Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 3 )

2018 ( 85 )

2017 ( 97 )

2016 ( 85 )

Custom range...

Search Results: 1 - 10 of 6499 matches for " BAI Shuangyou "
All listed articles are free for downloading (OA Articles)
Page 1 /6499
Display every page Item
Effects of iron/potassium molar ratio on mass of biogenic Fe(Ⅲ) hydroxysulfate precipitates in the FeSO4-K2SO4-H2O system and their environmental implications

BAI Shuangyou,LIANG Jianru,ZHOU Lixiang,

环境科学学报 , 2010,
Abstract: In the FeSO4-K2SO4-H2O biological oxidation system facilitated by Acidithiobacillus ferrooxidans, secondary ferric hydroxysulfate minerals are able to be synthesized including schwertmannite, potassium jarosite, and their mixture. In our system, the initial concentrations of ferrous iron were designed as 20, 40, 80 and 160 mmol·L-1 and the Fe/K molar ratios for each ferrous iron concentration treatment were designed as 3 to 200. The results show that treatment with lower initial Fe2+ levels such as 20 mmol·L-1 or 40 mmol·L-1 only produces a small amount of the precipitate with no more than 0.38 g produced after 72 h of reaction. With the increase of initial Fe2+ and the decrease of Fe/K molar ratios in the solution, the total amount of the precipitate formed by Acidithiobacillus ferrooxidans is greatly increased. For example, 4.48 g of jarosite are precipitated from 250mL of solution when the initial Fe2+ is 160 mmol·L-1and Fe/K is 3. The XRD pattern indicated that the precipitate is gradually transformed to crystallized jarosite from poorly-crystallized schwertmannite, exhibiting a close relationship between the mass produced and the mineral phase. For example, the amount of the precipitates formed as crystalline jarosite is much higher than that as poorly-crystallized schwertmannite. Therefore, the amount of biogenic minerals formed in the biological oxidation system depends, to a great extent, on the initial Fe2+ concentration and Fe/K molar ratio. This phenomenon is of potential significance in the removal of soluble Fe and SO2-4 from acid mine drainage.
Effects of storage time and recycling of resting Acidithiobacillus ferrooxidans cells on biogenic schwertmannite formation

BAI Shuangyou,LIANG Jianru,LIAO Yuehua,ZHOU Lixiang,

环境科学学报 , 2011,
Abstract: Schwertmannite biosynthesized by resting Acidithiobacillus ferrooxidans (A.ferrooxidans) with FeSO4 has high purity and specific surface area. It plays an important role in the removal of toxic heavy metals or metalloid in water environmental. To provide the optimum parameters for schwertmannite scale production, the effects of storage time of resting A.ferrooxidans cells and reuse of the recycling cells on the strain growth and its ability in facilitating Fe2+ oxidation and mineral formation were investigated through the flask experiments. The results indicated that the fresh resting A.ferrooxidans cells harvested within 30 d could completely oxidize 144 mmol L-1 Fe2+ to Fe3+ after 48 h in the system with initial pH 2.50. In the presence of excess SO42-, about 41.99% of the ferrous iron was transformed into the brown-red schwertmannite, and mineral weight reached 1.34 g in 250 mL system. Compared to fresh resting A.ferrooxidans cells, the Fe2+ oxidation percentage by the relatively aged resting A.ferrooxidans cells stored for 45 d at 4 °C was decreased by 5.61%, and the schwertmannite weight was decreased by 35.07%. Furthermore, the reuse of resting A.ferrooxidans cells resulted in a significant reduction of Fe2+ oxidation with only 1/7 of the Fe2+ oxidation ability of fresh resting cells, which was contributed to the oxidation ability decline of the reused cells itself and the cell density decrease of A.ferrooxidans due to absorption or wrapping by minerals. Therefore, the newly-prepared resting A.ferrooxidans cells should be used in time or its storage time should not exceed 30 d in the acidic solution at 4 °C. The resting A.ferrooxidans cells could be recycled and used for the biosynthesis of schwertmannite, but its efficiency was only about 15% of newly-prepared resting cells.
Characterization and As (Ⅲ) adsorption properties of schwertmannite synthesized by chemical or biological procedures

LI Zheying,LIANG Jianru,BAI Shuangyou,ZHOU Lixiang,

环境科学学报 , 2011,
Abstract: An amorphous ferric hydroxysulfate named schwertmannite,as a novel material,has played an important role in transference and passivation of toxic heavy metals. In this study,schwertmannite was synthesized by two different procedures:chemical oxidation of ferrous iron by H2O2 and bacterial oxidation of ferrous iron by resting Acidithiobacillusferrooxidans cells in ferrous sulfate solution. The components,structures and surface areas of the minerals were analyzed and characterized by XRD,SEM,Ic and BET. In ad...
Removal of As(Ⅲ)in simulated groundwater through adsorption by biosynthesized or chemosynthesized schwertmannite

LI Zheying,LIANG Jianru,BAI Shuangyou,ZHOU Lixiang,

环境科学学报 , 2011,
Abstract: 施氏矿物作为一种具有良好应用前景的高砷吸附材料已倍受人们关注。采用静态吸附实验对生物、化学成因施氏矿物去除模拟地下水中As(III)进行了研究。结果表明,在25℃,初始As(III)浓度为0.2mg/L,施氏矿物投加量为0.25g/L时,生物成因施氏矿物吸附3h后溶液中As(III)含量降低到10μg/L以下(地下水饮用标准),吸附最佳pH范围为6~10,化学成因施氏矿物在pH7~8,则需吸附平衡12h后溶液中As(III)含量才能达到10μg/L以下。当介质中存在PO43–和SiO32-时,生物成因施氏矿物表现出对As(III)专性吸附能力强于化学成因施氏矿物。等温吸附实验(25℃)表明,生物成因施氏矿物对As(III)的最大吸附量为101. 9mg/L,比化学成因施氏矿物(82.1mg/L)高出约24.1%,表现出更优异的吸附性能。
Enhancement of two-photon transition rate by selectively removing certain frequency comb teeth
Shuangyou Zhang,Wanpeng Yang,Jianye Zhao
Physics , 2015,
Abstract: We present experiments demonstrating an enhancement of resonant two-photon transition rate in 87Rb utilizing spectral phase manipulation of the excitation frequency comb. By selectively removing certain comb teeth, the resonant two-photon transition rate can be improved, and reach a factor of more than 1.8. The femtosecond pulse-train excitation of two-photon transition is investigated theoretically based on general multiphoton transitions and the results are compared with the experiments. The theory presented here gives a clear insight of physical mechanism of this quantum coherent control and indicates that it is simple, effective and universal for nonlinear interactions between frequency combs and matters.
Long-term Stabilization of Fiber Laser Using Phase-locking Technique with Ultra-low Phase Noise and Phase Drift
Dong Hou,Bo Ning,Shuangyou Zhang,Jiutao Wu,Jianye Zhao
Physics , 2014,
Abstract: We review the conventional phase-locking technique in the long-term stabilization of the mode-locked fiber laser and investigate the phase noise limitation of the conventional technique. To break the limitation, we propose an improved phase-locking technique with an optic-microwave phase detector in achieving the ultra-low phase noise and phase drift. The mechanism and the theoretical model of the novel phase-locking technique are also discussed. The long-term stabilization experiments demonstrate that the improved technique can achieve the long-term stabilization for the MLFL with ultra-low phase noise and phase drift. The excellent locking performance of the improved phase-locking technique implies that this technique can be used to stabilize the mode-locked fiber laser with the highly stable H-master or optical clock without stability loss.
Evaluation Indexes of Degree of Closeness between Strategy and Project Portfolio Allocation  [PDF]
Libiao Bai, Sijun Bai
American Journal of Operations Research (AJOR) , 2015, DOI: 10.4236/ajor.2015.51004
Abstract: The main activities in project portfolio allocation management are selecting the right project components given a strategy. It is crucial to establish a scientific system of evaluation indexes to guarantee the closeness between strategy and project portfolio allocation optimally. With organizations growing in sizes, the functions and objectives of project components are becoming more and more different. It is necessary to set evaluation indexes of the degree of closeness from the perspectives of financial, market share, social effects, and so on according to the strategy-oriented process of project portfolio allocation. This paper proposes a project portfolio allocation process under strategic orientation and evaluation indexes of the degree of closeness between strategy and project portfolio allocation. This will help projects managers make portfolio allocation decisions.
Consolidation Solutions of a Saturated Porothermoelastic Hollow Cylinder with Infinite Length  [PDF]
Engineering (ENG) , 2010, DOI: 10.4236/eng.2010.21005
Abstract: An analytical method is derived for the thermal consolidation of a saturated, porous, hollow cylinder with infinite length. The solutions in Laplace transform space are first obtained and then numerically inverted by Stehfest method. Two cases of boundary conditions are considered. First, variable thermal loadings are applied on the inner and outer pervious lateral surfaces of the hollow cylinder, and a variable mechanical loading with time is applied on the outer surface; while the displacement of the inner surface remains fixed. Secondly, variable thermal and mechanical loading are applied on the outer pervious surface, and the inner surface remains fixed, impervious and insulated. As two special problems, a solid cylinder with infinite length and a cylindrical cavity in a half-space body are also discussed. Finally, the evolutions of temperature, pore pressure and displacement with time along radial direction are analyzed by a numerical example.
A Public Value Based Framework for Evaluating the Performance of e-Government in China  [PDF]
Wenlin Bai
iBusiness (IB) , 2013, DOI: 10.4236/ib.2013.53B006

Much research has been done on evaluating the performance of e-government in China, but comprehensive pictures of research done on evaluation of performance of e-government can hardly be found in the Chinese literature. Besides, there are few theories to support the research and practice in evaluation. By analyzing existed literature, the paper proposes a conceptual framework for evaluating performance of e-government based on public value perspective. Delivery of public services, effectiveness of public organization and development of trust are identified and selected as three basic public values for analysis.

A Cultural Examination of Shapiro’s Translation of the Marsh Heroes’ Nicknames  [PDF]
Yanli Bai
Advances in Literary Study (ALS) , 2016, DOI: 10.4236/als.2016.43006
Abstract: What roles the culture plays in translating has been a focus in the translating circle. The stratifica-tional relation of language to cultural context in Systemic Functional Linguistics (SFL) makes it necessary that the process of translation should take the cultural factors into consideration. The present paper aims to discuss the parts that culture plays in translating by analyzing some prob-lems in Shapiro’s translation of the nicknames in the Outlaws of the Marsh. The paper starts off from the relation of language to culture context in translation in an SFL angle, followed with a brief introduction to the connotation and the artistic magic of the Marsh Heroes’ Nicknames and some examples of Shapiro’s translations of the nicknames, in order to demonstrate the importance of culture factors in translating.
Page 1 /6499
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.