有气流扰动下管流油水混合物粘度实验测量与计算模型

采用局部即时取样方法对水平管内油气水三相流动情况下各种混合比例的复杂混合物的流动粘度进行了实验研究,实验工质采用46号机械油、自来水和空气。以实验数据为基础提出了考虑流动参数变化影响的反相点预测关联式。考虑到管内油水两相的混合发展过程,以局部即时取样的实验数据为基础,提出了一个气流扰动下管内流动条件下油水混合物粘度的预测关系式,该模型考虑了油水两相本身的物性以及流动因素的影响。指出考虑流动参数影响的粘度预测模型能大大提高油气水三相流动情况下油水混合物实测粘度的预测精度。

环境中的抗生素与毒物兴奋效应综述

对毒物兴奋效应的出现、作用机制、普遍性及其对风险评估的影响,以及从细菌、藻类、植物、动物等不同水平对抗生素的毒物兴奋效应进行综述;并对该领域的研究进行总结和展望。

多种环境雌激素对淡水鱼联合毒性作用的预测和评价

为预测和评价多种环境激素对生物的联合毒性效应,通过对雄性鲫鱼卵黄蛋白原诱导作用探讨了17β-雌二醇、17α-乙炔基雌二醇、双酚A、辛基苯酚等几种环境雌激素联合作用的环境影响.确定了每种化合物的剂量-效应曲线,混合物由单个化合物等毒性固定浓度比例混合而成,实验得出的混合物效应与通过浓度相加或反应相加作用模型计算得出的混合物效应比较,结果有很好的一致性.上述结果证明了类雌激素化合物呈现相加作用方式,即使在单独作用无显著效应的较低浓度下也可产生显著的混合物效应,混合物效应可通过两类模型预测.由于环境污染物组成往往不明确,通过浓度相加作用模型预测的结果较为保守,在环境风险评价中更加实用.

Bayesian analysis for mixed-effects model defined by stochastic differential equations

The nonlinear mixed-effects model with stochastic differential equations （SDEs） is used to model the population pharmacokinetic （PPK） data that are extended from ordinary differential equations （ODEs） by adding a stochastic term to the state equation. Compared with the ODEs, the SDEs can model correlated residuals which are ubiquitous in actual pharmacokinetic problems. The Bayesian estimation is provided for nonlinear mixed-effects models based on stochastic differential equations. Combining the Gibbs and the Metropolis-Hastings algorithms, the population and individual parameter values are given through the parameter posterior predictive distributions. The analysis and simulation results show that the performance of the Bayesian estimation for mixed-effects SDEs model and analysis of population pharmacokinetic data is reliable. The results suggest that the proposed method is feasible for population pharmacokinetic data.

Nephelauxetic-Effect in DMS Zn_(1-x)Co_xSe and Effect of Pressure on Nephelauxetic-Effect

Based on the 3D electron's radial wave function of Co 2+ free ion,a Nephelauxetic effect modifying factor to modify the radial wave function is introduced when Co 2+ cations are put into the crystal field of Zn 1-x Co x Se.With the modified wave functions,the optical transitions for Zn 1-x Co x Se crystals are calculated.Moreover,based on the first principle of physics,the influences of high pressure to the Nephelauxetic effect modifying factor is considered,and the high pressure blue shift for the Zn 1-x Co x Se crystal absorption spectra are calculated and a shift rate of d E /d p =0 45meV/GPa is obtained.

Ba（d）^o-Ba（d）^o Mixing and New Physics Effects in a Top Quark Two-Higgs Doublet Model

We calculate the new physics contributions to the neutral Bd^o and Ba^o meson mass splitting △Md and △Ma induced by the box diagrams involving the charged-Higgs bosons in the top quark two-Higgs doublet model （T2HDM）. Using the precision data, we obtain the bounds on the parameter space of the T2HDM： （a） For fixed MH = 400 GeV and 5= [0°, 60°], the upper bound on tan β is tan β≤ 30 after the inclusion of major theoretical uncertainties; （b） For the case of tan β≤ 20, a light charged Higgs boson with a mass around 300 GeV is allowed; and （c） The bounds on tan β and MH are strongly correlated： a smaller （larger） tan β means a lighter （heavier） charged Higgs boson.

ELUTION OF TUNGSTEN BY SODIUM COMPOUNDS AND ACCELERATION EFFECTS OF COEXISTENT COUNTER IONS IN MIXED ELUANT

The elution of WO ions by NaOH. NaNO3 NaCl and NH4Cl on strong basicanion exchange resins in quaternary ammonium form I and the adsorption properties after elution were studied. In addition, the elution curse, the permeation curveand the exchange capacities of operation were presented. The eluate containingtungsten with high content and excessive eluant of low content were obtained by employing the process of eluting using mixed solution of NaCl and NaOH. It's possible to obtain Na2WO4. 2H2O with high purity by evaporating and crystallizing theeluate. The results of mixed elution showed that the diffusion coefficients of Cl-.OH- and WO ions in solution or exchange agent varied due to the coexistence ofcounter ions and then the exchange velocity of WO→Cl- and WOe→OH- wasaccelerated.

CO_2/N_2 separation using supported ionic liquid membranes with green and cost-effective [Choline][Pro]/PEG200 mixtures

The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.

Characteristics of fungal community structure during the decomposition of mixed foliage litter from Pinus massoniana and broadleaved tree species in southwestern China

Aims The conifer litter is fairly recalcitrant and nutrient poor,and broadleaved litter promotes coniferous litter decomposition by increasing degradable nutrients and promoting microbial metabolism.Mixing Pinus massoniana litter and three broadleaved litters may increase the diversity and abundance of fungal decomposers compared with those in P.massoniana litter and vary depending on the number and proportion of broadleaved species included.Methods We analysed the composition and diversity of fungal communities during mixed litter decomposition in southwestern China with 35 treatments(P.massoniana,Toona sinensis,Cinnamomum camphora and Sassafras tzumu litter)using Illumina high-throughput sequencing.Important Findings The mixed litters increased fungal diversity and richness compared with those in the single-species litter,except in the following treatments:P.massoniana litter accounting for 70%-80%in the P.massoniana+T.sinensis,P.massoniana+S.tzumu+T.sinensis and P.massoniana+S.tzumu+C.camphora combinations,and P.massoniana+S.tzumu+C.camphora+T.sinensis combination with small proportion of T.sinensis litter.The diversity and richness of the 7:1:2 combination of P.massoniana+C.camphora+T.sinensis were significantly higher than those in the other treatments.Ascomycota and Basidiomycota were the dominant phyla,and Aspergillus was the most abundant genus.The decomposition of litters from one needleleaf and one broadleaved species(6:4)and one needleleaf species and two broadleaved species(broadleaved litter accounting for 30%-40%)exhibited synergistic interactions throughout the decomposition process,and the relative abundance of fungi that decompose refractory substances increased.The P.massoniana+C.camphora+T.sinensis combination and a 30%-40%broadleaf litter proportion increased fungal diversity and accelerated the decomposition of recalcitrant coniferous litter.Therefore,C.camphora and T.sinensis are a potential candidate species for mixed planting with P.massoniana.

Facing different predators： adaptiveness of behavioral and morphological traits under predation

Predation is thought to be one of the main structuring forces in animal communities. However, se- lective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured be- havioral and morphological traits in young-of-the-year Eurasian perch Perca fluviatilis and com- pared their selective values in response to the 2 most common predators, adult perch and pike Esox lucius. Using mixed effects models and model averaging to analyze our data, we quantified and compared the selectivity of the 2 predators on the different morphological and behavioral traits. We found that selection on the behavioral traits was higher than on morphological traits and perch predators preyed overall more selectively than pike predators. Pike tended to positively se- lect shallow bodied and nonvigilant individuals （i.e. individuals not performing predator inspec- tion）. In contrast, perch predators selected mainly for bolder juvenile perch （i.e. individuals spend- ing more time in the open, more active）, which was most important. Our results are to the best of our knowledge the first that analyzed behavioral and morphological adaptations of juvenile perch facing 2 different predation strategies. We found that relative specific predation intensity for the di- vergent traits differed between the predators, providing some additional ideas why juvenile perch display such a high degree of phenotypic plasticity.

Feasibility of Pulse Combustion in Micro Gas Turbines

In gas turbines, a fast decrease of efficiency appears when the output decreases; the efficiency of a large gas tur-bine （20...30 MW） is in the order of 40 %, the efficiency of a 30 kW gas turbine with a recuperator is in the order of 25 %, but the efficiency of a very small gas turbine （2...6 kW） in the order of 4...6 % （or 8... 12 % with an op- timal recuperator）. This is mainly a result of the efficiency decrease in kinetic compressors, due to the Reynolds number effect. Losses in decelerating flow in a flow passage are sensitive to the Reynolds number effects. In con- trary to the compression, the efficiency of expansion in turbines is not so sensitive to the Reynolds number; very small turbines are made with rather good efficiency because the flow acceleration stabilizes the boundary layer. This study presents a system where the kinetic compressor of a gas turbine is replaced with a pulse combustor. The combustor is filled with a combustible gas mixture, ignited, and the generated high pressure gas is expanded in the turbine. The process is repeated frequently, thus producing a pulsating flow to the turbine; or almost a uni- form flow, if several parallel combustors are used and triggered a/ternately in a proper way. Almost all the com- pression work is made by the temperature increase from the combustion. This gas turbine type is investigated theoretically and its combustor also experimentally with the conclusion that in a 2 kW power size, the pulse flow gas turbine is not as attractive as expected due to the big size and weight of parallel combustors and due to the ef- ficiency being in the order of 8 % to 10 %. However, in special applications having a very low power demand, below 1000 W, this solution has better properties when compared to the conventional gas turbine and it could be worth of a more detailed investigation.