共查询到20条相似文献，搜索用时 31 毫秒
1.
Yongjiang Liu Wenjiao Xiao Yongfei Ma Sanzhong Li A.Yu.Peskov Zhaoxu Chen Tong Zhou Qingbin Guan 《国家科学评论(英文版)》2023,(2):17-19
<正>The term ’orocline’ was first proposed by Carey [1] to describe the structure as ’an orogenic system which has been flexed in plane to a horse-shoe or elbow shape’;it usually emphasizes that a previous straight mountain belt or tectonic units have been bended horizontally.Nowadays the orocline has been used to describe any curved mountain belt regardless of its original shape [2]. 相似文献
2.
《中国科学院院刊(英文版)》2005,19(4):206-207
Although a commonplace structure in nature, the helix remains a mystery to scientific researchers. In biology,the structure is important as DNA is helical and so does the substructure of many proteins. Since its discovery more than 50 years ago, the double helix has offered an important approach to interpret and make use of bio-organic structures. Yet, it is seldom to see a helical structure formed by inorganic crystalstate materials. 相似文献
3.
《中国科学院院刊(英文版)》2005,(4)
Although a commonplacestructure in nature, thehelix remains a mystery toscientific researchers. In biology,the structure is important as DNAis helical and so does the substruc-ture of many proteins. Since its dis-covery more than 50 years ago, thedouble helix has offered an impor-tant approach to interpret and makeuse of bio-organic structures. Yet,it is seldom to see a helical struc-ture formed by inorganic crystal-state materials.Recently a previously-un-known zinc oxide nanostructure that… 相似文献
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《中国科学院院刊(英文版)》2008,22(2):88-89
The regulatory mechanism for neuronal migration in the developing cortex is a major unsolved problem in developmental neurobiology. It is generally accepted that the migration of newborn pyramidal neurons from the ventrieular zone toward upper cortical layers is guided by radial glial fibers in the developing cortex, and that the laminar structure of the cortex isformed through regulated attachment and detachment of migrating neurons with radial glial fibers. However, whether the radial migration of cortical neurons can be guided by a gradient of diffusible factors is unknown, a potential guidance mechanism that has long been overlooked. 相似文献
6.
《中国科学院院刊(英文版)》2014,(3):259-260
<正>An apparent absence of Silurian fishes more than half-a-metre in length has been viewed as evidence that gnathostomes(jawed vertebrates)were restricted in size and diversity prior to the Devonian.A team led by Professor ZHU Min,Institute of Vertebrate Paleontology and Paleoanthropology(IVPP)of the Chinese Academy of Sciences has unearthed a bony fi sh with an estimated length of about 1 meter from the Silurian Kuanti Formation in Yunnan Province of southwestern China,revealing that pre-Devonian gnathostomes could attain comparatively large sizes.The study published on June 12 in the journal of Scientifi c Reports adds 相似文献
7.
《中国科学院院刊(英文版)》2006,20(3)
The Thunder of God Vine (Tripterygium wilfordii Hook F.), or Lei Gong Teng in Chinese, is a plant that has been used for ages by traditional Chinese medicine to treat inflammatory conditions. In recent years it has aroused attention of scientists around the world because of its proved efficacies in treating such diseases as rheumatoid arthritis. 相似文献
8.
《中国科学院院刊(英文版)》2006,(1)
In the present-day world, the focus of competitionamong countries has apparently shifted from theterritories or market shares as a conventional prac-tice in the 20th century to the race at the S&T frontiers.It is predictable that the future challenge facing Chinaas a primary strategic restraint will be the high-tech mo-nopoly by developed countries since science and tech-nology are the critical and fundamental factor in theinternational contest of overall national strength in com-ing years. O… 相似文献
9.
《中国科学院院刊(英文版)》2008,22(2):89-89
The fossils of a petite pterosaur （＂winged lizard＂ in Greek, a group of winged reptiles that ruled the skies from 206 million to 65 million years ago） has been discovered by CAS paleont＇ologists and their Brazilian co-workers in northeast China＇s Liaoning Province. The discovery was published 11 February online by the Proceedings＂ of the National Academy of Sciences. 相似文献
10.
《中国科学院院刊(英文版)》2015,(2):120-121
<正>Efficient biological degradation of cellulosic biomass has been recognized as one major bottleneck in production of cellulosic liquid fuels or biogas,and as the one key step in the carbon cycle of biosphere.In a new work published online in Nature Communications on 24 April,2015,a research team from the Single-Cell Center of the Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences discovered a new mechanism in microbial degradation of lignocellulose,by reporting that cellulosome stoichiometry is regulated by selective RNA 相似文献
11.
The associated evolution of raptorial foreleg and mantispid diversification during 200 million years
Dahang Lai Peichao Chen Shumin Li Xianzhe Xiang Haohong Ou Nuoyao Kang Jingtao Yang Hong Pang Chung Kun Shih Conrad C.Labandeira Dong Ren Qiang Yang Chaofan Shi 《国家科学评论(英文版)》2023,(12):49-52
<正>Adaptive evolution of predatory structure grants carnivores selective advantages[1], which evokes questions regarding the mechanism of functional adaptation via morphological variation and their potential impact on lineage diversification. Raptorial foreleg, as a key predatory structure in insects, is typically characterized by elongate coxae and stout femora possessing spines, and has evolved independently in many lineages [2]. 相似文献
12.
三种数值方法在几种六道木分类中的应用 总被引：1，自引：0，他引：1
In the last 10—20 years there has bee n increasing awareness of the problem con-
cerning the aims and practices of taxonomy. In particular, there has been growing
interest in the development of numerical methods in biological taxonomy as an aid to
making systematics a quantitative science, a step which comes in time to almost every
scientific discipline.
Numerical taxonomy is the evaluation by numerical methods of the affinity or
similarity between taxonomic units and the employment of these affinities in erecting
a hierarchic order of taxa. The present rapid development of these ideas is presuma-
bly a result of the development of computer techniques.
Numerical taxonomic approach has been applied to the studies of entomology and
microbiology in China to some extent since 1975. But so far it hasn’t been commonly
used in botany. The present report is a preliminary study on 9 spp. of the genus
Abelia. A set of binary data with 54 characters is used for computing association
coefficient; and a set of quantitative data with 47 characters for distance coefficient
and correlation coefficient. For the mathematical models were chosen the non-metric
simple matching association coefficient, the geometrical distance of Riemannian space
and correlation coefficient. Computational procedures are stepwise presented in detail
and computer programmes are written in the background of Algol-60 language. Cluster analysis is compared with simple linkage, average linkage and multi-correlation.
The results of DC and CC for 9 spp. of Abelia agree closely with the traditional
taxonomy, because the data we collected mainly come from morphological characters.
It would seem that the results of quantita tive data are more appropriate for seed
plants. It is, therefore, postulated that our programes are complementary and very
useful to a wide range of classification entities, such as microbes, animals and plants
in present situation in China.
In conclusion, a comparison between the conventional taxonomy and numerical
taxonomy has been made, and a brief discussion of three problems, i.e. the monothetic
versus polythetic, divisive versus agglomerative, weighting versus unweighting.
相似文献
13.
《中国科学院研究生院学报》1988,(1)
Based on the prediction made by many,a pion condensate shouldalready be present in ordinary finite nuclei,we have studied the effectof pion condensate in pion nucleus elastic scattering by using theGlauber multiple scattering theory.A calculation has been performedfor π-~(40)Ca elastic scattering at the incident energies of I15.5 MeVand 241 MeV,and then compared to the existing data available.Theresults strongly indicate that pion condensate completely have noadequate opportunity to manifest itself in pion nucleus scattering,atleast for small angle scattering. 相似文献
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A small-sized autonomous underwater vehicle(AUV) independently developed and built by CAS researchers has been designated as an underwater guard for the forthcoming Olympic Game in 2008 in Beijing. It has recently been approved by the Olympic Sub-committee of Sailing to be a component of the "underwater safety alert system" of the competition. 相似文献
16.
《中国科学院院刊(英文版)》2016,(3)
正Microalgae are organisms that can use sunlight to capture and assimilate atmospheric CO_2.They then store the solar energy and CO_2 in the form of energy-dense molecules such as triacylglycerol(TAG),which can be readily converted to oil.Therefore,the interest in microalgae as a scalable solution for clean fuel production and CO_2 sequestration has been growing. 相似文献
17.
《中国科学院院刊(英文版)》2006,(4)
Anational strategy for the HIV vaccine research and development (R&D) should be formulated as soon as possible so as to ensure a sound progress in this field, urges a report by the Academic Divi sions o f the C hinese A cademy of Scie nces (CASAD), the top national advisory body in science and technology. Entitled “A Proposal on China’s Strat- egy of the HIV Vaccine Research and Development,” the report has recently been submitted to the State Council, the country’s cabinet. This… 相似文献
18.
WU Ming 《中国科学院院刊(英文版)》2011,25(4):295-297
1. Status of IP commercialization in China A sound social ecosystem for IP (intellectual property) commercialization will not be established in China overnight because the training of IP professionals and the introducing of IP into management are both a process that takes time. In recent years, the CAS has conducted a series of training programs concerning IP management and service as well as IP team building. Over the past three years, more 相似文献
19.
<正>Batteries that convert the stored chemical energy directly into electricity have been known for hundreds of years.Take the lithium-ion battery as representative because of its high energy-conversion efficiency and long cycle life.It is widely used as a power accessory for electronic devices and has become an important part of modern electronics. 相似文献
20.
《中国科学院院刊(英文版)》2017,(2)
<正>ZENG Qingcun,a senior meteorologist and pioneer in numerical weather prediction from the CAS Institute of Atmospheric Physics,has been awarded the 61th International Meteorological Organization Prize.The prize,which was presented by the World Meteorological Organization(WMO),recognized 相似文献