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Solar Energy Harvesting Using a Timer-Based Relay Selection
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作者 Raed Alhamad Hatem Boujemaa 《Computers, Materials & Continua》 SCIE EI 2023年第1期2149-2159,共11页
In this paper,the throughput and delay of cooperative communications are derived when solar energy is used and relay node is selected using a timer.The source and relays harvest energy from sun using a photo voltaic s... In this paper,the throughput and delay of cooperative communications are derived when solar energy is used and relay node is selected using a timer.The source and relays harvest energy from sun using a photo voltaic system.The harvested power is used by the source to transmit data to the relays.Then,a selected relay amplifies the signal to the destination.Opportunistic,partial and reactive relay selection are used.The relay transmits when its timer elapses.The timer is set to a value proportional to the inverse of its Signal to Noise Ratio(SNR).Therefore,the relay with largest SNR will transmit first and its signal will be detected by the other relays that will remain idle to avoid collisions.Harvesting duration is optimized to maximize the throughput.Packet’s waiting time and total delay are also computed.We also derive the statistics of SNR when solar energy is used.The harvested power from sun is proportional to the sum of a deterministic radiation intensity and a random attenuation due to weather effects and clouds occlusion.The fixed radiation intensity depends on season,month and time t in hour.The throughput of cooperative communications with energy harvesting from sun was not yet studied. 展开更多
关键词 Solar energy harvesting timer based relay selection relaying techniques throughput and delay analysis
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Selection of Sinopec Lubricating Oil Producing Bases by Using the AHP Model 被引量:1
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作者 Song Yunchang Song Zhaozheng +2 位作者 Zheng Chengguo Jiang Qingzhe Xu Chunming 《Petroleum Science》 SCIE CAS CSCD 2007年第1期90-96,共7页
The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process (AHP) model for selecting lubricating-oil producing bases was developed. By using this ... The factors affecting the developmcnt of Sinopec lubricating oil were analyzed in this paper, and an analytic hierarchy process (AHP) model for selecting lubricating-oil producing bases was developed. By using this model, nine lubricating oil producing companies under Sinopec were comprehensively evaluated. The evaluation result showed that the Maoming Lubricating Oil Company (Guangdong province), Jingmen Lubricating Oil Company (Hubei province) and Changcheng Lube Oil Company (Beijing) are top three choices, and should be developed preferentially for the development of Sinopec producing bases of lubricating oil in the future. The conclusions provide the theoretical basis for selecting lubricating oil producing bases for decision makers. 展开更多
关键词 Lubricating oil analytic hierarchy process comprehensive evaluation selection of producing bases
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An Intrusion Detection System for SDN Using Machine Learning
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作者 G.Logeswari S.Bose T.Anitha 《Intelligent Automation & Soft Computing》 SCIE 2023年第1期867-880,共14页
Software Defined Networking(SDN)has emerged as a promising and exciting option for the future growth of the internet.SDN has increased the flexibility and transparency of the managed,centralized,and controlled network... Software Defined Networking(SDN)has emerged as a promising and exciting option for the future growth of the internet.SDN has increased the flexibility and transparency of the managed,centralized,and controlled network.On the other hand,these advantages create a more vulnerable environment with substantial risks,culminating in network difficulties,system paralysis,online banking frauds,and robberies.These issues have a significant detrimental impact on organizations,enterprises,and even economies.Accuracy,high performance,and real-time systems are necessary to achieve this goal.Using a SDN to extend intelligent machine learning methodologies in an Intrusion Detection System(IDS)has stimulated the interest of numerous research investigators over the last decade.In this paper,a novel HFS-LGBM IDS is proposed for SDN.First,the Hybrid Feature Selection algorithm consisting of two phases is applied to reduce the data dimension and to obtain an optimal feature subset.In thefirst phase,the Correlation based Feature Selection(CFS)algorithm is used to obtain the feature subset.The optimal feature set is obtained by applying the Random Forest Recursive Feature Elimination(RF-RFE)in the second phase.A LightGBM algorithm is then used to detect and classify different types of attacks.The experimental results based on NSL-KDD dataset show that the proposed system produces outstanding results compared to the existing methods in terms of accuracy,precision,recall and f-measure. 展开更多
关键词 Intrusion detection system light gradient boosting machine correlation based feature selection random forest recursive feature elimination software defined networks
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Apple leaf disease identification using genetic algorithm and correlation based feature selection method 被引量:15
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作者 Zhang Chuanlei Zhang Shanwen +2 位作者 Yang Jucheng Shi Yancui Chen Jia 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2017年第2期74-83,共10页
Apple leaf disease is one of the main factors to constrain the apple production and quality.It takes a long time to detect the diseases by using the traditional diagnostic approach,thus farmers often miss the best tim... Apple leaf disease is one of the main factors to constrain the apple production and quality.It takes a long time to detect the diseases by using the traditional diagnostic approach,thus farmers often miss the best time to prevent and treat the diseases.Apple leaf disease recognition based on leaf image is an essential research topic in the field of computer vision,where the key task is to find an effective way to represent the diseased leaf images.In this research,based on image processing techniques and pattern recognition methods,an apple leaf disease recognition method was proposed.A color transformation structure for the input RGB(Red,Green and Blue)image was designed firstly and then RGB model was converted to HSI(Hue,Saturation and Intensity),YUV and gray models.The background was removed based on a specific threshold value,and then the disease spot image was segmented with region growing algorithm(RGA).Thirty-eight classifying features of color,texture and shape were extracted from each spot image.To reduce the dimensionality of the feature space and improve the accuracy of the apple leaf disease identification,the most valuable features were selected by combining genetic algorithm(GA)and correlation based feature selection(CFS).Finally,the diseases were recognized by SVM classifier.In the proposed method,the selected feature subset was globally optimum.The experimental results of more than 90%correct identification rate on the apple diseased leaf image database which contains 90 disease images for there kinds of apple leaf diseases,powdery mildew,mosaic and rust,demonstrate that the proposed method is feasible and effective. 展开更多
关键词 apple leaf disease diseased leaf recognition region growing algorithm(RGA) genetic algorithm and correlation based feature selection(GA-CFS)
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Acupuncture therapy with point selection based on syndrome differentiation along the meridians for functional dyspepsia:a randomized controlled trial 被引量:1
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作者 Liu Hong-hua Zhang Guo-shan +4 位作者 Liu Hui-juan Li Duo-duo Liu Mi Chang Xiao-rong Liu Mai-lan 《Journal of Acupuncture and Tuina Science》 CSCD 2020年第5期352-358,共7页
Objective:To observe the difference in clinical efficacy between acupuncture with point selection based on syndrome differentiation along the meridians and acupuncture at non-meridian and non-acupoint points for funct... Objective:To observe the difference in clinical efficacy between acupuncture with point selection based on syndrome differentiation along the meridians and acupuncture at non-meridian and non-acupoint points for functional dyspepsia(FD).Methods:A total of 74 FD patients were randomized into an observation group and a control group,with 37 cases in each group.Both groups received acupuncture treatment.Zusanli(ST 36)and Neiguan(PC 6)were selected in the observation group,with Taichong(LR 3)and Neiting(ST 44)added for excess syndrome,and Gongsun(SP 4)and Yinlingquan(SP 9)added for deficiency syndrome.Four non-meridian and non-acupoint points were selected in the control group.The treatments in both groups were performed once a day with a 2-day break after 5 consecutive treatments,which constituted one treatment course.A total of 4 courses were performed.The scores of Nepean dyspepsia index(NDI)and Leeds dyspepsia questionnaire(LDQ)were recorded before and after treatment,and during follow-up(8,12,16,20 and 24 weeks after recruitment)to assess the clinical efficacy.Results:The NDI scores in the two groups after treatment and at each time point during follow-up were higher than those before treatment(all P<0.05),and the LDQ scores were lower than those before treatment(all P<0.05).The NDI scores after treatment and at each time point during follow-up in the observation group were higher than those in the control group(all P<0.01);the total LDQ score and scores of upper abdominal pain,postprandial satiety and upper abdominal burning sensation after treatment and at each time point during follow-up in the observation group were significantly lower than those in the control group(P<0.01 or P<0.05)..Conclusion:Acupuncture with point selection based on syndrome differentiation along the meridians has a better curative effect than acupuncture at non meridian and non-acupoint points in the treatment of FD. 展开更多
关键词 Acupuncture Therapy Point selection Meridian Point selection based on Syndrome Differentiation DYSPEPSIA Randomized Controlled Trial
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850 nm centered wavelength-swept laser based on a wavelength selection galvo filter
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作者 Muhammad Faizan Shirazi Mansik Jeon Jeehyun Kim 《Chinese Optics Letters》 SCIE EI CAS CSCD 2016年第1期49-52,共4页
A wavelength-swept laser is constructed using a free space external cavity configuration coupled with a fiber- based ring cavity at the 850 nm region. The external cavity filter employs a galvo-mirror scanner with a d... A wavelength-swept laser is constructed using a free space external cavity configuration coupled with a fiber- based ring cavity at the 850 nm region. The external cavity filter employs a galvo-mirror scanner with a diffraction grating for wavelength selection. The filter is connected to a ring cavity through an optical circulator. The ring cavity contains a broadband semiconductor optical amplifier with a high optical output. The perfor- mance of this laser is demonstrated with broad bandwidths and narrow linewidths. The 3 dB linewidth and the bandwidth of this source are 0.05 nm (-20 GHz) and 48 nm, respectively. The maximum output power is 26 mW at 160 mA current. 展开更多
关键词 length SOA nm centered wavelength-swept laser based on a wavelength selection galvo filter
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Step-size selection for split-step based nonlinear compensation with coherent detection in 112-Gb/s 16-QAM transmission
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作者 Chien-Yu Lin Rameez Asif +1 位作者 Michael Holtmannspoetter Bernhard Schmauss 《Chinese Optics Letters》 SCIE EI CAS CSCD 2012年第2期19-21,共3页
Non-uniform step-size distribution is implemented for split-step based nonlinear compensation in singlechannel 112-Gb/s 16 quadrature amplitude modulation (QAM) transmission. Numerical simulations of the system incl... Non-uniform step-size distribution is implemented for split-step based nonlinear compensation in singlechannel 112-Gb/s 16 quadrature amplitude modulation (QAM) transmission. Numerical simulations of the system including a 20 × 80 km uncompensated link are performed using logarithmic step size distribution to compensate signal distortions. 50% of reduction in number of steps with respect to using constant step sizes is observed. The performance is further improved by optimizing nonlinear calculating position (NLCP) in case of using constant step sizes while NLCP optimization becomes unnecessary when using logarithmic step sizes, which reduces the computational effort due to uniformly distributed nonlinear phase for all successive steps. 展开更多
关键词 QAM Step-size selection for split-step based nonlinear compensation with coherent detection in 112-Gb/s 16-QAM transmission dBm DBP
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Prediction of Gas Chromatographic Retention Indices of Organophosphates by DFT and VSMP Method
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作者 刘红艳 莫凌云 +1 位作者 李艳红 易忠胜 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第5期704-712,共9页
Polychlorinated dibenzothiophenes(PCDTs) are a group of important persistent organic pollutants.In the present study,geometrical optimization and electrostatic potential calculations have been performed for all 135 ... Polychlorinated dibenzothiophenes(PCDTs) are a group of important persistent organic pollutants.In the present study,geometrical optimization and electrostatic potential calculations have been performed for all 135 PCDTs congeners at the B3LYP/6-31G* level of theory.By means of the VSMP(variable selection and modeling based on prediction) program,one optimal descriptor(molecular polarizability,α) was selected to develop a QSRR model for the prediction of gas chromatographic retention indices(GC-RI) of PCDTs.The estimated correlation coefficients(r2) and LOO-validated correlation coefficients(q2),all more than 0.99,were built by multiple linear regression,which shows a good estimation ability and stability of the models.A prediction power for the external samples was validated by the model built from the training set with 17 polychlorinated dibenzothiophenes. 展开更多
关键词 polychlorinated dibenzothiophenes(PCDTs) retention indices(RI) density functional theory(DFT) variable selection and modeling based on prediction(VSMP) quantitative structure-retention relationship(QSRR)
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Expert systems for HPLC in biochemistry—The knowledge base for selection of HPLC column system in the separation of amino acids, peptides and proteins
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作者 ZHANG Yu-Kui ZOU Han-Fa +1 位作者 LU Pei-Zhang YAO Zhi-Jian 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1991年第5期441-447,共0页
The strategy of expert system for high performance liquid chromatography was discussed, the attentions are mainly placed on the knowledge base for selection of column system, separation modes and detection modes in th... The strategy of expert system for high performance liquid chromatography was discussed, the attentions are mainly placed on the knowledge base for selection of column system, separation modes and detection modes in the analysis of amino acids, peptides and proteins. 展开更多
关键词 The knowledge base for selection of HPLC column system in the separation of amino acids Expert systems for HPLC in biochemistry peptides and proteins base HPLC
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Compact on-chip 1×2 wavelength selective switch based on silicon microring resonator with nested pairs of subrings 被引量:3
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作者 Jiayang Wu Pan Cao +4 位作者 Ting Pan Yuxing Yang Ciyuan Qiu Christine Tremblay Yikai Su 《Photonics Research》 SCIE EI 2015年第1期9-14,共6页
We propose and experimentally demonstrate compact on-chip 1×2 wavelength selective switches(WSSs) based on silicon microring resonators(MRRs) with nested pairs of subrings(NPSs). Owing to the resonance splitting ... We propose and experimentally demonstrate compact on-chip 1×2 wavelength selective switches(WSSs) based on silicon microring resonators(MRRs) with nested pairs of subrings(NPSs). Owing to the resonance splitting induced by the inner NPSs, the proposed devices are capable of performing selective channel routing at certain resonance wavelengths of the outer MRRs. System demonstration of dynamic channel routing using fabricated devices with one and two NPSs is carried out for 10 Gb∕s non-return-to-zero signal. The experimental results verify the effectiveness of the fabricated devices as compact on-chip WSSs. 展开更多
关键词 NPS MRR Compact on-chip 1 wavelength selective switch based on silicon microring resonator with nested pairs of subrings
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Sorbents with high efficiency for CO2 capture based on amines-supported carbon for biogas upgrading 被引量:1
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作者 Lidia Pino Cristina Italiano +2 位作者 Antonio Vita Concetto Fabiano Vincenzo Recupero 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第10期138-150,共13页
Sorbents for CO2 capture have been prepared by wet impregnation of a commercial active carbon (Ketjen-black, Akzo Nobel) with two CO2-philic compounds, polyethylenimine (PEI) and tetraethylenepentamine (TEPA), r... Sorbents for CO2 capture have been prepared by wet impregnation of a commercial active carbon (Ketjen-black, Akzo Nobel) with two CO2-philic compounds, polyethylenimine (PEI) and tetraethylenepentamine (TEPA), respectively. The effects of amine amount (from 10 to 70 wt.%), CO2 concentration in the feed, sorption temperature and gas hourly space velocity on the CO2 capture performance have been investigated. The sorption capacity has been evaluated using the breakthrough method, with a fixed bed reactor equipped with on line gas chromatograph. The samples have been characterized by N2 adsorption-desorption, scanning electron microscopy and energy dispersive X-ray (SEM/EDX). A promising CO2 sorption capacity of 6.90 mmo1/gsorbent has been obtained with 70 wt.% of supported TEPA at 70℃ under a stream containing 80 vol% of CO2. Sorption tests, carried out with simulated biogas compositions (CH4/CO2 mixtures), have revealed an appreciable CO2 separation selectivity; stable performance was maintained for 20 adsorption-desorption cycles. 展开更多
关键词 CO2 capturePEI-TEPA based sorbentsAmine efficiencyBiogasSeparation selectivity
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Computing a ground appropriateness index for route selection in permafrost regions 被引量:1
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作者 Chi Zhang Quanli Gong +2 位作者 Yuanyuan Liu Jiao Yan Min Zhang 《Journal of Traffic and Transportation Engineering(English Edition)》 2017年第5期436-450,共15页
The reasonable calculation of ground appropriateness index in permafrost region is the precondition of highway route design in permafrost region. The theory of knowledge base and fuzzy mathematics are applied, and the... The reasonable calculation of ground appropriateness index in permafrost region is the precondition of highway route design in permafrost region. The theory of knowledge base and fuzzy mathematics are applied, and the damage effect of permafrost is considered in the paper. Based on the idea of protecting permafrost the calculation method of ground appro- priateness index is put forward. Firstly, based on the actual environment conditions, the paper determines the factors affecting the road layout in permafrost areas by qualitative and quantitative analysis, including the annual slope, the average annual ground temperature of permafrost, the amount of ice in frozen soil, and the interference engineering. Secondly, based on the knowledge base theory and the use of Delphi method, the paper establishes the knowledge base, the rule base of the permafrost region and inference mechanism. The method of selecting the road in permafrost region is completed and realized by using the software platform. Thirdly, taking the Tuotuo River to Kaixin Mountain section of permafrost region as an example, the application of the method is studied by using an ArcGIS platform. Results show that the route plan determined by the method of selecting the road in perma-frost region can avoid the high temperature and high ice content area, conform the terrain changes and evade the heat disturbance among the existing projects. A reasonable route plan can be achieved, and it can provide the basis for the next engineering construction. 展开更多
关键词 Road engineering Permafrost regions Highway route selection Knowledge base Fuzzy reasoning
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Superimposed Fiber Gratings Based Wavelength Selectable Fiber Laser
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作者 Yan Liu, Zhong-wei Tan, Ti-gang Ning, Shui-sheng Jian Institute of Lightwave Technology, Northern Jiaotong University, Beijing, P.R.China 《光学学报》 EI CAS CSCD 北大核心 2003年第S1期479-480,共2页
A novel wavelength selectable fiber ring laser was proposed. Superimposed fiber Bragg gratings with uniform reflectivity were made to serve as comb-like filter. Optical tunable filter combined with the comb filter rea... A novel wavelength selectable fiber ring laser was proposed. Superimposed fiber Bragg gratings with uniform reflectivity were made to serve as comb-like filter. Optical tunable filter combined with the comb filter realized fast and accurately wavelength selectivity. The SMSR at each wavelength is more than 50dB. 展开更多
关键词 OTF as Superimposed Fiber Gratings based Wavelength Selectable Fiber Laser length in be HAVE TING 一夕 of that
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Traditional Chinese medicinal herbs combined with epidermal growth factor receptor tyrosine kinase inhibitor for advanced non-small cell lung cancer: a systematic review and meta-analysis 被引量:19
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作者 Zhong-liang Liu Wei-rong Zhu +5 位作者 Wen-chao Zhou Hai-feng Ying Lan Zheng Yuan-biao Guo Jing-xian Chen Xiao-heng Shen 《Journal of Integrative Medicine》 SCIE CAS CSCD 2014年第4期346-358,共13页
BACKGROUND: Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) targeted treatment has been a standard therapy for advanced non-small cell lung cancer (NSCLC), but it is not tolerated well by al... BACKGROUND: Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) targeted treatment has been a standard therapy for advanced non-small cell lung cancer (NSCLC), but it is not tolerated well by all patients. In China, some studies have reported that traditional Chinese medicinal herbs (TCMHs) may increase efficacy and reduce toxicity when combined with EGFR-TKI, but outside of China few studies of this kind have been attempted. OBJECTIVE: This study is intended to systematically review the existing clinical evidence on TCMHs combined with EGFR-TKI for treatment of advanced NSCLC. SEARCH STRATEGY: PubMed, the Cochrane Library, the Excerpta Medica Database (EMBASE), the China BioMedical Literature (CBM), and the China National Knowledge Infrastructure (CNKI) and web site of the American Society of Clinical Oncology (ASCO), the European Society for Medical Oncology (ESMO), the World Conference of Lung Cancer (WCLC) were searched; the search included all documents published in English or Chinese before October 2013. INCLUSION CRITERIA: We selected randomized controlled trials based on specific criteria, the most important of which was that a TCMH plus EGFR-TKI treatment group was compared with an EGFR-TKI control group in patients with advanced NSCLC. DATA EXTRACTION AND ANALYSIS: The modified Jadad scale was used to assess the quality of studies. For each included study, patient characteristics, treatment details, therapeutic approach and clinical outcomes were collected on a standardized form. When disagreements on study inclusion or data extracted from a study emerged, the consensus of all coauthors provided the resolution. The clinical outcome metrics consisted of objective response rate (ORR; complete response + partial response divided by the total number of patients), disease control rate (DCR; complete response + partial response + no change divided by the total number of patients), survival rate, improved or stabilized Karnofsky performance status (KPS), and severe toxicity. RevMan 5.0 software was used for data syntheses and analyses. Risk ratio (RR) and 95% confidence interval (CI) were calculated; if the hypothesis of homogeneity was not rejected (P〉0.1, I2〈50%), the fixed-effect model was used to calculate the summary RR and the 95% CI. Otherwise, a random-effect model was used. 展开更多
关键词 In this review 19 studies were included based on the selection criteria. Of them 13
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Clinical study on acupuncture for primary insomnia 被引量:8
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作者 Shao Yue 《Journal of Acupuncture and Tuina Science》 CSCD 2017年第6期410-414,共5页
Objective: To observe the clinical effect of Acupuncture at Baihui(GV 20), Sishencong(EX-HN 1) and Anmian [Extra, locates at the midpoint between Yiming(EX-HN 14) and Fengchi(GB 20)] for primary insomnia. Met... Objective: To observe the clinical effect of Acupuncture at Baihui(GV 20), Sishencong(EX-HN 1) and Anmian [Extra, locates at the midpoint between Yiming(EX-HN 14) and Fengchi(GB 20)] for primary insomnia. Methods: A total of 112 patients with primary insomnia were randomized into an acupuncture group and a medication group according to the visiting sequence, 56 cases in each group. The acupuncture group was intervened by acupuncture at Baihui(GV 20), Sishencong(EX-HN 1) and Anmian [Extra, locates at the midpoint between Yiming(EX-HN 14) and Fengchi(GB 20)], and points selected based on syndrome differentiation, while the medication group was by oral intake of zopiclone tablet. The Pittsburgh sleep quality index(PSQI) was measured before and after treatment, and the clinical efficacy was compared after 1 month of treatment. Results: After treatment, subscales of PSQI and global score in the acupuncture group were improved, and intra-group comparisons showed statistical differences(all P〈0.05); subscales of sleep quality, sleep latency, sleep duration and global score of PSQI in the medication group were improved, showing statistical differences(all P〈0.05). Inter-group comparison of global and subscales scores of PSQI showed statistical differences(all P〈0.05). The total effective rate in the acupuncture group was 92.9%, higher than 67.9% in the medication group, and between-group comparison showed a statistical difference(P〈0.05). Conclusion: Acupuncture at Baihui(GV 20), Sishencong(EX-HN 1) and Anmian [Extra, locates at the midpoint between Yiming(EX-HN 14) and Fengchi(GB 20)] as the main treatment method can produce a better effect than oral intake of zopiclone tablet. 展开更多
关键词 Acupuncture Therapy Point Baihui (GV 20) Point Sishencong (EX-HN 1) Point Anmian (Extra) Points Headand Neck Point selection based on Syndrome Differentiation INSOMNIA
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Microstructure Characteristics of Inconel 625 Superalloy Manufactured by Selective Laser Melting 被引量:27
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作者 Shuai Li Qingsong Wei +2 位作者 Yusheng Shi Zicheng Zhu Danqing Zhang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2015年第9期946-952,共7页
Selective laser melting (SLM), an additive manufacturing process, is capable of manufacturing metallic parts with complex shapes directly from computer-aided design (CAD) models. SLM parts are created on a layer-b... Selective laser melting (SLM), an additive manufacturing process, is capable of manufacturing metallic parts with complex shapes directly from computer-aided design (CAD) models. SLM parts are created on a layer-by-layer manner, making it more flexible than traditional material processing techniques, in this paper, Inconel 625 alloy, a widely used material in the aerospace industry, were chosen as the build material. Scanning electron microscopy (SEM), electron back scattering diffraction (EBSD) and X-ray diffraction (XRD) analysis techniques were employed to analyze its microstructure. It was observed that the molten pool was composed of elongated columnar crystal, Due to the rapid cooling speed, the primary dendrite arm space was approximately 0.5 μm and the hardness of SLM state was very high (343 HV). The inverse pole figure (IPF) indicated that the growing orientation of the most grains was 〈001〉 due to the epitaxial growth and heat conduction. The XRD results revealed that the austenite structure with large lattice distortion was fully formed. No carbides or precipitated phases were found. After heat treatment the grains grew into two microstructures with distinct morphological characters, namely, rectangular grains and limited in the molten pool, and equiaxed grains along the molten boundaries. Upon experiencing the heat treatment, MC carbides with triangular shapes gradually precipitated. The results also identified that a large number of zigzag grain boundaries were formed. In this study, the grain formation and microstructure, and the laws of the molten pool evolution were also analyzed and discussed, 展开更多
关键词 Selective laser meltingNickel based superalloyTextureLattice constantZigzag grain boundary
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