检索结果-南通市图书馆

Optimization of thermal processing parameters of Ti555211 alloy using processing maps based on Murty criterion

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

Rare Metals 2016年第2期35卷 154-161页

作者： Zhen An jin-shan Li Yong Feng State Key Laboratory of Solidification Processing Northwestern Polytechnical University

Isothermal compression testing of Ti555211 titanium alloys was carried out at deformation temperatures from 750 to 950 °C in 50 °C intervals with a strain rate of0.001-1.000 s^（-1）. The high-temperature deformation behavior of the Ti555211 alloy was characterized by analysis of stress-strain behavior, kinetics and processing maps. A constitutive equation was formulated to describe the flow stress as a function of deformation temperature and strain rate, and the calculated apparent activation energies are found to be 454.50 and 207.52 k J mol^（-1）in the a b-phase and b-phase regions, respectively. A processing map based on the Murty instability criterion was developed at a strain of 0.7. The maps exhibit two domains of peak efficiency from 750 to 950 °C. A ＊60 % peak efficiency occurs at 800-850 °C/0.001-0.010 s^（-1）. The other peak efficiency of ＊60 % occurs at C950 °C/0.001-0.010 s^（-1）, which can be considered to be the optimum condition for high-temperature working of this ***, at strain rates of higher than 1.000 s^（-1）and deformation temperatures of 750 and 950 °C, clear process flow lines and bands of flow localization occur in the hightemperature deformation process, which should be avoided in Ti555211 alloy hot processing. The mechanism in stability domain and instability domain was also discussed.

关键词： Ti555211 titanium alloy High temperature Deformation behavior Processing maps

Microstructure evolution of a new near-β titanium alloy:Ti555211 during high-temperature deformation

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第11期34卷 757-763页

作者： Zhen An jin-shan Li Yong Feng State Key Laboratory of Solidification Processing Northwestern Polytechnical University

The isothermal compression testing of Ti555211 titanium alloys was carried out at deformation temperatures from 750 to 950 ℃ in 50 ℃ intervals,with strain rate of 0.001-1.000 s-1and height reduction of 20%-60%.The effect of processing parameters（deformation temperature,strain rate and deformation degree） on the microstructure evolution and the microstructure variables was *** results show that the content of primary α phase decreases with the increase in deformation *** effect of strain rate on microstructure variables of isothermally compressed Ti555211 alloy is mainly dependent on the deformation *** fine second α phase partly transforms to β phase due to the deformation heat effect at the high strain rate,α phase becomes globular with temperature increasing and strain rate *** contrast,α phase is refined with temperature decreasing and strain rate *** deformation degree has a little influence on the grain size and the morphology of primary α phase,but the effect of deformation degree on the morphology of second α phase is *** larger deformation degree is in favor of the globularization of lamellar α structure.

关键词： Titanium alloy High-temperature deformation Micros

Heterogeneous coverage method with multiple unmanned aerial vehicle assisted sink nodes

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2019年第4期25卷 395-400页

作者： jin shan jin Zhigang Electrical Automation and Information Engineering CollegeTianjin UniversityTianjin 300072P.R.China Fire and Rescue Department Bureau of Emergency Management of TianjinTianjin 300090P.R.China

A heterogeneous coverage method with multiple unmanned aerial vehicle assisted sink nodes(MUAVSs)for multi-objective optimization problem(MOP)is proposed,which is based on quantum wolf pack evolution algorithm(QWPEA)and power law entropy(PLE)*** method is composed of preset move and autonomous coordination stages for satisfying non-repeated coverage,connectedness,and energy balance of sink layer critical requirements,which is actualized to cover sensors layer in large-scale outside wireless sensor networks(WSNs).Simulation results show that the performance of the proposed technique is better than the existing related coverage technique.

关键词： wireless sensor network(WSN) coverage multi-unmanned aerial vehicle(MUAV) heterogeneous sink node quantum wolf pack evolution algorithm(QWPEA) power law entropy(PLE)

An Empirical Formula for Suspended Sediment Delivery Ratio of Main River after Confluence of Debris flow

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2013年第2期10卷 326-336页

作者： ZHANG jin-shan CUI Peng Key Laboratory of Mountain Hazard and Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences

In order to calculate the suspended sediment discharge of the flood debris flows into the main river,a small scale flume test was designed to simulate the process of confluence of Jiangjia Ravine and Xiangjiang River in Yunnan province,*** test observation and data analysis,suspended sediment discharge of Debris flow after its entry into the main river was found to have a close relation with the bulk density,the confluence angle of the Debris flow and the main river,the ratio between per unit width discharge of Debris flow and main *** on the measured and simulated results,and statistical analysis,an empirical formula was proposed for the suspended SDR(Sediment Delivery Ratio) of the main river after the confluence of Debris *** with the observed results of Debris flow in 2009,the error between the data calculated by the empirical formula and the monitored data is only about 10%.

关键词： Debris flow Confluence SuspendedSediment Delivery Ratio (SDR) Jiangjia Ravine Xiaojiang River Model

Prediction and Control of Thermal Scratch Defect on Surface of Strip in Tandem Cold Rolling

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2015年第2期22卷 106-114页

作者： jin-shan CHEN Chang-sheng LI State Key Laboratory of Rolling and Automation Northeastern University

The thermal scratch significantly influences the surface quality of the cold rolled stainless steel strip. In or der to establish a precise mathematical model of oil film thickness in deformation zone, the lubrication in cold rolling process of B443NT stainless steel strip was studied in the laboratory. According to the principle of statistics, a math- ematical model of critical oil film thickness in deformation zone for thermal scratch was built, with fitting and regres- sion analytical method, and then based on temperature comparison method, the criterion for deciding thermal scratch defect was put forward. Storing and calling data through SQI. Server 2005, a software on thermal scratch control was developed in the Microsoft Visual Studio 2008 environment by MFC technique for stainless steel in tandem cold roll- ing, and then it was used into the practical production. Statistical results demonstrated that the hit rate of thermal scratch arrives at 91.47%, the occurrence rate of thermal scratch is decreased by 87.81%, and rolling speed is in- creased by 7.3%. The developed software is of significance to the control of products quality of stainless steel strips, and the analysis and solution to the problem of thermal scratch defects in tandem cold rolling.

关键词： thermal serateh software design tandem cold rolling temperature stainless steel

Developing a quantitative index system for assessing sustainable forestry management in Heilongjiang Province,China： a case study

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2016年第3期27卷 611-619页

作者： jin-shan Yang Feng-you Wang College of Forestry Northeast Forestry UniversityHarbin 150040 China Guizhou University for Nationalities Guiyang 550025 China Department of Forestry Forest Resources Management Service Harbin 150090 Heilongjiang Province China

In this study, we developed a comprehensive index system for forestry sustainability of Heilongjiang Province, which includes forest resources sustainability,sustainable economic development, sustainable social development and sustainable advancement in science and technology. Based on this system and the regional forest development, we further evaluated the sustainability of Heilongjiang Province for year 2008-2013. The results show that even though the regional forestry has been preliminarily on the track of sustainable development, it is fragile. Four indicators, e.g. soil and water retention rate,forest stand growth（per unit area）, the proportion of national investment and the annual carbon sequestration have important impact on the sustainability, with a weight of 39.0 % in all the indicators. We also analyzed the factors hindering the sustainable development. It turns out that soil and water retention rate, forest stand growth（per unit area）,the proportion of science and technology funds, per capita GDP and the proportion of the tertiary industry production are the main factors hindering regional sustainable development, which accounts for 50.94 % of the total obstacle degrees in the system. At last, we discussed how to promote the regional sustainable development from the perspectives of forest resources sustainability, economic development sustainability, society development sustainability and the sustainable advancement of science and technology.

关键词： Regional forestry Sustainable development Index system Empirical analysis

Fiber Bending Flexibility Evaluation by Worm-like Chain Model

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2022年第5期40卷 526-531页

作者： Chao jin Hui Yu Chun-Fang Wu Hai-Bo Zhao shan-shan jin Yu-Liang Yang Hong-Dong Zhang Institute for Preservation and Conservation of Chinese Ancient Books Fudan UniversityShanghai 200433China Statekey laboratory of Molecular Engineering of polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China

A new method for characterizing fiber bending flexibility was developed by worm-like chain model proposed by Kratky-Porod,[1]which was first introduced to the pulp and paper field in this *** the three types of pulps,the experimental results were compared with the KP chain model,and the resulting determination coefficients were all above 0.95,which proved that the model was feasible to be applied to these three *** relation between fiber bending rigidity and that of cellulosic chains inside was discussed to deduce the fiber bending *** flexibility of an individual fiber can be approximated as the contribution of that of all the cellulose chains *** this method,the fiber flexibility values were determined to be in the range of 0.6×10^(11)-3.5×10^(11)N^(-1)·m^(-2),which was comparable to that of the conventional methods recorded in the literature.

关键词： Worm-like chain Fiber persistence length Fiber bending flexibility

Quantum advantages for image filtering on images with efficient encoding and lower-bounded signal-to-noise ratio

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 2-12页

作者： Zidong Cui shan jin Akira Sone Xiaoting Wang Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610051China Key Laboratory of Quantum Physics and Photonic Quantum Information Ministry of EducationUniversity of Electronic Science and Technology of ChinaChengdu 611731China Department of Physics University of MassachusettsBoston 02125USA

Quantum image processing has long been a fascinating field,but establishing the existence of quantum speedup for all images remains *** this study,we aim to identify a subset of images for which a quantum algorithm can be developed with a guaranteed ***,we present a quantum image filtering algorithm that exhibits an exponential speedup for efficiently encoded images with a lower-bounded signal-to-noise *** approach relies on a fixed-point Grover's search to emulate the effect of Hadamard multiplication with the filtering *** demonstrate its effectiveness,we apply our method to three typical filtering ***,we emphasize the significance of the efficient-encoding assumption by illustrating that the quantum speedup may diminish for images lacking efficient *** work underscores the importance of exploring image types and features to realize potential quantum advantages in image processing.

关键词： quantum computing quantum image filtering quantum speedup

DFT Study on Two C_4N_(12)O_4 Isomers with Pagodane- and Isopagodane-like Structures

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2005年第11期24卷 1264-1270页

作者： LIU Feng-Ling WANG jin-shan PENG Ling Department of Chemistry Shandong Normal University Jinan 250014 China

Geometries, energies, and vibrational frequencies for two C4N12O4 isomers with pagodane- and isopagodane-like structures have been calculated at the B3LYP/6-31G＊ *** 1 and 2 are of D2h and D2d symmetry, respectively. Heats of formation for the two C4N12O4 isomers have been estimated in this paper, indicating they would be reasonable candidates for high energy density materials.

关键词： two C4N12O4 isomers with pagodane-like structures high energy density material,B3LYP/6-31G* vibrational frequency heat of formation