循环冷却水中军团菌的控制

随着我国社会经济的不断发展,循环冷却水系统在工业、商业和民用设施以及大型公共设施中的应用日益广泛。然而,这些水系统在给人们生活带来便利的同时,也为一种严重危害人类健康的细菌——军团菌创造了滋生的场所。国外对军团菌的研究报道已经很多,有些国家甚至已经开始为控制军团菌进行立法,然而国内在这方面的报道很少,研究也不多。因此,通过对军团菌、军团病以及控制军团菌的方法的介绍,唤起全社会对军团菌的关注。     

碳氮磷比对菌胶团的影响与活性污泥膨胀的关系

在活性污泥法的曝气池中，由微生物形成的菌胶团与废水成分的碳、氮、磷比例有着密切关系。如果比例失调会导致菌胶团变性、解体，从而影响活性污泥的生物学特性与理化性质、发生“污泥膨胀”，影响废水处理效果。运用我国著名数学家华罗庚的《优选法》－“０．６１８”法，拟定维尼纶有机配水氮的实验区带为０．８－１０，在４个条件相同的反应器中作试验，结果证明：Ｃ：Ｎ：Ｐ＝１００：３．９６：０．９３的范围，菌胶团活性高，     

中国穿山甲资源现状及保护对策

论文对世界上穿山甲资源的种类、分布及其资源价值、价格和国内外贸易情况作了一般性的介绍,重点论述了我国穿山甲的资源现状、资源濒危原因及应采取的保护对策。指出:我国现有穿山甲资源量估计仅为50000～100000头,资源数量已大为下降,然而年需求量却高达200000头,供求矛盾十分突出。造成资源濒危的主要原因是利用过度、栖息地破坏、外来种入侵、穿山甲遗传性能衰竭。建议采取以就地保护为主的对策,建立穿山甲自然保护区,同时积极开展穿山甲人工驯养,加强药用穿山甲代用品的研究,以减轻对野生资源的捕捉压力,解决保护和利用的矛盾,为迁地保护作前期准备。还建议积极创造条件开展穿山甲离体保护技术的研究。     

相思树种子的质量评价模型

投影寻踪技术为一种新兴的非线性分析方法,但存在计算过程复杂、编程实现困难等缺陷,鉴于此,我们提出采用模拟退火法直接优化投影寻踪技术的投影函数和投影方向以克服目前投影寻踪技术的种种缺点.在此基础上,提出基于模拟退火法的改进的投影寻踪的相思树种子质量评价模型,利用该模型可把各相思树种批测定指标综合成一维投影值,投影值越大,表示该种批质量越好,根据投影值的大小可对相思树种批样本集进行合理评价.实例质量评价结果表明,直接由样本数据训练的改进投影寻踪林木种子质量评价模型用于相思树种子质量评价简单可行,具有较强的适用性和应用性,可操作性强.基于模拟退火法的改进的投影寻踪法可广泛应用于种子质量评价、群落分类及环境质量评价等研究中各类非线性、高维数据的分级与评价.表1参11     

广州城市人工水系统中军团菌的发生和分布

综合运用平板分离法、半巢式PCR和EnviroAmp PCR反向杂交检测试剂盒，对广州市部分人工水系统中条件致病菌军团菌属细菌进行分离和检测．结果表明，虽然阳性率随着采样时间和地点的不同而有所差异，但总体来说，广州市人工水系统中存在较高程度的军团菌的污染，中央空调冷却塔水中军团菌阳性率平均为84％，个别路段甚至达到了100%，自来水池中则达到了35％，，但在后者的水样中没有检测到最常见的致病菌嗜肺军团菌．对各种培养方法的优劣及军团菌的季节性发生和分布进行了初步讨论．图2表2参16     

Volatile substances in the pygidial secretion of gyrinid beetles (Coleoptera: Gyrinidae)

Summary Gyrinid beetles are common in freshwater habitats. They have paired pygidial glands with a secretion that contains high molecular weight substances rendering them toxic for predatory fish. In this paper we report on a laboratory study on volatile components released by three different gyrinid species when irritated. The volatile pattern had a clear difference between the different species.Gyrinus substriatus andG. aeratus, both produced 3-methyl-1-butanal and 3-methyl-1-butanol when irritated, but in quite different amounts. The third tested species,G. minutus, did not produce any substances above the detection level. It is suggested that the volatile compounds may be part of the beetles' communication and/or defence system.     

长沙市白蚁种类及危害情况调查

报道了长沙市区危害房屋及园林树木的白蚁种类及危害状况，经5年调查(2000年-2004年)结果表明：长沙市(不包括长、望、浏、宁四县)共有白蚁2科17种．主要危害房屋的为散白蚁及台湾乳白蚁，危害园林树木的是黑翅土白蚁及黄翅大白蚁．讨论了区系特点及近年危害新状况。     

蚯蚓粪中拮抗微生物分析

实验证明，蚯蚓对有机废弃物进行生物降解的产物一蚯蚓粪，在一定程度上能够控制一些蔬菜类植物苗期土传病害的发生．对此现象的一种解释是蚯蚓粪中含有一些拮抗微生物．从以牛粪为饵料生产的蚯蚓粪中分离出两株拮抗活性强、范围广的拮抗微生物并得到鉴定：0103A球孢链霉菌(Streptomyces globisporus)和0104A丁香苷链霉菌(Streptomyces syringini),该菌及其发酵液对多种病原菌的抑菌谱及胚根、盆栽生物测定实验表明：两株拮抗菌在蚯蚓粪对蔬菜苗期病害的控制中起重要作用．表8参17     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Enumeration of Legionella pneumophila in cooling tower water systems

Legionella pneumophila, the causative agent of Legionnaires disease, is known to colonise and frequently grow in cooling tower waters. Disease is acquired by inhaling aerosol contaminated by legionellae. Determination of the count of Legionella pneumophila in cooling tower waters may, therefore, be useful for risk assessment. In our survey, 103 water samples from 50 cooling towers were examined over a five-year period to indicate the seasonal distribution and the ecology of L. pneumophila, as regards temperature and pH. L. pneumophila serogroup 1 was found in 44% of the isolated strains, which is primarily responsible for the majority of Legionnaires disease. The large majority of examined towers had levels of L. pneumophila in the high-risk category. These cooling towers have been linked to many outbreaks of Legionnaires disease.