论高等学校共青团的工作职能的几点认识

随着高速发展的二十一世纪的来临，高等学校作为培养教育高素质复合型人才的主要基地，肩负的重担越来越重，而高等学校共青团的工作又是此项工作中不可替代的一个重要组成部分，它的工作职能也慢慢地发生着变化。创新、实践、服务等内容正在成为它的职能之一。使之越来越配合学校的全面素质教育。     

Microbial decomposition of leached or extracted dissolved organic carbon and nitrogen from pasture soils

Microbial decomposition of extracted and leached dissolved organic carbon (DOC) and nitrogen (DON) was demonstrated from three pasture soils in laboratory incubation studies. DOC concentration in water extracts ranged between 29 and 148 mg C L^?1 and DON concentration ranged between 2 and 63 mg N L^?1. Between 17 and 61 % of the DOC in the water extracts were respired as CO₂ by microbes by day 36. DON concentrations in the extracts declined more rapidly than DOC. Within the first 21 days of incubation, the concentration of DON was near zero without any significant change in the concentration of NO₃ ^? or NH₄ ⁺, indicating that microbes had utilized the organic pool of N preferentially. Decomposition of leached DOC (ranged between 7 and 66 mg C L^?1) and DON (ranged between 6 and 11 mg N L^?1) collected from large lysimeters (with perennial pasture; 50 cm diameter?×?80 cm deep) followed a similar pattern to that observed with soil extracts. Approximately 28 to 61 % of the DOC in leachates were respired as CO₂ by day 49. The concentration of DON in the leachates declined to below 1 mg N L^?1 within 7–14 days of the incubation, consistent with the observations made with extractable DON. Our results clearly show that DOC and DON components of the dissolved organic matter in pasture soils, whether extracted or leached, are highly decomposable and bioavailable and will influence local ecosystem functions and nutrient balances in grazed pasture systems and receiving water bodies.     

MINERAL COMPOSITION OF STRAWBERRY,MULBERRY AND CHERRY FRUITS AT DIFFERENT RIPENING STAGES AS ANALYZED BY INDUCTIVELY COUPLED PLASMA-OPTICAL EMISSION SPECTROSCOPY

Mineral contents of strawberry (Fragaria x ananassa), mulberry (Morus alba, M. nigra, M. macroura, and M. laevigata) and cherry (Prunus avium) fruits at un-ripened, semi-ripened and fully-ripened stages were investigated. The concentrations (mg kg^?1) of potassium (K), phosphorus (P), calcium (Ca), and magnesium (Mg) in the fruits (DW), at fully-ripened stage, varied from 2600 (mulberry) to 3300 (strawberry), 1854 (cherry) to 2954 (mulberry), 1855 (cherry) to 4375 (mulberry) and 1025 (cherry) to 2225 (mulberry), respectively. Sizeable amounts (mg kg^?1) of Zn 408 (strawberry) to 1110 (mulberry) and Fe 236 (cherry) to 1080 (mulberry) were also determined. Moreover, the tested fruits contained considerable amounts of sodium (Na), manganese (Mn), aluminum (Al), and copper (Cu). Overall, the concentrations of these minerals except K were found to decrease as fruit maturity progressed. The tested fruits, especially Morus species, can be explored as a rich source of Zn and Fe, the two essential elements that are in short supply in human diet.     

Charge characteristics of soil organo-mineral complexes and their effect on phosphate fixation

Soil is a complex system of mineral and organic components. The main reactive constituent of the mineral portion of soil is clay and of organic portion is humus from the microbial transformation of organic materials in the soil. Most of the biological and physico-chemical properties and the reactions of soil are due to clay and humus, the colloidal fraction of which being the most important. Many soil phenomena of great practical and fundamental importance such as sorption and exchange of ions, interaction with organic materials etc. originate from the surface charge of clay. The presence of organic matter in the soil and its union with the mineral portion affects these charge characteristics thus affecting many important physicochemical reactions in the soil.     

Year-round gelation characteristic of bassy chub Kyphosus lembus meat

ABSTRACT:   Year-round change in gelation of bassy chub ( Kyphosus lembus ) meat, collected from October 2001 to September 2002 off the coast of Nagasaki, was investigated. The fish meat exhibited a similar high gel-forming ability for all seasons, including pre- and post-spawning seasons. Freshwater washing of the meat did not improve its gel-forming ability. It was concluded that bassy chub meat could be used for thermal gel production in all seasons.     

新疆托木尔峰国家级自然保护区树附生地衣群落数量分类1）

在托木尔峰国家级自然保护区（海拔2200～3000 m）设置25个20 m×20 m的样地,调查样地内树附生地衣种类、地衣盖度和生境指标。以地衣种盖度为指标,应用除趋势对应分析法（ DCA）和双向指示种分析法（ TWINSPAN）对树附生地衣群落进行数量分类。根据数量分类结果并综合生境特征,将保护区树附生地衣划分为4个群落类型。群落A：茎口果粉衣（ Chaenotheca stemonea （ Ach．） Muell）＋黑蜈蚣衣（ Phaeophyscia nigricans （ Flk．） Moberg）＋枪石蕊群落（Cladonia coniocraea （Floerke） Spreng．）;群落B：黄烛衣（Candelaria concolor （Dicks．） Stein．）＋粉粒树花（ Ramalina pollinaria （ Westr．） Ach）．＋中国树花（ R．sinensis Jatta．）;群落C：柯贝尔副茶渍（ Lecania koerberi-ana Lahm．）＋金黄茶渍（ Candelariella aurella （ Hoffm．） Zahlbr．）＋粗糙猫耳衣（ Lepot gium brebisonii Mont．apud Webb．）;群落D：斑面蜈蚣衣（ Physcia aiop lia （ Humb．） Furnr．）＋类锈橙衣（ Caloplaca ferrugineoides （ H．Magn））＋污白雪花衣（ Anophychia ulto hir coied s （ Vain．） Vain．）。群落B和群落C的相似性最高,相似性系数为0．918;群落C和群落D的相似性系数为0．649;群落A与群落D相似性系数最低,相似性系数为0．264。树附生地衣的分布与海拔的关系较密切,高海拔和低海拔地带树附生地衣群落物种组成具有显著性差异。     

防治平菇厉眼茵蚊低毒农药的筛选

以平菇厉眼菌蚊(Lycoriella pluroti )3～4龄幼虫为目标虫,对8种低毒农药进行筛选试验.结果表明,高效氯氟氰菊酯对平菇厉眼菌蚊幼虫的毒力最强,其致死中浓度为0.005 mg/mL,对糙皮侧耳菌丝生长影响较弱,抑菌中浓度为0.023 mg/mL;在糙皮侧耳生产中,每袋使用该药剂30 mL处理的杀虫率达100％,10 mL处理的杀虫率为67.1％；喷施该药(10mL)7 d后子实体中无残留检出.高效氯氟氰菊酯适用于糙皮侧耳(Pleurotus ostreatus)生产中防治平菇厉眼菌蚊.     

乌鲁木齐南郊亚花松萝重金属含量及其大气污染评价的研究

[目的]利用地衣评价乌鲁木齐南郊空气质量.枝状地衣对空气中的要害气体非常敏感,具有体内富集作用,近年来地衣广泛的应用在空气质量评价中.[方法]采用地衣移植方法,从乌鲁木齐南山八一林场选择亚花松萝,移植到乌鲁木齐南郊的红雁池电厂、新疆大学校园、乌鲁木齐市动物园和乌鲁木齐市人民公园等4个不同点.移植后1和3个月后别取样,应用电感耦合等离子光谱直读法对移植地衣体内的Al、Cr、Cu、Fe、Mn、Ni、Zn等7种元素含量进行测定.[结果]亚花松萝体内被测定出的重金属元素种类和含量与移植时间之间存在显著性差异.随着地衣移植时间的延长被检测出的元素种类及含量明显增加,其中Al、Cr、Cu、Mn的含量在各移植点之间有显著性差异.[结论]亚花松萝重金属含量在生物评价乌鲁木齐南郊空气污染方面具有一定的研究价值.     

丛藓科和大帽藓科植物孢子的形态研究

利用光学显微镜(LM)和扫描电镜(SEM),对新疆昆仑山2科4属10种藓类孢子进行了观察。结果表明:所研究种类孢子体积小、孢壁薄、易褶皱、纹饰明显。同科属之间,孢子的形态、直径、近极面结构,特别是外壁纹饰的形状、分布均有差异。该研究可为苔藓植物系统分类、演化及化石孢子的鉴定提供依据。