The study was conducted in Zhifanggou Watershed,Shaanxi Province,China,to evaluate the effect of different vegetation types on hot-water extractable C,N and P fractions,with the aim to determine whether hot-water extr...The study was conducted in Zhifanggou Watershed,Shaanxi Province,China,to evaluate the effect of different vegetation types on hot-water extractable C,N and P fractions,with the aim to determine whether hot-water extractable fractions could be used as indicators of soil quality change in Loess Plateau.The six vegetation types established in 1975 were（i） Robinia pseudoacacia L.,（ii） Caragana korshinkii Kom.,（iii） Pinus tabulaeformis Carr.,（iv） P.tabulaeformis-Amorpha fruticosa L.,（v） R.pseudoacacia-A.fruticosa,and（vi） grassland.A cropped hillslope plot and a Platycladus orientalis L.native forest plot were used as references.The results indicated that the conversion of native forest to cropland resulted in a significant decline in the hot-water extractable C,N and P fractions.Hot-water extractable C,N,and P increased when cultivated land was revegetated,but after 30 years the amount of hot-water extractable C,N,and P in revegetated fields was still much lower compared to native forest.Hot-water extractable fractions increased more under mixed-forest than under pure-forest stands.Furthermore,there was a significant correlation between the hot-water extractable fractions and soil chemical and microbiological properties.The results showed that hot-water extractable fractions could be used as indicators of soil quality change on the Loess Plateau.展开更多
In this study, effects of hot water extract of Paecilomyces hepiali mycelia on hypertension parameters in spontaneously hypertensive rats (SHR) were investigated. The tested parameters included blood pressure, blood a...In this study, effects of hot water extract of Paecilomyces hepiali mycelia on hypertension parameters in spontaneously hypertensive rats (SHR) were investigated. The tested parameters included blood pressure, blood and urine biochemical composition, renin and angiotensin II levels in the blood. Prior to these tests, the extract was examined for toxicity. The fungus was cultivated in a solid medium composed of 40 g brown rice, 0.32 g glucose, 0.65 g sucrose, 2 g peptone and 65 ml corn steep liquor. No abnormality or harmful effects were observed in the toxicity test. Administration of a continuous-dose, once daily, to SHR for 27 weeks (from 13 weeks of age) decreased the systolic blood pressure (SBP) significantly. Levels of blood urea nitrogen, β-lipoprotein lipid peroxides and low density lipoprotein were significantly lower in the treated groups when compared to the control group. Urinary protein was significantly reduced in the middle and high dose groups. In comparison with the control group (0 mg/kg/10ml/day), significantly higher values were obtained for total cholesterol in groups that were given middle (170 mg/kg/10ml/day) and high (250 mg/kg/10ml/day) dosages. In all dosages (low, middle and high) the values for triglyceride were significantly higher than value found in the control group. In terms of angiotensin II levels, the value in the control group was markedly higher than values in the other groups. The results suggest that oral administration of hot water extract of P. hepiali mycelia has ability to control hypertension in rats.展开更多
Among the various techniques for enhancing the storage and consumption of energy in a thermal energy storage system,the establishment of thermal stratification in a hot-water container is an effective technology.The c...Among the various techniques for enhancing the storage and consumption of energy in a thermal energy storage system,the establishment of thermal stratification in a hot-water container is an effective technology.The current study aims to assess the performance of the thermal stratification for hot-water containers using(ANSYS Fluent)R.1.0,2022,through the study of the impact of different numbers of paraffin-filled containers,namely 3,5,and 7,that are equivalent to 5,7,and 9 kg of paraffin,respectively.To validate the present numerical model,a comparison between the current study results and the experimental findings from the literature was conducted,and the results demonstrated that there was a good approval between these results.The results of this study depict that the profile temperature at the outlet of the container indicates an enhancement in the Richardson number and stratification number by 37.9%and 45.8%,respectively,when the charging process is finished.Furthermore,increasing the number of paraffin-filled containers from 5 to 9 results in a 29.9%improvement in charging efficiency,resulting in an improvement in storage efficiency.Finally,the results have proven that the 3D CFD approach is a highly beneficial tool to assess the effect of PCM mass on stratification performance in a hot-water container.展开更多
Poplar wood chips were extracted in an acetic acid/sodium acetate(SA/AA)buffer solution at 180ºC for 60 minutes,with a solid-to-liquid ratio of 1:6,to investigate the effect of pH on the extraction performance in...Poplar wood chips were extracted in an acetic acid/sodium acetate(SA/AA)buffer solution at 180ºC for 60 minutes,with a solid-to-liquid ratio of 1:6,to investigate the effect of pH on the extraction performance in terms of chemical compositions of the extract.The pH was controlled by varying the concentrations of sodium acetate and acetic acid in the buffer system.Results showed that the SA/AA system could promote the dissolution of hemicellulose,obtaining more oligosaccharides and monosaccharides,and could also inhibit the excessive decomposition of monosaccharides.When extracting poplar wood chips in a SA/AA system of pH=3.7,the yield of oligosaccharides was the highest,while the contents of furfural and hydroxymethyl furfural decreased by 25%and 30%,respectively,compared to conventional water extraction systems.Moreover,the amount of lignin extracted in the S/AA process was also higher than that in a conventional hot water extraction process.展开更多
太阳能-空气源热泵热水系统(solar-air source heat pump hot water system, SAHWS)常用于宿舍楼宇供暖,通过对系统参数的优化设计可显著提高系统能效性能与环境友好性。为得到一种综合考虑SAHWS经济、能源、环保与节能的优化方法,提出...太阳能-空气源热泵热水系统(solar-air source heat pump hot water system, SAHWS)常用于宿舍楼宇供暖,通过对系统参数的优化设计可显著提高系统能效性能与环境友好性。为得到一种综合考虑SAHWS经济、能源、环保与节能的优化方法,提出了一种新型组合优化设计策略,并利用TRNSYS软件搭建系统仿真模型,以西安、西宁、拉萨这3座不同太阳能资源等级城市为例,对SAHWS运行工况对比分析。结果表明:与常用生命周期成本设计相比,所提出的组合优化设计不仅降低了系统成本,还有着较低的系统能耗;组合优化设计的热泵能耗与工作小时数最短,且有最低的热损,在投资成本、系统季节性能因子、太阳能保证率以及碳粉尘、二氧化碳排放量均有较好表现。展开更多
随着我国港口吞吐量日益增长,沿海水域交通变得繁忙且船舶事故时有发生。以舟山水域作为研究对象,利用热力图、DBSCAN聚类算法及Getis-Ord General G分析方法对舟山船舶事故数据进行综合分析,识别水域交通事故黑点,提供事故的空间分布,...随着我国港口吞吐量日益增长,沿海水域交通变得繁忙且船舶事故时有发生。以舟山水域作为研究对象,利用热力图、DBSCAN聚类算法及Getis-Ord General G分析方法对舟山船舶事故数据进行综合分析,识别水域交通事故黑点,提供事故的空间分布,并结合经纬度和事故严重程度信息揭示了潜在的高风险区域,从而为地区海事安全管理与事故预防提供科学依据。展开更多
基金financially supported by the Strategic Technology Project of Chinese Academy of Sciences,China(XDA05060300)the Science and Technology Research and Development Program of Shaanxi Province,China(2011KJXX63)the Fundamental Research Funds for the Central Universities,China(ZD2013021)
文摘The study was conducted in Zhifanggou Watershed,Shaanxi Province,China,to evaluate the effect of different vegetation types on hot-water extractable C,N and P fractions,with the aim to determine whether hot-water extractable fractions could be used as indicators of soil quality change in Loess Plateau.The six vegetation types established in 1975 were（i） Robinia pseudoacacia L.,（ii） Caragana korshinkii Kom.,（iii） Pinus tabulaeformis Carr.,（iv） P.tabulaeformis-Amorpha fruticosa L.,（v） R.pseudoacacia-A.fruticosa,and（vi） grassland.A cropped hillslope plot and a Platycladus orientalis L.native forest plot were used as references.The results indicated that the conversion of native forest to cropland resulted in a significant decline in the hot-water extractable C,N and P fractions.Hot-water extractable C,N,and P increased when cultivated land was revegetated,but after 30 years the amount of hot-water extractable C,N,and P in revegetated fields was still much lower compared to native forest.Hot-water extractable fractions increased more under mixed-forest than under pure-forest stands.Furthermore,there was a significant correlation between the hot-water extractable fractions and soil chemical and microbiological properties.The results showed that hot-water extractable fractions could be used as indicators of soil quality change on the Loess Plateau.
文摘In this study, effects of hot water extract of Paecilomyces hepiali mycelia on hypertension parameters in spontaneously hypertensive rats (SHR) were investigated. The tested parameters included blood pressure, blood and urine biochemical composition, renin and angiotensin II levels in the blood. Prior to these tests, the extract was examined for toxicity. The fungus was cultivated in a solid medium composed of 40 g brown rice, 0.32 g glucose, 0.65 g sucrose, 2 g peptone and 65 ml corn steep liquor. No abnormality or harmful effects were observed in the toxicity test. Administration of a continuous-dose, once daily, to SHR for 27 weeks (from 13 weeks of age) decreased the systolic blood pressure (SBP) significantly. Levels of blood urea nitrogen, β-lipoprotein lipid peroxides and low density lipoprotein were significantly lower in the treated groups when compared to the control group. Urinary protein was significantly reduced in the middle and high dose groups. In comparison with the control group (0 mg/kg/10ml/day), significantly higher values were obtained for total cholesterol in groups that were given middle (170 mg/kg/10ml/day) and high (250 mg/kg/10ml/day) dosages. In all dosages (low, middle and high) the values for triglyceride were significantly higher than value found in the control group. In terms of angiotensin II levels, the value in the control group was markedly higher than values in the other groups. The results suggest that oral administration of hot water extract of P. hepiali mycelia has ability to control hypertension in rats.
文摘Among the various techniques for enhancing the storage and consumption of energy in a thermal energy storage system,the establishment of thermal stratification in a hot-water container is an effective technology.The current study aims to assess the performance of the thermal stratification for hot-water containers using(ANSYS Fluent)R.1.0,2022,through the study of the impact of different numbers of paraffin-filled containers,namely 3,5,and 7,that are equivalent to 5,7,and 9 kg of paraffin,respectively.To validate the present numerical model,a comparison between the current study results and the experimental findings from the literature was conducted,and the results demonstrated that there was a good approval between these results.The results of this study depict that the profile temperature at the outlet of the container indicates an enhancement in the Richardson number and stratification number by 37.9%and 45.8%,respectively,when the charging process is finished.Furthermore,increasing the number of paraffin-filled containers from 5 to 9 results in a 29.9%improvement in charging efficiency,resulting in an improvement in storage efficiency.Finally,the results have proven that the 3D CFD approach is a highly beneficial tool to assess the effect of PCM mass on stratification performance in a hot-water container.
基金the National Natural Science Foundation of China(31540009 and 31370581)the Independent Innovation and Achievements Transformation Project of Shandong Province(2014CGZH0302)the Yellow River Mouth Scholar Program(DYRC20120105).
文摘Poplar wood chips were extracted in an acetic acid/sodium acetate(SA/AA)buffer solution at 180ºC for 60 minutes,with a solid-to-liquid ratio of 1:6,to investigate the effect of pH on the extraction performance in terms of chemical compositions of the extract.The pH was controlled by varying the concentrations of sodium acetate and acetic acid in the buffer system.Results showed that the SA/AA system could promote the dissolution of hemicellulose,obtaining more oligosaccharides and monosaccharides,and could also inhibit the excessive decomposition of monosaccharides.When extracting poplar wood chips in a SA/AA system of pH=3.7,the yield of oligosaccharides was the highest,while the contents of furfural and hydroxymethyl furfural decreased by 25%and 30%,respectively,compared to conventional water extraction systems.Moreover,the amount of lignin extracted in the S/AA process was also higher than that in a conventional hot water extraction process.
文摘太阳能-空气源热泵热水系统(solar-air source heat pump hot water system, SAHWS)常用于宿舍楼宇供暖,通过对系统参数的优化设计可显著提高系统能效性能与环境友好性。为得到一种综合考虑SAHWS经济、能源、环保与节能的优化方法,提出了一种新型组合优化设计策略,并利用TRNSYS软件搭建系统仿真模型,以西安、西宁、拉萨这3座不同太阳能资源等级城市为例,对SAHWS运行工况对比分析。结果表明:与常用生命周期成本设计相比,所提出的组合优化设计不仅降低了系统成本,还有着较低的系统能耗;组合优化设计的热泵能耗与工作小时数最短,且有最低的热损,在投资成本、系统季节性能因子、太阳能保证率以及碳粉尘、二氧化碳排放量均有较好表现。
文摘随着我国港口吞吐量日益增长,沿海水域交通变得繁忙且船舶事故时有发生。以舟山水域作为研究对象,利用热力图、DBSCAN聚类算法及Getis-Ord General G分析方法对舟山船舶事故数据进行综合分析,识别水域交通事故黑点,提供事故的空间分布,并结合经纬度和事故严重程度信息揭示了潜在的高风险区域,从而为地区海事安全管理与事故预防提供科学依据。
