检索结果-南通市图书馆

Continuous Method Development and Numerical Study of HHV Water Gas Production by Pulverized Coal

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第5期20卷 474-480页

作者： ren Ling Xia Dehong zhang Yan Department of Thermal Science and Energy Engineering School of Mechanical Engineering University of Science andTechnology Beijing China

In energy industries, it is always of difficulty to produce high heat value（HHV） gas continuously using pulverized coal. In this paper, a new type furnace for partitioned alternative gasification using pulverized coal is developed, in which the oxidation and reduction reaction occur alternatively with the dropping of pulverized coal and finally HHV gas could be continuously obtained at the reduction zone exit and low heat value（LHV） gas at the oxidation zone exit. Furthermore, the gasification characteristics and their factors in furnace are numerically simulated under two dimensional model with a self-coded program, based on heat, mass and energy transfer as well as reaction principles. It is found that the producing rate of HHV gas is 1.10Nm3/kg with heat value of ll.72MJ/Nm3, how- ever, that of LHV gas is 2.58Nm3/kg with heat value of 5.30MJ/Nm3, and the coal gas efficiency is 81.16% under optimized conditions.

关键词： pulverized coal gasification continuous method high heat value water gas

The 18.3% Silicon Solar Cells with Nano-Structured Surface and Rear Emitter

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2017年第2期34卷 122-125页

作者： Jun-Na zhang Lei Wang Zhun Dai Xun Tang you-Bo Liu De-ren Yang State Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027

A nano-structured surface is formed on the pyramid structure of n-type silicon solar cells by size-controlled silver nano-particle assisted etching. Such a nano-structure creates a front average weighted reflectance of less than 2.5% in the 300-1200nm range due to the broadband reflection suppression. The sodium hydroxide is used to obtain the low-area surface by post-etching the nano-structure, thus the severe carrier recombination associated with the nano-structured surface could be reduced. After emitter forming, screen printing and firing by means of the industrial fabrication protocol, an 18.3%-efficient nano-structured silicon solar cell with rear emitter is fabricated. The process of fabricating the solar cells matches well with industrial manufacture and shows promising prospects.

关键词： The 18.3 Silicon Solar Cells with Nano-Structured Surface and Rear Emitter

Multi-objective optimization for task offloading based on network calculus in fog environments

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2022年第5期8卷 825-833页

作者： Qian ren Kui Liu Lianming zhang College of Information Science and Engineering Hunan Normal UniversityChangsha410081China

With the widespread application of wireless communication technology and continuous improvements to Internet of Things(IoT)technology,fog computing architecture composed of edge,fog,and cloud layers have become a research *** architecture uses Fog Nodes(FNs)close to users to implement certain cloud functions while compensating for cloud ***,because of the limited computing and storage capabilities of a single FN,it is necessary to offload tasks to multiple cooperating FNs for task *** effectively and quickly realize task offloading,we use network calculus theory to establish an overall performance model for task offloading in a fog computing environment and propose a Globally Optimal Multi-objective Optimization algorithm for Task Offloading(GOMOTO)based on the performance *** results show that the proposed model and algorithm can effectively reduce the total delay and total energy consumption of the system and improve the network Quality of Service(QoS).

关键词： Fog computing Task offloading Multi-objective optimization Network calculus

A Humanoid Method for Extracting Abnormal Engine Sounds from Engine Acoustics Based on Adaptive Volterra Filter

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2012年第2期9卷 262-270页

作者： Li zhang Luquan ren Yaowu Shi Zhuhai College Jilin University Zhuhai 519041 P. R. China Key Laboratory of Bionic Engineering （Ministry of Education China） Jilin University Changchun 130022 P. R. China Communication College Jilin University Changchun 130022 P. R. China

The improvement of SNR （Signal-to-Noise Ratio） of abnormal engine sounds is of great help in improving the accuracy of engine fault diagnosis. By imitating the way that human technicians use to distinguish abnormal engine sounds from engine acoustics, a humanoid abnormal sound extracting method is proposed. By implementing adaptive Volterra filter in the canonical Adaptive Noise Cancellation （ANC） system, the proposed method is capable of tracing the engine baseline sound which exhibits an intrinsic nonlinear dynamics. Besides, by introducing a template noise tailored from the records of engine baseline sound and taking it as virtual input of the adaptive Volterra filter, the priori knowledge of engine baseline sound, such as inherent correlation, periodicity or phase information, and stochastic factors, is taken into consideration. The hybrid simulations prove that the proposed method is functional. Since the method proposed is essentially a single-sensor based ANC, hopefully, it may become an effective way to extricate the dilemma that canonical dual-sensor based ANC encounters when it is used in extracting fault-featured signals from observed signals.

关键词： bionic signal processing engine noise diagnosis adaptive Volterra filter adaptive noise cancellation

Molecular simulation of oligomer inhibitors for calcite scale

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

Particuology 2012年第3期10卷 266-275页

作者： Qiuyu zhang Hua ren Wenwen Wang Junping zhang Hepeng zhang School of Science Northwestern Polytechnical UniversityXi'an 710072China

Molecular simulation was performed to study the interaction between CaCO3 crystal and several oligomer inhibitors, by using the equilibrium morphology method to calculate the growth morphology of CaCO3 without inhibitors. The calculated morphology agreed well with SEM photographs. Then, a double-layer model was built to investigate the interaction between calcite crystal and oligomer inhibitors containing maleic anhydride （MA） and acrylic acid （AA）. Interaction energy per gram of an oligomer inhibitor was introduced as a scale of inhibition efficiency of different monomers. The results indicated that, for calcite scale inhibition, acrylamide （AM） and vinyl phosphonic acid （VPA） were the most efficient monomers, while allylsulfonic acid （AS） was the poorest. Increasing proportion of AM in dimer inhibitor molecule would improve the inhibition efficiency of MA, though, for a trimer, such as MA-AA-AM, certain sequence of monomers in the inhibitor molecule was necessary besides higher proportion of AM.

关键词： Molecular simulationCrystal morphology Interaction energy Scale inhibitorScale inhibition efficiency

Structural Scheme Optimization Design for the Stationary Platen of a Precision Plastic Injection Molding Machine

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2014年第4期27卷 714-721页

作者： ren Bin zhang Shuyou TAN Jianrong State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Department of Civil and Architectural Engineering City University of Hong Kong

The current development of precision plastic injection molding machines mainly focuses on how to save material and improve precision, but the two aims contradict each other. For a clamp unit, clamping precision improving depends on the design quality of the stationary platen. Compared with the parametric design of stationary platen, structural scheme design could obtain the optimization model with double objectives and multi-constraints. In this paper, a SE-160 precision plastic injection molding machine with 1600 kN clamping force is selected as the subject in the case study. During the motion of mold closing and opening, the stationary platen of SE-160 is subjected to a cyclic loading, which would cause the fatigue rupture of the tie bars in periodically long term operations. In order to reduce the deflection of the stationary platen, the FEA method is introduced to optimize the structure of the stationary platen. Firstly, an optimal topology model is established by variable density method. Then, structural topology optimizations of the stationary platen are done with the removable material from 50%, 60% to 70%. Secondly, the other two recommended optimization schemes are given and compared with the original structure. The result of performances comparison shows that the scheme II of the platen is the best one. By choosing the best alternative, the volume and the local maximal stress of the platen could be decreased, corresponding to cost-saving material and better mechanical properties. This paper proposes a structural optimization design scheme, which can save the material as well as improve the clamping precision of the precision plastic injection molding machine.

关键词： finite element analysis injection molding machine stationary platen topology optimization

Particle Erosion Resistance of Bionic Samples Inspired from Skin Structure of Desert Lizard, Laudakin stoliczkana

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2012年第4期9卷 465-469页

作者： He Huang Yan zhang Luquan ren Key Laboratory of Bionic Engineering (Ministry of Education China) Jilin University Changchun 130022 P. R. China College of Mechanical Engineering Tianjin University of Science and Technology Tianjin 300222 P. R. China

In order to improve the particle erosion resistance of engineering surfaces, this paper proposed a bionic sample which is inspired from the skin structure of desert lizard, Laudakin stoliczkana. The bionic sample consists of a hard shell （aluminum） and a soft core （silicone rubber） which form a two-layer composite structure. The sand blast tests indicated that the bionic sample has better particle erosion resistance. In steady erosion period, the weight loss per unit time of the bionic sample is about 10% smaller than the contrast sample. The anti-erosion mechanism of the bionic sample was studied by single particle impact test. The results show that, after the impact, the kinetic energy of the particle is reduced by 56.5% on the bionic sample which is higher than that on the contrast sample （31.2%）. That means the bionic sample can partly convert the kinetic energy of the particle into the deformation energy of the silicone rubber layer, thus the erosion is reduced.

关键词： bionics particle erosion sand blast desert lizard

Analogue Black Holes in Reactive Molecules

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 Physics Letters 2023年第5期40卷 1-5页

作者： ren zhang Chenwei Lv Qi Zhou School of Physics Xi’an Jiaotong UniversityXi’an 710049China Department of Physics and Astronomy Purdue UniversityWest LafayetteIN47907USA Purdue Quantum Science and Engineering Institute Purdue UniversityWest LafayetteIN47907USA

We show that reactive molecules with a unit probability of reaction naturally provide a simulator of some intriguing black hole *** unit reaction at the short distance acts as an event horizon and delivers a one-way traffic for matter waves passing through the potential barrier when two molecules interact by high partialwave scatterings or dipole-dipole *** particular,the scattering rate as a function of the incident energy exhibits a thermal-like distribution near the maximum of the interaction energy in the same manner as a scalar field scatters with the potential barrier outside the event horizon of a black *** a thermal-like scattering can be extracted from the temperature-dependent two-body loss rate measured in experiments on KRb and other molecules.

关键词： horizon outside passing

UV disinfection of Staphylococcus aureus in ballast water: Effect of growth phase on the disinfection kinetics and the mechanization at molecular level

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2016年第2期59卷 330-336页

作者： ren ZhiJun zhang Lin SHI Yue College of Aerospace and Civil Engineering Harbin Engineering University College of Power and Energy Engineering Harbin Engineering University

This work aimed to study the inactivate kinetics of Staphylococcus aureus （S. aureus） in artificial seawater by ultraviolet radi- ation, establish relationships between model parameters and growth phases, and explain the mechanization of UV disinfection by molecular biological detection. Investigations were carried out for the validation of Chick-Watson, Collins-Selleck, Horn and Biphasic models when S. aureus was in stationary phase （t=14 h）. The results showed that the Biphasic kinetic model＇s R2 turned out to be the highest one （R2=0.9892） and RMSE was less than 0.5 （RMSE =0.2699）. The Biphasic kinetic model was better fit for ultraviolet disinfection than the other three models under the circumstance of this experiment and chosen to fit the ultraviolet disinfection curves for microorganisms at three growth phases. The sensitivity of microorganisms under ultraviolet radiation was in the following order： in exponential phase 〉 in stationary phase 〉 in lag phase by comparing the indexes of the Biphasic model （kl and x）. Besides, agarose gel electrophoresis was used in order to directly assess the damage to DNA of mi- croorganisms that were exposed to the different dose of UV irradiation. The results revealed that DNA damage caused by UV radiation was an important reason for the microorganism inactivation and as the UV dose increased, there was greater damage caused in DNA.

关键词： UV disinfection kinetics growth phases Biphasic models DNA damage