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Accurate Analysis of Multi-Mode Interferometric Optical Fiber Sensor

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Photonic Sensors 2024年第1期14卷 48-58页

作者： lijun li Congying JIA Qian MA Tianzong XU College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao 266590.China State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology Qingdao 266590China

In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and *** suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,*** method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis *** the same time,this method is also beneficial to solve the repetitive problem of such sensors.

关键词： Window function FFT optical fiber interferometric sensor analysis method

Growth and Optical Applications of Centimeter-Long ZnO Nanocombs

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Nano Research 2008年第3期1卷 221-228页

作者： Ke Yu Qiuxiang Zhang Jin Wu lijun li Yuʼe Xu Shaohua Huang Ziqiang Zhu Key Laboratory for Polar Materials and Devices of Ministry of Education and Department of Electronic Engineering East ChinaNormal UniversityShanghai 200241China Department of Electronic Engineering Shanghai Jianqiao CollegeShanghai 201319China Surface Physics Laboratory Department of PhysicsFudan UniversityShanghai 200433China

Ultralong ZnO nanocombs have been synthesized on silicon substrates with a high growth rate of~7μm/s using a simple“thermal evaporation and condensation”method promoted by Cu *** lengths of the ZnO nanocombs range from several millimeters to more than one centimeter and the diameters of the branches are about 300 *** growth mechanism of the ultralong nanocombs and the catalytic behavior of the copper are *** nanocombs were readily separated and their applications as optical polarizer and grating were *** results show that the ultralong ZnO nanocombs can act as effective optical components in miniaturized integrated optics systems.

关键词： Zinc oxide nanocombs thermal evaporation polarizer grating

氢氧化镁-活性炭复合材料的制备及其对糖浆脱色工艺优化

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食品工业科技 2025年第1期46卷 201-207页

作者：陈金足韦晓雯农晶晶韩丽芳冯学唐婷范李利军程昊广西糖资源绿色加工重点实验室广西柳州螺蛳粉工程技术研究中心广西科技大学生物与化学工程学院广西柳州545006 蔗糖产业省部共建协同创新中心广西南宁530004

为寻找绿色环保且具有高吸附性的糖浆脱色材料,本文通过原位生成氢氧化镁沉积在活性炭表面,制备了氢氧化镁-活性炭复合材料,采用扫描电镜(SEM)、能谱仪(EDS)、比表面积和空隙度分析仪(BET)和X射线衍射仪(XRD)对制备的复合材料进行了表征... 详细信息

为寻找绿色环保且具有高吸附性的糖浆脱色材料,本文通过原位生成氢氧化镁沉积在活性炭表面,制备了氢氧化镁-活性炭复合材料,采用扫描电镜(SEM)、能谱仪(EDS)、比表面积和空隙度分析仪(BET)和X射线衍射仪(XRD)对制备的复合材料进行了表征,并以脱色率为指标,复合材料投入量、pH、脱色温度、脱色时间为影响因素,采用单因素及正交试验优化赤砂糖回溶糖浆脱色的最佳工艺。结果证明所制备的氢氧化镁-活性炭复合材料为多孔性,其比表面积和空隙率大、晶型结构良好、吸附能力强。糖浆脱色的最佳工艺为:复合材料用量为0.70 g,pH为10.00,脱色温度为50℃,脱色时间为50 min。在该工艺条件下的脱色率可达到80.7%,脱色效果明显优于商用活性炭。综上表明,氢氧化镁-活性炭复合材料对糖浆具有较理想的脱色效果,作为一种绿色材料在工业制糖方面具有一定的应用前景。

关键词：氢氧化镁活性炭赤砂糖回溶糖浆复合材料脱色

The effective pressure law for permeability of clay-rich sandstones

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Petroleum Science 2011年第2期8卷 194-199页

作者： Zhao Jinzhou Xiao Wenlian li Min Xiang Zuping li lijun Wang Jun State Key of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu Sichuan 610500 China Exploration ＆ Development Research Institute Sinopec Southwest Branch Chengdu Sichuan 610081 China

To study the relative sensitivity of permeability to pore pressure Pp and confining pressure Pc for clay-rich rocks, permeability measurements were performed on samples of four clay-rich sandstones. A new method （hereafter denoted the ＂slide method＂） was developed and used for analyzing the permeability data obtained. The effective pressure coefficients for permeability nk were calculated. The values of nk were found to be greater than 1.0 and insensitive to changes in pressure. These results confirmed observations previously made on clay-rich rocks. Also, the coefficients nk obtained had different characteristics for different samples because of differences in the types of clay they contained. The effective pressure law （σeff=Pc-nkPp） determined using the slide method gave better results about k（oefr） than classic Terzaghi＇s law （σeff=Pc-nkPp）.

关键词： Permeability effective pressure coefficient slide method clay sandstones

Fabrication and characteristics of double-clad fiber Bragg gratings

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Frontiers of Optoelectronics 2009年第1期2卷 68-75页

作者： lijun li Wande FAN Shenggui FU Yange liU Shuzhong YUAN Xiaoyi DONG College of Information and Electrical Engineering Shandong University of Science and Technology Institute of Modern Optics Nankai University

A double-clad fiber Bragg grating(DCFBG) is a kind of grating which is directly written into the core of a double-clad fiber(DCF). Because of its special structure,DCFBGs have potential applications in fiber communication and sensing. In this paper, some of the recent studies on DCFBG are reviewed, and the photosensitivity and thermal decay of DCFBG fabricated in different DCFs are investigated. The DCFBGs of diversiform reflectivity are fabricated, and the maximum reflectivity of the grating is 99.9%. Finally, the special characteristics of DCFBG, such as nonlinear and stress, are illustrated.

关键词： double-clad fiber fiber Bragg grating photosensitivity resonant nonlinearity

Efficient semi-analytical methods for the vibration response of and acoustic radiation from a periodical orthogonally rib-stiffened plate

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Chinese Journal of Acoustics 2019年第3期38卷 309-330页

作者： ZHOU Haian WANG Xiaoming WU Huayong MENG Jianbing li lijun School of Mechanical Engineering Shandong University of TechnologyZibo 255049 School of Mechanical Engineering Dalian University of TechnologyDalian 116024 School of Aeronautics Shandong Jiaotong UniversityJinan 250357 School of Transportation and Vehicle Engineering Shandong University of TechnologyZibo 255049

In order to theoretically predict and analyze the vibration response and acoustic radiation characteristics of a periodical orthogonally rib-stiffened plate,its vibro-acoustic equations of an underwater infinite model are *** rib-stiffened plate is stimulated by a harmonic plane *** using the Fourier transforms,Poisson’s summation formula and space harmonic method,the structural vibration response and acoustic radiation pressure are expressed as functions of displacement harmonic *** semi-analytical methods are proposed in this work,and then approximate solutions for finite terms of the harmonic components are obtained by employing the truncation *** of the vibration response,rib spacing and torsional moment of the ribs on the radiation pressure are examined,and the validity of the present methods is also *** results show that the torsional moment of the ribs affects the modal frequencies of the stiffened plate,which should not be neglected in engineering applications with high precision *** attachment of the ribs to the thin plate,its far field radiation pressure can be reduced in the low frequency range by adjusting rib spacing and cross sectional size of the ribs.

关键词： Efficient semi-analytical methods for the vibration response of and acoustic radiation from a periodical orthogonally rib-stiffened plate

Detection method of absence seizures based on Resnet and bidirectional GRU

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Acta Epileptologica 2023年第1期6卷 34-42页

作者： lijun li Hengxing Zhang Xiaomei liu Jie li Lei li Dan liu Jieqing Min Ping Zhu Huan Xia Shangkun Wang li Wang Kunming children‘s hospital Kunming 650000China Zhengzhou Zoneyet Technology Corp. LtdZhengzhou 450000China

Background Epilepsy is a common chronic neurological *** repeated seizure attacks have a great negative impact on patients’physical and mental *** diagnosis of epilepsy mainly depends on electroencephalogram(EEG)signals detection and *** are two main EEG signals detection methods for *** is the detection based on abnormal waveform,the other is the analysis of EEG signals based on the traditional machine *** feature extraction method of the traditional machine learning is difcult to capture the high-dimension information between adjacent *** In this paper,redundant information was removed from the data by Gaussian fltering,downsampling,and short-time Fourier *** Neural Networks(CNN)was used to extract the high-dimensional features of the preprocessed data,and then Gate Recurrent Unit(GRU)was used to combine the sequence information before and after,to fully integrate the adjacent information EEG signals and improve the accuracy of the model *** Four models were designed and *** experimental results showed that the prediction model based on deep residual network and bidirectional GRU had the best efect,and the test accuracy of the absence epilepsy test set reached 92%.Conclusions The prediction time of the network is only 10 sec when predicting four-hour EEG *** can be efectively used in EEG software to provide reference for doctors in EEG analysis and save doctors’time,which has great practical value.

关键词： Resnet Epilepsy GRU Electroencephalogram

Synthesis of Fe^(3+)-doped Aminated lignin as A Peroxidase Mimic for Colorimetric Detection of H_(2)O_(2) and Glucose

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Paper And Biomaterials 2021年第4期6卷 1-11页

作者： lijun li Xin liu Yixin Shi Jinhui Pang Jun Yang Feng Xu Xueming Zhang Beijing Key Laboratory of lignocellulosic Chemistry Beijing Forestry UniversityBeijing100083China College of Marine Science and Biological Engineering Qingdao University of Science and TechnologyQingdaoShandong Province266042China

Peroxidase plays an important role in living systems;however,its storage difficulty and easy inactivation have limited its applications in complex *** address these problems,herein,we proposed a method to synthesize peroxidase mimics by amination,carbonization,and Fe^(3+)-doping of industrial alkali *** Fe^(3+)-doped lignin-based peroxidase mimic(Fe-LPM),with active centers of coordination between Fe^(3+)and N atoms,showed higher tolerance to pH value and temperature than natural *** Fe-LPM,10-100 mmol/L of H_(2)O_(2) and glucose could be colorimetrically detected with the lowest detection limits of 80μmol/L and 1.5 mmol/L and visual detection limits of 1.0 mmol/L and 10 mmol/L,*** Fe-LPM maintained peroxidase-like activity after 10 cycles and could even be used for H_(2)O_(2) detection in practical *** work not only provides a new approach to synthesize peroxidase mimics using biomass materials but also promotes the high-value utilization of lignin.

关键词： amination lignin Fe^(3+)-doping peroxidase mimics

Emissions Trading Mode in America and China and Its Future

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Chinese Business Review 2004年第10期3卷 56-61页

作者： lijun li Yanli li Zhihui Song Master of Renmin University of China and associate prof. of School of Economics and Management Shijiazhuang.. Railway Institute Hebei China Postcode： 050043 Master of Tianjin University of Finance ＆ Economics and lecturer of Shijiazhuang Railway lnstitute Master of Sydney University and teaching assistant of Shijiazhuang Railway Institute

The emissions trading is a kind of sustainable development measures that is based on market mechanism, and its growing is closely connected with the market development level. The level of American emissions permits market is relatively high, and also predicts the prospect of professional bourse pattern. Most of emissions permits transactions in China are organized by government environment authority, which make it lack of market function. Emissions permits is a kind of property rights. It is important and profitable, while the emissions trading market obviously possesses the two-class of original allocation and second-time transfer. But there are some decisive differences between emissions permits and ordinary transaction object, so the specialized bourse for emissions trading should be built.

关键词： Emissions Market Bourse Auction