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81.
We examine some of Connes’ criticisms of Robinson’s infinitesimals starting in 1995. Connes sought to exploit the Solovay model ${\mathcal{S}}$ as ammunition against non-standard analysis, but the model tends to boomerang, undercutting Connes’ own earlier work in functional analysis. Connes described the hyperreals as both a “virtual theory” and a “chimera”, yet acknowledged that his argument relies on the transfer principle. We analyze Connes’ “dart-throwing” thought experiment, but reach an opposite conclusion. In ${\mathcal{S}}$ , all definable sets of reals are Lebesgue measurable, suggesting that Connes views a theory as being “virtual” if it is not definable in a suitable model of ZFC. If so, Connes’ claim that a theory of the hyperreals is “virtual” is refuted by the existence of a definable model of the hyperreal field due to Kanovei and Shelah. Free ultrafilters aren’t definable, yet Connes exploited such ultrafilters both in his own earlier work on the classification of factors in the 1970s and 80s, and in Noncommutative Geometry, raising the question whether the latter may not be vulnerable to Connes’ criticism of virtuality. We analyze the philosophical underpinnings of Connes’ argument based on Gödel’s incompleteness theorem, and detect an apparent circularity in Connes’ logic. We document the reliance on non-constructive foundational material, and specifically on the Dixmier trace ${-\hskip-9pt\int}$ (featured on the front cover of Connes’ magnum opus) and the Hahn–Banach theorem, in Connes’ own framework. We also note an inaccuracy in Machover’s critique of infinitesimal-based pedagogy. 相似文献
82.
考虑了金融调节和同类型的工农业,贸易企业的信贷操作函数之间的相互作用,利用分歧理论dx’2/dt=fi(xk,c),提供了有判据的简单数学模型,可进行财政分析,保持模型与实际金融状况的一致性,所提供的方法不仅可以描述统计数据并且可以通过调节程序计划地区企业的投资。 相似文献
83.
Vladimir G. Red'ko 《Foundations of Science》2000,5(3):323-338
The main problem discussed in this paper is: “Why and how did animal cognition abilities arise?” It is argued that investigations of the evolution of animal cognition abilities are very important from an epistemological point of view. A new direction for interdisciplinary researches – the creation and development of the theory of human logic origin – is proposed. The approaches to the origination of such a theory (mathematical models of ``intelligent invention'' of biological evolution, the cybernetic schemes of evolutionary progress and purposeful adaptive behavior) as well as potential interdisciplinary links of the theory are described and analyzed. 相似文献
84.
Tiziana Bascelli Piotr Błaszczyk Alexandre Borovik Vladimir Kanovei Karin U. Katz Mikhail G. Katz Semen S. Kutateladze Thomas McGaffey David M. Schaps David Sherry 《Foundations of Science》2018,23(2):267-296
Cauchy's sum theorem is a prototype of what is today a basic result on the convergence of a series of functions in undergraduate analysis. We seek to interpret Cauchy’s proof, and discuss the related epistemological questions involved in comparing distinct interpretive paradigms. Cauchy’s proof is often interpreted in the modern framework of a Weierstrassian paradigm. We analyze Cauchy’s proof closely and show that it finds closer proxies in a different modern framework. 相似文献
85.
STAR Consortium Saar K Beck A Bihoreau MT Birney E Brocklebank D Chen Y Cuppen E Demonchy S Dopazo J Flicek P Foglio M Fujiyama A Gut IG Gauguier D Guigo R Guryev V Heinig M Hummel O Jahn N Klages S Kren V Kube M Kuhl H Kuramoto T Kuroki Y Lechner D Lee YA Lopez-Bigas N Lathrop GM Mashimo T Medina I Mott R Patone G Perrier-Cornet JA Platzer M Pravenec M Reinhardt R Sakaki Y Schilhabel M Schulz H Serikawa T Shikhagaie M Tatsumoto S Taudien S Toyoda A Voigt B Zelenika D Zimdahl H Hubner N 《Nature genetics》2008,40(5):560-566
The laboratory rat is one of the most extensively studied model organisms. Inbred laboratory rat strains originated from limited Rattus norvegicus founder populations, and the inherited genetic variation provides an excellent resource for the correlation of genotype to phenotype. Here, we report a survey of genetic variation based on almost 3 million newly identified SNPs. We obtained accurate and complete genotypes for a subset of 20,238 SNPs across 167 distinct inbred rat strains, two rat recombinant inbred panels and an F2 intercross. Using 81% of these SNPs, we constructed high-density genetic maps, creating a large dataset of fully characterized SNPs for disease gene mapping. Our data characterize the population structure and illustrate the degree of linkage disequilibrium. We provide a detailed SNP map and demonstrate its utility for mapping of quantitative trait loci. This community resource is openly available and augments the genetic tools for this workhorse of physiological studies. 相似文献
86.
DT Jones N Jäger M Kool T Zichner B Hutter M Sultan YJ Cho TJ Pugh V Hovestadt AM Stütz T Rausch HJ Warnatz M Ryzhova S Bender D Sturm S Pleier H Cin E Pfaff L Sieber A Wittmann M Remke H Witt S Hutter T Tzaridis J Weischenfeldt B Raeder M Avci V Amstislavskiy M Zapatka UD Weber Q Wang B Lasitschka CC Bartholomae M Schmidt C von Kalle V Ast C Lawerenz J Eils R Kabbe V Benes P van Sluis J Koster R Volckmann D Shih MJ Betts RB Russell S Coco GP Tonini U Schüller V Hans N Graf YJ Kim C Monoranu 《Nature》2012,488(7409):100-105
Medulloblastoma is an aggressively growing tumour, arising in the cerebellum or medulla/brain stem. It is the most common malignant brain tumour in children, and shows tremendous biological and clinical heterogeneity. Despite recent treatment advances, approximately 40% of children experience tumour recurrence, and 30% will die from their disease. Those who survive often have a significantly reduced quality of life. Four tumour subgroups with distinct clinical, biological and genetic profiles are currently identified. WNT tumours, showing activated wingless pathway signalling, carry a favourable prognosis under current treatment regimens. SHH tumours show hedgehog pathway activation, and have an intermediate prognosis. Group 3 and 4 tumours are molecularly less well characterized, and also present the greatest clinical challenges. The full repertoire of genetic events driving this distinction, however, remains unclear. Here we describe an integrative deep-sequencing analysis of 125 tumour-normal pairs, conducted as part of the International Cancer Genome Consortium (ICGC) PedBrain Tumor Project. Tetraploidy was identified as a frequent early event in Group 3 and 4 tumours, and a positive correlation between patient age and mutation rate was observed. Several recurrent mutations were identified, both in known medulloblastoma-related genes (CTNNB1, PTCH1, MLL2, SMARCA4) and in genes not previously linked to this tumour (DDX3X, CTDNEP1, KDM6A, TBR1), often in subgroup-specific patterns. RNA sequencing confirmed these alterations, and revealed the expression of what are, to our knowledge, the first medulloblastoma fusion genes identified. Chromatin modifiers were frequently altered across all subgroups. These findings enhance our understanding of the genomic complexity and heterogeneity underlying medulloblastoma, and provide several potential targets for new therapeutics, especially for Group 3 and 4 patients. 相似文献
87.
Vladimir Korzh 《Cellular and molecular life sciences : CMLS》2018,75(3):375-383
The brain ventricular system (BVS) consists of brain ventricles and channels connecting ventricles filled with cerebrospinal fluid (CSF). The disturbance of CSF flow has been linked to neurodegenerative disease including hydrocephalus, which manifests itself as an abnormal expansion of BVS. This relatively common developmental disorder has been observed in human and domesticated animals and linked to functional deficiency of various cells lineages facing BVS, including the choroid plexus or ependymal cells that generate CSF or the ciliated cells that cilia beating generates CSF flow. To understand the underlying causes of hydrocephalus, several animal models were developed, including rodents (mice, rat, and hamster) and zebrafish. At another side of a spectrum of BVS anomalies there is the “slit-ventricle” syndrome, which develops due to insufficient inflation of BVS. Recent advances in functional genetics of zebrafish brought to light novel genetic elements involved in development of BVS and circulation of CSF. This review aims to reveal common elements of morphologically different BVS of zebrafish as a typical representative of teleosts and other vertebrates and illustrate useful features of the zebrafish model for studies of BVS. Along this line, recent analyses of the two novel zebrafish mutants affecting different subunits of the potassium voltage-gated channels allowed to emphasize an important functional convergence of the evolutionarily conserved elements of protein transport essential for BVS development, which were revealed by the zebrafish and mouse studies. 相似文献
88.
Vladimir N. Uversky 《Cellular and molecular life sciences : CMLS》2017,74(17):3065-3067
The concept of protein intrinsic disorder persistently penetrates into all areas of modern protein science. It cannot be ignored anymore, and cannot be shrugged off, as it represents a vital feature (or, more correctly, a broad spectrum of important features), which, when added to and mixed with features arising from the well established protein structure-function paradigm, complete the picture of a functioning protein. The field of protein intrinsic disorder is very dynamic and fast developing. This Multi-Author Review represents a snapshot of this field by introducing some recent advances. Articles assembled in this Multi-Author Review introduce some of the new aspects of intrinsic disorder, outline some fascinating ideas related to the intrinsically disordered proteins, their structure, and functionality, and show challenges related to the analysis of proteins carrying intrinsic disorder. 相似文献
89.
90.
Often the data units are described with discrete distributions (work described with citation distribution over time, population pyramid described as age-sex distribution etc.).When the set of such units is very large, appropriate clustering methods can reveal the typical patterns hidden in the data. 相似文献