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微波辅助sol-gel法合成Bi_(0.5)Na_(0.5)TiO_(3)粉体及其压电性能研究
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作者 武家莹 刘佳 +3 位作者 胡月 房国丽 郭小雷 范玉杰 《宁夏大学学报(自然科学版)》 CAS 2024年第2期218-224,共7页
采用微波辅助溶胶-凝胶(sol-gel)法制备Bi_(0.5)Na_(0.5)TiO_(3)(BNT)粉体,通过DSC/TG,XRD,SEM,FT-IR等表征方法,分析BNT的反应历程,煅烧温度对BNT成分、晶粒尺寸和压电性能的影响.结果表明,当微波煅烧温度为650℃时,可合成出高纯度BNT... 采用微波辅助溶胶-凝胶(sol-gel)法制备Bi_(0.5)Na_(0.5)TiO_(3)(BNT)粉体,通过DSC/TG,XRD,SEM,FT-IR等表征方法,分析BNT的反应历程,煅烧温度对BNT成分、晶粒尺寸和压电性能的影响.结果表明,当微波煅烧温度为650℃时,可合成出高纯度BNT粉体(30~120 nm),其居里温度为394℃,d_(33)=7.5 pC/N,ε_(r)=535.58,tanδ=0.29.对比传统马弗炉煅烧sol-gel法,微波辅助sol-gel法有利于提高BNT的介电性能和居里温度,降低介质损耗. 展开更多
关键词 钛酸铋钠 溶胶-凝胶(sol-gel)法 微波烧结 介电损耗 压电性能
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Sol-gel synthesis of nanometer silicon/silicon suboxide/carbon anode material
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作者 QIN Tong WANG Zheng LI Zhengzheng 《Baosteel Technical Research》 CAS 2024年第2期12-18,共7页
A stacked Si/SiO_(x)/C composite anode material with carbon-coated structure was prepared by sol-gel method combined with carbothermal reduction using organic silicon.The results of X-ray diffractometry, scanning elec... A stacked Si/SiO_(x)/C composite anode material with carbon-coated structure was prepared by sol-gel method combined with carbothermal reduction using organic silicon.The results of X-ray diffractometry, scanning electron microscopy, and elemental analysis show that the Si/SiO_(x)/C material is a secondary particle with a porous micronanostructure, and the presence of nanometer silicon does not affect the carbothermal reduction and carbon coating.Electrochemical test results indicate that the specific capacity and first coulombic efficiency of SiO_(x)/C composite with nanometer silicon can be increased to 1 946.05 mAh/g and 76.49%,respectively.The reversible specific capacity of Si/SiO_(x)/C material blended with graphite is 749.69 mAh/g after 100 cycles at a current density of 0.1 C,and the capacity retention rate is up to 89.03%.Therefore, the composite has excellent electrochemical cycle stability. 展开更多
关键词 sol-gel method nanometer silicon silicon suboxide anode material
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Systematic Cloud-Based Optimization: Twin-Fold Moth Flame Algorithm for VM Deployment and Load-Balancing
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作者 Umer Nauman Yuhong Zhang +1 位作者 Zhihui Li Tong Zhen 《Intelligent Automation & Soft Computing》 2024年第3期477-510,共34页
Cloud computing has gained significant recognition due to its ability to provide a broad range of online services and applications.Nevertheless,existing commercial cloud computing models demonstrate an appropriate des... Cloud computing has gained significant recognition due to its ability to provide a broad range of online services and applications.Nevertheless,existing commercial cloud computing models demonstrate an appropriate design by concentrating computational assets,such as preservation and server infrastructure,in a limited number of large-scale worldwide data facilities.Optimizing the deployment of virtual machines(VMs)is crucial in this scenario to ensure system dependability,performance,and minimal latency.A significant barrier in the present scenario is the load distribution,particularly when striving for improved energy consumption in a hypothetical grid computing framework.This design employs load-balancing techniques to allocate different user workloads across several virtual machines.To address this challenge,we propose using the twin-fold moth flame technique,which serves as a very effective optimization technique.Developers intentionally designed the twin-fold moth flame method to consider various restrictions,including energy efficiency,lifespan analysis,and resource expenditures.It provides a thorough approach to evaluating total costs in the cloud computing environment.When assessing the efficacy of our suggested strategy,the study will analyze significant metrics such as energy efficiency,lifespan analysis,and resource expenditures.This investigation aims to enhance cloud computing techniques by developing a new optimization algorithm that considers multiple factors for effective virtual machine placement and load balancing.The proposed work demonstrates notable improvements of 12.15%,10.68%,8.70%,13.29%,18.46%,and 33.39%for 40 count data of nodes using the artificial bee colony-bat algorithm,ant colony optimization,crow search algorithm,krill herd,whale optimization genetic algorithm,and improved Lévy-based whale optimization algorithm,respectively. 展开更多
关键词 Optimizing cloud computing deployment of virtual machines LOAD-BALANCING twin-fold moth flame algorithm grid computing computational resource distribution data virtualization
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Development of Modified Glasses by Transparent, Functional Hybrid Sol-Gel Nano-Ceramic Coatings, a Comparative Study
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作者 Md. Barkat Ullah Yeasmin Akter +1 位作者 Khodeja Afrin Md. Saiful Quddus 《World Journal of Engineering and Technology》 2024年第1期170-184,共15页
This paper concentrates on the development of glasses with self-cleaning surfaces exhibiting high water contact angles. In this study, we prepared super-hydrophobic nano-ceramic coated glass based on titania & sil... This paper concentrates on the development of glasses with self-cleaning surfaces exhibiting high water contact angles. In this study, we prepared super-hydrophobic nano-ceramic coated glass based on titania & silica using simple sol-gel & dip coating methods and studied the best composition of the coatings by altering ratios of titanium tetraisopropoxide (TTIP)/tetraethyl orthosilicate (TEOS) with different homogenizing agents. We characterized the coatings by surface roughness measurement, percentage of optical transmission, static contact angle, near-infrared (NIR) transmission, and diffuse reflectance. The fabrication of coatings on glass substrates played an important role in increasing the water contact angle of about 95° and visible & NIR transmission of about 90%. We compared our modified glass substrate with commercial low emissivity (Low E) glass using X-ray diffraction (XRD) analysis, which showed pure amorphous surface claiming excellent wettability and thus the prepared glass substrate could have a variety of applications in different fields. 展开更多
关键词 sol-gel Nano-Ceramic Coatings Self-Cleaning Glass Water Contact Angle Optical Transmission
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Sol-gel-based porous Ti-doped tungsten oxide films for high-performance dual-band electrochromic smart windows 被引量:1
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作者 Qiancheng Meng Sheng Cao +6 位作者 Juquan Guo Qingke Wang Ke Wang Tao Yang Ruosheng Zeng Jialong Zhao Bingsuo Zou 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第2期137-143,I0004,共8页
Dual-band electrochromic smart windows(DESWs)with independent control of the transmittance of near-infrared and visible light show great potential in the application of smart and energy-saving buildings.The current st... Dual-band electrochromic smart windows(DESWs)with independent control of the transmittance of near-infrared and visible light show great potential in the application of smart and energy-saving buildings.The current strategy for building DESWs is to screen materials for composite or prepare plasmonic nanocrystal films.These rigorous preparation processes seriously limit the further development of DESWs.Herein,we report a facile and effective sol-gel strategy using a foaming agent to achieve porous Ti-doped tungsten oxide film for the high performance of DESWs.The introduction of foaming agent polyvinylpyrrolidone during the film preparation can increase the specific surface area and free carrier concentration of the films and enhance their independent regulation ability of near-infrared electrochromism.As a result,the optimal film shows excellent dual-band electrochromic properties,including high optical modulation(84.9%at 633 nm and 90.3%at 1200 nm),high coloration efficiency(114.9 cm^(2) C^(-1) at 633 nm and 420.3 cm^(2) C^(-1) at 1200 nm),quick switching time,excellent bistability,and good cycle stability(the transmittance modulation losses at 633 and 1200 nm were 11%and 3.5%respectively after 1000 cycles).A demonstrated DESW fabricated by the sol-gel film showed effective management of heat and light of sunlight.This study represents a significant advance in the preparation of dual-band electrochromic films,which will shed new light on advancing electrochromic technology for future energy-saving smart buildings. 展开更多
关键词 ELECTROCHROMISM Tungsten oxide Smart windows sol-gel method Dual-band absorption
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Comparative structural and electrochemical properties of mixed P2/O′3-layered sodium nickel manganese oxide prepared by sol-gel and electrospinning methods:Effect of Na-excess content 被引量:2
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作者 Thongsuk Sichumsaeng Atchara Chinnakorn +3 位作者 Ornuma Kalawa Jintara Padchasri Pinit Kidkhunthod Santi Maensiri 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第10期1887-1896,共10页
The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X... The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X-ray diffraction results of the prepared NNMO without adding Na-excess content indicate sodium loss,while the mixed phase of P2/O′3-type layered NNMO presented after adding Na-excess content.Compared with the sol-gel method,the secondary phase of NiO is more suppressed by using the electrospinning method,which is further confirmed by field emission scanning electron microscope images.N_(2) adsorption-desorption isotherms show no remarkably difference in specific surface areas between different preparation methods and Na-excess contents.The analysis of X-ray absorption near edge structure indicates that the oxidation states of Ni and Mn are+2 and+4,respectively.For the electrochemical properties,superior electrochemical performance is observed in the NNMO electrode with a low Na-excess content of 5wt%.The highest specific capacitance is 36.07 F·g^(-1)at0.1 A·g^(-1)in the NNMO electrode prepared by using the sol-gel method.By contrast,the NNMO electrode prepared using the electrospinning method with decreased Na-excess content shows excellent cycling stability of 100%after charge-discharge measurements for 300 cycles.Therefore,controlling the Na excess in the precursor together with the preparation method is important for improving the electrochemical performance of Na-based electrode materials in supercapacitors. 展开更多
关键词 sodium nickel manganese oxide mixed P2/O′3-type Na-excess content sol-gel method electrospinning method electrochemical properties
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Investigation of UV photosensor properties of Al-doped SnO_(2) thin films deposited by sol-gel dip-coating method
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作者 Kaour Selma Benkara Salima +2 位作者 Bouabida Seddik Rechem Djamil Hadjeris Lazhar 《Journal of Semiconductors》 EI CAS CSCD 2023年第3期114-123,共10页
Transparent conducting aluminum doped tin oxide thin films were prepared by sol-gel dip coating method with differ-ent Al concentrations and characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), UV-... Transparent conducting aluminum doped tin oxide thin films were prepared by sol-gel dip coating method with differ-ent Al concentrations and characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), UV-Vis spectrophotometry and photoconductivity study. The variation observed in the properties of the measured films agrees with a difference in the film's thickness, which decreases when Al concentration augments. X-ray diffraction analysis reveals that all films are polycrystal-line with tetragonal structure, (110) plane being the strongest diffraction peak. The crystallite size calculated by the Debye Scher-rer’s formula decreases from 11.92 to 8.54 nm when Al concentration increases from 0 to 5 wt.%. AFM images showed grains uni-formly distributed in the deposited films. An average transmittance greater than 80% was measured for the films and an en-ergy gap value of about 3.9 eV was deduced from the optical analysis. Finally, the photosensitivity properties like current-voltage characteristics, ION/IOFF ratio, growth and decay time are studied and reported. Also, we have calculated the trap depth energy using the decay portion of the rise and decay curve photocurrent. 展开更多
关键词 tin oxide thin films sol-gel UV photodetector photoconductivity trap depth
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Structural evolution-enabled BiFeO3 modulated by strontium doping with enhanced dielectric,optical and superparamagnetic properties by a modified sol-gel method
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作者 Sharon V S Veena Gopalan E Malini K A 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期521-530,共10页
Multiferroic(BFO)nanoparticles doped with strontium with the general formula Bi1-xSrx FeO3(x=0,0.3,0.5,0.7)were synthesized using a modified sol-gel auto-combustion process.The structural,electrical,optical,and magnet... Multiferroic(BFO)nanoparticles doped with strontium with the general formula Bi1-xSrx FeO3(x=0,0.3,0.5,0.7)were synthesized using a modified sol-gel auto-combustion process.The structural,electrical,optical,and magnetic properties of the samples are discussed.The structural analysis,carried out using the x-ray powder diffraction technique,shows a structural transition from rhombohedral(R-3c)to cubic(Pm-3m)for the doping amount of strontium(Sr)equal to x=0.3.Morphological analysis of the prepared samples were carried out using scanning electron microscopy(SEM).Frequency-dependent dielectric constant and ac conductivity were studied.The doped samples,with improved dielectric properties,can be used to fabricate different optoelectronic devices.Strong dielectric dispersion and broad relaxation were exhibited by all the samples.Cole–Cole plots were employed as an effective tool to study the dispersion parameters,namely,the optical dielectric constant,static dielectric constant,relaxation time,and spreading factor.The activation energy was calculated from the relaxation peaks and Cole–Cole plots,which were found to be compatible with each other.The bandgap of the samples was calculated using diffuse reflectance spectral(DRS)analysis.Sharp and strong photoluminescence in the IR region was observed in the samples,similar to ZnO,which was reported for the first time.Room-temperature and low-temperature magnetization studies point towards the superparamagnetic nature of the samples,with an improvement in magnetic properties with doping.The antiferromagnetic behavior of bulk bismuth ferrite transforms to superparamagnetic in nature for both pure and Sr-substituted bismuth ferrite nanoparticles due to the close dimensions of crystallite size with magnetic domains leading to the break-down of the frustrated spin cycloidal moment. 展开更多
关键词 MULTIFERROICS sol-gel process x-ray spectra optical and dielectric properties
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Application of g-C_(3)N_(4)/sol-gel nanocomposite on AM60B magnesium alloy and investigation of its properties
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作者 Roghaye Samadianfard Davod Seifzadeh Burak Dikici 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第6期1113-1127,共15页
To protect the AM60B magnesium alloy from corrosion,a sol-gel coating containing hydroxylated g-C_(3)N_(4)nanoplates was applied.The chemical composition of the hydroxylated g-C_(3)N_(4)nanoplates was investigated usi... To protect the AM60B magnesium alloy from corrosion,a sol-gel coating containing hydroxylated g-C_(3)N_(4)nanoplates was applied.The chemical composition of the hydroxylated g-C_(3)N_(4)nanoplates was investigated using X-ray photoelectron spectroscopy(XPS).The hydroxylation process did not affect the crystal size,specific surface area,pore volume,average pore diameter,and thermal stability of the g-C_(3)N_(4)nanoplates.After incorporating pristine and hydroxylated g-C_(3)N_(4)nanoplates,dense sol-gel coatings were obtained.Transmission electron microscopy(TEM)revealed the uniform distribution of the modified g-C_(3)N_(4)in the coating.The average roughness of the coating was also reduced after adding the modified nanoplates due to the decreased aggregation tendency.Electrochemical impedance spectroscopy(EIS)examinations in simulated acid rain revealed a significant improvement in the anticorrosion properties of the sol-gel film after the addition of the modified g-C_(3)N_(4)due to the chemical bonding of the coating to the nanoplates. 展开更多
关键词 Mg alloy corrosion protection sol-gel g-C_(3)N_(4)nanocomposite electrochemical impedance spectroscopy
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Moth Flame Optimization Based FCNN for Prediction of Bugs in Software
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作者 C.Anjali Julia Punitha Malar Dhas J.Amar Pratap Singh 《Intelligent Automation & Soft Computing》 SCIE 2023年第5期1241-1256,共16页
The software engineering technique makes it possible to create high-quality software.One of the most significant qualities of good software is that it is devoid of bugs.One of the most time-consuming and costly softwar... The software engineering technique makes it possible to create high-quality software.One of the most significant qualities of good software is that it is devoid of bugs.One of the most time-consuming and costly software proce-dures isfinding andfixing bugs.Although it is impossible to eradicate all bugs,it is feasible to reduce the number of bugs and their negative effects.To broaden the scope of bug prediction techniques and increase software quality,numerous causes of software problems must be identified,and successful bug prediction models must be implemented.This study employs a hybrid of Faster Convolution Neural Network and the Moth Flame Optimization(MFO)algorithm to forecast the number of bugs in software based on the program data itself,such as the line quantity in codes,methods characteristics,and other essential software aspects.Here,the MFO method is used to train the neural network to identify optimal weights.The proposed MFO-FCNN technique is compared with existing methods such as AdaBoost(AB),Random Forest(RF),K-Nearest Neighbour(KNN),K-Means Clustering(KMC),Support Vector Machine(SVM)and Bagging Clas-sifier(BC)are examples of machine learning(ML)techniques.The assessment method revealed that machine learning techniques may be employed successfully and through a high level of accuracy.The obtained data revealed that the proposed strategy outperforms the traditional approach. 展开更多
关键词 Faster convolution neural network moth Flame Optimization(MFO) Support Vector Machine(SVM) AdaBoost(AB) software bug prediction
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飞蛾扑火优化的尺度比例感知空间长期跟踪器
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作者 黄鹤 熊武 +3 位作者 杨澜 吴琨 王会峰 高涛 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2024年第5期130-141,共12页
针对无人机长期跟踪过程中尺度变换导致目标丢失和跟踪精度低的问题,提出了一种基于飞蛾扑火优化(moth-flame optimization,MFO)的尺度比例感知空间长期跟踪器。首先,设计了高斯初始化以代替飞蛾扑火优化算法的随机初始化策略,降低优化... 针对无人机长期跟踪过程中尺度变换导致目标丢失和跟踪精度低的问题,提出了一种基于飞蛾扑火优化(moth-flame optimization,MFO)的尺度比例感知空间长期跟踪器。首先,设计了高斯初始化以代替飞蛾扑火优化算法的随机初始化策略,降低优化算法在跟踪过程中的计算复杂度,减少算力浪费;其次,结合快速梯度直方图特征,构建了改进的飞蛾扑火优化跟踪器;然后,为了解决无人机航拍长期跟踪中目标尺度变化的问题,设计了一种自适应尺度变换的判别尺度空间跟踪(discriminative scale space tracking,DSST)算法,进一步提出了一种尺度比例感知空间跟踪器,解决了尺度滤波器中因长宽比固定而导致的跟踪漂移;同时,分析了滤波器响应峰值在各背景下的变化情况,提出了一种能反映环境变化下跟踪置信度的指标,并通过置信度将MFO优化跟踪框架与尺度比例感知空间跟踪器相结合,解决了尺度变化与长期跟踪目标丢失的问题;最后,在无人机长期跟踪数据集上开展了性能验证。结果表明:提出的算法可有效防止漂移现象的发生,提升跟踪效率;与目前跟踪领域中12种同类文献算法进行对比可知,提出的算法精度较高,满足实时性,能够有效解决无人机长期跟踪下的尺度变化及目标丢失等问题。 展开更多
关键词 无人机 飞蛾扑火优化 DSST跟踪算法 相关滤波 长期跟踪
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吉林省中西部地区灯下蛾类群落结构及多样性
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作者 孙嵬 潘艺元 +3 位作者 苏前富 杨微 周佳春 高月波 《植物保护》 CAS CSCD 北大核心 2024年第2期267-277,共11页
为探明吉林省中西部地区蛾类昆虫的种类及组成,提供蛾类群落的多样性资料,本研究于2017年-2020年利用高空探照灯逐日诱集蛾类昆虫并分类,明确不同昆虫季节性种群动态,在此基础上对蛾类群落多样性进行分析。结果共采集、鉴定蛾类昆虫18科... 为探明吉林省中西部地区蛾类昆虫的种类及组成,提供蛾类群落的多样性资料,本研究于2017年-2020年利用高空探照灯逐日诱集蛾类昆虫并分类,明确不同昆虫季节性种群动态,在此基础上对蛾类群落多样性进行分析。结果共采集、鉴定蛾类昆虫18科227种,优势科为夜蛾科,种数占比达到49.34%。按为害植物类别,可分为农业害虫、林业害虫、果树害虫、蔬菜害虫等。蛾类昆虫4月始见,7、8月群落丰富度最高,7月群落多样性最高,群落均匀性随时间变化不明显。明确了不同月份优势度指数较高的种类。7、8月的蛾类群落相似性高,4、10月与各月的相似性低。本研究结果可为此区域蛾类害虫的监测预警与综合治理提供基础理论依据。 展开更多
关键词 蛾类害虫 种类组成 高空探照灯 虫源来源 群落多样性
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交配前后雌雄桑蚕蛾营养价值评价
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作者 林碧敏 钟杨生 +3 位作者 潘子文 张莹 严会超 陈芳艳 《食品与发酵工业》 CAS CSCD 北大核心 2024年第2期145-152,共8页
为深入了解桑蚕蛾的营养物质成分,检测了交配前后9芙雌雄蚕蛾蛋白质、脂肪酸和氨基酸的组成和含量。通过粗蛋白、粗脂肪、不饱和脂肪酸含量、动脉粥样硬化指数(indices of atherogenicity,IA)、血栓形成指数(thrombogenicity,IT)以及氨... 为深入了解桑蚕蛾的营养物质成分,检测了交配前后9芙雌雄蚕蛾蛋白质、脂肪酸和氨基酸的组成和含量。通过粗蛋白、粗脂肪、不饱和脂肪酸含量、动脉粥样硬化指数(indices of atherogenicity,IA)、血栓形成指数(thrombogenicity,IT)以及氨基酸评分、化学评分、必需氨基酸指数(essential amino acid index,EAAI)、营养指数(nutrition index,NI)和生物价(biological value,BV)等指标评价了蚕蛾的营养价值。结果表明,蚕蛾氨基酸和不饱和脂肪酸含量丰富,交配前雌蛾蛋白质(21.6%,鲜重)、总氨基酸(46.94 g/100 g)、必需氨基酸含量(15.86%)以及EAAI(99.33)、NI(21.45)和BV(96.57)最高,同时含有丰富的甜味、药效和支链氨基酸,粗脂肪含量(7.11%,鲜重)低,多不饱和脂肪酸占比(78.18%)高,IA(0.21)和IT(0.14)低,是理想的蛋白源。交配后的雄蛾粗脂肪(24.46%,鲜重)、不饱和脂肪酸(44.31 g/100 g)、亚麻酸含量(19.37 g/100 g)最高,IA(0.28)和IT(0.22)指数较低,是提取不饱和脂肪酸的优质原料。该研究为桑蚕蛾在食品领域的开发应用提供了理论依据。 展开更多
关键词 桑蚕蛾 粗蛋白 粗脂肪 脂肪酸 氨基酸 营养评价
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支持多任务的综合电子系统动态重构设计与实现
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作者 王小辉 张涛 陈春燕 《电子技术应用》 2024年第7期71-77,共7页
为了满足无人机多任务模式的要求,有效实现任务重构,对多任务模式下综合电子系统的重构问题进行研究,提出一种基于改进飞蛾扑火优化算法的重构算法。根据综合电子系统重构模型和重构算法,设计了多任务可重构综合电子系统。针对改进的飞... 为了满足无人机多任务模式的要求,有效实现任务重构,对多任务模式下综合电子系统的重构问题进行研究,提出一种基于改进飞蛾扑火优化算法的重构算法。根据综合电子系统重构模型和重构算法,设计了多任务可重构综合电子系统。针对改进的飞蛾扑火优化算法进行了仿真实验,并对实验结果进行分析验证,与差分进化算法和标准飞蛾扑火优化算法进行对比实验。实验证明重构算法通过对多目标进行优化,能够快速迭代生成高质量的重构蓝图,满足了综合电子系统的多任务模式需求。 展开更多
关键词 综合电子系统 重构 飞蛾扑火优化算法
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桃小食心虫性信息素的合成 被引量:1
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作者 王颎琳 孙效 +3 位作者 吴建伟 边庆花 王敏 钟江春 《农药学学报》 CAS CSCD 北大核心 2024年第2期402-407,共6页
桃小食心虫是我国最严重的蛀果害虫之一,利用其性信息素进行防控,具有高效、环保及不易产生抗性等优点。天然桃小食心虫性信息素(Z)-12-十九碳烯-9-酮与(Z)-13-二十碳烯-10-酮在昆虫体内含量极低,通过人工提取无法满足大规模防治需求。... 桃小食心虫是我国最严重的蛀果害虫之一,利用其性信息素进行防控,具有高效、环保及不易产生抗性等优点。天然桃小食心虫性信息素(Z)-12-十九碳烯-9-酮与(Z)-13-二十碳烯-10-酮在昆虫体内含量极低,通过人工提取无法满足大规模防治需求。本研究以3-溴-1-丙醇为原料,经四氢吡喃基(THP)保护、亲核取代、Brown P2-Ni还原(Ni(OAc)_(2)与NaBH4催化氢化)、格氏试剂加成与重铬酸吡啶鎓(PDC)氧化等7步反应,构建了一种高效合成桃小食心虫性信息素的方法;并首次将Brown P2-Ni还原用于桃小食心虫性信息素顺式碳碳双键的构建,总收率为5%。所构建的桃小食心虫性信息素合成方法操作简便,产品具有高度的区域选择性(Z:E>99:1),适用于桃小食心虫的绿色防控。 展开更多
关键词 桃小食心虫 性信息素 合成 Brown P2-Ni还原
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Sol-Gel法制备ZnO压敏陶瓷及其电性 被引量:30
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作者 刘素琴 黄可龙 +1 位作者 宋志方 彭斌 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2000年第2期376-380,共5页
采用溶胶-凝胶(sol-gel)工艺制备ZnO电压敏陶瓷粉体.探讨其制备的最佳工艺条件:以 Zn(NO3)2与 NaOH为反应前驱物制取胶体, Zn2+浓度控制在 0.5mol·L-1以上, pH值7.5左右,预烧温... 采用溶胶-凝胶(sol-gel)工艺制备ZnO电压敏陶瓷粉体.探讨其制备的最佳工艺条件:以 Zn(NO3)2与 NaOH为反应前驱物制取胶体, Zn2+浓度控制在 0.5mol·L-1以上, pH值7.5左右,预烧温度300℃,陶瓷烧结温度1200℃;制得的压敏电阻的非线性系数α=28;研究了稀土La2O3掺杂对该陶瓷电性的影响:低浓度掺杂时,可提高压敏电压,高浓度掺杂时;不呈现压敏特性;对粉体进行了X射线衍射和透射电镜分析,预烧后得到五元掺杂的ZnO粉体粒形呈球状,属六方晶系,粒径分布窄,约为40~80nm. 展开更多
关键词 ZnO陶瓷 sol-gel 压敏电阻
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TiO_2的微波辐射Sol-Gel法制备及其光催化性能 被引量:8
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作者 夏启斌 李忠 +2 位作者 奚红霞 徐科峰 肖静 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2003年第11期92-96,共5页
采用微波辐射Sol Gel法在石英砂表面制备负载型TiO2 光催化剂 ,考察不同加热方式 ,微波功率以及微波加热温度对溶胶质量的影响 ,微波加热反应制备的溶胶粒子平均粒径小于常规加热反应制备得到的溶胶粒子 ,微波加热反应适宜条件是微波功... 采用微波辐射Sol Gel法在石英砂表面制备负载型TiO2 光催化剂 ,考察不同加热方式 ,微波功率以及微波加热温度对溶胶质量的影响 ,微波加热反应制备的溶胶粒子平均粒径小于常规加热反应制备得到的溶胶粒子 ,微波加热反应适宜条件是微波功率6 0 0W ,反应温度为 90℃ .以苯酚为光催化降解研究对象 ,考察了两种方式制备的负载型TiO2 光催化剂的催化性能 ,实验结果表明微波辐射Sol Gol法制备的负载型TiO2 光催化剂光催化性能也优于常规Sol Gel法制备的负载型TiO2 光催化剂 . 展开更多
关键词 二氧化钛 微波 sol-gel 光催化
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Sol-Gel技术与纳米材料的化学剪裁 被引量:50
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作者 孙继红 张晔 +2 位作者 范文浩 吴东 孙予罕 《化学进展》 SCIE CAS CSCD 1999年第1期80-85,共6页
本文以SiO2纳米材料为实例,阐述了sol-gel化学的基本概念,讨论了SiO2纳米材料在结构剪裁和性能调控方面的研究进展和前沿问题,并指出sol-gel技术已经成为实现化学剪裁合成纳米材料的主要手段。
关键词 纳米技术 sol-gel 化学裁剪 纳米材料 二氧化硅
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基于改进飞蛾扑火优化算法的奶牛隐性乳腺炎特征选择 被引量:1
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作者 王智慧 代永强 刘欢 《黑龙江畜牧兽医》 CAS 北大核心 2024年第4期8-16,共9页
为了提高大型牧场奶牛隐性乳腺炎的诊断速度和准确率,进而降低奶牛养殖企业诊疗成本,本研究在基本算法中引入3种不同的改进策略,设计了一种新的飞蛾扑火优化(improved moth-flame optimization,IMFO)算法,在公认的加州大学欧文分校(univ... 为了提高大型牧场奶牛隐性乳腺炎的诊断速度和准确率,进而降低奶牛养殖企业诊疗成本,本研究在基本算法中引入3种不同的改进策略,设计了一种新的飞蛾扑火优化(improved moth-flame optimization,IMFO)算法,在公认的加州大学欧文分校(university of California Irvine,UCI)数据集上测试和评估了IMFO算法在奶牛隐性乳腺炎特征选择中的性能,并将试验结果与其他4种算法的测试结果进行比较分析,将IMFO算法用于奶牛群体改良(dairy herd improvement,DHI)数据的特征选择,并使用K最邻近(K-nearest neighbor,KNN)分类算法进行分类。结果表明:IMFO算法通过引入最优火焰引导(optimal flame guidance,OFG)策略,在寻优过程中使火焰和全局最优个体共同引导飞蛾飞行方向,有效避免了特征选择算法陷入局部最优;通过引入初始化混沌反向学习(initialize chaotic reverse learning,ICR)策略和自适应扰动(adaptive disturbance,AD)策略,提高了初始化模型的空间多样性和质量,增加了种群的多样性,避免了特征选择算法的早熟收敛。将IMFO特征选择算法和其他比较算法在UCI数据集和奶牛隐性乳腺炎疾病数据集上进行试验验证,IMFO与其他算法相比具有更好的特征筛选能力,有效提高了对奶牛隐性乳腺炎的预测性能。说明IMFO算法可提高大型牧场奶牛隐性乳腺炎的诊断速度和准确率。 展开更多
关键词 特征选择 飞蛾扑火优化算法 奶牛隐性乳腺炎 分类预测 火焰 种群多样性
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不同Ti/Ba摩尔比的钛酸钡纳米晶粉体的Sol-gel法制备与表征 被引量:18
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作者 吴淑荣 李东升 +1 位作者 畅柱国 熊为淼 《功能材料》 EI CAS CSCD 北大核心 1999年第2期179-181,共3页
采用Sol-gel法制备了不同Ti/Ba摩尔比的BayTixO3(x/y=0.990,1.000,1.010,1.020,1.045)纳米晶粉体。应用热分析、X射线粉末衍射、激光和透射电镜等技术对干凝胶热分解历程和粉... 采用Sol-gel法制备了不同Ti/Ba摩尔比的BayTixO3(x/y=0.990,1.000,1.010,1.020,1.045)纳米晶粉体。应用热分析、X射线粉末衍射、激光和透射电镜等技术对干凝胶热分解历程和粉体性能进行了研究,发现随Ti/Ba摩尔比的增加,粉体的平均晶粒尺寸、晶体结构和粉体粒度分布各呈现规律性变化。 展开更多
关键词 钛酸钡 纳米晶粉体 Ti/Ba摩尔比 sol-gel 表征
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