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Flow Field Characteristics for Parachute-projectile System

Chinese Journal of Mechanical Engineering 2011年第5期24卷 813-819页

作者： ZHU yong liU li wang Zhengping School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China

In the current research for parachute flow field nowadays,the size of parachutes in previous research are so large compared with their carriers that the effects of the carriers wake flow to parachute are always *** from such large parachutes,the parachute size in this paper is on the same magnitude with the carrier,thus,the carrier can obviously affect the parachute flow *** this paper,flow field characteristics of small parachute for projectile decelerating are researched through two approaches,namely,computational fluid dynamics（CFD） simulation and wind tunnel *** parachutes with various sizes are chosen for ***,the CFD simulation of flow field around these parachutes is carried out,and then the CFD simulation of parachute-projectile systems is *** to the simulation results,the phenomenon is observed that in the simulations of parachutes there are two vortex-rings at the wind shadow of parachutes,however,in the second simulations of parachute-projectile systems,two additional vortex-rings emerge inside the *** to these two inner vortex-rings,the pressure inside parachutes *** a result,the drag of parachute in simulation of parachute-projectile systems is about 20% smaller compared with the prior *** order to verify the numerical results of CFD simulations,wind tunnel tests are *** terms of the data of the wind tunnel tests,the CFD simulation for flow field characteristics is reasonable and *** results of both CFD simulation and wind tunnel tests demonstrated the influence of projectile wake flow to parachute drag can not be neglected if the parachute size is on the same magnitude with *** influence to parachute drag from the ratio of projectile diameter to parachute diameter is also analyzed both in CFD simulations and wind tunnel *** approach combined CFD simulation and wind tunnel tests proposed can be used to guide the design of such parachute whose si

关键词： parachute projectile flow field computational fluid dynamics(CFD) wind tunnel test

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THEORETICAL ESTIMATION OF GROUNDWATER DISCHARGE AND ASSOCIATED NUTRIENT LOADING TO A LAKE WITH GENTLE SLOPE BOTTOM

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Journal of Hydrodynamics 2007年第1期19卷 30-35页

作者： li yong wang Chao College of Environmental Science and Engineering Hohai University Nanjing 210098 China

A simple estimation model of groundwater discharge and nutrient flux from nearshore unconfined aquifer to lake was studied. It was supposed that the aquifer was permeable isotropic homogeneously and its thickness approximated to the depth of lake. Distribution of the hydraulic gradient and the specific discharge along the transect of the discharge zone were discussed. Results show that the groundwater discharge patterns vary with the inclination angle of lakeshore bottom. For a shallow lake with gentle slope bottom, the rate of discharge of groundwater to lake is not constant across a discharge zone, but the discharge is concentrated in a narrow portion of the littoral zone where the Dupuit assumptions are invalid. The width of the discharge zone is correlative with aquifer thickness and slope of the lake bottom. The distribution functions of hydraulic gradient and groundwater discharge rates accord exponentially with offshore distance.

关键词： shallow lake unconfined aquifer groundwaterdischarge nutrient loading

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Microstructure and embrittlement of the fine-grained heat-affected zone of ASTM4130 steel

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International Journal of Minerals,Metallurgy and Materials 2011年第4期18卷 419-423页

作者： li-ying li yong wang Tao Han Chao-wen li College of Mechanical and Electronic Engineering China University of Petroleum Dongying 257061 China

The mechanical properties and microstructure features of the fine-grained heat-affected zone（FGHAZ） of ASTM4130 steel was investigated by optical microscope（OM）,scanning electron microscope（SEM）,transmission electron microscope（TEM）,and welding thermal simulation *** is found that serious embrittlement occurs in the FGHAZ with an 81.37% decrease of toughness,compared with that of the base *** analysis reveals that the FGHAZ is mainly composed of acicular,equiaxed ferrite,granular ferrite,martensite,and martensite-austenite（M-A） *** FGHAZ embrittlement is mainly induced by granular ferrite because of carbides located at its boundaries and ***,the existence of martensite and M-A constituent,which distribute in a discontinuous network,is also detrimental to the mechanical properties.

关键词： ASTM4130 steel welding heat-affected zone microstructure embrittlement

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Rational construction of densely packed Si/MXene composite microspheres enables favorable sodium storage

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Rare Metals 2022年第5期41卷 1626-1636页

作者： Hui-Qi wang Ya-Xin Zhao li Gou li-yong wang Mei wang Ying li Sheng-liang Hu School of Energy and Power Engineering North University of ChinaTaiyuan 030051China School of Materials Science and Engineering North University of ChinaTaiyuan 030051China

The fast and reversible sodiation/desodiation of anode materials remains an indelible yet fascinating ***, a class of the densely packed Si/MXene composite microspheres is constructed and prepared, taking advantages of the synergistic effects of the activated Si nanoparticles and conductive flower-like MXene microspheres with ample ion-diffusion pathways. Consequently,the intrinsic MXene nanosheets with intelligently regulated interlayer spacing can accommodate the volume change induced strain during cycling, and the strong interaction between the Si and MXene matrix greatly contributes to the robust structural stability. As expected, the Si/MXene composite architecture exhibits boosted sodium storage performance, in terms of an inspiring reversible capacity of 751 mAh·g^(-1)at 0.1 A·g^(-1), remarkable long-term cycling stability of 376 mAh·g^(-1)at 0.1 A·g^(-1) over 500 cycles, and outstanding rate capability(after one consecutive current density changing from 0.1 to 2.0 A·g^(-1), a large capacity of 275 mAh·g^(-1) is regained after suddenly returning the initial current density back to 0.1 A·g^(-1) and in the subsequent 200 cycles this composite architecture anode still delivers a capacity of 332 mAh·g^(-1)). The kinetics analysis indicates superior pseudocapacitive property, high electronic conductivity, and favorable sodium-ion adsorption and diffusion capability,confirming fast sodium storage performance. Impressively, ex-situ X-ray diffraction and selected area electron diffraction characterizations corroborate the formation of NaSi;as the main sodiation products during the reversible evolutions of cycled proceeding with sodium-ion insertion. This work sheds light on the elaborate design of silicon-based nanostructured anodes towards advanced high-performance sodium-ion batteries.

关键词： Silicon MXene Composite microspheres Sodium-ion batteries Flower-like anode Efficient sodiumion storage

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A NEW CONSTRAINTS IDENTIFICATION TECHNIQUE-BASED QP-FREE ALGORITHM FOR THE SOLUTION OF INEQUAliTY CONSTRAINED MINIMIZATION PROBLEMS

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Journal of Computational Mathematics 2006年第5期24卷 591-608页

作者： Chang-yin Zhou Guo-ping He yong-li wang Department of Mathematics Shanghai Jiao Tong University Shanghai 200240 China College of Information Science and Engineering Shandong University of Science and Technology Qingdao 266510 China College of Information Science and Engineering Shandong University of Science and Technology Qingdao 266510 China

In this paper, we propose a feasible QP-free method for solving nonlinear inequality constrained optimization problems. A new working set is proposed to estimate the active set. Specially, to determine the working set, the new method makes use of the multiplier information from the previous iteration, eliminating the need to compute a multiplier function. At each iteration, two or three reduced symmetric systems of linear equations with a common coefficient matrix involving only constraints in the working set are solved, and when the iterate is sufficiently close to a KKT point, only two of them are involved. Moreover, the new algorithm is proved to be globally convergent to a KKT point under mild conditions. Without assuming the strict complementarity, the convergence rate is superlinear under a condition weaker than the strong second-order sufficiency condition. Numerical experiments illustrate the efficiency of the algorithm.

关键词： QP-free method Optimization Global convergence Superlinear convergence,Constraints identification technique.

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Syntheses and Biological Activities of Ethyl N-Hydroxy-N-(substituted)phenyloxamates as KARI Inhibitors

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Chemical Research in Chinese Universities 2007年第3期23卷 280-283页

作者： wang Bao-lei li Zheng-ming li yong-hong wang Su-hua Elemento-Organic Chemistry Institute State-Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 P. R. China

Nine ethyl N-hydroxy-N-（substituted） phenyloxamates （2a-2i）, based on the structure of the KARI inhibitor IpOHA, were synthesized. Their structures were established on the bases of 1^H NMR, IR, ESI-MS and elemental analyses. Among the nine compounds, four show in vitro inhibitory activity on rice KARI, with 2c and 2g[ Ki values of （35.2±4.9） and （49.4 ±6. 3） μmol/L] having similar activity to the precursor of IpOHA（A, Ki =34. 1±6. 7 μmol/L）. The results will be helpful to further molecular design of more potent KARI inhibitors.

关键词： KARI inhibitor IpOHA Phenyloxamate Synthesis Biological activity

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Synthesis, Crystal Structure and Insecticidal Activities of Novel Neonicotinoid Derivatives

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Chemical Research in Chinese Universities 2010年第3期26卷 380-383页

作者： ZHAO Yu wang Gang li yong-qiang wang Su-hua li Zheng-ming State Key Laboratory of Elemento-Organic Chemistry Research Institute of Elemento-Organic Chemistry National Pesticide Engineering Research Center（Tianjin） Nankai University Tianjin 300071 P. R. China

Ten new N-oxalyl derivatives of neonicotinoid compound were designed and synthesized. Their structures were confirmed by ^1H NMR spectra, elemental analysis and X-ray diffraction. The preliminary insecticidal activities of the new compounds were evaluated. The results of bioassays indicate that the title Compounds exhibit moderate insecticidal activities. Surprisingly, the insecticidal activity of compound 7b against bean aphids at 200 mg/kg is 100%, which is comoarable to that of the commercialized imidacloprid.

关键词： Neonicotinoid N-Oxalyl derivative Insecticidal activity Bean aphid Imidacloprid

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Cardioprotective effect of liposomal prostaglandin E1 on a porcine model of myocardial infarction reperfusion no-reflow

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第8期12卷 638-643页

作者： Jia-hui li Peng YANG Ai-li li yong wang Yuan-nan KE Xian-lun li Department of Cardiology China-Japan Friendship Hospital Beijing 100029 China

Objective： To evaluate whether liposomal prostaglandin E1 （lipo-PGE1） can decrease reperfusion no-reflow in a catheter-based porcine model of acute myocardial infarction （AMI）. Methods： Twenty-two male Chinese mini-swines were randomized into three groups： six in a sham-operation group, and eight each in the control and lipo-PGE1 groups. The distal part of the left anterior descending coronary artery （LAD） in the latter two groups was completely occluded for 2 h, and then reperfused for 3 h. lipo-PGE1 （1 pg/kg） was injected 10 min before LAD occlusion until reperfusion for 1 h in the lipo-PGE1 group. Hemodynamic data and proinflammatory cytokines were examined before AMI, 2 h after occlusion, and 1, 2, and 3 h after reperfusion. Myocardial contrast echocardiography （MCE） and double staining were performed to evaluate the myocardial no-reflow area （NRA）. Results： Left ventricular systolic pressure and end-diastolic pressure significantly improved in the lipo-PGE1 group after reperfusion compared with the control group and also 2 h after AMI （P〈0.05 for both）. MCE and double staining both showed that lipo-PGE1 decreased reperfusion NRA after AMI （P〈0.05, P〈0.01）. lipo-PGE1 decreased serum interleukin-6 （IL-6） and tumor necrosis factor-a （TNF-a） after myocardial infarction reperfusion （P〈0.05 for both）. Conclusions： lipo-PGE1 is cardioprotective in our porcine model of myocardial infarction reperfusion no-reflow, decreasing NRA and attenuating the inflammatory response.

关键词： liposomal prostaglandin E1 (lipo-PGE1) Reperfusion no-reflow Myocardial infarction

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Anti-self-discharge ultrathin all-inorganic electrochromic asymmetric supercapacitors enabling intelligent and effective energy storage

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Rare Metals 2023年第9期42卷 2957-2971页

作者： Lei liu Chen liu Meng-Ying wang Bin li Ke wang Xiang-Qian Fan li-yong wang Hui-Qi wang Sheng-liang Hu Xun-Gang Diao School of Energy and Power Engineering North University of ChinaTaiyuan030051China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of ScienceShenyang110016China School of Energy and Power Engineering Beihang UniversityBeijing100191China Research Center for Photovoltaics Shanghai Institute of Space Power-SourcesShanghai200245China National Key Laboratory of Electromagnetic Space Security Tianjin300308China

Electrochromic asymmetric supercapacitors(EASs), incorporating electrochromic and energy storage into one platform, are extremely desirable for next-generation civilian portable and smart electronic devices. However, the crucial challenge of their fast self-discharge rate is often overlooked, although it plays an important role in practical application. Unfortunately, very limited research on EAS has focused on this critical problem. Here, an ultrathin all-inorganic EAS with excellent anti-self-discharge performance and superior electrochromic behavior is designed and manufactured by introducing a thin nanofunctional layer at the electrode/electrolyte interface. The prototype all-inorganic EAS exhibited a wide working voltage of 2.2 V, a high energy/power density(81.2mWh·cm^(-3)/0.688 W·cm^(-3)and 30.6 mWh·cm^(-3)/11.02W·cm^(-3)), along with outstanding electrochemical and electrochromic performance even at high ***, the introduced Ta2O5layer can efficiently prohibit the redistribution and diffusion of the movable ions at the fully charged state, endowing the all-inorganic EAS with a tardy self-discharge rate of 12.6 mV·g^(-1),which is an extremely low value when compared with previous reported research. Significantly, the ultrathin allinorganic EASs could also well maintain a slow self-discharge rate and their original electrochemical characteristics under various environmental temperatures. We envision that the novel strategy of electrode/electrolyte interface engineering can effectively deal with the severe self-discharge challenge of EAS, and provide more opportunities for their practical applications.

关键词： Anti-self-discharge Electrochromic Asymmetric supercapacitors(ASCs) All-inorganic Interface

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Solidification microstructure of high borated stainless steels with rare earth and titanium additions

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Rare Metals 2020年第12期39卷 1483-1491页

作者： yong-wang li Hai-Tao liu Zhao-Jie wang Zhi-Heng Zhang Wei-Ting li Hui-Ying Shen Xiao-Ming Zhang Guo-Dong wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

To study the effects of rare earth(RE)and Ti on the solidification micros true ture of high borated stainless steels,1.6 wt%B stainless steel doped with RE and2.1 wt%B stainless steel doped with Ti were prepared by ingot casting,*** solidification microstructure of researched steels was characterized in *** modification mechanism was clarified based on the heterogeneous nucleation theory and the thermodynamic *** solidification microstructure of 1.6 wt%B and 2.1 wt%B stainless steels was characterized by the continuous and network-like eutectic borides around the matrix *** was found that the fine RE compounds could act as the heterogeneous nuclei for both borides and austenite during ***,the eutectic borides were more dispersed in the modified ***,lots of fine‘eutectic cells’were formed in the matrix *** a result of the preferential formation of TiB2 during solidification,the amount of the eutectic borides in the steel modified with Ti was significantly ***,the continuity of the eutectic borides network was *** a word,the present work provides a promising method to modify the solidification microstructure for high borated stainless steels.

关键词： Borated stainless steels Solidification microstructure Rare earth Titanium

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