O～3岁儿童微量元素检测及纠正150例观察与体会

对西安地区150例0～3岁儿童进行了六种微量元素：钙、锌、铜、铁、镁、硒的检测，发现微量元素缺乏可导致急慢性感染、免疫力低下、小儿营养不良、贫血、发育迟缓等症状。并对小儿营养不良、喂养不当进行矫正。其中铁、钙、锌同时缺乏占50％。     

速差催化动力学光度法同时测定痕量PO_4~(3-)和AsO_4~(3-)

首次基于和对Zr（Ⅳ）－MTB－CTMAB及Zr（Ⅳ）－MTB－CTMAB－LA体系不同的催化作用，建立了同时测量痕量和的速差催化动力学光度分析法。研究了24种共存离子的影响。对与质量比为1～7的标准混合样品进行了测定，相对误差小于10％。     

A class of (4,2)-disk pairs which are trivial

Suppose Δ?S³ is a ribbon disk and let D (Δ) denote the cononical properly embedded 2-disk obtained by pushing the interior of Δ into B⁴. A well-known conjecture states that the disk pair (B⁴, D(Δ)) is trivial provided the sphere pair ?(B⁴, D(Δ)) is trivial. We show here that the conjecture is true for those D(Δ) with the property that there is an embedded 2-disk, D²?S³, whose boundary is ?D(Δ) and which intersects Δ in ‘transverse double points’.     

The 6-property for simplicial complexes and a combinatorial Cartan-Hadamard theorem for manifolds

The 6-property for 2-dimensional simplicial complexes is the condition that every nontrivial circuit in the link of a vertex has length greater than or equal to six. If a compact -manifold has a 2-dimensional spine with the 6-property, then we show that the interior of is covered by euclidean -space. In dimension , we show further that such a 3-manifold is Haken.

     

Magnetic Properties of Nanoparticles Useful for SQUID Relaxometry in Biomedical Applications

We use dynamic susceptometry measurements to extract semiempirical temperature-dependent, 255-400 K, magnetic parameters that determine the behavior of single-core nanoparticles useful for SQUID relaxometry in biomedical applications. Volume susceptibility measurements were made in 5 K degree steps at nine frequencies in the 0.1-1000 Hz range, with a 0.2 mT amplitude probe field. The saturation magnetization (M_s) and anisotropy energy density (K) derived from the fitting of theoretical susceptibility to the measurements both increase with decreasing temperature; good agreement between the parameter values derived separately from the real and imaginary components is obtained. Characterization of the Néel relaxation time indicates that the conventional prefactor, 0.1 ns, is an upper limit, strongly correlated with the anisotropy energy density. This prefactor decreases substantially for lower temperatures as K increases. We find, using the values of the parameters determined from the real part of the susceptibility measurements at 300 K, that SQUID relaxometry measurements of relaxation and excitation curves on the same sample are well described.     

Two Comments Concerning the Uniqueness of Prime Factorizations for 3-Manifolds

The proof of the uniqueness of prime factorizations of non-orientable3-manifolds appearing in Hempel's text is patched.