CONSTRUCTION OF MECHANISM MODES OF GEOMETRICALLY UNSTABLE SYSTEMS IN LARGE DEFORMATION

针对仅有一个自由度的几何可变体系,基于大变形机构模态的特性,提出常变、瞬变的判断方法,进而对常变体系提出大变形机构模态的二元体构建算法。该算法将问题简化为类似于一元二次方程的求解,无须求解非线性超越方程组,可给出完备的模态解答和完整的解答路径及其分叉点。本法具有原理直观、公式简洁、解答完备的优点,可作为结构力学几何构造分析教学的补充内容。     

Measurement of ${M_{W^{+}}-M_{W^{-}}}$ at LHC

This paper is the second of the series of papers proposing dedicated strategies for precision measurements of the Standard Model parameters at the LHC. The common feature of these strategies is their robustness with respect to the systematic measurement and modeling error sources. Their impact on the precision of the measured parameters is reduced using dedicated observables and dedicated measurement procedures which exploit flexibilities of the collider and detector running modes. In the present paper we focus our attention on the measurement of the charge asymmetry of the W-boson mass. This measurement is of primordial importance for the LHC experimental program, both as a direct test of the charge-sign-independent coupling of the W-bosons to the matter particles and as a necessary first step towards the precision measurement of the charge-averaged W-boson mass. We propose and evaluate the LHC-specific strategy to measure the mass difference between the positively and negatively charged W-bosons, M_W⁺-M_W^-M_{W^{+}}-M_{W^{-}} . We show that its present precision can be improved at the LHC by a factor of 20. We argue that such a precision is beyond the reach of the standard measurement and calibration methods imported to the LHC from the Tevatron program.     

红外光谱法分析检验复印纸

本文利用装备有衰减全反射附件的红外光谱仪对62种不同产地、不同品牌的复印纸进行检验,建立了纤维素和无机填料峰面积的比值作为区分鉴别复印纸的新方法,区分度达到了91.96%,达到了无损、快速、准确检验区分的目的。     

Macroscopic and microscopic aspects of the temporomandibular joint related to its clinical implication

In order to obtain a precise diagnosis and treatment for temporomandibular dysfunctions, it is necessary to have morphological and functional knowledge of the temporomandibular joint. Anatomic components are important to the understanding of the complexity of temporomandibular joint. Nonetheless, just as important are the anatomic relationships that this joint has with the neighboring structures. Thus, the aim of this study was to present the anatomic relationships of the temporomandibular joint in its various surfaces: external or lateral, anterior, posterior, medial, superior, and posterosuperior, considering the morphological and histological aspects. Nine human heads, fixed in formalin (10%) underwent sagittal medial section and were subsequently dissected, evidencing the anatomic components of all surfaces to be analyzed. Components of the external surface were: skin, subcutaneous tissue, lymphatic ganglia, parotid gland, superficial temporal artery, transverse facial artery, zygomatic-orbital artery, superficial temporal vein, facial and auriculotemporal nerves, masseter muscle, and pre-auricular lymphonodus. The anterior surface comprised the masseter and lateral pterygoid muscles (upper and inferior heads), pterygoid venous plexus, mandibular notch, posterior deep temporal artery, masseteric nerve, and deep posterior temporal branches. Medial surface components were: internal maxillary artery, of which middle meningeal artery was one of the closest branches to the TMJ, anterior tympanic artery, inferior alveolar, lingual, auriculotemporal, and chorda tympani nerves, which belonged to the surface posterior to the anterior wall of the auditory duct; auricolotemporal nerve, parotid gland; and petrotympanic fissure. The cerebral fossa (meninges and encephalon) belonged to the superior surface and the ear belonged to the posterosuperior surface. Histologically, the temporomandibular joint is composed by different tissues that compound the mandibular head, mandibular fossa, and articular eminence of the temporomandibular joint. It was concluded that the temporomandibular joint is a complex structure and the clinician must have the ability to formulate the diagnosis based on the understanding of morphological aspects of the structures that compose the stomatognatic system.     

Strong correlations and magnetic frustration in the high Tc iron pnictides

We consider the iron pnictides in terms of a proximity to a Mott insulator. The superexchange interactions contain competing nearest-neighbor and next-nearest-neighbor components. In the undoped parent compound, these frustrated interactions lead to a two-sublattice collinear antiferromagnet (each sublattice forming a Néel ordering), with a reduced magnitude for the ordered moment. Electron or hole doping, together with the frustration effect, suppresses the magnetic ordering and allows a superconducting state. The exchange interactions favor a d-wave superconducting order parameter; in the notation appropriate for the Fe square lattice, its orbital symmetry is dxy. A number of existing and future experiments are discussed in light of the theoretical considerations.     

Anyonic loops in three-dimensional spin liquid and chiral spin liquid

We established a large class of exactly soluble spin liquids and chiral spin liquids on three-dimensional helix lattices by introducing Kitaev-type's spin coupling. In the chiral spin liquids, exact stable ground states with spontaneous breaking of the time reversal symmetry are found. The fractionalized loop excitations in both the spin and chiral spin liquids obey non-Abelian statistics. We characterize this kind of statistics by non-Abelian Berry phase and quantum algebra relation. The topological correlation of loops is independent of local order parameter and it measures the intrinsic global quantum entanglement of degenerate ground states.     

Intrinsic decoherence mechanisms in the microcavity polariton condensate

The fundamental mechanisms which control the phase coherence of the polariton Bose-Einstein condensate (BEC) are determined. It is shown that the combination of number fluctuations and interactions leads to decoherence with a characteristic Gaussian decay of the first-order correlation function. This line shape, and the long decay times ( approximately 150 ps) of both first- and second-order correlation functions, are explained quantitatively by a quantum-optical model which takes into account interactions, fluctuations, and gain and loss in the system. Interaction limited coherence times of this type have been predicted for atomic BECs, but are yet to be observed experimentally.     

Synchronized and desynchronized phases of exciton-polariton condensates in the presence of disorder

Condensation of exciton polaritons in semiconductor microcavities takes place despite in-plane disorder. Below the critical density, the inhomogeneity of the disorder limits the spatial extension of the ground state. Above the critical density, in the presence of weak disorder, this limitation is spontaneously overcome by the nonlinear interaction, resulting in an extended synchronized phase. In the case of strong disorder, several non-phase-locked condensates can be evidenced. The transition from a synchronized phase to a desynchronized phase is addressed by sampling the cavity disorder.     

三角银纳米柱的研究进展*

由于三角银纳米柱独特可调的光学性质及其在生物分子和无机离子检测等领域的重要应用前景而引起了人们的关注。本文综述了三角银纳米柱的研究进展,介绍了三角银纳米柱的光学性质,几种主要的制备方法,三角银纳米柱的表面修饰、颗粒膜的制备以及在无机离子检测中的应用,并对三角银纳米柱在应用中存在的结构不稳定性问题以及现行的解决方法进行了综述。     

Simultaneous determination of five active hydrolysis ingredients from Panax quinquefolium L. by HPLC‐ELSD

An effective method for simultaneous determination of five hydrolysis products of 20 (R)‐dammarane‐3β,6α,12β,20,25‐pentol, 24(R)‐ocotillol, 20(R)‐protopanaxatriol, 20(S)‐panaxatriol and 20(R)‐dammarane‐3β,12β,20,25‐tetrol was developed using high‐performance liquid chromatography with evaporative light scattering detection (HPLC‐ELSD). The hydrolysis products from Panax quinquefolium L. in the stems and leaves, berries, flower buds and roots components were successfully separated on a Kromasil C₁₈ column using methanol and water (83:17, v/v) as mobile phase in 18 min. The parameter for the ELSD was set to a probe temperature of 40°C and the nebulizer for nitrogen gas was adjusted to 3 L/min. All calibration curves showed good linear regression (r > 0.9975) within test ranges. The validation of the method included recovery, linearity, accuracy and precision (intra‐ and inter‐day variation). The accuracy and precision were satisfactory, with the overall intra‐ and inter‐day variation being less than 3.11%, and recoveries of this method were greater than 95.0%. This study developed an effective and rapid method for simultaneous determination of multiple hydrolysis components from Panax quinquefolium L. Copyright © 2010 John Wiley & Sons, Ltd.