The rehabilitation of an irrigation system along the Yellow River

The People's Victory Irrigation System which diverts water from the Yellow River of China covers a total irrigable area of 59 000 ha. The system encountered some serious problems in the first decade of its operation — salinity and waterlogging of irrigated land, siltation of irrigation and drainage channels, as well as a low efficiency of water use. This paper describes a series of structural and functional measures which have been adopted in the past 24 years for the rehabilitation of the system, including: improvement of the existing drainage system and construction of new drainage system on agricultural land, conjunctive use of surface and groundwater supplies, a comprehensive programme to reduce the levels of siltation as well as the implementation of improved water management practices. A model for the optimal operation of the system by using system analysis theory as an aid in reducing the operation and maintenance (O & M) costs has been developed in recent years. The results are that the soil salinity has been controlled and the agricultural production has increased whilst the efficiency of water use has improved and the siltation levels reduced. Experience gained on this system has been successfully used in developing and managing other irrigation projects along the lower reaches of the Yellow River. The proposed procedure of solving the said optimal model has also embodied some benefits from reducing O & M costs in operation.     

乌鳢免疫球蛋白M重链和免疫球蛋白轻链的克隆与特征分析

应用RACE-PCR方法克隆并鉴定了乌鳢免疫球蛋白M(i mmunoglobulin M,Ig M)重链(H)和免疫球蛋白轻链(L)全长cDNA。乌鳢IgH cDNA全长1 912个核苷酸(nt),包含1 797 nt的开放阅读框,编码598个氨基酸(aa)。IgH恒定区(CH)均包含1对保守的半胱氨酸残基形成链内二硫键,其中CH1区氨基末端存在保守的半胱氨酸残基与轻链形成链间二硫键,4个推测的N-糖基化位点(NXT和NXS)则分别位于CH1、CH2和CH4。序列比对发现乌鳢IgHCH1与CH2交界处氨基酸序列的插入使铰链区肽段较其他硬骨鱼IgH长,此外IgH CH4区羧基末端参与单体间聚合的半胱氨酸被赖氨酸替换,这反映乌鳢IgH分子结构的特异性。序列相似性比较显示乌鳢IgH与点带石斑鱼、黑鳍冰鱼、牙鲆、虹鳟的相似性依次为55%、50%、45%和36%,与斑马鱼类的相似性较低(为28%)。乌鳢IgL cDNA全长941 nt,包含729 nt的开放阅读框,编码242个aa。轻链可变区(VL)和恒定区(CL)均包含保守的半胱氨酸,形成链内和链间二硫键。序列比对分析表明乌鳢IgL与五条鰤和花狼IgL的相似性为78...     

湖南山羊传染性脓疱首次诊断

1991年3月我院胚胎移殖山羊和会同县农户山羊,口角上、下唇等部长有瘤状硬痂,疑为羊口疮.利用自然病例痂皮毒悬液,划痕接种健康山羊和家兔,山羊能复制出与自然病例相同的疾病,家兔亦能感染发病.利用人工感染康复家兔制备的高免血清,经琼脂扩散试验和对流免疫电泳试验均可出现特异性沉淀线,从而初步确诊本病为羊传染性脓疱.     

水稻辐射育种早期选择方法的研究

本试验利用放射线辐照水稻种子,进行诱变育种,探索辐射育种的M_1代选择方法。在原有工作的基础上,提出了M_1代单株综合性状好、结实率高为选择标准。几年的试验,均在受试材料的M_1代中获得符合际准的单株,并从中选育出新品种——“辐415”已用于水稻生产。     

纳米TiO_2对鸡肉源微生物的光催化抑菌效果研究

[目的]研究不同作用因素对纳米TiO_2的光催化活性影响,为纳米TiO_2光催化杀菌技术的开发与应用提供参考。[方法]以菌液初始浓度、光照强度和纳米TiO_2浓度为主要变量因素,研究不同因素条件下纳米TiO_2对鸡肉源微生物P.fluorescens和M.caseolyticus的光催化抑菌作用效果。[结果]纳米TiO_2浓度增加对P.fluorescens和M.caseolyticus的抑菌作用呈先升高后降低的趋势,最佳浓度值为0.4 g/L;增高光照强度,降低初始菌液浓度,纳米TiO_2的光催化抑菌效果增强;相同试验条件下,纳米TiO_2对P.fluorescens和M.caseolyticus的光催化抑菌作用一致,对M.caseolyticus的抑菌率始终低于P.fluorescens。[结论]M.caseolyticus对纳米TiO_2的光催化作用比P.fluorescens更加敏感。     

浙江水青冈的生境与群落初步调查

浙江水青冈是我国3级保护珍稀濒危植物台湾水青冈的一个变种,发现仅分布于浙江省永嘉县四海山林场。本文报道浙江水青冈的分布、生境、群落组成结构及天然更新等。     

The Proteomic Research of the Cure of Experimental Diabetes Deafness by Granules of Eliminating Phlegm and Removing Blood Stasis

Obiective:Observing the expression changes of serum proteome in model rats after intervention of the Granules of Eliminating Phlegm and Removing Blood Stasis (豁痰祛瘀颗粒 also known as GEPRB),screenin...     

不同饥饿程度的异色瓢虫成虫对烟蚜的捕食作用

试验研究不同饥饿程度的异色瓢虫雌、雄成虫对烟蚜的捕食作用。结果表明,不同饥饿程度的异色瓢虫雌成虫对烟蚜捕食作用的功能均Holling Ⅱ型反应模型;异色瓢虫雌成虫在各种饥饿条件下24h内对烟蚜的捕食量差异不显著;雌成虫捕食量大于雄成虫,且饥饿时间愈长,烟蚜密度愈大,两者的差异愈显著;异色瓢虫雌、雄成虫间在24h内的捕食速度（V）差异不显著,且与时间段(x)关系的模型分别为V＝5．8619x^-8087和V＝4.8583x^－0.7220;异色瓢虫雌、雄成虫对烟蚜的捕食量（Na）随着时间（t）的变化模型分别为Na=90／（1＋e^1.0886-0.1219t)和Na=90/(1 e^1.2702-0.1017t)。     

云南香蕉根际线虫种群动态的研究

在云南河口３块香蕉园内发现６种重要的植物寄生线虫,它们是南方根结线虫（Ｍｅｌｏｉｄｏｇｙｎｅ ｉｎｃｏｇｎｉｔａ）,螺旋线虫（Ｈｅｌｉｃｏｔｙｌｅｎｃｈｕｓ ｓｐｐ．）,纽带线虫（Ｈｏｐｌｏｌａｉｍｕｓ ｓｐｐ．）,矮化线虫９Ｔｙｌｅｎｃｈｏｒｈｙｎｃｈｕｓ ｓｐｐ．）,半轮线虫（Ｈｅｍｉｃｒｉｃｏｎｅｍｏｉｄｅｓ ｓｐ．）和毛刺线虫（Ｔｒｉｃｈｏｄｏｒｕｓ ｓｐｐ．）．根结线虫,纽带线虫,矮化线     

红壤山地决明属牧草辐射后代变异趋势的研究

利用^60Coγ射线（辐照剂量为300Gy,剂量率为4．6875Gy）辐照豆科决明属5个牧草品种的种子,通过盆栽混合收集M1代各个品种的种子,然后进行M2代试验观察和测定,了解其变异趋势。辐射M2代试验结果表明,辐照后5个决明品种的出苗率、茎长、叶宽、地上部干重都无显著差异;冠高34721有显著增长、茎粗2219有显著增长、分枝数86134有极显著增长和92985有显著降低、叶数86134有显著增长、叶长2219有显著增长;植株的营养成分（N、P、K）,全（K）2219有显著下降;植株的营养成分（氨基酸）,2219氨基酸总的含量有显著下降、且17种氮基酸都表现为不同程度的下降,86134氮基酸总的含量有显著增长、且17种氨基酸都表现为不同程度的增长。