Abstract:
:Accurate measurement of the lifetime of the neutron (which is unstable to beta decay) is important for understanding the weak nuclear force and the creation of matter during the Big Bang. Previous measurements of the neutron lifetime have mainly been limited by certain systematic errors; however, these could in principle be avoided by performing measurements on neutrons stored in a magnetic trap. Neutral-particle and charged-particle traps are widely used for studying both composite and elementary particles, because they allow long interaction times and isolation of particles from perturbing environments. Here we report the magnetic trapping of neutrons. The trapping region is filled with superfluid 4He, which is used to load neutrons into the trap and as a scintillator to detect their decay. Neutrons in the trap have a lifetime of 750(+330)(-200) seconds, mainly limited by their beta decay rather than trap losses. Our experiment verifies theoretical predictions regarding the loading process and magnetic trapping of neutrons. Further refinement of this method should lead to improved precision in the neutron lifetime measurement.
journal_name
Naturejournal_title
Natureauthors
Huffman PR,Brome CR,Butterworth JS,Coakley KJ,Dewey MS,Dzhosyuk SN,Golub R,Greene GL,Habicht K,Lamoreaux SK,Mattoni CE,McKinsey DN,Wietfeldt FE,Doyle JMdoi
10.1038/47444keywords:
subject
Has Abstractpub_date
2000-01-06 00:00:00pages
62-4issue
6765eissn
0028-0836issn
1476-4687journal_volume
403pub_type
杂志文章相关文献
NATURE文献大全abstract::Metastasis is the main cause of death in people with cancer. To colonize distant organs, circulating tumour cells must overcome many obstacles through mechanisms that we are only now starting to understand. These include infiltrating distant tissue, evading immune defences, adapting to supportive niches, surviving as ...
journal_title:Nature
pub_type: 杂志文章,评审
doi:10.1038/nature17038
更新日期:2016-01-21 00:00:00
abstract::Recognition of an avirulent pathogen triggers the rapid production of the reactive oxygen intermediates superoxide (O2-) and hydrogen peroxide (H2O2). This oxidative burst drives crosslinking of the cell wall, induces several plant genes involved in cellular protection and defence, and is necessary for the initiation ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/29087
更新日期:1998-08-06 00:00:00
abstract::The gal operon of Escherichia coli is controlled by two independent promotors--one is activated and the other inhibited by cyclic AMP and cyclic AMP receptor protein. The two promotors are modulated, however, by the same operator locus and receptor protein. ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/279492a0
更新日期:1979-06-07 00:00:00
abstract::The developmental fate of immature thymocytes is determined by the specificity of their T-cell antigen receptors (TCRs). Immature CD4+8+ thymocytes are positively selected to differentiate into mature T cells by recognition of peptides associated with major histocompatibility complex (MHC) encoded molecules on thymic ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/371067a0
更新日期:1994-09-01 00:00:00
abstract::Visual stimuli can acquire positive or negative value through their association with rewards and punishments, a process called reinforcement learning. Although we now know a great deal about how the brain analyses visual information, we know little about how visual representations become linked with values. To study t...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature04490
更新日期:2006-02-16 00:00:00
abstract::The epiblast (EPI) is the origin of all somatic and germ cells in mammals, and of pluripotent stem cells in vitro. To explore the ontogeny of human and primate pluripotency, here we perform comprehensive single-cell RNA sequencing for pre- and post-implantation EPI development in cynomolgus monkeys (Macaca fasciculari...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature19096
更新日期:2016-09-01 00:00:00
abstract::Effective interaction between T cells and their targets requires that recognition of specific antigen be coordinated with increased cell-cell adhesion. We show that antigen-receptor cross-linking increases the strength of the adhesion mechanism between lymphocyte function-associated molecule-1 (LFA-1) and intercellula...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/341619a0
更新日期:1989-10-19 00:00:00
abstract::The peptide GsMTx4, isolated from the venom of the tarantula Grammostola spatulata, is a selective inhibitor of stretch-activated cation channels (SACs). The mechanism of inhibition remains unknown; but both GsMTx4 and its enantiomer, enGsMTx4, modify the gating of SACs, thus violating a trademark of the traditional l...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature02743
更新日期:2004-07-08 00:00:00
abstract::The largest products of magmatic activity on Earth, the great bodies of granite and their corresponding large eruptions, have a dual nature: homogeneity at the large scale and spatial and temporal heterogeneity at the small scale. This duality calls for a mechanism that selectively removes the large-scale heterogeneit...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature09799
更新日期:2011-03-10 00:00:00
abstract::The repressor of phage 434 binds to six operator sites on the phage chromosome. A comparison of the sequences of these 14-base-pair (bp) operator sites reveals a striking pattern: at five of the six sites, the symmetrically arrayed outer eight base pairs (four in each half-site) are identical and the remaining site di...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/326886a0
更新日期:1987-04-30 00:00:00
abstract::Simple mathematical models of the transmission dynamics of human immunodeficiency virus help to clarify some of the essential relations between epidemiological factors, such as distributed incubation periods and heterogeneity in sexual activity, and the overall pattern of the AIDS epidemic. They also help to identify ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/326137a0
更新日期:1987-03-12 00:00:00
abstract::Extinction from habitat loss is the signature conservation problem of the twenty-first century. Despite its importance, estimating extinction rates is still highly uncertain because no proven direct methods or reliable data exist for verifying extinctions. The most widely used indirect method is to estimate extinction...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature09985
更新日期:2011-05-19 00:00:00
abstract::Stereopsis is the perception of depth based on small positional differences between images formed on the two retinae (known as binocular disparity). Neurons that respond selectively to binocular disparity were first described three decades ago, and have since been observed in many visual areas of the primate brain, in...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/29299
更新日期:1998-08-13 00:00:00
abstract::Microbiome-wide association studies have established that numerous diseases are associated with changes in the microbiota. These studies typically generate a long list of commensals implicated as biomarkers of disease, with no clear relevance to disease pathogenesis. If the field is to move beyond correlations and beg...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature25019
更新日期:2017-12-14 00:00:00
abstract::The initiation of immunoglobulin-E (IgE)-mediated allergic responses requires the binding of IgE antibody to its high-affinity receptor, Fc epsilonRI. Crosslinking of Fc epsilonRI initiates an intracellular signal transduction cascade that triggers the release of mediators of the allergic response. The interaction of ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/35018500
更新日期:2000-07-20 00:00:00
abstract::Aquaporin (AQP) water-channel proteins are freely permeated by water but not by ions or charged solutes. Although mammalian aquaporins were believed to be located in plasma membranes, rat AQP6 is restricted to intracellular vesicles in renal epithelia. Here we show that AQP6 is functionally distinct from other known a...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/46045
更新日期:1999-11-11 00:00:00
abstract::Parkinson's disease is characterized by loss of dopamine neurons in the substantia nigra1. Similar to other major neurodegenerative disorders, there are no disease-modifying treatments for Parkinson's disease. While most treatment strategies aim to prevent neuronal loss or protect vulnerable neuronal circuits, a poten...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/s41586-020-2388-4
更新日期:2020-06-01 00:00:00
abstract::Biodiversity is rapidly declining, and this may negatively affect ecosystem processes, including economically important ecosystem services. Previous studies have shown that biodiversity has positive effects on organisms and processes across trophic levels. However, only a few studies have so far incorporated an explic...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature09492
更新日期:2010-11-25 00:00:00
abstract::Erythroid differentiation entails the biogenesis of a membrane skeleton, a network of proteins underlying and interacting with the plasma membrane, whose major constituent is the heterodimeric protein spectrin, composed of two structurally similar but distinct subunits, alpha (relative molecular mass (Mr) 240,000) and...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/321085a0
更新日期:1986-05-01 00:00:00
abstract::The distribution, accumulation and circulation of oxygen and hydrogen in Earth's interior dictate the geochemical evolution of the hydrosphere, atmosphere and biosphere. The oxygen-rich atmosphere and iron-rich core represent two end-members of the oxygen-iron (O-Fe) system, overlapping with the entire pressure-temper...
journal_title:Nature
pub_type: 历史文章,杂志文章
doi:10.1038/nature18018
更新日期:2016-06-09 00:00:00
abstract::It is common knowledge that our feelings of alertness or drowsiness vary throughout the day. Indeed, this diurnal variation is so widely accepted that it has been used to validate the drowsy/alert component of activation obtained from mood adjective checklists. There is, however, some evidence from sleep deprivation a...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/313678a0
更新日期:1985-02-21 00:00:00
abstract:: ...
journal_title:Nature
pub_type: 评论,信件
doi:10.1038/d41586-019-00764-z
更新日期:2019-03-01 00:00:00
abstract::Inactivation of APC is a strongly predisposing event in the development of colorectal cancer, prompting the search for vulnerabilities specific to cells that have lost APC function. Signalling through the mTOR pathway is known to be required for epithelial cell proliferation and tumour growth, and the current paradigm...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature13896
更新日期:2015-01-22 00:00:00
abstract::Deposition of amyoid-beta peptide in the central nervous system is a hallmark of Alzheimer's disease and a possible cause of neurodegeneration. The factors that initiate or promote deposition of amyloid-beta peptide are not known. The transforming growth factor TGF-beta1 plays a central role in the response of the bra...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/39321
更新日期:1997-10-09 00:00:00
abstract::The refined 1.9-A resolution structure of the periplasmic D-galactose-binding protein (GBP) reveals a calcium ion surrounded by seven ligands, all protein oxygen atoms. A nine-residue loop (amino-acid positions 134-142), which is preceded by a beta-turn and followed by a beta-strand, provides five ligands from every s...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/327635a0
更新日期:1987-06-18 00:00:00
abstract::Cancer control by adaptive immunity involves a number of defined death and clearance mechanisms. However, efficient inhibition of exponential cancer growth by T cells and interferon-γ (IFN-γ) requires additional undefined mechanisms that arrest cancer cell proliferation. Here we show that the combined action of the T-...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature11824
更新日期:2013-02-21 00:00:00
abstract::Recent work has defined a class of transcriptional activators, members of which activate transcription in yeast, plant, insect and mammalian cells. These proteins contain two parts: one directs DNA binding and the other, called the activating region, presumably interacts with some component of the transcriptional mach...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/335563a0
更新日期:1988-10-06 00:00:00
abstract::Ever since Stephen Paget's 1889 hypothesis, metastatic organotropism has remained one of cancer's greatest mysteries. Here we demonstrate that exosomes from mouse and human lung-, liver- and brain-tropic tumour cells fuse preferentially with resident cells at their predicted destination, namely lung fibroblasts and ep...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature15756
更新日期:2015-11-19 00:00:00
abstract::The mechanism of action of antisteroids is not understood and explanations of their antagonistic activity have been sought at all levels of hormone action. It has been proposed that antisteroids, after binding to receptor, trap it into a non-activated (non DNA-binding) form possibly through interaction with a heat-sho...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/336695a0
更新日期:1988-12-15 00:00:00
abstract::The initiation of plate tectonics on Earth is a critical event in our planet's history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately 3 billion years ago) suggests that plates and plate boundaries became widespread over a period of 1 billion years. The ...
journal_title:Nature
pub_type: 杂志文章
doi:10.1038/nature13072
更新日期:2014-04-24 00:00:00