分类: 物理学 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We study in the effective Lagrangian approach the possibility of probing anomalous top quark charged current couplings in the single top production at a high energy e\gamma collider. We analyzed all possible dimension-six CP-conserving operators which can
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: Cooperative down-conversion (DC) with emission of two near-infrared photons for each blue photon absorbed was achieved in Tb3+/Yb3+ co-doped yttrium lithium fluoride single crystals grown by an improved Bridgman method. The luminescent properties of the c
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: The demand for fiberboards has been growing in recent years. However, emission of formaldehyde, which was the main component of adhesives in fiberboards, has caused environmental and health concerns. Industries are therefore pursuing green chemistry techn
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: Linear and hyperbranched poly(azomethine)s (PAMs)-based on triphenylamine moieties are synthesized and used as the functioning layers in the Ta/PAM/Pt resistive switching memory devices. Comparably, the hyperbranched PAM with isotropic architecture and se
分类: 物理学 >> 地球物理学、天文学和天体物理学 提交时间: 2024-01-09 合作期刊: 《Research in Astronomy and Astrophysics》
摘要: For high-precision pulsar timing analysis and low-frequency gravitational wave detection, it is essential to accurately determine pulsar pulse times of arrival (ToAs) and associated uncertainties. To measure the ToAs and their uncertainties, various cross-correlation-based techniques can be employed. We develop methodologies to investigate the impact of the template-matching method, profile shape, signal-to-noise ratio of both template and observation on ToA uncertainties. These methodologies are then applied to data from the International Pulsar Timing Array. We demonstrate that the Fourier domain Markov chain Monte Carlo method is generally superior to other methods, while the Gaussian interpolation shift method outperforms other methods in certain cases, such as profiles with large duty cycles or smooth profiles without sharp features. However, it is important to note that our study focuses solely on ToA uncertainty, and the optimal method for determining both ToA and ToA uncertainty may differ.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Metallic glasses are non-equilibrium materials and the glass transition temperature upon heating Tg,h can be used to characterize the kinetic stability of the glass. Annealing below the glass transition is well- known to induce relaxation processes that reduce the glass enthalpy. We demonstrate that a liquid- cooled Au-based metallic glass can achieve very high kinetic stability by an optimal annealing treat- ment to yield a large increase in Tg,h of 28 K; this is 3e5 times larger than the increase usually reported. The measured enthalpy decrease of 1100 J/mol is about 50% of the difference between the as-cooled glass and the equilibrium crystalline state and reaches the extrapolated enthalpy of the supercooled liquid. The optimal annealing conditions can be determined by an enthalpy-temperature-time (ETT) diagram which is proposed for the first time based on the comprehensive examination of relaxation processes. At equilibrium, a direct relation is established between the increase in kinetic stability as measured by the increase in Tgh and the enthalpy decrease.
分类: 生物学 >> 生物物理学 提交时间: 2016-05-18
摘要: A method for site-specific and high yield modification of tobacco mosaic virus coat protein (TMVCP) utilizing a genetic code expanding technology and copper free cycloaddition reaction has been established, and biotin-functionalized virus-like particles were built by the self-assembly of the protein monomers.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Novel ionic binders based on sulfonated polyether ether ketones and polysulfone backbones, bearing pendant lithiated fluorinated sulfonimide groups (SPEEK-PSI-Li and PSU-PSI-Li) were developed. Their performance in high performance silicon (Si) nano-particle anodes was studied in comparison with conventional binders such as lithiated sulfonated poly(ether-ether-ketone) containing fluorinated sulfonic acid side chains (SPEEK-PSA-Li), poly(vinylidene) difluoride (PVDF), sodium carboxymethyl cellulose (CMC) and alginate. Much superior to other anode binders, the ionic conducting SPEEK-PSI-Li binders could not only provide good adhesion properties, but also effectively reduce the over-potential during rapid charge and discharge cycles. When cycled at a current of 400 mA g 1, these anodes could maintain above 2000 mA h g 1 after 50 cycles. Even when cycled at a high current rate of 2000 mA g 1, the anodes with SPEEK-PSI-Li binders could be cycled above 500 mA h g 1 in 50 cycles. The superior performance of the novel SPEEK-PSI-Li binders could be attributed to their high cohesion capability, low solubility in electrolytes, high adaptability to volume fluctuation and high ionic conducting capability resulting from of the co-existence of flexible PEEK backbones, flexible fluorinated ether side chains, ionic transporting sulfonate groups, and pentadentate super ionic sulfonimide groups in the molecule structures.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-08
摘要: Linear and hyperbranched poly(azomethine)s (PAMs)-based on tri- phenylamine moieties are synthesized and used as the functioning layers in the Ta/PAM/Pt resistive switching memory devices. Com- parably, the hyperbranched PAM with isotropic architecture and semi-crystalline nature shows enhanced memory behaviors with more uniform distribution of the HRS and LRS resistances.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Two novel twisted anthracene derivatives, 2-(4-(10-(phenanthren-9-yl)anthracen-9-yl)phenyl)-1- phenyl-1H-phenanthro[9,10-d]-imidazole (p-PABPI) and 2-(3-(10-(phenan-thren-9-yl)anthracen-9-yl) phenyl)-1-phenyl-1H-phenanthro-[9,10-d]imidazole (m-PABPI), have been synthesized. Their photo- physical and photochemical properties are also investigated systemically. The non-doped fluorescent organic light-emitting diodes are fabricated by using anthracene derivatives as the emitters. The maximum current efficiencies are achieved to be 3.98 and 1.32 cd A 1 and the maximum power effi- ciencies are 2.80 and 1.14 lm W 1, respectively. The external quantum efficiency maximum (EQEmax) is 3.61% and 1.33% for p-PABPI and m-PABPI. Intriguingly, the efficiencies of p-PABPI are almost three times larger than that of m-PABPI with only the different molecular configuration. The results revealed a new rule of molecular design based on anthracene derivatives for obtaining high performance blue emission materials.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Thermally stable poly(triphenylamine) (PTPA) synthesized by an oxidative coupling reaction is used as the functional layer in memory devices, which exhibit non-volatile bistable resistive switching behavior with a large ON/OFF ratio over 5 108, a long retention time exceeding 8 103 s and a wide working temperature range of 30–390 K.