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Journal of Analysis and Testing 2018年第3期2卷 223-234页

作者： Yifei Wang pei chen Food Composition and Method Development Laboratory Beltsville Human Nutrition Research CenterAgricultural Research ServicesUS Department of AgricultureBeltsvilleMD 20705USA

Fuzzy chromatography mass spectrometric(FCMS)fingerprinting methods in combination with principal component analysis(PCA)and soft independent modeling by class analogy(SIMCA)were developed for phenolic profiling and differentiation of American cranberry *** FCMS fingerprinting methods,ion mobility fuzzy chromatography mass spectrometric(imFCMS)and conventional FCMS,are compared in the *** and SIMCA successfully differentiated the cultivars with both *** six cultivars used formed three distinct groups in the PCA score plots,and each group contained one wild selection cultivar and its genetically related hybrid(s).Compared with FCMS fingerprinting,imFCMS fingerprinting provided better intra-cultivar sample clustering and inter-cultivar sample separation in PCA and superior sample classifica-tion sensitivity in ***-performance liquid chromatography-high-resolution mass spectrometry(UPLC-HRMS)analysis was conducted on selected samples to profile the phenolic difference between the *** identification using UPLC-HRMS revealed that flavonoid compounds,including flavonol glycosides,proanthocyanidins and anthocyanins,are major components that contribute to the phenolic profile variation among cultivars.

关键词： Cranberry Mass spectrometry Ion mobility PCA SIMCA

Quantification of Total Glucosinolates and Isothiocyanates for Common Brassicaceous Vegetables Consumed in the US Market Using Cyclocondensation and Thiocyanate Ion Measurement Methods

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Journal of Analysis and Testing 2019年第4期3卷 313-321页

作者： Jianghao Sun pei chen Agricultural Research Service Beltsville Human Nutrition Research CenterMethods and Application of Food Composition LaboratoryUS Department of AgricultureBeltsvilleMD 20705USA

Glucosinolates are a group of important sulfur and nitrogen containing plant secondary metabolites found in Brassicaceous vegetables that are associated with many health *** is a growing interest in assessing dietary glucosinolates and their degradation products’isothiocyanates exposure to *** of glucosinolates in plants is a very challenging *** this study,the total glucosinolates from 22 commonly consumed Brassicaceous vegetables in the US market were determined by employing 1,2-benzenedithiol cyclocondensation for the determination of isothiocyanates(ITCs)from non-indole glucosinolates and a colorimetric method for the determination of thiocyanate ion(SCN^(−))from indole *** total glucosinolates were determined from the sum of these two *** the 22 investigated vegetables,the highest level of total ITCs was found in horse radish(5189.0±544.8 nmol/g dry weight)and the highest level of total SCN^(−)level was found in brussel sprouts(1294.0±141.6 nmol/g dry weight).The total glucosinolates ranged from 18.6±3.2 to 2271.2±215.3 nmol/g dry *** total glucosinolate and ITC data are necessary for the USDA glucosinolates database and important for establishing the relationship of glucosinolates to human nutrition.

关键词： Glucosinolate Isothiocyanate Thiocyanate ion Brassicaceous vegetables

Rationalizing phonon dispersion for lattice thermal conductivity of solids

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National Science Review 2018年第6期5卷 888-894页

作者： Zhiwei chen Xinyue Zhang Siqi Lin Lidong chen Yanzhong pei Interdisciplinary Materials Research Center School of Materials Science and Engineering Tongji University State Key Lab of High Performance Ceramics & Superfine Microstructures Shanghai Institute of Ceramics Chinese Academy of Sciences

Lattice thermal conductivity(κL) is one of the most fundamental properties of solids. The acoustic–elastic-wave assumption, proposed by Debye(Debye P. Ann Phys 1912; 344: 789–839), has led to linear phonon dispersion being the most common approximation for understanding phonon transport over the past century. Such an assumption does not take into account the effect of a periodic boundary condition on the phonon dispersion, originating from the nature of periodicity on atomic arrangements. Driven by modern demands on the thermal functionality of materials, with κLranging from ultra-low to ultra-high,any deviation from the Debye approximation in real materials becomes more and more significant. This work takes into account the periodic boundary condition, and therefore rationalizes the phonon dispersion to be more realistic. This significantly improves the precision for quickly predicting κLwithout any fitting parameters, as demonstrated in hundreds of materials, and offers a theoretical basis rationalizing κLto be lower than the minimum currently accepted based on the Debye dispersion. This work paves the way for designing solids with expected κLand particularly inspires the advancement of low-κLmaterials for thermal energy applications.

关键词： thermoelectric thermal conductivity minimal thermal conductivity phonon dispersion

Systematic Review on Wearable Lower Extremity Robotic Exoskeletons for Assisted Locomotion

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Journal of Bionic Engineering 2023年第2期20卷 436-469页

作者： shuang Qiu Zhongcai pei chen Wang Zhiyong Tang School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Lower extremity robotic exoskeletons(LEEX)can not only improve the ability of the human body but also provide healing treatment for people with lower extremity *** are a wide range of application needs and development prospects in the military,industry,medical treatment,consumption and other felds,which has aroused widespread concern in *** paper attempts to review LEEX technical ***,the history of LEEX is briefy ***,based on existing research,LEEX is classifed according to auxiliary body parts,structural forms,functions and felds,and typical LEEX prototypes and products are ***,the latest key technologies are analyzed and summarized,and the research contents,such as bionic structure and driving characteristics,human–robot interaction(HRI)and intentawareness,intelligent control strategy,and evaluation method of power-assisted walking efciency,are described in ***,existing LEEX problems and challenges are analyzed,a future development trend is proposed,and a multidisciplinary development direction of the key technology is provided.

关键词： Lower extremity robotic exoskeletons Bionic robot Classifcation method Human-robot interaction Biomechatronic

Study on time-varying seismic vulnerability and analysis of ECC-RC composite piers using high strength reinforcement bars in offshore environment

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Earthquake Engineering and Engineering Vibration 2022年第4期21卷 1035-1051页

作者： Liang Yan Zhao Fulin Luo Jun chen pei College of Civil Engineering Zhengzhou UniversityZhengzhou 450001China College of Mechanics and Safety Engineering Zhengzhou UniversityZhengzhou 450001China Wuhan Building Material Industry Design&Research Co. LtdWuhan 430000China

As the main seismic component of a bridge,seismic damage to the bridge pier has a greater effect on its subsequent *** the offshore chloride environment,the issues(e.g.,reinforcement bar corrosion and attenuation of concrete strength)of piers caused by chloride ion seriously curtail the normal service life and deteriorate the anti-seismic property of bridge *** engineered cementitious composite(ECC)-reinforced concrete(RC)composite pier with high strength reinforcement bars(HSRB)is expected to solve the above *** study aims to clarify the time-varying seismic vulnerability(SV)of the HSRBECC-RC composite pier during its full life cycle(FLC).Based on OpenSees,the refined finite element analysis models of RC pier,ECC-RC composite pier,and HSRBECC-RC composite pier have been ***,using the nonlinear time-path dynamic analysis method,the influence of chloride ion erosion on the time-dependent seismic vulnerability(SV)of these different piers in different service life and different peak ground acceleration(PGA)were analyzed from a dynamic point of *** research shows that the exceeding probability(EP)of the same damage level increases with the enhancement of service time and PGA and with the increase of destruction,the exceeding probability(EP)of slight damage(DL-1),moderate damage(DL-2),serious damage(DL-3),and complete collapse(DL-4)decreases in turn;the corrosion degree of chloride ion to piers is small during the early service period,the time-varying vulnerability curve of the bridge piers is almost the same as that of a new bridge,and during later service,as the extent of chloride ion corrosion deepens,exceeding probability(EP)under severe damage(DL-3)and complete collapse(DL-4)is increased,and the seismic performance is significantly enhanced.

关键词： bridge piers engineered cementitious composite(ECC) high strength reinforcement bars(HSRB) seismic vulnerability(SV) exceeding probability(EP) full life cycle(FLC)

Multi-target tracking algorithm based on PHD filter against multi-range-false-target jamming

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Journal of Systems Engineering and Electronics 2020年第5期31卷 859-870页

作者： TIAN chen pei Yang HOU Peng ZHAO Qian School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

Multi-range-false-target(MRFT) jamming is particularly challenging for tracking radar due to the dense clutter and the repeated multiple false targets. The conventional association-based multi-target tracking(MTT) methods suffer from high computational complexity and limited usage in the presence of MRFT *** order to solve the above problems, an efficient and adaptable probability hypothesis density(PHD) filter is proposed. Based on the gating strategy, the obtained measurements are firstly classified into the generalized newborn target and the existing target measurements. The two categories of measurements are independently used in the decomposed form of the PHD filter. Meanwhile,an amplitude feature is used to suppress the dense clutter. In addition, an MRFT jamming suppression algorithm is introduced to the filter. Target amplitude information and phase quantization information are jointly used to deal with MRFT jamming and the clutter by modifying the particle weights of the generalized newborn targets. Simulations demonstrate the proposed algorithm can obtain superior correct discrimination rate of MRFT, and high-accuracy tracking performance with high computational efficiency in the presence of MRFT jamming in the dense clutter.

关键词： multi-range-false-target(MRFT)jamming multi-target tracking(MTT) probability hypothesis density(PHD) target amplitude feature gating strategy

Effect of N,N-Dimethylglycine on Homocysteine Metabolism in Rats Fed Folate-Sufficient and Folate-Deficient Diets

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Biomedical and Environmental Sciences 2021年第5期34卷 356-363页

作者： LIU Yi Qun HUANG Ling He LIU pei pei XING Qing Bin HAN Feng WANG Qin chen shu Rong SUGIYAMA Kimio XIANG Xue Song HUANG Zhen Wu Key Laboratory of Trace Element Nutrition of National Health Commission National Institute of Nutrition and HealthChinese Center for Disease Control and PreventionBeijing 100050China Chinese Nutrition Society Beijing 100022China Beijing Dietetic Association Beijing 100050China Department of Applied Biological Chemistry Faculty of AgricultureShizuka University836 OhyaSuruga-kuShizuoka 422-8529Japan

Objective This study aimed to investigate the effects of N,N-dimethylglycine(DMG) on the concentration and metabolism of plasma homocysteine(pHcy) in folate-sufficient and folate-deficient *** In this study, 0.1% DMG was supplemented in 20% casein diets that were either folatesufficient(20 C) or folate-deficient(20 CFD). Blood and liver of rats were subjected to assays of Hcy and its metabolites. Hcy and its related metabolite concentrations were determined using a liquid chromatographic *** Folate deprivation significantly increased pHcy concentration in rats fed 20 C diet(from 14.19 ±0.39 μmol/L to 28.49 ± 0.50 μmol/L;P < 0.05). When supplemented with DMG, pHcy concentration was significantly decreased(12.23 ± 0.18 μmol/L) in rats fed 20 C diet but significantly increased(31.56 ±0.59 μmol/L) in rats fed 20 CFD. The hepatic methionine synthase activity in the 20 CFD group was significantly lower than that in the 20 C group;enzyme activity was unaffected by DMG supplementation regardless of folate sufficiency. The activity of hepatic cystathionine β-synthase(CBS) in the 20 CFD group was decreased but not in the 20 C group;DMG supplementation enhanced hepatic CBS activity in both groups, in which the effect was significant in the 20 C group but not in the other *** DMG supplementation exhibited hypohomocysteinemic effects under folate-sufficient conditions. By contrast, the combination of folate deficiency and DMG supplementation has deleterious effect on pHcy concentration.

关键词： Folate deficiency N,N-Dimethylglycine 5-methyltetrahydrofolate Plasma homocysteine

Dynamic disorder phonon scattering mediated by Cu atomic hopping and diffusion in Cu_(3)SbSe_(3)

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npj Computational Materials 2020年第1期6卷 380-386页

作者： chen Wang Yixuan Wu Yanzhong pei Yue chen Department of Mechanical Engineering The University of Hong KongPokfulam RoadHong KongSARChina Interdisciplinary Materials Research Center School of Materials Science and EngineeringTongji University4800 Caoan RoadShanghai 201804China HKU Shenzhen Institute of Research and Innovation Yuexing 2nd RoadNanshanShenzhen 518057China

Cu_(3)SbSe_(3) that exhibits distinct liquid-like sublattice due to the heterogeneous bonding environment has emerged as a promising low cost superionic semiconductor with intrinsic ultralow thermal ***,the relationship between atomic dynamics resulting in liquid-like diffusion and anomalous phonon transport properties remains poorly ***,combing ab initio molecular dynamics with temperature-dependent Raman measurements,we have performed a thorough investigation on the lattice dynamics of Cu_(3)SbSe_(3).Superionic transition is unveiled for both structurally inequivalent Cu atoms at elevated temperatures,while the Se-formed tetrahedral framework can simultaneously maintain.

关键词： diffusion phonon atomic

Characterization of molecular signature of the roots of Paeonia lactiflora during growth

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Chinese Journal of Natural Medicines 2017年第10期15卷 785-793页

作者： LIU pei XU Yuan YAN Hui chen Jing SHANG Er-Xin QIAN Da-Wei JIANG shu DUAN Jin-Ao Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization and National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine Nanjing University of Chinese MedicineNanjing 210023China Institute of Bioengineering Zhejiang Chinese Medical UniversityHangzhou 310053China

The roots of Paeoniae lactiflora *** widely consumed as crude drugs in Asian countries due to their remarkable beneficial health *** present research was undertaken to illuminate the dynamic changes in metabolites and enzymes and facilitate selection of the harvesting time when the herb can provide optimum health *** roots were analyzed at 12 stages of growth for monoterpenoid glycosides,phenols,nucleosides,nucleobases,amino acids,and polysaccharides by high-performance liquid chromatography with photodiode array detector,ultra-high pressure liquid chromatography coupled with tandem mass spectrometry,and UV *** enzyme activities of plant β-glucosidases and esterases were determined by UV *** total content of monoterpenoid glycosides and phenols peaked in *** nucleosides and nucleobases,the highest content appeared in *** maximum phasic accumulation of the total amino acids took place in March,and the content of total polysaccharides reached a peak value in ***,April,and March were selected as the appropriate harvesting times for producing natural medicinal or health food *** β-glucosidases and esterases showed the highest activity in December and May,*** the activity of β-glucosidase increased,esterase activity decreased,while the contents of oxypaeoniflora and paeoniflorin *** esterase activity increased,the contents of benzoylpaeoniflorin,paeoniflorin,and gallic acid *** conclusion,the results from the present study would be useful in determination of the suitable time for harvesting *** roots for medicinal purposes.

关键词： Paeonia lactiflora Primary and secondary metabolites Plant enzymes Dynamic change Growth stage

Study on Gyroscopic Effect of Floating Offshore Wind Turbines

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China Ocean Engineering 2021年第2期35卷 201-214页

作者： chen Jia-hao pei Ai-guo chen Peng HU Zhi-qiang Guangdong Electric Power Design Institute Co. Ltd.of China Energy Engineering GroupGuangzhou 510663China School of Engineering Newcastle UniversityNewcastle upon TyneNE17RUUK College of Shipbuilding Engineering Harbin Engineering UniversityHarbin 150001China

Compared with bottom-fixed wind turbines,the supporting platform of a floating offshore wind turbine has a larger range of motion,so the gyroscopic effects of the system will be more *** this paper,the mathematical analytic expression of the gyroscopic moment of a floating offshore wind turbine is derived ***,FAST software is utilized to perform a numerical analysis on the model of a spar-type horizontal axis floating offshore wind turbine,OC3-Hywind,so as to verify the correctness of the theoretical analytical formula and take an investigation on the characteristics of gyroscopic *** is found that the gyroscopic moment of the horizontal axis floating offshore wind turbine is essentially caused by the vector change of the rotating rotor,which may be due to the pitch or yaw motion of the floating platform or the yawing motion of the *** the rotor is rotating,the pitch motion of the platform mainly excites the gyroscopic moment in the rotor’s yaw direction,and the yaw motion of the platform largely excites the rotor’s gyroscopic moment in pitch direction,*** results show that the gyroscopic moment of the FOWT is roughly linearly related to the rotor’s inertia,the rotor speed,and the angular velocity of the platform motion.

关键词： floating offshore wind turbine gyroscopic effects yaw motion pitch motion numerical analysis