曝气生物滤池快速启动性能试验

目的研究在上流式二级曝气生物滤池短暂关闭后,采用通入常负荷待处理污水的方式,快速启动池体的性能.方法在水力负荷3.8m3/(m2.h)下启动,并提高到5.2m3/(m2.h),一二级曝气量分别为37.5L/h2、5L/h,对比关闭前自然挂膜时池体处理性能.结果运行23h后一级滤柱、二级滤柱同时启动成功,与自然挂膜耗时19d相比大大节省了时间.结论一二级滤柱和系统对COD的去除率稳定在60%、30%和80%以上,略低于关闭前同负荷下的对COD去除率(关闭前同负荷下对COD去除率分别为一级滤柱为68%,二级滤柱为40%,系统为90%).一二级滤柱和系统对NH3-N的去除率分别为94%、83%、99%.系统对色度、浊度去除率为73.8%和71.8%,略低于自然挂膜时(分别为81.7%和80%)的去除率.陶粒上生长着不连续的生物膜,表层陶粒被生物膜覆盖得多一些,中上层陶粒表面裸露得多一些,活性碳表面的生物膜覆盖率比陶粒略低.显微标定,陶粒表面生物膜厚度除凹陷处有较厚的生物膜外,一般维持在100μm以下,即处于膜活性厚度范围内.与关闭前滤料表面的生物相种群基本无差异.

Enhancement of Proton Exchange Membrane Fuel Cell Performance Using a Novel Tapered Gas Channel

Based on use of multi-dimensional models,this investigation simulates the performance of a proton exchange membrane fuel cell by varying the channel pattern.In the one-dimensional model,the porosity of the gas diffusion layer is 0.3.The model reveals the water vapor distribution of the fuel cell and demonstrates that the amount of water vapor increases linearly with the reduction reaction adjacent to the gas channel and the gas diffusion layer.Secondly,four novel tapered gas channels are simulated by a two-dimensional model.The model considers the distributions of oxygen,the pressure drop,the amount of water vapor distribution and the polarization curves.The results indicate that as the channel depth decreases,the oxygen in the tapered gas channel can be accel-erated and forced into the gas diffusion layer to improve the cell performance.The three-dimensional model is employed to simulate the phenomenon associated with four novel tapered gas channels.The results also show that the best performance is realized in the least tapered gas channel.Finally,an experimentally determined mechanism is found to be consistent with the results of the simulation.

Analysis and Applications of Clarifier-Thickener Model for the Secondary Clarifier

The effluent quality from a secondary clarifier in an activated sludge process depends on the performance in the secondary clarifier at great extent. Several models have been developed based on the Kynch solid flux theory to improve the clarifier performance at last decades. This paper proposed a model which is established according to the basis sedimentation process of the secondary clarifier and Kynch flux theory for a clarifier with feedwell in upper of tank and the diffusion effective are combined into the model, which benefts the further improvement of the model and makes the solutions fit to the measurement data in secondary clarifier,

Organic Solar Cells Flexible P3HT：PCBM Thin Film and Improving Its Performance

Organic solar cells （OSCs） is a new generation of solar cells have emerged as an alternative to conventional Si-based solar cells owing to their advantages of low cost, ease of fabrication and their potential for the manufacture of flexible and large area solar cells. So we chose that part to beginning study of the material and all parameters effects in environmental condition because the solar cell working in environment. In this study the fabrication of poly（3-hexylthiophene） （P3HT） and [6,6]-phenyl C61-butyric acid methyl ester （PCBM） blend flexible thin film using spin coating was reported. Process parameters like solvent, electron donor to acceptor ratio, concentration and temperature were also studied. We used solvent systems to make active layer of P3HT：PCBM composite and PEDOT：PSS as a buffer layer. Highest absorption was obtained for the flexible thin film made with 1：1 and 1：0.75 ratio of P3HT to PCBM. Chloroform solvent in 40 gm/ml concentration at 90 ~C was the optimum conditions to make flexible device.

Mg2＋-ion Conducting Polymer Electrolytes： Materials Characterization and All-Solid-State Battery Performance Studies

For All-Solid-State battery applications, Mg2＋-ion conducting polymer electrolytes and Mg-metal electrode are currently considered as alternate choices in place of Li＋-ion conducting polymer electrolytes/Li-metal electrode. Present paper reports fabrication of All-Solid-State battery based on the following Mg2＋-ion conducting nano composite polymer electrolyte （NCPE） films： [85PEO： 15Mg（C104）2] ＋ 5% TiO2 （〈 100 nm）, [85PEO： 15Mg（CIO4）2] ＋ 3% SiO2（-8 nm）. [85PEO： 15Mg（CIO4）2] ＋ 3% MgO （〈 100 nm）, [85PEO：15Mg（C1O4）2] ＋ 3% MgO （-44 μm）. NCPE films were prepared by hot-press technique. Solid Polymer Electrolyte （SPE） composition： [85PEO： 15Mg（CIO4）2], identified as high conducting film at room temperature, has been used as ISt--phase host and nano/micro particles of active （MgO）/passive （SiO2, TiO2） fillers as IInd-phase dispersoid. Filler particle dependent conductivity studies identified above mentioned NCPE films as optimum conducting composition （OCC） at room temperature. Ion transport behavior of SPE/NCPE film materials was investigated previously. Present paper reports materials characterization and cell performance studies on All-Solid-State batteries： Mg （Anode） Ⅱ SPE or NCPE films tt C＋MnO2＋Electrolyte （Cathode）. Open circuit voltage （OCV） obtained was in the range： 1.79-1.92 V. The batteries were discharged at room temperature under different load conditions and some important battery parameters have been evaluated from plateau region of cell-potential discharge profiles. All the batteries performed quite satisfactorily specially under low current drain states.

Nanostructuring the electronic conducting La_(0.8)Sr_(0.2)MnO_(3-δ) cathode for high-performance in proton-conducting solid oxide fuel cells below 600℃

Proton-conducting oxides offer a promising electrolyte solution for intermediate temperature solid oxide fuel cells（SOFCs） due to their high conductivity and low activation energy. However, the lower operation temperature leads to a reduced cathode activity and thus a poorer fuel cell performance. La_（0.8）Sr_（0.2）MnO_（3-δ）（LSM） is the classical cathode material for high-temperature SOFCs, which lack features as a proper SOFC cathode material at intermediate temperatures.Despite this, we here successfully couple nanostructured LSM cathode with proton-conducting electrolytes to operate below600℃ with desirable SOFC performance. Inkjet printing allows depositing nanostructured particles of LSM on Y-doped Ba ZrO_3（BZY） backbones as cathodes for proton-conducting SOFCs, which provides one of the highest power output for the BZY-based fuel cells below 600 ℃. This somehow changes the common knowledge that LSM can be applied as a SOFC cathode materials only at high temperatures（above 700 ℃）.

Surface plasmonic effect and scattering effect of Au nanorods on the performance of polymer bulk heterojunction solar cells

The surface plasmonic effect and scattering effect of gold nanorods(AuNRs) on the performance of bulk heterojunction photovoltaic devices based on the blend of polythiophene and fullerene are investigated.AuNRs enhance the excitation since the plasmonic effect increases the electric field,mainly in the area near the interface between the active layer and AuNRs.The results show that the incident photo-to-electron conversion efficiency(IPCE) obviously increases for the device with a layer of gold nanorods,resulting from the plasmonic effect of AuNRs in the range of 500-670 nm and the scattering effect in the range of 370-410 nm.The power conversion efficiency(PCE) is increased by 7.6% due to the near field effect of the localized surface plasmons(LSP) of AuNRs and the scattering effect.The short circuit current density is also increased by 9.1% owing to the introduction of AuNRs.However,AuNRs can cause a little deterioration in open circuit voltage.

Porous honeycomb-like C3N4/rGO composite as host for high performance Li-S batteries

Lithium-sulfur (Li-S) batteries have attracted extensive attention along with the urgent increasing demand for energy storage owing to the high theoretical specific capacity and energy density, abundant reserves and low cost of sulfur. However, the practical application of Li-S batteries is still impeded due to the low utilization of sulfur and serious shuttle-effect of lithium polysulfides (LiPSs). Here, we fabricated the porous honeycomb-like C3N4 (PHCN) through a hard template method. As a polar material, graphitic C3N4 has abundant nitrogen content (-58%), which can provide enough active sites to mitigate shuttle-effect, and then conductive reduced graphene oxide (rGO) was introduced to combine with PHCN to form PHCN/rGO composite in order to improve the utilization efficiency of sulfur. After sulfur loading, the PHCN/rGO/S cathode exhibited an initial discharge capacity of 1,061.1 mA h g^-1 at 0.2 C and outstanding rate performance at high current density of 5 C (495.1 mA h g^-1), and also retained 519 mA h g^-1, after 400 cycles at 1 C. Even at high sulfur loading (4.3 mg cm^-2), the capacity fade rate was only 0.16% per cycle at 0.5 C for 200 cycles. The above results demonstrate that the special design of PHCN/rGO composite as sulfur host has high potential application for Li-S rechargeable batteries.

Effects of polydopamine modification on self-grown Cu O cube anodes in lithium-ion batteries

We report the synthesis of Cut cubes with well-defined size and shape by thermal treatments of Cu2O cubes. Polydopamine （PDA） is introduced to modify the Cut cubes by the in-situ polymerization of the dopamine precursor. The initial specific ca- pacity of the lithium-ion batteries using the Cut cubes as anodes increases about 10 times at a 0.5 C rate as a result of the modification of PDA. The overall specific capacity for 100 cycles also increases effectively due to the introduction of PDA. So PDA as surface modifying agent significantly improves the electrochemical performance of the Cut anodes.

A higher performance dye-sensitized solar cell based on the modified PMII/EMIMBF_4 binary room temperature ionic liquid electrolyte

Additives and iodine(I_2) are used to modify the binary room temperature ionic liquid(RTIL) electrolyte to enhance the photovoltaic performance of dye-sensitized solar cells(DSSCs). The short-circuit current density(JSC) of 17.89 m A/ cm2, open circuit voltage(VOC) of 0.71 V and fill factor(FF) of 0.50 are achieved in the optimal device. An average photoelectric conversion efficiency(PCE) of 6.35% is achieved by optimization, which is over two times larger than that of the parent device before optimization(2.06%), while the maximum PCE can reach up to 6.63%.

Stereomeric effects of bisPC_(71)BM on polymer solar cell performance

Two stereomers of bisadduct analogues of [6, 6]-phenyl-C71-butyric acid methyl ester （bisPC71BM） were synthesized and their geometrical structures with cis- or trans-configuration were identified by X-ray crystallogra- phy. Although both of the bisPC71BM have similar spec- trometric and electrochemical properties, the spatial orientation of the two addition groups on C7o has impact on crystal packing and molecular assembly of bisPC71BM isomers and, in turn, photovoltaic performance in polymer solar cell based on poly（3-hexylthiophene） （P3HT） （with power conversion efficiency of 1.72 % and 1.84 % for the solar cells involving cis- and trans-bisPC71BM, respec- tively）. Although the power conversion efficiency remains to be improved, this work exemplifies that the photovoltaic properties of fullerene-based electron acceptors areinfluenced by aggregation of the stereomeric molecules and thus extends the guidelines for rational design of efficient fullerene acceptor.

General construction of lithiophilic 3D skeleton for dendrite-free lithium metal anode via a versatile MOF-derived route

The pursuit of high-mileage models results in the recurrence of lithium metal batteries(LMBs)to researchers’horizon.However,the lithium(Li)metal anode for LMBs undergoes the uncontrollable formation of Li dendrites and infinite volume change during cycling,impeding its practical application.To overcome these challenges,we developed a metal-organic framework(MOF)-derived pathway to construct lithiophilic three-dimensional(3D)skeleton using different substrates(e.g.,carbon cloth(CC)and Cu mesh)for dendrite-free lithium metal anodes.As a typical example,the MOF-derived ZnO/nitrogen-doped carbon(NC)nanosheet-modified 3D CC was well-constructed as a lithiophilic hierarchical host(CC@ZnO/NC@Li)for molten Li infiltration.Benefiting from the lithiophilic N-functional groups and LiZn alloy,the synthesized CC@ZnO/NC@Li composite anode promoted the uniform distribution of Li,resulting in a dendrite-free morphology.Meanwhile,the 3D conductive carbon skeleton enhanced the reaction kinetics and buffered the volume change of the electrode.The CC@ZnO/NC@Li composite anode presented a prolonged lifespan of over 1000 cycles at 5 mA cm^(−2) with a low overpotential of 19 mV.Coupled with a LiFePO_(4) cathode,the CC@ZnO/NC@Li composite anode also exhibited superior electrochemical properties in the full-cell system.This versatile strategy may open up the channel of designing multi-functional lithiophilic 3D hosts for the Li metal anode.

Synthesis of Li-doped Co_3O_4 truncated octahedra with improved performances in CO oxidation and lithium ion batteries

Single-crystalline Li-doped Co3O4 truncated octahedra with different doping contents were synthesized by a simple combustion method with the fuel of multi-walled carbon nanotubes(MWCNTs).Controlled experiments showed that the pristine well-defined Co3O4 octahedra were obtained with exposed surfaces of {111} planes without lithium doping.In comparison with the octahedra,the truncated Co3O4 octahedra were composed of original {111} planes and extra {100} planes.It could be attributable to the selective adsorption of lithium ions on the {100} planes,making these planes with higher surface energy coexist with the crystal faces of {111}.Furthermore,the Li-doped truncated octahedra and undoped octahedra were used as catalysts in CO oxidation and as anode materials for Li-ion batteries(LIBs).The measurements exhibited that the Li-doped octahedra with added {100} crystal faces showed improved catalytic activity and electrochemical property because of the exposure of the higher energy faces of {100} and enhanced conductivity by Li doping.