检索结果-南通市图书馆

Non-isothermal Crystallization Kinetics of Polyamide 6/Diaminemodified MWNTs Nanocomposite

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2009年第2期25卷 145-150页

作者： Hong Meng Guoxin Sui Guangyou xie rui Yang Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

The non-isothermal crystallization kinetics of polyamide 6/diamine-modified multi-walled carbon nanotube （PA6/D-MWNT） nanocomposite was investigated by differential scanning calorimetry （DSC）. The modified Avrami equation, the Ozawa equation and the combined Avrami/Ozawa equation were employed to analyze the non-isothermal crystallization data. The crystallization activation energies were also evaluated by the Kissinger method. It was found that the combined Avrami/Ozawa equation could successfully describe the non-isothermal crystallization process. The results showed that D-MWNTs not only acted as effective heterogeneous nucleating agents for PA6 and noticeably increased the crystallization temperature of PA6, but also influenced the mechanism of nucleation and crystal growth of PA6 and then reduced the overall crystallization rate of the neat PA6 matrix. The crystallization activation energy for the nanocomposite sample was greater than that of the neat PA6, which indicated that the addition of D-MWNTs hindered the mobility of PA6 chain segments.

关键词： Non-isothermal crystallization kinetics Carbon nanotubes Polyamide 6

Minimizing Outage Probability Driven Wireless Backhaul Scheme in Heterogeneous Networks

在线全文

学校读者我要写书评

暂无评论

China Communications 2022年第6期19卷 248-262页

作者： Zhenxing Li rui xie Kai Luo Tao Jiang Research Center of 6G Mobile Communications School of Cyber Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Shanghai Electric Control Research Institute Shanghai 200092China

Heterogeneous networks(Het Nets)attracts a lot of attention due to its high capacity and large coverage for future communication ***,with the large-scale deployment of small cells,HetNets bears dramatically increasing backhaul,which leads to a decrease of the outage *** improve the outage performance of Het Nets,we propose a wireless backhaul scheme for a two-layer HetNets,which automatically switches the three basic modes of orthogonal multiple access(OMA),nonorthogonal multiple access(NOMA)and cooperative non-orthogonal multiple access(CNOMA).First,we analyze the backhaul capacity and outage performance of these three basic ***,we design the power allocation schemes based on minimizing outage probability for NOMA and *** the designed power allocation schemes,we propose a wireless backhaul scheme that switches the three modes according to the channel quality among different base stations(BSs).Moreover,the closed-form of the corresponding outage probability is *** with the three basic modes,the proposed wireless backhaul scheme can achieve the best outage performance and a higher backhaul ***,all the analytical results are validated by simulations.

关键词： Het Nets wireless backhaul NOMA outage probability backhaul capacity

Wavefronts of a Nonlocal State-dependent Time Delay Model

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2020年第1期36卷 77-92页

作者： rui Jun xie Rong YUAN Zhi Hui YANG School of Statistics and Applied Mathematics Anhui University of Finance and EconomicsBengbu 233030P.R.China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

This paper is concerned with the travelling wavefronts of a nonlocal dispersal cooperation model with harvesting and state-dependent delay,which is assumed to be an increasing function of the population density with lower and upper ***,state-dependent delay is introduced into a nonlocal reaction-diffusion *** conditions of Schauder's fixed point theorem are proved by constructing a reasonable set of functionsΓ(see Section 2)and a pair of upper-lower solutions,so the existence of traveling wavefronts is *** present study is continuation of a previous work that highlights the Laplacian diffusion.

关键词： Nonlocality state-dependent delay cooperation traveling wavefronts

Maximum Power Point Tracking Technology for PV Systems: Current Status and Perspectives

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2024年第8期121卷 2009-2022页

作者： Bo Yang rui xie Zhengxun Guo Faculty of Electric Power Engineering Kunming University of Science and TechnologyKunming650500China Intelligent Electric Power Grid Key Laboratory of Sichuan Province Chengdu610065China Foshan Graduate School of Innovation Northeastern UniversityFoshan528311China College of Information Science and Engineering Northeastern UniversityShenyang110819China

Maximum power point tracking(MPPT)technology plays a key role in improving the energy conversion efficiency of photovoltaic(PV)systems,especially when multiple local maximum power points(LMPPs)occur under partial shading conditions(PSC).It is necessary to modify the operating point efficiently and accurately with the help of MPPT technology to maximize the collected *** though a lot of research has been carried out and impressive progress achieved for MPPT technology,it still faces some challenges and ***,the mathematical model established for PV cells is not precise ***,the existing algorithms are often optimized for specific conditions and lack comprehensive adaptability to the actual operating ***,a single algorithm may not be able to give full play to its *** the end,the selection criteria for choosing the suitable MPPT algorithm/converter combination to achieve better performance in a given scenario is very ***,this paper systematically discusses the current research status and challenges faced by PV MPPT technology around the three aspects of MPPT models,algorithms,and hardware *** in-depth thinking and discussion,it also puts forward positive perspectives on future development,and five forward-looking solutions to improve the performance of PV systems MPPT are suggested.

关键词： PV systems MPPT partial shading condition DC-DC converter

Value of cystatin C in predicting atrial fibrillation recurrence after radiofrequency catheter ablation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2018年第12期15卷 725-731页

作者： Li-Li JIN Ling YOU rui-Qin xie Department of Cardiology the Second Hospital of Hebei Medical UniversityShijiazhuangChina

Backgroud Recent studies have demonstrated that cystatin C is a valuable risk marker for cardiovascular disease morbidity and ***,we hypothesized that the pre-ablation cystatin C level was associated with post-ablation atrial fibrillation(AF)*** 207 patients were enrolled and completed in this prospective observational *** with AF scheduled for receive radiofrequency catheter ablation(RFCA)therapy were screened for the *** ablation therapy,electrocardiogram,24 h holter monitor,transesophageal echocardiography,serum cystatin C,high-sensitivity C-reactive protein,creatinine levels,and routine blood examinations were *** ablation,patients were followed up every week for the first month,and then at 2,3,6,9,and 12 ***,patients came back to out-patient clinic every six months *** or 24 h holter monitor were repeated if the patient experienced palpitations or every six *** recurrence was defined as atrial flbrillation/atrial flutter or atrial tachycardia lasting≥30 seconds within three months after *** Compared to patients with no AF recurrence,patients with recurrence had longer AF history(P=0.007),more early recurrence(P=0.000),a larger left atrium(P=0.004),and higher pre-ablation cystatin C levels(P=0.000).Multivariate regression analysis revealed that cystatin C and left atria(LA)diameter were risk factors for AF *** adjusting for LA diameter,the risk of AF recurrence increased 30%with every milligram cystatin C elevation(95%CI:1.117-1.523).Conclusions Pre-ablation cystatin C levels were associated with AF recurrence after RFCA therapy,an optimal cut-off value of 1.190 mg/L(sensitivity=0.576;specificity=0.851).

关键词： Atrial fibrillation Catheter ablation Cystatin C Recurrence

Squeezing in the Thermal Jaynes-Cummings Model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1996年第6期13卷 432-435页

作者： xie rui-hua ZOU You-tao LIU Dun-huan Department of Physics Nanjing UniversityNanjing 210008 Department of Physics Wuhan UniversityWuhan 430072 National Laboratory of Solid State Microstructures Institute for Solid State Physics Center for Advanced Studies in Science and Technology of Microstructures Nanjing UniversityNanjing 210008

We have studied the influence of thermal photons on the symmetry between the field and atomic squeezing(SFAS)exposed in the resonant vacuum-field Jaynes-Cummings model with an initially coherent *** have shown that when the number of thermal photons(Nav)is less than 0.01,the SFAS is not sensitive to the presence of thermal photons;when Nav≥0.01,the broken SFAS can be seen;when Nav≥0.1,the squeezed atom cannot radiate a squeezed field any ***,we have discussed the possibility of detection of the boken symmetry in superconducting maser cavity.

关键词： symmetry Cummings resonant

Graphene-based membranes for molecular and ionic separations in aqueous environments

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第11期25卷 1598-1605页

作者： Zhuang Liu Wei Wang Xiaojie Ju rui xie Liangyin Chu School of Chemical Engineering Sichuan UniversityChengdu 610065China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu 610065China Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM) Nanjing 211816China

Graphene-based laminar materials open up to new applications for molecular and ionic separations in aqueous environments due to the atomic thickness, mechanical strength, chemical stability and other fantastic *** advances on controlling the structure and chemical functionality of graphene-based membranes can potentially lead to new classes of tools for desalination, dehydration, toxicant rejection, specific ionic separation and so on. The recent developments of graphene-based membranes prepared by using a concept to form interlayer space between graphene sheets and creating nanoscale or sub-nanoscale pores in a graphene lattice, together with their mass-transfer mechanisms and potential applications in aqueous environments are reviewed. A summary and outlook is further provided on the opportunities and challenges in this arising *** article is expected to address the intricate details of mass transport through two distinct graphene-based membranes in aqueous environment and to optimize the fabrication of graphene-based membranes as a fascinating separation system for a wide range of applications.

关键词： Graphene membranesTwo-dimensional materialsSeparationWater treatmentDesalinationion selectivity

Simulation of drop breakage in liquid–liquid system by coupling of CFD and PBM: Comparison of breakage kernels and effects of agitator configurations

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2019年第5期27卷 1001-1014页

作者： rui xie Jun Li Yang Jin Da Zou Ming Chen Department of Chemical Engineering Sichuan University

This work focuses on drop breakage for liquid-liquid system with an adoption of numerical simulation by using computational fluid dynamics and population balance model (PBM) coupled with two-fluid model (TFM). Two different breakage kernels based on identical breakage mechanism but different descriptions of breaking time are take n into account in this work. Eight cases corresp on ding to distinct configurations of agitator are carried out to validate numerical predictions, namely agitators with different porosity and hole diameters, respectively implemented in Cases 1 to 5 and Cases 6 to 8. The results are compared with experimental data for testing the applicability of both kernels. Simulations are implemented, in this work, with an approach of class method for the solution of population balance model by the special-purpose computational fluid dynamics solver Fluent 16.1 based on finite volume method, and the grids used for meshing the solution domain are accomplished in a commercial software Gambit 2.4.6. The effects of configurations of agitator corresponding to different parameters mentioned above on final Sauter mean diameter are equally concentrated in this work. Analysis of both kernels and comparisons with experimental results reveal that, the second kernel has more decent agreement with experiments, and the results of investigations on effects of agitator configurations show that the in fluences of these parameters on Sauter mean diameter are marginal, but appropriate porosity and hole diameter are actually able to decrease Sauter mean diameter. These outcomes allow us to draw general conclusions and help investigate performances of liquid-liquid system.

关键词： Stirred vessel Liquid-liquid system Computational fluid dynamics Population balance model Breakage kernel Agitator configuration

Micromechanical properties of poly(N-isopropylacrylamide)hydrogel microspheres determined using a simple method

在线全文

学校读者我要写书评

暂无评论

Particuology 2015年第2期13卷 164-172页

作者： Mei Yuan Xiaojie Ju rui xie Wei Wang Liangyin Chu School of Chemical Engineering Sichuan University

Temperature-responsive poly（N-isopropylacrylamide）（PNIPAM） hydrogel microspheres have attracted extensive attention because of their promising diverse biomedical applications. A quantitative understanding of the micromechanical properties of these microspheres is essential for their practical application. Here, we report a simple method for the characterization of the elastic properties of PNIPAM hydrogel microspheres. The results show that PNIPAM hydrogel microspheres exhibit elastic deformation and the obtained force-deformation experimental data fits the Hertz theory well. The moduli of elasticity of the PNIPAM hydrogel microspheres prepared under different conditions were systematically investigated in this work for the first time. The PN1PAM hydrogel microsphere composition significantly affects their micromechanical properties and their temperature sensitivity behavior. PNIPAM hydrogel microspheres with a larger equilibrium volume change have a lower modulus of elasticity. The modulus of elasticity of the PNIPAM hydrogel microspheres at body temperature （37 ℃, above the lower critical solution temperature （LCST） of PNIPAM） is much higher than that at room temperature （25 ℃, below the LCST of PNIPAM） because ofthermo-induced volume shrinkage and an increase in stiffness. These results provide valuable guidance for the design of smart materials for practical biomedical applications. Moreover, the simple microcompression method presented here also provides a versatile way to investigate the micromechanical properties of microscopic biomedical materials.

关键词： Poly(N-isopropylacrylamide) Microspheres Micromechanical properties Modulus of elasticity Temperature-responsive volume change Lower critical solution temperature