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基于项目式课程的PEAS教学平台设计与实现
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作者 曾晨曦 陈静 《办公自动化》 2024年第9期13-15,34,共4页
项目式课程改革已成为职业教育三教改革的发展趋势和改革重点,在课程改革实践过程中,教师常常面临教学资源整合困难、项目管理效率低下以及学生成果展示受限等问题。为解决这些问题,设计与实现基于项目式课程的PEAS教学平台,以学生为中... 项目式课程改革已成为职业教育三教改革的发展趋势和改革重点,在课程改革实践过程中,教师常常面临教学资源整合困难、项目管理效率低下以及学生成果展示受限等问题。为解决这些问题,设计与实现基于项目式课程的PEAS教学平台,以学生为中心,强调项目经验的积累与共享,并提供综合的项目管理工具与数据分析功能,从而优化项目式课程的教学效果和学习体验,为项目式教学的实施提供有力支持,以期能为高校项目化教学信息平台建设提供经验和借鉴。 展开更多
关键词 项目式课程 项目经验积累与共享(peas)教学平台 平台设计与实现
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Evaluation of Rhizobium tropici-Derived Extracellular Polymeric Substances on Selected Soil Properties, Seed Germination, and Growth of Black-Eyed Peas (Vigna unguiculata)
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作者 Jonathan Alunge Metuge Erneste Havugimana +2 位作者 Jean Rugandirababisha Zachary N. Senwo Marie Chantal Mutimawurugo 《Agricultural Sciences》 2024年第5期548-564,共17页
Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility ... Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary. 展开更多
关键词 Rhizobium tropici Extracellular Polymeric Substances Soil Respiration Soil Microbial Biomass Black-Eyed peas
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PEAS抗静电母粒对HDPE单向拉膜性能的影响
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作者 王乃华 《塑料科技》 CAS 1998年第6期44-46,共3页
本文介绍了HDPE单向拉伸的生产配方和工艺,PEAS母粒对该产品具有良好的抗静电性,表面电阻达到1012Ω以下,以及母粒的用量与薄膜的强度、雾度之间的关系。
关键词 peas 抗静电母粒 表面电阻率 高密度聚乙烯 拉伸
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The Chemical Quality of Some Legumes, Peas, Fava Beans, Blue and White Lupins and Soybeans Cultivated in Finland
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作者 Marketta Saastamoinen Merja Eurola Veli Hietaniemi 《Journal of Agricultural Science and Technology(B)》 2013年第2期92-100,共9页
The cultivation and management of different legume species and their varieties were tested in South-Western Finland at farmers' fields in two years, 2010 and 2011. The studied legumes were peas and lava beans, and in... The cultivation and management of different legume species and their varieties were tested in South-Western Finland at farmers' fields in two years, 2010 and 2011. The studied legumes were peas and lava beans, and included also such species which are seldom or not normally cultivated in Finland, namely soybeans and blue and white lupins. Seed samples were collected from legume farms. The quality of different legume species was analysed and compared to each others. The chemical qualities were analysed for crude protein, fat, fibre, ash, nitrogen-free extract and phytic acid contents, and amino acid composition. The quality of the varieties of lupins and soybeans were compared to the quality of pea and fava bean varieties, which are generally cultivated nowadays in Finland. The highest protein contents were in soybean (369 and 379 g kg^-1) and white lupin (382 g kg^-1) and the lowest in pea varieties. Amino acid composition of legumes is good, but lupins have lower lysine content (g 100 g^-1 protein) than other legumes. High fat contents were in soybeans (91 and 100 g kg^-1) and white lupin (101 g kgl), and moderate in blue lupin (30-49 g kg^-1). Fuego fava bean variety had lower protein content than Kontu. The highest phytic acid contents were in soybeans (18.9 and 22.6 mg kg^-1) and the lowest in white lupin (6.2 mg kg^-1). Lupins are interesting protein crops, especially white lupin with high protein and fat and low phytic acid contents. Lupins are not day length sensitive, like soybean, and therefore valuable for long-day cultivation conditions The present research strengthens the good chemical quality of legumes for food and feed purposes. 展开更多
关键词 Protein fat amino acids phytic acid peas fava beans SOYBEANS blue and white lupins
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Intervarietal Variation in Proximate Composition and Antioxidant Potential of Dry Peas (Pisum sativum L)
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作者 Majeed Mudasir Chatha Shahzad-Ali-Shahid +3 位作者 Hussain Abdullah-ljaz ASI Muhammad-Rafique Mahboob Shahid Yousaf Muhammad 《Journal of Chemistry and Chemical Engineering》 2010年第11期7-15,共9页
The present research work was carried out to investigate the proximate composition and antioxidant capacities of newly invented varieties of dry peas. The proximate composition in terms of moisture (7.00-8.50%), ash... The present research work was carried out to investigate the proximate composition and antioxidant capacities of newly invented varieties of dry peas. The proximate composition in terms of moisture (7.00-8.50%), ash (3.85-4.97%), fiber (3.8-12.3%) and protein (17.3-18.8%) contents varied significantly with respect to various cultivars. Total phenolic contents (TPC), total flavonoids contents (TFC), percentage inhibition of peroxidation of linoleic acid system, reducing power and DPPH free radical scavenging capacity of different dry peas extracts were found in range of 0.651-0.684 g/100g of GAE, 0.021-0.041 g/100g of CE, 0.713-0.895, 40.051-84.608%, 18.097-24.591 mg/mL, respectively. The amount of TFC, and percent inhibition of per oxidation in linoleic system of different dry peas extracts varied significantly among various cultivars and solvents. From the results of present investigations it is reasonable to say that 80% methanolic extracts of dry peas have exhibited varying degree of antioxidant activity. 展开更多
关键词 Dry peas proximate analysis antioxidant activity source of antioxidant.
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Prognostic value of PEA3 subfamily gene expression in cholangiocarcinoma
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作者 Li Wang Zhe Zhang Hai-Zhang Ma 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第9期4014-4027,共14页
BACKGROUND Cholangiocarcinoma(CCA)is a lethal malignancy with limited treatment options and poor prognosis.The PEA3 subfamily of E26 transformation specific genes:ETV1,ETV4,and ETV5 are known to play significant roles... BACKGROUND Cholangiocarcinoma(CCA)is a lethal malignancy with limited treatment options and poor prognosis.The PEA3 subfamily of E26 transformation specific genes:ETV1,ETV4,and ETV5 are known to play significant roles in various cancers by influencing cell proliferation,invasion,and metastasis.AIM To analyze PEA3 subfamily gene expression levels in CCA and their correlation with clinical parameters to determine their prognostic value for CCA.METHODS The expression levels of PEA3 subfamily genes in pan-cancer and CCA data in the cancer genome atlas and genotype-tissue expression project databases were analyzed with R language software.Survival curve and receiver operating characteristic analyses were performed using the SurvMiner,Survival,and Procr language packages.The gene expression profiling interactive analysis 2.0 database was used to analyze the expression levels of PEA3 subfamily genes in different subtypes and stages of CCA.Web Gestalt was used to perform the gene ontology/Kyoto encyclopedia of genes and genomes(GO/KEGG)analysis,and STRING database analysis was used to determine the genes and proteins related to PEA3 subfamily genes.RESULTS ETV1,ETV4,and ETV5 expression levels were significantly increased in CCA.There were significant differences in ETV1,ETV4,and ETV5 expression levels among the different subtypes of CCA,and predictive analysis revealed that only high ETV1 and ETV4 expression levels were significantly associated with shorter overall survival in patients with CCA.GO/KEGG analysis revealed that PEA3 subfamily genes were closely related to transcriptional misregulation in cancer.In vitro and in vivo experiments revealed that PEA3 silencing inhibited the invasion and metastasis of CCA cells.CONCLUSION The expression level of ETV4 may be a predictive biomarker of survival in patients with CCA. 展开更多
关键词 PEA3 subfamily CHOLANGIOCARCINOMA The cancer genome atlas ETV4 The prognosis Prognostic biomarker
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Treatment and Clinical Management of Chronic Thromboembolic Pulmonary Hypertension:An Update of Literature Review
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作者 Yuan Ren Yingxian Sun +1 位作者 Zhiguang Yang Yanli Chen 《Congenital Heart Disease》 SCIE 2024年第2期157-176,共20页
Chronic thromboembolic pulmonary hypertension(CTEPH)is a chronic,progressive,debilitating,and life-threa-tening complication of pulmonary embolism(PE).Recent technological advances have permitted various treat-ment op... Chronic thromboembolic pulmonary hypertension(CTEPH)is a chronic,progressive,debilitating,and life-threa-tening complication of pulmonary embolism(PE).Recent technological advances have permitted various treat-ment options for the treatment of CTEPH,including surgery,angioplasty,and medical treatment,depending on the location and characteristics of lesions.Pulmonary endarterectomy(PEA)is the treatment of choice for CTEPH,as it offers excellent long-term outcomes and a high probability of recovery.Moreover,various medical and interventional therapies are currently being developed for patients with inoperable CTEPH.This review mainly summarizes the current treatment approaches of CTEPH,offering more options for specialist physicians to,thus,better manage chronic thromboembolic syndromes. 展开更多
关键词 Chronic thromboembolic pulmonary hypertension(CTEPH) chronic thromboembolic pulmonary disease(CTEPD) pulmonary endarterectomy(PEA) balloon pulmonary angioplasty(BPA) COVID-19
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Comparative study of green peas using with blanching & without blanching techniques
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作者 Om Prakash Pandey Bimal Kumar Mishra Ashok Misra 《Information Processing in Agriculture》 EI 2019年第2期285-296,共12页
This paper attempts to analyze the kinetics involved in the drying of green peas in‘with blanching’and‘without blanching’techniques.Blanching by hot water mixed with a solution of citric acid(0.1–0.2 mg/ml)at 70... This paper attempts to analyze the kinetics involved in the drying of green peas in‘with blanching’and‘without blanching’techniques.Blanching by hot water mixed with a solution of citric acid(0.1–0.2 mg/ml)at 70C–100C is the treatment provided to the samples of green peas.Experimental analysis shows that the moisture content in green peas of three different sizes is reduced at different temperatures and demonstrates the effect of the rate of drying of the moisture content.Under different diameters and temperatures,the parameters are analyzed using‘with blanching’and‘without blanching’techniques.It is observed that‘with blanching’process plays a significant role in the reduction of moisture content under different temperatures and diameters in a lesser time as compared to‘without blanching’.The operative activation energy and moisture diffusivity are described by using Fick’s law of diffusion.The calculation of effective moisture diffusivity can be done via the utilization of slope.The drying data is subjected to two models of mathematical nature:Simple Exponential model,and Page model.The performance of these models is examined by means of comparing the coefficient of determination(R2),chi-square(v2)and root mean square error(RMSE)between the experimental and forecasted value of moisture ratio obtained‘with blanching’and‘without blanching’.The experimental data was seen to be in accordance with the Page model.The comparisons of energy consumption,energy efficiency and also the cost of the drying processes for‘with blanching’and‘without blanching’have been accomplished to optimize and reduce process condition and the cost of the process,respectively. 展开更多
关键词 Hot air drying Green peas Drying kinetics BLANCHING Fluidized bed dryer
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The war of protecting peas
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《小学生必读(高年级版)》 2017年第6期36-37,共2页
关键词 The war of protecting peas
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安徽省优秀运动员对兴奋剂使用态度的调查研究 被引量:1
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作者 夏俊 宣磊 《当代体育科技》 2023年第13期45-48,共4页
为了有效地对安徽省专业运动员施行反兴奋剂宣传教育,通过调查专业运动员对使用兴奋剂的态度,分析不同因素对运动员态度变化影响的差异性。结果表明,当前专业运动员对兴奋剂使用态度仍处于良好水平,男性运动员与女性运动员使用兴奋剂的... 为了有效地对安徽省专业运动员施行反兴奋剂宣传教育,通过调查专业运动员对使用兴奋剂的态度,分析不同因素对运动员态度变化影响的差异性。结果表明,当前专业运动员对兴奋剂使用态度仍处于良好水平,男性运动员与女性运动员使用兴奋剂的风险相同。随着运动员年龄的增加,训练年限的增加,运动员等级的提升,运动员使用兴奋剂的风险随之降低。相较于非接触性运动项目,接触性运动项目具有更高的兴奋剂风险,建议接触性运动项目应作为反兴奋剂教育的重点。 展开更多
关键词 运动员 兴奋剂 态度 peas
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压电执行器改进Bouc-Wen模型及其定位补偿控制研究 被引量:4
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作者 周民瑞 周振华 +2 位作者 刘鑫 曹太山 李战慧 《振动与冲击》 EI CSCD 北大核心 2023年第10期155-164,共10页
针对多数迟滞模型无法描述压电陶瓷执行器(piezoelectric actuator,PEA)的非对称、率相关迟滞非线性,提出一种改进Bouc-Wen(improved Bouc-Wen,IBW)模型并基于提出的IBW模型对其补偿控制进行试验研究。首先,基于传统Bouc-Wen(classical ... 针对多数迟滞模型无法描述压电陶瓷执行器(piezoelectric actuator,PEA)的非对称、率相关迟滞非线性,提出一种改进Bouc-Wen(improved Bouc-Wen,IBW)模型并基于提出的IBW模型对其补偿控制进行试验研究。首先,基于传统Bouc-Wen(classical Bouc-Wen,CBW)迟滞模型引入两项非对称项并引入二阶IIR滤波器以精确描述压电陶瓷执行器的迟滞非线性,进一步分析了模型参数值与频率变化规律并修正率相关参数。然后,搭建基于NI CompactRIO测控系统压电陶瓷执行器精密定位试验平台,对提出的IBW模型进行了试验验证并基于IBW模型对其补偿控制进行了试验研究。试验结果表明:IBW模型性能显著优于传统Bouc-Wen模型和增强型Bouc-Wen(enhanced Bouc-Wen,EBW)模型,对于激励频率10~100 Hz多频正弦信号,IBW模型均方根误差相较于CBW模型和EBW模型分别下降了82.07%和62.10%,试验中压电陶瓷执行器实测最大输出位移6.15μm,基于IBW模型所提出复合补偿控制均方根误差为0.039μm,仅为最大输出位移的0.64%,最大跟踪误差仅为0.153μm。若忽略测量噪声,定位误差接近于零,说明所提出的IBW模型及其补偿控制算法有助于实现压电陶瓷执行器的高速、宽频超精密定位及主动振动控制。 展开更多
关键词 压电陶瓷执行器(PEA) 动态非对称迟滞 改进Bouc-Wen(IBW)模型 迟滞补偿控制
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Development of an Agrobacterium-mediated CRISPR/Cas9 system in pea(Pisum sativum L.) 被引量:2
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作者 Guan Li Rong Liu +15 位作者 Rongfang Xu Rajeev KVarshney Hanfeng Ding Mengwei Li Xin Yan Shuxian Huang Juan Li Dong Wang Yishan Ji Chenyu Wang Junguang He Yingfeng Luo Shenghan Gao Pengcheng Wei Xuxiao Zong Tao Yang 《The Crop Journal》 SCIE CSCD 2023年第1期132-139,共8页
Pea(Pisum sativum L.)is an annual cool-season legume crop.Owing to its role in sustainable agriculture as both a rotation and a cash crop,its global market is expanding and increased production is urgently needed.For ... Pea(Pisum sativum L.)is an annual cool-season legume crop.Owing to its role in sustainable agriculture as both a rotation and a cash crop,its global market is expanding and increased production is urgently needed.For both technical and regulatory reasons,neither conventional nor transgenic breeding techniques can keep pace with the demand for increased production.In answer to this challenge,CRISPR/Cas9 genome editing technology has been gaining traction in plant biology and crop breeding in recent years.However,there are currently no reports of the successful application of the CRISPR/Cas9 genome editing technology in pea.We developed a transient transformation system of hairy roots,mediated by Agrobacterium rhizogenes strain K599,to validate the efficiency of a CRISPR/Cas9 system.Further optimization resulted in an efficient vector,PsU6.3-tRNA-PsPDS3-en35S-PsCas9.We used this optimized CRISPR/Cas9 system to edit the pea phytoene desaturase(PsPDS)gene,causing albinism,by Agrobacterium-mediated genetic transformation.This is the first report of successful generation of gene-edited pea plants by this route. 展开更多
关键词 Agrobacterium-mediated transformation CRISPR/Cas9 PEA Genome editing
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Physical and emulsifying properties of pea protein:influence of combined physical modification by flaxseed gum and ultrasonic treatment 被引量:1
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作者 Jia Yang Fenghong Huang +6 位作者 Qingde Huang Da Ma Yashu Chen Dengfeng Peng Xiao Yu Qianchun Deng Fang Geng 《Food Science and Human Wellness》 SCIE CSCD 2023年第2期431-441,共11页
This study characterized and compared the physical and emulsifying properties of pea protein(PP)and its modified proteins(ultrasound treated-PP(PPU),flaxseed gum(FG)treated PP(PPFG)and ultrasound treated-PPFG(PPFGU)).... This study characterized and compared the physical and emulsifying properties of pea protein(PP)and its modified proteins(ultrasound treated-PP(PPU),flaxseed gum(FG)treated PP(PPFG)and ultrasound treated-PPFG(PPFGU)).The results showed FG triggered the formation of loosely attached complex with PP via physical modification under gentle magnetic stirring at pH 7.0,while ultrasound played an important role in reducing protein size,increasing surface hydrophobicity and molecular fluidity onto oil-water interface.So ultrasound further enhanced the interaction of PP with FG,and produced the PPFGU complex with smaller droplet size,higherζ-potential and lower turbidity.Further,combination of FG and ultrasound improved the physical properties of PP with higher viscosity,stiffer gels(defined as higher elastic modulus),stronger hydrophobic properties,better thermal stability,and fast protein absorption rate.Therefore,the PPFGU coarse emulsion performed highest emulsifying activity index(EAI)and emulsion stability index(ESI)that the stabilized nanoemulsion obtained smallest droplet size,higherζ-potential,and longest storage stability.The combination of FG and ultrasonic treatment will be an effective approach to improving the emulsifying property and thermal stability of PP,which can be considered as a potential plant-based emulsifier applied in the food industry. 展开更多
关键词 Pea protein Flaxseed gum Ultrasonic treatment Emulsifying properties Physical properties
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基于二维钙钛矿(PEA)_(2)PbI_(4)的光电探测器
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作者 蔡凯 靳志文 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2023年第9期1069-1075,I0004,共8页
二维(2D)钙钛矿以其固有的量子阱结构、较大的激子结合能和良好的稳定性,在光电应用领域中具有广阔的前景。然而,提高二维钙钛矿薄膜质量、降低成本并简化制备工艺仍然面临巨大的挑战。本工作在低退火温度(80℃)且无需其他特殊处理的条... 二维(2D)钙钛矿以其固有的量子阱结构、较大的激子结合能和良好的稳定性,在光电应用领域中具有广阔的前景。然而,提高二维钙钛矿薄膜质量、降低成本并简化制备工艺仍然面临巨大的挑战。本工作在低退火温度(80℃)且无需其他特殊处理的条件下,采用溶液法制备高质量二维钙钛矿(PEA)_(2)PbI_(4)薄膜,并进一步制备了光电探测器。结果表明,这种光电探测器有较低的暗电流(10^(-11)A),在450 nm光照下具有良好的响应度(107 mA·W^(-1))、较高的探测率(2.05×10^(12)Jones)和快速响应时间(250μs/330μs)。持续控制光照1200 s后,器件可以保持95%的光电流。此外,器件静置30 d后光电流几乎保持不变。本研究为开发稳定和高性能光电器件提供了良好的途径。 展开更多
关键词 二维钙钛矿 (PEA)_(2)PbI_(4) 光电探测器 低需求制备
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城市居住空间分异仿真模型框架研究 被引量:8
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作者 陶海燕 潘茂林 +1 位作者 黎夏 陈晓翔 《系统仿真学报》 EI CAS CSCD 北大核心 2007年第21期5086-5089,5092,共5页
城市居住空间分异研究中传统的基于微分方程的建模方法难以描述城市空间格局形成中所表现出来的复杂的时空变化,以及形成的原因。基于多智能体的"从下而上"的建模方法为研究城市空间结构提供了新的思路。以城市居住空间分异... 城市居住空间分异研究中传统的基于微分方程的建模方法难以描述城市空间格局形成中所表现出来的复杂的时空变化,以及形成的原因。基于多智能体的"从下而上"的建模方法为研究城市空间结构提供了新的思路。以城市居住空间分异现象的仿真模拟为例,采用PEAS描述物理世界模型,ERA方案构建面向对象的逻辑模型,Swarm实现仿真。提出的PEAS-ERA-SWARM多智能体建模与实现的方法,可以使研究人员快速构建高质量、可维护的多智能体仿真应用。 展开更多
关键词 多智能体 空间分异 SWARM 城市系统 peas ERA
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无线传感器网络多目标关联覆盖 被引量:8
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作者 刘丽萍 张强 孙雨耕 《天津大学学报》 EI CAS CSCD 北大核心 2009年第6期483-489,共7页
针对多目标网络覆盖中传感器节点和目标的关联关系,依据数据挖掘中的关联规则挖掘技术,设计了多目标关联覆盖算法MTACA.考虑到能量的有效性,利用关联规则挖掘方法动态地确定目标集合和传感器节点集合,通过节点集合工作状态的转换完成目... 针对多目标网络覆盖中传感器节点和目标的关联关系,依据数据挖掘中的关联规则挖掘技术,设计了多目标关联覆盖算法MTACA.考虑到能量的有效性,利用关联规则挖掘方法动态地确定目标集合和传感器节点集合,通过节点集合工作状态的转换完成目标的完全覆盖,延长了网络使用寿命.同时,改进了适应区域覆盖的PEAS算法,使其适应多目标覆盖的应用.通过仿真对MTACA和改进的PEAS算法进行了性能分析.结果表明:MTACA算法和改进的PEAS算法在目标完全覆盖能力和网络使用寿命上明显优于随机部署网络;MTACA算法在目标完全覆盖能力、网络使用寿命、网络剩余能量以及节点间能量消耗均匀性上明显优于改进PEAS算法. 展开更多
关键词 多目标覆盖 无线传感器网络 能量优化 关联规则挖掘 peas算法
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基于加权的无线传感器网络优化覆盖算法 被引量:4
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作者 张品 沈政 +1 位作者 董志远 郑立 《传感技术学报》 CAS CSCD 北大核心 2012年第7期993-998,共6页
针对无线传感器网络探测网络环境的自适应休眠算法(Probing Environment and Adaptive Sleeping,PEAS)在节点调度过程中,存在节点能耗不均衡、网络的生命周期较短的问题,提出一种基于加权的优化覆盖算法。该算法对最小频繁项的目标所对... 针对无线传感器网络探测网络环境的自适应休眠算法(Probing Environment and Adaptive Sleeping,PEAS)在节点调度过程中,存在节点能耗不均衡、网络的生命周期较短的问题,提出一种基于加权的优化覆盖算法。该算法对最小频繁项的目标所对应的传感节点按能量高低进行划分集合,使各集合能够独立覆盖最小频繁项的目标,以达到局部的优化。考虑到传感节点覆盖目标数和剩余能量对无线传感网络生存周期的影响,对边缘未覆盖的目标节点采用加权的方式进行覆盖。仿真结果表明:该算法能够均衡网络节点的能耗,有效地延长了网络的生命周期。 展开更多
关键词 无线传感器网络 集合 最小频繁项 加权 peas算法
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电阻型湿敏材料的核磁共振研究 被引量:1
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作者 华士英 王佳宇 辛耀权 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 1995年第5期779-781,共3页
利用核磁共振氢谱研究了不同湿度和温度条件下聚乙烯亚胺、聚乙烯铵盐及环氧乙烷3种电阻型湿敏材料。通过化学位移变化分析了材料的感湿机理,指出3种材料中的活泼氢和水作用后能形成新的活泼氢,新旧活泼氢可发生快速交换现象,并产... 利用核磁共振氢谱研究了不同湿度和温度条件下聚乙烯亚胺、聚乙烯铵盐及环氧乙烷3种电阻型湿敏材料。通过化学位移变化分析了材料的感湿机理,指出3种材料中的活泼氢和水作用后能形成新的活泼氢,新旧活泼氢可发生快速交换现象,并产生带电离子,因而材料的电阻值随湿度的增加而大幅度地降低。 展开更多
关键词 湿敏 核磁共振 氢谱 peas PEI PEO
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变压器油纸绝缘介质在直流电场中的空间电荷输运特性 被引量:36
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作者 廖瑞金 李伟 +3 位作者 杨丽君 郝建 周天春 周欣 《高电压技术》 EI CAS CSCD 北大核心 2011年第5期1057-1065,共9页
为得到换流变压器中使用的矿物油浸普通牛皮绝缘纸和油浸热稳定绝缘纸在直流电场中的空间电荷输运特性,对试样在3种不同等级外施直流电场作用下采用电声脉冲法(PEA)进行了空间电荷密度分布测量实验,分析了试样在加压时和去压后的空间电... 为得到换流变压器中使用的矿物油浸普通牛皮绝缘纸和油浸热稳定绝缘纸在直流电场中的空间电荷输运特性,对试样在3种不同等级外施直流电场作用下采用电声脉冲法(PEA)进行了空间电荷密度分布测量实验,分析了试样在加压时和去压后的空间电荷总量及其演变规律。实验发现:油浸普通牛皮绝缘纸的空间电荷注入起始阈值比油浸热稳定纸低,其体内易于注入电荷。加压时,油浸普通牛皮绝缘纸的空间电荷注入、输运和集聚现象比油浸热稳定绝缘纸试样更显著,且电荷注入量和注入速度均会随外施场强的升高而增大;去压后,油浸普通牛皮绝缘纸体内残留空间电荷量较油浸热稳定绝缘纸多,电荷消散所需时间较长。油浸普通牛皮绝缘纸介质体内陷阱是以相对油浸热稳定绝缘纸更高密度的浅陷阱分布为主。油纸绝缘介质材料差异对空间电荷输运特性的影响机制还有待深入研究和分析。 展开更多
关键词 变压器 油纸绝缘 空间电荷 电声脉冲(PEA) 输运 陷阱
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直流电压下多层油纸绝缘介质的界面空间电荷特性 被引量:32
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作者 周远翔 黄猛 +3 位作者 陈维江 孙清华 沙彦超 张灵 《高电压技术》 EI CAS CSCD 北大核心 2013年第6期1304-1311,共8页
空间电荷对油纸复合绝缘结构电气性能的影响由于测量上的困难而至今尚未明了,多层复合绝缘结构使得空间电荷特性更加复杂。为此,应用电声脉冲(PEA)方法研究了电压极性对纸-纸和纸-油这2种双层绝缘结构中以及界面处空间电荷特性的影响。... 空间电荷对油纸复合绝缘结构电气性能的影响由于测量上的困难而至今尚未明了,多层复合绝缘结构使得空间电荷特性更加复杂。为此,应用电声脉冲(PEA)方法研究了电压极性对纸-纸和纸-油这2种双层绝缘结构中以及界面处空间电荷特性的影响。研究发现在2种结构的界面处积聚的空间电荷极性与施加电压的极性一致。对2种结构中空间电荷特性进行了比较,结果表明纸-油结构中空间电荷的运动速率比纸-纸结构中慢,并且具有更深的陷阱能级。通过分析认为双层介质界面处存在的势垒导致了界面电荷的积聚,其极性由电极的电荷注入、界面的陷阱、电场和介质的电导等因素协同决定;绝缘材料陷阱能级的不同是造成2种绝缘结构空间电荷运动速率不同的因素之一。 展开更多
关键词 油纸绝缘 空间电荷 界面 电声脉冲 PEA 势垒 陷阱能级 电导
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