Wyniki wyszukiwania - Biblioteka Nauki

1

Non-diffraction fringes produced by thin biprism

100%

Liping Z. , Jianghong G. , Long X.

Optica Applicata

|

2012

|

tom Vol. 42, nr 4

699--711

EN

Thin biprism can form non-diffraction fringes when it is illuminated by coherent plane wave and the non-diffraction fringes have long focal length and uniform intensity distribution. Geometrical optics characteristic of thin biprism is analyzed. Non-diffraction field produced by thin biprism at the Fresnel zone is deduced with exact Fresnel integral and an approximation representation is obtained by the stationary phase method. Numerical calculation is utilized to investigate the properties of non-diffraction fringes and evaluate the influence of the diffractive field caused by rectangle aperture's square edge on the fringes. An experiment is setup to observe the intensity of the non-diffraction fringes.

2

Content and species of extracellular phosphorus in activated sludge of biological phosphorus removal systems

88%

Long X. , Tang R. , Xie C. , Fang Z. , Li Y.

Polish Journal of Environmental Studies

|

2019

|

tom 28

|

nr 5

EN

Extracellular polymeric substances (EPS) contain a large amount of phosphorus, but the content of extracellular phosphorus in activated sludge and the decomposition of extracellular polyphosphate (polyP) in extraction process is still unclear. In this study, the extraction efficiencies of extracellular phosphorus using sonication, cation exchange resin (CER) and sonication-CER methods were investigated and compared, taking the aerobic sludge from four lab-scale A/O-SBR reactors at different temperatures and in different matrices as the objects. The sonication-CER method was an efficient and reliable method for extracting EPS and extracellular phosphorus, which could avoid the decomposition of extracellular polyP and the massive lysis of a bacterial cell. Importantly, utilizing CER with two successive alkaline washes was a key factor for efficiently extracting extracellular phosphorus. The extracellular phosphorus content of aerobic-activated sludge in 4 A/O-SBR reactors was 28.17~73.13 mg P/g VSS, accounting for 59.6~74.1% TPsludge. Thereby phosphorus of sludge floc was mainly located in EPS. Furthermore, polyP was the main species of extracellular phosphorus in EBPR sludge, which mainly existed in the inner layer of sludge floc. There was a close relationship between the content and species of extracellular phosphorus and the EBPR performance of activated sludge.

3

Biological nitrogen removal in a flow-separating biochemical reactor with coral sand

75%

Long X. , Tang R. , Zhan B. , Fang Z. , Xie C. , Li Y.

Polish Journal of Environmental Studies

|

2019

|

tom 28

|

nr 5

EN

In order to provide some support for economically and effectively resolving the problem of water pollution around the islands in the South China Sea, biological nitrogen removal (BNR) performance and biotechnological characterization of the FSBR filled with abandoned coral sand were investigated. The results showed that the TN removal efficiency of the FSBR with a good performance of simultaneous nitrification and denitrification (SND) was 74.68±6.49% during the stable operation. The total biomass and removal efficiency of pollutants in the three reaction regions all decreased along the flow direction. Therefore, the first region was the key area for SND reaction and TN removal. In the first region, the nitrification process was the result of the combination of autotrophic nitrification and heterotrophic nitrification. Meanwhile, aerobic denitrification played a key role in the process of denitrification. In the region, the most denitrifying bacteria belonged to Proteobacteria, in which unclassified_ f _Comamonadace, Acidovorax and Dokdonella were the major aerobic denitrifying bacteria.

4

Carbon assimilation and sequestration by industrial crop Jerusalem artichoke in coastal saline land

63%

Chen M. , Xu Z. , Zhao J. , Chen Y. , Chen S. , Gao X. , Long X. , Shao H.

Acta Physiologiae Plantarum

|

2019

|

tom 41

|

nr 11

EN

Understanding the role of Jerusalem artichoke grown in low fertility coastal saline soil in carbon sequestration is important for characterizing the relationship between soil use in agriculture production and carbon sequestration. In the present study, the mechanisms of photosynthesis and carbon distribution were studied in three saline soils with different salt contents (Xinyang 0.6–1.0 g salt/kg; Dafeng 1.5–2.4 g salt/kg; Shuntai 3.8–4.5 g salt/kg) by characterizing the biomass production, carbon storage, and carbon sequestration in the soil under Jerusalem artichoke. The biomass production and carbon storage during the growth cycle of Jerusalem artichoke were significantly higher in Dafeng than the other plots. The highest carbon sequestration was found in the Xinyang plot. The organic matter content in the rhizosphere soil was 28–44% higher than that in the non-rhizosphere soil. The soil organic carbon content in the rhizosphere soil was higher than that in the non-rhizosphere soil. High soil salinities decreased the carbon storage of Jerusalem artichoke. Carbon sequestration in soil decreased with the increase in soil salinity.

5

Different Ignition Responses of Powdery and Bulky 1,3,5-Triamino-2,4,6-trinitrobenzene (TATB) Based Polymer-bonded Explosives under Ultra-high Voltage Electrostatic Discharge

63%

Lyu Z. , Long X. , Li Z. , Dai X. , Deng C. , He S. , Li M. , Yao K. , Wen Y.

Central European Journal of Energetic Materials

|

2018

|

tom Vol. 15, no. 2

283--298

EN

The electric spark induced ignition mechanism for explosives needs further study. The ignition of powdery and bulky TATB by electrostatic discharge (ESD) was investigated. Up to 200 kV ultra-high voltage ESD was applied to powdery and bulky explosives of two TATB-based polymer-bonded explosives (named PBX-1 and PBX-2). The results showed that the spark sensitivities of powdery and bulky explosives are extremely different for the same formulation. The 50% ignition voltages of powdery PBX-1 and PBX-2 were 10.8 kV and 8.5 kV, respectively, while the values for the bulky samples (tablets) were not less than 200 kV. Both heat and the electric field can be transmitted into the powdery samples, on the other hand only the electric field can be transmitted into the bulk samples. The electric field has a smaller contribution while the heat has a larger contribution to the ignition during an ESD, i.e., the thermal effect plays a main role in the ignition process. Our experimental results are in good agreement with recent results calculated by density functional theory.