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Outcomes of cardiac surgery in senior aged patients with ventricular dysfunction:analysis of a large national database

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Journal of Geriatric Cardiology 2021年第1期18卷 1-9页

作者： Han-Wei TANG kai CHEN Jian-Feng HOU Xiao-Hong HUANG sheng LIU Han-Ping MA sheng-Shou HU Department of Cardiovascular Surgery National Center for Cardiovascular DiseasesState Key Laboratory of Cardiovascular DiseaseFuwai HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Department of Special Medical Treatment Center Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Science and Peking Union Medical CollegeBeijingChina

OBJECTIVE In patients undergoing cardiac surgery,reduced preoperative ejection fraction(EF)and senior age are associated with a worse *** most outcome data available for these patients are mainly from Western surgical populations involving specific surgery types,our aim is to evaluate the real-world characteristics and perioperative outcomes of surgery in senior-aged heart failure patients with reduced EF across a broad range cardiac *** Data were obtained from the China Heart Failure Surgery Registry(China-HFSR)database,a nationwide multicenter registry study in China's *** variable regression analysis was performed in patients over 75 years old to identify risk factors associated with *** From 2012 to 2017,578 senior-aged(>75 years)patients were enrolled in China HFSR,21.1%of whom were *** coronary bypass grafting(CABG)were performed in 71.6%of patients,10.1%of patients underwent isolated valve surgery and 8.7%received CABG combined with valve ***-hospital mortality was 10.6%,and the major complication rate was 17.3%.Multivariate analysis identified diabetes mellitus(odds ratio(OR)=1.985),increased creatinine(OR=1.007),New York Heart Association(NYHA)Class III(OR=1.408),NYHA class IV(OR=1.955),cardiogenic shock(OR,6.271),and preoperative intra-aortic balloon pump insertion(OR=3.426)as independent predictors of in-hospital *** In senior-aged patients,preoperative evaluation should be carefully performed,and strict management of reversible factors needs more ***-aged patients commonly have a more severe disease status combined with more frequent comorbidities,which may lead to a high risk in mortality.

关键词： Western analysis of a large national database Outcomes of cardiac surgery in senior aged patients with ventricular dysfunction

Resource allocation for multiple description coding multicast in OFDM-based cognitive radio networks

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The Journal of China Universities of Posts and Telecommunications 2012年第5期19卷 51-57页

作者： LI sheng-yu XU Wen-jun GAO Yan NIU kai LIN Jia-ru School of Telecommunication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

The resource allocation scheme for the multiple description coding multicast （MDCM） in orthogonal frequency division multiplexing （OFDM-based） cognitive radio network （CRN） is studied in this paper, aiming at maximizing the total throughput of cognitive radio （CR） users, with constraints on sum transmit power, the maximal receiving rate of each CR user and the maximal total interference introduced to each primary user. With the analysis of the model, an algorithm, which consists of subcarrier assignment and power allocation using the sub-gradient updating method, is proposed. Meanwhile, to reduce the complexity, a suboptimal algorithm is also proposed, which divides the total transmit power into small slices and allocates them one by one. Moreover, the suboptimal algorithm is modified by adding an advanced water-filling process to improve the performance. The simulation results obtained in this paper show that the system throughput using the MDCM scheme is much higher than that using the conventional multicast （CM） scheme and the performance of the proposed suboptimal algorithms can approximate the MDCM scheme very well.

关键词： resource allocation MDCM cognitive radio sub-gradient method

Microstructure and creep properties of Ni-based single-crystal superalloys with Mo/Al addition at 760℃/850 MPa

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Rare Metals 2023年第11期42卷 3806-3813页

作者： Pei-Shan Cao Hui Wang Yi Ru Yun-Fei Liang sheng-kai Gong Key Laboratory of Aerospace Materials and Performance(Ministry of Education) School of Materials Science and EngineeringBeihang UniversityBeijing100191China

The effect of Mo and Al addition on the microstructure as well as creep rupture properties at760.C/850 MPa was investigated by transmission electron microscopy(TEM)in a Ni-based single-crystal(SC)alloy with the composition of Ni-6.5Al-8.0Mo-2.4Cr-6.2Ta-4.9Co-1.5Re-(0.01-0.05)Y(wt%).The microstructure analysis shows that 0.5 wt%Al addition induces rapid decrease in creep rupture life,and this can be attributed to the formation of dense stacking faults cutting intoγ'precipitates,which can be explained by the increase in Orowan stress caused by the narrowerγchannel width and the decrease in stacking faults ***,1.5 wt%Mo addition increases the anti-phase boundary energy and decreases the stacking faults energy,resulting in fewer stacking faults and thus a slight decrease in the creep rupture life.

关键词： Ni-based single-crystal superalloy Transmission electron microscopy Stacking faults Mo and Al addition Creep rupture properties

Quantile Regression for Thinning-based INAR(1)Models of Time Series of Counts

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Acta Mathematicae Applicatae Sinica 2021年第2期37卷 264-277页

作者： Dan-shu sheng De-hui WANG kai YANG Zi-ang WU School of Mathematics Jilin UniversityChangchun 130012China School of Economics Liaoning UniversityShenyang 110036China School of Mathematics and Statistics Changchun University of TechnologyChangchun 130012China

In this paper,we develop the quantile regression(QR)estimation for the first-order integer-valued autoregressive(INAR(1))models by defining the smoothing INAR(1)*** method is used to derive the QR estimators for the autoregressive coefficient and the quantile of *** consistency and asymptotic normality of the proposed estimators are *** performances of the proposed estimation procedures are evaluated by Monte Carlo *** results show that the proposed procedures perform well for simulations and a real data application.

关键词： INAR(1)process quantile regression parameter estimation jittering

Spontaneous growth of the reconnection electric field during magnetic reconnection with a guide field:A theoretical model and particle-in-cell simulations

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Chinese Physics B 2020年第7期29卷 369-374页

作者： kai Huang Quan-Ming Lu Rong-sheng Wang Shui Wang Key Laboratory of Geospace Environment Chinese Academy of SciencesDepartment of Geophysics and Planetary ScienceUniversity of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Comparative Planetology Hefei 230026China

Reconnection electric field is a key element of magnetic *** quantifies the change of magnetic topology and the dissipation of magnetic *** this work,two-dimensional(2D)particle-in-cell(PIC)simulations are performed to study the growth of the reconnection electric field in the electron diffusion region(EDR)during magnetic reconnection with a guide *** first,a seed electric field is produced due to the excitation of the tearing-mode ***,the reconnection electric field in the EDR,which is dominated by the electron pressure tensor term,suffers a spontaneous growth stage and grows exponentially until it saturates.A theoretical model is also proposed to explain such a kind of *** reconnection electric field in the EDR is found to be directly proportional to the electron outflow *** time derivative of electron outflow speed is proportional to the reconnection electric field in the EDR because the outflow is formed after the inflow electrons are accelerated by the reconnection electric field in the EDR and then directed away along the outflow *** kind of reinforcing process at last leads to the exponential growth of the reconnection electric field in the EDR.

关键词： magnetic reconnection reconnection electric field electron diffusion region particle-in-cell simulation

Rapid and Sensitive LC-MS/MS Method for Quantification of Fexofenadine in Human Plasma——Application to a Bioequivalence Study in Chinese Volunteers

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Chemical Research in Chinese Universities 2007年第5期23卷 514-517页

作者： TENG Guo-sheng TENG Le-sheng WU Yi TANG Yun-biao LIU Lan-ying GU Jing-kai　 Research Center for Drug Metabolism College of Life Science School of Pharmaceutical Science Jilin University Changchun 130021 P. R. China Department of Pharmacy General Hospital of Shenyang Military Command Shenyang 110016 P. R. China

A rapid and sensitive liquid chromatography-tandem mass spectrometry method（LC-MS/MS）was developed and validated for the quantification of fexofenadine in human plasma,to conduct comparative bioavailability *** plasma was extracted with a mixture of dichloromethane-diethyl ether（volume ratio 2∶3）in a basic environment and the extract was separated on a C18 column with a mobile phase consisting of acetonitrile-methanol-10 mmol/L ammonium acetate（volume ratio 45∶45∶10）.The analytes were detected via electrospray ionization（ESI）tandem mass spectrometry in the multiple-reaction-monitoring（MRM）*** linearity was within a range of 1-1000 ng/*** intra-and inter-day precision were〈4.1% and〈4.8%,respectively,and the accuracy was in the range of 95.0%-105%.The method was applied to the quantification of fexofenadine human plasma from 20 healthy male Chinese volunteers,according to a single dose,randomized,two-way crossover design with a two-week washout *** mean values of major pharmacokinetic parameters of ρmax,AUC0-48,AUC0-∞,tmax,and t1/2 were determined from the plasma *** analysis of variance（ANOVA）did not show any significant difference between the two products of fexofenadine and 90% confidence intervals fell within the acceptable range for bioequivalence.

关键词： Fexofenadine Bioequivalence LC-MS/MS Human plasma

Study on Sound-Speed Dispersion in A Sandy Sediment at Frequency Ranges of 0.5–3 kHz and 90–170 kHz

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China Ocean Engineering 2017年第1期31卷 103-113页

作者： YU sheng-qi LIU Bao-hua YU kai-ben KAN Guang-ming YANG Zhi-guo National Deep Sea Center State Oceanic Administration Qingdao 266237 China Key Laboratory of Marine Sedimentology and Environmental Geology First Institute of Oceanography Qingdao 266061 China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and Technology Qingdao 266237 China

In order to study the properties of sound-speed dispersion in a sandy sediment, the sound speed was measured both at high frequency （90-170 kHz） and low frequency （0.5-3 kHz） in laboratory environments. At high frequency, a sampling measurement was conducted with boiled and uncooked sand samples collected from the bottom of a large water tank. The sound speed was directly obtained through transmission measurement using single source and single hydrophone. At low frequency, an in situ measurement was conducted in the water tank, where the sandy sediment had been homogeneously paved at the bottom for a long time. The sound speed was indirectly inverted according to the traveling time of signals received by three buried hydrophones in the sandy sediment and the geometry in experiment. The results show that the mean sound speed is approximate 1710-1713 m/s with a weak positive gradient in the sand sample after being boiled （as a method to eliminate bubbles as much as possible） at high frequency, which agrees well with the predictions of Biot theory, the effective density fluid model （EDFM） and Buckingham＇s theory. However, the sound speed in the uncooked sandy sediment obviously decreases （about 80%） both at high frequency and low frequency due to plenty of bubbles in existence. And the sound-speed dispersion performs a weak negative gradient at high frequency. Finally, a water-unsaturated Biot model is presented for trying to explain the decrease of sound speed in the sandy sediment with plenty of bubbles.

关键词： acoustic properties of sediment sound-speed dispersion sandy sediment bubbles

Double network self-healing hydrogel based on hydrophobic association and ionic bond for formation plugging

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Petroleum Science 2022年第5期19卷 2150-2164页

作者： Ying-Rui Bai Qi-Tao Zhang Jin-sheng Sun Guan-Cheng Jiang kai-He Lv School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina CNPC Engineering Technology R&D Company Limited Beijing102206China College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China

Self-healing hydrogels have attracted tremendous attention in the field of oil and gas drilling and production engineering because of their excellent self-healing performance after physical *** this study,a series of double network self-healing(DN_(SA))hydrogels based on hydrophobic association and ionic bond were prepared for plugging pores and fractures in formations in oil and gas drilling and production *** mechanical,rheological,and self-healing properties of the DN_(SA)hydrogels were *** revealed that the DN_(SA)hydrogels exhibited excellent mechanical properties with a tensile stress of 0.67 MPa and toughness of 7069 kJ/cm^(3) owing to the synergistic effect of the double *** addition,the DN_(SA)hydrogels exhibited excellent compression resistance,notch insensitivity,and self-healing *** DN_(SA)-2 hydrogel was granulated and made into gel particles with different particle sizes and used as a plugging *** self-healing mechanism of DN_(SA)-2 hydrogel particles in fractures was explored,and it’s plugging effect on fractures of different widths and porous media of different permeabilities were *** results revealed that the plugging capacity of the DN_(SA)-2 hydrogel particles for a fracture with width of 5 mm and a porous medium with a permeability of 30μm^(2) was 3.45 and 4.21 MPa,respectively,which is significantly higher than those of commonly used plugging agents in the *** DN_(SA)hydrogels with excellent mechanical and self-healing properties prepared in this study will provide a new approach for applying hydrogels in oil and gas drilling and production engineering.

关键词： Self-healing hydrogel Hydrophobic association Ionic bond Mechanical property Rheological property Formation plugging

Multi-index analysis of the melting process of laterite metallized pellet

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1423-1430页

作者： Yun Wang Rong Zhu kai-lu Tu Guang-sheng Wei Shao-yan Hu Hong Li School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

Herein, a multi-index analysis of the nickel content of an alloy, output rate of the alloy, nickel recovery rate, and iron recovery rate during the melting of laterite metallized pellets was performed. The thermodynamic reduction behavior of oxides such as NiO, FeO, Fe_3 O_4, and Cr_2 O_3 was studied using the FactSage software, which revealed that SiO_2 is not conducive to the reduction of iron oxides, whereas the addition of basic oxides such as CaO and MgO is beneficial for the reduction of iron oxides. On the basis of a comprehensive analysis to achieve greater nickel recovery and lower iron recovery rates, the optimum experimental parameters in the orthogonal experiment were A3 B1 C3(t = 30 min, C/O = 0.4, R = 1.2); the indicators wNi, φalloy, ηNi, and ηFe had values of 15.0 wt%, 12.1%, 44.9%, and 96.4%, respectively. In single-factor experiments, increasing basicity(R) substantially improved the separation effect in the low-basicity range 0.5 ≤ R ≤ 0.8 but not in the high-basicity range 0.8 ≤ R ≤ 1.2. Similar results were obtained for the effect of the C/O ratio. Moreover, the recovery rate of nickel increased with increasing recovery rate of iron.

关键词： melting and separation laterite metallized pellet multi-index analysis basicity carbon-to-oxygen ratio