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The electrochemical behavior of N-n-undecy1-N＇-（sodium-p- amino-benzenesulfonate） thiourea and its interaction with bovine serum albumin

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Chinese Chemical Letters 2008年第5期19卷 581-584页

作者： Hong Xia Luo yang Du zhi xin Guo Department of Chemistry Renmin University of China Beijing 100872 China

In pH 5.5 phosphate buffer solution, N-n-undecyl-N＇-（sodium-p-amino-benzenesulfonate） thiourea （UPT） produced a pair of redox peaks on the bare glassy carbon electrode. At the multi-walled carbon nanotube （MWNT） modified electrode, the electrochemical behavior of UPT enhanced greatly. In the presence of bovine serum albumin （BSA）, the peak currents of UPT decreased linearly due to the formation of a super-molecular complex. This method was successfully applied to the determination of BSA in a bovine serum sample.

关键词： N-n-Undecyl-N'-(sodium-p-amino-benzenesulfonate) thiourea Carbon nanotube Electrocatalysis Bovine serum albumin

Effects of cadium, zinc and lead on soil enzyme activities

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Journal of Environmental Sciences 2006年第6期18卷 1135-1141页

作者： yang zhi-xin LIU Shu-qing ZHENG Da-wei FENG Sheng-dong College of Resource and Environment China Agricultural University Beijing 100094 China College of Resource and Environment Agricultural University of Hebei Baoding 071001 China

Heavy metal （HM） is a major hazard to the soil-plant system. This study investigated the combined effects of cadium （Cd）, zinc （Zn） and lead （Pb） on activities of four enzymes in soil, including calatase, urease, invertase and alkalin phosphatase. HM content in tops of canola and four enzymes activities in soil were analyzed at two months after the metal additions to the soil. Pb was not significantly inhibitory than the other heavy metals for the four enzyme activities and was shown to have a protective role on calatase activity in the combined presence of Cd, Zn and Pb; whereas Cd significantly inhibited the four enzyme activities, and Zn only inhibited urease and calatase activities. The inhibiting effect of Cd and Zn on urease and calatase activities can be intensified significantly by the additions of Zn and Cd. There was a negative synergistic inhibitory effect of Cd and Zn on the two enzymes in the presence of Cd, Zn and Pb. The urease activity was inhibited more by the HM combinations than by the metals alone and reduced approximately 20%--40% of urease activity. The intertase and alkaline phosphatase activities significantly decreased only with the increase of Cd concentration in the soil. It was shown that urease was much more sensitive to HM than the other enzymes. There was a obvious negative correlation between the ionic impulsion of HM in soil, the ionic impulsion of HM in canola plants tops and urease activity. It is concluded that the soil urease activity may be a sensitive tool for assessing additive toxic combination effect on soil biochemical parameters.

关键词： multiple heavy metal pollution canola plants soil enzyme ionic impulsion

A ^(15)N-Labeling Study of the Capture of Deep Soil Nitrate from Different Plant Systems

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Journal of Integrative Agriculture 2014年第1期13卷 167-176页

作者： yang zhi-xin WANG Jue DI Hong-jie ZHANG Li-juan JU Xiao-tang Key Laboratory for Farmland Eco-Environment Hebei Province/College of Resource and Environmental SciencesAgricultural University of Hebei Centre for Soil and Environmental Research PO Box 85084Lincoln University College of Agricultural Resources and Environmental Sciences China Agricultural University

The objective of this study was to determine the efficiency of different plant systems in capturing deep soil nitrate （NO3-） to reduce NO3- leaching in a field plot experiment using 15N labelling. The study was conducted on a calcareous alluvial soil on the North China Plains and the plant systems evaluated included alfalfa （Medicago sativa）, American black poplar （Populus nigra） and cocksfoot （Dactylis）. ^15N-labelled N fertilizer was injected to 90 cm depth to determine the recovery of ^15N by the plants. With conventional water and nutrient management, the total recovery of ^15N-labeled NO3--N was 23.4% by alfalfa after two consecutive growth years. The recovery was significantly higher than those by American black poplar （12.3%） and cocksfoot （11.4%）. The highest proportion of soil residual ~SN from the labeled fertilizer N （%Ndff） was detected around 90 cm soil depth at the time of the 1st year harvest and at 110-130 cm soil depth at time of the 2nd year harvest. Soil %Ndff in 0-80 cm depth was significantly higher in the alfalfa treatment than those in all the other treatments. The soil %Ndff below 100 cm depth was much lower in the alfalfa than those in all the other treatments. These results indicated that ^15N leaching losses in the alfalfa treatment were significantly lower than by those in the black poplar and cocksfoot treatments, due to the higher root density located in nitrate labeling zone of soil profile. In conclusion, alfalfa may be used as a plant to capture deep soil NO3- left from previous crops to reduce NO3- leaching in high intensity crop cultivation systems of North China Plain.

关键词： ^15N-labeled nitrate tree and forage grass alfalfa cocksfoot black poplar residual nitrate in subsoil capture ability

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弹簧刚度对敏感波纹密封件特性影响的分析

阀门 2024年第4期 441-447页

作者：韩新博张全厚张文良李秋杨志新孙铁霖沈阳仪表科学研究院有限公司辽宁沈阳110043

对某些特殊性能的波纹管,可以采取在波纹管内腔或外部配置圆柱螺旋弹簧的方式。本文通过对弹簧数据、p-w曲线特性数据的分析,包括均布力刚度、压力灵敏度、重复性误差、迟滞误差、最大量程等数据,同时通过Ansys软件对密封组件进行受力分... 详细信息

对某些特殊性能的波纹管,可以采取在波纹管内腔或外部配置圆柱螺旋弹簧的方式。本文通过对弹簧数据、p-w曲线特性数据的分析,包括均布力刚度、压力灵敏度、重复性误差、迟滞误差、最大量程等数据,同时通过Ansys软件对密封组件进行受力分析,探究弹簧对测量类敏感类波纹管组件的影响。结果表明,加入弹簧后,波纹管组件特性有改善,均布力刚度下降,压力灵敏度升高,重复性误差、迟滞误差、最大量程等减小,并且通过选择合适刚度的弹簧,可以使组件性能达到最佳。

关键词：弹簧均布力特性波纹管组件迟滞误差

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可降解地膜对烤烟产值、产量的影响

云南农业科技 2024年第2期 26-29页

作者：张楼兰杨新志岳芹湘杨明鏖郭婷番文健龙陵县植保植检站云南龙陵678300 保山市烟草公司龙陵分公司云南龙陵678300 龙陵县种子管理站云南龙陵678300 龙陵县农村经营管理站云南龙陵678300 龙陵县土壤肥料工作站云南龙陵678300

研究可降解地膜对烟草产值、产量的影响,将白色可降解地膜覆盖处理、黑色可降解地膜覆盖处理、普通地膜处理和不覆盖地膜处理的大田生育期、地膜降解率、大田农艺性状、病虫害情况、经济性状进行了比较。结果表明,黑色可降解地膜覆盖处... 详细信息

研究可降解地膜对烟草产值、产量的影响,将白色可降解地膜覆盖处理、黑色可降解地膜覆盖处理、普通地膜处理和不覆盖地膜处理的大田生育期、地膜降解率、大田农艺性状、病虫害情况、经济性状进行了比较。结果表明,黑色可降解地膜覆盖处理的烟叶产量为2805 kg·hm^(-2)、产值为79101元·hm^(-2)、上等烟比例为66.5%,均高于不覆盖地膜处理和普通地膜覆盖处理;在生长发育状况方面,用白色可降解地膜覆盖处理的株高、叶面积系数等均高于不覆盖地膜处理和普通地膜覆盖处理;在本试验条件下,从环境和经济性状来看,可降解地膜处理均好于普通地膜处理和不覆盖地膜处理;这表明了可降解地膜既满足了烟草需要盖膜的要求,也解决了地膜残留对于烟草的危害。

关键词：可降解地膜烤烟产值产量

超高效液相色谱-串联质谱检测蔗糖中47种农药残留量的方法

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药物分析杂志 2024年第6期44卷 979-989页

作者：谭菊英蒋洁刘庄蔚何虹杨欣智朱健萍邓鸣徐光辉王健赵庄卢日刚广西壮族自治区药品检验研究院南宁530021 中粮崇左糖业有限公司/广西壮族自治区甘蔗产业链延伸工程研究中心崇左532200 中粮营养健康研究院有限公司/营养健康与食品安全北京市重点实验室北京102209

目的:建立超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定蔗糖中47种农药残留量的方法。方法:蔗糖样品经酸性乙腈提取,氮气吹干浓缩,采用LC-MS/MS进行分析检测,在多反应检测模式(MRM)下,用空白基质标准曲线-内标法进行定量。结果:各待测... 详细信息

目的:建立超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定蔗糖中47种农药残留量的方法。方法:蔗糖样品经酸性乙腈提取,氮气吹干浓缩,采用LC-MS/MS进行分析检测,在多反应检测模式(MRM)下,用空白基质标准曲线-内标法进行定量。结果:各待测物质在一定浓度范围内线性良好(r>0.995),检测限为0.01~2.00μg·kg^(-1)。分别在蔗糖样品中添加47种农药标准溶液10、25、50μg·kg^(-1),进行标准添加回收试验,方法回收率为71.0%~106.0%,重复性RSD为0.90%~8.5%。15批蔗糖样品中2批检出噻虫嗪、噻虫胺,其余均未检出。结论:该方法具有前处理简单快捷、灵敏、准确等优点,符合农药残留检测要求,满足蔗糖中农药残留检测需要,可用于蔗糖的质量控制。

关键词：蔗糖农药残留液相色谱-质谱多反应监测模式基质效应内标法

Effective remediation of aged HMW-PAHs polluted agricultural soil by the combination of Fusarium sp, and smooth bromegrass (Bromus inermis Leyss.)

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Journal of Integrative Agriculture 2017年第1期16卷 199-209页

作者： SHI Wei ZHANG Xue-na JIA Hai-bin FENG Sheng-dong yang zhi-xin ZHAO Ou-ya LI Yu-ling Key Laboratory for Farmland Eco-Environment of Hebei Province/College of Resource and Environmental Sciences Agricultural University of Hebei Baoding 0710001 P.R. China College of Forestry Agricultural University of Hebei Baoding 0710001 P.R.China

Fusarium sp. strain ZH-H2 is capable to degrade high molecular weight polycyclic aromatic hydrocarbons （HMW-PAHs）, smooth bromegrass （Bromus inermis Leyss.） can also degrade 4- to 6-ring PAHs. Pot experiments were conducted to investigate how bromegrass and different inoculum sizes of ZH-H2 clean up HMW-PAHs in agricultural soil derived from a coal mine area. The results showed that, compared with control, different sizes of inocula of ZH-H2 effectively degraded HMW-PAHs, with removal rates of 19.01, 34.25 and 29.26% for 4-, 5- and 6-ring PAHs in the treatment with 1.0 g kg-1ZH- H2 incubation after 90 d. After 5 mon of cultivation, bromegrass reached degradation rate of these compounds by 12.66, 36.26 and 36.24%, respectively. By adding strain ZH-H2 to bromegrass, HMW-PAHs degradation was further improved up to 4.24 times greater than bromegrass （W）, in addition to the degradation rate of Bbf decrease. For removal rates of both 5- and 6-ring PAHs, addition of 0.5 g kg-1 Fusarium ZH-H2 to pots with bromegrass performed better than addition of 0.1 g kg-1, while the highest concentration of 1.0 g kg-1 Fusarium ZH-H2 did not further improve degradation. Degradation of4-ring PAHs showed no significant difference among different ZH-H2 incubations with bromegrass treatments. We found that the degradation rates of 4-, 5- and 6-ring PAHs in all treatments are significantly correlated in a positive, linear man- ner with activity of lignin peroxidase （LIP）（t=0.8065, 0.9350 and 0.9165, respectively）, while degradation of 5- and 6-ring PAHs is correlated to polyphenoloxidase （PPO） activity （r=0.7577 and 07806）. Our findings suggest that the combination of Fusarium sp. ZH-H2 and bromegrass offers a suitable alternative for phytoremediation of aged PAH-contaminated soil in coal mining areas, with a recommended inoculation size of 0.5 g Fusarium sp. ZH-H2 per kg soil.

关键词： coal mining area HMW-PAHs Fusarium smooth bromegrass enzymatic activities

Asymmetric alkenylation reaction of benzoxazinones with diarylethylenes catalyzed by B(C_(6)F_(5))_(3)/chiral phosphoric acid

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Chinese Chemical Letters 2024年第5期35卷 135-140页

作者： Zhen Liu zhi-Yuan Ren Chen yang Xiangyi Shao Li Chen xin Li State Key Laboratory of Elemento-Organic Chemistry Frontiers Science Center for New Organic MatterCollege of ChemistryNankai UniversityTianjin 300071China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Zhenhai High School of Zhejiang Ningbo 315299China

Catalytic enantioselective alkenylation is an efficient method to construct chiral alkene molecules,but the asymmetric alkenylation of simple alkenes catalyzed by metal-free catalysts remains an elusive ***,we reported an asymmetric alkenylation of benzoxazinones with diarylethylenes by utilizing a B(C_(6)F_(5))_(3)/chiral phosphoric acid catalyst.A broad of benzoxazinones and diarylethylenes with electron-withdrawing and electron-donating groups were tolerated(up to 95%yield and 97.5:2.5 e.r.)in the methodology under mild reaction ***,the synthetic utility was confirmed by the scaled-up reaction and transformations of the *** mechanism was preliminarily explored by control reactions,nonlinear effect experiment and DFT calculations.

关键词： Asymmetric alkenylation Simple alkenes Benzoxazinones B(C_(6)F_(5))_(3)/chiral phosphoric acid Theoretical calculations

Electrical characteristics of a fractional-order 3×n Fan network

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Communications in Theoretical Physics 2024年第4期76卷 176-187页

作者： zhi-Zhong Tan xin Wang Department of Physics Nantong UniversityNantong 226019China

In this article a new achievement of fractional-order 3×n Fan networks is *** the first step,the RT-I method is used to derive the general formulae of the equivalent impedance of fractional-order 3×n Fan *** the second part,the effects of five system parameters(L,C,n,α and β)on amplitude-frequency and phase-frequency characteristics are *** the same time,the amplitude-frequency and phase-frequency characteristics of the fractional order 3×n Fan network are revealed by Matlab *** work has important theoretical and practical significance for resistor network models in the field of natural science and engineering technology.

关键词： fractional-order circuit amplitude-frequency characteristics phase-frequency characteristics RT-V theory