期刊文献+
共找到1,036篇文章
< 1 2 52 >
每页显示 20 50 100
基于Maxent模型的中国喜旱莲子草时空传播规律研究 被引量:2
1
作者 刘晓梅 邢芬 +2 位作者 武梅 周红杰 李宏群 《安徽农学通报》 2016年第23期36-37,共2页
该研究基于喜旱莲子草(Alternanthera philoxeroides)在中国部分地区的标本采集分布数据,选取影响喜旱莲子草分布的19个生物气候变量作为环境因子,采用Maxent模型预测出目前喜旱莲子草的潜在分布区。根据潜在分布区预测结果,可以对相关... 该研究基于喜旱莲子草(Alternanthera philoxeroides)在中国部分地区的标本采集分布数据,选取影响喜旱莲子草分布的19个生物气候变量作为环境因子,采用Maxent模型预测出目前喜旱莲子草的潜在分布区。根据潜在分布区预测结果,可以对相关地区提出预警,帮助有关部门制定合理的防治措施,避免喜旱莲子草进一步扩散造成更大的危害。 展开更多
关键词 生物入侵 喜旱莲子草 Maxent模型 ROC曲线 刀切
下载PDF
中华五千年
2
作者 刘世新 王建 《民族音乐》 2000年第4期7-8,共2页
关键词 感情 独唱 民力 长征 中华 充满 历史 新月 刀切
下载PDF
The Tibetan Written Language
3
作者 I.N.Komarova 《中国藏学》 CSSCI 1992年第S1期373-377,共5页
From the middle of the 19th century the Tibetan language became the object of interest of Eu-ropean linguists not only as the instrument for the studies of the history and culture of the CentralAsia, but as an importa... From the middle of the 19th century the Tibetan language became the object of interest of Eu-ropean linguists not only as the instrument for the studies of the history and culture of the CentralAsia, but as an important component of Sino--Tibetan linguistics. The problems of the Tibetan writing system were specially studied by R. A. Miller, Geza U-rai, M. Hahn and in a more general way by A. Csoma De Koroshi, Jaschke, J. N. Reorich, 展开更多
关键词 门到门 刀切
下载PDF
南瓜妈妈
4
作者 张馨予 《故事作文(低年级版)》 2012年第5期40-41,共2页
自从奶奶回乡下后,妈妈就成了家里的大厨师。瞧,中午,妈妈抱来一个大南瓜,洗了洗,把它用刀切成两半,一半像一顶帽子,另一半像一个大饭碗。然后,妈妈再把它们切成一小块一小块放到锅里蒸。我想:哈哈,马上就可以吃到香甜的南瓜了!
关键词 南瓜 半像 小块 中午 厨师 帽子 刀切 饭碗 向日葵 南瓜粉
原文传递
LINEAMENTI FISIONOMICI,ECOLOGIA E FATTORI EDAFICI DELLA VEGETAZIONE DI ALCUNI MASSICCI CALCAREO-DOLOMITICI DELLE PREALPI LOMBARDE
5
作者 CESARE RAVAZZI 《Natural Disaster Reduction in China》 1990年第1期11-49,共39页
Physiognomical features,ecology and geopedological factors of the vegetation of somecalcareous-dolomitic massifs in the Lombard Pre-Alps(Northern Italy).I.Natural and seminatural grasslands.Natural and semi-natural gr... Physiognomical features,ecology and geopedological factors of the vegetation of somecalcareous-dolomitic massifs in the Lombard Pre-Alps(Northern Italy).I.Natural and seminatural grasslands.Natural and semi-natural grassland vegetation of calcareous-dolomitic Lombard Pre-Alps has been investigated,with synecological approach.Some physiognomical and ecological types have been identified and environmentalfactors have been described.A.Under the timberline:—discontinuous xerophylous sedge communities,dominated by Carex mucronata and creeping chamaephytes,and Festuca alpestris formation on extremely dry ridges with discontinuous soils.—Festuca spectabilis formation,pioneering dry stabilized detritus in mountain belt.—Sesleria varia-Carex humilis thermophilous communities,with Bromus erectus codominance,widelydiffused on steep sunny slopes with grey rendzina,in the submediterranean belt.—Caricion austroalpinae calcophilous communities.Sesleria-grasslands,rich in prealpine endemic element,are situated on cool slopes at low altitudes too.They are marked by Molinia coerulea.In the Fagus belt,Caricion austroalpine communities spread also in southern exposition.Here the Sesleria-vegetation isqualified by an endemic group that takes the place of thermophilous submediterranean elements.—Molinia coerulea neutral-acidic communities,on low permeability soils(《Terra Rossa》and its colluvium;soils on glacial deposits)and M.coerulea hygrophilous communities,along little valleys close to perennialsprings,in the submediterranen belt.—Schoenus nigricans hygrophilous formation,strictly connected with dripping springs,on travertines orhydromorphyc soils.B.Above the timberline:—Caricion austroalpinae calcophilous communities.The most widespread type is Carex sempervirens and S.varia dry grassland,rich in prealpine endemic element.It characterizes sunny slopes.Helictotricon parlato-rei becomes dominant where the substratum is highly percolating.On the contrary,at higher humidity,onhumiferous soils in the high-mountain-sub 展开更多
关键词 刀口 伽兰 日书 飞刀 气石 口才 刀切 刃刀 人力
原文传递
DIPLOMACY HITS A HIGH NOTE
6
作者 DING YING 《Beijing Review》 2008年第11期12-13,共2页
The New York Philharmonic’s concert in North Korea turns a new page in the history of North Korean-U.S.relationsAmerican poet Henry Wadsworth Longfellow said music was the universal language of mankind. His words ran... The New York Philharmonic’s concert in North Korea turns a new page in the history of North Korean-U.S.relationsAmerican poet Henry Wadsworth Longfellow said music was the universal language of mankind. His words rang true at the New York Philharmonic’s concert on February 26 in Pyongyang.The unprecedented per- formance showed that after a half-century of confrontation,North Korea and the United States finally found a language that could enhance their understanding of each other. The New York Philharmonic visited North Korea on February 25-27.It gave one formal concert in the East Pyongyang Grand Theater and played informally with North Korean musicians at other time, starting a prelude of more 展开更多
关键词 刀口 刀切
原文传递
I ROCK GLACIERS DEL PASSO DEL FOSCAGNO(Livigno, Sondrio)
7
作者 MAURO GUGLIELMIN 《Natural Disaster Reduction in China》 1989年第1期35-47,共13页
L’area oggetto di questa breve nota e della relativa carta geomorfologica è ubicata neipressi del Passo del Foscagno, in Aha Valtellina. Si tratta di un’area di passo alpino, caratterizzataprincipalmente da for... L’area oggetto di questa breve nota e della relativa carta geomorfologica è ubicata neipressi del Passo del Foscagno, in Aha Valtellina. Si tratta di un’area di passo alpino, caratterizzataprincipalmente da forme e depositi glaciali e periglaciali. A partire dall’Olocene l’azione prevalente èstata indubbiamente quella periglaciale che si manifesta con diverse forme minori, ma soprattutto, attra-verso i rock glaciers. In quest’area ne sono staff individuati dieci, quattro dei quali attivi, tre complessi,con una parte superiore attiva ed una inferiore inattiva o 《fossile》, ed infine i rimanenti tre del tutto inattivi.Scopo principale di questa breve nora è di illustrare le caratteristiche geometriche e morfologiche, ladistribuzione e le relazioni con le forme glaciali, di questi rock glaciers. The rock glaciers of the Foscagno Pass (Upper Valtellina). The area described in thispaper (and geomorphological map inserted) lies near Foscagno Pass, in The Upper Valtellina. It is anarea of alpine pass, expecially characterized by Periglacial and Glacial formation and deposits. SinceOlocene, surely, the Periglacial action has been the prevailing one. The Periglacial action has revealedby several minor forms, but aboveall, by rock glaciers. In this area ten rock glaciers are located, fourof these are active, three are complex, composed by two parts: the Upper part active and the Lowerpart inactive. Finally, the last three are completely inactive. The main purpose of this paper consistsin describing the geometrical and geomorphological characteristics, the distribution and the relationshipsof these rock glaciers with the glacial forms. 展开更多
关键词 山林 刀切
原文传递
ATLANTE DEGLI UCCELLI NIDIFICANTI IN PROVINCIA DI BRESCIA(Lombardia)AGGIUNTE 1985-1991
8
作者 PIERANDREA BRICHETTI 《Natural Disaster Reduction in China》 1990年第1期201-221,共21页
Updatings 1985-1991 to the Atlas of Breeding Birds in Provincia di Brescia(Lombardy).TheAuthor presents the following updatings(1985-1991)which raise to 166 the number of species nesting in theprovince.The new 7 recor... Updatings 1985-1991 to the Atlas of Breeding Birds in Provincia di Brescia(Lombardy).TheAuthor presents the following updatings(1985-1991)which raise to 166 the number of species nesting in theprovince.The new 7 recorded species are:Ardea purpurea,Cygnus olor,Larus ridibundus,confirmedbreeding,Aythya fuligula,Chlidonias niger,Sylvia cantillans,Panurus biarmicus,possible breeding.Thefollowings 8 species have not been recorded again:Arias crecca,confirmed breeding,Anas clypeata,Falcosubbuteo,Anthus pratensis,Acrocephalus schoenobaenus,Hippolais icterina,Ficedula hypoleuca,Serinuscitrinella,all only possible breeding.Increasing are recorded for Podiceps cristatus,Larus cachinnans,Meropsapiaster.Sylvia melanocephala,Sylvia nisoria,Sylvia communis,Remiz pendulinus,Pica pica,Corvusmonedula and Serinus serinus. 展开更多
关键词 刀口 气口 刀切
原文传递
CONTENTS OF MINZU YANJIU (ETHNO-NATIONAL STUDIES)1979-1999
9
《民族研究》 CSSCI 北大核心 1999年第S1期55-139,共85页
关键词 肠刀 凡人 刀切 刀比 刀刃 刃刀 切刀 堵口 环刀 田七
原文传递
Von—Mises统计量正则函数的自助(Boot—Strap)法
10
作者 姜民奇 黄吉成 荆成明 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 1991年第3期1-7,19,共8页
本文基于近似独立的刀切虚拟值,对Von-Mises统计量的正则函数(?)建立了Bootstrap法。在适当的条件下证明了f(V_n)的Bootstrap逼近的相合性,并讨论了这种逼近的收敛速度,达到了理想的Berry-Esscen下限。
关键词 V-M统计量 自助法 虚拟值 刀切
下载PDF
三悬刀切天下先 百虎国礼美名传
11
作者 化春光 《旅游时代》 2012年第1期90-93,共4页
他是刀切楷书的创始人,也是当代画虎名家、中华油画飞刀;他是明代"百虎堂"的二十代传人,又是北京古今华粹书画院院长,他是国宾礼特供书画艺术大师,也是国务院国宾礼特供艺术家编辑委员会秘书长、编辑委员会评委会主任、艺术总... 他是刀切楷书的创始人,也是当代画虎名家、中华油画飞刀;他是明代"百虎堂"的二十代传人,又是北京古今华粹书画院院长,他是国宾礼特供书画艺术大师,也是国务院国宾礼特供艺术家编辑委员会秘书长、编辑委员会评委会主任、艺术总监;他是《星光大道》特约嘉宾评委,又是《武林大会》特约嘉宾。他的身份看似有些复杂,然而熟悉他的人都知道,他只是一个热爱书画艺术,并为之探索、有所成就的书画全才。 展开更多
关键词 杨进 书画艺术 编辑委员会 宾礼 楷书 艺术大师 艺术家 刀切 中国书法 书法作品
原文传递
A SUBJECT INDEX Vol.13,1999
12
《Bulletin of the Chinese Academy of Sciences》 1999年第4期261-264,共4页
关键词 刀比 对口 刀切
下载PDF
AN ANALYSIS OF CHINESE WHEAT GERMPLASM AND MEASURES FOR ITS IMPROVEMENT
13
作者 Zhang Yifeng(CAS Institute of Geography) Wang Dasheng(CAS Office for Farming Research Projects)Li Zhanshe (Bureau of Agriculture of Huaiyuan County, Anhui Province) 《Bulletin of the Chinese Academy of Sciences》 1999年第2期115-118,共4页
China is one of the largest wheat producers and wheat consumers of the world today, occupying a pivotal position on the global cereal market. Since the introduction of the current reform drive and "open-door"... China is one of the largest wheat producers and wheat consumers of the world today, occupying a pivotal position on the global cereal market. Since the introduction of the current reform drive and "open-door" policy in 1978, Chinese wheat production has achieved an unprecedented success. Especially during this decade, bumper harvests were seen several years in succession, greatly reducing 展开更多
关键词 刀切
下载PDF
A SOUND ECONOMIC FUTURE
14
《Beijing Review》 2007年第44期12-14,共3页
"Promoting sound and rapid development of the national economy"is China’s goal for economic development in the following five years,as put forward by Hu Jintao, General Secretary of the Central Committee of... "Promoting sound and rapid development of the national economy"is China’s goal for economic development in the following five years,as put forward by Hu Jintao, General Secretary of the Central Committee of the Communist Party of China(CPC), in his report to the 17th National Congress of the Party. China used to target"rapid and sound"economic growth.The fact that soundness is preferred to speed for China’s economic growth reflects an important change in the economic outlook of the CPC—China is beginning to value the quality of economic growth rather than the speed. How to attain the goal of sound and rapid development for the national economy is the subject of Hu’s eight-point proposal. 展开更多
关键词 花山 川边 刃口 刀口 刀刃 比丘 飞动 瓦口 田七 刀切
原文传递
臭豆腐的制作
15
作者 丰硕 《农家科技》 1996年第3期36-37,共2页
臭豆腐是一种受人们喜爱的豆制品,具有闻着臭、吃着香的特殊风味。其制作方法是:1.制坯:将含水量为55~60%的豆腐用刀切成4.5×4.5×1.
关键词 臭豆腐 制作方法 豆制品 含水量 发酵时间 风味 制坯 毛坯 刀切 毛霉菌
下载PDF
快乐的暑假
16
作者 陈家栋 《小学生必读(中年级版)》 2021年第7期42-43,共2页
稀奇稀奇真稀奇,刀切西瓜有难题,一个西瓜大又圆,四刀切成九块齐,吃完却剩十块皮。毛超在大伯家玩,在西瓜地里学摘瓜、求瓜地面积,最后在切瓜时,毛超的一个问题难住了大家。
关键词 快乐 西瓜 刀切
原文传递
粘性土的微观结构分析技术研究 被引量:84
17
作者 施斌 姜洪涛 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2001年第6期864-870,共7页
重点介绍了工程粘性土微观结构研究方面的一些新技术、新成果和新发展,主要包括供扫描电镜(SEM)分析用的处理高含水量土样的冷冻刀切干燥法、定量评粘性土微观结构的图象处理技术、测定粘性土粒间胶结物化学成分的EDX技术和无... 重点介绍了工程粘性土微观结构研究方面的一些新技术、新成果和新发展,主要包括供扫描电镜(SEM)分析用的处理高含水量土样的冷冻刀切干燥法、定量评粘性土微观结构的图象处理技术、测定粘性土粒间胶结物化学成分的EDX技术和无损伤探测土体内部结构的CT技术. 展开更多
关键词 粘性土 微观结构 冷冻刀切 图象处理
下载PDF
生物群落多样性的测度方法VI:与多样性测度有关的统计问题 被引量:74
18
作者 刘灿然 马克平 +1 位作者 吕延华 康永亮 《生物多样性》 CAS CSCD 1998年第3期229-239,共11页
物种多样性测度是(群落的)总体参数,它们常常是未知的,需要通过抽样将它们估计出来,因此,必须了解估计量的抽样性质。本文对与一些多样性测度的均值、方差的估计和假设检验以及大、小样本分布等有关的问题作了综述。可以看出大多... 物种多样性测度是(群落的)总体参数,它们常常是未知的,需要通过抽样将它们估计出来,因此,必须了解估计量的抽样性质。本文对与一些多样性测度的均值、方差的估计和假设检验以及大、小样本分布等有关的问题作了综述。可以看出大多数多样性测度的抽样性质还不清楚,有些甚至根本就没有研究过。Pielou的合并样方法和刀切法是两个比较通用的方法,用它们可以解决其中的一些问题。但相比之下,刀切法更实用。 展开更多
关键词 群落 物种多样性 多样性测度 抽样 估计 刀切
下载PDF
宫颈环形电切术对妊娠影响的研究进展 被引量:89
19
作者 卢晓声 郑伟 《中国实用妇科与产科杂志》 CAS CSCD 北大核心 2007年第3期227-229,共3页
关键词 宫颈环形电切术 妊娠影响 子宫颈上皮内瘤样病变 LEEP 病理学检查 妇产科医生 宫颈病变 刀切
原文传递
我国上市公司可持续发展的计量模型与实证分析 被引量:54
20
作者 苏冬蔚 吴仰儒 《经济研究》 CSSCI 北大核心 2005年第1期106-116,共11页
随着我国对稳定发展资本市场的日益重视 ,如何客观评价上市公司自身的竞争优势、长期绩效和成长能力 ,从而科学认识其持续发展的内在规律已成为一个亟待研究和解决的重要问题。为此 ,本文构建出一个新颖的上市公司可持续发展计量模型 ,... 随着我国对稳定发展资本市场的日益重视 ,如何客观评价上市公司自身的竞争优势、长期绩效和成长能力 ,从而科学认识其持续发展的内在规律已成为一个亟待研究和解决的重要问题。为此 ,本文构建出一个新颖的上市公司可持续发展计量模型 ,并首次运用屏面数据计量方法进行实证研究 ,通过使用数理统计工具 ,如Mahalanobis广义距离、计算机集约法和刀切法 ,深入剖析我国上市公司长期绩效的形成机制 ,发现动态累积效益模型能深刻揭示出各类可持续发展指标之间错综复杂的内在关系、真实体现上市公司可持续发展的本质特征并客观评价上市公司的综合素质。 展开更多
关键词 上市公司 可持续发展 计量模型 绩效 中国 成长能力 司长 刀切 综合素质 客观评价
原文传递
上一页 1 2 52 下一页 到第
使用帮助 返回顶部