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1.
[目的]研究不同浓度NaCl对油葵幼苗干、鲜重及离子吸收和分布的影响.[方法]采用不同浓度NaCl溶液模拟盐胁迫环境,测定油葵幼苗干、鲜重及离子含量.[结果]NaCl胁迫抑制油葵幼苗生长,降低了幼苗干、鲜重.叶片鲜重下降最明显,200mmol/L NaCl胁迫时下降约60%;子叶鲜重下降最少,200mmol/L NaCl时下降约13%.干重的下降程度同鲜重相似1200mmol/L NaCl胁迫时,根、茎、叶、子叶的干重与对照组相比分别下降约35%,39%,55%和8%.NaCl胁迫下,油葵幼苗根和茎中Na+含量上升,K+含量下降;Na+主要集中在根和茎中.叶片中较少;根中K+含量下降最明显,叶片中K+含量相对较高.根和茎中Ca+,Mg2+含量下降,叶片和子叶中Ca2+含量相对稳定,子叶中mg2+含量略上升.[结论]油葵幼苗在NaCl胁迫下保持较高的矿物质元素吸收和运输以及相对稳定的离子平衡,可能是油葵具有较高耐盐性的原因.  相似文献   

2.
[目的]研究不同浓度NaCl处理对菠菜幼苗各组织器官的影响.[方法]分别用0、10、50 mmol/L NaCl溶液处理菠菜幼苗,测定各处理下菠菜幼苗根、茎、叶的鲜重、干重,抗氧化酶活性,可溶性蛋白和丙二醛(MDA)含量.[结果]菠菜根在低NaCl浓度(10 mmol/L)处理下已与对照组产生明显不同,表现为舍水量下降、MDA含量明显升高、保护酶活性和可溶性蛋白含量下降的现象;菠菜叶在低NaCl浓度(10 mmol/L)处理下则表现为含水量、保护酶活性和可溶性蛋白含量的轻微下降,只有在高NaCl浓度(50 mmol/L)处理下才产生与根类似的反应;而一定浓度范围的NaCl对茎的生理指标影响均不大.[结论]菠菜不同组织器官对Nacl浓度的敏感程度不同,根反应最灵敏,叶的敏感性其次,而茎则只在高浓度NaCl下显现出生理指标的轻微下降.  相似文献   

3.
[目的]探讨外源水杨酸(SA)对番茄耐盐性的影响,为SA在番茄生产中的应用提供理论依据.[方法]在盐胁迫条件下,对番茄喷施不同浓度(1、2、5 mmol/L)的SA,测定其叶片叶绿素含量、可溶性糖含量、过氧化物酶(POD)活性、相对电导率及根系活力,研究外源SA处理对番茄幼苗耐盐性的影响.[结果]外源SA能不同程度地提高番茄叶片叶绿素含量、可溶性糖含量、POD活性和根系活力,而降低叶片相对电导率.其中浓度2 mmol/L SA对叶绿素含量、POD活性和相对电导率的影响最佳,而浓度5 mmol/L SA对可溶性糖和根系活力的影响较大.[结论]外源SA能够提高番茄幼苗的耐盐性,但适宜施用浓度和施用周期尚需进一步研究.  相似文献   

4.
[目的]获得苹果园化肥投入和土壤碱解氮、速效磷和速效钾的含量状况.[方法]对25个农户苹果园化肥投入进行调查,采集土壤样品进行测定分析.[结果]氮磷钾养分平均投入量为839.6、520.4、899.7 kg/hm<.2>,氮磷钾养分的投入比为1.00:0.62:1.07.0~60cm土壤碱解氮、速效磷、速效钾平均含量分别为53.49、70.73、180.10 mg/kg,土壤中碱解氮、速效磷、速效钾的比例为1.00:1.32:3.37.[结论]苹果园化肥投入总体水平比较高.土壤碱解氮的含量总体偏低,土壤速效磷的含量偏高,土壤速效钾的含量较高.  相似文献   

5.
[目的]探讨蕹菜(Lpomoea aquatica)幼苗对NH3-N和P的吸收动力学特性,为富营养化水体的生态修复提供参考.[方法]采用改进的常规耗竭法,用Michaelis-Menten方程来描述蕹菜对NH3-N吸收速率与溶液浓度的相互关系,用一元二次多项式表示营养液中P的浓度与时间的关系.[结果]蕹菜对NH3-N的最大吸收常数Vmax为2.162 μmol/(gFW·h),亲和力常数Km为0.403 mmol/L,NH3-N浓度为0~0.25 mmol/L,吸收速率随着浓度的升高而增加,超过该浓度范围,吸收速率不再增加,逐渐趋于饱和.对P的最大吸收速率为6.442 μg/(gFW·h),亲和力常数为0.65 mg/L,P的浓度随着吸收时间的延长而减少,导致P浓度的降低,从而使吸收速率也相应的降低.[结论]蕹菜对NH3-N和P的吸收效果良好.  相似文献   

6.
[目的]摸清川南地区烟草土壤氮钾供肥水平、烟叶的氮钾吸收利用规律.[方法]研究了泸州市植烟土壤氮钾舍量和变化水平,烟株不同时期生物量增长和增长率,烟叶氮钾吸收量和钾氮比.[结果]植烟土壤氮素供应和烤烟对氮素的吸收不好,钾素供应和吸收较好,钾含量和钾氮比高;烤烟移栽后15 d左右土壤氯钾含量过高,流失严重.中后期不足,生物量较低,烤烟旺长期后移,烤烟生物量增长与氮钾供应不协调.[结论]应减少前期氮钾供应量,加大和调整移栽后45~75 d氮钾供应,保持移栽后75 d后一定量钾素的供应.提高烤烟生物量和烟叶舍钾量.  相似文献   

7.
[目的]研究土地利用方式对土壤养分剖面分布的影响.[方法]对北运河下游武清区土壤取样,测定土壤养分(pH、碱解氮、有效磷、速效钾、有机质)和土壤机械组成,结合武清区土地利用方式进行分析.[结果]不同土地利用方式对土壤机械组成有一定的影响,土壤剖面养分含量变化趋势为:有机质、碱解氮含量基本上呈抛"S"形分布,速效钾呈"U"形分布,而有效磷含量呈直线下降趋势.不同土地利用方式下耕层养分差异较明显.[结论]有效磷、有机质、碱解氮、速效钾含量具有一定的表聚性,以有效磷含量最有代表性.  相似文献   

8.
[目的]评价生物有机肥料的环境效应,进一步改善生物有机肥的性能.[方法]施用生物有机肥,研究生物有机肥时土壤氨挥发和土壤氮、磷、钾淋溶的影响.[结果]施用生物有机肥后果园根区域土壤氯挥发损失率减少;与施用化肥相比,氮、磷、钾的淋溶损失率减少.[结论]施用生物有机肥可以减少土壤中氨挥发损失和氮、磷、钾的淋溶损失,增强土壤的保肥性能.  相似文献   

9.
[目的]研究滁菊原产地域保护区土壤有机质和土壤养分的相关性,为滁菊原产地域保护区土壤精准化管理提供依据.[方法]采集滁菊原产地域保护区108个样品,对土壤有机质、全氮、全磷、全钾和速效氮、速效磷、速效钾含量进行了测定,并分析有机质与土壤养分的相关性.[结果]滁菊土壤中有机质含量与全氮、全磷、全钾、速效氮、速效磷含量表现为0.01水平显著正相关,与速效钾含量不存在相关性.[结论]滁菊原产地域保护区土壤有机质可以作为土壤营养状况的主要判断指标.  相似文献   

10.
[目的]研究不同浓度烯效唑浸种对小麦幼苗生长的影响.[方法]分别用0、20、40、60 mg/L烯效唑浸种处理,研究其对小麦幼苗形态指标和生理指标的影响.[结果]与对照相比,20、40、60 mg/L烯效唑处理后,幼苗株高分别降低9.35、10.78、12.16 cm,根干重分别增加7.18%、4.39%、1.73%.根冠比分别增加30.3%、20.5%、16.4%.总叶绿素含量分别增加8.9%、27.1%、37.8%,丙二醛含量分别降低28.7%、16.1%、6.9%,呼吸强度分别降低61.1%、19.6%、16.9%;烯效唑浓度为20 和40 mg/L时,根系活力分别增加53.8%、19.4%,而60 mg/L时根系活力比对照组降低11.3%.[结论]小麦生产过程中,烯效唑使用浓度以20 mg/L为宜.  相似文献   

11.
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)  相似文献   

12.
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.  相似文献   

13.
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".  相似文献   

14.
张兴强  叶运福 《冶金设备》2005,(6):71-72,47
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。  相似文献   

15.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
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。  相似文献   

16.
In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.  相似文献   

17.
18.
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。  相似文献   

19.
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.  相似文献   

20.
为了编制实用性强的基地建设行动方案,首先,确定参与式发展的主体,搭建一个"决策框架";其次,针对行动目标,提出不同参与主体,如管理者、农民、消费者等团队与个人的目标及行动内容;最后,工作应向重塑伙伴式合作关系,挖掘农民自我发展潜力,完成三大角色的转换,打造农业基地文化等方向推进.  相似文献   

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