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Hydroxysafflor yellow A protects against thioacetamide-induced liver fibrosis in rats via suppressing proinflammatory/fibrogenic mediators and promoting hepatic stellate cell senescence and apoptosis
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作者 Sayed H.Seif el-Din Olfat A.Hammam +4 位作者 Shahira M.Ezzat Samira Saleh Marwa M.Safar Walaa H.El-Maadawy Naglaa M.El-Lakkany 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2023年第8期348-358,共11页
Objective:To evaluate the effect of hydroxysafflor yellow A(HSYA)on thioacetamide-induced liver fibrosis.Methods:Thioacetamide was administered to rats intraperitoneally in doses of 200 mg/kg twice a week for 12 weeks... Objective:To evaluate the effect of hydroxysafflor yellow A(HSYA)on thioacetamide-induced liver fibrosis.Methods:Thioacetamide was administered to rats intraperitoneally in doses of 200 mg/kg twice a week for 12 weeks.Thioacetamide-intoxicated rats were given silymarin(50 mg/kg)or HSYA(5 mg/kg)orally every day for 8 weeks.Liver enzymes,fibrosis markers,histological changes as well as immunohistochemistry of TNF-α,IL-6,p21,α-SMA,and caspase-3 were examined.The effect of HSYA on HSC-T6 activation/proliferation and apoptosis was also determined in vitro.Results:HSYA decreased liver enzymes,TNF-α,IL-6,and p21 expressions,hepatic PDGF-B,TIMP-1,TGF-β1,and hydroxyproline levels,as well as fibrosis score(S2 vs.S4)compared to the thioacetamide group.HSYA also downregulatedα-SMA while increasing caspase-3 expression.Surprisingly,at 500μg/mL,HSYA had only a slightly suppressive effect on HSC proliferation,with a 9.5%reduction.However,it significantly reduced TGF-β1,inhibitedα-SMA expression,induced caspase-3 expression,and promoted cell senescence.Conclusions:HSYA may be a potential therapeutic agent for delaying and reversing the progression of liver fibrosis.More research on HSYA at higher doses and for a longer period is warranted. 展开更多
关键词 Hydroxysafflor yellow A THIOACETAMIDE Hepatic stellate cells Inflammatory markers Liver fibrosis p21 α-SMA ApOpTOSIS
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棉籽壳基质在 P.ostreatus生长过程中组份与微结构的变化及其对菌糠饲用价值的影响(英文) 被引量:9
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作者 李秀金 庞云芝 张瑞红 《农业工程学报》 EI CAS CSCD 北大核心 2001年第1期96-100,共5页
对棉籽基质在栽培 P.ostreatus过程中不同时期的干物质及主要组份含量进行了测定。对其微观结构的变化进行了显微观察。分析了组份与微观结构的变化对菌糠饲用价值的影响。结果表明 :与初始料相比 ,菌糠具有较高的干物质消化率 ,因而有... 对棉籽基质在栽培 P.ostreatus过程中不同时期的干物质及主要组份含量进行了测定。对其微观结构的变化进行了显微观察。分析了组份与微观结构的变化对菌糠饲用价值的影响。结果表明 :与初始料相比 ,菌糠具有较高的干物质消化率 ,因而有可能用作反刍动物的饲料。 展开更多
关键词 棉籽壳 菌糠 组份 饲料 饲用价值 食用菌废栽培
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P.ostreatus 8101菌株木质素降解酶的研究 被引量:2
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作者 刘尚旭 《重庆教育学院学报》 2002年第6期45-47,87,共4页
用对Bavendamm反应呈强阳性,对RB亮蓝显色能力强弱的方法,从40余株大型真菌中选出具有漆酶活力的属白腐茵的糙皮侧耳8101菌株.再测试该茵三种胞外木质素降解酶活性、产酶条件比较以及对麦草木质素降解能力分析,结果表明,8101的Lac、Lip... 用对Bavendamm反应呈强阳性,对RB亮蓝显色能力强弱的方法,从40余株大型真菌中选出具有漆酶活力的属白腐茵的糙皮侧耳8101菌株.再测试该茵三种胞外木质素降解酶活性、产酶条件比较以及对麦草木质素降解能力分析,结果表明,8101的Lac、Lip、Mnp与Cel、Hcel活性均高.因此,糙皮侧耳茵8101菌株可以考虑为秸杆木质索降解酶能力较强菌株之一. 展开更多
关键词 p.ostreatus8101菌株 木质素降解酶 真菌 漆酶 木质素过氧化物酶 锰过氧化物酶 纤维素 半纤维素 活性 造纸工业 废物处理
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多角度分析P.ostreatus改性对玉米秸厌氧消化产气性能的影响
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作者 黄文博 袁海荣 李秀金 《可再生能源》 CAS CSCD 北大核心 2021年第5期569-575,共7页
为提高玉米秸厌氧消化产气性能,采用Pleurotus ostreatus对其进行45 d改性试验。通过研究和分析不同改性时间的玉米秸对纤维素酶和木聚糖酶的吸附性、水解性及甲烷转化性的影响发现,经P. ostreatus改性25 d的玉米秸对纤维素酶和木聚糖... 为提高玉米秸厌氧消化产气性能,采用Pleurotus ostreatus对其进行45 d改性试验。通过研究和分析不同改性时间的玉米秸对纤维素酶和木聚糖酶的吸附性、水解性及甲烷转化性的影响发现,经P. ostreatus改性25 d的玉米秸对纤维素酶和木聚糖酶吸附率分别提高了42.5%和21.0%,纤维素酶和木聚糖酶水解率分别提高12.9%和75.3%,甲烷产率为272 mL/g,较对照组提高了16.7%,甲烷转化速率提高了19.0%,生物降解性提高了19.7%。研究结果表明,P. ostreatus改性能够提高玉米秸厌氧消化性能,最佳改性时间为25 d。 展开更多
关键词 多角度分析 p.ostreatus 玉米秸 酶吸附 酶水解 厌氧消化
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Autumn living coccolithophores in the Yellow Sea and the East China Sea 被引量:2
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作者 BAI Jie GU Xiaoyao +4 位作者 FENG Yuanyuan JIANG Wensheng JIN Haiyan CHEN Jianfang SUN Jun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第8期83-94,共12页
An investigation was carried out on living coccolithophores (LCs) distribution in the Yellow Sea and the East China Sea from October 17 to November 24, 2011. A total of 223 samples from different depths were col-lec... An investigation was carried out on living coccolithophores (LCs) distribution in the Yellow Sea and the East China Sea from October 17 to November 24, 2011. A total of 223 samples from different depths were col-lected at 48 stations. Totally 18 taxa belonging to coccolithophyceae were identified using a polarized micro-scope at the 1 000× magnification. The maximum species abundance was found at the outside of Transect P. The dominated species wereGephyrocapsa oceanica, Emiliania huxleyi,Helicosphaera carteri,andAlgiros-phaera robusta.The abundance of coccoliths and cells ranged 0-2 965.73 coccoliths/mL, and 0-119.16 cells/mL, with the average values of 471.00 coccoliths/mL and 23.42 cells/mL, respectively. The LCs in surface layer were mainly observed on the coastal belt and middle part of the survey area. The comparison among Transects A, F, P and E indicated lower species diversity and less abundance in the Yellow Sea than those of the East China Sea. The highest abundance of LCs was found in transect F and P. The coccolith abundance increased slightly from surface to bottom in the water column, but the highest value of the cell abundance was observed in the depth of 10-30 m. Temperature, depth and nutrient concentration were suggested as the major environmental factors controlling the distribution and species composition of LCs in the studying area based on canonical correspondence analysis (CCA). 展开更多
关键词 living coccolithophore geographic distribution yellow Sea East China Sea Transect p
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甘南黄河流域4种典型林分土壤C、N、P化学计量特征 被引量:2
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作者 刘婕 勾晓华 +5 位作者 刘建国 杨海江 李改香 李琴霞 瓦锦明 刘改香 《生态学报》 CAS CSCD 北大核心 2023年第13期5627-5637,共11页
土壤碳(C)、氮(N)、磷(P)是参与植物光合作用和影响生态系统初级生产力的主要元素。甘南高原是黄河流域重要的生态屏障,为了解该区不同林分土壤养分状况的差异,选取该区4种典型林分:云杉林、华北落叶松林、巴山冷杉林以及岷江冷杉糙皮... 土壤碳(C)、氮(N)、磷(P)是参与植物光合作用和影响生态系统初级生产力的主要元素。甘南高原是黄河流域重要的生态屏障,为了解该区不同林分土壤养分状况的差异,选取该区4种典型林分:云杉林、华北落叶松林、巴山冷杉林以及岷江冷杉糙皮桦混交林为研究对象,研究土壤C、N、P化学计量特征。结果表明:(1)岷江冷杉及糙皮桦混交林土壤C、N含量最高,云杉林土壤N、P含量最低。不同林分间P含量差异显著(P<0.05),不同土层间C、N含量差异均显著(P<0.05)。(2)云杉林土壤C∶N值显著高于其他林分,岷江冷杉及糙皮桦混交林土壤N∶P及C∶P高于其他林分。(3)海拔、土壤pH、容重与土壤含水量是影响土壤养分的重要因素。土壤C含量与N、P含量均显著相关(P<0.05)。总体来说,不同林分土壤化学计量特征具有显著差异,混交林土壤养分状况较纯林好,未来森林管理和植被建设中,可以通过选择合适的树种和提高树种多样性有效改善森林土壤质量。 展开更多
关键词 黄河流域 土壤C、N、p含量 化学计量特征 不同林分 海拔梯度
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Degradation of Oxo-Degradable-Polyethylene and Polylactic Acid Films Embodied in the Substrate of the Edible Fungus <i>Pleurotus ostreatus</i> 被引量:1
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作者 Dalia Santa Cruz-Navarro Rosa María Espinosa-Valdemar +2 位作者 Margarita Beltrán-Villavicencio Alethia Vázquez-Morillas Maribel Velasco-Pérez 《Natural Resources》 2014年第15期949-957,共9页
Degradable plastic mulch is being used to overcome the negative environmental impacts of burning and landfilling agricultural plastic waste. In this study P. ostreatus was used to model the capacity of a vegetal speci... Degradable plastic mulch is being used to overcome the negative environmental impacts of burning and landfilling agricultural plastic waste. In this study P. ostreatus was used to model the capacity of a vegetal species to degrade conventional and degradable plastic films. Plastics studied were oxo-degradable polyethylene (OXO-PE), UV-irradiated oxo-degradable polyethylene (UV-OXO-PE), polylactic acid (PLA) and conventional polyethylene (C-PE). The cultivation of P. ostreatus resulted in a reduction in the median of weight (78.2% - 80.2%) and volume (56.1% - 60.1%) of the substrate (wheat straw). Degradation of the plastics embodied was evidenced by a reduction in the median of the elongation at break (OXO-PE 475% to 109%, UV-OXO-PE 23% to 8%, PLA 596% to 398% and C-PE 505% to 304%) and an increase in the median of the carbonyl index (OXO-PE 0.062 to 0.114, UV-OXO-PE 0.098 to 0.145 and PLA 0.024 to 0.034). The Kruskal-Wallis test found no statistical difference (p = 0.384) between the medians of the biological efficiency for substrates containing plastics and the substrate without plastic. In conclusion, plastics embodied in the substrates used for cultivation of P. ostreatus are degraded and the degradation of these plastics does not affect the short term growth of P. ostreatus. 展开更多
关键词 plastic DEGRADATION p. ostreatus Mechanical properties CARBONYL Index Biological Efficiency
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Relationships Between Tidal Prism and Throat Area of Tidal Inlets Along Yellow Sea and Bohai Sea Coasts 被引量:4
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作者 Zhang Renshun and Wang Yaping Professor, Dept. of Geography, Nanjing Normal University, Nanjing 210024 Lecturer, Nanjing Normal University, Nanjing 210024 《China Ocean Engineering》 SCIE EI 1996年第2期229-238,共10页
The relationship between P (spring tidal prism) and A (throat area below mean sea level) is statistically analysed in terms of 29 tidal inlets or bays along the Huanghai Sea (Yellow Sea) and Bohai Sea coasts. For 15 o... The relationship between P (spring tidal prism) and A (throat area below mean sea level) is statistically analysed in terms of 29 tidal inlets or bays along the Huanghai Sea (Yellow Sea) and Bohai Sea coasts. For 15 of these tidal inlets, the best regression equation is A(km2) = 0.845 />(km3)1.20. The analysis shows that C and n are little different from those in the P-A relationship for the inlets of the South China Sea and East China Sea coasts. It is noted that the relationship between P and A is unstable because of the difference in sediment abundance. The study shows that a united P-A relationship can be obtained for the tidal inlets of lagoon type and bay-drowned-valley type, not containing some half-circle shape bays which confront deep water. These half-circle bays do not belong to tidal inlets because they do not have enough sediment abundance and are fairly open. 展开更多
关键词 tidal inlet p-A relationship Huanghai Sea (yellow Sea) Bohai Sea
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THE N/P RATIO IN THE NORTHERN SOUTH YELLOW SEA IN AUTUMN 被引量:1
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作者 林荣根 W.D.Yoon +1 位作者 吴景阳 马丽 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2002年第4期384-388,共5页
Study of horizontal and vertical distributions of the N/P (nitrogen versus phosphate) atom ratio in the northern South Yellow Sea showed that the ratio varied greatly in upper waters of the investigated area and was a... Study of horizontal and vertical distributions of the N/P (nitrogen versus phosphate) atom ratio in the northern South Yellow Sea showed that the ratio varied greatly in upper waters of the investigated area and was always much greater than the theoretical Redfield ratio of 16:1 found below the thermocline zone. It was in general higher near the coast and lower in the central part. With increasing depth, the ratio became smaller and smaller. This distribution pattern is attributed to: 1) the anthropogenic influence of the surface N and P which makes the N/P ratio differ from the normal value; 2) the easy adsorption of P on particles hinders P transport to the central part; 3) below the thermocline zone, the N and P mainly come from the remineralization of the sedimented phytoplankton residues which have almost the theoretical Redfield value and; 4) the existence of the Yellow Sea Bottom Cold Water which inhibits the vertical exchange of the water. 展开更多
关键词 氮/磷比率 黄海 秋季 分布规律 垂直分布 水平分布
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Effects of Metal Ions on the Activity of Cellulase Produced by Pleurotus ostreatus and Pleurotus eryngii
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作者 Hong Pei Shu Yilin Ke Lixia 《Meteorological and Environmental Research》 CAS 2015年第10期34-36,共3页
[ Objectivel The study aims to discuss the effects of metal ions on the activity of Pleurotus ostreatus and Pleurotus eryngii cellulose. [ Method] 0.5 mmol/L FeSO4, CuSO4, MnSO4 and ZnSO4 solutions were added to the b... [ Objectivel The study aims to discuss the effects of metal ions on the activity of Pleurotus ostreatus and Pleurotus eryngii cellulose. [ Method] 0.5 mmol/L FeSO4, CuSO4, MnSO4 and ZnSO4 solutions were added to the basal culture media containing silkworm excrement and rice husk, and the effects of metal ions on activity of FPA and Cx enzyme produced by P. ostreatus and P. eryngiiwere analyzed. [ Resultl The addi- tion of Zn2. and Mn~* to the basal culture media containing silkworm excrement and rice husk was beneficial to the improvement of the activity of FPA and Cx enzyme produced by P. ostreatus and P. eryngii, while the addition of Fe2+ and Cu2. inhibited the activity of the cellulase. EConclu- sion I The research could provide theoretical references for improvement of utilization rate of cellulase in silkworm excrement and rice husk. 展开更多
关键词 Metal ions p/eurotus ostreatus pleurotus eryngii FpA Cx enzyme China
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Soil Phosphorus Release to the Water Bodies in the Upland Fields of Yellow Soil Areas and Impacting Factor
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作者 LIU Fang LUO Hai-bo +3 位作者 SU Yin-ge LIU Yuan-sheng HE Teng-bin LONG Jian 《Agricultural Sciences in China》 CAS CSCD 2005年第12期916-923,共8页
Soil phosphorus release to the water bodies in the upland fields of yellow soil areas and impacting factor was studied in Guizhou province. The results showed that the content of dissolved active P of surface runoff f... Soil phosphorus release to the water bodies in the upland fields of yellow soil areas and impacting factor was studied in Guizhou province. The results showed that the content of dissolved active P of surface runoff from various upland fields of yellow-soil were significantly different, which the concentrations of dissolved active P of runoff correlated with the contents of available-P, amorphous oxides of A1, and organic matter in the soils. The amount of soil phosphorus release to the water bodies affected by the level of applying P fertilizer and the process of corn growth, which with fertilizing from 150 to 900 kg P205 ha^-1 in the soil with high P level, the average contents of dissolved active P in the permeability-water of the soil increased from 0.020 mg L^-1 to 0.137 mg L^-1. The amount of soil phosphorus release to the water bodies also affected by environmental factor, which the amount of soil phosphorus release significantly increased under the conditions that temperature is 30℃-35℃, water/soil ratios is 15:1-25:1, submergence-time by water is 12-18 h and pH value of acid rains is 3.82-3.73. 展开更多
关键词 Upland fields of yellow soil Soil F release Dissolved active p of runoff Impacting factor
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SiO_(2)-CTAB复合材料的制备及其对PNP的吸附性能
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作者 田月 董晓涵 苏毅 《化工进展》 EI CAS CSCD 北大核心 2023年第11期6064-6075,共12页
以黄磷炉渣为硅源,十六烷基三甲基溴化铵(CTAB)为负载剂,制备二氧化硅基复合吸附剂(SiO_(2)-CTAB)并研究其对废水中对硝基苯酚(PNP)的吸附性能。考察吸附过程中吸附温度、溶液pH、吸附剂投入量、PNP初始浓度和吸附时间对吸附效果的影响... 以黄磷炉渣为硅源,十六烷基三甲基溴化铵(CTAB)为负载剂,制备二氧化硅基复合吸附剂(SiO_(2)-CTAB)并研究其对废水中对硝基苯酚(PNP)的吸附性能。考察吸附过程中吸附温度、溶液pH、吸附剂投入量、PNP初始浓度和吸附时间对吸附效果的影响;探究吸附过程动力学、热力学及吸附剂再生性能并采用扫描电子显微镜、能量色散光谱仪、X射线光电子能谱、傅里叶变换红外光谱仪等手段对相关物质进行表征。结果表明:在实验研究范围内,最佳吸附条件为温度20℃、pH=6、吸附剂投入量1.5g/L。该条件下,对PNP最大吸附容量为157.2mg/g;对50mg/L的PNP模拟废水去除率可达96.95%。该吸附剂对PNP的吸附过程符合拟二级动力学模型,Langmuir吸附等温线模型能很好地描述该吸附行为。 展开更多
关键词 二氧化硅 十六烷基三甲基溴化铵 吸附材料 对硝基苯酚 黄磷炉渣
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Effects of low molecular weight organic acids on sorption and desorption behavior of p-chlorophenol by yellow earth
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作者 Daoyong ZHANG Xiangliang PAN +2 位作者 Shuimu LIAO Chenglin HUANG Jingmei ZHANG 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期133-133,共1页
关键词 黄土 吸附作用 有机酸 氯酚 土壤化学
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平菇、杏鲍菇和白灵菇菌丝多糖对·OH、DPPH·和NO_2^-的体外清除作用 被引量:25
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作者 刘海英 张运峰 +1 位作者 范永山 刘青 《中国农学通报》 CSCD 北大核心 2010年第17期26-30,共5页
为明确平菇、白灵菇和杏鲍菇菌丝多糖对·OH、DPPH·和NO2-自由基的清除能力。利用热水浸提法提取菌丝多糖,Sevag法纯化多糖,利用多功能酶标仪测定对·OH、DPPH·(1,1-diphenyl-2-picrylhydrazyl)、NO2-的清除率,利用DP... 为明确平菇、白灵菇和杏鲍菇菌丝多糖对·OH、DPPH·和NO2-自由基的清除能力。利用热水浸提法提取菌丝多糖,Sevag法纯化多糖,利用多功能酶标仪测定对·OH、DPPH·(1,1-diphenyl-2-picrylhydrazyl)、NO2-的清除率,利用DPS软件和MicroOrigin软件进行数据分析。结果表明,在200~2000μg/mL浓度范围内,白灵菇B10、杏鲍菇PL7和平菇P89菌丝多糖对DPPH·的清除率为5.98%~51.96%,EC50值分别为1.98、2.74和3.28mg/mL;对·OH清除率为43.51%~98.09%,PL7的EC50值溢出最小值,B10和P89的EC50值分别为49.6μg/mL和467.3μg/mL;对NO2-的清除率为10.22%~26.75%,P89的EC50值为5.3mg/mL,PL7和B10的菌丝多糖浓度高于500μg/mL时,清除率不再增加,最高值分别为18.53%和17.52%。菌种间抗氧化能力差异明显,同一菌株对不同自由基的清除能力也存在显著差异。3种供试菌种多糖具有较强的清除·OH能力,中等的清除DPPH·能力和较差的清除NO2-能力。杏鲍菇PL7和白灵菇B10菌丝多糖的清除·OH和DPPH·能力较强,而平菇P89具有较强的清除NO2-能力。 展开更多
关键词 平菇 白灵菇 杏鲍菇 菌丝多糖 体外清除 自由基
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p,p′-DDT在黄河兰州段沉积物上的吸附/解吸特性及影响因素研究 被引量:4
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作者 杨志群 姚焕炬 +2 位作者 任婷 成刚 高宏 《农业环境科学学报》 CAS CSCD 北大核心 2010年第1期174-179,共6页
采用批量平衡实验,研究了黄河兰州段沉积物对p,p′-DDT的吸附/解吸特性,并考察了环境因素温度、pH值、沉积物粒度等对吸附的影响。结果表明,p,p′-DDT在黄河兰州段沉积物上的吸附在24h内可以充分达到平衡。吸附过程是非线性的,Freundlic... 采用批量平衡实验,研究了黄河兰州段沉积物对p,p′-DDT的吸附/解吸特性,并考察了环境因素温度、pH值、沉积物粒度等对吸附的影响。结果表明,p,p′-DDT在黄河兰州段沉积物上的吸附在24h内可以充分达到平衡。吸附过程是非线性的,Freundlich模型可以较好地描述吸附行为,分配作用和表面吸附作用同时存在;解吸过程存在明显滞后性,即解吸要比吸附困难。正交结果表明吸附质浓度和吸附剂浓度对p,p′-DDT在沉积物上的吸附量有显著影响,而温度、pH值、有机质含量、沉积物粒度影响不显著。 展开更多
关键词 黄河 沉积物 p p′-DDT 吸附 影响因素
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兰州盆地黄河800ka B.P.阶地的发现及其古地磁年代 被引量:11
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作者 胡春生 潘保田 +1 位作者 苏怀 李吉均 《地理科学》 CSCD 北大核心 2009年第2期278-282,共5页
兰州东盆地的枣树沟黄河第四级阶地(T4),砾石层顶高出黄河河面84 m,其上堆积厚约64 m的风成黄土,黄土地层中包括八层古土壤,最底部发育了古土壤S8。光释光(OSL)测年结果显示古土壤S1上部的年龄为70.4±7.6 ka。黄土古土壤对比以及... 兰州东盆地的枣树沟黄河第四级阶地(T4),砾石层顶高出黄河河面84 m,其上堆积厚约64 m的风成黄土,黄土地层中包括八层古土壤,最底部发育了古土壤S8。光释光(OSL)测年结果显示古土壤S1上部的年龄为70.4±7.6 ka。黄土古土壤对比以及磁性地层学研究表明,枣树沟T4上覆风成黄土的年龄为865 ka,T4至少形成于865 ka B.P.。 展开更多
关键词 兰州盆地 黄河阶地 800ka B.p. 古地磁年代 发现
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不同生境条件下滨海芦苇湿地C、N、P化学计量特征 被引量:31
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作者 屈凡柱 孟灵 +3 位作者 付战勇 孙景宽 刘京涛 宋爱云 《生态学报》 CAS CSCD 北大核心 2018年第5期1731-1738,共8页
为阐明不同生境对黄河三角洲滨海芦苇湿地土壤和植物碳(C)氮(N)磷(P)含量及生态化学计量特征的影响,选取新生湿地和退耕湿地两种湿地类型为研究对象,对土壤和植物体C、N、P含量及其化学计量特征进行研究。研究表明:1)退耕芦苇湿地土壤TC... 为阐明不同生境对黄河三角洲滨海芦苇湿地土壤和植物碳(C)氮(N)磷(P)含量及生态化学计量特征的影响,选取新生湿地和退耕湿地两种湿地类型为研究对象,对土壤和植物体C、N、P含量及其化学计量特征进行研究。研究表明:1)退耕芦苇湿地土壤TC、TN的含量明显增加,TP的含量变化不大。2)新生湿地和退耕湿地土壤R_(C、N、P)分别为42.6:1.6:1、71.2:2.0:1,R_(NP)低于全球平均水平(13.1)和我国平均水平(5.2),土壤表现为N限制。新生湿地土壤剖面中,R_(CN)和R_(CP)变化剧烈;R_(NP)值随深度的增加而减小;退耕湿地土壤R_(C、N、P)值规律性较好,R_(CN)随深度的增加而变大,R_(CP)和R_(NP)值随深度的增加而减小。3)新生湿地和退耕湿地中芦苇整株R_(CN)、R_(CP)和R_(NP)平均值分别为78.2、1753、22.4;67.0、1539、23.0。开垦活动可以降低芦苇植物体R_(CN)和R_(CP)值,但由于芦苇植物体本身对R_(NP)的约束性较高,对R_(NP)值的影响不大,芦苇植株R_(NP)约为23。以上结论可以为黄河三角洲国家级自然保护区正在进行的湿地保护与恢复工作提供借鉴和参考。 展开更多
关键词 C、N p化学计量特征 不同生境 滨海芦苇湿地 黄河三角洲
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Labrasol对肠P-糖蛋白功能的影响 被引量:5
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作者 林玉莲 蒋学华 +3 位作者 杨俊毅 周静 张铃敏 山本昌 《华西药学杂志》 CAS CSCD 北大核心 2005年第2期139-142,共4页
目的 研究Labrasol对肠P -糖蛋白功能的影响。方法 用大鼠的离体肠段,通过体外Ussingchamber的转运实验,研究了Labrasol对P -糖蛋白底物若丹明1 2 3转运的影响,同时考察了非P -糖蛋白底物荧光黄在Labrasol作用下的转运行为。结果 低... 目的 研究Labrasol对肠P -糖蛋白功能的影响。方法 用大鼠的离体肠段,通过体外Ussingchamber的转运实验,研究了Labrasol对P -糖蛋白底物若丹明1 2 3转运的影响,同时考察了非P -糖蛋白底物荧光黄在Labrasol作用下的转运行为。结果 低浓度(0 .0 5 %~0 .0 75 %)的Labrasol能够抑制回肠与结肠中P -糖蛋白的功能。同时,对荧光黄的转运无显著影响。结论 Labrasol有望作为P -糖蛋白抑制剂,用于改善受P -糖蛋白介导药物的吸收,提高口服药物的生物利用度。 展开更多
关键词 p-糖蛋白 LABRASOL Ussing CHAMBER 荧光黄 若丹明123
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粉土p-y曲线的试验研究 被引量:31
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作者 王腾 王天霖 《岩土力学》 EI CAS CSCD 北大核心 2009年第5期1343-1346,共4页
进行了浸水黄河粉土中模型钢管桩的水平静力荷载试验,对试验弯矩用6阶多项式进行拟合,推得了黄河粉土的p-y曲线,并与API建议砂土和软黏土p-y曲线进行了比较。根据粉土试验p-y曲线,提出了黄河粉土p-y曲线的理论表达式,用此理论p-y曲线进... 进行了浸水黄河粉土中模型钢管桩的水平静力荷载试验,对试验弯矩用6阶多项式进行拟合,推得了黄河粉土的p-y曲线,并与API建议砂土和软黏土p-y曲线进行了比较。根据粉土试验p-y曲线,提出了黄河粉土p-y曲线的理论表达式,用此理论p-y曲线进行了水平荷载下模型桩的数值分析,并与试验测试弯矩进行了比较。研究结果表明:粉土的黏聚力对p-y曲线有很大的影响,忽略粉土黏聚力的抗力作用将导致桩基水平承载力的设计偏于保守;基于理论粉土p-y的模型桩的数值结果与试验弯矩值吻合得较好。 展开更多
关键词 p-Y曲线 黄河粉土 模型桩 试验研究
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秋季黄河pCO_2控制因素及水-气界面通量 被引量:30
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作者 张龙军 徐雪梅 温志超 《水科学进展》 EI CAS CSCD 北大核心 2009年第2期227-235,共9页
根据2006年11月1-10日,秋季黄河平水期二氧化碳分压(pCO2)的现场实测数据及相关同步观测资料,对黄河表层水pCO2的分布及其影响因素进行了研究。结果表明:水体pCO2在80-166 Pa,平均值110 Pa,在世界主要河流中属中等偏下水平;空间分布... 根据2006年11月1-10日,秋季黄河平水期二氧化碳分压(pCO2)的现场实测数据及相关同步观测资料,对黄河表层水pCO2的分布及其影响因素进行了研究。结果表明:水体pCO2在80-166 Pa,平均值110 Pa,在世界主要河流中属中等偏下水平;空间分布存在较大的不均匀性,中游高于上游和下游。浮游植物的光合作用对pCO2有一定的影响但强度较弱,即使在叶绿素最高值3.58μg/L的包头站pCO2仍达到91 Pa。黄河水体有机物含量较低且继承了陆源有机物难降解的特性,干流和库区EpCO2/AOU的比值为0.14和0.20,远低于生物好氧呼吸作用控制水体pCO2的理论下限0.62,因此,生物好氧呼吸作用对水体pCO2的贡献不大。悬浮物(TSS)含量为3.77-1308mg/L,溶解无机碳(DIC)含量为3.03-4.14 mmol/L,普遍高于世界其它河流且最大值均出现在潼关站;同时水体pCO2与TSS、PIC、DIC含量具有极好的正相关性。因此黄河流域强烈的机械侵蚀和化学风化作用形成的碳酸盐体系是控制水体pCO2的主要因素。利用Wanninkhof提出的淡水水-气交换系数的通量模式估算,黄河水域水-气界面CO2交换速率约为0.229μmol/m^2.s,秋季可向大气释放CO214.5亿moL,相当于8 250 km^2草原或是112 km^2森林一年的固碳量。黄河CO2释放通量与渥太华河相近,但要远小于亚马逊河。 展开更多
关键词 黄河 二氧化碳分压pCO2 控制因素 水-气界面CO2通量
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