三级流动式活性焦工艺在污水厂提标中的应用研究

采用三级流动式活性焦工艺处理污水厂生化出水,水料比为20 m^3/t·d时,处理周期为40 d,处理出水可从《城镇污水处理厂污染物排放标准》(GB 18918-2002)中的三级排放标准提升至一级A排放标准。本工艺具有较强的耐冲击负荷能力,相对稳定的出水水质,具备良好的应用价值。

表面活性剂水溶液弹性湍流特性实验研究

弹性湍流是本世纪初发现的一种新的流动现象,发生在具有弯曲流线的粘弹性流体低雷诺数流态下,对其发生机理和特性的认识还很匮乏.利用传统的二维低速粒子成像测速仪和高速动态粒子成像测速仪(PIV)实验研究了自由面旋转流中的弹性湍流的统计特性.对PIV测得的低雷诺数表面活性剂(十六烷基三甲基氯化铵)溶液粘弹性流体旋转流中水平面和子午面内的速度场进行了流型观测.结果表明实验测量的弹性湍流以大涡运动为特征,表现出在时间上随机而在空间上光滑的特性.

博客文学的形态特征初探

博客文学作为一种新兴的文学样式，经过短短几年的发展，已经具有了很多不同于传统文学的特征。具体到存在形态上，博客文学具有活性流动、超媒体组合、整体连贯等诸多特性，然而，由于博客文学的版权和稿费制度尚未形成，博客文学开始走向纸质出版，博客书的出现标志着两者由疏离走向统一。

Research on vibration characteristics of L-shaped plate using a mobility power flow approach

L-shaped plates have become an important focuses in structural vibration research. To determine their vibration characteristics, this paper applied a mobility power flow method. Firstly, the L-shaped plate was divided into two substructures to simplify analysis. The coupled bending moment was then deduced by applying a continuous vibration property on the common edge. Next, the response on any point of the plate and the input and transmitted power flow formulas were calculated. Numerical simulations showed the distribution of the coupled bending moment and the response of the whole structure. The validity of this method was verified by the SEA approach.

Oropharyngeal acid reflux and motility abnormalities of the proximal esophagus

AIM To investigate the relationship between pathological oropharyngeal(OP) acid exposure and esophageal motility in patients with extra-esophageal syndromes.METHODS In this prospective study we enrolled consecutive outpatients with extra-esophageal symptoms suspected to be related to gastroesophageal reflux disease(GERD). We enrolled only patients with a reflux symptom index(RSI) score-higher than 13 and with previous lung, allergy and ear, nose and throat evaluations excluding other specific diagnoses. All patients underwent 24-h OP pH-metry with the Dx probe and esophageal highresolution manometry(HRM). Patients were divided into two groups on the basis of a normal or pathological p H-metric finding(Ryan Score) and all manometric characteristics of the two groups were compared.RESULTS We examined 135 patients with chronic extra-esophageal syndromes. Fifty-one were considered eligible for the study. Of these, 42 decided to participate in the protocol. Patients were divided into two groups on the basis of normal or pathological OP acid exposure. All the HRM parameters were compared for the two groups. Significant differences were found in the median upper esophageal sphincter resting pressure(median 71 mmH g vs 126 mmH g, P = 0.004) and the median proximal contractile integral(median 215.5 cm·mmH g·s vs 313.5 cm·mmH g·s, P = 0.039), both being lower in the group with pathological OP acid exposure, and the number of contractions with small or large breaks, which were more frequent in the same group. This group also had a larger number of peristaltic contractions with breaks in the 20 mm Hg isobaric contour(38.7% vs 15.38%, P < 0.0001).CONCLUSION In patients with suspected GERD-related extraesophageal syndromes pathological OP acid exposure was associated with weaker proximal esophageal motility.

含微细颗粒的挥发性有机废气综合治理技术研究开发

工业的发展,带来了很多相关的环境污染问题。挥发性有机物(VOCs)是常见的污染物,对环境、动植物的生长及人类健康造成了极大的危害,因此越来越受到世界各国的重视,许多发达国家都颁布了相应的法令,限制VOCs的排放。含微细颗粒的挥发性有机废气由于多种物质成份并存,特别是橡胶行业炼胶废气一直是环保治理的难点。我们提出采用"预处理除油装置+活性炭流动床吸附+布袋除尘器+活性炭固定床吸附装置"的处理方式,能有效治理这类废气,尤其是针对橡胶行业炼胶废气,具有处理效率高、运行稳定、运行费用低、操作简便等特点。

Plastic-Flow Waves (“Slow-Waves") and Seismic Activity in Central-Eastern Asia

The results inferred from experiments with analogue models carried out previously have shown that two types of plastic-flow waves, “fast-waves" and “slow-waves", are induced in the lower lithosphere (including the lower crust and lithospheric mantle) under driving at plate boundaries and both of them are viscous gravity waves formed by the superposition of major and subsidiary waves. The major waves are similar to solitary waves and the subsidiary waves are traveling waves. The plastic-flow waves in the lower lithosphere control seismic activities in the overlying seismogenic layer and result in the distribution of earthquakes along the wave-crest belts. “Fast-waves" propagated with velocities of orders of magnitude of 100～102km/a have been verified by wave-controlled earthquake migration, showing the “decade waves" and “century waves" with the average periods of 10.8 and 93.4 a, respectively, which originate from the Himalayan driving boundary. According to the recognition of the patterns of the belt-like distribution of strong earthquakes with M S≥7.0, it is indicated further in this paper that the “slow-waves" with velocities of orders of magnitude of 100～101 m/a also originated under compression from the Himalayan driving boundary. Strong earthquakes with M S≥7.0 are controlled mainly by subsidiary waves, because the major waves with a duration of up to 106 a for each disturbance cannot result in the accumulation of enough energy for strong earthquakes due to the relaxation of the upper crust. The subsidiary waves propagate with an average wave length of 445 km, velocities of 0.81～2.80 m/a and periods of 0.16～0.55 Ma. The wave-generating time at the Himalayan driving boundary is about 1.34～4.59 Ma before present for the “slow-waves", corresponding to the stage from the Mid Pliocene to the Mid Early-Pleistocene and being identical with one of the major tectonic episodes of the Himalayan tectonic movement. It is shown from the recognition of the wave-controlled belts of strong earthquakes that two optimal patterns of wave-crest belts originated simultaneously from the eastern and western segments of the Himalayan arc, respectively. The overlap of wave-crest belts of these two systems is responsible for the relative concentration of energy and forms the seismic-energy-background zones for strong earthquakes with M S≥7.0.

Active control of structural vibration by piezoelectric stack actuators

This paper presents a general analytical model of flexible isolation system for application to the installation of high-speed machines and lightweight structures. Piezoelectric stack actuators are employed in the model to achieve vibration control of flexible structures, and dynamic characteristics are also investigated. Mobility technique is used to derive the governing equations of the system. The power flow transmitted into the foundation is solved and considered as a cost function to achieve optimal control of vibration isolation. Some numerical simulations revealed that the analytical model is effective as piezoelectric stack actuators can achieve substantial vibration attenuation by selecting proper value of the input voltage.

Identifying Diffusion Limiting Current to Unravel the Intrinsic Kinetics of Electrode Reactions Affected by Mass Transfer at Rotating Disk Electrode

Rotating disk electrode systems are widely used to study the kinetics of electrocatalytic reactions that may suffer from insufficient mass transfer of the reactants.Kinetic current density at certain overpotential calculated by the Koutecky-Levich equation is commonly used as the metrics to evaluate the activity of electrocatalysts.However,it is frequently found that the diffusion limiting current density is not correctly identified in the literatures.Instead of kinetic current density,the measured current density normalized by diffusion limiting current density(j/jL)has also been frequently under circumstance where its validity is not justified.By taking oxygen reduction reaction/hydrogen oxidation reaction/hydrogen evolution reaction as examples,we demonstrate that identifying the actual diffusion limiting current density for the same reaction under otherwise identical conditions from the experimental data is essential to accurately deduce kinetic current density.Our analysis reveals that j/jLis a rough activity metric which can only be used to qualitatively compare the activity trend under conditions that the mass transfer conditions and the roughness factor of the electrode are exactly the same.In addition,if one wants to use j/jLto compare the intrinsic activity,the concentration overpotential should be eliminated.

Variation of Floods Characteristics and Their Responses to Climate and Human Activities in Poyang Lake, China

The Poyang Lake is one of the most frequently flooded areas in China. Understanding the changing characteristics of floods as well as the affecting factors is an important prerequisite of flood disaster prevention and mitigation. The present study identified the characteristics variations of historical floods in the Poyang Lake and their tendencies based on the Mann-Kendall(M-K) test, and also investigated the related affecting factors, both from climate and human activities. The results revealed that the highest flood stages, duration as well as hazard coefficient of floods showed a long-term increasing linear trend during the last 60 years with the M-K statistic of 1.49, 1.60 and 1.50, respectively. And, a slightly increasing linear trend in the timing of the highest stages indicated the floods occurred later and later during the last six decades. The rainfall during the flood season and subsequent discharges of the Changjiang(Yangtze) River and runoff from the Poyang Lake Basin were mainly responsible for the severe flood situation in the Poyang Lake in the 1990 s. In addition, the intensive human activities, including land reclamation and levee construction, also played a supplementary role in increasing severity of major floods. While, the fewer floods in the Poyang Lake after 2000 can be attributed to not only the less rainfall over the Poyang Lake Basin and low discharges of the Changjiang River during flood periods, but also the stronger influences of human activity which increased the floodwater storage of the Poyang Lake than before.

WBC250稳定土厂拌设备粉料系统的改造

针对WBC2 5 0稳定土厂拌设备粉料系统在现场施工中存在的水泥流失量大、污染重的问题 ,并通过对改进后引发的进料不畅导致电机烧坏等新问题的分析 ,以理论为根据提出了在出料口处加装节流槽装置降低水泥的超量喷射 ,在料斗内加设第二层钢板增大水泥流动活性的解决方案 ,并在实践中逐步完善 ,对现有WBC2 5

Mini-review:Is alcohol consumption associated with gastroesophageal reflux disease?

Gastroesophageal reflux disease(GERD) is one of the most common disorders with an increasing incidence and prevalence.Alcohol consumption may be a risk factor for GERD;however,the relationship remains to be fully elucidated.The results of different studies are diverse and contradictory.Systematic investigations concerning this matter are inappropriate and further well-designed prospective studies are needed to clarify the effect of alcohol on GERD.

Ultrasonic-assisted plastic flow in a Zr-based metallic glass

Ultrasonic vibration can be used for the micro-molding of metallic glasses(MGs)due to stress-softening and fast surface-diffusion effects.However,the structural rearrangement under ultrasonic vibration and its impact on the mechanical response of metallic glasses remain a puzzle.In this work,the plastic flow of the Zr35Ti30Cu8.25Be26.75 metallic glass with the applied ultrasonic-vibration energy of 140 J was investigated by nanoindentation.Both Kelvin and Maxwell-Voigt models have been adopted to analyze the structural evolution during the creep deformation.The increase of the characteristic relaxation time and the peak intensity of relaxation spectra can be found in the sample after ultrasonic vibration.It effectively improves the activation energy of atomic diffusion during the glass transition(Eg)and the growth of the crystal nucleus(Ep).A more homogenous plastic deformation with a weak loading-rate sensitivity of stress exponent is observed in the ultrasonic-vibrated sample,which coincides with the low pile-up and penetration depth as shown in the cross profile of indents.The structural rearrangement under resonance actuation demonstrated in this work might help us better understand the defect-activation mechanism for the plastic flow of amorphous systems.

Experimental study on heat transfer characteristics of synthetic jet driven by piston actuator

Experimental investigation was conducted to investigate the impingement heat transfer performance of a synthetic jet driven by piston actuator on a constant heat flux surface. Effects of jet formation frequency, nozzle-to-surface spacing ratio and con- jugation of cross flow were considered. The synthetic jet is of stronger penetration and heat transfer capacity when the piston reciprocates at relatively high frequency. Similar to the continuous jet impingement, nozzle-to-surface spacing ratio plays an important role in the heat transfer enhancement of synthetic jet. The optimum nozzle-to-surface spacing ratio corresponding to maximum heat transfer enhancement is considerably high in the synthetic jet, as compared to that in a continuous jet, which indicates that the synthetic jet introduces a stronger entrainment and more vigorous penetration in the surrounding fluid. The convective heat transfer capacity is enhanced significantly under the conjugate action of a synthetic jet and cross flow in com- narison with their individual action.

Methionine-101 from one strain of H5N1 NS1 protein determines its IFN-antagonizing ability and subcellular distribution pattern

Influenza A virus NS1 protein has developed two main IFN-antagonizing mechanisms by inhibiting retinoic-acid-inducible gene I (RIG-I) signal transduction, or by suppressing cellular pre-mRNA processing through binding to cleavage and polyad-enylation specific factor 30 (CPSF30). However, the precise effects of NS1 on suppressing type I IFN induction have not been well characterized. Here we report that compared with PR/8/34 NS1, which is localized partially in the cytoplasm and has strong IFN-antagonizing ability via specifically inhibiting IFN-β promoter activity, H5N1 NS1 has strikingly different characteristics. It mainly accumulates in the nucleus of transfected cells and exerts rather weak IFN-counteracting ability through suppression of the overall gene expression. The M101I mutation of H5N1 NS1, namely H5-M101I, fully reversed its functions. H5-M101I gained the ability to specifically inhibit IFN-β promoter activity, translocate to the cytoplasm, and release CPSF30. The previously reported NES (nuclear export signal) (residues 138 147) was unable to lead H5N1 NS1 to translocate. This suggests that other residues may serve as a potent NES. Findings indicated that together with leucine-100, methionine-101 en- hanced the regional NES. In addition, methionine-101 was the key residue for the NS1-CPSF30 interaction. This study reveals the importance of methionine-101 in the influenza A virus life cycle and may provide valuable information for antiviral strategies.