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Spectral baseline estimation using penalized least squares with weights derived from the Bayesian method

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Nuclear Science and Techniques 2022年第11期33卷 144-157页

作者： Qian Wang Xin-Liang Yan Xiang-Cheng Chen Peng Shuai Meng Wang yu-hu zhang Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Van Swinderen Institute University of GroningenGroningen 9747 AAThe Netherlands

The penalized least squares(PLS)method with appropriate weights has proved to be a successful baseline estimation method for various spectral *** can extract the baseline from the spectrum while retaining the signal peaks in the presence of random *** algorithm is implemented by iterating over the weights of the data *** this study,we propose a new approach for assigning weights based on the Bayesian *** proposed method provides a self-consistent weighting formula and performs well,particularly for baselines with different curvature *** method was applied to analyze Schottky spectra obtained in 86Kr projectile fragmentation measurements in the experimental Cooler Storage Ring(CSRe)at *** provides an accurate and reliable storage lifetime with a smaller error bar than existing PLS *** is also a universal baseline-subtraction algorithm that can be used for spectrum-related experiments,such as precision nuclear mass and lifetime measurements in storage rings.

关键词： Penalized least squares Baseline correction Bayesian rule Spectrum analysis

Improved isochronous mass spectrometry with tune measurement

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Nuclear Science and Techniques 2024年第11期35卷 174-181页

作者： Han-yu Deng yuan-Ming Xing Xu Zhou yu-hu zhang Xin-Liang Yan Jin-Yang Shi Ting Liao Meng Wang CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

In conventional isochronous mass spectrometry(IMS)performed on a storage ring,the precision of mass measurements for short-lived nuclei depends on the accurate determination of the revolution times(T)of stored ***,the resolution of T inevitably deteriorates due to the magnetic rigidity spread of the ions,limiting the mass-resolving *** this study,we used the betatron tunes Q(the number of betatron oscillations per revolution)of the ions and established a correlation between T and *** this correlation,T was transformed to correspond to a fixed Q with higher *** these transformed T values,the masses of ^(63)Ge,^(65)As,^(67)Se,and ^(71)Kr agreed well with the mass values measured using the newly developed IMS(Bρ-IMS).We also studied the systematics of Coulomb displacement energies(CDEs)and found that anomalous staggering in CDEs was eliminated using new mass *** method of T transformation is highly effective for conventional IMS equipped with a single time-of-flight detector.

关键词： Isochronous Mass Spectrometry Storage ring Tune Natural chromaticity Nuclear mass measurement

Optimizing aerobic biodegradation of dichloromethane using response surface methodology

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Journal of Environmental Sciences 2009年第9期21卷 1276-1283页

作者： WU Shijin,yu Xiang,hu Zhihang,zhang Lili,CHEN Jianmeng College of Biological and Environmental Engineering,Zhejiang University of Technology,Hangzhou 310032,China College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310032 China. E-mail: wujan28@***

Response surface methodology （RSM） was employed to evaluate the optimum aerobic biodegradation of dichloromethane （DCM） in pure culture. The parameters investigated include the initial DCM concentration, glucose as an inducer and hydrogen peroxide as terminal electron acceptor （TEA）. Maximum aerobic biodegradation efficiency was predicted to occur when the initial DCM concentration was 380 mg/L, glucose 13.72 mg/L, and H202 115 mg/L. Under these conditions the aerobic biodegradation rate reached up to 93.18%, which was significantly higher than that obtained under original conditions. Without addition of glucose degradation efficiencies were ≤ 80% at DCM concentrations ≤ 326 mg/L. When concentrations of DCM were more than 480 rag/L, the addition of hydrogen peroxide did not help to significantly increase DCM degradation efficiency. When DCM concentrations increased from 240 to 480 rag/L, the overall DCM degradation efficiency decreased from 91% to 60% in the presence of HaO2 for 120 mg/L.

关键词： biodegradation dichloromethane response surface methodology

Study on Active Oxygen Quantum Yield,Insecticidal Activities and Stability of Diphenylthiophene

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Agricultural Sciences in China 2007年第4期6卷 458-465页

作者： CHEN Xiao-jun XU Han-hong WANG yu-jian hu Shan zhang Zhi-xiang zhang Yao-mou Key Laboratory of Pesticide and Chemical Biology Ministry of Education/Laboratory of Insect Toxicology South China Agricultural University Guangzhou 510642 P.R.China

Active oxygen quantum yield, insecticidal activities and stability of diphenylthiophene were studied for the first time. The results showed that maximum diphenylthiophene absorbency variety was 0.438 after irradiation for 280 min and that of α- terthienyl （α-T） was 0.480 after irradiation for 200 min with UV. LCs0 values ofdiphenylthiophene and α-T against 3rd instar larvae ofAedes albopictus were 9.18 × 10^-3 and 9.69× 10^-4 μg mL^-1 when treated for 24 h, respectively. LC50 values of the two chemicals against the 3rd instar larvae of Plutella xylostella were 267.87 and 222.22 μg mL^-1 when treated for 24 h, respectively. The half lives of diphenylthiophene and α-T in methanol were 113.62 and 10.65 h. Difference between quantum yield of diphenylthiophene and α-T was not significant and they all possessed high toxicity to Aedes albopictus and Plutella xylostella, but diphenylthiophene was more stable than α-T. It could be concluded that diphenylthiophene has overcome the deficiency of photoactivated insecticides which degraded quickly in the environment and could not be applied on the field. Diphenylthiophene could kill the insects and accelerate the degradation rate of triazophos. The benefits of diphenylthiophene can be further exploited and applied on the field.

关键词： diphenylthiophene insecticidal activities photocatalysis degradation

Co/Co_(7)Fe_(3)heterostructures with controllable alloying degree on carbon spheres as bifunctional electrocatalyst forrechargeable zinc-air batteries

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 476-487页

作者： Junkang Chen Yongyue Zhuang Yanxin Qiao yu zhang Aihua yuan hu Zhou School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is crucial for developing rechargeable zinc-air batteries(ZABs).Herein,an alloying-degree control strategy was employed to fabricate nitrogen-doped carbon sphere(NCS)decorated with dual-phase Co/Co_(7)Fe_(3)heterojunctions(CoFe@NCS).The phase composition of materials has been adjusted by controlling the alloying *** optimal CoFe_(0.08)@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA·cm^(-2)for OER in an alkaline *** intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co_(7)Fe_(3)alloy and metallic Co *** the CoFe_(0.08)@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery(ZAB),the device shows a high peak power-density(157 mW·cm^(-2))and maintains a stable voltage gap over 150 h,outperforming those of the benchmark(Pt/C+RuO_(2))-based *** particular,the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending *** work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.

关键词： bifunctional electrocatalysts oxygen reduction reaction oxygen evolution reaction zinc-air battery metal/alloy carbon sphere

Clinical outcomes and predictive model of platelet reactivity to clopidogrel after acute ischemic vascular events

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Chinese Medical Journal 2019年第9期132卷 1053-1062页

作者： Qi Ma Guang-Zhong Chen yu-hu zhang Li zhang Li-An huang Department of Neurology The First Affiliated HospitalJinan UniversityGuangzhouGuangdong 510632China Guangdong Geriatrics Institute Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouGuangdong 510080China Department of Neurosurgery Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouGuangdong 510080China Department of Neurology Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouGuangdong 510080China

Background:High on-treatment platelet reactivity (HTPR) has been suggested as a risk factor for patients with ischemic vascular *** explored a predictive model of platelet reactivity to clopidogrel and the relationship with clinical ***:A total of 441 patients were *** reactivity was measured by light transmittance aggregometry after receiving dual antiplatelet *** was defined by the consensus cutoff of maximal platelet aggregation >46% by light transmittance ***2C19 loss-of-function polymorphisms were identified by DNA microarray *** data were compared by binary logistic regression to find the risk *** primary endpoint was major adverse clinical events (MACEs),and patients were followed for a median time of 29 *** curves were constructed with Kaplan-Meier estimates and compared by logrank tests between the patients with HTPR and ***:The rate of HTPR was 17.2%.Logistic regression identified the following predictors of HTPR:age,therapy regimen,body mass index,diabetes history,CYP2C19^*2,or CYP2C19^*3 *** area under the curve of receiver operating characteristic for the HTPR predictive model was 0.793 (95% confidence interval:0.738–0.848).Kaplan-Meier analysis showed that patients with HTPR had a higher incidence of MACE than those with non-HTPR (21.1% vs.9.9%;χ^2 = 7.572,P = 0.010).Conclusions:Our results suggest that advanced age,higher body mass index,treatment with regular dual antiplatelet therapy,diabetes,and CYP2C19^*2 or CYP2C19^*3 carriers are significantly associated with HTPR to *** predictive model of HTPR has useful discrimination and good calibration and may predict long-term MACE.

关键词： High on-treatment platelet reactivity Clopidogrel CYP2C19 Light transmittance aggregometry Ischemic vascular events

Charge resolution in the isochronous mass spectrometry and the mass of ^(51)Co

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Nuclear Science and Techniques 2021年第4期32卷 30-37页

作者： Xu Zhou Meng Wang yu-hu zhang hu-Shan Xu You-Jin yuan Jian-Cheng Yang yu.A.Litvinov S.A.Litvinov Bo Mei Xin-Liang Yan Xing Xu Peng Shuai yuan-Ming Xing Rui-Jiu Chen Xiang-Cheng Chen Chao-Yi Fu Qi Zeng Ming-Ze Sun Hong-Fu Li Qian Wang Tong Bao Min zhang Min Si Han-yu Deng Ming-Zheng Liu Ting Liao Jin-Yang Shi yu-Nan Song Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China GSI Helmholtzzentrum fu¨r Schwerionenforschung Planckstraße 164291 DarmstadtGermany Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China School of Science Xi’an Jiaotong UniversityXi’an 710049China School of Nuclear Science and Engineering East China University of TechnologyNanchang 330013China CNRS/IN2P3 IJCLabUniversite´Paris-Saclay91405 OrsayFrance

Isochronous mass spectrometry(IMS)of heavyion storage rings is a powerful tool for the mass measurements of short-lived *** IMS experiments,masses are determined through precision measurements of the revolution times of the ions stored in the ***,the revolution times cannot be resolved for particles with nearly the same mass-to-charge(m/q)*** overcome this limitation and to extract the accurate revolution times for such pairs of ion species with very close m/q ratios,in our early work on particle identification,we analyzed the amplitudes of the timing signals from the detector based on the emission of secondary ***,the previous data analysis method is further improved by considering the signal amplitudes,detection efficiencies,and number of stored ions in the ring.A sensitive Z-dependent parameter is introduced in the data analysis,leading to a better resolution of ^(34)Ar^(18+) and ^(51)Co^(27+) with A/Z=17/*** mean revolution times of ^(34)Ar^(18+) and ^(51)Co^(27+) are deduced,although their time difference is merely 1.8 *** uncorrected,overlapped peak of these ions has a full width at half maximum of 7.7 *** mass excess of ^(51)Co was determined to be-27;332e41T keV,which is in agreement with the previous value of-27;342e48T keV.

关键词： Isochronous mass spectrometry Charge resolution Signal amplitude Micro-channel plate ^(51)Co

On the masses of A=54 isospin septet and the isobaric multiplet mass equation

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Chinese Physics C 2022年第6期46卷 124-128页

作者： Hong-Fu Li Xing Xu Meng Wang yu-hu zhang Chao-Yi Fu Wen-Jia huang Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Lanzhou University Lanzhou 730000China School ofNuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China School of Physics Xi'an Jiaotong UniversityXi'an 710049China Advanced Energy Science and Technology Guangdong Laboratory Huizhou 516003China

Using the ground-state mass of ^(52)Ni and two-proton decay energy of ^(54)Zn,the ground-state mass excess of ^(54)Zn is deduced to be-6504(85)*** value is about 2 MeV lower than the prediction of the quadratic form of the isobaric multiplet mass equation(IMME).A cubic fit to the existing mass data of the A=54,T=3 isospin multiplet yields a surprisingly large d coefficient of IMME,i.e.,d=18.6(27),being 6.9σdeviated from zero,and the resultant|b/c|ratio significantly deviates from the *** phenomenon is analyzed in this study,and we conclude that the breakdown of the quadratic form of IMME could be likely due to the mis-assignment of the T=3 isobaric analog state(IAS)in the T_(Z)=1 nucleus ^(54)Fe or extremely strong isospin mixing.

关键词： isobaric multiplet mass equation(IMME) mass ^(54)Zn

Fusion reactions around the barrier for Be+^(238)U

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Chinese Physics C 2021年第5期45卷 100-104页

作者： Bo Mei Dimiter L.Balabanski Wei hua yu-hu zhang Xiao-Hong Zhou Cen-Xi yuan Jun Su Sino-French Institute of Nuclear Engineering and Technology Sun Y at-sen UniversityZhuhai 519082China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Extreme Light Infrastructure Nuclear Physics “Horia Hulubei”National R&D Institute for Physics and Nuclear EngineeringStrada Reactorului 30077125 Bucharest MagureleRomania

Fusion-evaporation cross sections of^(238)U(^(9)Be,5n)^(242)Cm are measured over a wide energy range around the Coulomb *** measured cross sections are compared with model calculations using two codes,namely HIVAP2 and KE ***2 calculations overestimate the measured fusion-evaporation cross sections by a factor of approximately *** KEWPIE2 calculations,two approaches,namely the Wentzel-Kramers-Brillouin(WKB)approximation and the empirical barrier-distribution(EBD)method,are used for the capture probability;both of them properly describe the measured cross ***,fusion cross sections of^(7.9)Be+^(238)Umeas-ured in two experiments are applied to constrain model calculations further through three codes,i.e,HIVAP2,KEWPIE2,and *** in these codes are also examined by comparison with measured fusion cross *** the comparisons indicate that the K EWPIE2 calculations using the WKB approximation agree well with the measured cross sections of both fusion reactions 7.9 Be+^(238)U and the fusion-evaporation reaction 238U(9 Be,5n)242 *** using the fusion code CCFULL are also in good agreement with the measured fusion cross sections of 7.9 Be+^(238)U.

关键词： fusion-evaporation reaction ^(238)U fusion cross sections near barrier energies