Time domain finite volume method for the transient response and natural characteristics of structural-acoustic coupling in an enclosed cavity

A time domain finite volume method（TDFVM）based on wave theory is developed to analyze the transient response and natural characteristics of structural-acoustic coupling problems in an enclosed cavity.In the present method,the elastic dynamic equations and acoustic equation in heterogeneous medium are solved in solid domains and fluid domains respectively.The structural-acoustic coupling is implemented according to the continuity condition of the particle velocity along the normal direction and the normal traction equilibrium condition on the interface.Several numerical examples are presented to validate the effectiveness and accuracy of the present TDFVM.Then the effects of water depth on the acoustic and vibration characteristics and the natural characteristics of a structural-acoustic coupling system are analyzed.The numerical results show that the increase of water depth leads to a stronger coupling between the water and structure and the decrease of natural frequencies of coupling system,The computational cost and memory of this method are small and it can be applicable to structural-acoustic coupling problems in the heterogeneous fluid.     

Music,empathy and cultural understanding

In the age of the Internet and with the dramatic proliferation of mobile listening technologies, music has unprecedented global distribution and embeddedness in people's lives. It is a source of intense experiences of both the most intimate and solitary, and public and collective, kinds – from an individual with their smartphone and headphones, to large-scale live events and global simulcasts; and it increasingly brings together a huge range of cultures and histories, through developments in world music, sampling, the re-issue of historical recordings, and the explosion of informal and home music-making that circulates via YouTube. For many people, involvement with music can be among the most powerful and potentially transforming experiences in their lives. At the same time, there has been increasing interest in music's communicative and affective capacities, and its potential to act as an agent of social bonding and affiliation. This review critically discusses a considerable body of research and scholarship, across disciplines ranging from the neuroscience and psychology of music to cultural musicology and the sociology and anthropology of music, that provides evidence for music's capacity to promote empathy and social/cultural understanding through powerful affective, cognitive and social factors; and explores ways in which to connect and make sense of this disparate evidence (and counter-evidence). It reports the outcome of an empirical study that tests one aspect of those claims, demonstrating that ‘passive’ listening to the music of an unfamiliar culture can significantly change the cultural attitudes of listeners with high dispositional empathy; presents a model that brings together the primary components of the music and empathy research into a single framework; and considers both some of the applications, and some of the shortcomings and problems, of understanding music from the perspective of empathy.     

2D-Mueller-matrix tomography of optically anisotropic polycrystalline networks of biological tissues histological sections

A new technique of Mueller-matrix mapping of the birefringent structure of biological preparations of human organs tissues is suggested. The algorithms of reconstruction of average values and magnitude of fluctuations of the phase (birefringence) and amplitude (dichroism) of optically anisotropic structure of myocardium and connective tissue component of the vaginal wall histological section are proposed. The magnitudes and ranges of changes in the statistical moments of the 1st-4th order that characterize the distribution of average values and magnitude of fluctuations of birefringence and dichroism of the myocardium and connective tissue of the vaginal tissues histological sections were determined. Joint studies of distributions of the characteristics of phase and amplitude of the anisotropy of myocardium and connective tissue component of the vaginal wall tissues of different states were performed. The cases of various necrotic changes in the myocardium and pathological conditions of the vagina wall (prolapse of the genitals) are examined. Balanced accuracy of the method of Mueller-matrix polarization-phase and diffuse tomography of optically anisotropic polycrystalline networks in the differentiation of necrotic and pathological changes in human organs is determined.     

Design and simulation of the wire scanner for the injector linac of BEPC Ⅱ

BEPC Ⅱ,the upgrade project of Beijing Electron Positron Collider (BEPC),is an accelerator with large beam current and high luminosity,so an efficient and stable injector is required.Several beam diagnostic and monitoring instruments are used.A new diagnostic instrument--wire scanner,has been designed and will be used to nleasure the profile of the linac beam of BEPC Ⅱ.This paper describes the prototype of this system and the cause of heat generating of the wire.Some simulation results of the heat and force by using finite element method software-ANSYS(R),2) are presented and discussed.     

Temperature Sensitivity Control and Mechanical Stress Effect of Boron-Doped Long-Period Fiber Gratings

We will present in this work the quantitative analysis of the relationship between the doping concentrations of GeO 2 and B 2 O 3 in the core and cladding regions and the temperature sensitivity of the resonance wavelength shift in long-period fiber gratings (LPFGs). Based on this analysis, the temperature sensitivity was suppressed and enhanced to 0.002 nm/°C and 0.28 nm/°C, respectively. We will also discuss the effect of the residual mechanical stress on the optical and mechanical properties of LPFGs. In particular, we will present the measurement results of the dependence of the refractive index change and mechanical strength on the residual mechanical stress in the boron-doped fibers with depressed clad and matched clad.     

Modeling Gain Dynamics in EDFAs: Space-Resolved Versus Lumped Models

We present a detailed comparison of dynamic space- and frequency-resolved and lumped erbium-doped fiber amplifier (EDFA) models. The space- and frequency-resolved models are based on an iterative solution of propagation equations for pump, multiple signals, and spectral components of forward and backward propagating amplified spontaneous powers and rate equations for pump, metastable, and ground energy level population densities of erbium ion. In contrast to space-resolved models, the lumped model solves a single ordinary differential equation for time evolution of the length-averaged metastable level population and is therefore substantially less computer time consuming. Both the space, and frequency-resolved and the lumped models give almost identical results when used for an analysis of surviving channel power excursions in concatenated EDFAs fed by multiwavelength signal and add/drop scenarios. For a statistical analysis of output power and signal-tonoise ratio fluctuations in EDFA cascades fed by burst-mode packet traffic, only lumped models can be used.     

Spectroscopic and nano-molecular modeling investigation on the binary and ternary bindings of colchicine and lomefloxacin to Human serum albumin with the viewpoint of multi-drug therapy

Combination of several drugs is often necessary especially during long-term therapy. The competitive binding drugs can cause a decrease in the amount of drug bound to protein and increase the biological active fraction of the drug. The aim of this study is to analyze the interactions of Lomefloxacin (LMF) and Colchicine (COL) with human serum albumin (HSA) and to evaluate the mechanism of simultaneous binding of LMF and COL to protein. Fluorescence analysis was used to estimate the effect of drugs on the protein fluorescence and to define the binding and quenching properties of drugs-HSA complexes. The binding sites for LMF and COL were identified in tertiary structure of HSA with the use of spectrofluorescence analysis. The analysis of fluorescence quenching of HSA in the binary and ternary systems show that LMF does not affect the complex formed between COL and HSA. On the contrary, COL decreases the interaction between LMF and HSA. The results of synchronous fluorescence, resonance light scattering and circular dichroism spectra of binary and ternary systems show that binding of LMF and COL to HSA can induce micro-environmental and conformational changes in HSA. The simultaneous presence of LMF and COL in binding to HSA should be taken into account in the multi-drug therapy, and necessity of using a monitoring therapy owning to the possible increase of the uncontrolled toxic effects. Molecular modeling of the possible binding sites of LMF and COL in binary and ternary systems to HSA confirms the spectroscopic results.     

Astrophysical combustion

There are three main astrophysical combustion systems: the evolution of stars, formation of interstellar dust and particulates, and the transition to hadrons in the early universe. These are described in terms of general combustion concepts, such as ignition, laminar and turbulent flames, detonations, multiphase flows, and particle and soot formation. Viewed in this way, the universe and many of its most important astronomical components are combustion systems, and we should use these as naturally occurring laboratories for exploring new and familiar combustion regimes. A more detailed discussion focuses on one type of combustion system, the ignition and development of turbulent flames in Type Ia supernovae, and the importance of the transition to a detonation.     

陕北侏罗纪富镜煤和富惰煤分子结构的FTIR，XPS和13C NMR表征

侏罗纪优质煤炭资源为煤制油、制气等清洁高效利用提供了丰富的物质基础,其显微组分以富集惰质组为特征,而镜质组与惰质组大分子结构在很大程度上决定了煤的物理化学性质和工艺性能,进而决定了煤炭资源的综合利用效率及附加值。采集并制备了陕北侏罗纪煤田小保当煤矿和柠条塔煤矿的原煤(XR)、富镜质组煤(XV、NV)和富惰质组煤(XI、NI)样品,利用傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、固体13C核磁共振谱(13C NMR)等手段,结合煤质分析结果,定量表征了不同显微组分富集物分子结构的差异。研究结果表明：XI和NI煤中芳烃结构芳环取代程度低,主要以3个相邻、4~5个相邻的氢原子形式存在,苯环上氢原子较少被其他官能团取代,同时其结构中芳烃C═C骨架振动明显,脂肪结构中亚甲基伸缩振动强度较低,并且甲基含量略高于富镜煤,C═O基团相对含量略高,表明富惰煤有较多含氧桥键相连的芳香结构,其结构中脂族链、脂环基团脱落、断裂以及芳烃富集,支链相对较少且长度较短,芳碳率、芳香度、芳环缩合程度及成熟度较高。XV和NV煤中表面结构中碳的赋存形态“C—C,C—H”,“C—O”的相对含量高于富惰煤,反映其结构中应含较多的芳环取代的脂肪族侧链,XI和NI煤表面结构中氧的赋存形态以“C—O”为主,“C═O”和“COO—”明显高于富镜煤。XV和XI煤的芳碳率分别为57.91%和66.02%,脂甲基碳分别为10.02%和7.84%,质子化芳碳为非质子化芳碳的两倍,XV煤的羰基和羧基碳相对含量较高,两者桥碳和周碳之比分别为0.25和0.40,芳香核结构平均缩合环数分别为2.68和3.03,平均尺寸分别为0.448和0.676 nm,XI煤结构中芳香核以萘和蒽为主,支链化度L_γ分别为0.22和0.19,表明XV比XI存在较多脂肪侧链、饱和环结构,生烃(油)潜力大。     

景德镇仿龙泉青瓷与龙泉青瓷组成特征研究

龙泉青瓷不仅受到了国内外陶瓷爱好者的热捧,还被不同地区广大窑工争相效仿,其中以景德镇明清时期仿制最具代表性。利用能量色散X荧光光谱分析仪对38 件宋、元、明时期的龙泉青瓷以及明代景德镇仿龙泉青瓷进行了测试,并结合烧成温度分析结果,从时空角度对比分析了两地青瓷胎釉组成特征、演变规律和形成原因,有助于了解我国南方青釉瓷的演变发展、相互交流和影响,为不同产地青瓷的断源断代提供了一定的科学依据。     

The fundamental surface science of wurtzite gallium nitride

A review is presented that covers the experimental and theoretical literature relating to the preparation, electronic structure and chemical and physical properties of the surfaces of the wurtzite form of GaN. The discussion includes the adsorption of various chemical elements and of inorganic, organometallic and organic species. The focus is on work that contributes to a microscopic, atomistic understanding of GaN surfaces and interfaces, and the review concludes with an assessment of possible future directions.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

拉曼和紫外光谱法研究阿司匹林及其与DNA的相互作用

检测了阿司匹林对照品与肠溶片的常规拉曼光谱和表面增强拉曼光谱,归属了各个振动峰位和增强峰位;研究了阿司匹林溶液与DNA相互作用的表面增强拉曼光谱与紫外光谱。结果表明:阿司匹林对照品与肠溶片的NRS及SERS图谱基本一致,药品的辅料对阿司匹林的检测几乎没有影响;在SERS中,阿司匹林分子是通过羧基和苯环垂直吸附在纳米银表面;阿司匹林分子与DNA相互作用的主要键合模式是插入作用,阿司匹林中的苯环和CO插入到DNA双螺旋结构的碱基对之间,为深入了解此类药物的作用机理提供了十分重要的信息和有益的参考。     

不同比例有机无机肥配施土壤腐殖质组分的光谱学特征

以16年长期定位试验为基础,探讨不同比例有机无机肥配施对土壤腐殖质特征的影响。通过分离纯化腐殖质中的胡敏酸（HA）和富里酸（FA）组分,并利用元素分析、红外光谱和核磁共振研究分析了F1（70%化肥+30%有机肥）、F2（50%有机肥+50%化肥）和F3（100%有机肥）三种施肥方式下的HA和FA含量及结构变化。结果表明,F3对于提升HA和FA含量的效果优于F1和F2处理,说明有机肥的施用量越高,土壤腐殖质组分的含量就越高。元素分析表明,不同配比的有机无机肥对HA和FA各元素含量及原子比影响不同。F2和F3都提高了HA的缩合度,降低了氧化度和极性,其中F3的效果更加明显;有机肥的施用还能促进HA中含氮化合物的形成,并且在F2中的效果最好;有机肥的施用同样提高了FA的缩合度而降低了氧化度和极性并促进了含氮化合物的形成,尤其在F2处理中尤为明显。腐殖质红外光谱分析表明,与F1相比,F2和F3提高了HA中脂肪族化合物、碳水化合物物质的含量,FA的羧基基团、脂肪基团含量也增加,且在F3处理中表现最为显著;F2处理则降低了HA中脂肪烃物质的含量,FA中的碳水化合物则达到最高。13C核磁共振波谱分析显示,在三种处理中,有机肥的施用提高了HA和FA的脂化度而降低其芳化度,其中F2处理中HA官能团变化更加显著,FA在F3处理中则变化更加明显。综上所述,有机肥显著提高了土壤腐殖质组分含量,并且提高了HA和FA的脂化度降低其芳化度,但是不同用量有机肥下HA和FA的形成机制不同。     

NIR Spectroscopy and Imaging Techniques for Evaluation of Fish Quality—A Review

Abstract

Fish is a highly perishable product and it is particularly important to pay attention to its quality changes. Maintenance of the high quality of fish and fishery products necessitates development of means for precise and rapid quality evaluation. Near-infrared (NIR) spectroscopy and imaging techniques are proven technologies that can provide useful information for the estimation of quality attributes in fish and fishery products due to fast speed, noninvasiveness, ease of use, and minimal sample preparation. The aim of this review is to communicate perspectives and aspects relating to NIR spectroscopy and imaging techniques with regard to evaluation of chemical composition (fat, protein, and moisture), microbiological (freshness, spoilage, and nematodes), and sensory (flavor, texture, and color) attributes of fish and fishery products. Moreover, the usefulness of NIR spectroscopy and imaging techniques for fish authentication and classification are presented. Finally, some viewpoints on the current situation and suggestions for future research directions are proposed.     

20%辛·氰乳油在白菜和土壤中的残留及消解动态

建立了辛硫磷和甲氰菊酯混剂在白菜及土壤中残留分析方法,研究了20%辛·氰乳油在白菜和土壤中的最终残留和消解动态。应用20%辛·氰乳油以施药剂量0.150g/m2进行消解动态实验,实验结果表明,辛硫磷在白菜和土壤中的半衰期分别为2.7d和3.4d,甲氰菊酯在白菜和土壤中的半衰期分别为9.4d和9.5d。同时,辛·氰乳油在土壤和白菜样品中的最终残留量均小于其MRL(最高残留限量)0.05mg/kg,残留数据显示按推荐施药剂量0.050—0.075g/m~2在白菜上使用是安全的。     

Sono-electrolysis performance based on indirect continuous sonication and membraneless alkaline electrolysis: Experiment,modelling and analysis

In the present study, experiments of membraneless alkaline sono-electrolysis are combined to a mathematical model describing the performance of a sono-electrolyzer based on the electrochemical resistances and overpotentials (activation, Ohmic and concentration) and the oscillation of the acoustic cavitation bubble, and its related sono-physical and sonochemical effects, as a single unit and within population. The study aims to elucidate the mechanism of action of acoustic cavitation when coupled to alkaline electrolysis, using a membraneless H-cell configuration and indirect continuous sonication (40 kHz, 60 W_e). The calorimetric characterization constituted the bridge between experimental results and the numerical and simulation approach, while the quantification of the rate of produced hydrogen both experimentally and numerically highlighted the absence of the contribution of sonochemistry, and explained the role of ultrasounds by the action of shockwaves and microjets. Finally, the energetic sono-physical approach allowed an estimation of the predominance of the shockwaves and microjets effects according to the bubble size distribution within the population corresponding to the acoustic conditions of the study. The resulting macroscopic effect in sono-electrolysis process has been assessed considering the induced degassing. A reduction in the fraction of electrodes’ coverage by bubbles from 76% to 42% has been recorded, corresponding to a decrease of 7.2% in Ohmic resistance and 62.35% in bubble resistance.     

Exploring 2D materials at surfaces through synchrotron-based core-level photoelectron spectroscopy

The interest in understanding and controlling the properties of two-dimensional materials (2DMs) has fostered in the last years a significant and multidisciplinary research effort involving condensed matter physics and materials science. Although 2DMs have been investigated with a wide set of different experimental and theoretical methodologies, experiments carried out with surface-science based techniques were essential to elucidate many aspects of the properties of this family of materials. In particular, synchrotron-based X-ray photoelectron spectroscopy (XPS) has been playing a central role in casting light on the properties of 2DMs, providing an in-depth and precise characterization of these materials and helping to elucidate many elusive and intricate aspects related to them. XPS was crucial, for example, in understanding the mechanism of growth of several 2DMs at surfaces and in identifying the parameters governing it. Moreover, the chemical sensitivity of this technique is crucial in obtaining knowledge about functionalized 2DMs and in testing their behavior in several model chemical reactions. The achievements accomplished so far in this field have reached a maturity point for which a recap of the milestones is desirable. In this review, we will showcase relevant examples of studies on 2DMs for which synchrotron-based XPS, in combination with other techniques and state-of-the-art theoretical modeling of the electronic structure and of the growth mechanisms, was essential to unravel many aspects connected to the synthesis and properties of 2DMs at surfaces. The results highlighted herein and the methodologies followed to achieve them will serve as a guidance to researchers in testing and comparing their research outcomes and in stimulating further investigations to expand the knowledge of the broad and versatile 2DMs family.     

二阶导数荧光分光光度法同时测定色氨酸和酷氨酸

本文描述了用二阶导数荧光光度法同时测定色氨酸和酪氨酸。在 p H 7.4的条件下 ,用 2 2 1nm作为激发波长 ,记录色氨酸和酪氨酸的发射光谱 ,并进行二阶导数处理。色氨酸在 318nm处 ,酪氨酸在 2 83nm处 ,二阶导数峰高与浓度成线性关系。色氨酸工作曲线的线性回归方程为 c =0 .0 0 0 7H - 0 .0 0 4,r =0 .996 4,线性范围为 0 .0 0 4到 0 .2 0 0μg . m L- 1 。酪氨酸工作曲线的线性回归方程为 c =0 .0 0 12 H -0 .0 0 40 ,r=0 .9971。线性范围为 0 .0 0 2到 0 .2 5 0 μg· m L- 1 。实验了 p H、温度和干扰离子对测定的影响 ,测定了苹果中的色氨酸和酪氨酸的含量 ,回收率分别为 (92 .0～ 10 4.0 ) %和 (98.70～ 10 2 .0 ) % ,相对标准偏差分别为 3.5 %和 2 .8%。     

Party–state systems and their dynamics as networks

The dynamics of expansion and retreat of a network are detailed in the example of the birth and demise of party–state systems. This systemic network is described with the help of the interactive party–state (IPS) model through the interrelationship of individual party–state and economic decision-makers. The model also describes the causes of the internal dynamics of this network: its generators, its self-similarities and differences, as well as the dynamics of its operation and transformation. In view of the IPS model, I elaborate on the specific structure and dynamics of the Chinese party–state.