30 results on '"Limin Yang"'
Search Results
2. The complete chloroplast genome of Clematis hexapetala (Ranunculaceae) and its phylogenetic analysis
- Author
-
Yi Cui, Yingxin Sun, Yanzhe Ding, Jing Liu, Zhongming Han, Yunhe Wang, Mei Han, and Limin Yang
- Subjects
Genetics ,Molecular Biology - Published
- 2022
- Full Text
- View/download PDF
3. Complete chloroplast genome characterization and phylogenetic analysis of Clematis mandshurica (Ranunculaceae)
- Author
-
Yi Cui, Lihua Yang, Yanzhe Ding, Yingxin Sun, Jiao Wang, Yunfei Xi, Mei Han, Limin Yang, Zhongming Han, and Yunhe Wang
- Subjects
Genetics ,Molecular Biology - Published
- 2022
- Full Text
- View/download PDF
4. Epigenetic Alterations of the Promoter Region of the POMC Gene in Adolescent Depressive Disorder Patients with Nonsuicidal Self-injury Behaviors
- Author
-
Mengmeng Sun, Lina Wang, Tantan Ma, Lanfen Liu, Chao Han, Kaiyan Cui, Limin Yang, Xiaojiao Bi, Doudou Zheng, and Tianliang Zhang
- Subjects
Oncology ,Psychosis ,medicine.medical_specialty ,business.industry ,05 social sciences ,Bisulfite sequencing ,Methylation ,medicine.disease ,050105 experimental psychology ,03 medical and health sciences ,Psychiatry and Mental health ,0302 clinical medicine ,Internal medicine ,DNA methylation ,medicine ,Anxiety ,0501 psychology and cognitive sciences ,030212 general & internal medicine ,Epigenetics ,Family history ,medicine.symptom ,business ,General Psychology ,Depression (differential diagnoses) - Abstract
Purpose The incidence of nonsuicidal self-injury (NSSI) behavior among adolescents increases year by year. Patients with a history of both depression and NSSI behaviors tend to have greater risk of suicide. At present, the mechanism of adolescent depressive disorder patients with NSSI behaviors is not clear, epigenetic mechanism may be involved. Proopiomelanocortin (POMC) gene may be associated with depressive disorder. The purpose of this study was to investigate DNA methylation of POMC gene promoter region of adolescent depressive disorder patients with NSSI behaviors. Methods Bisulfite Sequencing PCR (BSP) was used to test the methylation level of POMC promoter of 15 adolescent depressive disorder patients with NSSI behaviors and 15 healthy controls (HC). Self-made questionnaires were used to collect clinical data of the case group and control group. Hamilton depression scale-24 (HAMD-24), Hamilton anxiety scale (HAMA), Symptom Checklist-90 (SCL-90) were used to evaluate the characteristics and severity of depressive, anxiety and psychotic symptoms. Adolescent self-injury questionnaire was used to assess NSSI behaviors and its severity. Results BSP analysis found that the POMC methylation level of cytosine-guanine dinucleotide 1 (CpG1) site was higher in the case group than that of HC (P
- Published
- 2020
- Full Text
- View/download PDF
5. Medical and surgical complications in pregnancy and obstetric labour complications in the Japan Environment and Children’s Study (JECS) cohort: a birth cohort study
- Author
-
Kazue Ishitsuka, Haruhiko Sago, Yukihiro Ohya, Hirohisa Saito, Mizuho Konishi, Tadayuki Ayabe, Tetsuo Shoda, Limin Yang, Kiwako Yamamoto-Hanada, and Hidetoshi Mezawa
- Subjects
Adult ,Gestational hypertension ,medicine.medical_specialty ,Complications of pregnancy ,Cohort Studies ,03 medical and health sciences ,Postoperative Complications ,0302 clinical medicine ,Japan ,Pregnancy ,Surveys and Questionnaires ,Epidemiology ,Humans ,Medicine ,030219 obstetrics & reproductive medicine ,business.industry ,Obstetrics ,Medical record ,Infant, Newborn ,Pregnancy Outcome ,Obstetrics and Gynecology ,medicine.disease ,Obstetric Labor Complications ,Pregnancy Complications ,Gestational diabetes ,030220 oncology & carcinogenesis ,Cohort ,Female ,business ,Genital Diseases, Female ,Follow-Up Studies ,Maternal Age ,Kidney disease - Abstract
This study aimed to describe the distribution of pregnancies with medical and obstetric complications based on the Japan Environment and Children's Study (JECS). We evaluated the distribution of the history of obstetric/gynaecological diseases, the history of obstetric labour complications, pregnancy with medical and surgical complications, and obstetric labour complications in participants in the JECS. Of 100,818 pregnant women with medical record entries after delivery, 15,305 (15.2%) had medical and surgical complications in pregnancy and 46,756 (46.4%) experienced obstetric labour complications. The proportion of pregnancies with heart disease, kidney disease and hepatitis was 0.3%, 0.3% and 0.1%, respectively. Gestational diabetes was diagnosed in 2715 (2.7%) women. The proportion of women with mild and severe gestational hypertension was 2.3% and 1%, respectively. The JECS is the largest birth cohort in Japan. These data will provide useful, basic information for perinatal care in Japan.IMPACT STATEMENTWhat is already known on this subject? Epidemiological studies have suggested that pre-existing diseases and complications of pregnancy, such as heart disease in pregnancy, gestational hypertension and gestational diabetes, may have implications for pregnancy outcomes, as well as for children's health and development.What the results of this study add? We evaluated the distribution of the history of obstetric/gynaecological diseases, the history of obstetric labour complications, medical and surgical complications in pregnancy, and obstetric labour complications using data from the Japan Environment and Children's Study (JECS).What the implications are of these findings for clinical practice and/or further research? The JECS is the largest birth cohort in Japan. Our data will provide useful, basic information for perinatal care in Japan.
- Published
- 2019
- Full Text
- View/download PDF
6. Determination of Organophosphorus Pesticides in Fortified Tomatoes by Fluorescence Quenching of Cadmium Selenium – Zinc Sulfide Quantum Dots
- Author
-
Lei Jiang, Xiaohui Zhang, and Limin Yang
- Subjects
Cadmium ,Passivation ,010401 analytical chemistry ,Biochemistry (medical) ,Clinical Biochemistry ,Inorganic chemistry ,chemistry.chemical_element ,Fluorescence sensing ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Zinc sulfide ,0104 chemical sciences ,Analytical Chemistry ,Oleic acid ,chemistry.chemical_compound ,chemistry ,Quantum dot ,Electrochemistry ,0210 nano-technology ,Organophosphorus pesticides ,Spectroscopy ,Selenium - Abstract
Quantum dots (QDs) have attracted great interest in fluorescence sensing. However, due to the surface passivation of QDs, it is still challenging to develop a sensing method based on the direct use...
- Published
- 2018
- Full Text
- View/download PDF
7. Time course of EEG activities in continuous tracking task: a pilot study
- Author
-
Wenya Nan, Qi Tang, Yong Hu, Frank F. Zhu, Feng Wan, Liyi Shen, and Limin Yang
- Subjects
Male ,medicine.medical_specialty ,Time Factors ,Alpha (ethology) ,Pilot Projects ,Electroencephalography ,Audiology ,Task (project management) ,Young Adult ,Reference Values ,Parietal Lobe ,Task Performance and Analysis ,medicine ,Humans ,Simulation ,Brain Mapping ,Resting state fMRI ,medicine.diagnostic_test ,Work (physics) ,Motor Cortex ,Healthy Volunteers ,Frontal Lobe ,Computer Science Applications ,Motor Skills ,Surgery ,Tracking (education) ,Primary motor cortex ,Family Practice ,Motor learning ,Psychology ,Psychomotor Performance - Abstract
Motor learning is crucial to surgical skills enhancement, but its neural mechanism has been investigated only using some simple tasks with limited motor involvement. This study aimed to gain more understanding of the neural dynamics during motor learning by investigating the time course of electroencephalogram (EEG) activities in the continuous tracking task that involves more motor components. One participant performed 16 trials of the continuous tracking task on Day1 and Day2 respectively. The 16-channel EEG signals were recorded and analyzed in both the resting and active states. Results showed that the tracking performance improved from Day1 to Day2. Regarding the EEG, it was found that the relative amplitude in the individual alpha band (IAB) decreased locally over primary motor cortex from the resting state to the active state on both days, and this reduction was more focused on the left primary motor cortex on Day2 compared to Day1. Moreover, in the active state the alpha coherence between central and frontal areas also significantly increased from Day1 to Day2. Time course of alpha activities may explain the tracking performance enhancement from Day1 to Day2. Future work will include more participants to extend the validity of current results.
- Published
- 2017
- Full Text
- View/download PDF
8. Synthesis and antitumour activity of arctigenin amino acid ester derivatives against H22 hepatocellular carcinoma
- Author
-
Yan Zhao, Enbo Cai, Mei Han, Gao Xiaorui, Yu Wang, Limin Yang, Shijie Guo, and Jing Xia
- Subjects
Carcinoma, Hepatocellular ,Antineoplastic Agents ,Chemistry Techniques, Synthetic ,Plant Science ,01 natural sciences ,Biochemistry ,Lignans ,Analytical Chemistry ,Structure-Activity Relationship ,chemistry.chemical_compound ,medicine ,Animals ,Humans ,Amino Acids ,Furans ,Nitrites ,Arctigenin ,chemistry.chemical_classification ,Mice, Inbred ICR ,Ester derivatives ,Aqueous solution ,010405 organic chemistry ,Chemistry ,Liver and kidney ,Liver Neoplasms ,Organic Chemistry ,Esters ,Biological activity ,medicine.disease ,Xenograft Model Antitumor Assays ,0104 chemical sciences ,Amino acid ,010404 medicinal & biomolecular chemistry ,Solubility ,Hepatocellular carcinoma ,Drug Screening Assays, Antitumor - Abstract
Arctigenin (ARG) is famous in its abundant pharmacological activity. However, many researches in it entered the bottleneck period because of its poor water solubility. The derivatives of ARG have been synthesised with five amino acids which have t-Butyloxy carbonyl (BOC) as a protective group. We examined the effects of removing BOC. The results showed that the amino acid derivatives without protective group have better water solubility and nitrite-clearing ability than ARG. Based on these results, ARG6′ and ARG9′ were selected at a dosage of 40 mg/kg to evaluate their antitumour activity. The percentage inhibition rate of ARG6′ and ARG9′ were 55.87 and 51.40, respectively, which was twice as much as ARG. Furthermore, they could increase liver and kidney indexes and produce less damage in these organs. In brief, this study provides a basis for new drug development.
- Published
- 2017
- Full Text
- View/download PDF
9. Compositions, mechanical properties and microstructures of cBN-based composites sintered with Al or TiC
- Author
-
Jianhong Gong, Limin Yang, Chu Xingrong, Zhenming Yue, and Zhao Xiaodi
- Subjects
010302 applied physics ,Materials science ,Sintering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Industrial and Manufacturing Engineering ,Isothermal process ,chemistry.chemical_compound ,chemistry ,Boron nitride ,High pressure ,0103 physical sciences ,Ceramics and Composites ,Oxidation process ,Composite material ,0210 nano-technology ,Thermal analysis - Abstract
Cubic boron nitride (cBN)-based composites were prepared from cBN–Al and cBN–TiC mixtures, respectively, under high pressure and high temperature (HPHT). During sintering, Al reacted with cBN and produced AlN and AlB2, while TiC did not react with cBN. With increasing Al from 5–20 wt-%, the strength of the cBN-based composites decreased first, then increased. AlN and AlB2 could strengthen the cBN-based composites to a certain extent. In the preparation from cBN–TiC, 10 wt-% addition of TiC was the optimal formulation to obtain the densest microstructure. Hardness of the two kinds of composites displayed different tendencies. On the other hand, cBN-based composites were treated at 1200°C for 1200 s. It was found that the isothermal oxidation process could be described by parabolic laws with slight oxidation scales formed on samples’ surfaces in different morphologies.
- Published
- 2017
- Full Text
- View/download PDF
10. An ongoing path of element-labeling/tagging strategies toward quantitative bioanalysis using ICP-MS
- Author
-
Qiuquan Wang, Yong Liang, and Limin Yang
- Subjects
Bioanalysis ,Chromatography ,Chemistry ,010401 analytical chemistry ,Computational biology ,010402 general chemistry ,01 natural sciences ,Instrumentation ,Spectroscopy ,0104 chemical sciences - Abstract
In the past dozen years, inductively coupled plasma–mass spectrometry (ICP-MS) has emerged as a spectacular tool for quantitative bioanalysis with the development of element-labeling/tagging strategies. These strategies are paving the way for ICP-MS-based bioanalysis from endogenous heteroelement labels through chemoselective to biospecific exogenous element tags, accompanied by great improvements in sensitivity and selectivity and thus accuracy as well. In this minireview, we critically describe such a developing process, focusing on the research activities performed in our laboratory and some achievements of enlightening significance. A look into the future of ICP-MS-based bioanalysis is proposed regarding the element-tagging strategy and analysis of microorganisms, novel methodological developments for gene and protein sequencing, and the mechanisms of a certain biological process to further understand the occurrence of disease and developments for relevant drug discovery and design, in additio...
- Published
- 2015
- Full Text
- View/download PDF
11. Retrospective Analysis on Clinical Pathway Literatures
- Author
-
Jun Xue, Limin Yang, Xian-Tao Huang, and Xue-Liang Wu
- Subjects
medicine.medical_specialty ,business.industry ,Status quo ,Applied Mathematics ,General Mathematics ,media_common.quotation_subject ,Data science ,Clinical pathway ,Knowledge base ,Basic research ,Process analysis ,Related research ,medicine ,Retrospective analysis ,Medical physics ,business ,media_common ,Research method - Abstract
Objective. To consult related documents, retrospectively study related research literature regarding the implementation of clinical pathway in China, and obtain knowledge of the status quo of clinical pathway application and the trend of its development in China. Method. Using the full-text databases of the China National Knowledge Infrastructure-China Hospital Knowledge Database (CHKD) periodicals as the data source, 1996–2010 as the time period and clinical pathway as the retrieval method to search for the literature data; performing analysis and research by processing data with Excel software, and using the literature metrology method, process analysis and retrospective research method. The Chinese literatures regarding clinical pathway between 1996 and 2010 are counted in terms of the distribution of basic research, application research and development research, respectively. Result. A total of 1,172 documents of clinical pathway research from 1996 to 2010 are obtained, and it is noted that th...
- Published
- 2014
- Full Text
- View/download PDF
12. An efficient method for change detection of soil, vegetation and water in the Northern Gulf of Mexico wetland ecosystem
- Author
-
John C. Brock, Collin G. Homer, Joyce Fry, and Limin Yang
- Subjects
geography ,geography.geographical_feature_category ,Abundance (ecology) ,Multispectral image ,Reference data (financial markets) ,General Earth and Planetary Sciences ,Environmental science ,Wetland ,Satellite imagery ,Ecosystem ,Vegetation ,Change detection ,Remote sensing - Abstract
Mapping and monitoring wetland ecosystems over large geographic areas based on remote sensing is challenging because of the spatial and spectral complexities of the inherent ecosystem dynamics. The main objective of this research was to develop and evaluate a new method for detecting and quantifying wetland changes in the Northern Gulf of Mexico NGOM region using multitemporal, multispectral, and multisensor remotely sensed data. The abundance of three land-cover types water, vegetation, and soil was quantified for each Landsat 30 m pixel for 1987, 2004, 2005, and 2006 using a regression tree algorithm. The performance of the algorithm was evaluated using an independent reference data set derived from a high-resolution QuickBird image, and several statistics including average error AE, relative error RE, and the Pearson correlation coefficient r . For per-pixel percentage estimation, the AE is under 10% for water prediction, 9.5–11.4% for vegetation, and 9–11.1% for soil. The correlation coefficients between predicted and reference data range from 0.90 to 0.96 for water, from 0.80 to 0.89 for vegetation, and from 0.79 to 0.86 for soil. The high accuracy achieved by this method is attributed to the high quality of training data and the rigorous calibrations applied to multisensor and multitemporal satellite imagery. Based on the multitemporal estimation of the three land-cover components, spatial and temporal changes of the land-cover types from 1987 to 2006 were quantified and analysed. The study demonstrates that the method provided useful information on the abundance and changes of the key land-cover types in the NGOM region where long-term disturbances and episodic events occurred. Such information is valuable for monitoring land and vegetation loss and recovery processes, and for understanding possible drivers of the coastal wetland evolution in the region.
- Published
- 2013
- Full Text
- View/download PDF
13. Body mass index for children aged 6–18 years in Beijing, China
- Author
-
Jiali Duan, Naoko Sakamoto, Limin Yang, Xin Guo, and Dongmei Qiu
- Subjects
Male ,Rural Population ,China ,Aging ,medicine.medical_specialty ,Pediatrics ,Percentile ,Adolescent ,Urban Population ,Physiology ,Epidemiology ,Body Mass Index ,Sex Factors ,Thinness ,Beijing ,Prevalence ,Genetics ,medicine ,Humans ,National level ,Obesity ,Child ,National data ,business.industry ,Public health ,Body Weight ,Age Factors ,Public Health, Environmental and Occupational Health ,Overweight ,medicine.disease ,Female ,business ,Body mass index ,Demography - Abstract
Obesity constitutes one of the most important worldwide public health concerns.To develop BMI percentile curves by age, sex and urban-rural regions for Beijing children and compare the results with Chinese national data and international references.Boys (4078) and girls (4077), aged 6-18 years, were recruited from 1 September to 30 November 2005 in Beijing, China. BMI percentile curves were constructed using the LMS method.BMI curves differed between boys and girls. BMI curves for urban children were higher than rural children at the upper percentile. Beijing BMI curves were higher than the Chinese national level. Beijing boys had a higher BMI in medium (6.5-14 years) and upper percentiles and a lower BMI in lower percentiles than WHO and developed references, whereas Beijing girls were lower in medium and lower percentiles, but higher compared to a WHO reference before age 15.5 years in upper percentiles.Beijing children are fatter than the Chinese national level. Beijing urban children are fatter than rural Beijing children. The polarization of BMI values for Beijing boys suggests these children face a dual-burden of nutrition. Effective policies and interventions to control obesity and underweight in Chinese children are necessary.
- Published
- 2013
- Full Text
- View/download PDF
14. Automated cloud and shadow detection and filling using two-date Landsat imagery in the USA
- Author
-
Joyce Fry, Patrick Danielson, PhilipA. Townsend, Suming Jin, Collin G. Homer, George Xian, and Limin Yang
- Subjects
Pixel ,Computer science ,business.industry ,Cloud detection ,Cloud computing ,Land cover ,Thematic Mapper ,Shadow ,General Earth and Planetary Sciences ,Computer vision ,Satellite imagery ,Artificial intelligence ,business ,Row ,Remote sensing - Abstract
A simple, efficient, and practical approach for detecting cloud and shadow areas in satellite imagery and restoring them with clean pixel values has been developed. Cloud and shadow areas are detected using spectral information from the blue, shortwave infrared, and thermal infrared bands of Landsat Thematic Mapper or Enhanced Thematic Mapper Plus imagery from two dates a target image and a reference image. These detected cloud and shadow areas are further refined using an integration process and a false shadow removal process according to the geometric relationship between cloud and shadow. Cloud and shadow filling is based on the concept of the Spectral Similarity Group SSG, which uses the reference image to find similar alternative pixels in the target image to serve as replacement values for restored areas. Pixels are considered to belong to one SSG if the pixel values from Landsat bands 3, 4, and 5 in the reference image are within the same spectral ranges. This new approach was applied to five Landsat path/rows across different landscapes and seasons with various types of cloud patterns. Results show that almost all of the clouds were captured with minimal commission errors, and shadows were detected reasonably well. Among five test scenes, the lowest producer's accuracy of cloud detection was 93.9% and the lowest user's accuracy was 89%. The overall cloud and shadow detection accuracy ranged from 83.6% to 99.3%. The pixel-filling approach resulted in a new cloud-free image that appears seamless and spatially continuous despite differences in phenology between the target and reference images. Our methods offer a straightforward and robust approach for preparing images for the new 2011 National Land Cover Database production.
- Published
- 2012
- Full Text
- View/download PDF
15. One-Pot Synthesis of 2-Arylthiazolines with 1-Butyl-3-Methylimidazolium Tribromide as a Catalytic Reagent
- Author
-
Liqiang Wu, Guangzhou Lu, and Limin Yang
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,2-Aminoethanethiol ,Reagent ,Organic Chemistry ,One-pot synthesis ,Organic chemistry ,Biochemistry ,1-butyl-3-methylimidazolium ,Tribromide ,Catalysis - Abstract
A simple, inexpensive, and efficient one-pot synthesis of 2-arylthiazoline derivatives under solvent-free conditions using a catalytic amount of 1-butyl-3-methylimidazolium tribromide with excellent product yields is reported. This methodology provides easy, quantitative access to various 2-arylthiazoline derivatives, using environmentally benign 1-butyl-3-methylimidazolium tribromide as a catalyst.
- Published
- 2012
- Full Text
- View/download PDF
16. Detecting post-fire burn severity and vegetation recovery using multitemporal remote sensing spectral indices and field-collected composite burn index data in a ponderosa pine forest
- Author
-
James E. Vogelmann, Hua Shi, Limin Yang, Donald O. Ohlen, Carl H. Key, Xuexia Chen, Chengquan Huang, and Matthew Rollins
- Subjects
Index (economics) ,Remote sensing (archaeology) ,Normalized burn ratio ,General Earth and Planetary Sciences ,Environmental science ,Ponderosa pine forest ,Enhanced vegetation index ,Vegetation ,Low correlation ,Normalized Difference Vegetation Index ,Remote sensing - Abstract
It is challenging to detect burn severity and vegetation recovery because of the relatively long time period required to capture the ecosystem characteristics. Multitemporal remote sensing data can provide multitemporal observations before, during and after a wildfire, and can improve the change detection accuracy. The goal of this study is to examine the correlations between multitemporal spectral indices and field-observed burn severity, and to provide a practical method to estimate burn severity and vegetation recovery. The study site is the Jasper Fire area in the Black Hills National Forest, South Dakota, that burned during August and September 2000. Six multitemporal Landsat images acquired from 2000 pre-fire, 2001 post-fire, 2002, 2003, 2005 and 2007 were used to assess burn severity. The normalized difference vegetation index NDVI, enhanced vegetation index EVI, normalized burn ratio NBR, integrated forest index IFI and the differences of these indices between the pre-fire and post-fire years were computed and analysed with 66 field-based composite burn index CBI plots collected in 2002. Results showed that differences of NDVI and differences of EVI between the pre-fire year and the first two years post-fire were highly correlated with the CBI scores. The correlations were low beyond the second year post-fire. Differences of NBR had good correlation with CBI scores in all study years. Differences of IFI had low correlation with CBI in the first year post-fire and had good correlation in later years. A CBI map of the burnt area was produced using regression tree models and the multitemporal images. The dynamics of four spectral indices from 2000 to 2007 indicated that both NBR and IFI are valuable for monitoring long-term vegetation recovery. The high burn severity areas had a much slower recovery than the moderate and low burn areas.
- Published
- 2011
- Full Text
- View/download PDF
17. Numerical Modeling of Wear Damage in Seals of a Wave Energy Converter with Hydraulic Power Take-Off under Random Loads
- Author
-
Torgeir Moan and Limin Yang
- Subjects
Engineering ,business.industry ,Mechanical Engineering ,Relative velocity ,Mechanical engineering ,Surfaces and Interfaces ,Mechanics ,Sea state ,Tribology ,Surfaces, Coatings and Films ,Mechanics of Materials ,Marine energy ,Lubrication ,Piston ring ,Hydraulic machinery ,Material properties ,business - Abstract
Understanding and managing the safety and reliability issues of ocean energy converters is a key factor in the development of viable technologies. The present article deals with wear in the high-pressure hydraulic power take-off machinery in a heaving-buoy wave energy converter. In this study, an abrasive wear model for such machinery is developed for the steady-state operation by considering the effects of sealed pressure, relative velocity, material properties, time-varying environmental conditions, and lubrication, with a focus on the piston ring. In particular, the dependence of the wear damage on the sea state condition is investigated. The dynamic parameter named instantaneous wear work rate (Load × Velocity) is numerically calculated in the time domain. An estimate of the average wear work rate in each sea state is computed on the basis of a wave scatter table (significant wave heights versus peak period). Long-term wear damage can then be accounted for by summing up the short-term wear damage mult...
- Published
- 2010
- Full Text
- View/download PDF
18. Silica Chloride–Catalyzed Synthesis of Thiiranes from Oxiranes Under Solvent-Free Conditions
- Author
-
Limin Yang, Fulin Yan, Lizhen Fang, Liqiang Wu, and Chunguang Yang
- Subjects
Inorganic Chemistry ,Reaction conditions ,chemistry.chemical_compound ,Solvent free ,Thiirane ,chemistry ,Organic Chemistry ,medicine ,Organic chemistry ,Biochemistry ,Chloride ,Catalysis ,medicine.drug - Abstract
A mild, simple, and efficient method for the synthesis of thiiranes from epoxides using a catalytic amount of silica chloride under solvent-free conditions has been developed. Experimental simplicity, simple work-up procedure, and solvent-free reaction conditions are important features of the present protocol.
- Published
- 2010
- Full Text
- View/download PDF
19. Synthesis of 14-Substituted-14H-Dibenzo[a,j] Xanthenes and 1,8-Dioxo-Octahydroxanthenes Using Silica Chloride (SiO2-Cl) Under Solvent-Free Conditions
- Author
-
Limin Yang, Chunguang Yang, Liqiang Wu, and Lijuan Yang
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,Solvent free ,chemistry ,Dimedone ,Organic Chemistry ,Condensation ,medicine ,Organic chemistry ,Heterogeneous catalysis ,Biochemistry ,Chloride ,medicine.drug - Abstract
A simple and efficient synthesis of 14-substituted-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydroxanthenes has been accomplished by the one-pot condensation of β-naphthol or dimedone and aldehydes under solvent-free conditions in the presence of SiO2-Cl as a heterogeneous catalyst.
- Published
- 2010
- Full Text
- View/download PDF
20. Synergistic use of optical and InSAR data for urban impervious surface mapping: a case study in Hong Kong
- Author
-
Limin Yang, Mingsheng Liao, Liming Jiang, and Hui Lin
- Subjects
Watershed ,Geospatial analysis ,Multispectral image ,Land-use planning ,computer.software_genre ,Urban climate ,Interferometric synthetic aperture radar ,Impervious surface ,General Earth and Planetary Sciences ,Environmental science ,Urban ecosystem ,computer ,Cartography ,Remote sensing - Abstract
A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning and watershed resource management, require accurate and up-to-date geospatial data of urban impervious surfaces. In this study, the potential of the synergistic use of optical and InSAR data in urban impervious surface mapping at the sub-pixel level was investigated. A case study in Hong Kong was conducted for this purpose by applying a classification and regression tree (CART) algorithm to SPOT 5 multispectral imagery and ERS-2 SAR data. Validated by reference data derived from high-resolution colour-infrared (CIR) aerial photographs, our results show that the addition of InSAR feature information can improve the estimation of impervious surface percentage (ISP) in comparison with using SPOT imagery alone. The improvement is especially notable in separating urban impervious surface from the vacant land/bare ground, which has been a difficult task in ISP modelling with optical remote sensing data. In addition, the results demonstrate the potential to map urban impervious surface by using InSAR data alone. This allows frequent monitoring of world's cities located in cloud-prone and rainy areas.
- Published
- 2009
- Full Text
- View/download PDF
21. Quantifying Sub-pixel Urban Impervious Surface through Fusion of Optical and InSAR Imagery
- Author
-
Limin Yang, Mingsheng Liao, Liming Jiang, and Hui Lin
- Subjects
Fusion ,Computer Science::Graphics ,Geography ,Pixel ,Interferometric synthetic aperture radar ,Astrophysics::Instrumentation and Methods for Astrophysics ,Impervious surface ,General Earth and Planetary Sciences ,Physics::Atmospheric and Oceanic Physics ,Remote sensing - Abstract
In this study, we explored the potential to improve urban impervious surface modeling and mapping with the synergistic use of optical and Interferometric Synthetic Aperture Radar (InSAR) imagery. W...
- Published
- 2009
- Full Text
- View/download PDF
22. Land Cover Classification in the Poyang Lake Region, China, Using Landsat TM and JERS-1 Synthetic Aperture Radar Data
- Author
-
Ying Liu, Huiyong Sang, Xiangming Xiao, Limin Yang, and Hui Lin
- Subjects
Synthetic aperture radar ,Geography ,geography.geographical_feature_category ,Pixel ,Land use ,Decision tree learning ,Decision tree ,General Earth and Planetary Sciences ,Satellite ,Wetland ,Land cover ,Computer Science Applications ,Remote sensing - Abstract
The Poyang Lake is the largest fresh water lake in China. As an internationally important wetlands, conservation of wild birds needs updated information on land use and land cover in the Poyang Lake region. This paper introduced a non-parametric knowledge-based classification method (decision tree classifier) for land cover classification in the Poyang Lake region. We merged optical sensor (Landsat 5 TM) image with Japanese Earth Resource Satellite-1(JERS-1) synthetic aperture radar (SAR) images. The overall accuracy of the classification result was about 82%, of which forest was classified with higher accuracy (over 87%) and less errors of omission and commission. Main classification errors came from the similar spectrum of different land cover classes in winter. The seasonal dynamics should be considered for selecting optical satellite images for classification when using this pixel-based classification algorithm. The results of this study suggests that the non-parametric decision tree classifi...
- Published
- 2007
- Full Text
- View/download PDF
23. Determination of Cadmium in Seawater by Vapor Generation Atomic Fluorescence Spectrometry After Online Preconcentration with a Novel Alkyl Phosphinic Acid Resin
- Author
-
Qiuquan Wang, Limin Yang, and Qiang Fu
- Subjects
Detection limit ,chemistry.chemical_classification ,Cadmium ,Chromatography ,Elution ,chemistry.chemical_element ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Matrix (chemical analysis) ,chemistry.chemical_compound ,chemistry ,Tartaric acid ,Seawater ,Enrichment factor ,Spectroscopy ,Alkyl - Abstract
Vapor generation atomic fluorescence spectrometry (VG‐AFS) coupled with online preconcentration on a short column (4.6 mm×50‐mm length) packed with a newly synthesized alkyl phosphinic acid resin (APAR) was developed for the determination of trace Cd in seawater. During the online preconcentration process, Cd in seawater was concentrated on the column while the matrix of seawater was separated flowing out of the column. Cd concentrated on the column was then eluted effectively from the column with 0.1 mol L−1 tartaric acid within 40 s. When the sample volume was 200 mL, an enrichment factor 189 was achieved. The detection limit of this proposed method for Cd is 2.67 ng L−1. The recovery of Cd is 96.6% obtained by spiking the correspondence standard, and the precision (RSD) is 4.34% (n=6). The established APAR/VG‐AFS was applied to the determination of soluble Cd in the seawater around Xiamen Island, China.
- Published
- 2007
- Full Text
- View/download PDF
24. Comparison of Land Cover Characterization Using EOS MISR and MODIS Data and a Decision Tree Classifier
- Author
-
Limin Yang
- Subjects
Standard error ,Geography ,Remote sensing (archaeology) ,Decision tree learning ,Geography, Planning and Development ,Land cover ,Rangeland ,Scale (map) ,Normalized Difference Vegetation Index ,Water Science and Technology ,Remote sensing - Abstract
Land cover characterization at a regional scale using spaceborne multi‐angle remote sensing data is in its infancy. A data mining technique was employed to evaluate the degree to which the accuracy of land cover classification can be increased using multi‐spectral, multi‐temporal and multi‐angle remote sensing data. The study area is around the Jornada Rangeland in New Mexico, USA with shrubland, woodland, grassland, desert barren land and irrigated cropland. Data used for this study included EOS MISR surface BRF and MODIS 16‐day NDVI composite acquired from 2002‐2003. Eight land cover types were classified using a decision tree algorithm with multiple classifications obtained to evaluate classification accuracy using different input data (MODIS data only, MISR data only, and MODIS plus MISR data). The overall classification accuracy from a five‐fold cross‐validation using MODIS data alone was 46% (standard error of 2.6%) as compared with 51% (standard error of 2.3%) using MISR data. The class‐sp...
- Published
- 2006
- Full Text
- View/download PDF
25. Oblique striping removal in remote sensing imagery based on wavelet transform
- Author
-
Jinsong Chen, Yun Shao, Limin Yang, and Hui Lin
- Subjects
Discrete wavelet transform ,business.industry ,Computer science ,Multispectral image ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Oblique case ,Wavelet transform ,Image (mathematics) ,Remote sensing (archaeology) ,Frequency domain ,General Earth and Planetary Sciences ,Computer vision ,Artificial intelligence ,Data striping ,business ,Remote sensing - Abstract
Oblique sharp and repetitive stripes in remote sensing imagery can distractingly and obstructively affect the interpretation and application of remote sensing data. A new methodology for removing oblique stripes, based on discrete wavelet transform (DWT), is proposed. DWT has been used to transform a multispectral image into a frequency domain to find the frequency components caused by stripes. The new technique has been tested taking CMODIS imagery as an example and evaluated by a number of indices. The results show that the proposed method can remove oblique stripes effectively and keep most image information.
- Published
- 2006
- Full Text
- View/download PDF
26. An approach for mapping large-area impervious surfaces: synergistic use of Landsat-7 ETM+ and high spatial resolution imagery
- Author
-
Bruce K. Wylie, Limin Yang, Collin G. Homer, Chengquan Huang, and Michael Coan
- Subjects
Geospatial analysis ,Land-use planning ,Land cover ,computer.software_genre ,Subpixel rendering ,Geography ,Thematic Mapper ,Urban climate ,Impervious surface ,General Earth and Planetary Sciences ,Urban ecosystem ,computer ,Cartography ,Remote sensing - Abstract
A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning, and resource management, require current and accurate geospatial data of urban impervious surfaces. We developed an approach to quantify urban impervious surfaces as a continuous variable by using multisensor and multisource datasets. Subpixel percent impervious surfaces at 30-m resolution were mapped using a regression tree model. The utility, practicality, and affordability of the proposed method for large-area imperviousness mapping were tested over three spatial scales (Sioux Falls, South Dakota, Richmond, Virginia, and the Chesapeake Bay areas of the United States). Average error of predicted versus actual percent impervious surface ranged from 8.8 to 11.4%, with correlation coefficients from 0.82 to 0.91. The approach is being implemented to map impervious surfaces for the entire United States as one of the major components of the circa 2000 national land cover database.
- Published
- 2003
- Full Text
- View/download PDF
27. Derivation of a tasselled cap transformation based on Landsat 7 at-satellite reflectance
- Author
-
Collin G. Homer, G. Zylstra, Bruce K. Wylie, Limin Yang, and Chengquan Huang
- Subjects
Brightness ,Transformation (function) ,Thematic Mapper ,Atmospheric correction ,General Earth and Planetary Sciences ,Environmental science ,Satellite ,Reflectivity ,Remote sensing - Abstract
A new tasselled cap transformation based on Landsat 7 at-satellite reflectance was developed. This transformation is most appropriate for regional applications where atmospheric correction is not feasible. The brightness, greenness and wetness of the derived transformation collectively explained over 97% of the spectral variance of the individual scenes used in this study.
- Published
- 2002
- Full Text
- View/download PDF
28. Development of a global land cover characteristics database and IGBP DISCover from 1 km AVHRR data
- Author
-
Donald O. Ohlen, James W. Merchant, Jesslyn F. Brown, Zhiliang Zhu, Bradley C. Reed, Thomas R. Loveland, and Limin Yang
- Subjects
Database ,Land use ,Biosphere ,Land cover ,computer.software_genre ,Data access layer ,Environmental studies ,Geography ,Information system ,Geological survey ,General Earth and Planetary Sciences ,Satellite imagery ,Cartography ,computer - Abstract
Researchers from the U.S. Geological Survey, University of Nebraska-Lincoln and the European Commission's Joint Research Centre, Ispra, Italy produced a 1 km resolution global land cover characteristics database for use in a wide range of continental-to global-scale environmental studies. This database provides a unique view of the broad patterns of the biogeographical and ecoclimatic diversity of the global land surface, and presents a detailed interpretation of the extent of human development. The project was carried out as an International Geosphere-Biosphere Programme, Data and Information Systems (IGBP-DIS) initiative. The IGBP DISCover global land cover product is an integral component of the global land cover database. DISCover includes 17 general land cover classes defined to meet the needs of IGBP core science projects. A formal accuracy assessment of the DISCover data layer will be completed in 1998. The 1 km global land cover database was developed through a continent-by-continent unsupervised ...
- Published
- 2000
- Full Text
- View/download PDF
29. Seasonal vegetation characteristics of the United States
- Author
-
Bradley C. Reed and Limin Yang
- Subjects
Geography ,business.industry ,Climatology ,Geography, Planning and Development ,Geological survey ,Satellite ,Data center ,Vegetation ,business ,Normalized Difference Vegetation Index ,Water Science and Technology - Abstract
The U.S. Geological Survey's EROS Data Center has created a prototype 1‐km resolution data base of vegetation seasonal characteristics. The characteristics are derived from time‐series NDVI data collected by the AVHRR satellite sensor. Information covering the 5 years 1989–1993 is included in the data base. Although quantitative validation of the seasonal characteristics cannot be made until several evaluation efforts are completed, general observations are possible by viewing images of the seasonal parameters. Figures 2 through 8 show several examples of the seasonal characteristics data base.
- Published
- 1997
- Full Text
- View/download PDF
30. Characteristics of the 1 km AVHRR data set for North America
- Author
-
Limin Yang and Zhiliang Zhu
- Subjects
Pixel ,Distortion ,Range (statistics) ,Atmospheric correction ,Solar zenith angle ,General Earth and Planetary Sciences ,Radiometry ,Missing data ,Geology ,Normalized Difference Vegetation Index ,Remote sensing - Abstract
The North America portion of a new global 1 km AVHRR time-series dataset was produced recently by the U.S. Geological Survey, EROS Data Center. Characteristics of the dataset were evaluated for scan-angle distribution, image area distortion as the result of map projection, distribution of high solar zenith angle, and cloud presence in image composites produced using maximum values of normalized difference vegetation index (NDVI). The evaluation showed that the compositing procedure exhibits a bias favouring off-nadir pixels, particularly at post-nadir (forward scanning) positions in the winter months. Results for scan angle distribution and image area distortion provide a basis for calculating the data's effective minimum mapping area for various geographical locations. The amount of missing data due to large solar zenith angle effect varies from 42 per cent in January to 1 per cent in July. Cloud contaminated pixels estimated for the thirty-six 10-day composites range from 7·5 per cent in May to...
- Published
- 1996
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.