Gas permeation properties of cardo polyaryletherketones containing different alkyl substituents

The gas permeation properties of a series of cardo polyaryletherketone materials are reported, In this series, the hydrogen atoms of benzene rings on the backbone are systematically replaced with different alkyl substituents. The effects of temperature and structure variation on gas permeability and selectivity are discussed in detail. The experimental results revealed that the polyetherketone obtained by the introduction of dimethyl and diisopropyl substituents to phenolphthalein unit is 3 similar to 6 times more permeable than the unmodified one for the gases studied.

Structure of hydrated dysprosium picolinate, [Dy(C5H4NCO2)(3)(H2O)(2)]2.8H(2)O

The crystal structure of the title compound was determined by X-ray diffraction. The dysprosium ion is eight-coordinated by three oxygen atoms and three nitrogen atoms from three picolinato ions and two water oxygen atoms. The nitrogen atom and one carboxyl oxygen atom of each picolinato ion are coordinated to the same dysprosium ion to form a five-membered chelating ring. The title compound exists as discrete molecules in the crystal structure.

含不同取代基的Cardo聚芳醚酮的气体透过性能

研究了带有不同烷基取代基的Ｃａｒｄｏ聚芳醚酮均质膜对Ｈ２、Ｏ２、Ｎ２、ＣＯ２和ＣＨ４气体的透气性能，讨论了气体透过对温度的依赖性。与未改性酚酞聚芳醚酮相比，在主链苯环上引入异丙基侧基会使气体透过系数提高３～６倍；每个结构单元苯环被４个甲基取代后，气体透过系数和选择分离系数同时得到较大改善，其中Ｈ２的透过系数为２２ｂａｒｒｅｒ，Ｈ２／Ｎ２分离系数为１１４。

交替马来酸酐共聚物多缩乙二醇酯盐络合物的离子传导性

交替马来酸酐共聚物多缩乙二醇酯盐络合物的离子传导性丁黎明，林云青，周子南，王佛松（中国科学院长春应用化学研究所，长春，１３００２２）关键词高分子固体电解质，离子电导率，玻璃化转变温度，离子传输，ＶＴＦ方程１９７３年，Ｐ．Ｖ．Ｗｒｉｇｈｔ等人［１］首次...

Dietary-morphological relationships of fishes in Liangzi Lake, China

Species in Liangzi Lake were clustered into four trophic groups: Hemiramphus kurumeus and Hemiculter bleekeri bleekeri fed predominantly on terrestrial insects; Carassius auratus auratus and Abbottina rivularis on non-animal food; Hypseleotris swinhonis, Ctenogobius giurinus, Pseudorasbora parva and Toxabramis swinhonis on cladocerans or copepods; Culterichthys erythropterus on decapod shrimps. Gut length, mouth width, mouth height, gill raker length and gill raker spacing, varied widely among species. With the exception of three species pairs (H. swinhonis, C. glurinus; C. erythropterus, H. kurumeus; T. swinhonis, H. bleekeri bleekeri), principal components analysis of morphological variables revealed over-dispersion of species. Canonical correspondence analysis of dietary and morphological data revealed five significant dietary-morphological correlations. The first three roots explained > 85% of the total variance. The first root reflected mainly the relationship of gut length to non-animal feud, with an increase in gut length associated with an increase in non-animal food. The second root was influenced strongly by the relationship of the gill raker spacing to consumption of copepods, with an increase in gill raker spacing associated positively with copepods in the diet. The third root was influenced by the relationship of mouth gape to consumption of fish and decapod shrimps, with an increase in mouth gape associated with more fish and decapod shrimps in the diet. These significant dietary-morphological relationships supported the eco-morphological hypotheses that fish morphology influence food use, and morphological variation is important in determining ecological segregation of co-existing fish species. (C) 2001 The Fisheries Society of the British Isles.

Seasonal and interannual variability of primary and export production in the South China Sea: a three-dimensional physical-biogeochemical model study

To investigate the seasonal and interannual variations in biological productivity in the South China Sea (SCS), a Pacific basin-wide physical - biogeochemical model has been developed and used to estimate the biological productivity and export flux in the SCS. The Pacific circulation model, based on the Regional Ocean Model Systems (ROMS), is forced with daily air-sea fluxes derived from the NCEP (National Centers for Environmental Prediction) reanalysis between 1990 and 2004. The biogeochemical processes are simulated with a carbon, Si(OH)(4), and nitrogen ecosystem (CoSiNE) model consisting of silicate, nitrate, ammonium, two phytoplankton groups (small phytoplankton and large phytoplankton), two zooplankton grazers (small micrograzers and large mesozooplankton), and two detritus pools. The ROMS-CoSiNE model favourably reproduces many of the observed features, such as ChI a, nutrients, and primary production (PP) in the SCS. The modelled depth-integrated PP over the euphotic zone (0-125 m) varies seasonally, with the highest value of 386 mg C m (-2) d (-1) during winter and the lowest value of 156 mg C m (-2) d (-1) during early summer. The annual mean value is 196 mg C m (-2) d (-1). The model-integrated annual mean new production (uptake of nitrate), in carbon units, is 64.4 mg C m (-2) d (-1) which yields an f-ratio of 0.33 for the entire SCS. The modelled export ratio (e-ratio: the ratio of export to PP) is 0.24 for the basin-wide SCS. The year-to-year variation of biological productivity in the SCS is weaker than the seasonal variation. The large phytoplankton group tends to dominate over the smaller phytoplankton group, and likely plays an important role in determining the interannual variability of primary and new production.

高寒湿地生态系统土壤有机物质补给及地-气CO_2交换特征

海北高寒湿地植物地上、地下生物现存量较高，2004年海北高寒湿地植物净初级生产力为1799．7gC•m~(-2)．由于家畜对湿地植物采食量低，每年将有大量的枯黄植物残留于地表，表现出地上、地下生物量以及苔鲜均成为土壤有机物质的补给源．由于区域温度低，积水严重，对植物残体分解缓慢，导致湿地土壤有机质含量很高，形成了厚达2m左右的泥炭层．观测结果表明，海北高寒湿地净生态系统CO_2交换量具有明显的季节变化，年内4月和10月存在两个CO_2释放高峰期，夏季的7～8月为一个强吸收期，全年来看为一个巨大的碳源．2004年净生态系统年碳交换量为76．7gC•m~(-2)．计算结果表明，植被的呼吸消耗量每年为1199．8gC•m~(-2)，其植物总固碳量为2999．5gC•m~(-2)，而土壤呼吸为1876．4gC•m~(-2)．

机器人多级自适应控制器的设计与数字仿真

本文提出了用多级自适应控制的方法实现机器人关节系统的自适应控制,并给出了两级自适应控制器的设计方法.最后以某机器人关节系统为对象对两级自适应控制器进行了仿真分析.

图像图形文字混合处理系统PANDA的设计与实现

本文描述了图像、图形、文字混合处理系统PANDA的设计与实现技术。详细讨论了PANDA系统的数据结构组织方法,其中包括多文件、多窗口处理的结构设计以及动态的数据结构设计,同时给出了PANDA系统在其实现过程中所使用的一些关键处理技术。

岩溶生态系统的土壤特性及其今后研究方向

岩溶石漠化退化土地是目前西南岩溶地区经济发展、生态恢复与重建工作中严重的问题之一。由于岩溶生态系统的独特性和脆弱性, 岩溶生态系统土壤具有不同于其它生态脆弱区土壤的特征, 本文将其归纳为成土速率决定的在人类活动尺度下土壤不可再生性即脆弱性、土壤侵蚀(土层丢失) 的独特性、土壤退化过程中空间分布的斑块化及其与岩性的相关性、土壤退化过程中有机碳活性成分下降和来源变化、土壤退化导致岩溶生态系统生态过程中断。因此, 在退化岩溶生态系统的研究中, 要加强对岩溶生态系统土壤特性及退化恢复理论的研究。

胡敏酸的结构特征及其吸附行为

使用0. 5 mol/L NaOH和0. 1 mol/L Na4 P2O7 溶液分别从土壤中提取胡敏酸,并且对其进行了元素分析、红外光谱、固态13C核磁共振的定性、定量研究。结果表明,两种胡敏酸的性质很相似,但也存在一些微小差异,Na4 P2O7 提取的胡敏酸比NaOH提取的具有芳香度较大、聚合度较高、极性官能团含量较多的特点。测定了菲在6个胡敏酸上的吸附等温线, Freundlich模型很好的拟合了所有吸附等温线,相关系数r均在0. 992以上。有机碳分配系数Koc与胡敏酸中极性碳(POC)之间存在明显的线性相关关系,并受到提取剂类型的影响。

Foundations of Actor Semantics

The actor message-passing model of concurrent computation has inspired new ideas in the areas of knowledge-based systems, programming languages and their semantics, and computer systems architecture. The model itself grew out of computer languages such as Planner, Smalltalk, and Simula, and out of the use of continuations to interpret imperative constructs within A-calculus. The mathematical content of the model has been developed by Carl Hewitt, Irene Greif, Henry Baker, and Giuseppe Attardi. This thesis extends and unifies their work through the following observations. The ordering laws postulated by Hewitt and Baker can be proved using a notion of global time. The most general ordering laws are in fact equivalent to an axiom of realizability in global time. Independence results suggest that some notion of global time is essential to any model of concurrent computation. Since nondeterministic concurrency is more fundamental than deterministic sequential computation, there may be no need to take fixed points in the underlying domain of a power domain. Power domains built from incomplete domains can solve the problem of providing a fixed point semantics for a class of nondeterministic programming languages in which a fair merge can be written. The event diagrams of Greif's behavioral semantics, augmented by Baker's pending events, form an incomplete domain. Its power domain is the semantic domain in which programs written in actor-based languages are assigned meanings. This denotational semantics is compatible with behavioral semantics. The locality laws postulated by Hewitt and Baker may be proved for the semantics of an actor-based language. Altering the semantics slightly can falsify the locality laws. The locality laws thus constrain what counts as an actor semantics.

Exercise for the management of type 2 diabetes: A review of the evidence

The aim is to critically review the more relevant evidence on the interrelationships between exercise and metabolic outcomes. The research questions addressed in the recent specific literature with the most relevant randomized controlled trials, meta-analysis and cohort studies are presented in three domains: aerobic exercise, resistance exercise, combined aerobic and resistance exercise. From this review appear that the effects of aerobic exercise are well established, and interventions with more vigorous aerobic exercise programs resulted in greater reductions in HbA1c, greater increase in VO2max and greater increase in insulin sensitivity. Considering the available evidence, it appears that resistance training could be an effective intervention to help glycemic control, especially considering that the effects of this form of intervention are comparable with what reported with aerobic exercise. Less studies have investigated whether combined resistance and aerobic training offers a synergistic and incremental effect on glycemic control; however, from the available evidences appear that combined exercise training seems to determine additional change in HbA1c that can be seen significant if compared with aerobic training alone and resistance training alone.

Psychologically Inspired Sensory-Motor Development in Early Robot Learning

Lee, M., Meng, Q. (2005). Psychologically Inspired Sensory-Motor Development in Early Robot Learning. International Journal of Advanced Robotic Systems, 325-334.