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Identification and Pathogen Characteristics Analysis of a Co-infection with CSFV,PRRSV and PCV2 被引量:2
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作者 吴锦艳 田宏 +6 位作者 尚佑军 王光祥 靳野 尹双辉 陈研 何建辉 刘湘涛 《Agricultural Science & Technology》 CAS 2010年第2期19-22,108,共5页
[Objective] The aim of this study was to identify swine diseases caused by CSFV,PRRSV and PCV2 and thus to analyze its pathogeny chracteristics.[Method] The tissues and viscera of the diseased swine were collected fro... [Objective] The aim of this study was to identify swine diseases caused by CSFV,PRRSV and PCV2 and thus to analyze its pathogeny chracteristics.[Method] The tissues and viscera of the diseased swine were collected from Xiangtan of Hunan(Code of HN/XT)to extract DNA and RNA for PCR amplification and sequencing.Meanwhile,the virulent strains were isolated and identified by cell separation technology.[Result] The sequencing analysis results showed that the amino acid homology between CSFV,PRRSV,PCV2 and sequen... 展开更多
关键词 Xiangtan of Hunan Porcine disease CO-INFECTION IDENTIFICATION Pathogeny characteristics
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Analysis of Emergy Structure,Function and Efficiency of Agro-ecosystem in Hunan Province 被引量:1
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作者 朱玉林 李明杰 +2 位作者 侯茂章 龙雨孜 王茂溪 《Agricultural Science & Technology》 CAS 2013年第1期186-192,共7页
[Objective] The aim was to explore function and efficiency of emergy input/ output of Hunan agricultural ecosystem to reveal relationship of human being with natural resources and environment. [Method] Emergy structur... [Objective] The aim was to explore function and efficiency of emergy input/ output of Hunan agricultural ecosystem to reveal relationship of human being with natural resources and environment. [Method] Emergy structure, function and efficien- cy of Hunan agricultural ecosystem were analyzed based on input/output data in Hunan Province in 2009 as per emergy theory. [Result] The structure characters of agricultural ecosystem were as follows: Hunan is characterized with traditional agri- culture, depending greatly on both human and animal labor. For industrial accessory emergy, chemical fertilizers make most contribution to the system, and agricultural mechanization is not satisfied. Furthermore, renewable ratio of industrial accessory emergy is lower, and development and potential of green energy is promising. In addition, prices of the products are lower, without consideration of contribution made by natural resources and environment. It also suggested that Hunan agricultural chain is short and added value of products is not high. In general, emergy output of farming and animal husbandry dominates and the prices are lower than those of forestry and fishery. The function of the system was as follows: With lower environ- mental load ratio, the system is overloaded by population and the index of sustain- able development was 5.96, suggesting that the system enjoys vitality and potential, but the economy is undeveloped and the pressure from natural resources and envi- ronment is not high. The emergy output ratio was a little lower than national level in 2009, suggesting Hunan agricultural production is extensive. [Conclusion] The re- search indicated that rapid increase of population should be controlled; surplus labor should be transferred; agricultural structure and products structure should be further adjusted; agricultural technology should be further developed; agdcultural mechaniza- tion and modernization should be improved. 展开更多
关键词 Energy analysis STRUCTURE FUNCTION EFFICIENCY Agriculture of Hunan Province introduction
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Two New Species of Freshwater Shrimps from Hunan Province,China (Decapoda:Atyidae:Caridina) 被引量:2
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作者 郭照良 梁象秋 《Zoological Research》 CAS CSCD 北大核心 2003年第1期45-48,共4页
Two new freshwater atyid shrimps, Caridina angustipes sp nov.and C clavipes sp nov.from Hunan Province,China are described. C angustipes sp nov.is similar to C baojingensis Guo,He et Bai,1992,b... Two new freshwater atyid shrimps, Caridina angustipes sp nov.and C clavipes sp nov.from Hunan Province,China are described. C angustipes sp nov.is similar to C baojingensis Guo,He et Bai,1992,but with longer rostrum,15-27 dorsal teeth,3-6 ventral teeth,and straighter inner margin of endopods in male 1st pleopods. C clavipes sp nov.is similar to C angustipes ,but with narrower distal and fewer spines on inner margin of endopds in male 1st pleopods,and shorter and thinner appendix masculina in male 2nd pleopods with only 1 spine on inner lateral margin and 4 spines in apex.The holotypes are deposited in Shanghai Fisheries University.Some representative paratypes are deposited in Foshan Science and Technology College. 展开更多
关键词 DECAPODA Atyidae CARIDINA New species Hunan ChinaChanges in Serum Testosterone and Cortisol Concentrations of Semi free Ranging Male Père Davids Deer in Rut Status$$$$ LI Chun wang 1 JIANG Zhi gang 1 3 ZENG Yan 1 YAN Cai e
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Analysis of Change of Cultivated Land and Grain Production in Hunan Province 被引量:1
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作者 谢红霞 谢永红 +2 位作者 王翠红 杨君 袁红 《Agricultural Science & Technology》 CAS 2011年第9期1327-1330,共4页
[Objective] This paper aimed at exploring the countermeasures for cultivated land protection and food security assurance and providing references for the formulation of policies related to cultivated land and grain pr... [Objective] This paper aimed at exploring the countermeasures for cultivated land protection and food security assurance and providing references for the formulation of policies related to cultivated land and grain production of the whole province.[Methods] Data of population,cultivated land,grain and others in Hunan Province during 1989 to 2008 were collected by county(district).The changes of cultivated land and grain production of the whole province were analyzed using Geographical Information System(GIS).[Results] The population was increasing continuously,the total area of cultivated land was reducing as a whole in spite of increasing in one or two year in one or two county,the total grain production and per capita grain yield was fluctuated within a certain range in recent 20 years of the whole province.The reducing of cultivated land was mainly due to the industrialization and urbanization development.The unbalanced quantity and quality of cultivated land,various natural disasters,readjustment of industry structure and inner readjustment in the agriculture,variety improvement and improvement of cultivated technology mainly affected of the grain production.[Conclusions] The protection of the quantity and quality of cultivated land has to be strengthened to ensure food security.It is important to enhance the ability of resisting drought and flood disasters by improving the construction of agriculture establishment in order to insure the productivity of cultivated land,to increase farmer’s enthusiasm for growing grain with favourable food policy,to improve the per unit area yield of grain by variety improvement and to increase grain sown area by enlarging the double-cropping rice sown area. 展开更多
关键词 Hunan Province Cultivated land GRAIN
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A NEW SPECIES OF HOMIDIA (COLLEMBOLA:ENTOMOBRYIDAE) FROM HUNAN PROVINCE, CHINA 被引量:5
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作者 陈建秀 《Entomotaxonomia》 CSCD 1998年第2期97-99,共3页
A new species, Homidia polyseta, is described from Mt. Tianzi, Zhangjiazai, Hunan Province, China. The species is similar to H. latifolia Chen & Li, 1998 (in press) in having leaflike setae on the mentum, but diff... A new species, Homidia polyseta, is described from Mt. Tianzi, Zhangjiazai, Hunan Province, China. The species is similar to H. latifolia Chen & Li, 1998 (in press) in having leaflike setae on the mentum, but differs from the latter by the presence of more setae on head, coxae, Th.III, Abd.I and Abd.IV, especially Abd.IV with more than 20 macrochaetae present on each side of both anterior and posterior parts. 展开更多
关键词 COLLEMBOLA ENTOMOBRYIDAE Homidia new species China
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Production Performance and Development Strategies of Double-cropping Rice in Hunan Province
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作者 邓文 彭既明 +4 位作者 刘英 祝琪雅 金龙新 刘晗 谭杰扬 《Agricultural Science & Technology》 CAS 2016年第12期2901-2904,共4页
ln the research, an empirical analysis was performed on production per-formance and influential factors of rice in Changsha County and Liling City. The re-sults showed that production scale has been closely linked to ... ln the research, an empirical analysis was performed on production per-formance and influential factors of rice in Changsha County and Liling City. The re-sults showed that production scale has been closely linked to age and education level of farmers. The larger scale, the higher comprehensive performance, but rele-vant efficiency tends to be lower. Sowing area and yield per unit area are major in-fluential factors of production performance of double-cropping rice, but the rest influ-ential factors are different upon production scale. Final y, developmental strategies are proposed for development of double-cropping rice. 展开更多
关键词 Double-cropping rice Mass production performance Development strategies Hunan Province
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Economic Evaluation on "Planting Three to Produce Four" High-yielding Project of Super Hybrid-rice in Hunan
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作者 邓文 彭既明 +4 位作者 刘英 金龙新 刘晗 刘军 黄振国 《Agricultural Science & Technology》 CAS 2015年第9期2048-2054,2069,共8页
The research conducted investigation and survey on 186 farm households in 2014 and carried out economic evaluation on "planting three to produce four" highyielding project of super hybrid rice. The results showed th... The research conducted investigation and survey on 186 farm households in 2014 and carried out economic evaluation on "planting three to produce four" highyielding project of super hybrid rice. The results showed that the project of "planting three to produce four" performed significantly in terms of increasing yields and incomes. For example, per unit area yield of one-season late hybrid rice and middleseason hybrid rice proved the highest, and net income from middle-season rice in Longhui was the highest. It is obvious that to increase per unit yield is key for improving net incomes and to reduce machine fees and worker fees is crucial for decreasing fees. 展开更多
关键词 Super hybrid-rice "Planting three to produce four" Economic evaluation HUNAN
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Production Efficiency of Four Main Crops in the Decade in Hunan Province
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作者 邓文 刘英 +3 位作者 祝琪雅 朱雅玲 王剑 何彩莲 《Agricultural Science & Technology》 CAS 2016年第2期460-466,共7页
The research explored productive efficiencies of main crops in the decade in Hunan by nonparametric DEA method and the results showed that net output value and net-profit rate of potato and sweet potato were extremely... The research explored productive efficiencies of main crops in the decade in Hunan by nonparametric DEA method and the results showed that net output value and net-profit rate of potato and sweet potato were extremely higher than those of rice and maize, and comprehensive efficiencies from high to low were potato, rice, sweet potato and maize. It is recommended that scales of rice, maize, and sweet potato should be reduced to certain extent and the scale of potato pro- duction extended. Besides, direct fee and labor cost should be lowered as much as possible to improve net-profit rate, accelerate crop S&T development and improve grain productive efficiency. 展开更多
关键词 CROPS Productive efficiency HUNAN
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Evaluation of Ecological Sustainability Based on Ecological Footprint in Hunan Province
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作者 曹胜 周卫军 +4 位作者 罗思颖 李娇 黄维丽 段群滔 宋彪 《Agricultural Science & Technology》 CAS 2017年第5期877-879,887,共4页
To make clear ecological sustainable development in Hunan Province, biomass resources and the energy consumption indexes of Hunan Province in 2013 were selected, and quantity analysis of the regional ecological consum... To make clear ecological sustainable development in Hunan Province, biomass resources and the energy consumption indexes of Hunan Province in 2013 were selected, and quantity analysis of the regional ecological consumption and the ecological carrying capacity was carried out using the ecological footprint method. The results showed that the net ecological deficit per capita was 1.718 hm2 in 2013 in Hunan Province, which indicated the regional development was beyond the scope of ecological carrying capacity. So, according to the present unsustainable situation, the corresponding development suggestions were put forward. 展开更多
关键词 Ecological sustainable development Ecological footprint Ecological ca-pacity suggestions Hunan Province
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Variation and Influence Factors of Yield Gravity Center of Flue-cured Tobacco in Hunan
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作者 邓文 周路阔 +5 位作者 谭杰扬 刘英 祝琪雅 王剑 朱雅玲 黄振国 《Agricultural Science & Technology》 CAS 2017年第9期1770-1776,共7页
The variation and influence factors of yield gravity center of flue-cured tobacco in Hunan were studied in 2006-2015 by regional gravity center method and grey correlation analysis. The results showed that the yields ... The variation and influence factors of yield gravity center of flue-cured tobacco in Hunan were studied in 2006-2015 by regional gravity center method and grey correlation analysis. The results showed that the yields of flue-cured tobacco in various areas in Hunan were mainly of the growing with fluctuation type. The yield gravity centers in the whole province and eastern, southern and western Hunan tobacco-growing areas overall moved in the north by west, south by west, west by south, and south by east directions, respectively; and the movements in the south-north direction were in order of eastern Hunan tobacco-growing area 〉whole province 〉western Hunan tobacco-growing area 〉southern Hunan tobacco-growing area, and the movements inthe east-west direction showed an order of eastern Hunan tobecco-growing area〉western Hunan tobacco-growing area〉whole province〉 southern Hunan tobacco-growing area. The main influence factors of the coordinates of the longitudes and the latitudes differed. The main influence factor was planting area in most cities or counties in the whole province, and was per unit area yield in a few cities or counties. It is advised to construct the "one main body and two wings" development pattern of flue-cured tobacco production in Hunan with southern Hunan tobacco-growing area as the main body and western and eastern Hunan tobacco-growing areas as the two wings. 展开更多
关键词 Flue-cured tobacco Yield gravity nan
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Regional Division of Production and Development Strategy of Citrus in Hunan Province
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作者 杨玉 邓文 +3 位作者 李健权 王卫红 黄国林 张平 《Agricultural Science & Technology》 CAS 2012年第9期2029-2033,共5页
[Objective] The aim was to research regional division of citrus production and development strategies in Hunan Province. [Method] According to Rural Statisti- cal Yearbook in Hunan Province during 2002-2011, Citrus in... [Objective] The aim was to research regional division of citrus production and development strategies in Hunan Province. [Method] According to Rural Statisti- cal Yearbook in Hunan Province during 2002-2011, Citrus in Hunan province were divided into three production regions, namely, superior region, sub-superior and non- superior region. On the base of the divisions, the ecological regionalization and brand strategy, Optimization of regional distribution and developing strategy were proposed, with consideration of avoiding frozen zones, in this paper. [Result] Fresh and processing bases of mandarin orange (C.unshiu Marc), and specialty industries of seedless ponkan(C.reticulata Blanco), Bingtang orange (C.sinensis Osbeck Bing- tangcheng), Dayongjuhuaxinyou (Cgrandis (L.) Osbeck Dayongjuhuaxinyou) and An- jiangxiangyou (C.grandis (L.) Osbeck Anjiangxiangyou) should be constructed, where fresh fruit is dominant, supplemented by canned fruit and juice. Industry belt of sat- suma orange, fresh or processing food, is mainly built, for proportion of early and earlier ripe satsuma orange is over 50% of total yield in Xiangzhong citrus zone; in- dustry belt of excellent fresh navel orange and processing sweet orange should be highlighted in Xiangnan. [Conclusion] The research provides references for decision- making for governments, especially on optimization of citrus production regions and development of citrus industry. 展开更多
关键词 CITRUS Regional division STRATEGY Hunan Province
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Research on the Agglomeration and Fluctuation Situation of Rice Production in Hunan Province
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作者 邓文 杨玉 《Agricultural Science & Technology》 CAS 2011年第10期1405-1410,共6页
[Objective] This paper aimed at studying the agglomeration and fluctuation situation of rice production in Hunan Province during the past 10 years.[Method] Data were collected from Hunan Rural Statistical Yearbook(20... [Objective] This paper aimed at studying the agglomeration and fluctuation situation of rice production in Hunan Province during the past 10 years.[Method] Data were collected from Hunan Rural Statistical Yearbook(2001-2010).Taking the concentration index of sown area and production(CDI) and the volatility index(VI) as the main indicators,the agglomeration and fluctuation situation of paddy rice,early-season rice,middle-season rice and single-season late rice,late-season rice,good quality early-season rice,good quality middle-season rice and good quality single-season late rice,good quality late-season rice production in each major rice-producing area of Hunan Province during the past 10 years had been studied.[Result] The orders of concentration index of sown areas and production of paddy rice,early-season rice,middle-season rice and single-season late rice,late-season rice,good quality early-season rice,good quality middle-season rice and good quality single-season late rice,good quality late-season rice in Hunan Province varied,but the orders of volatility index were consistent.The stable areas,relatively stable areas and fluctuant areas in sown areas and production of different major rice-producing areas were defined.[Conclusion] The research had provided basis for optimizing the layout of rice production in Hunan Province,promoting agglomeration and development of rice production and translating the comparative advantages into the competitive advantages. 展开更多
关键词 RICE AGGLOMERATION FLUCTUATION Hunan Province
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Status quo, Problems and Development Strategies of Crop Scientific and Technical Innovation in Hunan Province
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作者 邓文 杨玉 《Agricultural Science & Technology》 CAS 2014年第8期1428-1432,共5页
Based on status quo and existing problems of Hunan crop science and technology innovation, the research proposed "three orientations", including seeking, grasping and highlighting orientations, and "six projects" ... Based on status quo and existing problems of Hunan crop science and technology innovation, the research proposed "three orientations", including seeking, grasping and highlighting orientations, and "six projects" for solving the issues. It is recommended to improve multiple cropping index. 展开更多
关键词 Status quo Probiems Development strategies Hunan Crop Scientificand technical innovation
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“发现”章学诚与经史学的异轨分途——以张尔田、内藤湖南的交往为线索 被引量:2
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作者 周景耀 《北京大学学报(哲学社会科学版)》 CSSCI 北大核心 2023年第2期98-108,共11页
张尔田与日本学者内藤湖南以章学诚为纽带,成为惺惺相惜的学术知音,旗帜鲜明地倡扬章学。作为彼时中日学界名望颇重的学者,他们有关章氏之学与中国经史传统的看法,构成一种潜在的跨文化对话关系,为讨论章氏之学的越境受容与思想学术的... 张尔田与日本学者内藤湖南以章学诚为纽带,成为惺惺相惜的学术知音,旗帜鲜明地倡扬章学。作为彼时中日学界名望颇重的学者,他们有关章氏之学与中国经史传统的看法,构成一种潜在的跨文化对话关系,为讨论章氏之学的越境受容与思想学术的古今之变留下了空间。就思想理路而言,他们有关章氏之学的理解存在着根本性的差异,对中国经史传统的认知亦存在新旧之别。张尔田立足于中国传统学术脉络,持一种内生性的视角,对“六经皆史料”与“目光皆骛于外”的学风持鲜明的批判态度。内藤湖南怀揣现代学术意识,以“史料”论“六经皆史”,以对象化的、认识论的思维方式从外部打量、摆置中国学术,构成辨伪疑古风尚的先声。内藤的做法事实上是一种具有新型方法意识的“支那学”的体现,潜在地蕴含着“帝国”的视角,在中国现代学术建立的过程中产生了至关重要的影响。 展开更多
关键词 章学诚 张尔田 内藤湖南 六经皆史 现代史学
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Optimized Strategy for Layout of Crop Production Areas in Hunan Province
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作者 邓文 杨玉 《Agricultural Science & Technology》 CAS 2014年第11期2049-2052,共4页
The optimized strategy made a comprehensive consideration of resources, technology, market orientation, production scale, industry basis and layout based on the principle of crop security and farmers’ income increasi... The optimized strategy made a comprehensive consideration of resources, technology, market orientation, production scale, industry basis and layout based on the principle of crop security and farmers’ income increasing, and determined the general planning on layout and structure optimization of future crop production ar-eas, with present crop production, market outlook, future industry development, con-cluding crop production characteristics of the 4 crop regions, and proposing function orientation and highlights. 展开更多
关键词 Crop production Regional distribution Optimized strategy Hunan
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一场火调,消防大队成被告
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作者 欧阳冰 《时代消防》 2003年第1期24-25,共2页
关键词 株洲市 荷塘区公安消防大队 火灾原因 调查 湖南`
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Study on Agglomeration and Fluctuation Situation and Development Countermeasures of Economic Crop Production in Hunan Province 被引量:1
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作者 邓文 杨玉 《Agricultural Science & Technology》 CAS 2013年第5期797-802,共6页
[Objective] This paper aimed to investigate the agglomeration and fluctuation situation of economic crop production in Hunan Province and to propose related development countermeasures. [Method] With agglomeration ind... [Objective] This paper aimed to investigate the agglomeration and fluctuation situation of economic crop production in Hunan Province and to propose related development countermeasures. [Method] With agglomeration index and fluctuation index as main indicators, the agglomeration and fluctuation situation of the production of seven major economic crops in Hunan Province in recent decade was studied. [Result] The agglomeration index of sown area and yield of seven major economic crops in Hunan Province showed decreasing orders of ramie 〉 cotton 〉 tobacco 〉 rape〉 citrus 〉 tea 〉 vegetables, ramie 〉 cotton 〉 tobacco 〉 tea 〉 rape 〉 citrus 〉 vegetables, respectively; the fluctuation index of sown area and yield showed decreasing orders of ramie 〉 citrus 〉 vegetables 〉 cotton 〉 tea 〉 rape 〉 tobacco, citrus 〉 ramie 〉 tea 〉 cotton 〉 rape 〉 tobacco 〉 vegetables, respectively. In addition, stable regions, relatively stabte regions and fluctuation regions of sown area and yield in various main producing areas were identified, and corresponding development countermeasures were proposed. [Cenclusion] The key to accelerate the development of major economic crop production in Hunan Province is further improving the agglomeration level of vegetable, citrus, rape and tea production and focusing on maintaining the stability of citrus, ramie and cotton production in main producing areas. 展开更多
关键词 Economic crop AGGLOMERATION FLUCTUATION Development countermeasures Hunan Province
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绍兴平湖调与四明南词唱腔关系之探
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作者 杨晨 《音乐文化研究》 2020年第3期38-49,共12页
绍兴平湖调与四明南词的唱腔曲调均具有以下“一致性”表现:一、相同的“凤点头”三句体结煞段式;二、相同的字位安排与惯用的切分节奏;三、衬词起统一结构落音的作用;四、上、下腔句的落音之间构成了相对固定的音程关系;五、相同的典... 绍兴平湖调与四明南词的唱腔曲调均具有以下“一致性”表现:一、相同的“凤点头”三句体结煞段式;二、相同的字位安排与惯用的切分节奏;三、衬词起统一结构落音的作用;四、上、下腔句的落音之间构成了相对固定的音程关系;五、相同的典型乐汇;六、相同的结束式。由此可判断,绍兴平湖调与四明南词的唱腔具有同源关系。 展开更多
关键词 绍兴平湖调 四明南词 唱腔音乐 同源关系
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A new species of Megophrys (Amphibia:Anura:Megophryidae) from the northwestern Hunan Province,China 被引量:7
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作者 Xiaoyang MO Youhui SHEN Honghui LI Xiushan WU 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第4期432-436,共5页
A new species of Megophrys (Amphibia: Anura: Megophryidae), Megophrys tuberogranulatus Shen, Mo et Li, sp.nov. (Holotype HNUL 03080902, adult male, SVL: 38.2 mm), from Sangzhi County, Hunan Province, is described. Meg... A new species of Megophrys (Amphibia: Anura: Megophryidae), Megophrys tuberogranulatus Shen, Mo et Li, sp.nov. (Holotype HNUL 03080902, adult male, SVL: 38.2 mm), from Sangzhi County, Hunan Province, is described. Megophrystuberogranulatus is closely related to both Megophrys kuatunensis and Megophrys minor. Characters of the new species that differentiatethis species from close relatives are skin granulated with big tubercles on the dorsal sides of both thigh and tibia, thebigger inner metacarpal tubercle, upper eyelid wider than the interorbital space, hind limbs longer, overlapping of the left andright calcaneal parts. The type specimens are deposited in the Animal Museum of Life Sciences College of Hunan Normal University. 展开更多
关键词 Zootaxy MEGOPHRYIDAE Megophrys New species China
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Fixed Ammonium in Major Types of Paddy Soils in Hunan Province, China 被引量:11
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作者 ZHANG YANGZHU, LIAO JIPEI, SUN YUHUAN, FENG YUEHUA and HUANG YUNXIANGCollege of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China) 《Pedosphere》 SCIE CAS CSCD 2003年第3期199-208,共10页
The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner ... The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner method by laboratory and pot experiments. Results showed that the content of fixed ammoniumin the plough horizons ranged from 88.3 mg kg-1 to 388.1 mg kg-1, with 273.2 ± 77.7 mg kg-1 on average,accounting for 11.2% of total soil N on average. Content of fixed ammonium decreased in the order of newlylacustrine clayey paddy soil > alluvial sandy paddy soil > purple clayey paddy soil > newly alluvial sandypaddy soil > yellow clayey paddy soil > reddish-yellow clayey paddy soil > granitic sandy paddy soil. Therewere four distribution patterns of fixed ammonium in the profiles to 1-m depth, i.e., increase with the depth,decrease with increasing depth, no distinct change with the depth, and abrupt increase or decrease in somehorizon. Percentage of fixed ammonium in total N increased with the depth in most of the soils. Fixationof NH4+ by soil was higher at 30 ℃ than at 20 ℃ and 40 ℃, and continuous submergence benefited thefixation of NH4+ in newly alluvial sandy paddy soil, purple clayey paddy soil and alluvial sandy paddy soil,while alternating wetting and drying contributed to the fixation of NH4+ in yellow clayey paddy soil mostly.Fixed ammonium content in the test paddy soils was significantly correlated with < 0.01 mm clay content(P < 0.05), but not with < 0.001 mm clay content, total N, organic N and organic matter. Fixed ammoniumcontent varied with rice growth stages. Application of N fertilizer promoted fixation of NH4+ by soil, and Nuptake by rice plant promoted release of fixed ammonium from the soil. Recently fixed ammonium in paddysoil after N fertilizer application was nearly 100% available to rice plant, while native fixed ammonium wasonly partly available, varying with the soil type and rice type. 展开更多
关键词 affecting factors BIOAVAILABILITY fixed ammonium hunan province paddysoil
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