水杨酸对盐胁迫下西瓜种子萌发特性的影响     

韩志平  张海霞  高迎  安志鹏 《雁北师范学院学报》2011,27(5)

采用培养皿发芽法,研究了水杨酸浸种对盐胁迫下西瓜种子萌发和幼苗生长的影响。结果表明,300mmol/L NaCl溶液浸种显著降低了西瓜种子的发芽率、发芽势、发芽指数和活力指数及胚根长和胚芽鲜重;1.0mmol/L以下浓度水杨酸浸种使盐胁迫下西瓜种子萌发和幼苗生长量随水杨酸浓度提高而显著增加;2.0 mmol/L水杨酸浸种对盐胁迫下西瓜种子萌发和幼苗生长无明显影响,3.0 mmol/L水杨酸浸种进一步降低了盐胁迫下西瓜种子萌发和幼苗生长量。结果说明,较低浓度水杨酸浸种可缓解盐胁迫对西瓜种子萌发和幼苗生长的抑制作用,减轻西瓜种子萌发期盐胁迫伤害的最适水杨酸浓度为1.0 mmol/L。  相似文献   

由周作人“文学的自由”与“文艺的宽容”引发的思考     

郝艳萍 《楚雄师范学院学报》2011,26(2):7-11

曾高举"人的文学"的大旗、"五四"时期走在时代前列的周作人,在20、30年代却渐从新文学主潮的带头人变为他所说的"自由的思想者",主张"文学的自由"与"文艺的宽容"。但他的理论与行为成矛盾状态,于是引发了笔者对他所提出的这两个理论所涉及到的一些问题的思考:功利主义文学观与非功利主义文学观能否并存,文学批评是否应该讲究"宽容"。  相似文献   

Influence of organization learning on innovation output in manufacturing firms in Kenya     

《国际创新研究学报(英文)》2020,4(1):16-26

Knowledge entrepreneurship is increasingly becoming important in driving innovation for high levels of competitiveness. The purpose of this study was to investigate the relationship between Organization Learning (OL) and Innovation Output (IO) for improved performance in manufacturing firms in Kenya. The theoretical underpinnings on this study are the Schumpeter’s (1934) innovation theory of and the Gleick (1987) complexity theory. The methodology used was mixed method research because it provides a more holistic understanding of a thematic area. The research design that was used is cross-sectional design because it allows for making observations on different characteristics that exist within a group at a particular time. The target population was manufacturing firms across the country. Multi-stage sampling strategy was used to sample 303 respondents from 101 firms. Primary and secondary data were used to collect both qualitative and quantitative data. The questionnaire, interview schedule and a checklist of key informants were used to collect data. Content validity was used to ascertain the credibility of the research procedure and internal consistency technique was used to test for reliability. Correlation and linear regression were used to determine the relationship between OL and IO. Work disruptions were avoided by making prior arrangements and appointments. The findings indicate that OL has a significant influence on IO. It is recommended that lifelong learning, management support and risk tolerance should be encouraged to improve creativity. High creativity is important in raising the capacity to integrate internal and external knowledge for greater levels of IO. Further research should be carried out to find how customers and suppliers information can be utilized to enriched OL.  相似文献   

云科-18选3的孕穗期耐冷性评价及遗传研究   总被引：1，自引：0，他引：1  

李楠 《河池学院学报》2007,27(2):72-76

在湛江2004和2005年度,于自然条件下对237个水稻材料进行大田分期播种试验和人工气候箱定温试验。并对所有这些材料进行孕穗期耐冷性评价,其中来源于云南农科院并经单株选择的云科-18选3能耐受12℃的低温,是所有供试材料中最为耐冷的。用云科-18选3作母本与不耐冷材料R6067作父本杂交,以低温条件下的自交结实率作为孕穗期的耐冷性评价指标,采用王建康等分析软件,研究表明云科-18选3孕穗期耐冷性受一对主效基因控制。  相似文献   

求解非线性伏尔泰拉积分方程的有限差分方法     

苟斐斐  刘建军  刘卫东  罗莉涛 《中国科学院大学学报》2016,33(3):329-333

研究一类典型的伏尔泰拉积分方程的数值求解方法.通过数值差分离散积分方程,然后将积分方程演化为非线性代数方程组,通过迭代推进求解此类积分方程.分析这种求解方法的代数精度,证明此数值解法的精度高达Δt²阶,可以满足工程计算需要.通过数值仿真验证,数值解与解析解的误差为10^-5.如果采用更高阶的数值积分离散方式,可以获得更高阶精度.  相似文献   

Responses to oral glucose challenge differ by physical activity volume and intensity: A pilot study     

Trevor N. Simper  Cecile Morris  Anthony Lynn  Ciara O'Hagan  Karen Kilner 《运动与健康科学(英文)》2020,9(6):645-650

BackgroundOne-hour postprandial hyperglycemia is associated with increased risk of type 2 diabetes and cardiovascular disease. Physical activity (PA) has short-term beneficial effects on post-meal glucose response. This study compared the oral glucose tolerance test results of 3 groups of people with habitually different levels of PA.MethodsThirty-one adults without diabetes (age 25.9 ± 6.6 years; body mass index 23.8 ± 3.8 kg/m²; mean ± SD) were recruited and divided into 3 groups based on self-reported PA volume and intensity: low activity < 30 min/day of moderate-intensity activity (n = 11), moderately active ≥ 30 min/day of moderate-intensity PA (n = 10), and very active ≥ 60 min/day of PA at high intensity (n = 10). Participants completed an oral glucose tolerance test (50 g glucose) with capillary blood samples obtained at baseline, 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min post-ingestion.ResultsThere were no significant differences between groups for age or body fat percentage or glycated hemoglobin (p > 0.05). The groups were significantly different in terms of baseline glucose level (p = 0.003) and, marginally, for gender (p = 0.053) and BMI (p = 0.050). There was a statistically significant effect of PA on the 1-h postprandial glucose results (p = 0.029), with differences between very active and low activity groups (p = 0.008) but not between the moderately active and low activity groups (p = 0.360), even when baseline glucose level and gender differences were accounted for. For incremental area under the curve there was no significant effect of activity group once gender and body fat percentage had been accounted for (p = 0.401). Those in the low activity group took 15 min longer to reach peak glucose level than those in the very active group (p = 0.012).ConclusionThe results suggest that high levels of PA have a beneficial effect on postprandial blood glucose profiles when compared to low and moderate levels of activity.  相似文献   

昆虫抗寒性的生理机制及影响因子   总被引：1，自引：0，他引：1  

梅增霞  李建庆 《滨州学院学报》2006,22(3):57-61

昆虫是外温动物,在长期的进化过程中形成了一整套适应不良低温环境的抗寒机制.现主要总结了耐寒昆虫与耐冻昆虫对低温适应的生理机制以及环境因子对昆虫抗寒能力的影响作用.  相似文献   

甲醛法测定铵盐中总氮含量的有关问题讨论   总被引：1，自引：0，他引：1  

宋萍 《宜春学院学报》2003,25(2):39-39,68

对用甲醛法测定铵盐中总氮含量的测定原理、含量计算、以及实验注意条件等进行讨论，确保实验成功，提高样品测定结果的准确度．  相似文献   

植物金属硫蛋白及其在自由基清除中的作用   总被引：6，自引：0，他引：6  

全先庆  高翔 《临沂师范学院学报》2003,25(6):64-66

金属硫蛋白是一种诱导表达蛋白，是很好的羟自由基清除蛋白，其清除能力主要来源于蛋白中处于还原态的巯基．  相似文献   

Short-term reliability of inflammatory mediators and response to exercise in the heat     

Joshua H. Guy  Andrew M. Edwards  Catherine M. Miller  Glen B. Deakin  David B. Pyne 《Journal of sports sciences》2017,35(16):1622-1628

Prospective application of serum cytokines, lipopolysaccharide (LPS), and heat shock proteins (eHSPs) requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (7 day) reliability (at rest, n = 12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60-min cycling, 34.5°C and 70% RH, n = 20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin-6 (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and LPS. Test–retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-participant variation were IL-6 (19%, ±20%; CV, ±95% confidence limits (CL)) and LPS (23%, ±13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28–38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ±11%, P = < 0.001) and although CRP had a modest CV (12%, ±7%), it increased substantially post-exercise (P = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation.  相似文献