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Area-Optimized BCD-4221 VSLI Adder Architecture for High-Performance Computing
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作者 Dharamvir Kumar Manoranjan Pradhan 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第3期31-38,共8页
Decimal arithmetic circuits are promising to provide a solution for accurate decimal arithmetic operations which are not possible with binary arithmetic circuits.They can be used in banking,commercial and financial tr... Decimal arithmetic circuits are promising to provide a solution for accurate decimal arithmetic operations which are not possible with binary arithmetic circuits.They can be used in banking,commercial and financial transactions,scientific measurements,etc.This article presents the Very Large Scale Integration(VLSI)design of Binary Coded Decimal(BCD)-4221 area-optimized adder architecture using unconventional BCD-4221 representation.Unconventional BCD number representations such as BCD4221 also possess the additional advantage of more effectively representing the 10's complement representation which can be used to accelerate the decimal arithmetic operations.The design uses a binary Carry Lookahead Adder(CLA)along with some other logic blocks which are required to perform internal calculations with BCD-4221 numbers.The design is verified by using Xilinx Vivado 2016.1.Synthesis results have been obtained by Cadence Genus16.1 synthesis tool using 90 nm technology.The performance parameters such as area,power,delay,and area-delay Product(ADP)are compared with earlier reported circuits.Our proposed circuit shows significant area and ADP improvement over existing designs. 展开更多
关键词 VLSI design unconventional BCD representation BCD adder circuit computer arithmetic digital circuit
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Accelerated design of high-performance Mg-Mn-based magnesium alloys based on novel bayesian optimization
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作者 Xiaoxi Mi Lili Dai +4 位作者 Xuerui Jing Jia She Bjørn Holmedal Aitao Tang Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期750-766,共17页
Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing ... Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing their commercial utilization.With the rapid advancement of machine learning(ML)technology in recent years,the“data-driven''approach for alloy design has provided new perspectives and opportunities for enhancing the performance of Mg alloys.This paper introduces a novel regression-based Bayesian optimization active learning model(RBOALM)for the development of high-performance Mg-Mn-based wrought alloys.RBOALM employs active learning to automatically explore optimal alloy compositions and process parameters within predefined ranges,facilitating the discovery of superior alloy combinations.This model further integrates pre-established regression models as surrogate functions in Bayesian optimization,significantly enhancing the precision of the design process.Leveraging RBOALM,several new high-performance alloys have been successfully designed and prepared.Notably,after mechanical property testing of the designed alloys,the Mg-2.1Zn-2.0Mn-0.5Sn-0.1Ca alloy demonstrates exceptional mechanical properties,including an ultimate tensile strength of 406 MPa,a yield strength of 287 MPa,and a 23%fracture elongation.Furthermore,the Mg-2.7Mn-0.5Al-0.1Ca alloy exhibits an ultimate tensile strength of 211 MPa,coupled with a remarkable 41%fracture elongation. 展开更多
关键词 Mg-Mn-based alloys high-performance Alloy design Machine learning Bayesian optimization
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Optimization Techniques for GPU-Based Parallel Programming Models in High-Performance
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作者 Shuntao Tang Wei Chen 《信息工程期刊(中英文版)》 2024年第1期7-11,共5页
This study embarks on a comprehensive examination of optimization techniques within GPU-based parallel programming models,pivotal for advancing high-performance computing(HPC).Emphasizing the transition of GPUs from g... This study embarks on a comprehensive examination of optimization techniques within GPU-based parallel programming models,pivotal for advancing high-performance computing(HPC).Emphasizing the transition of GPUs from graphic-centric processors to versatile computing units,it delves into the nuanced optimization of memory access,thread management,algorithmic design,and data structures.These optimizations are critical for exploiting the parallel processing capabilities of GPUs,addressingboth the theoretical frameworks and practical implementations.By integrating advanced strategies such as memory coalescing,dynamic scheduling,and parallel algorithmic transformations,this research aims to significantly elevate computational efficiency and throughput.The findings underscore the potential of optimized GPU programming to revolutionize computational tasks across various domains,highlighting a pathway towards achieving unparalleled processing power and efficiency in HPC environments.The paper not only contributes to the academic discourse on GPU optimization but also provides actionable insights for developers,fostering advancements in computational sciences and technology. 展开更多
关键词 Optimization Techniques GPU-Based Parallel Programming Models high-performance Computing
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Expansion Performance and Microstructure of High-performance Concrete using Differently Scaled MgO Agents and Mineral Powder
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作者 TIAN Changjin WANG Youzhi +1 位作者 QIU Kai YANG Qilin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第6期1335-1347,共13页
To investigate the assumptions proposed in this paper,the evolution law governing the strength and expansion performance of MgO and nano-MgO micro-expansive concrete in the environment of mineral powder was firstly ob... To investigate the assumptions proposed in this paper,the evolution law governing the strength and expansion performance of MgO and nano-MgO micro-expansive concrete in the environment of mineral powder was firstly observed in this study.Secondly,SEM,XRD,and TG-DSC microscopic tests were conducted to reveal the effects of the active mineral-powder admixture on the hydration degree and expansion performance of MgO and nano-MgO in HPC.Our experimental results successfully verified our hypothesis,which indicated that the expansion performance of macro-MgO and nano-MgO was indeed depressed by the addition of active mineral power admixtures,even though the mechanical property of concrete composites was effectively improved.Furthermore,the hydration test also demonstrated the negative interference on the mineral powders,which was induced by the expansion agents.It is found the amounts of hydrates tend to decrease because the mineral powder ratio reaches and exceeds 40%.Moreover,it is also concluded the effect of expansion agents is governed by the alkalinity cement paste,especially for the nano-MgO.In other words,the expansion performance of nano-MgO will vary more obviously with the hydration process,than MgO.The results of this study provide that effective experimental and theoretical data support the hydration-inhibition mechanism of magnesium expansive agents. 展开更多
关键词 MGO Nano-MgO mineral powders high-performance concrete expansive agents MICROSTRUCTURES
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Measurement and analysis of defects in high-performance concrete with three-dimensional micro-computer tomography 被引量:8
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作者 郭丽萍 Andrea Carpinteri +1 位作者 孙伟 秦文超 《Journal of Southeast University(English Edition)》 EI CAS 2009年第1期83-88,共6页
In order to investigate the effects of two mineral admixtures (i. e., fly ash and ground slag)on initial defects existing in concrete microstructures, a high-resolution X-ray micro-CT( micro-focus computer tomogra... In order to investigate the effects of two mineral admixtures (i. e., fly ash and ground slag)on initial defects existing in concrete microstructures, a high-resolution X-ray micro-CT( micro-focus computer tomography)is employed to quantitatively analyze the initial defects in four series of highperformance concrete (HPC)specimens with additions of different mineral admixtures. The nigh-resolution 3D images of microstructures and filtered defects are reconstructed by micro- CT software. The size distribution and volume fractions of initial defects are analyzed based on 3D and 2D micro-CT images. The analysis results are verified by experimental results of watersuction tests. The results show that the additions of mineral admixtures in concrete as cementitious materials greatly change the geometrical properties of the microstructures and the spatial features of defects by physical-chemistry actions of these mineral admixtures. This is the major cause of the differences between the mechanical behaviors of HPC with and without mineral admixtures when the water-to-binder ratio and the size distribution of aggregates are constant. 展开更多
关键词 high-performance concrete DEFECT MICROSTRUCTURE X- ray micro-focus computer tomography mineral admixtures
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Preliminary Studies on High-performance Liquid Chro-matography Chemiluminescence Determination of theSaturated Fatty Acids(C_(16) C_(18))in Human Serum 被引量:1
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作者 段更利 中岛宪一郎 +1 位作者 黑田直敬 秋山修三 《Journal of Chinese Pharmaceutical Sciences》 CAS 1995年第1期22-29,共8页
The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture... The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture of chloroform-n-heptane.2-(4-Hydrazinocarbonyl- phenyl)-4,5-diphenylimidazole (HCPI) was used as a fluorescent labelling reagent of the fatty acids. The labelling reaction was carried out at 30℃ for 1 h at pH 6.5 and the resulting reaction mixture was sudjected to HPLC. The labelled fatty acid C_(17)(P-C_(17))was used as the internal standard. The la- belled fatty acids C_(16) and C_(18) were separated within 18 min on an ODS-8OTM column (150 mm× 6 mm ID,5μm,Tosoh Japan).The calibrlation curves of fatty acids from the spiked control serum were Y_1=-0.003 7 + 0.0028X_1,r=0.994 for FA C_( 16) and Y_2=0.00 1 2 + 0.00098X_2,r=0.999 for FA C_( 18),respectively.The average recoveries of facids from the spiked contrl serum were 107.2%(n=8,RSD=4.3%)for FA C_(16) and 97.35%(n=8, RSD=4.0%)for FA C_(18),respectively.The lower detection limits of fatty acids after reaction were 12μmol per 20μl injection for FA C_(16) and 18 μmol per 20μl injection for FA C_(18),respectively(signal to noise ratio, S/N=2).The HPLC/CL method was applied to the determination of FA C_(16) and FA C_(18) in normal human serum and the results showed that the concentrations of fatty acids in normal human serum were 0.134 ± 0.009 μ mol/ml serum(n=5) for FA C_(16) and 0.052±0.028 μmol/ml serum(n=5)for FA C_(18),respectively. 展开更多
关键词 Fatty acids high-performance Liquid Chromatography Peroxyoxalate chemi- luminescence detection Human serum
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Simultaneous determination of five nucleosides and nucleobases in Panax notoginseng using high-performance liquid chromatography 被引量:1
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作者 王静 王一涛 李绍平 《Journal of Chinese Pharmaceutical Sciences》 CAS 2007年第2期79-83,共5页
Aim To quantitatively determine five nucleosides and nucleobases, including cytidine, uridine, guanosine, adenosine and uracil in different parts of Panax notoginseng. Methods Separation was performed on a Zorbax SB-A... Aim To quantitatively determine five nucleosides and nucleobases, including cytidine, uridine, guanosine, adenosine and uracil in different parts of Panax notoginseng. Methods Separation was performed on a Zorbax SB-Aq column using a gradient elution with mobile phase of 8 mmol^L-1 ammonium acetate aqueous solution (A) and methanol (B). The assay was carried out at a flow rate of 1 mL·min^-1 at 25 ℃ with the diode-array detection at 260 nm. Results Cytidine, uridine, guanosine, adenosine and uracil had good linearity in the ranges of 1.79 - 57.40 μg·mL^-1 (r^2 = 1.0000), 3.30 - 105.60 μg·mL^-1 (r^2 = 1.0000), 3.09 - 98.80 μg·mL^ -1(r^2 = 0.9999), 2.77 - 88.60 μg·mL^-1 (r^2 = 1.0000) and 0.38 - 12.30 μg·mL ^-1 (r^2 = 1.0000) with average recoveries of 93.9%, 96.5%, 92.7%, 93.2% and 98.8%, respectively. The content of cytidine, uridine, guanosine, adenosine and uracil in different parts of P. notogingeng were significantly different. Conclusion This is the first report on quantitative determination of nucleosides and nucleobases in P notoginseng. 展开更多
关键词 Panax notoginseng NUCLEOSIDE NUCLEOBASE high-performance liquid chromatography (HPLC)
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High-Performance Liquid Chromatographical Analysis of Ginsenosides in Panax ginseng,P.quinquef(?)lium and P.notoginseng 被引量:1
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作者 郎文生 楼之岑 毕培曦 《Journal of Chinese Pharmaceutical Sciences》 CAS 1993年第2期133-143,共11页
The compositions and contents of ginsenbsides in Panax ginseng,P.quinquefolium and P.notoginseng were determined and compared by reversed-phase High-Performance Liquid Chro- matography(HPLC).The method was performed o... The compositions and contents of ginsenbsides in Panax ginseng,P.quinquefolium and P.notoginseng were determined and compared by reversed-phase High-Performance Liquid Chro- matography(HPLC).The method was performed on an Alltech Adsorbosphere HS C_(18) column,using 5×10^(-3)M NaH_2PO_4-H_3PO_4 buffer solution(pH 3.0)and acetonitrile-water(50:50)as gradient eluents. The baseline separation of ginsenosides Rb_1,Rb_2,Rb_1,Rc,Rd,Rf,Ro,and Re+Rg_1 was obtained in one analytical run.The ginsenosides are directly detected at 203 nm.The detection limit is 40μg at a signal to noise ratio of 3:1.The improved sample preparation and clean-up prior to injection with SEP-PAK C_(18)cartridge strongly reduced the front peaks caused by the impurities in the methanolic extracts of samples to afford a smooth baseline and clear background.The HPLC patterns of methanolic extracts mainly including the ginsenosides were found capable of serving as chemical fingerprints to differentiate the three species from each other.It was also found that there are no significant diffe- rences of the HPLC patterns between the wild Panax ginseng and the cultivated,the white and the red ginsengs,Chinese and Korean red ginsengs,and the tap roots of Panax ginseng collected in four consecutive months,only certain differences in contents of ginsenosides do exist.The contents of the nine major ginsenosides present in the rhizome,tap root and rootlet as well as the leaf of Panax quinquefolium were also determined and compared. 展开更多
关键词 Panax ginseng Panax quinquefolium Panax notoginseng GINSENOSIDES high-performance Liquid Chromatography(HPLC)
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Recent developments and applications on high-performance cast magnesium rare-earth alloys 被引量:58
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作者 Guohua Wu Cunlong Wang +1 位作者 Ming Sun Wenjiang Ding 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第1期1-20,共20页
During the past decades,with the increasing demands in lightweight structural materials,Mg alloys with low density and high performance have been extensively investigated and partly applied in some industries.Especial... During the past decades,with the increasing demands in lightweight structural materials,Mg alloys with low density and high performance have been extensively investigated and partly applied in some industries.Especially when rare earth(RE)elements are added as major alloying elements to Mg alloys,the alloy strength and creep resistance are greatly improved,which have promoted several series of Mg-RE alloys.This paper reviews the progress and developments of high-performance Mg-RE alloys in recent years with emphasis on cast alloys.The main contents include the alloy design,melt purification,grain refinement,castability,novel liquid casting and semisolid forming approaches,and the industrial applications or trials made of Mg-RE alloys.The review will provide insights for future developments of new alloys,techniques and applications of Mg alloys. 展开更多
关键词 Magnesium alloys Rare-earth elements high-performance DEVELOPMENTS Applications CAST
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High-Performance and Multifunctional Cement-Based Composite Material 被引量:12
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作者 Victor C. Li 《Engineering》 SCIE EI 2019年第2期250-260,共11页
Concrete is a continuously evolving material, and even the definition of high-performance concrete has changed over time. In this paper, high-performance characteristics of concrete material are considered to be those... Concrete is a continuously evolving material, and even the definition of high-performance concrete has changed over time. In this paper, high-performance characteristics of concrete material are considered to be those that support the desirable durability, resilience, and sustainability of civil infrastructure that directly impact our quality of life. It is proposed that high-performance material characteristics include tensile ductility, autogenous crack-width control, and material “greenness.” Furthermore, smart functionalities should be aimed at enhancing infrastructure durability, resilience, and sustainability by responding to changes in the surrounding environment of the structure in order to perform desirable functions, thus causing the material to behave in a manner more akin to certain biological materials. Based on recent advances in engineered cementitious composites (ECCs), this paper suggests that concrete embodying such high-performance characteristics and smart multifunctionalities can be designed, and holds the potential to fulfill the expected civil infrastructure needs of the 21st century. Highlights of relevant properties of ECCs are provided, and directions for necessary future research are indicated. 展开更多
关键词 high-performance concrete MULTIFUNCTION Smart CEMENT-BASED composite Durability RESILIENCE Sustainability Infrastructure
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Plasma free amino acid profiling of esophageal cancer using high-performance liquid chromatography spectroscopy 被引量:11
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作者 Hong Ma Ayshamgul Hasim +3 位作者 Batur Mamtimin Bin Kong Hai-Ping Zhang Ilyar Sheyhidin 《World Journal of Gastroenterology》 SCIE CAS 2014年第26期8653-8659,共7页
AIM: To perform plasma free amino acid (PFAA) profiling of esophageal squamous cell carcinoma (ESCC) patients at different pathological stages and healthy subjects.
关键词 Metabolomics high-performance liquid chromatography Esophageal squamous cell cancer PLASMA Amino acids
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Advancements in the preparation of high-performance liquid chromatographic organic polymer monoliths for the separation of small-molecule drugs 被引量:5
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作者 Xiali Ding Jing Yang Yuming Dong 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2018年第2期75-85,共11页
The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographer... The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency. 展开更多
关键词 high-performance LIQUID chromatography Polymer MONOLITH Preparation methods Small molecules
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High-performance self-assembly MnCo2O4 nanosheets for asymmetric supercapacitors 被引量:5
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作者 Jianwei Li Dongbin Xiong +2 位作者 Linzhe Wang Maleki Kheimeh Sari Hirbod Xifei Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第10期66-72,共7页
In this study,MnCo2O4 nanosheets were proposed to be utilized as an electrode material for supercapacitors.A two-step hydrothermal method with post-annealing treatment was employed in preparation of the nanostructures... In this study,MnCo2O4 nanosheets were proposed to be utilized as an electrode material for supercapacitors.A two-step hydrothermal method with post-annealing treatment was employed in preparation of the nanostructures.MnCo2O4 electrode delivered a high specific capacitance of 2000 F g^-1 at 0.5 A g^-1,remarkable high-rate capability of 1150 F g^-1 at 20 A g^-1,and an excellent cycling stability of 92.3%at 5 A g^-1 after 5000 cycles.It is found that a three-electrode supercapacitor based on MnCo2O4 exhibits a promising electrochemical performance,better than the other similar materials,benefited from the synergistic effects of MnCo2O4 nanosheets.In fact,the self-assembly of nanosheets structure with high specific surface area and mesoporous structure can potentially enhance the electrochemical performance of supercapacitors. 展开更多
关键词 high-performance SELF-ASSEMBLY MnCo2O4 NANOSHEETS ASYMMETRIC SUPERCAPACITORS
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INFLUENCE OF MINERAL ADMIXTURES ON MECHANICAL PROPERTIES OF HIGH-PERFORMANCE CONCRETE 被引量:4
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作者 Ma, Baoguo Li, Jinzong Peng, Jun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1999年第2期1-7,共7页
The improvements of the mechanical properties, including bulk density of fresh mixtures, elastic modulus, and compressive strengths of four high-performance concrete mixtures, made with the addition of fly ash, refine... The improvements of the mechanical properties, including bulk density of fresh mixtures, elastic modulus, and compressive strengths of four high-performance concrete mixtures, made with the addition of fly ash, refined ground blast - furnace microslag (microslag) and silica fume are studied. The concrete mixtures were determined based on the dispersion testing results. The study indicates that the elastic modulus at 28 and 91 days, and compressive strengths of the concretes are improved a lot when fly ash and microslag by 25 percent by weight of cement are added into the mixtures individually. The improvement is especially evident when silica fume by 5 percent and fly ash by 25 percent by weight of cement are added together into the mixture, while the fresh concrete mixture keeps a good workability. Through the analysis of chemically combined water ratios of the four mixtures at various hydration ages, it is found that the addition of all these mineral mixtures are beneficial to the hydration process, especially, at later stages, which might be one of the reasons for the improvement of mechanical properties. (Author abstract) 4 Refs. 展开更多
关键词 high-performance concrete mineral admixture mechanical properties
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Determination of gouty arthritis' biomarkers in human urine using reversed-phase high-performance liquid chromatography 被引量:4
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作者 Lei-Wen Xiang Jing Li +1 位作者 Jin-Ming Lin Hai-Fang Li 《Journal of Pharmaceutical Analysis》 SCIE CAS 2014年第2期153-158,共6页
Creatinine, uric acid, hypoxanthine and xanthine are important diagnostic biomarkers in human urine for gouty arthritis or renal disease diacrisis. A simple method for simultaneous determination of these biomarkers in... Creatinine, uric acid, hypoxanthine and xanthine are important diagnostic biomarkers in human urine for gouty arthritis or renal disease diacrisis. A simple method for simultaneous determination of these biomarkers in urine based on reversed-phase high-performance liquid chromatography (RP-HPLC) with ultraviolet (UV) detector was proposed. After pretreatment by dilution, centrifugation and filtration, the biomarkers in urine samples were separated by ODS-BP column by elution with methanol/50 mM NaH2PO4 buffer solution at pH 5.26 (5:95). Good linearity between peak areas and concentrations of standards was obtained for the biomarkers with correlation coefficients in the range of 0.9957-0.9993. The proposed analytical method has satisfactory repeatability (the recovery of data in a range of creatinine, uric acid, hypoxanthine and xanthine was 93.49-97.90%, 95.38-96.45%, 112.46-115.78%and 90.82-97.13%with standard deviation of o5%, respectively) and the limits of detection (LODs, S/N Z 3) for creatinine, uric acid, hypoxanthine, and xanthine were 0.010, 0.025, 0.050 and 0.025 mg/L, respectively. The established method was proved to be simple, accurate, sensitive and reliable for the quantitation of gouty arthritis' biomarkers in human urine samples. The ratio of creatinine to uric acid was found to be a possible factor for assessment of gouty arthritis. 展开更多
关键词 Gouty arthritis CREATININE Uric acid HYPOXANTHINE XANTHINE high-performance liquid chromatography
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SYNTHESIS AND PROPERTIES OF NOVEL POLY(IMINO KETONE)S AS HIGH-PERFORMANCE POLYMERS 被引量:11
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作者 Chang, Guan-jun Luo, Xuan +1 位作者 Zhang, Lin Lin, Run-xiong 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2008年第1期55-61,共7页
Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation... Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is... 展开更多
关键词 Di(4-bromophenyl)ketone Aromatic diamines Palladium-catalyzed aryl amination high-performance Poly(imino ketone)
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Influence of shrinkage-reducing admixture on drying shrinkage and mechanical properties of high-performance concrete 被引量:5
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作者 Nguyen Quangphu Jiang Linhua +2 位作者 Liu Jiaping Tian Qian Do Tienquan 《Water Science and Engineering》 EI CAS 2008年第4期67-74,共8页
High-performance concrete (HPC) has specific performance advantages over conventional concrete in strength and durability. HPC mixtures are usually produced with water/binder mass ratios (mW/mB) in the range of 0.... High-performance concrete (HPC) has specific performance advantages over conventional concrete in strength and durability. HPC mixtures are usually produced with water/binder mass ratios (mW/mB) in the range of 0.2-0.4, so volume changes of concrete as a result of drying, chemical reactions, and temperature change cannot be avoided. For these reasons, shrinkage and cracking are frequent phenomena. It is necessary to add some types of admixture for reduction of shrinkage and cracking of HPC. This study used a shrinkage-reducing admixture (SRA) for that purpose. Concrete was prepared with two different mW/mB (0.22 and 0.40) and four different mass fractions of SRA to binder (w(SRA) = 0%, 1%, 2%, and 4%). The mineral admixtures used for concrete mixes were: 25% fly ash (FA) and 25% slag by mass of binder for the mixture with mW/mB = 0.40, and 15% silica fume (SF) and 25% FA for the mixture with mW/mB = 0.22. Tests were conducted on 24 prismatic specimens, and shrinkage strains were measured through 120 days of drying. Compressive strength, splitting strength, and static modulus of elasticity were also determined. The results show that the SRA effectively reduces some mechanical properties of HPC. The reductions in compressive strength, splitting tensile strength, and elastic modulus of the concrete were 7%-24%, 9%-19%, and 5%-12%, respectively, after 90 days, compared to concrete mixtures without SRA. SRA can also help reduce drying shrinkage of concrete. The shrinkage strains of HPC with SRA were only as high as 41% of the average free shrinkage of concrete without SRA after 120 days of drying. 展开更多
关键词 high-performance concrete shrinkage-reducing admixture compressive strength elastic modulus splitting tensile strength drying shrinkage
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High-Performance Liquid Chromatographic Method for Determination of Germacrone in Rat Plasma 被引量:4
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作者 HEHai-bing TANGXing CUIFu-de 《Journal of Chinese Pharmaceutical Sciences》 CAS 2004年第3期190-192,共3页
Aim A reliable high-performance liquid chromatographic (HPLC) method wasdeveloped for determination of germacrone in rat plasma. Methods The plasma samples were treatedwith acetonitrile and analyzed by HPLC with UV de... Aim A reliable high-performance liquid chromatographic (HPLC) method wasdeveloped for determination of germacrone in rat plasma. Methods The plasma samples were treatedwith acetonitrile and analyzed by HPLC with UV detection at 244 nm. Results The limit of detectionwas 100 ng·mL^(-1) for germacrone in plasma and the linear range was 0.1004-15.06 μg·mL^(-1) inplasma. The RSD of intra-day and inter-day assay was 1.87% - 4.29% and 1.29% -5.15%, respectively.The recoveries of germacrone were over 95%. The endogenous substances in plasma did not show anyinterference in the analysis. Conclusion The method is accurate and convenient, and suitable forpharmacokinetic studies of germacrone in rats. 展开更多
关键词 high-performance liquid chromatography GERMACRONE volatile oil of rhizomacurcumae
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The effects of 12 weeks of functional strength training on muscle strength,volume and activity upon exposure to elevated Gz forces in high-performance aircraft personnel 被引量:6
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作者 Monika Rausch Frank Weber +3 位作者 Sven Kühn Carla Ledderhos Christoph Zinner Billy Sperlich 《Military Medical Research》 SCIE CSCD 2021年第4期481-489,共9页
Background:Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel,including inducing neck and back pain.The ... Background:Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel,including inducing neck and back pain.The purpose of this study was to examine the effects of 12 weeks of functional strength training on 1)the volume and strength of the neck and shoulder muscles and 2)muscular activity upon exposure to helmets of different masses and elevated Gz forces in a long-arm centrifuge in high-performance aircraft personnel.Methods:Eighteen participants underwent 12 weeks of functional strength training(n=12)or the control protocol(n=6)without additional strength training.Pre-and post-intervention tests included evaluations of isometric strength of the head extensor muscles,flexion,and lateral flexion and rotation,as well as magnetic resonance imaging(MRI)to measure the volume of the m.sternocleidomastoideus,m.trapezius,and deep neck muscles.Furthermore,during a long-arm centrifuge(+1.4 and+3Gz)protocol,the muscular activity levels of the m.sternocleidomastoideus,m.trapezius and m.erector spinae muscles were assessed without a flight helmet,with a helmet,and with a helmet and night vision goggles.Each participant’s perception of muscular strain was noted immediately after the long-arm centrifuge protocol.Results:The maximal isometric strength in all exercises and muscle volumes increased in the training group but not the control group(P<0.05).Relative muscle activity(%MVC)with a helmet decreased after the intervention in the training but not the control group(P=0.01).Relative muscle activity while wearing a helmet and night vision goggles was higher after intervention in the control group than in the training group(P<0.01).The perceived muscular strain of the neck muscles induced by the long-arm centrifuge did not differ between the groups.Conclusions:Twelve weeks of functional strength training improves the maximal isometric strength and volume of neck and shoulder muscles and leads to lower relative muscle activation upon exposure to elevated Gz forces in a long-arm centrifuge. 展开更多
关键词 Fighter pilots Long-arm centrifuge Muscular strain Strength training Neck muscle high-performance aircraft Gz forces
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Dispersive Liquid-liquid Microextraction Combined with High-performance Liquid Chromatography for the Determination of Clozapine and Chlorpromazine in Urine 被引量:3
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作者 陈静 熊朝梅 +1 位作者 阮金兰 苏邹 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2011年第2期277-284,共8页
A simple method has been proposed for the determination of clozapine (CLZ) and chlorpromazine (CPZ) in human urine by dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid ... A simple method has been proposed for the determination of clozapine (CLZ) and chlorpromazine (CPZ) in human urine by dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid chromatography-ultraviolet detector (HPLC-UV). All important variables influencing the extraction efficiency, such as pH, types of the extraction solvent and the disperser solvent and their volume, ionic strength and centrifugation time were investigated and optimized. Under the optimal conditions, the limit of detection (LODs) and quantification (LOQs) of the method were 13 and 39 ng/mL for CLZ, and 2 and 6 ng/mL for CPZ, respectively. The relative standard deviations (RSDs) of the targets were less than 5.1% (C=0.100 μg/mL, n=9). Good linear behaviors over the tested concentration ranges were obtained with the values of R20.999 for the targets. The absolute extraction efficiencies of CLZ and CPZ from the spiked blank urine samples were 98.3% and 97.8%, respectively. The applicability of the technique was validated by analyzing urine samples and the mean recoveries for spiked urine samples ranged from 93.3% to 105.0%. The method was successfully applied for the determination of CLZ and CPZ in real human urine. 展开更多
关键词 dispersive liquid-liquid microextraction CLOZAPINE CHLORPROMAZINE high-performance liquid chromatography human urine
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