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81.
Thode AM Kim KH Blackwell SB Greene CR Nations CS McDonald TL Macrander AM 《The Journal of the Acoustical Society of America》2012,131(5):3726-3747
An automated procedure has been developed for detecting and localizing frequency-modulated bowhead whale sounds in the presence of seismic airgun surveys. The procedure was applied to four years of data, collected from over 30 directional autonomous recording packages deployed over a 280 km span of continental shelf in the Alaskan Beaufort Sea. The procedure has six sequential stages that begin by extracting 25-element feature vectors from spectrograms of potential call candidates. Two cascaded neural networks then classify some feature vectors as bowhead calls, and the procedure then matches calls between recorders to triangulate locations. To train the networks, manual analysts flagged 219 471 bowhead call examples from 2008 and 2009. Manual analyses were also used to identify 1.17 million transient signals that were not whale calls. The network output thresholds were adjusted to reject 20% of whale calls in the training data. Validation runs using 2007 and 2010 data found that the procedure missed 30%-40% of manually detected calls. Furthermore, 20%-40% of the sounds flagged as calls are not present in the manual analyses; however, these extra detections incorporate legitimate whale calls overlooked by human analysts. Both manual and automated methods produce similar spatial and temporal call distributions. 相似文献
82.
Susanna Terracini Gianmaria Verzini 《Archive for Rational Mechanics and Analysis》2009,194(3):717-741
For the system(with k ≧ 3), we prove the existence for β large of positive radial solutions on \({\mathbb R^N}\) . We show that as β → + ∞, the profile of each component U i separates, in many pulses, from the others. Moreover, we can prescribe the location of such pulses in terms of the oscillations of the changing-sign solutions of the scalar equation ? ΔW + W = W3. Within an Hartree–Fock approximation, this provides a theoretical indication of phase separation into many nodal domains for the k-mixtures of Bose–Einstein condensates.
相似文献
$-\Delta U_i+ U_i=U_i^3-\beta U_i\sum_{j\neq i}U_j^2,\quad i=1,\dots,k,$
83.
Adnan S. Abu‐Surrah Tony Debaerdemaeker Wolfgang Huhn Bernhard Rieger Martti Klinga Timo Repo Markku Leskel 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):e42-e43
In the title compound, [Pd(CH3)2(C27H26P2)]·0.5C7H8, the Pd atom is at the centre of an approximately square‐planar arrangement of two P atoms and two methyl groups. The P—Pd—P angle [93.19 (3)°] is significantly larger than that in the corresponding dichloride complex [Pd(dppp)Cl2]. The toluene molecule is disordered across an inversion centre. 相似文献
84.
We study the effect of a forcing term in the context of the search of multiple nodal solutions u∈h 1(? N ) to a class of elliptic equations of type¶?Δu(x)=f(|x|,u(x))+h(|x|), x∈? N ,¶where f(|x|≡0 and f is superlinear but subcritical at infinity. 相似文献
85.
Ultrafast and selective labeling of endogenous proteins using affinity-based benzotriazole chemistry
Xiaoyi Xin Yu Zhang Massimiliano Gaetani Susanna L. Lundstrm Roman A. Zubarev Yuan Zhou Dale P. Corkery Yao-Wen Wu 《Chemical science》2022,13(24):7240
Chemical modification of proteins is enormously useful for characterizing protein function in complex biological systems and for drug development. Selective labeling of native or endogenous proteins is challenging owing to the existence of distinct functional groups in proteins and in living systems. Chemistry for rapid and selective labeling of proteins remains in high demand. Here we have developed novel affinity labeling probes using benzotriazole (BTA) chemistry. We showed that affinity-based BTA probes selectively and covalently label a lysine residue in the vicinity of the ligand binding site of a target protein with a reaction half-time of 28 s. The reaction rate constant is comparable to the fastest biorthogonal chemistry. This approach was used to selectively label different cytosolic and membrane proteins in vitro and in live cells. BTA chemistry could be widely useful for labeling of native/endogenous proteins, target identification and development of covalent inhibitors.Affinity-based benzotriazole (BTA) probes selectively and covalently label native proteins or endogenous proteins in cells with a fast reaction rate. It is enormously useful for characterizing protein function in biological systems and for drug development. 相似文献
86.
长期以来,天文学家精确的预测令世人惊讶。预言3000年4月26日,日全食可观察带,将顺着南美洲、大西洋和北非一线延伸,这一预测没有人反对。但试图描述病原体未来传播的科学家,必须面对非常大的不确定性。研究人员既缺乏关于传染病如何传播的可靠数据,感染能力的微小差异又可以成倍地扩大病毒的传播,从而难以预测各类流行病的严重程度。来自伊利诺伊大学的Nigel Goldenfeld和他的同事,最近以伊利诺伊州为例,开发了一个模型,评估非药物干预时COVID-19病毒传播的短期影响。研究者还探索和量化了模型的局限性,阐明了它无法预测的场景。他们使用该模型,向公民、临床医生和决策者,作出了示范性展示。 相似文献
87.
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89.
Susanna Piazzera 《Mathematical Methods in the Applied Sciences》2004,27(4):427-439
Within a semigroup framework, we discuss well posedness and qualitative behaviour of an age‐dependent population equation with delay in the birth process. Using positivity and Perron–Frobenius theory we obtain an explicit stability criterion. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
90.
We consider the efficient and robust numerical solution of elliptic problems with jumping coefficients occurring on a network of thin fractures. We present an iterative solution concept based on a hierarchical separation of the fractures and the surrounding rock matrix. Upper estimates for the convergence rates are independent of the width of the fractures and of the jumps of the coefficients. Inexact solution of the local subproblems is also considered. The theoretical results are illustrated by numerical experiments.