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141.
怀九河小流域生态系统近自然定量评价 总被引:1,自引:0,他引:1
从怀九河小流域生态系统的生态特征、地貌特征和水体特征三个方面入手,利用由22个定量指标组成的北京小流域生态系统近自然评价体系,对作为北京怀柔水库重要的入库河流-怀九河进行了实际评价。结果显示:怀九河17个小流域中仅有1个处于自然状态,6个处于近自然状态,8个处于退化自然状态,2个处于人工状态,总体受到了较大的人为干扰。并对评价结果进行聚类分析,结果呈现高度的一致性,为该体系的普及和推广提供必要的参考依据。 相似文献
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围绕小水电代燃料上网电价测算的关键技术,对模型构建和系统实现两方面分别进行了探讨,在计算方法、计算流程、计算判别的边界条件和遵循的基本原则以及计算系统的总体结构和功能设计等方面进行了详细设计与实现,基本确定了较为合理的测算模型并完成了系统的程序开发,为政府部门评估小水电代燃料工程的可行性提供快速决策的依据. 相似文献
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The literature to date has mainly explored the impact on public mental health of green spaces around residential areas, large urban parks, family gardens, blue spaces, national parks, etc., while few studies have examined the association of Small Urban Green Spaces (SUGS) with public mental health. The role, function, and service radius of SUGS in urban people’s lives are quite different from those of general green spaces, and the relationship and mechanism linking general green spaces to mental health cannot be fully applied to small parks. This work was conducted to: 1) investigate the relationship between SUGS and mental health; 2) understand what factors affect mental health; 3) determine what kind of SUGS is more conducive to improving mental health. SUGS’ designs and physical characteristics were evaluated with the Natural Environment Scoring Tool (NEST) and user information for 10 SUGS (1–5 ha) in Shanghai in 2021 was collected via a questionnaire. We developed a multilevel model for exploring the factors affecting mental health from two aspects: the individual level and the park level. This study found that SUGS and mental health were positively associated. In addition to individual–level variables like income, marital status, social cohesion, and use frequency, park–level variables such as usability, aesthetics–natural features, and civilized environment are also conducive to improving mental health, while entertainment facilities in SUGS have a negative association with mental health. There was no evidence that visit frequency, stay time, social cohesion, or physical exercise act as a mediator between park features and mental health. This study provides empirical evidence for the positive correlation between SUGS and mental health and presents a means of promoting public mental health with efficient SUGS planning and management. 相似文献
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龙盛2号西瓜是黑龙江省农业科学院园艺分院育成的适宜保护地栽培的极早熟小型西瓜一代杂种。早熟,全生育期75d,果实发育期25d;果实高球形,果皮翠绿覆深绿色条带,果形端正,果个均匀,外观漂亮,果实膨大速度快;果皮薄,厚0.5cm;瓜瓤黄色,瓤质脆沙细嫩,味甜爽口,口感风味佳,中心可溶性固形物含量12.55%;单果重2.0~2.5kg,果皮韧性好;抗枯萎病、炭疽病;667m2产量架式栽培3200kg左右,爬地栽培2200~2700kg。适宜黑龙江省及气候相似地区春季保护地栽培。 相似文献
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AIM: To evaluate the changes of somatotropin axis in pre-pubertal rats with catch-up growth born small for gestational age (CUG-SGA). METHODS: The SGA rat model was prepared by diet restriction in pregnant rats.Growth hormone (GH) excretion in 24-h urine, serum level of insulin-like growth factor-1 (IGF-1), the expression of IGF-l and insulin-like growth factor-1 receptor (IGF-1R) in the tibial growth plate and the mRNA expression of IGF-1 in liver were measured in infant rats at the end of week 4. RESULTS: The level of 24-h urinary GH excretion in CUG-SGA group were significantly higher than that in the rats of non-catch-up growth born small for gestational age (NCUG-SGA) group and appropriate for gestational age (AGA) group (both P<0.01). The serum level of IGF-1 and the mRNA expression of IGF-1 in liver in CUG-SGA group were similar to those in AGA group, but significantly higher than those in NCUG-SGA group. The thickness of the tibial growth plate in NCUG-SGA group was significantly lower than that in CUG-SGA group and AGA group. No difference of the growth plate thickness between CUG-SGA group and AGA group was observed, but the thickness of hypertrophy zone of the growth plate in CUG-SGA group were significantly higher than that in NCUG-SGA group and AGA group (both P<0.01). The expression of IGF-1 in the growth plate in CUG-SGA group was similar to that in AGA group but significantly higher than that in NCUG-SGA group (P<0.01). No difference of the IGF-1R expression in the growth plate among these 3 groups was found (P>0.05). CONCLUSION: GH/IGF-1 resistance exists in SGA rats with and without catch-up growth. 相似文献
150.
JI Qian-kun LI Jian-bin FAN Yang-hua XU Bin CHAI Yi JI Chen-xing ZHU Xin-gen 《园艺学报》2017,33(2):263-270
AIM: To study the effect of centromere protein W (CENP-W) down-regulation on human glioma U87 cells.METHODS: Small interfering RNA (siRNA) was used to inhibit the expression of CENP-W in the U87 cells. The interference effect of siRNA was evaluated by RT-qPCR and Western blot. The proliferation of the cells was analyzed by MTT assay, BrdU staining and colony formation experiment. Transwell chamber assay was used to detect the invasion ability of the cells. The cell migration ability was measured by a scratch test. The changes of the cell cycle distribution and apoptosis were analyzed by flow cytometry.RESULTS: The results of MTT assay, colony formation experiment and BrdU staining showed that the cell proliferation and colony formation abilities in experimental group were significantly lower than those in control group and negative control group. The results of Transwell and scratch experiments showed that the migration and invasion abilities in experimental group were weaker than those in blank control group and negative control group. The results of flow cytometry analysis showed that the cell cycle distribution in experimental group was arrested in G0/G1 phase. The percentage of apoptotic cells in experimental group was higher than that in control group (P<0.05).CONCLUSION: Down-regulation of CENP-W expression inhibits the proliferation, migration and invasion of human glioma cells and promotes the apoptosis of the cells, suggesting that CENP-W may be a potential target of gene therapy for human glioma. 相似文献