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Perspectives on water quality analysis emphasizing indexing,modeling,and application of artificial intelligence for comparison and trend forecasting
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作者 Rijurekha Dasgupta Subhasish Das +1 位作者 Gourab Banerjee Asis Mazumdar 《River》 2025年第2期265-286,共22页
reshwater essential for civilization faces risk from untreated effluents discharged by industries,agriculture,urban areas,and other sources.Increasing demand and abstraction of freshwater deteriorate the pollution sce... reshwater essential for civilization faces risk from untreated effluents discharged by industries,agriculture,urban areas,and other sources.Increasing demand and abstraction of freshwater deteriorate the pollution scenario more.Hence,water quality analysis(WQA)is an important task for researchers and policymakers to maintain sustainability and public health.This study aims to gather and discuss the methods used for WQA by the researchers,focusing on their advantages and limitations.Simultaneously,this study compares different WQA methods,discussing their trends and future directions.Publications from the past decade on WQA are reviewed,and insights are explored to aggregate them in particular categories.Three major approaches,namely—water quality indexing,water quality modeling(WQM)and artificial intelligence-based WQM,are recognized.Different methodologies adopted to execute these three approaches are presented in this study,which leads to formulate a comparative discussion.Using statistical operations and soft computing techniques have been done by researchers to combat the subjectivity error in indexing.To achieve better results,WQMs are being modified to incorporate the physical processes influencing water quality more robustly.The utilization of artificial intelligence was primarily restricted to conventional networks,but in the last 5 years,implications of deep learning have increased rapidly and exhibited good results with the hybridization of feature extracting and time series modeling.Overall,this study is a valuable resource for researchers dedicated to WQA. 展开更多
关键词 deep learning water quality analysis water quality index water quality modeling
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Evaluation of the Equality of Non-Polar Capillary Columns in GC/MS Analysis of Food Contact Plastics
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作者 Motoh Mutsuga Miku Yamaguchi +1 位作者 Yutaka Abe Hiroshi Akiyama 《American Journal of Analytical Chemistry》 2013年第9期476-487,共12页
Non-polar capillary columns for GC/MS are widely utilized in the analysis of additives for food contact materials. Though various kinds of non-polar capillary columns are commercially available, the equality of their ... Non-polar capillary columns for GC/MS are widely utilized in the analysis of additives for food contact materials. Though various kinds of non-polar capillary columns are commercially available, the equality of their performance has not been verified. Herein, ninety-six additives for food contact plastics were analyzed using fifteen kinds of columns, and the peak separation, retention times, and peak areas of each additive were compared. The additives, with various chemical properties, comprised forty four plasticizers, twenty lubricants, twenty antioxidants, nine ultraviolet absorbers, and three other compounds. 10 μg.mL-1 test solutions were prepared in acetone, and injected to the GC/MS. The fifteen columns were classified into five categories based on the chromatogram pattern and peak separation. To facilitate comparison of the retention time and detection sensitivity of the columns for the additives, the relative retention time (RRT) and relative peak area (RPA) were calculated by using dibutylphthalate or 4-tert-butylphenylsalicylate as an internal standard. The RRTs of the additives on each column were essentially similar. However, the RRT of the additives which were detected in the later stages differed slightly. Although the RPA of the plasticizers and lubricants were roughly similar, column-to-column differences were observed for certain additives, such as antioxidants and ultraviolet absorbers. Furthermore, certain fatty acids, antioxidants, two plasticizers, and two benzophenone type ultraviolet absorbers were not detected in the chromatograms of two columns. 展开更多
关键词 NON-POLAR CAPILLARY Column gc/MS analysis Additives for Food Contact PLASTICS RELATIVE Retention Time RELATIVE Peak Area
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GC法和GC/MS法在地区毒品情报分析中的应用 被引量:2
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作者 朱军 赵敬真 +2 位作者 于忠山 王俭 刘耀 《中国法医学杂志》 CSCD 2005年第5期281-283,共3页
目的探讨气相色谱法(GC)和气相色谱/质谱联用法(GC/MS)在地区毒品情报分析中的应用,并用于实际样品分析。方法采用GC/MS法定性分析毒品样品中的主成分、痕量杂质、掺假剂和稀释剂,并选择GC/FID法和内标标准曲线法定量分析上述各组分,通... 目的探讨气相色谱法(GC)和气相色谱/质谱联用法(GC/MS)在地区毒品情报分析中的应用,并用于实际样品分析。方法采用GC/MS法定性分析毒品样品中的主成分、痕量杂质、掺假剂和稀释剂,并选择GC/FID法和内标标准曲线法定量分析上述各组分,通过定性和定量数据的统计和分析,推断该地区的毒品状况。结果用GC/MS定性分析、GC/FID定量分析,和数据的统计比对,获得了某省某年27起海洛因毒品大案样品主成分、痕量杂质、掺假剂和稀释剂组成及含量的特征,发现该省缴获的大宗海洛因毒品主要以掺假和稀释后的产品出现,且咖啡因和扑热息痛为两种主要的掺假剂和稀释剂。结论GC/MS和GC/FID法在地区毒品情报分析和打击毒品犯罪中可以发挥重要作用。 展开更多
关键词 法医毒物分析 气相色谱法(gc) 气相色谱-质谱联用法(gc/MS) 毒品情报分析 gc/MS法 毒品犯罪 情报分析 气相色谱/质谱联用法 gc gc/FID 样品分析 定量分析 气相色谱法
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GC-IMS结合多元统计学比较不同产区市售酱香型白酒挥发性风味成分
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作者 冯雪莹 倪慧 +3 位作者 侯强川 叶明波 郭壮 王玉荣 《中国酿造》 北大核心 2026年第1期282-287,共6页
该研究将4个产自茅台镇和4个产自其他地区的市售酱香型白酒作为研究对象,采用气相色谱-离子迁移谱(GC-IMS)技术结合多元统计学方法,比较分析了不同产区市售酱香型白酒挥发性风味成分的差异。结果表明,8个白酒样品中共检出51种挥发性风... 该研究将4个产自茅台镇和4个产自其他地区的市售酱香型白酒作为研究对象,采用气相色谱-离子迁移谱(GC-IMS)技术结合多元统计学方法,比较分析了不同产区市售酱香型白酒挥发性风味成分的差异。结果表明,8个白酒样品中共检出51种挥发性风味成分,包括酯类24种、醇类9种、醛类10种和酮类8种。主成分分析(PCA)结果表明,茅台镇和其他产区酱香型白酒挥发性风味成分存在差异。基于相对气味活度值(ROAV)共筛选出6种关键挥发性风味化合物(ROAV>1),其中,对茅台镇酱香型白酒香气贡献更突出的为异戊酸乙酯、辛酸乙酯和乙酸异戊酯,ROAV分别为82.25、5.56、1.52,对其他产区酱香型白酒香气贡献更突出的为己酸乙酯、戊酸乙酯和丁酸乙酯,ROAV分别为33.19、32.55、10.48。 展开更多
关键词 酱香型白酒 茅台镇和其他地区 气相色谱-离子迁移谱 多元统计学分析 关键差异挥发性风味化合物
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基于HS-SPME-GC-MS技术的6种香型白酒中挥发性化合物差异分析
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作者 胡晓龙 李华 +5 位作者 雷旭东 韩素娜 张俊飞 邓鸣东 黄润娜 王晓毅 《轻工学报》 北大核心 2026年第1期1-15,共15页
【目的】进一步明晰4种基本香型和2种融合香型白酒挥发性化合物特征、关键香气及差异成分。【方法】采用顶空-固相微萃取-气相色谱-质谱联用(HS-SPME-GC-MS)技术、相对气味活度值(ROAV)法及正交偏最小二乘判别分析(OPLS-DA)法,对4种基... 【目的】进一步明晰4种基本香型和2种融合香型白酒挥发性化合物特征、关键香气及差异成分。【方法】采用顶空-固相微萃取-气相色谱-质谱联用(HS-SPME-GC-MS)技术、相对气味活度值(ROAV)法及正交偏最小二乘判别分析(OPLS-DA)法,对4种基本香型和2种融合香型白酒的挥发性化合物分布特征、关键香气成分及重要差异化合物进行分析。【结果】6种香型白酒中共鉴定出207种挥发性化合物,涵盖10个类别,主要为酯类、芳香族类、醇类、烯类、醛类和酮类化合物,且各香型白酒中的挥发性化合物组成差异明显,其中存在于所有香型、单一香型及2~5种香型白酒中的挥发性化合物分别为26种、77种及104种;清香型和米香型白酒中的挥发性化合物种类较少;陶融香型和兼香型白酒在挥发性化合物组成上均与浓香型和酱香型白酒更为相似。此外,己酸乙酯、辛酸乙酯、苯乙酸乙酯等10种挥发性化合物为1种或多种香型白酒的关键香气化合物;己酸乙酯、十四酸乙酯、十六酸乙酯、乙酸乙酯等13种挥发性化合物为区分6种香型白酒的重要差异挥发性化合物。【结论】不同香型白酒挥发性化合物组成存在明显差异,其关键香气化合物与差异化合物均以乙酯类为主,基本香型白酒工艺的科学融合是研制创新香型白酒的重要技术路径。 展开更多
关键词 白酒香型 顶空-固相微萃取-气相色谱-质谱联用技术 挥发性化合物 差异分析
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Analysis of vapor phase organics in air of Beijing, Langfang and Tianjin by capillary GC and GC/MS
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作者 Lai Cong, Wang Dechun, Wei Rurong and Yang WenxiangResearch Center for Eco-Environmental Sciences,Academia Sinica.P.O.Box 934,Beijing 100083,China 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1990年第1期99-108,共10页
The vapor phase organics (VPOs) in the air of Beijing, Langfang and Tianjin were detected by a capillary gas chromatography and GC/MS during the winter and the summer separately. The tentatively identified compounds i... The vapor phase organics (VPOs) in the air of Beijing, Langfang and Tianjin were detected by a capillary gas chromatography and GC/MS during the winter and the summer separately. The tentatively identified compounds include alkanes, cyclic hydrocarbons, alkenes, aromatics, acids, alcohols, aldehydes, ketones, esters, halocarbons and so on. The numbers of VPOs found are 118 in Beijing, 83 in Lang-fang and 65 in Tianjin in the winter, and 56, 39 and 72 in the summer respectively. Based on the data of some representative compounds determined quantitatively by GC and GC/MS, a profile of organic pollution in the air of the three cities is presented. 展开更多
关键词 vapor organics air pollution gc gc/MS analysis
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Published the papers of GC-MS analysis—Chemical drug
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《Journal of Pharmaceutical Analysis》 SCIE CAS 2011年第1期69-70,共2页
Song Qi, Liu Hu; Gao Shu. Screening and quantitative analysis of volatile markers in the breath of patients with breast cancer Acta Universitatis Medicinalis Anhui, 2010, 45(01) :76-79.
关键词 Chemical drug Published the papers of gc-MS analysis gc MS
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LOCATION OF DOUBLE BOND POSITION OF INSECT SEX PHEROMONE BY GC/MS ANALYSIS WITH CHEMICAL IONIZATION
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作者 Fan Lei KONG Jiangsu Institute of Ecomomes,Jintan Jiangsu,213200 《Chinese Chemical Letters》 SCIE CAS CSCD 1990年第2期109-112,共4页
Ozonolysis products of four lepidopteral pheromone were identified by methane CI-MS.The spectra obtained were notably simpler than those of EI-MS,the peak of molecular ion was normally close to the base peak,and the c... Ozonolysis products of four lepidopteral pheromone were identified by methane CI-MS.The spectra obtained were notably simpler than those of EI-MS,the peak of molecular ion was normally close to the base peak,and the characteristic fragment ions were high in m/z,thereby the interpretation was facilitated. 展开更多
关键词 MS gc LOCATION OF DOUBLE BOND POSITION OF INSECT SEX PHEROMONE BY gc/MS analysis WITH CHEMICAL IONIZATION
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基于HS-SPME-GC-MS分析“玉米香”保靖黄金茶挥发性成分 被引量:1
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作者 黄怀生 黎娜 +3 位作者 钟兴刚 石建云 李健权 粟本文 《茶叶通讯》 2025年第1期70-77,共8页
保靖黄金茶品质特征“香、绿、爽、浓”,“玉米香”为其中一类典型代表产品。采用HS-SPME-GC-MS分析“玉米香”保靖黄金茶挥发性成分的构成,共获得39个挥发性化合物,分别为醇类13个、醛类3个、酮类3个、酸类1个、酯类10个、烯烃类7个和... 保靖黄金茶品质特征“香、绿、爽、浓”,“玉米香”为其中一类典型代表产品。采用HS-SPME-GC-MS分析“玉米香”保靖黄金茶挥发性成分的构成,共获得39个挥发性化合物,分别为醇类13个、醛类3个、酮类3个、酸类1个、酯类10个、烯烃类7个和其他2个。其中,相对含量由高到低依次为醇类(78.57%)、酯类(5.89%)、烯烃类(5.58%)、酮类(5.10%)、醛类(2.05%)和其他类(1.86%),酸类最低为0.96%。以“清香”保靖黄金茶为对照,通过最小二乘法(PLS)和聚类分析进行差异化合物筛选,获得“玉米香”保靖黄金茶主要呈香物质为香叶醇、己酸己酯、反-3,7-芳樟醇氧化物Ⅱ、顺-3-己烯酸-顺-3-己烯酸酯、氧化芳樟醇Ⅱ(呋喃型)、水杨酸甲酯、柠檬烯、壬酸、二甲基戊酸甲酯、反-β-罗勒烯、苯甲醛、苯甲醇、辛醇、顺-己酸-3-己烯酯、橄榄醇、氧化芳樟醇Ⅰ(呋喃型)、苯甲酸叶醇酯、β-紫罗酮、壬醛、α-古巴烯、β-丁香烯、反-戊酸-2-己烯酯、4,8-二甲基-1,3,7-任三烯、反-丁酸-3-己烯酯、二甲基硫醚等化合物。 展开更多
关键词 保靖黄金茶 茶叶品质 挥发性成分 玉米香 gc-MS
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基于HS-GC-IMS、HS-SPME-GC-MS和UPLC-Q-Orbitrap-MS结合化学计量学探讨当归酒炙前后化学成分差异
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作者 孙雪豪 陈家璇 +5 位作者 尹佳鑫 韩潇 窦志英 李正 康利平 余河水 《中国中药杂志》 北大核心 2025年第14期3909-3917,共9页
基于顶空-气相色谱-离子迁移质谱(HS-GC-IMS)、顶空-固相微萃取-气相色谱-质谱(HS-SPME-GC-MS)和超高效液相色谱-四极杆-静电场轨道阱-质谱(UPLC-Q-Orbitrap-MS)技术结合化学计量学探讨当归在酒炙过程中物质基础变化的内涵。构建当归和... 基于顶空-气相色谱-离子迁移质谱(HS-GC-IMS)、顶空-固相微萃取-气相色谱-质谱(HS-SPME-GC-MS)和超高效液相色谱-四极杆-静电场轨道阱-质谱(UPLC-Q-Orbitrap-MS)技术结合化学计量学探讨当归在酒炙过程中物质基础变化的内涵。构建当归和酒当归的HS-GC-IMS指纹图谱,统计当归炮制前后各类挥发性成分的变化趋势并对其挥发性小分子物质进行表征。运用主成分分析(PCA)和正交偏最小二乘判别分析(OPLS-DA)进行区分和差异性分析。基于HS-GC-IMS技术从当归中鉴定出89种挥发性成分,包括14种不饱和烃类化合物、16种醛类、13种酮类、9种醇类、16种酯类、6种有机酸类和15种其他成分。利用HS-SPME-GC-MS技术鉴定出118种挥发性成分,包括42种不饱和烃类化合物、11种芳香类、30种醇类、8种烷类、6种有机酸类、4种酮类、7种醛类、5种酯类和5种其他挥发性成分。采用UPLC-Q-Orbitrap-MS技术鉴定出非挥发性物质76种。主成分分析显示3种技术下的当归和酒当归聚类明显,PCA和OPLS-DA可以区分当归和酒当归,同时发现VIP>1的化合物共145种可作为判断当归炮制质量的关键因子,如HS-GC-IMS定性出的4-甲基-3-戊烯-2-酮、2-甲基戊酸乙酯和2,4-二甲基-1,3-二氧戊环等化合物,HS-SPME-GC-MS定性出的当归酸、β-蒎烯和大根香叶烯B等化合物,UPLC-Q-Orbitrap-MS定性出的L-色氨酸、甘草利酮和川白芷素等化合物。综上,3种分析方法结合化学计量学可评价当归和酒当归化学成分物质基础差异性,为酒当归的炮制机制研究和临床应用提供参考。 展开更多
关键词 当归 酒当归 HS-gc-IMS HS-SPME-gc-MS UPLC-Q-Orbitrap-MS 主成分分析
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GC-MS analysis of volatile compounds of Perilla frutescens Britton var. Japonica accessions: morphological and seasonal variability 被引量:7
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作者 Bimal Kumar Ghimire Ji Hye Yoo +1 位作者 Chang Yeon Yu Ill-Min Chung 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2017年第7期705-714,共10页
Objective: To investigate the composition of volatile compounds in the different accessions of Perilla frutescens(P. frutescens) collected from various habitats of China and Japan. Methods: In the present study, the e... Objective: To investigate the composition of volatile compounds in the different accessions of Perilla frutescens(P. frutescens) collected from various habitats of China and Japan. Methods: In the present study, the essential oil from the leaves of P. frutescens cultivars from China and Japan was extracted by hydro-distillation and the chemical composition and concentration of the volatile components present in the oils were determined by gas chromatography–mass spectrometry(GC–MS) analysis. Results: Among the volatile components, the major proportion was of perilla ketone, which was followed by elemicin and beta-caryophyllene in the Chinese Perilla cultivars. The main component in the oil extracted from the Japanese accessions was myristicin, which was followed by perilla ketone and beta-caryophyllene. We could distinguish seven chemotypes, namely the perilla ketone(PK) type, perilla ketone, myristicin(PM) type, perilla ketone, unknown(PU) type, perilla ketone, beta-caryophyllene, myristicine(PB) type, perilla ketone, myristicin, unknown(PMU) type, perilla ketone, elemicine, myristicin, beta-caryophyllene(PEMB) type, and the perilla ketone, limonene, betacryophyllene, myristicin(L) type. Most of the accessions possessed higher essential oil content before the flowering time than at the flowering stage. The average plant height, leaf length, leaf width of the Chinese accessions was higher than those of the Japanese accessions. Conclusion:The results revealed that the harvest time and geographical origin caused polymorphisms in the essential oil composition and morphological traits in the Perilla accessions originating from China and Japan. Therefore, these chemotypes with desirable characters might be useful for industrial exploitation and for determining the harvest time. 展开更多
关键词 Perilla frutescens Essential oil gc–MS analysis Morphological character Harvesting time
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Evaluation of visual quality of spherical and aspherical intraocular lenses by Optical Quality Analysis System 被引量:11
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作者 Yan Chen Xue Wang +1 位作者 Chuan-Di Zhou Qiang Wu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第6期914-918,共5页
AIM: To evaluate the impact of spherical and aspherical intraocular lenses on the postoperative visual quality of age-related cataract patients using Optical Quality Analysis System (OQAS). METHODS: Seventy-four ... AIM: To evaluate the impact of spherical and aspherical intraocular lenses on the postoperative visual quality of age-related cataract patients using Optical Quality Analysis System (OQAS). METHODS: Seventy-four eyes with age-related cataracts were randomly divided into spherical and aspherical lens implantation groups. Best-corrected visual acuity (BCVA) was measured preoperatively, one day, one week, two weeks, one month and two months after surgery. A biometric systems analysis using the OQAS objective scattering index (OSI) was performed. RESULTS: There were no significant differences in visual acuity (P〉0.05) before and after spherical and aspheric lens implantation. There was a negative linear correction between the OSI value and BCVA (t-=-0.634, P=-0.000), and positive corrections between the OSI value and the lens LOCUS III value of nucleus color (NC), nucleus opacity (NO), cortex (C) and posterior lens capsular (P) (r=0.704, P=0.000; r=0.514, P=0.000; r=0.276, P=0.020; r=0.417, P=-0.000, respectively). OSI values of spherical vs aspherical lenses were 11.5±3.6 vs 11.8±3.4, 4.1±0.9 vs 3.3±0.8, 3.5±0.9 vs 2.7±0.7, 3.3±0.8 vs 2.6±0.7, 3.2±0.7 vs 2.5±0.8, and 3.2±0.8 vs 2.50.8 before and ld, 1, 2wk, 1 and 2mo after surgery, respectively. All time points varied significantly (P〈0.01) between the two groups. CONCLUSION: Aspherical IOLs does not significantly affect visual acuity compared with spherical IOLs. The OSI value, was significantly lower in the aspherical lens group compared with the spherical lens. This study shows that objective visual quality of aspheric IOLs is better than that of the spherical lens by means of OQAS biological measurement method. 展开更多
关键词 optical quality analysis system age-relatedcataract spherical lens aspherical lens objective scatteringindex
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GROUNDWATER QUALITY AND CONTAMINATION INDEX MAPPING IN CHANGCHUN CITY,CHINA 被引量:16
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作者 Hamadoun BOKAR 《Chinese Geographical Science》 SCIE CSCD 2004年第1期63-70,共8页
Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·... Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions. 展开更多
关键词 HYDROCHEMISTRY groundwater quality contaminant index linear regression analysis GIS mapping Changchun City
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GC/MS Analysis of Organic Compounds in Hot Water-Extractable Fraction from Shenfu Coal 被引量:8
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作者 LI Bao-min YUAN Cheng ZONG Zhi-min CAO Jing-pei LIU Guang-feng WEI Xian-yong 《Journal of China University of Mining and Technology》 EI 2007年第3期354-357,共4页
Shenfu Coal was extracted with hot pure water and slurry was isolated. The concentrated benzene-soluble fraction (CBSF) was analyzed with GC/MS and four types of organic compounds (OCs) were detected: HACOCs,DTEs,DMDT... Shenfu Coal was extracted with hot pure water and slurry was isolated. The concentrated benzene-soluble fraction (CBSF) was analyzed with GC/MS and four types of organic compounds (OCs) were detected: HACOCs,DTEs,DMDT and LCAs. The amount of benzyl benzoate which is the most abundant OC was calculated by an inter-nal standard method with an indicated amount of BP. The broken hydrogen bonds and ether bonds were responsible for the extraction of OCs from the coal .DTEs,DMDT and LCAs are essentially insoluble in water,whereas they are soluble,probably owing to intermolecular interaction of OCs with HACOCs. 展开更多
关键词 thermal extraction gc/MS analysis water-soluble fraction benzene-soluble fraction
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Signal quality analysis and quality check of BDS3 Precise Point Positioning in the Arctic Ocean 被引量:2
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作者 Xiaoguo Guan Hongzhou Chai +3 位作者 Guorui Xiao Zhenqiang Du Wenlong Qi Xueping Wang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第2期166-179,共14页
This study analyzes the signal quality and the accuracy of BeiDou 3 rd generation Satellite Navigation System(BDS3) Precise Point Positioning(PPP) in the Arctic Ocean. Assessment of signal quality of BDS3 includes sig... This study analyzes the signal quality and the accuracy of BeiDou 3 rd generation Satellite Navigation System(BDS3) Precise Point Positioning(PPP) in the Arctic Ocean. Assessment of signal quality of BDS3 includes signal to noise ratio(SNR), multipath(MP), dilution of precision(DOP), and code-minus-carrier combination(CC). The results show that, 5 to 13 satellites are visible at any time in the Arctic Ocean area as of September 2018, which are sufficient for positioning. In the mid-latitude oceanic region and in the Arctic Ocean, the SNR is 25–52 dB Hz and the MP ranges from-2 m to 2 m. As the latitude increases, the DOP values show large variation, which may be related to the distribution of BDS satellites. The CC values of signals B1 I and BIC range from-5 m to 5 m in the mid-latitude sea area and the Arctic Ocean, which means the effect of pseudorange noise is small. Moreover, as to obtain the external precise reference value for GNSS positioning in the Arctic Ocean region is difficult, it is hard to evaluate the accuracy of positioning results. An improved isotropy-based protection level method based on Receiver Autonomous Integrity Monitoring is proposed in the paper, which adopts median filter to smooth the gross errors to assess the precision and reliability of PPP in the Arctic Ocean. At first, the improved algorithm is verified with the data from the International GNSS Service Station Tixi. Then the accuracy of BDS3 PPP in the Arctic Ocean is calculated based on the improved algorithm. Which shows that the kinematic accuracy of PPP can reach the decimeter level in both the horizontal and vertical directions, and it meets the precision requirements of maritime navigation. 展开更多
关键词 BDS3 Arctic Ocean signal quality analysis protection level quality check Precise Point Positioning satellite navigation
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Network Management of Food Additives Quality Analysis and Inspection 被引量:3
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作者 Hairui Zhang Guofu Zhang Li Zhang 《Journal of Chemistry and Chemical Engineering》 2015年第7期468-471,共4页
In this paper, on the basis of the implementation of the national chemical industry standard analytical test methods and analysis of test items, a food additive quality analysis and inspection of network management ap... In this paper, on the basis of the implementation of the national chemical industry standard analytical test methods and analysis of test items, a food additive quality analysis and inspection of network management applications are developed using the development technology of Visual Basic language and computer system operating environment, to achieve a network management software for users on food additives of quality analytical testing. The software sets up an information sharing network platform for enterprise and quality management departments, which is a major innovation in the food additive quality analysis on test management methods and tools. 展开更多
关键词 Food additives quality analysis Visual Basic language network management software development.
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Intelligent Management Based on Chemical Reagent Quality Analysis 被引量:2
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作者 Hairui Zhang Guofu Zhang Li Zhang 《Journal of Chemistry and Chemical Engineering》 2016年第7期336-340,共5页
Access database technology and Visual Basic programming language are used to develop a set of chemical reagents quality analysis and inspection of intelligent management application software, and its stability was inv... Access database technology and Visual Basic programming language are used to develop a set of chemical reagents quality analysis and inspection of intelligent management application software, and its stability was investigated. The results show that the sotfware is used to manage intelligently the quality analysis of chemical reagents test each linkage, to upload and save the analysis of test data and results in the network in time for users, to build a network of information sharing platform for enterprises and quality management departments, and its quality of chemical reagents test results is used to manage by the computer with practical application value. The software is simple, convenient, fast, friendly interface, stable operation, accurate and reliable results, with a high value to promote the application. 展开更多
关键词 Chemical reagent quality analysis test visual basic language software development intelligent management.
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Research of Water Quality Analysis,Treatment and Reuse Technology for Rainwater on the North University Campus 被引量:1
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作者 Chen Shufang Shi Jingwei +1 位作者 Shao Yanjun Tu Chao 《Meteorological and Environmental Research》 CAS 2018年第1期62-65,共4页
The pollution situation of different underlying surface and the change rule of each water quality index were researched,on the basis of rainwater quality monitoring by different approaches in a university campus. The ... The pollution situation of different underlying surface and the change rule of each water quality index were researched,on the basis of rainwater quality monitoring by different approaches in a university campus. The results showed that due to some factors,such as the underlying surface material pollution,road materials,road surface pollution condition and surrounding atmospheric environment quality,the pollution of different underlying surface rainwater would be different. Main pollutants of rainwater runoff in the city campus area were such as COD,SS,NH;-N,TP,etc. Ultimately,along with the increase of accumulated rainfall,the pollutants tended to gradually decrease. The road rain pollution was more serious than roof runoff pollution and the early rain pollution was serious,but the late rain water quality was much better. According to the rainwater conditions,subsequent rainwater recycling technology and processing technology were determined as a way to alleviate the problem of water shortage and water pollution. 展开更多
关键词 NORTH Rainwater on campus Water quality analysis Variation rule Reuse technology
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基于感官、电子鼻和GC-IMS分析的东北臭酱气味特征判别 被引量:2
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作者 汲生泷 李美善 +2 位作者 李凤林 陈福玉 魏登 《食品与机械》 北大核心 2025年第4期44-53,共10页
[目的]探究4种市售臭酱挥发性风味的差异性并进行气味特征判别。[方法]利用感官剖面、电子鼻结合气相色谱—离子迁移谱法(gas chromatography-ion mobility spectrometry,GC-IMS)全面分析4种臭酱中挥发性风味的差异性及气味特征。[结果]... [目的]探究4种市售臭酱挥发性风味的差异性并进行气味特征判别。[方法]利用感官剖面、电子鼻结合气相色谱—离子迁移谱法(gas chromatography-ion mobility spectrometry,GC-IMS)全面分析4种臭酱中挥发性风味的差异性及气味特征。[结果]4种东北臭酱中的主要挥发性有机化合物(volatile organic compounds,VOCs)为酯类、酸类、醛类、酮类以及吡嗪、呋喃和吡咯等杂环类挥发物;酸香、腐香是构成臭酱“闻着臭”的核心气味,CJ1臭酱的刺激性“臭味”较突出;CJ2臭酱气味层次感更强;CJ3臭酱气味较融合;CJ4臭酱臭味较轻,清香和芳香味重且柔和;不同臭酱中的气味特征具有明显的差异。[结论]基于感官剖面、电子鼻结合GC-IMS技术能够全面有效区分和判别4种不同市售臭酱的挥发性风味特征。 展开更多
关键词 东北臭酱 感官剖面分析 电子鼻 gc-IMS 聚类分析
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Chemical composition, antioxidant activity and GC-MS analysis of juice and peel oil of grapefruit varieties cultivated in India 被引量:5
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作者 Shahnawaz Ahmed H S Rattanpal +2 位作者 Khalid Gul Rouf Ahmad Dar Akash Sharma 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第7期1634-1642,共9页
Citrus family especially Grapefruit,has attained considerable attention due to the presence of a number of essential components that have cardiovascular and anti-hypertensive properties.The juice and essential oil ext... Citrus family especially Grapefruit,has attained considerable attention due to the presence of a number of essential components that have cardiovascular and anti-hypertensive properties.The juice and essential oil extracted from eight recently released grapefruit cultivars were used to study physicochemical and antioxidant properties.The total soluble solids(TSS),titratable acidity(TA) and pH of juice samples extracted from various grapefruit varieties differed significantly.The refractive index,specific gravity and optical rotation values for the oil varied from 1.473 to 1.396,0.863 to 0.847 and +93 to +86,respectively.The percent 2,2-diphenyl-1-picrylhydrazyl radical activity(% DPPH activity) and ferric reducing antioxidant power(FRAP) values for grapefruit juice and peel oil varied from 24.06 to 18.79,2.91 to 1.44 mmol g^–1 and 84.87 to 74.73,7.76 to 5.73 mmol g^-1,respectively.There were significant differences in physicochemical,antioxidant properties and volatile profiles of extracted juice and oil.The oil exhibited higher DPPH and FRAP values than the juice.Among different components identified which accounted for over 99% of the volatile fraction,limonene,myrcene,and benzopyran were major components in all oil samples. 展开更多
关键词 GRAPEFRUIT JUICE essential oil PHYSICOCHEMICAL PROPERTIES antioxidant PROPERTIES gc-MS analysis
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