过剩热焓松弛CO_2和甲苯在PET薄膜中渗透的影响

本文研究了非晶态、未取向PET薄膜样品在低于T_g温度以下热处理,结构的变化和过剩热焓松弛对CO_2和甲苯溶剂在样品中渗透速率的影响。结果表明,随退火时间增加,从T_g转变吸热峰确定的过剩热焓松弛量、 T_g温度、密度增加,而反式构象含量减少。除分子链堆砌密度提高或自由体积下降外,没有发现非晶相有结构上的变化。因此,CO_2在样品中随退火时间的增加渗透速率下降。然而,由于样品脆性增加和甲苯的溶胀作用,样品表面出现裂纹,使甲苯在样品中的表观渗透速率增加。     

Monte Carlo calculations of the mean squared force in molecular liquids

The mean squared intermolecular force (F²₁) on a molecule in a diatomic liquid has been evaluated by a Monte Carlo calculation at reduced density p^* = 0.8 and reduced temperature 7^* = 0.72. The isotropic intermolecular potential is of Lennard-Jones form; anisotropic multipolar and overlap potentials of various strengths are used. For the largest strengths studied, the anisotropic contribution to (F²₁) is about 50–60% of the isotropic one.     

350例儿童血液中微量元素铁、锌、钙、硒临床分析

临床观察了350例儿童血液微量元素铁、锌、钙、硒缺乏对儿童生长发育的影响。观察结果表明，此350例患儿存在不同程度的微量元素缺乏。其中硒的缺乏最为严重，达91．7％；钙缺乏达85，7％；锌缺乏达25．4％。350例儿童均存在不同程度的生长发育迟缓和多汗、厌食、头发稀少和反复呼吸道感染、贫血、佝偻病等。     

乳腺疾病患者发中微量元素含量分析

用原子吸收法对 765名乳腺疾病患者发中的Ca、Mg、Cu、Fe、Zn、Se含量进行了测定。结果表明 ,患者头发中Zn、Fe、Cu、Mg的含量均在正常范围内 (P >0 0 5 ) ;而头发中Ca含量明显高于正常值 (P >0 0 1 ) ,发Se含量明显低于正常值。提示乳腺疾病与硒低钙高有明显关系     

N′-(取代嘧啶-2-基)-N-菊酰硫脲的合成与生物活性研究

采用活性基团拼接法, 将第一菊酸构型中的最高活性组分(＋)-反式菊酸以及二氯菊酸引入到含取代嘧啶环的酰基硫脲结构中, 合成了5个未见文献报道的N′-(取代嘧啶-2-基)-N-(＋)-反式菊酰硫脲衍生物(3a～3e)和3个均未见文献报道的N′-(取代嘧啶-2-基)-N-二氯菊酰硫脲(3f～3h), 结构经元素分析、IR和¹H NMR得到确证. 初步的生物活性测试结果表明: 大部分化合物具有较好的杀菌活性, 有的化合物兼具除草和杀菌活性, 有的化合物兼具杀虫和杀菌活性.     

Argon and nitrogen adsorption in disordered nanoporous carbons: simulation and experiment

We report experimental measurements of the isosteric heats of adsorption for argon and nitrogen in two microporous saccharose-based carbons, using a Tian-Calvet microcalorimeter. These data are used to test recently developed molecular models of these carbons, obtained by a constrained reverse Monte Carlo method. Grand canonical Monte Carlo simulation is used to calculate the adsorption isotherms and isosteric heats for these systems, and the results for the latter are compared to the experimental data. For argon, excellent quantitative agreement is obtained over the entire range of pore filling. In the case of nitrogen, very good agreement is obtained over the range of coverage 0.25 < or = gamma/gamma 0 < or = 0.85, but discrepancies are observed at lower and higher coverages. The discrepancy at low coverage may be due to the presence of oxygenated groups on the pore surfaces, which are not taken into account in the model. The differences at high coverage are believed to arise from the presence of a few mesopores, which again are not included in the model. Pair correlation functions (argon-carbon and argon-argon) are determined from the simulations and are discussed as a function of pore filling. Snapshots of the simulations are presented and provide a picture of the pore filling process.     

分馏萃取提纯金的方法研究

本文报道了在常温条件下,用磷酸三丁酯(TBP)做萃取剂,反萃取金的分馏萃取提纯金的工艺方法,使金的纯度、回收率大大提高。该项技术既可降低投资成本,且适用于金矿自动化及规模化连续生产。     

S~1×S~1-INDEX THEORY ON PRODUCT SPACE

1.IntroductionLetGbeacompactLiegroupandlet{T(g)}.EGbeanisometricrepresentationofGoveraBanachspaceX.Anindex(for{T(g)}..G)isamappingfromtheclosedinvariantsubsetofXintoNU{ co}suchthat(i)indA=0ifandonlyifA=0;(n)ifR:A-Bisequivariantandcontinuous,thenmdASmdB;(iii)ifAiscompactinvariant,thereisaclosedinvarialltneighborhoodNofAsuchthatmdN~mdA;(tv)md(AUB)5mdA mdBforallinvariantsubsetsAandB.Itiswellknownthatindextheories,especiallyZZ-indextheoryandSI-indextheory,areveryusefulinthestudyofth…     

一类非线性扩散系统非平凡非负周期解的存在性

In this paper,by the method of upper and lower solutions,we establish the existence of the non-trivial nonnegative periodic solutions for a class of degenerate diffusion system arising from dynamics of biological groups.