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Effect of Lead Stress on Growth Characteristics and Physiological Indexes of Alternanthera philoxeroides
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作者 熊勇 张振宇 杨青松 《Agricultural Science & Technology》 CAS 2011年第3期347-349,362,共4页
[Objective] The paper aimed to discuss effects of different concentrations of lead stress on Alternanthera philoxeroides growth and physiological indices,to explore phytoremediation methods for removal of lead polluti... [Objective] The paper aimed to discuss effects of different concentrations of lead stress on Alternanthera philoxeroides growth and physiological indices,to explore phytoremediation methods for removal of lead pollution. [Method] A. philoxeroides in water culture was treated with different concentration of lead,and then,its external injury was observed,its growth and physiological indexes were measured. [Result] A. philoxeroides biomass and chlorophyll content decreased; conductivity and malonaldehyde (MDA ) content were increased; the SOD,POD and CAT activities showed a trend of first increase and then decrease with increase in concentration of lead stress. [Conclusion] With increase in lead concentration,the cell membrane permeability increased and MDA had a higher accumulation,antioxidant enzymes activity decreased,the normal oxidative metabolism of A. philoxeroides was severely affected,leading it to wilt. 展开更多
关键词 lead stress Alternanthera philoxeroides Griseb Growth characteristics Physiological indexes
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Effects of exogenous salicylic acid on growth and H_2O_2-metabolizing enzymes in rice seedlings under lead stress 被引量:30
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作者 CHEN Jing ZHU Cheng LI Li-ping SUN Zhong-yang PAN Xue-bo 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第1期44-49,共6页
Salicylic acid (SA) was an essential component of the plant resistance to pathogens and also plays an important role in mediating plant response to some abiotic stress. The possible effects of SA on the growth and H... Salicylic acid (SA) was an essential component of the plant resistance to pathogens and also plays an important role in mediating plant response to some abiotic stress. The possible effects of SA on the growth and H2O2-metabolizing enzymes in rice seedlings under lead stress were studied. When rice seedlings grown in nutrient solution containing Pb^2+ (0, 0.05, 0.15, 0.25 mmol/L) for 18 d, the plant biomass as well as the chlorophyll content of leaves decreased with increasing Pb concentration. The pre-treatment with SA (treated with 0.1 mmol/L SA for 48 h before Pb stress) partially protected seedlings from Pb toxicity. The chlorophyll contents were significant higher in leaves of Pb-exposed with SA pre-treatment seedlings than in Pb-exposed plants at the same Pb intensity. SA pre-treated alone could significantly increase the length of shoot and root of seedlings but the vigour difference was not marked under long-term exposure to Pb toxicity. SA pre-treated influence the H2O2 level in leaves of seedlings by up-regulating the activity of superoxide dismutase (SOD), repressing the activity of catalase (CAT) and ascorbate peroxidase (APX) depending on the concentrations of Pb^2+ in the growth medium. The results supported the conclusion that SA played a positive role in rice seedlings against Pb toxicity. 展开更多
关键词 ascorbate peroxidase CATALASE H2O2 lead stress rice (Oryza sativa L.) salicylic acid superoxide dismutase
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Physiological and Biochemical Responses of Iris pseudacorus to Lead Stress
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作者 Song WANG Wei BO +2 位作者 Jin WANG Hongmei KANG Xiaowei KE 《Agricultural Biotechnology》 CAS 2021年第5期79-82,85,共5页
[Objectives]This study was conducted to discuss the Pb-enrichment ability of Iris pseudacorus,and reveal the effects of different concentrations of Pb stress on the physiological metabolism of I.pseudacorus.[Methods]I... [Objectives]This study was conducted to discuss the Pb-enrichment ability of Iris pseudacorus,and reveal the effects of different concentrations of Pb stress on the physiological metabolism of I.pseudacorus.[Methods]I.pseudacorus L.as a test material was cultured by the nutrient solution culture method and analyzed for malondialdehyde(MDA),glutathione(GSH),cysteine(Cys)and proline(Pro)contents of plant leaves as well as catalase(CAT)and superoxide dismutase(SOD)activity under different concentrations of Pb stress(0,200,400,600,800,1000,1200 mg/L).[Results]With the increase of Pb concentration,the Pb content of leaves and roots gradually increased,and the order of increase was root>leaf.Roots and leaves reached maximums at the high concentration of 1200 mg/L Pb,and their contents were 9034.6 and 11.2 mg/kg,respectively.Under Pb stress,the contents of GSH,Cys and Pro,and the activity of CAT and SOD in I.pseudacorus showed a trend of first increasing and then decreasing with the increase of Pb concentration,and each index reached a maximum under the treatment of 400 mg/L.The level of MDA in the leaves of I.pseudacorus rose significantly under Pb stress,indicating that Pb stress caused the cell membrane of I.pseudacorus to be damaged by peroxidation.[Conclusions]This study provides a theoretical basis for further research and use of this plant for metal pollution remediation in the future. 展开更多
关键词 Iris pseudacorus lead stress ACCUMULATION PHYSIOLOGY
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Effects of lead stress on Vg expression in the beet armyworm over five successive generations 被引量:1
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作者 SU Hong-hua YANG Yong +3 位作者 QIAN Yuan-yuan YE Zi-bo CHEN Yu-qing YANG Yi-zhong 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第1期134-142,共9页
Heavy metals have been found to be endocrine disruptors in invertebrates.Lead is one of the most widespread elements of contamination,but there has been no research about the effects of lead stress on vitellogenin(Vg)... Heavy metals have been found to be endocrine disruptors in invertebrates.Lead is one of the most widespread elements of contamination,but there has been no research about the effects of lead stress on vitellogenin(Vg) gene expression in insects exposed to lead over multiple generations.In this paper,the effects of different concentrations of lead(0,0.3,4.8 and 76.8 mg kg^(–1)) on the expression of Vg in the beet armyworm over five successive generations were studied.The results showed that lead stress had significant effects on Vg expression in a dose-dependent manner.For females at the larval and adult stages,as lead concentration increased,Vg expression was significantly inhibited; for males at these two developmental stages,Vg expression was induced and increased as lead concentration increased.In addition,with the increase over stressed generations,inhibited effects for females and induced effects for males at the larval and adult stages became increasingly more obvious.However,at the pupal stage,Vg expression in the two genders was different from that at the larval and adult stages.The results indicate that lead stress can upregulate Vg expression in males which should be a useful indicator for environmental risk assessment. 展开更多
关键词 SPODOPTERA EXIGUA lead stress VITELLOGENIN gene EXPRESSION females males
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Mitigative Effect of <i>Bacillus subtilis</i>QM3 on Root Morphology and Resistance Enzyme Activity of Wheat Root under Lead Stress
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作者 Yang Hao Haitao Wu +1 位作者 Yanfang Liu Qingping Hu 《Advances in Microbiology》 2015年第6期469-478,共10页
Lead (Pb) is an environmental pollutant extremely toxic to plants and other living organisms including humans. In order to research the relieve effect of Bacillus subtilis QM3 on wheat roots (Triticum aestivum L.), af... Lead (Pb) is an environmental pollutant extremely toxic to plants and other living organisms including humans. In order to research the relieve effect of Bacillus subtilis QM3 on wheat roots (Triticum aestivum L.), after wheat seeds germination for two days, wheat root caused, the experimental materials were divided into four large groups and each large group was placed in 6 petri dishes as six small groups, and then four large groups respectively cultivated with sterile water (CK), 108 CFU/ml B. subtilis QM3 (B1), 107 CFU/ml B. subtilis QM3 (B2) and 106 CFU/ml B. subtilis QM3 (B3) for 2 days, after that stressed with lead nitrate, Pb (NO)2, Pb2+ concentration calculation at five concentrations (50, 250, 500, 1000, 2000 mg/L), sterile water and different Pb2+ concentration liquid respectively cultivated the 6 small groups in each large group measuring root morpholog and assaying changes of antioxidant enzyme activity. The results showed that: with the increase of the Pb2+ concentration, root morphology index and the activity of antioxidant enzyme increased first and then decreased. Root morphology index reached the maximum in 50 mg/L Pb2+ concentration. B. subtilis QM3 clearly promoted the growth of the root and the antioxidant enzyme activity (p 0.05). Without Pb stress, B. subtilis QM3 had the best improving effect on root morphology. When Pb2+ concentration was 50 mg/L, superoxide dismutase (SOD) and ascorbate peroxidase (APX) reached the maximum. SOD activity, compared with CK, B1, B2 and B3 respectively, increased by 8.05%, 27.41% and 9.79%. APX activity, compared with CK, B1, B2 and B3 respectively, increased by 52.70%, 111.15% and 14.16%. Catalase (CAT) and peroxidase (POD) reached the maximum at the Pb2+ concentration was 500 mg/L. CAT activity, compared with CK, B1, B2 and B3 respectively, increased by 59.93%, 83.46% and 70.59%. POD activity, compared with CK, B1, B2 and B3 respectively, increased by 2.88%, 10.11% and 7.67%. Result suggested that B. subtilis QM3 could improve root growth and antioxidant enzyme activity of the wheat root under lead stress. 展开更多
关键词 B. SUBTILIS QM3 RESISTANCE Enzyme Activity ROOT Morphology lead stress
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Lead Induced Oxidative Stress: Beneficial Effects of Kombucha Tea 被引量:6
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作者 P.DIPTI B.YOGESH +7 位作者 A.K.KAIN T.PAULINE B.ANJU M.SAIRAM B.SINGH S.S.MONGIA G.ILAVAZHAGAN DEVENDRA KUMAR W.SELVAMURTHY 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2003年第3期276-282,共7页
Objective To evaluate the effect of oral administration of Kombucha tea (K-tea) on lead induced oxidative stress. Methods Sprague Dawley rats were administered 1 mL of 3.8% lead acetate solution daily alone or in comb... Objective To evaluate the effect of oral administration of Kombucha tea (K-tea) on lead induced oxidative stress. Methods Sprague Dawley rats were administered 1 mL of 3.8% lead acetate solution daily alone or in combination with K-tea orally for 45 d, and the antioxidant status and lipid peroxidation were evaluated. Results Oral administration of lead acetate to rats enhanced lipid peroxidation and release of creatine phosphokinase and decreased levels of reduced glutathione (GSH) and antioxidant enzymes (superoxide dismutase, SOD and glutathione peroxidase, GPx). Lead treatment did not alter humoral immunity, but inhibited DTH response when compared to the control. Lead administration also increased DNA fragmentation in liver. Oral administration of Kombucha tea to rats exposed to lead decreased lipid peroxidation and DNA damage with a concomitant increase in the reduced glutathione level and GPx activity. Kombucha tea supplementation relieved the lead induced immunosuppression to appreciable levels. Conclusion The results suggest that K-tea has potent antioxidant and immunomodulating properties. 展开更多
关键词 lead Oxidative stress Kombucha tea Antioxidant activity
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Lead Exposure and Oxidative Stress in Coal Miners 被引量:1
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作者 Zlatko Zimet Marjan Bilban +3 位作者 Teja Fabjan Kristina Suhadolc Borut Poljsak Josko Osredkar 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2017年第11期841-845,共5页
We aimed to investigate the short-term correlation between blood lead levels and oxidative stress generation in coal miners. The study involved 94 male coal miners from the Velenje Coal mine, arranged into four groups... We aimed to investigate the short-term correlation between blood lead levels and oxidative stress generation in coal miners. The study involved 94 male coal miners from the Velenje Coal mine, arranged into four groups: three groups according to the number of consecutive working days, and a fourth control group. Miners who worked for three consecutive days had higher blood levels of lead and 8-isoprostane than the control group(P 〈 0.001). Correlation between lead and 8-isoprostane was of medium strength(r = 0.512, P 〈 0.001). Short-term lead environmental exposure can potentially harmful and should be considered when formulating improvements in working processes. 展开更多
关键词 lead Exposure Oxidative stress in Coal Miners
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绝缘子引线腐蚀断裂研究
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作者 高明起 徐玉娟 +2 位作者 张亚刚 董东 王强 《电镀与涂饰》 CAS 北大核心 2024年第1期50-58,共9页
[目的]绝缘子作为微波组件内、外部的连接器件,其引线与玻璃封接处容易断裂。[方法]采用金相显微镜、扫描电镜、能谱仪等手段对上述断裂的原因进行分析。[结果]通过机理探讨与现场观察相结合,确定症结在于应力腐蚀开裂。绝缘子引线断裂... [目的]绝缘子作为微波组件内、外部的连接器件,其引线与玻璃封接处容易断裂。[方法]采用金相显微镜、扫描电镜、能谱仪等手段对上述断裂的原因进行分析。[结果]通过机理探讨与现场观察相结合,确定症结在于应力腐蚀开裂。绝缘子引线断裂分为3个阶段:点蚀过程及裂纹萌生,裂纹扩展,以及纯力学快速断裂。[结论]采用化学抛光与机械研磨相结合、镍金交叉镀覆的新工艺可以消除绝缘子引线封接处镀层应力敏感性和应力条件,令镀层的结合力、耐盐雾性能及焊接性能均达到工艺要求。 展开更多
关键词 绝缘子 引线 断裂 应力腐蚀 化学抛光 交叉镀覆
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硅对锰-铅复合胁迫下水稻幼苗叶片细胞壁多糖组分中锰和铅含量的影响
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作者 韦丹蒙 黄秋婵 +3 位作者 兰娟 梁海红 黄自如 朱思凤 《西南农业学报》 CSCD 北大核心 2024年第8期1809-1815,共7页
【目的】探究不同浓度SiO_(2)对锰-铅(Mn-Pb)复合胁迫下水稻幼苗叶片细胞壁多糖组分中Mn和Pb含量的影响,为利用农艺措施治理矿区农田重金属复合污染提供理论依据。【方法】在模拟矿区重金属污染前提下,先用水培法将水稻种子培养至5叶1心... 【目的】探究不同浓度SiO_(2)对锰-铅(Mn-Pb)复合胁迫下水稻幼苗叶片细胞壁多糖组分中Mn和Pb含量的影响,为利用农艺措施治理矿区农田重金属复合污染提供理论依据。【方法】在模拟矿区重金属污染前提下,先用水培法将水稻种子培养至5叶1心期,然后用2 mmol/L Mn^(2+)+2 mmol/L Pb2+溶液复合胁迫水稻幼苗。设6个不同的SiO_(2)处理浓度:0(对照,CK)、70、90、110、130和150 mg/L。处理后提取水稻幼苗叶片细胞壁多糖组分,测定和分析其中Mn和Pb含量。【结果】施加SiO_(2)增加细胞壁多糖组分(果胶质、半纤维素和纤维素)中Mn和Pb含量。与CK相比,当SiO_(2)浓度为70~110 mg/L时,细胞壁果胶质中Mn和Pb含量较高;SiO_(2)处理下果胶质中Pb含量大于Mn含量,当SiO_(2)浓度小于90 mg/L时,水稻幼苗叶片细胞壁中Pb含量小于Mn含量。SiO_(2)浓度为110 mg/L时,在半纤维素和纤维素中Mn和Pb含量均较高;水稻幼苗叶片细胞壁半纤维素中Pb含量大于Mn含量,SiO_(2)浓度小于90 mg/L时,纤维素中Pb含量为负值。未施加SiO_(2)时,Mn和Pb的主要结合位点分别为纤维素和果胶质,施加SiO_(2)使Pb的主要结合位点转移为半纤维素。【结论】SiO_(2)能增加重金属Mn和Pb在细胞壁多糖组分中的含量。Mn-Pb复合胁迫下,SiO_(2)浓度为110 mg/L时,Mn和Pb的含量在细胞壁、果胶质、半纤维素和纤维素中均较多。 展开更多
关键词 锰-铅复合胁迫 水稻 细胞壁多糖组分
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纳米硒(SeNPs)缓解烟草幼苗铅胁迫和促生效应
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作者 杜仲阳 杨泽 +8 位作者 梁梦静 刘义珍 崔红利 史达明 薛金爱 孙岩 张春辉 季春丽 李润植 《生物技术通报》 CAS CSCD 北大核心 2024年第7期183-196,共14页
【目的】旨在探究纳米硒(SeNPs)对铅(Pb)胁迫烟草幼苗的生长、抗逆性、铅吸收和转运的影响,以揭示SeNPs的促生效应、富硒和阻滞铅吸收及转运的机制。【方法】以普通烟草(Nicotianatabacum)为研究对象,通过盆栽实验设置不同处理,包括低剂... 【目的】旨在探究纳米硒(SeNPs)对铅(Pb)胁迫烟草幼苗的生长、抗逆性、铅吸收和转运的影响,以揭示SeNPs的促生效应、富硒和阻滞铅吸收及转运的机制。【方法】以普通烟草(Nicotianatabacum)为研究对象,通过盆栽实验设置不同处理,包括低剂量(100 mg/L)和高剂量(200 mg/L)Pb胁迫,无机硒(Na2SeO3)、SeNPs处理和空白对照组。测定各处理组烟草幼苗的生物量、光合生理参数、抗氧化酶活性、脂质过氧化产物含量以及相关基因表达水平,分析铅和硒在植物体内的含量和分布。【结果】与对照组相比,硒处理显著促进了烟草幼苗的生长和光合作用,SeNPs促生效应更显著。硒处理还增强了烟草幼苗的抗氧化酶(SOD、POD和APX等)活性和抗氧化物质(抗坏血酸和谷胱甘肽等)的含量,降低了脂质过氧化产物(H2O2和MDA)的积累。在铅胁迫条件下,硒处理可显著提高烟草幼苗中硒的含量,同时降低铅的吸收和转运率。【结论】纳米硒能显著提高植物生物量,保护光合系统,激活抗氧化系统,阻滞铅吸收和转运,促进植物硒富集和改善植物对铅胁迫的抗性。 展开更多
关键词 纳米硒 铅胁迫 烟草幼苗 促生效应 抗氧化系统 生物有效性 分子机制
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基于Keap1/Nrf2/ARE信号通路探讨高良姜总黄酮对铅诱导HK-2细胞损伤的保护作用 被引量:1
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作者 陈燕燕 夏道宗 《中成药》 CAS CSCD 北大核心 2024年第4期1135-1142,共8页
目的 探讨高良姜总黄酮对铅(Pb)诱导人肾皮质近曲小管上皮细胞(HK-2)细胞损伤的保护作用。方法 体外培养HK-2细胞,MTT法检测不同质量浓度高良姜总黄酮和Pb对HK-2细胞活力的影响。设置对照组、高良姜总黄酮对照组、模型组和高良姜总黄酮... 目的 探讨高良姜总黄酮对铅(Pb)诱导人肾皮质近曲小管上皮细胞(HK-2)细胞损伤的保护作用。方法 体外培养HK-2细胞,MTT法检测不同质量浓度高良姜总黄酮和Pb对HK-2细胞活力的影响。设置对照组、高良姜总黄酮对照组、模型组和高良姜总黄酮组,除对照组和高良姜总黄酮对照组外各组均给予200μmol/L Pb诱导细胞损伤,同时高良姜总黄酮对照组和高良姜总黄酮组给予100μg/mL高良姜总黄酮干预24 h。通过Hoechst 33258荧光染色法联合annexin V-FITC/PI双标记流式细胞术检测细胞凋亡情况,荧光显微镜法观察Pb诱导及高良姜总黄酮干预对细胞内ROS水平的影响,试剂盒法检测细胞内氧化应激指标ROS、MDA、GSH水平和GSH-Px、CAT、SOD活性,ELISA法检测细胞培养上清液IL-1β、IL-6、TNF-α水平,Western bolt法检测细胞Keap1/Nrf2/HO-1信号通路相关蛋白及caspase-3蛋白表达。结果 与对照组比较,高良姜总黄酮(12.5~200μg/mL)对HK-2细胞活力没有显著影响。与模型组比较,高良姜总黄酮可减少Pb诱导HK-2细胞的凋亡(P<0.05),减轻细胞皱缩等细胞凋亡形态学变化,上调细胞内SOD、CAT、GSH-Px活性及GSH水平(P<0.05),降低细胞内MDA、ROS水平(P<0.05),上调Keap1/Nrf2/HO-1信号通路相关蛋白及caspase-3蛋白表达(P<0.05)。结论 高良姜总黄酮可能通过调控Keap1/Nrf2/ARE信号通路相关蛋白表达,对Pb诱导HK-2细胞损伤起保护作用。 展开更多
关键词 高良姜总黄酮 铅中毒 HK-2细胞 氧化应激 Keap1/Nrf2/ARE信号通路
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苦参总黄酮对醋酸铅诱导小鼠睾丸间质细胞氧化应激的改善作用及对Keap1/Nrf2信号通路的影响
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作者 刘玥欣 来永巍 +5 位作者 王艳春 徐博 路倩 安英 任旷 范红艳 《吉林大学学报(医学版)》 CAS CSCD 北大核心 2024年第2期320-325,共6页
目的:观察苦参总黄酮(SF)对醋酸铅(LA)诱导的小鼠睾丸间质细胞TM3氧化应激的改善作用及其对KELCH状ECH相关蛋白1(Keap1)/细胞中核因子E2相关因子2(Nrf2)信号通路的影响,探讨SF改善由LA诱导的TM3细胞氧化应激的相关作用机制。方法:利用... 目的:观察苦参总黄酮(SF)对醋酸铅(LA)诱导的小鼠睾丸间质细胞TM3氧化应激的改善作用及其对KELCH状ECH相关蛋白1(Keap1)/细胞中核因子E2相关因子2(Nrf2)信号通路的影响,探讨SF改善由LA诱导的TM3细胞氧化应激的相关作用机制。方法:利用噻唑蓝(MTT)法检测不同浓度(0、10、20、50和80µmol·L^(-1))LA和不同浓度(0、12.5、25.0、50.0和80.0 mg·L^(-1))SF分别干预24 h后的TM3细胞存活率;将TM3细胞随机分为空白对照组、LA组、LA+低剂量SF组、LA+中剂量SF组和LA+高剂量SF组。除空白对照组外,其他各组均采用50µmol·L^(-1)LA诱导TM3细胞24 h建立TM3细胞氧化应激模型,其中LA+低剂量SF组、LA+中剂量SF组和LA+高剂量SF组TM3细胞再分别给予12.5、25.0和50.0 mg·L^(-1)SF。利用MTT法检测TM3细胞存活率;WST-1法和硫代巴比妥酸(TBA)法检测TM3细胞中超氧化物歧化酶(SOD)活性和丙二醛(MDA)水平;Western blotting法检测Nrf2、Keap1和含半胱氨酸的天冬氨酸蛋白水解酶9(Caspase-9)蛋白表达水平。结果:MTT法检测,与0µmol·L^(-1)LA组比较,10、20、50和80µmol·L^(-1)LA组TM3细胞存活率明显降低(P<0.01);与0 mg·L^(-1)SF组比较,12.5、25.0、50.0和80.0 mg·L^(-1)SF组TM3细胞存活率明显降低(P<0.05或P<0.01);与LA组比较,LA+低剂量SF组、LA+中剂量SF组和LA+高剂量SF组TM3细胞存活率明显升高(P<0.01);WST-1法和TBA法检测,与LA组比较,LA+低剂量SF组、LA+中剂量SF组和LA+高剂量SF组TM3细胞中SOD活性明显升高(P<0.01),MDA水平明显降低(P<0.01);Western blotting法检测,与LA组比较,LA+低剂量SF组、LA+中剂量SF组和LA+高剂量SF组TM3细胞中Nrf2蛋白表达水平明显升高(P<0.01),Keap1和Caspase-9蛋白表达水平明显降低(P<0.01)。结论:SF对LA诱导TM3细胞氧化应激具有一定改善作用,并可降低TM3细胞中Keap1蛋白表达水平,升高TM3细胞中Nrf2蛋白表达水平。 展开更多
关键词 苦参总黄酮 醋酸铅 睾丸间质细胞 氧化应激 KELCH状ECH相关蛋白1 核因子E2相关因子2
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小型铅芯橡胶支座剪切性能试验研究
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作者 韩淼 刘祥辉 +2 位作者 杜红凯 蒋金卫 杨杰川 《振动工程学报》 EI CSCD 北大核心 2024年第2期326-335,共10页
通过对小型铅芯橡胶支座(LRB)进行剪切试验,研究了支座剪应变、压应力和加载频率对支座等效水平刚度、屈服后刚度、屈服力和等效阻尼比的影响。结果表明:随着剪应变的增大,支座的等效水平刚度和屈服后刚度减小,屈服力增大,等效阻尼比呈... 通过对小型铅芯橡胶支座(LRB)进行剪切试验,研究了支座剪应变、压应力和加载频率对支座等效水平刚度、屈服后刚度、屈服力和等效阻尼比的影响。结果表明:随着剪应变的增大,支座的等效水平刚度和屈服后刚度减小,屈服力增大,等效阻尼比呈线性减小;随着竖向压应力的增大,支座的等效水平刚度减小,屈服后刚度呈线性减小,屈服力和等效阻尼比呈线性增大;加载频率对支座的剪切性能基本没有影响,可以忽略;100%剪应变以内,施加的剪应变和压应力没有对隔震支座造成损伤;剪应变超过100%的大变形和大压应力会使支座进入塑性,造成支座部分永久性损伤。建议根据振动台试验的工况顺序及支座在振动台试验的最大实际变形设计拟静力试验的工况。提出日本规范等效水平刚度计算公式的修正系数,并与振动台试验实测值进行对照,证明了修正后的计算公式计算精度有所提高。 展开更多
关键词 小型铅芯橡胶支座 剪应变 压应力 加载频率 振动台试验
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基于FLAC^(3D)对某铅锌矿巷道稳定性及采空区治理方案研究
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作者 王海峰 苏成哲 +1 位作者 李继红 刘波 《甘肃冶金》 2024年第2期1-4,共4页
根据Hoek-Brown准则,采用Roclab1.0软件对岩石力学实验参数数据计算,获取矿体和围岩的岩石力学参数,在此基础上运用FLAC^(3D)数值模拟铅锌矿山矿体回采后,采空区围岩及巷道最大主应力、竖向位移、塑性区的变化情况,判定铅锌矿体回采对... 根据Hoek-Brown准则,采用Roclab1.0软件对岩石力学实验参数数据计算,获取矿体和围岩的岩石力学参数,在此基础上运用FLAC^(3D)数值模拟铅锌矿山矿体回采后,采空区围岩及巷道最大主应力、竖向位移、塑性区的变化情况,判定铅锌矿体回采对现有巷道的影响,最终为现场采空区治理提供相应的理论依据。 展开更多
关键词 铅锌矿山 采空区:数值模拟 最大主应力 塑性区
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大采高工作面沿空侧巷道超前区域围岩控制研究
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作者 翟春佳 邓亮 常毛毛 《煤》 2024年第1期18-21,共4页
文章以小保当煤矿112204工作面开采为工程背景,采用理论分析、数值模拟、现场施工和电磁辐射监测的方法对其沿空侧的回风平巷超前段围岩稳定性进行研究分析,结果表明:112204工作面超前支承应力与邻近112203采空区侧向支承应力叠加影响,... 文章以小保当煤矿112204工作面开采为工程背景,采用理论分析、数值模拟、现场施工和电磁辐射监测的方法对其沿空侧的回风平巷超前段围岩稳定性进行研究分析,结果表明:112204工作面超前支承应力与邻近112203采空区侧向支承应力叠加影响,将导致支承应力叠加区内煤岩体极易发生失稳破坏;适当地增加支承应力叠加区内煤岩体的剪切破断角值和侧向围压值能够有效提升支承应力叠加区内煤岩体失稳破坏时所需的支承应力临界值;实施优化支护和注浆措施后,实体煤帮内电磁辐射均值降幅达64.6%,此时煤岩体失稳破坏程度大幅度改善,围岩处于较好的控制状态,能够很好地服务于112204工作面回采作业。 展开更多
关键词 支承应力 沿空巷道 超前区域 耦合注浆 电磁辐射
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Effection of Lead Poisoning and Newcastle Disease Vaccine on Development of Egg Yellow Feather Quail 被引量:3
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作者 PANG You-zhi ZHAO De-ming +3 位作者 ZHAO Shu-juan YANG You-bing CHEN Sheng CUI Yan-jun 《Animal Husbandry and Feed Science》 CAS 2011年第2期29-33,48,共6页
[ Objective] To investigate the effects of Newcastle disease vaccination and lead exposure on growth and development of egg yellow feather quail. [ Method] Ninety 14-day-old quails were assigned randomly to 10 groups ... [ Objective] To investigate the effects of Newcastle disease vaccination and lead exposure on growth and development of egg yellow feather quail. [ Method] Ninety 14-day-old quails were assigned randomly to 10 groups ( n = 9), and they fed and drunk at liberty. A 2 ×5 factorial design was used. The quail immunized with ND vaccine and those non-immunized were exposed to lead at a dosage of 0, 50,500, 1 000 and 2 000 mg/L, respectively. [Result] The ND immunization reduced body weight significantly ( P 〈 0.01 ) and increased liver index and serum levels of hy- aluronic acid in quail within 1 -2 weeks post inoculation. The quail exposed to 2 000 mg/L lead acetate had significantly lower body weight than the control ( P 〈 0.01 ). From 7 weeks old, the same inhibitory effect was observed in the quail'exposed to lead at different dosages ( P 〈 0.01 ). In addition, the lead poisoning could cause decreased feed intake, depilation, gonadal dysgenesis, and increased serum levels of hyaluronic acid. [ Conduslon] The inhibitory effect of ND vaccination on growth of quail occurs within 1 -2 weeks post inoculation; thus, the effects of immune stress should not be worried in quail production. The lead poisoning has significant effects on body weight and feed intake of quail, and lead dosage and duration affect the inhibitory effects of lead. Gonadal dysgenesis is an important indicator of lead poisoning in. quail. The serum levels of hyaluronic acid can be used to determine whether the quail have been immunized with ND vaccine or have contacted lead pollutants. 展开更多
关键词 QUAIL DEVELOPMENT Hyaluronic acid lead poisoning stress
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高温铅铋轴流泵叶轮冲磨蚀特性研究
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作者 常杰元 黎义斌 +3 位作者 杨从新 马文生 张人会 周欢 《核科学与工程》 CAS CSCD 北大核心 2024年第3期572-581,共10页
为研究铅铋轴流泵叶轮冲磨蚀特性,基于液态铅铋的冲磨蚀破坏机理分析,利用边界层理论建立冲磨蚀数学模型,采用SST k-ω湍流模型对0.8Q_(d)、1.0Q_(d)和1.2Q_(d)三种方案下泵内流动进行数值计算,获得了叶片冲磨蚀分布及壁面流速、流态、... 为研究铅铋轴流泵叶轮冲磨蚀特性,基于液态铅铋的冲磨蚀破坏机理分析,利用边界层理论建立冲磨蚀数学模型,采用SST k-ω湍流模型对0.8Q_(d)、1.0Q_(d)和1.2Q_(d)三种方案下泵内流动进行数值计算,获得了叶片冲磨蚀分布及壁面流速、流态、壁面熵产率与冲磨蚀的影响关系。结果表明:高冲磨蚀区域主要分布在叶片进口边靠近泵壳一侧;随铅铋泵入口流量增加和壁面流态紊乱加剧,叶片受冲磨蚀影响增大;当液态铅铋的最大流速不高于10m/s时,叶片受冲磨蚀影响较小,而最大流速高于10m/s时,叶片表面冲磨蚀急剧加重;叶片表面高冲磨蚀区域是高壁面熵产率主要分布区域,且液态铅铋的冲磨蚀行为与壁面熵产率呈正相关关系。 展开更多
关键词 高温液态铅铋合金 轴流泵 数值模拟 叶轮 冲磨蚀 切应力 壁面流速 壁面熵产率
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Effect of Fe Particle on the Surface Peeling in Cu-Fe-P Lead Frame 被引量:1
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作者 苏娟华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2006年第3期18-20,共3页
Under the surface peeling of Cu- Fe- P lead frame alloy larger Fe particles were observed by energy dispersive spectroscopy. By using the large strain two-dinension plane strain model and elastic plastic finite elemen... Under the surface peeling of Cu- Fe- P lead frame alloy larger Fe particles were observed by energy dispersive spectroscopy. By using the large strain two-dinension plane strain model and elastic plastic finite element method, the cause for peeling damage of Cu-Fe-P lead frame aUoy was investigated. The results show that when the content of Fe particles is more than 30% at local Fe-rich area the intense stress coacentration in the Fe particle would make the Fe particle broken up. The high equivalent stress mutation and the mismatch of equivalent strain 10% at the two sides of intefrace make it easy to develop the crack and peeling damage on finish rolling. The larger Fe particles in the Cu-Fe-P alloy should be avoided. 展开更多
关键词 Cu-Fe-P lead frame surface peeling equivalent stress equivalent strain
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Chronic exercise training versus acute endurance exercise in reducing neurotoxicity in rats exposed to lead acetate 被引量:3
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作者 Mohammad Shahandeh Valiollah Dabidi Roshan +2 位作者 Somayeh Hosseinzadeh Soleiman Mahjoub Vaginak Sarkisian 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第8期714-722,共9页
After intraperitoneal injection of 20 mg/kg lead acetate, rats received 8 weeks of treadmill exercise (15-22 m/min, 25-64 minutes) and/or treadmill exercise at 1.6 km/h until exhaustion. The markers related to neuro... After intraperitoneal injection of 20 mg/kg lead acetate, rats received 8 weeks of treadmill exercise (15-22 m/min, 25-64 minutes) and/or treadmill exercise at 1.6 km/h until exhaustion. The markers related to neurotoxicity were measured by enzyme-linked immunosorbent assay method. 8 weeks of treadmill exercise significantly increased brain-derived neurotrophic factor level in the hippocampus (P = 0.04) and plasma level of total antioxidant capacity of rats exposed to lead acetate (P 〈 0.001), and significantly decreased plasma level of malondialdehyde (P 〈 0.001). Acute exercise only decreased the hippocampal malondialdehyde level (P = 0.09) and increased brain-derived neurotrophic factor level in the hippocampus (P = 0.66). Acute exercise also enhanced the total antioxidant capacity in rats exposed to lead acetate, insignificantly (P = 0.99), These findings suggest that chronic treadmill exercise can significantly decrease neurotoxicity and alleviate oxidative stress in rats exposed to lead acetate. However, acute endurance exercise was not associated with these beneficial effects. 展开更多
关键词 neural regeneration NEUROREHABILITATION long-term exercise training endurance exercise TREADMILL lead poisoning NEUROTOXICITY oxidative stress HIPPOCAMPUS brain-derived neurotrophic factor NEUROREGENERATION
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An Evaluation of the Mitigating Effects of Α-Tocopherol (Vitamin E) and Ascorbic Acid (Vitamin C) on the Renal Function and Histology of Adult Male Albino Wistar Rats with Sub-Acute Lead Acetate Exposure 被引量:2
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作者 Datonye Dennis Alasia Pedro Chimezie Emem-Chioma Sunday Ogbu Ojeka 《Occupational Diseases and Environmental Medicine》 2020年第2期35-49,共15页
Objectives: The aim of this study was to verify mitigating effects of the antioxidants α tocopherol (Vitamin E) and ascorbic acid (Vitamin C) on lead induced renal toxicity in adult male Wistar rats. Methods: A total... Objectives: The aim of this study was to verify mitigating effects of the antioxidants α tocopherol (Vitamin E) and ascorbic acid (Vitamin C) on lead induced renal toxicity in adult male Wistar rats. Methods: A total of 36 mature male Wistar rats separated into 1 control group fed with rat feeds and water only and 3 study groups fed with 10 mg/ml of lead acetate, 10 mg/ml of lead acetate + 200 mg/2ml of vitamin C and 10 mg/ml of lead acetate + 100 mg/2ml of vitamin E respectively in addition to feds and water for 28 days were used. Blood samples were obtained for renal indices and the kidneys of all rats were harvested, weighed and prepared for histological examination. Result: The percentage weight gain was highest among control rats (20.70%), followed by lead + vitamin E group (18.42%), lead + vitamin C group (17.00%) and the least amongst the lead group (9.50%). The mean serum uric acid of 419.20 ± 35.80 μmol/L in the lead treatment group was significantly higher than 395.50 ± 15.35 μmol/L, 393.30 ± 14.16 μmol/L and 387.67 ± 14.56 μmol/L in the lead + vitamin C group, lead + vitamin E group and controls respectively. The extent and proportion of renal tissue damage was higher in the lead-treated group and the commonest renal abnormalities observed were tubular and interstitial damage seen in 90.00% of rats in the lead-treated group compared to 75.00% and 60.00% in the lead + vitamin C and the lead + vitamin E groups respectively while the control rats had a normal histological appearance. Conclusions: The sub-acute administration of lead acetate may have inhibitory effect on growth of animals, and adversely affect renal function and histology with uric acid as a more reliable marker of lead induced renal toxicity compared to urea and creatinine. The histologic parameters of tubulointerstitial abnormalities were also consistent with lead toxicity. Antioxidants were useful in reducing lead induced renal damage and growth inhibition with vitamin E producing a more potent effect compared to Vitamin C. 展开更多
关键词 lead ACETATE Toxicity OXIDATIVE Tissue stress ANTIOXIDANTS Prevention
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