铝基复合阻燃剂的制备及应用性能研究初探

本文采用两步法,经过表面多层包覆改性及无机-有机多层包覆改性处理,制备出一种铝基复合阻燃剂,使其初始分解温度达到260℃以上,活化指数达到90%。有无毒、不产生腐蚀性气体、热稳定性好、不会产生二次污染、价格低廉等优点,可应用于热塑性树脂和热固性树脂,可直接、也可改性后与树脂混合,具有阻燃和抑烟双重功能。

炔丙基化酚醛树脂的合成

酚醛树脂具有阻燃、耐烧蚀等独特性能，在航天领域有广泛的应用。但其固化物具有脆性大，耐热氧化性差，贮存性不理想及不适于大部件的缠绕工艺等缺点限制了应用范围，从酚醛树脂分子结构和固化化学着手进行改性，正成为防热复合材料基体树脂研究的热点。本成果合成出新型自固化型含炔基酚醛树脂，

Simultaneous heterotrophic nitrification and aerobic denitrification at high initial phenol concentration by isolated bacterium Diaphorobacter sp. PD-7

A strain capable of phenol degradation, hetemtrophic nitrification and aerobic denitrification was isolated from activated sludge of coking-plant wastewater ponds under aerobic condition. Based on its morphology, physiology, biochemical analysis and phylogenetic characteristics, the isolate was identified as Diaphorobacter sp. PD-7. Biodegradation tests of phenol showed that the maximum phenol degradation occurred at the late phase of exponential growth stages, with 1400 mg·L^-1 phenol completely degraded within 85 h. Diaphorobacter sp. PD-7 accumulated a vast quantity of phenol hydroxylase in this physiological phase, ensuring that the cells quickly utilize phenol as a sole carbon and energy source. The kinetic behavior ofDiaphorobacter sp. PD-7 in batch cultures was investigated over a wide range of initial phenol concentrations （0-1400mg·L^-1） by using the Haldane model, which adequately describes the dynamic behavior of phenol biodegradation by strain Diaphombacter sp. PD-7. At initial phenol concentration of 1400mg· L^-l, batch experiments （0.25 L flask） of nitrogen removal under aerobic condition gave almost entirely removal of 120.69mg· L^- 1 ammonium nitrogen within 75 h, while nitrate nitrogen removal reached 91% within 65 h. Moreover, hydroxylamine oxidase, periplasmic nitrate reductase and nitrite reductase were successfully expressed in the isolate.

Numerical investigation on freeze-drying of aqueous material frozen with pre-built pores

Freeze-drying of the initially porous frozen material with pre-built pores from liquid material was found experimentally to save drying time by over 30% with an initial saturation being 0.28 compared with the conventional operation with the initial saturation being 1, using mannitol as the solid material. In order to understand the mass and heat transfer phenomena of this novel process, a two-dimensional mathematical model of coupled mass and heat transfer was derived with reference to the cylindrical coordinate system. Three adsorption–desorption equilibrium relationships between the vapour pressure and saturation value namely, power-law, Redhead's style and Kelvin's style equation, were tested. Kelvin's style in exponential form of adsorption equilibrium relation gave an excellent agreement between the model prediction and experimental measurement when the equation parameter, γ, of 5000 was applied. Analyses of temperature and ice saturation profiles show that additional heat needs to be supplied to increase the sample temperature in order to promote the desorption process. Simulation also shows that there is a threshold initial porosity after which the drying time decreased with the increase in the initial porosity. Enhanced freeze-drying is expected to be achieved by simultaneously enhancing mass and heat transfer of the process.

呼伦贝尔草甸草原优势种贝加尔针茅根系组织和地上部分凋落物的分解

采用凋落物分解袋法,研究了呼伦贝尔草甸草原主要优势种贝加尔针茅(Stipa baicalensis)根系组织和地上部分凋落物分解的季节动态以及凋落物的放置位置(置于地表和15cm土壤表层)对分解的影响。结果表明,置于表层土壤中的根系组织和地上部分凋落物的分解速率比置于地表的快,但是根系组织在两个放置位置分解的差异不显著。无论置于地表还是置于表层土壤中,地上部分凋落物的分解均快于根系组织的凋落物分解。在分解过程中,凋落物碳(C)损失的季节变化模式与重量损失相似;而氮(N)变化模式明显不同,地上部分凋落物表现为释放—累积—释放,根系则表现为释放—累积,并且地上部分或者根系在不同放置位置中N含量变化的差异较小。地上部分和根系组织凋落物的初始化学组成的差异可能是导致其分解过程差异显著的主要原因,其次的原因才是土壤含水量。因此,该地区未来环境温度、湿度因子的变化将会显著影响贝加尔针茅地上部分凋落物的分解过程,而对根系组织凋落物的分解作用较小。

ON THE PRIMARY DECOMPOSITION THEOREM OF MODULAR LIE SUPERALGEBRAS

This gives some identities of associative Lie superalgebras and some properties of modular Lie superalgebras. Furthermore, the primary decomposition theorem of modular Lie superalgebras is shown. It is well known that the primary decomposition theorem of modular Lie algebras has played an important role in the classification of the finite-dimensional simple modular Lie algebras （see [5, 6]）. Analogously, the primary decomposition theorem of modular Lie superalgebras may play an important role in the open classification of the finite dimensional simple modular Lie superalgebras.

Biodegradation of Pentachloronitrobenzene by Labrys portucalensis pcnb-21 Isolated from Polluted Soil

A bacterial strain, pcnb-21, capable of degrading pentaehloronitrobenzene （PCNB） under aerobic and anoxic conditions, was isolated from a long-term PCNB-polluted soil by an enrichment culture technique and identified as Labrys portucalensis based upon its morphological, physiological and biochemical properties, as well as 16S rRNA gene sequence analysis. Effects of different factors, such as temperature and pH, on PCNB biodegradation were studied. Strain pcnb-21 efficiently degraded PCNB at temperatures from 20 to 30 ℃ and initial pH values from 4 to 7, which might be the first time that a Labrys strain was found capable of eflClciently degrading PC1NB. The degradation of PCNB was affected by oxygen, and the degradation decreased with increasing aeration. Exogenous electron donors such as glucose, lactic acid and succinic acid promoted the biodegradation of PCNB, while electron acceptors such as sodium nitrite, sodium sulfate, sodium nitrate and sodium sulfate inhibited PCNB biodegradation. The degradation of PCNB in sterile and non-sterile soils by a green fluorescent protein （GFP）-labeled strain, pcnb-21-gfp, was also studied. Cells of pcnb-21-gfp efficiently degraded 100 mg kg-1 PCNB in sterile and non-sterile soils and could not be detected after 42 days. Strain pcnb-21 might be useful in bioremediating PCNB-polluted soils and environment.