期刊文献+
共找到295篇文章
< 1 2 15 >
每页显示 20 50 100
抽水蓄能电站蚀变岩力学特征及工程性能研究
1
作者 樊柱军 刘志伟 +1 位作者 贺鸣 冯超越 《西北水电》 2024年第4期38-44,共7页
蚀变岩体的存在对抽水蓄能电站工程岩体的稳定性有重要影响。通过室内压缩试验、剪切试验、蠕变试验、渗透试验及现场饱和剪切试验、干湿循环剪切试验等手段,分析了不同蚀变程度岩体力学特征。试验结果表明:强蚀变、弱蚀变、微蚀变岩体... 蚀变岩体的存在对抽水蓄能电站工程岩体的稳定性有重要影响。通过室内压缩试验、剪切试验、蠕变试验、渗透试验及现场饱和剪切试验、干湿循环剪切试验等手段,分析了不同蚀变程度岩体力学特征。试验结果表明:强蚀变、弱蚀变、微蚀变岩体饱和抗压强度平均值分别为为0.2、37.9、71.8 MPa,其工程性状分别和残坡积风化物、强风化、弱风化等岩体相似;弱蚀变岩体由于矿物颗粒较粗,其内摩擦角43.10°~46.55°,比微蚀变内摩擦角39.2°~42.8°,有一定程度的增加;在抗渗透变形破坏方面,强蚀变岩体重塑样的临界渗透破坏坡降在5.356~9.773,具有碎石、砂土等渗透变形破坏特征;强蚀变岩体具有蠕变效应,强度随时间存在降低;强蚀变岩体水理化特征较明显,干湿循环后,抗剪强度出现降低0%~6%。基于蚀变岩体工程力学性能特征,建立了蚀变岩体的工程性能分级量化指标,研究成果对工程处置具有较好的指导意义。 展开更多
关键词 蚀变岩体 饱和抗压强度 渗透变形破坏 蠕变效应 水理化 量化指标
下载PDF
砂岩蠕变特性的水物理化学作用效应试验研究 被引量:28
2
作者 刘建 李鹏 +1 位作者 乔丽苹 朱杰兵 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2008年第12期2540-2550,共11页
针对干燥、饱水以及不同离子浓度和酸碱度水溶液循环流动作用至水–岩反应平衡后的砂岩试件,完成一系列单轴压缩蠕变试验。根据试验结果,通过对不同应力水平下干燥砂岩和饱水砂岩的应变–时间关系、瞬时应变、蠕变应变及蠕变速率的比较... 针对干燥、饱水以及不同离子浓度和酸碱度水溶液循环流动作用至水–岩反应平衡后的砂岩试件,完成一系列单轴压缩蠕变试验。根据试验结果,通过对不同应力水平下干燥砂岩和饱水砂岩的应变–时间关系、瞬时应变、蠕变应变及蠕变速率的比较分析,揭示饱水砂岩蠕变特性的水物理作用效应与机制。在此基础上,分别针对砂岩在酸碱度相同而离子浓度不同以及酸碱度不同而离子浓度相同这两类流动水溶液作用后,其应变–时间关系、瞬时应变、蠕变应变及蠕变速率的差异性开展系统研究,获得砂岩蠕变特性的水溶液离子浓度影响效应和酸碱度影响效应,进而探讨其水物理化学作用机制。研究结果表明,饱水砂岩蠕变性质比干燥砂岩明显;上述不同流动水溶液作用后的砂岩蠕变特性又比干燥、饱水砂岩显著;饱水砂岩蠕变特性主要存在水物理作用效应;而不同流动水溶液作用后砂岩的蠕变特性则兼具水物理作用效应和水化学作用效应;砂岩蠕变的水溶液离子浓度作用效应呈现出离子浓度越高则蠕变特性越显著的特点。研究成果对于岩石流变力学及水–岩相互作用领域的理论与应用研究,具有良好的启示与借鉴意义。 展开更多
关键词 岩石力学 砂岩 蠕变特性 理化学作用 试验研究 机制分析
下载PDF
砂岩水物理化学损伤机制研究 被引量:79
3
作者 乔丽苹 刘建 冯夏庭 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2007年第10期2117-2124,共8页
通过对不同水环境下砂岩孔隙率、pH值演变和矿物蚀变等开展一系列的试验研究,从微细观层次分析砂岩的水物理化学损伤机制,在此基础上,提出以蒸馏水环境下测得的次生孔隙率为基础,从总次生孔隙率中将水化学作用产生的次生孔隙率分离出来... 通过对不同水环境下砂岩孔隙率、pH值演变和矿物蚀变等开展一系列的试验研究,从微细观层次分析砂岩的水物理化学损伤机制,在此基础上,提出以蒸馏水环境下测得的次生孔隙率为基础,从总次生孔隙率中将水化学作用产生的次生孔隙率分离出来的方法,进而建立基于次生孔隙率变化的砂岩水物理化学损伤变量表达式;另一方面,通过对浸泡180 d时的砂岩试件进行CT扫描,将损伤计算结果与CT检测结果进行了对比分析。研究结果表明,砂岩水物理损伤主要受水流导致的矿物颗粒间胶结物与碎屑运移和扩散影响,与水化学损伤与离子浓度、pH值等水环境变化密切相关;二者所诱发的次生空隙是水物理化学作用影响砂岩力学性质的主要原因;水–岩反应后某一时刻砂岩的总次生孔隙率可由水物理作用和水化学作用产生的次生孔隙率两部分构成。砂岩水物理化学损伤计算结果与CT检测结果的对比分析表明,采用所提出的砂岩损伤变量表达式来描述其水物理化学损伤是可行的。 展开更多
关键词 岩石力学 砂岩 理化学作用 损伤机制 次生孔隙率 CT扫描
下载PDF
砂岩弹塑性力学特性的水物理化学作用效应——试验研究与本构模型 被引量:27
4
作者 刘建 乔丽苹 李鹏 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2009年第1期20-29,共10页
针对干燥、饱水、蒸馏水以及不同离子浓度和pH值水溶液循环流动作用至水–岩反应平衡后的砂岩试件,开展一系列单轴压缩试验和CT损伤测试,获得这些不同状态及水溶液作用后砂岩试件的应力–应变关系全过程曲线和CT扫描结果;分别研究砂岩... 针对干燥、饱水、蒸馏水以及不同离子浓度和pH值水溶液循环流动作用至水–岩反应平衡后的砂岩试件,开展一系列单轴压缩试验和CT损伤测试,获得这些不同状态及水溶液作用后砂岩试件的应力–应变关系全过程曲线和CT扫描结果;分别研究砂岩弹塑性力学特性包括应力–应变关系、弹性模量、峰值强度及残余强度的水物理作用和水化学作用效应与机制;基于CT检测结果开展相应的水物理化学损伤分析;在此基础上,通过分析水物理化学作用对砂岩应力–应变关系的影响特征与规律,探讨并采用改进的Duncan模型来描述存在水物理化学作用效应的砂岩非线性弹性变形行为。研究结果对于水–岩相互作用及相关领域的理论与应用研究,具有良好的促进与借鉴作用。 展开更多
关键词 岩石力学 砂岩 弹塑性力学特性 理化学作用 试验研究 损伤分析 本构模型
下载PDF
南水北调中线水源区生物监测研究 被引量:4
5
作者 李玉英 高宛莉 +3 位作者 王庆林 梁子安 胡兰群 程序 《安徽农业科学》 CAS 北大核心 2008年第16期6929-6931,6955,共4页
在生态调查基础上从理化指标和浮游生物角度对南水北调中线水源区进行了生态监测。结果表明,2004-2006年的水理化检测指标中除总氮指标外,其他均符合Ⅰ类水质标准;水源区浮游动物27属41种(含变种)和浮游植物8门67属161种(含变种);... 在生态调查基础上从理化指标和浮游生物角度对南水北调中线水源区进行了生态监测。结果表明,2004-2006年的水理化检测指标中除总氮指标外,其他均符合Ⅰ类水质标准;水源区浮游动物27属41种(含变种)和浮游植物8门67属161种(含变种);在检出的浮游生物中未发现水体重污染指示种,污染指示种中有浮游动物3种和浮游植物21属24种(含变种)。综合评价中线水源区为寡污型水体,处于中营养状态。 展开更多
关键词 北调中线源区 浮游生物 水理化性质 年际变化
下载PDF
中科院新疆理化技术研究所水脱盐新法获专利
6
《新疆化工》 2014年第2期39-39,共1页
由中国科学院新疆理化技术研究所科研人员开发的一种水脱盐的新方法,日前获得国家发明专利。目前常见的海水淡化方法主要有蒸馏法、冷冻法、离子交换法和膜法。理化所科研人员发明的水脱盐新方法将蒸馏法和膜法有机结合,利用膜法的浓盐... 由中国科学院新疆理化技术研究所科研人员开发的一种水脱盐的新方法,日前获得国家发明专利。目前常见的海水淡化方法主要有蒸馏法、冷冻法、离子交换法和膜法。理化所科研人员发明的水脱盐新方法将蒸馏法和膜法有机结合,利用膜法的浓盐水侧的高压驱动文丘里喷射泵的负压来降低后续的蒸发压力,使蒸发过程在1个标准大气压之下进行,降低了蒸,,;, 展开更多
关键词 中科院新疆理化技术研究所脱盐新法获专利
下载PDF
灌溉溶滤对西北地区红层风化泥岩不排水抗剪强度的影响 被引量:7
7
作者 何蕾 文宝萍 《水文地质工程地质》 CAS CSCD 北大核心 2014年第3期47-52,共6页
西北地区灌溉引发大量黄土-红层泥岩滑坡,其中快速滑坡的活动机理与灌溉溶滤后泥岩中易溶盐含量降低及其不排水抗剪强度密切相关。本文以兰州及其附近两处白垩系红层风化泥岩为例,探讨了溶滤后风化泥岩不排水抗剪强度的变化特征。结果显... 西北地区灌溉引发大量黄土-红层泥岩滑坡,其中快速滑坡的活动机理与灌溉溶滤后泥岩中易溶盐含量降低及其不排水抗剪强度密切相关。本文以兰州及其附近两处白垩系红层风化泥岩为例,探讨了溶滤后风化泥岩不排水抗剪强度的变化特征。结果显示,溶滤后风化泥岩不排水强度显著降低。其内在机理涉及两方面的水-土综合作用,其一,易溶盐流失,风化泥岩颗粒间胶结弱化,粗颗粒分散,粘粒增多;再之,粘粒增多后,泥岩内产生较高的孔隙水压力,有效应力随之降低。 展开更多
关键词 红层风化泥岩 不排抗剪强度 易溶盐含量 孔隙压力 -土物理化学作用
下载PDF
内蒙古自治区饮水型地方性氟中毒理化改水病区分布及家庭净水器使用情况调查
8
作者 刘一君 崔娜 +5 位作者 常子丽 王璇 李艳红 郭志伟 赵成祥 李振林 《中华地方病学杂志》 CAS 北大核心 2024年第1期35-38,共4页
目的了解内蒙古自治区饮水型地方性氟中毒理化改水病区分布及家庭净水器使用情况。方法2021年4-10月,在内蒙古自治区进行理化改水的饮水型地方性氟中毒病区开展调查,调查内容包括病区村的基本情况(常住户数、常住人口数、历史水氟含量)... 目的了解内蒙古自治区饮水型地方性氟中毒理化改水病区分布及家庭净水器使用情况。方法2021年4-10月,在内蒙古自治区进行理化改水的饮水型地方性氟中毒病区开展调查,调查内容包括病区村的基本情况(常住户数、常住人口数、历史水氟含量)及居民户净水器使用情况;并采集调查家庭末梢水水样,检测水氟含量。计算净水器安装率、正常使用率、正常使用水氟合格率及更换滤芯部门覆盖户数占比。结果内蒙古自治区饮水型地方性氟中毒理化改水病区分布在全区11个盟市的2735个病区村,常住户数192950户,常住人口数540216人;各盟市历史水氟含量均值为2.18 mg/L,现水氟含量均值为0.40 mg/L。共安装净水器134763户,安装率为69.84%(134763/192950)。共调查居民10773户,正常使用10396户,正常使用率为96.50%(10396/10773);其中,正常使用水氟合格10158户,水氟合格率为97.71%(10158/10396)。10396户正常使用净水器居民中,3974户(38.23%)滤芯使用时间在1年之内,水氟合格3961户,水氟合格率为99.67%(3961/3974);6422户(61.77%)滤芯使用时间大于1年,水氟合格6197户,水氟合格率为96.50%(6197/6422);不同滤芯使用时间净水器水氟合格率比较,差异有统计学意义(χ^(2)=110.73,P<0.001)。10773户调查居民中,更换滤芯部门覆盖10470户,占97.19%(10470/10773)。结论内蒙古自治区饮水型地方性氟中毒理化改水病区分布广,家庭净水器正常使用率较高,滤芯使用时间大于1年的家庭净水器水氟合格率较低。 展开更多
关键词 理化 家庭净
原文传递
饱水时间对板岩物理力学特性劣化影响的试验研究 被引量:5
9
作者 李涛 赵建军 +2 位作者 解明礼 谭盛宇 汪果 《科学技术与工程》 北大核心 2018年第6期217-222,共6页
通过单轴压缩试验、直剪试验和为期120 d饱水三轴压缩试验,结合板岩成分,研究了板岩在饱水之后的力学性质变化和水物理化学损伤机理。研究表明:自然浸水条件下,在最初4 d吸水率变化较大,约8 d之后板岩吸水率趋于稳定,但水岩作用依旧存... 通过单轴压缩试验、直剪试验和为期120 d饱水三轴压缩试验,结合板岩成分,研究了板岩在饱水之后的力学性质变化和水物理化学损伤机理。研究表明:自然浸水条件下,在最初4 d吸水率变化较大,约8 d之后板岩吸水率趋于稳定,但水岩作用依旧存在且明显滞后于吸水率的变化;随饱水时间的增长,各项力学参数试验均有衰减,饱水60 d后,板岩峰值强度趋于稳定。板岩水物理损伤主要受库区水环境影响,水物理损伤主要受水流导致矿物颗粒间胶结物和碎屑的运移和扩散,这与水化学损伤的水环境p H等密切相关。通过质量与强度变量,从宏观上量化评估板岩损伤劣化程度。 展开更多
关键词 长期饱 板岩 力学性质 理化学损伤
下载PDF
走程序化、规范化、科学化的管理是当前农村供水后期运行管理的当务之急——对我区利用世界银行进行农村卫生改水项目旗县的调查报告
10
作者 齐义斌 《内蒙古科技与经济》 1999年第S1期44-45,共2页
根据农村改水项目水厂后期管理中存在的实际问题,提出改进解决的办法。
关键词 转贷程序化 管理规范化 成本合理化 制度的建立 健全
下载PDF
处理焦化废水存在的问题及技术进展研究
11
作者 瞿涛 彭治平 王学芹 《数码设计》 2019年第16期45-45,共1页
本文结合目前焦化废水处理存在的问题,指出焦化废水处理技术进展趋势及治理新模式。
关键词 焦化废 处理技术 发展研究
下载PDF
Influence of Water Stress on the Physiological and Biochemical Characteristics of Scutellaria Baicalensis Georgi 被引量:8
12
作者 刘金花 张永清 +2 位作者 李佳 胡晶红 李中辉 《Agricultural Science & Technology》 CAS 2010年第6期22-25,共4页
Previous studies have shown that water stress can stimulate biosynthesis of secondary metabolites,and physiological and biochemical characteristics of plant can play a key role in its defense responses to water stress... Previous studies have shown that water stress can stimulate biosynthesis of secondary metabolites,and physiological and biochemical characteristics of plant can play a key role in its defense responses to water stress.So the physiological and biochemical characteristics of potted Scutellaria baicalensis Georgi plants were investigated under continuous water stress condition.The results showed that the water content in roots,stems and leaves,together with chlorophyll content of the leaves decreased as the water stress strengthened.Simultaneously,the specific leaf weight increased,and the content of proline and soluble sugar in Scutellaria baicalensis Georgi leaves increased significantly.The changing trends of the baicalin content in the roots,stems and leaves of Scutellaria baicalensis Georgi were different.It increased continuously in roots,while ascended constantly in the stems and leaves during the early days under the water stress,but decreased sharply under the heavy stress.In conclusion,proline and soluble sugar had a close correlation with the drought resistance of Scutellaria baicalensis Georgi.Moderate drought is in favor of synthesizing the secondary metabolites. 展开更多
关键词 Scutellaria baicalensis Georgi Water stress Physiology and biochemical BAICALIN
下载PDF
Applications of seismic techniques to gas hydrates prediction 被引量:3
13
作者 刘彦君 刘喜武 +2 位作者 刘大锰 王燕津 赵迎新 《Applied Geophysics》 SCIE CSCD 2008年第1期67-73,共7页
Based on the sensitivity of geophysical response to gas hydrates contained in sediments, we studied the prediction of gas hydrates with seismic techniques, including seismic attributes analysis, AVO, inverted velocity... Based on the sensitivity of geophysical response to gas hydrates contained in sediments, we studied the prediction of gas hydrates with seismic techniques, including seismic attributes analysis, AVO, inverted velocity field construction for dipping formations, and pseudo-well constrained impedance inversion. We used an optimal integration of geophysical techniques results in a set of reliable and effective workflows to predict gas hydrates. The results show that the integrated analysis of the combination of reflectivity amplitude, instantaneous phase, interval velocity, relative impedance, absolute impedance, and AVO intercept is a valid combination of techniques for identifying the BSR (Bottom Simulated Reflector) from the lower boundary of the gas hydrates. Integration of seismic sections, relative and absolute impedance sections, and interval velocity sections can improve the validity of gas hydrates determination. The combination of instantaneous frequency, energy half attenuation time, interval velocity, AVO intercept, AVO product, and AVO fluid factor accurately locates the escaped gas beneath the BSR. With these conclusions, the combined techniques have been used to successfully predict the gas hydrates in the Dongsha Sea area. 展开更多
关键词 Geophysical data special processing gas hydrates BSR prediction.
下载PDF
Theoretical Studies on Mechanism and Rate Constant of Gas Phase Hydrolysis of Glyoxal Catalyzed by Sulfuric Acid
14
作者 黄明强 蔡顺有 +4 位作者 廖颖敏 赵卫雄 胡长进 王振亚 张为俊 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第3期335-343,I0001,I0002,共11页
The gas phase hydration of glyoxal (HCOCHO) in the presence of sulfuric acid (H2SO4) were studied by the high-level quantum chemical calculations with M06-2X and CCSD(T) theoretical methods and the conventional ... The gas phase hydration of glyoxal (HCOCHO) in the presence of sulfuric acid (H2SO4) were studied by the high-level quantum chemical calculations with M06-2X and CCSD(T) theoretical methods and the conventional transition state theory (CTST). The mechanism and rate constant of the five different reaction paths are consid- ered corresponding to HCOCHO+H2O, HCOCHO+H2O… H2O, HCOCHO… H2O+H2O, HCOCHO+H2O… H2SO4 and HCOCHO… H2O+H2SOa. Results show that H2SO4 has a strong catalytic ability, which can significantly reduce the energy barrier for the hydration reaction of glyoxal. The energy barrier of hydrolysis of glyoxal in gas phase is lowered to 7.08 kcal/mol from 37.15 kcal/mol relative to pre-reactive complexes at the CCSD(T)/6- 311++G(3df, 3pd)//M06-2X/6-311++G(3df, 3pd) level of theory. The rate constant of the H2SO4 catalyzed hydrolysis of glyoxal is 1.34×10-11 cm3/(molecule.s), about 1013 higher than that involving catalysis by an equal number of water molecules, and is greater than the reaction rate of glyoxal reaction with OH radicals of 1.10×10-11 cm3/(molecule·s) at the room temperature, indicating that the gas phase hydrolysis of glyoxal of H2SO4 catalyst is feasible and could compete with the reaction glyoxal+OH under certain atmospheric condi- tions. This study may provide useful information on understanding the mechanistic features of inorganic acid-catalyzed hydration of glyoxal for the formation of oligomer. 展开更多
关键词 GLYOXAL HYDROLYSIS Sulfuric acid Acid-catalyzed mechanism
下载PDF
Physiological Basis of Photosynthetic Tolerance to Photooxidation and Shading in Rice 被引量:13
15
作者 李霞 焦德茂 《Acta Botanica Sinica》 CSCD 2000年第12期1271-1277,共7页
Thirty genotypes from rice germplasm were identified under photooxidation and shading condition and divided into four basic types : (1) cultivars tolerant to both photooxidation and shading, (2) cultivars tolerant to... Thirty genotypes from rice germplasm were identified under photooxidation and shading condition and divided into four basic types : (1) cultivars tolerant to both photooxidation and shading, (2) cultivars tolerant to photooxidation but sensitive to shading, (3) cultivars tolerant to shading but sensitive to photooxidation, and (4) cultivars sensitive to photooxidation and shading. A comparative study of photosynthetic characteristics of a cultivar (cv. Wuyujing 3) that is tolerant and a cultivar (cv. Xiangxian) that is sensitive to both photoinhibition and shading showed that the photochemical efficiency of PSⅡ ( F v/F m ) and the content of PSⅡ_D1 protein in the tolerant cultivar “Wuyujing 3” decreased less under photoinhibition conditions as compared with “Xiangxian”. Under photooxidation conditions, superoxide dismutase was induced rapidly to a higher level and the active oxygen O - built up to a lower level in “Wuyujing 3” than in “Xiangxian”. At the same time, the photosynthetic rate decreased by 23% in “Wuyujing 3” vs. 64% in “Xiangxian”. Shading (20% natural light) during the booting stage caused only small decreases (7%-13%) in RuBisCO activity and the photosynthetic rate in “Wuyujing 3” but showed marked decreases (57%-64%) in “Xiangxian” which corresponded to the decreases in grain yield in the two cultivars (38% and 73%, respectively). The correlation analysis showed that the tolerance to photooxidation is mainly related to PSⅡ_D1 and that to shading is mainly related to RuBisCO activity. This study provided a simple and effective screening method and physiological basis for crop breeding in enhancing tolerance to both high and low radiation. 展开更多
关键词 PHOTOOXIDATION SHADE RICE PSⅡphotochemical efficiency RuBi0
下载PDF
Ag Deposition Forms and Uniformity on Porous Silicon by Electrochemical Method 被引量:1
16
作者 宋晓岚 徐大余 +2 位作者 杨海平 喻振兴 邱冠周 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第2期211-216,I0002,共7页
The electrochemical deposition technique was applied to achieve porous silicon (PS) surface passivated with Ag deposition for improving the properties of PS photoluminescence. The relation of Ag depositing forms to ... The electrochemical deposition technique was applied to achieve porous silicon (PS) surface passivated with Ag deposition for improving the properties of PS photoluminescence. The relation of Ag depositing forms to current density and the effect of PS hydrophilic surface on deposition uniformity were investigated. The experimental results indicated that there were two critical current densities (maximum and minimum) in which Ag was absent and electroplated on PS surface correspondingly, and the range of current density for deposition of Ag on porous silicon was from 50 μA/cm^2 to 400 μA/cm^2. The process of changing PS surface from hydrophobic into hydrophilic had positive effect on Ag deposition uniformity. Under the same experimental conditions, PS hydrophobic surface presented uneven Ag deposition.However, hydrophilic surface treated with SC-1 solution was even. Finally, the effect of PS surface passivation with Ag even deposition on photoluminescence intensity and stabilization of PS was studied. It was discovered that Ag passivation inhibited the degradation of PL intensity effectively. In addition, excessive Ag deposition had a quenching effect on room-temperature visible photoluminescence of PS. 展开更多
关键词 Porous silicon Photoluminescence Hydrophilic process Ag deposition Passivation
下载PDF
Study on the Changes of Physiological Indexes of Water Spinach in Eutrophication Water 被引量:1
17
作者 李艳蔷 李兆华 +2 位作者 姜应和 宛晶 赵丽娅 《Agricultural Science & Technology》 CAS 2010年第11期73-76,共4页
[Objective] Effect of hypoxic water culture on physiological characteristic of water spinach and its hypoxia tolerance were studied.[Method] Water spinach was planted in soil and eutrophication water by means of float... [Objective] Effect of hypoxic water culture on physiological characteristic of water spinach and its hypoxia tolerance were studied.[Method] Water spinach was planted in soil and eutrophication water by means of floating bed,respectively,and the change of physiological indexes including chlorophyll,proline(Pro),malondialdehyde(MDA),soluble sugar and soluble protein in water spinach leaves at mature stage was researched,while the hypoxia tolerance of water spinach and the effect of plant density on water spinach growth were discussed in our paper.[Result] In the hypoxic eutrophication water,the content of total chlorophyll,malondialdehyde,soluble sugar and soluble protein in water spinach leaves was lower than that of soil culture,with higher proline content,which showed that water spinach had better tolerance to hypoxic eutrophication water;the higher the plant density,the lower the chlorophyll content in water spinach leaves,and there was no significant effect of plant density on proline and malondialdehyde content,while soluble protein content was higher under high plant density.[Conclusion] The best plant density of water spinach was 66 plants per floating bed with the area of 2 m2,which could provide theoretical basis for the application of water spinach in floating bed. 展开更多
关键词 Water spinach Eutrophication water Plant density Physiological index
下载PDF
Research of Oxidation Resistance of PVDF Hollow Fiber Membrane Used in Water Treatment
18
作者 曾令强 王志强 陈文清 《Agricultural Science & Technology》 CAS 2010年第9期17-21,共5页
[Objective] The aim was to research the influences of different formulations on oxidation resistance of PVDF hollow fiber membrane.[Method]The immersion precipitation phase inversion method was employed to make castin... [Objective] The aim was to research the influences of different formulations on oxidation resistance of PVDF hollow fiber membrane.[Method]The immersion precipitation phase inversion method was employed to make casting solution with different formulations into hollow fiber membrane.The membrane was immersed in 1% NaClO solution for testing its performance changes.[Result]The membrane made by materials with bigger molecular weight had better oxidation resistance performance;the surfactant tween-80 could increase water flux,but lead to lower rupture intension;Pore-forming agent PEG400 do better than PVP in the oxidation resistance of membrane.[Conclusion]This study will provide a good idea for the development of the PVDF membrane with high oxidation resistance. 展开更多
关键词 Water treatment Hollow fiber membrane Oxidation resistance
下载PDF
Ion Product of Pure Water Characterized by Physics-Based Water Model
19
作者 揭斌斌 蕯支唐 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第2期167-170,I0001,共5页
Pure water has been characterized for nearly a century, by its dissociation into hydronium (H3O)1+ and hydroxide (HO)1- ions. As a chemical equilibrium reaction, the equilibrium constant, known as the ion product... Pure water has been characterized for nearly a century, by its dissociation into hydronium (H3O)1+ and hydroxide (HO)1- ions. As a chemical equilibrium reaction, the equilibrium constant, known as the ion product or the product of the equilibrium concentration of the two ion species, has been extensively measured by chemists over the liquid water temperature and pressure range. The experimental data have been nonlinear least-squares fitted to chemical thermodynamic-based equilibrium equations, which have been accepted as the industrial standard for 35 years. In this study, a new and statistical-physics-based water ion product equation is presented, in which, the ions are the positively charged protons and the negatively charged proton-holes or prohols. Nonlinear least squares fits of our equation to the experimental data in the 0-100℃ pure liquid water range, give a factor of two better precision than the 35-year industrial standard. 展开更多
关键词 Solid state physics Liquid state chemistry Pure water Ion product Positiveproton Negative proton-hole or prohol
下载PDF
Hydrolysis Mechanism of the NAMI-A-type Antitumor Complex (HL)[trans-RuCl4L(dmso-S)] (L=1-methyl-l,2,4-triazole)
20
作者 陈兰美 陈锦灿 +3 位作者 廖思燕 刘江琴 罗辉 郑康成 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第4期383-390,I0003,共9页
The hydrolysis process of Ru(III) complex (HL)[trans-RuC14L(dmso-S)] (L=l-methyl-l,2,4- triazole and dmso-S=S-dimethyl sulfoxide) (1), a potential antitumor complex similar to the well-known antitumor agent ... The hydrolysis process of Ru(III) complex (HL)[trans-RuC14L(dmso-S)] (L=l-methyl-l,2,4- triazole and dmso-S=S-dimethyl sulfoxide) (1), a potential antitumor complex similar to the well-known antitumor agent (Him)[trans-RuC14 (dmso-S)(im)] (NAMI-A, im=imidazole), was investigated using density functional theory combined with the conductor-like polarizable continuum model approach. Tile structural characteristics and the detailed energy profiles for the hydrolysis processes of this complex were obtained. For the first hydrolysis step, complex 1 has slightly higher barrier energies than the reported anticancer drug NAMI-A, and the result is in accordance with the experimental evidence indicating larger half-life for complex 1. For the second hydrolysis step, the formation of cis-diaqua species is thermodynamic preferred to that of trans isomers. In addition, on the basis of the analysis of electronic characteristics of species in the hydrolysis process, the trend in nucleophilic attack abilities of hydrolysis products by pertinent biomolecules is revealed and predicted. 展开更多
关键词 NAMI-A-type complex Anticancer activity HYDROLYSIS Density functional theory Conductor-like polarizable continuum model
下载PDF
上一页 1 2 15 下一页 到第
使用帮助 返回顶部