基于感兴趣区的图像编码与渐进传输

本文采用一种任意形状的整型或非整型小波变换 ,结合高效的SPIHT(SetPartitioningInHierarchicalTrees)图像编码算法 ,分别实现了任意形状感兴趣区的无损压缩和非感兴趣的有损压缩算法 .另外本文还提出了两种感兴趣区优先编码策略 ,可以保证在极低的码率下感兴趣区的重建质量远远好于非感兴趣区的重建质量 ,满足用户快速、个性化的浏览需求 .这些方法得到的压缩码流都具有嵌入的特点 。

NiTi形状记忆合金表面TiO_2薄膜的制备及其血液相容性

采用溶胶 凝胶法在NiTi合金表面制备了TiO2薄膜,用DSC分析了凝胶在加热过程中发生的转变。结果表明:在NiTi表面形成金红石型TiO2薄膜;覆盖有TiO2薄膜的NiTi合金与NiTi基体及316L不锈钢、Ti6Al4V相比,凝血时间延长,溶血率下降,说明TiO2膜可提高NiTi合金血液相容性。

Synthesis and Structure of anti-Configuration Complex [Cu(tssb)_2]·2[(H_3O)Cl]·4H_2O

The title complex [Cu(tssb)2]2[(H3O)Cl]4H2O (C18H34Cl2CuN2O14S2) (tssb = tau- rine salicylaldehyde Schiff base) has been synthesized by the reaction of taurine salicylaldehyde Schiff base (tssb) and copper acetate in water-ethanol. Its single-crystal structure was determined by X-ray diffraction method. The crystal structure belongs to triclinic, space group P1 with a = 0.7407(1), b = 1.3329(3), c = 1.5736(3) nm, ?= 103.800(4), ?= 95.030(4), ?= 104.416(4)? Mr = 701.06, V = 1.4433(5) nm3, Z = 2, Dc = 1.613 g/cm3, = 1.153 mm-1 and F(000) = 726. The compound is an infinitely expanding three-dimensional network connected with hydrogen bonds. The Cu(Ⅱ) atom is coordinated by two nitrogen and two oxygen atoms to form a distorted planar coordination compound which adopts anti-configuration because two sulfonic acid groups are posi- tioned diagonally on a plane.

Development of A Fully Nonlinear Numerical Wave Tank

A fully nonlinear numerical wave tank based on the solution of the σ-transformed Navier-Stokes equation is developed in this study. The numerical wave is generated from the inflow boundary, where the surface elevation and/or velocity are specified by use of the analytical solution or the laboratory data. The Sommerfeld/Orlanski radiation condition in conjunction with an artificial damping zone is applied to reduce wave reflection from the outflow boundary. The whole numerical solution procedures are split into three steps, i.e., advection, diffusion and propagation, and a new method, the Lagrange-Euler Method, instead of the MAC or VOF method, is introduced to solve the free surface elevation at the new time step. Several typical wave cases, including solitary waves, regular waves and irregular waves, are simulated in the wave tank. The robustness and accuracy of the NWT are verified by the good agreement between the numerical results and the linear or nonlinear analytical solutions. This research will be further developed by study of wave-wave, wave-current, wave-structure or wave-jet interaction in the future.

Composite surfactants aided solvothermal synthesis and catalytic hydrogenation property of oil soluble bimetallic CoMoS nanoparticles

Oil-soluble bimetallic CoMoS nanoparticles were successfully synthesized by a composite-surfactants-aided-solvothermal process.The surface hydrophilicity and functionality of the products were investigated through transmission electron microscopy （TEM）,Fourier transform infrared （FTIR） spectra,and Ultraviolet （UV） spectra analysis.The catalytic performance of hydrogenation on the CoMoS nanoparticles was studied with naphthalene as a model compound.It was found that CoMoS catalysts supported on active carbon （AC） was more active than conventional MoS2/γ-Al2O3.The activity of CoMoS/AC can be tailored through the change of the Co/（Co＋Mo） atomic ratio.

Shear Stress Regulates Tumor Cell Mechanics and Actomyosin-Dependent Survival and Chemoresistance

Metastasis is the main cause of cancer death,and tumor cells mainly disseminate to the distal organs through the blood circulation,in which they experience considerable levels of fluid shear stress.CTCs are heterogeneous with diverse subpopulations of distinct genotypes and phenotypes and the frequency of CTCs is correlated with poor prognosis and overall survival in cancer patients.Less than 0.01%of them may eventually generate metastatic tumors in secondary sites,indicating the inefficiency of metastasis.Nevertheless,metastasis accounts for over 90%of cancer-related deaths,suggesting that a subpopulation of CTCs are able to survive the metastatic process and form metastases.To target metastasis,it is thus essential to understand the roles of various factors during dissemination in the survival and functions of CTCs.However,the effects of hemodynamic shear stress on biophysical properties and functions of CTCs in suspension are not fully understood.This study was to investigate the effect of hemodynamic shear stress on the survival and anti-chemotherapy ability of suspended circulating tumor cells during metastasis,and the effect of actomyosin activity on this regulation.In this study,we developed a circulatory system to generate physiologic levels of hemodynamic shear stress,which mimicked certain important aspects of the CTC microenvironment in blood circulation.The survival of tumor cells in suspension,as a model for real CTCs,under different shear stress and circulation duration was examined.We found that the majority of breast tumor cells s in suspension can be eliminated by hemodynamic shear stress.The surviving cells exhibit unique biophysical properties,including significantly retarded cell adhesion,mesenchymal-like cell morphology,and reduced F-actin expression and cellular stiffness.Cancer stem cells which has been reported in other papers have lower stiffness compared with conventional tumor cells showed significantly higher survival in blood flow.Importantly,low actomyosin activity promotes the survival of CTCs in blood shear flow while high actomyosin activity inhibits tumor cells surviving shear stress treatment.These findings might be explained by the up-and down-regulation of the anti-apoptosis genes.Soft surviving tumor cells held survival advantages in shear flow and higher resistance to chemotherapy.Metastasis is closely linked with chemoresistance.However,the underlying mechanisms have not been fully understood,in particular,the roles of hemodynamic shear stress and actomyosin-dependent cell mechanics in drug resistance of CTCs remain unclear.Inhibiting actomyosin activity in suspended tumor cells enhanced chemoresistance,while activating actomyosin suppressed this ability.These findings might be associated with the corresponding changes in multidrug resistance related genes.Our study unveils the regulatory roles of actomyosin in the survival and drug resistance of circulating tumor cells in hemodynamic shear flow,which imply the importance of fluid shear stress and actomyosin activity in tumor metastasis.Our findings reveal a new mechanism by which circulating tumor cells are able to survive hemodynamic shear stress and chemotherapy and may offer a new potential strategy to target circulating tumor cells in shear flow and combat chemoresistance through actomyosin.

Optimum line reclosing time for the enhancement of interconnected power system stability

Automatic line reclosing schemes used in an extra-high-voltage power system is an economical and effective means to maintain transient stability. A novel method is proposed in the paper to adaptively optimize the automatic line reclosing time after a transient fault for enhancement of interconnected power system transient stability. Both the study on the transient energy over network and the structure-preserving multi-machines power system model illustrate that the excessive convergence of potential energy on the lines with a certain cutset deteriorate power system stability, and therefore, an optimum line reclosing strategy can be established by minimizing the change in transient potential energy distribution across a cutset lines in the vicinity of the faulty line as an optimization target, and the optimal reclosure time is set to the time of minimum line phase angle difference. Without any pre-determined knowledge, the method is adaptive to various power system operation modes and fault conditions, and easy to implement because only a limited number of data measured at one location on a tie-line linking sub-networks are required. Simulations have been performed with the OMIB(One Machine and Infinite Bus System) and a real inter-connected power system to verify the applicability of the method proposed.

Numerical simulation for separation of multi-phase immiscible fluids in porous media

Based on a lattice Boltzmann method and general principles of porous flow, a numerical technique is presented for analysing the separation of multi-phase immiscible fluids in porous media. The total body force acting on fluid particles is modified by axiding relative permeability in Nithiarasu＇s expression with an axiditional surface tension term. As a test of this model, we simulate the phase separation for the case of two immiscible fluids. The numerical results show that the two coupling relative permeability coefficients K12 and K21 have the same magnitude, so the linear flux-forcing relationships satisfy Onsager reciprocity. Phase separation phenomenon is shown with the time evolution of density distribution and bears a strong similarity to the results obtained from other numerical models and the flows in sands. At the same time, the dynamical rules in this model are local, therefore it can be run on massively parallel computers with well computational efficiency.

A select link analysis method based on logit–weibit hybrid model

Select link analysis provides information of where traffic comes from and goes to at selected links.This disaggregate information has wide applications in practice.The state-of-the-art planning software packages often adopt the user equilibrium(UE) model for select link analysis.However,empirical studies have repeatedly revealed that the stochastic user equilibrium model more accurately predicts observed mean and variance of choices than the UE model.This paper proposes an alternative select link analysis method by making use of the recently developed logit–weibit hybrid model,to alleviate the drawbacks of both logit and weibit models while keeping a closed-form route choice probability expression.To enhance the applicability in large-scale networks,Bell’s stochastic loading method originally developed for logit model is adapted to the hybrid model.The features of the proposed method are twofold:(1) unique O–D-specific link flow pattern and more plausible behavioral realism attributed to the hybrid route choice model and(2) applicability in large-scale networks due to the link-based stochastic loading method.An illustrative network example and a case study in a large-scale network are conducted to demonstrate the efficiency and effectiveness of the proposed select link analysis method as well as applications of O–D-specific link flow information.A visualizationmethod is also proposed to enhance the understanding of O–D-specific link flow originally in the form of a matrix.

Transition-Metal-Free Allylic Defluorination Cross-Electrophile Coupling Employing Rongalite

Comprehensive Summary The conversion of CF3-alkenes to gem-difluoroalkenes using reductive cross-coupling strategy has received much attention in recent years,however,the use of green and readily available reducing salt to mediate these reactions remains to be explored.In this work,a concise construction of gem-difluoroalkenes,which requires neither a catalyst nor a metal reducing agent,was established.Rongalite,a safe and inexpensive industrial product,was employed as both a radical initiator and reductant.This procedure was compatible with both linear and cyclic diaryliodonium salts,enabling a wide variety of substrates(>70 examples).The utility of this approach was demonstrated through gram-scale synthesis and efficient late-stage functionalizations of anti-inflammatory drugs.

Vertical structures of PM_(10) and PM_(2.5) and their dynamical character in low atmosphere in Beijing urban areas

The vertical structures and their dynamical character of PM2.5 and PM10 over Beijing urban areas are revealed using the 1 min mean continuous mass concentration data of PM2.5 and PM10 at 8, 100, and 320 m heights of the meteorological observation tower of 325 m at Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP CAS tower hereafter) on 10―26 August, 2003, as well as the daily mean mass concentration data of PM2.5 and PM10 and the continuous data of CO and NO2 at 8, 100 (low layer), 200 (middle layer), and 320 m (high layer) heights, in combination with the same period meteorological field observation data of the meteorological tower. The vertical distributions of aerosols observed on IAP CAS tower in Beijing can be roughly divided into two patterns: gradually and rapidly decreasing patterns, I.e. The vertical distribution of aerosols in calm weather or on pollution day belongs to the gradually decreasing pattern, while one on clean day or weak cold air day belongs to the rapidly decreasing pattern. The vertical distributive characters of aerosols were closely related with the dynamical/thermal structure and turbulence character of the atmosphere boundary layer. On the clean day, the low layer PM2.5 and PM10 concentrations were close to those at 8 m height, while the concentrations rapidly decreased at the high layer, and their values were only one half of those at 8 m, especially, the concentration of PM2.5 dropped even more. On the clean day, there existed stronger turbulence below 150 m, aerosols were well mixed, but blocked by the more stronger inversion layer aloft, and meanwhile, at various heights, especially in the high layer, the horizontal wind speed was larger, resulting in the rapid decrease of aerosol concentration, I.e. Resulting in the obvious vertical difference of aerosol concentrations between the low and high layers. On the pollution day, the concentrations of PM2.5 and PM10 at the low, middle, and high layers dropped successively by, on average, about 10% for each layer in comparison with those at 8 m height. On pollution days, in company with the low wind speed, there existed two shallow inversion layers in the boundary layer, but aerosols might be, to some extent, mixed below the inversion layer, therefore, on the pollution day the concentrations of PM2.5 and PM10 dropped with height slowly; and the observational results also show that the concentrations at 320 m height were obviously high under SW and SE winds, but at other heights, the concentrations were not correlated with wind directions. The computational results of footprint analysis suggest that this was due to the fact that the 320 m height was impacted by the pollutants transfer of southerly flow from the southern peripheral heavier polluted areas, such as Baoding, and Shijiazhuang of Hebei Province, Tianjin, and Shandong Province, etc., while the low layer was only affected by Beijing's local pollution source. The computational results of power spectra and periods preliminarily reveal that under the condition of calm weather, the periods of PM10 concentration at various heights of the tower were on the order of minutes, while in cases of larger wind speed, the concentrations of PM2.5 and PM10 at 320 m height not only had the short periods of minute-order, but also the longer periods of hour order. Consistent with the conclusion previously drawn by Ding et al., that air pollutants at different heights and at different sites in Beijing had the character of "in-phase" variation, was also observed for the diurnal variation and mean diurnal variation of PM2.5 and PM10 at various heights of the tower in this experiment, again confirming the "in-phase" temporal/spatial distributive character of air pollutants in the urban canopy of Beijing. The gentle double-peak character of the mean diurnal variation of PM2.5 and PM10 was closely related with the evident/similar diurnal variation of turbulent momentum fluxes, sensible heat fluxes, and turbulent kinetic energy at various heights in the urban canopy. Besides, under the condition of calm weather, the concentration of PM2.5 and PM10 declined with height slowly, it was 90% of 8 m concentration at the low layer, a little lesser than 90% at the middle layer, and 80% at the high layer, respectively. Under the condition of weak cold air weather, the concentration remarkably dropped with height, it was 70% of 8 m concentration at the low layer, and 20%―30% at the middle and high layers, especially the concentration of PM2.5 was even lower.

Multi-type sensor placement and response reconstruction for structural health monitoring of long-span suspension bridges

This study is devoted to the experimental validation of the multi-type sensor placement and response reconstruction method for structural health monitoring of long-span suspension bridges. The method for multi-type sensor placement and response reconstruction is briefly described. A test bed, comprising of a physical model and an updated finite element(FE) model of a long-span suspension bridge is also concisely introduced. The proposed method is then applied to the test bed; the equation of motion of the test bed subject to ground motion, the objective function for sensor location optimization, the principles for mode selection and multi-type response reconstruction are established. A numerical study using the updated FE model is performed to select the sensor types,numbers, and locations. Subsequently, with the identified sensor locations and some practical considerations, fiber Bragg grating(FBG) sensors, laser displacement transducers, and accelerometers are installed on the physical bridge model. Finally, experimental investigations are conducted to validate the proposed method. The experimental results show that the reconstructed responses using the measured responses from the limited number of multitype sensors agree well with the actual bridge responses.The proposed method is validated to be feasible and effective for the monitoring of structural behavior of longspan suspension bridges.

治理与规管——试析如何走出医疗卫生改革困境

本文认为，治理与规管的研究是中国目前医疗卫生研究的薄弱环节，需要特别引起重视。文章从基本卫生与新医新药的双轨制造成治理和规管的难题入手，运用规管的视角，分析了投入不足、医疗保险低覆盖、药品和医疗机械价格不合理、公立医院的体制障碍和卫生行政部门监管不力等5个使医疗卫生陷入困境的论点，提出放弃治理与规管不但导致所有的现行问题更加严重，而且也使修正的行为变得没有意义或具负面效应。最后，作者讨论了中国规管失效的一般性原因，提出建立独立于行政机构的公立卫生服务规管机构可能是推进中国医疗卫生公平、实现全民初级卫生保健的一种规范性选择。

Synthesis,Crystal Structure,Fluorescence Property and Antibacterial Activity of Two Unprecedented One-dimensional Chain Metal-organic Coordination Polymers: Zn(H-SSA)(Phen)(H_2O)_2and Cu(H-SSA)(Phen)(H_2O)_2

The reaction of 5 sulfosalicylic acid (H 3 SSA) with o phenanthroline (Phen), NaOH, and MCl 2 (M=Zn, Cu) affords Zn(H SSA)(Phen)(H 2O) 2 (1) and Cu(H SSA)(Phen)(H 2O) 2 (2), respectively. Compounds 1 and 2 are characterized by elemental analysis, IR, fluorescence spectra and single crystal X ray diffraction analysis. The X ray diffraction analyses reveal that compounds 1 and 2 are isostructure. The 5 sulfosalicylic acid ligand loses two protons at the sulfo group and carboxylic group during the reaction. The Zn(II) and Cu(II) ions are six coordinated and adopt distorted octahedral geometry, which are surrounded by two N atoms from Phen, two O atoms from two water molecules, one O atom from —SO 3 group and one oxygen from carboxylic group of the other H SSA. Compounds 1 and 2 have unprecedented one dimensional linear chain formed by a repeating mononuclear structural unit, which is bridged by H SSA. The fluorescence intensity of 1 and 2 is stronger than that of Phen and H 3 SSA at 400 nm. The lowest excited single states of these complexes are assigned as mainly Phen localized 1(π,π *). The antibacterial activity test shows that compounds 1 and 2 strongly inhibit the growth of Streptococcus haemolyticus, Straphylococcus aureus and Escherichia coli .

LARGE EDDY SIMULATION OF VERTICAL JET IMPINGEMENT WITH A FREE SURFACE

The flow characteristics of a 2D slot jet vertically impinging on free surfaces are numerically investigated by the Large Eddy Simulation （LES） with a dynamic Sub-Grid Scale （SGS） model. The σ-coordinate transformation is introduced to map the depth-variable physical domain to a depth-uniform computational domain. The split-operator scheme, which splits the solution procedure into advection, diffusion and pressure propagation steps, is employed to solve the instantaneous velocity and pressure field. A fully nonlinear Lagrange-Euler method is used to compute the free surface elevation. The numerical results show that the jet retains good self-similarity in the Zone of Eestablished Flow （ZEF）, while the turbulence of jet shifts gradually from isotropic to anisotropic in the Zone of Surface Impingement （ZSI）. When the jet approaches the free surface, the centerline velocity decreases rapidly and the flow is deflected by the free surface. Two symmetrical surface jets are formed in the Zone of Horizontal Jets （ZHJ）. An approximate Guassian distribution of super-elevation is also formed on the free surface. The computed results are in good agreement with the available experimental data.

Stepped chirped fiber Bragg grating encoder/decoder for spectral OCDMA

Based on the coupled-mode theory of fiber grating and codes theory, the design of an optical code division multiple access (OCDMA) encoder/decoder with stepped chirped fiber Bragg grating (SCFBG) has been proposed. The length of each uniform subgrating, the realization of encoding and decoding are provided. Numerical result is also presented and discussed.

THE STRUCTURE-PRESERVING METHODS FOR THE DEGASPERIS-PROCESI EQUATION

This paper gives several structure-preserving schemes for the Degasperis-Procesi equation which has bi-Hamiltonian structures consisted of both complex and non-local Hamiltonian differential operators. For this sake, few structure-preserving schemes have been proposed so far. In our work, based on one of the bi-Hamiltonian structures, a symplectic scheme and two new energy-preserving schemes are constructed. The symplecticity comes straightly from the application of the implicit midpoint method on the semi-discrete system which is proved to remain Hamiltonian, while the energy conservation is derived by the combination of the averaged vector field method of second and fourth order, respectively. Some numerical results are presented to show that the three schemes do have the advantages in numerical stability, accuracy in long time computing and ability to preserve the invariants of the DP equation.

Post-disaster Psychosocial Capacity Building for Women in a Chinese Rural Village

Mental health interventions following disasters have been criticized as individualistic, incomplete, and culturally insensitive. This article showcases the effects of a culturally relevant and sustainable psychosocial capacitybuilding project at the epicenter of the 2008 Wenchuan Earthquake. Specifically, the project focuses on women, a group that has received limited attention in post-disaster recovery in China. This qualitative research study(N = 14)sheds light on the characteristics and processes of the implementation of a post-disaster psychosocial intervention project in rural China. In addition, by adopting the Success Case Method as an evaluation approach, this study elucidates its effects on the psychological and social changes of the disaster victims. The findings capture five aspects of psychosocial changes: enriched daily life, better mood,enhanced self-confidence, increased willingness to socialize, and the provision of mutual help. This study hopes to encourage more culturally relevant and empowering practices for women in building their psychosocial capacity after disasters.