pH及浓度对次氯酸钠除藻效果的影响

[目的]研究次氯酸钠在不同浓度和不同pH条件下对羊角月牙藻的杀灭效果.[方法]以细胞数和叶绿素a作为检测项目,研究次氯酸钠在不同条件下对羊角月牙藻的杀灭效果以及叶绿素a褪色后的藻细胞活性.[结果]次氯酸钠浓度越高,叶绿素a的褪色效果越好,但细胞数减少量变化不明显.在3mg/L的NaClO条件下,pH为4.7的藻液中叶绿素a褪色率(62%)是pH为9.4(5%)的12倍.叶绿素a褪色率为95%和100%的藻液离心后重新接种到新鲜培养基中,藻细胞的数量呈逐渐下降趋势.[结论]pH越低,次氯酸钠的除藻效果越好.叶绿素a褪色后藻细胞失去了生长繁殖的能力.通过调节pH和NaClO浓度相结合的方法可有效抑制藻类生长,控制藻类的爆发.     

芘胁迫对玉米幼苗生长及生理指标的影响

[目的]探讨芘胁迫对玉米幼苗生长及生理指标的影响.[方法]通过水培试验,研究了4个浓度(0、0.5、1.0和2.0 mg/L)的芘对2种玉米市祥1号(敏感品种)和广甜3号(耐性品种)幼苗生长及生理指标的影响.[结果]在试验浓度范围内,随芘浓度的升高,市祥1号叶绿素a和叶绿素b含量呈先升高后降低的趋势,相对生长量和绝对生长速率呈下降趋势,根系和叶片丙二醛(MDA)含量呈上升趋势;广甜3号相对生长量、绝对生长速率和叶绿素a含量呈先上升后下降趋势,叶绿素b和根系MDA含量呈上升趋势,叶片MDA含量呈下降趋势.与对照相比,市祥1号在0.5～1.0 mg/L芘处理对叶绿素a和叶绿素b含量显著增加,芘浓度≥2.0 mg/L时则显著降低,芘浓度≥1.0 mg/L时根系和叶片MDA含量显著增加,而相对生长量和绝对生长速率显著降低;广甜3号在芘浓度≥1.0 mg/L时叶绿素a和叶绿素b含量显著增加.芘浓度与敏感品种市祥1号的相对生长量和绝对生长速率呈显著负相关,与根系MDA含量呈显著正相关;芘浓度与耐性品种广甜3号叶绿素b含量和根系MDA含量呈显著正相关.[结论]为玉米苗期的管理措施提供了依据.     

信号分子N-乙酰高丝氨酸内酯(AHLs)诱导铜绿微囊藻细胞凋亡的研究

[目的]研究信号分子N-乙酰高丝氨酸内酯(AHLs)与铜绿微囊藻细胞凋亡的关系.[方法]以铜绿微囊藻为试验材料,采用5μmol/L AHLs处理铜绿微囊藻细胞,用DAPI染色后观察细胞凋亡的形态.[结果]AHLs在I μmol/L浓度下能诱导铜绿微囊藻的细胞凋亡,从而抑制铜绿微囊藻的生长和增殖.[结论]该研究结果为治理铜绿微囊藻水华爆发提供了科学依据.     

滇池凤眼莲生长对水生植物的影响

[目的]探讨入侵植物凤眼莲生长对滇池水生植物的影响.[方法]通过测定不同月份滇池浮游植物、沉水植物(篦齿眼子菜)的叶绿素含量,结合凤眼莲根培养液对铜绿微囊藻的化感作用,探讨凤眼莲生长对滇池水生植物的影响.[结果]滇池凤眼莲生长降低了浮游植物及沉水植物(篦齿眼子菜)的叶绿素含量,对二者的生长有一定的抑制作用;凤眼莲根培养液明显抑制了铜绿微囊藻的生长.[结论]该研究为滇池凤眼莲生态安全防控提供了科学依据.     

镍胁迫对玉米苗根系生长及膜保护系统的影响

[目的]研究镍(Ni<'2+>)胁迫对玉米(Zea mays L.)根系生长及膜保护系统的影响.[方法]以玉米为材料,研究了不同浓度Ni<'2+> 胁迫对玉米幼苗根系生长、根系活力及根系中超氧化物歧化酶(SOD)、过氧化物酶(POD)活性和丙二醛(MDA)含量的影响.[结果]不同浓度Ni<'2+> 处理对玉米幼苗根系具有低浓度的促进效应和高浓度的抑制效应,且随着浓度的增加抑制效应逐渐增强.根系长度、鲜重、根系活力、SOD活性、POD 活性、MDA 含量在3个处理阶段(10、30、30 d)变化趋于相同;随着玉米幼苗的生长,各项指标变化更加明显.根系活力在Ni<'2+>浓度为50 mg/kg(土)时最强,随着Ni<'2+>浓度的升高而逐渐减弱;根系保护酶系统中SOD和POD活性随着Ni<'2+>浓度的增加而呈现先升高后下降的变化趋势,在Ni<'2+>浓度为50 mg/kg(土)时出现峰值;根系细胞内MDA 含量在低Ni<'2+>浓度处理下增幅较小,Ni<'2+>浓度在100～800 mg/kg(土)时增加显著.[结论]Ni<'2+> 浓度低于50 mg/kg(土)时对玉米幼苗期根系的生长有促进作用,而超过该浓度则表现为抑制作用,Ni<'2+>浓度越高,抑制作用越明显.     

累托石/Cu_2O光催化剂对微囊藻的杀灭性能研究

利用累托石/Cu_2O纳米复合光催化剂在可见光照射下进行光催化杀灭铜绿微囊藻的实验研究,考察了Cu_2O与累托石/Cu_2O纳米复合材料在不同的光强以及不同的材料量下对降解铜绿微囊藻效果的影响,发现Cu_2O与累托石复合之后形成的材料加强了光催化降解铜绿微囊藻的效果,同时,复合材料用量为0.1g/L条件下可以达到最佳的降解效果,测定藻细胞叶绿素a的浓度可以达到96%左右。说明累托石/Cu_2O纳米复合材料在可见光条件下具有很好的降解铜绿微囊藻的效果。     

多氯联苯对2种微藻的急性毒性研究

[目的]研究多氯联苯对海洋浮游植物的急性毒性.[方法]选择珠江口海域赤潮优势种锥状斯氏藻和热带骨条藻进行多氯联苯急性毒性试验,研究其半效应浓度(EC<,50>),分析多氯联苯对其生长以及超氧化歧化酶(SOD)和过氧化氢酶(CAT)的影响.[结果]多氯联苯对锥状斯氏藻、热带骨条藻生长有明显的抑制作用,对2种藻类的96 h半效应浓度(EC<,50>)分别为0.103和0.009 mg/L.低浓度多氯联苯对2种微藻的SOD和CAT活性有诱导作用.当多氯联苯浓度超过一定阈值,酶活性下降;与锥状斯氏藻相比,热带骨条藻对多氯联苯暴露更敏感,耐受力较差.[结论]该研究为深入研究持久性污染物对海洋浮游植物的毒性效应提供了依据.     

水芹水浸提液对小球藻生长及抗氧化酶活性的影响

[目的]研究水芹水浸提液对小球藻生长及其抗氧化酶活性的影响.[方法]采用小球藻在不同浓度的水芹水浸提液中纯培养的方法,测定小球藻生长速率、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、·O2- 产生速率及丙二醛(MDA)含量的变化.[结果]10g/L水芹水浸提液处理下,SOD和POD活性逐步上升,至试验结束时都维持在较高的水平,·O2-产生速率和MDA含量与对照间无显著差异;20～50 g/L水芹水浸提液处理,藻细胞的SOD、POD活性、·O2-产生速率及MDA含量均呈先开高后降低的趋势,并且有浓度效应.[结论]水芹水浸提液对小球藻具有化惑效应.10 g/L水芹水浸提液对小球藻的生长具有明显的促进效应,20～50 g/L水芹水浸提液对小球藻有明显的克生作用.     

La~(3+)对盐胁迫下钝顶节旋藻色素含量及抗氧化酶活性的影响

以内蒙古高原碱湖土著钝顶节旋藻为实验材料,用0.3 mol/L的Na Cl进行盐胁迫处理,研究了盐胁迫处理条件下不同浓度La3+对节旋藻生长速率,叶绿素a、类胡萝卜素含量以及抗氧化酶活性的影响。结果表明:La3+处理浓度为24.75μmol/L~40.98μmol/L处理4 d后,CAT、POD活性明显增强(P0.05);处理10 d,La3+处理浓度为8.31μmol/L~40.98μmol/L可促进节旋藻叶绿素a的合成,24.75μmol/L~57.01μmol/L处理组类胡萝卜素含量最高;不同La3+浓度处理组藻细胞的生长速率差异不显著(P0.05)。     

野生乳头百合组织培养及快速繁殖研究

[目的]筛选野生乳头百合组织培养最适宜的培养基.[方法]以野生乳头百合的鳞片、株芽、茎段和叶片为外植体进行组织培养.采用的基本培养基为:MS、B5和White,各培养基均附加0.03 mg/L NAA.分化培齐基设置4种配方:MS+2.00 mg/L 6-BA+0.20mg/L NAA、MS+0.20 mg/L 6-BA+1.00mg/L IAA、MS+0.10 mg/L KT+0.10 mg/L NAA、MS+0.03mg/L NAA.继代增殖培养基设6种配方:MS+0.03 mg/L NAA、MS+2.00 mg/L 6-BA+0.20 mg/L NAA、MS+0.20 mg/L 6-BA+1.00 mg/L IAA、MS+0.10 mg/L KT、MS+0.20 mg/L KT+0.20 mg/L NAA、MS+0.10mg/L KT十0.15 mg/L NAA.生根培养基设置4种配方:MS+1.00 mg/L IBA、MS+1.00mg/L IBA+0.20mg/L 6-BA、1/2MS+1.00mg/L IBA+0.20mg/L 6-BA、White+1.00mg/L IBA+0.20mg/L 6-BA.[结果]MS最适基本培养基;鳞片在MS+0.03 mg/LNAA上分化效果最好;株芽和叶片在MS+2.00 mg/L6-BA+0.20 mg/LNAA中分化效果最好;茎段在MS+0.20 mg/L IAA从中培养效果最好;最适的继代增殖培养基为MS+0.10 mg/LKT+0.15 mg/LNAA;无根子球和小苗在1/2MS+0.20mg/L6-BA+1.00 mg/L IBA上易生根.在大田栽培中,以鳞片和株芽为外植体的组培苗生长状况较好,生长能力强.[结论]该研究筛选出野生乳头百合最佳的快速繁殖培养基,为野生乳头百合的快速繁殖奠定了基础.     

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。     

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。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

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.     

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.     

参与式农业基地建设行动方案设计

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.