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Normal Forms for Periodic Orbits of Real Vector Fields

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Acta Mathematica Sinica,English Series 2008年第5期24卷 797-808页

作者： Ping wang Hao wu wei Gu LI School of Mathematical Sciences Peking University Beijing 100871 P. R. China

We consider normal forms of real vector fields near periodic orbits and provide sufficient conditions for their smooth linearization. In addition, the main results also assert the existence of vertical local foliation... 详细信息

关键词： normal form Homotopy method foliation

Left atrial minimum volume by real-time three-dimensional echocardiography as an indicator of diastolic dysfunction

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Chinese Medical Journal 2013年第22期126卷 4227-4231页

作者： LIN Qiong-wen wang wu-gang wu wei-chun wang Hao Department of Echocardiography Fuwai Hospital Chinese Academy of Medical Sciences Peking Union Medical College Beijing 100037 China

Background Left atrial （LA） maximum volume is becoming a prognostic biomarker for left ventricular （LV） diastolic dysfunction. However, we assessed LV diastolic function by measuring LA phasic volumes using real-time threedimensional echocardiography （RT3DE） in patients with stable coronary artery disease （CAD）. Methods Sixty-five stable CAD patients with normal LV ejection fraction （LVEF） were divided into three groups according to degree of coronary stenosis： control （n=15） with 〈50% stenosis as control group, mildS （n=25） with mild stenosis （50%- 70%） and severeS （n=25） with 〉70% stenosis. LA phasic volumes and function were evaluated and compared using RT3DE and two dimensional echocardiography （2DE）. N-terminal pro-B-type natriuretic peptide （NT-proBNP） levels were examined. The correlations of RT3DE-derived parameters with other conventional indices were analyzed. Results Significant correlations between RT3DE and 2DE for LA volume measurements were： control, r=0.93; mildS, 1=0.94; severeS, r=0.90 （all P 〈0.05）. Patients with severe coronary stenosis presented higher NT-proBNP level, indices of LA minimum volume and volume before atrial contraction, but lower LA total emptying fraction （LAEF） and LAEFpass^ve. Significant correlations of RT3DE derived LA volume indices with E/E＇（r=0.695） and NF-proBNP （r=0.630） level were found. Conclusions RT3DE derived, LA indices correlate well with NT-proBNP level and may be superior to 2DE measurements for the evaluation of LV diastolic dysfunction. Enlargement of LA minimum volume in stable CAD patients without systolic dysfunction appears earlier and may be better correlated with LV diastolic function than that of LA maximum volume.

关键词： real-time three-dimensional echocardiography left atrial volume diastolic dysfunction, coronary arterydisease, N terminal pro B type natriuretic peptide

Delayed Serratia marcescens endocarditis associated with intracardiac foreign body

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Chinese Medical Journal 2007年第5期120卷 437-440页

作者： YANG Li wang Jing-feng wu wei Department of Cardiology Second Afftliated Hospital Sun Yat-Sen University Guangzhou 510120 China

Traumatic or iatrogenic metallic foreign body retained in the heart is not a rare entity. Infective endocarditis associated with a retained nonmetallic foreign body is exceptionally rare. This report describes what we believe is the case of a special nonmetallic foreign body （a bamboo stick） retained in the heart, complicated by delayed Serratia marcescens endocarditis in a boy who had previously unrecognized injury of his heart.

关键词： foreign body endocarditis echocardiography

Synthesis and Crystal Structure of 4-Nitro-2-[(2-diethylaminoethylimino)methyl]phenol

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1179-1182页

作者： wang Feng-wu wei Yi-Jun ZHU Qi-Yong Department of Chemistry Huainan Normal College Huainan 232001 China

The title Schiff base compound C13H19N3O3 synthesized by the condensation of equimolar 5-nitrosalicylaldehyde and N,N-diethylethane-1,2-diamine consists of two independent molecules. The compound was characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pbca with a = 13.151 （3）, b = 20.609（4）, c = 20.991 （4） °A, Z = 16, V = 5689（2） °A^3, Dc = 1.239 g/cm^3, Mr = 265.31, λ（MoKa） = 0.71073 °A, μ= 0.089 mm^-1, F（000） = 2272, R = 0.0732 and wR = 0.1454. A total of 5264 unique reflections were collected, of which 2023 with I 〉 2σ（I） were observed. As expected, the molecule adopts trans configuration about the C=N double bond. The molecules in the crystal are linked through intermolecular hydrogen bonds and π-π interactions, forming a 3-D network.

关键词： Schiff base crystal structure hydrogen bonds π-π interactions

Simultaneous nitrogen and phosphor removal in an aerobic submerged membrane bioreactor

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Journal of Environmental Sciences 2006年第3期18卷 439-445页

作者： wang Zhi-wei wu Zhi-chao GU Guo-wei YU Guo-ping MA Lu-ming State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and Engineering Tongji University Shanghai200092 China.

Simultaneous nitrification and denitrification （SND） effect and phosphor removal were investigated in a one-staged aerobic submerged membrane bioreactor on pilot-scale with mixed liquor suspended solids （MLSS） 19--20 g/L. The effects of DO concentration, sludge floc size distribution on SND were studied. Test results suggested that SND was successfully performed in the membrane bioreactor （MBR） and about 70% total nitrogen removal efficiency was achieved when DO concentration was set to 0.2-- 0.3 mg/L. The main mechanisms governing SND were the suitable sludge floc size and the low DO concentration which was caused by low oxygen transfer rate with such a high MLSS concentration in the MBR. In the meantime, phosphor removal was also studied with polymer ferric sulfate （PFS） addition and 14 mg/L dosage of PFS was proper for the MBR to remove phosphor. PFS addition also benefited the MBR operation owing to its reduction of extracellular polymer substances （EPS） of mixed liquor.

关键词： membrane bioreactor (MBR) flat-sheet membrane simultaneous nitrification and denitrifiction (SND) phosphorremoval wastewater treatment oxygen transfer rate

A New Method in Determining Potential Region of Precipitation Enhancement Above Coastal Land

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Journal of Ocean University of China 2010年第4期9卷 309-316页

作者： wang Yilin wu wei Shandong Provincial Meteorological Institute Jinan 250031P.R.China

To ensure the effectiveness of the operation of artificial precipitation enhancement, a potential region for the operation should be determined in *** cloud microphysical measurements needed for the determination of the potential region of cloud seeding are not available before the operation of routine precipitation enhancement, a new method based on the growth process of ice crystal is put forward for determining the potential region using the numerical weather prediction model *** ice supersaturation, accumulated water vapor within minus temperature layer (≥9 mm), and upward water vapor transportation are adopted as criteria to determine the potential time, height and region of cloud seeding, and the real-time radar images are applied to make decisions on the seeding *** criteria and Doppler radar images are studied in a case of precipitation enhancement characterized by significant water vapor supply from the north part of a tropical cyclone in the northwest Pacific, which shows that the ocean plays a crucial role in the advection transportation of water vapor to the potential region of the coastal *** study presents a new method to determine the potential region of precipitation enhancement using macro-physical quantities under ice crystal growth *** method possesses a clear physical significance and can be readily applied with the required and easily predicted parameters.

关键词： precipitation enhancement criteria seeding potential region new method

Graph neural network-based scheduling for multi-UAV-enabled communications in D2D networks

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Digital Communications and Networks 2024年第1期10卷 45-52页

作者： Pei Li Lingyi wang wei wu Fuhui Zhou Baoyun wang Qihui wu Nanjing University of Posts and Telecommunications Nanjing210023China Nanjing University of Aeronautics and Astronautics Nanjing210016China

In this paper,we jointly design the power control and position dispatch for Multi-Unmanned Aerial Vehicle(UAV)-enabled communication in Device-to-Device(D2D)*** objective is to maximize the total transmission rate of Downlink Users(DUs).Meanwhile,the Quality of Service(QoS)of all D2D users must be *** comprehensively considered the interference among D2D communications and downlink *** original problem is strongly non-convex,which requires high computational complexity for traditional optimization *** to make matters worse,the results are not necessarily globally *** this paper,we propose a novel Graph Neural Networks(GNN)based approach that can map the considered system into a specific graph structure and achieve the optimal solution in a low complexity ***,we first construct a GNN-based model for the proposed network,in which the transmission links and interference links are formulated as vertexes and edges,***,by taking the channel state information and the coordinates of ground users as the inputs,as well as the location of UAVs and the transmission power of all transmitters as outputs,we obtain the mapping from inputs to outputs through training the parameters of *** results verified that the way to maximize the total transmission rate of DUs can be extracted effectively via the training on ***,it also shows that the performance of proposed GNN-based method is better than that of traditional means.

关键词： Unmanned aerial vehicle D2 Dcommunication Graph neural network Power control Position planning

Numerical Analysis on Charging Performance of the Macro-Encapsulating Combined Sensible-Latent Heat Storage System with Structural Parameters

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Journal of Thermal Science 2024年第3期33卷 1026-1036页

作者： wang wei PAN Zhenfei wang Jingfu wu Yuting MA Chongfang Key Laboratory of Enhanced Heat Transfer and Energy Conservation Ministry of EducationCollege of Energy and Power EngineeringBeijing University of TechnologyBeijing100124China Key Laboratory of Heat Transfer and Energy Conversion Beijing MunicipalityCollege of Energy and Power EngineeringBeijing University of TechnologyBeijing100124China

For combined sensible-latent heat storage system(CSLHS)(termed as the hybrid configuration),macro encapsulation can effectively solve the leakage problem of ***,due to the poor thermal conductivity of PCMs,the charging performance of the hybrid configuration slightly increases compared to the solid structure(with only sensible materials).Meanwhile,the natural convection in the PCMs zone could improve the charging ***,how to improve natural convection intensity is a key issue for the CSLHS by macro *** is found that adding fins can significantly enhance natural convection and accelerate the melting of *** this paper,we proposed the hybrid configuration with fins built-in by macro encapsulation,and analyzed its charging performance with different fin structural parameters in the PCM zone by CFD *** the case,the sensible heat storage material is high-temperature concrete and the PCM is a low-melting-point mixed molten *** analyzed the effects of fin number,fin length and fin thickness on the charging performance of the hybrid configuration *** the result,the charging performance increases with the fin number,but the increase rate gradually *** the fin number is 6,the charging performance increases by 20.18%compared to the situation without *** charging performance increases gradually with the fin *** with the hybrid configuration without fin,for each 10 mm increase in fin length,its charging performances increase by 4.09%,5.26%,7.02%,8.77%,11.70%,and 15.79%,*** from number and length of fins,the effect of thickness on the charging performance is very *** the fin thickness increased from 1 mm to 4 mm,the charging performance only increased by 2.3%.It indicates that the main reason for the improving the charging performance is to increase the natural convection intensity by dividing the PCM zone through *** results show that the charging performance

关键词： macro-encapsulation hybrid configuration natural convection structural parameter charging performance

Congenital left ventricular diverticulum, a rare chest fluoroscopy finding： a case report

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Chinese Medical Journal 2011年第5期124卷 783-786页

作者： wang Zhi-wei wu Hong-bing MAO Zhi-fu HU Xiao-ping Department of Cardiovascular Surgery Renmin Hospital of Wuhan University Wuhan Hubei 430060 China

Congenital left ventricular diverticulum is a very rare cardiac abnormality and it is not completely understood about its etiology, clinical manifestation, diagnosis, treatment and prognosis. This article presents a case of large congenital diverticulum of the left ventricle. The clinical manifestation included paroxysmal supraventricular tachycardia. The diagnosis was made by chest fluoroscopy observation and confirmed by 64-slice CT-angiography. The arrhythmia alleviated instead of antiarrhythmic drugs but by radiofrequency catheter ablation. Due to the rapid growth of the diverticulum, the patient underwent surgical resection finally. Owing to the fatal risks, clinicians should improve the understanding of this disease by deeply studving more cases, in order to standardize the treatment.

关键词： congenital left ventricular diverticulum chest fluoroscopy CT-angiography