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STRONGLY CONVERGENT INERTIAL FORWARD-BACKWARD-FORWARD ALGORITHM WITHOUT ON-LINE RULE FOR VARIATIONAL INEQUALITIES
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作者 姚永红 Abubakar ADAMU Yekini SHEHU 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期551-566,共16页
This paper studies a strongly convergent inertial forward-backward-forward algorithm for the variational inequality problem in Hilbert spaces.In our convergence analysis,we do not assume the on-line rule of the inerti... This paper studies a strongly convergent inertial forward-backward-forward algorithm for the variational inequality problem in Hilbert spaces.In our convergence analysis,we do not assume the on-line rule of the inertial parameters and the iterates,which have been assumed by several authors whenever a strongly convergent algorithm with an inertial extrapolation step is proposed for a variational inequality problem.Consequently,our proof arguments are different from what is obtainable in the relevant literature.Finally,we give numerical tests to confirm the theoretical analysis and show that our proposed algorithm is superior to related ones in the literature. 展开更多
关键词 forward-backward-forward algorithm inertial extrapolation variational inequality on-line rule
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宫颈癌调强计划Portal Dosimetry剂量验证中拼接野的应用分析
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作者 时飞跃 吕懂霞 +5 位作者 付林 庄洁颖 王敏 秦伟 赵环宇 魏晓为 《中国医疗设备》 2024年第10期73-78,共6页
目的提出一种生成Portal Dosimetry(以下简称PD)分野的拼接野(以下简称PD拼接野)方法,并对宫颈癌计划的PD拼接野进行分析研究。方法选取20例宫颈癌患者的七野调强治疗计划进行研究,治疗计划中每个大野分成1对分野。首先制作仅含分野的P... 目的提出一种生成Portal Dosimetry(以下简称PD)分野的拼接野(以下简称PD拼接野)方法,并对宫颈癌计划的PD拼接野进行分析研究。方法选取20例宫颈癌患者的七野调强治疗计划进行研究,治疗计划中每个大野分成1对分野。首先制作仅含分野的PD剂量验证计划,然后使用直线加速器出束执行。通过矩阵拼接和矩阵叠加,分别得到每对PD分野对应的PD拼接野和PD大野。使用PD软件模块,得到PD拼接野和PD大野的伽玛通过率,分别记为Gp和Gd。使用Gm表示每对PD分野的平均伽玛通过率值。对Gp、Gd和Gm进行统计分析和比较研究。结果所有140个射野的Gp、Gd和Gm的值分别为98.78%±0.70%、97.34%±1.25%和98.87%±0.51%。两两比较结果显示,Gp和Gd差异具有统计学意义(P<0.05);Gp和Gm的数据差异较小。对每个PD验证计划,计算所有同一类射野对应的计划验证通过率(Gplan)。对Gplan数据进行统计分析显示,PD拼接野和PD大野差异具有统计学意义(P<0.05),PD拼接野和PD分野的数据差异较小。结论本文提出的PD拼接野概念为评价PD剂量验证结果提供了有益的参考信息。 展开更多
关键词 宫颈癌 分野 拼接野 伽玛通过率 Portal dosimetry 调强放射治疗 矩阵拼接
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Multi-Sensor Intelligent System for On-Line and Real-Time Moneitoring Tool Cutting State in FMS 被引量:1
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作者 徐春广 王信义 +1 位作者 邢济收 杨大勇 《Journal of Beijing Institute of Technology》 EI CAS 1997年第3期258-266,共9页
The principle and the constitution of an intelligent system for on-line and real-time montitoring tool cutting state were discussed and a synthetic sensors schedule combined a new type fluid acoustic emission sens... The principle and the constitution of an intelligent system for on-line and real-time montitoring tool cutting state were discussed and a synthetic sensors schedule combined a new type fluid acoustic emission sensor (AE) with motor current sensor was presented. The parallel communication between control system of machine tools, the monitoring intelligent system,and several decision-making systems for identifying tool cutting state was established It can auto - matically select the sensor way ,monitoring mode and identifying method in machining process- ing so as to build a successful and effective intelligent system for on -line and real-time moni- toring cutting tool states in FMS. 展开更多
关键词 tool cutting state on-line monitoring intelligent system acoustic emission sensor
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Development and Application of On-Line Corrosion Monitoring Device for Condenser Tube 被引量:1
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作者 曹杰玉 宋敬霞 +2 位作者 汪德良 龙国军 孙本达 《Electricity》 2004年第2期31-35,共5页
This paper introduces the development and industrial application of an on-line corrosion monitoring device for condenser tubes. Corrosion sensors are made up of representative condenser tubes chosen by eddy current te... This paper introduces the development and industrial application of an on-line corrosion monitoring device for condenser tubes. Corrosion sensors are made up of representative condenser tubes chosen by eddy current test, which enable the monitoring result to be consistent with the corrosion of actual condenser tubes. Localized corrosion rate of condenser tubes can be measured indirectly by a galvanic couple made up of tube segments with and without pits. Using this technology, corrosion problems can be found in time and accurately, and anticorrosive measures be made more economic and effective. Applications in two power plants showed the corrosion measurements are fast and accurate. 展开更多
关键词 condenser tube CORROSION on-line monitoring INSTRUMENTATION
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Effects of on-line solution and off-line heat treatment on microstructure and hardness of die-cast AZ91D alloy 被引量:1
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作者 徐玉磊 张奎 +3 位作者 李兴刚 雷健 袁海波 刘正 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2652-2658,共7页
The effects of on-line solution, off-line solution and aging heat treatment on the microstructure and hardness of the die-cast AZ91D alloys were investigated. Brinell hardness of die-cast AZ91D alloy increases through... The effects of on-line solution, off-line solution and aging heat treatment on the microstructure and hardness of the die-cast AZ91D alloys were investigated. Brinell hardness of die-cast AZ91D alloy increases through on-line solution and off-line aging treatment but decreases after off-line solution treatment. By X-ray diffractometry, optical microscopy, differential thermal analysis, scanning electron microscopy and X-ray energy dispersive spectroscopy, it is found that the microstructures of the die-cast AZ91D magnesium alloy before and after on-line solution and off-line aging are similar, consisting of α-Mg and β-Al12Mg17. The precipitation of Al element is prevented by on-line solution so that the effect of solid solution strengthening is enhanced. The β-Al12Mg17 phases precipitate from supersaturated Mg solid solution after off-line aging treatment, and lead to microstructure refinement of AZ91D alloy, so the effect of precipitation hardening is enhanced. The β-Al12Mg17 phases dissolve in the substructure after off-line solution treatment, which leads to that the grain boundary strengthening phase is reduced significantly and the hardness of die cast AZ91D is reduced. 展开更多
关键词 die-cast magnesium alloy AZ91D alloy on-line solution off-line solution treatment aging treatment β-Al12Mg17 phases microstructure refinement precipitation hardening
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Semi on-line scheduling for maximizing the minimum machine completion time on three uniform machines 被引量:2
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作者 罗润梓 孙世杰 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第6期591-595,共5页
The paper investigates a semi on-line scheduling problem wherein the largest processing time of jobs done by three uniform machines M1, M2, M3 is known in advance. A speed si (s1=1, s2=r, s3=s, 1≤r≤s) is associated ... The paper investigates a semi on-line scheduling problem wherein the largest processing time of jobs done by three uniform machines M1, M2, M3 is known in advance. A speed si (s1=1, s2=r, s3=s, 1≤r≤s) is associated with machine Mi. Our goal is to maximize Cmin?the minimum workload of the three machines. We present a min3 algorithm and prove its competitive ratio is max{r+1,(3s+r+1)/(1+r+s)}, with the lower bound being at least max{2,r}. We also claim the competitive ratio of min3 algo- rithm cannot be improved and is the best possible for 1≤s≤2, r=1. 展开更多
关键词 SCHEDULING Semi on-line Competitive ratio
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Semi On-line Scheduling Problem for Maximizing the Minimum Machine Completion Time on mIdentical Machines 被引量:1
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作者 罗润梓 孙世杰 《Journal of Shanghai University(English Edition)》 CAS 2005年第2期99-102,共4页
In this paper, a semi on-line version on m ide ntical machines M 1, M 2, …,M m(m≥3) was considered, where th e processing time of the largest job is known in advance. Our goal is to maximiz e the minimum machine ... In this paper, a semi on-line version on m ide ntical machines M 1, M 2, …,M m(m≥3) was considered, where th e processing time of the largest job is known in advance. Our goal is to maximiz e the minimum machine load, an NPLS algorithm was presented and its worst-case ratio was proved to be equal to m-1 which is the best possible value. It is concluded that if the total processing time of jobs is also known to be greater than (2m-1)p max where p max is the largest job' s processing time, then the worst-case ratio is 2-1/m. 展开更多
关键词 SCHEDULING semi on-line worst-case ratio.
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Cobalt Determination by Means of Flow Injection On-line Sorbent Preconcentration-Flame Atomic Absorption Spectrometry with 1-Nitroso-2-naphthol as a Complexing Reagent
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作者 YIN Xue-feng ALI Akbar +3 位作者 XU Guang-ming LING Yun-yang GAO Jian YE Mei-ying 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2001年第3期264-270,共7页
The suitability of 1-nitroso-2-naphthol(NN) as a complexing agent for on-line preconcentration of cobalt eluted on the C_(18) microcolumn by means of the FI-FAAS system was tested. Various parameters affecting the com... The suitability of 1-nitroso-2-naphthol(NN) as a complexing agent for on-line preconcentration of cobalt eluted on the C_(18) microcolumn by means of the FI-FAAS system was tested. Various parameters affecting the complex formation and its elution were optimized. A 2.3×10^(-3) mol/L reagent solution and the aqueous sample solution acidified with 0.1% (volume fraction) nitric acid were on-line mixed (6.4 mL/min) on a reaction coil set at (65±1)℃ and flowed through the microcolumn for 30 s. The pH of the mixed solution was adjusted to 3—4 with HNO_3(1 mol/L) or NaOH(1 mol/L). The adsorbed complexes in the microcolumn were eluted into the nebulizer of FAAS in 10 s with ethanol acidified with 1% HNO_3(3.0 mL/min). A good precision(1.6% for 100μg/L Co(Ⅱ), n=10), a high enrichment factor 17.2, with detection limit (3σ) 3.2μg/L, and sample throughput (90 h^(-1)) were obtained. The method was applied to the certified reference materials(CRMs), NBS-362 and NBS-364, for the determination of cobalt and the results were in good agreement with the certified values. 展开更多
关键词 Cobalt FI on-line preconcentration AAS 1-Nitroso-2-naphthol
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Integrated On-line Instrumentation System of Magnetic Properties Measurement
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作者 D.G.Park, Y.Y.Song. H.Song and J.H.Hong (Korea Atomic Energy Research Institute, Yusong P.O.Box 105, Taejon, 305-600 Korea) C.G.Kim (Department of Physics, Sun Moon Univ., Asan-si, Chungnam, 336840 Korea) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第2期248-249,共2页
A portable microcomputer-controlled inspection system has been developed for detection of magnetic properties of soft magnetic materials. It incorporates custom designed software for control of the magnetic field duri... A portable microcomputer-controlled inspection system has been developed for detection of magnetic properties of soft magnetic materials. It incorporates custom designed software for control of the magnetic field during operation such as demagnetization, field sweeping, and for data logging and analysis. Results are recorded using a 12-bit analog to digital converter and are then stored on disk. The magnetic hysteresis loop and Barkhausen noise data can be converted into important magnetic parameters: coecivity, remanence, and hysteresis loss, Barkhausen amplitude, and Barkhausen noise energy. This system incorporated with the magnetostriction, and magnetoacoustic emission, is then related with the nondestructive detection of material degradation. 展开更多
关键词 line Integrated on-line Instrumentation System of Magnetic Properties Measurement
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DETERMINATION OF ANTIMONY IN WATER SAMPLES BY FLOW-INJECTION HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY WITH ON-LINE ION-EXCHANGE COLUMN PRECONCENTRATION
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作者 Shu Kun XU and Zhao Lun FANG Institute of Applied Ecology, Academia Sinica, Shenyang, 110015 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第11期915-918,共4页
On-line ion-exchange separation and preconcentration were combined with flow-injection hydride generation atomic absorption spectrometry (HGAAS) to determine ultra-trace amounts of antimony in water samples. Antimony(... On-line ion-exchange separation and preconcentration were combined with flow-injection hydride generation atomic absorption spectrometry (HGAAS) to determine ultra-trace amounts of antimony in water samples. Antimony(Ⅲ) was preconcentrated on a micro-column packed with CPG-8Q chelating ion-exchanger using time-based sample loading and eluted by 4 mol l^(-1) HCl directly into the hydride generation AAS system. A detection limit (3σ) of 0.0015μg l^(-1) Sb(Ⅲ) was obtained on the basis of a 20 fold enrichment and with a sampling frequency of 60h^(-1). The precision was 1.0% r.s.d.(n=11) at the 0.5μg l^(-1) Sb(Ⅲ) level. Recoveries for the analysis of antimony in tap water, snow water and sea water samples were in the range 97-102%. 展开更多
关键词 Zhang DETERMINATION OF ANTIMONY IN WATER SAMPLES BY FLOW-INJECTION HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY WITH on-line ION-EXCHANGE COLUMN PRECONCENTRATION SQ CPG ION LINE
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PRECONCENTRATION OF TRACE ZINC IN SEAWATER ON CPPI RESIN BY FIA AND ON-LINE DETECTION BY ICP-AFS
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作者 Dong Xing YUAN Peng Yuan YANG Xiao Ru WANG Ben Li HUANG Department of Chemistry,Xiamen University,Xiamen,361005 《Chinese Chemical Letters》 SCIE CAS CSCD 1990年第3期237-238,共2页
A quite new type of chelating resin Carboxymethylated Polyethylenimine-Polymethylenepolyphenylene Isocyanate(CPPI)is used for the preconcentration of Zn from high salt water such as seawater. The preconcentration is c... A quite new type of chelating resin Carboxymethylated Polyethylenimine-Polymethylenepolyphenylene Isocyanate(CPPI)is used for the preconcentration of Zn from high salt water such as seawater. The preconcentration is controlled through the technique of Flow Injection Analysis(FIA).The concentrated sample solution is then directly transferred to an Inductively Coupled Plasma-Atomic Fluorescence Spectrometer(ICP-AFS)for determination.The detection limit of Zn by the technique is about 0.06 ppb. 展开更多
关键词 CPPI PRECONCENTRATION OF TRACE ZINC IN SEAWATER ON CPPI RESIN BY FIA AND on-line DETECTION BY ICP-AFS FIA ICP LINE
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Stylistic Analysis on English On-line Chat
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作者 别尽秋 闻扬波 《海外英语》 2013年第6X期224-225,227,共3页
Based on the fact that on-line chat has become the most developing language form in the information age, this article point out the stylistic features of on-line English chat. Though in written language form, such lan... Based on the fact that on-line chat has become the most developing language form in the information age, this article point out the stylistic features of on-line English chat. Though in written language form, such language is spoken language in nature, thus it is worthwhile to analyze this special phaenomenon in lexical and grammatical level. 展开更多
关键词 on-line ENGLISH STYLISTIC ANALYSIS LEXICAL grammat
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State Maintenance of On-line Monitoring for High Voltage Equipment
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《Electricity》 1997年第2期35-36,共2页
关键词 LINE State Maintenance of on-line Monitoring for High Voltage Equipment
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Improvement on On-line Ferrograph Image Identification 被引量:8
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作者 WU Tonghai WANG Weigang +2 位作者 WU Jiaoyi MAO Junhong XIE Youbai 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第1期1-6,共6页
A newly developed on-line visual ferrograph(OLVF) gives a new way for engine wear state monitoring. However, the reliability of on-line wear debris image processing is challenged in both monitoring ship engines and ... A newly developed on-line visual ferrograph(OLVF) gives a new way for engine wear state monitoring. However, the reliability of on-line wear debris image processing is challenged in both monitoring ship engines and the Caterpillar bench test, which weren't reported in previous studies. Two problems were encountered in monitoring engines and processing images. First, small wear debris becomes hard to be identified from the image background after monitoring for a period of time. Second, the identification accuracy for wear debris is greatly reduced by background noise because of oil getting dark after nmning a period of time. Therefore, the methods adopted in image processing are examined. Two main reasons for the problems in wear debris identification are generalized as follows. Generally, the binary threshold was determined by global image pixels, and was easily affected by the non-objective zone in the image. The boundary of the objective zone in the binary image was misrecognized because of oil color becoming lighter during monitoring. Accordingly, improvements were made as follows. The objective zone in a global binary image was identified by scanning a column of pixels, and then a secondary binary process confined in the objective zone was carried out to identify small wear debris. Linear filtering with a specific template was used to depress noise in a binary image, and then a low-pass filtering was performed to eliminate the residual noise. Furthermore, the morphology parameters of single wear debris were extracted by separating each wear debris by a gray stack, and two indexes, WRWR (relative wear rate) and WRWS (relative wear severity), were proposed for wear description. New indexes were provided for on-line monitoring of engines. 展开更多
关键词 image analysis on-line ferrograph wear debris OIL
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Differences in the behavior characteristics between Daphnia magna and Japanese madaka in an on-line biomonitoring system 被引量:7
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作者 Zongming Ren Zijian Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第5期703-708,共6页
It is important to select suitable organisms to adapt the requirement of different environment monitoring purposes.Following our previous study,the behavioral responses of Daphnia magna and Japanese madaka (Oryzias l... It is important to select suitable organisms to adapt the requirement of different environment monitoring purposes.Following our previous study,the behavioral responses of Daphnia magna and Japanese madaka (Oryzias latipes) were investigated and compared under flow-through conditions in an on-line biomonitoring system.The results showed that both D.magna and Japanese madaka had similar biological clock,but the circadian rhythms of Japanese madaka was more clearly recorded than that of D.magna.And the sensitivity of D.magna was about two orders of magnitudes higher than that of Japanese madaka in different types of toxic chemicals (dichlorovos,deltamethrin and cadmium chloride).However,when both animals were used in an on-line biomonitoring system,the life span of D.magna was less than 7 days and Japanese madaka could last for more than one month without feeding.Therefore,D.magna was proposed to be a more sensitive bioindicator and was suitable for short term monitoring the pollution events at concentration level closing to the water quality standard,while Japanese madaka was more suitable for the long-term monitoring for accidental discharges. 展开更多
关键词 Daphnia magna Japanese madaka on-line biomonitoring behavioral responses
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A New Algorithm for On-Line Handwriting Signature Verification Based on Evolutionary Computation 被引量:7
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作者 ZHENG Jianbin ZHU Guangxi 《Wuhan University Journal of Natural Sciences》 CAS 2006年第3期596-600,共5页
The paper proposes an on-line signature verification algorithm, through which test sample and template signatures can be optimizedly matched, based on evolutionary computation (EC). Firstly, the similarity of signat... The paper proposes an on-line signature verification algorithm, through which test sample and template signatures can be optimizedly matched, based on evolutionary computation (EC). Firstly, the similarity of signature curve segment is defined, and shift and scale transforms are also introduced due to the randoness of on-line signature. Secondly, this paper puts forward signature verification matching algorithm after establishment of the mathematical model. Thirdly, the concrete realization of the algorithm based on EC is discussed as well. In addition, the influence of shift and scale on the matching result is fully considered in the algorithm. Finally, a computation example is given, and the matching results between the test sample curve and the template signature curve are analyzed in detail, The preliminary experiments reveal that the type of signature verification problem can be solved by EC. 展开更多
关键词 on-line signature signature verification evolutionary computation
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Sequential injection spectrophotometric determination of nanomolar nitrite in seawater by on-line preconcentration with HLB cartridge 被引量:4
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作者 ZHANG Min YUAN Dongxing +2 位作者 HUANG Yongming CHEN Guohe ZHANG Zhen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2010年第1期100-107,共8页
The unstable state of nitrite results in its very low concentration in seawater, which is below the limit of detection (LOD) of conventional techniques of analysis. Some sensitivity-enhanced methods have been propos... The unstable state of nitrite results in its very low concentration in seawater, which is below the limit of detection (LOD) of conventional techniques of analysis. Some sensitivity-enhanced methods have been proposed for the determination of nitrite at nanomolar level to illustrate the role of nitrite in the marine nitrogen cycle. However, most of previous reports are not widely accepted, because of their complexity and cost equipment or intensive labor requirement. In this study, a simple automatic system for the determination of nanomolar level nitrite using on-line preconcentration with spectrophotometric detection was described..An Oasis HLB cartridge was adopted to quantitatively enrich the pink-colored azo compound, formed from nitrite via Griess reaction. The cartridge was rinsed with water and ethanol (volume fraction is 55%, the same below), in turn, then eluted by an eluent containing 50% ethanol and 0.25 M(mol/dm^3) H2SO4, and determined at 543 nm with a 2 cm path-length flow cell. Under the optimized experimental conditions, the calibration curve showed a good linearity in the range of 1.4 85.7 aM, and the LOD (3a) was estimated to be 0.5 nM. The relative standard deviations of 7 measurements were 4.0% and 1.0% for the samples spiked at 7.1 and 28.6 nM, respectively. The recoveries for the different natural water samples were between 92.2%-108.4%. Each HLB cartridge could be reused for at least 50 times. As compared with other SPE methods, the advantages of this method included the free of interference from salinity variation and less sample consuming. The results of the application of the proposed method to natural water showed good agreement with liquid waveguide capillary cell detection method. 展开更多
关键词 NITRITE seawater on-line preconcentration sequential injection solid phase extraction
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Self-adaptive PID controller of microwave drying rotary device tuning on-line by genetic algorithms 被引量:6
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作者 杨彪 梁贵安 +5 位作者 彭金辉 郭胜惠 李玮 张世敏 李英伟 白松 《Journal of Central South University》 SCIE EI CAS 2013年第10期2685-2692,共8页
The control design, based on self-adaptive PID with genetic algorithms(GA) tuning on-line was investigated, for the temperature control of industrial microwave drying rotary device with the multi-layer(IMDRDWM) and wi... The control design, based on self-adaptive PID with genetic algorithms(GA) tuning on-line was investigated, for the temperature control of industrial microwave drying rotary device with the multi-layer(IMDRDWM) and with multivariable nonlinear interaction of microwave and materials. The conventional PID control strategy incorporated with optimization GA was put forward to maintain the optimum drying temperature in order to keep the moisture content below 1%, whose adaptation ability included the cost function of optimization GA according to the output change. Simulations on five different industrial process models and practical temperature process control system for selenium-enriched slag drying intensively by using IMDRDWM were carried out systematically, indicating the reliability and effectiveness of control design. The parameters of proposed control design are all on-line implemented without iterative predictive calculations, and the closed-loop system stability is guaranteed, which makes the developed scheme simpler in its synthesis and application, providing the practical guidelines for the control implementation and the parameter design. 展开更多
关键词 industrial microwave DRYING ROTARY device SELF-ADAPTIVE PID controller genetic algorithm on-line tuning SELENIUM-ENRICHED SLAG
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Automatic analytical approach for the determination of 12 illicit drugs and nicotine metabolites in wastewater using on-line SPE-UHPLC-MS/MS 被引量:6
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作者 Jingyuan Wang Likai Qia +8 位作者 Chenzhi Hou Tingting Zhang Mengyi Chen Haitao Meng Mengxiang Su Hui Xu Zhendong Hua Youmei Wang Bin Di 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2021年第6期739-745,共7页
In this study,we developed a novel on-line solid phase extraction(SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illic... In this study,we developed a novel on-line solid phase extraction(SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illicit drugs and metabolites(methamphetamine,amphetamine,morphine,codeine,6-monoacetylmorphine,benzoylecgonine,3,4-methylenedioxymethamphetamine,3,4-methylenedioxyamphetamine,cocaine,ketamine,norketamine,and methcathinone)and cotinine(COT)in wastewater samples.The analysis was performed by loading 2 m L of the sample onto an Oasis hydrophilic-lipophilic balance cartridge and using a cleanup step(5%methanol)to eliminate interference with a total run time of 13 min.The isotope-labeled internal standard method was used to quantify the target substances and correct for unavoidable losses and matrix effects during the on-line SPE process.Typical analytical characteristics used for method validation were sensitivity,linearity,precision,repeatability,recovery,and matrix effects.The limit of detection(LOD)and limit of quantification(LOQ)of each target were set at 0.20 ng/L and 0.50 ng/L,respectively.The linearity was between 0.5 ng/L and250 ng/L,except for that of COT.The intra-and inter-day precisions were<10.45%and 25.64%,respectively,and the relative recovery ranged from 83.74%to 162.26%.The method was used to analyze various wastewater samples from 33 cities in China,and the results were compared with the experimental results of identical samples analyzed using off-line SPE.The difference rate was between 19.91%and-20.44%,and the error range could be considered acceptable.These findings showed that on-line SPE is a suitable alternative to off-line SPE for the analysis of illicit drugs in samples. 展开更多
关键词 Illicit drugs and metabolites Wastewater analysis on-line solid phase extraction Ultra-high-performance liquid CHROMATOGRAPHY Mass spectrometry
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Reagent optimization for on-line simultaneous polarographic determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of anextremely large excess of Zn^(2+) 被引量:4
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作者 WANG Guo-wei YANG Chun-hua +2 位作者 ZHU Hong-qiu LI Yong-gang GUI Wei-hua 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2199-2204,共6页
Reagents are optimized for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in zinc sulfate solution, which contains an extremely large excess of Zn^(2+). First, the reagents and their d... Reagents are optimized for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in zinc sulfate solution, which contains an extremely large excess of Zn^(2+). First, the reagents and their doses for the experiment are selected according to the characteristics of the zinc sulfate solution. Then, the reagent doses are optimized by analyzing the influence of reagent dose on the polarographic parameters(i.e. half-wave potential E_(1/2) and limiting diffusion current I_p). Finally, the optimization results are verified by simultaneously determining trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+). The determination results indicate that the optimized reagents exhibit wide linearity, low detection limits, high accuracy and good precision for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+). 展开更多
关键词 on-line simultaneous determination trace polymetallic ions reagent optimization high concentration ratio
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