Sanitary Sewage Treatment with Jet Inner-loop Bioreactor

0　IntroductionThejetloopreactorhasthecharacteristicsofbothjetandloopflow .Ononehand ,theairsuckedinisdispersedintosmallgasbubblesbecauseoftheshearingforcecausedbythehighvelocityjet,producinganincreasedinterfacialcontactbe tweengasandliquid ,thusthemasstransferefficiencyisin creased .Ontheotherhand ,aregularloopflowisformedbecauseofmutualimpetusofbothjetandair lift,thusdramaticallyim provestheperformancesofmixture ,diffusion ,masstransferandheattransferofthematerial.Withoutmechanicdriving ,the…     

Effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete

The effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete (SCGC) was investigated in this paper. The work focused on the concrete mixes with a fixed water-to-geopolymer solid (W/Gs) ratio of 0.33 by mass and a constant total binder content of 400 kg/m3. The mass fractions of silica fume that replaced fly ash in this research were 0wt%, 5wt%, 10wt%, and 15wt%. The workability-related fresh properties of SCGC were assessed through slump flow, V-funnel, and L-box test methods. Hardened concrete tests were limited to compressive, splitting tensile and flexural strengths, all of which were measured at the age of 1, 7, and 28 d after 48-h oven curing. The results indicate that the addition of silica fume as a partial replacement of fly ash results in the loss of workability; nevertheless, the mechanical properties of hardened SCGC are significantly improved by incorporating silica fume, especially up to 10wt%. Applying this percentage of silica fume results in 4.3% reduction in the slump flow; however, it increases the compressive strength by 6.9%, tensile strength by 12.8% and flexural strength by 11.5%.     

Food-Chain Model of Grassland Degradation and Its Restoration Process in Northern Tibet Plateau：A Case Study in Nierong County

Based on the model of grassland climate ecological productivity, the process of grassland degradation and its restoration mechanism in northern Tibetan Plateau were discussed by the model of food-chain in which the environmental and human factors were corrected. The results of case study in Nierong County showed that： ① the climate trend of becoming warmer, more droughts and gales were conflicted with the restoration of grassland degradation, even under level of perfect management the climate ecological productivity was declined from 89. 3 kg/m^2 of 1983 to 71.8 kg/m^2 of 2003; ② from 1983 to 2003, the population increased fast, while the variation of livestock on hand was little, and the cost of its maintaining is rapid grassland degradation; ③ on the present condition of overgrazing, the livestock on hand can be maintained on the level of theoretical carrying capacity in 2033 by applying the mechanism of food-chain in grassland ecological system controlled with expected coefficients, so that to realize the policy of determining the quantity of livestock according to grass growth.     

自密实高性能混凝土配合比试验

采用福建省粉煤灰作为细掺料 ,以高效减水剂、增粘剂、引气剂和膨胀剂研制成复合外加剂 .成功配制出流动性好、穿越钢筋能力强的自密实高性能混凝土 .采用塌落筒、倒塌落筒仪、L型流速仪、Orimet流速仪和实际浇筑钢筋混凝土框架以综合测试其新拌混凝土的施工性能 .测试表明 ,该自密实混凝土较好地解决了混凝土高流动性与材料抗离析性之间的矛盾 ,满足免振捣的施工要求 .     

Hot deformation behavior of Super304H austenitic heat resistant steel

The hot compression tests of Super304H austenitic heat resistant steel were carried out at 800–1200℃ and 0.005–5 s-1 using a Gleeble 3500 thermal-mechanical simulator, and its deformation behavior was analyzed. The results show that the flow stress of Super304H steel decreases with the decrease of strain rate and the increase of deformation temperature; the hot deformation activation energy of the steel is 485 kJ/mol. The hot deformation equation and the relationship between the peak stress and the deformation temperature and strain rate is obtained. The softening caused by deformation heating cannot be neglected when both the deformation temperature and strain rate are higher.     

Preparation of semi-solid aluminum alloy slurry poured through a water-cooled serpentine channel

A water-cooled serpentine channel pouring process was invented to produce semi-solid A356 aluminum alloy slurry for rheocasting, and the effects of pouring temperature and circulating cooling water flux on the microstructure of the slurry were investigated. The results show that at the pouring temperature of 640-680℃ and the circulating cooling water flux of 0.9 m3/h, the semi-solid A356 aluminum alloy slurry with spherical primary α(Al) grains can be obtained, whose shape factors are between 0.78 and 0.86 and the grain diameter can reach 48-68 μm. When the pouring temperatures are at 660-680℃, only a very thin solidified shell remains inside the serpentine channel and can be removed easily. When the serpentine channel is cooled with circulating water, the microstructure of the semi-solid slurry can be improved, and the serpentine channel is quickly cooled to room temperature after the completion of one pouring. In terms of the productivity of the special equipment, the water-cooled serpentine channel is economical and efficient.     

不同密度等级泡沫混凝土的性能和孔结构

泡沫混凝土的密度等级对其性能有显著影响。笔者制备了干密度在300～1 000 kg/m~3范围内的泡沫混凝土,对其浆体流动度、抗压强度、吸水率和干燥收缩进行了测试,利用X射线计算机断层扫描成像(X-ray computed tomography, X-CT)对试件的孔结构进行表征。结果显示:随着泡沫混凝土密度等级增加,其浆体流动度先增大后减小,密度为600 kg/m~3时流动度最大;抗压强度随密度等级增加而逐渐增大,并与密度等级之间存在指数关系;干燥收缩和吸水率均随密度等级增加逐渐减小,这是由于其内部孔隙率降低、封闭孔增多所致。X-CT分析结果显示,密度低于600 kg/m~3的泡沫混凝土内部孔隙分布不均,试件表面的大孔较多,这是由于浆体与泡沫的体积比过低、浆体无法均匀地包裹在泡沫表面所致。     

PWS编索法在轻型悬索桥上的应用

分析了轻型悬索桥主索的材料和施工方法，简要介绍了ＰＷＳ编索法，总结了该法在安溪凤城悬索桥上的应用情况．应用结果表明，主索在架设翻越塔架时应设有足够的滚轮以防止绕包带崩裂，应采取构造措施防止索夹滑动，成品索的生产标准应尽早制定     

C80高性能泵送混凝土的配制技术

通过对试验结果的分析，讨论了在常规的材料及通用的工艺方法条件下矿渣和粉煤灰对高性能混凝土的影响，阐述了如何利用矿渣掺合料、粉煤灰、减水剂掺量及水胶比的不同，运用常规的材料及通用的工艺方法，在满足混凝土性能要求的前提下，调节早期强度与后期强度增长之间的关系，确定出使混凝土各组分充分发挥效应的最佳组合。在水泥用量仅350kg/m^3的条件下，配制出强度等级C80的高性能泵送混凝土，28d龄期抗压强度接近100MPa，混凝土坍落度达到220mm左右。     

Optimizing Conditions of Enhancing Granule Sludge Concentration and Performance

An expanded granular sludge bed （EGSB） reactor was adopted to study the influence factors and rule of enhancing granular sludge concentration and performance. The experiment was performed at 33 ℃, pH 6.0-8.0 with continuous flow by adding proper quantity of nutritional trace elements. The results show that SLR was the key of steady operation of EGSB reactor. The increment of the granular sludge was influenced by volume loading rate （VLR）, liquid up-flow velocity and sludge loading rate （SLR）. Concentration of granular sludge increased rapidly when liquid up-flow velocity was over 0.94 m · h^-1 with SLR being at 1.0-2.0 d ^-1. With the propriety parameters： liquid up-flow velocity 2.52 m · h^-1, SLR 1.0-2.2 d^-1 and VLR 8.2-13.1 kg · m ^3 · d^-1, 23 days＇ continuous operation resulted in an increment by over 80% of granular sludge concentration in the EGSB reactor, plus good granular sludge property.     

用矿物掺和料配制高性能混凝土的研究

目的配制高性能混凝土。方法利用矿物掺和料来实现配制高性能混凝土之目的。结果从高性能混凝土的特性出发,选用20%粉煤灰、30%矿渣微粉进行单独等量取代水泥。通过对各组试样的工作性能、力学性能以及耐久性能的比较,研究对高性能混凝土的影响,并对其作用特点进行初步分析。结果表明:采用定量粉煤灰、矿渣微粉及少量减水剂可配制28d强度大于73~90MPa,坍落度大于225mm的C60和C80高性能混凝土。结论粉煤灰和矿渣微粉可以用于配制高性能混凝土。     

大掺量粉煤灰再生混凝土的试验研究

采用废弃混凝土再生骨料、普通硅酸盐水泥和粉煤灰等原材料,通过正交试验找出影响再生混凝土强度和坍落度的主要因素及大掺量粉煤灰再生混凝土的最优配比。试验结果表明,再生骨料替代率是影响再生混凝土强度和坍落度的显著因素,在普通成型工艺和养护条件下可以配制出抗压强度59M Pa,塌落度215 mm,粉煤灰掺量30%的高性能再生混凝土。     

Estimation of soil respiration in a paddy ecosystem in the subtropical resion of China

Water vapor, energy exchange, and CO2 flux were measured continuously from 2003 to 2005 using the eddy covariance technique in a paddy ecosystem in the subtropical region of China. The CO2 fluxes at nighttime during fallow periods （from middle October to late April） were used to analyze the dynamics of soil respiration and its relationship with soil temperature, and to simulate the annual dynamics of soil respiration in paddy ecosystems. The variation of soil respiration showed a clear seasonal pattern. The soil respiration rates at night during the fallow periods were 52--398 mg· m^-2· h^-1, and exponentially correlated （P〈0.001） with soil temperatures at different depths of soil （5, 10, and 20 cm）, particularly the temperature measured at a depth of 5 cm. Based on the simulated exponential equations developed, annual average soil respiration rates and total soil respiration of paddy soil in the subtropical region of China were estimated to be 178.5--259.9 mg· m^-2· h^-1 and 1.56--2.28 kg· m^-2· a^-1, respectively. The simulation equations can be applied to evaluating soil respiration in paddy ecosystems during the rice-growing season.     

The presence of phosphorylation form of D1 protein in its cross-linked aggregates in high light treated spinach leaves in vivo

Photosystem Ⅱ (PS Ⅱ ) is a pigment-protein com-plex that catalyses the primary photochemistry leading to oxygen evolution and electron flow in oxygenic phototrophs. The reaction center of PSⅡ is composed of the D1 and D2 proteins to which all the redox…     

GPS monitoring of the crustal motion in southwestern China

Through GPS carrier phases observation in southwestern China during 1991–1997, the velocity field within eastern Qinghai-Xizang (Tibet) and its neighbour regions has been established. The velocity of those sites in and west of Chuan-Dian block is mostly 5–10 mm · a^™1 relative to the fiduciary station CHDU (Chengdu), and the motion in Chuan-Qing and Yangtze blocks east of the Xianshuihe-Xiaojiang fault is weak with a velocity of about 0–7 mm · a⁻¹. The velocity vector in these areas indicates a clockwise rotation vortex rather than the so-called intensive eastward pushing or eastward escape. The main pattern of the crustal deformation is a clockwise rotation vortex structure and a differential slip along the boundary fault between different blocks.     

Application of Nanometer-Size Titanium Dioxide in Extreme-Trace V（Ⅴ） Analysis

0Introduction Vanadiumplaysanimportantroleinmodernindustry,es peciallyinsteelandchemicalindustry.Forinstance,itscompoundsarewidelyappliedintheproceduresofvitrioland petroleumchemicalmanufactureascatalyzers[14].Vanadium hasseveralvalences,butgenerallyitslowvalencesturnintohighoneseasilyinenvironment[5].BecauseV(Ⅴ)isthemost stableandpoisonousone,weoftenlayemphasisonitinenvi ronmentalpollutioncontrol.Vanadiumexistsinenvironmentalwaterwithextremelylowconcentration.Inseawateritscontentislessthan…     

聚脲涂覆钢板结构抗爆性能试验研究

研究聚脲不同涂覆方式下单钢板与箱体结构的抗爆性能.进行了15.7 kg/m2相同面密度条件下2.0,1.5与1.2 mm三种厚度钢板的无涂覆、迎爆面涂覆结构抗40 g TNT外爆载荷试验,相同钢板厚度条件下1.5 mm与1.2 mm两种厚度钢板的无涂覆、迎爆面涂覆与背爆面涂覆结构抗60 g TNT外爆载荷试验,以及3.0 mm厚钢板所组成箱体的无涂覆、迎爆面涂覆与背爆面涂覆结构抗140 g TNT内爆载荷试验,通过对比不同涂覆结构的变形与破坏行为,分析聚脲涂层对结构抗爆性能的影响.结果表明,等面密度时迎爆面涂覆聚脲不能提高钢板的抗爆性能,等钢板厚度时涂覆聚脲能够有效提高钢板与箱体结构分别在外爆与内爆载荷下的抗爆性能,且背爆面涂覆时效果优于迎爆面涂覆.      

微坍落度混凝土技术及其在碾压混凝土坝等工程中的应用

通过近年来从潘家口到玄庙观等碾压混凝土（RCC）筑坝的研究和创新，提出微坍落度混凝土（MSC），使原坍落度为零改为趋近于零且小于0．5cm．这样，保留了原零坍落度混凝土（ZSC）的各种优点，如与相邻的碾压混凝土的各种性质（包括力学和热学性能指标）相近，温度变形相近或相容，故抗裂性能好．此外，它还弥补了原来的缺点，即改善了混凝土的稠度，有利于平仓振捣，提高施工进度和质量，并改善靠近模板、地基、止水片及廊道孔洞部附近有钢筋部位的质量．在大坝等大体积工程、厚度不大的厂房、水闸、涵管等水工建筑物、工民建和桥梁等工程领域中，随着施工设施和工艺水平的提高，这种微坍落度混凝土具有良好的或潜在的发展前景．     

An explanation to the high efficiency ofm-THPC (temporfin) used in photodynamic therapy

Meso-tetrahydroxylphenyl chlorin (m-THPC) is one of the most efficient prospective sensitizers used in photodynamic therapy (PDT). ESR spectroscopy, fluorescence quenching experiments and cyclic voltammogram measurement were used to study its redox properties. The results showed that the ability of m-THPC generating superoxide radical anions was very strong, and the rate constant of m-THPC fluorescence quenching by oxygen k_q (O₂)=1.46×10¹⁰ mol^-1·s^-1. The values of fluorescence quen- ching rate constant of m-THPC by some other electron acceptors, such as methyl viologen (MV²⁺) and anthraquinone (An), were also measured. And they were k_q (MV²⁺)=5.51×10⁹ mol^-1·s^-1, k_q (An)=7.81×10⁹ mol^-1·s^-1. The oxidation potential of m-THPC was examined to be +0.62 V (vs. NHE) in acetonitrile. All these suggested that m-THPC should be a much stronger electron donor than photofrin, the currently used in clinical photodrug, and may react easily through electron transfer with biological matter to yield various radicals. So it seemed reasonable that the type Ⅰ reaction may play an important role in the high activity of m-THPC-PDT.     

Identifying paleoflood deposits archived in Zhongba Site, the Three Gorges reservoir region of the Yangtze River, China

Based on the principle that the present is the key to the past, detailed analyses, such as AMS ^14C dating, grain size, component and morphology of heavy minerals, micro-morphology of zircon, Rb/Sr, magnetic susceptibility and total organic carbon （TOC）, were conducted to identify paleoflood sediments archived in Zhongba Site. The results indicate that the plaeoflood sediments bear great similarities with modern flood sediments in the following aspects： （1） probability cumulative curves mainly show a pattern of 3-4 segments; （2） grain-size distribution of suspended matter ranges between 3 and 10（I）; （3） the sediments are well-sorted, most of which are suspended matter （〉50%）; （4） the same species, quantity and morphology of heavy minerals; （5） scanning electronic microscope images show that shapes of zircon are mainly oval and nearly spheral, rounded due to long-distance transport; （6） higher Rb/Sr values （0.55-0.66）than those of sediments from cultural layers （0.03-0.26）; （7） magnetic susceptibility values （133.73-433.05 10^-6m^3/kg） are lower than those of sediments from cultural layers （959.25-2442.44 10^-6 m^3/kg）; （8） TOC （0.14%- 0.33%） are lower than those of sediments from cultural layers （1.13%-2.95%）. Our results demonstrate that, except for the 1981 flood, there are at least six paleoflood events that occurred during the Qing Dynasty, the middle of Song Dynasty, the early Warring States （400BC-350BC）, the West Zhou Dynasty （920BC-900BC）, the Xia Dynasty （2070BC-1600BC）, and the late Neolithic Age （3000BC-2300BC）, respectively.