17O-核磁共振法研究农药微乳剂浊点与 其组份之间的相关性

农药微乳剂浊点是微乳剂的主要质量技术指标之一。研究了3种不同种类农药的微乳剂组份与浊点的关系,并利用17O-核磁共振(17O-NMR)方法对其机理进行了探究。研究表明:浊点与表面活性剂、助表面活性剂与水之间形成的氢键强度成正相关;随着水质硬度的上升,浊点下降。建议选用亲水性强的表面活性剂和极性较强的助表面活性剂来配制微乳剂,同时为了节约成本和便于工厂生产,可采用自来水来配制农药微乳剂,而采取其他措施来提高农药微乳剂的浊点。     

陕北黄土高原多沙粗沙区乡村聚落土壤水蚀定位观测研究

为研究乡村聚落的土壤侵蚀,在陕北榆林、绥德、延安建立观测站,于2003年对乡村聚落中的户间道路、户间空地、院落在降雨时的次径流泥沙含量、平均含沙量、次侵蚀强度及观测期降雨形成的总侵蚀强度,进行了观测与分析。其观测结果,均说明户间道路、户间空地径流平均含沙量较大,榆林为29.37g/L、29.96g/L,缓德为21.06g/L、17.53g/L、延安为54.6g/L2、9.18g/L,而院落平均径流含沙量较小,榆林、绥德、延安分别为9.47g/L、8.64g/L、14.87g/L。观测期降雨侵蚀总强度,三个观测站均以户间道路最大,分别为1142t/km2、2156.6t/km26、285.7t/km2;户间空地次之,分别为744.5t/km2、1192.6t/km2、1953.2t/km2;院落较小,分别为161.1t/km23、78.7t/km2、1274.3t/km2。说明乡村聚落土壤侵蚀不可忽视,应加强防治。     

核盘菌在亚麻上侵染致病的微观过程

 第1次利用电子显微镜对核盘菌在亚麻叶片上侵染致病的微观过程进行深入细致的观察。结果表明,该菌在侵入叶表面之前可能产生某些酶类物质来软化溶解亚麻叶表面角质层,以帮助该菌对叶表面的侵入。本文还对菌丝和子囊孢子侵染过程的异同进行了比较。     

兔肉的速冻

本文简单阐述了兔肉的速冻特点及规律 ,并对影响其质量的重要因素进行了分析 ,对兔肉的冷冻生产有指导意义     

聚合物类型降凝剂及其应用

在原油中添加降凝剂，可以降低原油凝点，改善原油低温流动性，以利于实现含蜡原油管常温输送。聚合物类型的降凝剂可分为均聚物和共聚物两类，分别介绍了近几年国内外常用的聚合物类型降凝剂的合成方法、化学结构式和应用情况。     

Diagnosis of dehydratase inhibitors in melanin biosynthesis inhibitor (MBI-D) resistance by primer-introduced restriction enzyme analysis in scytalone dehydratase gene of Magnaporthe grisea

We have established a simple diagnosis method for rice blast fungus resistant to MBI-D. This involves the preparation of PCR templates directly from the lesions in combination with primer-introduced restriction enzyme analysis PCR (PIRA-PCR).     

桑尺蠖越冬幼虫的耐寒性研究

研究了桑尺蠖越冬幼虫的耐寒能力 ,测定了虫体内抗寒物质的组成成分 ,并对其耐寒机理作了初步探讨。结果表明 :越冬幼虫从越冬初期至越冬滞育期 ,4龄幼虫的平均过冷却点从初期的-1 7 2℃下降至滞育期的 -2 4 4℃ ;5龄幼虫的平均过冷却点从 -1 3 4℃下降至 -2 4 8℃。越冬幼虫体内水分、糖元、脂肪含量下降 ,其中以糖元含量下降明显 ;越冬幼虫以“小分子糖—氨基酸—糖蛋白”物质系统形成抗寒基质 ,增强耐寒性。     

大黄鱼鱼苗耗氧率和窒息点的研究

为了给大黄鱼的生理学及大黄鱼养殖的放养密度、水质管理、饵料利用以及活鱼运输等提供技术参考依据,对大黄鱼基础代谢水平进行测定。在3种水温(14,20,25℃)条件下测定大黄鱼[Pseudosciaena crocea(Richardson)]鱼苗(体长7.8~9.1 cm,体重6.61~8.85 g)的耗氧状况,据此计算出大黄鱼鱼苗的耗氧率,及瞬时耗氧率与溶氧量及水温的相关关系。结果表明,大黄鱼鱼苗耐低氧能力差,其耗氧率和窒息点溶解氧水平都随水温的升高而增大,14℃时两者为2.833μg/(g.min)和1.42 mg/L;25℃时两者为4.677μg/(g.min)和2.27 mg/L。大黄鱼鱼苗的瞬时耗氧率在其呼吸生理的某个时段出现特殊现象:当水中溶解氧下降至其浮头点和昏迷临界点之间时,瞬时耗氧率会在一个较短的时间范围内呈现跳跃式提升,这种现象在已有的鱼类耗氧率研究中从未出现过。此后的瞬时耗氧率急速下降至最低点,其呼吸类型可归属于逆向型。     

Landscape ecology of <Emphasis Type="Italic">Phragmites australis</Emphasis> invasion in networks of linear wetlands

The interaction between landscape structure and spatial patterns of plant invasion has been little addressed by ecologists despite the new insights it can provide. Because of their spatial configuration as highly connected networks, linear wetlands such as roadside or agricultural ditches, can serve as corridors facilitating invasion at the landscape scale, but species dynamics in these important habitats are not well known. We conducted a landscape scale analysis of Phragmites australis invasion patterns (1985–2002 and 1987–2002) in two periurban areas of southern Québec (Canada) focusing on the interaction between the network of linear wetlands and the adjacent land-uses. Results show that, at the beginning of the reference period, the two landscapes were relatively non-invaded and populations occurred mostly in roadside habitats which then served as invasion foci into other parts of the landscape. The intrinsic rates of increase of P. australis populations in linear anthropogenic habitats were generally higher than those reported for natural wetlands. Riparian habitats along streams and rivers were little invaded compared to anthropogenic linear wetlands, except when they intersected transportation rights-of-way. Bivariate spatial point pattern analysis of colonization events using both Euclidian and network distances generally showed spatial dependence (association) to source populations. An autologistic regression model that included landscape and edaphic variables selected transportation rights-of-way as the best predictor of P. australis occurrence patterns in one of the landscapes. Given the high invasion rates observed, managers of linear wetlands should carefully monitor expansion patterns especially when roads intersect landscapes of conservation or economic value.     

加降凝剂输油技术的现状及发展方向

输油管道添加降凝剂是改善原油代温流变性的一种物理化学方法，从降凝剂的筛选和复配，处理条件，应用方式，配套设施、应用效果等方面系统地介绍了含蜡原油添加降凝剂输送工艺的研究及应用现状，指出了降凝剂在研究和应用中存在的问题，对添加降凝剂的输油技术进行了客观评价，展望了降凝输油技术的发展方向。