冰核细菌防治技术初步研究

通过 Vali法和抑菌圈法测定了化学药剂和生防拮抗菌对冰核活性细菌的杀灭、抑制效果和对冰核活性的破坏作用 ,并用生测方法测定了药剂对活体植株上的冰核活性细菌的杀灭作用 ,又应用人工模拟霜冻法试验检测了药剂和生防菌的实际防御霜冻的效果。结果表明药剂和生防菌对冰核细菌都有一定作用。其中药剂作用快 ,对冰蛋白有破坏作用 ,生防菌作用持久 ,但对冰蛋白无明显破坏作用     

细菌素应用研究进展

细菌素是乳酸菌在发酵过程中产生的代谢产物。本文介绍了细菌素在食品工业中的广泛应用以及在生物医药和饲料工业方面的应用前景。     

光合细菌应用的研究进展

光合细菌是自然环境中一类能进行光合作用的特殊微生物，它含有丰富的营养，能产生各种活性物质，在人类生活的许多方面发挥着重要的作用。本文从水产养殖、畜牧业、种植业、废水处理、新能源等方面介绍了其应用进展和前景，为光合细菌深入研究和应用提供参考。     

广西北部湾海域表层海水细菌多样性及其潜在生物合成基因研究

本研究选取广西北部湾3处近海海域,以其表层海水作为研究对象进行细菌多样性分析,旨在挖掘潜在抗生素生物合成的菌株.选用传统稀释涂布法和基于16S rRNA基因序列的系统发育树分析海水中可培养细菌多样性,并对其基因组DNA进行抗生素生物合成基因聚酮合酶(PKS)基因、非核糖体肽合成酶(NRPS)基因及卤化酶(Halo)基因...     

乳酸菌的细菌素及乳链菌肽在食品工业中的发酵与应用

乳酸菌的细菌素是具有抗菌活性的多肽、蛋白质或蛋白质复合物，其中 乳链菌肽是一种广泛应用的高效，无毒的天然食品防腐剂，评述了乳酸菌素的分类剂乳链菌肽在食品工业中的发酵和应用前景。     

磷细菌剂在小麦上应用研究

】磷细菌剂（土壤磷活化剂，生物磷肥）系用自行分离筛选的ＨＭ０３３２和ＨＭ４８３解磷细菌研制的微生物肥料。多年盆栽，小区试验和田间简单对比试验，增产效果显著、亩增小麦１６．７—４２．７ｋｇ。增产率６．２—１９．８％。并有改善小麦品质，提高土壤速效磷含量，培肥土壤的作用。     

细菌监测技术在生活垃圾处理中的应用研究

提出运用土壤细菌学5项实验技术指标及方法,按国家标准UDC(微生物土壤部分)评价:相对洁净、轻度污染、中度污染、重度污染4个等级指示进行细菌监测技术的方法。对比研究生活垃圾处理及再生产品的卫生学质量标准,在生活垃圾资源利用还没有形成产业化、规范化之前,将细菌监测技术应用在生活垃圾处理中;选择最优组合方案,将垃圾中细菌消灭在形成腐败气味之前,能更科学、更环保、更快捷、更省时、更省力地解决好生活垃圾在堆积、运输、处理过程中释放有毒气体的难题。     

人工种子的若干理论问题与应用研究

人工种子又称合成种子或体细胞种子,Murashige1977年首先提出高速度、大规模生产繁殖体的设想,并于1978年提出人工种子的概念;1981年 Lawrence 等研究了芹菜和莴苣体细胞包襄的液胶包埋带技术以后,便有越来越多的人工种子方面的报道。自1987年桑树腋芽包裹的人工种子获得成功以来,以微器官为繁殖体的人工种子研究日益增多。人工种子是八十年代起始的一项新兴技术,它可以作为实现农、林、园艺作物良种化的一项革新技术,在农业生产上发挥重要作用。     

滇池治理人工湿地植物的筛选与应用研究

对适用于滇池水体污染治理的水生植物进行引种、筛选、配置及应用研究，结果表明依据引种筛选获得46种适用水生植物配置的人工湿地示范工程系统，对处理滇池入湖河道污水具有良好的适应性，对污水中主要污染物的去除率达64．9％～83.4％。中还对香蒲、茭草、旱伞竹等6种主要湿地植物的生长情况跟踪观察结果。     

硝酸酸沉四钼酸铵过饱和溶液的成核研究

测量了不同温度和不同过饱和比下硝酸酸沉四钼酸铵过饱和溶液的成核诱导时间,讨论了温度及过饱和比对成核诱导时间和成核速率的影响.结果表明,四钼酸铵过饱和溶液的成核速率随着温度的升高和过饱和比的增大而增大.在实验温度范围内均匀成核和非均匀成核之间的临界过饱和比为3.0~6.0.根据均匀成核理论,计算了不同温度下的固液界面张力、临界半径和临界成核自由能.讨论了四钼酸铵结晶的条件,认为在成核阶段应采用较高的温度和过饱和比,而在晶核长大阶段应控制较小的过饱和比,以利于获得均匀、完整的晶体.     

Water activity as the determinant for homogeneous ice nucleation in aqueous solutions

The unique properties of water in the supercooled (metastable) state are not fully understood. In particular, the effects of solutes and mechanical pressure on the kinetics of the liquid-to-solid phase transition of supercooled water and aqueous solutions to ice have remained unresolved. Here we show from experimental data that the homogeneous nucleation of ice from supercooled aqueous solutions is independent of the nature of the solute, but depends only on the water activity of the solution--that is, the ratio between the water vapour pressures of the solution and of pure water under the same conditions. In addition, we show that the presence of solutes and the application of pressure have a very similar effect on ice nucleation. We present a thermodynamic theory for homogeneous ice nucleation, which expresses the nucleation rate coefficient as a function of water activity and pressure. Recent observations from clouds containing ice are in good agreement with our theory and our results should help to overcome one of the main weaknesses of numerical models of the atmosphere, the formulation of cloud processes.     

Molecular dynamics simulation of the ice nucleation and growth process leading to water freezing

Upon cooling, water freezes to ice. This familiar phase transition occurs widely in nature, yet unlike the freezing of simple liquids, it has never been successfully simulated on a computer. The difficulty lies with the fact that hydrogen bonding between individual water molecules yields a disordered three-dimensional hydrogen-bond network whose rugged and complex global potential energy surface permits a large number of possible network configurations. As a result, it is very challenging to reproduce the freezing of 'real' water into a solid with a unique crystalline structure. For systems with a limited number of possible disordered hydrogen-bond network structures, such as confined water, it is relatively easy to locate a pathway from a liquid state to a crystalline structure. For pure and spatially unconfined water, however, molecular dynamics simulations of freezing are severely hampered by the large number of possible network configurations that exist. Here we present a molecular dynamics trajectory that captures the molecular processes involved in the freezing of pure water. We find that ice nucleation occurs once a sufficient number of relatively long-lived hydrogen bonds develop spontaneously at the same location to form a fairly compact initial nucleus. The initial nucleus then slowly changes shape and size until it reaches a stage that allows rapid expansion, resulting in crystallization of the entire system.     

Construction of ice nucleation active <Emphasis Type="Italic">Enterobacter cloacae</Emphasis> for control of insect pests

Ice nucleation active(INA)bacteria are the most potent heterogeneous ice nuclei in nature,which have become an important biological resource for diverse applications.Many researches have proved that INA bacteria can raise the supercooling points(SCPs)of insect pests,then reduce their cold hardiness.However,INA bacteria‘s inefficient colonization on the surface or in the guts of insects,and the high incidence of frost injury induced by their release hampered the application of INA bacteria in controlling insect pests in agricultural fields.In this study,we constructed a recombinant plasmid mob-Tn5-iceA with the ability of broad-host-range conjugal mobilization and integration of the ina gene of icaA into chromosomal DNA of many gram-negative bacteria by Tn5 transposition.In addition,Ent.cloacae strains stably carrying iceA and expressing high ice nucleation activity(INA),even in the absence of antibiotic pressure,were constructed through conjugal mobilization and Tn5 transposition.Ent,cloacae strains have benn reported to be able to efficently colonize in the guts of insects,but have weak plant epiphytic ability.Therefore,these transgenic Ent.Cloacae may be promising candidates for control of insect pests in agricultural fields.     

干冰冷喷射清洗技术及其应用

介绍了干冰喷射清洗的机理、国内外现状、对金属与橡胶工业模具的清洗实验结果及其应用领域与特点.进行了相关技术参数的推算.并对其喷射清洗系统进行了工频耐压及泄露电流的测试,结论是该系统可以实现输变电设备、线路的在线清洗,是一种真正的绿色清洗技术,对于保护环境、实现清洁生产具有广泛和深远的意义.     

细粒酒精模型冰的物理性质研究

依据实测数据 ,给出酒精溶液冻结温度和制冰过程中冰池大厅气温、冰表面附近气温、冰温和溶液温度 .介绍模型冰密度、冰内未冻液体含量的实测方法和结果 .得出模型冰物理性质的制约因素和力学性质不受冰温控制的推论     

花生固氮根瘤菌应用研究

应用花生固氮根瘤菌，通过拌种方法在花生种子中接种，种植在未种过花生的花岗岩发育的壤土中，进行固氮效果测定。结果表明，施用的花生固氮根瘤菌明显增加了花生的结瘤量，植株生长健壮，群体生长旺盛，增加植株生物量，结荚率提高11%，植株含氮量提高52.9%，籽仁含氮量提高52.5%，产量提高40%，增产效果显著。     

滇池上层底泥解磷菌的区系特点

利用有机磷及无机磷培养基分别分离滇池上层底泥12个样品中的解磷菌,从细菌的数量、种类、分布特点来探讨滇池上层底泥解磷菌的区系特点.     

硅酸盐细菌JF88菌选育的研究

笔者分离到硅酸盐细菌JF88菌株，经鉴定为邻单胞菌属，用四苯硼钠比浊法对该萝株的解钾能力进行测定，结果为实验组水溶性钾含量比对照组增加30．5％，用磷钼比色法对该菌的解磷能力进行测定，结果为JF88菌株的解磷能力是美国菌肥商品生产菌种MB1的15．79倍，用直接记数法测得JF88菌株的生长繁殖速度超过MB1。