厌氧复合菌系的筛选及含纤维素原料预处理复合菌剂的研究

本文从不同厌氧生境中获得7组(C-2、Y-2、L-2 、NZ、H-3、CZ、L-3)具有纤维素降解能力的复合菌系。经过不断传代、淘汰纤维素降解能力降低的菌系，最后得到一组高效、传代稳定的厌氧纤维素分解复合菌系L-3。该菌系可使滤纸在42 h内溃烂，并能在分解纤维素的同时产氢气。对L-3复合菌系的产酶条件进行了研究，结果表明，在实验范围内该菌系的产酶最适条件为：pH 6.5，温度37 ℃，接种量5 %，最佳碳源为滤纸，最佳氮源为硫酸铵。第10天测得羧甲基纤维素酶(CMCase)、滤纸酶(FPA)、外切葡聚糖酶(C1)、β-葡聚糖苷酶(β-glucodase)的酶活分别为0.216 U/ml、0.101 U/ml、0.132 U/ml、0.002 U/ml，滤纸失重率70.6 %。发酵代谢产物乙醇和丁酸含量分别可达1378 mg/L 、2695 mg/L，发酵产生的气体中氢气含量最高可达70.2 %。DGGE结果表明该菌系主要由14种菌组成，其中有三株菌在发酵前后菌数发生了明显的变化，说明在以滤纸为底物的降解过程中，这三株菌起到了重要作用，对这三株菌进行了分子生物学鉴定，初步定为Clostridium phytofermentans、Clostridium cellulovorans、Desulfovibrio sp。 利用实验室分离得到的纤维素降解菌，最终配制出由10、X-1、X-13、ST-13、L-3组成的好氧-厌氧纤维素降解复合菌剂。以秸秆为发酵底物，菌剂接种量1%，利用复合菌剂预处理后的秸秆，发酵总产气量相对于对照提高了71.62%，甲烷含量最高可达70.08%。 A group of microbial consortia L-3 was isolated from the anaerobic fermentation residue of corn stalk, which could degrade cellulose and produce hydrogen. The CMCase, FPA, C1 and β-glucosidase activity of L-3 could reach to 0.216 U/ml, 0.101 U/ml, 0.132 U/ml and 0.002 U/ml, respectively. In the filter degrading process, the filter paper collapsed in the liquid culture within 42 h and the filter degrading rate could reach to 70.6% in the 13 days, meanwhile, hydrogen was determined and the highest hydrogen content was 70.2%. The optimum cellulase-degrading conditions were filter papaer as the carbon source, (NH4)2SO4 as the nitrogen source, 37 ℃ and pH 6.5 in this experiment. DGGE results showed that the microbial consortia L-3 mainly included 14 strains. The amount of 3 strains were changed during the fermentation. These strains were identified as Clostridium phytofermentans、Clostridium cellulovorans、Desulfovibrio sp by 16S rDNA sequence analysis. The cellulose- degrading microbial agent was composed by 10, X-1, X-13, ST-13, L-3 which were isolated in the laboratory. The straw pretreated by cellulose-degrading microbial agent was used to ferment, the total biogas production increased by 72% comparing to the control. The content of methane could reach to 70.08%。

The record of cultivated rice from archaeobiotogical evidence in northwestern China 5000 years ago

IEECAS SKLLQG

巴丹吉林查格勒布剖面记录的150ka BP以来的常量化学元素波动

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有关湖泊沉积^137Cs深度分布资料解译的探讨

IEECAS SKLLQG

Impacts of the embedded windings to the field quality of dipole

Cooler Storage Ring (CSR) of Heavy Ion Research Facility in Lanzhou (HIRFL) consists of a main ring (CSRm) and an experimental ring (CSRe). Two particular C-type dipoles with embedded windings are used in the injection beam line of CSRm. They also act as the prototype dipoles of CSRe. The windings are designed to improve the field quality by their trimming current. The current impacts on field homogeneity and multipole components are investigated by a hall sensor and a long coil, respectively. The experiment shows that a field homogeneity of +/- 1.0 x 10(-3) can be reached by adjusting the trimming currents, though the multipole components change correspondingly. In our case, the quadrupole component is decreased to a low level with the octupole, decapole and 12-pole ones increased slightly when the trimming current is optimized.

长白山北坡河岸带群落植物区系分析

对吉林省二道白河河岸带植物区系的研究结果表明,河岸带植被中共有维管束植物68科169属288种,其中包括蕨类植物11科16属26种,种子植物57科153属262种种子植物中,裸子植物3科6属9种,被子植物54科147属253种;被子植物中,双子叶植物45科118属212种,单子叶植物9科29属41种,由此可见二道白河河岸带的植物种类较为丰富,对其中被子植物分布区类型的分析表明,二道白河流域河岸带种子植物区系科、属的分布类型较为丰富,在科级水平上有6个分布类型2个变型,在属级水平上有9个分布类型7个变型,河岸带植物区系呈温带特性,各类温带分布类型117属,占河岸带种子植物153属的76.5％。二道白河流域河岸带植物区系地理联系广泛,与热带植物区系和东亚区系具有一定的联系,但与地中海植物区系的联系甚少。表明河岸带在生物多样性保护中的重要作用。

环境中基因工程微生物生态学研究

详细阐述了基因工程微生物(GEM)在环境释放中需考虑的主要问题:GEM的构建、基因转移、适合度、扩散、转运和潜在的生态影响等,并针对GEM特定的生态学特征和生态影响,提出了基因工程微生物生态学研究宜采取“具体问题具体分析”的策略,制定相应的研究方案,为安全有效地在非受控条件下应用GEM铺平道路。

Square lamellar structure having phase-separated microdomain in H-shaped block copolymer thin film

The morphology of a H-shaped block copolymer (poly(ethylene glycol) backbone and polystyrene branches (PS)(2)PEG(PS)(2)) in a thin film has been investigated. A peculiar square lamella that has a phase-separated microdomain at its surface is obtained after spin coating. The experimental temperature plays a critical role in the lamellar formation. The copolymer first self-assembles into square lamellar micelles with an incomplete crystalline core due to the crystallizability of PEG.

A mechanistic study of electrochemical oxidation processes of (OEP)Mg(II) in the presence of anions

In the presence of F-, OH-, Cl-, electrochemical redox of (OEP)Mg(II) [2,3, 7,8,12,13,17,18 octaethyl-21H, 23H-porphine magnesium (II)] are investigated in DCE/0.1 mol/L solution by cyclic voltammetry and spectroelectrochemistry, In the presence of anions, anions are axially coordinated to (OEP)Mg(II) generate (OEP)Mg(II)Y, the E-1/2 of (OEP)MS(II)Y oxidation are negatively shifted. A chemical reaction following the second oxidation step is observed, the E-1/2 of the reaction product is obtained. Mechanism of (OEP)Mg(II) in the halogen and OH- anions titration process has been proposed.

阴离子存在下(OEP)MG(Ⅱ)的电化学氧化机理研究

用电化学滴定和现场光谱电化学方法研究考察了DCE中OH~－，F~-和Cl-等阴离子存在下的（OEP）Mg（Ⅱ）的电极氧化过程．发现阴离子能与（OEP）Mg（目）轴向配位，形成五配位化合物，从而引起（OEP）Mg（Ⅱ）的氧化峰电位的负移；在生成二价环阳离子的过程中伴随后行化学反应．获得了反应产物的氧化还原峰电位.

高效离心分配色谱仪对异丙基膦酸单(1-己基-4-乙基)-辛酯-稀土萃取体系的研究

首次用高效离心分配色谱仪（ＨＰＣＰＣ）研究用异丙基膦酸单（１－己基－４－已基）辛酯（ＰＴ－２）分离三价重稀土元素，以分离 Ｙｂ（Ⅲ）， Ｅｒ（Ⅲ）及 Ｌｕ（Ⅲ）为例，考察了流动相酸度、流速、固定相浓度、ＨＰＣＰＣ的转速等因素对ＨＰＣＰＣ分离稀土效果的影响，并用ＨＰＣＰＣ法和液－液萃取法研究了ＰＴ－２萃取重稀土的机理。

计算机自动结构解析专家系统研究──一个新的拓扑等价性识别算法

介绍了一个正确识别化合物结构或结构片断中各原子的拓扑等价性问题的新算法。算法中引入了节点矩阵Ｎ和键矩阵Ｂ，并由这两个新矩阵来计算化合物结构图中的各节点的特征值，以此来表征节点的环境特征，从而识别节点的拓扑等价性，以保证结构解析专家系统结构产生器的穷举和非冗余性。