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Investigati on sonsimultaneous determination of silver and mercury in catalytic-ligandsub stitution reaction with stopped-flow technique calibrated by synergistic effect
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作者 Wang Jianhua , He Ronghuan(Chemistry Department of Yantai Normal College, Yantai 264025 , China) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1995年第4期414-421,共8页
Investigationsonsimultaneousdeterminationofsilverandmercuryincatalytic-ligandsubstitutionreactionwithstopped... Investigationsonsimultaneousdeterminationofsilverandmercuryincatalytic-ligandsubstitutionreactionwithstopped-flowtechniquecal... 展开更多
关键词 kinetic stopped FIA synergistic catalytic coefficient simultaneous determination mercury(II) silver(I).
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The evolution and instability of wake structure around an impulsively stopped sphere with a streamwise magnetic field for 600≤Re≤1400
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作者 Zheng-Gang Cai Jun-Hua Pan Ming-Jiu Ni 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2022年第10期80-91,共12页
The evolution of wake structure in a flow around an impulsively stopped sphere in an incompressible viscous fluid is investigated under the influence of a streamwise magnetic field at moderate Reynolds numbers.The res... The evolution of wake structure in a flow around an impulsively stopped sphere in an incompressible viscous fluid is investigated under the influence of a streamwise magnetic field at moderate Reynolds numbers.The research parameter range is 600≤Re≤1400 and 0≤N≤10,where Re and N are the Reynolds number and the interaction parameter,respectively.A vortex ring system is developed,which contains the primary and secondary vortex rings after stopping the sphere.The flow will keep axisymmetric before stopping the sphere for the purpose to investigate the instability of shedding vortex rings.Without the magnetic field,an azimuthal instability will develop on the secondary vortex ring when the Reynolds number is large enough,e.g.,Re=1200.It is caused by the centrifugal movement of the secondary vortex ring and this instability can be suppressed by the streamwise magnetic field.Furthermore,an obvious oscillation caused by the motion of the primary vortex ring on the drag force is found after stopping the sphere.The amplitude of such oscillation increases with enlarging the Reynolds number but decreases with enlarging the magnetic field intensity. 展开更多
关键词 Impulsively stopped sphere Magnetic field Azimuthal instability Drag force
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Foreign Investments in China Stopped Falling and Restored Stability
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《China's Foreign Trade》 2001年第3期10-10,共1页
关键词 In Foreign Investments in China stopped Falling and Restored Stability US
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基于STOP行为观察的大学生学习行为研究
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作者 张盈盈 薛淑萍 +2 位作者 骆柯嘉 索若淇 张泽林 《吕梁学院学报》 2025年第2期92-95,100,共5页
大学生的学习行为显著影响学习效率和学习质量.如何纠正大学生的不良学习行为、提高学习质量,是高校教学改革和人才培养的重要问题.本文基于杜邦STOP行为观察方法,结合PDCA动态循环构建了大学生学习行为观察模型,统计了某高校安全工程... 大学生的学习行为显著影响学习效率和学习质量.如何纠正大学生的不良学习行为、提高学习质量,是高校教学改革和人才培养的重要问题.本文基于杜邦STOP行为观察方法,结合PDCA动态循环构建了大学生学习行为观察模型,统计了某高校安全工程专业大学生的不良学习行为,并应用层次分析法定量分析了不良学习行为对学习质量的影响.研究表明,大学生学习质量的影响因素排序为:课堂学习行为>课外学习行为>学习环境因素.在课堂学习行为中,未按时上课、玩电子产品、未参与课堂互动等因素的影响较明显;在课外学习行为中,作业抄袭、思考少、学习进度拖沓等因素的影响较大;在学习环境因素中,噪声大、照明不足等因素影响较大. 展开更多
关键词 STOP行为观察 层次分析法 大学生学习行为
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STOPPED PROCESSES OF TEMPORALLY HOMOGENEOUS MARKOV JUMP PROCESSES
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作者 何声武 汪嘉冈 《Chinese Science Bulletin》 SCIE EI CAS 1992年第8期623-626,共4页
Let X=(X, (ω))<sub>(</sub>t≥0 be a jump process defined on a complete probability space (Ω, F, P):
关键词 MARKOV JUMP PROCESS stopped PROCESS STOPPING time COMPENSATOR of random measure.
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Being the Driver or a Passenger?
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作者 Ruth Devlin 《空中英语教室(初级版.大家说英语)》 2025年第10期30-31,54,共3页
When you go somewhere,do you like to be the driver or a passenger?When you are the driver,you are in control.You can go fast or slow.You can pick the route.When and where do you stop?You decide.You enjoy the feeling o... When you go somewhere,do you like to be the driver or a passenger?When you are the driver,you are in control.You can go fast or slow.You can pick the route.When and where do you stop?You decide.You enjoy the feeling of driving.Ifs fun! 展开更多
关键词 control ENJOYMENT speed DRIVER PASSENGER STOP decision ROUTE
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Detection of PRMT1 inhibitors with stopped flow fluorescence
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作者 Kun Qian Hao Hu +1 位作者 Hui Xu Y George Zheng 《Signal Transduction and Targeted Therapy》 SCIE 2018年第1期274-283,共10页
Protein arginine methyltransferases(PRMTs)are crucial epigenetic regulators in eukaryotic organisms that serve as histone writers for chromatin remodeling.PRMTs also methylate a variety of non-histone protein substrat... Protein arginine methyltransferases(PRMTs)are crucial epigenetic regulators in eukaryotic organisms that serve as histone writers for chromatin remodeling.PRMTs also methylate a variety of non-histone protein substrates to modulate their function and activity.The development of potent PRMT inhibitors has become an emerging and imperative research area in the drug discovery field to provide novel therapeutic agents for treating diseases and as tools to investigate the biological functions of PRMTs.PRMT1 is the major type I enzyme that catalyzes the formation of asymmetric dimethyl arginine,and PRMT1 plays important regulatory roles in signal transduction,transcriptional activation,RNA splicing,and DNA repair.Aberrant expression of PRMT1 is found in many types of cancers,pulmonary diseases,cardiovascular disease,diabetes,and renal diseases.PRMT1 is a highly promising target for therapeutic development.We created a stopped flow fluorescence-based assay for PRMT1 inhibitor detection and characterization that has the advantages of being homogeneous,nonradioactive,and mix-and-measure in nature,allowing for continuous measurement of the methylation reaction and its inhibition.To our knowledge,this is the first continuous assay for PRMT1 reaction detection and inhibitor characterization.The approach is not only capable of quantitatively determining the potency(IC50)of PRMT1 inhibitors but can also distinguish cofactor-competitive inhibitors,substrate-competitive inhibitors,and mixed-type inhibitors. 展开更多
关键词 PRMT1 stopped COMPETITIVE
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小蝌蚪找妈妈
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作者 邱许慧 《今日教育(幼教金刊)》 2025年第6期55-57,共3页
活动意图在观察季节更迭的过程中,幼儿对生活中小蝌蚪蜕变为青蛙的过程充满好奇。教师恰当地引入了我国第一部水墨动画片《小蝌蚪找妈妈》,于是幼儿在阅读绘本故事时,开始创作《小蝌蚪找妈妈》水墨连环画。本次活动设计作为幼儿兴趣的延... 活动意图在观察季节更迭的过程中,幼儿对生活中小蝌蚪蜕变为青蛙的过程充满好奇。教师恰当地引入了我国第一部水墨动画片《小蝌蚪找妈妈》,于是幼儿在阅读绘本故事时,开始创作《小蝌蚪找妈妈》水墨连环画。本次活动设计作为幼儿兴趣的延伸,借力现代信息科技软件Stop Motion,在幼儿了解定格动画的基础上,通过人工智能工具推动活动进一步发展,鼓励幼儿创作《小蝌蚪找妈妈》定格动画微电影,帮助幼儿感受科技的力量,获得有趣、有益的体验。 展开更多
关键词 幼儿教育 水墨动画片 Stop Motion 定格动画
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Experiments on the Start-Up and Shutdown of a Centrifugal Pump and Performance Prediction
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作者 Yuliang Zhang Zezhou Yang +3 位作者 Lianghuai Tong Yanjuan Zhao Xiaoqi Jia Anda Han 《Fluid Dynamics & Materials Processing》 2025年第4期891-938,共48页
This paper investigates the start-up and shutdown phases of a five-bladed closed-impeller centrifugal pump through experimental analysis,capturing the temporal evolution of its hydraulic performances.The study also pr... This paper investigates the start-up and shutdown phases of a five-bladed closed-impeller centrifugal pump through experimental analysis,capturing the temporal evolution of its hydraulic performances.The study also predicts the transient characteristics of the pump under non-rated operating conditions to assess the accuracy of various machine learning methods in forecasting its instantaneous performance.Results indicate that the pump’s transient behavior in power-frequency mode markedly differs from that in frequency-conversion mode.Specifically,the power-frequency mode achieves steady-state values faster and exhibits smaller fluctuations before stabilization compared to the other mode.During the start-up phase,as the steady-state flow rate increases,inlet and outlet pressures and head also rise,while torque and shaft power decrease,with rotational speed remaining largely unchanged.Conversely,during the shutdown phase,no significant changes were observed in torque,shaft power,or rotational speed.Six machine learning models,including Gaussian Process Regression(GPR),Decision Tree Regression(DTR),and Deep Learning Networks(DLN),demonstrated high accuracy in predicting the hydraulic performance of the centrifugal pump during the start-up and shutdown phases in both power-frequency and frequency-conversion conditions.The findings provide a theoretical foundation for improved prediction of pump hydraulic performance.For instance,when predicting head and flow rate during power-frequency start-up,GPR achieved absolute and relative errors of 0.54 m(7.84%)and 0.21 m3/h(13.57%),respectively,while the Feedforward Neural Network(FNN)reported errors of 0.98 m(8.24%)and 0.10 m3/h(16.71%).By contrast,the Support Vector Machine Regression(SVMR)and Generalized Additive Model(GAM)generally yielded less satisfactory prediction accuracy compared to the other methods. 展开更多
关键词 Centrifugal pumps starting and stopping period power frequency frequency conversion external characteristic machine learning
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Effect of gold doping on relativistic electron beam transport in high-density plasma
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作者 Zi-Yan Zhang Wei-Min Wang 《Chinese Physics B》 2025年第7期95-102,共8页
We investigate the influence of gold doping on the transport range of a relativistic electron beam in high-density deuterium–tritium(DT)fuel,which could be encountered in the double-cone ignition laser fusion.We deve... We investigate the influence of gold doping on the transport range of a relativistic electron beam in high-density deuterium–tritium(DT)fuel,which could be encountered in the double-cone ignition laser fusion.We develop the stopping power model to include gold doping and then analyze the influence of Coulomb collision and bremsstrahlung on the electron transport range with different gold doping ratios,consistent with the Geant4 simulations.When the gold doping ratio increases from 0.5%to 30%,the transport range of a 10 Me V electron beam is decreased by 9.6%and 18.5%via the bremsstrahlung.For the 1 Me V beam,the decrease of the range becomes 0.7%and 1.0%.We also investigate the transverse broadening of the electron beam and radiated photon energy reabsorption in a spherical target.When the gold doping ratio is 2%and the beam energy is increased from 1 Me V to 5 Me V,the bremsstrahlung photons cover 2.6%to 10.3%of the total beam energy.Meanwhile,the reabsorbed photon energy is reduced from 31.6%to 8.9%. 展开更多
关键词 double-cone ignition(DCI)scheme stopping power GEANT4 BREMSSTRAHLUNG
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小蝌蚪找妈妈——大班综合活动
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作者 邱许慧 《山东教育》 2025年第23期92-94,共3页
设计意图近期,孩子们对小蝌蚪变为青蛙的过程充满好奇。随后,经典童话故事《小蝌蚪找妈妈》走进了孩子们的视野。孩子们在阅读绘本故事后,创作出了自己的《小蝌蚪找妈妈》水墨连环画。我国第一部水墨动画片就是《小蝌蚪找妈妈》,其取材... 设计意图近期,孩子们对小蝌蚪变为青蛙的过程充满好奇。随后,经典童话故事《小蝌蚪找妈妈》走进了孩子们的视野。孩子们在阅读绘本故事后,创作出了自己的《小蝌蚪找妈妈》水墨连环画。我国第一部水墨动画片就是《小蝌蚪找妈妈》,其取材于画家齐白石创作的鱼虾等形象。受此启发,本次活动以《小蝌蚪找妈妈》故事内容为题材,以定格动画制作软件Stop Motion Stodio(以下简称Stop Motion)为媒介,以人工智能赋能活动实施. 展开更多
关键词 定格动画 小蝌蚪找妈妈 Stop Motion
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Advances in dual energy computed tomography approach for proton stopping power ratio computation in radiotherapy
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作者 Charles Ekene Chika 《World Journal of Radiology》 2025年第6期24-38,共15页
To address the sensitive and uncertain limitations of single-energy computed tomography(CT)calibration methods in computing proton stopping power ratio during treatment planning,different methods have been proposed us... To address the sensitive and uncertain limitations of single-energy computed tomography(CT)calibration methods in computing proton stopping power ratio during treatment planning,different methods have been proposed using a dual energy CT approach.This paper reviews the most recent dual-energy CT approaches for computing proton stopping power ratio.These include image domain and projection domain methods.The advantages and uncertainties of these methods are analyzed based on existing studies.This paper highlights recent advances in dual energy CT,discussing their implementation,advantages,limitations,and potential for clinical adoption. 展开更多
关键词 Dual energy computed tomography Stopping power ratio Machine learning Mathematical model Image domain Projection domain RADIOTHERAPY Alternating minimization algorithm Electron density Mean excitation energy
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Study on photoluminescence and thermoluminescence of Y_(2-x)Sm_(x)MgTiO_(6)phosphors
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作者 Hao Liu Lu-Yan Wang +1 位作者 Zheng-Ye Xiong Jing-Yuan Guo 《Nuclear Science and Techniques》 2025年第7期157-166,共10页
Double perovskite matrix materials have recently attracted considerable interest due to their structural flexibility,ease of doping,and excellent thermal stability.While photoluminescence(PL)studies of rare-earth-dope... Double perovskite matrix materials have recently attracted considerable interest due to their structural flexibility,ease of doping,and excellent thermal stability.While photoluminescence(PL)studies of rare-earth-doped double perovskites are common,research on their thermoluminescence(TL)properties is less extensive.This study synthesized a series of Y_(2-x)Sm_(x)MgTiO_(6)(0≤x≤0.1)samples using a high-temperature solid-state method.X-ray diffraction(XRD)analysis confirmed a monoclinic crystal structure(space group P2_(1)∕n),with Sm^(3+)ions substituting for Y^(3+)ions in Y_(2)MgTiO_(6).The PL results indicated that the optimal doping concentration was Y_(1.95)Sm_(0.05)MgTiO_(6),exhibiting emission peaks at 568,605,652,and 715 nm under 409 nm blue light excitation.The TL measurements for different doping concentrations showed that the Y_(1.98)Sm_(0.02)MgTiO_(6)phosphors exhibited the strongest TL signals.The TL peaks observed at 530 and 610 K correspond to defects in the matrix and Sm^(3+)dopants,respectively.The T_(m)-T_(stop)analysis revealed that the TL curve of Y_(1.98)Sm_(0.02)MgTiO_(6)phosphors was a superposition of seven peaks.Computerized glow curve deconvolution(CGCD)was performed on the TL of the sample according to the results of three-dimensional thermoluminescence spectra(3D-TL)and T_(m)-T_(stop),and the trap depths in the sample were estimated to range from 0.69 to 1.49 eV.Additionally,the lifetimes of each overlapping peak were calculated using the fitting parameters.Furthermore,the dose-response test showed that the saturation dose of the sample was high(9956 Gy).Therefore,this material can serve as a thermoluminescent dosimeter for high-dose measurements.The saturation dose for the lowest-temperature overlapping peak was 102 Gy,which correlated with its specific energy-level lifetime,whereas the other overlapping peaks also exhibited favorable linear relationships. 展开更多
关键词 Y_(2)MgTiO_(6) THERMOLUMINESCENCE T_(m)-T_(stop) Computerized glow curve deconvolution DOSE-RESPONSE
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The Day the Milk Stopped Flowing
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作者 LAN XINZHEN 《Beijing Review》 2011年第17期34-35,共2页
Government crackdowns may put the dairy industry back on the right track,but more action will be necessary to ensure dairy safety Nearly half of China’s dairy enter-p rises will be forced to suspend operations or clo... Government crackdowns may put the dairy industry back on the right track,but more action will be necessary to ensure dairy safety Nearly half of China’s dairy enter-p rises will be forced to suspend operations or close their facilities following a watchdog ins pectiont hat found many dairy producers have been operating below quality safety standards. 展开更多
关键词 The Day the Milk stopped Flowing
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Mr.Han Qide,Vice Chairman of the CPPCC and CPAPD President led a CPAPD delegation on a good-will visit to Turkey and Israel and stopped over in Egypt June 10-19,2013
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《Peace》 2013年第2期2-4,61,共4页
Mr.Han Qide and his party meeting with Prof.Mehmet SAGLAM,Vice Speaker of the Grand National Assembly of Turkey.Mr.Han Qide meeting with Mr.Shimon Peres,the President of Israel.Mr.Han Qide and his party attending Chin... Mr.Han Qide and his party meeting with Prof.Mehmet SAGLAM,Vice Speaker of the Grand National Assembly of Turkey.Mr.Han Qide meeting with Mr.Shimon Peres,the President of Israel.Mr.Han Qide and his party attending China-Turkey NGO Roundtable Meeting.Mr.Han Qide and his party attending the China-Israel Friendly Associations and Think Tanks Workshop. 展开更多
关键词 OVER WILL Mr.Han Qide Vice Chairman of the CPPCC and CPAPD President led a CPAPD delegation on a good-will visit to Turkey and Israel and stopped over in Egypt June 10-19 2013
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3-D CFD simulation of transients in multiple pump system with some pumps being stopped 被引量:2
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作者 Yue-fei Liu Jian-xu Zhou +2 位作者 Qiang Guo Ai-li Shen Jian Zhang 《Journal of Hydrodynamics》 SCIE EI CSCD 2021年第3期583-592,共10页
The computational fluid dynamics(CFD)approach can be used to obtain both internal and external characteristics of centrifugal pumps,and the variations of the hydrodynamic force,the pressure and the torque on the blade... The computational fluid dynamics(CFD)approach can be used to obtain both internal and external characteristics of centrifugal pumps,and the variations of the hydrodynamic force,the pressure and the torque on the blades acquired by the CFD are highly associated with the safety of the pumping system.Based on the CFD simulations,this paper investigates the stopping characteristics of multiple pumps with some pumps being stopped.The 3-D geometric model is built,including all 6 pumps,the valves,the pipes,the tanks and other components,and using the Realizable k-ε turbulence model.The CFD results for the operating points agree well with the results from the theoretical analysis.With some pumps being stopped,the key parameters of the operating pumps would not be stable,with a larger fluctuation;the direction of the hydrodynamic force might be opposite with more than 3 stopped pumps.For the stopped pumps,the maximum reverse values of the discharge and the rotational speed would be larger when fewer pumps are stopped,and could be more than 120%of the rated values,which is dangerous for the pumping system.The CFD results could help understanding the stopping process of multiple pump systems with some pumps being stopped. 展开更多
关键词 Centrifugal pumps some pumps stop computational fluid dynamics(CFD) operating points maximum reverse value
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茶树STOP基因家族的鉴定及表达模式分析 被引量:2
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作者 龙露 汤丹丹 +3 位作者 陈玮 谭礼强 陈盛相 唐茜 《茶叶科学》 CAS CSCD 北大核心 2024年第3期386-398,共13页
STOP(Sensitive to proton rhizotoxicity)是一类C_(2)H_(2)型锌指结构转录因子,在植物多种胁迫耐受机制中发挥重要调控作用。基于茶树(Camellia sinensis)全基因组数据共鉴定出6个STOP家族基因,并运用生物信息学和实时荧光定量PCR(qRT-... STOP(Sensitive to proton rhizotoxicity)是一类C_(2)H_(2)型锌指结构转录因子,在植物多种胁迫耐受机制中发挥重要调控作用。基于茶树(Camellia sinensis)全基因组数据共鉴定出6个STOP家族基因,并运用生物信息学和实时荧光定量PCR(qRT-PCR)等方法对其进行分析。结果表明,6个CsSTOPs基因编码376~505个氨基酸,蛋白质分子量为42.17~56.36 kDa,理论等电点为5.53~8.85,均为不稳定蛋白;蛋白质保守结构域分析发现,它们均含zf-C_(2)H_(2)保守结构域;系统进化分析显示,茶树的STOP基因与拟南芥、甜橙、烟草的同源性较高;启动子顺式作用元件分析发现,CsSTOPs具有许多与生长发育、激素响应及非生物胁迫相关的作用元件;茶树各器官的转录组数据分析结果表明,CsSTOP1在根、果实、成熟叶片中的表达量较高,CsSTOP2在幼嫩叶片中的表达量较高,CsSTOP3在老叶中的表达量较高,而Cs STOP4和Cs STOP5在各个器官中的表达都较低。CsSTOPs基因能够被PEG诱导的干旱胁迫、盐胁迫、茉莉酸甲酯胁迫和冷胁迫处理诱导表达,说明CsSTOPs基因参与调控茶树生长发育和响应非生物胁迫过程。qRT-PCR检测发现,CsSTOPs、CsGS1s和CsGDHs基因在高NH_(4)^(+)浓度处理(4.5 mmol·L^(-1))的峨眉问春茶树叶和根中的表达量均高于对照处理(CK),尤其是叶中CsSTOPs、CsGS1.1、CsGS1.3和CsGDH2在高NH_(4)^(+)浓度处理下的表达量显著高于对照。研究结果初步解析了CsSTOPs的基本特征和功能,发现CsSTOPs可响应高NH_(4)^(+)浓度处理,可能与CsGS1s和CsGDHs协同调控茶树适应高NH_(4)^(+)环境的过程。 展开更多
关键词 茶树 STOP基因家族 生物信息学分析 基因表达
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英雄小狗,挽救生命
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作者 袁泉 《疯狂英语(新读写)》 2024年第3期37-39,77,共4页
狗聪明、有洞察力、精力充沛,甚至是现实生活中的英雄。主题语境:人与动物篇幅:346词建议用时:7分钟1 Dogs are incredible. They can be intelligent, insightful, energetic, and real-life heroes! Today, we are commending a dog n... 狗聪明、有洞察力、精力充沛,甚至是现实生活中的英雄。主题语境:人与动物篇幅:346词建议用时:7分钟1 Dogs are incredible. They can be intelligent, insightful, energetic, and real-life heroes! Today, we are commending a dog named Axel, a hero to his whole family. 2 Rescued by the Tanner family in Spring, Axel is about one year old. On August 26, 2023, Axel awakened his owners, Daines and Amanda Tanner, at 5:00 am. Thinking the dog just wanted out, Daines sleepily opened the door. But Axel had stopped in front of the door leading to their 17-year-old son's room and wouldn't budge. 展开更多
关键词 stopped RESCUE INSIGHT
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BRACO-19和TMPyP4在HBV-1.3mer质粒感染模型对HBV转录和复制的抑制作用 被引量:1
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作者 马海洋 贺丽娜 +1 位作者 吕树娟 余莉 《中国病原生物学杂志》 CSCD 北大核心 2024年第9期999-1003,1008,共6页
目的探讨G-四链体小分子配体BRACO-19和TMPyP4对乙型肝炎病毒转录和复制的影响。方法利用含有HBV全基因组1.3倍复制子(HBV 1.3-mer)质粒转染HepG2细胞感染模型,BRACO-19和TMPyP4分别作用48 h,酶联免疫吸附试验检测上清表面抗原(HBsAg)和... 目的探讨G-四链体小分子配体BRACO-19和TMPyP4对乙型肝炎病毒转录和复制的影响。方法利用含有HBV全基因组1.3倍复制子(HBV 1.3-mer)质粒转染HepG2细胞感染模型,BRACO-19和TMPyP4分别作用48 h,酶联免疫吸附试验检测上清表面抗原(HBsAg)和e抗原(HBeAg)表达水平,实时荧光定量PCR检测细胞内HBV Total RNA、3.5kbRNA以及DNA表达水平,将HBV DNA用plasmid SafeTMATP-Dependent DNase 37℃作用3 h后,定量PCR检测病毒cccDNA的表达;QGRS Mapper软件分析HBV推定的四链体形成序列(putative quadruplex-forming sequences,PQS),并在HBV 1.3-mer质粒DNA上设计PQS区域上下游引物及非PQS区域对照引物,两种小分子配体分别作用HBV 1.3-mer质粒DNA,qPCR stop试验分别定量PQS和非PQS区域DNA扩增水平,1%琼脂糖凝胶电泳可视化验证。结果20μmol/L BRACO-19和TMPyP4作用HepG2转染模型显著抑制HBsAg和HBeAg的表达水平,HBV的Total RNA、3.5 kb RNA、DNA和cccDNA水平相较于对照组均显著下调。通过不同浓度BRACO-19和TMPyP4作用HBV质粒DNA,qPCR stop试验发现随着BRACO-19和TMPyP4药物浓度递增可以显著抑制DNA聚合酶在基因组中三个HBV PQS区域的扩增。结论小分子配体BRACO-19和TMPyP4均能抑制HBV转染模型中的转录和复制,HBV基因存在富含鸟嘌呤的四链体形成序列,BRACO-19和TMPyP4特异性阻滞DNA聚合酶在HBV的PQS区域复制延伸。 展开更多
关键词 乙型肝炎病毒 BRACO-19 TMPyP4 PCR stop assay
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Influence of erbium on structural,and charged particles,photons,and neutrons shielding properties of Ba_(1-x)Er_(x)SnO_(3) perovskite ceramics
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作者 M.K.h.Hamad Nidal Dwaikat +7 位作者 M.H.A.Mhareb M.I.Sayyed R.M.Hamad Y.S.M.Alajerami M.A.Almessiere Gameel Saleh Ahmad Hussein Alomari K.A.Ziq 《Journal of Rare Earths》 SCIE EI CAS CSCD 2024年第4期724-732,共9页
Five perovskite ceramics samples of Ba_(1-x)Er_(x)SnO_(3) with x=0.00,0.05,0.10,0.15,and 0.20 were synthesized using the conventional solid-state reaction method.The prepared samples were characterized by X-ray diffra... Five perovskite ceramics samples of Ba_(1-x)Er_(x)SnO_(3) with x=0.00,0.05,0.10,0.15,and 0.20 were synthesized using the conventional solid-state reaction method.The prepared samples were characterized by X-ray diffraction(XRD),Fourier transforms infrared(FTIR),and UV-Vis spectroscopy.The shielding properties against ionizing radiation were also investigated.The XRD analysis shows the perovskite cubic structure as the major phase in all samples.The FTIR reveals a distinctive band around 614-620 cm^(-1) ascribed to the antisymmetric O-Sn-O vibration.UV-Vis spectroscopy was used to determine the bandgap according to diffuse reflectance,and the results display a fixed enhancement in the bandgap from 3.2 to 3.3 eV for all samples.Gamma-ray shielding properties of the synthesized samples were experimentally measured and compared with XCOM computational results.The relative differences(Δ,%)between experimental and theo retical values are low and fall within the 0.446%-7.10%range.The addition of Er leads to the enhanced density,neutron,and gamma shielding features.In contrast,charged particles’shielding parameters gradually reduce with rising Er contents.These results suggest that Ba_(1-x)Er_(x)SnO_(3) samples can be used in different radiation shielding applications. 展开更多
关键词 PEROVSKITE Ceramics Gamma ray shielding Mass stopping power Rare earths
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