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排序方式: 共有87条查询结果,搜索用时 31 毫秒
71.
James R. Henderson 《Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics》2010,41(1):1-8
The Copenhagen interpretation of quantum mechanics is the dominant view of the theory among working physicists, if not philosophers. There are, however, several strains of Copenhagenism extant, each largely accepting Born's assessment of the wave function as the most complete possible specification of a system and the notion of collapse as a completely random event. This paper outlines three of these sub-interpretations, typing them by what the author of each names as the trigger of quantum-mechanical collapse. Visions of the theory from von Neumann, Heisenberg, and Wheeler offer different mechanisms to break the continuous, deterministic, superposition-laden quantum chain and yield discrete, probabilistic, classical results in response to von Neumann's catastrophe of infinite regress. 相似文献
72.
Haiman CA Garcia RR Kolonel LN Henderson BE Wu AH Le Marchand L 《Nature genetics》2008,40(3):259-60; author reply 260-1
73.
用一种深掺杂硅材料制成的微型流量传感器来测量呼吸气流的流量 ,并用信号处理电路对微型流量传感器的输出进行鉴别 ,就可以监视呼吸系统状态的微小变化 .传感器偏置电压的变化对系统的稳定性有重要的影响 .通常 ,温度和环境的变化会使某些被认为是常量的参量发生意外的变化 .信号处理系统部分论述了使用自动补偿系统来消除上述变化的影响 ,并给出了实用电子设备中 ,消除各种干扰因素的一些方法 . 相似文献
74.
Chloroplast DNA sequence from a miocene Magnolia species 总被引:18,自引:0,他引:18
E M Golenberg D E Giannasi M T Clegg C J Smiley M Durbin D Henderson G Zurawski 《Nature》1990,344(6267):656-658
DNA has been successfully extracted from several samples of preserved tissue, the oldest so far reported originating from a 13,000-year-old ground sloth. Both severe damage to the preserved DNA, primarily due to oxidation of the pyrimidines, has prevented the acquisition of sequence data from ancient samples except in a few cases. We report here the extraction of DNA from fossil leaf samples from the Miocene Clarkia deposit (17-20 Myr old), the amplification of an 820-base pair (bp) DNA fragment from the chloroplast gene rbcL from a fossil of the genus Magnolia, and its subsequent sequencing. The sequence was verified by comparison with published and unpublished rbcL sequences. These results extend our ability to analyse ancient DNA and may open new avenues into problems in palaeobotany, biogeography, and in the calibration of mutation rates. 相似文献
75.
76.
A 7-A resolution map of the purple membrane has been obtained by electron microscopy of tilted, unstained specimens. The protein in the membrane contains seven, closely packed, alpha-helical segments which extend roughly perpendicular to the plane of the membrane for most of its width. Lipid bilayer regions fill the spaces between the protein molecules. 相似文献
77.
Types of cell contacts in arterial smooth muscle 总被引:1,自引:0,他引:1
Ruth M. Henderson 《Cellular and molecular life sciences : CMLS》1975,31(1):103-105
Zusammenfassung Nachweis, dass in Arteriolen sowie in präkapillaren Arteriolen des Hunde-Duodenums nur eine einfache Aneinanderlagerung der Muskelzellen erfolgt und keine gap junctions, wie sie in den Muskelschichten der Hohlwandorgane vorhanden sind. 相似文献
78.
Epitaxy of rare earth element fluorcarbonate minerals from carbonatite dyke at Bayan Obo, Inner Mongolia, China 总被引:1,自引:0,他引:1
Xueming Yang Peishan Zhang Kejie Tao Xiaoyong Yang Shuangxi Chen Minglong Zou M. J. Le Bas R. N. Wilson R. Ranson L. S. Campbell T. C. Williams P. Henderson 《科学通报(英文版)》1998,43(13):1107-1107
Rare earth element fluorocarbonate minerals such as bastnaesite and parisite are firstly discovered in carbonatite dykes from
Bayan Obo, Inner Mongolia, China. Bastnaesite rarely occurs as homogeneously single crystal, but contains microfine phase
of parisite. They form regular intergrowth along (0001) plane net, which is identified as epitaxy. This eptactic texture results
from the variation of chemical composition of crystallizing agents of those minerals that crystallize directly from carbonatite
magma. 相似文献
79.
Loveday C Turnbull C Ramsay E Hughes D Ruark E Frankum JR Bowden G Kalmyrzaev B Warren-Perry M Snape K Adlard JW Barwell J Berg J Brady AF Brewer C Brice G Chapman C Cook J Davidson R Donaldson A Douglas F Greenhalgh L Henderson A Izatt L Kumar A Lalloo F Miedzybrodzka Z Morrison PJ Paterson J Porteous M Rogers MT Shanley S Walker L;Breast Cancer Susceptibility Collaboration 《Nature genetics》2011,43(9):879-882
Recently, RAD51C mutations were identified in families with breast and ovarian cancer. This observation prompted us to investigate the role of RAD51D in cancer susceptibility. We identified eight inactivating RAD51D mutations in unrelated individuals from 911 breast-ovarian cancer families compared with one inactivating mutation identified in 1,060 controls (P = 0.01). The association found here was principally with ovarian cancer, with three mutations identified in the 59 pedigrees with three or more individuals with ovarian cancer (P = 0.0005). The relative risk of ovarian cancer for RAD51D mutation carriers was estimated to be 6.30 (95% CI 2.86-13.85, P = 4.8 × 10(-6)). By contrast, we estimated the relative risk of breast cancer to be 1.32 (95% CI 0.59-2.96, P = 0.50). These data indicate that RAD51D mutation testing may have clinical utility in individuals with ovarian cancer and their families. Moreover, we show that cells deficient in RAD51D are sensitive to treatment with a PARP inhibitor, suggesting a possible therapeutic approach for cancers arising in RAD51D mutation carriers. 相似文献
80.