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Search Results: 1 - 10 of 4711 matches for " Guan Yueqiang "
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Effect of adding Limnodrilus hoffmeisteri on performance of activated sludge and microfauna structure of wastewater treatment system

Guan Yueqiang,Yang Xiufen,Zhang Na,Zhou Kexin,

环境工程学报 , 2013,
Abstract: 研究了实验室模拟条件下添加霍甫水丝蚓(Limnodrilus hoffmeisteri)对活性污泥水处理系统的影响。实验设对照组和实验组各一个,各设3个平行缸,实验组每缸添加水丝蚓100条,每个批次的实验周期为20 h,循环7 d。结果显示,实验组和对照组的出水COD去除率分别为(69.6±1.7)%和(67.9±2.5)%,两者无显著差异;实验组和对照组的活性污泥沉降比SV(%)分别为(16.39±0.30)%和(16.98±0.46)%,活性污泥浓度MLSS分别为(2.48±0.16)g/L和(2.61±0.12)g/L,活性污泥指数SVI分别为(66.35±3.51)和(65.19±2.57)mL/g,两组的SV和MLSS差异显著,说明添加水丝蚓在短期内起到减少污泥量、提高污泥沉降性能的作用。添加霍夫水丝蚓短期内不影响微型动物的种类组成,但使原生动物总密度下降。实验组和对照组污泥生物指数SBI均为7,质量等级为Ⅱ。上述结果可为剩余污泥减量化应用提供参考依据。
Soil Erosion and Its Relationship to the Spatial Distribution of Land Use Patterns in the Lancang River Watershed, Yunnan Province, China  [PDF]
Yueqiang Li, Shanghong Zhang, Yang Peng
Agricultural Sciences (AS) , 2015, DOI: 10.4236/as.2015.68080
Abstract: The Lancang River Watershed is one of the most biologically diverse areas in the world. The river flows through Yunnan Province, China, which suffered serious deforestation since the 1980s; this in turn led to increased soil erosion in the region. To investigate the influence of the spatial distribution of land use and slope on soil erosion in the Lancang River Watershed, the Soil and Water Assessment Tool (SWAT) model was used to establish hydrological models using two-phase land use maps (1975 and 1985), a soil map, and meteorological data from 11 gauging stations. The satisfactory values of Nash-Sutcliffe efficiency Ens and correlation coefficient R2 during the calibration and validation period indicated that SWAT can be used in this area to simulate the average annual soil erosion under different land use scenarios change. By comparing soil erosion rate under different land use scenarios change, forests and grasslands had similar effects on preventing soil erosion. A parameter, soil erosion increment (Ei), was used to assess the effects of slope on soil erosion. The results revealed that variation in sediment yield was more sensitive to land use change for slopes exceeded 25° than for slopes being 0° - 15°. The spatial distribution of land use also had a relationship to soil erosion. Compared with the soil erosion rate in each sub-watershed using two-phase land use maps, the soil erosion rate increased when the percent cover of natural vegetation decreased. The results of this study provide baseline data for soil conservation and protection of the environment and ecology of the Lancang River Watershed in Yunnan Province.
Effect of heavy metal ions on wastewater treatment with activated sludge

Huo Peishu,Guan Yueqiang,Zhou Kexin,Liu Biao,Wu Jianyong,Li Ji,

环境工程学报 , 2010,
Abstract: 研究了Hg2+、Cd2+、Pb2+ 3种金属离子对活性污泥系统处理污水效能的影响。通过对出水理化指标和生物指标的测定反映Hg2+、Cd2+、Pb2+对活性污泥系统运转效能的影响。结果表明:实验第4 d,Hg2+ (0.3、 0.4、0.5和0.6 mg/L), Cd2+ (15、20、 25和30 mg/L)和 Pb2+ (300、400、600和800 mg/L)各实验组出水的COD、SVI等均有显著影响。在实验中得出,对COD影响最为明显的为浓度600 mg/L 和800 mg/L Pb2+实验组,在第4 d时,出水的COD去除率已经为零。锐利楯纤虫对Hg2+的浓度变化耐受力较强;点钟虫对Cd2+的浓度变化耐受力较强;杯钟虫对Cd2+的浓度变化耐受力较强。锐利楯纤虫对Pb2+和Cd2+的浓度变化较为敏感;点钟虫对Hg2+的浓度变化较为敏感;小口钟虫对Pb2+的浓度变化较为敏感。
Toroidal modeling of interaction between resistive wall mode and plasma flow
Yueqiang Liu,Youwen Sun
Physics , 2013, DOI: 10.1063/1.4793449
Abstract: The non-linear interplay between the resistive wall mode (RWM) and the toroidal plasma flow is numerically investigated in a full toroidal geometry, by simultaneously solving the initial value problems for the n=1 RWM and the n=0 toroidal force balance equation. Here n is the toroidal mode number. The neoclassical toroidal viscous torque is identified as the major momentum sink that brakes the toroidal plasma flow during the non-linear evolution of the RWM. This holds for a mode that is initially either unstable or stable. For an initially stable RWM, the braking of the flow, and hence the eventual growth of the mode, depends critically on the initial perturbation amplitude.
The Structure of Modified Fe-Ni Bioxide Composite Nanoparticles Using Fe(NO3)3  [PDF]
Yueqiang Lin, Jian Li, Lihua Lin, Xiaodong Liu, Longlong Chen, Decai Li
Advances in Nanoparticles (ANP) , 2013, DOI: 10.4236/anp.2013.24040

Composite nanoparticles containing a γ-Fe2O3 core, Ni2O3 external shell and FeCl3·6H2O outermost layer can be synthesized by chemically induced transition in FeCl2 solution. These may be modified by treatment with Fe(NO3)3 to obtain particles for the preparation of ionic ferrofluids. Vibrating sample magnetometer (VSM) measurements and transmission electron microscopy (TEM) observations show that after Fe(NO3)3 treatment, the specific magnetization becomes weaker and the size becomes larger for treated particles compared with the untreated particles. Using energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), the structure of the particles before and after the treatment is revealed. The experimental results show that the γ-Fe2O3

Toroidal modeling of penetration of the resonant magnetic perturbation field
Yueqiang Liu,A. Kirk,Y. Sun
Physics , 2013, DOI: 10.1063/1.4799535
Abstract: A toroidal, quasi-linear model is proposed to study the penetration dynamics of the resonant magnetic perturbation (RMP) field into the plasma. The model couples the linear, fluid plasma response to a toroidal momentum balance equation, which includes torques induced by both fluid electromagnetic force and by (kinetic) neoclassical toroidal viscous force. The numerical results for a test toroidal equilibrium quantify the effects of various physical parameters on the field penetration and on the plasma rotation braking. The neoclassical toroidal viscous torque plays a dominant role in certain region of the plasma, for the RMP penetration problem considered in this work.
Effects of Three Nitrification Inhibitors on the Nitrogen Conversion in Purple Soil and Its Effect on the Nitrogen Uptake of Citrus Seedlings  [PDF]
Wenli Li, Zhenzhen Zhang, Danping Li, Chaoyi Guo, Yujiang Li, Min Yang, Xiaojun Shi, Yueqiang Zhang
Agricultural Sciences (AS) , 2018, DOI: 10.4236/as.2018.96045
Abstract: Experiments were carried out to study the effects of nitrification inhibitors (NI) on the transformation of soil nitrogen (N) in purple soil and the effects on the N accumulation in different organs of citrus seedlings. In incubation and pot experiments, the rate of nitrification inhibitors 2-chloro-6-trichloro-methyl pyridine (Nitrapyrin), 3,4-dimethylpyrazole phosphate (DMPP) and dicyandiamide (DCD) was 2.4%, 1.0% and 5.0% of N rate, respectively. The trend of different nitrification inhibitors on ammonium nitrogen ( NH+4-N ), nitrate nitrogen ( NO-3-N ) content and pH was compared in incubation experiment; and the effect of different NI on the dry matter quality, N uptake of citrus seedling was studied in pot experiment. The results showed that NI could significantly inhibit soil nitrification in the early culture period (p < 0.05). The inhibitory degree of NI on nitrification showed the strong tendency at the beginning and then decreased. During the whole experiment, nitrification inhibition rates were 4.4% - 48.5% (En), 6.7% - 9.8% (DMPP) and 5.1% - 97.2% (DCD), respectively. Compared with the control, the application of NI increased the plant height and dry matter accumulation of potted citrus seedlings by 7.6% - 8.6% and 1.0% - 3.8%, respectively. And application of NI also increased the absorption of N by citrus roots and leaves by 9.0% - 17.9% and 0.6% - 7.2%, respectively. Overall, all the three nitrification inhibitors could significantly delay the soil nitrification process in purple soil, with the order of inhibition ability of DCD > DMPP > En (calculated as nitrogen application rate). Application of NI increased the height and dry matter accumulation, N accumulation of citrus seedling grown in pot experiment. Thus, application of NI would be helpful for improving N use efficiency in
Adaptive Motion Segmentation for Changing Background  [PDF]
Yepeng Guan
Journal of Software Engineering and Applications (JSEA) , 2009, DOI: 10.4236/jsea.2009.22014
Abstract: Segmentation of moving objects efficiently from video sequence is very important for many applications. Background subtraction is a common method typically used to segment moving objects in image sequences taken from a statistic camera. Some existing algorithms cannot adapt to changing circumstances and require manual calibration in terms of specification of parameters or some hypotheses for changing background. An adaptive motion segmentation method is developed according to motion variation and chromatic characteristics, which prevents undesired corruption of the background model and does not consider the adaptation coefficient. RGB color space is selected instead of introducing complex color models to segment moving objects and suppress shadows. A color ratio for 4-connected neighbors of a pixel and multi-scale wavelet transformation are combined to suppress shadows. The mentioned approach is scene-independent and high correct segmentation. It has been shown that the approach is robust and efficient to detect moving objects by experiments.
Moved Score Confidence Intervals for Means of Discrete Distributions  [PDF]
Yu Guan
Open Journal of Statistics (OJS) , 2011, DOI: 10.4236/ojs.2011.12009
Abstract: Let X denote a discrete distribution as Poisson, binomial or negative binomial variable. The score confidence interval for the mean of X is obtained based on inverting the hypothesis test and the central limit theorem is discussed and recommended widely. But it has sharp downward spikes for small means. This paper proposes to move the score interval left a little (about 0.04 unit), called by moved score confidence interval. Numerical computation and Edgeworth expansion show that the moved score interval is analogous to the score interval completely and behaves better for moderate means; for small means the moved interval raises the infimum of the coverage probability and improves the sharp spikes significantly. Especially, it has unified explicit formulations to compute easily.
Ethnic Difference of Disease Prevalence in Rural China: Examples and Explanations  [PDF]
Ming Guan
Health (Health) , 2015, DOI: 10.4236/health.2015.74052
Abstract: Ethnic difference of disease prevalence has attracted great attentions in recent years in China, but few researches have summarized analysis available on ethnic difference of disease prevalence in rural China. The PubMed Central, Wiley Inter science, Science direct, Biomed central, CNKI and Springer-link were searched to identify studies published between January 1984 and October 2014 on ethnic inequality of health status in rural China. Distinct ethnic differences of disease prevalence exist in rural China. Results across disciplines put different explanations on the ethnic differences from ethnicity, infant feeding, and inequality in maternal health services utilization angles. The ethnic inequality of health status in rural China can be reduced by policy makers to allocate more resources towards health service in ethnic rural China.
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