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Pseudo-Semi-Overlap Functions-Based Fuzzy Rough Sets Applied to Image Edge Extraction
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作者 Ran Yin Minge Chen +2 位作者 Yu Liu Yafei Zhao Jianwei Li 《Journal of Applied Mathematics and Physics》 2024年第7期2347-2366,共20页
As an extension of overlap functions, pseudo-semi-overlap functions are a crucial class of aggregation functions. Therefore, (I, PSO)-fuzzy rough sets are introduced, utilizing pseudo-semi-overlap functions, and furth... As an extension of overlap functions, pseudo-semi-overlap functions are a crucial class of aggregation functions. Therefore, (I, PSO)-fuzzy rough sets are introduced, utilizing pseudo-semi-overlap functions, and further extended for applications in image edge extraction. Firstly, a new clustering function, the pseudo-semi-overlap function, is introduced by eliminating the symmetry and right continuity present in the overlap function. The relaxed nature of this function enhances its applicability in image edge extraction. Secondly, the definitions of (I, PSO)-fuzzy rough sets are provided, using (I, PSO)-fuzzy rough sets, a pair of new fuzzy mathematical morphological operators (IPSOFMM operators) is proposed. Finally, by combining the fuzzy C-means algorithm and IPSOFMM operators, a novel image edge extraction algorithm (FCM-IPSO algorithm) is proposed and implemented. Compared to existing algorithms, the FCM-IPSO algorithm exhibits more image edges and a 73.81% decrease in the noise introduction rate. The outstanding performance of (I, PSO)-fuzzy rough sets in image edge extraction demonstrates their practical application value. 展开更多
关键词 Pseudo-semi-Overlap Functions Fuzzy Rough Set Fuzzy Mathematical Morphology Image Edge extraction
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真空冻干/快速溶剂萃取-气相色谱-质谱法测定土壤中35种不同种类半挥发性有机物
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作者 邓云江 邓昭祥 +4 位作者 韩洁莲 杨健 钟蕾 杜作灵 张安丰 《分析科学学报》 CAS CSCD 北大核心 2024年第2期190-198,共9页
建立了真空冻干/快速溶剂萃取-气相色谱-质谱法(GC-MS)测定土壤中35种不同种类半挥发性有机物(SVOCs)的方法。样品经真空冷冻脱水、快速溶剂萃取、旋转蒸发浓缩以及固相萃取SPE小柱净化后,氮吹定容,采用GC-MS上机测定。结果表明:土壤中3... 建立了真空冻干/快速溶剂萃取-气相色谱-质谱法(GC-MS)测定土壤中35种不同种类半挥发性有机物(SVOCs)的方法。样品经真空冷冻脱水、快速溶剂萃取、旋转蒸发浓缩以及固相萃取SPE小柱净化后,氮吹定容,采用GC-MS上机测定。结果表明:土壤中35种SVOCs在10~1000μg/L范围内线性相关系数r^(2)≥0.991,方法检出限为0.034~0.40μg/kg,方法定量限为0.14~1.20μg/kg;以空白样品为基体进行加标回收实验,所得加标回收率为71.2%~113%,相对标准偏差(RSDs,n=7)为0.38%~13.3%,替代物荧蒽-D 10回收率为84.0%~92.5%;经实际样品检测验证,该方法灵敏、快速、准确可靠,适用于土壤中35种不同种类SVOCs的分析检测。 展开更多
关键词 土壤 真空冻干 半挥发性有机物 快速溶剂萃取 气相色谱-质谱
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基于Tri-training的社交媒体药物不良反应实体抽取
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作者 何忠玻 严馨 +2 位作者 徐广义 张金鹏 邓忠莹 《计算机工程与应用》 CSCD 北大核心 2024年第3期177-186,共10页
社交媒体因其数据的实时性,对其充分利用可以弥补传统医疗文献药物不良反应中实体抽取的迟滞性问题,但社交媒体文本面临标注数据成本高、数据噪声大等问题,使得模型难以发挥良好的效果。针对社交媒体大量未标注语料存在标注成本高的问题... 社交媒体因其数据的实时性,对其充分利用可以弥补传统医疗文献药物不良反应中实体抽取的迟滞性问题,但社交媒体文本面临标注数据成本高、数据噪声大等问题,使得模型难以发挥良好的效果。针对社交媒体大量未标注语料存在标注成本高的问题,采用Tri-training半监督的方法进行社交媒体药物不良反应实体抽取,通过三个学习器Transformer+CRF、BiLSTM+CRF和IDCNN+CRF对未标注数据进行标注,再利用一致性评价函数迭代地扩展训练集,最后通过加权投票整合模型输出标签。针对社交媒体的文本不正式性(口语化严重、错别字等)问题,通过融合字与词两个粒度的向量作为整个模型嵌入层的输入,来提取更丰富的语义信息。实验结果表明,提出的模型在“好大夫在线”网站获取的数据集上取得了良好表现。 展开更多
关键词 中文社交媒体 药物不良反应 实体抽取 半监督学习 TRI-TRAINING
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液液萃取气相色谱-串联质谱法测定含油半固体食品中19种邻苯二甲酸酯类化合物 被引量:1
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作者 管悦 泮燕媚 《化学分析计量》 CAS 2024年第4期90-94,100,共6页
建立液液萃取结合气相色谱-串联质谱法测定含油半固体食品中19种邻苯二甲酸酯类化合物含量。样品经正己烷饱和的乙腈提取,提取液与乙腈饱和的正己烷液液萃取净化,采用HP-5MS色谱柱分离,多反应监测模式定量分析。19种邻苯二甲酸酯类化合... 建立液液萃取结合气相色谱-串联质谱法测定含油半固体食品中19种邻苯二甲酸酯类化合物含量。样品经正己烷饱和的乙腈提取,提取液与乙腈饱和的正己烷液液萃取净化,采用HP-5MS色谱柱分离,多反应监测模式定量分析。19种邻苯二甲酸酯类化合物的质量浓度在20~1000μg/L范围内线性相关系数均大于0.9993,方法检出限为0.0012~0.060 mg/kg,定量限为0.0036~0.18 mg/kg,0.2、1.0、7.5 mg/kg低、中、高三水平加标试验的平均回收率为81.2%~100.7%,测定结果的相对标准偏差为0.9%~5.7%(n=6)。该方法适用于含油半固体食品中19种邻苯二甲酸酯类化合物的定量分析。 展开更多
关键词 含油半固体食品 邻苯二甲酸酯 液液萃取 气相色谱-串联质谱法
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基于(I,O_(s))-模糊粗糙集的图像边缘提取和特征选择应用
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作者 尹燃 陈敏歌 +2 位作者 刘玉 赵雅菲 李建伟 《数学建模及其应用》 2024年第3期45-57,共13页
首先,利用半重叠函数和模糊粗糙集,构造了(I,O_(s))-模糊粗糙集模型,提高了模型的灵活性和适应性;其次,将该模型与模糊C-均值算法相结合,提出了一种新的图像边缘提取算法,该算法在较低引入率的情况下,能够提取到完整的图像边缘;最后,基... 首先,利用半重叠函数和模糊粗糙集,构造了(I,O_(s))-模糊粗糙集模型,提高了模型的灵活性和适应性;其次,将该模型与模糊C-均值算法相结合,提出了一种新的图像边缘提取算法,该算法在较低引入率的情况下,能够提取到完整的图像边缘;最后,基于(I,O_(s))-模糊粗糙集模型,提出了一种新的特征选择算法,相较于传统的特征选择算法,该算法在保持高分类精度的情况下,可以选择更少的属性条件.实验证明,基于(I,O_(s))-模糊粗糙集模型的算法具有可行性和有效性,可以为相关研究和领域提供支持. 展开更多
关键词 半重叠函数 模糊粗糙集 图像边缘提取 特征选择
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全自动固相萃取-气相色谱-三重四级杆质谱法测定地表水中20种半挥发性有机物
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作者 蒋晓霞 丛媛媛 +1 位作者 汪碧芬 金晓霞 《化学分析计量》 CAS 2024年第9期56-63,共8页
建立全自动固相萃取-气相色谱-三重四级杆质谱联用仪测定地表水中20种半挥发性有机物的分析方法。用全自动固相萃取装置对半挥发性有机污染物进行提取、富集,经DB-5MS色谱柱(30 m×0.25 mm,0.25μm)分离,用全扫描模式定性,以多反应... 建立全自动固相萃取-气相色谱-三重四级杆质谱联用仪测定地表水中20种半挥发性有机物的分析方法。用全自动固相萃取装置对半挥发性有机污染物进行提取、富集,经DB-5MS色谱柱(30 m×0.25 mm,0.25μm)分离,用全扫描模式定性,以多反应监测(MRM)模式联合内标法定量分析。20种半挥发性有机物的质量浓度在20~1000μg/L范围内与色谱峰面积具有良好的线性关系,相关系数均大于0.9990,方法检出限为0.010~0.023μg/L。样品加标平均回收率为83.5%~103.1%,测定结果的相对标准偏差为0.76%~3.08%(n=6)。该方法既可提高萃取效率,又具有灵敏度高、准确度高等优点,适用于地表水中微量半挥发性有机物的分析。 展开更多
关键词 全自动固相萃取 气相色谱-三重四级杆质谱联用法 多反应监测模式 半挥发性有机物 地表水
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Semi-LC/MS技术快速定量分析黄芪样品中黄芪甲苷含量 被引量:3
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作者 郑重 宋凤瑞 +3 位作者 刘舒 赵先恩 刘志强 刘淑莹 《质谱学报》 EI CAS CSCD 北大核心 2012年第4期208-211,共4页
为了测定黄芪中的黄芪甲苷含量,应用半高效液相色谱-质谱串联技术(Semi-LC/MS),以薯蓣皂苷为内标化合物,仅用一段色谱保护柱分离掉大部分干扰性成分,同时使目标化合物富集,采用Waters公司的多反应监测(MRM)扫描模式检测。结果表明:黄芪... 为了测定黄芪中的黄芪甲苷含量,应用半高效液相色谱-质谱串联技术(Semi-LC/MS),以薯蓣皂苷为内标化合物,仅用一段色谱保护柱分离掉大部分干扰性成分,同时使目标化合物富集,采用Waters公司的多反应监测(MRM)扫描模式检测。结果表明:黄芪甲苷在2.85~57.0mg/L的范围内线性关系良好,稳定性和重复性实验RSD<3%,样品回收率达98.9%。Semi-LC/MS方法可以对黄芪样品中黄芪甲苷进行快速定量分析,是一种黄芪甲苷的简单、高效、灵敏的定量检测方法。 展开更多
关键词 黄芪甲苷 半高效液相色谱-质谱串联技术(semi—LC/MS) 多反应监测(MRM) 定量分析
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Synthesis and Solid Phase Extraction Performance Study of NNAL-specific Molecularly Imprinted Polymers Using Dummy Templates 被引量:2
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作者 张志丹 郑赛晶 +3 位作者 杨俊 王维妙 刘百战 朱晓兰 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第3期361-368,I0004,共9页
Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(a... Dummy molecularly imprinted polymers (DMIPs) for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were produced using three structural analogues as dummy template molecules. The chosen analogues were 4-(acetymethylamino)-1-(3-pyridyl)-butanol, 4- (methylamino)-1-(3-pyridyl)-1-butanol, and 1-(3-pyridyl)-1,4,-butanediol. The molecular recognition characteristics of the produced polymers were evaluated by X-ray photoelec- tron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). Interactions between NNAL and methacrylic acid should be cooperative hydrogen bonds while the ni- trogen atom of the pyridine ring and the oxygen atom of the nitroso group in NNAL are two of the hydrogen-bond acceptors. It was further demonstrated that DMIP synthesized by 4-(acetymethylamino)-1-(3-pyridyl)-butanol had the best binding performance by XPS and FT-IR. Then dummy molecularly imprinted solid phase extraction (DMISPE) was developed for the determination of the analyte using the hit polymer as the sorbing material. Under optimal conditions, the recovery of NNAL dissolved in standard solution reached 93%. And the investigated polymer exhibited much higher binding of NNAL when nicotine was acted as the competitive molecule. Also the proposed method was applied to the measurement of NNAL spiked in blank urine samples with recoveries ranging from 87.2% to 101.2%. 展开更多
关键词 Molecularly imprinted polymer Dummy template 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol Solid phase extraction
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Parameter Extraction for 2-π Equivalent Circuit Model of RF CMOS Spiral Inductors 被引量:1
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作者 高巍 余志平 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第4期667-673,共7页
A novel parameter extraction method with rational functions is presented for the 2-πequivalent circuit model of RF CMOS spiral inductors. The final S-parameters simulated by the circuit model closely match experiment... A novel parameter extraction method with rational functions is presented for the 2-πequivalent circuit model of RF CMOS spiral inductors. The final S-parameters simulated by the circuit model closely match experimental data. The extraction strategy is straightforward and can be easily implemented as a CAD tool to model spiral inductors. The resulting circuit models will be very useful for RF circuit designers. 展开更多
关键词 2-π compact model parameters extraction RF CMOS spiral inductors
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金露梅中一种α-葡萄糖苷酶抑制剂的提取富集及活性研究 被引量:2
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作者 张俊焱 李成慧 +3 位作者 左文明 李锦萍 刘力宽 曾阳 《天然产物研究与开发》 CAS CSCD 2023年第3期460-466,共7页
本研究采用AB-8大孔吸附树脂、半制备高效液相色谱对金露梅枝叶中槲皮素-7-O-β-D-葡糖苷酸提取分离,并通过13 C NMR鉴定其化学结构,最后采用以4-硝基酚-α-D-吡喃葡萄糖苷(pNPG)为底物的酶抑制剂筛选模型检测其对α-葡萄糖苷酶的抑制... 本研究采用AB-8大孔吸附树脂、半制备高效液相色谱对金露梅枝叶中槲皮素-7-O-β-D-葡糖苷酸提取分离,并通过13 C NMR鉴定其化学结构,最后采用以4-硝基酚-α-D-吡喃葡萄糖苷(pNPG)为底物的酶抑制剂筛选模型检测其对α-葡萄糖苷酶的抑制活性和类型。结果显示:槲皮素-7-O-β-D-葡糖苷酸分布在20%乙醇大孔吸附树脂(AB-8)洗脱液中,采用半制备高效液相色谱和高效液相色谱分离纯化得槲皮素-7-O-β-D-葡糖苷酸2481.8 mg,纯度为97.95%。活性检测结果表明,槲皮素-7-O-β-D-葡糖苷酸对α-葡萄糖苷酶的最大抑制率为94.67%,IC 50为0.259 mmol/L,抑制率显著高于阳性对照药物阿卡波糖,且抑制剂类型为竞争性抑制。 展开更多
关键词 金露梅 槲皮素-7-O-β-D-葡糖苷酸 半制备高效液相色谱 提取富集 Α-葡萄糖苷酶抑制剂
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Integrative Extraction of Ergosterol, (1→3)-α-D-Glucan and Chitosan from Penicillium chrysogenum Mycelia 被引量:11
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作者 王天奇 李翰祥 +1 位作者 王满意 谭天伟 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第5期725-729,共5页
Abstract Ergosterol,(1→3)-α-D-glucan and chitosan are important biomaterials. In this research, a process has been developed to integratively extract ergosterol, (1→3)-α-D-glucan, and chitosan from Penicillium... Abstract Ergosterol,(1→3)-α-D-glucan and chitosan are important biomaterials. In this research, a process has been developed to integratively extract ergosterol, (1→3)-α-D-glucan, and chitosan from Penicillium chrysongenum mycelium. First the mycelia are pretreated with 0.1mol·L^-1 of NaOH. After recovery by centrifugation the solid portion is made to undergo saponification and deacetylation reactaons by addition of 2mol·L^-1 NaOH and et anol.After reaction, extraction is carried out by addition of petroleum ether, which separates the reaction mixture into two phases. The upper layer of petroleum ether contains extracted ergosterol, and the .bottom layer of NaOH solution contains (1→3)-α-DEglucan; the chitosan is on the mycelia residuum. After isolation, the recovery yield of ergosterol is 0.52% of dry mycelium. That of (1→3)-α-D-glucan is about 8.2%; and chitosan is 5.7% with 86% deacetylation. The compositions have been characterized by 1R, HPLC analyses. 展开更多
关键词 ERGOSTEROL (1→3)-α-D-glucan CHITOSAN extractION Penicillium chrysogenum
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Simple Modifications to Standard TRIzol®Protocol Allow High-Yield RNA Extraction from Cells on Resorbable Materials 被引量:3
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作者 Juliana Tsz Yan Lee Wai Hung Tsang King Lau Chow 《Journal of Biomaterials and Nanobiotechnology》 2011年第1期41-48,共8页
Resorbable bioceramics are attractive for medical applications such as bone substitution. Biochemical analysis on cells cultured on these biomaterials is vital to predict the impact of the materials in vivo and RNA ex... Resorbable bioceramics are attractive for medical applications such as bone substitution. Biochemical analysis on cells cultured on these biomaterials is vital to predict the impact of the materials in vivo and RNA extraction is an essential step in gene expression study using RT-qPCR. In this study, we describe simple modifications to the TRIzol? RNA extraction protocol widely used in biology and these allow high-yield extraction of RNA from cells on resorbable calcium phosphates. Without the modifications, RNA is trapped in the co-precipitated calcium compounds, rendering TRIzol? extraction method infeasible. Among the modifications, the use of extra TRIzol? to dilute the lysate before the RNA precipitation step is critical for extraction of RNA from porous ?-tricalcium phosphate (?-TCP) discs. We also investigate the rationale behind the undesirable precipitation so as to provide clues about the modifications required for other resorbable materials with high application potential in bone tissue engineering. 展开更多
关键词 Calcium Phosphate RESORBABLE MATERIALS RNA extractION TRIZOL Acid Guanidium THIOCYANATE - Phenol - CHLOROFORM extractION TRI Reagent TRIsure
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Matrix Solid-phase Dispersion Extraction of Alkaloids from the Roots of Aconitum kusnezoffii Reichb 被引量:2
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作者 WEI Wei LI Xu-wen SHI Xiao-lei ZHOU Hong-yu YANG Rui-jie ZHANG Han-qi JIN Yong-ri 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第1期23-27,共5页
Matrix solid-phase dispersion(MSPD) was developed for the extraction of four alkaloids, including aconitine, mesaconitine, hypaconitine and deoxyaconitine, from the roots ofAconitum kusnezoffii Reichb. The determina... Matrix solid-phase dispersion(MSPD) was developed for the extraction of four alkaloids, including aconitine, mesaconitine, hypaconitine and deoxyaconitine, from the roots ofAconitum kusnezoffii Reichb. The determination of the analyte was carried out by high performance liquid chromatography with UV detection. The alkaline alumina was used as sorbent. The mixture of acetonitrile and water was used as elution solvent. Several extraction parameters, such as type of sorbent, the ratio of sample to solid support material, type of the elution solvent and the volume of the elution solvent were tested. Mean recoveries ranged from 93.16% to 102.73%, with relative standard deviations from 0.27% to 4.17%. With the extraction efficiency and time expenditure taken into account, MSPD extraction should be a comparatively good method. 展开更多
关键词 Matrix solid-phase dispersion Aconitine-type alkaloid Aconitum kusnezoffii Reichb. extractION High-performance liquid chromatography 1005-9040(2011 -01-023-05
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Extraction of essential oil from shaddock peel and analysis of its components by gas chromatography-mass spectrometry 被引量:2
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作者 周尽花 周春山 +1 位作者 蒋新宇 谢练武 《Journal of Central South University of Technology》 EI 2006年第1期44-48,共5页
Essential oil, with more than thirty kinds of compounds separated and identified by gas chromatography-mass spectrometry, was extracted from Shatian shaddock peel and Sweet shaddock peel by squeeze-steam distillation ... Essential oil, with more than thirty kinds of compounds separated and identified by gas chromatography-mass spectrometry, was extracted from Shatian shaddock peel and Sweet shaddock peel by squeeze-steam distillation and direct steam distillation method. Among their composition, the main components are terpene compounds, which account for 93.926% (mass fraction, the same below) and 85.843% of essential oils extracted from Shatian shaddock peel and Sweet shaddock peel, respectively. Although nootkatone is the major contributor of shaddock characteristic scent, and its contents are 1.069% and 1.749% of essential oils from Sweet shaddock peel and Shatian shaddock peel, respectively. The results show that squeeze-steam distillation gives higher yield and good quality of essential oil and the compositions of essential oils from two kinds of shaddock peels are different, but the main contributors of the shaddock scent are the same. 展开更多
关键词 essential oil Shatian shaddock Sweet shaddock gas chromatography - mass spectrometry nootkatone extractION
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Solvent extraction of copper and ammonia from ammoniacal solutions using sterically hindered β-diketone 被引量:2
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作者 胡慧萍 刘春轩 +2 位作者 韩雪涛 梁啟文 陈启元 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第10期2026-2031,共6页
Extraction of copper and ammonia from Cu2+-NH3-Cl--H2O solution using laboratorialy synthesized sterically hindered β-diketone(4,4-dimethyl-1-(4-dodecylphenyl)-1,3-pentanedione) was studied.The effects of the copper ... Extraction of copper and ammonia from Cu2+-NH3-Cl--H2O solution using laboratorialy synthesized sterically hindered β-diketone(4,4-dimethyl-1-(4-dodecylphenyl)-1,3-pentanedione) was studied.The effects of the copper concentration,the total ammonia concentration,the initial pH in the aqueous phase,the phase ratio,and the temperature on copper extraction ratio and ammonia extraction in loaded organic phase were investigated using this sterically hindered β-diketone.Under the conditions of temperature 25℃,contact time of two phases 30 min,phase ratio 1-1,concentration of copper 3 g/L,concentration of total ammonia 3 mol/L,aqueous pH 8.43,and the concentration of β-diketone in organic phase 20%(volume fraction),ammonia in aqueous phase is much lower to be extracted by organic phase(just 14.5 mg/L),while the extraction rate of copper is 95.09%. 展开更多
关键词 ammoniacal solution 4 4-dimethyl-1-(4-dodecylphenyl)-1 3-pentanedione copper solvent extraction
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Extraction Equilibria of Trimellitic and [ 1,1′-Biphenyl]-2,2′-dicarboxylic Acid with 1-Octanol, 50%TBP, and 10%TRPO in Kerosene 被引量:2
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作者 周智勇 秦炜 戴猷元 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第6期867-870,共4页
To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equil... To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equilibrium of the acids were studied with 1-octanol, 50% tributyl phosphate (TBP) in kerosene, and 10% trialkylphosphine oxide (TRPO) in kerosene. The results showed that the degree of extraction of [1,1′-biphenyl]-2,2′-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent, and the extraction capacity with TRPO is more effective than the one with TBP. The extraction behavior of aromatic polyacid is different from that of carboxylic acid, and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove [1,1′-biphenyl]-2,2′-dicarboxylic acid from the mixture of trimellitic acid and [1,1′-biphenyl]-2,2′-dicarboxylic acid. Because the weak hydrogen bond association exists between -OH in 1-octanol and -COOH in aromatic acid, the extractive selectivity of [ 1, 1′-biphenyl]-2,2′-dicarboxylic to trimellitic acid depends on the stoichiometric ratio. 展开更多
关键词 trimellitic acid [1 1′-biphenyl]-2 2′-dicarboxylic acid extraction equilibrium 1-octanol TBP and TRPO
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超声波-半仿生法提取桑叶黄酮及其活性的研究 被引量:1
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作者 张锡宇 黄瑜 +3 位作者 石统帅 赵海桃 邱隽蒙 符群 《北京林业大学学报》 CAS CSCD 北大核心 2023年第9期147-156,共10页
【目的】对桑叶黄酮的提取工艺及其自由基清除能力,对α-葡萄糖苷酶和α-淀粉酶的活性抑制作用进行研究,旨在获得充分保持桑叶黄酮活性的新型制备方法,为桑叶资源开发利用提供理论依据。【方法】采用超声波–半仿生法提取桑叶黄酮,考察... 【目的】对桑叶黄酮的提取工艺及其自由基清除能力,对α-葡萄糖苷酶和α-淀粉酶的活性抑制作用进行研究,旨在获得充分保持桑叶黄酮活性的新型制备方法,为桑叶资源开发利用提供理论依据。【方法】采用超声波–半仿生法提取桑叶黄酮,考察液料比、超声时间、超声温度、超声功率4个因素对桑叶黄酮得率和DPPH·以及OH·的平均清除率的影响,通过响应面试验优化桑叶黄酮提取工艺,评价桑叶黄酮对α-葡萄糖苷酶和α-淀粉酶的抑制作用。【结果】桑叶黄酮最佳提取工艺为液料比30 mL/g、提取总时间97 min(3个阶段的时间比例为1∶2∶2)、超声温度49℃、超声功率400 W,黄酮得率为(38.23±0.42) mg/g,自由基平均清除率为(57.04±0.97)%。桑叶黄酮对α-葡萄糖苷酶和α-淀粉酶活性抑制的IC_(50)值为(1.081±0.130) g/L和(1.204±0.190) g/L。超声波–半仿生法比单一超声波法提取桑叶黄酮的自由基清除能力强,比单一半仿生法提取桑叶黄酮的得率高。【结论】采用超声波辅助半仿生法提取的桑叶黄酮具有良好的自由基清除能力,且对α-葡萄糖苷酶和α-淀粉酶有抑制作用,与单一提取法相比,超声波–半仿生法提取桑叶黄酮具备更高的生物活性和得率。桑叶黄酮可开发为高糖人群调节血糖的产品,超声波–半仿生法可为工业制备桑叶黄酮提供良好的技术储备。 展开更多
关键词 桑叶 黄酮提取 半仿生 响应面
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微波萃取-SPE柱净化/气相色谱-质谱法测定固体废物中53种半挥发性有机物 被引量:3
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作者 蒋建军 卢光磊 +1 位作者 刘丽 向勇 《分析测试学报》 CAS CSCD 北大核心 2023年第4期464-472,共9页
采用微波辅助萃取技术,结合固相萃取(SPE)小柱净化,建立了固体废物中53种半挥发性有机物的气相色谱-质谱检测方法。通过优化前处理条件,选择以丙酮-正己烷(1∶1,体积比)为萃取剂,微波萃取温度为100℃,萃取时间为15 min,萃取液经硅酸镁... 采用微波辅助萃取技术,结合固相萃取(SPE)小柱净化,建立了固体废物中53种半挥发性有机物的气相色谱-质谱检测方法。通过优化前处理条件,选择以丙酮-正己烷(1∶1,体积比)为萃取剂,微波萃取温度为100℃,萃取时间为15 min,萃取液经硅酸镁固相萃取柱净化,DB-5MS(30 m×0.25μm×0.25 mm)色谱柱分离,结合电子轰击电离源(EI)选择离子监测(SIM)模式,采用内标法进行定量检测。实验表明:53种半挥发性有机物在0.2~5.0 mg/L范围内线性良好,相关系数(r)均不小于0.998,对典型固体废物灰渣和生化污泥样品的检出限分别为0.002~0.015 mg/kg和0.004~0.027 mg/kg,定量下限分别为0.008~0.060 mg/kg和0.016~0.108 mg/kg。在0.5、1.0、2.0 mg/kg 3个加标水平下,灰渣样品的平均加标回收率为70.7%~98.5%,相对标准偏差(RSD,n=6)为1.7%~14%;生化污泥样品的平均加标回收率为71.8%~105%,RSD(n=6)为1.2%~15%。该方法快速准确、环保可靠、试剂用量少、检测效率高,可满足固体废物中53种半挥发性有机物的高通量检测要求。 展开更多
关键词 半挥发性有机物 固体废物 微波萃取 固相萃取 气相色谱-质谱联用
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基于半监督学习-多通道卷积神经网络的加氢裂化产品性质预测 被引量:2
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作者 王晨 罗文山 +3 位作者 陆鹏飞 李保良 曹晓红 杨纪 《石油学报(石油加工)》 EI CAS CSCD 北大核心 2023年第1期97-108,共12页
提出了一种用于加氢裂化产品性质预测的半监督学习-多通道卷积神经网络(SSL-MCCNN),通过逐层卷积实现加氢裂化工艺流程空间域局部特征提取,并基于多通道采样实现了时域特征提取。在应对模型训练中由于产品性质数据量不足导致的小样本学... 提出了一种用于加氢裂化产品性质预测的半监督学习-多通道卷积神经网络(SSL-MCCNN),通过逐层卷积实现加氢裂化工艺流程空间域局部特征提取,并基于多通道采样实现了时域特征提取。在应对模型训练中由于产品性质数据量不足导致的小样本学习问题方面,基于教师-学生半监督学习(TS-SSL)生成虚拟样本集实现了数据扩充,进一步提升了模型预测性能。基于SSL-MCCNN对煤油-柴油加氢裂化工业装置重石脑油密度和柴油闪点预测的均方根误差(RMSE)分别为0.83和1.03,判定系数(R 2)分别为0.90和0.98,与BP神经网络(BPNN)和径向基神经网络(RBFNN)相比,SSL-MCCNN在实现最小RMSE的同时达到了最优R 2。实验结果表明,所提出的SSL-MCCNN有效提取了加氢裂化工艺流程的时空域特征,显著提升了模型预测性能。 展开更多
关键词 半监督学习 多通道卷积神经网络 加氢裂化 特征提取 产品性质 预测
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Decomposition Theorems for Semi-order Fuzzy Supermartingales and Submartingales
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作者 冯玉瑚 《Journal of China Textile University(English Edition)》 EI CAS 2000年第2期96-99,共4页
Based on semi - order fuzzy supermaringales andsubmartingales, the semi- order fuzzy supermartingaleand submartingale theory is developed. The main resultis to generalize the Doob decomposition and the Riesz de-compos... Based on semi - order fuzzy supermaringales andsubmartingales, the semi- order fuzzy supermartingaleand submartingale theory is developed. The main resultis to generalize the Doob decomposition and the Riesz de-composition theorems of standard martingale theory tosemi - order fuzzy supermaringales and submartingales.The structure of semi - order fuzzy supermaringales andsubmartingales and the conditions of that they has Doobdecomposition (resp. Riesz decomposition) are discussedin detail. 展开更多
关键词 semi - order FUZZY SUPERMARTINGALE submartin-gale Doob DECOMPOSITION RIESZ DECOMPOSITION .
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