In-situ characterization of gas-liquid precipitation reaction in a spray using rainbow refractometry

Gas-liquid precipitation reactions in terms of a spray exist widely in energy, chemical, and environmental engineering. In this paper, a rainbow refractometry-based method is used to measure the reaction process of these spray-based gas-liquid precipitation reactions in a non-intrusive way. Rainbow refractometry can simultaneously provide information on thermochemical and physical properties of droplets. A global rainbow measurement system was built to characterize a CO₂ absorption reaction. Rainbow signals of spray droplets of Ca(OH)₂ solutions before and after CO₂ absorption were recorded and processed. Results indicated that the average refractive index of saturated H₂O-Ca(OH)₂ solution was 1.335 69, which accorded with the Abbe measurement. After the absorption reaction, the refractive index of droplets decreased to 1.335 17 which is close to that of water. The reaction extent was therefore reflected in the change of the refractive index of droplets. An extra experiment of CO₂ absorbed by Ba(OH)₂ solutions was conducted. The refractive index of droplets decreased with the reaction process, which acted well as an evolution indicator of the reaction. A heat transfer analysis of the reaction was also carried out. Due to the high heat dissipation performance of fine droplets, the temperature increase in the measurement volume was estimated to be less than 0.61 K, which has almost no effect on the measured results. The rainbow refractometry-based method shows good potential for in-situ characterization of a gas-liquid precipitation reaction.     

托马斯·斯当东与马戛尔尼使团使华

文章回顾了乔治·托马斯·斯当东（George Thomas Staunton）在英国马戛尔尼使团使华过程中的活动,重点论述了随同该使团使华对斯当东一生的影响,旨在引起史学界对这位曾在中英关系史上产生过重要影响的英国中国问题专家的关注。     

Fluorescence Properties of Eu^3＋：Y2SiO5 Single Crystal

Fluorescence properties of Eu^3 :Y2SiO5 have been investigated.Transitions between ^5D and ^7Fwere were studied with transmission spectra,fluorescence spectra,photoluminescence excitation(or absorption) spectra and site selective fluorescence spectra.The X-ray powder diffraction pattern of Eu^3 :Y2SiO5 shows that the crystal belong to monoclinic,and lattice‘s constants a,b,c and β arc obtaned by a simulation with the measured diffraction angles.     

Expression of a fusion protein of human ciliary neurotrophic factor and soluble CNTF-Receptor and identification of its activity

INTRODUCTIONCiliaryneurotrophicfactor (CNTF)isanat urallyoccurringproteinwithamolecularmassofapproximately 2 2kDa .Itisexpressedinglialcellswithinthecentralandperipheralnervoussystems.CNTFstimulatesgeneexpression ,cellsurvivalordifferentiationinavarietyof…     

Study on the Mathematical Model of Hydraulic Jump Atomization

An equation of atomization quantity from energy dissipation by hydraulic jump was derived from the dimensional analysis. By applying Gauss diffusion equation, the spray diffusion rule in valley was studied under the condition of continuous linear source and random wind direction. By considering the spray-rain switching process, coagulation, condensation and evaporation of droplets, the air temperature, air relative humidity,spray density and the rainfall intensity in the lower reaches of the linear source were calculated. The 3-D numerical simulation fitted well with prototype monitoring. Finally, the prediction of atomization influence on environments for Xiangjiaba Hydropower Station was conducted.     

A Conceptual Model (The Six Mirrors of the Classroom) and It’s Application to Teaching and Learning About Microorganisms

In this paper a conceptual model of instruction “the six mirrors of the classroom” used as a frame for teaching a learning topic, the microorganisms are depicted. The paper consists of four sections: (a) the six mirrors of the classroom model (SMC); (b) the SMC as implemented in the expository and cooperative modes of instruction in classrooms and results; (c) a “Journey of Inquiry into the Wonderful World of Microorganisms” (JIWWM), developed according to the Science–Technology–Environment–Peace–Society (STEPS) approach; and (d) teaching and learning the JIWWM, in ninth-grade classes, within the SMC model. The results show that science topic can be taught in the frame of the mirrors of the classroom. When the instructional goals of the teachers used the mirror “1, classroom organization” and mirror “6, pupils’ social behavior” and the third ring around the all six mirrors cooperative skills were practiced, academic outcomes were achieved, and attitudes toward environmental preservation and peace improved. The SMC model can serve as a valuable tool for teachers, since it can design their teaching and learning settings in a more controlled environment, in terms of objectives, teachers’ and students’ social behaviors, and academic outcomes.     

Liquid film dryout model for predicting critical heat flux in annular two-phase flow

Gas-liquid two-phase flow and heat transfer can be encountered in numerous fields, such as chemical engineering, refrigeration, nuclear power reactor, metallurgical industry, spaceflight. Its critical heat flux （CHF） is one of the most important factors for the system security of engineering applications. Since annular flow is the most common flow pattern in gas-liquid two-phase flow, predicting CHF of annular two-phase flow is more significant. Many studies have shown that the liquid film dryout model is successful for that prediction, and determining the following parameters will exert predominant effects on the accuracy of this model： onset of annular flow, inception criterion for droplets entrainment, entrainment fraction, droplets deposition and entrainment rates. The main theoretical results achieved on the above five parameters are reviewed; also, limitations in the existing studies and problems for further research are discussed.     

Undercooling and Solidification of Sn—Pb Alloy Droplets Prepared by Uniform Droplet Spray

The undercooling and solidification of 150μm and 185μm droplets of Sn-5%Pb alloy prepared by the uniform droplet spray(UDS) process have been investigated.The enthalpy of the droplet has been measured by non-adiabatic calorimetric method as a function of the flight distance.A droplet solidification simulation model has been used to compare with the experimental data.The results show that the enthalpy released by the droplets in the calorimeter 11.88J/g and 22.29J/g less than the simulated values up to a certain flight distance at 0.485m and 0.460m for 150μm and 185μm droplets respectively,but agrees with the expected values at larger distance.The nucleation of the droplets takes place at the distance where the experimental and simulated enthalpy values agree.The droplets quenched before nucleation solidify into metastable supersaturated solid solution and have large undercooling.The formation of the metastable structure in the droplets has been verified metallographically and by calculations based on a thermodynamic model.     

Raman crystal lasers in the visible and near-infrared

Raman lasers based on potassium gadolinium tungstate and lead tungstate crystals pumped bya≈120 ps Nd: YAG laser at 1.064 μm were developed. High reflection mirrors for the Stokes wavelength have been used to generate near-infrared and eye safe spectral region of 1.15–1.32 μm. Second harmonic generation of the generated Raman lasers was observed. Eifficient multiple Stokes and anti-Stokes picosecond generation in 64 crystals have been shown to exhibit stimulated Raman scattering on about 700 lines covering the whole visible and near-infrared spectrum. All stimulated Raman scattering (SRS) wavelengths in the visible and near-infrared spectrum are identified and attributed to the SRS-active vibration modes of these crystals.     

美国驻日本大使馆对1975年金日成访华的反应

朝鲜半岛对日本国家安全具有十分重要的意义。1975年4月,在印度支那革命迅速发展之际,金日成率领朝鲜党政代表团访问中国。这引起了日本的高度关注。日本主要担心朝鲜和平统一半岛的政策若发生变化,势必对日本安全造成重大影响。而日本盟友美国亦十分重视关乎日本安全的朝鲜半岛局势的变动。美国驻东京大使馆一方面评论日本对金日成访华的认知,另一方面密切关注日本探寻金日成访华的详情。而且,美国驻日使馆还从第三方外交机构收集有关金日成访华的信息。在获得大量信息的基础上,美国驻日使馆的评估为福特政府对朝鲜半岛形势的判断提供了重要的参考意见,并为美国维持对朝鲜半岛政策现状提供了更充分的依据。     

CFD simulation with enhancement factor of sulfur dioxide absorption in the spray scrubber

A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model. A continuous concentration change ofH＋ was solved by iterative coupling using Matlab, and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption. The calculations show that the enhancement factor exponentially grows with an increasing value ofpH and logarithmically decays with an increasing value of the driving force. To verify the accuracy of the model, experiments were also carried out, and the results suggest that the model, after combining the physical performance of the spray and the enhancement factor, can more precisely describe SO2 absorption in a spray scrubber. Furthermore, a commercial computational fluid dynamics （CFD） tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption. The results of numerical simulation can provide a basis for further design and optimization of the scrubber.     

国民政府时期中日地方层面交涉模式——以“平潭惨案”为例

中日双方交涉具有层面性。＂平潭惨案＂发生后,国民政府采取地方层面交涉模式反复交涉于日本驻华领事;日本驻华领事则独当一面,在中日交涉中发挥着主力作用。地方层面交涉模式有利于防止事件升级,确保双方关系的稳定。然而,随着中日矛盾激化,这一模式难以适应日益紧张的中日关系,国民政府被迫转换外交策略,地方层面交涉处理危机的模式随之寿终正寝。     

罗丹明6G与金纳米微粒相互作用的光谱特征

研究了罗丹明6G与金纳米微粒相互作用的RRS光谱、荧光光谱和吸收光谱的特征,发现:当体系中存在过量的罗丹明6G染料时,金纳米微粒在一定的浓度范围内分别与体系的RRS强度、荧光强度、吸光度成正比,且灵敏度高,其检出限达到纳克级.由此,可以建立RRS法、荧光猝灭法、吸收光度法来测定溶液中的金纳米微粒.     

Refined empirical line method to calibrate IKONOS imagery

INTRODUCTION To extract quantitative biophysical parameter such as leaf biomass and leaf chlorophyll concentra- tion from the remotely sensed imagery accurately, the effects of atmospheric scattering and absorption must be removed. Atmospheric effects add to or diminish true ground reflectance, if the atmospheric spectral features are not properly removed. A significant analytical bias could be introduced for data interpre- tation (Ben-Dor and Levin, 2000). Many approaches have been deve…     

English phonological specificity predicts early French reading difficulty in emerging bilingual children

The purpose of the present study was to examine the predictive value of a dynamic test of English and French lexical specificity on at-risk reading classification in 13 at-risk and 44 not at-risk emerging English (L1)–French (L2) bilingual Grade 1 children (M = 75.87 months, SD = 3.18) enrolled in an early French immersion program in Canada. Lexical specificity was assessed with a computerized word learning game in which children were taught new English (e.g., “foal” and “sole”) and French (e.g., bac “bin” and bague “ring”) word pairs contrasted by minimal phonological differences. The results indicated that the dynamic test of lexical specificity in English contributed significantly to the prediction of children’s French at-risk reading status at the end of Grade 1 after controlling for French phonological awareness and nonverbal reasoning skills. However, French lexical specificity did not predict children’s reading risk classification in French after controlling for French phonological awareness. Thus, it may be feasible to identify at-risk status in emerging bilinguals using dynamic measures in their stronger language.     

Effects of pH and<Emphasis Type="Italic">Eh</Emphasis> on release of nitrogen and phosphorus from sediments of West Lake

The effects of pH andEh on release of nitrogen and phosphorus from sediments of West Lake under different conditions were investigated by simulation test. Results showed that the net flux of NH₄ ⁺-N release from sediments increased with pH, but NO₃ ⁻-N showed negative-going release at all tested pH levels. The net flux of NH₄ ⁺-N release from sediments was higher under anaerobic or aerobic condition of the overlying water, but only under aerobic condition would net release of NO₃ ⁻-N occur. It was also shown that phosphorus released was mainly in its inorganic form, higher pH and anaerobic conditions of overlying water greatly stimulated release of phosphorus. In situ measurement at several West Lake locations indicated that sediment resuspension induced by boat propeller stimulated nutrients release from sediment into overlying water. Project (No.294059) supported by National Natural Science Foundation of Zhejiang Province, China     

圆柱坐标系下用于FDTD的总场-散射场连接边界条件研究

在三维柱坐标系下给出了麦克斯韦方程在完全匹配层(PML)吸收边界条件中的时域有限差分(PDTD)表达式,从而把FDTD推广到三维复柱坐标系中并加以实现.为了模拟柱面波在空间的传播,给出了在柱坐标系下完整的总场和散射场的连接边界条件.最后,模拟了柱面波在自由空间中的传播及空心圆柱体在柱面波入射下的近场和远场散射特性.     

Simulation of sludge blanket height in clarifiers

Sludge blanket height (SBH) is an important parameter in the clarifier design, operation and control. Based on an overview and classification of SBH algorithms, a modified SBH algorithm is proposed by incorporating a threshold concentration limit into a relative concentration sharp change algorithm to eliminate the disturbance of compression interfaces on the correct simulation of SBH. Pilot-scale test data are adopted to compare reliability of three SBH algorithms reported in literature and the modified SBH algorithm developed in this paper. Calculated results demonstrate that the three SBH algorithms give results with large deviation (> 50%) from measured SBH, especially under low solid flux conditions. The modified algorithm is computationally efficient and reliable in matching the measured data. It is incorporated into a one-dimensional clarifier model for stable simulation of pilot-scale experimental clarifier data and into dynamic simulation of a full-scale wastewater treatment plant (WWTP) clarifier data. Project supported by the National Natural Science Foundation of China (Grant No.501380107)     

马戛尔尼使团与天津

在马戛尔尼使团访华的过程中,天津始终是其关注的焦点和活动中心之一:从殚精竭虑地要在天津登岸到对天津细致入微地观察,直至不遗余力地谋求在天津开埠。对该使团与天津的不解之缘进行历史回顾和反思显然是不无裨益的。     

马戛尔尼使团与天津

在马戛尔尼使团访华的过程中,天津始终是其关注的焦点和活动中心之一：从殚精竭虑地要在天津登岸到对天津细致入微地观察,直至不遗余力地谋求在天津开埠.对该使团与天津的不解之缘进行历史回顾和反思显然是不无裨益的.