSCILLATION AND ASYMPTOTIC BEHAVIOR OF SOLUTIONS OF DELAY DIFFERENTIAL EQUATIONS WITH IMPULSES

ＯＳＣＩＬＬＡＴＩＯＮＡＮＤＡＳＹＭＰＴＯＴＩＣＢＥＨＡＶＩＯＲＯＦＳＯＬＵＴＩＯＮＳＯＦＤＥＬＡＹＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＷＩＴＨＩＭＰＵＬＳＥＳＳｈｅｎＪｉａｎｈｕａ（申建华）＆ＷａｎｇＺｈｉｃｈｅｎｇ（王志成）（ＨｕｎａｎＵｎ...     

A NECESSARY AND SUFFICIENT CONDITION FOR THE OSCILLATION OF HIGHER-ORDER NEUTRAL EQUATIONS WITH SEVERAL DELAYS

Consider the higher-order neutral delay differential equationd~t/dt~n(x(t)+sum from i=1 to lp_ix(t-τ_i)-sum from j=1 to mr_jx(t-ρ_j))+sum from k=1 to Nq_kx(t-u_k)=0,(A)where the coefficients and the delays are nonnegative constants with n≥2 even. Then anecessary and sufficient condition for the oscillation of (A) is that the characteristicequationλ~n+λ~nsum from i=1 to lp_ie~(-λτ_i-λ~n)sum from j=1 to mr_je~(-λρ_j)+sum from k=1 to Nq_ke~(-λρ_k)=0has no real roots.     

多组分食品色素的多波长分析

本文对五组分样品进行多波长定量分析。考虑了背景校正、截距校正,用用正交法设计校正标准溶液,分析准确度较高.     

Electron paramagnetic resonance study on Cu[(C6H11O)2PS2]2 complex single crystal

X-band EPR studies on Cu[(C₆H₁₁O)₂PS₂]₂ complex single crystal at room temperature were reported. The EPR spectrum shows that the hyperfine structure is produced by ⁶³Cu nuclei, and the ligand hyperfine structure by ³¹P nuclei. The spin-Hamiltonian parameters were rigorously calculated using a least-squares-fitting technique, specially adapted to noncoincident g and A tensors systems. The principal values of g tensor imply that Cu²⁺ occupies the site consisting of four ligands S, and is tetragonal symmetric, but the principal values of A tensor in Cu—S₄ plane reveal a large anisotropy caused by the presence of two ligands P. One of principal axes for g and A tensors is coincident, and they are perpendicular to the Cu—S₄ plane. It was found that the interaction between electron spin and ligands ³¹P nuclear spin is isotropic and the hyperfine-coupling constant A^P related ligands was obtained.     

Almost all rooted maps have large representativity

Let M be a map on a surface S. The edge-width of M is the length of a shortest noncontractible cycle of M. The face-width (or, representativity) of M is the smallest number of intersections a noncontractible curve in S has with M. (The edge-width and face-width of a planar map may be defined to be infinity.) A map is a large-edge-width embedding (LEW-embedding) if its maximum face valency is less than its edge-width. For several families of rooted maps on a given surface, we prove that there are positive constants C₁ and C₂, depending on the family and the surface, such that

• 1 almost all maps with n edges have face-width and edge-width greater than c₁ log n, and
• 2 the fraction of such maps that are LEW-embeddings and the fraction that are not LEW-embeddings both exceed n^{? >C2}.