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Development of 400-μW cryogen-free dilution refrigerators for quantum experiments
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作者 关翔 樊洁 +2 位作者 边勇波 程智刚 姬忠庆 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期28-35,共8页
We have successfully developed cryogen-free dilution refrigerators with medium cooling power that can be applied to quantum experiments. Breakthroughs have been made in some key technologies and components of heat swi... We have successfully developed cryogen-free dilution refrigerators with medium cooling power that can be applied to quantum experiments. Breakthroughs have been made in some key technologies and components of heat switches and dilution units. Our prototype has been running continuously and stably for more than 100 hours below 10 m K, with a minimum temperature of 7.6 m K and a cooling power of 450 μW at 100 m K. At the same time, we have also made progress in the application of dilution refrigerators, such as quantum computing, low-temperature detector, and magnet integration. These indicators and test results indicate good prospects for application in physics, astronomy, and quantum information. 展开更多
关键词 cryogen-free dilution refrigerator quantum computing low-temperature detector superconducting magnet
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Effect of CO_(2) dilution on laminar burning velocities,combustion characteristics and NO_(x) emissions of CH_(4)/air mixtures 被引量:2
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作者 Wenlong Dong Longkai Xiang +2 位作者 Jian Gao Bingbing Qiu Huaqiang Chu 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第5期119-136,共18页
The laminar combustion characteristics of CH_(4)/air premixed flames with CO_(2) addition are systemically studied.Experimental measurements and numerical simulations of the laminar burning velocity(LBV)are performed ... The laminar combustion characteristics of CH_(4)/air premixed flames with CO_(2) addition are systemically studied.Experimental measurements and numerical simulations of the laminar burning velocity(LBV)are performed in CH_(4)/CO_(2)/Air flames with various CO_(2) doping ratio under equivalence ratios of 1.0–1.4.GRI 3.0 mech and Aramco mech are employed for predicting LBV,adiabatic flame temperature(AFT),important intermediate radicals(CH_(3),H,OH,O)and NO_(x) emissions(NO,NO_(2),N2O),as well as the sensitivity analysis is also conducted.The detail analysis of experiment and simulation reveals that as the CO_(2) addition increases from 0%to 40%,the LBVs and AFTs decrease monotonously.Under the same CO_(2) doping ratio,the LBVs and AFTs increase first and then decrease with the increase of equivalence ratio,and the maximum of LBV is reached at equivalence ratio of 1.05.The mole fraction tendency of important intermediates and NO_(x) with equivalence ratio and CO_(2) doping ratio are similar to the LBVs and AFTs.Reaction H+O_(2)⇔O+OH is found to be responsible for the promotion of the generation of important intermediates and NO_(x) under the equivalence ratios and CO_(2) addition through sensitivity analysis.The sensitivity coefficients of elementary reactions that the increasing of CO_(2) doping ratio promotes or inhibits formation of intermediate radicals and NO_(x) decreases. 展开更多
关键词 CO_(2)dilution Laminar burning velocity Adiabatic flame temperature Sensitivity analysis
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Dilution characteristics of dual buoyant jets in wavy cross-flow environment 被引量:1
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作者 Ebenezer Otoo Yong-ping Chen +1 位作者 Zhen-shan Xu Yu-hang Chen 《Water Science and Engineering》 EI CAS CSCD 2023年第1期83-93,共11页
Due to the difference in density between the discharge effluent and coastal water,partially treated wastewater is often discharged into the marine environment as a buoyant jet via submarine outfalls with multiport dif... Due to the difference in density between the discharge effluent and coastal water,partially treated wastewater is often discharged into the marine environment as a buoyant jet via submarine outfalls with multiport diffusers.The dilution characteristics of effluent discharge(dual buoyant jets)in a wavy cross-flow environment were studied in a laboratory.The planar laser-induced fluorescence technique was used to obtain the concentration data of the jets.The effects of different environmental variables on the diffusion and dilution characteristics of the jets were examined through physical experiments,dimensional analysis,and empirical formulations.It was found that the dilution process of the dual jets could be divided into two components:the original jet component and the effluent cloud component.The jet-to-current velocity ratio was the main parameter affecting the concentration levels of the effluent cloud.The merging of the two jets increased the jet concentration in the flow field.When the jets traveled further downstream,the axial dilution increased gradually and then increased significantly along the axis.Under the effects of strong waves,the concentration contours branched into two peaks,and the mean dilution became more significant than under the effects of weak waves.Therefore,the dilution of the effluent discharge was expected to be significant under strong wave effects because the hydrodynamic force increased.A dilution equation was derived to improve our understanding of the dilution process of buoyant jets in a wavy cross-flow environment.This equation was used to determine the influences of the jet-to-current velocity ratio,wave-to-current velocity ratio,and Strouhal number on the minimum jet dilution.It revealed that the wave and buoyancy effects in effluent discharges were significant. 展开更多
关键词 Minimum dilution Wavy cross-flow Dual buoyant jets Dimensional analysis Effluent discharge
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Clinical value of chemiluminescence method for detection of antinuclear antibody profiles 被引量:1
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作者 Hui-Yao Xiang Xi-Ying Xiang +3 位作者 Ting-Bo Ten Xie Ding Yu-Wen Liu Chun-Hua Luo 《World Journal of Clinical Cases》 SCIE 2023年第28期6688-6697,共10页
BACKGROUND Antinuclear antibodies(ANAs)are crucial in diagnosing autoimmune diseases,mainly systemic lupus erythematosus(SLE).This study aimed to compare the performance of chemiluminescence assay(CLIA)and line immuno... BACKGROUND Antinuclear antibodies(ANAs)are crucial in diagnosing autoimmune diseases,mainly systemic lupus erythematosus(SLE).This study aimed to compare the performance of chemiluminescence assay(CLIA)and line immunoassay(LIA)in detecting ANAs in patients with autoimmune diseases,evaluate their diagnostic accuracy for SLE,and develop a novel diagnostic model using CLIA-detected antibodies for SLE.Specimens from patients with autoimmune diseases and physical examination specimens were collected to parallel detect specific antibodies.Individual antibodies'diagnostic performance and a model combining multiple antibodies were assessed.The findings provide valuable insights into improving the diagnosis of SLE through innovative approaches.AIM To compare the performance of CLIA and LIA in detecting ANAs in patients with autoimmune diseases,assess their accuracy for SLE,and develop a novel diagnostic model using CLIA-detected antibodies for SLE.METHODS Specimens have been obtained from 270 patients with clinically diagnosed autoimmune disorders,as well as 130 physical examination specimens.After that,parallel detection of anti-double-stranded DNA(dsDNA)antibody,anti-histone(Histone)antibody,anti-nucleosome(Nuc)antibody,anti-Smith(Sm)antibody,anti-ribosomal P protein(Rib-P)antibody,anti-sicca syndrome A(Ro60)antibody,anti-sicca syndrome A(Ro52)antibody,anti-sicca syndrome(SSB)antibody,anticentromere protein B(Cenp-B)antibody,anti-DNA topoisomerase 1(Scl-70)antibody,anti-histidyl tRNA synthetase(Jo-1)antibody,and anti-mitochondrial M2(AMA-M2)antibody was performed using CLIA and LIA.The detection rates,compliance rates,and diagnostic performance for SLE were compared between the two methodologies,followed by developing a novel diagnostic model for SLE.RESULTS CLIA and LIA exhibited essentially comparable detection rates for anti-dsDNA antibody,anti-Histone antibody,anti-Nuc antibody,anti-Sm antibody,anti-Rib-P antibody,anti-Ro60 antibody,anti-Ro52 antibody,anti-SSB antibody,anti-Cenp-B antibody,anti-DNAScl-70 antibody,anti-Jo-1 antibody and anti-AMA-M2 antibody(P>0.05).The two methods displayed identical results for the detection of anti-dsDNA antibody,anti-Histone antibody,anti-Nuc antibody,anti-Sm antibody,anti-Ro60 antibody,anti-Ro52 antibody,anti-SSB antibody,anti-Cenp-B antibody,anti-Scl-70 antibody,and anti-AMA-M2 antibody(Kappa>0.7,P<0.05),but showed a moderate agreement for the detection of anti-Rib-P antibody and anti-Jo-1 antibody(Kappa=0.671 and 0.665;P<0.05).In addition,the diagnostic performance of these antibodies detected by both methods was similar for SLE.The diagnostic model's area under the curve values,sensitivity,and specificity,including an anti-dsDNA antibody and an anti-Ro60 antibody detected by CLIA,were 0.997,0.962,and 0.978,respectively.These values were higher than the diagnostic performance of individual antibodies.CONCLUSION CLIA and LIA demonstrated excellent overall consistency in detecting ANA profiles.A diagnostic model based on CLIA-detected antibodies can successfully contribute to developing a novel technique for detecting SLE. 展开更多
关键词 chemiluminescence assay Immunoblotting Antinuclear antibody profile Autoimmune diseases Systemic lupus erythematosus Diagnostic model
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What Is the Difference between Post- and Pre-Dilution in On-Line Haemodiafiltration in the Removing of Median-Molecular-Weight Toxins?
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作者 Konstantinos S. Mavromatidis Irini M. Kalogiannidou Ploumis S. Passadakis 《Journal of Biosciences and Medicines》 CAS 2023年第3期105-119,共15页
Introduction: β<sub>2</sub>-microglobulin and prolactin are medium-molecular-weight toxins. We believe that the rate of removal of these molecules, using filters with two different surfaces, in post- and ... Introduction: β<sub>2</sub>-microglobulin and prolactin are medium-molecular-weight toxins. We believe that the rate of removal of these molecules, using filters with two different surfaces, in post- and pre-dilution haemodiafiltration, will be of interest to the literature. Methods: We studied, in 12 haemodialyzed patients, the removal of those, with filter with surface of 2.5 m<sup>2</sup> (Group A) or 2.1 m<sup>2</sup> (Group B) with post-dilution haemodiafiltration, and with a filter with surface 2.5 m<sup>2</sup> with pre-dilution (Group C). Results: Satisfactory removal of β<sub>2</sub>-microglobulin (best with post-dilution) was found, and a good rate of removal of prolactin without the filter surface played a role in both cases. Conclusion: The elimination of β<sub>2</sub>-microglobulin in post-dilution is not affected by the filter surface area. Pre-dilution achieves removal of β<sub>2</sub>-microglobulin, less than that of post-dilution. Prolactin was removed satisfactorily regardless of the filter surface in post-dilution, and its removal appears to be less than that of β<sub>2</sub>-microglobulin. 展开更多
关键词 HAEMODIAFILTRATION Pre-dilution Post-dilution β2-Microglobulin Prolactin
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Regulating the dopant clustering in LiZnAs-based diluted magnetic semiconductor
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作者 贾子航 周波 +1 位作者 姜振益 张小东 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期617-623,共7页
Tuning of the magnetic interaction plays the vital role in reducing the clustering of magnetic dopant in diluted magnetic semiconductors(DMS).Due to the not well understood magnetic mechanism and the interplay between... Tuning of the magnetic interaction plays the vital role in reducing the clustering of magnetic dopant in diluted magnetic semiconductors(DMS).Due to the not well understood magnetic mechanism and the interplay between different magnetic mechanisms,no efficient and universal tuning strategy is proposed at present.Here,the magnetic interactions and formation energies of isovalent-doped(Mn) and aliovalent(Cr)-doped LiZnAs are studied based on density functional theory(DFT).It is found that the dopant–dopant distance-dependent magnetic interaction is highly sensitive to the carrier concentration and carrier type and can only be explained by the interplay between two magnetic mechanisms,i.e.,superexchange and Zener’s p–d exchange model.Thus,the magnetic behavior and clustering of magnetic dopant can be tuned by the interplay between two magnetic mechanisms.The insensitivity of the tuning effect to U parameter suggests that our strategy could be universal to other DMS. 展开更多
关键词 diluted magnetic semiconductor dopant distribution first-principles calculations
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Correlation of work function and stacking fault energy through Kelvin probe force microscopy and nanohardness in diluteα-magnesium
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作者 Yigit Türe Ali Arslan Kaya +2 位作者 Hüseyin Aydin Jiang Peng Servet Turan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期237-250,共14页
Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.This investigation incorporated the difference in the‘Work ... Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.This investigation incorporated the difference in the‘Work Function'(ΔWF)measured via Kelvin Probe Force Microscopy(KPFM),as a property directly affected by interatomic bond types,i.e.the electronic structure,nanoindentation measurements,and Stacking Fault Energy values reported in the literature.It was shown that the nano-hardness of the solid-solutionα-Mg phase changed in the order of Mg-Ca>Mg-Sr>Mg-Ba.Thus,it was shown,by also considering the nano-hardness levels,that SFE of a solid-solution is closely correlated with its‘Work Function'level.Nano-hardness measurements on the eutectics andΔWF difference between eutectic phases enabled an assessment of the relative bond strength and the pertinent electronic structures of the eutectics in the three alloys.Correlation withΔWF and at least qualitative verification of those computed SFE values with some experimental measurement techniques were considered important as those computational methods are based on zero Kelvin degree,relatively simple atomic models and a number of assumptions.As asserted by this investigation,if the results of measurement techniques can be qualitatively correlated with those of the computational methods,it can be possible to evaluate the electronic structures in alloys,starting from binary systems,going to ternary and then multi-elemental systems.Our investigation has shown that such a qualitative correlation is possible.After all,the SFE values are not treated as absolute values but rather become essential in comparative investigations when assessing the influences of alloying elements at a fundamental level,that is,free electron density distributions.Our study indicated that the principles of‘electronic metallurgy'in developing multi-elemental alloy systems can be followed via practical experimental methods,i.e.ΔWF measurements using KPFM and nanoindentation. 展开更多
关键词 Mg alloys dilute alloys Work function Stacking fault energy Kelvin probe force microscopy Short range order Miedema NANOINDENTATION EUTECTICS
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First-Principle Study on the Electronic Structure and Optical Property of New Diluted Magnetic Semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO
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作者 Zhou Wenjie 《材料科学与工程(中英文B版)》 2024年第1期14-20,共7页
The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first... The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first-principles calculation.The calculation results indicate that(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO is a direct bandgap semiconductor with a bandgap of 1.1 eV.The Fermi surface is asymmetric and exhibits spin splitting phenomenon.The new type of dilute magnetic semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO exhibits significant light loss around 70 eV,with light reflection gradually increasing after 30 eV,and light absorption mainly occurring around 8-30 eV.These results also provide a basis for the discovery of more types of 1111 phase new dilute magnetic semiconductors in the future. 展开更多
关键词 First-principles calculation electronic structure optical property new diluted magnetic semiconductor
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Determination the Vigor of Rice Seed with Different Degrees of Aging with Ultraweak Chemiluminescence During Early Imbibition 被引量:12
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作者 陈文利 邢达 何永红 《Acta Botanica Sinica》 CSCD 2002年第11期1376-1379,共4页
用高灵敏度的单光子计数系统探测人工老化 (40℃ ,相对湿度 90 % ) 0、7、14和 2 1d的水稻种子吸胀初期的超弱化学发光强度变化 ,首次观测到水稻 (OryzasativaL .)种子吸胀初期超弱化学发光强度与其老化程度有关。加水激活水稻种子的超... 用高灵敏度的单光子计数系统探测人工老化 (40℃ ,相对湿度 90 % ) 0、7、14和 2 1d的水稻种子吸胀初期的超弱化学发光强度变化 ,首次观测到水稻 (OryzasativaL .)种子吸胀初期超弱化学发光强度与其老化程度有关。加水激活水稻种子的超弱化学发光 ,其强度依赖于种子的老化程度。实验结果表明水稻种子的人工老化时间越短 ,则吸胀初期 (2 0~ 30min)超弱化学发光的强度越强 ,萌发率越高。水稻种子萌发率与超弱化学发光强度呈显著正相关。观测水稻种子吸胀初期超弱化学发光强度的变化可望成为检测种子老化程度的一种快速、简便、无损伤的新方法。 展开更多
关键词 rice seeds ultraweak chemiluminescence early imbibition accelerated aging
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Chemiluminescence Determination of Benzoic Acid Using A Solid-Phase Verdigris Reactor 被引量:1
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作者 王晓妮 张洁 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第3期283-286,共4页
A new chemiluminescence flow system has been developed for sequential determina-tion of benzoic acid based on the reaction of the compound with copper carbonate entrapped in a solid-phase reactor. It was found that t... A new chemiluminescence flow system has been developed for sequential determina-tion of benzoic acid based on the reaction of the compound with copper carbonate entrapped in a solid-phase reactor. It was found that the unsaturated complex of Cu(II) and benzoic acid (1:1) has strong catalytic effect on the luminol-H2O2 chemiluminescence reaction. The calibration graph is linear over the range of 0.025 ~ 60 g/mL of benzoic acid, with a relative standard deviation of less than 3.0 %, and the detection limit is 0.01礸穖L-1. The proposed method was applied to the determination of benzoic acid content in different pharmaceutical formulations. 展开更多
关键词 Benzoic acid chemiluminescence solid-phase reactor pharmaceutical formulations.
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Flow injection chemiluminescence determination of meloxicam using potassium permanganate and formaldehyde system 被引量:1
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作者 贾宝秀 曹明亮 +3 位作者 刘彩红 李玉琴 李珂 齐永秀 《Journal of Chinese Pharmaceutical Sciences》 CAS 2008年第1期35-40,共6页
A simple, rapid and sensitive flow injection chemiluminescence (FI-CL) method has been developed for the determination of meloxicam. The method is based on the CL-emitting reaction between meloxicam and potassium pe... A simple, rapid and sensitive flow injection chemiluminescence (FI-CL) method has been developed for the determination of meloxicam. The method is based on the CL-emitting reaction between meloxicam and potassium permanganate in a hydrochloric acid medium, enhanced by formaldehyde (HCHO). Under optimum conditions, calibration curve over the range of 1.0-20.0μg/mL was obtained. The proposed method was successfully applied to the determination of meloxicam in capsules with no evi- dence of interference from common excipients. The detection limit of this method was 25.6 ng/mL. The relative standard deviation was 2.1% for 10.0 μg/mL meloxicam. The sample throughput was found to be 120 samples/h. 展开更多
关键词 MELOXICAM Flow injection chemiluminescence FORMALDEHYDE Pharmaceutical analysis
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Study on the metastable state of dilution of spectinomycin 被引量:3
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作者 鲍颖 王静康 +2 位作者 王永莉 戚振 王宏斌 《中国抗生素杂志》 CAS CSCD 北大核心 2003年第1期10-16,22,共8页
采用诱导期法和直接法研究了大观霉素溶析结晶的介稳态.新相形成由多核机理控制.由多核机理得到两个操作温度下溶析结晶的介稳区.实验考察了丙酮浓度和温度对溶析结晶介稳态的影响.随着丙酮浓度的增大或温度的降低,诱导期延长.介稳区宽... 采用诱导期法和直接法研究了大观霉素溶析结晶的介稳态.新相形成由多核机理控制.由多核机理得到两个操作温度下溶析结晶的介稳区.实验考察了丙酮浓度和温度对溶析结晶介稳态的影响.随着丙酮浓度的增大或温度的降低,诱导期延长.介稳区宽度随溶解度的减小而变宽.大观霉素初级成核的过饱和度水平较高,属于第Ⅰ类物系.根据经典成核理论估算了大观霉素成核参数.这些实验结果对大观霉素溶析结晶工业生产的控制具有重要意义. 展开更多
关键词 大观霉素 溶析结晶 超溶解度 介稳区
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Chemiluminescence detection of permanganate index (COD_(Mn)) by a luminol-KMnO_4 based reaction 被引量:15
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作者 TIAN Jinjun HU Yonggang ZHANG Jie 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第2期252-256,共5页
A novel chemiluminescence (CL) system for determination of permanganate index (CODMn) combined with flow injection analysis has been proposed in this study. On the basis of the chemiluminescent reaction of luminol... A novel chemiluminescence (CL) system for determination of permanganate index (CODMn) combined with flow injection analysis has been proposed in this study. On the basis of the chemiluminescent reaction of luminol-KMnO4 system, light emission caused by luminol-KMnO4 system was detected by the photomultiplier tube, and its intensity caused by the appearance of KMnO4 after sample digestion was inversely proportional to CODMn. Effects for CODMn determining such as pH, concentrations and interference were investigated in detail. A detection limit of 0.3 mg/L CODMn with a linear range of 0.3-200 mg/L for its theoretical CODMn was obtained under the optimized experimental conditions. The relative standard deviation was 4.3% for 5.0 mg/L CODMn (n = 11). This CL flow system for determining CODMn was simple, rapid, and suitable for automatic analysis. The data obtained by the present method were fairly in good agreement with those obtained by the standard titrimetric method. It has been applied to determine real samples with satisfactory results. 展开更多
关键词 FLOW-INJECTION chemiluminescence permanganate index (CODMn) luminol-KMnO4
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Recent advances in electrogenerated chemiluminescence biosensing methods for pharmaceuticals 被引量:8
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作者 Yu Zhang Rui Zhang +2 位作者 Xiaolin Yang Honglan Qi Chengxiao Zhang 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2019年第1期9-19,共11页
Electrogenerated chemiluminescence(electrochemiluminescence, ECL) generates species at electrode surfaces, which undergoes electron-transfer reactions and forms excited states to emit light. It has become a very power... Electrogenerated chemiluminescence(electrochemiluminescence, ECL) generates species at electrode surfaces, which undergoes electron-transfer reactions and forms excited states to emit light. It has become a very powerful analytical technique and has been widely used in such as clinical testing, biowarfare agent detection, and pharmaceutical analysis. This review focuses on the current trends of molecular recognition-based biosensing methods for pharmaceutical analysis since 2010. It introduces a background of ECL and presents the recent ECL developments in ECL immunoassay(ECLIA), immunosensors, enzyme-based biosensors, aptamer-based biosensors, and molecularly imprinted polymers(MIP)-based sensors. At last, the future perspective for these analytical methods is briefly discussed. 展开更多
关键词 Electrogenerated chemiluminescence PHARMACEUTICAL ANALYSIS IMMUNOASSAY Biosensors
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Determination of resveratrol in red wine by solid phase extraction-flow injection chemiluminescence method 被引量:7
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作者 Juan Juan Ren Hai Yan Liu +2 位作者 Yu Hong Hao Pin Gang He Yu Zhi Fang 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第8期985-988,共4页
A sensitive flow injection chemiluminescence method has been developed for the detection of resveratrol in red wine based on the fact that resveratrol can greatly enhance chemiluminescence reaction between KMnO4 and H... A sensitive flow injection chemiluminescence method has been developed for the detection of resveratrol in red wine based on the fact that resveratrol can greatly enhance chemiluminescence reaction between KMnO4 and HCHO in sulfuric acid medium. Analytes were pre-concentrated on solid sorbents (C18 solid-phase extraction cartridges). Under the optimum conditions, the proposed method allows the measurement of resveratrol over the range of 1.32 × 10^-8 to 1.32 × 10^-5 mol/L with a detection limit of 3.30 ×10^-9 mol/L, and the relative standard deviation for 1.32 ×10^-5 mol/L resveratrol (n = 11) is 3.8%. This method has been successfully applied for the determination of the resveratrol in red wine. Furthermore, the possible reaction mechanism was also discussed. 展开更多
关键词 RESVERATROL Solid phase extraction How-injection chemiluminescence Potassium permanganate FORMALDEHYDE
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Chemiluminescence Determination of Molybdenum by on-Line Reduction with a Flow Injection System 被引量:4
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作者 Zhi Jia ZHU (Experimental Center, Hebei Normal University, Shijiazhuang 050016) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第5期427-430,共4页
The chemiluminescence (CL) reaction between lucigenin (Lu) and molybdenum (III) produced by a Jones reductor was investigated using a flow injection system. On the basis of this, a novel method for the determination o... The chemiluminescence (CL) reaction between lucigenin (Lu) and molybdenum (III) produced by a Jones reductor was investigated using a flow injection system. On the basis of this, a novel method for the determination of trace amount of molybdenum has been established. The emission intensity was linear with molybdenum concentration in the range of 0.1-1000 ng/mL; the detection limit was 0.02 ng/mL molybdenum; the relative standard deviation was less than 2% for the determination of 0.1 ng/mL molybdenum (n=11). The method has been applied successfully to the analysis of trace molybdenum in water and steel samples. 展开更多
关键词 chemiluminescence analysis reductant FLOW-INJECTION MOLYBDENUM LUCIGENIN
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Geometric dilution of precision for GPS single-point positioning based on four satellites 被引量:5
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作者 Wang Huihui Zhan Xingqun Zhang Yanhua 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第5期1058-1062,F0003,共6页
To improve the positioning accuracy in GPS point positioning, the geometric dilution of precision (GDOP) including HDOP, VDOP, TDOP, PDOP is commonly considered. The properties of the DOP for the GPS satellite navig... To improve the positioning accuracy in GPS point positioning, the geometric dilution of precision (GDOP) including HDOP, VDOP, TDOP, PDOP is commonly considered. The properties of the DOP for the GPS satellite navigation system are studied and the coordinate system is improved in order to decrease the amount of variables. In the end, by simulation and discussing the results, the corresponding conclusions are presented. 展开更多
关键词 GPS dilution of precision GDOP NAVIGATION simulation.
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Solid Phase Extraction Chemiluminescence Determination of Methamidaphos on Vegetables 被引量:5
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作者 LI Xiao-zhou GUAN Ting-ting +2 位作者 ZHOU Chi YIN Ji-qiu ZHANG Yi-hua 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第1期21-24,共4页
The determination of the methamidaphos pesticide residue on vegetables with a simple solid phase extract(SPE) flow injection(FI) -chemiluminescence(CL) method is described. The method is based on the enhancing e... The determination of the methamidaphos pesticide residue on vegetables with a simple solid phase extract(SPE) flow injection(FI) -chemiluminescence(CL) method is described. The method is based on the enhancing effect of methamidaphos on the CL reaction of luminol with hydrogen peroxide in an alkaline solution. Under the optimal conditions, the CL intensity is linear to the methamidaphos mass concentration in a range of 0. 2-13μg/mL ( r= 0. 9992). The detection limit(3σ) is 0. 047μg/mL. The relative standard deviations for the analysis of three samples are 1.8%, 2.5% and 3.7% ( n = 5 ), respectively. The recovery is in a range of 90%-109% by the method. In this work, this method was successfully applied to the determination of the methamidaphos residue on some vegetable samples. 展开更多
关键词 chemiluminescence Flow injection Solid phase extraction Methamidaphos
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Simultaneous determination of captopril and hydrochlorothiazide by time-resolved chemiluminescence with artificial neural network calibration 被引量:5
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作者 Han-Chun Yao Min Sun +2 位作者 Xiao-Feng Yang Zhen-Zhong Zhang Hua Li 《Journal of Pharmaceutical Analysis》 SCIE CAS 2011年第1期32-38,共7页
The combined use of chemometrics and chemiluminescence(CL)measurements,with the aid of the stopped-flow mixing technique,developed a simple time-resolved CL method for the simultaneous determination of captopril(CP... The combined use of chemometrics and chemiluminescence(CL)measurements,with the aid of the stopped-flow mixing technique,developed a simple time-resolved CL method for the simultaneous determination of captopril(CPL)and hydrochlorothiazide(HCT).The stopped-flow technique in a continuous-flow system was employed in this work in order to emphasize the kinetic differences between the two analytes in cerium(IV)-rhodamine 6G CL system.After the flow was stopped,an initial rise of CL signal was observed for HCT standards,while a direct decay of CL signal was obtained for CPL standards.The mixed CL signal was monitored and recorded on the whole process of continuous-flow/stopped-flow,and the obtained data were processed by the chemometric approach of artificial neural network.The relative prediction error(RPE)of CPL and HCT was 5.9% and 8.7%,respectively.The recoveries of CPL and HCT in tablets were found to fall in the range between 95% and 106%.The proposed method was successfully applied to the simultaneous determination of CPL and HCT in a compound pharmaceutical formulation. 展开更多
关键词 time-resolved chemiluminescence artificial neural network CAPTOPRIL HYDROCHLOROTHIAZIDE
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Preparation of Nano-sized Zirconium Carbide Powders through a Novel Active Dilution Self-propagating High Temperature Synthesis Method 被引量:6
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作者 达奥运 龙飞 +5 位作者 WANG Jilin XING Weihong WANG Yang ZHANG Fan 王为民 FU Zhengyi 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第4期729-734,共6页
High quality nano-sized zirconium carbide (ZrC) powders were successfully fabricated via a developed chemical active dilution self-propagating high-temperature synthesis (SHS) method assisted by ball milling pretr... High quality nano-sized zirconium carbide (ZrC) powders were successfully fabricated via a developed chemical active dilution self-propagating high-temperature synthesis (SHS) method assisted by ball milling pretreatment process using traditional cheap zirconium dioxide powder (ZrO2), magnesium powder (Mg) and sucrose (C12H22Oll) as raw materials. FSEM, TEM, HRTEM, SAED, XRD, FTIR and Raman, ICP- AES, laser particle size analyzer, oxygen and nitrogen analyzer, carbon/sulfur determinator and TG-DSC were employed for the characterization of the morphology, structure, chemical composition and thermal stability of the as-synthesized ZrC samples. The as-synthesized samples demonstrated high purity, low oxygen content and evenly distributed ZrC nano-powders with an average particle size of 50nm. In addition, the effects of endothermic rate and the possible chemical reaction mechanism were also discussed. 展开更多
关键词 zirconium carbide ZRC self-propagating high-temperature synthesis active dilution NANO-POWDERS ball milling
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