白洋淀沿湖农田施氮量对冬小麦产量和土壤硝态氮累积的影响

[目的]研究白洋淀沿湖农田施氮量对冬小麦产量及土壤中硝态氮累积的影响.[方法]选择2块具有代表性的农田进行田问小区试验,研究不同施氮量对该地区小麦产量构成因素、氮肥利用率及土壤硝态氮累积量的影响.[结果]适宜施氮量可显著提高小麦的穗粒数、千粒重等产量构成因素及氮肥利用率.土壤硝态氮主要集中在0～30 cm土层,其含量随施氯量的增加而增加.随着小麦生育期的推移,0～90 cm土体中硝态氮累积量呈下降趋势.成熟期,当施氮量分别高于其适宜施氮量时,土体中硝态氮累积量随施氮量增加而显著增加,从而增加了硝态氮下移的风险.[结论]综合考虑产量和环境效益,在该试验条件下,马堡和张六试验点冬小麦的适宜施氮量分别为225、90 kg/hm2.     

沿江低洼地有机无机肥配施对早稻生长和产量的影响

[目的]探明沿江双季稻区适宜紫云英、沼肥还田量和化肥施用量下水稻优质高产氮肥运筹技术.[方法]将不同比例的有机肥(紫云英、沼肥)与化学肥料配合施用,并设计不同的氮肥运筹方式,观测各施肥处理对早稻茎蘖动态、生育进程动态、经济性状和产量的影响.[结果]有机无机肥配施能促进早稻茎蘖生长,但与有机肥及其种类关系不大,而以氮肥运筹方式影响明显,施用紫云英后氮肥运筹方式为5:3:2萌蘖苗最多,氮肥后移水稻灌浆时期增长.施用紫云英或沼肥后不同氮肥运筹方式对水稻产量影响与单质化肥氮肥运筹结果一致,基、蘖、穗肥为5:3:2产量最高.[结论]早稻施用紫云英情况下,氮肥运筹方式宜采用基、蘖、穗肥比例为5:3:2的施肥方式.     

杂交水稻高产栽培精确施氮技术参数的确定及验证研究

[目的]确定并验证杂交水稻高产栽培精确施氮技术的3个重要参数.[方法]以黔优18、茂优601等品种为试材,在贵州省小河、乌当和兴义进行试验示范,求取了杂交籼稻精确定氮高产栽培中的3个重要参数,并对其进行了论证示范.[结果]3个参数分别为:①100 kg稻谷吸氮量:1.85 kg(迟熟籼稻)、1.82 kg(早熟籼稻);②土壤空白供氮量在95.92～133.41 kg/hm2;③氮肥当季利用率:当基蘖肥与穗肥比例为5∶5时,得出获取高产的氮肥当季利用率为45.18%(迟熟籼稻)、44.72%(早熟籼稻).根据获得的3个参数分别在当地进行示范,均获1.2 t/hm2以上产量.[结论]为指导贵州省不同稻区的科学施肥提供了理论依据.     

相同肥料用量紫云英与化肥配施对水稻生长及产量的影响

[目的]探讨在安徽省沿江及皖南稻区的双季水稻种植模式下,相同肥料用量紫云英与化肥配施对水稻生长发育及产量的影响.[方法]进行早稻施肥效应试验,分析水稻生长发育各期间生理指标、经济性状与不同施肥处理的关系.[结果]化肥-紫云英配施的水稻分蘖质量较高、有效穗较多;虽使水稻分蘖期和成熟期推迟,但对农业生产无显著影响;紫云英的肥效相对化肥较慢,第1季对产量的促进并不明显,但在第2季的增产明显.综合各个处理生长发育状况、经济性状和产量,60%化肥+40%紫云英配施是比较合适的化肥-紫云英配施比例.[结论]紫云英在一定程度上可以取代化肥,提供水稻生长发育需要的氮素,并且在比例、用量合理的情况下,第1季总体产量不受显著影响.作为绿肥,紫云英对后续作物及土壤的改善效应有待进一步研究.     

2个早稻品种最佳氮肥施用量研究

[目的]探讨2个早稻品种在江汉平原的最佳氮肥施用量.[方法]对两优9168和华两优103进行225、150和75 kg/hm2 3个不同氮肥施用量试验,筛选2个早稻品种的最佳氮肥施用量.[结果]供试品种间生育期差异未达显等水平,氮肥施用量对生育期影响极显著,随着氮肥施用量的减少,水稻全生育期有延长趋势;氮肥施用量对产量影响显著,随着氮肥施肥量的减少,产量呈递减趋势;氮肥施用量对经济系数影响显著.且均在150 kg/hm2 水平下经济系数最大.[结论]该研究为水稻生产提供了参考依据.     

不同密度和肥力条件对丰两优香一号产量及经济性状的影响

[目的]为优质超级杂交稻丰两优香一号的高产栽培技术体系的集成提供技术支撑.[方法]在大田试验条件下,比较不同种植密度与施氮量条件下丰两优香一号的产量及经济性状.[结果]在低密度条件下,增施氮肥有利于丰两优香一号产量的提高;而在高密度条件下增施氮肥反而会导致产量下降.在株行距19.0 cm×20.0 cm、谷秧2粒/穴、施氮肥180 kg/hm2条件下,产量较高.[结论]不同密度和肥力条件对丰两优香一号产量及经济性状都有显著影响.在浙江衢州中等肥力田种植,以种植密度26.25万穴/hm2左右,每穴2拉谷秧, 施纯氮180 kg/hm2左右为佳.     

施肥对潮土养分非匀衡化的土壤修复研究

[目的]研究施肥对不同处理的土壤修复作用.[方法]利用盆栽试验对长期不合理施肥导致土壤养分失衡及生产力下降的土壤进行施肥修复.[结果]试验结果表明:有机、无机肥配合施用是快速修复土壤养分和提高生产力的最佳方法;NP、NPK是既均衡土壤肥力又提高作物产量的无机肥施用方式;对土壤有效磷、氮极度缺乏的土壤,单施磷肥、氮肥效果极显著,其肥效在小麦上与NPK相同.[结论]长期施化肥的土壤对化肥的依赖性更强,停止施肥,玉米产量下降78.6%,小麦产量下降52.8%;而长期施NK和PK肥的土壤,停止施肥反而产量增加,NK处理玉米产量提高112%,小麦产量增加182%,PK处理中玉米产量增加15.1%,小麦产量增加59%;单施有机肥的当季效果不如化肥,但后效明显好于化肥.     

辽星1号高产高效栽培氮肥和密度管理研究

[目的]研究辽星1号高产高效栽培的肥密管理模式.[方法]以辽星1号为材料,研究不同氮肥水平、氮肥运筹方式及插秧密度对辽星1号产量、产量构成因子和经济效益的影响.[结果]最适施氮量为225 kg/hm2,产量为9 550.5 kg/hm2,经济效益最高;在此基础上,氮肥运筹方式以基肥∶蘖肥∶穗肥∶粒肥=4∶3∶2∶1的处理产量最高,比对照处理增产16.7%;插秧密度为33.3 cm×15.0 cm时辽星1号产量较高.[结论]适宜的氮肥管理模式和种植密度能够显著提高水稻产量.     

不同基肥施用量对连钱草生长情况及品质的影响

[目的]解决连钱草生产基肥的施用量问题.[方法]试验设4个基肥施用量处理:A.12 000 kg/hm<'2>(CK)、B.19 500 kg/hm<'2>、C.27 000 ks/hm<'2>、D.34 500 kg/hm<'2>;基肥用量的2/3栽前施于厢面,1/3移栽时施于窝内.[结果]连钱草生长势随着基肥施用量的增加有增加的趋势,封厢时间随基肥量的增加有提前的趋势.除处理D (34 500 kg/hm<'2>)中连钱草最大叶柄长、株高略劣于对照A(12 000kg/hm<'2>)外,其他处理的生长性状均优于对照A(12 000 kg/hm<'2>).连钱草产量随着基肥施用量的增加呈增加的趋势,但增幅逐步下降,施肥效用递减.[结论]连钱草较好的基肥施用量为19 500、27 000 kg/hm<'2>.     

不同施肥模式下玉米-土壤系统磷锌的动态变化

[目的]研究不同施肥模式下玉米-土壤系统磷锌的动态变化规律,为制定合理的玉米高产施肥模式提供理论依据.[方法]采用田间试验法,研究不同施肥模式下玉米干物质积累、产量及磷锌的动态变化规律.[结果]随着生育期的延长,各处理玉米干物质和磷锌积累量均呈"S"型变化;不同施肥模式中,各生育时期高产田的土壤速效磷较常规田和低产田分别提高6.2%～15.2%和41.6%～87.0%;成熟期植株干物重分别提高8.3%和25.4%,植株磷累积量分别增加14.6%和43.5%,植株锌累积量分别增加40.2%和74.0%.[结论]高产田中有机无机肥合理配施,玉米增产效果显著,产量达12 286.7 kg/hm2.     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.