Hydraulic modeling of an anaerobic expanded bed reactor for municipal sewage treatment

Anaerobic expanded bed reactor （AEBR） is mostly used for the treatment of fairly low strength wastewaters. Since the performance of AEBR largely depends on its hydraulic characteristics, residence time distribution （RTD） method is commonly used for investigation of the hydraulic characteristics of AEBR under different ascending velocity of mixed liquor. In this paper, a pilot-scale AEBR reactor is investigated for treatment of municipal sewage in which lithium chloride is used as a tracer. The results show that the AEBR could be considered as the superimposition of several constant stirred tank reactors （CSTR） and the increase of hydraulic up-flow velocity could increase the number of the CSTR and decrease the volume rate of the dead zone. The optimal up-flow velocity of the investigated AEBR was approximately 1.9 rn/h in the municipal sewage treatment.     

Investigation of a spherical-section ultrasound phased array for hepatic ablation

A 3D ultrasound thermal model with a 3D finite element representation for modeling the thermal diffusion effects for hepatic ablation induced by spherical-section ultrasound phased array was developed. The model was first validated against available published measured data in rat liver. Using the validated model,effects of blood perfusion and heating schemes on lesion formation were studied for both single focus and split-focus intensity patterns. It was shown that for single focus sonication pattern the short-duration(～2 s) and high-intensity(～1250 W/cm2) heating scheme can completely reduce the cooling effect of the blood perfusion. The lesion shape and size were significantly altered by perfusion for split-focus pattern even with a rapid heating scheme when the focus spacing was larger than 2.4 mm. Underdosed areas might be present between two foci. Prolonging ex-posure time or shortening focus spacing can reduce the cool region between two foci. In addition,the influences of thermal and acoustic parameters were also studied. When the therapy depth is short(<5 cm) ,the lesion size monotonically increases with increasing attenuation coefficient that ranges from 5.4 to 11 Np/(m?MHz) .     

Effect of selected fungi on the reduction of gossypol levels and nutritional value during solid substrate fermentation of cottonseed meal

The objective of this work was to investigate the effect of six individual strains of fungi on the reduction of gossypol levels and nutritional value during solid substrate fen＇aentation of cottonseed meal （CSM）. Six groups of disinfected CSM substrate were incubated for 48 h after inoculation with either of the fungi C. capsuligena ZD- 1, C. tropicalis ZD-3, S. cerevisae ZD-5, A. terricola ZD-6, A. oryzae ZD-7, or A. niger ZD-8. One not inoculated group （substrate） was used as a control. Levels of initial and final free gossypol （FG）, crude protein （CP）, amino acids （AA） and in vitro digestibility were assayed. The experiment was done in triplicate. The experimental results indicated that microbial fermentation could greatly decrease （P〈0.05） FG levels in CSM. The detoxification efficiency differed between the species of microorganisms applied. From the perspective of reducing CSM potential toxicity, C. tropicalis ZD-3 was most successful followed by S. cerevisae ZD-5 and A. niger ZD-8. They could reduce FG levels of CSM to 29.8, 63.07 and 81.50 mg/kg based on DM （dry matter）, respectively, and their detoxification rates were 94.57%, 88.51% and 85.16%, respectively. If crude protein, amino acids content and their in vitro digestibility were also taken into account, Aniger ZD-8 may be the best choice. The CP content of CSM substrate fermented by C. tropicalis ZD-3 and A. niger ZD-8 were improved by 10.76% and 22.24%; the TAA （total amino acids） contents were increased by 7.06% and 11.46%, and the EAA （essential amino acids） were raised by 7.77% and 12.64%, respectively. Especially, the levels of methionine, lysine and threonine were improved greatly （P〈0.05）. The in vitro CP digestibility of CSM fermented by C. tropicalis ZD-3 and A. niger ZD-8 was improved by 13.42% and 18.22%, the TAA were increased by 17.75% and 22.88%, and the EAA by 16.61% and 21.01%, respectively. In addition, the in vitro digestibility of methionine, lysine and threonine was also improved greatly （P〈0.05）.     

反应堆工程课程设计实践教学的探索与实践

反应堆工程课程设计是普通高等学校核反应堆工程专业人才培养过程的重要实践性教学活动。缺乏核反应堆装置大型核设施是我国培养核反应堆工程人才高校开展实践教学所面临的主要困难。南华大学从选取实践教学硬件和软件、选题、教学过程、互动式指导、练习、成绩考核及总结等方面对反应堆工程课程设计教学进行了实践,初步探索出一种适合我国普通高等学校开展反应堆工程课程设计的实践教学模式。     

Novel photocatalytic reactor for degradation of DDT in water and its optimization model

A novel photocatalytic reactor was developed to remove （1,1-bis（4-chlorophenyl）-2,2,2-trichloroethane） （DDT） from water. In the reactor, a cenosphere was used to support TiO2 film made by means of sol-gel. Because the cenospheres were coated with TiO2, their specific gravity was slightly increased from the original 0.6-0.8 to 0.8-0.9, so that they were able to be suspended in water. With the mixed operation of a bubbler, the water in the reactor was in a well-fluidized state. The bottom of the reactor is a sand filter bed, which can be used to prevent the photocatalyst from being lost. A mathematical model of the reactor has been developed in the two primary influential factors： ultraviolet （UV） light intensity and photocatalyst concentration. With such a model, the reactor can be designed more reasonably.     

Effects of the electrode materials and its structure on denitrification in a bio-electrode reactor

Ｓｔｒｕｃｔｕｒｅ ｏｎ Ｄｅｎｉｔｒｉｆｉｃａｔｉｏｎ ｉｎ ａ Ｂｉｏ－ｅｌｅｃｔｒｏｄｅ ＲｅａｃｔｏｒTX１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｅｎｓｉｖｅａｇｒｉｃｕｌｔｕｒｅａｎｄｉｎｄｕｓｔｒｉａｌｗａｓｔｅｗａｔｅｒｄｉｓ－ｃｈａｒｇｅｄｈａ...     

Impact of nodular size on the predictive values of gray-scale, color-Doppler ultrasound, and sonoelastography for assessment of thyroid nodules

Objective:To define the roles of gray-scale,color-Doppler ultrasound,and sonoelastography for the assessment of thyroid nodule to determine whether nodule size affects the differential diagnosis of ben...     

Combined process of sequencing batch reactor activated sludge process and constructed wetland for domestic wastewater treatment

By combining sequencing batch reactor （SBR） activated sludge process and constructed wetland （CW）, this study is to achieve the domestic wastewater treatment. Our purpose was to determine the optimum operating parameters of the combined process. The process involved advantages and shortages of SBR and CW. Under normal temperature, the 3rd cycle （SBR’s operation cycle is 8 h： inflow for 1 h, limited aeration for 3 h, sediment for 1 h, outflow for 1 h, and idling for 2 h; CW’s hydraulic retention time （HRT） is 24.8 h and hydraulic loading is 24.5 m^3/m^2 d） was the best cyclic mode. The effluents can meet the standard GB/T18921-2002： “The reuse of urban recycling water： water quality standard for scenic environment use”. In the 3rd cycle, the efficiency of CW was the maximum, and energy consumption of SBR was the minimum. Under the condition of low dissolved oxygen, the removing efficiency of chemical oxygen demand （COD） and ammonia was not affected obviously. Simultaneously, nitrification and denitrification phenomena occured and phosphorus was absorbed obviously.     

一个用于体外评价超声造影剂显影效果的系统（英文）

构建并评价了一个用于体外研究超声造影剂显影效果的系统,该系统包括一套数字化B型超声诊断仪Belson3000A、仿组织超声体模和用于图像量化分析的软件.制备了具有不同反射强度的仿组织超声体模,通过对这些体模材料超声成像,研究了B超系统的线性范围、参数设置和系统的重复性等.超声成像设置为：输出声功率为4.8 ～12.3mW,探头的中心频率为3.5MHz,总增益为50dB.利用该系统,对自制备的表面活性剂微气泡和一种商用造影剂进行了显影成像.结果表明超声图像的灰度值随声功率的增加而增大,强反射特性的超声体模成像时,这种增加趋势更明显.该系统适合用于体外评价超声造影剂的显影效果,为体外表征超声微气泡造影剂的显影能力提供了一种简单、有效、实时的评价方法.     

A fast automatic recognition and location algorithm for fetal genital organs in ultrasound images

howed true positive (TP) and true negative (77V) results from 80.5% (265 from 329) and 83.0% (415 from 500) of samples, respectively. The average computation time was 453 ms per image.     

CANON process for nitrogen removal from effluents of municipal sewage treatment plants

The feasibility and performance of nitrogen removal from municipal sewage were investigated through the completely autotrophic nitrogen removal over nitrite (CANON) process in a continuous reactor. CANON process was successfully started up with the transformation of nitrogen into gas by mass-balance analysis. For the synthetic waste-water (up to 480 mg NH4+-N/(L·d)), removal rates of the ammonia nitrogen and total nitrogen (TN) were about 80% and 55%, respectively, at 1.25 h hydraulic retention time (HRT). For the secondary effluent of municipal sewage, the effluent concentrations of NH4+-N and TN were below 5 mg/L and 9 mg/L, respectively. It is in accordance with the water quality standard for scenic environment with the reuse of urban recycling water (GB/T 18921-2002).     

Biodegradability of leachates from Chinese and German municipal solid waste

The quantitative and qualitative composition of Chinese municipal solid waste （MSW） differs significantly from German waste. The focus of this paper is on whether these differences also lead to dissimilar qualities of leachates during storage or landfilling. Leachates ingredients determine the appropriate treatment technique. MSW compositions of the two cities Guilin （China） and Essen （Germany）, each with approx. 600000 inhabitants, are used to simulate Chinese and German MSW types. A sequencing batch reactor （SBR） is used, combining aerobic and anaerobic reaction principles, to test the biodegradability of leachates. Leachates are tested for temperature, pH-value, redox potentials, and oxygen concentration. Chemical oxygen demand （COD） values are determined. Within 8 h, the biodegradation rates for both kinds of leachates are more than 90%. Due to the high organic content of Chinese waste, the degradation rate for Guilin MSW leachate is even higher, up to 97%. The effluent from SBR technique is suitable for direct discharge into bodies of water.     

Antitumor and antimicrobial activities of endophytic fungi from medicinal parts of Aquilaria sinensis

The purpose of this study was to isolate and characterize endophytic fungi from the stem tissue which can produce fragrant ingredients in Aquilaria sinensis (also called agarwood) to determine their antitumor and antimicrobial activities. Twenty-eight fungal endophytes were isolated from agarwood by strict sterile sample preparation and were classified into 14 genera and 4 taxonomic classes (Sordariomycetes, Dothideomycetes, Saccharomycetes, and Zygomycetes) based on molecular identification. Of the 28 isolates, 13 (46.4%) showed antimicrobial activity against at least one of the test strains by the agar well diffusion method, and 23 isolates (82.1%) displayed antitumor activity against at least one of five cancer cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The diameters of inhibition zones of YNAS07, YNAS14, HNAS04, HNAS05, HNAS08, and HNAS11 were equal to or higher than 14.0 mm against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, B. subtilis, Aspergillus fumigatus, and B. subtilis, respectively. The inhibition rates of YNAS06, YNAS08, and HNAS06 were not less than 60% to 293-T, 293-T, and SKVO3 cells, respectively. These results suggest that the endophytic fungi associated with agarwood will provide us with not only useful micro-ecological information, but also potential antimicrobial and antitumor agents.     

一种基于PLC的多模控制系统的研制

本文介绍一种基于PLC的智能控制系统,该系统以PLC为核心,采用多模分段控制算法,成功地实现了反应器和干燥器的温度控制。系统操作简单,控制精度高,实用性强,有较好的推广应用价值。     

啤酒厂厌氧池(UASB)的调节与恢复

针对某啤酒厂污水处理过程中使用的升流式厌氧池(UASB)进行了调节与恢复,通过监测厌氧池的pH与COD等数据找出UASB反应器处理效果差的原因,然后对三相分离器、布水管等进行调整,并二次启动厌氧池,恢复了UASB反应器的处理功能.     

加氢脱硫滴流床反应器数学模型的建立和工业应用

在前期研究获得催化剂Co-Mo/Al₂O₃-TiO₂加氢脱硫动力学数据的基础上,对加氢脱硫滴流床反应器进行研究,建立数学模型,用于模拟百万吨柴油加氢脱硫滴流床反应器的传质传热过程、床层压降大小及催化剂使用效果。结果显示,生产硫含量符合欧Ⅳ车用标准的柴油,催化床层高度需要8.5 m;床层压降和床层温度变化均在合理范围内。     

实验教学用光催化氧化装置的研制和应用

光催化氧化作为一种能有效去除难降解有机物的技术方法,在污染治理与控制中越来越受到重视,并在实际工程中得到较为广泛的应用,其基本原理和方法在环境化学等课程的课堂教学中讲授。然而,主要用于科研的光催化氧化装置在本科实验教学过程中存在占地面积大,复套数难以提高等不足,为此研制了适用于本科实验教学的光催化氧化实验装置。研发的装置具有体积较小、造价较低、使用方便等特点,通过多届本科生实验教学的应用,获得了满意的实验效果。     

Evaluation of thermal imaging system and thermal radiation detector for real-time condition monitoring of high power frequency converters

We have carried out at laboratory test to study the feasibility of using thermal radiation detectors for online thermal monitoring of electrical systems in wind turbines. A 25 kW frequency converter is instrumented with a thermal camera, operating in the 8-14 μm wave- length range, and a single-pixel thermopile sensor, operating in the 4-8 μm wavelength range, to monitor the temperature development of the power electronics under various load sequences. Both systems performed satisfactorily with insignificant temperature deviations when compared to data from calibrated point contact sensor. With spatial averaging over a 7 mm × 7 mm for the camera and temporal averaging over 60 s for the thermo- pile sensor, we reduce the root mean square noise to 45 mK and 68 mK respectively. The low cost and simple operation of the thermopile sensor make it very attractive for condition monitoring applications, whereas the attractive feature of the camera is the possibility of multi-point or distributed temperature measurements.     

形成性评价与终结性评价并重高职英语测评体系构建

高职英语作为专业课程的辅助课程,主要体现出其应用能力,沿用原有的终结式考试已经不能体现出学生对本门课技能掌握情况。鉴于此教师对考核方式进行改革,加强考核引导和过程控制,注重学生英语应用能力培养及提高,建立基于过程控制的高职英语课程形成性考核与终结性考核并重的考核体系,深化高职英语课程改革,促进高职学生英语应用能力的提高。