歌唱不足故‘叫喊’之——戏曲唱论七题

演唱列戏曲“四功”(唱、念、做、舞 )“五法”(口、眼、手、身、步 )之首 ,足见其在戏曲———综合艺术中的无比重要性。今仍传世的各个戏种的演唱 ,又多与民间 (歌曲、说唱的 )歌唱艺术有着直接的千丝万缕的传承关系 ,即今之绝大多数的戏曲演唱 ,确属华夏口语音乐中歌唱艺术的集大成者。若将其进行文语性耙梳 ,对中华民族歌唱艺术理论体系构建的最终完成 。

Intensification of levofloxacin sono-degradation in a US/H_2O_2 system with Fe_3O_4 magnetic nanoparticles

Fe3O4 magnetic nanoparticles(MNPs) were synthesised, characterised, and used as a peroxidase mimetic to accelerate levofloxacin sono-degradation in an ultrasound(US)/H2O2 system. The Fe3O4 MNPs were in nanometre scale with an average diameter of approximately 12 to 18 nm. The introduction of Fe3O4 MNPs increased levofloxacin sono-degradation in the US/H2O2 system. Experimental parameters, such as Fe3O4 MNP dose, initial solution p H, and H2O2 concentration, were investigated by a one-factor-at-a-time approach. The results showed that Fe3O4 MNPs enhanced levofloxacin removal in the p H range from 4.0 to 9.0. Levofloxacin removal ratio increased with Fe3O4 MNP dose up to 1.0 g·L-1and with H2O2 concentration until reaching the maximum. Moreover, three main intermediate compounds were identified by HPLC with electrospray ionisation tandem mass spectrometry, and a possible degradation pathway was proposed. This study suggests that combination of H2O2, Fe3O4 MNPs and US is a good way to improve the degradation efficiency of antibiotics.

Estimation of suspended sediment concentrations using Pulse-coherent Acoustic Doppler Profiler (PCADP)

The objective of the study is to investigate the suitability of using Pulse-coherent Acoustic Doppler Profiler (PCADP) to estimate suspended sediment concentration (SSC). The acoustic backscatter intensity was corrected for spreading and absorption loss, then calibrated with OBS and finally converted to SSC. The results show that there is a good correlation between SSC and backscatter intensity with R value of 0.74. The mean relative error is 22.4%. Then the time span of little particle size variation was also analyzed to exclude the influence of size variation. The correlation coefficient increased to 0.81 and the error decreased to 18.9%. Our results suggest that the PCADP can meet the requirement of other professional instruments to estimate SSC with the errors between 20% and 50%, and can satisfy the need of dynamics study of suspended particles.

Internal solitary waves on the southwest shelf of Dongsha Island observed from mooring ADCP

Internal solitary waves （ISWs） are frequently observed in the area between Dongsha Island （DI） and Taiwan Island. However, there have been few in-situ observations southwest of DI. To improve our knowledge of ISWs in this area, we observed the ISWs over the continental shelf （115.4°E, 20.3°N） from Aug. 29 to Oct. 10, 2011 with temperature sensors and an acoustic Doppler current profiler （ADCP）. The observations showed that the a fully developed ISW produced a current whose maximum westward velocity was 0.92 rrds and maximum northward velocity was 0.47 m/s. During the 41-day observation period the ISWs appeared for three periods with about 7-day gaps between each period. During each day, two types of ISWs were observed. The first type of wave arrived regularly diurnally at the same time each day, with a similar pattern to that of the type-a wave identified by Ramp et al. （2004）. The second type arrived about 12 h after the first type and was delayed about 1 hour each day; this wave type was related to the type-b wave. Thus, our observations confirmed that both type-a and type-b waves can reach the area southwest of the DI. Moreover, the waves observed by the mooring propagated toward the directions of 270°-315° clockwise from true north, indicating obvious refraction from uneven topography around DI.

Inversion of river-bottom sediment parameters using mechanically sampled specimens and subbottom profiling data

The study of river dynamics requires knowledge of physical parameters, such as porosity, permeability, and wave propagation velocity, of river-bottom sediments. To do so, sediment properties are determined on mechanically sampled specimens and from subbottom profiling. However, mechanical sampling introduces disturbances that affect test results, with the exception of grain-size distribution. In this study, we perform inversion of acoustic data using the grain-size distribution of mechanically sampled specimens and the relation between porosity and permeability from the Kozeny-Carman equation as prior information. The wave reflection coefficient of the water-silt interface is extracted from the raw subbottom profile. Based on the effective density fluid model, we combine the Kozeny-Carman equation and the wave reflection coefficient. We use experimental data from two Yellow River reservoirs to obtain the wave velocity and density of multiple sections and their spatial variations, and find that the inversion and testing results are in good agreement.

Ultrasonic Studies of 4-Aminobutyric Acid in Aqueous Salbutamol Sulphate Solutions at Different Temperatures

Ultrasonic speeds of 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·kg^-1 aqueous salbutamol sulphate（SBS） solutions are measured at 308.15,313.15 and 318.15 K.Isentropic compressibility kS,change in isentropic compressibility△k S,relative change in isentropic compressibility（ △kS /kS^0） ,apparent molal compressibility kφ,limiting apparent molal compressibility kφ^0 ,transfer limiting apparent molal compressibility k φ^0,hydration number nH,pair and triplet interaction parameters kAS,kASS are estimated.The above parameters are used to interpret the solute-solute and solute-solvent interactions of 4-aminobutyric acid in the aqueous salbutamol sulphate solutions.

Parameter estimation of sediment in the Yellow River based on the porous medium acoustic theory

Presently,the use of sub-bottom profiler sonar signals is limited to inversing the physical parameters of the sediment in the surface layer(first layer).In this study,based on the acoustic theory of porous medium,the acoustic inversion of the physical parameters of the lower layer(second layer)sediment is studied.When acoustic waves propagate in water and sediment media,interlayer reflection and transmission,intralayer attenuation,and other processes change the energy.The reflection and transmission coefficients of acoustic waves incident perpendicularly to the water–sediment and sediment–sediment interfaces are derived,and the effects of the reflection and transmission process of acoustic waves on the amplitude are quantified.The relationship between the frequency shift and relaxation time of the transmitted signal in different particle size sediments is established to estimate the corresponding attenuation coefficient using the frequency shift of each layer signal.On this basis,combined with the diffusion process of acoustic waves,the equation for extracting the acoustic wave reflection and transmission coefficients of each layer at the interface is derived from the measured sonar signal.Further calculations show that the sediment parameters have a greater influence on the reflection coefficient,and the feasibility of calculating the physical parameters of the lower sediment using the reflection coefficient has been proved.Under the premise of obtaining the physical parameters of surface sediment,this study provides specific methods and steps for inverting the physical parameters of the lower sediment.The on-site detection in the Xiaolangdi reservoir area of the Yellow River,combined with the sediment sampling test results,proved that the proposed method of inversion of the lower sediment parameters based on the porous medium acoustic theory is feasible.

Airflow patterns upwind of obstacles and their significance for echo dune formation:A field measurement of the effects of the windward slope angle

The velocities in front of five topographic obstacles with windward slope angles between 45~ and 80~ were measured using ul- trasonic anemometers in the field at the southeastern margin of the Tengger Desert. The characteristics of the horizontal and vertical velocities indicated that the airflow pattern was significantly influenced by the ohstacle＇s windward slope angle. The horizontal flow decelerated but the vertical flow accelerated upwind of the obstacles when the windward slope was less than 60~, but a reversed flow formed in front of steeper obstacles. The size of the area occupied by the reversed horizontal compo- nent increased with increasing windward slope, but the region of reversed vertical velocity became narrower and taller. Air- flow turbulence was strengthened as the wind approached the obstacle, and low-frequency high-energy velocity fluctuations were observed upwind of the obstacle, and could affect the entrainment and saltation processes of sand particles. Turbulence intensities for both the horizontal and vertical components of the airflow increased with increasing windward slope and with decreasing distance from the obstacle. The deceleration and downward movement of airflow upwind of the obstacle would re- sult in supersaturation of the air-sand flow, leading to deposition of moving sand, and these deposited grains would become the material basis for the formation of echo dunes. The reversed airflow would both determine the initial position of the echo dune and provide the necessary motive power to subsequently shape the echo dune.