麋鹿茸、马鹿茸和梅花鹿茸营养成分的分析比较研究

对麋鹿茸,马鹿茸,梅花鹿茸中的水分,粗蛋白,粗脂肪,膳食纤维,水溶性和脂溶性维生素,氨基酸和无宏量及微量元素进行了测定,和比较,结果表明,麋鹿茸与马鹿茸和梅花鹿茸的化学分成及含量相近,鹿鹿茸中膳食纤维和必需无机元素含量高于其它两种鹿茸,填补了麋鹿研究的空白,为鹿资源的保护,发展,开发和利用提供了营养学依据。     

Laser Ablation Inductively Coupled Plasma Mass Spectrometry for Determination of Trace Elements in Geological Glasses

 Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used as a powerful multielement analytical method for trace analysis of geological glasses which are useful as reference materials for geochemical in-situ microanalytical work. The quantification of the analytical results was carried out using the BCR-2G and NIST 612 glass standard reference material (SRM). The experimentally determined relative sensitivity coefficients (RSC) for both SRMs vary between 0.2 and 3 for most of the elements, with increasing mass an increasing of relative sensitivity coefficients was observed. The relative standard deviation (RSD) for determination of trace element concentration of most elements (N=3) are between 2 and 10%. The determination of trace elements in various geological glasses by LA-ICP-MS yielded a good agreement with the reference values and those results of other trace analytical methods. Received October 15, 1999. Revision April 14, 2000.     

小儿佝偻病血中微量元素的观察

对７１例确诊为不同阶段的佝偻病患儿同时进行观察血液中微量元素锌、铜、铅以及血清钙、磷、碱性磷酸酶的变化。结果表明，佝偻病组的血铸、血钙、血磷均低于正常组，血铅、ＡＫＰ高于正常组，血铜则两组无大差异，但铜／锌比值正常组为０．２２±０．６３明显低于佝偻病组０．３６±０．５５，ｔ＝３．２０，Ｐ＜０．０５．各期佝偻病微量元素的变化与正常儿对比，在佝偻病的初期血磷略低于正常，血锌明显减少，碱性磷酸酶升高。在疾病的激期钙、磷、锌明显低于正常，碱性磷酸酶及铅升高，恢复期各元素基本恢复正常。     

Multi-element characterization of silicon nitride powders by atomic and mass spectrometric solution methods

A sample pretreatment technique for silicon nitride involving digestion and matrix/traces separation was developed by means of radiotracers and applied to analysis of this material by inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry and graphite furnace atomic absorption spectrometry. The results obtained for a high purity silicon nitride material by these methods are compared each with the other and with those obtained by neutron activation analysis. The limits of detection and the capabilities of the methods are compared and discussed.     

合成丙交酯中微量水分分析

合成丙交酯中微量水分分析徐溢，柳胜春（重庆大学化工学院分析教研室６３００４４）关键词丙交酯，微量水，定量分析丙交酯是人工合成骨材料聚乳酸的合成中间体，其性能决定着合成产品的品质，要获得高质量的合成材料，对中间体的分析和监测十分重要。一般要求丙交酯中间...     

Stepwise annealing of poly(butylene terephthalate)

Annealing of poly(butylene terephthalate) (PBT) was studied by differential scanning calorimetry (DSC) and small angle X‐ray scattering (SAXS) measurement. A PBT sample was annealed at a recrystallization temperature where recrystallization occurs with a maximum rate in the heating process of the sample. In the subsequent annealing steps, the annealed sample was annealed repeatedly at the recrystallization temperatures, and the stepwise annealing sample was obtained. Peak melting temperature (T_m) and sharpness of DSC peak of the stepwise annealing sample increased with the annealing step. A high melting‐temperature sample was obtained in a short time, and T_m increased up to 238.5°C which is higher than all the T_m values that appear in the literature. The long period calculated from SAXS curves of the stepwise annealing sample increased with the annealing step. The increase of crystallite size and perfection of the crystal in the stepwise annealing process is suggested. Annealing experiment indicated that T^°_m should be higher than about 235°C. T_m increased linearly with the annealing temperature of the final step in the stepwise annealing (T_a). The equilibrium melting temperature (T^°_m) for PBT was estimated to be 247°C by the application of a Hoffman–Weeks plot to the relation between T_m vs. T_a. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2420–2429, 1999     

Synthesis and properties of aromatic polyimides derived from 2,2,′3,3′‐biphenyltetracarboxylic dianhydride

2,2,′3,3′‐Biphenyltetracarboxylic dianhydride (2,2,′3,3′‐BPDA) was prepared by a coupling reaction of dimethyl 3‐iodophthalate. The X‐ray single‐crystal structure determination showed that this dianhydride had a bent and noncopolanar structure, presenting a striking contrast to its isomer, 3,3,′4,4′‐BPDA. This dianhydride was reacted with aromatic diamines in a polar aprotic solvent such as N,N‐dimethylacetamide (DMAc) to form polyamic acid intermediates, which imidized chemically to polyimides with inherent viscosities of 0.34–0.55 dL/g, depending on the diamine used. The polyimides from 2,2,′3,3′‐BPDA exhibited a good solubility and were dissolved in polar aprotic solvents and polychlorocarbons. These polyimides have high glass transition temperatures above 283°C. Thermogravimetric analyses indicated that these polyimides were fairly stable up to 500°C, and the 5% weight loss temperatures were recorded in the range of 534–583°C in nitrogen atmosphere and 537–561°C in air atmosphere. All polyimides were amorphous according to X‐ray determination. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1425–1433, 1999     

Synthesis and characterization of arsacycloalkanes and their palladium and platinum complexes,and X‐ray structure of [PdCl2(PhAsCH2CH2CH2CH2CH2)2]

Reactions of PhAsCl₂ with BrMg(CH₂)_nMgBr (n = 4 or 5) in THF gave phenylarsacycloalkanes as colourless oily liquids which could be distilled under vacuum. Treatment of PhAs(CH₂)_n­with MCl₂(RCN)₂ (M = Pd or Pt; R = Ph­or Me) afforded mononuclear complexes, [MCl₂{PhAs(CH₂)_n}₂]. Reactions with [Pt₂Cl₂(μ‐Cl)₂(PEt₃)₂] gave mixed‐ligand complexes, [PtCl₂(PEt₃){PhAs(CH₂)_n]. The palladium complexes adopt a trans geometry whereas the platinum complexes exist in a cis configuration. The crystal and molecular structure of [PdCl₂(PhAsCH₂CH₂CH₂CH₂CH₂)₂] was determined by X‐ray diffraction methods. The molecule consists of a square‐planar palladium atom with trans chlorides and trans arsa ligands. The six‐membered ‘AsC₅′ ring adopts a chair conformation. Copyright © 1999 John Wiley & Sons, Ltd.     

Flexural properties of fiber‐reinforced polypropylene composites with and without a transcrystalline layer

The flexural properties of isotactic polypropylene (PP) matrix composites reinforced with 5–30 vol% of unidirectional pitch‐based carbon, polyacrylonitrile (PAN)‐based carbon, e‐glass or aramid fibers were measured using both static and dynamic test methods. Previous research has shown that these pitch‐based carbon and aramid fibers are capable of densely nucleating PP crystals at the fiber surface, leading to the growth of an oriented interphase termed a “transcrystalline layer” (TCL), while the e‐glass and PAN‐based carbon fibers show no nucleating ability. The PP matrices examined included unmodified homopolymers, nucleated homopolymers and PP grafted with maleic anhydride (MA). The composites based on the unmodified PP homopolymers all exhibited poor fiber/matrix adhesion, regardless of fiber type and presence or absence of a TCL. The addition of nucleating agent to the PP matrix had no measurable effect on either the amount of TCL material in pitch‐based carbon‐fiber‐reinforced composites, as measured by wide‐angle X‐ray scattering, WAXS, or the static flexural properties of the composites reinforced with either type of carbon fiber. However, MA grafting reduced the transcrystalline fraction of the matrix in pitch‐based carbon‐fiber‐reinforced composites; at the highest level of MA grafting, the TCL was completely suppressed. In addition, high levels of MA grafting improved the transverse flexural modulus of the composites containing both types of carbon fibers, and reduced the extent of fiber pull‐out, indicating an improvement in fiber/matrix adhesion. Copyright © 1999 John Wiley & Sons, Ltd.     

[Co(g5‐Me5C5)(g3‐tBu2PPCH–CH3)] aus [Co(g5‐Me5C5)(g2‐C2H4)2] und tBu2P–P=P(Me)tBu2

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XVII [1] [Co(g⁵‐Me₅C₅)(g³‐^tBu₂PPCH–CH₃)] from [Co(g⁵‐Me₅C₅)(g²‐C₂H₄)₂] and ^tBu₂P–P=P(Me)^tBu₂ [Co(η⁵‐Me₅C₅)(η³‐^tBu₂PPCH–CH₃)] 1 is formed in the reaction of [Co(η⁵‐Me₅C₅)(η²‐C₂H₄)₂] 2 with ^tBu₂P–P 4 (generated from ^tBu₂P–P=P(Me)^tBu₂ 3 ) by elimination of one C₂H₄ ligand and coupling of the phosphinophosphinidene with the second one. The structure of 1 is proven by ³¹P, ¹³C, ¹H NMR spectra and the X‐ray structure analysis. Within the ligand ^tBu₂P¹P²C¹H–CH₃ in 1 , the angle P1–P2–C1 amounts to 90°. The Co, P1, P2, C1 atoms in 1 look like a „butterfly”︁. The reaction of 2 with a mixture of ^tBu₂P–P=P(Me)^tBu₂ 3 and ^tBu–C?P 5 yields [Co(η⁵‐Me₅C₅){η⁴‐(^tBuCP)₂}] 6 and 1 . While 6 is spontaneously formed, 1 appears only after complete consumption of 5 .