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α particle preformation and shell effect for heavy and superheavy nuclei

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Chinese Physics C 2018年第7期42卷 65-74页

作者： yan-wei zhao Shu-Qing Guo Hong-Fei Zhang School of Nuclear Science and Technology Lanzhou University Lanzhou 730000 China Joint Department for Nuclear Physics Lanzhou University and Institute of Modern Physics CAS Lanzhou 730000 China

The α particle preformation factor is extracted within a generalized liquid drop model for Z=84-92 isotopes and N=126, 128, 152, 162, 176, 184 isotones. The calculated results show clearly that the shell effects play a key role in α particle preformation. The closer the proton and neutron numbers are to the magic numbers, the more difficult the formation of the α cluster inside the mother nucleus is. The preformation factors of the isotopes reflect that N=126 is a magic number for Po, Rn, Ra, and Th isotopes, but for U isotopes the weakening of the influence of the N=126 shell closure is evident. The trend of the factors for N=126 and N=128 isotones also support this conclusion. We extend the calculations for N=152, 162, 176, 184 isotones to explore the magic numbers for heavy and superheavy nuclei, which are probably present near Z=108 to N=152, 162 isotones and Z=116 to N=176, 184 isotones. The results also show that another subshell closure may exist after Z=124 in the superheavy nuclei. This is useful for future experiments.

关键词： α particle preformation generalized liquid drop model shell effect magic number

Hexagonal boron nitride based slippery liquid infused porous surface with anti-corrosion, anti-contaminant and anti-icing properties for protecting magnesium alloy

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Chinese Chemical Letters 2024年第4期35卷 532-538页

作者： Wenhao yan Shuaiya Xue Xuerui zhao wei Zhang Jian Li Key Laboratory of Eco-Functional Polymer Materials of the Ministry of Education College of Chemistry and Chemical EngineeringNorthwest Normal UniversityLanzhou 730070China

In an era where the concept of green development is deeply rooted, magnesium(Mg) alloy as a light metal has a long-term development prospect in the process of energy saving, emission reduction and environmental improvement. However, anti-corrosion performance of Mg alloy is poor due to the high chemical activity and low equilibrium potential, which limits the development of Mg alloy ***, three-dimensional mesopore hollow polypyrrole spheres(MHPS) were prepared, and the MHPS was inserted into the middle of the stacked hexagon boron nitride(h-BN) lamellae, which allowed the hBN to be separated forming a further composite with abundant pore structure. Subsequently, the MHPS/hBN-OH composite was uniformly sprayed on the Mg alloy surface via simple spraying method to form the superhydrophobic surface(SHS). Finally, the slippery liquid infused porous surface(SLIPS) was successfully fabricated by applying drops of silicone lubricant on the superhydrophobic coating surface. After a series of characterization and testing, the results showed that the stacking of h-BN lamellae was significantly reduced after h-BN was successfully embedded by MHPS. In addition, the fabricated SLIPS have excellent self-cleaning, mechanical stability, anti-icing and anti-corrosion properties. Therefore, the method of embedding polymer microspheres not only offers a new strategy for h-BN exfoliation, but also the successful prepared SLIPS largely retards the corrosion of Mg alloy while providing new ideas for the development of SLIPS.

关键词： Anti-corrosion Mg alloy Hexagon boron nitride Polypyrrole SLIPS

Enhancing personalized exercise recommendation with student and exercise portraits

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Journal of Electronic Science and Technology 2024年第2期22卷 91-109页

作者： wei-wei Gao Hui-Fang Ma yan zhao Jing Wang Quan-Hong Tian College of Computer Science and Engineering Northwest Normal UniversityLanzhou730070China Computer Center of Gansu Province Lanzhou730070China

The exercise recommendation system is emerging as a promising application in online learning scenarios,providing personalized recommendations to assist students with explicit learning *** solutions generally follow a collaborative filtering paradigm,while the implicit connections between students(exercises)have been largely *** this study,we aim to propose an exercise recommendation paradigm that can reveal the latent connections between student-student(exercise-exercise).Specifically,a new framework was proposed,namely personalized exercise recommendation with student and exercise portraits(PERP).It consists of three sequential and interdependent modules:Collaborative student exercise graph(CSEG)construction,joint random walk,and recommendation list ***,CSEG is created as a unified heterogeneous graph with students’response behaviors and student(exercise)***,a joint random walk to take full advantage of the spectral properties of nearly uncoupled Markov chains is performed on CSEG,which allows for full exploration of both similar exercises that students have finished and connections between students(exercises)with similar ***,we propose to optimize the recommendation list to obtain different exercise *** analyses of two public datasets,the results demonstrated that PERP can satisfy novelty,accuracy,and diversity.

关键词： Educational data mining Exercise recommend Joint random walk Nearly uncoupled Markov chains Optimization Personalized learning

Association of the Apolipoprotein B Gene Polymorphisms With Essential Hypertension in Northern Chinese Han Population

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Biomedical and Environmental Sciences 2007年第3期20卷 260-264页

作者： wei-yan zhao JIAN-FENG HUANG LAI-YUAN WANG HONG-FAN LI PENG-HUA ZHANG QI zhao SHU-FENG CHEN DONG-FENG GU Department of Evidence Based Medicine and Division of Population Genetics Cardiovascular Institute and Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100037 China National Human Genome Center Beijing 100176 China

Objective To study the association of the apolipoprotein B gene polymorphisms with essential hypertension in Northern Chinese Han population. Methods XbaI and EcoRl polymorphisms of the apolipoprotein B （APOB） gene were genotyped by polymerase chain reaction （PCR） and restriction fragment-length polymorphism （RFLP） method in 503 unrelated hypertensive patients and 490 healthy controls recruited from international collaborative study of cardiovascular disease in Asia （InterAsia）. Results The difference in the genotypic distributions could be neglected across the groups. The prevalence of X＋ allele in healthy controls （4.8%） was less frequent in Chinese, and there was no significant difference in the frequency of the X＋ allele between cases （5.7%） and controls （P=0.38）. The observed E- allele frequencies were closely similar among groups （5.9% in cases vs 5.0% in controls, P=0.39）. Logitstic regression analyses revealed that the lack of association still persisted after adjustment of other environmental factors. Haplotype analysis showed that X-E＋ was most frequent and no haplotype could significantly contribute to essential hypertension. Conclusion The APOB gene XbaI and EcoRI polymorphisms are not associated with essential hypertension in the Northern Chinese Han population. Future studies on single nucleotide polymorphisms in larger samples are needed to further investigate the possible contribution of the APOB gene to essential hypertension.

关键词： Essential hypertension APOB gene Polymorphisms Case-control study

Tunable VO_(2) cavity enables multispectral manipulation from visible to microwave frequencies

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Light(Science & Applications) 2024年第3期13卷 510-518页

作者： Hang wei Jinxin Gu Tao zhao Zhiyuan yan He-Xiu Xu Shuliang Dou Cheng-wei Qiu Yao Li Center for Composite Materials and Structure Harbin Institute of TechnologyHarbin 150001China National University of Singapore Department of Electrical&Computer EngineeringSingapore 117583Singapore School of Chemical Engineering and Technology Harbin Institute of TechnologyHarbin 150001China Suzhou Laboratory Suzhou 215123China

Optical materials capable of dynamically manipulating electromagnetic waves are an emerging field in memories,optical modulators,and thermal ***,their multispectral design preliminarily attracts much attention,aiming to enhance their efficiency and integration of ***,the multispectral manipulation based on these materials is challenging due to their ubiquitous wavelength dependence restricting their capacity to narrow *** this article,we cascade multiple tunable optical cavities with selective-transparent layers,enabling a universal approach to overcoming wavelength dependence and establishing a multispectral platform with highly integrated *** on it,we demonstrate the multispectral(ranging from 400 nm to 3 cm),fast response speed(0.9 s),and reversible manipulation based on a typical phase change material,vanadium *** platform involves tandem VO_(2)-based Fabry–Pérot(F-P)cavities enabling the customization of optical responses at target bands *** can achieve broadband color-changing capacity in the visible region(a shift of~60 nm in resonant wavelength)and is capable of freely switching between three typical optical models(transmittance,reflectance,and absorptance)in the infrared to microwave regions with drastic amplitude tunability exceeding *** work represents a state-of-art advance in multispectral optics and material science,providing a critical approach for expanding the multispectral manipulation ability of optical systems.

关键词： spectral microwave visible

Study on the mechanism and law of temperature,humidity and moisture content on the mechanical properties of molded fiber products

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Journal of Bioresources and Bioproducts 2024年第3期9卷 351-368页

作者： Zhiqiang Fu Tong zhao Hu Wang Jingyi wei Haozhe Liu Liying Duan yan Wang Ruixiang yan School of Light Industry Science and Engineering Tianjin University of Science and TechnologyTianjin 300457China Department of Transportation and Vehicle Engineering Tangshan UniversityTangshan 063000HebeiChina College of Mechanical Engineering Tianjin University of Science and TechnologyTianjin 300457China

The change of temperature, humidity and moisture content (MC) will lead to the change of mechanical properties of molded fiber products (MFP). However, it is difficult to decouple the effects of temperature, humidity and MC on the mechanical properties of MFP, and predict the mechanical properties of MFP during the use. In this study, the laws and mechanism of mechanical properties of MFP with ambient temperature, humidity and MC were studied. The results showed that the direct effect of temperature (20−70 °C) on mechanical properties of MFP was insignificant, and the mechanical properties of MFP were mainly changed by MC. The MC was related to ambient temperature and humidity, and the relationship between the three could be described by the modified Guggenheim-Anderson-de Boer (GAB) model (20−70 °C and 30 %–90 % relative humidity). With the increase of MC, the elastic modulus and fracture strain was increased and decreased linearly, the yield strength and failure strength were presented GaussAmp laws, and the failure strain was presented asymptotic regressed distribution law. Two fracture modes of MFP, brittle fracture and ductile fracture, were revealed by the scanning electron microscopy of the mesoscopic fiber structure of sugarcane bagasse molded fiber products. The mathematical models and the changes of fiber structure were verified by wheat straw molded fiber products and waste paper molded fiber products. This study was contributed to understand the effects and mechanism of the change of temperature, humidity and MC on the mechanical properties of MFP.

关键词： Temperature Relative humidity Moisture content Molded fiber products Mechanical properties

Analysis of Synonymous Codon Usage Bias in Chlamydia

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Acta Biochimica et Biophysica Sinica 2005年第1期37卷 1-10页

作者： Hui L(?) wei-Ming zhao~* yan ZHENG Hong WANG Mei QI Xiu-Ping YU Department of Medical Microbiology,School of Medicine,Shangdong University,Jinan 250012,China Department of Medical Microbiology School of Medicine Shandong University Jinan 250012 China.

Chlamydiae are obligate intracellular bacterial pathogens that cause ocular and sexuallytransmitted diseases,and are associated with cardiovascular *** analysis of codon usage mayimprove our understanding of the evolution and pathogenesis of Chlamydia and allow reengineering of targetgenes to improve their expression for gene ***,we analyzed the codon usage of ***,***(here indicating biovar trachoma and LGV),***,and *** using the codonusage database and the CUSP(Create a codon usage table)program of EMBOSS(The European MolecularBiology Open Software Suite).The results show that the four genomes have similar codon usage patterns,with a strong bias towards the codons with A and T at the third codon *** with Homosapiens,the four chlamydial species show discordant seven or eight preferred *** ENC(effectivenumber of codons used in a gene)-plot reveals that the genetic heterogeneity in Chlamydia is constrained bythe G+C content,while translational selection and gene length exert relatively weaker ***,mutational pressure appears to be the major determinant of the codon usage variation among the *** addition,we compared the codon preferences of *** with those of ***,yeast,adenovirus and Homo *** are 23 codons showing distinct usage differences between *** ***,24 between *** and adenovirus,21 between *** and Homo sapiens,butonly six codons between *** and ***,the yeast system may be more suitable for theexpression of chlamydial ***,we compared the codon preferences of *** with those ofsix eukaryotes,eight prokaryotes and 23 *** is a strong positive correlation between the differ-ences in coding GC content and the variations in codon bias(r=0.905,P<0,001).We conclude that thevariation of codon bias between *** and other organisms is much less influenced b

关键词： Chlamydia codon usage bias GC content gene expression

Detwinning and Anneal-Hardening Behaviors of Pre-Twinned AZ31 Alloys under Cryogenic Loading

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1551-1563页

作者： Lingyu zhao wei Zhu Chao Zhang Yunchang Xin Changjian yan Yao Cheng zhaoyang Jin School of Mechanical Engineering Yangzhou UniversityYangzhou225127China Key Laboratory for Light-weight Materials Nanjing Tech UniversityNanjing210009China Institute of Corrosion Science and Technology Guangzhou510070GuangdongChina Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing Institute of TechnologyNanjing211167China

Detwinning behavior of a pre-twinned magnesium alloy AZ31 at cryogenic temperature was investigated,also with a focus on the annealing hardening behavior of samples with different fractions of ***-compression along the transverse direction with strains of 1.7%,3.0%,and 6.0% was applied to generated[1012]*** behavior,microstructure,and texture evolution during subsequent tension were *** results show that low temperature did not change the fact that detwinning still pre-dominated in the pre-twinned samples under reverse ***,a relatively harder migration of twin boundaries was found at cryogenic *** annealing hardening of 27-40 MPa was observed in the pre-twinned samples,and such a hardening effect shows a close relation with the fraction of pre-twins or the level of *** annealing hardening effect disappeared if the matrix was consumed by twins along with the increased pre-compression *** corresponding reasons for the annealing hardening behavior were discussed.

关键词： Mg alloys Detwinning Annealing hardening Cryogenic temperature Mechanical property

Modulating redox transition kinetics by anion regulation in Ni-Fe-X(X=O,S,Se,N,and P)electrocatalyst for efficient water oxidation

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Nano Research 2024年第6期17卷 4720-4728页

作者： Liting wei Kaini Zhang Rui zhao Lei Zhang yan Zhang Suyi yang Jinzhan Su International Research Center for Renewable Energy&State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China Department of Applied Chemistry Yuncheng UniversityYuncheng 044000China

NiFe-based electrocatalysts will experience dynamical surface reconstruction during oxygen evolution reaction(OER)process,and the derived metal(oxy)hydroxide hybrids on the surface have been considered as the actual active species for *** efforts have been dedicated to understanding the surface reconstruction,but there is rare research on recognizing the origin of improved performance derived from anion species of ***,the OER electrocatalytic characteristics were tuned with different anions in NiFe-based catalyst,using NiFe-based oxides/nitride/sulfide/selenides/phosphides(NiFeX,X=O,N,S,Se,and P)as the model *** combination of X-ray photoelectronic spectroscopy,electrochemical tests,operando spectroscopic characterizations,and density functional theory(DFT)calculations,reveals that anion with lower electronegativity in NiFe-based catalyst leads to higher conductivity and delayed valence transition of Ni sites,as well as optimized adsorption behavior towards oxygen intermediates,contributing to enhanced OER ***,NiFeP electrocatalyst demonstrates an ultralow overpotential of 265 mV at 20 mA·cm−2 for OER,as well as long-term *** work not only offers further insights into the effect of anionic electronegativity on the intrinsic OER electrocatalytic properties of NiFe-based electrocatalyst but also provides guide to design efficient non-noble metal-based electrocatalysts for water oxidation.

关键词： oxygen evolution reaction(OER) anion species electronegativity valence transition