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| 1 | Response-surface-based structural reliability analysis with random and interval mixed uncertainties显示文摘Traditional reliability analysis requires probability distributions of all the uncertain parameters.However,in many practical applications,the variation bounds can be only determined for the parameters with limited information.A complex hybrid reliability problem then will be caused when the random and interval variables coexist in a same structure.In this paper,by introducing the response surface technique,we develop a new hybrid reliability method to efficiently compute the interval of the failure probability of the structure due to the probability-interval hybrid uncertainty.The present method consists of a sequence of iterations.At each step,a response surface model is constructed for the limit-state function by using a quadratic polynomial and a modified axial experimental design method.An approximate hybrid reliability problem is created based on the response surface model,which is subsequently solved by an efficient decoupling approach.An updating strategy is suggested to improve the quality of the response surface and whereby ensure the reliability analysis precision.A computational procedure is then summarized for the whole iterations.Four numerical examples and also a practical application are provided to demonstrate the effectiveness of the present method. | HAN Xu JIANG Chao LIU LiXin LIU Jie LONG XiangYun | 2014 | Science China(Technological Sciences)2014，57，7： | 14 |
| 2 | Research of an SHPB Device in Two-by-Two Form for Impact Experiments of Concrete-Like Heterogeneous Materials显示文摘A split Hopkinson pressure bar(SHPB)device in two-by-two form,including the bar bundle form and the single cylindrical bar form,was designed in response to the demand for the dynamic mechanical experiments for brittle materials such as concrete,rock,etc.The stress waveforms generated through a projectile impacting two different types of incident bars have been studied based on the one-dimensional stress wave theory and numerical simulation method.At last,based on the established two types of mesoscale concrete models with random convex polyhedral aggregates,we performed comparison analysis of SHPB numerical simulations for concrete materials with bar bundle and single cylindrical bar separately,so as to provide technical support for the manufacture and development of this experimental device.The results showed that the introduced two-by-two form SHPB device expanded the scope of practical application,and the wave dispersion effect existing in a large-diameter bar can be evidently reduced when we employed the bar bundle form,indicating its applicability to the dynamic mechanical experiments of concrete-like heterogeneous materials. | Ruiqi Guo Huiqi Ren Lei Zhang Zhilin Long Xiangyun Wu Hailu Wang | 2021 | Acta Mechanica Solida Sinica2021，34，4： | 2 |
| 3 | Diffusion and Adsorption of Tetralin Hydrocracking Reaction on Different Zeolites by Molecular Simulation显示文摘Three different zeolite catalysts with different pore sizes(MFI-type,BEA-type,and FAU-type zeolites)have been prepared.The influence of different zeolite catalysts on reactivity and product shape selectivity of tetralin is investigated.Clear differences are observed in the reactivity of tetralin and distribution of products achieved by different catalysts.The diffusion and adsorption behavior of the reactant tetralin and its intermediates,n-butylbenzene and 1-methylindane under the reaction conditions are simulated using molecular simulation methods.Upon combining simulation results and experimental observations,it is shown that the difference in diffusion coefficient and competitive adsorption capacity can explain the reactivity of tetralin and the selectivity of products.The steric hindrance of the MFI-type zeolite mainly limits the key step of ring opening of tetralin,leading to lower selectivity of ring-opening products.n-Butylbenzene molecules can diffuse sufficiently fast in the large pores of FAU-type zeolite and the weak adsorption capacity of n-butylbenzene leads to its insufficient cracking.In addition,it also explains the reason that the BEA-type zeolite has the best BTX selectivity,because it can satisfy both good ring-opening activity and sufficient butylbenzene cracking depth. | Sun Lijie Fan Yaming Dong Songtao Xian Ce Long Xiangyun Li Dadong | 2021 | China Petroleum Processing & Petrochemical Technology2021，23，1： | 1 |
| 4 | Robust Remaining Useful Life Estimation Based on an Improved Unscented Kalman Filtering Method显示文摘In the Prognostics and Health Management(PHM),remaining useful life(RUL)is very important and utilized to ensure the reliability and safety of the operation of complex mechanical systems.Recently,unscented Kalman filtering(UKF)has been applied widely in the RUL estimation.For a degradation system,the relationship between its monitored measurements and its degradation states is assumed to be nonlinear in the conventional UKF.However,in some special degradation systems,their monitored measurements have a linear relation with their degradation states.For these special problems,it may bring estimation errors to use the UKF method directly.Besides,many uncertain factors can result in the fluctuations of the estimated results,which may have a bad influence on the RUL estimation method.As a result,a robust RUL estimation approach is proposed in this paper to reduce the errors and randomness of estimation results for this kind of degradation problems.Firstly,an improved unscented Kalman filtering is established utilizing the Kalman filtering(KF)method and a linear adaptive strategy.The linear adaptive strategy is used to adjust its noise term adaptively.Then,the robust RUL estimation is realized by the improved UKF.At last,three problems are investigated to demonstrate the effectiveness of the proposed method. | Shenkun Zhao Chao Jiang Zhe Zhang Xiangyun Long | 2020 | Computer Modeling in Engineering & Sciences2020，，6： | 1 |
| 5 | Monolayer Oxide Modification on HZSM-5 and Its Role in Selective Methylation of Toluene显示文摘MonolayerOxideModificationonHZSM5andItsRoleinSelectiveMethylationofToluene①LongXiangyun,ZhaoBiying②,HuangHuizhong,XieYouchan... | Long Xiangyun, Zhao BiyingTo whom all correspondence should be addressed., Huang Huizhong, Xie Youchang (Institute of Physical Chemistry, Peking University, Beijing 100871) | 1997 | 石油学报(石油加工)1997，13，S1： | 1 |
| 6 | QUANTUM CHEMICAL MECHANISM ON THE SURFACE OXIDATION AND FLOTATION OF SULPHIDE MINERALS显示文摘The surfaces of galena and pyrite,the adsorption of oxygen,and the reactions of ethyl xanthate on the sulfides were studied using quantum chemical calculations.In addition,the surface electron structures of the minerals were discussed.According to the results,the mechanisms of ionic exchange reaction and dixanthogen adsorption for the xanthate notation of galena and pyrite were explained.The important role of oxygen in collector and collectorless flotation processes was also investigated. | Wang Dianzuo Long Xiangyun Sun Shuiyu | 1991 | Transactions of Nonferrous Metals Society of China1991，1，1： | 1 |
| 7 | Early Diagnosis of Bipolar Disorder Coming Soon:Application of an Oxidative Stress Injury Biomarker(BIOS)Model显示文摘Early distinction of bipolar disorder(BD)from major depressive disorder(MDD)is difficult since no tools are available to estimate the risk of BD.In this study,we aimed to develop and validate a model of oxidative stress injury for predicting BD.Data were collected from 1252 BD and 1359 MDD patients,including 64 MDD patients identified as converting to BD from 2009 through 2018.30 variables from a randomly-selected subsample of 1827(70%)patients were used to develop the model,including age,sex,oxidative stress markers(uric acid,bilirubin,albumin,and prealbumin),sex hormones,cytokines,thyroid and liver function,and glycolipid metabolism.Univariate analyses and the Least Absolute Shrinkage and Selection Operator were applied for data dimension reduction and variable selection.Multivariable logistic regression was used to construct a model for predicting bipolar disorder by oxidative stress biomarkers(BIOS)on a nomogram.Internal validation was assessed in the remaining 784 patients(30%),and independent external validation was done with data from 3797 matched patients from five other hospitals in China.10 predictors,mainly oxidative stress markers,were shown on the nomogram.The BIOS model showed good discrimination in the training sample,with an AUC of 75.1%(95%CI:72.9%–77.3%),sensitivity of 0.66,and specificity of 0.73.The discrimination was good both in internal validation(AUC 72.1%,68.6%–75.6%)and external validation(AUC 65.7%,63.9%–67.5%).In this study,we developed a nomogram centered on oxidative stress injury,which could help in the individualized prediction of BD.For better real-world practice,a set of measurements,especially on oxidative stress markers,should be emphasized using big data in psychiatry. | Zhiang Niu Xiaohui Wu Yuncheng Zhu Lu Yang Yifan Shi Yun Wang Hong Qiu Wenjie Gu Yina Wu Xiangyun Long Zheng Lu Shaohua Hu Zhijian Yao Haichen Yang Tiebang Liu Yong Xia Zhiyu Chen Jun Chen Yiru Fang | 2022 | Neuroscience Bulletin2022，38，9： | 1 |
| 8 | A Study on the Coking Sites ofγ-Alumina Surface Using 1-Methylnaphthalene as the Model Reactant显示文摘The support γ-Al_2O_3 was treated with 1-methylnaphthalene as the model reactant by respectively using the chemical static adsorption method and the accelerated coking method to study the coking sites of γ-Al_2O_3 surface. The carbon species formed on γ-Al_2O_3 surface were analyzed by CAT-CS, TG-MS, IR-OH, and Py-IR techniques. The results of characterization by CAT-CS and TG-MS techniques indicated that the carbon species formed during the chemical static adsorption process is mainly composed of the reversibly adsorbed coke precursors with a lowly-condensed state, while that formed after the accelerated coking process is probably related with the irreversibly adsorbed coke deposits with a highlycondensed state. The results of characterization by IR-OH and Py-IR techniques further implied that the formation of the two kinds of carbon species, i.e., coke precursors and coke deposits, are closely related with the basic hydroxyl groups and the strong Lewis acid sites on γ-Al_2O_3 surface. The results lead to a deep insight into the coking mechanism on the alumina surface. | Hu Anpeng Han Wei Zhang Le Long Xiangyun Li Mingfeng Nie Hong | 2018 | China Petroleum Processing & Petrochemical Technology2018，20，4： | 0 |
| 9 | GRB 220408B:A Three-episode Burst from a Precessing Jet显示文摘Jet precession has previously been proposed to explain the apparently repeating features in the light curves of a few gamma-ray bursts(GRBs).In this paper,we further apply the precession model to a bright GRB 220408B by examining both its temporal and spectral consistency with the predictions of the model.As one of the recently confirmed GRBs observed by our GRID CubeSat mission,GRB 220408B is noteworthy as it exhibits three apparently similar emission episodes.Furthermore,the similarities are reinforced by their strong temporal correlations and similar features in terms of spectral evolution and spectral lags.Our analysis demonstrates that these features can be well explained by the modulated emission of a Fast-Rise-Exponential-Decay(FRED)shape light curve intrinsically produced by a precessing jet with a precession period of 18.4_(-0.2)~(+0.2)s,a nutation period of11.1_(-0.2)~(+0.2)s and viewed off-axis.This study provides a straightforward explanation for the complex yet similar multiepisode GRB light curves. | Zijian Zhang Yi-Han Iris Yin Chenyu Wang Xiangyu Ivy Wang Jun Yang Yan-Zhi Meng Zi-Ke Liu Guo-Yin Chen Xiaoping Fu Huaizhong Gao Sihao Li Yihui Liu Xiangyun Long Yong-Chang Ma Xiaofan Pan Yuanze Sun Wei Wu Zirui Yang Zhizhen Ye Xiaoyu Yu Shuheng Zhao Xutao Zheng Tao Zhou Qing-Wen Tang Qiurong Yan Rong Zhou Zhonghai Wang Hua Feng Ming Zeng Bin-Bin Zhang | 2023 | Research in Astronomy and Astrophysics2023，23，11： | 0 |
| 10 | Electronic struture of titanium silicides显示文摘ELECTRONICSTRUCTUREOFTITANIUMSILICIDESLong,Xiangyun(DepartmentofChemistry,CentralSouthUniversityofTechnology,Changsha410083)C... | Long, Xiangyun(Department of Chemistry,Central South University of Technology,Changsha 410083)Chong , Zheng(Department of Chemistry,Northern Illinois University,Dekalb 60115,U.S.A.) | 1994 | 中国有色金属学会会刊:英文版1994，4，3： | 0 |
| 11 | Discrimination of background events in the PolarLight X-ray polarimeter显示文摘PolarLight is a space-borne X-ray polarimeter that measures the X-ray polarization via electron tracking in an ionization chamber.It is a collimated instrument and thus suffers from the background on the whole detector plane.The majority of background events are induced by high energy charged particles and show ionization morphologies distinct from those produced by X-rays of interest.Comparing on-source and off-source observations,we find that the two datasets display different distributions on image properties.The boundaries between the source and background distributions are obtained and can be used for background discrimination.Such a means can remove over 70%of the background events measured with PolarLight.This approaches the theoretical upper limit of the background fraction that is removable and justifies its effectiveness.For observations with the Crab nebula,the background contamination decreases from 25%to 8%after discrimination,indicative of a polarimetric sensitivity of around 0.2 Crab for PolarLight.This work also provides insights into future X-ray polarimetric telescopes. | Jiahuan Zhu Hong Li Hua Feng Jiahui Huang Xiangyun Long Qiong Wu Weichun Jiang Massimo Minuti Saverio Citraro Hikmat Nasimi Dongxin Yang Jiandong Yu Ge Jin Ming Zeng Peng An Luca Baldini Ronaldo Bellazzini Alessandro Brez Luca Latronico Carmelo Sgrò Gloria Spandre Michele Pinchera Fabio Muleri Paolo Soffitta Enrico Costa | 2021 | Research in Astronomy and Astrophysics2021，21，9： | 0 |
| 12 | Flux Relaxation and Pinning Potential in Weak Links of Sintered T1_(2)Ba_(2)Ca_(2)Cu_(3)O_(10+x)显示文摘We have measured directly the low field magnetization and its time decay of weak link superconductor in the sintered T1_(2)Ba_(2)Ca_(2)Cu_(3)O_(10+x).The decay of magnetization with time at the field intensities of 5,10,15,20 and 50 Oe was observed to follow the law of logarithm,M∝Int.The pinning potential derived from the slope of the magnetization decay is about 0.045~0.075eV. | CAO Xiaowen FENG Shangshen LONG Xiangyun WU Yusheng PENG Huotain QI Zhiwei PENG Qiyun FANG Junren | 1991 | Chinese Physics Letters1991，8，6： | 0 |
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