研究以计算化学的相关知识为基础,利用GAUSSIAN软件包,Multiwfn和VMD等专业软件把化学知识中抽象的概念进行可视化。通过“视觉传达”理念的运用,以达到增加学习兴趣、加深理解化学概念的目的。研究以芳香环定位效应、分子间(内)的氢键...研究以计算化学的相关知识为基础,利用GAUSSIAN软件包,Multiwfn和VMD等专业软件把化学知识中抽象的概念进行可视化。通过“视觉传达”理念的运用,以达到增加学习兴趣、加深理解化学概念的目的。研究以芳香环定位效应、分子间(内)的氢键及影响酸性的因素和π键特性为例,分别采用了双描述法/福井函数,约化密度梯度法/相互作用区域指示函数法(Reduced Density Gradient/Interaction Region Indicator,RDG/IRI)和电子定域性(Localized Orbital Locator,LOL)的图形分析。该方法所涉及的图形制作易于掌握,并在未来的教学实践和教材制作质量提供参考。展开更多
To identify the main sources responsible for soil heavy metal contamination, 70 topsoils were sampled from the Daxing County in the urban-rural transition zone of Beijing. The concentrations of heavy metals Cu, Zn, Pb...To identify the main sources responsible for soil heavy metal contamination, 70 topsoils were sampled from the Daxing County in the urban-rural transition zone of Beijing. The concentrations of heavy metals Cu, Zn, Pb, Cr, Cd, Ni, As, Se, Hg, and Co; the soil texture; and the organic matter content were determined for each soil sample. Descriptive statistics and geostatistics were used to analyze the data, and Kriging analysis was used to estimate the unobserved points and to map the spatial patterns of soil heavy metals. The results showed that the concentrations of all the soil heavy metals exceeded their background levels with the exception of As and Se. However, only the Cd concentration in some areas exceeded the critical value of the national soil quality standard. The semivariance analysis showed that the spatial correlation distances for soil Cu, Zn, Cr, Cd, As, Ni, and Co ranged from 4.0 to 7.0 km, but soil Se, Pb, and Hg had a larger correlation distance. Soil Co, Se, Cd, Cu and Zn showed a strong spatial correlation, whereas the other soil heavy metals showed medium spatial correlation. Soil heavy metal concentrations were related to soil texture, organic matter content, and the accumulation of heavy metals in the soils, which was because of air deposition and use of water from the Liangshui, Xinfeng, and Fenghe rivers that are contaminated by wastewater and sewage for the purpose of irrigation of fields. Hence, a comprehensive treatment plan for these rivers should be formulated.展开更多
In China, rural settlements are usually multifunctional complex of natural societies and they also play important productive function. This study explored the spatiotemporal evolution of the productive function of thr...In China, rural settlements are usually multifunctional complex of natural societies and they also play important productive function. This study explored the spatiotemporal evolution of the productive function of three rural settlements, i.e.,Hetaoyuan, Dawengshan, and Gaoqiao, in the Yimeng Mountain in Shandong province of eastern China.Residents lived in this three types of rural settlements were all involved in agricultural production(i.e., grain threshing, drying and storage), which had remained dominant in Hetaoyuan. Dawengshan became an industrial-oriented settlement, while Gaoqiao became a commercial-oriented settlement. This evolution was reflected in the livelihood strategy changes of rural households and the transition of rural settlements changes. The choice of livelihood strategy was affected by the livelihood assets and policies, which resulted in the spatiotemporal evolution of the productive function of rural settlements. This study can provide references for the implementation and adjustment of rural residential land consolidation policies and the improvement of production and the quality of rural life in future.展开更多
To probe into regulating functions of allicin, diallyldisulfid-S-oxide, on electron transport in the inner membrane of mitochondria isolated from beef heart, under the anaerobic, hypoxia, and oxygenating conditions in...To probe into regulating functions of allicin, diallyldisulfid-S-oxide, on electron transport in the inner membrane of mitochondria isolated from beef heart, under the anaerobic, hypoxia, and oxygenating conditions in the presence of rotenone（complex I inhibitor） at 37 ℃, we optimized the isolation method for isolating mitochondria from beef heart and used the technique for measuring dissolved oxygen content at the right moment so as to investigate the effects of allicin on the respiratory control of mitochondria in state 4 and state 3, P/O ratio, and respiratory control ratio（RCR）. The results show that the optimized isolated requirements were that all the operations were always kept at 0-4 ℃, the ratio between sample and isolation medium was 1：4, the filter was a four-layer gauze, two centrifugations in different sections. First section： 2500g, 10 min; second section 7000g, 20 min. The results indicate that the capacity of dissolved oxygen in state 3 was increased and that of dissolved oxygen in state 4 was almost stabilized in mitochondria from beef heart.展开更多
文摘研究以计算化学的相关知识为基础,利用GAUSSIAN软件包,Multiwfn和VMD等专业软件把化学知识中抽象的概念进行可视化。通过“视觉传达”理念的运用,以达到增加学习兴趣、加深理解化学概念的目的。研究以芳香环定位效应、分子间(内)的氢键及影响酸性的因素和π键特性为例,分别采用了双描述法/福井函数,约化密度梯度法/相互作用区域指示函数法(Reduced Density Gradient/Interaction Region Indicator,RDG/IRI)和电子定域性(Localized Orbital Locator,LOL)的图形分析。该方法所涉及的图形制作易于掌握,并在未来的教学实践和教材制作质量提供参考。
基金Project supported by the National Natural Science Foundation of China (Nos. 40401025 and 49871005)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0412)
文摘To identify the main sources responsible for soil heavy metal contamination, 70 topsoils were sampled from the Daxing County in the urban-rural transition zone of Beijing. The concentrations of heavy metals Cu, Zn, Pb, Cr, Cd, Ni, As, Se, Hg, and Co; the soil texture; and the organic matter content were determined for each soil sample. Descriptive statistics and geostatistics were used to analyze the data, and Kriging analysis was used to estimate the unobserved points and to map the spatial patterns of soil heavy metals. The results showed that the concentrations of all the soil heavy metals exceeded their background levels with the exception of As and Se. However, only the Cd concentration in some areas exceeded the critical value of the national soil quality standard. The semivariance analysis showed that the spatial correlation distances for soil Cu, Zn, Cr, Cd, As, Ni, and Co ranged from 4.0 to 7.0 km, but soil Se, Pb, and Hg had a larger correlation distance. Soil Co, Se, Cd, Cu and Zn showed a strong spatial correlation, whereas the other soil heavy metals showed medium spatial correlation. Soil heavy metal concentrations were related to soil texture, organic matter content, and the accumulation of heavy metals in the soils, which was because of air deposition and use of water from the Liangshui, Xinfeng, and Fenghe rivers that are contaminated by wastewater and sewage for the purpose of irrigation of fields. Hence, a comprehensive treatment plan for these rivers should be formulated.
基金supported by the National Natural Science Foundation of China(Grant Nos.41671519 and 41771560)
文摘In China, rural settlements are usually multifunctional complex of natural societies and they also play important productive function. This study explored the spatiotemporal evolution of the productive function of three rural settlements, i.e.,Hetaoyuan, Dawengshan, and Gaoqiao, in the Yimeng Mountain in Shandong province of eastern China.Residents lived in this three types of rural settlements were all involved in agricultural production(i.e., grain threshing, drying and storage), which had remained dominant in Hetaoyuan. Dawengshan became an industrial-oriented settlement, while Gaoqiao became a commercial-oriented settlement. This evolution was reflected in the livelihood strategy changes of rural households and the transition of rural settlements changes. The choice of livelihood strategy was affected by the livelihood assets and policies, which resulted in the spatiotemporal evolution of the productive function of rural settlements. This study can provide references for the implementation and adjustment of rural residential land consolidation policies and the improvement of production and the quality of rural life in future.
基金Supported by the National Natural Science Foundation of China(Nos.30570404 and 30670458)
文摘To probe into regulating functions of allicin, diallyldisulfid-S-oxide, on electron transport in the inner membrane of mitochondria isolated from beef heart, under the anaerobic, hypoxia, and oxygenating conditions in the presence of rotenone（complex I inhibitor） at 37 ℃, we optimized the isolation method for isolating mitochondria from beef heart and used the technique for measuring dissolved oxygen content at the right moment so as to investigate the effects of allicin on the respiratory control of mitochondria in state 4 and state 3, P/O ratio, and respiratory control ratio（RCR）. The results show that the optimized isolated requirements were that all the operations were always kept at 0-4 ℃, the ratio between sample and isolation medium was 1：4, the filter was a four-layer gauze, two centrifugations in different sections. First section： 2500g, 10 min; second section 7000g, 20 min. The results indicate that the capacity of dissolved oxygen in state 3 was increased and that of dissolved oxygen in state 4 was almost stabilized in mitochondria from beef heart.
