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Assessing Net Primary Production in Montane Wetlands from Proximal, Airborne, and Satellite Remote Sensing

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Advances in Remote Sensing 2016年第2期5卷 118-130页

作者： Michael Maguigan John Rodgers Padmanava Dash qingmin meng National Strategic Planning and Analysis Research Center Mississippi State University Starkville MS USA Department of Geosciences Mississippi State University Mississippi State MS USA

In this study, several vegetation indices were examined in order to determine the most sensitive vegetation index for monitoring southern Appalachian wetlands. Three levels of platforms (in situ, airborne, and satellite) for sensors were also examined in conjunction with vegetation indices. Net primary production (NPP) data were gathered to use as a measure of wetland function. Along with the in situ radiometers, National Agricultural Imagery Program (NAIP) data and Landsat 8 Operational Land Imager (OLI) data were gathered in order to calculate vegetation indices at three platforms. At the in situ level, VARI700 was the most sensitive vegetation index in terms of NPP (r2 = 0.65, p 2 = 0.35, p = 0.11). At the satellite level, the DVI appeared to have a positive relationship with NPP. For most indices there was a drop in the coefficient of determination with NPP when the platform altitude increased, with the exception of NDVI when increasing altitude from in situ to airborne. This study provides a novel methodology comparing reflectance and vegetation indices at three platform levels.

关键词： Net Primary Production Montane Wetland In Situ Airborne Satellite

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铁路货车120系列控制阀作用优化研究

铁道技术监督 2024年第5期52卷 43-47页

作者：徐毅孟庆民张阿龙张守成中车齐齐哈尔车辆有限公司大连研发中心辽宁大连116052 中国铁路哈尔滨局集团有限公司黑龙江哈尔滨150006 郑州煤机长壁机械有限公司河南郑州450000

为解决120系列控制阀在小减压量制动后缓解工况下缓解波速度低,在紧急制动后缓解工况充风时间长、耗费能源高,以及120-1型控制阀在常用全制动工况下制动缸压力差异大,在常用全制动后缓解工况下缓解波速度低、再充风时间延长的问题,提出... 详细信息

为解决120系列控制阀在小减压量制动后缓解工况下缓解波速度低,在紧急制动后缓解工况充风时间长、耗费能源高,以及120-1型控制阀在常用全制动工况下制动缸压力差异大,在常用全制动后缓解工况下缓解波速度低、再充风时间延长的问题,提出以下优化方案:利用列车管和副风缸中压缩空气的压力差,控制加速缓解阀开启,优化常用制动后加速缓解作用;在紧急阀部分设计紧急加速缓解功能,实现紧急制动后加速缓解作用;在局减排气通路上,设计由副风缸和制动缸中压缩空气的压力差控制的开闭结构,实现常用制动加速作用关闭。

关键词：货车控制阀工作原理问题分析优化

Active Control Strategy for Offshore Structures Accounting for AMD Constraints

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High Technology Letters 2004年第4期10卷 63-68页

作者：嵇春艳 LI Huajun meng qingmin School of Naval Architecture and Ocean Engineering Jiangsu University of Science and Technology Zhenjiang 212003 P.R.China College of Engineering Ocean University of China Qingdao 266071 P.R.China

Most of active mass damper systems are designed or installed for the onshore structural response reduction to quite small earthquake or strong wind excitation. When they are applied to offshore structures, they will stop their operations during severe sea state (including strong wind, wave and fluid). For controlling the excessive vibration of offshore structure excited by wave loading, this paper presents a methodology keeping AMD operations even in severe sea state. And the controller was designed by LQG control algorithm accounting for the limits of AMD stroke and control input force. In order to investigate the feasibility and effectiveness of the proposed method, a numerical example applied to an offshore platform is presented in this paper. The numerical results demonstrate that the proposed algorithm is effective in reducing the vibration of offshore structure by choosing appropriate feedback gain among several gain candidates based on the AMD limits.

关键词：主动控制系统 AMD 建筑物海岸地震预防措施设计方案

Synthesis of ITQ-2 zeolite under static conditions and its properties

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Science China Chemistry 2006年第2期49卷 148-154页

作者： LIU Baijun HUO Huijuan meng qingmin GAO Shansong Key Laboratory of Catalysis of China National Petroleum Corporation China University of Petroleum Beijing 102249 China Key Laboratory of Catalysis of China National Petroleum Corporation China University of Petroleum Beijing 102249 China Key Laboratory of Catalysis of China National Petroleum Corporation China University of Petroleum Beijing 102249 China Key Laboratory of Catalysis of China National Petroleum Corporation China University of Petroleum Beijing 102249 China

Using silica gel as the precursor, MCM-22(p) was synthesized under the static conditions. Then ITQ-2 zeolite was obtained by using n-cetyltrimethylammonium bromide (CTAB) and tetrapro- pylammonium hydroxide (TPAOH) as the swelling agents to swell the pores of MCM-22(p). The ob- tained zeolite was characterized by XRD, SEM, BET, NH3-TPD. The results show that the zeolite had the best swelling when MCM-22(p):CTAB:TPAOH=1:4:1. The synthesis duration and temperature did not influence significantly the pore swelling. Except TPAOH, CTAB can also be used together with tetrabuthylammonium hydroxide (TBAOH) as the pore swelling agent. There was contribution of sur- face area and pore volume from the mesoporous pores in the ITQ-2 zeolite and it also showed weaker acidity than MCM-22. However, the ITQ-2 supported NiW catalyst showed higher activity and selec- tivity to the middle distillates in the hydrocracking of vacuum gasoil (VGO) than MCM-22 supported catalyst. This implied that the diffusion of large molecules of heavy oil in the catalyst was facilitated due to the presence of the mesoporous pores and hence higher activity and selectivity to middle dis- tillates.

关键词： static crystallization, zeolite ITQ-2, swelling agent, delaminated zeolite, hydrocracking.

DISTRIBUTED PROPORTIONAL FAIR FREQUENCY ALLOCATION ACROSS MULTIPLE BASE STATIONS

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Journal of Electronics(China) 2013年第4期30卷 335-340页

作者： Du Peng meng qingmin College of Automation Nanjing University of Posts and Telecommunications College of Telecommunications and Information Engineering Nanjing University of Posts and Telecommunications Interdisciplinary Centre for Security Reliability and Trust (SnT) the University of Luxembourg

The problem of distributed proportional fair inter-cell frequency allocation for flat-structured cellular systems is studied in this paper. We firstly propose a framework of the frequency allocation in which the whole frequency allocation process is decomposed into many consecutive stages, then identify that for each stage the key is to find the Maximum Weight Independent Set (MWIS) in a given weighted conflict graph in the distributed manner. A new distributed algorithm for MWIS is described in which each node iteratively exchanges messages with neighbors. With this distributed MWIS algorithm, a new distributed proportional fair frequency allocation scheme is presented. The performance of the proposed algorithm is tested in computer experiments simulating the Long Term Evolution (LTE) cellular systems. Simulation results show the performance of the proposed distributed proportional fair frequency allocation scheme is comparable with the centralized ones.

关键词：频率分配比例计算机模拟实验基站算法描述蜂窝系统分配方案性能测试

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食管肉瘤样癌的临床病理分析(英文)

The Chinese-German Journal of Clinical Oncology 2014年第5期13卷 235-239页

作者： Changshan Li Jingzhong Xu Shenghua Tian qingmin meng Gangping Wang Department of Radiology Rizhao People's Hospital Department of Internal Medicine Rizhao Jufeng Hospital Department of Internal Medicine Rizhao Traditional Chinese Medicine Hospital Department of Radiology The Central Hospital of Tai'an Department of Clinical Pathology Rizhao People's Hospital

Objective: The purpose of this study was to study the clinical, imaging characters and pathological characteristics of esophageal sarcomatoid carcinoma. Methods: We reviewed 23 cases of esophageal sarcomatoid carcinoma from January 2006 to December 2013 in four hospitals. The data of patients who were esophageal sarcomatoid carcinoma operated were retrospectively analyzed. All cases had completed upper gastrointestinal barium images materials and 14 of these cases had completed CT images materials. Upper gastrointestinal barium images and CT imaging features include tumor location, size, shape, and strengthen, etc. The biological parameters of lesions including the express of cytokeratin AE1/AE3, 34βE12, p63, Vimentin, desmin, Actin, S-100 and Ki-67 detected by immunhistochemical UltraSensitiveTM S-P method(n = 23), and the patients' data of contrastographic picture(n = 23), imaging characters of CT scan(n = 14), and their relationship were studied. Results: Upper gastrointestinal barium images, CT imaging and gastrointestinal fiberscopy revealed lobulated intraluminal filling defect 0.4 cm to 5.7 cm × 3.5 cm × 1.3 cm(mean = 3. 7 cm) in the mid(n = 14), lower(n = 7) and upper(n = 2) intrathoracic esophagus. Among 23 cases of esophageal sarcomatoid carcinoma, 19 patients were of mushroom type, 2 patients was of ulcer type, and 2 patients were of medulla type; 19 patients were pedunculated, and 4 patients were no pedunculated(2 patients was of ulcer type). The tumor surface was relatively smooth and esophageal compliance was maintained. The pathological changes of esophagus such as lightly locked, rigid wall no-manifest partly, esophageal lumens expand partly, major filling sublobe defect could be shown through contrast medium. Normal esophagus was no unpack obviously over pathological changes. Enhanced computed tomography showed tumors in the intrathoracic esophagus and 8 lymph nodes metastases in 3 cases. Histologically, carcinomatous and sarcomatous components coexist. Microscopically, the tumor comprised poorly

关键词：食管癌肉瘤病理分析临床细胞角蛋白免疫组化染色食管肿瘤 CT图像

Micro-mechanism Study on the Different Antioxidants Protective Effect of Vegetable Oil by ReaxFF Molecular Dynamics

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1269-1279页

作者： Haoxi Cong Xuefeng Hu Hao Pan qingmin Li State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

The aging problem of vegetable oil has severely restricted the popularization and application of vegetable oil transformers.Adding antioxidants is the most recommended solution.At present,there is insufficient research on the micromechanism application of the protective effect of antioxidants on vegetable oil.In this paper,multiple vegetable oil models with different types and concentrations of antioxidants are established.Then the molecular dynamics simulation based on ReaxFF is carried out at different temperatures and oxygen content.Results show that the protective mechanism of antioxidants is to release H and combine this with free radicals generated by the decomposition of unsaturated fatty acids(UFA)in the oil.In addition,the protective effects of four antioxidants show different results.The stronger ones are tert-butyl hydroquinone(TBHQ)and butylated hydroxytoluene(BHT),while the weaker ones are butylated hydroxyanisole(BHA)and propyl gallate(PG).TBHQ has a better protective effect at lower concentrations,but the decomposition of UFA is promoted at higher concentrations.When the temperature rises,the decomposition of UFA is promoted.With the addition of oxygen,smaller molecular compounds are easily oxidized,and the decomposition of UFA is accelerated.The above research could reveal the microscopic mechanism of antioxidant protection on vegetable oil,providing theoretical references for further exploration of effective vegetable oil aging protection technology.

关键词： Antioxidant molecular dynamics transformer vegetable oil

SINR-BASED ANTENNA COMBINING FOR MULTIUSER MIMO-OFDM WITH LIMITED FEEDBACK

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Journal of Electronics(China) 2011年第3期28卷 328-333页

作者： Lu Min Feng Guangzeng meng qingmin College of Telecommunications and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

A multiuser Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) broadcast channel is considered where both transmitter and receivers are equipped with multiple antennas. The Channel State Information (CSI) is quantized and provided through limited feedback links. In the first part of this work, the Maximum Expected SINR Combining (MESC) strategy for feedback decrease is investigated. Then a combination of MESC with subcarrier assigning is presented to further reduce the feedback load. The basic idea is the subcarriers are partitioned into resource blocks. For each block, only one quantized channel vector is feedback. The simulation results show MESC can obtain the performance gain over the relevant combiner strategies in MIMO-OFDM system. Moreover the effectiveness on the reduction of feedback overhead by the use of partitioning blocks in the studied system is evaluated.

关键词： Multiuser Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) Limited feedback Quantization

Numerical simulation of formaldehyde distribution characteristics in the high-speed train cabin

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Building Simulation 2024年第2期17卷 285-300页

作者： Fan Wu Hang Dong Chao Yu Hengkui Li qingmin Cui Renze Xu Key Laboratory of Traffic Safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangshaHunan410075China Joint International Research Laboratory of Key Technologies for Rail Traffic Safety ChangshaHunan410075China National&Local Joint Engineering Research Center of Safety Technology for Rail Vehicle ChangshaHunan410075China School of Software Henan University of EngineeringZhengzhouHenan451191China

The global concern over indoor air pollution in public vehicles has grown significantly.With a focus on enhancing passengers’comfort and health,this study endeavors to investigate the distribution characteristics of formaldehyde within a high-speed train cabin by employing a computational fluid dynamics(CFD)model which is experimentally validated in a real cabin scenario.The research focuses on analyzing the impact of air supply modes,temperature,relative humidity,and fresh air change rate on the distribution and concentration of formaldehyde.The results demonstrate that the difference in average formaldehyde concentration between the two air supply modes is below 1.3%,but the top air supply mode leads to a higher accumulation of formaldehyde near the sidewalls,while the bottom air supply mode promotes a more uniform distribution of formaldehyde.Furthermore,the temperature,relative humidity,and fresh air change rate are the primary factors affecting formaldehyde concentration levels,but they have modest effects on formaldehyde’s distribution pattern within the cabin.As the temperature and relative humidity increase,the changes in formaldehyde concentrations in response to variations in these factors become more evident.Importantly,the formaldehyde concentration may surpass the standard limit of 0.10 mg/m^(3)if the fresh air change rate falls below 212 m^(3)/h.This research provides a systematic approach and referenceable results for exploring formaldehyde pollution in high-speed train cabins.

关键词： indoor air pollution formaldehyde CFD simulation high-speed train ventilation