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Anomalous top-quark coupling effects in rare B and K decays

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Chinese Science Bulletin 2014年第29期59卷 3760-3770页

作者： ya-dong yang Xing-Bo Yuan Institute of Particle Physics Central China Normal University Key Laboratory of Quark and Lepton Physics Ministry of Education

The Large Hadron Collider at CERN is performing direct searches for top-quark anomalous flavorchanging neutral current(FCNC)***,these processes may be correlated closely with the lowenergy rare B and K meson *** this paper,we review the anomalous top-quark coupling effects in these low-energy flavor transitions,summarize the flavor constraints and discuss their implications for direct detection of top-FCNC processes at the Large Hadron Collider.

关键词：耦合效应顶夸克反常大型强子对撞机 K衰变欧洲核子研究中心中性线电流直接搜索

b→cτ■ decay in supersymmetry with R-parity violation

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Chinese Physics C 2019年第8期43卷 46-58页

作者： dong-yang Wang ya-dong yang Xing-Bo Yuan Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE) Central China Normal University

In past years,several hints of lepton flavor universality（LFU）violation have emerged from the b→ct■,and b→sl+*** recently,the Belle Collaboration has reported the first measurement of the D* longitudinal polarization fraction in the B→D*τV *** by this intriguing result,along with the recent measurements of RJ/Ψand τ polarization,we present the study of b→ct■ decays in supersymmetry（SUSY）with R-parity violation（RPV）.We consider B→D（*）t■,Bc→ηct■,Bc→J/ψt■ and ∧b→∧ct■ modes and focus on the branching ratios,LFU ratios,forward-backward asymmetries,polarizations of daughter hadrons,and the τ *** RPV SUSY was capable of explaining the RD（*） anomalies at the 2σ level,after taking into account various flavor *** the allowed parameter space,the differential branching fractions and LFU ratios are largely enhanced by the SUSY effects,especially in the large dilepton invariant mass ***,a lower bound B（B+→K+vv）>7.37×10-6 is *** observables could provide testable signatures at the high-luminosity LHC and SuperKEKB,and correlate with direct searches for SUSY.

关键词： supersymmetry R-parity violation heavy flavor hadron b-quark semi-leptonic decay

Phenomenology of b→cτ■ decays in a scalar leptoquark model

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Chinese Physics C 2019年第8期43卷 66-80页

作者： Han yan ya-dong yang Xing-Bo Yuan Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE) Central China Normal University

During the past few years,signs of lepton flavor universality(LFU)violation have been observed in b→cτ■ and b→sl+***,the D* and τ polarization fractions P_L^D* and P_L~τ in B→D*τ■decay were likewise measured by the Belle *** by these intriguing results,we revisit the RD(*)and RK(*) anomalies in a scalar leptoquark(LQ)model,where two scalar LQs,one of which is a S U(2)L singlet and the other a S U(2)L triplet,are introduced *** consider five b→ cτ■ mediated decays,B→D(*)τ■,B^c→ηcτ■,Bc→J/ψt■,and ∧_b→∧_cτ■,and focus on the LQ effects on the q^2 distributions of the branching fractions,LFU ratios,and various angular observables in these *** the combined constraints of the available data on RD(*),RJ/ψ,P_L~τ(D*),and pLD*,we perform scans for the LQ couplings and make predictions for a number of *** it is found that both the differential branching fractions and LFU ratios are largely enhanced by the LQ effects,with the latter expected to provide testable signatures at the SuperKEKB and High-Luminosity LHC experiments.

关键词： new physics leptoquark B decay

Association between four adipokines and insulin sensitivity in patients with obesity, type 1 or type 2 diabetes mellitus,and in the general Chinese population

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Chinese Medical Journal 2010年第15期123卷 2018-2022页

作者： YUAN Tao ZHAO Wei-gang SUN Qi FU Yong dong Ying-yue dong ya-xiu yang Guo-hua WANG Heng Department of Endocrinology Key Laboratory of EndocrinologyMinistry of Health Peking Union Medical College HospitalChinese Academy of Medical Science and Peking Union Medical College Beijing 100730 China

Background Hyperinsulinemic euglycemic clamp is the gold standard to evaluate the insulin sensitity, but it is too complicated and expensive to use in *** tried to find an alternative indicator to reflect insulin *** evaluate the association between the four adipokines, adiponectin, leptin, resistin and tumor necrosis factor-α （TNF-α） with insulin sensitivity, we used a hyperinsulinemic euglycemic clamp to test insulin sensitivity in Chinese patients with obesity and type 1 or type 2 diabetes mellitus versus *** In this parallel control study, we tested insulin sensitivity using a hyperinsulinemic euglycemic clamp in different groups, then examined levels of adiponectin, leptin, resistin and TNF-α in serum, and the relationship between the different adipokines and glucose disposal rate （M value）, as well as insulin sensitivity index （M value/insulin, M/I）,which are the ＂gold standard＂ indices of insulin *** There were significant differences in mean leptin values in the four adipokines from the four different groups （P〈0.001; comparison of the variation between different groups was analyzed by variance analysis）.Compared to controls （using multiple comparison two-way Dunnett t test）, only the leptin level showed significant differences in the four adipokines from the four different groups at the same time （P 〈0.001）.The association analysis between the different adipokines and M or M/I values also showed that only leptin negatively correlated with M （r=-0.64, P 〈0.001） or M/I values （r=-0.56, P〈0.001）; there was no relationship between the other three adipokines and M or M/I *** Only leptin was associated with M or M/I ***, leptin might be one of the predictive factors of the degree of insulin resistance and risk of the accompanying disease.

关键词： adipokines leptin hyperinsulinemic euglycemic clamp diabetes mellitus metabolic syndrome insulin sensitivity index

Engineering FeOOH/Ni(OH)_(2) heterostructures on Ni_(3)S_(2)surface to enhance seawater splitting

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Rare Metals 2024年第5期43卷 1989-1998页

作者： Chen yang ya-dong Li Li-Juan Cao Xi-Long Wang Han-Pu Liang Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Sino-Danish College University of Chinese Academy of SciencesBeijing 100049China

The construction of highly stable and efficient electrocatalysts is desirable for seawater splitting but remains challenging due to the high concentration of Cl-in ***,FeOOH/Ni(OH)_(2)heterostructure supported on Ni_(3)S_(2)-covered nickel foam(Fe–Ni/Ni_(3)S_(2)/NF)was fabricated by hydrothermal and etching methods,as well as anodic oxidation *** electronic structure of FeOOH and Ni(OH)_(2)could be modulated after depositing FeOOH nanoparticles on Ni(OH)_(2)nanosheet,which greatly boosted the catalytic *** the catalyst used as an electrode for oxygen evolution reaction(OER),it needed low overpotentials of 266 and 368 m V to achieve current densities of 100 and 800 m A·cm^(-2),respectively,in 1 mol·L^(-1)KOH+seawater *** can operate continuously at 100 m A·cm^(-2)for 400 h without obvious ***,in situ generated SO_(4)^(2-)from inner Ni_(3)S_(2)during electrolysis process would accumulate on the surface of active sites to form passivation layers to repel Cl^(-),which seemed to be responsible for superior *** study not only synthesizes an OER catalyst for highly selective and stable seawater splitting,but also gives a novel approach for industrial hydrogen production.

关键词： Anodic oxidation Heterostructure Oxygen evolution reaction Seawater splitting

Partition of Initiators in Quasi-static Precipitation Polymerization of AAm/MAc

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Chinese Journal of Polymer Science 2014年第10期32卷 1400-1412页

作者：倪恨美 Hui Zhang Guo-xia Chen Jun-xiu Liu ya-dong yang Li-jun Zhang Min Wu Kan Zhan Yu-lu Chen School of Chemistry and Chemical Engineering Southeast University

In order to investigate the partition of initiators for quasi-static precipitation polymerization of acrylamide （AAm） and methacrylic acid （MAc） in ethanol, azo-initiators were employed with various functional groups such as --COOCH3 （V- 601, dimethyl 2,2＇-azobis（isobutyrate））, --CN （V-65, 2,2＇-Azobis（2,4-diemthylvaleronitrile））, --COOH （V-501, 4,4＇-azobis（4-cyanovaleric acid）） and --NH-（VA-061, 2,2＇-azobis[2-（2-imidazolin-2-yl）propane]）, respectively. Particle size, induction time and kinetics of polymerization were investigated by the scanning electron microscopy （SEM） and gravimetry. It was observed that the polymerization parameters, such as the particle size, induction time and polymerization rate, were considerably affected by the functional groups of initiators. Besides, the monomer concentration also played important roles in the particle formation. By using V-601, the polymerization rate was strongly correlated with the total surface area of particles and the concentration of initiators. However, by using V-50 l, the polymerization rate was strongly related to WoQo, where W0 is the initial concentration of monomers and Ci,0, the initial concentration of initiators. The results indicated that the different functional groups determined the different partition types of initiators between the minimonomer droplets and the continuous phase due to the molecular interactions of initiator and monomers. V-601 was all partitioned in the continuous phase, but a part of V-65 was partitioned in the minimonomer droplets. Besides the V-501 dissolved in the continuous phase, a part of V-501 was adsorbed on the surface of minimonomer droplets. VA-061 destroyed the stability of minimonomer droplets by the formation of zwitterions with MAA.

关键词： Partition of initiator Precipitation of polymerization Quasi-static state Methacrylic acid and acrylamide

Non-dimensional analysis on blast wave propagation in foam concrete:Minimum thickness to avoid stress enhancement

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Defence Technology（防务技术） 2024年第6期36卷 30-46页

作者： ya yang Xiangzhen Kong Qin Fang State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjing 210007JiangsuChina

Foam concrete is a prospective material in defense engineering to protect structures due to its high energy absorption capability resulted from the long plateau ***,stress enhancement rather than stress mitigation may happen when foam concrete is used as sacrificial claddings placed in the path of an incoming blast *** investigate this interesting phenomenon,a one-dimensional difference model for blast wave propagation in foam concrete is firstly proposed and numerically solved by improving the second-order Godunov *** difference model and numerical algorithm are validated against experimental results including both the stress mitigation and the stress *** difference model is then used to numerically analyze the blast wave propagation and deformation of material in which the effects of blast loads,stress-strain relation and length of foam concrete are *** particular,the concept of minimum thickness of foam concrete to avoid stress enhancement is ***,non-dimensional analysis on the minimum thickness is conducted and an empirical formula is proposed by curve-fitting the numerical data,which can provide a reference for the application of foam concrete in defense engineering.

关键词： Foam concrete Blast wave propagation Non-dimensional analysis Stress enhancement

Intermediate phase-assisted growth of CsPbBr_(3) for high performance of carbon-based perovskite solar cells

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Rare Metals 2024年第5期43卷 2222-2229页

作者： Bo-yan Liu He-Ming yang Yu-dong Zuo Zhi-Hao Tao Jun-Chun Li ya-Jing Chang Guo-Qing Tong yang Jiang School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China State Key Laboratory of Pulsed Power Laser Technology National University of Defense TechnologyHefei 230037China

CsPbBr_(3)inorganic perovskites have been regarded as the promising materials in the field of photo-voltaics because of the high tolerance against *** high energy barrier of phase transition from lead bromide(PbBr_(2))to CsPbBr_(3)perovskite and low solubility of perovskite in organic solvent impede the further improvement of device performance in terms of CsPbBr_(3)solar ***,an intermediate phase-assisted growth of CsPbBr_(3)perovskite was proposed by introducing tetraphenylphosphonium bromide(TPPB)as *** TPPB is expected to react with PbBr_(2)in organic solvent to form an intermediate phase of[***]-PbBr_(2),which not only effectively improves the crystallinity of PbBr2 crystals,but also greatly reduces the phase transition energy barrier,leading to uniform and compact CsPbBr_(3)perovskite films with large grain size and high *** combination with carbon electrode,the CsPbBr_(3)solar cells yield a champion device performance of 9.57%in comparison of pristine CsPbBr_(3)solar cells showing a low efficiency of 8.17%.Furthermore,the intermediate phaseassisted growth of CsPbBr_(3)-based solar cells displays an outstanding storage over720 h.

关键词： CsPbBr_(3) Perovskite solar cells Carbon electrode Hole transport layer free Intermediate phase

Fabricating functionally graded Fe-Cr-Co permanent magnetic alloys via laser powder bed fusion

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Journal of Iron and Steel Research International 2024年第3期31卷 729-737页

作者： ya-zhou He ya-qing Hou Peng Shen Hao Zhang dong Zhou Hang Su Central Iron and Steel Research Institute Co. Ltd.Beijing 100081China Material Digital R&D Center China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China

Laser powder bed fusion(LPBF)in-situ alloying technology offers the possibility to construct gradient materials with varied structures and *** graded Fe-Cr-Co permanent magnetic alloys were fabricated by LPBF and in-situ alloying mixed powders of Fe,Cr,and Co *** effects of different Fe,Cr and Co contents on the microstructure,magnetic properties and hardness of Fe-Cr-Co alloys prepared by LPBF were *** as-built Fe-Cr-Co alloys present a single body-centered-cubic phase and have a homogeneous distribution of *** mechanical properties and magnetic properties of the compositionally graded sample show a gradient *** the increase in Cr content,the Vickers hardness of the sample increases,and the saturation magnetization of the sample *** optimal magnetic properties in an isotropic state are given as coercivity HcB=21.65 kA/m,remanence Br=0.70 T and energy product(BH)_(max)=5.35 kJ/m^(3),which are comparable to or higher than the reported magnetic properties in an isotropic state prepared by traditional powder *** in-situ alloying technology has the potential to further explore Fe-Cr-Co magnetic materials,such as those consisting of multiple or more constituent elements,and to maximize the compositional flexibility of magnetic materials.

关键词： Fe-Cr-Co alloy Laser powder bed fusion In-situ alloying Functional material Magnetic property