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新职业青年分类分化研究——基于河北省的调查
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作者 李茂 路瑞红 +1 位作者 刘鹏 王晨阳 《经济论坛》 2021年第5期126-132,共7页
新职业青年的分类分化是技术进步和市场需求联合推动的结果,有其内在发展的必然性,但某些消极分化内容将不利于个人前途、行业发展及全面小康社会的建设。文章以河北省为例,通过问卷数据分析,指出目前新职业青年分类分化的基本特征,提... 新职业青年的分类分化是技术进步和市场需求联合推动的结果,有其内在发展的必然性,但某些消极分化内容将不利于个人前途、行业发展及全面小康社会的建设。文章以河北省为例,通过问卷数据分析,指出目前新职业青年分类分化的基本特征,提出控制消极分化、助力新职业青年健康发展的对策建议。 展开更多
关键词 新职业 青年 分类分化 河北
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三种肺癌组织学分类比较 被引量:3
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作者 李维华 《中国肺癌杂志》 CAS 2000年第6期401-403,共3页
关键词 肺癌 组织学分类 国际组织学分类 分化表型分类
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CT与MR诊断鞍区原发性小圆细胞性未分化肉瘤的临床案例分析
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作者 程少磊 彭迪 +2 位作者 王琼 胡兴荣 余美英 《CT理论与应用研究(中英文)》 2023年第4期559-565,共7页
目的:探讨鞍区原发性小圆细胞性未分化肉瘤的临床表现、病理特征及影像特点,以提高对该病的影像诊断及鉴别诊断能力。方法:回顾性分析1例经手术病理证实为鞍区原发性小圆细胞性未分化肉瘤的临床病理特征、CT及MR表现,并复习文献。结果:C... 目的:探讨鞍区原发性小圆细胞性未分化肉瘤的临床表现、病理特征及影像特点,以提高对该病的影像诊断及鉴别诊断能力。方法:回顾性分析1例经手术病理证实为鞍区原发性小圆细胞性未分化肉瘤的临床病理特征、CT及MR表现,并复习文献。结果:CT平扫示鞍区偏右侧呈稍低密度影,增强欠均匀强化,并累及邻近颅骨;MRI示T1WI呈低信号,T2WI、液体衰减反转恢复(FLAIR)呈略高信号,扩散加权成像(DWI)序列上呈高信号,信号欠均匀;增强病灶较明显强化,边缘较光整,邻近蝶鞍后床突可见骨质破坏。结论:鞍区原发性小圆细胞未分化肉瘤罕见,其临床和影像表现无明显特异性,确诊仍需依靠病理组织学检查。 展开更多
关键词 CT诊断 鞍区 分化/未分类软组织肉瘤
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腹壁CIC重排肉瘤1例并文献复习
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作者 廖艳芳 黄玺瑞 +1 位作者 赵佩佩 赵海燕 《诊断病理学杂志》 2024年第11期1079-1081,1085,共4页
目的探讨CIC重排肉瘤的临床症状、病理特征、诊疗过程及预后。方法回顾分析广东省深圳市龙岗中心医院2023年1月经手术切除标本确诊的1例腹壁CIC重排肉瘤的影像学、组织学、免疫组化、分子检测,同时结合文献总结CIC重排肉瘤的病理诊断要... 目的探讨CIC重排肉瘤的临床症状、病理特征、诊疗过程及预后。方法回顾分析广东省深圳市龙岗中心医院2023年1月经手术切除标本确诊的1例腹壁CIC重排肉瘤的影像学、组织学、免疫组化、分子检测,同时结合文献总结CIC重排肉瘤的病理诊断要点与临床预后的关系。结果患者,青年男性,右侧腹壁肿物进行性增大。肉眼观肿瘤境界相对清楚,切面坏死伴囊性变;低倍镜下,可见大片坏死,瘤细胞弥漫成片分布,部分区域呈分叶状或结节状;高倍镜下,瘤细胞胞界不清,核呈圆形或卵圆形,少数细胞核呈多角状,染色质空泡状、核仁明显,核分裂象约10个/10HPF。免疫组化:CD99、WT-I和Fli-1阳性、Ki-67约60%阳性,CK、EMA、SMA、Desmin、S100、HMB45、CD34和OCT3/4阴性。分子检测:荧光原位杂交方法检测CIC断裂基因为阳性,EWSR1断裂基因为阴性。结论CIC重排肉瘤为罕见病,预后差,结合临床病理学特征及分子遗传学检测有助于明确诊断。 展开更多
关键词 分化/未分类肉瘤 CIC 病理特征 预后
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Chemical constituents from Sappan Lignum 被引量:7
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作者 陈玉平 刘蕾 +3 位作者 周雨虹 温晶 姜勇 屠鹏飞 《Journal of Chinese Pharmaceutical Sciences》 CAS 2008年第1期82-86,共5页
To study the chemical constituents of Sappan Lignum. Chemical constituents were isolated by method of solvent extraction, repeated chromatography with silica gel, Sephadex LH-20, and ODS. The structures were elucidate... To study the chemical constituents of Sappan Lignum. Chemical constituents were isolated by method of solvent extraction, repeated chromatography with silica gel, Sephadex LH-20, and ODS. The structures were elucidated based on spectro- scopic data. Fourteen compounds were isolated and their structures were identified as brazilin (1), sappanone B (2), (E)-3-(3,4- dihydroxybenzylidene)-7-hydroxychroman-4-one (3), 3-deoxysappanone B (4), brazilide A (5), euxanthone (6), quercetin (7), rhamnetin (8), sappanchalcone (9), 3-deoxysappanchalcone (10), butein (11), 2,4,5-trihydroxybenzaldehyde (12), 3,8,9-trihydroxy- 6H-benzo[c]chromen-6-one (13) and 13-sitosterol (14). Compounds 12 and 13 were two new natural compounds, and the ^13C NMR data of compound 13 were reported for the first time. Compound 6 was the first xanthone isolated from the genus Caesalpinia. 展开更多
关键词 Caesalpinia sappan Chemical constituents CHEMOTAXONOMY
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Is it possible to differentiate gastric GISTs from gastric leiomyomas by EUS? 被引量:14
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作者 Gwang Ha Kim Do Youn Park +5 位作者 Suk Kim Dae Hwan Kim Dong Heon Kim Cheol Woong Choi Jeong Heo Geun Am Song 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第27期3376-3381,共6页
AIM: To evaluate the ultrasonog raphy (EUS) features of gastric gastrointestinal stromal tumors (GISTs) as compared with gastric leiomyomas and then to determine the EUS features that could predict malignant GISTs.MET... AIM: To evaluate the ultrasonog raphy (EUS) features of gastric gastrointestinal stromal tumors (GISTs) as compared with gastric leiomyomas and then to determine the EUS features that could predict malignant GISTs.METHODS: We evaluated the endoscopic EUS features in 53 patients with gastric mesenchymal tumors conf irmed by histopathologic diagnosis. The GISTs were classif ied into benign and malignant groups according to the histological risk classif ication.RESULTS: Immunohistochemical analyses demon-strated 7 leiomyomas and 46 GISTs. Inhomogenicity, hyperechogenic spots, a marginal halo and higher echogenicity as compared with the surrounding muscle layer appeared more frequently in the GISTs than in the leiomyomas (P < 0.05). The presence of at least two of these four features had a sensitivity of 89.1% and a specifi city of 85.7% for predicting GISTs. Except for tumor size and irregularity of the border, most of the EUS features were not helpful for predicting the malignant potential of GISTs. On multivariate analysis, only the maximal diameter of the GISTs was an independent predictor. The optimal size for predicting malignant GISTs was 35 mm. The sensitivity and specificity using this value were 92.3% and 78.8%, respectively.CONCLUSION: EUS may help to differentiate gastric GISTs from gastric leiomyomas. Once GISTs are suspected, surgery should be considered if the size is greater than 3.5 cm. 展开更多
关键词 Endoscopic ultrasonography Gastrointestinal stromal tumor STOMACH
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Knowledge-Based Classification in Automated Soil Mapping 被引量:10
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作者 ZHOU BIN and WANG RENCHAOInstitute of Agricultural Remote Sensing and Information Technology Application, Zhejiang University, Hangzhou 310029 (China) 《Pedosphere》 SCIE CAS CSCD 2003年第3期209-218,共10页
A machine-learning approach was developed for automated building of knowledgebases for soil resources mapping by using a classification tree to generate knowledge from trainingdata. With this method, building a knowle... A machine-learning approach was developed for automated building of knowledgebases for soil resources mapping by using a classification tree to generate knowledge from trainingdata. With this method, building a knowledge base for automated soil mapping was easier than usingthe conventional knowledge acquisition approach. The knowledge base built by classification tree wasused by the knowledge classifier to perform the soil type classification of Longyou County,Zhejiang Province, China using Landsat TM bi-temporal images and CIS data. To evaluate theperformance of the resultant knowledge bases, the classification results were compared to existingsoil map based on a field survey. The accuracy assessment and analysis of the resultant soil mapssuggested that the knowledge bases built by the machine-learning method was of good quality formapping distribution model of soil classes over the study area. 展开更多
关键词 CLASSIFICATION classification tree KNOWLEDGE-BASED rule extracting soilmapping
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Urban Expansion in China Based on Remote Sensing Technology:A Review 被引量:7
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作者 ZHANG Zengxiang LIU Fang +9 位作者 ZHAO Xiaoli WANG Xiao SHI Lifeng XU Jinyong YU Sisi WEN Qingke ZUO Lijun YI Ling HU Shunguang LIU Bin 《Chinese Geographical Science》 SCIE CSCD 2018年第5期727-743,共17页
Urban areas and its evolution are important anthropogenic indicators and human ecological footprints, and play decisive roles in environmental change analysis, global geo-conditional monitoring, and sustainable develo... Urban areas and its evolution are important anthropogenic indicators and human ecological footprints, and play decisive roles in environmental change analysis, global geo-conditional monitoring, and sustainable development. China has the highest rate of urban expansion and has emerged as an urban expansion hotspot worldwide. In this paper, the progress of studies on Chinese urban expansion based on remote sensing technology are summarized and analyzed from the aspects of urban area definition, remotely sensed imagery applied in urban expansion, monitoring methods of urban expansion, and urban expansion applications. Existing issues and future directions of Chinese urban expansion are discussed and proposed. Results indicate that: 1) The fusion of multi-source remotely sensed imagery is imperative to meet the needs of urban expansion with various monitoring terms and frequencies on different scales and dimensions. 2) To guarantee the classification accuracy and efficiency and describe urban expansion and its influences on local land use simultaneously, the combination of visual interpretation and automatic classification is the tendency of future monitoring methods of urban areas. 3) Urban expansion data have become the prerequisite for recognizing the urban development process, excavating its driving forces, simulating and predicting the future development directions, and also is conducive to revealing and explaining urban ecological and environmental issues. 4) In the past decades, Chinese scholars have promoted the application of remote sensing technology in the urban expansion field, with data construction, methods and models developing from the quotation stage to improvement and innovation stage; however, an independent and consistent urban expansion data on the national scale with long-term and high-frequency(such as annual monitoring) monitoring is still lacking. 展开更多
关键词 urban areas urban expansion spatial resolution monitoring methods remote sensing China
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Evaluation and classification of residential greenbelt quality based on factor analysis & clustering analysis:An example of Xinxiang City,China 被引量:1
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作者 乔丽芳 张毅川 齐安国 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第4期311-314,共4页
Five factors expressing greenbelt quality and one factor expressing quantity were adopted for evaluation of the residential greenbelt, and the AHP (Analytical Hierarchy Process) method was used to determine the valu... Five factors expressing greenbelt quality and one factor expressing quantity were adopted for evaluation of the residential greenbelt, and the AHP (Analytical Hierarchy Process) method was used to determine the value of factors. Thirty residential areas were selected as the samples. Two principal components were extracted and their expression was constructed by method of factor anlysis, therefore, quality evaluation of residential greenbelt was obtained. The accuracy of the function and implement quality classification toward the residential greenbelts in Xinxiang City were validated by clustering analysis method. The results showed that the greenbelt quality of fourteen residential areas was higher than the average level, of which eleven were newly-built residential areas. The 30 residential areas were classified into three types according to their greenbelt features and their formation by clustering analysis method. Finally rational proposal basing on aforesaid evaluating results was proposed for construction and renewal of residential greenbelt, upon which directive basis was provided for construction and renewal of residential greenbelt. 展开更多
关键词 residential area greenbelt quality EVALUATION factor analysis clustering analysis
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Monitoring urban land cover and vegetation change by multi-temporal remote sensing information 被引量:10
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作者 DU Peijun LI Xingli +2 位作者 CAO Wen LUO Yan ZHANG Huapeng 《Mining Science and Technology》 EI CAS 2010年第6期922-932,共11页
In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a ... In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a hierarchical classifier system that uses different feature inputs for specific classes and conducted a classification post-processing approach to improve its accuracy. From our statistical analysis of changes in urban land cover from 1987 to 2007, we conclude that built-up land areas have obviously increased, while farmland has seen in a continuous loss due to urban growth and human activities. A NDVI difference approach was used to extract information on changes in vegetation. A false change information elimination approach was developed based on prior knowledge and statistical analysis. The areas of vegetation cover have been in continuous decline over the past 20 years, although some measures have been adopted to protect and maintain urban vegetation. Given the stability of underground coal exploitation since 1990s, urban growth has become the major driving force in vegetation loss, which is different from the vegetation change driven by coal exploitation mainly before 1990. 展开更多
关键词 urban settlement land cover change VEGETATION hierarchical classifier system URBANIZATION NDVI NDVI difference urban remote sensing
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Steroid sex hormone dynamics during estradiol-17β induced gonadal differentiation in Paralichthys olivaceus(Teleostei) 被引量:3
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作者 孙鹏 尤锋 +5 位作者 刘梦侠 吴志昊 文爱韵 李军 徐永立 张培军 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第2期254-259,共6页
Steroid sex hormones, such as estradiol-17β (E2) and testosterone (T), are important regulators of sex change in fish. In this study, we examined the effects of E2 treatment on the dynamics of E2 and T during gon... Steroid sex hormones, such as estradiol-17β (E2) and testosterone (T), are important regulators of sex change in fish. In this study, we examined the effects of E2 treatment on the dynamics of E2 and T during gonadal differentiation in the olive flounder Paralichtbys olivaceus using histology and radioimmunoassay (RIA). Flounder larvae were divided into five groups (G0~G4), and fed with 0 (control), 0.2, 2, 20 and 100 mg E2/kg feed from 35 to 110 day post hatching (dph). Fish growth in the G1 and G2 groups was not significantly different from that of the control group (P〉0.05), while fish in the G3 and G4 groups were less active and showed growth depression and high mortality. The gonads of fish in the G3 and G4 groups were smaller and surrounded by hyperplastic connective tissue. The frequency of females in the G0-G4 groups was 54.5%, 75.0%, 100%, 100% and 93.3%, respectively. The RIA analyses of E2 and T showed that T levels decreased during gonadal differentiation, and increased slightly at the onset of ovarian differentiation, while E2 levels increased gradually and peaked at the onset of ovarian differentiation in the control group. In the E2-treated groups, T levels decreased before the onset of ovarian differentiation. E2 levels were high on the 48 dph, but declined to a lower level on the 54 dph, and then increased gradually during gonadal differentiation. And a sharp increase of E2 levels were observed in all E2-treated groups at the onset of ovarian differentiation. The data suggest that T and E2 play important roles during gonadal differentiation, and an E2 dose of 2 mg/kg feed could induce sex reversal in P olivaceus. 展开更多
关键词 olive flounder gonadal differentiation estradiol-17β (E2) testosterone (T) exogenous E2 treatment
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Regional Allocation of CO_2 Intensity Reduction Targets Based on Cluster Analysis 被引量:9
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作者 YANG Yuan CAI Wen-Jia +1 位作者 WANG Can WANG Si-Qiang 《Advances in Climate Change Research》 SCIE 2012年第4期220-228,共9页
To meet China's CO2 intensity target of 40%-45% reduction by 2020 based on the 2005 level, a regional allocation method based on cluster analysis is developed. Thirty Chinese provinces are classified into six groups ... To meet China's CO2 intensity target of 40%-45% reduction by 2020 based on the 2005 level, a regional allocation method based on cluster analysis is developed. Thirty Chinese provinces are classified into six groups based on economy, emissions, and reduction potential indicators. Under the equity principle, the two most developed groups axe assigned the highest reduction targets (55% and 65%, respectively). However, their reduction potent!al is limited. Under the efficiency principle, the two groups with the highest reduction potential take the highest targets (48% and 61%, respectively), but their economy is relatively backward. When equity and efficiency are equally weighted, the 5th group with a prominent reduction potential takes the highest target (54%), and the 2nd and the 3rd groups with large industry scales take the second highest target (49%). However, under all the three allocation schemes, the targets are not greater than 40% for the 4th and the 6th groups, which have a relatively low economic ability, emissions, and reduction potential. Due to inconsistency between economic and reduction potential, corresponding market mechanisms and policy instruments should be established to ensure equity and efficiency of regional target allocation. 展开更多
关键词 C02 intensity reduction targets allocation cluster analysis regional difference
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Sentiment classification model for bullet screen based on self-attention mechanism 被引量:2
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作者 ZHAO Shuxu LIU Lijiao MA Qinjing 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第4期479-488,共10页
With the development of short video industry,video and bullet screen have become important ways to spread public opinions.Public attitudes can be timely obtained through emotional analysis on bullet screen,which can a... With the development of short video industry,video and bullet screen have become important ways to spread public opinions.Public attitudes can be timely obtained through emotional analysis on bullet screen,which can also reduce difficulties in management of online public opinions.A convolutional neural network model based on multi-head attention is proposed to solve the problem of how to effectively model relations among words and identify key words in emotion classification tasks with short text contents and lack of complete context information.Firstly,encode word positions so that order information of input sequences can be used by the model.Secondly,use a multi-head attention mechanism to obtain semantic expressions in different subspaces,effectively capture internal relevance and enhance dependent relationships among words,as well as highlight emotional weights of key emotional words.Then a dilated convolution is used to increase the receptive field and extract more features.On this basis,the above multi-attention mechanism is combined with a convolutional neural network to model and analyze the seven emotional categories of bullet screens.Testing from perspectives of model and dataset,experimental results can validate effectiveness of our approach.Finally,emotions of bullet screens are visualized to provide data supports for hot event controls and other fields. 展开更多
关键词 bullet screen text sentiment classification self-attention mechanism visual analysis hot events control
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An Assessment of Changes in Bioclimatic Types in Sichuan Province, 1961-2010 被引量:1
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作者 LU Ya-feng LIU Yan-Qing +2 位作者 XU Pei WANG Yu-kuan LIU Yuan 《Journal of Mountain Science》 SCIE CSCD 2015年第1期145-153,共9页
Assessing the impact of climate change is important for ecosystem conservation and plant recovery, especially in climate sensitive regions. Various studies suggested that the KSppen classification is an effective meth... Assessing the impact of climate change is important for ecosystem conservation and plant recovery, especially in climate sensitive regions. Various studies suggested that the KSppen classification is an effective method to depict climate change. However, these studies were restricted to large scales or of limited accuracy due to uncertainties in climate model projections. In addition, the impact of elevation on the shift of climate zones, as compared with other factors, is less emphasized. To address these issues we compiled the KSppen Climate Classification (period 1961-2olo) for the study area, Sichuan Province, China. The spatial resolution was selected as x km x x km. Sichuan Province may be characterized by 3 main climate classes and 1o subtypes. The east-west gradient of the climatic regimes in Siehuan is represented by the main climate classes, warm temperate climates (C), snow climates (D) and polar climates (E), at which the most abundant class is C. The most abundant subtype is snow climate with dry winter and cool summer (Dwe). Shifts in K/Sppen climate classes reflect the observed trend of increasing temperature. Finally, the elevation showed an obvious impact on the distribution and the change of climate classes in Siehuan Province. The shift of areas covered by KSppen climate classes increases with elevation. 展开更多
关键词 Koppen Climate Classification CLIMATECHANGE ELEVATION SICHUAN
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Mild Extraction Technique for Flavonoids from Leaves of Nypa fruiticans and Chemical Analysis of Its Components
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作者 Uche Eunice Ekpunobi Augustine Nnaluo Eboatu Patrice-Anthony Chudi Okoye Theresa Uzoma Onuegbu 《Journal of Chemistry and Chemical Engineering》 2012年第2期101-108,共8页
Eight flavonoid derivatives: rutin, quercetin-3-glucoside, quercetin, luteolin-7-glucoside, isorhmnetin-3-sulphate, kaempferol-3,7-diglucoside,'luteolin and kaempferol have been extracted and characterized from Nipa... Eight flavonoid derivatives: rutin, quercetin-3-glucoside, quercetin, luteolin-7-glucoside, isorhmnetin-3-sulphate, kaempferol-3,7-diglucoside,'luteolin and kaempferol have been extracted and characterized from Nipa palm. Mild extraction technique involving the use of HPLC-DAD-MS was used. The structures of the flavonoids were determined on the basis of mass spectroscopy. Separation of the crude extract by paper chromatography (PC) on forestall as solvent system gave one major yellowish brown spot which had Rf value of 3.9. The Rf value and maximum absorption from UV spectroscopy were the same as those of quercetin standard. The most prominent compound was quercetin followed by three others: kaempferol-3,7-diglucoside, luteolin-7-glucoside, and isorhmnetin-3 -sulphate. 展开更多
关键词 Nipa palm FLAVONOIDS EXTRACTS SPECTROSCOPY characterization.
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Essential Oil Composition of Six Pinus L. Taxa (Pinaceae) from Canada and Their Chemotaxonomy 被引量:1
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作者 Omer Kilic Alpaslan Kocak 《Journal of Agricultural Science and Technology(B)》 2014年第1期67-73,共7页
In this study six Pinus L. taxa from Canada (P. strobus L., P. parviflora Siebold & Zucc., P. mugo Turra subsp, mugo, P. resinosa Sol. ex Alton, P. flexilis E. James and P. nigra J. F. Arnold) were studied to deter... In this study six Pinus L. taxa from Canada (P. strobus L., P. parviflora Siebold & Zucc., P. mugo Turra subsp, mugo, P. resinosa Sol. ex Alton, P. flexilis E. James and P. nigra J. F. Arnold) were studied to determine on chemical characters of studied taxa. For this purpose, essential oil from needles of the six Pinus taxa were investigated by HS-SPME/GC-MS. 38, 33, 39, 28, 31 and 46 compounds were respectively identified from each species representing 95.90%, 95.07%, 95.79%, 96.20%, 93.05% and 96.25% of the oil. The results have given some clues on the chemotaxonomy of this genus and are of usable potentials of the plants as renewable resources. Although the essential oil composition of studied taxa showed chemical divergences because of climatical, seasonal, geographical and geological factors, but the major compounds of plant derivatives are generally similar and the major compounds are chemotaxonomical markers for studied taxa. 展开更多
关键词 PINUS PINACEAE essential oil CANADA HS-SPME/GC-MS.
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Taxonomy of the lesser jerboa Jaculus jaculus (Dipodidae,Rodentia) based on allozymic and morphological variation
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作者 Abderraouf BEN FALEH Abdelwaheb BEN OTHMEN Khaled SAID 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第4期421-431,共11页
The lesser Egyptian jerboa Jaculus jaculus, is a member of the subfamily Dipodinae, known to have a number of subspecies. Previous studies of J. jaculus from North Africa found various morphological forms of unknown t... The lesser Egyptian jerboa Jaculus jaculus, is a member of the subfamily Dipodinae, known to have a number of subspecies. Previous studies of J. jaculus from North Africa found various morphological forms of unknown taxonomic status, which are frequently grouped into two taxa: J. jaculus and J. deserti. We assessed the taxonomic status of this taxon in Tunisia using allozymic (phylogenetic analysis of 23 genetic loci encoding 16 enzymatic proteins) and morphological (multivariate analysis of 13 craniodental characters) analyses of 136 J. jaculus specimens collected from seven localities within its distribution range. Allozymic analysis clearly indicated the existence of two distinct groups of J. jaculus, with a mean genetic distance (D) value of 0.99 and FΩ=0.52. Individuals within the two groups did not show any obvious geographical structuration, even within the Matmata locality which represents the meeting point for the two groups where they were found in sympatry. Additionally, morphometric analysis of 13 craniodental characters was clearly separated the two groups. These results were obtained over a very restricted area of the total distribution of J. jaculus and strongly suggest the occurrence of two separate and often sympatric species within the currently accepted J.jaculus in Tunisia: J.jaculus and J. deserti 展开更多
关键词 DIPODIDAE Jaculus jaculus TAXONOMY ALLOZYME Morphomotric analysis Tunisia
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Improved ultrasonic differentiation model for structural coal types based on neural network
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作者 TIAN Zi-jian WANG Fu-zhong +1 位作者 LI Tao BAI Shan-shan 《Mining Science and Technology》 EI CAS 2009年第2期199-204,共6页
In order to solve the difficulty of detailed recognition of subdivisions of structural coal types,a differentiation model that combines BP neural network with an ultrasonic reflection method is proposed.Structural coa... In order to solve the difficulty of detailed recognition of subdivisions of structural coal types,a differentiation model that combines BP neural network with an ultrasonic reflection method is proposed.Structural coal types are recognized based on a suitable consideration of ultrasonic speed,an ultrasonic attenuation coefficient,characteristics of ultrasonic transmission and other parameters relating to structural coal types.We have focused on a computational model of ultrasonic speed,attenuation coefficient in coal and differentiation algorithm of structural coal types based on a BP neural network.Experiments demonstrate that the model can distinguish structural coal types effectively.It is important for the improved ultrasonic differentiation model to predict coal and gas outbursts. 展开更多
关键词 ULTRASONIC structural coal types BP neural network coal ultrasonic attenuation coefficient coal ultrasonic speed
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Taxonomy and molecular evolution of secondary metabolism pathway of isoflavones biosynthesis
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作者 XIA Xun-li YANG Guang-xiao HE Guang-yuan 《Journal of Life Sciences》 2009年第5期14-20,共7页
We compared the cDNA sequences and amino acid sequences of Chalcone synthase (CHS), Chalcone isomerase (CH1), and lsoflavone synthase (IFS) in isoflavone biosynthesis pathway, found that their similarity were no... We compared the cDNA sequences and amino acid sequences of Chalcone synthase (CHS), Chalcone isomerase (CH1), and lsoflavone synthase (IFS) in isoflavone biosynthesis pathway, found that their similarity were not always consistent; then we compared the amino acid sequences of CHS, CHI, and IFS, found that the clustering relationship of CHS and CHI were different in 13 kind of species; CHS and IFS were the same or similar in leguminous plants Medicago sativa, Medicago truncatula, Pisum sativum, Pueraria Montana, and Glycine max however disaccording with CHI. We prefer the amino acid sequence for cDNA sequence for evolution analysis, and think that the secondary metabolism mostly attributing to environmental stresses, and the functional genes on secondary metabolism pathway are unsuitable for taxonomy analysis. 展开更多
关键词 CHI CHS IFS TAXONOMY molecular evolution
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Essential Oil Composition of Four Endemic Tanacetum L. (Asteraceae) Taxa from Turkey and a Chemotaxonomic Approach
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作者 ǒmer Kilic 《Journal of Agricultural Science and Technology(A)》 2014年第3期197-202,共6页
In this study the essential oil components aerial parts of Tanacetum heterotomum (Bornm.) Grierson, T. zahlbruckneri (Nab.) Griersson, T. densum (Lab.) Schultz Bip. subsp, amani Heywood and T. cadmeum (Boiss.)... In this study the essential oil components aerial parts of Tanacetum heterotomum (Bornm.) Grierson, T. zahlbruckneri (Nab.) Griersson, T. densum (Lab.) Schultz Bip. subsp, amani Heywood and T. cadmeum (Boiss.) Heywood subsp, orientale were examined by HS-SPME/GC-MS technique. Thirty six, thirty nine, forty and forty five constituents were determined representing 88.9%, 90.1%, 90.8% and 91.5% of the oil, respectively. The main compounds of studied Tanacetum L. taxa; borneol, α-pinene, 1,8-cineole, β-pinene, camphor, germacrene D, spathulenol are determined. Studied Tanacetum taxa showed congruency with the discription in Flora of Turkey as morphological properties; on the contrary essential oil composition were detected very quiet diverse infrageneric level. Chemotypes of Tanacetum L. taxa were reported as borneol, germacrene D, spathulenol, α-pinene, 1,8-cineole, β-pinene and camphor. The results obtained from this study were discussed in terms of chemotaxonomy and natural products. 展开更多
关键词 Tanacetum L. essential oil CHEMOTAXONOMY natural products.
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