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天然草地植被覆盖度的高光谱遥感估算模型 总被引:8,自引:3,他引:8
利用ASD FieldSpec Pro FRTM光谱仪,对内蒙古自治区锡林郭勒盟的天然草地进行高光谱遥感地面观测,并计算天然草地植被覆盖度;选择25个高光谱特征变量与天然草地植被覆盖度进行相关性分析.结果表明,共有17个变量通过极显著性检验,尤以红边波长范围内一阶微分波段值总和(SDr)的相关系数0.781为最高在此基础上将观测数据分成两组:一组观测数据作为训练样本(n=49),运用单变量线性、非线性和逐步回归方法,建立植被覆盖度高光谱遥感估算模型;另一组观测数据作为检验样本(n=32),进行精度检验分析结果显示,采用逐步回归分析方法,运用冠层原始反射率数据估算草地植被覆盖度的效果并不理想;而以红边波长范围内一阶微分波段值的总和(SDr)为变量的线性回归方程是最佳估算模型,模型标准差为10.4%,估算精度为83.99%. 相似文献
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大豆植株不同冠层种子活力及其萌发中抗氧化酶活性 总被引:1,自引:0,他引:1
以吉农15号和吉农24号大豆(Glycine max)品种为材料,根据植株高度平均分为下部、中下部、中部、中上部和上部5个冠层,分析不同冠层种子百粒重、种子活力及萌发7天子叶中抗氧化酶活性和丙二醛含量的变化。结果表明,随着植株冠层的升高,大豆百粒重呈先略上升后逐渐下降的趋势,上部冠层种子的百粒重最小。大豆植株下部与中下部冠层种子的发芽率和发芽势较高;并且该两层的种子活力指数显著高于中上部与上部冠层,种子萌发后幼苗的茎粗也显著大于中上部及上部冠层幼苗。下部与中下部冠层种子萌发时子叶中的抗氧化酶活性高于上部,而丙二醛含量低于上部,说明该两层的大豆种子活力高,萌发后幼苗健壮且子叶新陈代谢旺盛,是优选良种的最佳冠层。 相似文献
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Yongmei Hou Peicheng Hu Yanping Liang Zhanyu Mo 《Cell biochemistry and biophysics》2014,69(3):531-537
The objective of the study was to evaluate the effects of cognitive behavioral therapy [sleep-related behavior modification and progressive muscle relaxation on insomnia of maintenance hemodialysis (MHD) patients] on improving insomnia of MHD patients. 103 MHD patients complicated with insomnia were randomly assigned to treatment (n = 52) and control (n = 51) groups. The control group was treated with conventional hemodialysis, and the treatment group was additionally treated with cognitive behavioral therapy for 3 months (sleep-related behavior modification and progressive muscle relaxation). All cases were assessed by Symptom Checklist 90 (SCL-90) and Pittsburgh Sleep Quality Index (PSQI) before and 2, 4, 6, 8, 10, and 12 weeks after treatment. Fifty-one patients in the treatment group and 47 patients in the control group completed the experiments. After treatment, the total mean scores were (1.94 ± 0.50/2.29 ± 0.31); scores of somatization, depression, anxiety, hostility, and additional items were (1.87 ± 0.58/2.56 ± 0.26), (2.25 ± 0.80/2.79 ± 0.50), (1.79 ± 0.26/2.37 ± 0.34), (1.71 ± 0.46/2.25 ± 0.43), and (1.91 ± 0.67/2.26 ± 0.59) in SCL-90, respectively. The total scores for PSQI were (12.63 ± 2.27/16.40 ± 2.16); scores of subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, hypnotics, and daytime dysfunction which were (1.98 ± 0.76/2.57 ± 0.58), (1.75 ± 0.59/2.60 ± 0.50), (2.10 ± 0.50/2.62 ± 0.53), (2.06 ± 0.47/2.57 ± 0.54), (2.04 ± 0.69/2.45 ± 0.72), (1.02 ± 0.79/1.51 ± 0.98), and (1.69 ± 0.55/2.09 ± 0.58), respectively, were significantly lower in the treatment group compared with the control group. However, there were no significant differences in the scores of factors of obsessive–compulsive (2.26 ± 0.62/2.32 ± 0.38), interpersonal sensitivity (2.23 ± 0.64/2.43 ± 0.47), phobic anxiety (1.98 ± 0.62/2.01 ± 0.67), paranoid ideation (1.55 ± 0.43/1.69 ± 0.39), and psychoticism (1.57 ± 0.46/1.66 ± 0.49). The conclusion is that sleep-related behavior modification in combination with progressive muscle relaxation effectively improved the mental state and sleep quality of MHD patients with insomnia. 相似文献